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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 
addTypeForNEON(EVT VT,EVT PromotedBitwiseVT)477 void AArch64TargetLowering::addTypeForNEON(EVT VT, EVT PromotedBitwiseVT) {
478   if (VT == MVT::v2f32) {
479     setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
480     AddPromotedToType(ISD::LOAD, VT.getSimpleVT(), MVT::v2i32);
481 
482     setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
483     AddPromotedToType(ISD::STORE, VT.getSimpleVT(), MVT::v2i32);
484   } else if (VT == MVT::v2f64 || VT == MVT::v4f32) {
485     setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
486     AddPromotedToType(ISD::LOAD, VT.getSimpleVT(), MVT::v2i64);
487 
488     setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
489     AddPromotedToType(ISD::STORE, VT.getSimpleVT(), MVT::v2i64);
490   }
491 
492   // Mark vector float intrinsics as expand.
493   if (VT == MVT::v2f32 || VT == MVT::v4f32 || VT == MVT::v2f64) {
494     setOperationAction(ISD::FSIN, VT.getSimpleVT(), Expand);
495     setOperationAction(ISD::FCOS, VT.getSimpleVT(), Expand);
496     setOperationAction(ISD::FPOWI, VT.getSimpleVT(), Expand);
497     setOperationAction(ISD::FPOW, VT.getSimpleVT(), Expand);
498     setOperationAction(ISD::FLOG, VT.getSimpleVT(), Expand);
499     setOperationAction(ISD::FLOG2, VT.getSimpleVT(), Expand);
500     setOperationAction(ISD::FLOG10, VT.getSimpleVT(), Expand);
501     setOperationAction(ISD::FEXP, VT.getSimpleVT(), Expand);
502     setOperationAction(ISD::FEXP2, VT.getSimpleVT(), Expand);
503   }
504 
505   setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT.getSimpleVT(), Custom);
506   setOperationAction(ISD::INSERT_VECTOR_ELT, VT.getSimpleVT(), Custom);
507   setOperationAction(ISD::BUILD_VECTOR, VT.getSimpleVT(), Custom);
508   setOperationAction(ISD::VECTOR_SHUFFLE, VT.getSimpleVT(), Custom);
509   setOperationAction(ISD::EXTRACT_SUBVECTOR, VT.getSimpleVT(), Custom);
510   setOperationAction(ISD::SRA, VT.getSimpleVT(), Custom);
511   setOperationAction(ISD::SRL, VT.getSimpleVT(), Custom);
512   setOperationAction(ISD::SHL, VT.getSimpleVT(), Custom);
513   setOperationAction(ISD::AND, VT.getSimpleVT(), Custom);
514   setOperationAction(ISD::OR, VT.getSimpleVT(), Custom);
515   setOperationAction(ISD::SETCC, VT.getSimpleVT(), Custom);
516   setOperationAction(ISD::CONCAT_VECTORS, VT.getSimpleVT(), Legal);
517 
518   setOperationAction(ISD::SELECT, VT.getSimpleVT(), Expand);
519   setOperationAction(ISD::SELECT_CC, VT.getSimpleVT(), Expand);
520   setOperationAction(ISD::VSELECT, VT.getSimpleVT(), Expand);
521   setLoadExtAction(ISD::EXTLOAD, VT.getSimpleVT(), Expand);
522 
523   // CNT supports only B element sizes.
524   if (VT != MVT::v8i8 && VT != MVT::v16i8)
525     setOperationAction(ISD::CTPOP, VT.getSimpleVT(), Expand);
526 
527   setOperationAction(ISD::UDIV, VT.getSimpleVT(), Expand);
528   setOperationAction(ISD::SDIV, VT.getSimpleVT(), Expand);
529   setOperationAction(ISD::UREM, VT.getSimpleVT(), Expand);
530   setOperationAction(ISD::SREM, VT.getSimpleVT(), Expand);
531   setOperationAction(ISD::FREM, VT.getSimpleVT(), Expand);
532 
533   setOperationAction(ISD::FP_TO_SINT, VT.getSimpleVT(), Custom);
534   setOperationAction(ISD::FP_TO_UINT, VT.getSimpleVT(), Custom);
535 
536   if (Subtarget->isLittleEndian()) {
537     for (unsigned im = (unsigned)ISD::PRE_INC;
538          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
539       setIndexedLoadAction(im, VT.getSimpleVT(), Legal);
540       setIndexedStoreAction(im, VT.getSimpleVT(), Legal);
541     }
542   }
543 }
544 
addDRTypeForNEON(MVT VT)545 void AArch64TargetLowering::addDRTypeForNEON(MVT VT) {
546   addRegisterClass(VT, &AArch64::FPR64RegClass);
547   addTypeForNEON(VT, MVT::v2i32);
548 }
549 
addQRTypeForNEON(MVT VT)550 void AArch64TargetLowering::addQRTypeForNEON(MVT VT) {
551   addRegisterClass(VT, &AArch64::FPR128RegClass);
552   addTypeForNEON(VT, MVT::v4i32);
553 }
554 
getSetCCResultType(LLVMContext &,EVT VT) const555 EVT AArch64TargetLowering::getSetCCResultType(LLVMContext &, EVT VT) const {
556   if (!VT.isVector())
557     return MVT::i32;
558   return VT.changeVectorElementTypeToInteger();
559 }
560 
561 /// computeKnownBitsForTargetNode - Determine which of the bits specified in
562 /// Mask are known to be either zero or one and return them in the
563 /// KnownZero/KnownOne bitsets.
computeKnownBitsForTargetNode(const SDValue Op,APInt & KnownZero,APInt & KnownOne,const SelectionDAG & DAG,unsigned Depth) const564 void AArch64TargetLowering::computeKnownBitsForTargetNode(
565     const SDValue Op, APInt &KnownZero, APInt &KnownOne,
566     const SelectionDAG &DAG, unsigned Depth) const {
567   switch (Op.getOpcode()) {
568   default:
569     break;
570   case AArch64ISD::CSEL: {
571     APInt KnownZero2, KnownOne2;
572     DAG.computeKnownBits(Op->getOperand(0), KnownZero, KnownOne, Depth + 1);
573     DAG.computeKnownBits(Op->getOperand(1), KnownZero2, KnownOne2, Depth + 1);
574     KnownZero &= KnownZero2;
575     KnownOne &= KnownOne2;
576     break;
577   }
578   case ISD::INTRINSIC_W_CHAIN: {
579    ConstantSDNode *CN = cast<ConstantSDNode>(Op->getOperand(1));
580     Intrinsic::ID IntID = static_cast<Intrinsic::ID>(CN->getZExtValue());
581     switch (IntID) {
582     default: return;
583     case Intrinsic::aarch64_ldaxr:
584     case Intrinsic::aarch64_ldxr: {
585       unsigned BitWidth = KnownOne.getBitWidth();
586       EVT VT = cast<MemIntrinsicSDNode>(Op)->getMemoryVT();
587       unsigned MemBits = VT.getScalarType().getSizeInBits();
588       KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits);
589       return;
590     }
591     }
592     break;
593   }
594   case ISD::INTRINSIC_WO_CHAIN:
595   case ISD::INTRINSIC_VOID: {
596     unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
597     switch (IntNo) {
598     default:
599       break;
600     case Intrinsic::aarch64_neon_umaxv:
601     case Intrinsic::aarch64_neon_uminv: {
602       // Figure out the datatype of the vector operand. The UMINV instruction
603       // will zero extend the result, so we can mark as known zero all the
604       // bits larger than the element datatype. 32-bit or larget doesn't need
605       // this as those are legal types and will be handled by isel directly.
606       MVT VT = Op.getOperand(1).getValueType().getSimpleVT();
607       unsigned BitWidth = KnownZero.getBitWidth();
608       if (VT == MVT::v8i8 || VT == MVT::v16i8) {
609         assert(BitWidth >= 8 && "Unexpected width!");
610         APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 8);
611         KnownZero |= Mask;
612       } else if (VT == MVT::v4i16 || VT == MVT::v8i16) {
613         assert(BitWidth >= 16 && "Unexpected width!");
614         APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
615         KnownZero |= Mask;
616       }
617       break;
618     } break;
619     }
620   }
621   }
622 }
623 
getScalarShiftAmountTy(EVT LHSTy) const624 MVT AArch64TargetLowering::getScalarShiftAmountTy(EVT LHSTy) const {
625   return MVT::i64;
626 }
627 
getMaximalGlobalOffset() const628 unsigned AArch64TargetLowering::getMaximalGlobalOffset() const {
629   // FIXME: On AArch64, this depends on the type.
630   // Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
631   // and the offset has to be a multiple of the related size in bytes.
632   return 4095;
633 }
634 
635 FastISel *
createFastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo) const636 AArch64TargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
637                                       const TargetLibraryInfo *libInfo) const {
638   return AArch64::createFastISel(funcInfo, libInfo);
639 }
640 
getTargetNodeName(unsigned Opcode) const641 const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const {
642   switch (Opcode) {
643   default:
644     return nullptr;
645   case AArch64ISD::CALL:              return "AArch64ISD::CALL";
646   case AArch64ISD::ADRP:              return "AArch64ISD::ADRP";
647   case AArch64ISD::ADDlow:            return "AArch64ISD::ADDlow";
648   case AArch64ISD::LOADgot:           return "AArch64ISD::LOADgot";
649   case AArch64ISD::RET_FLAG:          return "AArch64ISD::RET_FLAG";
650   case AArch64ISD::BRCOND:            return "AArch64ISD::BRCOND";
651   case AArch64ISD::CSEL:              return "AArch64ISD::CSEL";
652   case AArch64ISD::FCSEL:             return "AArch64ISD::FCSEL";
653   case AArch64ISD::CSINV:             return "AArch64ISD::CSINV";
654   case AArch64ISD::CSNEG:             return "AArch64ISD::CSNEG";
655   case AArch64ISD::CSINC:             return "AArch64ISD::CSINC";
656   case AArch64ISD::THREAD_POINTER:    return "AArch64ISD::THREAD_POINTER";
657   case AArch64ISD::TLSDESC_CALL:      return "AArch64ISD::TLSDESC_CALL";
658   case AArch64ISD::ADC:               return "AArch64ISD::ADC";
659   case AArch64ISD::SBC:               return "AArch64ISD::SBC";
660   case AArch64ISD::ADDS:              return "AArch64ISD::ADDS";
661   case AArch64ISD::SUBS:              return "AArch64ISD::SUBS";
662   case AArch64ISD::ADCS:              return "AArch64ISD::ADCS";
663   case AArch64ISD::SBCS:              return "AArch64ISD::SBCS";
664   case AArch64ISD::ANDS:              return "AArch64ISD::ANDS";
665   case AArch64ISD::FCMP:              return "AArch64ISD::FCMP";
666   case AArch64ISD::FMIN:              return "AArch64ISD::FMIN";
667   case AArch64ISD::FMAX:              return "AArch64ISD::FMAX";
668   case AArch64ISD::DUP:               return "AArch64ISD::DUP";
669   case AArch64ISD::DUPLANE8:          return "AArch64ISD::DUPLANE8";
670   case AArch64ISD::DUPLANE16:         return "AArch64ISD::DUPLANE16";
671   case AArch64ISD::DUPLANE32:         return "AArch64ISD::DUPLANE32";
672   case AArch64ISD::DUPLANE64:         return "AArch64ISD::DUPLANE64";
673   case AArch64ISD::MOVI:              return "AArch64ISD::MOVI";
674   case AArch64ISD::MOVIshift:         return "AArch64ISD::MOVIshift";
675   case AArch64ISD::MOVIedit:          return "AArch64ISD::MOVIedit";
676   case AArch64ISD::MOVImsl:           return "AArch64ISD::MOVImsl";
677   case AArch64ISD::FMOV:              return "AArch64ISD::FMOV";
678   case AArch64ISD::MVNIshift:         return "AArch64ISD::MVNIshift";
679   case AArch64ISD::MVNImsl:           return "AArch64ISD::MVNImsl";
680   case AArch64ISD::BICi:              return "AArch64ISD::BICi";
681   case AArch64ISD::ORRi:              return "AArch64ISD::ORRi";
682   case AArch64ISD::BSL:               return "AArch64ISD::BSL";
683   case AArch64ISD::NEG:               return "AArch64ISD::NEG";
684   case AArch64ISD::EXTR:              return "AArch64ISD::EXTR";
685   case AArch64ISD::ZIP1:              return "AArch64ISD::ZIP1";
686   case AArch64ISD::ZIP2:              return "AArch64ISD::ZIP2";
687   case AArch64ISD::UZP1:              return "AArch64ISD::UZP1";
688   case AArch64ISD::UZP2:              return "AArch64ISD::UZP2";
689   case AArch64ISD::TRN1:              return "AArch64ISD::TRN1";
690   case AArch64ISD::TRN2:              return "AArch64ISD::TRN2";
691   case AArch64ISD::REV16:             return "AArch64ISD::REV16";
692   case AArch64ISD::REV32:             return "AArch64ISD::REV32";
693   case AArch64ISD::REV64:             return "AArch64ISD::REV64";
694   case AArch64ISD::EXT:               return "AArch64ISD::EXT";
695   case AArch64ISD::VSHL:              return "AArch64ISD::VSHL";
696   case AArch64ISD::VLSHR:             return "AArch64ISD::VLSHR";
697   case AArch64ISD::VASHR:             return "AArch64ISD::VASHR";
698   case AArch64ISD::CMEQ:              return "AArch64ISD::CMEQ";
699   case AArch64ISD::CMGE:              return "AArch64ISD::CMGE";
700   case AArch64ISD::CMGT:              return "AArch64ISD::CMGT";
701   case AArch64ISD::CMHI:              return "AArch64ISD::CMHI";
702   case AArch64ISD::CMHS:              return "AArch64ISD::CMHS";
703   case AArch64ISD::FCMEQ:             return "AArch64ISD::FCMEQ";
704   case AArch64ISD::FCMGE:             return "AArch64ISD::FCMGE";
705   case AArch64ISD::FCMGT:             return "AArch64ISD::FCMGT";
706   case AArch64ISD::CMEQz:             return "AArch64ISD::CMEQz";
707   case AArch64ISD::CMGEz:             return "AArch64ISD::CMGEz";
708   case AArch64ISD::CMGTz:             return "AArch64ISD::CMGTz";
709   case AArch64ISD::CMLEz:             return "AArch64ISD::CMLEz";
710   case AArch64ISD::CMLTz:             return "AArch64ISD::CMLTz";
711   case AArch64ISD::FCMEQz:            return "AArch64ISD::FCMEQz";
712   case AArch64ISD::FCMGEz:            return "AArch64ISD::FCMGEz";
713   case AArch64ISD::FCMGTz:            return "AArch64ISD::FCMGTz";
714   case AArch64ISD::FCMLEz:            return "AArch64ISD::FCMLEz";
715   case AArch64ISD::FCMLTz:            return "AArch64ISD::FCMLTz";
716   case AArch64ISD::NOT:               return "AArch64ISD::NOT";
717   case AArch64ISD::BIT:               return "AArch64ISD::BIT";
718   case AArch64ISD::CBZ:               return "AArch64ISD::CBZ";
719   case AArch64ISD::CBNZ:              return "AArch64ISD::CBNZ";
720   case AArch64ISD::TBZ:               return "AArch64ISD::TBZ";
721   case AArch64ISD::TBNZ:              return "AArch64ISD::TBNZ";
722   case AArch64ISD::TC_RETURN:         return "AArch64ISD::TC_RETURN";
723   case AArch64ISD::SITOF:             return "AArch64ISD::SITOF";
724   case AArch64ISD::UITOF:             return "AArch64ISD::UITOF";
725   case AArch64ISD::SQSHL_I:           return "AArch64ISD::SQSHL_I";
726   case AArch64ISD::UQSHL_I:           return "AArch64ISD::UQSHL_I";
727   case AArch64ISD::SRSHR_I:           return "AArch64ISD::SRSHR_I";
728   case AArch64ISD::URSHR_I:           return "AArch64ISD::URSHR_I";
729   case AArch64ISD::SQSHLU_I:          return "AArch64ISD::SQSHLU_I";
730   case AArch64ISD::WrapperLarge:      return "AArch64ISD::WrapperLarge";
731   case AArch64ISD::LD2post:           return "AArch64ISD::LD2post";
732   case AArch64ISD::LD3post:           return "AArch64ISD::LD3post";
733   case AArch64ISD::LD4post:           return "AArch64ISD::LD4post";
734   case AArch64ISD::ST2post:           return "AArch64ISD::ST2post";
735   case AArch64ISD::ST3post:           return "AArch64ISD::ST3post";
736   case AArch64ISD::ST4post:           return "AArch64ISD::ST4post";
737   case AArch64ISD::LD1x2post:         return "AArch64ISD::LD1x2post";
738   case AArch64ISD::LD1x3post:         return "AArch64ISD::LD1x3post";
739   case AArch64ISD::LD1x4post:         return "AArch64ISD::LD1x4post";
740   case AArch64ISD::ST1x2post:         return "AArch64ISD::ST1x2post";
741   case AArch64ISD::ST1x3post:         return "AArch64ISD::ST1x3post";
742   case AArch64ISD::ST1x4post:         return "AArch64ISD::ST1x4post";
743   case AArch64ISD::LD1DUPpost:        return "AArch64ISD::LD1DUPpost";
744   case AArch64ISD::LD2DUPpost:        return "AArch64ISD::LD2DUPpost";
745   case AArch64ISD::LD3DUPpost:        return "AArch64ISD::LD3DUPpost";
746   case AArch64ISD::LD4DUPpost:        return "AArch64ISD::LD4DUPpost";
747   case AArch64ISD::LD1LANEpost:       return "AArch64ISD::LD1LANEpost";
748   case AArch64ISD::LD2LANEpost:       return "AArch64ISD::LD2LANEpost";
749   case AArch64ISD::LD3LANEpost:       return "AArch64ISD::LD3LANEpost";
750   case AArch64ISD::LD4LANEpost:       return "AArch64ISD::LD4LANEpost";
751   case AArch64ISD::ST2LANEpost:       return "AArch64ISD::ST2LANEpost";
752   case AArch64ISD::ST3LANEpost:       return "AArch64ISD::ST3LANEpost";
753   case AArch64ISD::ST4LANEpost:       return "AArch64ISD::ST4LANEpost";
754   }
755 }
756 
757 MachineBasicBlock *
EmitF128CSEL(MachineInstr * MI,MachineBasicBlock * MBB) const758 AArch64TargetLowering::EmitF128CSEL(MachineInstr *MI,
759                                     MachineBasicBlock *MBB) const {
760   // We materialise the F128CSEL pseudo-instruction as some control flow and a
761   // phi node:
762 
763   // OrigBB:
764   //     [... previous instrs leading to comparison ...]
765   //     b.ne TrueBB
766   //     b EndBB
767   // TrueBB:
768   //     ; Fallthrough
769   // EndBB:
770   //     Dest = PHI [IfTrue, TrueBB], [IfFalse, OrigBB]
771 
772   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
773   MachineFunction *MF = MBB->getParent();
774   const BasicBlock *LLVM_BB = MBB->getBasicBlock();
775   DebugLoc DL = MI->getDebugLoc();
776   MachineFunction::iterator It = MBB;
777   ++It;
778 
779   unsigned DestReg = MI->getOperand(0).getReg();
780   unsigned IfTrueReg = MI->getOperand(1).getReg();
781   unsigned IfFalseReg = MI->getOperand(2).getReg();
782   unsigned CondCode = MI->getOperand(3).getImm();
783   bool NZCVKilled = MI->getOperand(4).isKill();
784 
785   MachineBasicBlock *TrueBB = MF->CreateMachineBasicBlock(LLVM_BB);
786   MachineBasicBlock *EndBB = MF->CreateMachineBasicBlock(LLVM_BB);
787   MF->insert(It, TrueBB);
788   MF->insert(It, EndBB);
789 
790   // Transfer rest of current basic-block to EndBB
791   EndBB->splice(EndBB->begin(), MBB, std::next(MachineBasicBlock::iterator(MI)),
792                 MBB->end());
793   EndBB->transferSuccessorsAndUpdatePHIs(MBB);
794 
795   BuildMI(MBB, DL, TII->get(AArch64::Bcc)).addImm(CondCode).addMBB(TrueBB);
796   BuildMI(MBB, DL, TII->get(AArch64::B)).addMBB(EndBB);
797   MBB->addSuccessor(TrueBB);
798   MBB->addSuccessor(EndBB);
799 
800   // TrueBB falls through to the end.
