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1 //===-- AArch64ISelLowering.cpp - AArch64 DAG Lowering Implementation  ----===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the AArch64TargetLowering class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AArch64ISelLowering.h"
15 #include "AArch64PerfectShuffle.h"
16 #include "AArch64Subtarget.h"
17 #include "AArch64MachineFunctionInfo.h"
18 #include "AArch64TargetMachine.h"
19 #include "AArch64TargetObjectFile.h"
20 #include "MCTargetDesc/AArch64AddressingModes.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/CodeGen/CallingConvLower.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/IR/Intrinsics.h"
28 #include "llvm/IR/Type.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/raw_ostream.h"
33 #include "llvm/Target/TargetOptions.h"
34 using namespace llvm;
35 
36 #define DEBUG_TYPE "aarch64-lower"
37 
38 STATISTIC(NumTailCalls, "Number of tail calls");
39 STATISTIC(NumShiftInserts, "Number of vector shift inserts");
40 
41 enum AlignMode {
42   StrictAlign,
43   NoStrictAlign
44 };
45 
46 static cl::opt<AlignMode>
47 Align(cl::desc("Load/store alignment support"),
48       cl::Hidden, cl::init(NoStrictAlign),
49       cl::values(
50           clEnumValN(StrictAlign,   "aarch64-strict-align",
51                      "Disallow all unaligned memory accesses"),
52           clEnumValN(NoStrictAlign, "aarch64-no-strict-align",
53                      "Allow unaligned memory accesses"),
54           clEnumValEnd));
55 
56 // Place holder until extr generation is tested fully.
57 static cl::opt<bool>
58 EnableAArch64ExtrGeneration("aarch64-extr-generation", cl::Hidden,
59                           cl::desc("Allow AArch64 (or (shift)(shift))->extract"),
60                           cl::init(true));
61 
62 static cl::opt<bool>
63 EnableAArch64SlrGeneration("aarch64-shift-insert-generation", cl::Hidden,
64                          cl::desc("Allow AArch64 SLI/SRI formation"),
65                          cl::init(false));
66 
67 //===----------------------------------------------------------------------===//
68 // AArch64 Lowering public interface.
69 //===----------------------------------------------------------------------===//
createTLOF(const Triple & TT)70 static TargetLoweringObjectFile *createTLOF(const Triple &TT) {
71   if (TT.isOSBinFormatMachO())
72     return new AArch64_MachoTargetObjectFile();
73 
74   return new AArch64_ELFTargetObjectFile();
75 }
76 
AArch64TargetLowering(TargetMachine & TM)77 AArch64TargetLowering::AArch64TargetLowering(TargetMachine &TM)
78     : TargetLowering(TM, createTLOF(Triple(TM.getTargetTriple()))) {
79   Subtarget = &TM.getSubtarget<AArch64Subtarget>();
80 
81   // AArch64 doesn't have comparisons which set GPRs or setcc instructions, so
82   // we have to make something up. Arbitrarily, choose ZeroOrOne.
83   setBooleanContents(ZeroOrOneBooleanContent);
84   // When comparing vectors the result sets the different elements in the
85   // vector to all-one or all-zero.
86   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
87 
88   // Set up the register classes.
89   addRegisterClass(MVT::i32, &AArch64::GPR32allRegClass);
90   addRegisterClass(MVT::i64, &AArch64::GPR64allRegClass);
91 
92   if (Subtarget->hasFPARMv8()) {
93     addRegisterClass(MVT::f16, &AArch64::FPR16RegClass);
94     addRegisterClass(MVT::f32, &AArch64::FPR32RegClass);
95     addRegisterClass(MVT::f64, &AArch64::FPR64RegClass);
96     addRegisterClass(MVT::f128, &AArch64::FPR128RegClass);
97   }
98 
99   if (Subtarget->hasNEON()) {
100     addRegisterClass(MVT::v16i8, &AArch64::FPR8RegClass);
101     addRegisterClass(MVT::v8i16, &AArch64::FPR16RegClass);
102     // Someone set us up the NEON.
103     addDRTypeForNEON(MVT::v2f32);
104     addDRTypeForNEON(MVT::v8i8);
105     addDRTypeForNEON(MVT::v4i16);
106     addDRTypeForNEON(MVT::v2i32);
107     addDRTypeForNEON(MVT::v1i64);
108     addDRTypeForNEON(MVT::v1f64);
109 
110     addQRTypeForNEON(MVT::v4f32);
111     addQRTypeForNEON(MVT::v2f64);
112     addQRTypeForNEON(MVT::v16i8);
113     addQRTypeForNEON(MVT::v8i16);
114     addQRTypeForNEON(MVT::v4i32);
115     addQRTypeForNEON(MVT::v2i64);
116   }
117 
118   // Compute derived properties from the register classes
119   computeRegisterProperties();
120 
121   // Provide all sorts of operation actions
122   setOperationAction(ISD::GlobalAddress, MVT::i64, Custom);
123   setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
124   setOperationAction(ISD::SETCC, MVT::i32, Custom);
125   setOperationAction(ISD::SETCC, MVT::i64, Custom);
126   setOperationAction(ISD::SETCC, MVT::f32, Custom);
127   setOperationAction(ISD::SETCC, MVT::f64, Custom);
128   setOperationAction(ISD::BRCOND, MVT::Other, Expand);
129   setOperationAction(ISD::BR_CC, MVT::i32, Custom);
130   setOperationAction(ISD::BR_CC, MVT::i64, Custom);
131   setOperationAction(ISD::BR_CC, MVT::f32, Custom);
132   setOperationAction(ISD::BR_CC, MVT::f64, Custom);
133   setOperationAction(ISD::SELECT, MVT::i32, Custom);
134   setOperationAction(ISD::SELECT, MVT::i64, Custom);
135   setOperationAction(ISD::SELECT, MVT::f32, Custom);
136   setOperationAction(ISD::SELECT, MVT::f64, Custom);
137   setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
138   setOperationAction(ISD::SELECT_CC, MVT::i64, Custom);
139   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
140   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
141   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
142   setOperationAction(ISD::JumpTable, MVT::i64, Custom);
143 
144   setOperationAction(ISD::SHL_PARTS, MVT::i64, Custom);
145   setOperationAction(ISD::SRA_PARTS, MVT::i64, Custom);
146   setOperationAction(ISD::SRL_PARTS, MVT::i64, Custom);
147 
148   setOperationAction(ISD::FREM, MVT::f32, Expand);
149   setOperationAction(ISD::FREM, MVT::f64, Expand);
150   setOperationAction(ISD::FREM, MVT::f80, Expand);
151 
152   // Custom lowering hooks are needed for XOR
153   // to fold it into CSINC/CSINV.
154   setOperationAction(ISD::XOR, MVT::i32, Custom);
155   setOperationAction(ISD::XOR, MVT::i64, Custom);
156 
157   // Virtually no operation on f128 is legal, but LLVM can't expand them when
158   // there's a valid register class, so we need custom operations in most cases.
159   setOperationAction(ISD::FABS, MVT::f128, Expand);
160   setOperationAction(ISD::FADD, MVT::f128, Custom);
161   setOperationAction(ISD::FCOPYSIGN, MVT::f128, Expand);
162   setOperationAction(ISD::FCOS, MVT::f128, Expand);
163   setOperationAction(ISD::FDIV, MVT::f128, Custom);
164   setOperationAction(ISD::FMA, MVT::f128, Expand);
165   setOperationAction(ISD::FMUL, MVT::f128, Custom);
166   setOperationAction(ISD::FNEG, MVT::f128, Expand);
167   setOperationAction(ISD::FPOW, MVT::f128, Expand);
168   setOperationAction(ISD::FREM, MVT::f128, Expand);
169   setOperationAction(ISD::FRINT, MVT::f128, Expand);
170   setOperationAction(ISD::FSIN, MVT::f128, Expand);
171   setOperationAction(ISD::FSINCOS, MVT::f128, Expand);
172   setOperationAction(ISD::FSQRT, MVT::f128, Expand);
173   setOperationAction(ISD::FSUB, MVT::f128, Custom);
174   setOperationAction(ISD::FTRUNC, MVT::f128, Expand);
175   setOperationAction(ISD::SETCC, MVT::f128, Custom);
176   setOperationAction(ISD::BR_CC, MVT::f128, Custom);
177   setOperationAction(ISD::SELECT, MVT::f128, Custom);
178   setOperationAction(ISD::SELECT_CC, MVT::f128, Custom);
179   setOperationAction(ISD::FP_EXTEND, MVT::f128, Custom);
180 
181   // Lowering for many of the conversions is actually specified by the non-f128
182   // type. The LowerXXX function will be trivial when f128 isn't involved.
183   setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
184   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
185   setOperationAction(ISD::FP_TO_SINT, MVT::i128, Custom);
186   setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
187   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
188   setOperationAction(ISD::FP_TO_UINT, MVT::i128, Custom);
189   setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
190   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
191   setOperationAction(ISD::SINT_TO_FP, MVT::i128, Custom);
192   setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
193   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
194   setOperationAction(ISD::UINT_TO_FP, MVT::i128, Custom);
195   setOperationAction(ISD::FP_ROUND, MVT::f32, Custom);
196   setOperationAction(ISD::FP_ROUND, MVT::f64, Custom);
197 
198   // Variable arguments.
199   setOperationAction(ISD::VASTART, MVT::Other, Custom);
200   setOperationAction(ISD::VAARG, MVT::Other, Custom);
201   setOperationAction(ISD::VACOPY, MVT::Other, Custom);
202   setOperationAction(ISD::VAEND, MVT::Other, Expand);
203 
204   // Variable-sized objects.
205   setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
206   setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
207   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Expand);
208 
209   // Exception handling.
210   // FIXME: These are guesses. Has this been defined yet?
211   setExceptionPointerRegister(AArch64::X0);
212   setExceptionSelectorRegister(AArch64::X1);
213 
214   // Constant pool entries
215   setOperationAction(ISD::ConstantPool, MVT::i64, Custom);
216 
217   // BlockAddress
218   setOperationAction(ISD::BlockAddress, MVT::i64, Custom);
219 
220   // Add/Sub overflow ops with MVT::Glues are lowered to NZCV dependences.
221   setOperationAction(ISD::ADDC, MVT::i32, Custom);
222   setOperationAction(ISD::ADDE, MVT::i32, Custom);
223   setOperationAction(ISD::SUBC, MVT::i32, Custom);
224   setOperationAction(ISD::SUBE, MVT::i32, Custom);
225   setOperationAction(ISD::ADDC, MVT::i64, Custom);
226   setOperationAction(ISD::ADDE, MVT::i64, Custom);
227   setOperationAction(ISD::SUBC, MVT::i64, Custom);
228   setOperationAction(ISD::SUBE, MVT::i64, Custom);
229 
230   // AArch64 lacks both left-rotate and popcount instructions.
231   setOperationAction(ISD::ROTL, MVT::i32, Expand);
232   setOperationAction(ISD::ROTL, MVT::i64, Expand);
233 
234   // AArch64 doesn't have {U|S}MUL_LOHI.
235   setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
236   setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
237 
238 
239   // Expand the undefined-at-zero variants to cttz/ctlz to their defined-at-zero
240   // counterparts, which AArch64 supports directly.
241   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Expand);
242   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Expand);
243   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Expand);
244   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Expand);
245 
246   setOperationAction(ISD::CTPOP, MVT::i32, Custom);
247   setOperationAction(ISD::CTPOP, MVT::i64, Custom);
248 
249   setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
250   setOperationAction(ISD::SDIVREM, MVT::i64, Expand);
251   setOperationAction(ISD::SREM, MVT::i32, Expand);
252   setOperationAction(ISD::SREM, MVT::i64, Expand);
253   setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
254   setOperationAction(ISD::UDIVREM, MVT::i64, Expand);
255   setOperationAction(ISD::UREM, MVT::i32, Expand);
256   setOperationAction(ISD::UREM, MVT::i64, Expand);
257 
258   // Custom lower Add/Sub/Mul with overflow.
259   setOperationAction(ISD::SADDO, MVT::i32, Custom);
260   setOperationAction(ISD::SADDO, MVT::i64, Custom);
261   setOperationAction(ISD::UADDO, MVT::i32, Custom);
262   setOperationAction(ISD::UADDO, MVT::i64, Custom);
263   setOperationAction(ISD::SSUBO, MVT::i32, Custom);
264   setOperationAction(ISD::SSUBO, MVT::i64, Custom);
265   setOperationAction(ISD::USUBO, MVT::i32, Custom);
266   setOperationAction(ISD::USUBO, MVT::i64, Custom);
267   setOperationAction(ISD::SMULO, MVT::i32, Custom);
268   setOperationAction(ISD::SMULO, MVT::i64, Custom);
269   setOperationAction(ISD::UMULO, MVT::i32, Custom);
270   setOperationAction(ISD::UMULO, MVT::i64, Custom);
271 
272   setOperationAction(ISD::FSIN, MVT::f32, Expand);
273   setOperationAction(ISD::FSIN, MVT::f64, Expand);
274   setOperationAction(ISD::FCOS, MVT::f32, Expand);
275   setOperationAction(ISD::FCOS, MVT::f64, Expand);
276   setOperationAction(ISD::FPOW, MVT::f32, Expand);
277   setOperationAction(ISD::FPOW, MVT::f64, Expand);
278   setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
279   setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
280 
281   // AArch64 has implementations of a lot of rounding-like FP operations.
282   static MVT RoundingTypes[] = { MVT::f32, MVT::f64};
283   for (unsigned I = 0; I < array_lengthof(RoundingTypes); ++I) {
284     MVT Ty = RoundingTypes[I];
285     setOperationAction(ISD::FFLOOR, Ty, Legal);
286     setOperationAction(ISD::FNEARBYINT, Ty, Legal);
287     setOperationAction(ISD::FCEIL, Ty, Legal);
288     setOperationAction(ISD::FRINT, Ty, Legal);
289     setOperationAction(ISD::FTRUNC, Ty, Legal);
290     setOperationAction(ISD::FROUND, Ty, Legal);
291   }
292 
293   setOperationAction(ISD::PREFETCH, MVT::Other, Custom);
294 
295   if (Subtarget->isTargetMachO()) {
296     // For iOS, we don't want to the normal expansion of a libcall to
297     // sincos. We want to issue a libcall to __sincos_stret to avoid memory
298     // traffic.
299     setOperationAction(ISD::FSINCOS, MVT::f64, Custom);
300     setOperationAction(ISD::FSINCOS, MVT::f32, Custom);
301   } else {
302     setOperationAction(ISD::FSINCOS, MVT::f64, Expand);
303     setOperationAction(ISD::FSINCOS, MVT::f32, Expand);
304   }
305 
306   // AArch64 does not have floating-point extending loads, i1 sign-extending
307   // load, floating-point truncating stores, or v2i32->v2i16 truncating store.
308   setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
309   setLoadExtAction(ISD::EXTLOAD, MVT::f64, Expand);
310   setLoadExtAction(ISD::EXTLOAD, MVT::f80, Expand);
311   setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Expand);
312   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
313   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
314   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
315   setTruncStoreAction(MVT::f128, MVT::f80, Expand);
316   setTruncStoreAction(MVT::f128, MVT::f64, Expand);
317   setTruncStoreAction(MVT::f128, MVT::f32, Expand);
318   setTruncStoreAction(MVT::f128, MVT::f16, Expand);
319   // Indexed loads and stores are supported.
320   for (unsigned im = (unsigned)ISD::PRE_INC;
321        im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
322     setIndexedLoadAction(im, MVT::i8, Legal);
323     setIndexedLoadAction(im, MVT::i16, Legal);
324     setIndexedLoadAction(im, MVT::i32, Legal);
325     setIndexedLoadAction(im, MVT::i64, Legal);
326     setIndexedLoadAction(im, MVT::f64, Legal);
327     setIndexedLoadAction(im, MVT::f32, Legal);
328     setIndexedStoreAction(im, MVT::i8, Legal);
329     setIndexedStoreAction(im, MVT::i16, Legal);
330     setIndexedStoreAction(im, MVT::i32, Legal);
331     setIndexedStoreAction(im, MVT::i64, Legal);
332     setIndexedStoreAction(im, MVT::f64, Legal);
333     setIndexedStoreAction(im, MVT::f32, Legal);
334   }
335 
336   // Trap.
337   setOperationAction(ISD::TRAP, MVT::Other, Legal);
338 
339   // We combine OR nodes for bitfield operations.
340   setTargetDAGCombine(ISD::OR);
341 
342   // Vector add and sub nodes may conceal a high-half opportunity.
343   // Also, try to fold ADD into CSINC/CSINV..
344   setTargetDAGCombine(ISD::ADD);
345   setTargetDAGCombine(ISD::SUB);
346 
347   setTargetDAGCombine(ISD::XOR);
348   setTargetDAGCombine(ISD::SINT_TO_FP);
349   setTargetDAGCombine(ISD::UINT_TO_FP);
350 
351   setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
352 
353   setTargetDAGCombine(ISD::ANY_EXTEND);
354   setTargetDAGCombine(ISD::ZERO_EXTEND);
355   setTargetDAGCombine(ISD::SIGN_EXTEND);
356   setTargetDAGCombine(ISD::BITCAST);
357   setTargetDAGCombine(ISD::CONCAT_VECTORS);
358   setTargetDAGCombine(ISD::STORE);
359 
360   setTargetDAGCombine(ISD::MUL);
361 
362   setTargetDAGCombine(ISD::SELECT);
363   setTargetDAGCombine(ISD::VSELECT);
364 
365   setTargetDAGCombine(ISD::INTRINSIC_VOID);
366   setTargetDAGCombine(ISD::INTRINSIC_W_CHAIN);
367   setTargetDAGCombine(ISD::INSERT_VECTOR_ELT);
368 
369   MaxStoresPerMemset = MaxStoresPerMemsetOptSize = 8;
370   MaxStoresPerMemcpy = MaxStoresPerMemcpyOptSize = 4;
371   MaxStoresPerMemmove = MaxStoresPerMemmoveOptSize = 4;
372 
373   setStackPointerRegisterToSaveRestore(AArch64::SP);
374 
375   setSchedulingPreference(Sched::Hybrid);
376 
377   // Enable TBZ/TBNZ
378   MaskAndBranchFoldingIsLegal = true;
379 
380   setMinFunctionAlignment(2);
381 
382   RequireStrictAlign = (Align == StrictAlign);
383 
384   setHasExtractBitsInsn(true);
385 
386   if (Subtarget->hasNEON()) {
387     // FIXME: v1f64 shouldn't be legal if we can avoid it, because it leads to
388     // silliness like this:
389     setOperationAction(ISD::FABS, MVT::v1f64, Expand);
390     setOperationAction(ISD::FADD, MVT::v1f64, Expand);
391     setOperationAction(ISD::FCEIL, MVT::v1f64, Expand);
392     setOperationAction(ISD::FCOPYSIGN, MVT::v1f64, Expand);
393     setOperationAction(ISD::FCOS, MVT::v1f64, Expand);
394     setOperationAction(ISD::FDIV, MVT::v1f64, Expand);
395     setOperationAction(ISD::FFLOOR, MVT::v1f64, Expand);
396     setOperationAction(ISD::FMA, MVT::v1f64, Expand);
397     setOperationAction(ISD::FMUL, MVT::v1f64, Expand);
398     setOperationAction(ISD::FNEARBYINT, MVT::v1f64, Expand);
399     setOperationAction(ISD::FNEG, MVT::v1f64, Expand);
400     setOperationAction(ISD::FPOW, MVT::v1f64, Expand);
401     setOperationAction(ISD::FREM, MVT::v1f64, Expand);
402     setOperationAction(ISD::FROUND, MVT::v1f64, Expand);
403     setOperationAction(ISD::FRINT, MVT::v1f64, Expand);
404     setOperationAction(ISD::FSIN, MVT::v1f64, Expand);
405     setOperationAction(ISD::FSINCOS, MVT::v1f64, Expand);
406     setOperationAction(ISD::FSQRT, MVT::v1f64, Expand);
407     setOperationAction(ISD::FSUB, MVT::v1f64, Expand);
408     setOperationAction(ISD::FTRUNC, MVT::v1f64, Expand);
409     setOperationAction(ISD::SETCC, MVT::v1f64, Expand);
410     setOperationAction(ISD::BR_CC, MVT::v1f64, Expand);
411     setOperationAction(ISD::SELECT, MVT::v1f64, Expand);
412     setOperationAction(ISD::SELECT_CC, MVT::v1f64, Expand);
413     setOperationAction(ISD::FP_EXTEND, MVT::v1f64, Expand);
414 
415     setOperationAction(ISD::FP_TO_SINT, MVT::v1i64, Expand);
416     setOperationAction(ISD::FP_TO_UINT, MVT::v1i64, Expand);
417     setOperationAction(ISD::SINT_TO_FP, MVT::v1i64, Expand);
418     setOperationAction(ISD::UINT_TO_FP, MVT::v1i64, Expand);
419     setOperationAction(ISD::FP_ROUND, MVT::v1f64, Expand);
420 
421     setOperationAction(ISD::MUL, MVT::v1i64, Expand);
422 
423     // AArch64 doesn't have a direct vector ->f32 conversion instructions for
424     // elements smaller than i32, so promote the input to i32 first.
425     setOperationAction(ISD::UINT_TO_FP, MVT::v4i8, Promote);
426     setOperationAction(ISD::SINT_TO_FP, MVT::v4i8, Promote);
427     setOperationAction(ISD::UINT_TO_FP, MVT::v4i16, Promote);
428     setOperationAction(ISD::SINT_TO_FP, MVT::v4i16, Promote);
429     // Similarly, there is no direct i32 -> f64 vector conversion instruction.
430     setOperationAction(ISD::SINT_TO_FP, MVT::v2i32, Custom);
431     setOperationAction(ISD::UINT_TO_FP, MVT::v2i32, Custom);
432     setOperationAction(ISD::SINT_TO_FP, MVT::v2i64, Custom);
433     setOperationAction(ISD::UINT_TO_FP, MVT::v2i64, Custom);
434 
435     // AArch64 doesn't have MUL.2d:
436     setOperationAction(ISD::MUL, MVT::v2i64, Expand);
437     setOperationAction(ISD::ANY_EXTEND, MVT::v4i32, Legal);
438     setTruncStoreAction(MVT::v2i32, MVT::v2i16, Expand);
439     // Likewise, narrowing and extending vector loads/stores aren't handled
440     // directly.
441     for (unsigned VT = (unsigned)MVT::FIRST_VECTOR_VALUETYPE;
442          VT <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++VT) {
443 
444       setOperationAction(ISD::SIGN_EXTEND_INREG, (MVT::SimpleValueType)VT,
445                          Expand);
446 
447       setOperationAction(ISD::MULHS, (MVT::SimpleValueType)VT, Expand);
448       setOperationAction(ISD::SMUL_LOHI, (MVT::SimpleValueType)VT, Expand);
449       setOperationAction(ISD::MULHU, (MVT::SimpleValueType)VT, Expand);
450       setOperationAction(ISD::UMUL_LOHI, (MVT::SimpleValueType)VT, Expand);
451 
452       setOperationAction(ISD::BSWAP, (MVT::SimpleValueType)VT, Expand);
453 
454       for (unsigned InnerVT = (unsigned)MVT::FIRST_VECTOR_VALUETYPE;
455            InnerVT <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++InnerVT)
456         setTruncStoreAction((MVT::SimpleValueType)VT,
457                             (MVT::SimpleValueType)InnerVT, Expand);
458       setLoadExtAction(ISD::SEXTLOAD, (MVT::SimpleValueType)VT, Expand);
459       setLoadExtAction(ISD::ZEXTLOAD, (MVT::SimpleValueType)VT, Expand);
460       setLoadExtAction(ISD::EXTLOAD, (MVT::SimpleValueType)VT, Expand);
461     }
462 
463     // AArch64 has implementations of a lot of rounding-like FP operations.
464     static MVT RoundingVecTypes[] = {MVT::v2f32, MVT::v4f32, MVT::v2f64 };
465     for (unsigned I = 0; I < array_lengthof(RoundingVecTypes); ++I) {
466       MVT Ty = RoundingVecTypes[I];
467       setOperationAction(ISD::FFLOOR, Ty, Legal);
468       setOperationAction(ISD::FNEARBYINT, Ty, Legal);
469       setOperationAction(ISD::FCEIL, Ty, Legal);
470       setOperationAction(ISD::FRINT, Ty, Legal);
471       setOperationAction(ISD::FTRUNC, Ty, Legal);
472       setOperationAction(ISD::FROUND, Ty, Legal);
473     }
474   }
475 
476   // Prefer likely predicted branches to selects on out-of-order cores.
477   if (Subtarget->isCortexA57())
478     PredictableSelectIsExpensive = true;
479 }
480 
addTypeForNEON(EVT VT,EVT PromotedBitwiseVT)481 void AArch64TargetLowering::addTypeForNEON(EVT VT, EVT PromotedBitwiseVT) {
482   if (VT == MVT::v2f32) {
483     setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
484     AddPromotedToType(ISD::LOAD, VT.getSimpleVT(), MVT::v2i32);
485 
486     setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
487     AddPromotedToType(ISD::STORE, VT.getSimpleVT(), MVT::v2i32);
488   } else if (VT == MVT::v2f64 || VT == MVT::v4f32) {
489     setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
490     AddPromotedToType(ISD::LOAD, VT.getSimpleVT(), MVT::v2i64);
491 
492     setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
493     AddPromotedToType(ISD::STORE, VT.getSimpleVT(), MVT::v2i64);
494   }
495 
496   // Mark vector float intrinsics as expand.
497   if (VT == MVT::v2f32 || VT == MVT::v4f32 || VT == MVT::v2f64) {
498     setOperationAction(ISD::FSIN, VT.getSimpleVT(), Expand);
499     setOperationAction(ISD::FCOS, VT.getSimpleVT(), Expand);
500     setOperationAction(ISD::FPOWI, VT.getSimpleVT(), Expand);
501     setOperationAction(ISD::FPOW, VT.getSimpleVT(), Expand);
502     setOperationAction(ISD::FLOG, VT.getSimpleVT(), Expand);
503     setOperationAction(ISD::FLOG2, VT.getSimpleVT(), Expand);
504     setOperationAction(ISD::FLOG10, VT.getSimpleVT(), Expand);
505     setOperationAction(ISD::FEXP, VT.getSimpleVT(), Expand);
506     setOperationAction(ISD::FEXP2, VT.getSimpleVT(), Expand);
507   }
508 
509   setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT.getSimpleVT(), Custom);
510   setOperationAction(ISD::INSERT_VECTOR_ELT, VT.getSimpleVT(), Custom);
511   setOperationAction(ISD::BUILD_VECTOR, VT.getSimpleVT(), Custom);
512   setOperationAction(ISD::VECTOR_SHUFFLE, VT.getSimpleVT(), Custom);
513   setOperationAction(ISD::EXTRACT_SUBVECTOR, VT.getSimpleVT(), Custom);
514   setOperationAction(ISD::SRA, VT.getSimpleVT(), Custom);
515   setOperationAction(ISD::SRL, VT.getSimpleVT(), Custom);
516   setOperationAction(ISD::SHL, VT.getSimpleVT(), Custom);
517   setOperationAction(ISD::AND, VT.getSimpleVT(), Custom);
518   setOperationAction(ISD::OR, VT.getSimpleVT(), Custom);
519   setOperationAction(ISD::SETCC, VT.getSimpleVT(), Custom);
520   setOperationAction(ISD::CONCAT_VECTORS, VT.getSimpleVT(), Legal);
521 
522   setOperationAction(ISD::SELECT, VT.getSimpleVT(), Expand);
523   setOperationAction(ISD::SELECT_CC, VT.getSimpleVT(), Expand);
524   setOperationAction(ISD::VSELECT, VT.getSimpleVT(), Expand);
525   setLoadExtAction(ISD::EXTLOAD, VT.getSimpleVT(), Expand);
526 
527   // CNT supports only B element sizes.
528   if (VT != MVT::v8i8 && VT != MVT::v16i8)
529     setOperationAction(ISD::CTPOP, VT.getSimpleVT(), Expand);
530 
531   setOperationAction(ISD::UDIV, VT.getSimpleVT(), Expand);
532   setOperationAction(ISD::SDIV, VT.getSimpleVT(), Expand);
533   setOperationAction(ISD::UREM, VT.getSimpleVT(), Expand);
534   setOperationAction(ISD::SREM, VT.getSimpleVT(), Expand);
535   setOperationAction(ISD::FREM, VT.getSimpleVT(), Expand);
536 
537   setOperationAction(ISD::FP_TO_SINT, VT.getSimpleVT(), Custom);
538   setOperationAction(ISD::FP_TO_UINT, VT.getSimpleVT(), Custom);
539 
540   if (Subtarget->isLittleEndian()) {
541     for (unsigned im = (unsigned)ISD::PRE_INC;
542          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
543       setIndexedLoadAction(im, VT.getSimpleVT(), Legal);
544       setIndexedStoreAction(im, VT.getSimpleVT(), Legal);
545     }
546   }
547 }
548 
addDRTypeForNEON(MVT VT)549 void AArch64TargetLowering::addDRTypeForNEON(MVT VT) {
550   addRegisterClass(VT, &AArch64::FPR64RegClass);
551   addTypeForNEON(VT, MVT::v2i32);
552 }
553 
addQRTypeForNEON(MVT VT)554 void AArch64TargetLowering::addQRTypeForNEON(MVT VT) {
555   addRegisterClass(VT, &AArch64::FPR128RegClass);
556   addTypeForNEON(VT, MVT::v4i32);
557 }
558 
getSetCCResultType(LLVMContext &,EVT VT) const559 EVT AArch64TargetLowering::getSetCCResultType(LLVMContext &, EVT VT) const {
560   if (!VT.isVector())
561     return MVT::i32;
562   return VT.changeVectorElementTypeToInteger();
563 }
564 
565 /// computeKnownBitsForTargetNode - Determine which of the bits specified in
566 /// Mask are known to be either zero or one and return them in the
567 /// KnownZero/KnownOne bitsets.
computeKnownBitsForTargetNode(const SDValue Op,APInt & KnownZero,APInt & KnownOne,const SelectionDAG & DAG,unsigned Depth) const568 void AArch64TargetLowering::computeKnownBitsForTargetNode(
569     const SDValue Op, APInt &KnownZero, APInt &KnownOne,
570     const SelectionDAG &DAG, unsigned Depth) const {
571   switch (Op.getOpcode()) {
572   default:
573     break;
574   case AArch64ISD::CSEL: {
575     APInt KnownZero2, KnownOne2;
576     DAG.computeKnownBits(Op->getOperand(0), KnownZero, KnownOne, Depth + 1);
577     DAG.computeKnownBits(Op->getOperand(1), KnownZero2, KnownOne2, Depth + 1);
578     KnownZero &= KnownZero2;
579     KnownOne &= KnownOne2;
580     break;
581   }
582   case ISD::INTRINSIC_W_CHAIN: {
583    ConstantSDNode *CN = cast<ConstantSDNode>(Op->getOperand(1));
584     Intrinsic::ID IntID = static_cast<Intrinsic::ID>(CN->getZExtValue());
585     switch (IntID) {
586     default: return;
587     case Intrinsic::aarch64_ldaxr:
588     case Intrinsic::aarch64_ldxr: {
589       unsigned BitWidth = KnownOne.getBitWidth();
590       EVT VT = cast<MemIntrinsicSDNode>(Op)->getMemoryVT();
591       unsigned MemBits = VT.getScalarType().getSizeInBits();
592       KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits);
593       return;
594     }
595     }
596     break;
597   }
598   case ISD::INTRINSIC_WO_CHAIN:
599   case ISD::INTRINSIC_VOID: {
600     unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
601     switch (IntNo) {
602     default:
603       break;
604     case Intrinsic::aarch64_neon_umaxv:
605     case Intrinsic::aarch64_neon_uminv: {
606       // Figure out the datatype of the vector operand. The UMINV instruction
607       // will zero extend the result, so we can mark as known zero all the
608       // bits larger than the element datatype. 32-bit or larget doesn't need
609       // this as those are legal types and will be handled by isel directly.
610       MVT VT = Op.getOperand(1).getValueType().getSimpleVT();
611       unsigned BitWidth = KnownZero.getBitWidth();
612       if (VT == MVT::v8i8 || VT == MVT::v16i8) {
613         assert(BitWidth >= 8 && "Unexpected width!");
614         APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 8);
615         KnownZero |= Mask;
616       } else if (VT == MVT::v4i16 || VT == MVT::v8i16) {
617         assert(BitWidth >= 16 && "Unexpected width!");
618         APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
619         KnownZero |= Mask;
620       }
621       break;
622     } break;
623     }
624   }
625   }
626 }
627 
getScalarShiftAmountTy(EVT LHSTy) const628 MVT AArch64TargetLowering::getScalarShiftAmountTy(EVT LHSTy) const {
629   return MVT::i64;
630 }
631 
getMaximalGlobalOffset() const632 unsigned AArch64TargetLowering::getMaximalGlobalOffset() const {
633   // FIXME: On AArch64, this depends on the type.
634   // Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
635   // and the offset has to be a multiple of the related size in bytes.
636   return 4095;
637 }
638 
639 FastISel *
createFastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo) const640 AArch64TargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
641                                       const TargetLibraryInfo *libInfo) const {
642   return AArch64::createFastISel(funcInfo, libInfo);
643 }
644 
getTargetNodeName(unsigned Opcode) const645 const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const {
646   switch (Opcode) {
647   default:
648     return nullptr;
649   case AArch64ISD::CALL:              return "AArch64ISD::CALL";
650   case AArch64ISD::ADRP:              return "AArch64ISD::ADRP";
651   case AArch64ISD::ADDlow:            return "AArch64ISD::ADDlow";
652   case AArch64ISD::LOADgot:           return "AArch64ISD::LOADgot";
653   case AArch64ISD::RET_FLAG:          return "AArch64ISD::RET_FLAG";
654   case AArch64ISD::BRCOND:            return "AArch64ISD::BRCOND";
655   case AArch64ISD::CSEL:              return "AArch64ISD::CSEL";
656   case AArch64ISD::FCSEL:             return "AArch64ISD::FCSEL";
657   case AArch64ISD::CSINV:             return "AArch64ISD::CSINV";
658   case AArch64ISD::CSNEG:             return "AArch64ISD::CSNEG";
659   case AArch64ISD::CSINC:             return "AArch64ISD::CSINC";
660   case AArch64ISD::THREAD_POINTER:    return "AArch64ISD::THREAD_POINTER";
661   case AArch64ISD::TLSDESC_CALL:      return "AArch64ISD::TLSDESC_CALL";
662   case AArch64ISD::ADC:               return "AArch64ISD::ADC";
663   case AArch64ISD::SBC:               return "AArch64ISD::SBC";
664   case AArch64ISD::ADDS:              return "AArch64ISD::ADDS";
665   case AArch64ISD::SUBS:              return "AArch64ISD::SUBS";
666   case AArch64ISD::ADCS:              return "AArch64ISD::ADCS";
667   case AArch64ISD::SBCS:              return "AArch64ISD::SBCS";
668   case AArch64ISD::ANDS:              return "AArch64ISD::ANDS";
669   case AArch64ISD::FCMP:              return "AArch64ISD::FCMP";
670   case AArch64ISD::FMIN:              return "AArch64ISD::FMIN";
671   case AArch64ISD::FMAX:              return "AArch64ISD::FMAX";
672   case AArch64ISD::DUP:               return "AArch64ISD::DUP";
673   case AArch64ISD::DUPLANE8:          return "AArch64ISD::DUPLANE8";
674   case AArch64ISD::DUPLANE16:         return "AArch64ISD::DUPLANE16";
675   case AArch64ISD::DUPLANE32:         return "AArch64ISD::DUPLANE32";
676   case AArch64ISD::DUPLANE64:         return "AArch64ISD::DUPLANE64";
677   case AArch64ISD::MOVI:              return "AArch64ISD::MOVI";
678   case AArch64ISD::MOVIshift:         return "AArch64ISD::MOVIshift";
679   case AArch64ISD::MOVIedit:          return "AArch64ISD::MOVIedit";
680   case AArch64ISD::MOVImsl:           return "AArch64ISD::MOVImsl";
681   case AArch64ISD::FMOV:              return "AArch64ISD::FMOV";
682   case AArch64ISD::MVNIshift:         return "AArch64ISD::MVNIshift";
683   case AArch64ISD::MVNImsl:           return "AArch64ISD::MVNImsl";
684   case AArch64ISD::BICi:              return "AArch64ISD::BICi";
685   case AArch64ISD::ORRi:              return "AArch64ISD::ORRi";
686   case AArch64ISD::BSL:               return "AArch64ISD::BSL";
687   case AArch64ISD::NEG:               return "AArch64ISD::NEG";
688   case AArch64ISD::EXTR:              return "AArch64ISD::EXTR";
689   case AArch64ISD::ZIP1:              return "AArch64ISD::ZIP1";
690   case AArch64ISD::ZIP2:              return "AArch64ISD::ZIP2";
691   case AArch64ISD::UZP1:              return "AArch64ISD::UZP1";
692   case AArch64ISD::UZP2:              return "AArch64ISD::UZP2";
693   case AArch64ISD::TRN1:              return "AArch64ISD::TRN1";
694   case AArch64ISD::TRN2:              return "AArch64ISD::TRN2";
695   case AArch64ISD::REV16:             return "AArch64ISD::REV16";
696   case AArch64ISD::REV32:             return "AArch64ISD::REV32";
697   case AArch64ISD::REV64:             return "AArch64ISD::REV64";
698   case AArch64ISD::EXT:               return "AArch64ISD::EXT";
699   case AArch64ISD::VSHL:              return "AArch64ISD::VSHL";
700   case AArch64ISD::VLSHR:             return "AArch64ISD::VLSHR";
701   case AArch64ISD::VASHR:             return "AArch64ISD::VASHR";
702   case AArch64ISD::CMEQ:              return "AArch64ISD::CMEQ";
703   case AArch64ISD::CMGE:              return "AArch64ISD::CMGE";
704   case AArch64ISD::CMGT:              return "AArch64ISD::CMGT";
705   case AArch64ISD::CMHI:              return "AArch64ISD::CMHI";
706   case AArch64ISD::CMHS:              return "AArch64ISD::CMHS";
707   case AArch64ISD::FCMEQ:             return "AArch64ISD::FCMEQ";
708   case AArch64ISD::FCMGE:             return "AArch64ISD::FCMGE";
709   case AArch64ISD::FCMGT:             return "AArch64ISD::FCMGT";
710   case AArch64ISD::CMEQz:             return "AArch64ISD::CMEQz";
711   case AArch64ISD::CMGEz:             return "AArch64ISD::CMGEz";
712   case AArch64ISD::CMGTz:             return "AArch64ISD::CMGTz";
713   case AArch64ISD::CMLEz:             return "AArch64ISD::CMLEz";
714   case AArch64ISD::CMLTz:             return "AArch64ISD::CMLTz";
715   case AArch64ISD::FCMEQz:            return "AArch64ISD::FCMEQz";
716   case AArch64ISD::FCMGEz:            return "AArch64ISD::FCMGEz";
717   case AArch64ISD::FCMGTz:            return "AArch64ISD::FCMGTz";
718   case AArch64ISD::FCMLEz:            return "AArch64ISD::FCMLEz";
719   case AArch64ISD::FCMLTz:            return "AArch64ISD::FCMLTz";
720   case AArch64ISD::NOT:               return "AArch64ISD::NOT";
721   case AArch64ISD::BIT:               return "AArch64ISD::BIT";
722   case AArch64ISD::CBZ:               return "AArch64ISD::CBZ";
723   case AArch64ISD::CBNZ:              return "AArch64ISD::CBNZ";
724   case AArch64ISD::TBZ:               return "AArch64ISD::TBZ";
725   case AArch64ISD::TBNZ:              return "AArch64ISD::TBNZ";
726   case AArch64ISD::TC_RETURN:         return "AArch64ISD::TC_RETURN";
727   case AArch64ISD::SITOF:             return "AArch64ISD::SITOF";
728   case AArch64ISD::UITOF:             return "AArch64ISD::UITOF";
729   case AArch64ISD::SQSHL_I:           return "AArch64ISD::SQSHL_I";
730   case AArch64ISD::UQSHL_I:           return "AArch64ISD::UQSHL_I";
731   case AArch64ISD::SRSHR_I:           return "AArch64ISD::SRSHR_I";
732   case AArch64ISD::URSHR_I:           return "AArch64ISD::URSHR_I";
733   case AArch64ISD::SQSHLU_I:          return "AArch64ISD::SQSHLU_I";
734   case AArch64ISD::WrapperLarge:      return "AArch64ISD::WrapperLarge";
735   case AArch64ISD::LD2post:           return "AArch64ISD::LD2post";
736   case AArch64ISD::LD3post:           return "AArch64ISD::LD3post";
737   case AArch64ISD::LD4post:           return "AArch64ISD::LD4post";
738   case AArch64ISD::ST2post:           return "AArch64ISD::ST2post";
739   case AArch64ISD::ST3post:           return "AArch64ISD::ST3post";
740   case AArch64ISD::ST4post:           return "AArch64ISD::ST4post";
741   case AArch64ISD::LD1x2post:         return "AArch64ISD::LD1x2post";
742   case AArch64ISD::LD1x3post:         return "AArch64ISD::LD1x3post";
743   case AArch64ISD::LD1x4post:         return "AArch64ISD::LD1x4post";
744   case AArch64ISD::ST1x2post:         return "AArch64ISD::ST1x2post";
745   case AArch64ISD::ST1x3post:         return "AArch64ISD::ST1x3post";
746   case AArch64ISD::ST1x4post:         return "AArch64ISD::ST1x4post";
747   case AArch64ISD::LD1DUPpost:        return "AArch64ISD::LD1DUPpost";
748   case AArch64ISD::LD2DUPpost:        return "AArch64ISD::LD2DUPpost";
749   case AArch64ISD::LD3DUPpost:        return "AArch64ISD::LD3DUPpost";
750   case AArch64ISD::LD4DUPpost:        return "AArch64ISD::LD4DUPpost";
751   case AArch64ISD::LD1LANEpost:       return "AArch64ISD::LD1LANEpost";
752   case AArch64ISD::LD2LANEpost:       return "AArch64ISD::LD2LANEpost";
753   case AArch64ISD::LD3LANEpost:       return "AArch64ISD::LD3LANEpost";
754   case AArch64ISD::LD4LANEpost:       return "AArch64ISD::LD4LANEpost";
755   case AArch64ISD::ST2LANEpost:       return "AArch64ISD::ST2LANEpost";
756   case AArch64ISD::ST3LANEpost:       return "AArch64ISD::ST3LANEpost";
757   case AArch64ISD::ST4LANEpost:       return "AArch64ISD::ST4LANEpost";
758   }
759 }
760 
761 MachineBasicBlock *
EmitF128CSEL(MachineInstr * MI,MachineBasicBlock * MBB) const762 AArch64TargetLowering::EmitF128CSEL(MachineInstr *MI,
763                                     MachineBasicBlock *MBB) const {
764   // We materialise the F128CSEL pseudo-instruction as some control flow and a
765   // phi node:
766 
767   // OrigBB:
768   //     [... previous instrs leading to comparison ...]
769   //     b.ne TrueBB
770   //     b EndBB
771   // TrueBB:
772   //     ; Fallthrough
773   // EndBB:
774   //     Dest = PHI [IfTrue, TrueBB], [IfFalse, OrigBB]
775 
776   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
777   MachineFunction *MF = MBB->getParent();
778   const BasicBlock *LLVM_BB = MBB->getBasicBlock();
779   DebugLoc DL = MI->getDebugLoc();
780   MachineFunction::iterator It = MBB;
781   ++It;
782 
783   unsigned DestReg = MI->getOperand(0).getReg();
784   unsigned IfTrueReg = MI->getOperand(1).getReg();
785   unsigned IfFalseReg = MI->getOperand(2).getReg();
786   unsigned CondCode = MI->getOperand(3).getImm();
787   bool NZCVKilled = MI->getOperand(4).isKill();
788 
789   MachineBasicBlock *TrueBB = MF->CreateMachineBasicBlock(LLVM_BB);
790   MachineBasicBlock *EndBB = MF->CreateMachineBasicBlock(LLVM_BB);
791   MF->insert(It, TrueBB);
792   MF->insert(It, EndBB);
793 
794   // Transfer rest of current basic-block to EndBB
795   EndBB->splice(EndBB->begin(), MBB, std::next(MachineBasicBlock::iterator(MI)),
796                 MBB->end());
797   EndBB->transferSuccessorsAndUpdatePHIs(MBB);
798 
799   BuildMI(MBB, DL, TII->get(AArch64::Bcc)).addImm(CondCode).addMBB(TrueBB);
800   BuildMI(MBB, DL, TII->get(AArch64::B)).addMBB(EndBB);
801   MBB->addSuccessor(TrueBB);
802   MBB->addSuccessor(EndBB);
803 
804   // TrueBB falls through to the end.
805   TrueBB->addSuccessor(EndBB);
806 
807   if (!NZCVKilled) {
808     TrueBB->addLiveIn(AArch64::NZCV);
809     EndBB->addLiveIn(AArch64::NZCV);
810   }
811 
812   BuildMI(*EndBB, EndBB->begin(), DL, TII->get(AArch64::PHI), DestReg)
813       .addReg(IfTrueReg)
814       .addMBB(TrueBB)
815       .addReg(IfFalseReg)
816       .addMBB(MBB);
817 
818   MI->eraseFromParent();
819   return EndBB;
820 }
821 
822 MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr * MI,MachineBasicBlock * BB) const823 AArch64TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
824                                                  MachineBasicBlock *BB) const {
825   switch (MI->getOpcode()) {
826   default:
827 #ifndef NDEBUG
828     MI->dump();
829 #endif
830     llvm_unreachable("Unexpected instruction for custom inserter!");
831 
832   case AArch64::F128CSEL:
833     return EmitF128CSEL(MI, BB);
834 
835   case TargetOpcode::STACKMAP:
836   case TargetOpcode::PATCHPOINT:
837     return emitPatchPoint(MI, BB);
838   }
839 }
840 
841 //===----------------------------------------------------------------------===//
842 // AArch64 Lowering private implementation.
843 //===----------------------------------------------------------------------===//
844 
845 //===----------------------------------------------------------------------===//
846 // Lowering Code
847 //===----------------------------------------------------------------------===//
848 
849 /// changeIntCCToAArch64CC - Convert a DAG integer condition code to an AArch64
850 /// CC
changeIntCCToAArch64CC(ISD::CondCode CC)851 static AArch64CC::CondCode changeIntCCToAArch64CC(ISD::CondCode CC) {
852   switch (CC) {
853   default:
854     llvm_unreachable("Unknown condition code!");
855   case ISD::SETNE:
856     return AArch64CC::NE;
857   case ISD::SETEQ:
858     return AArch64CC::EQ;
859   case ISD::SETGT:
860     return AArch64CC::GT;
861   case ISD::SETGE:
862     return AArch64CC::GE;
863   case ISD::SETLT:
864     return AArch64CC::LT;
865   case ISD::SETLE:
866     return AArch64CC::LE;
867   case ISD::SETUGT:
868     return AArch64CC::HI;
869   case ISD::SETUGE:
870     return AArch64CC::HS;
871   case ISD::SETULT:
872     return AArch64CC::LO;
873   case ISD::SETULE:
874     return AArch64CC::LS;
875   }
876 }
877 
878 /// changeFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64 CC.
changeFPCCToAArch64CC(ISD::CondCode CC,AArch64CC::CondCode & CondCode,AArch64CC::CondCode & CondCode2)879 static void changeFPCCToAArch64CC(ISD::CondCode CC,
880                                   AArch64CC::CondCode &CondCode,
881                                   AArch64CC::CondCode &CondCode2) {
882   CondCode2 = AArch64CC::AL;
883   switch (CC) {
884   default:
885     llvm_unreachable("Unknown FP condition!");
886   case ISD::SETEQ:
887   case ISD::SETOEQ:
888     CondCode = AArch64CC::EQ;
889     break;
890   case ISD::SETGT:
891   case ISD::SETOGT:
892     CondCode = AArch64CC::GT;
893     break;
894   case ISD::SETGE:
895   case ISD::SETOGE:
896     CondCode = AArch64CC::GE;
897     break;
898   case ISD::SETOLT:
899     CondCode = AArch64CC::MI;
900     break;
901   case ISD::SETOLE:
902     CondCode = AArch64CC::LS;
903     break;
904   case ISD::SETONE:
905     CondCode = AArch64CC::MI;
906     CondCode2 = AArch64CC::GT;
907     break;
908   case ISD::SETO:
909     CondCode = AArch64CC::VC;
910     break;
911   case ISD::SETUO:
912     CondCode = AArch64CC::VS;
913     break;
914   case ISD::SETUEQ:
915     CondCode = AArch64CC::EQ;
916     CondCode2 = AArch64CC::VS;
917     break;
918   case ISD::SETUGT:
919     CondCode = AArch64CC::HI;
920     break;
921   case ISD::SETUGE:
922     CondCode = AArch64CC::PL;
923     break;
924   case ISD::SETLT:
925   case ISD::SETULT:
926     CondCode = AArch64CC::LT;
927     break;
928   case ISD::SETLE:
929   case ISD::SETULE:
930     CondCode = AArch64CC::LE;
931     break;
932   case ISD::SETNE:
933   case ISD::SETUNE:
934     CondCode = AArch64CC::NE;
935     break;
936   }
937 }
938 
939 /// changeVectorFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64
940 /// CC usable with the vector instructions. Fewer operations are available
941 /// without a real NZCV register, so we have to use less efficient combinations
942 /// to get the same effect.
changeVectorFPCCToAArch64CC(ISD::CondCode CC,AArch64CC::CondCode & CondCode,AArch64CC::CondCode & CondCode2,bool & Invert)943 static void changeVectorFPCCToAArch64CC(ISD::CondCode CC,
944                                         AArch64CC::CondCode &CondCode,
945                                         AArch64CC::CondCode &CondCode2,
946                                         bool &Invert) {
947   Invert = false;
948   switch (CC) {
949   default:
950     // Mostly the scalar mappings work fine.
951     changeFPCCToAArch64CC(CC, CondCode, CondCode2);
952     break;
953   case ISD::SETUO:
954     Invert = true; // Fallthrough
955   case ISD::SETO:
956     CondCode = AArch64CC::MI;
957     CondCode2 = AArch64CC::GE;
958     break;
959   case ISD::SETUEQ:
960   case ISD::SETULT:
961   case ISD::SETULE:
962   case ISD::SETUGT:
963   case ISD::SETUGE:
964     // All of the compare-mask comparisons are ordered, but we can switch
965     // between the two by a double inversion. E.g. ULE == !OGT.
966     Invert = true;
967     changeFPCCToAArch64CC(getSetCCInverse(CC, false), CondCode, CondCode2);
968     break;
969   }
970 }
971 
isLegalArithImmed(uint64_t C)972 static bool isLegalArithImmed(uint64_t C) {
973   // Matches AArch64DAGToDAGISel::SelectArithImmed().
974   return (C >> 12 == 0) || ((C & 0xFFFULL) == 0 && C >> 24 == 0);
975 }
976 
emitComparison(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDLoc dl,SelectionDAG & DAG)977 static SDValue emitComparison(SDValue LHS, SDValue RHS, ISD::CondCode CC,
978                               SDLoc dl, SelectionDAG &DAG) {
979   EVT VT = LHS.getValueType();
980 
981   if (VT.isFloatingPoint())
982     return DAG.getNode(AArch64ISD::FCMP, dl, VT, LHS, RHS);
983 
984   // The CMP instruction is just an alias for SUBS, and representing it as
985   // SUBS means that it's possible to get CSE with subtract operations.
986   // A later phase can perform the optimization of setting the destination
987   // register to WZR/XZR if it ends up being unused.
988   unsigned Opcode = AArch64ISD::SUBS;
989 
990   if (RHS.getOpcode() == ISD::SUB && isa<ConstantSDNode>(RHS.getOperand(0)) &&
991       cast<ConstantSDNode>(RHS.getOperand(0))->getZExtValue() == 0 &&
992       (CC == ISD::SETEQ || CC == ISD::SETNE)) {
993     // We'd like to combine a (CMP op1, (sub 0, op2) into a CMN instruction on
994     // the grounds that "op1 - (-op2) == op1 + op2". However, the C and V flags
995     // can be set differently by this operation. It comes down to whether
996     // "SInt(~op2)+1 == SInt(~op2+1)" (and the same for UInt). If they are then
997     // everything is fine. If not then the optimization is wrong. Thus general
998     // comparisons are only valid if op2 != 0.
999 
1000     // So, finally, the only LLVM-native comparisons that don't mention C and V
1001     // are SETEQ and SETNE. They're the only ones we can safely use CMN for in
1002     // the absence of information about op2.
1003     Opcode = AArch64ISD::ADDS;
1004     RHS = RHS.getOperand(1);
1005   } else if (LHS.getOpcode() == ISD::AND && isa<ConstantSDNode>(RHS) &&
1006              cast<ConstantSDNode>(RHS)->getZExtValue() == 0 &&
1007              !isUnsignedIntSetCC(CC)) {
1008     // Similarly, (CMP (and X, Y), 0) can be implemented with a TST
1009     // (a.k.a. ANDS) except that the flags are only guaranteed to work for one
1010     // of the signed comparisons.
1011     Opcode = AArch64ISD::ANDS;
1012     RHS = LHS.getOperand(1);
1013     LHS = LHS.getOperand(0);
1014   }
1015 
1016   return DAG.getNode(Opcode, dl, DAG.getVTList(VT, MVT::i32), LHS, RHS)
1017       .getValue(1);
1018 }
1019 
getAArch64Cmp(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDValue & AArch64cc,SelectionDAG & DAG,SDLoc dl)1020 static SDValue getAArch64Cmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
1021                              SDValue &AArch64cc, SelectionDAG &DAG, SDLoc dl) {
1022   if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
1023     EVT VT = RHS.getValueType();
1024     uint64_t C = RHSC->getZExtValue();
1025     if (!isLegalArithImmed(C)) {
1026       // Constant does not fit, try adjusting it by one?
1027       switch (CC) {
1028       default:
1029         break;
1030       case ISD::SETLT:
1031       case ISD::SETGE:
1032         if ((VT == MVT::i32 && C != 0x80000000 &&
1033              isLegalArithImmed((uint32_t)(C - 1))) ||
1034             (VT == MVT::i64 && C != 0x80000000ULL &&
1035              isLegalArithImmed(C - 1ULL))) {
1036           CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
1037           C = (VT == MVT::i32) ? (uint32_t)(C - 1) : C - 1;
1038           RHS = DAG.getConstant(C, VT);
1039         }
1040         break;
1041       case ISD::SETULT:
1042       case ISD::SETUGE:
1043         if ((VT == MVT::i32 && C != 0 &&
1044              isLegalArithImmed((uint32_t)(C - 1))) ||
1045             (VT == MVT::i64 && C != 0ULL && isLegalArithImmed(C - 1ULL))) {
1046           CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
1047           C = (VT == MVT::i32) ? (uint32_t)(C - 1) : C - 1;
1048           RHS = DAG.getConstant(C, VT);
1049         }
1050         break;
1051       case ISD::SETLE:
1052       case ISD::SETGT:
1053         if ((VT == MVT::i32 && C != 0x7fffffff &&
1054              isLegalArithImmed((uint32_t)(C + 1))) ||
1055             (VT == MVT::i64 && C != 0x7ffffffffffffffULL &&
1056              isLegalArithImmed(C + 1ULL))) {
1057           CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
1058           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;
1059           RHS = DAG.getConstant(C, VT);
1060         }
1061         break;
1062       case ISD::SETULE:
1063       case ISD::SETUGT:
1064         if ((VT == MVT::i32 && C != 0xffffffff &&
1065              isLegalArithImmed((uint32_t)(C + 1))) ||
1066             (VT == MVT::i64 && C != 0xfffffffffffffffULL &&
1067              isLegalArithImmed(C + 1ULL))) {
1068           CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
1069           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;
1070           RHS = DAG.getConstant(C, VT);
1071         }
1072         break;
1073       }
1074     }
1075   }
1076 
1077   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
1078   AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
1079   AArch64cc = DAG.getConstant(AArch64CC, MVT::i32);
1080   return Cmp;
1081 }
1082 
1083 static std::pair<SDValue, SDValue>
getAArch64XALUOOp(AArch64CC::CondCode & CC,SDValue Op,SelectionDAG & DAG)1084 getAArch64XALUOOp(AArch64CC::CondCode &CC, SDValue Op, SelectionDAG &DAG) {
1085   assert((Op.getValueType() == MVT::i32 || Op.getValueType() == MVT::i64) &&
1086          "Unsupported value type");
1087   SDValue Value, Overflow;
1088   SDLoc DL(Op);
1089   SDValue LHS = Op.getOperand(0);
1090   SDValue RHS = Op.getOperand(1);
1091   unsigned Opc = 0;
1092   switch (Op.getOpcode()) {
1093   default:
1094     llvm_unreachable("Unknown overflow instruction!");
1095   case ISD::SADDO:
1096     Opc = AArch64ISD::ADDS;
1097     CC = AArch64CC::VS;
1098     break;
1099   case ISD::UADDO:
1100     Opc = AArch64ISD::ADDS;
1101     CC = AArch64CC::HS;
1102     break;
1103   case ISD::SSUBO:
1104     Opc = AArch64ISD::SUBS;
1105     CC = AArch64CC::VS;
1106     break;
1107   case ISD::USUBO:
1108     Opc = AArch64ISD::SUBS;
1109     CC = AArch64CC::LO;
1110     break;
1111   // Multiply needs a little bit extra work.
1112   case ISD::SMULO:
1113   case ISD::UMULO: {
1114     CC = AArch64CC::NE;
1115     bool IsSigned = (Op.getOpcode() == ISD::SMULO) ? true : false;
1116     if (Op.getValueType() == MVT::i32) {
1117       unsigned ExtendOpc = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
1118       // For a 32 bit multiply with overflow check we want the instruction
1119       // selector to generate a widening multiply (SMADDL/UMADDL). For that we
1120       // need to generate the following pattern:
1121       // (i64 add 0, (i64 mul (i64 sext|zext i32 %a), (i64 sext|zext i32 %b))
1122       LHS = DAG.getNode(ExtendOpc, DL, MVT::i64, LHS);
1123       RHS = DAG.getNode(ExtendOpc, DL, MVT::i64, RHS);
1124       SDValue Mul = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
1125       SDValue Add = DAG.getNode(ISD::ADD, DL, MVT::i64, Mul,
1126                                 DAG.getConstant(0, MVT::i64));
1127       // On AArch64 the upper 32 bits are always zero extended for a 32 bit
1128       // operation. We need to clear out the upper 32 bits, because we used a
1129       // widening multiply that wrote all 64 bits. In the end this should be a
1130       // noop.
1131       Value = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Add);
1132       if (IsSigned) {
1133         // The signed overflow check requires more than just a simple check for
1134         // any bit set in the upper 32 bits of the result. These bits could be
1135         // just the sign bits of a negative number. To perform the overflow
1136         // check we have to arithmetic shift right the 32nd bit of the result by
1137         // 31 bits. Then we compare the result to the upper 32 bits.
1138         SDValue UpperBits = DAG.getNode(ISD::SRL, DL, MVT::i64, Add,
1139                                         DAG.getConstant(32, MVT::i64));
1140         UpperBits = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, UpperBits);
1141         SDValue LowerBits = DAG.getNode(ISD::SRA, DL, MVT::i32, Value,
1142                                         DAG.getConstant(31, MVT::i64));
1143         // It is important that LowerBits is last, otherwise the arithmetic
1144         // shift will not be folded into the compare (SUBS).
1145         SDVTList VTs = DAG.getVTList(MVT::i32, MVT::i32);
1146         Overflow = DAG.getNode(AArch64ISD::SUBS, DL, VTs, UpperBits, LowerBits)
1147                        .getValue(1);
1148       } else {
1149         // The overflow check for unsigned multiply is easy. We only need to
1150         // check if any of the upper 32 bits are set. This can be done with a
1151         // CMP (shifted register). For that we need to generate the following
1152         // pattern:
1153         // (i64 AArch64ISD::SUBS i64 0, (i64 srl i64 %Mul, i64 32)
1154         SDValue UpperBits = DAG.getNode(ISD::SRL, DL, MVT::i64, Mul,
1155                                         DAG.getConstant(32, MVT::i64));
1156         SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1157         Overflow =
1158             DAG.getNode(AArch64ISD::SUBS, DL, VTs, DAG.getConstant(0, MVT::i64),
1159                         UpperBits).getValue(1);
1160       }
1161       break;
1162     }
1163     assert(Op.getValueType() == MVT::i64 && "Expected an i64 value type");
1164     // For the 64 bit multiply
1165     Value = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
1166     if (IsSigned) {
1167       SDValue UpperBits = DAG.getNode(ISD::MULHS, DL, MVT::i64, LHS, RHS);
1168       SDValue LowerBits = DAG.getNode(ISD::SRA, DL, MVT::i64, Value,
1169                                       DAG.getConstant(63, MVT::i64));
1170       // It is important that LowerBits is last, otherwise the arithmetic
1171       // shift will not be folded into the compare (SUBS).
1172       SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1173       Overflow = DAG.getNode(AArch64ISD::SUBS, DL, VTs, UpperBits, LowerBits)
1174                      .getValue(1);
1175     } else {
1176       SDValue UpperBits = DAG.getNode(ISD::MULHU, DL, MVT::i64, LHS, RHS);
1177       SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1178       Overflow =
1179           DAG.getNode(AArch64ISD::SUBS, DL, VTs, DAG.getConstant(0, MVT::i64),
1180                       UpperBits).getValue(1);
1181     }
1182     break;
1183   }
1184   } // switch (...)
1185 
1186   if (Opc) {
1187     SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::i32);
1188 
1189     // Emit the AArch64 operation with overflow check.
1190     Value = DAG.getNode(Opc, DL, VTs, LHS, RHS);
1191     Overflow = Value.getValue(1);
1192   }
1193   return std::make_pair(Value, Overflow);
1194 }
1195 
LowerF128Call(SDValue Op,SelectionDAG & DAG,RTLIB::Libcall Call) const1196 SDValue AArch64TargetLowering::LowerF128Call(SDValue Op, SelectionDAG &DAG,
1197                                              RTLIB::Libcall Call) const {
1198   SmallVector<SDValue, 2> Ops;
1199   for (unsigned i = 0, e = Op->getNumOperands(); i != e; ++i)
1200     Ops.push_back(Op.getOperand(i));
1201 
1202   return makeLibCall(DAG, Call, MVT::f128, &Ops[0], Ops.size(), false,
1203                      SDLoc(Op)).first;
1204 }
1205 
LowerXOR(SDValue Op,SelectionDAG & DAG)1206 static SDValue LowerXOR(SDValue Op, SelectionDAG &DAG) {
1207   SDValue Sel = Op.getOperand(0);
1208   SDValue Other = Op.getOperand(1);
1209 
1210   // If neither operand is a SELECT_CC, give up.
1211   if (Sel.getOpcode() != ISD::SELECT_CC)
1212     std::swap(Sel, Other);
1213   if (Sel.getOpcode() != ISD::SELECT_CC)
1214     return Op;
1215 
1216   // The folding we want to perform is:
1217   // (xor x, (select_cc a, b, cc, 0, -1) )
1218   //   -->
1219   // (csel x, (xor x, -1), cc ...)
1220   //
1221   // The latter will get matched to a CSINV instruction.
1222 
1223   ISD::CondCode CC = cast<CondCodeSDNode>(Sel.getOperand(4))->get();
1224   SDValue LHS = Sel.getOperand(0);
1225   SDValue RHS = Sel.getOperand(1);
1226   SDValue TVal = Sel.getOperand(2);
1227   SDValue FVal = Sel.getOperand(3);
1228   SDLoc dl(Sel);
1229 
1230   // FIXME: This could be generalized to non-integer comparisons.
1231   if (LHS.getValueType() != MVT::i32 && LHS.getValueType() != MVT::i64)
1232     return Op;
1233 
1234   ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
1235   ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
1236 
1237   // The the values aren't constants, this isn't the pattern we're looking for.
1238   if (!CFVal || !CTVal)
1239     return Op;
1240 
1241   // We can commute the SELECT_CC by inverting the condition.  This
1242   // might be needed to make this fit into a CSINV pattern.
1243   if (CTVal->isAllOnesValue() && CFVal->isNullValue()) {
1244     std::swap(TVal, FVal);
1245     std::swap(CTVal, CFVal);
1246     CC = ISD::getSetCCInverse(CC, true);
1247   }
1248 
1249   // If the constants line up, perform the transform!
1250   if (CTVal->isNullValue() && CFVal->isAllOnesValue()) {
1251     SDValue CCVal;
1252     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
1253 
1254     FVal = Other;
1255     TVal = DAG.getNode(ISD::XOR, dl, Other.getValueType(), Other,
1256                        DAG.getConstant(-1ULL, Other.getValueType()));
1257 
1258     return DAG.getNode(AArch64ISD::CSEL, dl, Sel.getValueType(), FVal, TVal,
1259                        CCVal, Cmp);
1260   }
1261 
1262   return Op;
1263 }
1264 
LowerADDC_ADDE_SUBC_SUBE(SDValue Op,SelectionDAG & DAG)1265 static SDValue LowerADDC_ADDE_SUBC_SUBE(SDValue Op, SelectionDAG &DAG) {
1266   EVT VT = Op.getValueType();
1267 
1268   // Let legalize expand this if it isn't a legal type yet.
1269   if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
1270     return SDValue();
1271 
1272   SDVTList VTs = DAG.getVTList(VT, MVT::i32);
1273 
1274   unsigned Opc;
1275   bool ExtraOp = false;
1276   switch (Op.getOpcode()) {
1277   default:
1278     llvm_unreachable("Invalid code");
1279   case ISD::ADDC:
1280     Opc = AArch64ISD::ADDS;
1281     break;
1282   case ISD::SUBC:
1283     Opc = AArch64ISD::SUBS;
1284     break;
1285   case ISD::ADDE:
1286     Opc = AArch64ISD::ADCS;
1287     ExtraOp = true;
1288     break;
1289   case ISD::SUBE:
1290     Opc = AArch64ISD::SBCS;
1291     ExtraOp = true;
1292     break;
1293   }
1294 
1295   if (!ExtraOp)
1296     return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0), Op.getOperand(1));
1297   return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0), Op.getOperand(1),
1298                      Op.getOperand(2));
1299 }
1300 
LowerXALUO(SDValue Op,SelectionDAG & DAG)1301 static SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) {
1302   // Let legalize expand this if it isn't a legal type yet.
1303   if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
1304     return SDValue();
1305 
1306   AArch64CC::CondCode CC;
1307   // The actual operation that sets the overflow or carry flag.
1308   SDValue Value, Overflow;
1309   std::tie(Value, Overflow) = getAArch64XALUOOp(CC, Op, DAG);
1310 
1311   // We use 0 and 1 as false and true values.
1312   SDValue TVal = DAG.getConstant(1, MVT::i32);
1313   SDValue FVal = DAG.getConstant(0, MVT::i32);
1314 
1315   // We use an inverted condition, because the conditional select is inverted
1316   // too. This will allow it to be selected to a single instruction:
1317   // CSINC Wd, WZR, WZR, invert(cond).
1318   SDValue CCVal = DAG.getConstant(getInvertedCondCode(CC), MVT::i32);
1319   Overflow = DAG.getNode(AArch64ISD::CSEL, SDLoc(Op), MVT::i32, FVal, TVal,
1320                          CCVal, Overflow);
1321 
1322   SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
1323   return DAG.getNode(ISD::MERGE_VALUES, SDLoc(Op), VTs, Value, Overflow);
1324 }
1325 
1326 // Prefetch operands are:
1327 // 1: Address to prefetch
1328 // 2: bool isWrite
1329 // 3: int locality (0 = no locality ... 3 = extreme locality)
1330 // 4: bool isDataCache
LowerPREFETCH(SDValue Op,SelectionDAG & DAG)1331 static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG) {
1332   SDLoc DL(Op);
1333   unsigned IsWrite = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue();
1334   unsigned Locality = cast<ConstantSDNode>(Op.getOperand(3))->getZExtValue();
1335   // The data thing is not used.
1336   // unsigned isData = cast<ConstantSDNode>(Op.getOperand(4))->getZExtValue();
1337 
1338   bool IsStream = !Locality;
1339   // When the locality number is set
1340   if (Locality) {
1341     // The front-end should have filtered out the out-of-range values
1342     assert(Locality <= 3 && "Prefetch locality out-of-range");
1343     // The locality degree is the opposite of the cache speed.
1344     // Put the number the other way around.
1345     // The encoding starts at 0 for level 1
1346     Locality = 3 - Locality;
1347   }
1348 
1349   // built the mask value encoding the expected behavior.
1350   unsigned PrfOp = (IsWrite << 4) |     // Load/Store bit
1351                    (Locality << 1) |    // Cache level bits
1352                    (unsigned)IsStream;  // Stream bit
1353   return DAG.getNode(AArch64ISD::PREFETCH, DL, MVT::Other, Op.getOperand(0),
1354                      DAG.getConstant(PrfOp, MVT::i32), Op.getOperand(1));
1355 }
1356 
LowerFP_EXTEND(SDValue Op,SelectionDAG & DAG) const1357 SDValue AArch64TargetLowering::LowerFP_EXTEND(SDValue Op,
1358                                               SelectionDAG &DAG) const {
1359   assert(Op.getValueType() == MVT::f128 && "Unexpected lowering");
1360 
1361   RTLIB::Libcall LC;
1362   LC = RTLIB::getFPEXT(Op.getOperand(0).getValueType(), Op.getValueType());
1363 
1364   return LowerF128Call(Op, DAG, LC);
1365 }
1366 
LowerFP_ROUND(SDValue Op,SelectionDAG & DAG) const1367 SDValue AArch64TargetLowering::LowerFP_ROUND(SDValue Op,
1368                                              SelectionDAG &DAG) const {
1369   if (Op.getOperand(0).getValueType() != MVT::f128) {
1370     // It's legal except when f128 is involved
1371     return Op;
1372   }
1373 
1374   RTLIB::Libcall LC;
1375   LC = RTLIB::getFPROUND(Op.getOperand(0).getValueType(), Op.getValueType());
1376 
1377   // FP_ROUND node has a second operand indicating whether it is known to be
1378   // precise. That doesn't take part in the LibCall so we can't directly use
1379   // LowerF128Call.
1380   SDValue SrcVal = Op.getOperand(0);
1381   return makeLibCall(DAG, LC, Op.getValueType(), &SrcVal, 1,
1382                      /*isSigned*/ false, SDLoc(Op)).first;
1383 }
1384 
LowerVectorFP_TO_INT(SDValue Op,SelectionDAG & DAG)1385 static SDValue LowerVectorFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
1386   // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
1387   // Any additional optimization in this function should be recorded
1388   // in the cost tables.
1389   EVT InVT = Op.getOperand(0).getValueType();
1390   EVT VT = Op.getValueType();
1391 
1392   if (VT.getSizeInBits() < InVT.getSizeInBits()) {
1393     SDLoc dl(Op);
1394     SDValue Cv =
1395         DAG.getNode(Op.getOpcode(), dl, InVT.changeVectorElementTypeToInteger(),
1396                     Op.getOperand(0));
1397     return DAG.getNode(ISD::TRUNCATE, dl, VT, Cv);
1398   }
1399 
1400   if (VT.getSizeInBits() > InVT.getSizeInBits()) {
1401     SDLoc dl(Op);
1402     SDValue Ext = DAG.getNode(ISD::FP_EXTEND, dl, MVT::v2f64, Op.getOperand(0));
1403     return DAG.getNode(Op.getOpcode(), dl, VT, Ext);
1404   }
1405 
1406   // Type changing conversions are illegal.
1407   return Op;
1408 }
1409 
LowerFP_TO_INT(SDValue Op,SelectionDAG & DAG) const1410 SDValue AArch64TargetLowering::LowerFP_TO_INT(SDValue Op,
1411                                               SelectionDAG &DAG) const {
1412   if (Op.getOperand(0).getValueType().isVector())
1413     return LowerVectorFP_TO_INT(Op, DAG);
1414 
1415   if (Op.getOperand(0).getValueType() != MVT::f128) {
1416     // It's legal except when f128 is involved
1417     return Op;
1418   }
1419 
1420   RTLIB::Libcall LC;
1421   if (Op.getOpcode() == ISD::FP_TO_SINT)
1422     LC = RTLIB::getFPTOSINT(Op.getOperand(0).getValueType(), Op.getValueType());
1423   else
1424     LC = RTLIB::getFPTOUINT(Op.getOperand(0).getValueType(), Op.getValueType());
1425 
1426   SmallVector<SDValue, 2> Ops;
1427   for (unsigned i = 0, e = Op->getNumOperands(); i != e; ++i)
1428     Ops.push_back(Op.getOperand(i));
1429 
1430   return makeLibCall(DAG, LC, Op.getValueType(), &Ops[0], Ops.size(), false,
1431                      SDLoc(Op)).first;
1432 }
1433 
LowerVectorINT_TO_FP(SDValue Op,SelectionDAG & DAG)1434 static SDValue LowerVectorINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
1435   // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
1436   // Any additional optimization in this function should be recorded
1437   // in the cost tables.
1438   EVT VT = Op.getValueType();
1439   SDLoc dl(Op);
1440   SDValue In = Op.getOperand(0);
1441   EVT InVT = In.getValueType();
1442 
1443   if (VT.getSizeInBits() < InVT.getSizeInBits()) {
1444     MVT CastVT =
1445         MVT::getVectorVT(MVT::getFloatingPointVT(InVT.getScalarSizeInBits()),
1446                          InVT.getVectorNumElements());
1447     In = DAG.getNode(Op.getOpcode(), dl, CastVT, In);
1448     return DAG.getNode(ISD::FP_ROUND, dl, VT, In, DAG.getIntPtrConstant(0));
1449   }
1450 
1451   if (VT.getSizeInBits() > InVT.getSizeInBits()) {
1452     unsigned CastOpc =
1453         Op.getOpcode() == ISD::SINT_TO_FP ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
1454     EVT CastVT = VT.changeVectorElementTypeToInteger();
1455     In = DAG.getNode(CastOpc, dl, CastVT, In);
1456     return DAG.getNode(Op.getOpcode(), dl, VT, In);
1457   }
1458 
1459   return Op;
1460 }
1461 
LowerINT_TO_FP(SDValue Op,SelectionDAG & DAG) const1462 SDValue AArch64TargetLowering::LowerINT_TO_FP(SDValue Op,
1463                                             SelectionDAG &DAG) const {
1464   if (Op.getValueType().isVector())
1465     return LowerVectorINT_TO_FP(Op, DAG);
1466 
1467   // i128 conversions are libcalls.
1468   if (Op.getOperand(0).getValueType() == MVT::i128)
1469     return SDValue();
1470 
1471   // Other conversions are legal, unless it's to the completely software-based
1472   // fp128.
1473   if (Op.getValueType() != MVT::f128)
1474     return Op;
1475 
1476   RTLIB::Libcall LC;
1477   if (Op.getOpcode() == ISD::SINT_TO_FP)
1478     LC = RTLIB::getSINTTOFP(Op.getOperand(0).getValueType(), Op.getValueType());
1479   else
1480     LC = RTLIB::getUINTTOFP(Op.getOperand(0).getValueType(), Op.getValueType());
1481 
1482   return LowerF128Call(Op, DAG, LC);
1483 }
1484 
LowerFSINCOS(SDValue Op,SelectionDAG & DAG) const1485 SDValue AArch64TargetLowering::LowerFSINCOS(SDValue Op,
1486                                             SelectionDAG &DAG) const {
1487   // For iOS, we want to call an alternative entry point: __sincos_stret,
1488   // which returns the values in two S / D registers.
1489   SDLoc dl(Op);
1490   SDValue Arg = Op.getOperand(0);
1491   EVT ArgVT = Arg.getValueType();
1492   Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1493 
1494   ArgListTy Args;
1495   ArgListEntry Entry;
1496 
1497   Entry.Node = Arg;
1498   Entry.Ty = ArgTy;
1499   Entry.isSExt = false;
1500   Entry.isZExt = false;
1501   Args.push_back(Entry);
1502 
1503   const char *LibcallName =
1504       (ArgVT == MVT::f64) ? "__sincos_stret" : "__sincosf_stret";
1505   SDValue Callee = DAG.getExternalSymbol(LibcallName, getPointerTy());
1506 
1507   StructType *RetTy = StructType::get(ArgTy, ArgTy, NULL);
1508   TargetLowering::CallLoweringInfo CLI(DAG);
1509   CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
1510     .setCallee(CallingConv::Fast, RetTy, Callee, std::move(Args), 0);
1511 
1512   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
1513   return CallResult.first;
1514 }
1515 
LowerOperation(SDValue Op,SelectionDAG & DAG) const1516 SDValue AArch64TargetLowering::LowerOperation(SDValue Op,
1517                                               SelectionDAG &DAG) const {
1518   switch (Op.getOpcode()) {
1519   default:
1520     llvm_unreachable("unimplemented operand");
1521     return SDValue();
1522   case ISD::GlobalAddress:
1523     return LowerGlobalAddress(Op, DAG);
1524   case ISD::GlobalTLSAddress:
1525     return LowerGlobalTLSAddress(Op, DAG);
1526   case ISD::SETCC:
1527     return LowerSETCC(Op, DAG);
1528   case ISD::BR_CC:
1529     return LowerBR_CC(Op, DAG);
1530   case ISD::SELECT:
1531     return LowerSELECT(Op, DAG);
1532   case ISD::SELECT_CC:
1533     return LowerSELECT_CC(Op, DAG);
1534   case ISD::JumpTable:
1535     return LowerJumpTable(Op, DAG);
1536   case ISD::ConstantPool:
1537     return LowerConstantPool(Op, DAG);
1538   case ISD::BlockAddress:
1539     return LowerBlockAddress(Op, DAG);
1540   case ISD::VASTART:
1541     return LowerVASTART(Op, DAG);
1542   case ISD::VACOPY:
1543     return LowerVACOPY(Op, DAG);
1544   case ISD::VAARG:
1545     return LowerVAARG(Op, DAG);
1546   case ISD::ADDC:
1547   case ISD::ADDE:
1548   case ISD::SUBC:
1549   case ISD::SUBE:
1550     return LowerADDC_ADDE_SUBC_SUBE(Op, DAG);
1551   case ISD::SADDO:
1552   case ISD::UADDO:
1553   case ISD::SSUBO:
1554   case ISD::USUBO:
1555   case ISD::SMULO:
1556   case ISD::UMULO:
1557     return LowerXALUO(Op, DAG);
1558   case ISD::FADD:
1559     return LowerF128Call(Op, DAG, RTLIB::ADD_F128);
1560   case ISD::FSUB:
1561     return LowerF128Call(Op, DAG, RTLIB::SUB_F128);
1562   case ISD::FMUL:
1563     return LowerF128Call(Op, DAG, RTLIB::MUL_F128);
1564   case ISD::FDIV:
1565     return LowerF128Call(Op, DAG, RTLIB::DIV_F128);
1566   case ISD::FP_ROUND:
1567     return LowerFP_ROUND(Op, DAG);
1568   case ISD::FP_EXTEND:
1569     return LowerFP_EXTEND(Op, DAG);
1570   case ISD::FRAMEADDR:
1571     return LowerFRAMEADDR(Op, DAG);
1572   case ISD::RETURNADDR:
1573     return LowerRETURNADDR(Op, DAG);
1574   case ISD::INSERT_VECTOR_ELT:
1575     return LowerINSERT_VECTOR_ELT(Op, DAG);
1576   case ISD::EXTRACT_VECTOR_ELT:
1577     return LowerEXTRACT_VECTOR_ELT(Op, DAG);
1578   case ISD::BUILD_VECTOR:
1579     return LowerBUILD_VECTOR(Op, DAG);
1580   case ISD::VECTOR_SHUFFLE:
1581     return LowerVECTOR_SHUFFLE(Op, DAG);
1582   case ISD::EXTRACT_SUBVECTOR:
1583     return LowerEXTRACT_SUBVECTOR(Op, DAG);
1584   case ISD::SRA:
1585   case ISD::SRL:
1586   case ISD::SHL:
1587     return LowerVectorSRA_SRL_SHL(Op, DAG);
1588   case ISD::SHL_PARTS:
1589     return LowerShiftLeftParts(Op, DAG);
1590   case ISD::SRL_PARTS:
1591   case ISD::SRA_PARTS:
1592     return LowerShiftRightParts(Op, DAG);
1593   case ISD::CTPOP:
1594     return LowerCTPOP(Op, DAG);
1595   case ISD::FCOPYSIGN:
1596     return LowerFCOPYSIGN(Op, DAG);
1597   case ISD::AND:
1598     return LowerVectorAND(Op, DAG);
1599   case ISD::OR:
1600     return LowerVectorOR(Op, DAG);
1601   case ISD::XOR:
1602     return LowerXOR(Op, DAG);
1603   case ISD::PREFETCH:
1604     return LowerPREFETCH(Op, DAG);
1605   case ISD::SINT_TO_FP:
1606   case ISD::UINT_TO_FP:
1607     return LowerINT_TO_FP(Op, DAG);
1608   case ISD::FP_TO_SINT:
1609   case ISD::FP_TO_UINT:
1610     return LowerFP_TO_INT(Op, DAG);
1611   case ISD::FSINCOS:
1612     return LowerFSINCOS(Op, DAG);
1613   }
1614 }
1615 
1616 /// getFunctionAlignment - Return the Log2 alignment of this function.
getFunctionAlignment(const Function * F) const1617 unsigned AArch64TargetLowering::getFunctionAlignment(const Function *F) const {
1618   return 2;
1619 }
1620 
1621 //===----------------------------------------------------------------------===//
1622 //                      Calling Convention Implementation
1623 //===----------------------------------------------------------------------===//
1624 
1625 #include "AArch64GenCallingConv.inc"
1626 
1627 /// Selects the correct CCAssignFn for a the given CallingConvention
1628 /// value.
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg) const1629 CCAssignFn *AArch64TargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1630                                                      bool IsVarArg) const {
1631   switch (CC) {
1632   default:
1633     llvm_unreachable("Unsupported calling convention.");
1634   case CallingConv::WebKit_JS:
1635     return CC_AArch64_WebKit_JS;
1636   case CallingConv::C:
1637   case CallingConv::Fast:
1638     if (!Subtarget->isTargetDarwin())
1639       return CC_AArch64_AAPCS;
1640     return IsVarArg ? CC_AArch64_DarwinPCS_VarArg : CC_AArch64_DarwinPCS;
1641   }
1642 }
1643 
LowerFormalArguments(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,SDLoc DL,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const1644 SDValue AArch64TargetLowering::LowerFormalArguments(
1645     SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
1646     const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
1647     SmallVectorImpl<SDValue> &InVals) const {
1648   MachineFunction &MF = DAG.getMachineFunction();
1649   MachineFrameInfo *MFI = MF.getFrameInfo();
1650 
1651   // Assign locations to all of the incoming arguments.
1652   SmallVector<CCValAssign, 16> ArgLocs;
1653   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
1654                  getTargetMachine(), ArgLocs, *DAG.getContext());
1655 
1656   // At this point, Ins[].VT may already be promoted to i32. To correctly
1657   // handle passing i8 as i8 instead of i32 on stack, we pass in both i32 and
1658   // i8 to CC_AArch64_AAPCS with i32 being ValVT and i8 being LocVT.
1659   // Since AnalyzeFormalArguments uses Ins[].VT for both ValVT and LocVT, here
1660   // we use a special version of AnalyzeFormalArguments to pass in ValVT and
1661   // LocVT.
1662   unsigned NumArgs = Ins.size();
1663   Function::const_arg_iterator CurOrigArg = MF.getFunction()->arg_begin();
1664   unsigned CurArgIdx = 0;
1665   for (unsigned i = 0; i != NumArgs; ++i) {
1666     MVT ValVT = Ins[i].VT;
1667     std::advance(CurOrigArg, Ins[i].OrigArgIndex - CurArgIdx);
1668     CurArgIdx = Ins[i].OrigArgIndex;
1669 
1670     // Get type of the original argument.
1671     EVT ActualVT = getValueType(CurOrigArg->getType(), /*AllowUnknown*/ true);
1672     MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : MVT::Other;
1673     // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
1674     if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
1675       ValVT = MVT::i8;
1676     else if (ActualMVT == MVT::i16)
1677       ValVT = MVT::i16;
1678 
1679     CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
1680     bool Res =
1681         AssignFn(i, ValVT, ValVT, CCValAssign::Full, Ins[i].Flags, CCInfo);
1682     assert(!Res && "Call operand has unhandled type");
1683     (void)Res;
1684   }
1685   assert(ArgLocs.size() == Ins.size());
1686   SmallVector<SDValue, 16> ArgValues;
1687   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
1688     CCValAssign &VA = ArgLocs[i];
1689 
1690     if (Ins[i].Flags.isByVal()) {
1691       // Byval is used for HFAs in the PCS, but the system should work in a
1692       // non-compliant manner for larger structs.
1693       EVT PtrTy = getPointerTy();
1694       int Size = Ins[i].Flags.getByValSize();
1695       unsigned NumRegs = (Size + 7) / 8;
1696 
1697       // FIXME: This works on big-endian for composite byvals, which are the common
1698       // case. It should also work for fundamental types too.
1699       unsigned FrameIdx =
1700         MFI->CreateFixedObject(8 * NumRegs, VA.getLocMemOffset(), false);
1701       SDValue FrameIdxN = DAG.getFrameIndex(FrameIdx, PtrTy);
1702       InVals.push_back(FrameIdxN);
1703 
1704       continue;
1705     }
1706 
1707     if (VA.isRegLoc()) {
1708       // Arguments stored in registers.
1709       EVT RegVT = VA.getLocVT();
1710 
1711       SDValue ArgValue;
1712       const TargetRegisterClass *RC;
1713 
1714       if (RegVT == MVT::i32)
1715         RC = &AArch64::GPR32RegClass;
1716       else if (RegVT == MVT::i64)
1717         RC = &AArch64::GPR64RegClass;
1718       else if (RegVT == MVT::f32)
1719         RC = &AArch64::FPR32RegClass;
1720       else if (RegVT == MVT::f64 || RegVT.is64BitVector())
1721         RC = &AArch64::FPR64RegClass;
1722       else if (RegVT == MVT::f128 || RegVT.is128BitVector())
1723         RC = &AArch64::FPR128RegClass;
1724       else
1725         llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
1726 
1727       // Transform the arguments in physical registers into virtual ones.
1728       unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
1729       ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
1730 
1731       // If this is an 8, 16 or 32-bit value, it is really passed promoted
1732       // to 64 bits.  Insert an assert[sz]ext to capture this, then
1733       // truncate to the right size.
1734       switch (VA.getLocInfo()) {
1735       default:
1736         llvm_unreachable("Unknown loc info!");
1737       case CCValAssign::Full:
1738         break;
1739       case CCValAssign::BCvt:
1740         ArgValue = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), ArgValue);
1741         break;
1742       case CCValAssign::AExt:
1743       case CCValAssign::SExt:
1744       case CCValAssign::ZExt:
1745         // SelectionDAGBuilder will insert appropriate AssertZExt & AssertSExt
1746         // nodes after our lowering.
1747         assert(RegVT == Ins[i].VT && "incorrect register location selected");
1748         break;
1749       }
1750 
1751       InVals.push_back(ArgValue);
1752 
1753     } else { // VA.isRegLoc()
1754       assert(VA.isMemLoc() && "CCValAssign is neither reg nor mem");
1755       unsigned ArgOffset = VA.getLocMemOffset();
1756       unsigned ArgSize = VA.getLocVT().getSizeInBits() / 8;
1757 
1758       uint32_t BEAlign = 0;
1759       if (ArgSize < 8 && !Subtarget->isLittleEndian())
1760         BEAlign = 8 - ArgSize;
1761 
1762       int FI = MFI->CreateFixedObject(ArgSize, ArgOffset + BEAlign, true);
1763 
1764       // Create load nodes to retrieve arguments from the stack.
1765       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
1766       SDValue ArgValue;
1767 
1768       // For NON_EXTLOAD, generic code in getLoad assert(ValVT == MemVT)
1769       ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
1770       MVT MemVT = VA.getValVT();
1771 
1772       switch (VA.getLocInfo()) {
1773       default:
1774         break;
1775       case CCValAssign::BCvt:
1776         MemVT = VA.getLocVT();
1777         break;
1778       case CCValAssign::SExt:
1779         ExtType = ISD::SEXTLOAD;
1780         break;
1781       case CCValAssign::ZExt:
1782         ExtType = ISD::ZEXTLOAD;
1783         break;
1784       case CCValAssign::AExt:
1785         ExtType = ISD::EXTLOAD;
1786         break;
1787       }
1788 
1789       ArgValue = DAG.getExtLoad(ExtType, DL, VA.getLocVT(), Chain, FIN,
1790                                 MachinePointerInfo::getFixedStack(FI),
1791                                 MemVT, false, false, false, nullptr);
1792 
1793       InVals.push_back(ArgValue);
1794     }
1795   }
1796 
1797   // varargs
1798   if (isVarArg) {
1799     if (!Subtarget->isTargetDarwin()) {
1800       // The AAPCS variadic function ABI is identical to the non-variadic
1801       // one. As a result there may be more arguments in registers and we should
1802       // save them for future reference.
1803       saveVarArgRegisters(CCInfo, DAG, DL, Chain);
1804     }
1805 
1806     AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
1807     // This will point to the next argument passed via stack.
1808     unsigned StackOffset = CCInfo.getNextStackOffset();
1809     // We currently pass all varargs at 8-byte alignment.
1810     StackOffset = ((StackOffset + 7) & ~7);
1811     AFI->setVarArgsStackIndex(MFI->CreateFixedObject(4, StackOffset, true));
1812   }
1813 
1814   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
1815   unsigned StackArgSize = CCInfo.getNextStackOffset();
1816   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
1817   if (DoesCalleeRestoreStack(CallConv, TailCallOpt)) {
1818     // This is a non-standard ABI so by fiat I say we're allowed to make full
1819     // use of the stack area to be popped, which must be aligned to 16 bytes in
1820     // any case:
1821     StackArgSize = RoundUpToAlignment(StackArgSize, 16);
1822 
1823     // If we're expected to restore the stack (e.g. fastcc) then we'll be adding
1824     // a multiple of 16.
1825     FuncInfo->setArgumentStackToRestore(StackArgSize);
1826 
1827     // This realignment carries over to the available bytes below. Our own
1828     // callers will guarantee the space is free by giving an aligned value to
1829     // CALLSEQ_START.
1830   }
1831   // Even if we're not expected to free up the space, it's useful to know how
1832   // much is there while considering tail calls (because we can reuse it).
1833   FuncInfo->setBytesInStackArgArea(StackArgSize);
1834 
1835   return Chain;
1836 }
1837 
saveVarArgRegisters(CCState & CCInfo,SelectionDAG & DAG,SDLoc DL,SDValue & Chain) const1838 void AArch64TargetLowering::saveVarArgRegisters(CCState &CCInfo,
1839                                                 SelectionDAG &DAG, SDLoc DL,
1840                                                 SDValue &Chain) const {
1841   MachineFunction &MF = DAG.getMachineFunction();
1842   MachineFrameInfo *MFI = MF.getFrameInfo();
1843   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
1844 
1845   SmallVector<SDValue, 8> MemOps;
1846 
1847   static const MCPhysReg GPRArgRegs[] = { AArch64::X0, AArch64::X1, AArch64::X2,
1848                                           AArch64::X3, AArch64::X4, AArch64::X5,
1849                                           AArch64::X6, AArch64::X7 };
1850   static const unsigned NumGPRArgRegs = array_lengthof(GPRArgRegs);
1851   unsigned FirstVariadicGPR =
1852       CCInfo.getFirstUnallocated(GPRArgRegs, NumGPRArgRegs);
1853 
1854   unsigned GPRSaveSize = 8 * (NumGPRArgRegs - FirstVariadicGPR);
1855   int GPRIdx = 0;
1856   if (GPRSaveSize != 0) {
1857     GPRIdx = MFI->CreateStackObject(GPRSaveSize, 8, false);
1858 
1859     SDValue FIN = DAG.getFrameIndex(GPRIdx, getPointerTy());
1860 
1861     for (unsigned i = FirstVariadicGPR; i < NumGPRArgRegs; ++i) {
1862       unsigned VReg = MF.addLiveIn(GPRArgRegs[i], &AArch64::GPR64RegClass);
1863       SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
1864       SDValue Store =
1865           DAG.getStore(Val.getValue(1), DL, Val, FIN,
1866                        MachinePointerInfo::getStack(i * 8), false, false, 0);
1867       MemOps.push_back(Store);
1868       FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(), FIN,
1869                         DAG.getConstant(8, getPointerTy()));
1870     }
1871   }
1872   FuncInfo->setVarArgsGPRIndex(GPRIdx);
1873   FuncInfo->setVarArgsGPRSize(GPRSaveSize);
1874 
1875   if (Subtarget->hasFPARMv8()) {
1876     static const MCPhysReg FPRArgRegs[] = {
1877         AArch64::Q0, AArch64::Q1, AArch64::Q2, AArch64::Q3,
1878         AArch64::Q4, AArch64::Q5, AArch64::Q6, AArch64::Q7};
1879     static const unsigned NumFPRArgRegs = array_lengthof(FPRArgRegs);
1880     unsigned FirstVariadicFPR =
1881         CCInfo.getFirstUnallocated(FPRArgRegs, NumFPRArgRegs);
1882 
1883     unsigned FPRSaveSize = 16 * (NumFPRArgRegs - FirstVariadicFPR);
1884     int FPRIdx = 0;
1885     if (FPRSaveSize != 0) {
1886       FPRIdx = MFI->CreateStackObject(FPRSaveSize, 16, false);
1887 
1888       SDValue FIN = DAG.getFrameIndex(FPRIdx, getPointerTy());
1889 
1890       for (unsigned i = FirstVariadicFPR; i < NumFPRArgRegs; ++i) {
1891         unsigned VReg = MF.addLiveIn(FPRArgRegs[i], &AArch64::FPR128RegClass);
1892         SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::f128);
1893 
1894         SDValue Store =
1895             DAG.getStore(Val.getValue(1), DL, Val, FIN,
1896                          MachinePointerInfo::getStack(i * 16), false, false, 0);
1897         MemOps.push_back(Store);
1898         FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(), FIN,
1899                           DAG.getConstant(16, getPointerTy()));
1900       }
1901     }
1902     FuncInfo->setVarArgsFPRIndex(FPRIdx);
1903     FuncInfo->setVarArgsFPRSize(FPRSaveSize);
1904   }
1905 
1906   if (!MemOps.empty()) {
1907     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
1908   }
1909 }
1910 
1911 /// LowerCallResult - Lower the result values of a call into the
1912 /// appropriate copies out of appropriate physical registers.