801   TrueBB->addSuccessor(EndBB);
802 
803   if (!NZCVKilled) {
804     TrueBB->addLiveIn(AArch64::NZCV);
805     EndBB->addLiveIn(AArch64::NZCV);
806   }
807 
808   BuildMI(*EndBB, EndBB->begin(), DL, TII->get(AArch64::PHI), DestReg)
809       .addReg(IfTrueReg)
810       .addMBB(TrueBB)
811       .addReg(IfFalseReg)
812       .addMBB(MBB);
813 
814   MI->eraseFromParent();
815   return EndBB;
816 }
817 
818 MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr * MI,MachineBasicBlock * BB) const819 AArch64TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
820                                                  MachineBasicBlock *BB) const {
821   switch (MI->getOpcode()) {
822   default:
823 #ifndef NDEBUG
824     MI->dump();
825 #endif
826     llvm_unreachable("Unexpected instruction for custom inserter!");
827 
828   case AArch64::F128CSEL:
829     return EmitF128CSEL(MI, BB);
830 
831   case TargetOpcode::STACKMAP:
832   case TargetOpcode::PATCHPOINT:
833     return emitPatchPoint(MI, BB);
834   }
835 }
836 
837 //===----------------------------------------------------------------------===//
838 // AArch64 Lowering private implementation.
839 //===----------------------------------------------------------------------===//
840 
841 //===----------------------------------------------------------------------===//
842 // Lowering Code
843 //===----------------------------------------------------------------------===//
844 
845 /// changeIntCCToAArch64CC - Convert a DAG integer condition code to an AArch64
846 /// CC
changeIntCCToAArch64CC(ISD::CondCode CC)847 static AArch64CC::CondCode changeIntCCToAArch64CC(ISD::CondCode CC) {
848   switch (CC) {
849   default:
850     llvm_unreachable("Unknown condition code!");
851   case ISD::SETNE:
852     return AArch64CC::NE;
853   case ISD::SETEQ:
854     return AArch64CC::EQ;
855   case ISD::SETGT:
856     return AArch64CC::GT;
857   case ISD::SETGE:
858     return AArch64CC::GE;
859   case ISD::SETLT:
860     return AArch64CC::LT;
861   case ISD::SETLE:
862     return AArch64CC::LE;
863   case ISD::SETUGT:
864     return AArch64CC::HI;
865   case ISD::SETUGE:
866     return AArch64CC::HS;
867   case ISD::SETULT:
868     return AArch64CC::LO;
869   case ISD::SETULE:
870     return AArch64CC::LS;
871   }
872 }
873 
874 /// changeFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64 CC.
changeFPCCToAArch64CC(ISD::CondCode CC,AArch64CC::CondCode & CondCode,AArch64CC::CondCode & CondCode2)875 static void changeFPCCToAArch64CC(ISD::CondCode CC,
876                                   AArch64CC::CondCode &CondCode,
877                                   AArch64CC::CondCode &CondCode2) {
878   CondCode2 = AArch64CC::AL;
879   switch (CC) {
880   default:
881     llvm_unreachable("Unknown FP condition!");
882   case ISD::SETEQ:
883   case ISD::SETOEQ:
884     CondCode = AArch64CC::EQ;
885     break;
886   case ISD::SETGT:
887   case ISD::SETOGT:
888     CondCode = AArch64CC::GT;
889     break;
890   case ISD::SETGE:
891   case ISD::SETOGE:
892     CondCode = AArch64CC::GE;
893     break;
894   case ISD::SETOLT:
895     CondCode = AArch64CC::MI;
896     break;
897   case ISD::SETOLE:
898     CondCode = AArch64CC::LS;
899     break;
900   case ISD::SETONE:
901     CondCode = AArch64CC::MI;
902     CondCode2 = AArch64CC::GT;
903     break;
904   case ISD::SETO:
905     CondCode = AArch64CC::VC;
906     break;
907   case ISD::SETUO:
908     CondCode = AArch64CC::VS;
909     break;
910   case ISD::SETUEQ:
911     CondCode = AArch64CC::EQ;
912     CondCode2 = AArch64CC::VS;
913     break;
914   case ISD::SETUGT:
915     CondCode = AArch64CC::HI;
916     break;
917   case ISD::SETUGE:
918     CondCode = AArch64CC::PL;
919     break;
920   case ISD::SETLT:
921   case ISD::SETULT:
922     CondCode = AArch64CC::LT;
923     break;
924   case ISD::SETLE:
925   case ISD::SETULE:
926     CondCode = AArch64CC::LE;
927     break;
928   case ISD::SETNE:
929   case ISD::SETUNE:
930     CondCode = AArch64CC::NE;
931     break;
932   }
933 }
934 
935 /// changeVectorFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64
936 /// CC usable with the vector instructions. Fewer operations are available
937 /// without a real NZCV register, so we have to use less efficient combinations
938 /// to get the same effect.
changeVectorFPCCToAArch64CC(ISD::CondCode CC,AArch64CC::CondCode & CondCode,AArch64CC::CondCode & CondCode2,bool & Invert)939 static void changeVectorFPCCToAArch64CC(ISD::CondCode CC,
940                                         AArch64CC::CondCode &CondCode,
941                                         AArch64CC::CondCode &CondCode2,
942                                         bool &Invert) {
943   Invert = false;
944   switch (CC) {
945   default:
946     // Mostly the scalar mappings work fine.
947     changeFPCCToAArch64CC(CC, CondCode, CondCode2);
948     break;
949   case ISD::SETUO:
950     Invert = true; // Fallthrough
951   case ISD::SETO:
952     CondCode = AArch64CC::MI;
953     CondCode2 = AArch64CC::GE;
954     break;
955   case ISD::SETUEQ:
956   case ISD::SETULT:
957   case ISD::SETULE:
958   case ISD::SETUGT:
959   case ISD::SETUGE:
960     // All of the compare-mask comparisons are ordered, but we can switch
961     // between the two by a double inversion. E.g. ULE == !OGT.
962     Invert = true;
963     changeFPCCToAArch64CC(getSetCCInverse(CC, false), CondCode, CondCode2);
964     break;
965   }
966 }
967 
isLegalArithImmed(uint64_t C)968 static bool isLegalArithImmed(uint64_t C) {
969   // Matches AArch64DAGToDAGISel::SelectArithImmed().
970   return (C >> 12 == 0) || ((C & 0xFFFULL) == 0 && C >> 24 == 0);
971 }
972 
emitComparison(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDLoc dl,SelectionDAG & DAG)973 static SDValue emitComparison(SDValue LHS, SDValue RHS, ISD::CondCode CC,
974                               SDLoc dl, SelectionDAG &DAG) {
975   EVT VT = LHS.getValueType();
976 
977   if (VT.isFloatingPoint())
978     return DAG.getNode(AArch64ISD::FCMP, dl, VT, LHS, RHS);
979 
980   // The CMP instruction is just an alias for SUBS, and representing it as
981   // SUBS means that it's possible to get CSE with subtract operations.
982   // A later phase can perform the optimization of setting the destination
983   // register to WZR/XZR if it ends up being unused.
984   unsigned Opcode = AArch64ISD::SUBS;
985 
986   if (RHS.getOpcode() == ISD::SUB && isa<ConstantSDNode>(RHS.getOperand(0)) &&
987       cast<ConstantSDNode>(RHS.getOperand(0))->getZExtValue() == 0 &&
988       (CC == ISD::SETEQ || CC == ISD::SETNE)) {
989     // We'd like to combine a (CMP op1, (sub 0, op2) into a CMN instruction on
990     // the grounds that "op1 - (-op2) == op1 + op2". However, the C and V flags
991     // can be set differently by this operation. It comes down to whether
992     // "SInt(~op2)+1 == SInt(~op2+1)" (and the same for UInt). If they are then
993     // everything is fine. If not then the optimization is wrong. Thus general
994     // comparisons are only valid if op2 != 0.
995 
996     // So, finally, the only LLVM-native comparisons that don't mention C and V
997     // are SETEQ and SETNE. They're the only ones we can safely use CMN for in
998     // the absence of information about op2.
999     Opcode = AArch64ISD::ADDS;
1000     RHS = RHS.getOperand(1);
1001   } else if (LHS.getOpcode() == ISD::AND && isa<ConstantSDNode>(RHS) &&
1002              cast<ConstantSDNode>(RHS)->getZExtValue() == 0 &&
1003              !isUnsignedIntSetCC(CC)) {
1004     // Similarly, (CMP (and X, Y), 0) can be implemented with a TST
1005     // (a.k.a. ANDS) except that the flags are only guaranteed to work for one
1006     // of the signed comparisons.
1007     Opcode = AArch64ISD::ANDS;
1008     RHS = LHS.getOperand(1);
1009     LHS = LHS.getOperand(0);
1010   }
1011 
1012   return DAG.getNode(Opcode, dl, DAG.getVTList(VT, MVT::i32), LHS, RHS)
1013       .getValue(1);
1014 }
1015 
getAArch64Cmp(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDValue & AArch64cc,SelectionDAG & DAG,SDLoc dl)1016 static SDValue getAArch64Cmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
1017                              SDValue &AArch64cc, SelectionDAG &DAG, SDLoc dl) {
1018   if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
1019     EVT VT = RHS.getValueType();
1020     uint64_t C = RHSC->getZExtValue();
1021     if (!isLegalArithImmed(C)) {
1022       // Constant does not fit, try adjusting it by one?
1023       switch (CC) {
1024       default:
1025         break;
1026       case ISD::SETLT:
1027       case ISD::SETGE:
1028         if ((VT == MVT::i32 && C != 0x80000000 &&
1029              isLegalArithImmed((uint32_t)(C - 1))) ||
1030             (VT == MVT::i64 && C != 0x80000000ULL &&
1031              isLegalArithImmed(C - 1ULL))) {
1032           CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
1033           C = (VT == MVT::i32) ? (uint32_t)(C - 1) : C - 1;
1034           RHS = DAG.getConstant(C, VT);
1035         }
1036         break;
1037       case ISD::SETULT:
1038       case ISD::SETUGE:
1039         if ((VT == MVT::i32 && C != 0 &&
1040              isLegalArithImmed((uint32_t)(C - 1))) ||
1041             (VT == MVT::i64 && C != 0ULL && isLegalArithImmed(C - 1ULL))) {
1042           CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
1043           C = (VT == MVT::i32) ? (uint32_t)(C - 1) : C - 1;
1044           RHS = DAG.getConstant(C, VT);
1045         }
1046         break;
1047       case ISD::SETLE:
1048       case ISD::SETGT:
1049         if ((VT == MVT::i32 && C != 0x7fffffff &&
1050              isLegalArithImmed((uint32_t)(C + 1))) ||
1051             (VT == MVT::i64 && C != 0x7ffffffffffffffULL &&
1052              isLegalArithImmed(C + 1ULL))) {
1053           CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
1054           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;
1055           RHS = DAG.getConstant(C, VT);
1056         }
1057         break;
1058       case ISD::SETULE:
1059       case ISD::SETUGT:
1060         if ((VT == MVT::i32 && C != 0xffffffff &&
1061              isLegalArithImmed((uint32_t)(C + 1))) ||
1062             (VT == MVT::i64 && C != 0xfffffffffffffffULL &&
1063              isLegalArithImmed(C + 1ULL))) {
1064           CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
1065           C = (VT == MVT::i32) ? (uint32_t)(C + 1) : C + 1;
1066           RHS = DAG.getConstant(C, VT);
1067         }
1068         break;
1069       }
1070     }
1071   }
1072 
1073   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
1074   AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
1075   AArch64cc = DAG.getConstant(AArch64CC, MVT::i32);
1076   return Cmp;
1077 }
1078 
1079 static std::pair<SDValue, SDValue>
getAArch64XALUOOp(AArch64CC::CondCode & CC,SDValue Op,SelectionDAG & DAG)1080 getAArch64XALUOOp(AArch64CC::CondCode &CC, SDValue Op, SelectionDAG &DAG) {
1081   assert((Op.getValueType() == MVT::i32 || Op.getValueType() == MVT::i64) &&
1082          "Unsupported value type");
1083   SDValue Value, Overflow;
1084   SDLoc DL(Op);
1085   SDValue LHS = Op.getOperand(0);
1086   SDValue RHS = Op.getOperand(1);
1087   unsigned Opc = 0;
1088   switch (Op.getOpcode()) {
1089   default:
1090     llvm_unreachable("Unknown overflow instruction!");
1091   case ISD::SADDO:
1092     Opc = AArch64ISD::ADDS;
1093     CC = AArch64CC::VS;
1094     break;
1095   case ISD::UADDO:
1096     Opc = AArch64ISD::ADDS;
1097     CC = AArch64CC::HS;
1098     break;
1099   case ISD::SSUBO:
1100     Opc = AArch64ISD::SUBS;
1101     CC = AArch64CC::VS;
1102     break;
1103   case ISD::USUBO:
1104     Opc = AArch64ISD::SUBS;
1105     CC = AArch64CC::LO;
1106     break;
1107   // Multiply needs a little bit extra work.
1108   case ISD::SMULO:
1109   case ISD::UMULO: {
1110     CC = AArch64CC::NE;
1111     bool IsSigned = (Op.getOpcode() == ISD::SMULO) ? true : false;
1112     if (Op.getValueType() == MVT::i32) {
1113       unsigned ExtendOpc = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
1114       // For a 32 bit multiply with overflow check we want the instruction
1115       // selector to generate a widening multiply (SMADDL/UMADDL). For that we
1116       // need to generate the following pattern:
1117       // (i64 add 0, (i64 mul (i64 sext|zext i32 %a), (i64 sext|zext i32 %b))
1118       LHS = DAG.getNode(ExtendOpc, DL, MVT::i64, LHS);
1119       RHS = DAG.getNode(ExtendOpc, DL, MVT::i64, RHS);
1120       SDValue Mul = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
1121       SDValue Add = DAG.getNode(ISD::ADD, DL, MVT::i64, Mul,
1122                                 DAG.getConstant(0, MVT::i64));
1123       // On AArch64 the upper 32 bits are always zero extended for a 32 bit
1124       // operation. We need to clear out the upper 32 bits, because we used a
1125       // widening multiply that wrote all 64 bits. In the end this should be a
1126       // noop.
1127       Value = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Add);
1128       if (IsSigned) {
1129         // The signed overflow check requires more than just a simple check for
1130         // any bit set in the upper 32 bits of the result. These bits could be
1131         // just the sign bits of a negative number. To perform the overflow
1132         // check we have to arithmetic shift right the 32nd bit of the result by
1133         // 31 bits. Then we compare the result to the upper 32 bits.
1134         SDValue UpperBits = DAG.getNode(ISD::SRL, DL, MVT::i64, Add,
1135                                         DAG.getConstant(32, MVT::i64));
1136         UpperBits = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, UpperBits);
1137         SDValue LowerBits = DAG.getNode(ISD::SRA, DL, MVT::i32, Value,
1138                                         DAG.getConstant(31, MVT::i64));
1139         // It is important that LowerBits is last, otherwise the arithmetic
1140         // shift will not be folded into the compare (SUBS).
1141         SDVTList VTs = DAG.getVTList(MVT::i32, MVT::i32);
1142         Overflow = DAG.getNode(AArch64ISD::SUBS, DL, VTs, UpperBits, LowerBits)
1143                        .getValue(1);
1144       } else {
1145         // The overflow check for unsigned multiply is easy. We only need to
1146         // check if any of the upper 32 bits are set. This can be done with a
1147         // CMP (shifted register). For that we need to generate the following
1148         // pattern:
1149         // (i64 AArch64ISD::SUBS i64 0, (i64 srl i64 %Mul, i64 32)
1150         SDValue UpperBits = DAG.getNode(ISD::SRL, DL, MVT::i64, Mul,
1151                                         DAG.getConstant(32, MVT::i64));
1152         SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1153         Overflow =
1154             DAG.getNode(AArch64ISD::SUBS, DL, VTs, DAG.getConstant(0, MVT::i64),
1155                         UpperBits).getValue(1);
1156       }
1157       break;
1158     }
1159     assert(Op.getValueType() == MVT::i64 && "Expected an i64 value type");
1160     // For the 64 bit multiply
1161     Value = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
1162     if (IsSigned) {
1163       SDValue UpperBits = DAG.getNode(ISD::MULHS, DL, MVT::i64, LHS, RHS);
1164       SDValue LowerBits = DAG.getNode(ISD::SRA, DL, MVT::i64, Value,
1165                                       DAG.getConstant(63, MVT::i64));
1166       // It is important that LowerBits is last, otherwise the arithmetic
1167       // shift will not be folded into the compare (SUBS).
1168       SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1169       Overflow = DAG.getNode(AArch64ISD::SUBS, DL, VTs, UpperBits, LowerBits)
1170                      .getValue(1);
1171     } else {
1172       SDValue UpperBits = DAG.getNode(ISD::MULHU, DL, MVT::i64, LHS, RHS);
1173       SDVTList VTs = DAG.getVTList(MVT::i64, MVT::i32);
1174       Overflow =
1175           DAG.getNode(AArch64ISD::SUBS, DL, VTs, DAG.getConstant(0, MVT::i64),
1176                       UpperBits).getValue(1);
1177     }
1178     break;
1179   }
1180   } // switch (...)
1181 
1182   if (Opc) {
1183     SDVTList VTs = DAG.getVTList(Op->getValueType(0), MVT::i32);
1184 
1185     // Emit the AArch64 operation with overflow check.
1186     Value = DAG.getNode(Opc, DL, VTs, LHS, RHS);
1187     Overflow = Value.getValue(1);
1188   }
1189   return std::make_pair(Value, Overflow);
1190 }
1191 
LowerF128Call(SDValue Op,SelectionDAG & DAG,RTLIB::Libcall Call) const1192 SDValue AArch64TargetLowering::LowerF128Call(SDValue Op, SelectionDAG &DAG,
1193                                              RTLIB::Libcall Call) const {
1194   SmallVector<SDValue, 2> Ops;
1195   for (unsigned i = 0, e = Op->getNumOperands(); i != e; ++i)
1196     Ops.push_back(Op.getOperand(i));
1197 
1198   return makeLibCall(DAG, Call, MVT::f128, &Ops[0], Ops.size(), false,
1199                      SDLoc(Op)).first;
1200 }
1201 
LowerXOR(SDValue Op,SelectionDAG & DAG)1202 static SDValue LowerXOR(SDValue Op, SelectionDAG &DAG) {
1203   SDValue Sel = Op.getOperand(0);
1204   SDValue Other = Op.getOperand(1);
1205 
1206   // If neither operand is a SELECT_CC, give up.
1207   if (Sel.getOpcode() != ISD::SELECT_CC)
1208     std::swap(Sel, Other);
1209   if (Sel.getOpcode() != ISD::SELECT_CC)
1210     return Op;
1211 
1212   // The folding we want to perform is:
1213   // (xor x, (select_cc a, b, cc, 0, -1) )
1214   //   -->
1215   // (csel x, (xor x, -1), cc ...)
1216   //
1217   // The latter will get matched to a CSINV instruction.
1218 
1219   ISD::CondCode CC = cast<CondCodeSDNode>(Sel.getOperand(4))->get();
1220   SDValue LHS = Sel.getOperand(0);
1221   SDValue RHS = Sel.getOperand(1);
1222   SDValue TVal = Sel.getOperand(2);
1223   SDValue FVal = Sel.getOperand(3);
1224   SDLoc dl(Sel);
1225 
1226   // FIXME: This could be generalized to non-integer comparisons.
1227   if (LHS.getValueType() != MVT::i32 && LHS.getValueType() != MVT::i64)
1228     return Op;
1229 
1230   ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
1231   ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
1232 
1233   // The the values aren't constants, this isn't the pattern we're looking for.