LowerCallResult(SDValue Chain,SDValue InFlag,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,SDLoc DL,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals,bool isThisReturn,SDValue ThisVal) const1913 SDValue AArch64TargetLowering::LowerCallResult(
1914     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg,
1915     const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
1916     SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
1917     SDValue ThisVal) const {
1918   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
1919                           ? RetCC_AArch64_WebKit_JS
1920                           : RetCC_AArch64_AAPCS;
1921   // Assign locations to each value returned by this call.
1922   SmallVector<CCValAssign, 16> RVLocs;
1923   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
1924                  getTargetMachine(), RVLocs, *DAG.getContext());
1925   CCInfo.AnalyzeCallResult(Ins, RetCC);
1926 
1927   // Copy all of the result registers out of their specified physreg.
1928   for (unsigned i = 0; i != RVLocs.size(); ++i) {
1929     CCValAssign VA = RVLocs[i];
1930 
1931     // Pass 'this' value directly from the argument to return value, to avoid
1932     // reg unit interference
1933     if (i == 0 && isThisReturn) {
1934       assert(!VA.needsCustom() && VA.getLocVT() == MVT::i64 &&
1935              "unexpected return calling convention register assignment");
1936       InVals.push_back(ThisVal);
1937       continue;
1938     }
1939 
1940     SDValue Val =
1941         DAG.getCopyFromReg(Chain, DL, VA.getLocReg(), VA.getLocVT(), InFlag);
1942     Chain = Val.getValue(1);
1943     InFlag = Val.getValue(2);
1944 
1945     switch (VA.getLocInfo()) {
1946     default:
1947       llvm_unreachable("Unknown loc info!");
1948     case CCValAssign::Full:
1949       break;
1950     case CCValAssign::BCvt:
1951       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
1952       break;
1953     }
1954 
1955     InVals.push_back(Val);
1956   }
1957 
1958   return Chain;
1959 }
1960 
isEligibleForTailCallOptimization(SDValue Callee,CallingConv::ID CalleeCC,bool isVarArg,bool isCalleeStructRet,bool isCallerStructRet,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,const SmallVectorImpl<ISD::InputArg> & Ins,SelectionDAG & DAG) const1961 bool AArch64TargetLowering::isEligibleForTailCallOptimization(
1962     SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg,
1963     bool isCalleeStructRet, bool isCallerStructRet,
1964     const SmallVectorImpl<ISD::OutputArg> &Outs,
1965     const SmallVectorImpl<SDValue> &OutVals,
1966     const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const {
1967   // For CallingConv::C this function knows whether the ABI needs
1968   // changing. That's not true for other conventions so they will have to opt in
1969   // manually.
1970   if (!IsTailCallConvention(CalleeCC) && CalleeCC != CallingConv::C)
1971     return false;
1972 
1973   const MachineFunction &MF = DAG.getMachineFunction();
1974   const Function *CallerF = MF.getFunction();
1975   CallingConv::ID CallerCC = CallerF->getCallingConv();
1976   bool CCMatch = CallerCC == CalleeCC;
1977 
1978   // Byval parameters hand the function a pointer directly into the stack area
1979   // we want to reuse during a tail call. Working around this *is* possible (see
1980   // X86) but less efficient and uglier in LowerCall.
1981   for (Function::const_arg_iterator i = CallerF->arg_begin(),
1982                                     e = CallerF->arg_end();
1983        i != e; ++i)
1984     if (i->hasByValAttr())
1985       return false;
1986 
1987   if (getTargetMachine().Options.GuaranteedTailCallOpt) {
1988     if (IsTailCallConvention(CalleeCC) && CCMatch)
1989       return true;
1990     return false;
1991   }
1992 
1993   // Now we search for cases where we can use a tail call without changing the
1994   // ABI. Sibcall is used in some places (particularly gcc) to refer to this
1995   // concept.
1996 
1997   // I want anyone implementing a new calling convention to think long and hard
1998   // about this assert.
1999   assert((!isVarArg || CalleeCC == CallingConv::C) &&
2000          "Unexpected variadic calling convention");
2001 
2002   if (isVarArg && !Outs.empty()) {
2003     // At least two cases here: if caller is fastcc then we can't have any
2004     // memory arguments (we'd be expected to clean up the stack afterwards). If
2005     // caller is C then we could potentially use its argument area.
2006 
2007     // FIXME: for now we take the most conservative of these in both cases:
2008     // disallow all variadic memory operands.
2009     SmallVector<CCValAssign, 16> ArgLocs;
2010     CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(),
2011                    getTargetMachine(), ArgLocs, *DAG.getContext());
2012 
2013     CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForCall(CalleeCC, true));
2014     for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i)
2015       if (!ArgLocs[i].isRegLoc())
2016         return false;
2017   }
2018 
2019   // If the calling conventions do not match, then we'd better make sure the
2020   // results are returned in the same way as what the caller expects.
2021   if (!CCMatch) {
2022     SmallVector<CCValAssign, 16> RVLocs1;
2023     CCState CCInfo1(CalleeCC, false, DAG.getMachineFunction(),
2024                     getTargetMachine(), RVLocs1, *DAG.getContext());
2025     CCInfo1.AnalyzeCallResult(Ins, CCAssignFnForCall(CalleeCC, isVarArg));
2026 
2027     SmallVector<CCValAssign, 16> RVLocs2;
2028     CCState CCInfo2(CallerCC, false, DAG.getMachineFunction(),
2029                     getTargetMachine(), RVLocs2, *DAG.getContext());
2030     CCInfo2.AnalyzeCallResult(Ins, CCAssignFnForCall(CallerCC, isVarArg));
2031 
2032     if (RVLocs1.size() != RVLocs2.size())
2033       return false;
2034     for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
2035       if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
2036         return false;
2037       if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
2038         return false;
2039       if (RVLocs1[i].isRegLoc()) {
2040         if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
2041           return false;
2042       } else {
2043         if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
2044           return false;
2045       }
2046     }
2047   }
2048 
2049   // Nothing more to check if the callee is taking no arguments
2050   if (Outs.empty())
2051     return true;
2052 
2053   SmallVector<CCValAssign, 16> ArgLocs;
2054   CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(),
2055                  getTargetMachine(), ArgLocs, *DAG.getContext());
2056 
2057   CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForCall(CalleeCC, isVarArg));
2058 
2059   const AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
2060 
2061   // If the stack arguments for this call would fit into our own save area then
2062   // the call can be made tail.
2063   return CCInfo.getNextStackOffset() <= FuncInfo->getBytesInStackArgArea();
2064 }
2065 
addTokenForArgument(SDValue Chain,SelectionDAG & DAG,MachineFrameInfo * MFI,int ClobberedFI) const2066 SDValue AArch64TargetLowering::addTokenForArgument(SDValue Chain,
2067                                                    SelectionDAG &DAG,
2068                                                    MachineFrameInfo *MFI,
2069                                                    int ClobberedFI) const {
2070   SmallVector<SDValue, 8> ArgChains;
2071   int64_t FirstByte = MFI->getObjectOffset(ClobberedFI);
2072   int64_t LastByte = FirstByte + MFI->getObjectSize(ClobberedFI) - 1;
2073 
2074   // Include the original chain at the beginning of the list. When this is
2075   // used by target LowerCall hooks, this helps legalize find the
2076   // CALLSEQ_BEGIN node.
2077   ArgChains.push_back(Chain);
2078 
2079   // Add a chain value for each stack argument corresponding
2080   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
2081                             UE = DAG.getEntryNode().getNode()->use_end();
2082        U != UE; ++U)
2083     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U))
2084       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr()))
2085         if (FI->getIndex() < 0) {
2086           int64_t InFirstByte = MFI->getObjectOffset(FI->getIndex());
2087           int64_t InLastByte = InFirstByte;
2088           InLastByte += MFI->getObjectSize(FI->getIndex()) - 1;
2089 
2090           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
2091               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
2092             ArgChains.push_back(SDValue(L, 1));
2093         }
2094 
2095   // Build a tokenfactor for all the chains.
2096   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
2097 }
2098 
DoesCalleeRestoreStack(CallingConv::ID CallCC,bool TailCallOpt) const2099 bool AArch64TargetLowering::DoesCalleeRestoreStack(CallingConv::ID CallCC,
2100                                                    bool TailCallOpt) const {
2101   return CallCC == CallingConv::Fast && TailCallOpt;
2102 }
2103 
IsTailCallConvention(CallingConv::ID CallCC) const2104 bool AArch64TargetLowering::IsTailCallConvention(CallingConv::ID CallCC) const {
2105   return CallCC == CallingConv::Fast;
2106 }
2107 
2108 /// LowerCall - Lower a call to a callseq_start + CALL + callseq_end chain,
2109 /// and add input and output parameter nodes.
2110 SDValue
LowerCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const2111 AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
2112                                  SmallVectorImpl<SDValue> &InVals) const {
2113   SelectionDAG &DAG = CLI.DAG;
2114   SDLoc &DL = CLI.DL;
2115   SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
2116   SmallVector<SDValue, 32> &OutVals = CLI.OutVals;
2117   SmallVector<ISD::InputArg, 32> &Ins = CLI.Ins;
2118   SDValue Chain = CLI.Chain;
2119   SDValue Callee = CLI.Callee;
2120   bool &IsTailCall = CLI.IsTailCall;
2121   CallingConv::ID CallConv = CLI.CallConv;
2122   bool IsVarArg = CLI.IsVarArg;
2123 
2124   MachineFunction &MF = DAG.getMachineFunction();
2125   bool IsStructRet = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
2126   bool IsThisReturn = false;
2127 
2128   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
2129   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
2130   bool IsSibCall = false;
2131 
2132   if (IsTailCall) {
2133     // Check if it's really possible to do a tail call.
2134     IsTailCall = isEligibleForTailCallOptimization(
2135         Callee, CallConv, IsVarArg, IsStructRet,
2136         MF.getFunction()->hasStructRetAttr(), Outs, OutVals, Ins, DAG);
2137     if (!IsTailCall && CLI.CS && CLI.CS->isMustTailCall())
2138       report_fatal_error("failed to perform tail call elimination on a call "
2139                          "site marked musttail");
2140 
2141     // A sibling call is one where we're under the usual C ABI and not planning
2142     // to change that but can still do a tail call:
2143     if (!TailCallOpt && IsTailCall)
2144       IsSibCall = true;
2145 
2146     if (IsTailCall)
2147       ++NumTailCalls;
2148   }
2149 
2150   // Analyze operands of the call, assigning locations to each operand.
2151   SmallVector<CCValAssign, 16> ArgLocs;
2152   CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(),
2153                  getTargetMachine(), ArgLocs, *DAG.getContext());
2154 
2155   if (IsVarArg) {
2156     // Handle fixed and variable vector arguments differently.
2157     // Variable vector arguments always go into memory.
2158     unsigned NumArgs = Outs.size();
2159 
2160     for (unsigned i = 0; i != NumArgs; ++i) {
2161       MVT ArgVT = Outs[i].VT;
2162       ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
2163       CCAssignFn *AssignFn = CCAssignFnForCall(CallConv,
2164                                                /*IsVarArg=*/ !Outs[i].IsFixed);
2165       bool Res = AssignFn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
2166       assert(!Res && "Call operand has unhandled type");
2167       (void)Res;
2168     }
2169   } else {
2170     // At this point, Outs[].VT may already be promoted to i32. To correctly
2171     // handle passing i8 as i8 instead of i32 on stack, we pass in both i32 and
2172     // i8 to CC_AArch64_AAPCS with i32 being ValVT and i8 being LocVT.
2173     // Since AnalyzeCallOperands uses Ins[].VT for both ValVT and LocVT, here
2174     // we use a special version of AnalyzeCallOperands to pass in ValVT and
2175     // LocVT.
2176     unsigned NumArgs = Outs.size();
2177     for (unsigned i = 0; i != NumArgs; ++i) {
2178       MVT ValVT = Outs[i].VT;
2179       // Get type of the original argument.
2180       EVT ActualVT = getValueType(CLI.getArgs()[Outs[i].OrigArgIndex].Ty,
2181                                   /*AllowUnknown*/ true);
2182       MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : ValVT;
2183       ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
2184       // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
2185       if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
2186         ValVT = MVT::i8;
2187       else if (ActualMVT == MVT::i16)
2188         ValVT = MVT::i16;
2189 
2190       CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
2191       bool Res = AssignFn(i, ValVT, ValVT, CCValAssign::Full, ArgFlags, CCInfo);
2192       assert(!Res && "Call operand has unhandled type");
2193       (void)Res;
2194     }
2195   }
2196 
2197   // Get a count of how many bytes are to be pushed on the stack.
2198   unsigned NumBytes = CCInfo.getNextStackOffset();
2199 
2200   if (IsSibCall) {
2201     // Since we're not changing the ABI to make this a tail call, the memory
2202     // operands are already available in the caller's incoming argument space.
2203     NumBytes = 0;
2204   }
2205 
2206   // FPDiff is the byte offset of the call's argument area from the callee's.
2207   // Stores to callee stack arguments will be placed in FixedStackSlots offset
2208   // by this amount for a tail call. In a sibling call it must be 0 because the
2209   // caller will deallocate the entire stack and the callee still expects its
2210   // arguments to begin at SP+0. Completely unused for non-tail calls.
2211   int FPDiff = 0;
2212 
2213   if (IsTailCall && !IsSibCall) {
2214     unsigned NumReusableBytes = FuncInfo->getBytesInStackArgArea();
2215 
2216     // Since callee will pop argument stack as a tail call, we must keep the
2217     // popped size 16-byte aligned.
2218     NumBytes = RoundUpToAlignment(NumBytes, 16);
2219 
2220     // FPDiff will be negative if this tail call requires more space than we
2221     // would automatically have in our incoming argument space. Positive if we
2222     // can actually shrink the stack.
2223     FPDiff = NumReusableBytes - NumBytes;
2224 
2225     // The stack pointer must be 16-byte aligned at all times it's used for a
2226     // memory operation, which in practice means at *all* times and in
2227     // particular across call boundaries. Therefore our own arguments started at
2228     // a 16-byte aligned SP and the delta applied for the tail call should
2229     // satisfy the same constraint.
2230     assert(FPDiff % 16 == 0 && "unaligned stack on tail call");
2231   }
2232 
2233   // Adjust the stack pointer for the new arguments...
2234   // These operations are automatically eliminated by the prolog/epilog pass
2235   if (!IsSibCall)
2236     Chain =
2237         DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true), DL);
2238 
2239   SDValue StackPtr = DAG.getCopyFromReg(Chain, DL, AArch64::SP, getPointerTy());
2240 
2241   SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
2242   SmallVector<SDValue, 8> MemOpChains;
2243 
2244   // Walk the register/memloc assignments, inserting copies/loads.
2245   for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size(); i != e;
2246        ++i, ++realArgIdx) {
2247     CCValAssign &VA = ArgLocs[i];
2248     SDValue Arg = OutVals[realArgIdx];
2249     ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
2250 
2251     // Promote the value if needed.
2252     switch (VA.getLocInfo()) {
2253     default:
2254       llvm_unreachable("Unknown loc info!");
2255     case CCValAssign::Full:
2256       break;
2257     case CCValAssign::SExt:
2258       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Arg);
2259       break;
2260     case CCValAssign::ZExt:
2261       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
2262       break;
2263     case CCValAssign::AExt:
2264       if (Outs[realArgIdx].ArgVT == MVT::i1) {
2265         // AAPCS requires i1 to be zero-extended to 8-bits by the caller.
2266         Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
2267         Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i8, Arg);
2268       }
2269       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg);
2270       break;
2271     case CCValAssign::BCvt:
2272       Arg = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Arg);
2273       break;
2274     case CCValAssign::FPExt:
2275       Arg = DAG.getNode(ISD::FP_EXTEND, DL, VA.getLocVT(), Arg);
2276       break;
2277     }
2278 
2279     if (VA.isRegLoc()) {
2280       if (realArgIdx == 0 && Flags.isReturned() && Outs[0].VT == MVT::i64) {
2281         assert(VA.getLocVT() == MVT::i64 &&
2282                "unexpected calling convention register assignment");
2283         assert(!Ins.empty() && Ins[0].VT == MVT::i64 &&
2284                "unexpected use of 'returned'");
2285         IsThisReturn = true;
2286       }
2287       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
2288     } else {
2289       assert(VA.isMemLoc());
2290 
2291       SDValue DstAddr;
2292       MachinePointerInfo DstInfo;
2293 
2294       // FIXME: This works on big-endian for composite byvals, which are the
2295       // common case. It should also work for fundamental types too.
2296       uint32_t BEAlign = 0;
2297       unsigned OpSize = Flags.isByVal() ? Flags.getByValSize() * 8
2298                                         : VA.getLocVT().getSizeInBits();
2299       OpSize = (OpSize + 7) / 8;
2300       if (!Subtarget->isLittleEndian() && !Flags.isByVal()) {
2301         if (OpSize < 8)
2302           BEAlign = 8 - OpSize;
2303       }
2304       unsigned LocMemOffset = VA.getLocMemOffset();
2305       int32_t Offset = LocMemOffset + BEAlign;
2306       SDValue PtrOff = DAG.getIntPtrConstant(Offset);
2307       PtrOff = DAG.getNode(ISD::ADD, DL, getPointerTy(), StackPtr, PtrOff);
2308 
2309       if (IsTailCall) {
2310         Offset = Offset + FPDiff;
2311         int FI = MF.getFrameInfo()->CreateFixedObject(OpSize, Offset, true);
2312 
2313         DstAddr = DAG.getFrameIndex(FI, getPointerTy());
2314         DstInfo = MachinePointerInfo::getFixedStack(FI);
2315 
2316         // Make sure any stack arguments overlapping with where we're storing
2317         // are loaded before this eventual operation. Otherwise they'll be
2318         // clobbered.
2319         Chain = addTokenForArgument(Chain, DAG, MF.getFrameInfo(), FI);
2320       } else {
2321         SDValue PtrOff = DAG.getIntPtrConstant(Offset);
2322 
2323         DstAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), StackPtr, PtrOff);
2324         DstInfo = MachinePointerInfo::getStack(LocMemOffset);
2325       }
2326 
2327       if (Outs[i].Flags.isByVal()) {
2328         SDValue SizeNode =
2329             DAG.getConstant(Outs[i].Flags.getByValSize(), MVT::i64);
2330         SDValue Cpy = DAG.getMemcpy(
2331             Chain, DL, DstAddr, Arg, SizeNode, Outs[i].Flags.getByValAlign(),
2332             /*isVolatile = */ false,
2333             /*alwaysInline = */ false, DstInfo, MachinePointerInfo());
2334 
2335         MemOpChains.push_back(Cpy);
2336       } else {
2337         // Since we pass i1/i8/i16 as i1/i8/i16 on stack and Arg is already
2338         // promoted to a legal register type i32, we should truncate Arg back to
2339         // i1/i8/i16.
2340         if (VA.getValVT() == MVT::i1 || VA.getValVT() == MVT::i8 ||
2341             VA.getValVT() == MVT::i16)
2342           Arg = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Arg);
2343 
2344         SDValue Store =
2345             DAG.getStore(Chain, DL, Arg, DstAddr, DstInfo, false, false, 0);
2346         MemOpChains.push_back(Store);
2347       }
2348     }
2349   }
2350 
2351   if (!MemOpChains.empty())
2352     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
2353 
2354   // Build a sequence of copy-to-reg nodes chained together with token chain
2355   // and flag operands which copy the outgoing args into the appropriate regs.
2356   SDValue InFlag;
2357   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2358     Chain = DAG.getCopyToReg(Chain, DL, RegsToPass[i].first,
2359                              RegsToPass[i].second, InFlag);
2360     InFlag = Chain.getValue(1);
2361   }
2362 
2363   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
2364   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
2365   // node so that legalize doesn't hack it.
2366   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
2367       Subtarget->isTargetMachO()) {
2368     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2369       const GlobalValue *GV = G->getGlobal();
2370       bool InternalLinkage = GV->hasInternalLinkage();
2371       if (InternalLinkage)
2372         Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0, 0);
2373       else {
2374         Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0,
2375                                             AArch64II::MO_GOT);
2376         Callee = DAG.getNode(AArch64ISD::LOADgot, DL, getPointerTy(), Callee);
2377       }
2378     } else if (ExternalSymbolSDNode *S =
2379                    dyn_cast<ExternalSymbolSDNode>(Callee)) {
2380       const char *Sym = S->getSymbol();
2381       Callee =
2382           DAG.getTargetExternalSymbol(Sym, getPointerTy(), AArch64II::MO_GOT);
2383       Callee = DAG.getNode(AArch64ISD::LOADgot, DL, getPointerTy(), Callee);
2384     }
2385   } else if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2386     const GlobalValue *GV = G->getGlobal();
2387     Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0, 0);
2388   } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
2389     const char *Sym = S->getSymbol();
2390     Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy(), 0);
2391   }
2392 
2393   // We don't usually want to end the call-sequence here because we would tidy
2394   // the frame up *after* the call, however in the ABI-changing tail-call case
2395   // we've carefully laid out the parameters so that when sp is reset they'll be
2396   // in the correct location.
2397   if (IsTailCall && !IsSibCall) {
2398     Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
2399                                DAG.getIntPtrConstant(0, true), InFlag, DL);
2400     InFlag = Chain.getValue(1);
2401   }
2402 
2403   std::vector<SDValue> Ops;
2404   Ops.push_back(Chain);
2405   Ops.push_back(Callee);
2406 
2407   if (IsTailCall) {
2408     // Each tail call may have to adjust the stack by a different amount, so
2409     // this information must travel along with the operation for eventual
2410     // consumption by emitEpilogue.
2411     Ops.push_back(DAG.getTargetConstant(FPDiff, MVT::i32));
2412   }
2413 
2414   // Add argument registers to the end of the list so that they are known live
2415   // into the call.
2416   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2417     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
2418                                   RegsToPass[i].second.getValueType()));
2419 
2420   // Add a register mask operand representing the call-preserved registers.
2421   const uint32_t *Mask;
2422   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2423   const AArch64RegisterInfo *ARI =
2424       static_cast<const AArch64RegisterInfo *>(TRI);
2425   if (IsThisReturn) {
2426     // For 'this' returns, use the X0-preserving mask if applicable
2427     Mask = ARI->getThisReturnPreservedMask(CallConv);
2428     if (!Mask) {
2429       IsThisReturn = false;
2430       Mask = ARI->getCallPreservedMask(CallConv);
2431     }
2432   } else
2433     Mask = ARI->getCallPreservedMask(CallConv);
2434 
2435   assert(Mask && "Missing call preserved mask for calling convention");
2436   Ops.push_back(DAG.getRegisterMask(Mask));
2437 
2438   if (InFlag.getNode())
2439     Ops.push_back(InFlag);
2440 
2441   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2442 
2443   // If we're doing a tall call, use a TC_RETURN here rather than an
2444   // actual call instruction.
2445   if (IsTailCall)
2446     return DAG.getNode(AArch64ISD::TC_RETURN, DL, NodeTys, Ops);
2447 
2448   // Returns a chain and a flag for retval copy to use.
2449   Chain = DAG.getNode(AArch64ISD::CALL, DL, NodeTys, Ops);
2450   InFlag = Chain.getValue(1);
2451 
2452   uint64_t CalleePopBytes = DoesCalleeRestoreStack(CallConv, TailCallOpt)
2453                                 ? RoundUpToAlignment(NumBytes, 16)
2454                                 : 0;
2455 
2456   Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
2457                              DAG.getIntPtrConstant(CalleePopBytes, true),
2458                              InFlag, DL);
2459   if (!Ins.empty())
2460     InFlag = Chain.getValue(1);
2461 
2462   // Handle result values, copying them out of physregs into vregs that we
2463   // return.
2464   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
2465                          InVals, IsThisReturn,
2466                          IsThisReturn ? OutVals[0] : SDValue());
2467 }
2468 
CanLowerReturn(CallingConv::ID CallConv,MachineFunction & MF,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,LLVMContext & Context) const2469 bool AArch64TargetLowering::CanLowerReturn(
2470     CallingConv::ID CallConv, MachineFunction &MF, bool isVarArg,
2471     const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context) const {
2472   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
2473                           ? RetCC_AArch64_WebKit_JS
2474                           : RetCC_AArch64_AAPCS;
2475   SmallVector<CCValAssign, 16> RVLocs;
2476   CCState CCInfo(CallConv, isVarArg, MF, getTargetMachine(), RVLocs, Context);
2477   return CCInfo.CheckReturn(Outs, RetCC);
2478 }
2479 
2480 SDValue
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,SDLoc DL,SelectionDAG & DAG) const2481 AArch64TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
2482                                    bool isVarArg,
2483                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
2484                                    const SmallVectorImpl<SDValue> &OutVals,
2485                                    SDLoc DL, SelectionDAG &DAG) const {
2486   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
2487                           ? RetCC_AArch64_WebKit_JS
2488                           : RetCC_AArch64_AAPCS;
2489   SmallVector<CCValAssign, 16> RVLocs;
2490   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
2491                  getTargetMachine(), RVLocs, *DAG.getContext());
2492   CCInfo.AnalyzeReturn(Outs, RetCC);
2493 
2494   // Copy the result values into the output registers.
2495   SDValue Flag;
2496   SmallVector<SDValue, 4> RetOps(1, Chain);
2497   for (unsigned i = 0, realRVLocIdx = 0; i != RVLocs.size();
2498        ++i, ++realRVLocIdx) {
2499     CCValAssign &VA = RVLocs[i];
2500     assert(VA.isRegLoc() && "Can only return in registers!");
2501     SDValue Arg = OutVals[realRVLocIdx];
2502 
2503     switch (VA.getLocInfo()) {
2504     default:
2505       llvm_unreachable("Unknown loc info!");
2506     case CCValAssign::Full:
2507       if (Outs[i].ArgVT == MVT::i1) {
2508         // AAPCS requires i1 to be zero-extended to i8 by the producer of the
2509         // value. This is strictly redundant on Darwin (which uses "zeroext
2510         // i1"), but will be optimised out before ISel.
2511         Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
2512         Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
2513       }
2514       break;
2515     case CCValAssign::BCvt:
2516       Arg = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Arg);
2517       break;
2518     }
2519 
2520     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Arg, Flag);
2521     Flag = Chain.getValue(1);
2522     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
2523   }
2524 
2525   RetOps[0] = Chain; // Update chain.
2526 
2527   // Add the flag if we have it.
2528   if (Flag.getNode())
2529     RetOps.push_back(Flag);
2530 
2531   return DAG.getNode(AArch64ISD::RET_FLAG, DL, MVT::Other, RetOps);
2532 }
2533 
2534 //===----------------------------------------------------------------------===//
2535 //  Other Lowering Code
2536 //===----------------------------------------------------------------------===//
2537 
LowerGlobalAddress(SDValue Op,SelectionDAG & DAG) const2538 SDValue AArch64TargetLowering::LowerGlobalAddress(SDValue Op,
2539                                                   SelectionDAG &DAG) const {
2540   EVT PtrVT = getPointerTy();
2541   SDLoc DL(Op);
2542   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
2543   unsigned char OpFlags =
2544       Subtarget->ClassifyGlobalReference(GV, getTargetMachine());
2545 
2546   assert(cast<GlobalAddressSDNode>(Op)->getOffset() == 0 &&
2547          "unexpected offset in global node");
2548 
2549   // This also catched the large code model case for Darwin.
2550   if ((OpFlags & AArch64II::MO_GOT) != 0) {
2551     SDValue GotAddr = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, OpFlags);
2552     // FIXME: Once remat is capable of dealing with instructions with register
2553     // operands, expand this into two nodes instead of using a wrapper node.
2554     return DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, GotAddr);
2555   }
2556 
2557   if (getTargetMachine().getCodeModel() == CodeModel::Large) {
2558     const unsigned char MO_NC = AArch64II::MO_NC;
2559     return DAG.getNode(
2560         AArch64ISD::WrapperLarge, DL, PtrVT,
2561         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G3),
2562         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G2 | MO_NC),
2563         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G1 | MO_NC),
2564         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G0 | MO_NC));
2565   } else {
2566     // Use ADRP/ADD or ADRP/LDR for everything else: the small model on ELF and
2567     // the only correct model on Darwin.
2568     SDValue Hi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2569                                             OpFlags | AArch64II::MO_PAGE);
2570     unsigned char LoFlags = OpFlags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC;
2571     SDValue Lo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, LoFlags);
2572 
2573     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
2574     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
2575   }
2576 }
2577 
2578 /// \brief Convert a TLS address reference into the correct sequence of loads
2579 /// and calls to compute the variable's address (for Darwin, currently) and
2580 /// return an SDValue containing the final node.
2581 
2582 /// Darwin only has one TLS scheme which must be capable of dealing with the
2583 /// fully general situation, in the worst case. This means:
2584 ///     + "extern __thread" declaration.
2585 ///     + Defined in a possibly unknown dynamic library.
2586 ///
2587 /// The general system is that each __thread variable has a [3 x i64] descriptor
2588 /// which contains information used by the runtime to calculate the address. The
2589 /// only part of this the compiler needs to know about is the first xword, which
2590 /// contains a function pointer that must be called with the address of the
2591 /// entire descriptor in "x0".
2592 ///
2593 /// Since this descriptor may be in a different unit, in general even the
2594 /// descriptor must be accessed via an indirect load. The "ideal" code sequence
2595 /// is:
2596 ///     adrp x0, _var@TLVPPAGE
2597 ///     ldr x0, [x0, _var@TLVPPAGEOFF]   ; x0 now contains address of descriptor
2598 ///     ldr x1, [x0]                     ; x1 contains 1st entry of descriptor,
2599 ///                                      ; the function pointer
2600 ///     blr x1                           ; Uses descriptor address in x0
2601 ///     ; Address of _var is now in x0.
2602 ///
2603 /// If the address of _var's descriptor *is* known to the linker, then it can
2604 /// change the first "ldr" instruction to an appropriate "add x0, x0, #imm" for
2605 /// a slight efficiency gain.
2606 SDValue
LowerDarwinGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2607 AArch64TargetLowering::LowerDarwinGlobalTLSAddress(SDValue Op,
2608                                                    SelectionDAG &DAG) const {
2609   assert(Subtarget->isTargetDarwin() && "TLS only supported on Darwin");
2610 
2611   SDLoc DL(Op);
2612   MVT PtrVT = getPointerTy();
2613   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
2614 
2615   SDValue TLVPAddr =
2616       DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2617   SDValue DescAddr = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TLVPAddr);
2618 
2619   // The first entry in the descriptor is a function pointer that we must call
2620   // to obtain the address of the variable.
2621   SDValue Chain = DAG.getEntryNode();
2622   SDValue FuncTLVGet =
2623       DAG.getLoad(MVT::i64, DL, Chain, DescAddr, MachinePointerInfo::getGOT(),
2624                   false, true, true, 8);
2625   Chain = FuncTLVGet.getValue(1);
2626 
2627   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2628   MFI->setAdjustsStack(true);
2629 
2630   // TLS calls preserve all registers except those that absolutely must be
2631   // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
2632   // silly).
2633   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2634   const AArch64RegisterInfo *ARI =
2635       static_cast<const AArch64RegisterInfo *>(TRI);
2636   const uint32_t *Mask = ARI->getTLSCallPreservedMask();
2637 
2638   // Finally, we can make the call. This is just a degenerate version of a
2639   // normal AArch64 call node: x0 takes the address of the descriptor, and
2640   // returns the address of the variable in this thread.
2641   Chain = DAG.getCopyToReg(Chain, DL, AArch64::X0, DescAddr, SDValue());
2642   Chain =
2643       DAG.getNode(AArch64ISD::CALL, DL, DAG.getVTList(MVT::Other, MVT::Glue),
2644                   Chain, FuncTLVGet, DAG.getRegister(AArch64::X0, MVT::i64),
2645                   DAG.getRegisterMask(Mask), Chain.getValue(1));
2646   return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Chain.getValue(1));
2647 }
2648 
2649 /// When accessing thread-local variables under either the general-dynamic or
2650 /// local-dynamic system, we make a "TLS-descriptor" call. The variable will
2651 /// have a descriptor, accessible via a PC-relative ADRP, and whose first entry
2652 /// is a function pointer to carry out the resolution. This function takes the
2653 /// address of the descriptor in X0 and returns the TPIDR_EL0 offset in X0. All
2654 /// other registers (except LR, NZCV) are preserved.
2655 ///
2656 /// Thus, the ideal call sequence on AArch64 is:
2657 ///
2658 ///     adrp x0, :tlsdesc:thread_var
2659 ///     ldr x8, [x0, :tlsdesc_lo12:thread_var]
2660 ///     add x0, x0, :tlsdesc_lo12:thread_var
2661 ///     .tlsdesccall thread_var
2662 ///     blr x8
2663 ///     (TPIDR_EL0 offset now in x0).
2664 ///
2665 /// The ".tlsdesccall" directive instructs the assembler to insert a particular
2666 /// relocation to help the linker relax this sequence if it turns out to be too
2667 /// conservative.
2668 ///
2669 /// FIXME: we currently produce an extra, duplicated, ADRP instruction, but this
2670 /// is harmless.
LowerELFTLSDescCall(SDValue SymAddr,SDValue DescAddr,SDLoc DL,SelectionDAG & DAG) const2671 SDValue AArch64TargetLowering::LowerELFTLSDescCall(SDValue SymAddr,
2672                                                    SDValue DescAddr, SDLoc DL,
2673                                                    SelectionDAG &DAG) const {
2674   EVT PtrVT = getPointerTy();
2675 
2676   // The function we need to call is simply the first entry in the GOT for this
2677   // descriptor, load it in preparation.
2678   SDValue Func = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, SymAddr);
2679 
2680   // TLS calls preserve all registers except those that absolutely must be
2681   // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
2682   // silly).
2683   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2684   const AArch64RegisterInfo *ARI =
2685       static_cast<const AArch64RegisterInfo *>(TRI);
2686   const uint32_t *Mask = ARI->getTLSCallPreservedMask();
2687 
2688   // The function takes only one argument: the address of the descriptor itself
2689   // in X0.
2690   SDValue Glue, Chain;
2691   Chain = DAG.getCopyToReg(DAG.getEntryNode(), DL, AArch64::X0, DescAddr, Glue);
2692   Glue = Chain.getValue(1);
2693 
2694   // We're now ready to populate the argument list, as with a normal call:
2695   SmallVector<SDValue, 6> Ops;
2696   Ops.push_back(Chain);
2697   Ops.push_back(Func);
2698   Ops.push_back(SymAddr);
2699   Ops.push_back(DAG.getRegister(AArch64::X0, PtrVT));
2700   Ops.push_back(DAG.getRegisterMask(Mask));
2701   Ops.push_back(Glue);
2702 
2703   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2704   Chain = DAG.getNode(AArch64ISD::TLSDESC_CALL, DL, NodeTys, Ops);
2705   Glue = Chain.getValue(1);
2706 
2707   return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Glue);
2708 }
2709 
2710 SDValue
LowerELFGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2711 AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
2712                                                 SelectionDAG &DAG) const {
2713   assert(Subtarget->isTargetELF() && "This function expects an ELF target");
2714   assert(getTargetMachine().getCodeModel() == CodeModel::Small &&
2715          "ELF TLS only supported in small memory model");
2716   const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2717 
2718   TLSModel::Model Model = getTargetMachine().getTLSModel(GA->getGlobal());
2719 
2720   SDValue TPOff;
2721   EVT PtrVT = getPointerTy();
2722   SDLoc DL(Op);
2723   const GlobalValue *GV = GA->getGlobal();
2724 
2725   SDValue ThreadBase = DAG.getNode(AArch64ISD::THREAD_POINTER, DL, PtrVT);
2726 
2727   if (Model == TLSModel::LocalExec) {
2728     SDValue HiVar = DAG.getTargetGlobalAddress(
2729         GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
2730     SDValue LoVar = DAG.getTargetGlobalAddress(
2731         GV, DL, PtrVT, 0,
2732         AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
2733 
2734     TPOff = SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
2735                                        DAG.getTargetConstant(16, MVT::i32)),
2736                     0);
2737     TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, LoVar,
2738                                        DAG.getTargetConstant(0, MVT::i32)),
2739                     0);
2740   } else if (Model == TLSModel::InitialExec) {
2741     TPOff = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2742     TPOff = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TPOff);
2743   } else if (Model == TLSModel::LocalDynamic) {
2744     // Local-dynamic accesses proceed in two phases. A general-dynamic TLS
2745     // descriptor call against the special symbol _TLS_MODULE_BASE_ to calculate
2746     // the beginning of the module's TLS region, followed by a DTPREL offset
2747     // calculation.
2748 
2749     // These accesses will need deduplicating if there's more than one.
2750     AArch64FunctionInfo *MFI =
2751         DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
2752     MFI->incNumLocalDynamicTLSAccesses();
2753 
2754     // Accesses used in this sequence go via the TLS descriptor which lives in
2755     // the GOT. Prepare an address we can use to handle this.
2756     SDValue HiDesc = DAG.getTargetExternalSymbol(
2757         "_TLS_MODULE_BASE_", PtrVT, AArch64II::MO_TLS | AArch64II::MO_PAGE);
2758     SDValue LoDesc = DAG.getTargetExternalSymbol(
2759         "_TLS_MODULE_BASE_", PtrVT,
2760         AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
2761 
2762     // First argument to the descriptor call is the address of the descriptor
2763     // itself.
2764     SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
2765     DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
2766 
2767     // The call needs a relocation too for linker relaxation. It doesn't make
2768     // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
2769     // the address.
2770     SDValue SymAddr = DAG.getTargetExternalSymbol("_TLS_MODULE_BASE_", PtrVT,
2771                                                   AArch64II::MO_TLS);
2772 
2773     // Now we can calculate the offset from TPIDR_EL0 to this module's
2774     // thread-local area.
2775     TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
2776 
2777     // Now use :dtprel_whatever: operations to calculate this variable's offset
2778     // in its thread-storage area.
2779     SDValue HiVar = DAG.getTargetGlobalAddress(
2780         GV, DL, MVT::i64, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
2781     SDValue LoVar = DAG.getTargetGlobalAddress(
2782         GV, DL, MVT::i64, 0,
2783         AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
2784 
2785     SDValue DTPOff =
2786         SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
2787                                    DAG.getTargetConstant(16, MVT::i32)),
2788                 0);
2789     DTPOff =
2790         SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, DTPOff, LoVar,
2791                                    DAG.getTargetConstant(0, MVT::i32)),
2792                 0);
2793 
2794     TPOff = DAG.getNode(ISD::ADD, DL, PtrVT, TPOff, DTPOff);
2795   } else if (Model == TLSModel::GeneralDynamic) {
2796     // Accesses used in this sequence go via the TLS descriptor which lives in
2797     // the GOT. Prepare an address we can use to handle this.
2798     SDValue HiDesc = DAG.getTargetGlobalAddress(
2799         GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_PAGE);
2800     SDValue LoDesc = DAG.getTargetGlobalAddress(
2801         GV, DL, PtrVT, 0,
2802         AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
2803 
2804     // First argument to the descriptor call is the address of the descriptor
2805     // itself.
2806     SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
2807     DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
2808 
2809     // The call needs a relocation too for linker relaxation. It doesn't make
2810     // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
2811     // the address.
2812     SDValue SymAddr =
2813         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2814 
2815     // Finally we can make a call to calculate the offset from tpidr_el0.
2816     TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
2817   } else
2818     llvm_unreachable("Unsupported ELF TLS access model");
2819 
2820   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadBase, TPOff);
2821 }
2822 
LowerGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2823 SDValue AArch64TargetLowering::LowerGlobalTLSAddress(SDValue Op,
2824                                                      SelectionDAG &DAG) const {
2825   if (Subtarget->isTargetDarwin())
2826     return LowerDarwinGlobalTLSAddress(Op, DAG);
2827   else if (Subtarget->isTargetELF())
2828     return LowerELFGlobalTLSAddress(Op, DAG);
2829 
2830   llvm_unreachable("Unexpected platform trying to use TLS");
2831 }
LowerBR_CC(SDValue Op,SelectionDAG & DAG) const2832 SDValue AArch64TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
2833   SDValue Chain = Op.getOperand(0);
2834   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
2835   SDValue LHS = Op.getOperand(2);
2836   SDValue RHS = Op.getOperand(3);
2837   SDValue Dest = Op.getOperand(4);
2838   SDLoc dl(Op);
2839 
2840   // Handle f128 first, since lowering it will result in comparing the return
2841   // value of a libcall against zero, which is just what the rest of LowerBR_CC
2842   // is expecting to deal with.
2843   if (LHS.getValueType() == MVT::f128) {
2844     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
2845 
2846     // If softenSetCCOperands returned a scalar, we need to compare the result
2847     // against zero to select between true and false values.
2848     if (!RHS.getNode()) {
2849       RHS = DAG.getConstant(0, LHS.getValueType());
2850       CC = ISD::SETNE;
2851     }
2852   }
2853 
2854   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a branch
2855   // instruction.
2856   unsigned Opc = LHS.getOpcode();
2857   if (LHS.getResNo() == 1 && isa<ConstantSDNode>(RHS) &&
2858       cast<ConstantSDNode>(RHS)->isOne() &&
2859       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
2860        Opc == ISD::USUBO || Opc == ISD::SMULO || Opc == ISD::UMULO)) {
2861     assert((CC == ISD::SETEQ || CC == ISD::SETNE) &&
2862            "Unexpected condition code.");
2863     // Only lower legal XALUO ops.
2864     if (!DAG.getTargetLoweringInfo().isTypeLegal(LHS->getValueType(0)))
2865       return SDValue();
2866 
2867     // The actual operation with overflow check.
2868     AArch64CC::CondCode OFCC;
2869     SDValue Value, Overflow;
2870     std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, LHS.getValue(0), DAG);
2871 
2872     if (CC == ISD::SETNE)
2873       OFCC = getInvertedCondCode(OFCC);
2874     SDValue CCVal = DAG.getConstant(OFCC, MVT::i32);
2875 
2876     return DAG.getNode(AArch64ISD::BRCOND, SDLoc(LHS), MVT::Other, Chain, Dest,
2877                        CCVal, Overflow);
2878   }
2879 
2880   if (LHS.getValueType().isInteger()) {
2881     assert((LHS.getValueType() == RHS.getValueType()) &&
2882            (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
2883 
2884     // If the RHS of the comparison is zero, we can potentially fold this
2885     // to a specialized branch.
2886     const ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS);
2887     if (RHSC && RHSC->getZExtValue() == 0) {
2888       if (CC == ISD::SETEQ) {
2889         // See if we can use a TBZ to fold in an AND as well.
2890         // TBZ has a smaller branch displacement than CBZ.  If the offset is
2891         // out of bounds, a late MI-layer pass rewrites branches.
2892         // 403.gcc is an example that hits this case.
2893         if (LHS.getOpcode() == ISD::AND &&
2894             isa<ConstantSDNode>(LHS.getOperand(1)) &&
2895             isPowerOf2_64(LHS.getConstantOperandVal(1))) {
2896           SDValue Test = LHS.getOperand(0);
2897           uint64_t Mask = LHS.getConstantOperandVal(1);
2898 
2899           // TBZ only operates on i64's, but the ext should be free.
2900           if (Test.getValueType() == MVT::i32)
2901             Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64);
2902 
2903           return DAG.getNode(AArch64ISD::TBZ, dl, MVT::Other, Chain, Test,
2904                              DAG.getConstant(Log2_64(Mask), MVT::i64), Dest);
2905         }
2906 
2907         return DAG.getNode(AArch64ISD::CBZ, dl, MVT::Other, Chain, LHS, Dest);
2908       } else if (CC == ISD::SETNE) {
2909         // See if we can use a TBZ to fold in an AND as well.
2910         // TBZ has a smaller branch displacement than CBZ.  If the offset is
2911         // out of bounds, a late MI-layer pass rewrites branches.
2912         // 403.gcc is an example that hits this case.
2913         if (LHS.getOpcode() == ISD::AND &&
2914             isa<ConstantSDNode>(LHS.getOperand(1)) &&
2915             isPowerOf2_64(LHS.getConstantOperandVal(1))) {
2916           SDValue Test = LHS.getOperand(0);
2917           uint64_t Mask = LHS.getConstantOperandVal(1);
2918 
2919           // TBNZ only operates on i64's, but the ext should be free.
2920           if (Test.getValueType() == MVT::i32)
2921             Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64);
2922 
2923           return DAG.getNode(AArch64ISD::TBNZ, dl, MVT::Other, Chain, Test,
2924                              DAG.getConstant(Log2_64(Mask), MVT::i64), Dest);
2925         }
2926 
2927         return DAG.getNode(AArch64ISD::CBNZ, dl, MVT::Other, Chain, LHS, Dest);
2928       }
2929     }
2930 
2931     SDValue CCVal;
2932     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
2933     return DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, Chain, Dest, CCVal,
2934                        Cmp);
2935   }
2936 
2937   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
2938 
2939   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
2940   // clean.  Some of them require two branches to implement.
2941   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
2942   AArch64CC::CondCode CC1, CC2;
2943   changeFPCCToAArch64CC(CC, CC1, CC2);
2944   SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
2945   SDValue BR1 =
2946       DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, Chain, Dest, CC1Val, Cmp);
2947   if (CC2 != AArch64CC::AL) {
2948     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
2949     return DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, BR1, Dest, CC2Val,
2950                        Cmp);
2951   }
2952 
2953   return BR1;
2954 }
2955 
LowerFCOPYSIGN(SDValue Op,SelectionDAG & DAG) const2956 SDValue AArch64TargetLowering::LowerFCOPYSIGN(SDValue Op,
2957                                               SelectionDAG &DAG) const {
2958   EVT VT = Op.getValueType();
2959   SDLoc DL(Op);
2960 
2961   SDValue In1 = Op.getOperand(0);
2962   SDValue In2 = Op.getOperand(1);
2963   EVT SrcVT = In2.getValueType();
2964   if (SrcVT != VT) {
2965     if (SrcVT == MVT::f32 && VT == MVT::f64)
2966       In2 = DAG.getNode(ISD::FP_EXTEND, DL, VT, In2);
2967     else if (SrcVT == MVT::f64 && VT == MVT::f32)
2968       In2 = DAG.getNode(ISD::FP_ROUND, DL, VT, In2, DAG.getIntPtrConstant(0));
2969     else
2970       // FIXME: Src type is different, bail out for now. Can VT really be a
2971       // vector type?
2972       return SDValue();
2973   }
2974 
2975   EVT VecVT;
2976   EVT EltVT;
2977   SDValue EltMask, VecVal1, VecVal2;
2978   if (VT == MVT::f32 || VT == MVT::v2f32 || VT == MVT::v4f32) {
2979     EltVT = MVT::i32;
2980     VecVT = MVT::v4i32;
2981     EltMask = DAG.getConstant(0x80000000ULL, EltVT);
2982 
2983     if (!VT.isVector()) {
2984       VecVal1 = DAG.getTargetInsertSubreg(AArch64::ssub, DL, VecVT,
2985                                           DAG.getUNDEF(VecVT), In1);
2986       VecVal2 = DAG.getTargetInsertSubreg(AArch64::ssub, DL, VecVT,
2987                                           DAG.getUNDEF(VecVT), In2);
2988     } else {
2989       VecVal1 = DAG.getNode(ISD::BITCAST, DL, VecVT, In1);
2990       VecVal2 = DAG.getNode(ISD::BITCAST, DL, VecVT, In2);
2991     }
2992   } else if (VT == MVT::f64 || VT == MVT::v2f64) {
2993     EltVT = MVT::i64;
2994     VecVT = MVT::v2i64;
2995 
2996     // We want to materialize a mask with the the high bit set, but the AdvSIMD
2997     // immediate moves cannot materialize that in a single instruction for
2998     // 64-bit elements. Instead, materialize zero and then negate it.
2999     EltMask = DAG.getConstant(0, EltVT);
3000 
3001     if (!VT.isVector()) {
3002       VecVal1 = DAG.getTargetInsertSubreg(AArch64::dsub, DL, VecVT,
3003                                           DAG.getUNDEF(VecVT), In1);
3004       VecVal2 = DAG.getTargetInsertSubreg(AArch64::dsub, DL, VecVT,
3005                                           DAG.getUNDEF(VecVT), In2);
3006     } else {
3007       VecVal1 = DAG.getNode(ISD::BITCAST, DL, VecVT, In1);
3008       VecVal2 = DAG.getNode(ISD::BITCAST, DL, VecVT, In2);
3009     }
3010   } else {
3011     llvm_unreachable("Invalid type for copysign!");
3012   }
3013 
3014   std::vector<SDValue> BuildVectorOps;
3015   for (unsigned i = 0; i < VecVT.getVectorNumElements(); ++i)
3016     BuildVectorOps.push_back(EltMask);
3017 
3018   SDValue BuildVec = DAG.getNode(ISD::BUILD_VECTOR, DL, VecVT, BuildVectorOps);
3019 
3020   // If we couldn't materialize the mask above, then the mask vector will be
3021   // the zero vector, and we need to negate it here.
3022   if (VT == MVT::f64 || VT == MVT::v2f64) {
3023     BuildVec = DAG.getNode(ISD::BITCAST, DL, MVT::v2f64, BuildVec);
3024     BuildVec = DAG.getNode(ISD::FNEG, DL, MVT::v2f64, BuildVec);
3025     BuildVec = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, BuildVec);
3026   }
3027 
3028   SDValue Sel =
3029       DAG.getNode(AArch64ISD::BIT, DL, VecVT, VecVal1, VecVal2, BuildVec);
3030 
3031   if (VT == MVT::f32)
3032     return DAG.getTargetExtractSubreg(AArch64::ssub, DL, VT, Sel);
3033   else if (VT == MVT::f64)
3034     return DAG.getTargetExtractSubreg(AArch64::dsub, DL, VT, Sel);
3035   else
3036     return DAG.getNode(ISD::BITCAST, DL, VT, Sel);
3037 }
3038 
LowerCTPOP(SDValue Op,SelectionDAG & DAG) const3039 SDValue AArch64TargetLowering::LowerCTPOP(SDValue Op, SelectionDAG &DAG) const {
3040   if (DAG.getMachineFunction().getFunction()->getAttributes().hasAttribute(
3041           AttributeSet::FunctionIndex, Attribute::NoImplicitFloat))
3042     return SDValue();
3043 
3044   // While there is no integer popcount instruction, it can
3045   // be more efficiently lowered to the following sequence that uses
3046   // AdvSIMD registers/instructions as long as the copies to/from
3047   // the AdvSIMD registers are cheap.
3048   //  FMOV    D0, X0        // copy 64-bit int to vector, high bits zero'd
3049   //  CNT     V0.8B, V0.8B  // 8xbyte pop-counts
3050   //  ADDV    B0, V0.8B     // sum 8xbyte pop-counts
3051   //  UMOV    X0, V0.B[0]   // copy byte result back to integer reg
3052   SDValue Val = Op.getOperand(0);
3053   SDLoc DL(Op);
3054   EVT VT = Op.getValueType();
3055   SDValue ZeroVec = DAG.getUNDEF(MVT::v8i8);
3056 
3057   SDValue VecVal;
3058   if (VT == MVT::i32) {
3059     VecVal = DAG.getNode(ISD::BITCAST, DL, MVT::f32, Val);
3060     VecVal = DAG.getTargetInsertSubreg(AArch64::ssub, DL, MVT::v8i8, ZeroVec,
3061                                        VecVal);
3062   } else {
3063     VecVal = DAG.getNode(ISD::BITCAST, DL, MVT::v8i8, Val);
3064   }
3065 
3066   SDValue CtPop = DAG.getNode(ISD::CTPOP, DL, MVT::v8i8, VecVal);
3067   SDValue UaddLV = DAG.getNode(
3068       ISD::INTRINSIC_WO_CHAIN, DL, MVT::i32,
3069       DAG.getConstant(Intrinsic::aarch64_neon_uaddlv, MVT::i32), CtPop);
3070 
3071   if (VT == MVT::i64)
3072     UaddLV = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, UaddLV);
3073   return UaddLV;
3074 }
3075 
LowerSETCC(SDValue Op,SelectionDAG & DAG) const3076 SDValue AArch64TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
3077 
3078   if (Op.getValueType().isVector())
3079     return LowerVSETCC(Op, DAG);
3080 
3081   SDValue LHS = Op.getOperand(0);
3082   SDValue RHS = Op.getOperand(1);
3083   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
3084   SDLoc dl(Op);
3085 
3086   // We chose ZeroOrOneBooleanContents, so use zero and one.
3087   EVT VT = Op.getValueType();
3088   SDValue TVal = DAG.getConstant(1, VT);
3089   SDValue FVal = DAG.getConstant(0, VT);
3090 
3091   // Handle f128 first, since one possible outcome is a normal integer
3092   // comparison which gets picked up by the next if statement.
3093   if (LHS.getValueType() == MVT::f128) {
3094     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
3095 
3096     // If softenSetCCOperands returned a scalar, use it.
3097     if (!RHS.getNode()) {
3098       assert(LHS.getValueType() == Op.getValueType() &&
3099              "Unexpected setcc expansion!");
3100       return LHS;
3101     }
3102   }
3103 
3104   if (LHS.getValueType().isInteger()) {
3105     SDValue CCVal;
3106     SDValue Cmp =
3107         getAArch64Cmp(LHS, RHS, ISD::getSetCCInverse(CC, true), CCVal, DAG, dl);
3108 
3109     // Note that we inverted the condition above, so we reverse the order of
3110     // the true and false operands here.  This will allow the setcc to be
3111     // matched to a single CSINC instruction.
3112     return DAG.getNode(AArch64ISD::CSEL, dl, VT, FVal, TVal, CCVal, Cmp);
3113   }
3114 
3115   // Now we know we're dealing with FP values.
3116   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
3117 
3118   // If that fails, we'll need to perform an FCMP + CSEL sequence.  Go ahead
3119   // and do the comparison.
3120   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
3121 
3122   AArch64CC::CondCode CC1, CC2;
3123   changeFPCCToAArch64CC(CC, CC1, CC2);
3124   if (CC2 == AArch64CC::AL) {
3125     changeFPCCToAArch64CC(ISD::getSetCCInverse(CC, false), CC1, CC2);
3126     SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3127 
3128     // Note that we inverted the condition above, so we reverse the order of
3129     // the true and false operands here.  This will allow the setcc to be
3130     // matched to a single CSINC instruction.
3131     return DAG.getNode(AArch64ISD::CSEL, dl, VT, FVal, TVal, CC1Val, Cmp);
3132   } else {
3133     // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't
3134     // totally clean.  Some of them require two CSELs to implement.  As is in
3135     // this case, we emit the first CSEL and then emit a second using the output
3136     // of the first as the RHS.  We're effectively OR'ing the two CC's together.
3137 
3138     // FIXME: It would be nice if we could match the two CSELs to two CSINCs.
3139     SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3140     SDValue CS1 =
3141         DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, FVal, CC1Val, Cmp);
3142 
3143     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
3144     return DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, CS1, CC2Val, Cmp);
3145   }
3146 }
3147 
3148 /// A SELECT_CC operation is really some kind of max or min if both values being
3149 /// compared are, in some sense, equal to the results in either case. However,
3150 /// it is permissible to compare f32 values and produce directly extended f64
3151 /// values.
3152 ///
3153 /// Extending the comparison operands would also be allowed, but is less likely
3154 /// to happen in practice since their use is right here. Note that truncate
3155 /// operations would *not* be semantically equivalent.
selectCCOpsAreFMaxCompatible(SDValue Cmp,SDValue Result)3156 static bool selectCCOpsAreFMaxCompatible(SDValue Cmp, SDValue Result) {
3157   if (Cmp == Result)
3158     return true;
3159 
3160   ConstantFPSDNode *CCmp = dyn_cast<ConstantFPSDNode>(Cmp);
3161   ConstantFPSDNode *CResult = dyn_cast<ConstantFPSDNode>(Result);
3162   if (CCmp && CResult && Cmp.getValueType() == MVT::f32 &&
3163       Result.getValueType() == MVT::f64) {
3164     bool Lossy;
3165     APFloat CmpVal = CCmp->getValueAPF();
3166     CmpVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &Lossy);
3167     return CResult->getValueAPF().bitwiseIsEqual(CmpVal);
3168   }
3169 
3170   return Result->getOpcode() == ISD::FP_EXTEND && Result->getOperand(0) == Cmp;
3171 }
3172 
LowerSELECT(SDValue Op,SelectionDAG & DAG) const3173 SDValue AArch64TargetLowering::LowerSELECT(SDValue Op,
3174                                            SelectionDAG &DAG) const {
3175   SDValue CC = Op->getOperand(0);
3176   SDValue TVal = Op->getOperand(1);
3177   SDValue FVal = Op->getOperand(2);
3178   SDLoc DL(Op);
3179 
3180   unsigned Opc = CC.getOpcode();
3181   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a select
3182   // instruction.
3183   if (CC.getResNo() == 1 &&
3184       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
3185        Opc == ISD::USUBO || Opc == ISD::SMULO || Opc == ISD::UMULO)) {
3186     // Only lower legal XALUO ops.
3187     if (!DAG.getTargetLoweringInfo().isTypeLegal(CC->getValueType(0)))
3188       return SDValue();
3189 
3190     AArch64CC::CondCode OFCC;
3191     SDValue Value, Overflow;
3192     std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, CC.getValue(0), DAG);
3193     SDValue CCVal = DAG.getConstant(OFCC, MVT::i32);
3194 
3195     return DAG.getNode(AArch64ISD::CSEL, DL, Op.getValueType(), TVal, FVal,
3196                        CCVal, Overflow);
3197   }
3198 
3199   if (CC.getOpcode() == ISD::SETCC)
3200     return DAG.getSelectCC(DL, CC.getOperand(0), CC.getOperand(1), TVal, FVal,
3201                            cast<CondCodeSDNode>(CC.getOperand(2))->get());
3202   else
3203     return DAG.getSelectCC(DL, CC, DAG.getConstant(0, CC.getValueType()), TVal,
3204                            FVal, ISD::SETNE);
3205 }
3206 
LowerSELECT_CC(SDValue Op,SelectionDAG & DAG) const3207 SDValue AArch64TargetLowering::LowerSELECT_CC(SDValue Op,
3208                                               SelectionDAG &DAG) const {
3209   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
3210   SDValue LHS = Op.getOperand(0);
3211   SDValue RHS = Op.getOperand(1);
3212   SDValue TVal = Op.getOperand(2);
3213   SDValue FVal = Op.getOperand(3);
3214   SDLoc dl(Op);
3215 
3216   // Handle f128 first, because it will result in a comparison of some RTLIB
3217   // call result against zero.
3218   if (LHS.getValueType() == MVT::f128) {
3219     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
3220 
3221     // If softenSetCCOperands returned a scalar, we need to compare the result
3222     // against zero to select between true and false values.
3223     if (!RHS.getNode()) {
3224       RHS = DAG.getConstant(0, LHS.getValueType());
3225       CC = ISD::SETNE;
3226     }
3227   }
3228 
3229   // Handle integers first.
3230   if (LHS.getValueType().isInteger()) {
3231     assert((LHS.getValueType() == RHS.getValueType()) &&
3232            (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
3233 
3234     unsigned Opcode = AArch64ISD::CSEL;
3235 
3236     // If both the TVal and the FVal are constants, see if we can swap them in
3237     // order to for a CSINV or CSINC out of them.
3238     ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
3239     ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
3240 
3241     if (CTVal && CFVal && CTVal->isAllOnesValue() && CFVal->isNullValue()) {
3242       std::swap(TVal, FVal);
3243       std::swap(CTVal, CFVal);
3244       CC = ISD::getSetCCInverse(CC, true);
3245     } else if (CTVal && CFVal && CTVal->isOne() && CFVal->isNullValue()) {
3246       std::swap(TVal, FVal);
3247       std::swap(CTVal, CFVal);
3248       CC = ISD::getSetCCInverse(CC, true);
3249     } else if (TVal.getOpcode() == ISD::XOR) {
3250       // If TVal is a NOT we want to swap TVal and FVal so that we can match
3251       // with a CSINV rather than a CSEL.
3252       ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(TVal.getOperand(1));
3253 
3254       if (CVal && CVal->isAllOnesValue()) {
3255         std::swap(TVal, FVal);
3256         std::swap(CTVal, CFVal);
3257         CC = ISD::getSetCCInverse(CC, true);
3258       }
3259     } else if (TVal.getOpcode() == ISD::SUB) {
3260       // If TVal is a negation (SUB from 0) we want to swap TVal and FVal so
3261       // that we can match with a CSNEG rather than a CSEL.
3262       ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(TVal.getOperand(0));
3263 
3264       if (CVal && CVal->isNullValue()) {
3265         std::swap(TVal, FVal);
3266         std::swap(CTVal, CFVal);
3267         CC = ISD::getSetCCInverse(CC, true);
3268       }
3269     } else if (CTVal && CFVal) {
3270       const int64_t TrueVal = CTVal->getSExtValue();
3271       const int64_t FalseVal = CFVal->getSExtValue();
3272       bool Swap = false;
3273 
3274       // If both TVal and FVal are constants, see if FVal is the
3275       // inverse/negation/increment of TVal and generate a CSINV/CSNEG/CSINC
3276       // instead of a CSEL in that case.
3277       if (TrueVal == ~FalseVal) {
3278         Opcode = AArch64ISD::CSINV;
3279       } else if (TrueVal == -FalseVal) {
3280         Opcode = AArch64ISD::CSNEG;
3281       } else if (TVal.getValueType() == MVT::i32) {
3282         // If our operands are only 32-bit wide, make sure we use 32-bit
3283         // arithmetic for the check whether we can use CSINC. This ensures that
3284         // the addition in the check will wrap around properly in case there is
3285         // an overflow (which would not be the case if we do the check with
3286         // 64-bit arithmetic).
3287         const uint32_t TrueVal32 = CTVal->getZExtValue();
3288         const uint32_t FalseVal32 = CFVal->getZExtValue();
3289 
3290         if ((TrueVal32 == FalseVal32 + 1) || (TrueVal32 + 1 == FalseVal32)) {
3291           Opcode = AArch64ISD::CSINC;
3292 
3293           if (TrueVal32 > FalseVal32) {
3294             Swap = true;
3295           }
3296         }
3297         // 64-bit check whether we can use CSINC.
3298       } else if ((TrueVal == FalseVal + 1) || (TrueVal + 1 == FalseVal)) {
3299         Opcode = AArch64ISD::CSINC;
3300 
3301         if (TrueVal > FalseVal) {
3302           Swap = true;
3303         }
3304       }
3305 
3306       // Swap TVal and FVal if necessary.
3307       if (Swap) {
3308         std::swap(TVal, FVal);
3309         std::swap(CTVal, CFVal);
3310         CC = ISD::getSetCCInverse(CC, true);
3311       }
3312 
3313       if (Opcode != AArch64ISD::CSEL) {
3314         // Drop FVal since we can get its value by simply inverting/negating
3315         // TVal.
3316         FVal = TVal;
3317       }
3318     }
3319 
3320     SDValue CCVal;
3321     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
3322 
3323     EVT VT = Op.getValueType();
3324     return DAG.getNode(Opcode, dl, VT, TVal, FVal, CCVal, Cmp);
3325   }
3326 
3327   // Now we know we're dealing with FP values.
3328   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
3329   assert(LHS.getValueType() == RHS.getValueType());
3330   EVT VT = Op.getValueType();
3331 
3332   // Try to match this select into a max/min operation, which have dedicated
3333   // opcode in the instruction set.
3334   // FIXME: This is not correct in the presence of NaNs, so we only enable this
3335   // in no-NaNs mode.
3336   if (getTargetMachine().Options.NoNaNsFPMath) {
3337     SDValue MinMaxLHS = TVal, MinMaxRHS = FVal;
3338     if (selectCCOpsAreFMaxCompatible(LHS, MinMaxRHS) &&
3339         selectCCOpsAreFMaxCompatible(RHS, MinMaxLHS)) {
3340       CC = ISD::getSetCCSwappedOperands(CC);
3341       std::swap(MinMaxLHS, MinMaxRHS);
3342     }
3343 
3344     if (selectCCOpsAreFMaxCompatible(LHS, MinMaxLHS) &&
3345         selectCCOpsAreFMaxCompatible(RHS, MinMaxRHS)) {
3346       switch (CC) {
3347       default:
3348         break;
3349       case ISD::SETGT:
3350       case ISD::SETGE:
3351       case ISD::SETUGT:
3352       case ISD::SETUGE:
3353       case ISD::SETOGT:
3354       case ISD::SETOGE:
3355         return DAG.getNode(AArch64ISD::FMAX, dl, VT, MinMaxLHS, MinMaxRHS);
3356         break;
3357       case ISD::SETLT:
3358       case ISD::SETLE:
3359       case ISD::SETULT:
3360       case ISD::SETULE:
3361       case ISD::SETOLT:
3362       case ISD::SETOLE:
3363         return DAG.getNode(AArch64ISD::FMIN, dl, VT, MinMaxLHS, MinMaxRHS);
3364         break;
3365       }
3366     }
3367   }
3368 
3369   // If that fails, we'll need to perform an FCMP + CSEL sequence.  Go ahead
3370   // and do the comparison.
3371   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
3372 
3373   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
3374   // clean.  Some of them require two CSELs to implement.
3375   AArch64CC::CondCode CC1, CC2;
3376   changeFPCCToAArch64CC(CC, CC1, CC2);
3377   SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3378   SDValue CS1 = DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, FVal, CC1Val, Cmp);
3379 
3380   // If we need a second CSEL, emit it, using the output of the first as the
3381   // RHS.  We're effectively OR'ing the two CC's together.
3382   if (CC2 != AArch64CC::AL) {
3383     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
3384     return DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, CS1, CC2Val, Cmp);
3385   }
3386 
3387   // Otherwise, return the output of the first CSEL.
3388   return CS1;
3389 }
3390 
LowerJumpTable(SDValue Op,SelectionDAG & DAG) const3391 SDValue AArch64TargetLowering::LowerJumpTable(SDValue Op,
3392                                               SelectionDAG &DAG) const {
3393   // Jump table entries as PC relative offsets. No additional tweaking
3394   // is necessary here. Just get the address of the jump table.
3395   JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
3396   EVT PtrVT = getPointerTy();
3397   SDLoc DL(Op);
3398 
3399   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
3400       !Subtarget->isTargetMachO()) {
3401     const unsigned char MO_NC = AArch64II::MO_NC;
3402     return DAG.getNode(
3403         AArch64ISD::WrapperLarge, DL, PtrVT,
3404         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G3),
3405         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G2 | MO_NC),
3406         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G1 | MO_NC),
3407         DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
3408                                AArch64II::MO_G0 | MO_NC));
3409   }
3410 
3411   SDValue Hi =
3412       DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_PAGE);
3413   SDValue Lo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
3414                                       AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
3415   SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3416   return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3417 }
3418 
LowerConstantPool(SDValue Op,SelectionDAG & DAG) const3419 SDValue AArch64TargetLowering::LowerConstantPool(SDValue Op,
3420                                                  SelectionDAG &DAG) const {
3421   ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
3422   EVT PtrVT = getPointerTy();
3423   SDLoc DL(Op);
3424 
3425   if (getTargetMachine().getCodeModel() == CodeModel::Large) {
3426     // Use the GOT for the large code model on iOS.
3427     if (Subtarget->isTargetMachO()) {
3428       SDValue GotAddr = DAG.getTargetConstantPool(
3429           CP->getConstVal(), PtrVT, CP->getAlignment(), CP->getOffset(),
3430           AArch64II::MO_GOT);
3431       return DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, GotAddr);
3432     }
3433 
3434     const unsigned char MO_NC = AArch64II::MO_NC;
3435     return DAG.getNode(
3436         AArch64ISD::WrapperLarge, DL, PtrVT,
3437         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3438                                   CP->getOffset(), AArch64II::MO_G3),
3439         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3440                                   CP->getOffset(), AArch64II::MO_G2 | MO_NC),
3441         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3442                                   CP->getOffset(), AArch64II::MO_G1 | MO_NC),
3443         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3444                                   CP->getOffset(), AArch64II::MO_G0 | MO_NC));
3445   } else {
3446     // Use ADRP/ADD or ADRP/LDR for everything else: the small memory model on
3447     // ELF, the only valid one on Darwin.
3448     SDValue Hi =
3449         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3450                                   CP->getOffset(), AArch64II::MO_PAGE);
3451     SDValue Lo = DAG.getTargetConstantPool(
3452         CP->getConstVal(), PtrVT, CP->getAlignment(), CP->getOffset(),
3453         AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
3454 
3455     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3456     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3457   }
3458 }
3459 
LowerBlockAddress(SDValue Op,SelectionDAG & DAG) const3460 SDValue AArch64TargetLowering::LowerBlockAddress(SDValue Op,
3461                                                SelectionDAG &DAG) const {
3462   const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
3463   EVT PtrVT = getPointerTy();
3464   SDLoc DL(Op);
3465   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
3466       !Subtarget->isTargetMachO()) {
3467     const unsigned char MO_NC = AArch64II::MO_NC;
3468     return DAG.getNode(
3469         AArch64ISD::WrapperLarge, DL, PtrVT,
3470         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G3),
3471         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G2 | MO_NC),
3472         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G1 | MO_NC),
3473         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G0 | MO_NC));
3474   } else {
3475     SDValue Hi = DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_PAGE);
3476     SDValue Lo = DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_PAGEOFF |
3477                                                              AArch64II::MO_NC);
3478     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3479     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3480   }
3481 }
3482 
LowerDarwin_VASTART(SDValue Op,SelectionDAG & DAG) const3483 SDValue AArch64TargetLowering::LowerDarwin_VASTART(SDValue Op,
3484                                                  SelectionDAG &DAG) const {
3485   AArch64FunctionInfo *FuncInfo =
3486       DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
3487 
3488   SDLoc DL(Op);
3489   SDValue FR =
3490       DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(), getPointerTy());
3491   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3492   return DAG.getStore(Op.getOperand(0), DL, FR, Op.getOperand(1),
3493                       MachinePointerInfo(SV), false, false, 0);
3494 }
3495 
LowerAAPCS_VASTART(SDValue Op,SelectionDAG & DAG) const3496 SDValue AArch64TargetLowering::LowerAAPCS_VASTART(SDValue Op,
3497                                                 SelectionDAG &DAG) const {
3498   // The layout of the va_list struct is specified in the AArch64 Procedure Call
3499   // Standard, section B.3.
3500   MachineFunction &MF = DAG.getMachineFunction();
3501   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
3502   SDLoc DL(Op);
3503 
3504   SDValue Chain = Op.getOperand(0);
3505   SDValue VAList = Op.getOperand(1);
3506   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3507   SmallVector<SDValue, 4> MemOps;
3508 
3509   // void *__stack at offset 0
3510   SDValue Stack =
3511       DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(), getPointerTy());
3512   MemOps.push_back(DAG.getStore(Chain, DL, Stack, VAList,
3513                                 MachinePointerInfo(SV), false, false, 8));
3514 
3515   // void *__gr_top at offset 8
3516   int GPRSize = FuncInfo->getVarArgsGPRSize();
3517   if (GPRSize > 0) {
3518     SDValue GRTop, GRTopAddr;
3519 
3520     GRTopAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3521                             DAG.getConstant(8, getPointerTy()));
3522 
3523     GRTop = DAG.getFrameIndex(FuncInfo->getVarArgsGPRIndex(), getPointerTy());
3524     GRTop = DAG.getNode(ISD::ADD, DL, getPointerTy(), GRTop,
3525                         DAG.getConstant(GPRSize, getPointerTy()));
3526 
3527     MemOps.push_back(DAG.getStore(Chain, DL, GRTop, GRTopAddr,
3528                                   MachinePointerInfo(SV, 8), false, false, 8));
3529   }
3530 
3531   // void *__vr_top at offset 16
3532   int FPRSize = FuncInfo->getVarArgsFPRSize();
3533   if (FPRSize > 0) {
3534     SDValue VRTop, VRTopAddr;
3535     VRTopAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3536                             DAG.getConstant(16, getPointerTy()));
3537 
3538     VRTop = DAG.getFrameIndex(FuncInfo->getVarArgsFPRIndex(), getPointerTy());
3539     VRTop = DAG.getNode(ISD::ADD, DL, getPointerTy(), VRTop,
3540                         DAG.getConstant(FPRSize, getPointerTy()));
3541 
3542     MemOps.push_back(DAG.getStore(Chain, DL, VRTop, VRTopAddr,
3543                                   MachinePointerInfo(SV, 16), false, false, 8));
3544   }
3545 
3546   // int __gr_offs at offset 24
3547   SDValue GROffsAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3548                                    DAG.getConstant(24, getPointerTy()));
3549   MemOps.push_back(DAG.getStore(Chain, DL, DAG.getConstant(-GPRSize, MVT::i32),
3550                                 GROffsAddr, MachinePointerInfo(SV, 24), false,
3551                                 false, 4));
3552 
3553   // int __vr_offs at offset 28
3554   SDValue VROffsAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3555                                    DAG.getConstant(28, getPointerTy()));
3556   MemOps.push_back(DAG.getStore(Chain, DL, DAG.getConstant(-FPRSize, MVT::i32),
3557                                 VROffsAddr, MachinePointerInfo(SV, 28), false,
3558                                 false, 4));
3559 
3560   return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
3561 }
3562 
LowerVASTART(SDValue Op,SelectionDAG & DAG) const3563 SDValue AArch64TargetLowering::LowerVASTART(SDValue Op,
3564                                             SelectionDAG &DAG) const {
3565   return Subtarget->isTargetDarwin() ? LowerDarwin_VASTART(Op, DAG)
3566                                      : LowerAAPCS_VASTART(Op, DAG);
3567 }
3568 
LowerVACOPY(SDValue Op,SelectionDAG & DAG) const3569 SDValue AArch64TargetLowering::LowerVACOPY(SDValue Op,
3570                                            SelectionDAG &DAG) const {
3571   // AAPCS has three pointers and two ints (= 32 bytes), Darwin has single
3572   // pointer.
3573   unsigned VaListSize = Subtarget->isTargetDarwin() ? 8 : 32;
3574   const Value *DestSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
3575   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
3576 
3577   return DAG.getMemcpy(Op.getOperand(0), SDLoc(Op), Op.getOperand(1),
3578                        Op.getOperand(2), DAG.getConstant(VaListSize, MVT::i32),
3579                        8, false, false, MachinePointerInfo(DestSV),
3580                        MachinePointerInfo(SrcSV));
3581 }
3582 
LowerVAARG(SDValue Op,SelectionDAG & DAG) const3583 SDValue AArch64TargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
3584   assert(Subtarget->isTargetDarwin() &&
3585          "automatic va_arg instruction only works on Darwin");
3586 
3587   const Value *V = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3588   EVT VT = Op.getValueType();
3589   SDLoc DL(Op);
3590   SDValue Chain = Op.getOperand(0);
3591   SDValue Addr = Op.getOperand(1);
3592   unsigned Align = Op.getConstantOperandVal(3);
3593 
3594   SDValue VAList = DAG.getLoad(getPointerTy(), DL, Chain, Addr,
3595                                MachinePointerInfo(V), false, false, false, 0);
3596   Chain = VAList.getValue(1);
3597 
3598   if (Align > 8) {
3599     assert(((Align & (Align - 1)) == 0) && "Expected Align to be a power of 2");
3600     VAList = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3601                          DAG.getConstant(Align - 1, getPointerTy()));
3602     VAList = DAG.getNode(ISD::AND, DL, getPointerTy(), VAList,
3603                          DAG.getConstant(-(int64_t)Align, getPointerTy()));
3604   }
3605 
3606   Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
3607   uint64_t ArgSize = getDataLayout()->getTypeAllocSize(ArgTy);
3608 
3609   // Scalar integer and FP values smaller than 64 bits are implicitly extended
3610   // up to 64 bits.  At the very least, we have to increase the striding of the
3611   // vaargs list to match this, and for FP values we need to introduce
3612   // FP_ROUND nodes as well.
3613   if (VT.isInteger() && !VT.isVector())
3614     ArgSize = 8;
3615   bool NeedFPTrunc = false;
3616   if (VT.isFloatingPoint() && !VT.isVector() && VT != MVT::f64) {
3617     ArgSize = 8;
3618     NeedFPTrunc = true;
3619   }
3620 
3621   // Increment the pointer, VAList, to the next vaarg
3622   SDValue VANext = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3623                                DAG.getConstant(ArgSize, getPointerTy()));
3624   // Store the incremented VAList to the legalized pointer
3625   SDValue APStore = DAG.getStore(Chain, DL, VANext, Addr, MachinePointerInfo(V),
3626                                  false, false, 0);
3627 
3628   // Load the actual argument out of the pointer VAList
3629   if (NeedFPTrunc) {
3630     // Load the value as an f64.
3631     SDValue WideFP = DAG.getLoad(MVT::f64, DL, APStore, VAList,
3632                                  MachinePointerInfo(), false, false, false, 0);
3633     // Round the value down to an f32.
3634     SDValue NarrowFP = DAG.getNode(ISD::FP_ROUND, DL, VT, WideFP.getValue(0),
3635                                    DAG.getIntPtrConstant(1));
3636     SDValue Ops[] = { NarrowFP, WideFP.getValue(1) };
3637     // Merge the rounded value with the chain output of the load.
3638     return DAG.getMergeValues(Ops, DL);
3639   }
3640 
3641   return DAG.getLoad(VT, DL, APStore, VAList, MachinePointerInfo(), false,
3642                      false, false, 0);
3643 }
3644 
LowerFRAMEADDR(SDValue Op,SelectionDAG & DAG) const3645 SDValue AArch64TargetLowering::LowerFRAMEADDR(SDValue Op,
3646                                               SelectionDAG &DAG) const {
3647   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
3648   MFI->setFrameAddressIsTaken(true);
3649 
3650   EVT VT = Op.getValueType();
3651   SDLoc DL(Op);
3652   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
3653   SDValue FrameAddr =
3654       DAG.getCopyFromReg(DAG.getEntryNode(), DL, AArch64::FP, VT);
3655   while (Depth--)
3656     FrameAddr = DAG.getLoad(VT, DL, DAG.getEntryNode(), FrameAddr,
3657                             MachinePointerInfo(), false, false, false, 0);
3658   return FrameAddr;
3659 }
3660 
3661 // FIXME? Maybe this could be a TableGen attribute on some registers and
3662 // this table could be generated automatically from RegInfo.
getRegisterByName(const char * RegName,EVT VT) const3663 unsigned AArch64TargetLowering::getRegisterByName(const char* RegName,
3664                                                   EVT VT) const {
3665   unsigned Reg = StringSwitch<unsigned>(RegName)
3666                        .Case("sp", AArch64::SP)
3667                        .Default(0);
3668   if (Reg)
3669     return Reg;
3670   report_fatal_error("Invalid register name global variable");
3671 }
3672 
LowerRETURNADDR(SDValue Op,SelectionDAG & DAG) const3673 SDValue AArch64TargetLowering::LowerRETURNADDR(SDValue Op,
3674                                                SelectionDAG &DAG) const {
3675   MachineFunction &MF = DAG.getMachineFunction();
3676   MachineFrameInfo *MFI = MF.getFrameInfo();
3677   MFI->setReturnAddressIsTaken(true);
3678 
3679   EVT VT = Op.getValueType();
3680   SDLoc DL(Op);
3681   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
3682   if (Depth) {
3683     SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
3684     SDValue Offset = DAG.getConstant(8, getPointerTy());
3685     return DAG.getLoad(VT, DL, DAG.getEntryNode(),
3686                        DAG.getNode(ISD::ADD, DL, VT, FrameAddr, Offset),
3687                        MachinePointerInfo(), false, false, false, 0);
3688   }
3689 
3690   // Return LR, which contains the return address. Mark it an implicit live-in.
3691   unsigned Reg = MF.addLiveIn(AArch64::LR, &AArch64::GPR64RegClass);
3692   return DAG.getCopyFromReg(DAG.getEntryNode(), DL, Reg, VT);
3693 }
3694 
3695 /// LowerShiftRightParts - Lower SRA_PARTS, which returns two
3696 /// i64 values and take a 2 x i64 value to shift plus a shift amount.
LowerShiftRightParts(SDValue Op,SelectionDAG & DAG) const3697 SDValue AArch64TargetLowering::LowerShiftRightParts(SDValue Op,
3698                                                     SelectionDAG &DAG) const {
3699   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
3700   EVT VT = Op.getValueType();
3701   unsigned VTBits = VT.getSizeInBits();
3702   SDLoc dl(Op);
3703   SDValue ShOpLo = Op.getOperand(0);
3704   SDValue ShOpHi = Op.getOperand(1);
3705   SDValue ShAmt = Op.getOperand(2);
3706   SDValue ARMcc;
3707   unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
3708 
3709   assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
3710 
3711   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64,
3712                                  DAG.getConstant(VTBits, MVT::i64), ShAmt);
3713   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
3714   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64, ShAmt,
3715                                    DAG.getConstant(VTBits, MVT::i64));
3716   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
3717 
3718   SDValue Cmp = emitComparison(ExtraShAmt, DAG.getConstant(0, MVT::i64),
3719                                ISD::SETGE, dl, DAG);
3720   SDValue CCVal = DAG.getConstant(AArch64CC::GE, MVT::i32);
3721 
3722   SDValue FalseValLo = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
3723   SDValue TrueValLo = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
3724   SDValue Lo =
3725       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValLo, FalseValLo, CCVal, Cmp);
3726 
3727   // AArch64 shifts larger than the register width are wrapped rather than
3728   // clamped, so we can't just emit "hi >> x".
3729   SDValue FalseValHi = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
3730   SDValue TrueValHi = Opc == ISD::SRA
3731                           ? DAG.getNode(Opc, dl, VT, ShOpHi,
3732                                         DAG.getConstant(VTBits - 1, MVT::i64))
3733                           : DAG.getConstant(0, VT);
3734   SDValue Hi =
3735       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValHi, FalseValHi, CCVal, Cmp);
3736 
3737   SDValue Ops[2] = { Lo, Hi };
3738   return DAG.getMergeValues(Ops, dl);
3739 }
3740 
3741 /// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
3742 /// i64 values and take a 2 x i64 value to shift plus a shift amount.
LowerShiftLeftParts(SDValue Op,SelectionDAG & DAG) const3743 SDValue AArch64TargetLowering::LowerShiftLeftParts(SDValue Op,
3744                                                  SelectionDAG &DAG) const {
3745   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
3746   EVT VT = Op.getValueType();
3747   unsigned VTBits = VT.getSizeInBits();
3748   SDLoc dl(Op);
3749   SDValue ShOpLo = Op.getOperand(0);
3750   SDValue ShOpHi = Op.getOperand(1);
3751   SDValue ShAmt = Op.getOperand(2);
3752   SDValue ARMcc;
3753 
3754   assert(Op.getOpcode() == ISD::SHL_PARTS);
3755   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64,
3756                                  DAG.getConstant(VTBits, MVT::i64), ShAmt);
3757   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
3758   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64, ShAmt,
3759                                    DAG.getConstant(VTBits, MVT::i64));
3760   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
3761   SDValue Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
3762 
3763   SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
3764 
3765   SDValue Cmp = emitComparison(ExtraShAmt, DAG.getConstant(0, MVT::i64),
3766                                ISD::SETGE, dl, DAG);
3767   SDValue CCVal = DAG.getConstant(AArch64CC::GE, MVT::i32);
3768   SDValue Hi =
3769       DAG.getNode(AArch64ISD::CSEL, dl, VT, Tmp3, FalseVal, CCVal, Cmp);
3770 
3771   // AArch64 shifts of larger than register sizes are wrapped rather than
3772   // clamped, so we can't just emit "lo << a" if a is too big.
3773   SDValue TrueValLo = DAG.getConstant(0, VT);
3774   SDValue FalseValLo = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
3775   SDValue Lo =
3776       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValLo, FalseValLo, CCVal, Cmp);
3777 
3778   SDValue Ops[2] = { Lo, Hi };
3779   return DAG.getMergeValues(Ops, dl);
3780 }
3781 
isOffsetFoldingLegal(const GlobalAddressSDNode * GA) const3782 bool AArch64TargetLowering::isOffsetFoldingLegal(
3783     const GlobalAddressSDNode *GA) const {
3784   // The AArch64 target doesn't support folding offsets into global addresses.
3785   return false;
3786 }
3787 
isFPImmLegal(const APFloat & Imm,EVT VT) const3788 bool AArch64TargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
3789   // We can materialize #0.0 as fmov $Rd, XZR for 64-bit and 32-bit cases.
3790   // FIXME: We should be able to handle f128 as well with a clever lowering.
3791   if (Imm.isPosZero() && (VT == MVT::f64 || VT == MVT::f32))
3792     return true;
3793 
3794   if (VT == MVT::f64)
3795     return AArch64_AM::getFP64Imm(Imm) != -1;
3796   else if (VT == MVT::f32)
3797     return AArch64_AM::getFP32Imm(Imm) != -1;
3798   return false;
3799 }
3800 
3801 //===----------------------------------------------------------------------===//
3802 //                          AArch64 Optimization Hooks
3803 //===----------------------------------------------------------------------===//
3804 
3805 //===----------------------------------------------------------------------===//
3806 //                          AArch64 Inline Assembly Support
3807 //===----------------------------------------------------------------------===//
3808 
3809 // Table of Constraints
3810 // TODO: This is the current set of constraints supported by ARM for the
3811 // compiler, not all of them may make sense, e.g. S may be difficult to support.
3812 //
3813 // r - A general register
3814 // w - An FP/SIMD register of some size in the range v0-v31
3815 // x - An FP/SIMD register of some size in the range v0-v15
3816 // I - Constant that can be used with an ADD instruction
3817 // J - Constant that can be used with a SUB instruction
3818 // K - Constant that can be used with a 32-bit logical instruction
3819 // L - Constant that can be used with a 64-bit logical instruction
3820 // M - Constant that can be used as a 32-bit MOV immediate
3821 // N - Constant that can be used as a 64-bit MOV immediate
3822 // Q - A memory reference with base register and no offset
3823 // S - A symbolic address
3824 // Y - Floating point constant zero
3825 // Z - Integer constant zero
3826 //
3827 //   Note that general register operands will be output using their 64-bit x
3828 // register name, whatever the size of the variable, unless the asm operand
3829 // is prefixed by the %w modifier. Floating-point and SIMD register operands
3830 // will be output with the v prefix unless prefixed by the %b, %h, %s, %d or
3831 // %q modifier.
3832 
3833 /// getConstraintType - Given a constraint letter, return the type of
3834 /// constraint it is for this target.
3835 AArch64TargetLowering::ConstraintType
getConstraintType(const std::string & Constraint) const3836 AArch64TargetLowering::getConstraintType(const std::string &Constraint) const {
3837   if (Constraint.size() == 1) {
3838     switch (Constraint[0]) {
3839     default:
3840       break;
3841     case 'z':
3842       return C_Other;
3843     case 'x':
3844     case 'w':
3845       return C_RegisterClass;
3846     // An address with a single base register. Due to the way we
3847     // currently handle addresses it is the same as 'r'.
3848     case 'Q':
3849       return C_Memory;
3850     }
3851   }
3852   return TargetLowering::getConstraintType(Constraint);
3853 }
3854 
3855 /// Examine constraint type and operand type and determine a weight value.
3856 /// This object must already have been set up with the operand type
3857 /// and the current alternative constraint selected.
3858 TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo & info,const char * constraint) const3859 AArch64TargetLowering::getSingleConstraintMatchWeight(
3860     AsmOperandInfo &info, const char *constraint) const {
3861   ConstraintWeight weight = CW_Invalid;
3862   Value *CallOperandVal = info.CallOperandVal;
3863   // If we don't have a value, we can't do a match,
3864   // but allow it at the lowest weight.
3865   if (!CallOperandVal)
3866     return CW_Default;
3867   Type *type = CallOperandVal->getType();
3868   // Look at the constraint type.
3869   switch (*constraint) {
3870   default:
3871     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3872     break;
3873   case 'x':
3874   case 'w':
3875     if (type->isFloatingPointTy() || type->isVectorTy())
3876       weight = CW_Register;
3877     break;
3878   case 'z':
3879     weight = CW_Constant;
3880     break;
3881   }
3882   return weight;
3883 }
3884 
3885 std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const std::string & Constraint,MVT VT) const3886 AArch64TargetLowering::getRegForInlineAsmConstraint(
3887     const std::string &Constraint, MVT VT) const {
3888   if (Constraint.size() == 1) {
3889     switch (Constraint[0]) {
3890     case 'r':
3891       if (VT.getSizeInBits() == 64)
3892         return std::make_pair(0U, &AArch64::GPR64commonRegClass);
3893       return std::make_pair(0U, &AArch64::GPR32commonRegClass);
3894     case 'w':
3895       if (VT == MVT::f32)
3896         return std::make_pair(0U, &AArch64::FPR32RegClass);
3897       if (VT.getSizeInBits() == 64)
3898         return std::make_pair(0U, &AArch64::FPR64RegClass);
3899       if (VT.getSizeInBits() == 128)
3900         return std::make_pair(0U, &AArch64::FPR128RegClass);
3901       break;
3902     // The instructions that this constraint is designed for can
3903     // only take 128-bit registers so just use that regclass.
3904     case 'x':
3905       if (VT.getSizeInBits() == 128)
3906         return std::make_pair(0U, &AArch64::FPR128_loRegClass);
3907       break;
3908     }
3909   }
3910   if (StringRef("{cc}").equals_lower(Constraint))
3911     return std::make_pair(unsigned(AArch64::NZCV), &AArch64::CCRRegClass);
3912 
3913   // Use the default implementation in TargetLowering to convert the register
3914   // constraint into a member of a register class.
3915   std::pair<unsigned, const TargetRegisterClass *> Res;
3916   Res = TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
3917 
3918   // Not found as a standard register?
3919   if (!Res.second) {
3920     unsigned Size = Constraint.size();
3921     if ((Size == 4 || Size == 5) && Constraint[0] == '{' &&
3922         tolower(Constraint[1]) == 'v' && Constraint[Size - 1] == '}') {
3923       const std::string Reg =
3924           std::string(&Constraint[2], &Constraint[Size - 1]);
3925       int RegNo = atoi(Reg.c_str());
3926       if (RegNo >= 0 && RegNo <= 31) {
3927         // v0 - v31 are aliases of q0 - q31.
3928         // By default we'll emit v0-v31 for this unless there's a modifier where
3929         // we'll emit the correct register as well.
3930         Res.first = AArch64::FPR128RegClass.getRegister(RegNo);
3931         Res.second = &AArch64::FPR128RegClass;
3932       }
3933     }
3934   }
3935 
3936   return Res;
3937 }
3938 
3939 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3940 /// vector.  If it is invalid, don't add anything to Ops.
LowerAsmOperandForConstraint(SDValue Op,std::string & Constraint,std::vector<SDValue> & Ops,SelectionDAG & DAG) const3941 void AArch64TargetLowering::LowerAsmOperandForConstraint(
3942     SDValue Op, std::string &Constraint, std::vector<SDValue> &Ops,
3943     SelectionDAG &DAG) const {
3944   SDValue Result;
3945 
3946   // Currently only support length 1 constraints.