1234   if (!CFVal || !CTVal)
1235     return Op;
1236 
1237   // We can commute the SELECT_CC by inverting the condition.  This
1238   // might be needed to make this fit into a CSINV pattern.
1239   if (CTVal->isAllOnesValue() && CFVal->isNullValue()) {
1240     std::swap(TVal, FVal);
1241     std::swap(CTVal, CFVal);
1242     CC = ISD::getSetCCInverse(CC, true);
1243   }
1244 
1245   // If the constants line up, perform the transform!
1246   if (CTVal->isNullValue() && CFVal->isAllOnesValue()) {
1247     SDValue CCVal;
1248     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
1249 
1250     FVal = Other;
1251     TVal = DAG.getNode(ISD::XOR, dl, Other.getValueType(), Other,
1252                        DAG.getConstant(-1ULL, Other.getValueType()));
1253 
1254     return DAG.getNode(AArch64ISD::CSEL, dl, Sel.getValueType(), FVal, TVal,
1255                        CCVal, Cmp);
1256   }
1257 
1258   return Op;
1259 }
1260 
LowerADDC_ADDE_SUBC_SUBE(SDValue Op,SelectionDAG & DAG)1261 static SDValue LowerADDC_ADDE_SUBC_SUBE(SDValue Op, SelectionDAG &DAG) {
1262   EVT VT = Op.getValueType();
1263 
1264   // Let legalize expand this if it isn't a legal type yet.
1265   if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
1266     return SDValue();
1267 
1268   SDVTList VTs = DAG.getVTList(VT, MVT::i32);
1269 
1270   unsigned Opc;
1271   bool ExtraOp = false;
1272   switch (Op.getOpcode()) {
1273   default:
1274     llvm_unreachable("Invalid code");
1275   case ISD::ADDC:
1276     Opc = AArch64ISD::ADDS;
1277     break;
1278   case ISD::SUBC:
1279     Opc = AArch64ISD::SUBS;
1280     break;
1281   case ISD::ADDE:
1282     Opc = AArch64ISD::ADCS;
1283     ExtraOp = true;
1284     break;
1285   case ISD::SUBE:
1286     Opc = AArch64ISD::SBCS;
1287     ExtraOp = true;
1288     break;
1289   }
1290 
1291   if (!ExtraOp)
1292     return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0), Op.getOperand(1));
1293   return DAG.getNode(Opc, SDLoc(Op), VTs, Op.getOperand(0), Op.getOperand(1),
1294                      Op.getOperand(2));
1295 }
1296 
LowerXALUO(SDValue Op,SelectionDAG & DAG)1297 static SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) {
1298   // Let legalize expand this if it isn't a legal type yet.
1299   if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
1300     return SDValue();
1301 
1302   AArch64CC::CondCode CC;
1303   // The actual operation that sets the overflow or carry flag.
1304   SDValue Value, Overflow;
1305   std::tie(Value, Overflow) = getAArch64XALUOOp(CC, Op, DAG);
1306 
1307   // We use 0 and 1 as false and true values.
1308   SDValue TVal = DAG.getConstant(1, MVT::i32);
1309   SDValue FVal = DAG.getConstant(0, MVT::i32);
1310 
1311   // We use an inverted condition, because the conditional select is inverted
1312   // too. This will allow it to be selected to a single instruction:
1313   // CSINC Wd, WZR, WZR, invert(cond).
1314   SDValue CCVal = DAG.getConstant(getInvertedCondCode(CC), MVT::i32);
1315   Overflow = DAG.getNode(AArch64ISD::CSEL, SDLoc(Op), MVT::i32, FVal, TVal,
1316                          CCVal, Overflow);
1317 
1318   SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::i32);
1319   return DAG.getNode(ISD::MERGE_VALUES, SDLoc(Op), VTs, Value, Overflow);
1320 }
1321 
1322 // Prefetch operands are:
1323 // 1: Address to prefetch
1324 // 2: bool isWrite
1325 // 3: int locality (0 = no locality ... 3 = extreme locality)
1326 // 4: bool isDataCache
LowerPREFETCH(SDValue Op,SelectionDAG & DAG)1327 static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG) {
1328   SDLoc DL(Op);
1329   unsigned IsWrite = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue();
1330   unsigned Locality = cast<ConstantSDNode>(Op.getOperand(3))->getZExtValue();
1331   // The data thing is not used.
1332   // unsigned isData = cast<ConstantSDNode>(Op.getOperand(4))->getZExtValue();
1333 
1334   bool IsStream = !Locality;
1335   // When the locality number is set
1336   if (Locality) {
1337     // The front-end should have filtered out the out-of-range values
1338     assert(Locality <= 3 && "Prefetch locality out-of-range");
1339     // The locality degree is the opposite of the cache speed.
1340     // Put the number the other way around.
1341     // The encoding starts at 0 for level 1
1342     Locality = 3 - Locality;
1343   }
1344 
1345   // built the mask value encoding the expected behavior.
1346   unsigned PrfOp = (IsWrite << 4) |     // Load/Store bit
1347                    (Locality << 1) |    // Cache level bits
1348                    (unsigned)IsStream;  // Stream bit
1349   return DAG.getNode(AArch64ISD::PREFETCH, DL, MVT::Other, Op.getOperand(0),
1350                      DAG.getConstant(PrfOp, MVT::i32), Op.getOperand(1));
1351 }
1352 
LowerFP_EXTEND(SDValue Op,SelectionDAG & DAG) const1353 SDValue AArch64TargetLowering::LowerFP_EXTEND(SDValue Op,
1354                                               SelectionDAG &DAG) const {
1355   assert(Op.getValueType() == MVT::f128 && "Unexpected lowering");
1356 
1357   RTLIB::Libcall LC;
1358   LC = RTLIB::getFPEXT(Op.getOperand(0).getValueType(), Op.getValueType());
1359 
1360   return LowerF128Call(Op, DAG, LC);
1361 }
1362 
LowerFP_ROUND(SDValue Op,SelectionDAG & DAG) const1363 SDValue AArch64TargetLowering::LowerFP_ROUND(SDValue Op,
1364                                              SelectionDAG &DAG) const {
1365   if (Op.getOperand(0).getValueType() != MVT::f128) {
1366     // It's legal except when f128 is involved
1367     return Op;
1368   }
1369 
1370   RTLIB::Libcall LC;
1371   LC = RTLIB::getFPROUND(Op.getOperand(0).getValueType(), Op.getValueType());
1372 
1373   // FP_ROUND node has a second operand indicating whether it is known to be
1374   // precise. That doesn't take part in the LibCall so we can't directly use
1375   // LowerF128Call.
1376   SDValue SrcVal = Op.getOperand(0);
1377   return makeLibCall(DAG, LC, Op.getValueType(), &SrcVal, 1,
1378                      /*isSigned*/ false, SDLoc(Op)).first;
1379 }
1380 
LowerVectorFP_TO_INT(SDValue Op,SelectionDAG & DAG)1381 static SDValue LowerVectorFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
1382   // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
1383   // Any additional optimization in this function should be recorded
1384   // in the cost tables.
1385   EVT InVT = Op.getOperand(0).getValueType();
1386   EVT VT = Op.getValueType();
1387 
1388   if (VT.getSizeInBits() < InVT.getSizeInBits()) {
1389     SDLoc dl(Op);
1390     SDValue Cv =
1391         DAG.getNode(Op.getOpcode(), dl, InVT.changeVectorElementTypeToInteger(),
1392                     Op.getOperand(0));
1393     return DAG.getNode(ISD::TRUNCATE, dl, VT, Cv);
1394   }
1395 
1396   if (VT.getSizeInBits() > InVT.getSizeInBits()) {
1397     SDLoc dl(Op);
1398     SDValue Ext = DAG.getNode(ISD::FP_EXTEND, dl, MVT::v2f64, Op.getOperand(0));
1399     return DAG.getNode(Op.getOpcode(), dl, VT, Ext);
1400   }
1401 
1402   // Type changing conversions are illegal.
1403   return Op;
1404 }
1405 
LowerFP_TO_INT(SDValue Op,SelectionDAG & DAG) const1406 SDValue AArch64TargetLowering::LowerFP_TO_INT(SDValue Op,
1407                                               SelectionDAG &DAG) const {
1408   if (Op.getOperand(0).getValueType().isVector())
1409     return LowerVectorFP_TO_INT(Op, DAG);
1410 
1411   if (Op.getOperand(0).getValueType() != MVT::f128) {
1412     // It's legal except when f128 is involved
1413     return Op;
1414   }
1415 
1416   RTLIB::Libcall LC;
1417   if (Op.getOpcode() == ISD::FP_TO_SINT)
1418     LC = RTLIB::getFPTOSINT(Op.getOperand(0).getValueType(), Op.getValueType());
1419   else
1420     LC = RTLIB::getFPTOUINT(Op.getOperand(0).getValueType(), Op.getValueType());
1421 
1422   SmallVector<SDValue, 2> Ops;
1423   for (unsigned i = 0, e = Op->getNumOperands(); i != e; ++i)
1424     Ops.push_back(Op.getOperand(i));
1425 
1426   return makeLibCall(DAG, LC, Op.getValueType(), &Ops[0], Ops.size(), false,
1427                      SDLoc(Op)).first;
1428 }
1429 
LowerVectorINT_TO_FP(SDValue Op,SelectionDAG & DAG)1430 static SDValue LowerVectorINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
1431   // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
1432   // Any additional optimization in this function should be recorded
1433   // in the cost tables.
1434   EVT VT = Op.getValueType();
1435   SDLoc dl(Op);
1436   SDValue In = Op.getOperand(0);
1437   EVT InVT = In.getValueType();
1438 
1439   if (VT.getSizeInBits() < InVT.getSizeInBits()) {
1440     MVT CastVT =
1441         MVT::getVectorVT(MVT::getFloatingPointVT(InVT.getScalarSizeInBits()),
1442                          InVT.getVectorNumElements());
1443     In = DAG.getNode(Op.getOpcode(), dl, CastVT, In);
1444     return DAG.getNode(ISD::FP_ROUND, dl, VT, In, DAG.getIntPtrConstant(0));
1445   }
1446 
1447   if (VT.getSizeInBits() > InVT.getSizeInBits()) {
1448     unsigned CastOpc =
1449         Op.getOpcode() == ISD::SINT_TO_FP ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
1450     EVT CastVT = VT.changeVectorElementTypeToInteger();
1451     In = DAG.getNode(CastOpc, dl, CastVT, In);
1452     return DAG.getNode(Op.getOpcode(), dl, VT, In);
1453   }
1454 
1455   return Op;
1456 }
1457 
LowerINT_TO_FP(SDValue Op,SelectionDAG & DAG) const1458 SDValue AArch64TargetLowering::LowerINT_TO_FP(SDValue Op,
1459                                             SelectionDAG &DAG) const {
1460   if (Op.getValueType().isVector())
1461     return LowerVectorINT_TO_FP(Op, DAG);
1462 
1463   // i128 conversions are libcalls.
1464   if (Op.getOperand(0).getValueType() == MVT::i128)
1465     return SDValue();
1466 
1467   // Other conversions are legal, unless it's to the completely software-based
1468   // fp128.
1469   if (Op.getValueType() != MVT::f128)
1470     return Op;
1471 
1472   RTLIB::Libcall LC;
1473   if (Op.getOpcode() == ISD::SINT_TO_FP)
1474     LC = RTLIB::getSINTTOFP(Op.getOperand(0).getValueType(), Op.getValueType());
1475   else
1476     LC = RTLIB::getUINTTOFP(Op.getOperand(0).getValueType(), Op.getValueType());
1477 
1478   return LowerF128Call(Op, DAG, LC);
1479 }
1480 
LowerFSINCOS(SDValue Op,SelectionDAG & DAG) const1481 SDValue AArch64TargetLowering::LowerFSINCOS(SDValue Op,
1482                                             SelectionDAG &DAG) const {
1483   // For iOS, we want to call an alternative entry point: __sincos_stret,
1484   // which returns the values in two S / D registers.
1485   SDLoc dl(Op);
1486   SDValue Arg = Op.getOperand(0);
1487   EVT ArgVT = Arg.getValueType();
1488   Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
1489 
1490   ArgListTy Args;
1491   ArgListEntry Entry;
1492 
1493   Entry.Node = Arg;
1494   Entry.Ty = ArgTy;
1495   Entry.isSExt = false;
1496   Entry.isZExt = false;
1497   Args.push_back(Entry);
1498 
1499   const char *LibcallName =
1500       (ArgVT == MVT::f64) ? "__sincos_stret" : "__sincosf_stret";
1501   SDValue Callee = DAG.getExternalSymbol(LibcallName, getPointerTy());
1502 
1503   StructType *RetTy = StructType::get(ArgTy, ArgTy, NULL);
1504   TargetLowering::CallLoweringInfo CLI(DAG);
1505   CLI.setDebugLoc(dl).setChain(DAG.getEntryNode())
1506     .setCallee(CallingConv::Fast, RetTy, Callee, std::move(Args), 0);
1507 
1508   std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
1509   return CallResult.first;
1510 }
1511 
LowerOperation(SDValue Op,SelectionDAG & DAG) const1512 SDValue AArch64TargetLowering::LowerOperation(SDValue Op,
1513                                               SelectionDAG &DAG) const {
1514   switch (Op.getOpcode()) {
1515   default:
1516     llvm_unreachable("unimplemented operand");
1517     return SDValue();
1518   case ISD::GlobalAddress:
1519     return LowerGlobalAddress(Op, DAG);
1520   case ISD::GlobalTLSAddress:
1521     return LowerGlobalTLSAddress(Op, DAG);
1522   case ISD::SETCC:
1523     return LowerSETCC(Op, DAG);
1524   case ISD::BR_CC:
1525     return LowerBR_CC(Op, DAG);
1526   case ISD::SELECT:
1527     return LowerSELECT(Op, DAG);
1528   case ISD::SELECT_CC:
1529     return LowerSELECT_CC(Op, DAG);
1530   case ISD::JumpTable:
1531     return LowerJumpTable(Op, DAG);
1532   case ISD::ConstantPool:
1533     return LowerConstantPool(Op, DAG);
1534   case ISD::BlockAddress:
1535     return LowerBlockAddress(Op, DAG);
1536   case ISD::VASTART:
1537     return LowerVASTART(Op, DAG);
1538   case ISD::VACOPY:
1539     return LowerVACOPY(Op, DAG);
1540   case ISD::VAARG:
1541     return LowerVAARG(Op, DAG);
1542   case ISD::ADDC:
1543   case ISD::ADDE:
1544   case ISD::SUBC:
1545   case ISD::SUBE:
1546     return LowerADDC_ADDE_SUBC_SUBE(Op, DAG);
1547   case ISD::SADDO:
1548   case ISD::UADDO:
1549   case ISD::SSUBO:
1550   case ISD::USUBO:
1551   case ISD::SMULO:
1552   case ISD::UMULO:
1553     return LowerXALUO(Op, DAG);
1554   case ISD::FADD:
1555     return LowerF128Call(Op, DAG, RTLIB::ADD_F128);
1556   case ISD::FSUB:
1557     return LowerF128Call(Op, DAG, RTLIB::SUB_F128);
1558   case ISD::FMUL:
1559     return LowerF128Call(Op, DAG, RTLIB::MUL_F128);
1560   case ISD::FDIV:
1561     return LowerF128Call(Op, DAG, RTLIB::DIV_F128);
1562   case ISD::FP_ROUND:
1563     return LowerFP_ROUND(Op, DAG);
1564   case ISD::FP_EXTEND:
1565     return LowerFP_EXTEND(Op, DAG);
1566   case ISD::FRAMEADDR:
1567     return LowerFRAMEADDR(Op, DAG);
1568   case ISD::RETURNADDR:
1569     return LowerRETURNADDR(Op, DAG);
1570   case ISD::INSERT_VECTOR_ELT:
1571     return LowerINSERT_VECTOR_ELT(Op, DAG);
1572   case ISD::EXTRACT_VECTOR_ELT:
1573     return LowerEXTRACT_VECTOR_ELT(Op, DAG);
1574   case ISD::BUILD_VECTOR:
1575     return LowerBUILD_VECTOR(Op, DAG);
1576   case ISD::VECTOR_SHUFFLE:
1577     return LowerVECTOR_SHUFFLE(Op, DAG);
1578   case ISD::EXTRACT_SUBVECTOR:
1579     return LowerEXTRACT_SUBVECTOR(Op, DAG);
1580   case ISD::SRA:
1581   case ISD::SRL:
1582   case ISD::SHL:
1583     return LowerVectorSRA_SRL_SHL(Op, DAG);
1584   case ISD::SHL_PARTS:
1585     return LowerShiftLeftParts(Op, DAG);
1586   case ISD::SRL_PARTS:
1587   case ISD::SRA_PARTS:
1588     return LowerShiftRightParts(Op, DAG);
1589   case ISD::CTPOP:
1590     return LowerCTPOP(Op, DAG);
1591   case ISD::FCOPYSIGN:
1592     return LowerFCOPYSIGN(Op, DAG);
1593   case ISD::AND:
1594     return LowerVectorAND(Op, DAG);
1595   case ISD::OR:
1596     return LowerVectorOR(Op, DAG);
1597   case ISD::XOR:
1598     return LowerXOR(Op, DAG);
1599   case ISD::PREFETCH:
1600     return LowerPREFETCH(Op, DAG);
1601   case ISD::SINT_TO_FP:
1602   case ISD::UINT_TO_FP:
1603     return LowerINT_TO_FP(Op, DAG);
1604   case ISD::FP_TO_SINT:
1605   case ISD::FP_TO_UINT:
1606     return LowerFP_TO_INT(Op, DAG);
1607   case ISD::FSINCOS:
1608     return LowerFSINCOS(Op, DAG);
1609   }
1610 }
1611 
1612 /// getFunctionAlignment - Return the Log2 alignment of this function.
getFunctionAlignment(const Function * F) const1613 unsigned AArch64TargetLowering::getFunctionAlignment(const Function *F) const {
1614   return 2;
1615 }
1616 
1617 //===----------------------------------------------------------------------===//
1618 //                      Calling Convention Implementation
1619 //===----------------------------------------------------------------------===//
1620 
1621 #include "AArch64GenCallingConv.inc"
1622 
1623 /// Selects the correct CCAssignFn for a the given CallingConvention
1624 /// value.
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg) const1625 CCAssignFn *AArch64TargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1626                                                      bool IsVarArg) const {
1627   switch (CC) {
1628   default:
1629     llvm_unreachable("Unsupported calling convention.");
1630   case CallingConv::WebKit_JS:
1631     return CC_AArch64_WebKit_JS;
1632   case CallingConv::C:
1633   case CallingConv::Fast:
1634     if (!Subtarget->isTargetDarwin())
1635       return CC_AArch64_AAPCS;
1636     return IsVarArg ? CC_AArch64_DarwinPCS_VarArg : CC_AArch64_DarwinPCS;
1637   }
1638 }
1639 
LowerFormalArguments(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,SDLoc DL,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const1640 SDValue AArch64TargetLowering::LowerFormalArguments(
1641     SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
1642     const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
1643     SmallVectorImpl<SDValue> &InVals) const {
1644   MachineFunction &MF = DAG.getMachineFunction();
1645   MachineFrameInfo *MFI = MF.getFrameInfo();
1646 
1647   // Assign locations to all of the incoming arguments.
1648   SmallVector<CCValAssign, 16> ArgLocs;
1649   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
1650                  getTargetMachine(), ArgLocs, *DAG.getContext());
1651 
1652   // At this point, Ins[].VT may already be promoted to i32. To correctly
1653   // handle passing i8 as i8 instead of i32 on stack, we pass in both i32 and
1654   // i8 to CC_AArch64_AAPCS with i32 being ValVT and i8 being LocVT.
1655   // Since AnalyzeFormalArguments uses Ins[].VT for both ValVT and LocVT, here
1656   // we use a special version of AnalyzeFormalArguments to pass in ValVT and
1657   // LocVT.