3947   if (Constraint.length() != 1)
3948     return;
3949 
3950   char ConstraintLetter = Constraint[0];
3951   switch (ConstraintLetter) {
3952   default:
3953     break;
3954 
3955   // This set of constraints deal with valid constants for various instructions.
3956   // Validate and return a target constant for them if we can.
3957   case 'z': {
3958     // 'z' maps to xzr or wzr so it needs an input of 0.
3959     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
3960     if (!C || C->getZExtValue() != 0)
3961       return;
3962 
3963     if (Op.getValueType() == MVT::i64)
3964       Result = DAG.getRegister(AArch64::XZR, MVT::i64);
3965     else
3966       Result = DAG.getRegister(AArch64::WZR, MVT::i32);
3967     break;
3968   }
3969 
3970   case 'I':
3971   case 'J':
3972   case 'K':
3973   case 'L':
3974   case 'M':
3975   case 'N':
3976     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
3977     if (!C)
3978       return;
3979 
3980     // Grab the value and do some validation.
3981     uint64_t CVal = C->getZExtValue();
3982     switch (ConstraintLetter) {
3983     // The I constraint applies only to simple ADD or SUB immediate operands:
3984     // i.e. 0 to 4095 with optional shift by 12
3985     // The J constraint applies only to ADD or SUB immediates that would be
3986     // valid when negated, i.e. if [an add pattern] were to be output as a SUB
3987     // instruction [or vice versa], in other words -1 to -4095 with optional
3988     // left shift by 12.
3989     case 'I':
3990       if (isUInt<12>(CVal) || isShiftedUInt<12, 12>(CVal))
3991         break;
3992       return;
3993     case 'J': {
3994       uint64_t NVal = -C->getSExtValue();
3995       if (isUInt<12>(NVal) || isShiftedUInt<12, 12>(NVal))
3996         break;
3997       return;
3998     }
3999     // The K and L constraints apply *only* to logical immediates, including
4000     // what used to be the MOVI alias for ORR (though the MOVI alias has now
4001     // been removed and MOV should be used). So these constraints have to
4002     // distinguish between bit patterns that are valid 32-bit or 64-bit
4003     // "bitmask immediates": for example 0xaaaaaaaa is a valid bimm32 (K), but
4004     // not a valid bimm64 (L) where 0xaaaaaaaaaaaaaaaa would be valid, and vice
4005     // versa.
4006     case 'K':
4007       if (AArch64_AM::isLogicalImmediate(CVal, 32))
4008         break;
4009       return;
4010     case 'L':
4011       if (AArch64_AM::isLogicalImmediate(CVal, 64))
4012         break;
4013       return;
4014     // The M and N constraints are a superset of K and L respectively, for use
4015     // with the MOV (immediate) alias. As well as the logical immediates they
4016     // also match 32 or 64-bit immediates that can be loaded either using a
4017     // *single* MOVZ or MOVN , such as 32-bit 0x12340000, 0x00001234, 0xffffedca
4018     // (M) or 64-bit 0x1234000000000000 (N) etc.
4019     // As a note some of this code is liberally stolen from the asm parser.
4020     case 'M': {
4021       if (!isUInt<32>(CVal))
4022         return;
4023       if (AArch64_AM::isLogicalImmediate(CVal, 32))
4024         break;
4025       if ((CVal & 0xFFFF) == CVal)
4026         break;
4027       if ((CVal & 0xFFFF0000ULL) == CVal)
4028         break;
4029       uint64_t NCVal = ~(uint32_t)CVal;
4030       if ((NCVal & 0xFFFFULL) == NCVal)
4031         break;
4032       if ((NCVal & 0xFFFF0000ULL) == NCVal)
4033         break;
4034       return;
4035     }
4036     case 'N': {
4037       if (AArch64_AM::isLogicalImmediate(CVal, 64))
4038         break;
4039       if ((CVal & 0xFFFFULL) == CVal)
4040         break;
4041       if ((CVal & 0xFFFF0000ULL) == CVal)
4042         break;
4043       if ((CVal & 0xFFFF00000000ULL) == CVal)
4044         break;
4045       if ((CVal & 0xFFFF000000000000ULL) == CVal)
4046         break;
4047       uint64_t NCVal = ~CVal;
4048       if ((NCVal & 0xFFFFULL) == NCVal)
4049         break;
4050       if ((NCVal & 0xFFFF0000ULL) == NCVal)
4051         break;
4052       if ((NCVal & 0xFFFF00000000ULL) == NCVal)
4053         break;
4054       if ((NCVal & 0xFFFF000000000000ULL) == NCVal)
4055         break;
4056       return;
4057     }
4058     default:
4059       return;
4060     }
4061 
4062     // All assembler immediates are 64-bit integers.
4063     Result = DAG.getTargetConstant(CVal, MVT::i64);
4064     break;
4065   }
4066 
4067   if (Result.getNode()) {
4068     Ops.push_back(Result);
4069     return;
4070   }
4071 
4072   return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4073 }
4074 
4075 //===----------------------------------------------------------------------===//
4076 //                     AArch64 Advanced SIMD Support
4077 //===----------------------------------------------------------------------===//
4078 
4079 /// WidenVector - Given a value in the V64 register class, produce the
4080 /// equivalent value in the V128 register class.
WidenVector(SDValue V64Reg,SelectionDAG & DAG)4081 static SDValue WidenVector(SDValue V64Reg, SelectionDAG &DAG) {
4082   EVT VT = V64Reg.getValueType();
4083   unsigned NarrowSize = VT.getVectorNumElements();
4084   MVT EltTy = VT.getVectorElementType().getSimpleVT();
4085   MVT WideTy = MVT::getVectorVT(EltTy, 2 * NarrowSize);
4086   SDLoc DL(V64Reg);
4087 
4088   return DAG.getNode(ISD::INSERT_SUBVECTOR, DL, WideTy, DAG.getUNDEF(WideTy),
4089                      V64Reg, DAG.getConstant(0, MVT::i32));
4090 }
4091 
4092 /// getExtFactor - Determine the adjustment factor for the position when
4093 /// generating an "extract from vector registers" instruction.
getExtFactor(SDValue & V)4094 static unsigned getExtFactor(SDValue &V) {
4095   EVT EltType = V.getValueType().getVectorElementType();
4096   return EltType.getSizeInBits() / 8;
4097 }
4098 
4099 /// NarrowVector - Given a value in the V128 register class, produce the
4100 /// equivalent value in the V64 register class.
NarrowVector(SDValue V128Reg,SelectionDAG & DAG)4101 static SDValue NarrowVector(SDValue V128Reg, SelectionDAG &DAG) {
4102   EVT VT = V128Reg.getValueType();
4103   unsigned WideSize = VT.getVectorNumElements();
4104   MVT EltTy = VT.getVectorElementType().getSimpleVT();
4105   MVT NarrowTy = MVT::getVectorVT(EltTy, WideSize / 2);
4106   SDLoc DL(V128Reg);
4107 
4108   return DAG.getTargetExtractSubreg(AArch64::dsub, DL, NarrowTy, V128Reg);
4109 }
4110 
4111 // Gather data to see if the operation can be modelled as a
4112 // shuffle in combination with VEXTs.
ReconstructShuffle(SDValue Op,SelectionDAG & DAG) const4113 SDValue AArch64TargetLowering::ReconstructShuffle(SDValue Op,
4114                                                   SelectionDAG &DAG) const {
4115   assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
4116   SDLoc dl(Op);
4117   EVT VT = Op.getValueType();
4118   unsigned NumElts = VT.getVectorNumElements();
4119 
4120   SmallVector<SDValue, 2> SourceVecs;
4121   SmallVector<unsigned, 2> MinElts;
4122   SmallVector<unsigned, 2> MaxElts;
4123 
4124   for (unsigned i = 0; i < NumElts; ++i) {
4125     SDValue V = Op.getOperand(i);
4126     if (V.getOpcode() == ISD::UNDEF)
4127       continue;
4128     else if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT) {
4129       // A shuffle can only come from building a vector from various
4130       // elements of other vectors.
4131       return SDValue();
4132     }
4133 
4134     // Record this extraction against the appropriate vector if possible...
4135     SDValue SourceVec = V.getOperand(0);
4136     unsigned EltNo = cast<ConstantSDNode>(V.getOperand(1))->getZExtValue();
4137     bool FoundSource = false;
4138     for (unsigned j = 0; j < SourceVecs.size(); ++j) {
4139       if (SourceVecs[j] == SourceVec) {
4140         if (MinElts[j] > EltNo)
4141           MinElts[j] = EltNo;
4142         if (MaxElts[j] < EltNo)
4143           MaxElts[j] = EltNo;
4144         FoundSource = true;
4145         break;
4146       }
4147     }
4148 
4149     // Or record a new source if not...
4150     if (!FoundSource) {
4151       SourceVecs.push_back(SourceVec);
4152       MinElts.push_back(EltNo);
4153       MaxElts.push_back(EltNo);
4154     }
4155   }
4156 
4157   // Currently only do something sane when at most two source vectors
4158   // involved.
4159   if (SourceVecs.size() > 2)
4160     return SDValue();
4161 
4162   SDValue ShuffleSrcs[2] = { DAG.getUNDEF(VT), DAG.getUNDEF(VT) };
4163   int VEXTOffsets[2] = { 0, 0 };
4164   int OffsetMultipliers[2] = { 1, 1 };
4165 
4166   // This loop extracts the usage patterns of the source vectors
4167   // and prepares appropriate SDValues for a shuffle if possible.
4168   for (unsigned i = 0; i < SourceVecs.size(); ++i) {
4169     unsigned NumSrcElts = SourceVecs[i].getValueType().getVectorNumElements();
4170     SDValue CurSource = SourceVecs[i];
4171     if (SourceVecs[i].getValueType().getVectorElementType() !=
4172         VT.getVectorElementType()) {
4173       // It may hit this case if SourceVecs[i] is AssertSext/AssertZext.
4174       // Then bitcast it to the vector which holds asserted element type,
4175       // and record the multiplier of element width between SourceVecs and
4176       // Build_vector which is needed to extract the correct lanes later.
4177       EVT CastVT =
4178           EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(),
4179                            SourceVecs[i].getValueSizeInBits() /
4180                                VT.getVectorElementType().getSizeInBits());
4181 
4182       CurSource = DAG.getNode(ISD::BITCAST, dl, CastVT, SourceVecs[i]);
4183       OffsetMultipliers[i] = CastVT.getVectorNumElements() / NumSrcElts;
4184       NumSrcElts *= OffsetMultipliers[i];
4185       MaxElts[i] *= OffsetMultipliers[i];
4186       MinElts[i] *= OffsetMultipliers[i];
4187     }
4188 
4189     if (CurSource.getValueType() == VT) {
4190       // No VEXT necessary
4191       ShuffleSrcs[i] = CurSource;
4192       VEXTOffsets[i] = 0;
4193       continue;
4194     } else if (NumSrcElts < NumElts) {
4195       // We can pad out the smaller vector for free, so if it's part of a
4196       // shuffle...
4197       ShuffleSrcs[i] = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, CurSource,
4198                                    DAG.getUNDEF(CurSource.getValueType()));
4199       continue;
4200     }
4201 
4202     // Since only 64-bit and 128-bit vectors are legal on ARM and
4203     // we've eliminated the other cases...
4204     assert(NumSrcElts == 2 * NumElts &&
4205            "unexpected vector sizes in ReconstructShuffle");
4206 
4207     if (MaxElts[i] - MinElts[i] >= NumElts) {
4208       // Span too large for a VEXT to cope
4209       return SDValue();
4210     }
4211 
4212     if (MinElts[i] >= NumElts) {
4213       // The extraction can just take the second half
4214       VEXTOffsets[i] = NumElts;
4215       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4216                                    DAG.getIntPtrConstant(NumElts));
4217     } else if (MaxElts[i] < NumElts) {
4218       // The extraction can just take the first half
4219       VEXTOffsets[i] = 0;
4220       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4221                                    DAG.getIntPtrConstant(0));
4222     } else {
4223       // An actual VEXT is needed
4224       VEXTOffsets[i] = MinElts[i];
4225       SDValue VEXTSrc1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4226                                      DAG.getIntPtrConstant(0));
4227       SDValue VEXTSrc2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4228                                      DAG.getIntPtrConstant(NumElts));
4229       unsigned Imm = VEXTOffsets[i] * getExtFactor(VEXTSrc1);
4230       ShuffleSrcs[i] = DAG.getNode(AArch64ISD::EXT, dl, VT, VEXTSrc1, VEXTSrc2,
4231                                    DAG.getConstant(Imm, MVT::i32));
4232     }
4233   }
4234 
4235   SmallVector<int, 8> Mask;
4236 
4237   for (unsigned i = 0; i < NumElts; ++i) {
4238     SDValue Entry = Op.getOperand(i);
4239     if (Entry.getOpcode() == ISD::UNDEF) {
4240       Mask.push_back(-1);
4241       continue;
4242     }
4243 
4244     SDValue ExtractVec = Entry.getOperand(0);
4245     int ExtractElt =
4246         cast<ConstantSDNode>(Op.getOperand(i).getOperand(1))->getSExtValue();
4247     if (ExtractVec == SourceVecs[0]) {
4248       Mask.push_back(ExtractElt * OffsetMultipliers[0] - VEXTOffsets[0]);
4249     } else {
4250       Mask.push_back(ExtractElt * OffsetMultipliers[1] + NumElts -
4251                      VEXTOffsets[1]);
4252     }
4253   }
4254 
4255   // Final check before we try to produce nonsense...
4256   if (isShuffleMaskLegal(Mask, VT))
4257     return DAG.getVectorShuffle(VT, dl, ShuffleSrcs[0], ShuffleSrcs[1],
4258                                 &Mask[0]);
4259 
4260   return SDValue();
4261 }
4262 
4263 // check if an EXT instruction can handle the shuffle mask when the
4264 // vector sources of the shuffle are the same.
isSingletonEXTMask(ArrayRef<int> M,EVT VT,unsigned & Imm)4265 static bool isSingletonEXTMask(ArrayRef<int> M, EVT VT, unsigned &Imm) {
4266   unsigned NumElts = VT.getVectorNumElements();
4267 
4268   // Assume that the first shuffle index is not UNDEF.  Fail if it is.
4269   if (M[0] < 0)
4270     return false;
4271 
4272   Imm = M[0];
4273 
4274   // If this is a VEXT shuffle, the immediate value is the index of the first
4275   // element.  The other shuffle indices must be the successive elements after
4276   // the first one.
4277   unsigned ExpectedElt = Imm;
4278   for (unsigned i = 1; i < NumElts; ++i) {
4279     // Increment the expected index.  If it wraps around, just follow it
4280     // back to index zero and keep going.
4281     ++ExpectedElt;
4282     if (ExpectedElt == NumElts)
4283       ExpectedElt = 0;
4284 
4285     if (M[i] < 0)
4286       continue; // ignore UNDEF indices
4287     if (ExpectedElt != static_cast<unsigned>(M[i]))
4288       return false;
4289   }
4290 
4291   return true;
4292 }
4293 
4294 // check if an EXT instruction can handle the shuffle mask when the
4295 // vector sources of the shuffle are different.
isEXTMask(ArrayRef<int> M,EVT VT,bool & ReverseEXT,unsigned & Imm)4296 static bool isEXTMask(ArrayRef<int> M, EVT VT, bool &ReverseEXT,
4297                       unsigned &Imm) {
4298   // Look for the first non-undef element.
4299   const int *FirstRealElt = std::find_if(M.begin(), M.end(),
4300       [](int Elt) {return Elt >= 0;});
4301 
4302   // Benefit form APInt to handle overflow when calculating expected element.
4303   unsigned NumElts = VT.getVectorNumElements();
4304   unsigned MaskBits = APInt(32, NumElts * 2).logBase2();
4305   APInt ExpectedElt = APInt(MaskBits, *FirstRealElt + 1);
4306   // The following shuffle indices must be the successive elements after the
4307   // first real element.
4308   const int *FirstWrongElt = std::find_if(FirstRealElt + 1, M.end(),
4309       [&](int Elt) {return Elt != ExpectedElt++ && Elt != -1;});
4310   if (FirstWrongElt != M.end())
4311     return false;
4312 
4313   // The index of an EXT is the first element if it is not UNDEF.
4314   // Watch out for the beginning UNDEFs. The EXT index should be the expected
4315   // value of the first element.  E.g.
4316   // <-1, -1, 3, ...> is treated as <1, 2, 3, ...>.
4317   // <-1, -1, 0, 1, ...> is treated as <2*NumElts-2, 2*NumElts-1, 0, 1, ...>.
4318   // ExpectedElt is the last mask index plus 1.
4319   Imm = ExpectedElt.getZExtValue();
4320 
4321   // There are two difference cases requiring to reverse input vectors.
4322   // For example, for vector <4 x i32> we have the following cases,
4323   // Case 1: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, -1, 0>)
4324   // Case 2: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, 7, 0>)
4325   // For both cases, we finally use mask <5, 6, 7, 0>, which requires
4326   // to reverse two input vectors.
4327   if (Imm < NumElts)
4328     ReverseEXT = true;
4329   else
4330     Imm -= NumElts;
4331 
4332   return true;
4333 }
4334 
4335 /// isREVMask - Check if a vector shuffle corresponds to a REV
4336 /// instruction with the specified blocksize.  (The order of the elements
4337 /// within each block of the vector is reversed.)
isREVMask(ArrayRef<int> M,EVT VT,unsigned BlockSize)4338 static bool isREVMask(ArrayRef<int> M, EVT VT, unsigned BlockSize) {
4339   assert((BlockSize == 16 || BlockSize == 32 || BlockSize == 64) &&
4340          "Only possible block sizes for REV are: 16, 32, 64");
4341 
4342   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
4343   if (EltSz == 64)
4344     return false;
4345 
4346   unsigned NumElts = VT.getVectorNumElements();
4347   unsigned BlockElts = M[0] + 1;
4348   // If the first shuffle index is UNDEF, be optimistic.
4349   if (M[0] < 0)
4350     BlockElts = BlockSize / EltSz;
4351 
4352   if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
4353     return false;
4354 
4355   for (unsigned i = 0; i < NumElts; ++i) {
4356     if (M[i] < 0)
4357       continue; // ignore UNDEF indices
4358     if ((unsigned)M[i] != (i - i % BlockElts) + (BlockElts - 1 - i % BlockElts))
4359       return false;
4360   }
4361 
4362   return true;
4363 }
4364 
isZIPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4365 static bool isZIPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4366   unsigned NumElts = VT.getVectorNumElements();
4367   WhichResult = (M[0] == 0 ? 0 : 1);
4368   unsigned Idx = WhichResult * NumElts / 2;
4369   for (unsigned i = 0; i != NumElts; i += 2) {
4370     if ((M[i] >= 0 && (unsigned)M[i] != Idx) ||
4371         (M[i + 1] >= 0 && (unsigned)M[i + 1] != Idx + NumElts))
4372       return false;
4373     Idx += 1;
4374   }
4375 
4376   return true;
4377 }
4378 
isUZPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4379 static bool isUZPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4380   unsigned NumElts = VT.getVectorNumElements();
4381   WhichResult = (M[0] == 0 ? 0 : 1);
4382   for (unsigned i = 0; i != NumElts; ++i) {
4383     if (M[i] < 0)
4384       continue; // ignore UNDEF indices
4385     if ((unsigned)M[i] != 2 * i + WhichResult)
4386       return false;
4387   }
4388 
4389   return true;
4390 }
4391 
isTRNMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4392 static bool isTRNMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4393   unsigned NumElts = VT.getVectorNumElements();
4394   WhichResult = (M[0] == 0 ? 0 : 1);
4395   for (unsigned i = 0; i < NumElts; i += 2) {
4396     if ((M[i] >= 0 && (unsigned)M[i] != i + WhichResult) ||
4397         (M[i + 1] >= 0 && (unsigned)M[i + 1] != i + NumElts + WhichResult))
4398       return false;
4399   }
4400   return true;
4401 }
4402 
4403 /// isZIP_v_undef_Mask - Special case of isZIPMask for canonical form of
4404 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4405 /// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
isZIP_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4406 static bool isZIP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4407   unsigned NumElts = VT.getVectorNumElements();
4408   WhichResult = (M[0] == 0 ? 0 : 1);
4409   unsigned Idx = WhichResult * NumElts / 2;
4410   for (unsigned i = 0; i != NumElts; i += 2) {
4411     if ((M[i] >= 0 && (unsigned)M[i] != Idx) ||
4412         (M[i + 1] >= 0 && (unsigned)M[i + 1] != Idx))
4413       return false;
4414     Idx += 1;
4415   }
4416 
4417   return true;
4418 }
4419 
4420 /// isUZP_v_undef_Mask - Special case of isUZPMask for canonical form of
4421 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4422 /// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
isUZP_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4423 static bool isUZP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4424   unsigned Half = VT.getVectorNumElements() / 2;
4425   WhichResult = (M[0] == 0 ? 0 : 1);
4426   for (unsigned j = 0; j != 2; ++j) {
4427     unsigned Idx = WhichResult;
4428     for (unsigned i = 0; i != Half; ++i) {
4429       int MIdx = M[i + j * Half];
4430       if (MIdx >= 0 && (unsigned)MIdx != Idx)
4431         return false;
4432       Idx += 2;
4433     }
4434   }
4435 
4436   return true;
4437 }
4438 
4439 /// isTRN_v_undef_Mask - Special case of isTRNMask for canonical form of
4440 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4441 /// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
isTRN_v_undef_Mask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4442 static bool isTRN_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4443   unsigned NumElts = VT.getVectorNumElements();
4444   WhichResult = (M[0] == 0 ? 0 : 1);
4445   for (unsigned i = 0; i < NumElts; i += 2) {
4446     if ((M[i] >= 0 && (unsigned)M[i] != i + WhichResult) ||
4447         (M[i + 1] >= 0 && (unsigned)M[i + 1] != i + WhichResult))
4448       return false;
4449   }
4450   return true;
4451 }
4452 
isINSMask(ArrayRef<int> M,int NumInputElements,bool & DstIsLeft,int & Anomaly)4453 static bool isINSMask(ArrayRef<int> M, int NumInputElements,
4454                       bool &DstIsLeft, int &Anomaly) {
4455   if (M.size() != static_cast<size_t>(NumInputElements))
4456     return false;
4457 
4458   int NumLHSMatch = 0, NumRHSMatch = 0;
4459   int LastLHSMismatch = -1, LastRHSMismatch = -1;
4460 
4461   for (int i = 0; i < NumInputElements; ++i) {
4462     if (M[i] == -1) {
4463       ++NumLHSMatch;
4464       ++NumRHSMatch;
4465       continue;
4466     }
4467 
4468     if (M[i] == i)
4469       ++NumLHSMatch;
4470     else
4471       LastLHSMismatch = i;
4472 
4473     if (M[i] == i + NumInputElements)
4474       ++NumRHSMatch;
4475     else
4476       LastRHSMismatch = i;
4477   }
4478 
4479   if (NumLHSMatch == NumInputElements - 1) {
4480     DstIsLeft = true;
4481     Anomaly = LastLHSMismatch;
4482     return true;
4483   } else if (NumRHSMatch == NumInputElements - 1) {
4484     DstIsLeft = false;
4485     Anomaly = LastRHSMismatch;
4486     return true;
4487   }
4488 
4489   return false;
4490 }
4491 
isConcatMask(ArrayRef<int> Mask,EVT VT,bool SplitLHS)4492 static bool isConcatMask(ArrayRef<int> Mask, EVT VT, bool SplitLHS) {
4493   if (VT.getSizeInBits() != 128)
4494     return false;
4495 
4496   unsigned NumElts = VT.getVectorNumElements();
4497 
4498   for (int I = 0, E = NumElts / 2; I != E; I++) {
4499     if (Mask[I] != I)
4500       return false;
4501   }
4502 
4503   int Offset = NumElts / 2;
4504   for (int I = NumElts / 2, E = NumElts; I != E; I++) {
4505     if (Mask[I] != I + SplitLHS * Offset)
4506       return false;
4507   }
4508 
4509   return true;
4510 }
4511 
tryFormConcatFromShuffle(SDValue Op,SelectionDAG & DAG)4512 static SDValue tryFormConcatFromShuffle(SDValue Op, SelectionDAG &DAG) {
4513   SDLoc DL(Op);
4514   EVT VT = Op.getValueType();
4515   SDValue V0 = Op.getOperand(0);
4516   SDValue V1 = Op.getOperand(1);
4517   ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Op)->getMask();
4518 
4519   if (VT.getVectorElementType() != V0.getValueType().getVectorElementType() ||
4520       VT.getVectorElementType() != V1.getValueType().getVectorElementType())
4521     return SDValue();
4522 
4523   bool SplitV0 = V0.getValueType().getSizeInBits() == 128;
4524 
4525   if (!isConcatMask(Mask, VT, SplitV0))
4526     return SDValue();
4527 
4528   EVT CastVT = EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(),
4529                                 VT.getVectorNumElements() / 2);
4530   if (SplitV0) {
4531     V0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V0,
4532                      DAG.getConstant(0, MVT::i64));
4533   }
4534   if (V1.getValueType().getSizeInBits() == 128) {
4535     V1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V1,
4536                      DAG.getConstant(0, MVT::i64));
4537   }
4538   return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, V0, V1);
4539 }
4540 
4541 /// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
4542 /// the specified operations to build the shuffle.
GeneratePerfectShuffle(unsigned PFEntry,SDValue LHS,SDValue RHS,SelectionDAG & DAG,SDLoc dl)4543 static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
4544                                       SDValue RHS, SelectionDAG &DAG,
4545                                       SDLoc dl) {
4546   unsigned OpNum = (PFEntry >> 26) & 0x0F;
4547   unsigned LHSID = (PFEntry >> 13) & ((1 << 13) - 1);
4548   unsigned RHSID = (PFEntry >> 0) & ((1 << 13) - 1);
4549 
4550   enum {
4551     OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
4552     OP_VREV,
4553     OP_VDUP0,
4554     OP_VDUP1,
4555     OP_VDUP2,
4556     OP_VDUP3,
4557     OP_VEXT1,
4558     OP_VEXT2,
4559     OP_VEXT3,
4560     OP_VUZPL, // VUZP, left result
4561     OP_VUZPR, // VUZP, right result
4562     OP_VZIPL, // VZIP, left result
4563     OP_VZIPR, // VZIP, right result
4564     OP_VTRNL, // VTRN, left result
4565     OP_VTRNR  // VTRN, right result
4566   };
4567 
4568   if (OpNum == OP_COPY) {
4569     if (LHSID == (1 * 9 + 2) * 9 + 3)
4570       return LHS;
4571     assert(LHSID == ((4 * 9 + 5) * 9 + 6) * 9 + 7 && "Illegal OP_COPY!");
4572     return RHS;
4573   }
4574 
4575   SDValue OpLHS, OpRHS;
4576   OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
4577   OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
4578   EVT VT = OpLHS.getValueType();
4579 
4580   switch (OpNum) {
4581   default:
4582     llvm_unreachable("Unknown shuffle opcode!");
4583   case OP_VREV:
4584     // VREV divides the vector in half and swaps within the half.
4585     if (VT.getVectorElementType() == MVT::i32 ||
4586         VT.getVectorElementType() == MVT::f32)
4587       return DAG.getNode(AArch64ISD::REV64, dl, VT, OpLHS);
4588     // vrev <4 x i16> -> REV32
4589     if (VT.getVectorElementType() == MVT::i16)
4590       return DAG.getNode(AArch64ISD::REV32, dl, VT, OpLHS);
4591     // vrev <4 x i8> -> REV16
4592     assert(VT.getVectorElementType() == MVT::i8);
4593     return DAG.getNode(AArch64ISD::REV16, dl, VT, OpLHS);
4594   case OP_VDUP0:
4595   case OP_VDUP1:
4596   case OP_VDUP2:
4597   case OP_VDUP3: {
4598     EVT EltTy = VT.getVectorElementType();
4599     unsigned Opcode;
4600     if (EltTy == MVT::i8)
4601       Opcode = AArch64ISD::DUPLANE8;
4602     else if (EltTy == MVT::i16)
4603       Opcode = AArch64ISD::DUPLANE16;
4604     else if (EltTy == MVT::i32 || EltTy == MVT::f32)
4605       Opcode = AArch64ISD::DUPLANE32;
4606     else if (EltTy == MVT::i64 || EltTy == MVT::f64)
4607       Opcode = AArch64ISD::DUPLANE64;
4608     else
4609       llvm_unreachable("Invalid vector element type?");
4610 
4611     if (VT.getSizeInBits() == 64)
4612       OpLHS = WidenVector(OpLHS, DAG);
4613     SDValue Lane = DAG.getConstant(OpNum - OP_VDUP0, MVT::i64);
4614     return DAG.getNode(Opcode, dl, VT, OpLHS, Lane);
4615   }
4616   case OP_VEXT1:
4617   case OP_VEXT2:
4618   case OP_VEXT3: {
4619     unsigned Imm = (OpNum - OP_VEXT1 + 1) * getExtFactor(OpLHS);
4620     return DAG.getNode(AArch64ISD::EXT, dl, VT, OpLHS, OpRHS,
4621                        DAG.getConstant(Imm, MVT::i32));
4622   }
4623   case OP_VUZPL:
4624     return DAG.getNode(AArch64ISD::UZP1, dl, DAG.getVTList(VT, VT), OpLHS,
4625                        OpRHS);
4626   case OP_VUZPR:
4627     return DAG.getNode(AArch64ISD::UZP2, dl, DAG.getVTList(VT, VT), OpLHS,
4628                        OpRHS);
4629   case OP_VZIPL:
4630     return DAG.getNode(AArch64ISD::ZIP1, dl, DAG.getVTList(VT, VT), OpLHS,
4631                        OpRHS);
4632   case OP_VZIPR:
4633     return DAG.getNode(AArch64ISD::ZIP2, dl, DAG.getVTList(VT, VT), OpLHS,
4634                        OpRHS);
4635   case OP_VTRNL:
4636     return DAG.getNode(AArch64ISD::TRN1, dl, DAG.getVTList(VT, VT), OpLHS,
4637                        OpRHS);
4638   case OP_VTRNR:
4639     return DAG.getNode(AArch64ISD::TRN2, dl, DAG.getVTList(VT, VT), OpLHS,
4640                        OpRHS);
4641   }
4642 }
4643 
GenerateTBL(SDValue Op,ArrayRef<int> ShuffleMask,SelectionDAG & DAG)4644 static SDValue GenerateTBL(SDValue Op, ArrayRef<int> ShuffleMask,
4645                            SelectionDAG &DAG) {
4646   // Check to see if we can use the TBL instruction.
4647   SDValue V1 = Op.getOperand(0);
4648   SDValue V2 = Op.getOperand(1);
4649   SDLoc DL(Op);
4650 
4651   EVT EltVT = Op.getValueType().getVectorElementType();
4652   unsigned BytesPerElt = EltVT.getSizeInBits() / 8;
4653 
4654   SmallVector<SDValue, 8> TBLMask;
4655   for (int Val : ShuffleMask) {
4656     for (unsigned Byte = 0; Byte < BytesPerElt; ++Byte) {
4657       unsigned Offset = Byte + Val * BytesPerElt;
4658       TBLMask.push_back(DAG.getConstant(Offset, MVT::i32));
4659     }
4660   }
4661 
4662   MVT IndexVT = MVT::v8i8;
4663   unsigned IndexLen = 8;
4664   if (Op.getValueType().getSizeInBits() == 128) {
4665     IndexVT = MVT::v16i8;
4666     IndexLen = 16;
4667   }
4668 
4669   SDValue V1Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V1);
4670   SDValue V2Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V2);
4671 
4672   SDValue Shuffle;
4673   if (V2.getNode()->getOpcode() == ISD::UNDEF) {
4674     if (IndexLen == 8)
4675       V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V1Cst);
4676     Shuffle = DAG.getNode(
4677         ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4678         DAG.getConstant(Intrinsic::aarch64_neon_tbl1, MVT::i32), V1Cst,
4679         DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4680                     makeArrayRef(TBLMask.data(), IndexLen)));
4681   } else {
4682     if (IndexLen == 8) {
4683       V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V2Cst);
4684       Shuffle = DAG.getNode(
4685           ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4686           DAG.getConstant(Intrinsic::aarch64_neon_tbl1, MVT::i32), V1Cst,
4687           DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4688                       makeArrayRef(TBLMask.data(), IndexLen)));
4689     } else {
4690       // FIXME: We cannot, for the moment, emit a TBL2 instruction because we
4691       // cannot currently represent the register constraints on the input
4692       // table registers.
4693       //  Shuffle = DAG.getNode(AArch64ISD::TBL2, DL, IndexVT, V1Cst, V2Cst,
4694       //                   DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4695       //                               &TBLMask[0], IndexLen));
4696       Shuffle = DAG.getNode(
4697           ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4698           DAG.getConstant(Intrinsic::aarch64_neon_tbl2, MVT::i32), V1Cst, V2Cst,
4699           DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4700                       makeArrayRef(TBLMask.data(), IndexLen)));
4701     }
4702   }
4703   return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Shuffle);
4704 }
4705 
getDUPLANEOp(EVT EltType)4706 static unsigned getDUPLANEOp(EVT EltType) {
4707   if (EltType == MVT::i8)
4708     return AArch64ISD::DUPLANE8;
4709   if (EltType == MVT::i16)
4710     return AArch64ISD::DUPLANE16;
4711   if (EltType == MVT::i32 || EltType == MVT::f32)
4712     return AArch64ISD::DUPLANE32;
4713   if (EltType == MVT::i64 || EltType == MVT::f64)
4714     return AArch64ISD::DUPLANE64;
4715 
4716   llvm_unreachable("Invalid vector element type?");
4717 }
4718 
LowerVECTOR_SHUFFLE(SDValue Op,SelectionDAG & DAG) const4719 SDValue AArch64TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op,
4720                                                    SelectionDAG &DAG) const {
4721   SDLoc dl(Op);
4722   EVT VT = Op.getValueType();
4723 
4724   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
4725 
4726   // Convert shuffles that are directly supported on NEON to target-specific
4727   // DAG nodes, instead of keeping them as shuffles and matching them again
4728   // during code selection.  This is more efficient and avoids the possibility
4729   // of inconsistencies between legalization and selection.
4730   ArrayRef<int> ShuffleMask = SVN->getMask();
4731 
4732   SDValue V1 = Op.getOperand(0);
4733   SDValue V2 = Op.getOperand(1);
4734 
4735   if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0],
4736                                        V1.getValueType().getSimpleVT())) {
4737     int Lane = SVN->getSplatIndex();
4738     // If this is undef splat, generate it via "just" vdup, if possible.
4739     if (Lane == -1)
4740       Lane = 0;
4741 
4742     if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR)
4743       return DAG.getNode(AArch64ISD::DUP, dl, V1.getValueType(),
4744                          V1.getOperand(0));
4745     // Test if V1 is a BUILD_VECTOR and the lane being referenced is a non-
4746     // constant. If so, we can just reference the lane's definition directly.
4747     if (V1.getOpcode() == ISD::BUILD_VECTOR &&
4748         !isa<ConstantSDNode>(V1.getOperand(Lane)))
4749       return DAG.getNode(AArch64ISD::DUP, dl, VT, V1.getOperand(Lane));
4750 
4751     // Otherwise, duplicate from the lane of the input vector.
4752     unsigned Opcode = getDUPLANEOp(V1.getValueType().getVectorElementType());
4753 
4754     // SelectionDAGBuilder may have "helpfully" already extracted or conatenated
4755     // to make a vector of the same size as this SHUFFLE. We can ignore the
4756     // extract entirely, and canonicalise the concat using WidenVector.
4757     if (V1.getOpcode() == ISD::EXTRACT_SUBVECTOR) {
4758       Lane += cast<ConstantSDNode>(V1.getOperand(1))->getZExtValue();
4759       V1 = V1.getOperand(0);
4760     } else if (V1.getOpcode() == ISD::CONCAT_VECTORS) {
4761       unsigned Idx = Lane >= (int)VT.getVectorNumElements() / 2;
4762       Lane -= Idx * VT.getVectorNumElements() / 2;
4763       V1 = WidenVector(V1.getOperand(Idx), DAG);
4764     } else if (VT.getSizeInBits() == 64)
4765       V1 = WidenVector(V1, DAG);
4766 
4767     return DAG.getNode(Opcode, dl, VT, V1, DAG.getConstant(Lane, MVT::i64));
4768   }
4769 
4770   if (isREVMask(ShuffleMask, VT, 64))
4771     return DAG.getNode(AArch64ISD::REV64, dl, V1.getValueType(), V1, V2);
4772   if (isREVMask(ShuffleMask, VT, 32))
4773     return DAG.getNode(AArch64ISD::REV32, dl, V1.getValueType(), V1, V2);
4774   if (isREVMask(ShuffleMask, VT, 16))
4775     return DAG.getNode(AArch64ISD::REV16, dl, V1.getValueType(), V1, V2);
4776 
4777   bool ReverseEXT = false;
4778   unsigned Imm;
4779   if (isEXTMask(ShuffleMask, VT, ReverseEXT, Imm)) {
4780     if (ReverseEXT)
4781       std::swap(V1, V2);
4782     Imm *= getExtFactor(V1);
4783     return DAG.getNode(AArch64ISD::EXT, dl, V1.getValueType(), V1, V2,
4784                        DAG.getConstant(Imm, MVT::i32));
4785   } else if (V2->getOpcode() == ISD::UNDEF &&
4786              isSingletonEXTMask(ShuffleMask, VT, Imm)) {
4787     Imm *= getExtFactor(V1);
4788     return DAG.getNode(AArch64ISD::EXT, dl, V1.getValueType(), V1, V1,
4789                        DAG.getConstant(Imm, MVT::i32));
4790   }
4791 
4792   unsigned WhichResult;
4793   if (isZIPMask(ShuffleMask, VT, WhichResult)) {
4794     unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
4795     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4796   }
4797   if (isUZPMask(ShuffleMask, VT, WhichResult)) {
4798     unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
4799     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4800   }
4801   if (isTRNMask(ShuffleMask, VT, WhichResult)) {
4802     unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
4803     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4804   }
4805 
4806   if (isZIP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4807     unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
4808     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4809   }
4810   if (isUZP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4811     unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
4812     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4813   }
4814   if (isTRN_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4815     unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
4816     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4817   }
4818 
4819   SDValue Concat = tryFormConcatFromShuffle(Op, DAG);
4820   if (Concat.getNode())
4821     return Concat;
4822 
4823   bool DstIsLeft;
4824   int Anomaly;
4825   int NumInputElements = V1.getValueType().getVectorNumElements();
4826   if (isINSMask(ShuffleMask, NumInputElements, DstIsLeft, Anomaly)) {
4827     SDValue DstVec = DstIsLeft ? V1 : V2;
4828     SDValue DstLaneV = DAG.getConstant(Anomaly, MVT::i64);
4829 
4830     SDValue SrcVec = V1;
4831     int SrcLane = ShuffleMask[Anomaly];
4832     if (SrcLane >= NumInputElements) {
4833       SrcVec = V2;
4834       SrcLane -= VT.getVectorNumElements();
4835     }
4836     SDValue SrcLaneV = DAG.getConstant(SrcLane, MVT::i64);
4837 
4838     EVT ScalarVT = VT.getVectorElementType();
4839     if (ScalarVT.getSizeInBits() < 32)
4840       ScalarVT = MVT::i32;
4841 
4842     return DAG.getNode(
4843         ISD::INSERT_VECTOR_ELT, dl, VT, DstVec,
4844         DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ScalarVT, SrcVec, SrcLaneV),
4845         DstLaneV);
4846   }
4847 
4848   // If the shuffle is not directly supported and it has 4 elements, use
4849   // the PerfectShuffle-generated table to synthesize it from other shuffles.
4850   unsigned NumElts = VT.getVectorNumElements();
4851   if (NumElts == 4) {
4852     unsigned PFIndexes[4];
4853     for (unsigned i = 0; i != 4; ++i) {
4854       if (ShuffleMask[i] < 0)
4855         PFIndexes[i] = 8;
4856       else
4857         PFIndexes[i] = ShuffleMask[i];
4858     }
4859 
4860     // Compute the index in the perfect shuffle table.
4861     unsigned PFTableIndex = PFIndexes[0] * 9 * 9 * 9 + PFIndexes[1] * 9 * 9 +
4862                             PFIndexes[2] * 9 + PFIndexes[3];
4863     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
4864     unsigned Cost = (PFEntry >> 30);
4865 
4866     if (Cost <= 4)
4867       return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
4868   }
4869 
4870   return GenerateTBL(Op, ShuffleMask, DAG);
4871 }
4872 
resolveBuildVector(BuildVectorSDNode * BVN,APInt & CnstBits,APInt & UndefBits)4873 static bool resolveBuildVector(BuildVectorSDNode *BVN, APInt &CnstBits,
4874                                APInt &UndefBits) {
4875   EVT VT = BVN->getValueType(0);
4876   APInt SplatBits, SplatUndef;
4877   unsigned SplatBitSize;
4878   bool HasAnyUndefs;
4879   if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
4880     unsigned NumSplats = VT.getSizeInBits() / SplatBitSize;
4881 
4882     for (unsigned i = 0; i < NumSplats; ++i) {
4883       CnstBits <<= SplatBitSize;
4884       UndefBits <<= SplatBitSize;
4885       CnstBits |= SplatBits.zextOrTrunc(VT.getSizeInBits());
4886       UndefBits |= (SplatBits ^ SplatUndef).zextOrTrunc(VT.getSizeInBits());
4887     }
4888 
4889     return true;
4890   }
4891 
4892   return false;
4893 }
4894 
LowerVectorAND(SDValue Op,SelectionDAG & DAG) const4895 SDValue AArch64TargetLowering::LowerVectorAND(SDValue Op,
4896                                               SelectionDAG &DAG) const {
4897   BuildVectorSDNode *BVN =
4898       dyn_cast<BuildVectorSDNode>(Op.getOperand(1).getNode());
4899   SDValue LHS = Op.getOperand(0);
4900   SDLoc dl(Op);
4901   EVT VT = Op.getValueType();
4902 
4903   if (!BVN)
4904     return Op;
4905 
4906   APInt CnstBits(VT.getSizeInBits(), 0);
4907   APInt UndefBits(VT.getSizeInBits(), 0);
4908   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
4909     // We only have BIC vector immediate instruction, which is and-not.
4910     CnstBits = ~CnstBits;
4911 
4912     // We make use of a little bit of goto ickiness in order to avoid having to
4913     // duplicate the immediate matching logic for the undef toggled case.
4914     bool SecondTry = false;
4915   AttemptModImm:
4916 
4917     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
4918       CnstBits = CnstBits.zextOrTrunc(64);
4919       uint64_t CnstVal = CnstBits.getZExtValue();
4920 
4921       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
4922         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
4923         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4924         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4925                                   DAG.getConstant(CnstVal, MVT::i32),
4926                                   DAG.getConstant(0, MVT::i32));
4927         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4928       }
4929 
4930       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
4931         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
4932         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4933         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4934                                   DAG.getConstant(CnstVal, MVT::i32),
4935                                   DAG.getConstant(8, MVT::i32));
4936         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4937       }
4938 
4939       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
4940         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
4941         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4942         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4943                                   DAG.getConstant(CnstVal, MVT::i32),
4944                                   DAG.getConstant(16, MVT::i32));
4945         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4946       }
4947 
4948       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
4949         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
4950         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4951         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4952                                   DAG.getConstant(CnstVal, MVT::i32),
4953                                   DAG.getConstant(24, MVT::i32));
4954         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4955       }
4956 
4957       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
4958         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
4959         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
4960         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4961                                   DAG.getConstant(CnstVal, MVT::i32),
4962                                   DAG.getConstant(0, MVT::i32));
4963         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4964       }
4965 
4966       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
4967         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
4968         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
4969         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4970                                   DAG.getConstant(CnstVal, MVT::i32),
4971                                   DAG.getConstant(8, MVT::i32));
4972         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4973       }
4974     }
4975 
4976     if (SecondTry)
4977       goto FailedModImm;
4978     SecondTry = true;
4979     CnstBits = ~UndefBits;
4980     goto AttemptModImm;
4981   }
4982 
4983 // We can always fall back to a non-immediate AND.
4984 FailedModImm:
4985   return Op;
4986 }
4987 
4988 // Specialized code to quickly find if PotentialBVec is a BuildVector that
4989 // consists of only the same constant int value, returned in reference arg
4990 // ConstVal
isAllConstantBuildVector(const SDValue & PotentialBVec,uint64_t & ConstVal)4991 static bool isAllConstantBuildVector(const SDValue &PotentialBVec,
4992                                      uint64_t &ConstVal) {
4993   BuildVectorSDNode *Bvec = dyn_cast<BuildVectorSDNode>(PotentialBVec);
4994   if (!Bvec)
4995     return false;
4996   ConstantSDNode *FirstElt = dyn_cast<ConstantSDNode>(Bvec->getOperand(0));
4997   if (!FirstElt)
4998     return false;
4999   EVT VT = Bvec->getValueType(0);
5000   unsigned NumElts = VT.getVectorNumElements();
5001   for (unsigned i = 1; i < NumElts; ++i)
5002     if (dyn_cast<ConstantSDNode>(Bvec->getOperand(i)) != FirstElt)
5003       return false;
5004   ConstVal = FirstElt->getZExtValue();
5005   return true;
5006 }
5007 
getIntrinsicID(const SDNode * N)5008 static unsigned getIntrinsicID(const SDNode *N) {
5009   unsigned Opcode = N->getOpcode();
5010   switch (Opcode) {
5011   default:
5012     return Intrinsic::not_intrinsic;
5013   case ISD::INTRINSIC_WO_CHAIN: {
5014     unsigned IID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
5015     if (IID < Intrinsic::num_intrinsics)
5016       return IID;
5017     return Intrinsic::not_intrinsic;
5018   }
5019   }
5020 }
5021 
5022 // Attempt to form a vector S[LR]I from (or (and X, BvecC1), (lsl Y, C2)),
5023 // to (SLI X, Y, C2), where X and Y have matching vector types, BvecC1 is a
5024 // BUILD_VECTORs with constant element C1, C2 is a constant, and C1 == ~C2.
5025 // Also, logical shift right -> sri, with the same structure.
tryLowerToSLI(SDNode * N,SelectionDAG & DAG)5026 static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
5027   EVT VT = N->getValueType(0);
5028 
5029   if (!VT.isVector())
5030     return SDValue();
5031 
5032   SDLoc DL(N);
5033 
5034   // Is the first op an AND?
5035   const SDValue And = N->getOperand(0);
5036   if (And.getOpcode() != ISD::AND)
5037     return SDValue();
5038 
5039   // Is the second op an shl or lshr?
5040   SDValue Shift = N->getOperand(1);
5041   // This will have been turned into: AArch64ISD::VSHL vector, #shift
5042   // or AArch64ISD::VLSHR vector, #shift
5043   unsigned ShiftOpc = Shift.getOpcode();
5044   if ((ShiftOpc != AArch64ISD::VSHL && ShiftOpc != AArch64ISD::VLSHR))
5045     return SDValue();
5046   bool IsShiftRight = ShiftOpc == AArch64ISD::VLSHR;
5047 
5048   // Is the shift amount constant?
5049   ConstantSDNode *C2node = dyn_cast<ConstantSDNode>(Shift.getOperand(1));
5050   if (!C2node)
5051     return SDValue();
5052 
5053   // Is the and mask vector all constant?
5054   uint64_t C1;
5055   if (!isAllConstantBuildVector(And.getOperand(1), C1))
5056     return SDValue();
5057 
5058   // Is C1 == ~C2, taking into account how much one can shift elements of a
5059   // particular size?
5060   uint64_t C2 = C2node->getZExtValue();
5061   unsigned ElemSizeInBits = VT.getVectorElementType().getSizeInBits();
5062   if (C2 > ElemSizeInBits)
5063     return SDValue();
5064   unsigned ElemMask = (1 << ElemSizeInBits) - 1;
5065   if ((C1 & ElemMask) != (~C2 & ElemMask))
5066     return SDValue();
5067 
5068   SDValue X = And.getOperand(0);
5069   SDValue Y = Shift.getOperand(0);
5070 
5071   unsigned Intrin =
5072       IsShiftRight ? Intrinsic::aarch64_neon_vsri : Intrinsic::aarch64_neon_vsli;
5073   SDValue ResultSLI =
5074       DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5075                   DAG.getConstant(Intrin, MVT::i32), X, Y, Shift.getOperand(1));
5076 
5077   DEBUG(dbgs() << "aarch64-lower: transformed: \n");
5078   DEBUG(N->dump(&DAG));
5079   DEBUG(dbgs() << "into: \n");
5080   DEBUG(ResultSLI->dump(&DAG));
5081 
5082   ++NumShiftInserts;
5083   return ResultSLI;
5084 }
5085 
LowerVectorOR(SDValue Op,SelectionDAG & DAG) const5086 SDValue AArch64TargetLowering::LowerVectorOR(SDValue Op,
5087                                              SelectionDAG &DAG) const {
5088   // Attempt to form a vector S[LR]I from (or (and X, C1), (lsl Y, C2))
5089   if (EnableAArch64SlrGeneration) {
5090     SDValue Res = tryLowerToSLI(Op.getNode(), DAG);
5091     if (Res.getNode())
5092       return Res;
5093   }
5094 
5095   BuildVectorSDNode *BVN =
5096       dyn_cast<BuildVectorSDNode>(Op.getOperand(0).getNode());
5097   SDValue LHS = Op.getOperand(1);
5098   SDLoc dl(Op);
5099   EVT VT = Op.getValueType();
5100 
5101   // OR commutes, so try swapping the operands.
5102   if (!BVN) {
5103     LHS = Op.getOperand(0);
5104     BVN = dyn_cast<BuildVectorSDNode>(Op.getOperand(1).getNode());
5105   }
5106   if (!BVN)
5107     return Op;
5108 
5109   APInt CnstBits(VT.getSizeInBits(), 0);
5110   APInt UndefBits(VT.getSizeInBits(), 0);
5111   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
5112     // We make use of a little bit of goto ickiness in order to avoid having to
5113     // duplicate the immediate matching logic for the undef toggled case.
5114     bool SecondTry = false;
5115   AttemptModImm:
5116 
5117     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
5118       CnstBits = CnstBits.zextOrTrunc(64);
5119       uint64_t CnstVal = CnstBits.getZExtValue();
5120 
5121       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5122         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5123         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5124         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5125                                   DAG.getConstant(CnstVal, MVT::i32),
5126                                   DAG.getConstant(0, MVT::i32));
5127         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5128       }
5129 
5130       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5131         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5132         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5133         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5134                                   DAG.getConstant(CnstVal, MVT::i32),
5135                                   DAG.getConstant(8, MVT::i32));
5136         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5137       }
5138 
5139       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5140         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5141         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5142         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5143                                   DAG.getConstant(CnstVal, MVT::i32),
5144                                   DAG.getConstant(16, MVT::i32));
5145         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5146       }
5147 
5148       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5149         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5150         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5151         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5152                                   DAG.getConstant(CnstVal, MVT::i32),
5153                                   DAG.getConstant(24, MVT::i32));
5154         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5155       }
5156 
5157       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5158         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5159         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5160         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5161                                   DAG.getConstant(CnstVal, MVT::i32),
5162                                   DAG.getConstant(0, MVT::i32));
5163         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5164       }
5165 
5166       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5167         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5168         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5169         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5170                                   DAG.getConstant(CnstVal, MVT::i32),
5171                                   DAG.getConstant(8, MVT::i32));
5172         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5173       }
5174     }
5175 
5176     if (SecondTry)
5177       goto FailedModImm;
5178     SecondTry = true;
5179     CnstBits = UndefBits;
5180     goto AttemptModImm;
5181   }
5182 
5183 // We can always fall back to a non-immediate OR.
5184 FailedModImm:
5185   return Op;
5186 }
5187 
5188 // Normalize the operands of BUILD_VECTOR. The value of constant operands will
5189 // be truncated to fit element width.
NormalizeBuildVector(SDValue Op,SelectionDAG & DAG)5190 static SDValue NormalizeBuildVector(SDValue Op,
5191                                     SelectionDAG &DAG) {
5192   assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
5193   SDLoc dl(Op);
5194   EVT VT = Op.getValueType();
5195   EVT EltTy= VT.getVectorElementType();
5196 
5197   if (EltTy.isFloatingPoint() || EltTy.getSizeInBits() > 16)
5198     return Op;
5199 
5200   SmallVector<SDValue, 16> Ops;
5201   for (unsigned I = 0, E = VT.getVectorNumElements(); I != E; ++I) {
5202     SDValue Lane = Op.getOperand(I);
5203     if (Lane.getOpcode() == ISD::Constant) {
5204       APInt LowBits(EltTy.getSizeInBits(),
5205                     cast<ConstantSDNode>(Lane)->getZExtValue());
5206       Lane = DAG.getConstant(LowBits.getZExtValue(), MVT::i32);
5207     }
5208     Ops.push_back(Lane);
5209   }
5210   return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
5211 }
5212 
LowerBUILD_VECTOR(SDValue Op,SelectionDAG & DAG) const5213 SDValue AArch64TargetLowering::LowerBUILD_VECTOR(SDValue Op,
5214                                                  SelectionDAG &DAG) const {
5215   SDLoc dl(Op);
5216   EVT VT = Op.getValueType();
5217   Op = NormalizeBuildVector(Op, DAG);
5218   BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
5219 
5220   APInt CnstBits(VT.getSizeInBits(), 0);
5221   APInt UndefBits(VT.getSizeInBits(), 0);
5222   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
5223     // We make use of a little bit of goto ickiness in order to avoid having to
5224     // duplicate the immediate matching logic for the undef toggled case.
5225     bool SecondTry = false;
5226   AttemptModImm:
5227 
5228     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
5229       CnstBits = CnstBits.zextOrTrunc(64);
5230       uint64_t CnstVal = CnstBits.getZExtValue();
5231 
5232       // Certain magic vector constants (used to express things like NOT
5233       // and NEG) are passed through unmodified.  This allows codegen patterns
5234       // for these operations to match.  Special-purpose patterns will lower
5235       // these immediates to MOVIs if it proves necessary.
5236       if (VT.isInteger() && (CnstVal == 0 || CnstVal == ~0ULL))
5237         return Op;
5238 
5239       // The many faces of MOVI...
5240       if (AArch64_AM::isAdvSIMDModImmType10(CnstVal)) {
5241         CnstVal = AArch64_AM::encodeAdvSIMDModImmType10(CnstVal);
5242         if (VT.getSizeInBits() == 128) {
5243           SDValue Mov = DAG.getNode(AArch64ISD::MOVIedit, dl, MVT::v2i64,
5244                                     DAG.getConstant(CnstVal, MVT::i32));
5245           return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5246         }
5247 
5248         // Support the V64 version via subregister insertion.
5249         SDValue Mov = DAG.getNode(AArch64ISD::MOVIedit, dl, MVT::f64,
5250                                   DAG.getConstant(CnstVal, MVT::i32));
5251         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5252       }
5253 
5254       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5255         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5256         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5257         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5258                                   DAG.getConstant(CnstVal, MVT::i32),
5259                                   DAG.getConstant(0, MVT::i32));
5260         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5261       }
5262 
5263       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5264         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5265         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5266         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5267                                   DAG.getConstant(CnstVal, MVT::i32),
5268                                   DAG.getConstant(8, MVT::i32));
5269         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5270       }
5271 
5272       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5273         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5274         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5275         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5276                                   DAG.getConstant(CnstVal, MVT::i32),
5277                                   DAG.getConstant(16, MVT::i32));
5278         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5279       }
5280 
5281       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5282         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5283         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5284         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5285                                   DAG.getConstant(CnstVal, MVT::i32),
5286                                   DAG.getConstant(24, MVT::i32));
5287         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5288       }
5289 
5290       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5291         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5292         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5293         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5294                                   DAG.getConstant(CnstVal, MVT::i32),
5295                                   DAG.getConstant(0, MVT::i32));
5296         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5297       }
5298 
5299       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5300         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5301         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5302         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5303                                   DAG.getConstant(CnstVal, MVT::i32),
5304                                   DAG.getConstant(8, MVT::i32));
5305         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5306       }
5307 
5308       if (AArch64_AM::isAdvSIMDModImmType7(CnstVal)) {
5309         CnstVal = AArch64_AM::encodeAdvSIMDModImmType7(CnstVal);
5310         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5311         SDValue Mov = DAG.getNode(AArch64ISD::MOVImsl, dl, MovTy,
5312                                   DAG.getConstant(CnstVal, MVT::i32),
5313                                   DAG.getConstant(264, MVT::i32));
5314         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5315       }
5316 
5317       if (AArch64_AM::isAdvSIMDModImmType8(CnstVal)) {
5318         CnstVal = AArch64_AM::encodeAdvSIMDModImmType8(CnstVal);
5319         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5320         SDValue Mov = DAG.getNode(AArch64ISD::MOVImsl, dl, MovTy,
5321                                   DAG.getConstant(CnstVal, MVT::i32),
5322                                   DAG.getConstant(272, MVT::i32));
5323         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5324       }
5325 
5326       if (AArch64_AM::isAdvSIMDModImmType9(CnstVal)) {
5327         CnstVal = AArch64_AM::encodeAdvSIMDModImmType9(CnstVal);
5328         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v16i8 : MVT::v8i8;
5329         SDValue Mov = DAG.getNode(AArch64ISD::MOVI, dl, MovTy,
5330                                   DAG.getConstant(CnstVal, MVT::i32));
5331         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5332       }
5333 
5334       // The few faces of FMOV...
5335       if (AArch64_AM::isAdvSIMDModImmType11(CnstVal)) {
5336         CnstVal = AArch64_AM::encodeAdvSIMDModImmType11(CnstVal);
5337         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4f32 : MVT::v2f32;
5338         SDValue Mov = DAG.getNode(AArch64ISD::FMOV, dl, MovTy,
5339                                   DAG.getConstant(CnstVal, MVT::i32));
5340         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5341       }
5342 
5343       if (AArch64_AM::isAdvSIMDModImmType12(CnstVal) &&
5344           VT.getSizeInBits() == 128) {
5345         CnstVal = AArch64_AM::encodeAdvSIMDModImmType12(CnstVal);
5346         SDValue Mov = DAG.getNode(AArch64ISD::FMOV, dl, MVT::v2f64,
5347                                   DAG.getConstant(CnstVal, MVT::i32));
5348         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5349       }
5350 
5351       // The many faces of MVNI...
5352       CnstVal = ~CnstVal;
5353       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5354         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5355         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5356         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5357                                   DAG.getConstant(CnstVal, MVT::i32),
5358                                   DAG.getConstant(0, MVT::i32));
5359         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5360       }
5361 
5362       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5363         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5364         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5365         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5366                                   DAG.getConstant(CnstVal, MVT::i32),
5367                                   DAG.getConstant(8, MVT::i32));
5368         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5369       }
5370 
5371       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5372         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5373         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5374         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5375                                   DAG.getConstant(CnstVal, MVT::i32),
5376                                   DAG.getConstant(16, MVT::i32));
5377         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5378       }
5379 
5380       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5381         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5382         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5383         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5384                                   DAG.getConstant(CnstVal, MVT::i32),
5385                                   DAG.getConstant(24, MVT::i32));
5386         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5387       }
5388 
5389       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5390         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5391         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5392         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5393                                   DAG.getConstant(CnstVal, MVT::i32),
5394                                   DAG.getConstant(0, MVT::i32));
5395         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5396       }
5397 
5398       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5399         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5400         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5401         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5402                                   DAG.getConstant(CnstVal, MVT::i32),
5403                                   DAG.getConstant(8, MVT::i32));
5404         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5405       }
5406 
5407       if (AArch64_AM::isAdvSIMDModImmType7(CnstVal)) {
5408         CnstVal = AArch64_AM::encodeAdvSIMDModImmType7(CnstVal);
5409         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5410         SDValue Mov = DAG.getNode(AArch64ISD::MVNImsl, dl, MovTy,
5411                                   DAG.getConstant(CnstVal, MVT::i32),
5412                                   DAG.getConstant(264, MVT::i32));
5413         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5414       }
5415 
5416       if (AArch64_AM::isAdvSIMDModImmType8(CnstVal)) {
5417         CnstVal = AArch64_AM::encodeAdvSIMDModImmType8(CnstVal);
5418         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5419         SDValue Mov = DAG.getNode(AArch64ISD::MVNImsl, dl, MovTy,
5420                                   DAG.getConstant(CnstVal, MVT::i32),
5421                                   DAG.getConstant(272, MVT::i32));
5422         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5423       }
5424     }
5425 
5426     if (SecondTry)
5427       goto FailedModImm;
5428     SecondTry = true;
5429     CnstBits = UndefBits;
5430     goto AttemptModImm;
5431   }
5432 FailedModImm:
5433 
5434   // Scan through the operands to find some interesting properties we can
5435   // exploit:
5436   //   1) If only one value is used, we can use a DUP, or
5437   //   2) if only the low element is not undef, we can just insert that, or
5438   //   3) if only one constant value is used (w/ some non-constant lanes),
5439   //      we can splat the constant value into the whole vector then fill
5440   //      in the non-constant lanes.
5441   //   4) FIXME: If different constant values are used, but we can intelligently
5442   //             select the values we'll be overwriting for the non-constant
5443   //             lanes such that we can directly materialize the vector
5444   //             some other way (MOVI, e.g.), we can be sneaky.
5445   unsigned NumElts = VT.getVectorNumElements();
5446   bool isOnlyLowElement = true;
5447   bool usesOnlyOneValue = true;
5448   bool usesOnlyOneConstantValue = true;
5449   bool isConstant = true;
5450   unsigned NumConstantLanes = 0;
5451   SDValue Value;
5452   SDValue ConstantValue;
5453   for (unsigned i = 0; i < NumElts; ++i) {
5454     SDValue V = Op.getOperand(i);
5455     if (V.getOpcode() == ISD::UNDEF)
5456       continue;
5457     if (i > 0)
5458       isOnlyLowElement = false;
5459     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
5460       isConstant = false;
5461 
5462     if (isa<ConstantSDNode>(V) || isa<ConstantFPSDNode>(V)) {
5463       ++NumConstantLanes;
5464       if (!ConstantValue.getNode())
5465         ConstantValue = V;
5466       else if (ConstantValue != V)
5467         usesOnlyOneConstantValue = false;
5468     }
5469 
5470     if (!Value.getNode())
5471       Value = V;
5472     else if (V != Value)
5473       usesOnlyOneValue = false;
5474   }
5475 
5476   if (!Value.getNode())
5477     return DAG.getUNDEF(VT);
5478 
5479   if (isOnlyLowElement)
5480     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
5481 
5482   // Use DUP for non-constant splats.  For f32 constant splats, reduce to
5483   // i32 and try again.
5484   if (usesOnlyOneValue) {
5485     if (!isConstant) {
5486       if (Value.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
5487           Value.getValueType() != VT)
5488         return DAG.getNode(AArch64ISD::DUP, dl, VT, Value);
5489 
5490       // This is actually a DUPLANExx operation, which keeps everything vectory.
5491 
5492       // DUPLANE works on 128-bit vectors, widen it if necessary.
5493       SDValue Lane = Value.getOperand(1);
5494       Value = Value.getOperand(0);
5495       if (Value.getValueType().getSizeInBits() == 64)
5496         Value = WidenVector(Value, DAG);
5497 
5498       unsigned Opcode = getDUPLANEOp(VT.getVectorElementType());
5499       return DAG.getNode(Opcode, dl, VT, Value, Lane);
5500     }
5501 
5502     if (VT.getVectorElementType().isFloatingPoint()) {
5503       SmallVector<SDValue, 8> Ops;
5504       MVT NewType =
5505           (VT.getVectorElementType() == MVT::f32) ? MVT::i32 : MVT::i64;
5506       for (unsigned i = 0; i < NumElts; ++i)
5507         Ops.push_back(DAG.getNode(ISD::BITCAST, dl, NewType, Op.getOperand(i)));
5508       EVT VecVT = EVT::getVectorVT(*DAG.getContext(), NewType, NumElts);
5509       SDValue Val = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, Ops);
5510       Val = LowerBUILD_VECTOR(Val, DAG);
5511       if (Val.getNode())
5512         return DAG.getNode(ISD::BITCAST, dl, VT, Val);
5513     }
5514   }
5515 
5516   // If there was only one constant value used and for more than one lane,
5517   // start by splatting that value, then replace the non-constant lanes. This
5518   // is better than the default, which will perform a separate initialization
5519   // for each lane.
5520   if (NumConstantLanes > 0 && usesOnlyOneConstantValue) {
5521     SDValue Val = DAG.getNode(AArch64ISD::DUP, dl, VT, ConstantValue);
5522     // Now insert the non-constant lanes.
5523     for (unsigned i = 0; i < NumElts; ++i) {
5524       SDValue V = Op.getOperand(i);
5525       SDValue LaneIdx = DAG.getConstant(i, MVT::i64);
5526       if (!isa<ConstantSDNode>(V) && !isa<ConstantFPSDNode>(V)) {
5527         // Note that type legalization likely mucked about with the VT of the
5528         // source operand, so we may have to convert it here before inserting.
5529         Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Val, V, LaneIdx);
5530       }
5531     }
5532     return Val;
5533   }
5534 
5535   // If all elements are constants and the case above didn't get hit, fall back
5536   // to the default expansion, which will generate a load from the constant
5537   // pool.
5538   if (isConstant)
5539     return SDValue();
5540 
5541   // Empirical tests suggest this is rarely worth it for vectors of length <= 2.
5542   if (NumElts >= 4) {
5543     SDValue shuffle = ReconstructShuffle(Op, DAG);
5544     if (shuffle != SDValue())
5545       return shuffle;
5546   }
5547 
5548   // If all else fails, just use a sequence of INSERT_VECTOR_ELT when we
5549   // know the default expansion would otherwise fall back on something even
5550   // worse. For a vector with one or two non-undef values, that's
5551   // scalar_to_vector for the elements followed by a shuffle (provided the
5552   // shuffle is valid for the target) and materialization element by element
5553   // on the stack followed by a load for everything else.
5554   if (!isConstant && !usesOnlyOneValue) {
5555     SDValue Vec = DAG.getUNDEF(VT);
5556     SDValue Op0 = Op.getOperand(0);
5557     unsigned ElemSize = VT.getVectorElementType().getSizeInBits();
5558     unsigned i = 0;
5559     // For 32 and 64 bit types, use INSERT_SUBREG for lane zero to
5560     // a) Avoid a RMW dependency on the full vector register, and
5561     // b) Allow the register coalescer to fold away the copy if the
5562     //    value is already in an S or D register.
5563     if (Op0.getOpcode() != ISD::UNDEF && (ElemSize == 32 || ElemSize == 64)) {
5564       unsigned SubIdx = ElemSize == 32 ? AArch64::ssub : AArch64::dsub;
5565       MachineSDNode *N =
5566           DAG.getMachineNode(TargetOpcode::INSERT_SUBREG, dl, VT, Vec, Op0,
5567                              DAG.getTargetConstant(SubIdx, MVT::i32));
5568       Vec = SDValue(N, 0);
5569       ++i;
5570     }
5571     for (; i < NumElts; ++i) {
5572       SDValue V = Op.getOperand(i);
5573       if (V.getOpcode() == ISD::UNDEF)
5574         continue;
5575       SDValue LaneIdx = DAG.getConstant(i, MVT::i64);
5576       Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Vec, V, LaneIdx);
5577     }
5578     return Vec;
5579   }
5580 
5581   // Just use the default expansion. We failed to find a better alternative.
5582   return SDValue();
5583 }
5584 
LowerINSERT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG) const5585 SDValue AArch64TargetLowering::LowerINSERT_VECTOR_ELT(SDValue Op,
5586                                                       SelectionDAG &DAG) const {
5587   assert(Op.getOpcode() == ISD::INSERT_VECTOR_ELT && "Unknown opcode!");
5588 
5589   // Check for non-constant lane.
5590   if (!isa<ConstantSDNode>(Op.getOperand(2)))
5591     return SDValue();
5592 
5593   EVT VT = Op.getOperand(0).getValueType();
5594 
5595   // Insertion/extraction are legal for V128 types.
5596   if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32 ||
5597       VT == MVT::v2i64 || VT == MVT::v4f32 || VT == MVT::v2f64)
5598     return Op;
5599 
5600   if (VT != MVT::v8i8 && VT != MVT::v4i16 && VT != MVT::v2i32 &&
5601       VT != MVT::v1i64 && VT != MVT::v2f32)
5602     return SDValue();
5603 
5604   // For V64 types, we perform insertion by expanding the value
5605   // to a V128 type and perform the insertion on that.
5606   SDLoc DL(Op);
5607   SDValue WideVec = WidenVector(Op.getOperand(0), DAG);
5608   EVT WideTy = WideVec.getValueType();
5609 
5610   SDValue Node = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, WideTy, WideVec,
5611                              Op.getOperand(1), Op.getOperand(2));
5612   // Re-narrow the resultant vector.
5613   return NarrowVector(Node, DAG);
5614 }
5615 
5616 SDValue
LowerEXTRACT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG) const5617 AArch64TargetLowering::LowerEXTRACT_VECTOR_ELT(SDValue Op,
5618                                                SelectionDAG &DAG) const {
5619   assert(Op.getOpcode() == ISD::EXTRACT_VECTOR_ELT && "Unknown opcode!");
5620 
5621   // Check for non-constant lane.
5622   if (!isa<ConstantSDNode>(Op.getOperand(1)))
5623     return SDValue();
5624 
5625   EVT VT = Op.getOperand(0).getValueType();
5626 
5627   // Insertion/extraction are legal for V128 types.
5628   if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32 ||
5629       VT == MVT::v2i64 || VT == MVT::v4f32 || VT == MVT::v2f64)
5630     return Op;
5631 
5632   if (VT != MVT::v8i8 && VT != MVT::v4i16 && VT != MVT::v2i32 &&
5633       VT != MVT::v1i64 && VT != MVT::v2f32)
5634     return SDValue();
5635 
5636   // For V64 types, we perform extraction by expanding the value
5637   // to a V128 type and perform the extraction on that.
5638   SDLoc DL(Op);
5639   SDValue WideVec = WidenVector(Op.getOperand(0), DAG);
5640   EVT WideTy = WideVec.getValueType();
5641 
5642   EVT ExtrTy = WideTy.getVectorElementType();
5643   if (ExtrTy == MVT::i16 || ExtrTy == MVT::i8)
5644     ExtrTy = MVT::i32;
5645 
5646   // For extractions, we just return the result directly.
5647   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ExtrTy, WideVec,
5648                      Op.getOperand(1));
5649 }
5650 
LowerEXTRACT_SUBVECTOR(SDValue Op,SelectionDAG & DAG) const5651 SDValue AArch64TargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
5652                                                       SelectionDAG &DAG) const {
5653   EVT VT = Op.getOperand(0).getValueType();
5654   SDLoc dl(Op);
5655   // Just in case...
5656   if (!VT.isVector())
5657     return SDValue();
5658 
5659   ConstantSDNode *Cst = dyn_cast<ConstantSDNode>(Op.getOperand(1));
5660   if (!Cst)
5661     return SDValue();
5662   unsigned Val = Cst->getZExtValue();
5663 
5664   unsigned Size = Op.getValueType().getSizeInBits();
5665   if (Val == 0) {
5666     switch (Size) {
5667     case 8:
5668       return DAG.getTargetExtractSubreg(AArch64::bsub, dl, Op.getValueType(),
5669                                         Op.getOperand(0));
5670     case 16:
5671       return DAG.getTargetExtractSubreg(AArch64::hsub, dl, Op.getValueType(),
5672                                         Op.getOperand(0));
5673     case 32:
5674       return DAG.getTargetExtractSubreg(AArch64::ssub, dl, Op.getValueType(),
5675                                         Op.getOperand(0));
5676     case 64:
5677       return DAG.getTargetExtractSubreg(AArch64::dsub, dl, Op.getValueType(),
5678                                         Op.getOperand(0));
5679     default:
5680       llvm_unreachable("Unexpected vector type in extract_subvector!");
5681     }
5682   }
5683   // If this is extracting the upper 64-bits of a 128-bit vector, we match
5684   // that directly.
5685   if (Size == 64 && Val * VT.getVectorElementType().getSizeInBits() == 64)
5686     return Op;
5687 
5688   return SDValue();
5689 }
5690 
isShuffleMaskLegal(const SmallVectorImpl<int> & M,EVT VT) const5691 bool AArch64TargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
5692                                                EVT VT) const {
5693   if (VT.getVectorNumElements() == 4 &&
5694       (VT.is128BitVector() || VT.is64BitVector())) {
5695     unsigned PFIndexes[4];
5696     for (unsigned i = 0; i != 4; ++i) {
5697       if (M[i] < 0)
5698         PFIndexes[i] = 8;
5699       else
5700         PFIndexes[i] = M[i];
5701     }
5702 
5703     // Compute the index in the perfect shuffle table.
5704     unsigned PFTableIndex = PFIndexes[0] * 9 * 9 * 9 + PFIndexes[1] * 9 * 9 +
5705                             PFIndexes[2] * 9 + PFIndexes[3];
5706     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
5707     unsigned Cost = (PFEntry >> 30);
5708 
5709     if (Cost <= 4)
5710       return true;
5711   }
5712 
5713   bool DummyBool;
5714   int DummyInt;
5715   unsigned DummyUnsigned;
5716 
5717   return (ShuffleVectorSDNode::isSplatMask(&M[0], VT) || isREVMask(M, VT, 64) ||
5718           isREVMask(M, VT, 32) || isREVMask(M, VT, 16) ||
5719           isEXTMask(M, VT, DummyBool, DummyUnsigned) ||
5720           // isTBLMask(M, VT) || // FIXME: Port TBL support from ARM.
5721           isTRNMask(M, VT, DummyUnsigned) || isUZPMask(M, VT, DummyUnsigned) ||
5722           isZIPMask(M, VT, DummyUnsigned) ||
5723           isTRN_v_undef_Mask(M, VT, DummyUnsigned) ||
5724           isUZP_v_undef_Mask(M, VT, DummyUnsigned) ||
5725           isZIP_v_undef_Mask(M, VT, DummyUnsigned) ||
5726           isINSMask(M, VT.getVectorNumElements(), DummyBool, DummyInt) ||
5727           isConcatMask(M, VT, VT.getSizeInBits() == 128));
5728 }
5729 
5730 /// getVShiftImm - Check if this is a valid build_vector for the immediate
5731 /// operand of a vector shift operation, where all the elements of the
5732 /// build_vector must have the same constant integer value.
getVShiftImm(SDValue Op,unsigned ElementBits,int64_t & Cnt)5733 static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
5734   // Ignore bit_converts.
5735   while (Op.getOpcode() == ISD::BITCAST)
5736     Op = Op.getOperand(0);
5737   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
5738   APInt SplatBits, SplatUndef;
5739   unsigned SplatBitSize;
5740   bool HasAnyUndefs;
5741   if (!BVN || !BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
5742                                     HasAnyUndefs, ElementBits) ||
5743       SplatBitSize > ElementBits)
5744     return false;
5745   Cnt = SplatBits.getSExtValue();
5746   return true;
5747 }
5748 
5749 /// isVShiftLImm - Check if this is a valid build_vector for the immediate
5750 /// operand of a vector shift left operation.  That value must be in the range:
5751 ///   0 <= Value < ElementBits for a left shift; or
5752 ///   0 <= Value <= ElementBits for a long left shift.
isVShiftLImm(SDValue Op,EVT VT,bool isLong,int64_t & Cnt)5753 static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
5754   assert(VT.isVector() && "vector shift count is not a vector type");
5755   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
5756   if (!getVShiftImm(Op, ElementBits, Cnt))
5757     return false;
5758   return (Cnt >= 0 && (isLong ? Cnt - 1 : Cnt) < ElementBits);
5759 }
5760 
5761 /// isVShiftRImm - Check if this is a valid build_vector for the immediate
5762 /// operand of a vector shift right operation.  For a shift opcode, the value
5763 /// is positive, but for an intrinsic the value count must be negative. The
5764 /// absolute value must be in the range:
5765 ///   1 <= |Value| <= ElementBits for a right shift; or
5766 ///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
isVShiftRImm(SDValue Op,EVT VT,bool isNarrow,bool isIntrinsic,int64_t & Cnt)5767 static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
5768                          int64_t &Cnt) {
5769   assert(VT.isVector() && "vector shift count is not a vector type");
5770   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
5771   if (!getVShiftImm(Op, ElementBits, Cnt))
5772     return false;
5773   if (isIntrinsic)
5774     Cnt = -Cnt;
5775   return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits / 2 : ElementBits));
5776 }
5777 
LowerVectorSRA_SRL_SHL(SDValue Op,SelectionDAG & DAG) const5778 SDValue AArch64TargetLowering::LowerVectorSRA_SRL_SHL(SDValue Op,
5779                                                       SelectionDAG &DAG) const {
5780   EVT VT = Op.getValueType();
5781   SDLoc DL(Op);
5782   int64_t Cnt;
5783 
5784   if (!Op.getOperand(1).getValueType().isVector())
5785     return Op;
5786   unsigned EltSize = VT.getVectorElementType().getSizeInBits();
5787 
5788   switch (Op.getOpcode()) {
5789   default:
5790     llvm_unreachable("unexpected shift opcode");
5791 
5792   case ISD::SHL:
5793     if (isVShiftLImm(Op.getOperand(1), VT, false, Cnt) && Cnt < EltSize)
5794       return DAG.getNode(AArch64ISD::VSHL, SDLoc(Op), VT, Op.getOperand(0),
5795                          DAG.getConstant(Cnt, MVT::i32));
5796     return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5797                        DAG.getConstant(Intrinsic::aarch64_neon_ushl, MVT::i32),
5798                        Op.getOperand(0), Op.getOperand(1));
5799   case ISD::SRA:
5800   case ISD::SRL:
5801     // Right shift immediate
5802     if (isVShiftRImm(Op.getOperand(1), VT, false, false, Cnt) &&
5803         Cnt < EltSize) {
5804       unsigned Opc =
5805           (Op.getOpcode() == ISD::SRA) ? AArch64ISD::VASHR : AArch64ISD::VLSHR;
5806       return DAG.getNode(Opc, SDLoc(Op), VT, Op.getOperand(0),
5807                          DAG.getConstant(Cnt, MVT::i32));
5808     }
5809 
5810     // Right shift register.  Note, there is not a shift right register
5811     // instruction, but the shift left register instruction takes a signed
5812     // value, where negative numbers specify a right shift.
5813     unsigned Opc = (Op.getOpcode() == ISD::SRA) ? Intrinsic::aarch64_neon_sshl
5814                                                 : Intrinsic::aarch64_neon_ushl;
5815     // negate the shift amount
5816     SDValue NegShift = DAG.getNode(AArch64ISD::NEG, DL, VT, Op.getOperand(1));
5817     SDValue NegShiftLeft =
5818         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5819                     DAG.getConstant(Opc, MVT::i32), Op.getOperand(0), NegShift);
5820     return NegShiftLeft;
5821   }
5822 
5823   return SDValue();
5824 }
5825 
EmitVectorComparison(SDValue LHS,SDValue RHS,AArch64CC::CondCode CC,bool NoNans,EVT VT,SDLoc dl,SelectionDAG & DAG)5826 static SDValue EmitVectorComparison(SDValue LHS, SDValue RHS,
5827                                     AArch64CC::CondCode CC, bool NoNans, EVT VT,
5828                                     SDLoc dl, SelectionDAG &DAG) {
5829   EVT SrcVT = LHS.getValueType();
5830 
5831   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(RHS.getNode());
5832   APInt CnstBits(VT.getSizeInBits(), 0);
5833   APInt UndefBits(VT.getSizeInBits(), 0);
5834   bool IsCnst = BVN && resolveBuildVector(BVN, CnstBits, UndefBits);
5835   bool IsZero = IsCnst && (CnstBits == 0);
5836 
5837   if (SrcVT.getVectorElementType().isFloatingPoint()) {
5838     switch (CC) {
5839     default:
5840       return SDValue();
5841     case AArch64CC::NE: {
5842       SDValue Fcmeq;
5843       if (IsZero)
5844         Fcmeq = DAG.getNode(AArch64ISD::FCMEQz, dl, VT, LHS);
5845       else
5846         Fcmeq = DAG.getNode(AArch64ISD::FCMEQ, dl, VT, LHS, RHS);
5847       return DAG.getNode(AArch64ISD::NOT, dl, VT, Fcmeq);
5848     }
5849     case AArch64CC::EQ:
5850       if (IsZero)
5851         return DAG.getNode(AArch64ISD::FCMEQz, dl, VT, LHS);
5852       return DAG.getNode(AArch64ISD::FCMEQ, dl, VT, LHS, RHS);
5853     case AArch64CC::GE:
5854       if (IsZero)
5855         return DAG.getNode(AArch64ISD::FCMGEz, dl, VT, LHS);
5856       return DAG.getNode(AArch64ISD::FCMGE, dl, VT, LHS, RHS);
5857     case AArch64CC::GT:
5858       if (IsZero)
5859         return DAG.getNode(AArch64ISD::FCMGTz, dl, VT, LHS);
5860       return DAG.getNode(AArch64ISD::FCMGT, dl, VT, LHS, RHS);
5861     case AArch64CC::LS:
5862       if (IsZero)
5863         return DAG.getNode(AArch64ISD::FCMLEz, dl, VT, LHS);
5864       return DAG.getNode(AArch64ISD::FCMGE, dl, VT, RHS, LHS);
5865     case AArch64CC::LT:
5866       if (!NoNans)
5867         return SDValue();
5868     // If we ignore NaNs then we can use to the MI implementation.
5869     // Fallthrough.
5870     case AArch64CC::MI:
5871       if (IsZero)
5872         return DAG.getNode(AArch64ISD::FCMLTz, dl, VT, LHS);
5873       return DAG.getNode(AArch64ISD::FCMGT, dl, VT, RHS, LHS);
5874     }
5875   }
5876 
5877   switch (CC) {
5878   default:
5879     return SDValue();
5880   case AArch64CC::NE: {
5881     SDValue Cmeq;
5882     if (IsZero)
5883       Cmeq = DAG.getNode(AArch64ISD::CMEQz, dl, VT, LHS);
5884     else
5885       Cmeq = DAG.getNode(AArch64ISD::CMEQ, dl, VT, LHS, RHS);
5886     return DAG.getNode(AArch64ISD::NOT, dl, VT, Cmeq);
5887   }
5888   case AArch64CC::EQ:
5889     if (IsZero)
5890       return DAG.getNode(AArch64ISD::CMEQz, dl, VT, LHS);
5891     return DAG.getNode(AArch64ISD::CMEQ, dl, VT, LHS, RHS);
5892   case AArch64CC::GE:
5893     if (IsZero)
5894       return DAG.getNode(AArch64ISD::CMGEz, dl, VT, LHS);
5895     return DAG.getNode(AArch64ISD::CMGE, dl, VT, LHS, RHS);
5896   case AArch64CC::GT:
5897     if (IsZero)
5898       return DAG.getNode(AArch64ISD::CMGTz, dl, VT, LHS);
5899     return DAG.getNode(AArch64ISD::CMGT, dl, VT, LHS, RHS);
5900   case AArch64CC::LE:
5901     if (IsZero)
5902       return DAG.getNode(AArch64ISD::CMLEz, dl, VT, LHS);
5903     return DAG.getNode(AArch64ISD::CMGE, dl, VT, RHS, LHS);
5904   case AArch64CC::LS:
5905     return DAG.getNode(AArch64ISD::CMHS, dl, VT, RHS, LHS);
5906   case AArch64CC::LO:
5907     return DAG.getNode(AArch64ISD::CMHI, dl, VT, RHS, LHS);
5908   case AArch64CC::LT:
5909     if (IsZero)
5910       return DAG.getNode(AArch64ISD::CMLTz, dl, VT, LHS);
5911     return DAG.getNode(AArch64ISD::CMGT, dl, VT, RHS, LHS);
5912   case AArch64CC::HI:
5913     return DAG.getNode(AArch64ISD::CMHI, dl, VT, LHS, RHS);
5914   case AArch64CC::HS:
5915     return DAG.getNode(AArch64ISD::CMHS, dl, VT, LHS, RHS);
5916   }
5917 }
5918 
LowerVSETCC(SDValue Op,SelectionDAG & DAG) const5919 SDValue AArch64TargetLowering::LowerVSETCC(SDValue Op,
5920                                            SelectionDAG &DAG) const {
5921   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
5922   SDValue LHS = Op.getOperand(0);
5923   SDValue RHS = Op.getOperand(1);
5924   SDLoc dl(Op);
5925 
5926   if (LHS.getValueType().getVectorElementType().isInteger()) {
5927     assert(LHS.getValueType() == RHS.getValueType());
5928     AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
5929     return EmitVectorComparison(LHS, RHS, AArch64CC, false, Op.getValueType(),
5930                                 dl, DAG);
5931   }
5932 
5933   assert(LHS.getValueType().getVectorElementType() == MVT::f32 ||
5934          LHS.getValueType().getVectorElementType() == MVT::f64);
5935 
5936   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
5937   // clean.  Some of them require two branches to implement.
5938   AArch64CC::CondCode CC1, CC2;
5939   bool ShouldInvert;
5940   changeVectorFPCCToAArch64CC(CC, CC1, CC2, ShouldInvert);
5941 
5942   bool NoNaNs = getTargetMachine().Options.NoNaNsFPMath;
5943   SDValue Cmp =
5944       EmitVectorComparison(LHS, RHS, CC1, NoNaNs, Op.getValueType(), dl, DAG);
5945   if (!Cmp.getNode())
5946     return SDValue();
5947 
5948   if (CC2 != AArch64CC::AL) {
5949     SDValue Cmp2 =
5950         EmitVectorComparison(LHS, RHS, CC2, NoNaNs, Op.getValueType(), dl, DAG);
5951     if (!Cmp2.getNode())
5952       return SDValue();
5953 
5954     Cmp = DAG.getNode(ISD::OR, dl, Cmp.getValueType(), Cmp, Cmp2);
5955   }
5956 
5957   if (ShouldInvert)
5958     return Cmp = DAG.getNOT(dl, Cmp, Cmp.getValueType());
5959 
5960   return Cmp;
5961 }
5962 
5963 /// getTgtMemIntrinsic - Represent NEON load and store intrinsics as
5964 /// MemIntrinsicNodes.  The associated MachineMemOperands record the alignment
5965 /// specified in the intrinsic calls.
getTgtMemIntrinsic(IntrinsicInfo & Info,const CallInst & I,unsigned Intrinsic) const5966 bool AArch64TargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
5967                                                const CallInst &I,
5968                                                unsigned Intrinsic) const {
5969   switch (Intrinsic) {
5970   case Intrinsic::aarch64_neon_ld2:
5971   case Intrinsic::aarch64_neon_ld3:
5972   case Intrinsic::aarch64_neon_ld4:
5973   case Intrinsic::aarch64_neon_ld1x2:
5974   case Intrinsic::aarch64_neon_ld1x3:
5975   case Intrinsic::aarch64_neon_ld1x4:
5976   case Intrinsic::aarch64_neon_ld2lane:
5977   case Intrinsic::aarch64_neon_ld3lane:
5978   case Intrinsic::aarch64_neon_ld4lane:
5979   case Intrinsic::aarch64_neon_ld2r:
5980   case Intrinsic::aarch64_neon_ld3r:
5981   case Intrinsic::aarch64_neon_ld4r: {
5982     Info.opc = ISD::INTRINSIC_W_CHAIN;
5983     // Conservatively set memVT to the entire set of vectors loaded.
5984     uint64_t NumElts = getDataLayout()->getTypeAllocSize(I.getType()) / 8;
5985     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
5986     Info.ptrVal = I.getArgOperand(I.getNumArgOperands() - 1);
5987     Info.offset = 0;
5988     Info.align = 0;
5989     Info.vol = false; // volatile loads with NEON intrinsics not supported
5990     Info.readMem = true;
5991     Info.writeMem = false;
5992     return true;
5993   }
5994   case Intrinsic::aarch64_neon_st2:
5995   case Intrinsic::aarch64_neon_st3:
5996   case Intrinsic::aarch64_neon_st4:
5997   case Intrinsic::aarch64_neon_st1x2:
5998   case Intrinsic::aarch64_neon_st1x3:
5999   case Intrinsic::aarch64_neon_st1x4:
6000   case Intrinsic::aarch64_neon_st2lane:
6001   case Intrinsic::aarch64_neon_st3lane:
6002   case Intrinsic::aarch64_neon_st4lane: {
6003     Info.opc = ISD::INTRINSIC_VOID;
6004     // Conservatively set memVT to the entire set of vectors stored.
6005     unsigned NumElts = 0;
6006     for (unsigned ArgI = 1, ArgE = I.getNumArgOperands(); ArgI < ArgE; ++ArgI) {
6007       Type *ArgTy = I.getArgOperand(ArgI)->getType();
6008       if (!ArgTy->isVectorTy())
6009         break;
6010       NumElts += getDataLayout()->getTypeAllocSize(ArgTy) / 8;
6011     }
6012     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
6013     Info.ptrVal = I.getArgOperand(I.getNumArgOperands() - 1);
6014     Info.offset = 0;
6015     Info.align = 0;
6016     Info.vol = false; // volatile stores with NEON intrinsics not supported
6017     Info.readMem = false;
6018     Info.writeMem = true;
6019     return true;
6020   }
6021   case Intrinsic::aarch64_ldaxr:
6022   case Intrinsic::aarch64_ldxr: {
6023     PointerType *PtrTy = cast<PointerType>(I.getArgOperand(0)->getType());
6024     Info.opc = ISD::INTRINSIC_W_CHAIN;
6025     Info.memVT = MVT::getVT(PtrTy->getElementType());
6026     Info.ptrVal = I.getArgOperand(0);
6027     Info.offset = 0;
6028     Info.align = getDataLayout()->getABITypeAlignment(PtrTy->getElementType());
6029     Info.vol = true;
6030     Info.readMem = true;
6031     Info.writeMem = false;
6032     return true;
6033   }
6034   case Intrinsic::aarch64_stlxr:
6035   case Intrinsic::aarch64_stxr: {
6036     PointerType *PtrTy = cast<PointerType>(I.getArgOperand(1)->getType());
6037     Info.opc = ISD::INTRINSIC_W_CHAIN;
6038     Info.memVT = MVT::getVT(PtrTy->getElementType());
6039     Info.ptrVal = I.getArgOperand(1);
6040     Info.offset = 0;
6041     Info.align = getDataLayout()->getABITypeAlignment(PtrTy->getElementType());
6042     Info.vol = true;
6043     Info.readMem = false;
6044     Info.writeMem = true;
6045     return true;
6046   }
6047   case Intrinsic::aarch64_ldaxp:
6048   case Intrinsic::aarch64_ldxp: {
6049     Info.opc = ISD::INTRINSIC_W_CHAIN;
6050     Info.memVT = MVT::i128;
6051     Info.ptrVal = I.getArgOperand(0);
6052     Info.offset = 0;
6053     Info.align = 16;
6054     Info.vol = true;
6055     Info.readMem = true;
6056     Info.writeMem = false;
6057     return true;
6058   }
6059   case Intrinsic::aarch64_stlxp:
6060   case Intrinsic::aarch64_stxp: {
6061     Info.opc = ISD::INTRINSIC_W_CHAIN;
6062     Info.memVT = MVT::i128;
6063     Info.ptrVal = I.getArgOperand(2);
6064     Info.offset = 0;
6065     Info.align = 16;
6066     Info.vol = true;
6067     Info.readMem = false;
6068     Info.writeMem = true;
6069     return true;
6070   }
6071   default:
6072     break;
6073   }
6074 
6075   return false;
6076 }
6077 
6078 // Truncations from 64-bit GPR to 32-bit GPR is free.
isTruncateFree(Type * Ty1,Type * Ty2) const6079 bool AArch64TargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const {
6080   if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
6081     return false;
6082   unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
6083   unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
6084   return NumBits1 > NumBits2;
6085 }
isTruncateFree(EVT VT1,EVT VT2) const6086 bool AArch64TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
6087   if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
6088     return false;
6089   unsigned NumBits1 = VT1.getSizeInBits();
6090   unsigned NumBits2 = VT2.getSizeInBits();
6091   return NumBits1 > NumBits2;
6092 }
6093 
6094 // All 32-bit GPR operations implicitly zero the high-half of the corresponding
6095 // 64-bit GPR.
isZExtFree(Type * Ty1,Type * Ty2) const6096 bool AArch64TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
6097   if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
6098     return false;
6099   unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
6100   unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
6101   return NumBits1 == 32 && NumBits2 == 64;
6102 }
isZExtFree(EVT VT1,EVT VT2) const6103 bool AArch64TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
6104   if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
6105     return false;
6106   unsigned NumBits1 = VT1.getSizeInBits();
6107   unsigned NumBits2 = VT2.getSizeInBits();
6108   return NumBits1 == 32 && NumBits2 == 64;
6109 }
6110 
isZExtFree(SDValue Val,EVT VT2) const6111 bool AArch64TargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
6112   EVT VT1 = Val.getValueType();
6113   if (isZExtFree(VT1, VT2)) {
6114     return true;
6115   }
6116 
6117   if (Val.getOpcode() != ISD::LOAD)
6118     return false;
6119 
6120   // 8-, 16-, and 32-bit integer loads all implicitly zero-extend.