1658   unsigned NumArgs = Ins.size();
1659   Function::const_arg_iterator CurOrigArg = MF.getFunction()->arg_begin();
1660   unsigned CurArgIdx = 0;
1661   for (unsigned i = 0; i != NumArgs; ++i) {
1662     MVT ValVT = Ins[i].VT;
1663     std::advance(CurOrigArg, Ins[i].OrigArgIndex - CurArgIdx);
1664     CurArgIdx = Ins[i].OrigArgIndex;
1665 
1666     // Get type of the original argument.
1667     EVT ActualVT = getValueType(CurOrigArg->getType(), /*AllowUnknown*/ true);
1668     MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : MVT::Other;
1669     // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
1670     if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
1671       ValVT = MVT::i8;
1672     else if (ActualMVT == MVT::i16)
1673       ValVT = MVT::i16;
1674 
1675     CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
1676     bool Res =
1677         AssignFn(i, ValVT, ValVT, CCValAssign::Full, Ins[i].Flags, CCInfo);
1678     assert(!Res && "Call operand has unhandled type");
1679     (void)Res;
1680   }
1681   assert(ArgLocs.size() == Ins.size());
1682   SmallVector<SDValue, 16> ArgValues;
1683   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
1684     CCValAssign &VA = ArgLocs[i];
1685 
1686     if (Ins[i].Flags.isByVal()) {
1687       // Byval is used for HFAs in the PCS, but the system should work in a
1688       // non-compliant manner for larger structs.
1689       EVT PtrTy = getPointerTy();
1690       int Size = Ins[i].Flags.getByValSize();
1691       unsigned NumRegs = (Size + 7) / 8;
1692 
1693       // FIXME: This works on big-endian for composite byvals, which are the common
1694       // case. It should also work for fundamental types too.
1695       unsigned FrameIdx =
1696         MFI->CreateFixedObject(8 * NumRegs, VA.getLocMemOffset(), false);
1697       SDValue FrameIdxN = DAG.getFrameIndex(FrameIdx, PtrTy);
1698       InVals.push_back(FrameIdxN);
1699 
1700       continue;
1701     }
1702 
1703     if (VA.isRegLoc()) {
1704       // Arguments stored in registers.
1705       EVT RegVT = VA.getLocVT();
1706 
1707       SDValue ArgValue;
1708       const TargetRegisterClass *RC;
1709 
1710       if (RegVT == MVT::i32)
1711         RC = &AArch64::GPR32RegClass;
1712       else if (RegVT == MVT::i64)
1713         RC = &AArch64::GPR64RegClass;
1714       else if (RegVT == MVT::f32)
1715         RC = &AArch64::FPR32RegClass;
1716       else if (RegVT == MVT::f64 || RegVT.is64BitVector())
1717         RC = &AArch64::FPR64RegClass;
1718       else if (RegVT == MVT::f128 || RegVT.is128BitVector())
1719         RC = &AArch64::FPR128RegClass;
1720       else
1721         llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
1722 
1723       // Transform the arguments in physical registers into virtual ones.
1724       unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
1725       ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
1726 
1727       // If this is an 8, 16 or 32-bit value, it is really passed promoted
1728       // to 64 bits.  Insert an assert[sz]ext to capture this, then
1729       // truncate to the right size.
1730       switch (VA.getLocInfo()) {
1731       default:
1732         llvm_unreachable("Unknown loc info!");
1733       case CCValAssign::Full:
1734         break;
1735       case CCValAssign::BCvt:
1736         ArgValue = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), ArgValue);
1737         break;
1738       case CCValAssign::AExt:
1739       case CCValAssign::SExt:
1740       case CCValAssign::ZExt:
1741         // SelectionDAGBuilder will insert appropriate AssertZExt & AssertSExt
1742         // nodes after our lowering.
1743         assert(RegVT == Ins[i].VT && "incorrect register location selected");
1744         break;
1745       }
1746 
1747       InVals.push_back(ArgValue);
1748 
1749     } else { // VA.isRegLoc()
1750       assert(VA.isMemLoc() && "CCValAssign is neither reg nor mem");
1751       unsigned ArgOffset = VA.getLocMemOffset();
1752       unsigned ArgSize = VA.getLocVT().getSizeInBits() / 8;
1753 
1754       uint32_t BEAlign = 0;
1755       if (ArgSize < 8 && !Subtarget->isLittleEndian())
1756         BEAlign = 8 - ArgSize;
1757 
1758       int FI = MFI->CreateFixedObject(ArgSize, ArgOffset + BEAlign, true);
1759 
1760       // Create load nodes to retrieve arguments from the stack.
1761       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
1762       SDValue ArgValue;
1763 
1764       // For NON_EXTLOAD, generic code in getLoad assert(ValVT == MemVT)
1765       ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
1766       MVT MemVT = VA.getValVT();
1767 
1768       switch (VA.getLocInfo()) {
1769       default:
1770         break;
1771       case CCValAssign::BCvt:
1772         MemVT = VA.getLocVT();
1773         break;
1774       case CCValAssign::SExt:
1775         ExtType = ISD::SEXTLOAD;
1776         break;
1777       case CCValAssign::ZExt:
1778         ExtType = ISD::ZEXTLOAD;
1779         break;
1780       case CCValAssign::AExt:
1781         ExtType = ISD::EXTLOAD;
1782         break;
1783       }
1784 
1785       ArgValue = DAG.getExtLoad(ExtType, DL, VA.getLocVT(), Chain, FIN,
1786                                 MachinePointerInfo::getFixedStack(FI),
1787                                 MemVT, false, false, false, nullptr);
1788 
1789       InVals.push_back(ArgValue);
1790     }
1791   }
1792 
1793   // varargs
1794   if (isVarArg) {
1795     if (!Subtarget->isTargetDarwin()) {
1796       // The AAPCS variadic function ABI is identical to the non-variadic
1797       // one. As a result there may be more arguments in registers and we should
1798       // save them for future reference.
1799       saveVarArgRegisters(CCInfo, DAG, DL, Chain);
1800     }
1801 
1802     AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
1803     // This will point to the next argument passed via stack.
1804     unsigned StackOffset = CCInfo.getNextStackOffset();
1805     // We currently pass all varargs at 8-byte alignment.
1806     StackOffset = ((StackOffset + 7) & ~7);
1807     AFI->setVarArgsStackIndex(MFI->CreateFixedObject(4, StackOffset, true));
1808   }
1809 
1810   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
1811   unsigned StackArgSize = CCInfo.getNextStackOffset();
1812   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
1813   if (DoesCalleeRestoreStack(CallConv, TailCallOpt)) {
1814     // This is a non-standard ABI so by fiat I say we're allowed to make full
1815     // use of the stack area to be popped, which must be aligned to 16 bytes in
1816     // any case:
1817     StackArgSize = RoundUpToAlignment(StackArgSize, 16);
1818 
1819     // If we're expected to restore the stack (e.g. fastcc) then we'll be adding
1820     // a multiple of 16.
1821     FuncInfo->setArgumentStackToRestore(StackArgSize);
1822 
1823     // This realignment carries over to the available bytes below. Our own
1824     // callers will guarantee the space is free by giving an aligned value to
1825     // CALLSEQ_START.
1826   }
1827   // Even if we're not expected to free up the space, it's useful to know how
1828   // much is there while considering tail calls (because we can reuse it).
1829   FuncInfo->setBytesInStackArgArea(StackArgSize);
1830 
1831   return Chain;
1832 }
1833 
saveVarArgRegisters(CCState & CCInfo,SelectionDAG & DAG,SDLoc DL,SDValue & Chain) const1834 void AArch64TargetLowering::saveVarArgRegisters(CCState &CCInfo,
1835                                                 SelectionDAG &DAG, SDLoc DL,
1836                                                 SDValue &Chain) const {
1837   MachineFunction &MF = DAG.getMachineFunction();
1838   MachineFrameInfo *MFI = MF.getFrameInfo();
1839   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
1840 
1841   SmallVector<SDValue, 8> MemOps;
1842 
1843   static const MCPhysReg GPRArgRegs[] = { AArch64::X0, AArch64::X1, AArch64::X2,
1844                                           AArch64::X3, AArch64::X4, AArch64::X5,
1845                                           AArch64::X6, AArch64::X7 };
1846   static const unsigned NumGPRArgRegs = array_lengthof(GPRArgRegs);
1847   unsigned FirstVariadicGPR =
1848       CCInfo.getFirstUnallocated(GPRArgRegs, NumGPRArgRegs);
1849 
1850   unsigned GPRSaveSize = 8 * (NumGPRArgRegs - FirstVariadicGPR);
1851   int GPRIdx = 0;
1852   if (GPRSaveSize != 0) {
1853     GPRIdx = MFI->CreateStackObject(GPRSaveSize, 8, false);
1854 
1855     SDValue FIN = DAG.getFrameIndex(GPRIdx, getPointerTy());
1856 
1857     for (unsigned i = FirstVariadicGPR; i < NumGPRArgRegs; ++i) {
1858       unsigned VReg = MF.addLiveIn(GPRArgRegs[i], &AArch64::GPR64RegClass);
1859       SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
1860       SDValue Store =
1861           DAG.getStore(Val.getValue(1), DL, Val, FIN,
1862                        MachinePointerInfo::getStack(i * 8), false, false, 0);
1863       MemOps.push_back(Store);
1864       FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(), FIN,
1865                         DAG.getConstant(8, getPointerTy()));
1866     }
1867   }
1868   FuncInfo->setVarArgsGPRIndex(GPRIdx);
1869   FuncInfo->setVarArgsGPRSize(GPRSaveSize);
1870 
1871   if (Subtarget->hasFPARMv8()) {
1872     static const MCPhysReg FPRArgRegs[] = {
1873         AArch64::Q0, AArch64::Q1, AArch64::Q2, AArch64::Q3,
1874         AArch64::Q4, AArch64::Q5, AArch64::Q6, AArch64::Q7};
1875     static const unsigned NumFPRArgRegs = array_lengthof(FPRArgRegs);
1876     unsigned FirstVariadicFPR =
1877         CCInfo.getFirstUnallocated(FPRArgRegs, NumFPRArgRegs);
1878 
1879     unsigned FPRSaveSize = 16 * (NumFPRArgRegs - FirstVariadicFPR);
1880     int FPRIdx = 0;
1881     if (FPRSaveSize != 0) {
1882       FPRIdx = MFI->CreateStackObject(FPRSaveSize, 16, false);
1883 
1884       SDValue FIN = DAG.getFrameIndex(FPRIdx, getPointerTy());
1885 
1886       for (unsigned i = FirstVariadicFPR; i < NumFPRArgRegs; ++i) {
1887         unsigned VReg = MF.addLiveIn(FPRArgRegs[i], &AArch64::FPR128RegClass);
1888         SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::f128);
1889 
1890         SDValue Store =
1891             DAG.getStore(Val.getValue(1), DL, Val, FIN,
1892                          MachinePointerInfo::getStack(i * 16), false, false, 0);
1893         MemOps.push_back(Store);
1894         FIN = DAG.getNode(ISD::ADD, DL, getPointerTy(), FIN,
1895                           DAG.getConstant(16, getPointerTy()));
1896       }
1897     }
1898     FuncInfo->setVarArgsFPRIndex(FPRIdx);
1899     FuncInfo->setVarArgsFPRSize(FPRSaveSize);
1900   }
1901 
1902   if (!MemOps.empty()) {
1903     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
1904   }
1905 }
1906 
1907 /// LowerCallResult - Lower the result values of a call into the
1908 /// 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) const1909 SDValue AArch64TargetLowering::LowerCallResult(
1910     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg,
1911     const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc DL, SelectionDAG &DAG,
1912     SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
1913     SDValue ThisVal) const {
1914   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
1915                           ? RetCC_AArch64_WebKit_JS
1916                           : RetCC_AArch64_AAPCS;
1917   // Assign locations to each value returned by this call.
1918   SmallVector<CCValAssign, 16> RVLocs;
1919   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
1920                  getTargetMachine(), RVLocs, *DAG.getContext());
1921   CCInfo.AnalyzeCallResult(Ins, RetCC);
1922 
1923   // Copy all of the result registers out of their specified physreg.
1924   for (unsigned i = 0; i != RVLocs.size(); ++i) {
1925     CCValAssign VA = RVLocs[i];
1926 
1927     // Pass 'this' value directly from the argument to return value, to avoid
1928     // reg unit interference
1929     if (i == 0 && isThisReturn) {
1930       assert(!VA.needsCustom() && VA.getLocVT() == MVT::i64 &&
1931              "unexpected return calling convention register assignment");
1932       InVals.push_back(ThisVal);
1933       continue;
1934     }
1935 
1936     SDValue Val =
1937         DAG.getCopyFromReg(Chain, DL, VA.getLocReg(), VA.getLocVT(), InFlag);
1938     Chain = Val.getValue(1);
1939     InFlag = Val.getValue(2);
1940 
1941     switch (VA.getLocInfo()) {
1942     default:
1943       llvm_unreachable("Unknown loc info!");
1944     case CCValAssign::Full:
1945       break;
1946     case CCValAssign::BCvt:
1947       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
1948       break;
1949     }
1950 
1951     InVals.push_back(Val);
1952   }
1953 
1954   return Chain;
1955 }
1956 
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) const1957 bool AArch64TargetLowering::isEligibleForTailCallOptimization(
1958     SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg,
1959     bool isCalleeStructRet, bool isCallerStructRet,
1960     const SmallVectorImpl<ISD::OutputArg> &Outs,
1961     const SmallVectorImpl<SDValue> &OutVals,
1962     const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const {
1963   // For CallingConv::C this function knows whether the ABI needs
1964   // changing. That's not true for other conventions so they will have to opt in
1965   // manually.
1966   if (!IsTailCallConvention(CalleeCC) && CalleeCC != CallingConv::C)
1967     return false;
1968 
1969   const MachineFunction &MF = DAG.getMachineFunction();
1970   const Function *CallerF = MF.getFunction();
1971   CallingConv::ID CallerCC = CallerF->getCallingConv();
1972   bool CCMatch = CallerCC == CalleeCC;
1973 
1974   // Byval parameters hand the function a pointer directly into the stack area
1975   // we want to reuse during a tail call. Working around this *is* possible (see
1976   // X86) but less efficient and uglier in LowerCall.
1977   for (Function::const_arg_iterator i = CallerF->arg_begin(),
1978                                     e = CallerF->arg_end();
1979        i != e; ++i)
1980     if (i->hasByValAttr())
1981       return false;
1982 
1983   if (getTargetMachine().Options.GuaranteedTailCallOpt) {
1984     if (IsTailCallConvention(CalleeCC) && CCMatch)
1985       return true;
1986     return false;
1987   }
1988 
1989   // Now we search for cases where we can use a tail call without changing the
1990   // ABI. Sibcall is used in some places (particularly gcc) to refer to this
1991   // concept.
1992 
1993   // I want anyone implementing a new calling convention to think long and hard
1994   // about this assert.
1995   assert((!isVarArg || CalleeCC == CallingConv::C) &&
1996          "Unexpected variadic calling convention");
1997 
1998   if (isVarArg && !Outs.empty()) {
1999     // At least two cases here: if caller is fastcc then we can't have any
2000     // memory arguments (we'd be expected to clean up the stack afterwards). If
2001     // caller is C then we could potentially use its argument area.
2002 
2003     // FIXME: for now we take the most conservative of these in both cases:
2004     // disallow all variadic memory operands.
2005     SmallVector<CCValAssign, 16> ArgLocs;
2006     CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(),
2007                    getTargetMachine(), ArgLocs, *DAG.getContext());
2008 
2009     CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForCall(CalleeCC, true));
2010     for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i)
2011       if (!ArgLocs[i].isRegLoc())
2012         return false;
2013   }
2014 
2015   // If the calling conventions do not match, then we'd better make sure the
2016   // results are returned in the same way as what the caller expects.
2017   if (!CCMatch) {
2018     SmallVector<CCValAssign, 16> RVLocs1;
2019     CCState CCInfo1(CalleeCC, false, DAG.getMachineFunction(),
2020                     getTargetMachine(), RVLocs1, *DAG.getContext());
2021     CCInfo1.AnalyzeCallResult(Ins, CCAssignFnForCall(CalleeCC, isVarArg));
2022 
2023     SmallVector<CCValAssign, 16> RVLocs2;
2024     CCState CCInfo2(CallerCC, false, DAG.getMachineFunction(),
2025                     getTargetMachine(), RVLocs2, *DAG.getContext());
2026     CCInfo2.AnalyzeCallResult(Ins, CCAssignFnForCall(CallerCC, isVarArg));
2027 
2028     if (RVLocs1.size() != RVLocs2.size())
2029       return false;
2030     for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
2031       if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
2032         return false;
2033       if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
2034         return false;
2035       if (RVLocs1[i].isRegLoc()) {
2036         if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
2037           return false;
2038       } else {
2039         if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
2040           return false;
2041       }
2042     }
2043   }
2044 
2045   // Nothing more to check if the callee is taking no arguments
2046   if (Outs.empty())
2047     return true;
2048 
2049   SmallVector<CCValAssign, 16> ArgLocs;
2050   CCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(),
2051                  getTargetMachine(), ArgLocs, *DAG.getContext());
2052 
2053   CCInfo.AnalyzeCallOperands(Outs, CCAssignFnForCall(CalleeCC, isVarArg));
2054 
2055   const AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
2056 
2057   // If the stack arguments for this call would fit into our own save area then
2058   // the call can be made tail.
2059   return CCInfo.getNextStackOffset() <= FuncInfo->getBytesInStackArgArea();
2060 }
2061 
addTokenForArgument(SDValue Chain,SelectionDAG & DAG,MachineFrameInfo * MFI,int ClobberedFI) const2062 SDValue AArch64TargetLowering::addTokenForArgument(SDValue Chain,
2063                                                    SelectionDAG &DAG,
2064                                                    MachineFrameInfo *MFI,
2065                                                    int ClobberedFI) const {
2066   SmallVector<SDValue, 8> ArgChains;
2067   int64_t FirstByte = MFI->getObjectOffset(ClobberedFI);
2068   int64_t LastByte = FirstByte + MFI->getObjectSize(ClobberedFI) - 1;
2069 
2070   // Include the original chain at the beginning of the list. When this is
2071   // used by target LowerCall hooks, this helps legalize find the
2072   // CALLSEQ_BEGIN node.
2073   ArgChains.push_back(Chain);
2074 
2075   // Add a chain value for each stack argument corresponding
2076   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
2077                             UE = DAG.getEntryNode().getNode()->use_end();
2078        U != UE; ++U)
2079     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U))
2080       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr()))
2081         if (FI->getIndex() < 0) {
2082           int64_t InFirstByte = MFI->getObjectOffset(FI->getIndex());
2083           int64_t InLastByte = InFirstByte;
2084           InLastByte += MFI->getObjectSize(FI->getIndex()) - 1;
2085 
2086           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
2087               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
2088             ArgChains.push_back(SDValue(L, 1));
2089         }
2090 
2091   // Build a tokenfactor for all the chains.
2092   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
2093 }
2094 
DoesCalleeRestoreStack(CallingConv::ID CallCC,bool TailCallOpt) const2095 bool AArch64TargetLowering::DoesCalleeRestoreStack(CallingConv::ID CallCC,
2096                                                    bool TailCallOpt) const {
2097   return CallCC == CallingConv::Fast && TailCallOpt;
2098 }
2099 
IsTailCallConvention(CallingConv::ID CallCC) const2100 bool AArch64TargetLowering::IsTailCallConvention(CallingConv::ID CallCC) const {
2101   return CallCC == CallingConv::Fast;
2102 }
2103 
2104 /// LowerCall - Lower a call to a callseq_start + CALL + callseq_end chain,
2105 /// and add input and output parameter nodes.
2106 SDValue
LowerCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const2107 AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
2108                                  SmallVectorImpl<SDValue> &InVals) const {
2109   SelectionDAG &DAG = CLI.DAG;
2110   SDLoc &DL = CLI.DL;
2111   SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
2112   SmallVector<SDValue, 32> &OutVals = CLI.OutVals;
2113   SmallVector<ISD::InputArg, 32> &Ins = CLI.Ins;
2114   SDValue Chain = CLI.Chain;
2115   SDValue Callee = CLI.Callee;
2116   bool &IsTailCall = CLI.IsTailCall;
2117   CallingConv::ID CallConv = CLI.CallConv;
2118   bool IsVarArg = CLI.IsVarArg;
2119 
2120   MachineFunction &MF = DAG.getMachineFunction();
2121   bool IsStructRet = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
2122   bool IsThisReturn = false;
2123 
2124   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
2125   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
2126   bool IsSibCall = false;
2127 
2128   if (IsTailCall) {
2129     // Check if it's really possible to do a tail call.
2130     IsTailCall = isEligibleForTailCallOptimization(
2131         Callee, CallConv, IsVarArg, IsStructRet,
2132         MF.getFunction()->hasStructRetAttr(), Outs, OutVals, Ins, DAG);
2133     if (!IsTailCall && CLI.CS && CLI.CS->isMustTailCall())
2134       report_fatal_error("failed to perform tail call elimination on a call "
2135                          "site marked musttail");
2136 
2137     // A sibling call is one where we're under the usual C ABI and not planning
2138     // to change that but can still do a tail call:
2139     if (!TailCallOpt && IsTailCall)
2140       IsSibCall = true;
2141 
2142     if (IsTailCall)
2143       ++NumTailCalls;
2144   }
2145 
2146   // Analyze operands of the call, assigning locations to each operand.
2147   SmallVector<CCValAssign, 16> ArgLocs;
2148   CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(),
2149                  getTargetMachine(), ArgLocs, *DAG.getContext());
2150 
2151   if (IsVarArg) {
2152     // Handle fixed and variable vector arguments differently.
2153     // Variable vector arguments always go into memory.
2154     unsigned NumArgs = Outs.size();
2155 
2156     for (unsigned i = 0; i != NumArgs; ++i) {
2157       MVT ArgVT = Outs[i].VT;
2158       ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
2159       CCAssignFn *AssignFn = CCAssignFnForCall(CallConv,
2160                                                /*IsVarArg=*/ !Outs[i].IsFixed);
2161       bool Res = AssignFn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
2162       assert(!Res && "Call operand has unhandled type");
2163       (void)Res;
2164     }
2165   } else {
2166     // At this point, Outs[].VT may already be promoted to i32. To correctly
2167     // handle passing i8 as i8 instead of i32 on stack, we pass in both i32 and
2168     // i8 to CC_AArch64_AAPCS with i32 being ValVT and i8 being LocVT.
2169     // Since AnalyzeCallOperands uses Ins[].VT for both ValVT and LocVT, here
2170     // we use a special version of AnalyzeCallOperands to pass in ValVT and
2171     // LocVT.
2172     unsigned NumArgs = Outs.size();
2173     for (unsigned i = 0; i != NumArgs; ++i) {
2174       MVT ValVT = Outs[i].VT;
2175       // Get type of the original argument.
2176       EVT ActualVT = getValueType(CLI.getArgs()[Outs[i].OrigArgIndex].Ty,
2177                                   /*AllowUnknown*/ true);
2178       MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : ValVT;
2179       ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
2180       // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
2181       if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
2182         ValVT = MVT::i8;
2183       else if (ActualMVT == MVT::i16)
2184         ValVT = MVT::i16;
2185 
2186       CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
2187       bool Res = AssignFn(i, ValVT, ValVT, CCValAssign::Full, ArgFlags, CCInfo);
2188       assert(!Res && "Call operand has unhandled type");
2189       (void)Res;
2190     }
2191   }
2192 
2193   // Get a count of how many bytes are to be pushed on the stack.
2194   unsigned NumBytes = CCInfo.getNextStackOffset();
2195 
2196   if (IsSibCall) {
2197     // Since we're not changing the ABI to make this a tail call, the memory
2198     // operands are already available in the caller's incoming argument space.
2199     NumBytes = 0;
2200   }
2201 
2202   // FPDiff is the byte offset of the call's argument area from the callee's.
2203   // Stores to callee stack arguments will be placed in FixedStackSlots offset
2204   // by this amount for a tail call. In a sibling call it must be 0 because the
2205   // caller will deallocate the entire stack and the callee still expects its
2206   // arguments to begin at SP+0. Completely unused for non-tail calls.
2207   int FPDiff = 0;
2208 
2209   if (IsTailCall && !IsSibCall) {
2210     unsigned NumReusableBytes = FuncInfo->getBytesInStackArgArea();
2211 
2212     // Since callee will pop argument stack as a tail call, we must keep the
2213     // popped size 16-byte aligned.
2214     NumBytes = RoundUpToAlignment(NumBytes, 16);
2215 
2216     // FPDiff will be negative if this tail call requires more space than we
2217     // would automatically have in our incoming argument space. Positive if we
2218     // can actually shrink the stack.
2219     FPDiff = NumReusableBytes - NumBytes;
2220 
2221     // The stack pointer must be 16-byte aligned at all times it's used for a
2222     // memory operation, which in practice means at *all* times and in
2223     // particular across call boundaries. Therefore our own arguments started at
2224     // a 16-byte aligned SP and the delta applied for the tail call should
2225     // satisfy the same constraint.
2226     assert(FPDiff % 16 == 0 && "unaligned stack on tail call");
2227   }
2228 
2229   // Adjust the stack pointer for the new arguments...
2230   // These operations are automatically eliminated by the prolog/epilog pass
2231   if (!IsSibCall)
2232     Chain =
2233         DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true), DL);
2234 
2235   SDValue StackPtr = DAG.getCopyFromReg(Chain, DL, AArch64::SP, getPointerTy());
2236 
2237   SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
2238   SmallVector<SDValue, 8> MemOpChains;
2239 
2240   // Walk the register/memloc assignments, inserting copies/loads.
2241   for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size(); i != e;
2242        ++i, ++realArgIdx) {
2243     CCValAssign &VA = ArgLocs[i];
2244     SDValue Arg = OutVals[realArgIdx];
2245     ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
2246 
2247     // Promote the value if needed.
2248     switch (VA.getLocInfo()) {
2249     default:
2250       llvm_unreachable("Unknown loc info!");
2251     case CCValAssign::Full:
2252       break;
2253     case CCValAssign::SExt:
2254       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Arg);
2255       break;
2256     case CCValAssign::ZExt:
2257       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
2258       break;
2259     case CCValAssign::AExt:
2260       if (Outs[realArgIdx].ArgVT == MVT::i1) {
2261         // AAPCS requires i1 to be zero-extended to 8-bits by the caller.
2262         Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
2263         Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i8, Arg);
2264       }
2265       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg);
2266       break;
2267     case CCValAssign::BCvt:
2268       Arg = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Arg);
2269       break;
2270     case CCValAssign::FPExt:
2271       Arg = DAG.getNode(ISD::FP_EXTEND, DL, VA.getLocVT(), Arg);
2272       break;
2273     }
2274 
2275     if (VA.isRegLoc()) {
2276       if (realArgIdx == 0 && Flags.isReturned() && Outs[0].VT == MVT::i64) {
2277         assert(VA.getLocVT() == MVT::i64 &&
2278                "unexpected calling convention register assignment");
2279         assert(!Ins.empty() && Ins[0].VT == MVT::i64 &&
2280                "unexpected use of 'returned'");
2281         IsThisReturn = true;
2282       }
2283       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
2284     } else {
2285       assert(VA.isMemLoc());
2286 
2287       SDValue DstAddr;
2288       MachinePointerInfo DstInfo;
2289 
2290       // FIXME: This works on big-endian for composite byvals, which are the
2291       // common case. It should also work for fundamental types too.
2292       uint32_t BEAlign = 0;
2293       unsigned OpSize = Flags.isByVal() ? Flags.getByValSize() * 8
2294                                         : VA.getLocVT().getSizeInBits();
2295       OpSize = (OpSize + 7) / 8;
2296       if (!Subtarget->isLittleEndian() && !Flags.isByVal()) {
2297         if (OpSize < 8)
2298           BEAlign = 8 - OpSize;
2299       }
2300       unsigned LocMemOffset = VA.getLocMemOffset();
2301       int32_t Offset = LocMemOffset + BEAlign;
2302       SDValue PtrOff = DAG.getIntPtrConstant(Offset);
2303       PtrOff = DAG.getNode(ISD::ADD, DL, getPointerTy(), StackPtr, PtrOff);
2304 
2305       if (IsTailCall) {
2306         Offset = Offset + FPDiff;
2307         int FI = MF.getFrameInfo()->CreateFixedObject(OpSize, Offset, true);
2308 
2309         DstAddr = DAG.getFrameIndex(FI, getPointerTy());
2310         DstInfo = MachinePointerInfo::getFixedStack(FI);
2311 
2312         // Make sure any stack arguments overlapping with where we're storing
2313         // are loaded before this eventual operation. Otherwise they'll be
2314         // clobbered.
2315         Chain = addTokenForArgument(Chain, DAG, MF.getFrameInfo(), FI);
2316       } else {
2317         SDValue PtrOff = DAG.getIntPtrConstant(Offset);
2318 
2319         DstAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), StackPtr, PtrOff);
2320         DstInfo = MachinePointerInfo::getStack(LocMemOffset);
2321       }
2322 
2323       if (Outs[i].Flags.isByVal()) {
2324         SDValue SizeNode =
2325             DAG.getConstant(Outs[i].Flags.getByValSize(), MVT::i64);
2326         SDValue Cpy = DAG.getMemcpy(
2327             Chain, DL, DstAddr, Arg, SizeNode, Outs[i].Flags.getByValAlign(),
2328             /*isVolatile = */ false,
2329             /*alwaysInline = */ false, DstInfo, MachinePointerInfo());
2330 
2331         MemOpChains.push_back(Cpy);
2332       } else {
2333         // Since we pass i1/i8/i16 as i1/i8/i16 on stack and Arg is already
2334         // promoted to a legal register type i32, we should truncate Arg back to
2335         // i1/i8/i16.
2336         if (VA.getValVT() == MVT::i1 || VA.getValVT() == MVT::i8 ||
2337             VA.getValVT() == MVT::i16)
2338           Arg = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Arg);
2339 
2340         SDValue Store =
2341             DAG.getStore(Chain, DL, Arg, DstAddr, DstInfo, false, false, 0);
2342         MemOpChains.push_back(Store);
2343       }
2344     }
2345   }
2346 
2347   if (!MemOpChains.empty())
2348     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
2349 
2350   // Build a sequence of copy-to-reg nodes chained together with token chain
2351   // and flag operands which copy the outgoing args into the appropriate regs.
2352   SDValue InFlag;
2353   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2354     Chain = DAG.getCopyToReg(Chain, DL, RegsToPass[i].first,
2355                              RegsToPass[i].second, InFlag);
2356     InFlag = Chain.getValue(1);
2357   }
2358 
2359   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
2360   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
2361   // node so that legalize doesn't hack it.
2362   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
2363       Subtarget->isTargetMachO()) {
2364     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2365       const GlobalValue *GV = G->getGlobal();
2366       bool InternalLinkage = GV->hasInternalLinkage();
2367       if (InternalLinkage)
2368         Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0, 0);
2369       else {
2370         Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0,
2371                                             AArch64II::MO_GOT);
2372         Callee = DAG.getNode(AArch64ISD::LOADgot, DL, getPointerTy(), Callee);
2373       }
2374     } else if (ExternalSymbolSDNode *S =
2375                    dyn_cast<ExternalSymbolSDNode>(Callee)) {
2376       const char *Sym = S->getSymbol();
2377       Callee =
2378           DAG.getTargetExternalSymbol(Sym, getPointerTy(), AArch64II::MO_GOT);
2379       Callee = DAG.getNode(AArch64ISD::LOADgot, DL, getPointerTy(), Callee);
2380     }
2381   } else if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2382     const GlobalValue *GV = G->getGlobal();
2383     Callee = DAG.getTargetGlobalAddress(GV, DL, getPointerTy(), 0, 0);
2384   } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
2385     const char *Sym = S->getSymbol();
2386     Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy(), 0);
2387   }
2388 
2389   // We don't usually want to end the call-sequence here because we would tidy
2390   // the frame up *after* the call, however in the ABI-changing tail-call case
2391   // we've carefully laid out the parameters so that when sp is reset they'll be
2392   // in the correct location.
2393   if (IsTailCall && !IsSibCall) {
2394     Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
2395                                DAG.getIntPtrConstant(0, true), InFlag, DL);
2396     InFlag = Chain.getValue(1);
2397   }
2398 
2399   std::vector<SDValue> Ops;
2400   Ops.push_back(Chain);
2401   Ops.push_back(Callee);
2402 
2403   if (IsTailCall) {
2404     // Each tail call may have to adjust the stack by a different amount, so
2405     // this information must travel along with the operation for eventual
2406     // consumption by emitEpilogue.
2407     Ops.push_back(DAG.getTargetConstant(FPDiff, MVT::i32));
2408   }
2409 
2410   // Add argument registers to the end of the list so that they are known live
2411   // into the call.
2412   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2413     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
2414                                   RegsToPass[i].second.getValueType()));
2415 
2416   // Add a register mask operand representing the call-preserved registers.
2417   const uint32_t *Mask;
2418   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2419   const AArch64RegisterInfo *ARI =
2420       static_cast<const AArch64RegisterInfo *>(TRI);
2421   if (IsThisReturn) {
2422     // For 'this' returns, use the X0-preserving mask if applicable
2423     Mask = ARI->getThisReturnPreservedMask(CallConv);
2424     if (!Mask) {
2425       IsThisReturn = false;
2426       Mask = ARI->getCallPreservedMask(CallConv);
2427     }
2428   } else
2429     Mask = ARI->getCallPreservedMask(CallConv);
2430 
2431   assert(Mask && "Missing call preserved mask for calling convention");
2432   Ops.push_back(DAG.getRegisterMask(Mask));
2433 
2434   if (InFlag.getNode())
2435     Ops.push_back(InFlag);
2436 
2437   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2438 
2439   // If we're doing a tall call, use a TC_RETURN here rather than an
2440   // actual call instruction.
2441   if (IsTailCall)
2442     return DAG.getNode(AArch64ISD::TC_RETURN, DL, NodeTys, Ops);
2443 
2444   // Returns a chain and a flag for retval copy to use.
2445   Chain = DAG.getNode(AArch64ISD::CALL, DL, NodeTys, Ops);
2446   InFlag = Chain.getValue(1);
2447 
2448   uint64_t CalleePopBytes = DoesCalleeRestoreStack(CallConv, TailCallOpt)
2449                                 ? RoundUpToAlignment(NumBytes, 16)
2450                                 : 0;
2451 
2452   Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
2453                              DAG.getIntPtrConstant(CalleePopBytes, true),
2454                              InFlag, DL);
2455   if (!Ins.empty())
2456     InFlag = Chain.getValue(1);
2457 
2458   // Handle result values, copying them out of physregs into vregs that we
2459   // return.
2460   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
2461                          InVals, IsThisReturn,
2462                          IsThisReturn ? OutVals[0] : SDValue());
2463 }
2464 
CanLowerReturn(CallingConv::ID CallConv,MachineFunction & MF,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,LLVMContext & Context) const2465 bool AArch64TargetLowering::CanLowerReturn(
2466     CallingConv::ID CallConv, MachineFunction &MF, bool isVarArg,
2467     const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context) const {
2468   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
2469                           ? RetCC_AArch64_WebKit_JS
2470                           : RetCC_AArch64_AAPCS;
2471   SmallVector<CCValAssign, 16> RVLocs;
2472   CCState CCInfo(CallConv, isVarArg, MF, getTargetMachine(), RVLocs, Context);
2473   return CCInfo.CheckReturn(Outs, RetCC);
2474 }
2475 
2476 SDValue
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,SDLoc DL,SelectionDAG & DAG) const2477 AArch64TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
2478                                    bool isVarArg,
2479                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
2480                                    const SmallVectorImpl<SDValue> &OutVals,
2481                                    SDLoc DL, SelectionDAG &DAG) const {
2482   CCAssignFn *RetCC = CallConv == CallingConv::WebKit_JS
2483                           ? RetCC_AArch64_WebKit_JS
2484                           : RetCC_AArch64_AAPCS;
2485   SmallVector<CCValAssign, 16> RVLocs;
2486   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
2487                  getTargetMachine(), RVLocs, *DAG.getContext());
2488   CCInfo.AnalyzeReturn(Outs, RetCC);
2489 
2490   // Copy the result values into the output registers.
2491   SDValue Flag;
2492   SmallVector<SDValue, 4> RetOps(1, Chain);
2493   for (unsigned i = 0, realRVLocIdx = 0; i != RVLocs.size();
2494        ++i, ++realRVLocIdx) {
2495     CCValAssign &VA = RVLocs[i];
2496     assert(VA.isRegLoc() && "Can only return in registers!");
2497     SDValue Arg = OutVals[realRVLocIdx];
2498 
2499     switch (VA.getLocInfo()) {
2500     default:
2501       llvm_unreachable("Unknown loc info!");
2502     case CCValAssign::Full:
2503       if (Outs[i].ArgVT == MVT::i1) {
2504         // AAPCS requires i1 to be zero-extended to i8 by the producer of the
2505         // value. This is strictly redundant on Darwin (which uses "zeroext
2506         // i1"), but will be optimised out before ISel.
2507         Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
2508         Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
2509       }
2510       break;
2511     case CCValAssign::BCvt:
2512       Arg = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Arg);
2513       break;
2514     }
2515 
2516     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Arg, Flag);
2517     Flag = Chain.getValue(1);
2518     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
2519   }
2520 
2521   RetOps[0] = Chain; // Update chain.
2522 
2523   // Add the flag if we have it.
2524   if (Flag.getNode())
2525     RetOps.push_back(Flag);
2526 
2527   return DAG.getNode(AArch64ISD::RET_FLAG, DL, MVT::Other, RetOps);
2528 }
2529 
2530 //===----------------------------------------------------------------------===//
2531 //  Other Lowering Code
2532 //===----------------------------------------------------------------------===//
2533 
LowerGlobalAddress(SDValue Op,SelectionDAG & DAG) const2534 SDValue AArch64TargetLowering::LowerGlobalAddress(SDValue Op,
2535                                                   SelectionDAG &DAG) const {
2536   EVT PtrVT = getPointerTy();
2537   SDLoc DL(Op);
2538   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
2539   unsigned char OpFlags =
2540       Subtarget->ClassifyGlobalReference(GV, getTargetMachine());
2541 
2542   assert(cast<GlobalAddressSDNode>(Op)->getOffset() == 0 &&
2543          "unexpected offset in global node");
2544 
2545   // This also catched the large code model case for Darwin.
2546   if ((OpFlags & AArch64II::MO_GOT) != 0) {
2547     SDValue GotAddr = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, OpFlags);
2548     // FIXME: Once remat is capable of dealing with instructions with register
2549     // operands, expand this into two nodes instead of using a wrapper node.
2550     return DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, GotAddr);
2551   }
2552 
2553   if (getTargetMachine().getCodeModel() == CodeModel::Large) {
2554     const unsigned char MO_NC = AArch64II::MO_NC;
2555     return DAG.getNode(
2556         AArch64ISD::WrapperLarge, DL, PtrVT,
2557         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G3),
2558         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G2 | MO_NC),
2559         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G1 | MO_NC),
2560         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_G0 | MO_NC));
2561   } else {
2562     // Use ADRP/ADD or ADRP/LDR for everything else: the small model on ELF and
2563     // the only correct model on Darwin.
2564     SDValue Hi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2565                                             OpFlags | AArch64II::MO_PAGE);
2566     unsigned char LoFlags = OpFlags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC;
2567     SDValue Lo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, LoFlags);
2568 
2569     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
2570     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
2571   }
2572 }
2573 
2574 /// \brief Convert a TLS address reference into the correct sequence of loads
2575 /// and calls to compute the variable's address (for Darwin, currently) and
2576 /// return an SDValue containing the final node.
2577 
2578 /// Darwin only has one TLS scheme which must be capable of dealing with the
2579 /// fully general situation, in the worst case. This means:
2580 ///     + "extern __thread" declaration.
2581 ///     + Defined in a possibly unknown dynamic library.
2582 ///
2583 /// The general system is that each __thread variable has a [3 x i64] descriptor
2584 /// which contains information used by the runtime to calculate the address. The
2585 /// only part of this the compiler needs to know about is the first xword, which
2586 /// contains a function pointer that must be called with the address of the
2587 /// entire descriptor in "x0".