6121   return (VT1.isSimple() && !VT1.isVector() && VT1.isInteger() &&
6122           VT2.isSimple() && !VT2.isVector() && VT2.isInteger() &&
6123           VT1.getSizeInBits() <= 32);
6124 }
6125 
hasPairedLoad(Type * LoadedType,unsigned & RequiredAligment) const6126 bool AArch64TargetLowering::hasPairedLoad(Type *LoadedType,
6127                                           unsigned &RequiredAligment) const {
6128   if (!LoadedType->isIntegerTy() && !LoadedType->isFloatTy())
6129     return false;
6130   // Cyclone supports unaligned accesses.
6131   RequiredAligment = 0;
6132   unsigned NumBits = LoadedType->getPrimitiveSizeInBits();
6133   return NumBits == 32 || NumBits == 64;
6134 }
6135 
hasPairedLoad(EVT LoadedType,unsigned & RequiredAligment) const6136 bool AArch64TargetLowering::hasPairedLoad(EVT LoadedType,
6137                                           unsigned &RequiredAligment) const {
6138   if (!LoadedType.isSimple() ||
6139       (!LoadedType.isInteger() && !LoadedType.isFloatingPoint()))
6140     return false;
6141   // Cyclone supports unaligned accesses.
6142   RequiredAligment = 0;
6143   unsigned NumBits = LoadedType.getSizeInBits();
6144   return NumBits == 32 || NumBits == 64;
6145 }
6146 
memOpAlign(unsigned DstAlign,unsigned SrcAlign,unsigned AlignCheck)6147 static bool memOpAlign(unsigned DstAlign, unsigned SrcAlign,
6148                        unsigned AlignCheck) {
6149   return ((SrcAlign == 0 || SrcAlign % AlignCheck == 0) &&
6150           (DstAlign == 0 || DstAlign % AlignCheck == 0));
6151 }
6152 
getOptimalMemOpType(uint64_t Size,unsigned DstAlign,unsigned SrcAlign,bool IsMemset,bool ZeroMemset,bool MemcpyStrSrc,MachineFunction & MF) const6153 EVT AArch64TargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
6154                                                unsigned SrcAlign, bool IsMemset,
6155                                                bool ZeroMemset,
6156                                                bool MemcpyStrSrc,
6157                                                MachineFunction &MF) const {
6158   // Don't use AdvSIMD to implement 16-byte memset. It would have taken one
6159   // instruction to materialize the v2i64 zero and one store (with restrictive
6160   // addressing mode). Just do two i64 store of zero-registers.
6161   bool Fast;
6162   const Function *F = MF.getFunction();
6163   if (Subtarget->hasFPARMv8() && !IsMemset && Size >= 16 &&
6164       !F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
6165                                        Attribute::NoImplicitFloat) &&
6166       (memOpAlign(SrcAlign, DstAlign, 16) ||
6167        (allowsUnalignedMemoryAccesses(MVT::f128, 0, &Fast) && Fast)))
6168     return MVT::f128;
6169 
6170   return Size >= 8 ? MVT::i64 : MVT::i32;
6171 }
6172 
6173 // 12-bit optionally shifted immediates are legal for adds.
isLegalAddImmediate(int64_t Immed) const6174 bool AArch64TargetLowering::isLegalAddImmediate(int64_t Immed) const {
6175   if ((Immed >> 12) == 0 || ((Immed & 0xfff) == 0 && Immed >> 24 == 0))
6176     return true;
6177   return false;
6178 }
6179 
6180 // Integer comparisons are implemented with ADDS/SUBS, so the range of valid
6181 // immediates is the same as for an add or a sub.
isLegalICmpImmediate(int64_t Immed) const6182 bool AArch64TargetLowering::isLegalICmpImmediate(int64_t Immed) const {
6183   if (Immed < 0)
6184     Immed *= -1;
6185   return isLegalAddImmediate(Immed);
6186 }
6187 
6188 /// isLegalAddressingMode - Return true if the addressing mode represented
6189 /// by AM is legal for this target, for a load/store of the specified type.
isLegalAddressingMode(const AddrMode & AM,Type * Ty) const6190 bool AArch64TargetLowering::isLegalAddressingMode(const AddrMode &AM,
6191                                                   Type *Ty) const {
6192   // AArch64 has five basic addressing modes:
6193   //  reg
6194   //  reg + 9-bit signed offset
6195   //  reg + SIZE_IN_BYTES * 12-bit unsigned offset
6196   //  reg1 + reg2
6197   //  reg + SIZE_IN_BYTES * reg
6198 
6199   // No global is ever allowed as a base.
6200   if (AM.BaseGV)
6201     return false;
6202 
6203   // No reg+reg+imm addressing.
6204   if (AM.HasBaseReg && AM.BaseOffs && AM.Scale)
6205     return false;
6206 
6207   // check reg + imm case:
6208   // i.e., reg + 0, reg + imm9, reg + SIZE_IN_BYTES * uimm12
6209   uint64_t NumBytes = 0;
6210   if (Ty->isSized()) {
6211     uint64_t NumBits = getDataLayout()->getTypeSizeInBits(Ty);
6212     NumBytes = NumBits / 8;
6213     if (!isPowerOf2_64(NumBits))
6214       NumBytes = 0;
6215   }
6216 
6217   if (!AM.Scale) {
6218     int64_t Offset = AM.BaseOffs;
6219 
6220     // 9-bit signed offset
6221     if (Offset >= -(1LL << 9) && Offset <= (1LL << 9) - 1)
6222       return true;
6223 
6224     // 12-bit unsigned offset
6225     unsigned shift = Log2_64(NumBytes);
6226     if (NumBytes && Offset > 0 && (Offset / NumBytes) <= (1LL << 12) - 1 &&
6227         // Must be a multiple of NumBytes (NumBytes is a power of 2)
6228         (Offset >> shift) << shift == Offset)
6229       return true;
6230     return false;
6231   }
6232 
6233   // Check reg1 + SIZE_IN_BYTES * reg2 and reg1 + reg2
6234 
6235   if (!AM.Scale || AM.Scale == 1 ||
6236       (AM.Scale > 0 && (uint64_t)AM.Scale == NumBytes))
6237     return true;
6238   return false;
6239 }
6240 
getScalingFactorCost(const AddrMode & AM,Type * Ty) const6241 int AArch64TargetLowering::getScalingFactorCost(const AddrMode &AM,
6242                                                 Type *Ty) const {
6243   // Scaling factors are not free at all.
6244   // Operands                     | Rt Latency
6245   // -------------------------------------------
6246   // Rt, [Xn, Xm]                 | 4
6247   // -------------------------------------------
6248   // Rt, [Xn, Xm, lsl #imm]       | Rn: 4 Rm: 5
6249   // Rt, [Xn, Wm, <extend> #imm]  |
6250   if (isLegalAddressingMode(AM, Ty))
6251     // Scale represents reg2 * scale, thus account for 1 if
6252     // it is not equal to 0 or 1.
6253     return AM.Scale != 0 && AM.Scale != 1;
6254   return -1;
6255 }
6256 
isFMAFasterThanFMulAndFAdd(EVT VT) const6257 bool AArch64TargetLowering::isFMAFasterThanFMulAndFAdd(EVT VT) const {
6258   VT = VT.getScalarType();
6259 
6260   if (!VT.isSimple())
6261     return false;
6262 
6263   switch (VT.getSimpleVT().SimpleTy) {
6264   case MVT::f32:
6265   case MVT::f64:
6266     return true;
6267   default:
6268     break;
6269   }
6270 
6271   return false;
6272 }
6273 
6274 const MCPhysReg *
getScratchRegisters(CallingConv::ID) const6275 AArch64TargetLowering::getScratchRegisters(CallingConv::ID) const {
6276   // LR is a callee-save register, but we must treat it as clobbered by any call
6277   // site. Hence we include LR in the scratch registers, which are in turn added
6278   // as implicit-defs for stackmaps and patchpoints.
6279   static const MCPhysReg ScratchRegs[] = {
6280     AArch64::X16, AArch64::X17, AArch64::LR, 0
6281   };
6282   return ScratchRegs;
6283 }
6284 
6285 bool
isDesirableToCommuteWithShift(const SDNode * N) const6286 AArch64TargetLowering::isDesirableToCommuteWithShift(const SDNode *N) const {
6287   EVT VT = N->getValueType(0);
6288     // If N is unsigned bit extraction: ((x >> C) & mask), then do not combine
6289     // it with shift to let it be lowered to UBFX.
6290   if (N->getOpcode() == ISD::AND && (VT == MVT::i32 || VT == MVT::i64) &&
6291       isa<ConstantSDNode>(N->getOperand(1))) {
6292     uint64_t TruncMask = N->getConstantOperandVal(1);
6293     if (isMask_64(TruncMask) &&
6294       N->getOperand(0).getOpcode() == ISD::SRL &&
6295       isa<ConstantSDNode>(N->getOperand(0)->getOperand(1)))
6296       return false;
6297   }
6298   return true;
6299 }
6300 
shouldConvertConstantLoadToIntImm(const APInt & Imm,Type * Ty) const6301 bool AArch64TargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
6302                                                               Type *Ty) const {
6303   assert(Ty->isIntegerTy());
6304 
6305   unsigned BitSize = Ty->getPrimitiveSizeInBits();
6306   if (BitSize == 0)
6307     return false;
6308 
6309   int64_t Val = Imm.getSExtValue();
6310   if (Val == 0 || AArch64_AM::isLogicalImmediate(Val, BitSize))
6311     return true;
6312 
6313   if ((int64_t)Val < 0)
6314     Val = ~Val;
6315   if (BitSize == 32)
6316     Val &= (1LL << 32) - 1;
6317 
6318   unsigned LZ = countLeadingZeros((uint64_t)Val);
6319   unsigned Shift = (63 - LZ) / 16;
6320   // MOVZ is free so return true for one or fewer MOVK.
6321   return (Shift < 3) ? true : false;
6322 }
6323 
6324 // Generate SUBS and CSEL for integer abs.
performIntegerAbsCombine(SDNode * N,SelectionDAG & DAG)6325 static SDValue performIntegerAbsCombine(SDNode *N, SelectionDAG &DAG) {
6326   EVT VT = N->getValueType(0);
6327 
6328   SDValue N0 = N->getOperand(0);
6329   SDValue N1 = N->getOperand(1);
6330   SDLoc DL(N);
6331 
6332   // Check pattern of XOR(ADD(X,Y), Y) where Y is SRA(X, size(X)-1)
6333   // and change it to SUB and CSEL.
6334   if (VT.isInteger() && N->getOpcode() == ISD::XOR &&
6335       N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1 &&
6336       N1.getOpcode() == ISD::SRA && N1.getOperand(0) == N0.getOperand(0))
6337     if (ConstantSDNode *Y1C = dyn_cast<ConstantSDNode>(N1.getOperand(1)))
6338       if (Y1C->getAPIntValue() == VT.getSizeInBits() - 1) {
6339         SDValue Neg = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT),
6340                                   N0.getOperand(0));
6341         // Generate SUBS & CSEL.
6342         SDValue Cmp =
6343             DAG.getNode(AArch64ISD::SUBS, DL, DAG.getVTList(VT, MVT::i32),
6344                         N0.getOperand(0), DAG.getConstant(0, VT));
6345         return DAG.getNode(AArch64ISD::CSEL, DL, VT, N0.getOperand(0), Neg,
6346                            DAG.getConstant(AArch64CC::PL, MVT::i32),
6347                            SDValue(Cmp.getNode(), 1));
6348       }
6349   return SDValue();
6350 }
6351 
6352 // performXorCombine - Attempts to handle integer ABS.
performXorCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6353 static SDValue performXorCombine(SDNode *N, SelectionDAG &DAG,
6354                                  TargetLowering::DAGCombinerInfo &DCI,
6355                                  const AArch64Subtarget *Subtarget) {
6356   if (DCI.isBeforeLegalizeOps())
6357     return SDValue();
6358 
6359   return performIntegerAbsCombine(N, DAG);
6360 }
6361 
performMulCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6362 static SDValue performMulCombine(SDNode *N, SelectionDAG &DAG,
6363                                  TargetLowering::DAGCombinerInfo &DCI,
6364                                  const AArch64Subtarget *Subtarget) {
6365   if (DCI.isBeforeLegalizeOps())
6366     return SDValue();
6367 
6368   // Multiplication of a power of two plus/minus one can be done more
6369   // cheaply as as shift+add/sub. For now, this is true unilaterally. If
6370   // future CPUs have a cheaper MADD instruction, this may need to be
6371   // gated on a subtarget feature. For Cyclone, 32-bit MADD is 4 cycles and
6372   // 64-bit is 5 cycles, so this is always a win.
6373   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
6374     APInt Value = C->getAPIntValue();
6375     EVT VT = N->getValueType(0);
6376     if (Value.isNonNegative()) {
6377       // (mul x, 2^N + 1) => (add (shl x, N), x)
6378       APInt VM1 = Value - 1;
6379       if (VM1.isPowerOf2()) {
6380         SDValue ShiftedVal =
6381             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6382                         DAG.getConstant(VM1.logBase2(), MVT::i64));
6383         return DAG.getNode(ISD::ADD, SDLoc(N), VT, ShiftedVal,
6384                            N->getOperand(0));
6385       }
6386       // (mul x, 2^N - 1) => (sub (shl x, N), x)
6387       APInt VP1 = Value + 1;
6388       if (VP1.isPowerOf2()) {
6389         SDValue ShiftedVal =
6390             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6391                         DAG.getConstant(VP1.logBase2(), MVT::i64));
6392         return DAG.getNode(ISD::SUB, SDLoc(N), VT, ShiftedVal,
6393                            N->getOperand(0));
6394       }
6395     } else {
6396       // (mul x, -(2^N + 1)) => - (add (shl x, N), x)
6397       APInt VNM1 = -Value - 1;
6398       if (VNM1.isPowerOf2()) {
6399         SDValue ShiftedVal =
6400             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6401                         DAG.getConstant(VNM1.logBase2(), MVT::i64));
6402         SDValue Add =
6403             DAG.getNode(ISD::ADD, SDLoc(N), VT, ShiftedVal, N->getOperand(0));
6404         return DAG.getNode(ISD::SUB, SDLoc(N), VT, DAG.getConstant(0, VT), Add);
6405       }
6406       // (mul x, -(2^N - 1)) => (sub x, (shl x, N))
6407       APInt VNP1 = -Value + 1;
6408       if (VNP1.isPowerOf2()) {
6409         SDValue ShiftedVal =
6410             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6411                         DAG.getConstant(VNP1.logBase2(), MVT::i64));
6412         return DAG.getNode(ISD::SUB, SDLoc(N), VT, N->getOperand(0),
6413                            ShiftedVal);
6414       }
6415     }
6416   }
6417   return SDValue();
6418 }
6419 
performIntToFpCombine(SDNode * N,SelectionDAG & DAG)6420 static SDValue performIntToFpCombine(SDNode *N, SelectionDAG &DAG) {
6421   EVT VT = N->getValueType(0);
6422   if (VT != MVT::f32 && VT != MVT::f64)
6423     return SDValue();
6424   // Only optimize when the source and destination types have the same width.
6425   if (VT.getSizeInBits() != N->getOperand(0).getValueType().getSizeInBits())
6426     return SDValue();
6427 
6428   // If the result of an integer load is only used by an integer-to-float
6429   // conversion, use a fp load instead and a AdvSIMD scalar {S|U}CVTF instead.
6430   // This eliminates an "integer-to-vector-move UOP and improve throughput.
6431   SDValue N0 = N->getOperand(0);
6432   if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
6433       // Do not change the width of a volatile load.
6434       !cast<LoadSDNode>(N0)->isVolatile()) {
6435     LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6436     SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(), LN0->getBasePtr(),
6437                                LN0->getPointerInfo(), LN0->isVolatile(),
6438                                LN0->isNonTemporal(), LN0->isInvariant(),
6439                                LN0->getAlignment());
6440 
6441     // Make sure successors of the original load stay after it by updating them
6442     // to use the new Chain.
6443     DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), Load.getValue(1));
6444 
6445     unsigned Opcode =
6446         (N->getOpcode() == ISD::SINT_TO_FP) ? AArch64ISD::SITOF : AArch64ISD::UITOF;
6447     return DAG.getNode(Opcode, SDLoc(N), VT, Load);
6448   }
6449 
6450   return SDValue();
6451 }
6452 
6453 /// An EXTR instruction is made up of two shifts, ORed together. This helper
6454 /// searches for and classifies those shifts.
findEXTRHalf(SDValue N,SDValue & Src,uint32_t & ShiftAmount,bool & FromHi)6455 static bool findEXTRHalf(SDValue N, SDValue &Src, uint32_t &ShiftAmount,
6456                          bool &FromHi) {
6457   if (N.getOpcode() == ISD::SHL)
6458     FromHi = false;
6459   else if (N.getOpcode() == ISD::SRL)
6460     FromHi = true;
6461   else
6462     return false;
6463 
6464   if (!isa<ConstantSDNode>(N.getOperand(1)))
6465     return false;
6466 
6467   ShiftAmount = N->getConstantOperandVal(1);
6468   Src = N->getOperand(0);
6469   return true;
6470 }
6471 
6472 /// EXTR instruction extracts a contiguous chunk of bits from two existing
6473 /// registers viewed as a high/low pair. This function looks for the pattern:
6474 /// (or (shl VAL1, #N), (srl VAL2, #RegWidth-N)) and replaces it with an
6475 /// EXTR. Can't quite be done in TableGen because the two immediates aren't
6476 /// independent.
tryCombineToEXTR(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)6477 static SDValue tryCombineToEXTR(SDNode *N,
6478                                 TargetLowering::DAGCombinerInfo &DCI) {
6479   SelectionDAG &DAG = DCI.DAG;
6480   SDLoc DL(N);
6481   EVT VT = N->getValueType(0);
6482 
6483   assert(N->getOpcode() == ISD::OR && "Unexpected root");
6484 
6485   if (VT != MVT::i32 && VT != MVT::i64)
6486     return SDValue();
6487 
6488   SDValue LHS;
6489   uint32_t ShiftLHS = 0;
6490   bool LHSFromHi = 0;
6491   if (!findEXTRHalf(N->getOperand(0), LHS, ShiftLHS, LHSFromHi))
6492     return SDValue();
6493 
6494   SDValue RHS;
6495   uint32_t ShiftRHS = 0;
6496   bool RHSFromHi = 0;
6497   if (!findEXTRHalf(N->getOperand(1), RHS, ShiftRHS, RHSFromHi))
6498     return SDValue();
6499 
6500   // If they're both trying to come from the high part of the register, they're
6501   // not really an EXTR.
6502   if (LHSFromHi == RHSFromHi)
6503     return SDValue();
6504 
6505   if (ShiftLHS + ShiftRHS != VT.getSizeInBits())
6506     return SDValue();
6507 
6508   if (LHSFromHi) {
6509     std::swap(LHS, RHS);
6510     std::swap(ShiftLHS, ShiftRHS);
6511   }
6512 
6513   return DAG.getNode(AArch64ISD::EXTR, DL, VT, LHS, RHS,
6514                      DAG.getConstant(ShiftRHS, MVT::i64));
6515 }
6516 
tryCombineToBSL(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)6517 static SDValue tryCombineToBSL(SDNode *N,
6518                                 TargetLowering::DAGCombinerInfo &DCI) {
6519   EVT VT = N->getValueType(0);
6520   SelectionDAG &DAG = DCI.DAG;
6521   SDLoc DL(N);
6522 
6523   if (!VT.isVector())
6524     return SDValue();
6525 
6526   SDValue N0 = N->getOperand(0);
6527   if (N0.getOpcode() != ISD::AND)
6528     return SDValue();
6529 
6530   SDValue N1 = N->getOperand(1);
6531   if (N1.getOpcode() != ISD::AND)
6532     return SDValue();
6533 
6534   // We only have to look for constant vectors here since the general, variable
6535   // case can be handled in TableGen.
6536   unsigned Bits = VT.getVectorElementType().getSizeInBits();
6537   uint64_t BitMask = Bits == 64 ? -1ULL : ((1ULL << Bits) - 1);
6538   for (int i = 1; i >= 0; --i)
6539     for (int j = 1; j >= 0; --j) {
6540       BuildVectorSDNode *BVN0 = dyn_cast<BuildVectorSDNode>(N0->getOperand(i));
6541       BuildVectorSDNode *BVN1 = dyn_cast<BuildVectorSDNode>(N1->getOperand(j));
6542       if (!BVN0 || !BVN1)
6543         continue;
6544 
6545       bool FoundMatch = true;
6546       for (unsigned k = 0; k < VT.getVectorNumElements(); ++k) {
6547         ConstantSDNode *CN0 = dyn_cast<ConstantSDNode>(BVN0->getOperand(k));
6548         ConstantSDNode *CN1 = dyn_cast<ConstantSDNode>(BVN1->getOperand(k));
6549         if (!CN0 || !CN1 ||
6550             CN0->getZExtValue() != (BitMask & ~CN1->getZExtValue())) {
6551           FoundMatch = false;
6552           break;
6553         }
6554       }
6555 
6556       if (FoundMatch)
6557         return DAG.getNode(AArch64ISD::BSL, DL, VT, SDValue(BVN0, 0),
6558                            N0->getOperand(1 - i), N1->getOperand(1 - j));
6559     }
6560 
6561   return SDValue();
6562 }
6563 
performORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6564 static SDValue performORCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
6565                                 const AArch64Subtarget *Subtarget) {
6566   // Attempt to form an EXTR from (or (shl VAL1, #N), (srl VAL2, #RegWidth-N))
6567   if (!EnableAArch64ExtrGeneration)
6568     return SDValue();
6569   SelectionDAG &DAG = DCI.DAG;
6570   EVT VT = N->getValueType(0);
6571 
6572   if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
6573     return SDValue();
6574 
6575   SDValue Res = tryCombineToEXTR(N, DCI);
6576   if (Res.getNode())
6577     return Res;
6578 
6579   Res = tryCombineToBSL(N, DCI);
6580   if (Res.getNode())
6581     return Res;
6582 
6583   return SDValue();
6584 }
6585 
performBitcastCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6586 static SDValue performBitcastCombine(SDNode *N,
6587                                      TargetLowering::DAGCombinerInfo &DCI,
6588                                      SelectionDAG &DAG) {
6589   // Wait 'til after everything is legalized to try this. That way we have
6590   // legal vector types and such.
6591   if (DCI.isBeforeLegalizeOps())
6592     return SDValue();
6593 
6594   // Remove extraneous bitcasts around an extract_subvector.
6595   // For example,
6596   //    (v4i16 (bitconvert
6597   //             (extract_subvector (v2i64 (bitconvert (v8i16 ...)), (i64 1)))))
6598   //  becomes
6599   //    (extract_subvector ((v8i16 ...), (i64 4)))
6600 
6601   // Only interested in 64-bit vectors as the ultimate result.
6602   EVT VT = N->getValueType(0);
6603   if (!VT.isVector())
6604     return SDValue();
6605   if (VT.getSimpleVT().getSizeInBits() != 64)
6606     return SDValue();
6607   // Is the operand an extract_subvector starting at the beginning or halfway
6608   // point of the vector? A low half may also come through as an
6609   // EXTRACT_SUBREG, so look for that, too.
6610   SDValue Op0 = N->getOperand(0);
6611   if (Op0->getOpcode() != ISD::EXTRACT_SUBVECTOR &&
6612       !(Op0->isMachineOpcode() &&
6613         Op0->getMachineOpcode() == AArch64::EXTRACT_SUBREG))
6614     return SDValue();
6615   uint64_t idx = cast<ConstantSDNode>(Op0->getOperand(1))->getZExtValue();
6616   if (Op0->getOpcode() == ISD::EXTRACT_SUBVECTOR) {
6617     if (Op0->getValueType(0).getVectorNumElements() != idx && idx != 0)
6618       return SDValue();
6619   } else if (Op0->getMachineOpcode() == AArch64::EXTRACT_SUBREG) {
6620     if (idx != AArch64::dsub)
6621       return SDValue();
6622     // The dsub reference is equivalent to a lane zero subvector reference.
6623     idx = 0;
6624   }
6625   // Look through the bitcast of the input to the extract.
6626   if (Op0->getOperand(0)->getOpcode() != ISD::BITCAST)
6627     return SDValue();
6628   SDValue Source = Op0->getOperand(0)->getOperand(0);
6629   // If the source type has twice the number of elements as our destination
6630   // type, we know this is an extract of the high or low half of the vector.
6631   EVT SVT = Source->getValueType(0);
6632   if (SVT.getVectorNumElements() != VT.getVectorNumElements() * 2)
6633     return SDValue();
6634 
6635   DEBUG(dbgs() << "aarch64-lower: bitcast extract_subvector simplification\n");
6636 
6637   // Create the simplified form to just extract the low or high half of the
6638   // vector directly rather than bothering with the bitcasts.
6639   SDLoc dl(N);
6640   unsigned NumElements = VT.getVectorNumElements();
6641   if (idx) {
6642     SDValue HalfIdx = DAG.getConstant(NumElements, MVT::i64);
6643     return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, Source, HalfIdx);
6644   } else {
6645     SDValue SubReg = DAG.getTargetConstant(AArch64::dsub, MVT::i32);
6646     return SDValue(DAG.getMachineNode(TargetOpcode::EXTRACT_SUBREG, dl, VT,
6647                                       Source, SubReg),
6648                    0);
6649   }
6650 }
6651 
performConcatVectorsCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6652 static SDValue performConcatVectorsCombine(SDNode *N,
6653                                            TargetLowering::DAGCombinerInfo &DCI,
6654                                            SelectionDAG &DAG) {
6655   // Wait 'til after everything is legalized to try this. That way we have
6656   // legal vector types and such.
6657   if (DCI.isBeforeLegalizeOps())
6658     return SDValue();
6659 
6660   SDLoc dl(N);
6661   EVT VT = N->getValueType(0);
6662 
6663   // If we see a (concat_vectors (v1x64 A), (v1x64 A)) it's really a vector
6664   // splat. The indexed instructions are going to be expecting a DUPLANE64, so
6665   // canonicalise to that.
6666   if (N->getOperand(0) == N->getOperand(1) && VT.getVectorNumElements() == 2) {
6667     assert(VT.getVectorElementType().getSizeInBits() == 64);
6668     return DAG.getNode(AArch64ISD::DUPLANE64, dl, VT,
6669                        WidenVector(N->getOperand(0), DAG),
6670                        DAG.getConstant(0, MVT::i64));
6671   }
6672 
6673   // Canonicalise concat_vectors so that the right-hand vector has as few
6674   // bit-casts as possible before its real operation. The primary matching
6675   // destination for these operations will be the narrowing "2" instructions,
6676   // which depend on the operation being performed on this right-hand vector.
6677   // For example,
6678   //    (concat_vectors LHS,  (v1i64 (bitconvert (v4i16 RHS))))
6679   // becomes
6680   //    (bitconvert (concat_vectors (v4i16 (bitconvert LHS)), RHS))
6681 
6682   SDValue Op1 = N->getOperand(1);
6683   if (Op1->getOpcode() != ISD::BITCAST)
6684     return SDValue();
6685   SDValue RHS = Op1->getOperand(0);
6686   MVT RHSTy = RHS.getValueType().getSimpleVT();
6687   // If the RHS is not a vector, this is not the pattern we're looking for.
6688   if (!RHSTy.isVector())
6689     return SDValue();
6690 
6691   DEBUG(dbgs() << "aarch64-lower: concat_vectors bitcast simplification\n");
6692 
6693   MVT ConcatTy = MVT::getVectorVT(RHSTy.getVectorElementType(),
6694                                   RHSTy.getVectorNumElements() * 2);
6695   return DAG.getNode(
6696       ISD::BITCAST, dl, VT,
6697       DAG.getNode(ISD::CONCAT_VECTORS, dl, ConcatTy,
6698                   DAG.getNode(ISD::BITCAST, dl, RHSTy, N->getOperand(0)), RHS));
6699 }
6700 
tryCombineFixedPointConvert(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6701 static SDValue tryCombineFixedPointConvert(SDNode *N,
6702                                            TargetLowering::DAGCombinerInfo &DCI,
6703                                            SelectionDAG &DAG) {
6704   // Wait 'til after everything is legalized to try this. That way we have
6705   // legal vector types and such.
6706   if (DCI.isBeforeLegalizeOps())
6707     return SDValue();
6708   // Transform a scalar conversion of a value from a lane extract into a
6709   // lane extract of a vector conversion. E.g., from foo1 to foo2:
6710   // double foo1(int64x2_t a) { return vcvtd_n_f64_s64(a[1], 9); }
6711   // double foo2(int64x2_t a) { return vcvtq_n_f64_s64(a, 9)[1]; }
6712   //
6713   // The second form interacts better with instruction selection and the
6714   // register allocator to avoid cross-class register copies that aren't
6715   // coalescable due to a lane reference.
6716 
6717   // Check the operand and see if it originates from a lane extract.
6718   SDValue Op1 = N->getOperand(1);
6719   if (Op1.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
6720     // Yep, no additional predication needed. Perform the transform.
6721     SDValue IID = N->getOperand(0);
6722     SDValue Shift = N->getOperand(2);
6723     SDValue Vec = Op1.getOperand(0);
6724     SDValue Lane = Op1.getOperand(1);
6725     EVT ResTy = N->getValueType(0);
6726     EVT VecResTy;
6727     SDLoc DL(N);
6728 
6729     // The vector width should be 128 bits by the time we get here, even
6730     // if it started as 64 bits (the extract_vector handling will have
6731     // done so).
6732     assert(Vec.getValueType().getSizeInBits() == 128 &&
6733            "unexpected vector size on extract_vector_elt!");
6734     if (Vec.getValueType() == MVT::v4i32)
6735       VecResTy = MVT::v4f32;
6736     else if (Vec.getValueType() == MVT::v2i64)
6737       VecResTy = MVT::v2f64;
6738     else
6739       llvm_unreachable("unexpected vector type!");
6740 
6741     SDValue Convert =
6742         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VecResTy, IID, Vec, Shift);
6743     return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ResTy, Convert, Lane);
6744   }
6745   return SDValue();
6746 }
6747 
6748 // AArch64 high-vector "long" operations are formed by performing the non-high
6749 // version on an extract_subvector of each operand which gets the high half:
6750 //
6751 //  (longop2 LHS, RHS) == (longop (extract_high LHS), (extract_high RHS))
6752 //
6753 // However, there are cases which don't have an extract_high explicitly, but
6754 // have another operation that can be made compatible with one for free. For
6755 // example:
6756 //
6757 //  (dupv64 scalar) --> (extract_high (dup128 scalar))
6758 //
6759 // This routine does the actual conversion of such DUPs, once outer routines
6760 // have determined that everything else is in order.
tryExtendDUPToExtractHigh(SDValue N,SelectionDAG & DAG)6761 static SDValue tryExtendDUPToExtractHigh(SDValue N, SelectionDAG &DAG) {
6762   // We can handle most types of duplicate, but the lane ones have an extra
6763   // operand saying *which* lane, so we need to know.
6764   bool IsDUPLANE;
6765   switch (N.getOpcode()) {
6766   case AArch64ISD::DUP:
6767     IsDUPLANE = false;
6768     break;
6769   case AArch64ISD::DUPLANE8:
6770   case AArch64ISD::DUPLANE16:
6771   case AArch64ISD::DUPLANE32:
6772   case AArch64ISD::DUPLANE64:
6773     IsDUPLANE = true;
6774     break;
6775   default:
6776     return SDValue();
6777   }
6778 
6779   MVT NarrowTy = N.getSimpleValueType();
6780   if (!NarrowTy.is64BitVector())
6781     return SDValue();
6782 
6783   MVT ElementTy = NarrowTy.getVectorElementType();
6784   unsigned NumElems = NarrowTy.getVectorNumElements();
6785   MVT NewDUPVT = MVT::getVectorVT(ElementTy, NumElems * 2);
6786 
6787   SDValue NewDUP;
6788   if (IsDUPLANE)
6789     NewDUP = DAG.getNode(N.getOpcode(), SDLoc(N), NewDUPVT, N.getOperand(0),
6790                          N.getOperand(1));
6791   else
6792     NewDUP = DAG.getNode(AArch64ISD::DUP, SDLoc(N), NewDUPVT, N.getOperand(0));
6793 
6794   return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(N.getNode()), NarrowTy,
6795                      NewDUP, DAG.getConstant(NumElems, MVT::i64));
6796 }
6797 
isEssentiallyExtractSubvector(SDValue N)6798 static bool isEssentiallyExtractSubvector(SDValue N) {
6799   if (N.getOpcode() == ISD::EXTRACT_SUBVECTOR)
6800     return true;
6801 
6802   return N.getOpcode() == ISD::BITCAST &&
6803          N.getOperand(0).getOpcode() == ISD::EXTRACT_SUBVECTOR;
6804 }
6805 
6806 /// \brief Helper structure to keep track of ISD::SET_CC operands.
6807 struct GenericSetCCInfo {
6808   const SDValue *Opnd0;
6809   const SDValue *Opnd1;
6810   ISD::CondCode CC;
6811 };
6812 
6813 /// \brief Helper structure to keep track of a SET_CC lowered into AArch64 code.
6814 struct AArch64SetCCInfo {
6815   const SDValue *Cmp;
6816   AArch64CC::CondCode CC;
6817 };
6818 
6819 /// \brief Helper structure to keep track of SetCC information.
6820 union SetCCInfo {
6821   GenericSetCCInfo Generic;
6822   AArch64SetCCInfo AArch64;
6823 };
6824 
6825 /// \brief Helper structure to be able to read SetCC information.  If set to
6826 /// true, IsAArch64 field, Info is a AArch64SetCCInfo, otherwise Info is a
6827 /// GenericSetCCInfo.
6828 struct SetCCInfoAndKind {
6829   SetCCInfo Info;
6830   bool IsAArch64;
6831 };
6832 
6833 /// \brief Check whether or not \p Op is a SET_CC operation, either a generic or
6834 /// an
6835 /// AArch64 lowered one.
6836 /// \p SetCCInfo is filled accordingly.
6837 /// \post SetCCInfo is meanginfull only when this function returns true.
6838 /// \return True when Op is a kind of SET_CC operation.
isSetCC(SDValue Op,SetCCInfoAndKind & SetCCInfo)6839 static bool isSetCC(SDValue Op, SetCCInfoAndKind &SetCCInfo) {
6840   // If this is a setcc, this is straight forward.
6841   if (Op.getOpcode() == ISD::SETCC) {
6842     SetCCInfo.Info.Generic.Opnd0 = &Op.getOperand(0);
6843     SetCCInfo.Info.Generic.Opnd1 = &Op.getOperand(1);
6844     SetCCInfo.Info.Generic.CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
6845     SetCCInfo.IsAArch64 = false;
6846     return true;
6847   }
6848   // Otherwise, check if this is a matching csel instruction.
6849   // In other words:
6850   // - csel 1, 0, cc
6851   // - csel 0, 1, !cc
6852   if (Op.getOpcode() != AArch64ISD::CSEL)
6853     return false;
6854   // Set the information about the operands.
6855   // TODO: we want the operands of the Cmp not the csel
6856   SetCCInfo.Info.AArch64.Cmp = &Op.getOperand(3);
6857   SetCCInfo.IsAArch64 = true;
6858   SetCCInfo.Info.AArch64.CC = static_cast<AArch64CC::CondCode>(
6859       cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue());
6860 
6861   // Check that the operands matches the constraints:
6862   // (1) Both operands must be constants.
6863   // (2) One must be 1 and the other must be 0.
6864   ConstantSDNode *TValue = dyn_cast<ConstantSDNode>(Op.getOperand(0));
6865   ConstantSDNode *FValue = dyn_cast<ConstantSDNode>(Op.getOperand(1));
6866 
6867   // Check (1).
6868   if (!TValue || !FValue)
6869     return false;
6870 
6871   // Check (2).
6872   if (!TValue->isOne()) {
6873     // Update the comparison when we are interested in !cc.
6874     std::swap(TValue, FValue);
6875     SetCCInfo.Info.AArch64.CC =
6876         AArch64CC::getInvertedCondCode(SetCCInfo.Info.AArch64.CC);
6877   }
6878   return TValue->isOne() && FValue->isNullValue();
6879 }
6880 
6881 // Returns true if Op is setcc or zext of setcc.
isSetCCOrZExtSetCC(const SDValue & Op,SetCCInfoAndKind & Info)6882 static bool isSetCCOrZExtSetCC(const SDValue& Op, SetCCInfoAndKind &Info) {
6883   if (isSetCC(Op, Info))
6884     return true;
6885   return ((Op.getOpcode() == ISD::ZERO_EXTEND) &&
6886     isSetCC(Op->getOperand(0), Info));
6887 }
6888 
6889 // The folding we want to perform is:
6890 // (add x, [zext] (setcc cc ...) )
6891 //   -->
6892 // (csel x, (add x, 1), !cc ...)
6893 //
6894 // The latter will get matched to a CSINC instruction.
performSetccAddFolding(SDNode * Op,SelectionDAG & DAG)6895 static SDValue performSetccAddFolding(SDNode *Op, SelectionDAG &DAG) {
6896   assert(Op && Op->getOpcode() == ISD::ADD && "Unexpected operation!");
6897   SDValue LHS = Op->getOperand(0);
6898   SDValue RHS = Op->getOperand(1);
6899   SetCCInfoAndKind InfoAndKind;
6900 
6901   // If neither operand is a SET_CC, give up.
6902   if (!isSetCCOrZExtSetCC(LHS, InfoAndKind)) {
6903     std::swap(LHS, RHS);
6904     if (!isSetCCOrZExtSetCC(LHS, InfoAndKind))
6905       return SDValue();
6906   }
6907 
6908   // FIXME: This could be generatized to work for FP comparisons.
6909   EVT CmpVT = InfoAndKind.IsAArch64
6910                   ? InfoAndKind.Info.AArch64.Cmp->getOperand(0).getValueType()
6911                   : InfoAndKind.Info.Generic.Opnd0->getValueType();
6912   if (CmpVT != MVT::i32 && CmpVT != MVT::i64)
6913     return SDValue();
6914 
6915   SDValue CCVal;
6916   SDValue Cmp;
6917   SDLoc dl(Op);
6918   if (InfoAndKind.IsAArch64) {
6919     CCVal = DAG.getConstant(
6920         AArch64CC::getInvertedCondCode(InfoAndKind.Info.AArch64.CC), MVT::i32);
6921     Cmp = *InfoAndKind.Info.AArch64.Cmp;
6922   } else
6923     Cmp = getAArch64Cmp(*InfoAndKind.Info.Generic.Opnd0,
6924                       *InfoAndKind.Info.Generic.Opnd1,
6925                       ISD::getSetCCInverse(InfoAndKind.Info.Generic.CC, true),
6926                       CCVal, DAG, dl);
6927 
6928   EVT VT = Op->getValueType(0);
6929   LHS = DAG.getNode(ISD::ADD, dl, VT, RHS, DAG.getConstant(1, VT));
6930   return DAG.getNode(AArch64ISD::CSEL, dl, VT, RHS, LHS, CCVal, Cmp);
6931 }
6932 
6933 // The basic add/sub long vector instructions have variants with "2" on the end
6934 // which act on the high-half of their inputs. They are normally matched by
6935 // patterns like:
6936 //
6937 // (add (zeroext (extract_high LHS)),
6938 //      (zeroext (extract_high RHS)))
6939 // -> uaddl2 vD, vN, vM
6940 //
6941 // However, if one of the extracts is something like a duplicate, this
6942 // instruction can still be used profitably. This function puts the DAG into a
6943 // more appropriate form for those patterns to trigger.
performAddSubLongCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6944 static SDValue performAddSubLongCombine(SDNode *N,
6945                                         TargetLowering::DAGCombinerInfo &DCI,
6946                                         SelectionDAG &DAG) {
6947   if (DCI.isBeforeLegalizeOps())
6948     return SDValue();
6949 
6950   MVT VT = N->getSimpleValueType(0);
6951   if (!VT.is128BitVector()) {
6952     if (N->getOpcode() == ISD::ADD)
6953       return performSetccAddFolding(N, DAG);
6954     return SDValue();
6955   }
6956 
6957   // Make sure both branches are extended in the same way.
6958   SDValue LHS = N->getOperand(0);
6959   SDValue RHS = N->getOperand(1);
6960   if ((LHS.getOpcode() != ISD::ZERO_EXTEND &&
6961        LHS.getOpcode() != ISD::SIGN_EXTEND) ||
6962       LHS.getOpcode() != RHS.getOpcode())
6963     return SDValue();
6964 
6965   unsigned ExtType = LHS.getOpcode();
6966 
6967   // It's not worth doing if at least one of the inputs isn't already an
6968   // extract, but we don't know which it'll be so we have to try both.
6969   if (isEssentiallyExtractSubvector(LHS.getOperand(0))) {
6970     RHS = tryExtendDUPToExtractHigh(RHS.getOperand(0), DAG);
6971     if (!RHS.getNode())
6972       return SDValue();
6973 
6974     RHS = DAG.getNode(ExtType, SDLoc(N), VT, RHS);
6975   } else if (isEssentiallyExtractSubvector(RHS.getOperand(0))) {
6976     LHS = tryExtendDUPToExtractHigh(LHS.getOperand(0), DAG);
6977     if (!LHS.getNode())
6978       return SDValue();
6979 
6980     LHS = DAG.getNode(ExtType, SDLoc(N), VT, LHS);
6981   }
6982 
6983   return DAG.getNode(N->getOpcode(), SDLoc(N), VT, LHS, RHS);
6984 }
6985 
6986 // Massage DAGs which we can use the high-half "long" operations on into
6987 // something isel will recognize better. E.g.
6988 //
6989 // (aarch64_neon_umull (extract_high vec) (dupv64 scalar)) -->
6990 //   (aarch64_neon_umull (extract_high (v2i64 vec)))
6991 //                     (extract_high (v2i64 (dup128 scalar)))))
6992 //
tryCombineLongOpWithDup(unsigned IID,SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6993 static SDValue tryCombineLongOpWithDup(unsigned IID, SDNode *N,
6994                                        TargetLowering::DAGCombinerInfo &DCI,
6995                                        SelectionDAG &DAG) {
6996   if (DCI.isBeforeLegalizeOps())
6997     return SDValue();
6998 
6999   SDValue LHS = N->getOperand(1);
7000   SDValue RHS = N->getOperand(2);
7001   assert(LHS.getValueType().is64BitVector() &&
7002          RHS.getValueType().is64BitVector() &&
7003          "unexpected shape for long operation");
7004 
7005   // Either node could be a DUP, but it's not worth doing both of them (you'd
7006   // just as well use the non-high version) so look for a corresponding extract
7007   // operation on the other "wing".