2588 ///
2589 /// Since this descriptor may be in a different unit, in general even the
2590 /// descriptor must be accessed via an indirect load. The "ideal" code sequence
2591 /// is:
2592 ///     adrp x0, _var@TLVPPAGE
2593 ///     ldr x0, [x0, _var@TLVPPAGEOFF]   ; x0 now contains address of descriptor
2594 ///     ldr x1, [x0]                     ; x1 contains 1st entry of descriptor,
2595 ///                                      ; the function pointer
2596 ///     blr x1                           ; Uses descriptor address in x0
2597 ///     ; Address of _var is now in x0.
2598 ///
2599 /// If the address of _var's descriptor *is* known to the linker, then it can
2600 /// change the first "ldr" instruction to an appropriate "add x0, x0, #imm" for
2601 /// a slight efficiency gain.
2602 SDValue
LowerDarwinGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2603 AArch64TargetLowering::LowerDarwinGlobalTLSAddress(SDValue Op,
2604                                                    SelectionDAG &DAG) const {
2605   assert(Subtarget->isTargetDarwin() && "TLS only supported on Darwin");
2606 
2607   SDLoc DL(Op);
2608   MVT PtrVT = getPointerTy();
2609   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
2610 
2611   SDValue TLVPAddr =
2612       DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2613   SDValue DescAddr = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TLVPAddr);
2614 
2615   // The first entry in the descriptor is a function pointer that we must call
2616   // to obtain the address of the variable.
2617   SDValue Chain = DAG.getEntryNode();
2618   SDValue FuncTLVGet =
2619       DAG.getLoad(MVT::i64, DL, Chain, DescAddr, MachinePointerInfo::getGOT(),
2620                   false, true, true, 8);
2621   Chain = FuncTLVGet.getValue(1);
2622 
2623   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2624   MFI->setAdjustsStack(true);
2625 
2626   // TLS calls preserve all registers except those that absolutely must be
2627   // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
2628   // silly).
2629   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2630   const AArch64RegisterInfo *ARI =
2631       static_cast<const AArch64RegisterInfo *>(TRI);
2632   const uint32_t *Mask = ARI->getTLSCallPreservedMask();
2633 
2634   // Finally, we can make the call. This is just a degenerate version of a
2635   // normal AArch64 call node: x0 takes the address of the descriptor, and
2636   // returns the address of the variable in this thread.
2637   Chain = DAG.getCopyToReg(Chain, DL, AArch64::X0, DescAddr, SDValue());
2638   Chain =
2639       DAG.getNode(AArch64ISD::CALL, DL, DAG.getVTList(MVT::Other, MVT::Glue),
2640                   Chain, FuncTLVGet, DAG.getRegister(AArch64::X0, MVT::i64),
2641                   DAG.getRegisterMask(Mask), Chain.getValue(1));
2642   return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Chain.getValue(1));
2643 }
2644 
2645 /// When accessing thread-local variables under either the general-dynamic or
2646 /// local-dynamic system, we make a "TLS-descriptor" call. The variable will
2647 /// have a descriptor, accessible via a PC-relative ADRP, and whose first entry
2648 /// is a function pointer to carry out the resolution. This function takes the
2649 /// address of the descriptor in X0 and returns the TPIDR_EL0 offset in X0. All
2650 /// other registers (except LR, NZCV) are preserved.
2651 ///
2652 /// Thus, the ideal call sequence on AArch64 is:
2653 ///
2654 ///     adrp x0, :tlsdesc:thread_var
2655 ///     ldr x8, [x0, :tlsdesc_lo12:thread_var]
2656 ///     add x0, x0, :tlsdesc_lo12:thread_var
2657 ///     .tlsdesccall thread_var
2658 ///     blr x8
2659 ///     (TPIDR_EL0 offset now in x0).
2660 ///
2661 /// The ".tlsdesccall" directive instructs the assembler to insert a particular
2662 /// relocation to help the linker relax this sequence if it turns out to be too
2663 /// conservative.
2664 ///
2665 /// FIXME: we currently produce an extra, duplicated, ADRP instruction, but this
2666 /// is harmless.
LowerELFTLSDescCall(SDValue SymAddr,SDValue DescAddr,SDLoc DL,SelectionDAG & DAG) const2667 SDValue AArch64TargetLowering::LowerELFTLSDescCall(SDValue SymAddr,
2668                                                    SDValue DescAddr, SDLoc DL,
2669                                                    SelectionDAG &DAG) const {
2670   EVT PtrVT = getPointerTy();
2671 
2672   // The function we need to call is simply the first entry in the GOT for this
2673   // descriptor, load it in preparation.
2674   SDValue Func = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, SymAddr);
2675 
2676   // TLS calls preserve all registers except those that absolutely must be
2677   // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
2678   // silly).
2679   const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
2680   const AArch64RegisterInfo *ARI =
2681       static_cast<const AArch64RegisterInfo *>(TRI);
2682   const uint32_t *Mask = ARI->getTLSCallPreservedMask();
2683 
2684   // The function takes only one argument: the address of the descriptor itself
2685   // in X0.
2686   SDValue Glue, Chain;
2687   Chain = DAG.getCopyToReg(DAG.getEntryNode(), DL, AArch64::X0, DescAddr, Glue);
2688   Glue = Chain.getValue(1);
2689 
2690   // We're now ready to populate the argument list, as with a normal call:
2691   SmallVector<SDValue, 6> Ops;
2692   Ops.push_back(Chain);
2693   Ops.push_back(Func);
2694   Ops.push_back(SymAddr);
2695   Ops.push_back(DAG.getRegister(AArch64::X0, PtrVT));
2696   Ops.push_back(DAG.getRegisterMask(Mask));
2697   Ops.push_back(Glue);
2698 
2699   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2700   Chain = DAG.getNode(AArch64ISD::TLSDESC_CALL, DL, NodeTys, Ops);
2701   Glue = Chain.getValue(1);
2702 
2703   return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Glue);
2704 }
2705 
2706 SDValue
LowerELFGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2707 AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
2708                                                 SelectionDAG &DAG) const {
2709   assert(Subtarget->isTargetELF() && "This function expects an ELF target");
2710   assert(getTargetMachine().getCodeModel() == CodeModel::Small &&
2711          "ELF TLS only supported in small memory model");
2712   const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2713 
2714   TLSModel::Model Model = getTargetMachine().getTLSModel(GA->getGlobal());
2715 
2716   SDValue TPOff;
2717   EVT PtrVT = getPointerTy();
2718   SDLoc DL(Op);
2719   const GlobalValue *GV = GA->getGlobal();
2720 
2721   SDValue ThreadBase = DAG.getNode(AArch64ISD::THREAD_POINTER, DL, PtrVT);
2722 
2723   if (Model == TLSModel::LocalExec) {
2724     SDValue HiVar = DAG.getTargetGlobalAddress(
2725         GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
2726     SDValue LoVar = DAG.getTargetGlobalAddress(
2727         GV, DL, PtrVT, 0,
2728         AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
2729 
2730     TPOff = SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
2731                                        DAG.getTargetConstant(16, MVT::i32)),
2732                     0);
2733     TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, LoVar,
2734                                        DAG.getTargetConstant(0, MVT::i32)),
2735                     0);
2736   } else if (Model == TLSModel::InitialExec) {
2737     TPOff = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2738     TPOff = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TPOff);
2739   } else if (Model == TLSModel::LocalDynamic) {
2740     // Local-dynamic accesses proceed in two phases. A general-dynamic TLS
2741     // descriptor call against the special symbol _TLS_MODULE_BASE_ to calculate
2742     // the beginning of the module's TLS region, followed by a DTPREL offset
2743     // calculation.
2744 
2745     // These accesses will need deduplicating if there's more than one.
2746     AArch64FunctionInfo *MFI =
2747         DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
2748     MFI->incNumLocalDynamicTLSAccesses();
2749 
2750     // Accesses used in this sequence go via the TLS descriptor which lives in
2751     // the GOT. Prepare an address we can use to handle this.
2752     SDValue HiDesc = DAG.getTargetExternalSymbol(
2753         "_TLS_MODULE_BASE_", PtrVT, AArch64II::MO_TLS | AArch64II::MO_PAGE);
2754     SDValue LoDesc = DAG.getTargetExternalSymbol(
2755         "_TLS_MODULE_BASE_", PtrVT,
2756         AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
2757 
2758     // First argument to the descriptor call is the address of the descriptor
2759     // itself.
2760     SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
2761     DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
2762 
2763     // The call needs a relocation too for linker relaxation. It doesn't make
2764     // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
2765     // the address.
2766     SDValue SymAddr = DAG.getTargetExternalSymbol("_TLS_MODULE_BASE_", PtrVT,
2767                                                   AArch64II::MO_TLS);
2768 
2769     // Now we can calculate the offset from TPIDR_EL0 to this module's
2770     // thread-local area.
2771     TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
2772 
2773     // Now use :dtprel_whatever: operations to calculate this variable's offset
2774     // in its thread-storage area.
2775     SDValue HiVar = DAG.getTargetGlobalAddress(
2776         GV, DL, MVT::i64, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
2777     SDValue LoVar = DAG.getTargetGlobalAddress(
2778         GV, DL, MVT::i64, 0,
2779         AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
2780 
2781     SDValue DTPOff =
2782         SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
2783                                    DAG.getTargetConstant(16, MVT::i32)),
2784                 0);
2785     DTPOff =
2786         SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, DTPOff, LoVar,
2787                                    DAG.getTargetConstant(0, MVT::i32)),
2788                 0);
2789 
2790     TPOff = DAG.getNode(ISD::ADD, DL, PtrVT, TPOff, DTPOff);
2791   } else if (Model == TLSModel::GeneralDynamic) {
2792     // Accesses used in this sequence go via the TLS descriptor which lives in
2793     // the GOT. Prepare an address we can use to handle this.
2794     SDValue HiDesc = DAG.getTargetGlobalAddress(
2795         GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_PAGE);
2796     SDValue LoDesc = DAG.getTargetGlobalAddress(
2797         GV, DL, PtrVT, 0,
2798         AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
2799 
2800     // First argument to the descriptor call is the address of the descriptor
2801     // itself.
2802     SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
2803     DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
2804 
2805     // The call needs a relocation too for linker relaxation. It doesn't make
2806     // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
2807     // the address.
2808     SDValue SymAddr =
2809         DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
2810 
2811     // Finally we can make a call to calculate the offset from tpidr_el0.
2812     TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
2813   } else
2814     llvm_unreachable("Unsupported ELF TLS access model");
2815 
2816   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadBase, TPOff);
2817 }
2818 
LowerGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const2819 SDValue AArch64TargetLowering::LowerGlobalTLSAddress(SDValue Op,
2820                                                      SelectionDAG &DAG) const {
2821   if (Subtarget->isTargetDarwin())
2822     return LowerDarwinGlobalTLSAddress(Op, DAG);
2823   else if (Subtarget->isTargetELF())
2824     return LowerELFGlobalTLSAddress(Op, DAG);
2825 
2826   llvm_unreachable("Unexpected platform trying to use TLS");
2827 }
LowerBR_CC(SDValue Op,SelectionDAG & DAG) const2828 SDValue AArch64TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
2829   SDValue Chain = Op.getOperand(0);
2830   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
2831   SDValue LHS = Op.getOperand(2);
2832   SDValue RHS = Op.getOperand(3);
2833   SDValue Dest = Op.getOperand(4);
2834   SDLoc dl(Op);
2835 
2836   // Handle f128 first, since lowering it will result in comparing the return
2837   // value of a libcall against zero, which is just what the rest of LowerBR_CC
2838   // is expecting to deal with.
2839   if (LHS.getValueType() == MVT::f128) {
2840     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
2841 
2842     // If softenSetCCOperands returned a scalar, we need to compare the result
2843     // against zero to select between true and false values.
2844     if (!RHS.getNode()) {
2845       RHS = DAG.getConstant(0, LHS.getValueType());
2846       CC = ISD::SETNE;
2847     }
2848   }
2849 
2850   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a branch
2851   // instruction.
2852   unsigned Opc = LHS.getOpcode();
2853   if (LHS.getResNo() == 1 && isa<ConstantSDNode>(RHS) &&
2854       cast<ConstantSDNode>(RHS)->isOne() &&
2855       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
2856        Opc == ISD::USUBO || Opc == ISD::SMULO || Opc == ISD::UMULO)) {
2857     assert((CC == ISD::SETEQ || CC == ISD::SETNE) &&
2858            "Unexpected condition code.");
2859     // Only lower legal XALUO ops.
2860     if (!DAG.getTargetLoweringInfo().isTypeLegal(LHS->getValueType(0)))
2861       return SDValue();
2862 
2863     // The actual operation with overflow check.
2864     AArch64CC::CondCode OFCC;
2865     SDValue Value, Overflow;
2866     std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, LHS.getValue(0), DAG);
2867 
2868     if (CC == ISD::SETNE)
2869       OFCC = getInvertedCondCode(OFCC);
2870     SDValue CCVal = DAG.getConstant(OFCC, MVT::i32);
2871 
2872     return DAG.getNode(AArch64ISD::BRCOND, SDLoc(LHS), MVT::Other, Chain, Dest,
2873                        CCVal, Overflow);
2874   }
2875 
2876   if (LHS.getValueType().isInteger()) {
2877     assert((LHS.getValueType() == RHS.getValueType()) &&
2878            (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
2879 
2880     // If the RHS of the comparison is zero, we can potentially fold this
2881     // to a specialized branch.
2882     const ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS);
2883     if (RHSC && RHSC->getZExtValue() == 0) {
2884       if (CC == ISD::SETEQ) {
2885         // See if we can use a TBZ to fold in an AND as well.
2886         // TBZ has a smaller branch displacement than CBZ.  If the offset is
2887         // out of bounds, a late MI-layer pass rewrites branches.
2888         // 403.gcc is an example that hits this case.
2889         if (LHS.getOpcode() == ISD::AND &&
2890             isa<ConstantSDNode>(LHS.getOperand(1)) &&
2891             isPowerOf2_64(LHS.getConstantOperandVal(1))) {
2892           SDValue Test = LHS.getOperand(0);
2893           uint64_t Mask = LHS.getConstantOperandVal(1);
2894 
2895           // TBZ only operates on i64's, but the ext should be free.
2896           if (Test.getValueType() == MVT::i32)
2897             Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64);
2898 
2899           return DAG.getNode(AArch64ISD::TBZ, dl, MVT::Other, Chain, Test,
2900                              DAG.getConstant(Log2_64(Mask), MVT::i64), Dest);
2901         }
2902 
2903         return DAG.getNode(AArch64ISD::CBZ, dl, MVT::Other, Chain, LHS, Dest);
2904       } else if (CC == ISD::SETNE) {
2905         // See if we can use a TBZ to fold in an AND as well.
2906         // TBZ has a smaller branch displacement than CBZ.  If the offset is
2907         // out of bounds, a late MI-layer pass rewrites branches.
2908         // 403.gcc is an example that hits this case.
2909         if (LHS.getOpcode() == ISD::AND &&
2910             isa<ConstantSDNode>(LHS.getOperand(1)) &&
2911             isPowerOf2_64(LHS.getConstantOperandVal(1))) {
2912           SDValue Test = LHS.getOperand(0);
2913           uint64_t Mask = LHS.getConstantOperandVal(1);
2914 
2915           // TBNZ only operates on i64's, but the ext should be free.
2916           if (Test.getValueType() == MVT::i32)
2917             Test = DAG.getAnyExtOrTrunc(Test, dl, MVT::i64);
2918 
2919           return DAG.getNode(AArch64ISD::TBNZ, dl, MVT::Other, Chain, Test,
2920                              DAG.getConstant(Log2_64(Mask), MVT::i64), Dest);
2921         }
2922 
2923         return DAG.getNode(AArch64ISD::CBNZ, dl, MVT::Other, Chain, LHS, Dest);
2924       }
2925     }
2926 
2927     SDValue CCVal;
2928     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
2929     return DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, Chain, Dest, CCVal,
2930                        Cmp);
2931   }
2932 
2933   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
2934 
2935   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
2936   // clean.  Some of them require two branches to implement.
2937   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
2938   AArch64CC::CondCode CC1, CC2;
2939   changeFPCCToAArch64CC(CC, CC1, CC2);
2940   SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
2941   SDValue BR1 =
2942       DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, Chain, Dest, CC1Val, Cmp);
2943   if (CC2 != AArch64CC::AL) {
2944     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
2945     return DAG.getNode(AArch64ISD::BRCOND, dl, MVT::Other, BR1, Dest, CC2Val,
2946                        Cmp);
2947   }
2948 
2949   return BR1;
2950 }
2951 
LowerFCOPYSIGN(SDValue Op,SelectionDAG & DAG) const2952 SDValue AArch64TargetLowering::LowerFCOPYSIGN(SDValue Op,
2953                                               SelectionDAG &DAG) const {
2954   EVT VT = Op.getValueType();
2955   SDLoc DL(Op);
2956 
2957   SDValue In1 = Op.getOperand(0);
2958   SDValue In2 = Op.getOperand(1);
2959   EVT SrcVT = In2.getValueType();
2960   if (SrcVT != VT) {
2961     if (SrcVT == MVT::f32 && VT == MVT::f64)
2962       In2 = DAG.getNode(ISD::FP_EXTEND, DL, VT, In2);
2963     else if (SrcVT == MVT::f64 && VT == MVT::f32)
2964       In2 = DAG.getNode(ISD::FP_ROUND, DL, VT, In2, DAG.getIntPtrConstant(0));
2965     else
2966       // FIXME: Src type is different, bail out for now. Can VT really be a
2967       // vector type?
2968       return SDValue();
2969   }
2970 
2971   EVT VecVT;
2972   EVT EltVT;
2973   SDValue EltMask, VecVal1, VecVal2;
2974   if (VT == MVT::f32 || VT == MVT::v2f32 || VT == MVT::v4f32) {
2975     EltVT = MVT::i32;
2976     VecVT = MVT::v4i32;
2977     EltMask = DAG.getConstant(0x80000000ULL, EltVT);
2978 
2979     if (!VT.isVector()) {
2980       VecVal1 = DAG.getTargetInsertSubreg(AArch64::ssub, DL, VecVT,
2981                                           DAG.getUNDEF(VecVT), In1);
2982       VecVal2 = DAG.getTargetInsertSubreg(AArch64::ssub, DL, VecVT,
2983                                           DAG.getUNDEF(VecVT), In2);
2984     } else {
2985       VecVal1 = DAG.getNode(ISD::BITCAST, DL, VecVT, In1);
2986       VecVal2 = DAG.getNode(ISD::BITCAST, DL, VecVT, In2);
2987     }
2988   } else if (VT == MVT::f64 || VT == MVT::v2f64) {
2989     EltVT = MVT::i64;
2990     VecVT = MVT::v2i64;
2991 
2992     // We want to materialize a mask with the the high bit set, but the AdvSIMD
2993     // immediate moves cannot materialize that in a single instruction for
2994     // 64-bit elements. Instead, materialize zero and then negate it.
2995     EltMask = DAG.getConstant(0, EltVT);
2996 
2997     if (!VT.isVector()) {
2998       VecVal1 = DAG.getTargetInsertSubreg(AArch64::dsub, DL, VecVT,
2999                                           DAG.getUNDEF(VecVT), In1);
3000       VecVal2 = DAG.getTargetInsertSubreg(AArch64::dsub, DL, VecVT,
3001                                           DAG.getUNDEF(VecVT), In2);
3002     } else {
3003       VecVal1 = DAG.getNode(ISD::BITCAST, DL, VecVT, In1);
3004       VecVal2 = DAG.getNode(ISD::BITCAST, DL, VecVT, In2);
3005     }
3006   } else {
3007     llvm_unreachable("Invalid type for copysign!");
3008   }
3009 
3010   std::vector<SDValue> BuildVectorOps;
3011   for (unsigned i = 0; i < VecVT.getVectorNumElements(); ++i)
3012     BuildVectorOps.push_back(EltMask);
3013 
3014   SDValue BuildVec = DAG.getNode(ISD::BUILD_VECTOR, DL, VecVT, BuildVectorOps);
3015 
3016   // If we couldn't materialize the mask above, then the mask vector will be
3017   // the zero vector, and we need to negate it here.
3018   if (VT == MVT::f64 || VT == MVT::v2f64) {
3019     BuildVec = DAG.getNode(ISD::BITCAST, DL, MVT::v2f64, BuildVec);
3020     BuildVec = DAG.getNode(ISD::FNEG, DL, MVT::v2f64, BuildVec);
3021     BuildVec = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, BuildVec);
3022   }
3023 
3024   SDValue Sel =
3025       DAG.getNode(AArch64ISD::BIT, DL, VecVT, VecVal1, VecVal2, BuildVec);
3026 
3027   if (VT == MVT::f32)
3028     return DAG.getTargetExtractSubreg(AArch64::ssub, DL, VT, Sel);
3029   else if (VT == MVT::f64)
3030     return DAG.getTargetExtractSubreg(AArch64::dsub, DL, VT, Sel);
3031   else
3032     return DAG.getNode(ISD::BITCAST, DL, VT, Sel);
3033 }
3034 
LowerCTPOP(SDValue Op,SelectionDAG & DAG) const3035 SDValue AArch64TargetLowering::LowerCTPOP(SDValue Op, SelectionDAG &DAG) const {
3036   if (DAG.getMachineFunction().getFunction()->getAttributes().hasAttribute(
3037           AttributeSet::FunctionIndex, Attribute::NoImplicitFloat))
3038     return SDValue();
3039 
3040   // While there is no integer popcount instruction, it can
3041   // be more efficiently lowered to the following sequence that uses
3042   // AdvSIMD registers/instructions as long as the copies to/from
3043   // the AdvSIMD registers are cheap.
3044   //  FMOV    D0, X0        // copy 64-bit int to vector, high bits zero'd
3045   //  CNT     V0.8B, V0.8B  // 8xbyte pop-counts
3046   //  ADDV    B0, V0.8B     // sum 8xbyte pop-counts
3047   //  UMOV    X0, V0.B[0]   // copy byte result back to integer reg
3048   SDValue Val = Op.getOperand(0);
3049   SDLoc DL(Op);
3050   EVT VT = Op.getValueType();
3051   SDValue ZeroVec = DAG.getUNDEF(MVT::v8i8);
3052 
3053   SDValue VecVal;
3054   if (VT == MVT::i32) {
3055     VecVal = DAG.getNode(ISD::BITCAST, DL, MVT::f32, Val);
3056     VecVal = DAG.getTargetInsertSubreg(AArch64::ssub, DL, MVT::v8i8, ZeroVec,
3057                                        VecVal);
3058   } else {
3059     VecVal = DAG.getNode(ISD::BITCAST, DL, MVT::v8i8, Val);
3060   }
3061 
3062   SDValue CtPop = DAG.getNode(ISD::CTPOP, DL, MVT::v8i8, VecVal);
3063   SDValue UaddLV = DAG.getNode(
3064       ISD::INTRINSIC_WO_CHAIN, DL, MVT::i32,
3065       DAG.getConstant(Intrinsic::aarch64_neon_uaddlv, MVT::i32), CtPop);
3066 
3067   if (VT == MVT::i64)
3068     UaddLV = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, UaddLV);
3069   return UaddLV;
3070 }
3071 
LowerSETCC(SDValue Op,SelectionDAG & DAG) const3072 SDValue AArch64TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
3073 
3074   if (Op.getValueType().isVector())
3075     return LowerVSETCC(Op, DAG);
3076 
3077   SDValue LHS = Op.getOperand(0);
3078   SDValue RHS = Op.getOperand(1);
3079   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
3080   SDLoc dl(Op);
3081 
3082   // We chose ZeroOrOneBooleanContents, so use zero and one.
3083   EVT VT = Op.getValueType();
3084   SDValue TVal = DAG.getConstant(1, VT);
3085   SDValue FVal = DAG.getConstant(0, VT);
3086 
3087   // Handle f128 first, since one possible outcome is a normal integer
3088   // comparison which gets picked up by the next if statement.
3089   if (LHS.getValueType() == MVT::f128) {
3090     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
3091 
3092     // If softenSetCCOperands returned a scalar, use it.
3093     if (!RHS.getNode()) {
3094       assert(LHS.getValueType() == Op.getValueType() &&
3095              "Unexpected setcc expansion!");
3096       return LHS;
3097     }
3098   }
3099 
3100   if (LHS.getValueType().isInteger()) {
3101     SDValue CCVal;
3102     SDValue Cmp =
3103         getAArch64Cmp(LHS, RHS, ISD::getSetCCInverse(CC, true), CCVal, DAG, dl);
3104 
3105     // Note that we inverted the condition above, so we reverse the order of
3106     // the true and false operands here.  This will allow the setcc to be
3107     // matched to a single CSINC instruction.
3108     return DAG.getNode(AArch64ISD::CSEL, dl, VT, FVal, TVal, CCVal, Cmp);
3109   }
3110 
3111   // Now we know we're dealing with FP values.
3112   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
3113 
3114   // If that fails, we'll need to perform an FCMP + CSEL sequence.  Go ahead
3115   // and do the comparison.
3116   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
3117 
3118   AArch64CC::CondCode CC1, CC2;
3119   changeFPCCToAArch64CC(CC, CC1, CC2);
3120   if (CC2 == AArch64CC::AL) {
3121     changeFPCCToAArch64CC(ISD::getSetCCInverse(CC, false), CC1, CC2);
3122     SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3123 
3124     // Note that we inverted the condition above, so we reverse the order of
3125     // the true and false operands here.  This will allow the setcc to be
3126     // matched to a single CSINC instruction.
3127     return DAG.getNode(AArch64ISD::CSEL, dl, VT, FVal, TVal, CC1Val, Cmp);
3128   } else {
3129     // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't
3130     // totally clean.  Some of them require two CSELs to implement.  As is in
3131     // this case, we emit the first CSEL and then emit a second using the output
3132     // of the first as the RHS.  We're effectively OR'ing the two CC's together.
3133 
3134     // FIXME: It would be nice if we could match the two CSELs to two CSINCs.
3135     SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3136     SDValue CS1 =
3137         DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, FVal, CC1Val, Cmp);
3138 
3139     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
3140     return DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, CS1, CC2Val, Cmp);
3141   }
3142 }
3143 
3144 /// A SELECT_CC operation is really some kind of max or min if both values being
3145 /// compared are, in some sense, equal to the results in either case. However,
3146 /// it is permissible to compare f32 values and produce directly extended f64
3147 /// values.
3148 ///
3149 /// Extending the comparison operands would also be allowed, but is less likely
3150 /// to happen in practice since their use is right here. Note that truncate
3151 /// operations would *not* be semantically equivalent.
selectCCOpsAreFMaxCompatible(SDValue Cmp,SDValue Result)3152 static bool selectCCOpsAreFMaxCompatible(SDValue Cmp, SDValue Result) {
3153   if (Cmp == Result)
3154     return true;
3155 
3156   ConstantFPSDNode *CCmp = dyn_cast<ConstantFPSDNode>(Cmp);
3157   ConstantFPSDNode *CResult = dyn_cast<ConstantFPSDNode>(Result);
3158   if (CCmp && CResult && Cmp.getValueType() == MVT::f32 &&
3159       Result.getValueType() == MVT::f64) {
3160     bool Lossy;
3161     APFloat CmpVal = CCmp->getValueAPF();
3162     CmpVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &Lossy);
3163     return CResult->getValueAPF().bitwiseIsEqual(CmpVal);
3164   }
3165 
3166   return Result->getOpcode() == ISD::FP_EXTEND && Result->getOperand(0) == Cmp;
3167 }
3168 
LowerSELECT(SDValue Op,SelectionDAG & DAG) const3169 SDValue AArch64TargetLowering::LowerSELECT(SDValue Op,
3170                                            SelectionDAG &DAG) const {
3171   SDValue CC = Op->getOperand(0);
3172   SDValue TVal = Op->getOperand(1);
3173   SDValue FVal = Op->getOperand(2);
3174   SDLoc DL(Op);
3175 
3176   unsigned Opc = CC.getOpcode();
3177   // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a select
3178   // instruction.
3179   if (CC.getResNo() == 1 &&
3180       (Opc == ISD::SADDO || Opc == ISD::UADDO || Opc == ISD::SSUBO ||
3181        Opc == ISD::USUBO || Opc == ISD::SMULO || Opc == ISD::UMULO)) {
3182     // Only lower legal XALUO ops.
3183     if (!DAG.getTargetLoweringInfo().isTypeLegal(CC->getValueType(0)))
3184       return SDValue();
3185 
3186     AArch64CC::CondCode OFCC;
3187     SDValue Value, Overflow;
3188     std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, CC.getValue(0), DAG);
3189     SDValue CCVal = DAG.getConstant(OFCC, MVT::i32);
3190 
3191     return DAG.getNode(AArch64ISD::CSEL, DL, Op.getValueType(), TVal, FVal,
3192                        CCVal, Overflow);
3193   }
3194 
3195   if (CC.getOpcode() == ISD::SETCC)
3196     return DAG.getSelectCC(DL, CC.getOperand(0), CC.getOperand(1), TVal, FVal,
3197                            cast<CondCodeSDNode>(CC.getOperand(2))->get());
3198   else
3199     return DAG.getSelectCC(DL, CC, DAG.getConstant(0, CC.getValueType()), TVal,
3200                            FVal, ISD::SETNE);
3201 }
3202 
LowerSELECT_CC(SDValue Op,SelectionDAG & DAG) const3203 SDValue AArch64TargetLowering::LowerSELECT_CC(SDValue Op,
3204                                               SelectionDAG &DAG) const {
3205   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
3206   SDValue LHS = Op.getOperand(0);
3207   SDValue RHS = Op.getOperand(1);
3208   SDValue TVal = Op.getOperand(2);
3209   SDValue FVal = Op.getOperand(3);
3210   SDLoc dl(Op);
3211 
3212   // Handle f128 first, because it will result in a comparison of some RTLIB
3213   // call result against zero.
3214   if (LHS.getValueType() == MVT::f128) {
3215     softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, dl);
3216 
3217     // If softenSetCCOperands returned a scalar, we need to compare the result
3218     // against zero to select between true and false values.
3219     if (!RHS.getNode()) {
3220       RHS = DAG.getConstant(0, LHS.getValueType());
3221       CC = ISD::SETNE;
3222     }
3223   }
3224 
3225   // Handle integers first.
3226   if (LHS.getValueType().isInteger()) {
3227     assert((LHS.getValueType() == RHS.getValueType()) &&
3228            (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
3229 
3230     unsigned Opcode = AArch64ISD::CSEL;
3231 
3232     // If both the TVal and the FVal are constants, see if we can swap them in
3233     // order to for a CSINV or CSINC out of them.
3234     ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
3235     ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
3236 
3237     if (CTVal && CFVal && CTVal->isAllOnesValue() && CFVal->isNullValue()) {
3238       std::swap(TVal, FVal);
3239       std::swap(CTVal, CFVal);
3240       CC = ISD::getSetCCInverse(CC, true);
3241     } else if (CTVal && CFVal && CTVal->isOne() && CFVal->isNullValue()) {
3242       std::swap(TVal, FVal);
3243       std::swap(CTVal, CFVal);
3244       CC = ISD::getSetCCInverse(CC, true);
3245     } else if (TVal.getOpcode() == ISD::XOR) {
3246       // If TVal is a NOT we want to swap TVal and FVal so that we can match
3247       // with a CSINV rather than a CSEL.
3248       ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(TVal.getOperand(1));
3249 
3250       if (CVal && CVal->isAllOnesValue()) {
3251         std::swap(TVal, FVal);
3252         std::swap(CTVal, CFVal);
3253         CC = ISD::getSetCCInverse(CC, true);
3254       }
3255     } else if (TVal.getOpcode() == ISD::SUB) {
3256       // If TVal is a negation (SUB from 0) we want to swap TVal and FVal so
3257       // that we can match with a CSNEG rather than a CSEL.
3258       ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(TVal.getOperand(0));
3259 
3260       if (CVal && CVal->isNullValue()) {
3261         std::swap(TVal, FVal);
3262         std::swap(CTVal, CFVal);
3263         CC = ISD::getSetCCInverse(CC, true);
3264       }
3265     } else if (CTVal && CFVal) {
3266       const int64_t TrueVal = CTVal->getSExtValue();
3267       const int64_t FalseVal = CFVal->getSExtValue();
3268       bool Swap = false;
3269 
3270       // If both TVal and FVal are constants, see if FVal is the
3271       // inverse/negation/increment of TVal and generate a CSINV/CSNEG/CSINC
3272       // instead of a CSEL in that case.
3273       if (TrueVal == ~FalseVal) {
3274         Opcode = AArch64ISD::CSINV;
3275       } else if (TrueVal == -FalseVal) {
3276         Opcode = AArch64ISD::CSNEG;
3277       } else if (TVal.getValueType() == MVT::i32) {
3278         // If our operands are only 32-bit wide, make sure we use 32-bit
3279         // arithmetic for the check whether we can use CSINC. This ensures that
3280         // the addition in the check will wrap around properly in case there is
3281         // an overflow (which would not be the case if we do the check with
3282         // 64-bit arithmetic).
3283         const uint32_t TrueVal32 = CTVal->getZExtValue();
3284         const uint32_t FalseVal32 = CFVal->getZExtValue();
3285 
3286         if ((TrueVal32 == FalseVal32 + 1) || (TrueVal32 + 1 == FalseVal32)) {
3287           Opcode = AArch64ISD::CSINC;
3288 
3289           if (TrueVal32 > FalseVal32) {
3290             Swap = true;
3291           }
3292         }
3293         // 64-bit check whether we can use CSINC.
3294       } else if ((TrueVal == FalseVal + 1) || (TrueVal + 1 == FalseVal)) {
3295         Opcode = AArch64ISD::CSINC;
3296 
3297         if (TrueVal > FalseVal) {
3298           Swap = true;
3299         }
3300       }
3301 
3302       // Swap TVal and FVal if necessary.
3303       if (Swap) {
3304         std::swap(TVal, FVal);
3305         std::swap(CTVal, CFVal);
3306         CC = ISD::getSetCCInverse(CC, true);
3307       }
3308 
3309       if (Opcode != AArch64ISD::CSEL) {
3310         // Drop FVal since we can get its value by simply inverting/negating
3311         // TVal.
3312         FVal = TVal;
3313       }
3314     }
3315 
3316     SDValue CCVal;
3317     SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, dl);
3318 
3319     EVT VT = Op.getValueType();
3320     return DAG.getNode(Opcode, dl, VT, TVal, FVal, CCVal, Cmp);
3321   }
3322 
3323   // Now we know we're dealing with FP values.
3324   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
3325   assert(LHS.getValueType() == RHS.getValueType());
3326   EVT VT = Op.getValueType();
3327 
3328   // Try to match this select into a max/min operation, which have dedicated
3329   // opcode in the instruction set.
3330   // FIXME: This is not correct in the presence of NaNs, so we only enable this
3331   // in no-NaNs mode.
3332   if (getTargetMachine().Options.NoNaNsFPMath) {
3333     SDValue MinMaxLHS = TVal, MinMaxRHS = FVal;
3334     if (selectCCOpsAreFMaxCompatible(LHS, MinMaxRHS) &&
3335         selectCCOpsAreFMaxCompatible(RHS, MinMaxLHS)) {
3336       CC = ISD::getSetCCSwappedOperands(CC);
3337       std::swap(MinMaxLHS, MinMaxRHS);
3338     }
3339 
3340     if (selectCCOpsAreFMaxCompatible(LHS, MinMaxLHS) &&
3341         selectCCOpsAreFMaxCompatible(RHS, MinMaxRHS)) {
3342       switch (CC) {
3343       default:
3344         break;
3345       case ISD::SETGT:
3346       case ISD::SETGE:
3347       case ISD::SETUGT:
3348       case ISD::SETUGE:
3349       case ISD::SETOGT:
3350       case ISD::SETOGE:
3351         return DAG.getNode(AArch64ISD::FMAX, dl, VT, MinMaxLHS, MinMaxRHS);
3352         break;
3353       case ISD::SETLT:
3354       case ISD::SETLE:
3355       case ISD::SETULT:
3356       case ISD::SETULE:
3357       case ISD::SETOLT:
3358       case ISD::SETOLE:
3359         return DAG.getNode(AArch64ISD::FMIN, dl, VT, MinMaxLHS, MinMaxRHS);
3360         break;
3361       }
3362     }
3363   }
3364 
3365   // If that fails, we'll need to perform an FCMP + CSEL sequence.  Go ahead
3366   // and do the comparison.
3367   SDValue Cmp = emitComparison(LHS, RHS, CC, dl, DAG);
3368 
3369   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
3370   // clean.  Some of them require two CSELs to implement.
3371   AArch64CC::CondCode CC1, CC2;
3372   changeFPCCToAArch64CC(CC, CC1, CC2);
3373   SDValue CC1Val = DAG.getConstant(CC1, MVT::i32);
3374   SDValue CS1 = DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, FVal, CC1Val, Cmp);
3375 
3376   // If we need a second CSEL, emit it, using the output of the first as the
3377   // RHS.  We're effectively OR'ing the two CC's together.
3378   if (CC2 != AArch64CC::AL) {
3379     SDValue CC2Val = DAG.getConstant(CC2, MVT::i32);
3380     return DAG.getNode(AArch64ISD::CSEL, dl, VT, TVal, CS1, CC2Val, Cmp);
3381   }
3382 
3383   // Otherwise, return the output of the first CSEL.
3384   return CS1;
3385 }
3386 
LowerJumpTable(SDValue Op,SelectionDAG & DAG) const3387 SDValue AArch64TargetLowering::LowerJumpTable(SDValue Op,
3388                                               SelectionDAG &DAG) const {
3389   // Jump table entries as PC relative offsets. No additional tweaking
3390   // is necessary here. Just get the address of the jump table.
3391   JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
3392   EVT PtrVT = getPointerTy();
3393   SDLoc DL(Op);
3394 
3395   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
3396       !Subtarget->isTargetMachO()) {
3397     const unsigned char MO_NC = AArch64II::MO_NC;
3398     return DAG.getNode(
3399         AArch64ISD::WrapperLarge, DL, PtrVT,
3400         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G3),
3401         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G2 | MO_NC),
3402         DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_G1 | MO_NC),
3403         DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
3404                                AArch64II::MO_G0 | MO_NC));
3405   }
3406 
3407   SDValue Hi =
3408       DAG.getTargetJumpTable(JT->getIndex(), PtrVT, AArch64II::MO_PAGE);
3409   SDValue Lo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
3410                                       AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
3411   SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3412   return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3413 }
3414 
LowerConstantPool(SDValue Op,SelectionDAG & DAG) const3415 SDValue AArch64TargetLowering::LowerConstantPool(SDValue Op,
3416                                                  SelectionDAG &DAG) const {
3417   ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
3418   EVT PtrVT = getPointerTy();
3419   SDLoc DL(Op);
3420 
3421   if (getTargetMachine().getCodeModel() == CodeModel::Large) {
3422     // Use the GOT for the large code model on iOS.
3423     if (Subtarget->isTargetMachO()) {
3424       SDValue GotAddr = DAG.getTargetConstantPool(
3425           CP->getConstVal(), PtrVT, CP->getAlignment(), CP->getOffset(),
3426           AArch64II::MO_GOT);
3427       return DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, GotAddr);
3428     }
3429 
3430     const unsigned char MO_NC = AArch64II::MO_NC;
3431     return DAG.getNode(
3432         AArch64ISD::WrapperLarge, DL, PtrVT,
3433         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3434                                   CP->getOffset(), AArch64II::MO_G3),
3435         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3436                                   CP->getOffset(), AArch64II::MO_G2 | MO_NC),
3437         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3438                                   CP->getOffset(), AArch64II::MO_G1 | MO_NC),
3439         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3440                                   CP->getOffset(), AArch64II::MO_G0 | MO_NC));
3441   } else {
3442     // Use ADRP/ADD or ADRP/LDR for everything else: the small memory model on
3443     // ELF, the only valid one on Darwin.