7008   if (isEssentiallyExtractSubvector(LHS)) {
7009     RHS = tryExtendDUPToExtractHigh(RHS, DAG);
7010     if (!RHS.getNode())
7011       return SDValue();
7012   } else if (isEssentiallyExtractSubvector(RHS)) {
7013     LHS = tryExtendDUPToExtractHigh(LHS, DAG);
7014     if (!LHS.getNode())
7015       return SDValue();
7016   }
7017 
7018   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, SDLoc(N), N->getValueType(0),
7019                      N->getOperand(0), LHS, RHS);
7020 }
7021 
tryCombineShiftImm(unsigned IID,SDNode * N,SelectionDAG & DAG)7022 static SDValue tryCombineShiftImm(unsigned IID, SDNode *N, SelectionDAG &DAG) {
7023   MVT ElemTy = N->getSimpleValueType(0).getScalarType();
7024   unsigned ElemBits = ElemTy.getSizeInBits();
7025 
7026   int64_t ShiftAmount;
7027   if (BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(2))) {
7028     APInt SplatValue, SplatUndef;
7029     unsigned SplatBitSize;
7030     bool HasAnyUndefs;
7031     if (!BVN->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
7032                               HasAnyUndefs, ElemBits) ||
7033         SplatBitSize != ElemBits)
7034       return SDValue();
7035 
7036     ShiftAmount = SplatValue.getSExtValue();
7037   } else if (ConstantSDNode *CVN = dyn_cast<ConstantSDNode>(N->getOperand(2))) {
7038     ShiftAmount = CVN->getSExtValue();
7039   } else
7040     return SDValue();
7041 
7042   unsigned Opcode;
7043   bool IsRightShift;
7044   switch (IID) {
7045   default:
7046     llvm_unreachable("Unknown shift intrinsic");
7047   case Intrinsic::aarch64_neon_sqshl:
7048     Opcode = AArch64ISD::SQSHL_I;
7049     IsRightShift = false;
7050     break;
7051   case Intrinsic::aarch64_neon_uqshl:
7052     Opcode = AArch64ISD::UQSHL_I;
7053     IsRightShift = false;
7054     break;
7055   case Intrinsic::aarch64_neon_srshl:
7056     Opcode = AArch64ISD::SRSHR_I;
7057     IsRightShift = true;
7058     break;
7059   case Intrinsic::aarch64_neon_urshl:
7060     Opcode = AArch64ISD::URSHR_I;
7061     IsRightShift = true;
7062     break;
7063   case Intrinsic::aarch64_neon_sqshlu:
7064     Opcode = AArch64ISD::SQSHLU_I;
7065     IsRightShift = false;
7066     break;
7067   }
7068 
7069   if (IsRightShift && ShiftAmount <= -1 && ShiftAmount >= -(int)ElemBits)
7070     return DAG.getNode(Opcode, SDLoc(N), N->getValueType(0), N->getOperand(1),
7071                        DAG.getConstant(-ShiftAmount, MVT::i32));
7072   else if (!IsRightShift && ShiftAmount >= 0 && ShiftAmount < ElemBits)
7073     return DAG.getNode(Opcode, SDLoc(N), N->getValueType(0), N->getOperand(1),
7074                        DAG.getConstant(ShiftAmount, MVT::i32));
7075 
7076   return SDValue();
7077 }
7078 
7079 // The CRC32[BH] instructions ignore the high bits of their data operand. Since
7080 // the intrinsics must be legal and take an i32, this means there's almost
7081 // certainly going to be a zext in the DAG which we can eliminate.
tryCombineCRC32(unsigned Mask,SDNode * N,SelectionDAG & DAG)7082 static SDValue tryCombineCRC32(unsigned Mask, SDNode *N, SelectionDAG &DAG) {
7083   SDValue AndN = N->getOperand(2);
7084   if (AndN.getOpcode() != ISD::AND)
7085     return SDValue();
7086 
7087   ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(AndN.getOperand(1));
7088   if (!CMask || CMask->getZExtValue() != Mask)
7089     return SDValue();
7090 
7091   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, SDLoc(N), MVT::i32,
7092                      N->getOperand(0), N->getOperand(1), AndN.getOperand(0));
7093 }
7094 
performIntrinsicCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)7095 static SDValue performIntrinsicCombine(SDNode *N,
7096                                        TargetLowering::DAGCombinerInfo &DCI,
7097                                        const AArch64Subtarget *Subtarget) {
7098   SelectionDAG &DAG = DCI.DAG;
7099   unsigned IID = getIntrinsicID(N);
7100   switch (IID) {
7101   default:
7102     break;
7103   case Intrinsic::aarch64_neon_vcvtfxs2fp:
7104   case Intrinsic::aarch64_neon_vcvtfxu2fp:
7105     return tryCombineFixedPointConvert(N, DCI, DAG);
7106     break;
7107   case Intrinsic::aarch64_neon_fmax:
7108     return DAG.getNode(AArch64ISD::FMAX, SDLoc(N), N->getValueType(0),
7109                        N->getOperand(1), N->getOperand(2));
7110   case Intrinsic::aarch64_neon_fmin:
7111     return DAG.getNode(AArch64ISD::FMIN, SDLoc(N), N->getValueType(0),
7112                        N->getOperand(1), N->getOperand(2));
7113   case Intrinsic::aarch64_neon_smull:
7114   case Intrinsic::aarch64_neon_umull:
7115   case Intrinsic::aarch64_neon_pmull:
7116   case Intrinsic::aarch64_neon_sqdmull:
7117     return tryCombineLongOpWithDup(IID, N, DCI, DAG);
7118   case Intrinsic::aarch64_neon_sqshl:
7119   case Intrinsic::aarch64_neon_uqshl:
7120   case Intrinsic::aarch64_neon_sqshlu:
7121   case Intrinsic::aarch64_neon_srshl:
7122   case Intrinsic::aarch64_neon_urshl:
7123     return tryCombineShiftImm(IID, N, DAG);
7124   case Intrinsic::aarch64_crc32b:
7125   case Intrinsic::aarch64_crc32cb:
7126     return tryCombineCRC32(0xff, N, DAG);
7127   case Intrinsic::aarch64_crc32h:
7128   case Intrinsic::aarch64_crc32ch:
7129     return tryCombineCRC32(0xffff, N, DAG);
7130   }
7131   return SDValue();
7132 }
7133 
performExtendCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7134 static SDValue performExtendCombine(SDNode *N,
7135                                     TargetLowering::DAGCombinerInfo &DCI,
7136                                     SelectionDAG &DAG) {
7137   // If we see something like (zext (sabd (extract_high ...), (DUP ...))) then
7138   // we can convert that DUP into another extract_high (of a bigger DUP), which
7139   // helps the backend to decide that an sabdl2 would be useful, saving a real
7140   // extract_high operation.
7141   if (!DCI.isBeforeLegalizeOps() && N->getOpcode() == ISD::ZERO_EXTEND &&
7142       N->getOperand(0).getOpcode() == ISD::INTRINSIC_WO_CHAIN) {
7143     SDNode *ABDNode = N->getOperand(0).getNode();
7144     unsigned IID = getIntrinsicID(ABDNode);
7145     if (IID == Intrinsic::aarch64_neon_sabd ||
7146         IID == Intrinsic::aarch64_neon_uabd) {
7147       SDValue NewABD = tryCombineLongOpWithDup(IID, ABDNode, DCI, DAG);
7148       if (!NewABD.getNode())
7149         return SDValue();
7150 
7151       return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), N->getValueType(0),
7152                          NewABD);
7153     }
7154   }
7155 
7156   // This is effectively a custom type legalization for AArch64.
7157   //
7158   // Type legalization will split an extend of a small, legal, type to a larger
7159   // illegal type by first splitting the destination type, often creating
7160   // illegal source types, which then get legalized in isel-confusing ways,
7161   // leading to really terrible codegen. E.g.,
7162   //   %result = v8i32 sext v8i8 %value
7163   // becomes
7164   //   %losrc = extract_subreg %value, ...
7165   //   %hisrc = extract_subreg %value, ...
7166   //   %lo = v4i32 sext v4i8 %losrc
7167   //   %hi = v4i32 sext v4i8 %hisrc
7168   // Things go rapidly downhill from there.
7169   //
7170   // For AArch64, the [sz]ext vector instructions can only go up one element
7171   // size, so we can, e.g., extend from i8 to i16, but to go from i8 to i32
7172   // take two instructions.
7173   //
7174   // This implies that the most efficient way to do the extend from v8i8
7175   // to two v4i32 values is to first extend the v8i8 to v8i16, then do
7176   // the normal splitting to happen for the v8i16->v8i32.
7177 
7178   // This is pre-legalization to catch some cases where the default
7179   // type legalization will create ill-tempered code.
7180   if (!DCI.isBeforeLegalizeOps())
7181     return SDValue();
7182 
7183   // We're only interested in cleaning things up for non-legal vector types
7184   // here. If both the source and destination are legal, things will just
7185   // work naturally without any fiddling.
7186   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
7187   EVT ResVT = N->getValueType(0);
7188   if (!ResVT.isVector() || TLI.isTypeLegal(ResVT))
7189     return SDValue();
7190   // If the vector type isn't a simple VT, it's beyond the scope of what
7191   // we're  worried about here. Let legalization do its thing and hope for
7192   // the best.
7193   if (!ResVT.isSimple())
7194     return SDValue();
7195 
7196   SDValue Src = N->getOperand(0);
7197   MVT SrcVT = Src->getValueType(0).getSimpleVT();
7198   // If the source VT is a 64-bit vector, we can play games and get the
7199   // better results we want.
7200   if (SrcVT.getSizeInBits() != 64)
7201     return SDValue();
7202 
7203   unsigned SrcEltSize = SrcVT.getVectorElementType().getSizeInBits();
7204   unsigned ElementCount = SrcVT.getVectorNumElements();
7205   SrcVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize * 2), ElementCount);
7206   SDLoc DL(N);
7207   Src = DAG.getNode(N->getOpcode(), DL, SrcVT, Src);
7208 
7209   // Now split the rest of the operation into two halves, each with a 64
7210   // bit source.
7211   EVT LoVT, HiVT;
7212   SDValue Lo, Hi;
7213   unsigned NumElements = ResVT.getVectorNumElements();
7214   assert(!(NumElements & 1) && "Splitting vector, but not in half!");
7215   LoVT = HiVT = EVT::getVectorVT(*DAG.getContext(),
7216                                  ResVT.getVectorElementType(), NumElements / 2);
7217 
7218   EVT InNVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getVectorElementType(),
7219                                LoVT.getVectorNumElements());
7220   Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InNVT, Src,
7221                    DAG.getIntPtrConstant(0));
7222   Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InNVT, Src,
7223                    DAG.getIntPtrConstant(InNVT.getVectorNumElements()));
7224   Lo = DAG.getNode(N->getOpcode(), DL, LoVT, Lo);
7225   Hi = DAG.getNode(N->getOpcode(), DL, HiVT, Hi);
7226 
7227   // Now combine the parts back together so we still have a single result
7228   // like the combiner expects.
7229   return DAG.getNode(ISD::CONCAT_VECTORS, DL, ResVT, Lo, Hi);
7230 }
7231 
7232 /// Replace a splat of a scalar to a vector store by scalar stores of the scalar
7233 /// value. The load store optimizer pass will merge them to store pair stores.
7234 /// This has better performance than a splat of the scalar followed by a split
7235 /// vector store. Even if the stores are not merged it is four stores vs a dup,
7236 /// followed by an ext.b and two stores.
replaceSplatVectorStore(SelectionDAG & DAG,StoreSDNode * St)7237 static SDValue replaceSplatVectorStore(SelectionDAG &DAG, StoreSDNode *St) {
7238   SDValue StVal = St->getValue();
7239   EVT VT = StVal.getValueType();
7240 
7241   // Don't replace floating point stores, they possibly won't be transformed to
7242   // stp because of the store pair suppress pass.
7243   if (VT.isFloatingPoint())
7244     return SDValue();
7245 
7246   // Check for insert vector elements.
7247   if (StVal.getOpcode() != ISD::INSERT_VECTOR_ELT)
7248     return SDValue();
7249 
7250   // We can express a splat as store pair(s) for 2 or 4 elements.
7251   unsigned NumVecElts = VT.getVectorNumElements();
7252   if (NumVecElts != 4 && NumVecElts != 2)
7253     return SDValue();
7254   SDValue SplatVal = StVal.getOperand(1);
7255   unsigned RemainInsertElts = NumVecElts - 1;
7256 
7257   // Check that this is a splat.
7258   while (--RemainInsertElts) {
7259     SDValue NextInsertElt = StVal.getOperand(0);
7260     if (NextInsertElt.getOpcode() != ISD::INSERT_VECTOR_ELT)
7261       return SDValue();
7262     if (NextInsertElt.getOperand(1) != SplatVal)
7263       return SDValue();
7264     StVal = NextInsertElt;
7265   }
7266   unsigned OrigAlignment = St->getAlignment();
7267   unsigned EltOffset = NumVecElts == 4 ? 4 : 8;
7268   unsigned Alignment = std::min(OrigAlignment, EltOffset);
7269 
7270   // Create scalar stores. This is at least as good as the code sequence for a
7271   // split unaligned store wich is a dup.s, ext.b, and two stores.
7272   // Most of the time the three stores should be replaced by store pair
7273   // instructions (stp).
7274   SDLoc DL(St);
7275   SDValue BasePtr = St->getBasePtr();
7276   SDValue NewST1 =
7277       DAG.getStore(St->getChain(), DL, SplatVal, BasePtr, St->getPointerInfo(),
7278                    St->isVolatile(), St->isNonTemporal(), St->getAlignment());
7279 
7280   unsigned Offset = EltOffset;
7281   while (--NumVecElts) {
7282     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i64, BasePtr,
7283                                     DAG.getConstant(Offset, MVT::i64));
7284     NewST1 = DAG.getStore(NewST1.getValue(0), DL, SplatVal, OffsetPtr,
7285                           St->getPointerInfo(), St->isVolatile(),
7286                           St->isNonTemporal(), Alignment);
7287     Offset += EltOffset;
7288   }
7289   return NewST1;
7290 }
7291 
performSTORECombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG,const AArch64Subtarget * Subtarget)7292 static SDValue performSTORECombine(SDNode *N,
7293                                    TargetLowering::DAGCombinerInfo &DCI,
7294                                    SelectionDAG &DAG,
7295                                    const AArch64Subtarget *Subtarget) {
7296   if (!DCI.isBeforeLegalize())
7297     return SDValue();
7298 
7299   StoreSDNode *S = cast<StoreSDNode>(N);
7300   if (S->isVolatile())
7301     return SDValue();
7302 
7303   // Cyclone has bad performance on unaligned 16B stores when crossing line and
7304   // page boundries. We want to split such stores.
7305   if (!Subtarget->isCyclone())
7306     return SDValue();
7307 
7308   // Don't split at Oz.
7309   MachineFunction &MF = DAG.getMachineFunction();
7310   bool IsMinSize = MF.getFunction()->getAttributes().hasAttribute(
7311       AttributeSet::FunctionIndex, Attribute::MinSize);
7312   if (IsMinSize)
7313     return SDValue();
7314 
7315   SDValue StVal = S->getValue();
7316   EVT VT = StVal.getValueType();
7317 
7318   // Don't split v2i64 vectors. Memcpy lowering produces those and splitting
7319   // those up regresses performance on micro-benchmarks and olden/bh.
7320   if (!VT.isVector() || VT.getVectorNumElements() < 2 || VT == MVT::v2i64)
7321     return SDValue();
7322 
7323   // Split unaligned 16B stores. They are terrible for performance.
7324   // Don't split stores with alignment of 1 or 2. Code that uses clang vector
7325   // extensions can use this to mark that it does not want splitting to happen
7326   // (by underspecifying alignment to be 1 or 2). Furthermore, the chance of
7327   // eliminating alignment hazards is only 1 in 8 for alignment of 2.
7328   if (VT.getSizeInBits() != 128 || S->getAlignment() >= 16 ||
7329       S->getAlignment() <= 2)
7330     return SDValue();
7331 
7332   // If we get a splat of a scalar convert this vector store to a store of
7333   // scalars. They will be merged into store pairs thereby removing two
7334   // instructions.
7335   SDValue ReplacedSplat = replaceSplatVectorStore(DAG, S);
7336   if (ReplacedSplat != SDValue())
7337     return ReplacedSplat;
7338 
7339   SDLoc DL(S);
7340   unsigned NumElts = VT.getVectorNumElements() / 2;
7341   // Split VT into two.
7342   EVT HalfVT =
7343       EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(), NumElts);
7344   SDValue SubVector0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, StVal,
7345                                    DAG.getIntPtrConstant(0));
7346   SDValue SubVector1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, StVal,
7347                                    DAG.getIntPtrConstant(NumElts));
7348   SDValue BasePtr = S->getBasePtr();
7349   SDValue NewST1 =
7350       DAG.getStore(S->getChain(), DL, SubVector0, BasePtr, S->getPointerInfo(),
7351                    S->isVolatile(), S->isNonTemporal(), S->getAlignment());
7352   SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i64, BasePtr,
7353                                   DAG.getConstant(8, MVT::i64));
7354   return DAG.getStore(NewST1.getValue(0), DL, SubVector1, OffsetPtr,
7355                       S->getPointerInfo(), S->isVolatile(), S->isNonTemporal(),
7356                       S->getAlignment());
7357 }
7358 
7359 /// Target-specific DAG combine function for post-increment LD1 (lane) and
7360 /// post-increment LD1R.
performPostLD1Combine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,bool IsLaneOp)7361 static SDValue performPostLD1Combine(SDNode *N,
7362                                      TargetLowering::DAGCombinerInfo &DCI,
7363                                      bool IsLaneOp) {
7364   if (DCI.isBeforeLegalizeOps())
7365     return SDValue();
7366 
7367   SelectionDAG &DAG = DCI.DAG;
7368   EVT VT = N->getValueType(0);
7369 
7370   unsigned LoadIdx = IsLaneOp ? 1 : 0;
7371   SDNode *LD = N->getOperand(LoadIdx).getNode();
7372   // If it is not LOAD, can not do such combine.
7373   if (LD->getOpcode() != ISD::LOAD)
7374     return SDValue();
7375 
7376   LoadSDNode *LoadSDN = cast<LoadSDNode>(LD);
7377   EVT MemVT = LoadSDN->getMemoryVT();
7378   // Check if memory operand is the same type as the vector element.
7379   if (MemVT != VT.getVectorElementType())
7380     return SDValue();
7381 
7382   // Check if there are other uses. If so, do not combine as it will introduce
7383   // an extra load.
7384   for (SDNode::use_iterator UI = LD->use_begin(), UE = LD->use_end(); UI != UE;
7385        ++UI) {
7386     if (UI.getUse().getResNo() == 1) // Ignore uses of the chain result.
7387       continue;
7388     if (*UI != N)
7389       return SDValue();
7390   }
7391 
7392   SDValue Addr = LD->getOperand(1);
7393   SDValue Vector = N->getOperand(0);
7394   // Search for a use of the address operand that is an increment.
7395   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(), UE =
7396        Addr.getNode()->use_end(); UI != UE; ++UI) {
7397     SDNode *User = *UI;
7398     if (User->getOpcode() != ISD::ADD
7399         || UI.getUse().getResNo() != Addr.getResNo())
7400       continue;
7401 
7402     // Check that the add is independent of the load.  Otherwise, folding it
7403     // would create a cycle.
7404     if (User->isPredecessorOf(LD) || LD->isPredecessorOf(User))
7405       continue;
7406     // Also check that add is not used in the vector operand.  This would also
7407     // create a cycle.
7408     if (User->isPredecessorOf(Vector.getNode()))
7409       continue;
7410 
7411     // If the increment is a constant, it must match the memory ref size.
7412     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
7413     if (ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode())) {
7414       uint32_t IncVal = CInc->getZExtValue();
7415       unsigned NumBytes = VT.getScalarSizeInBits() / 8;
7416       if (IncVal != NumBytes)
7417         continue;
7418       Inc = DAG.getRegister(AArch64::XZR, MVT::i64);
7419     }
7420 
7421     SmallVector<SDValue, 8> Ops;
7422     Ops.push_back(LD->getOperand(0));  // Chain
7423     if (IsLaneOp) {
7424       Ops.push_back(Vector);           // The vector to be inserted
7425       Ops.push_back(N->getOperand(2)); // The lane to be inserted in the vector
7426     }
7427     Ops.push_back(Addr);
7428     Ops.push_back(Inc);
7429 
7430     EVT Tys[3] = { VT, MVT::i64, MVT::Other };
7431     SDVTList SDTys = DAG.getVTList(ArrayRef<EVT>(Tys, 3));
7432     unsigned NewOp = IsLaneOp ? AArch64ISD::LD1LANEpost : AArch64ISD::LD1DUPpost;
7433     SDValue UpdN = DAG.getMemIntrinsicNode(NewOp, SDLoc(N), SDTys, Ops,
7434                                            MemVT,
7435                                            LoadSDN->getMemOperand());
7436 
7437     // Update the uses.
7438     std::vector<SDValue> NewResults;
7439     NewResults.push_back(SDValue(LD, 0));             // The result of load
7440     NewResults.push_back(SDValue(UpdN.getNode(), 2)); // Chain
7441     DCI.CombineTo(LD, NewResults);
7442     DCI.CombineTo(N, SDValue(UpdN.getNode(), 0));     // Dup/Inserted Result
7443     DCI.CombineTo(User, SDValue(UpdN.getNode(), 1));  // Write back register
7444 
7445     break;
7446   }
7447   return SDValue();
7448 }
7449 
7450 /// Target-specific DAG combine function for NEON load/store intrinsics
7451 /// to merge base address updates.
performNEONPostLDSTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7452 static SDValue performNEONPostLDSTCombine(SDNode *N,
7453                                           TargetLowering::DAGCombinerInfo &DCI,
7454                                           SelectionDAG &DAG) {
7455   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
7456     return SDValue();
7457 
7458   unsigned AddrOpIdx = N->getNumOperands() - 1;
7459   SDValue Addr = N->getOperand(AddrOpIdx);
7460 
7461   // Search for a use of the address operand that is an increment.
7462   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(),
7463        UE = Addr.getNode()->use_end(); UI != UE; ++UI) {
7464     SDNode *User = *UI;
7465     if (User->getOpcode() != ISD::ADD ||
7466         UI.getUse().getResNo() != Addr.getResNo())
7467       continue;
7468 
7469     // Check that the add is independent of the load/store.  Otherwise, folding
7470     // it would create a cycle.
7471     if (User->isPredecessorOf(N) || N->isPredecessorOf(User))
7472       continue;
7473 
7474     // Find the new opcode for the updating load/store.
7475     bool IsStore = false;
7476     bool IsLaneOp = false;
7477     bool IsDupOp = false;
7478     unsigned NewOpc = 0;
7479     unsigned NumVecs = 0;
7480     unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
7481     switch (IntNo) {
7482     default: llvm_unreachable("unexpected intrinsic for Neon base update");
7483     case Intrinsic::aarch64_neon_ld2:       NewOpc = AArch64ISD::LD2post;
7484       NumVecs = 2; break;
7485     case Intrinsic::aarch64_neon_ld3:       NewOpc = AArch64ISD::LD3post;
7486       NumVecs = 3; break;
7487     case Intrinsic::aarch64_neon_ld4:       NewOpc = AArch64ISD::LD4post;
7488       NumVecs = 4; break;
7489     case Intrinsic::aarch64_neon_st2:       NewOpc = AArch64ISD::ST2post;
7490       NumVecs = 2; IsStore = true; break;
7491     case Intrinsic::aarch64_neon_st3:       NewOpc = AArch64ISD::ST3post;
7492       NumVecs = 3; IsStore = true; break;
7493     case Intrinsic::aarch64_neon_st4:       NewOpc = AArch64ISD::ST4post;
7494       NumVecs = 4; IsStore = true; break;
7495     case Intrinsic::aarch64_neon_ld1x2:     NewOpc = AArch64ISD::LD1x2post;
7496       NumVecs = 2; break;
7497     case Intrinsic::aarch64_neon_ld1x3:     NewOpc = AArch64ISD::LD1x3post;
7498       NumVecs = 3; break;
7499     case Intrinsic::aarch64_neon_ld1x4:     NewOpc = AArch64ISD::LD1x4post;
7500       NumVecs = 4; break;
7501     case Intrinsic::aarch64_neon_st1x2:     NewOpc = AArch64ISD::ST1x2post;
7502       NumVecs = 2; IsStore = true; break;
7503     case Intrinsic::aarch64_neon_st1x3:     NewOpc = AArch64ISD::ST1x3post;
7504       NumVecs = 3; IsStore = true; break;
7505     case Intrinsic::aarch64_neon_st1x4:     NewOpc = AArch64ISD::ST1x4post;
7506       NumVecs = 4; IsStore = true; break;
7507     case Intrinsic::aarch64_neon_ld2r:      NewOpc = AArch64ISD::LD2DUPpost;
7508       NumVecs = 2; IsDupOp = true; break;
7509     case Intrinsic::aarch64_neon_ld3r:      NewOpc = AArch64ISD::LD3DUPpost;
7510       NumVecs = 3; IsDupOp = true; break;
7511     case Intrinsic::aarch64_neon_ld4r:      NewOpc = AArch64ISD::LD4DUPpost;
7512       NumVecs = 4; IsDupOp = true; break;
7513     case Intrinsic::aarch64_neon_ld2lane:   NewOpc = AArch64ISD::LD2LANEpost;
7514       NumVecs = 2; IsLaneOp = true; break;
7515     case Intrinsic::aarch64_neon_ld3lane:   NewOpc = AArch64ISD::LD3LANEpost;
7516       NumVecs = 3; IsLaneOp = true; break;
7517     case Intrinsic::aarch64_neon_ld4lane:   NewOpc = AArch64ISD::LD4LANEpost;
7518       NumVecs = 4; IsLaneOp = true; break;
7519     case Intrinsic::aarch64_neon_st2lane:   NewOpc = AArch64ISD::ST2LANEpost;
7520       NumVecs = 2; IsStore = true; IsLaneOp = true; break;
7521     case Intrinsic::aarch64_neon_st3lane:   NewOpc = AArch64ISD::ST3LANEpost;
7522       NumVecs = 3; IsStore = true; IsLaneOp = true; break;
7523     case Intrinsic::aarch64_neon_st4lane:   NewOpc = AArch64ISD::ST4LANEpost;
7524       NumVecs = 4; IsStore = true; IsLaneOp = true; break;
7525     }
7526 
7527     EVT VecTy;
7528     if (IsStore)
7529       VecTy = N->getOperand(2).getValueType();
7530     else
7531       VecTy = N->getValueType(0);
7532 
7533     // If the increment is a constant, it must match the memory ref size.
7534     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
7535     if (ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode())) {
7536       uint32_t IncVal = CInc->getZExtValue();
7537       unsigned NumBytes = NumVecs * VecTy.getSizeInBits() / 8;
7538       if (IsLaneOp || IsDupOp)
7539         NumBytes /= VecTy.getVectorNumElements();
7540       if (IncVal != NumBytes)
7541         continue;
7542       Inc = DAG.getRegister(AArch64::XZR, MVT::i64);
7543     }
7544     SmallVector<SDValue, 8> Ops;
7545     Ops.push_back(N->getOperand(0)); // Incoming chain
7546     // Load lane and store have vector list as input.
7547     if (IsLaneOp || IsStore)
7548       for (unsigned i = 2; i < AddrOpIdx; ++i)
7549         Ops.push_back(N->getOperand(i));
7550     Ops.push_back(Addr); // Base register
7551     Ops.push_back(Inc);
7552 
7553     // Return Types.
7554     EVT Tys[6];
7555     unsigned NumResultVecs = (IsStore ? 0 : NumVecs);
7556     unsigned n;
7557     for (n = 0; n < NumResultVecs; ++n)
7558       Tys[n] = VecTy;
7559     Tys[n++] = MVT::i64;  // Type of write back register
7560     Tys[n] = MVT::Other;  // Type of the chain
7561     SDVTList SDTys = DAG.getVTList(ArrayRef<EVT>(Tys, NumResultVecs + 2));
7562 
7563     MemIntrinsicSDNode *MemInt = cast<MemIntrinsicSDNode>(N);
7564     SDValue UpdN = DAG.getMemIntrinsicNode(NewOpc, SDLoc(N), SDTys, Ops,
7565                                            MemInt->getMemoryVT(),
7566                                            MemInt->getMemOperand());
7567 
7568     // Update the uses.
7569     std::vector<SDValue> NewResults;
7570     for (unsigned i = 0; i < NumResultVecs; ++i) {
7571       NewResults.push_back(SDValue(UpdN.getNode(), i));
7572     }
7573     NewResults.push_back(SDValue(UpdN.getNode(), NumResultVecs + 1));
7574     DCI.CombineTo(N, NewResults);
7575     DCI.CombineTo(User, SDValue(UpdN.getNode(), NumResultVecs));
7576 
7577     break;
7578   }
7579   return SDValue();
7580 }
7581 
7582 // Optimize compare with zero and branch.
performBRCONDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7583 static SDValue performBRCONDCombine(SDNode *N,
7584                                     TargetLowering::DAGCombinerInfo &DCI,
7585                                     SelectionDAG &DAG) {
7586   SDValue Chain = N->getOperand(0);
7587   SDValue Dest = N->getOperand(1);
7588   SDValue CCVal = N->getOperand(2);
7589   SDValue Cmp = N->getOperand(3);
7590 
7591   assert(isa<ConstantSDNode>(CCVal) && "Expected a ConstantSDNode here!");
7592   unsigned CC = cast<ConstantSDNode>(CCVal)->getZExtValue();
7593   if (CC != AArch64CC::EQ && CC != AArch64CC::NE)
7594     return SDValue();
7595 
7596   unsigned CmpOpc = Cmp.getOpcode();
7597   if (CmpOpc != AArch64ISD::ADDS && CmpOpc != AArch64ISD::SUBS)
7598     return SDValue();
7599 
7600   // Only attempt folding if there is only one use of the flag and no use of the
7601   // value.
7602   if (!Cmp->hasNUsesOfValue(0, 0) || !Cmp->hasNUsesOfValue(1, 1))
7603     return SDValue();
7604 
7605   SDValue LHS = Cmp.getOperand(0);
7606   SDValue RHS = Cmp.getOperand(1);
7607 
7608   assert(LHS.getValueType() == RHS.getValueType() &&
7609          "Expected the value type to be the same for both operands!");
7610   if (LHS.getValueType() != MVT::i32 && LHS.getValueType() != MVT::i64)
7611     return SDValue();
7612 
7613   if (isa<ConstantSDNode>(LHS) && cast<ConstantSDNode>(LHS)->isNullValue())
7614     std::swap(LHS, RHS);
7615 
7616   if (!isa<ConstantSDNode>(RHS) || !cast<ConstantSDNode>(RHS)->isNullValue())
7617     return SDValue();
7618 
7619   if (LHS.getOpcode() == ISD::SHL || LHS.getOpcode() == ISD::SRA ||
7620       LHS.getOpcode() == ISD::SRL)
7621     return SDValue();
7622 
7623   // Fold the compare into the branch instruction.
7624   SDValue BR;
7625   if (CC == AArch64CC::EQ)
7626     BR = DAG.getNode(AArch64ISD::CBZ, SDLoc(N), MVT::Other, Chain, LHS, Dest);
7627   else
7628     BR = DAG.getNode(AArch64ISD::CBNZ, SDLoc(N), MVT::Other, Chain, LHS, Dest);
7629 
7630   // Do not add new nodes to DAG combiner worklist.
7631   DCI.CombineTo(N, BR, false);
7632 
7633   return SDValue();
7634 }
7635 
7636 // vselect (v1i1 setcc) ->
7637 //     vselect (v1iXX setcc)  (XX is the size of the compared operand type)
7638 // FIXME: Currently the type legalizer can't handle VSELECT having v1i1 as
7639 // condition. If it can legalize "VSELECT v1i1" correctly, no need to combine
7640 // such VSELECT.
performVSelectCombine(SDNode * N,SelectionDAG & DAG)7641 static SDValue performVSelectCombine(SDNode *N, SelectionDAG &DAG) {
7642   SDValue N0 = N->getOperand(0);
7643   EVT CCVT = N0.getValueType();
7644 
7645   if (N0.getOpcode() != ISD::SETCC || CCVT.getVectorNumElements() != 1 ||
7646       CCVT.getVectorElementType() != MVT::i1)
7647     return SDValue();
7648 
7649   EVT ResVT = N->getValueType(0);
7650   EVT CmpVT = N0.getOperand(0).getValueType();
7651   // Only combine when the result type is of the same size as the compared
7652   // operands.
7653   if (ResVT.getSizeInBits() != CmpVT.getSizeInBits())
7654     return SDValue();
7655 
7656   SDValue IfTrue = N->getOperand(1);
7657   SDValue IfFalse = N->getOperand(2);
7658   SDValue SetCC =
7659       DAG.getSetCC(SDLoc(N), CmpVT.changeVectorElementTypeToInteger(),
7660                    N0.getOperand(0), N0.getOperand(1),
7661                    cast<CondCodeSDNode>(N0.getOperand(2))->get());
7662   return DAG.getNode(ISD::VSELECT, SDLoc(N), ResVT, SetCC,
7663                      IfTrue, IfFalse);
7664 }
7665 
7666 /// A vector select: "(select vL, vR, (setcc LHS, RHS))" is best performed with
7667 /// the compare-mask instructions rather than going via NZCV, even if LHS and
7668 /// RHS are really scalar. This replaces any scalar setcc in the above pattern
7669 /// with a vector one followed by a DUP shuffle on the result.
performSelectCombine(SDNode * N,SelectionDAG & DAG)7670 static SDValue performSelectCombine(SDNode *N, SelectionDAG &DAG) {
7671   SDValue N0 = N->getOperand(0);
7672   EVT ResVT = N->getValueType(0);
7673 
7674   if (!N->getOperand(1).getValueType().isVector())
7675     return SDValue();
7676 
7677   if (N0.getOpcode() != ISD::SETCC || N0.getValueType() != MVT::i1)
7678     return SDValue();
7679 
7680   SDLoc DL(N0);
7681 
7682   EVT SrcVT = N0.getOperand(0).getValueType();
7683   SrcVT = EVT::getVectorVT(*DAG.getContext(), SrcVT,
7684                            ResVT.getSizeInBits() / SrcVT.getSizeInBits());
7685   EVT CCVT = SrcVT.changeVectorElementTypeToInteger();
7686 
7687   // First perform a vector comparison, where lane 0 is the one we're interested
7688   // in.
7689   SDValue LHS =
7690       DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, SrcVT, N0.getOperand(0));
7691   SDValue RHS =
7692       DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, SrcVT, N0.getOperand(1));
7693   SDValue SetCC = DAG.getNode(ISD::SETCC, DL, CCVT, LHS, RHS, N0.getOperand(2));
7694 
7695   // Now duplicate the comparison mask we want across all other lanes.
7696   SmallVector<int, 8> DUPMask(CCVT.getVectorNumElements(), 0);
7697   SDValue Mask = DAG.getVectorShuffle(CCVT, DL, SetCC, SetCC, DUPMask.data());
7698   Mask = DAG.getNode(ISD::BITCAST, DL, ResVT.changeVectorElementTypeToInteger(),
7699                      Mask);
7700 
7701   return DAG.getSelect(DL, ResVT, Mask, N->getOperand(1), N->getOperand(2));
7702 }
7703 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const7704 SDValue AArch64TargetLowering::PerformDAGCombine(SDNode *N,
7705                                                  DAGCombinerInfo &DCI) const {
7706   SelectionDAG &DAG = DCI.DAG;
7707   switch (N->getOpcode()) {
7708   default:
7709     break;
7710   case ISD::ADD:
7711   case ISD::SUB:
7712     return performAddSubLongCombine(N, DCI, DAG);
7713   case ISD::XOR:
7714     return performXorCombine(N, DAG, DCI, Subtarget);
7715   case ISD::MUL:
7716     return performMulCombine(N, DAG, DCI, Subtarget);
7717   case ISD::SINT_TO_FP:
7718   case ISD::UINT_TO_FP:
7719     return performIntToFpCombine(N, DAG);
7720   case ISD::OR:
7721     return performORCombine(N, DCI, Subtarget);
7722   case ISD::INTRINSIC_WO_CHAIN:
7723     return performIntrinsicCombine(N, DCI, Subtarget);
7724   case ISD::ANY_EXTEND:
7725   case ISD::ZERO_EXTEND:
7726   case ISD::SIGN_EXTEND:
7727     return performExtendCombine(N, DCI, DAG);
7728   case ISD::BITCAST:
7729     return performBitcastCombine(N, DCI, DAG);
7730   case ISD::CONCAT_VECTORS:
7731     return performConcatVectorsCombine(N, DCI, DAG);
7732   case ISD::SELECT:
7733     return performSelectCombine(N, DAG);
7734   case ISD::VSELECT:
7735     return performVSelectCombine(N, DCI.DAG);
7736   case ISD::STORE:
7737     return performSTORECombine(N, DCI, DAG, Subtarget);
7738   case AArch64ISD::BRCOND:
7739     return performBRCONDCombine(N, DCI, DAG);
7740   case AArch64ISD::DUP:
7741     return performPostLD1Combine(N, DCI, false);
7742   case ISD::INSERT_VECTOR_ELT:
7743     return performPostLD1Combine(N, DCI, true);
7744   case ISD::INTRINSIC_VOID:
7745   case ISD::INTRINSIC_W_CHAIN:
7746     switch (cast<ConstantSDNode>(N->getOperand(1))->getZExtValue()) {
7747     case Intrinsic::aarch64_neon_ld2:
7748     case Intrinsic::aarch64_neon_ld3:
7749     case Intrinsic::aarch64_neon_ld4:
7750     case Intrinsic::aarch64_neon_ld1x2:
7751     case Intrinsic::aarch64_neon_ld1x3:
7752     case Intrinsic::aarch64_neon_ld1x4:
7753     case Intrinsic::aarch64_neon_ld2lane:
7754     case Intrinsic::aarch64_neon_ld3lane:
7755     case Intrinsic::aarch64_neon_ld4lane:
7756     case Intrinsic::aarch64_neon_ld2r:
7757     case Intrinsic::aarch64_neon_ld3r:
7758     case Intrinsic::aarch64_neon_ld4r:
7759     case Intrinsic::aarch64_neon_st2:
7760     case Intrinsic::aarch64_neon_st3:
7761     case Intrinsic::aarch64_neon_st4:
7762     case Intrinsic::aarch64_neon_st1x2:
7763     case Intrinsic::aarch64_neon_st1x3:
7764     case Intrinsic::aarch64_neon_st1x4:
7765     case Intrinsic::aarch64_neon_st2lane:
7766     case Intrinsic::aarch64_neon_st3lane:
7767     case Intrinsic::aarch64_neon_st4lane:
7768       return performNEONPostLDSTCombine(N, DCI, DAG);
7769     default:
7770       break;
7771     }
7772   }
7773   return SDValue();
7774 }
7775 
7776 // Check if the return value is used as only a return value, as otherwise
7777 // we can't perform a tail-call. In particular, we need to check for
7778 // target ISD nodes that are returns and any other "odd" constructs
7779 // that the generic analysis code won't necessarily catch.
isUsedByReturnOnly(SDNode * N,SDValue & Chain) const7780 bool AArch64TargetLowering::isUsedByReturnOnly(SDNode *N,
7781                                                SDValue &Chain) const {
7782   if (N->getNumValues() != 1)
7783     return false;
7784   if (!N->hasNUsesOfValue(1, 0))
7785     return false;
7786 
7787   SDValue TCChain = Chain;
7788   SDNode *Copy = *N->use_begin();
7789   if (Copy->getOpcode() == ISD::CopyToReg) {
7790     // If the copy has a glue operand, we conservatively assume it isn't safe to
7791     // perform a tail call.
7792     if (Copy->getOperand(Copy->getNumOperands() - 1).getValueType() ==
7793         MVT::Glue)
7794       return false;
7795     TCChain = Copy->getOperand(0);
7796   } else if (Copy->getOpcode() != ISD::FP_EXTEND)
7797     return false;
7798 
7799   bool HasRet = false;
7800   for (SDNode *Node : Copy->uses()) {
7801     if (Node->getOpcode() != AArch64ISD::RET_FLAG)
7802       return false;
7803     HasRet = true;
7804   }
7805 
7806   if (!HasRet)
7807     return false;
7808 
7809   Chain = TCChain;
7810   return true;
7811 }
7812 
7813 // Return whether the an instruction can potentially be optimized to a tail
7814 // call. This will cause the optimizers to attempt to move, or duplicate,
7815 // return instructions to help enable tail call optimizations for this
7816 // instruction.
mayBeEmittedAsTailCall(CallInst * CI) const7817 bool AArch64TargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
7818   if (!CI->isTailCall())
7819     return false;
7820 
7821   return true;
7822 }
7823 
getIndexedAddressParts(SDNode * Op,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,bool & IsInc,SelectionDAG & DAG) const7824 bool AArch64TargetLowering::getIndexedAddressParts(SDNode *Op, SDValue &Base,
7825                                                    SDValue &Offset,
7826                                                    ISD::MemIndexedMode &AM,
7827                                                    bool &IsInc,
7828                                                    SelectionDAG &DAG) const {
7829   if (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB)
7830     return false;
7831 
7832   Base = Op->getOperand(0);
7833   // All of the indexed addressing mode instructions take a signed
7834   // 9 bit immediate offset.
7835   if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Op->getOperand(1))) {
7836     int64_t RHSC = (int64_t)RHS->getZExtValue();
7837     if (RHSC >= 256 || RHSC <= -256)
7838       return false;
7839     IsInc = (Op->getOpcode() == ISD::ADD);
7840     Offset = Op->getOperand(1);
7841     return true;
7842   }
7843   return false;
7844 }
7845 
getPreIndexedAddressParts(SDNode * N,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const7846 bool AArch64TargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
7847                                                       SDValue &Offset,
7848                                                       ISD::MemIndexedMode &AM,
7849                                                       SelectionDAG &DAG) const {
7850   EVT VT;
7851   SDValue Ptr;
7852   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7853     VT = LD->getMemoryVT();
7854     Ptr = LD->getBasePtr();
7855   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7856     VT = ST->getMemoryVT();
7857     Ptr = ST->getBasePtr();
7858   } else
7859     return false;
7860 
7861   bool IsInc;
7862   if (!getIndexedAddressParts(Ptr.getNode(), Base, Offset, AM, IsInc, DAG))
7863     return false;
7864   AM = IsInc ? ISD::PRE_INC : ISD::PRE_DEC;
7865   return true;
7866 }
7867 
getPostIndexedAddressParts(SDNode * N,SDNode * Op,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const7868 bool AArch64TargetLowering::getPostIndexedAddressParts(
7869     SDNode *N, SDNode *Op, SDValue &Base, SDValue &Offset,
7870     ISD::MemIndexedMode &AM, SelectionDAG &DAG) const {
7871   EVT VT;
7872   SDValue Ptr;
7873   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7874     VT = LD->getMemoryVT();
7875     Ptr = LD->getBasePtr();
7876   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7877     VT = ST->getMemoryVT();
7878     Ptr = ST->getBasePtr();
7879   } else
7880     return false;
7881 
7882   bool IsInc;
7883   if (!getIndexedAddressParts(Op, Base, Offset, AM, IsInc, DAG))
7884     return false;
7885   // Post-indexing updates the base, so it's not a valid transform
7886   // if that's not the same as the load's pointer.
7887   if (Ptr != Base)
7888     return false;
7889   AM = IsInc ? ISD::POST_INC : ISD::POST_DEC;
7890   return true;
7891 }
7892 
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const7893 void AArch64TargetLowering::ReplaceNodeResults(
7894     SDNode *N, SmallVectorImpl<SDValue> &Results, SelectionDAG &DAG) const {
7895   switch (N->getOpcode()) {
7896   default:
7897     llvm_unreachable("Don't know how to custom expand this");
7898   case ISD::FP_TO_UINT:
7899   case ISD::FP_TO_SINT:
7900     assert(N->getValueType(0) == MVT::i128 && "unexpected illegal conversion");
7901     // Let normal code take care of it by not adding anything to Results.
7902     return;
7903   }
7904 }
7905 
shouldExpandAtomicInIR(Instruction * Inst) const7906 bool AArch64TargetLowering::shouldExpandAtomicInIR(Instruction *Inst) const {
7907   // Loads and stores less than 128-bits are already atomic; ones above that
7908   // are doomed anyway, so defer to the default libcall and blame the OS when
7909   // things go wrong:
7910   if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
7911     return SI->getValueOperand()->getType()->getPrimitiveSizeInBits() == 128;
7912   else if (LoadInst *LI = dyn_cast<LoadInst>(Inst))
7913     return LI->getType()->getPrimitiveSizeInBits() == 128;
7914 
7915   // For the real atomic operations, we have ldxr/stxr up to 128 bits.
7916   return Inst->getType()->getPrimitiveSizeInBits() <= 128;
7917 }
7918 
7919 TargetLoweringBase::LegalizeTypeAction
getPreferredVectorAction(EVT VT) const7920 AArch64TargetLowering::getPreferredVectorAction(EVT VT) const {
7921   MVT SVT = VT.getSimpleVT();
7922   // During type legalization, we prefer to widen v1i8, v1i16, v1i32  to v8i8,
7923   // v4i16, v2i32 instead of to promote.
7924   if (SVT == MVT::v1i8 || SVT == MVT::v1i16 || SVT == MVT::v1i32
7925       || SVT == MVT::v1f32)
7926     return TypeWidenVector;
7927 
7928   return TargetLoweringBase::getPreferredVectorAction(VT);
7929 }
7930 
emitLoadLinked(IRBuilder<> & Builder,Value * Addr,AtomicOrdering Ord) const7931 Value *AArch64TargetLowering::emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
7932                                              AtomicOrdering Ord) const {
7933   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
7934   Type *ValTy = cast<PointerType>(Addr->getType())->getElementType();
7935   bool IsAcquire =
7936       Ord == Acquire || Ord == AcquireRelease || Ord == SequentiallyConsistent;
7937 
7938   // Since i128 isn't legal and intrinsics don't get type-lowered, the ldrexd
7939   // intrinsic must return {i64, i64} and we have to recombine them into a
7940   // single i128 here.
7941   if (ValTy->getPrimitiveSizeInBits() == 128) {
7942     Intrinsic::ID Int =
7943         IsAcquire ? Intrinsic::aarch64_ldaxp : Intrinsic::aarch64_ldxp;
7944     Function *Ldxr = llvm::Intrinsic::getDeclaration(M, Int);
7945 
7946     Addr = Builder.CreateBitCast(Addr, Type::getInt8PtrTy(M->getContext()));
7947     Value *LoHi = Builder.CreateCall(Ldxr, Addr, "lohi");
7948 
7949     Value *Lo = Builder.CreateExtractValue(LoHi, 0, "lo");
7950     Value *Hi = Builder.CreateExtractValue(LoHi, 1, "hi");
7951     Lo = Builder.CreateZExt(Lo, ValTy, "lo64");
7952     Hi = Builder.CreateZExt(Hi, ValTy, "hi64");
7953     return Builder.CreateOr(
7954         Lo, Builder.CreateShl(Hi, ConstantInt::get(ValTy, 64)), "val64");
7955   }
7956 
7957   Type *Tys[] = { Addr->getType() };
7958   Intrinsic::ID Int =
7959       IsAcquire ? Intrinsic::aarch64_ldaxr : Intrinsic::aarch64_ldxr;
7960   Function *Ldxr = llvm::Intrinsic::getDeclaration(M, Int, Tys);
7961 
7962   return Builder.CreateTruncOrBitCast(
7963       Builder.CreateCall(Ldxr, Addr),
7964       cast<PointerType>(Addr->getType())->getElementType());
7965 }
7966 
emitStoreConditional(IRBuilder<> & Builder,Value * Val,Value * Addr,AtomicOrdering Ord) const7967 Value *AArch64TargetLowering::emitStoreConditional(IRBuilder<> &Builder,
7968                                                    Value *Val, Value *Addr,
7969                                                    AtomicOrdering Ord) const {
7970   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
7971   bool IsRelease =
7972       Ord == Release || Ord == AcquireRelease || Ord == SequentiallyConsistent;
7973 
7974   // Since the intrinsics must have legal type, the i128 intrinsics take two
7975   // parameters: "i64, i64". We must marshal Val into the appropriate form
7976   // before the call.
7977   if (Val->getType()->getPrimitiveSizeInBits() == 128) {
7978     Intrinsic::ID Int =
7979         IsRelease ? Intrinsic::aarch64_stlxp : Intrinsic::aarch64_stxp;
7980     Function *Stxr = Intrinsic::getDeclaration(M, Int);
7981     Type *Int64Ty = Type::getInt64Ty(M->getContext());
7982 
7983     Value *Lo = Builder.CreateTrunc(Val, Int64Ty, "lo");
7984     Value *Hi = Builder.CreateTrunc(Builder.CreateLShr(Val, 64), Int64Ty, "hi");
7985     Addr = Builder.CreateBitCast(Addr, Type::getInt8PtrTy(M->getContext()));
7986     return Builder.CreateCall3(Stxr, Lo, Hi, Addr);
7987   }
7988 
7989   Intrinsic::ID Int =
7990       IsRelease ? Intrinsic::aarch64_stlxr : Intrinsic::aarch64_stxr;
7991   Type *Tys[] = { Addr->getType() };
7992   Function *Stxr = Intrinsic::getDeclaration(M, Int, Tys);
7993 
7994   return Builder.CreateCall2(
7995       Stxr, Builder.CreateZExtOrBitCast(
7996                 Val, Stxr->getFunctionType()->getParamType(0)),
7997       Addr);
7998 }
7999