3444     SDValue Hi =
3445         DAG.getTargetConstantPool(CP->getConstVal(), PtrVT, CP->getAlignment(),
3446                                   CP->getOffset(), AArch64II::MO_PAGE);
3447     SDValue Lo = DAG.getTargetConstantPool(
3448         CP->getConstVal(), PtrVT, CP->getAlignment(), CP->getOffset(),
3449         AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
3450 
3451     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3452     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3453   }
3454 }
3455 
LowerBlockAddress(SDValue Op,SelectionDAG & DAG) const3456 SDValue AArch64TargetLowering::LowerBlockAddress(SDValue Op,
3457                                                SelectionDAG &DAG) const {
3458   const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
3459   EVT PtrVT = getPointerTy();
3460   SDLoc DL(Op);
3461   if (getTargetMachine().getCodeModel() == CodeModel::Large &&
3462       !Subtarget->isTargetMachO()) {
3463     const unsigned char MO_NC = AArch64II::MO_NC;
3464     return DAG.getNode(
3465         AArch64ISD::WrapperLarge, DL, PtrVT,
3466         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G3),
3467         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G2 | MO_NC),
3468         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G1 | MO_NC),
3469         DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_G0 | MO_NC));
3470   } else {
3471     SDValue Hi = DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_PAGE);
3472     SDValue Lo = DAG.getTargetBlockAddress(BA, PtrVT, 0, AArch64II::MO_PAGEOFF |
3473                                                              AArch64II::MO_NC);
3474     SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, Hi);
3475     return DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, Lo);
3476   }
3477 }
3478 
LowerDarwin_VASTART(SDValue Op,SelectionDAG & DAG) const3479 SDValue AArch64TargetLowering::LowerDarwin_VASTART(SDValue Op,
3480                                                  SelectionDAG &DAG) const {
3481   AArch64FunctionInfo *FuncInfo =
3482       DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
3483 
3484   SDLoc DL(Op);
3485   SDValue FR =
3486       DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(), getPointerTy());
3487   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3488   return DAG.getStore(Op.getOperand(0), DL, FR, Op.getOperand(1),
3489                       MachinePointerInfo(SV), false, false, 0);
3490 }
3491 
LowerAAPCS_VASTART(SDValue Op,SelectionDAG & DAG) const3492 SDValue AArch64TargetLowering::LowerAAPCS_VASTART(SDValue Op,
3493                                                 SelectionDAG &DAG) const {
3494   // The layout of the va_list struct is specified in the AArch64 Procedure Call
3495   // Standard, section B.3.
3496   MachineFunction &MF = DAG.getMachineFunction();
3497   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
3498   SDLoc DL(Op);
3499 
3500   SDValue Chain = Op.getOperand(0);
3501   SDValue VAList = Op.getOperand(1);
3502   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3503   SmallVector<SDValue, 4> MemOps;
3504 
3505   // void *__stack at offset 0
3506   SDValue Stack =
3507       DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(), getPointerTy());
3508   MemOps.push_back(DAG.getStore(Chain, DL, Stack, VAList,
3509                                 MachinePointerInfo(SV), false, false, 8));
3510 
3511   // void *__gr_top at offset 8
3512   int GPRSize = FuncInfo->getVarArgsGPRSize();
3513   if (GPRSize > 0) {
3514     SDValue GRTop, GRTopAddr;
3515 
3516     GRTopAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3517                             DAG.getConstant(8, getPointerTy()));
3518 
3519     GRTop = DAG.getFrameIndex(FuncInfo->getVarArgsGPRIndex(), getPointerTy());
3520     GRTop = DAG.getNode(ISD::ADD, DL, getPointerTy(), GRTop,
3521                         DAG.getConstant(GPRSize, getPointerTy()));
3522 
3523     MemOps.push_back(DAG.getStore(Chain, DL, GRTop, GRTopAddr,
3524                                   MachinePointerInfo(SV, 8), false, false, 8));
3525   }
3526 
3527   // void *__vr_top at offset 16
3528   int FPRSize = FuncInfo->getVarArgsFPRSize();
3529   if (FPRSize > 0) {
3530     SDValue VRTop, VRTopAddr;
3531     VRTopAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3532                             DAG.getConstant(16, getPointerTy()));
3533 
3534     VRTop = DAG.getFrameIndex(FuncInfo->getVarArgsFPRIndex(), getPointerTy());
3535     VRTop = DAG.getNode(ISD::ADD, DL, getPointerTy(), VRTop,
3536                         DAG.getConstant(FPRSize, getPointerTy()));
3537 
3538     MemOps.push_back(DAG.getStore(Chain, DL, VRTop, VRTopAddr,
3539                                   MachinePointerInfo(SV, 16), false, false, 8));
3540   }
3541 
3542   // int __gr_offs at offset 24
3543   SDValue GROffsAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3544                                    DAG.getConstant(24, getPointerTy()));
3545   MemOps.push_back(DAG.getStore(Chain, DL, DAG.getConstant(-GPRSize, MVT::i32),
3546                                 GROffsAddr, MachinePointerInfo(SV, 24), false,
3547                                 false, 4));
3548 
3549   // int __vr_offs at offset 28
3550   SDValue VROffsAddr = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3551                                    DAG.getConstant(28, getPointerTy()));
3552   MemOps.push_back(DAG.getStore(Chain, DL, DAG.getConstant(-FPRSize, MVT::i32),
3553                                 VROffsAddr, MachinePointerInfo(SV, 28), false,
3554                                 false, 4));
3555 
3556   return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
3557 }
3558 
LowerVASTART(SDValue Op,SelectionDAG & DAG) const3559 SDValue AArch64TargetLowering::LowerVASTART(SDValue Op,
3560                                             SelectionDAG &DAG) const {
3561   return Subtarget->isTargetDarwin() ? LowerDarwin_VASTART(Op, DAG)
3562                                      : LowerAAPCS_VASTART(Op, DAG);
3563 }
3564 
LowerVACOPY(SDValue Op,SelectionDAG & DAG) const3565 SDValue AArch64TargetLowering::LowerVACOPY(SDValue Op,
3566                                            SelectionDAG &DAG) const {
3567   // AAPCS has three pointers and two ints (= 32 bytes), Darwin has single
3568   // pointer.
3569   unsigned VaListSize = Subtarget->isTargetDarwin() ? 8 : 32;
3570   const Value *DestSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
3571   const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
3572 
3573   return DAG.getMemcpy(Op.getOperand(0), SDLoc(Op), Op.getOperand(1),
3574                        Op.getOperand(2), DAG.getConstant(VaListSize, MVT::i32),
3575                        8, false, false, MachinePointerInfo(DestSV),
3576                        MachinePointerInfo(SrcSV));
3577 }
3578 
LowerVAARG(SDValue Op,SelectionDAG & DAG) const3579 SDValue AArch64TargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
3580   assert(Subtarget->isTargetDarwin() &&
3581          "automatic va_arg instruction only works on Darwin");
3582 
3583   const Value *V = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
3584   EVT VT = Op.getValueType();
3585   SDLoc DL(Op);
3586   SDValue Chain = Op.getOperand(0);
3587   SDValue Addr = Op.getOperand(1);
3588   unsigned Align = Op.getConstantOperandVal(3);
3589 
3590   SDValue VAList = DAG.getLoad(getPointerTy(), DL, Chain, Addr,
3591                                MachinePointerInfo(V), false, false, false, 0);
3592   Chain = VAList.getValue(1);
3593 
3594   if (Align > 8) {
3595     assert(((Align & (Align - 1)) == 0) && "Expected Align to be a power of 2");
3596     VAList = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3597                          DAG.getConstant(Align - 1, getPointerTy()));
3598     VAList = DAG.getNode(ISD::AND, DL, getPointerTy(), VAList,
3599                          DAG.getConstant(-(int64_t)Align, getPointerTy()));
3600   }
3601 
3602   Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
3603   uint64_t ArgSize = getDataLayout()->getTypeAllocSize(ArgTy);
3604 
3605   // Scalar integer and FP values smaller than 64 bits are implicitly extended
3606   // up to 64 bits.  At the very least, we have to increase the striding of the
3607   // vaargs list to match this, and for FP values we need to introduce
3608   // FP_ROUND nodes as well.
3609   if (VT.isInteger() && !VT.isVector())
3610     ArgSize = 8;
3611   bool NeedFPTrunc = false;
3612   if (VT.isFloatingPoint() && !VT.isVector() && VT != MVT::f64) {
3613     ArgSize = 8;
3614     NeedFPTrunc = true;
3615   }
3616 
3617   // Increment the pointer, VAList, to the next vaarg
3618   SDValue VANext = DAG.getNode(ISD::ADD, DL, getPointerTy(), VAList,
3619                                DAG.getConstant(ArgSize, getPointerTy()));
3620   // Store the incremented VAList to the legalized pointer
3621   SDValue APStore = DAG.getStore(Chain, DL, VANext, Addr, MachinePointerInfo(V),
3622                                  false, false, 0);
3623 
3624   // Load the actual argument out of the pointer VAList
3625   if (NeedFPTrunc) {
3626     // Load the value as an f64.
3627     SDValue WideFP = DAG.getLoad(MVT::f64, DL, APStore, VAList,
3628                                  MachinePointerInfo(), false, false, false, 0);
3629     // Round the value down to an f32.
3630     SDValue NarrowFP = DAG.getNode(ISD::FP_ROUND, DL, VT, WideFP.getValue(0),
3631                                    DAG.getIntPtrConstant(1));
3632     SDValue Ops[] = { NarrowFP, WideFP.getValue(1) };
3633     // Merge the rounded value with the chain output of the load.
3634     return DAG.getMergeValues(Ops, DL);
3635   }
3636 
3637   return DAG.getLoad(VT, DL, APStore, VAList, MachinePointerInfo(), false,
3638                      false, false, 0);
3639 }
3640 
LowerFRAMEADDR(SDValue Op,SelectionDAG & DAG) const3641 SDValue AArch64TargetLowering::LowerFRAMEADDR(SDValue Op,
3642                                               SelectionDAG &DAG) const {
3643   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
3644   MFI->setFrameAddressIsTaken(true);
3645 
3646   EVT VT = Op.getValueType();
3647   SDLoc DL(Op);
3648   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
3649   SDValue FrameAddr =
3650       DAG.getCopyFromReg(DAG.getEntryNode(), DL, AArch64::FP, VT);
3651   while (Depth--)
3652     FrameAddr = DAG.getLoad(VT, DL, DAG.getEntryNode(), FrameAddr,
3653                             MachinePointerInfo(), false, false, false, 0);
3654   return FrameAddr;
3655 }
3656 
3657 // FIXME? Maybe this could be a TableGen attribute on some registers and
3658 // this table could be generated automatically from RegInfo.
getRegisterByName(const char * RegName,EVT VT) const3659 unsigned AArch64TargetLowering::getRegisterByName(const char* RegName,
3660                                                   EVT VT) const {
3661   unsigned Reg = StringSwitch<unsigned>(RegName)
3662                        .Case("sp", AArch64::SP)
3663                        .Default(0);
3664   if (Reg)
3665     return Reg;
3666   report_fatal_error("Invalid register name global variable");
3667 }
3668 
LowerRETURNADDR(SDValue Op,SelectionDAG & DAG) const3669 SDValue AArch64TargetLowering::LowerRETURNADDR(SDValue Op,
3670                                                SelectionDAG &DAG) const {
3671   MachineFunction &MF = DAG.getMachineFunction();
3672   MachineFrameInfo *MFI = MF.getFrameInfo();
3673   MFI->setReturnAddressIsTaken(true);
3674 
3675   EVT VT = Op.getValueType();
3676   SDLoc DL(Op);
3677   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
3678   if (Depth) {
3679     SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
3680     SDValue Offset = DAG.getConstant(8, getPointerTy());
3681     return DAG.getLoad(VT, DL, DAG.getEntryNode(),
3682                        DAG.getNode(ISD::ADD, DL, VT, FrameAddr, Offset),
3683                        MachinePointerInfo(), false, false, false, 0);
3684   }
3685 
3686   // Return LR, which contains the return address. Mark it an implicit live-in.
3687   unsigned Reg = MF.addLiveIn(AArch64::LR, &AArch64::GPR64RegClass);
3688   return DAG.getCopyFromReg(DAG.getEntryNode(), DL, Reg, VT);
3689 }
3690 
3691 /// LowerShiftRightParts - Lower SRA_PARTS, which returns two
3692 /// i64 values and take a 2 x i64 value to shift plus a shift amount.
LowerShiftRightParts(SDValue Op,SelectionDAG & DAG) const3693 SDValue AArch64TargetLowering::LowerShiftRightParts(SDValue Op,
3694                                                     SelectionDAG &DAG) const {
3695   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
3696   EVT VT = Op.getValueType();
3697   unsigned VTBits = VT.getSizeInBits();
3698   SDLoc dl(Op);
3699   SDValue ShOpLo = Op.getOperand(0);
3700   SDValue ShOpHi = Op.getOperand(1);
3701   SDValue ShAmt = Op.getOperand(2);
3702   SDValue ARMcc;
3703   unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
3704 
3705   assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
3706 
3707   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64,
3708                                  DAG.getConstant(VTBits, MVT::i64), ShAmt);
3709   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
3710   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64, ShAmt,
3711                                    DAG.getConstant(VTBits, MVT::i64));
3712   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
3713 
3714   SDValue Cmp = emitComparison(ExtraShAmt, DAG.getConstant(0, MVT::i64),
3715                                ISD::SETGE, dl, DAG);
3716   SDValue CCVal = DAG.getConstant(AArch64CC::GE, MVT::i32);
3717 
3718   SDValue FalseValLo = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
3719   SDValue TrueValLo = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
3720   SDValue Lo =
3721       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValLo, FalseValLo, CCVal, Cmp);
3722 
3723   // AArch64 shifts larger than the register width are wrapped rather than
3724   // clamped, so we can't just emit "hi >> x".
3725   SDValue FalseValHi = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
3726   SDValue TrueValHi = Opc == ISD::SRA
3727                           ? DAG.getNode(Opc, dl, VT, ShOpHi,
3728                                         DAG.getConstant(VTBits - 1, MVT::i64))
3729                           : DAG.getConstant(0, VT);
3730   SDValue Hi =
3731       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValHi, FalseValHi, CCVal, Cmp);
3732 
3733   SDValue Ops[2] = { Lo, Hi };
3734   return DAG.getMergeValues(Ops, dl);
3735 }
3736 
3737 /// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
3738 /// i64 values and take a 2 x i64 value to shift plus a shift amount.
LowerShiftLeftParts(SDValue Op,SelectionDAG & DAG) const3739 SDValue AArch64TargetLowering::LowerShiftLeftParts(SDValue Op,
3740                                                  SelectionDAG &DAG) const {
3741   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
3742   EVT VT = Op.getValueType();
3743   unsigned VTBits = VT.getSizeInBits();
3744   SDLoc dl(Op);
3745   SDValue ShOpLo = Op.getOperand(0);
3746   SDValue ShOpHi = Op.getOperand(1);
3747   SDValue ShAmt = Op.getOperand(2);
3748   SDValue ARMcc;
3749 
3750   assert(Op.getOpcode() == ISD::SHL_PARTS);
3751   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64,
3752                                  DAG.getConstant(VTBits, MVT::i64), ShAmt);
3753   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
3754   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i64, ShAmt,
3755                                    DAG.getConstant(VTBits, MVT::i64));
3756   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
3757   SDValue Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
3758 
3759   SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
3760 
3761   SDValue Cmp = emitComparison(ExtraShAmt, DAG.getConstant(0, MVT::i64),
3762                                ISD::SETGE, dl, DAG);
3763   SDValue CCVal = DAG.getConstant(AArch64CC::GE, MVT::i32);
3764   SDValue Hi =
3765       DAG.getNode(AArch64ISD::CSEL, dl, VT, Tmp3, FalseVal, CCVal, Cmp);
3766 
3767   // AArch64 shifts of larger than register sizes are wrapped rather than
3768   // clamped, so we can't just emit "lo << a" if a is too big.
3769   SDValue TrueValLo = DAG.getConstant(0, VT);
3770   SDValue FalseValLo = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
3771   SDValue Lo =
3772       DAG.getNode(AArch64ISD::CSEL, dl, VT, TrueValLo, FalseValLo, CCVal, Cmp);
3773 
3774   SDValue Ops[2] = { Lo, Hi };
3775   return DAG.getMergeValues(Ops, dl);
3776 }
3777 
isOffsetFoldingLegal(const GlobalAddressSDNode * GA) const3778 bool AArch64TargetLowering::isOffsetFoldingLegal(
3779     const GlobalAddressSDNode *GA) const {
3780   // The AArch64 target doesn't support folding offsets into global addresses.
3781   return false;
3782 }
3783 
isFPImmLegal(const APFloat & Imm,EVT VT) const3784 bool AArch64TargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
3785   // We can materialize #0.0 as fmov $Rd, XZR for 64-bit and 32-bit cases.
3786   // FIXME: We should be able to handle f128 as well with a clever lowering.
3787   if (Imm.isPosZero() && (VT == MVT::f64 || VT == MVT::f32))
3788     return true;
3789 
3790   if (VT == MVT::f64)
3791     return AArch64_AM::getFP64Imm(Imm) != -1;
3792   else if (VT == MVT::f32)
3793     return AArch64_AM::getFP32Imm(Imm) != -1;
3794   return false;
3795 }
3796 
3797 //===----------------------------------------------------------------------===//
3798 //                          AArch64 Optimization Hooks
3799 //===----------------------------------------------------------------------===//
3800 
3801 //===----------------------------------------------------------------------===//
3802 //                          AArch64 Inline Assembly Support
3803 //===----------------------------------------------------------------------===//
3804 
3805 // Table of Constraints
3806 // TODO: This is the current set of constraints supported by ARM for the
3807 // compiler, not all of them may make sense, e.g. S may be difficult to support.
3808 //
3809 // r - A general register
3810 // w - An FP/SIMD register of some size in the range v0-v31
3811 // x - An FP/SIMD register of some size in the range v0-v15
3812 // I - Constant that can be used with an ADD instruction
3813 // J - Constant that can be used with a SUB instruction
3814 // K - Constant that can be used with a 32-bit logical instruction
3815 // L - Constant that can be used with a 64-bit logical instruction
3816 // M - Constant that can be used as a 32-bit MOV immediate
3817 // N - Constant that can be used as a 64-bit MOV immediate
3818 // Q - A memory reference with base register and no offset
3819 // S - A symbolic address
3820 // Y - Floating point constant zero
3821 // Z - Integer constant zero
3822 //
3823 //   Note that general register operands will be output using their 64-bit x
3824 // register name, whatever the size of the variable, unless the asm operand
3825 // is prefixed by the %w modifier. Floating-point and SIMD register operands
3826 // will be output with the v prefix unless prefixed by the %b, %h, %s, %d or
3827 // %q modifier.
3828 
3829 /// getConstraintType - Given a constraint letter, return the type of
3830 /// constraint it is for this target.
3831 AArch64TargetLowering::ConstraintType
getConstraintType(const std::string & Constraint) const3832 AArch64TargetLowering::getConstraintType(const std::string &Constraint) const {
3833   if (Constraint.size() == 1) {
3834     switch (Constraint[0]) {
3835     default:
3836       break;
3837     case 'z':
3838       return C_Other;
3839     case 'x':
3840     case 'w':
3841       return C_RegisterClass;
3842     // An address with a single base register. Due to the way we
3843     // currently handle addresses it is the same as 'r'.
3844     case 'Q':
3845       return C_Memory;
3846     }
3847   }
3848   return TargetLowering::getConstraintType(Constraint);
3849 }
3850 
3851 /// Examine constraint type and operand type and determine a weight value.
3852 /// This object must already have been set up with the operand type
3853 /// and the current alternative constraint selected.
3854 TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo & info,const char * constraint) const3855 AArch64TargetLowering::getSingleConstraintMatchWeight(
3856     AsmOperandInfo &info, const char *constraint) const {
3857   ConstraintWeight weight = CW_Invalid;
3858   Value *CallOperandVal = info.CallOperandVal;
3859   // If we don't have a value, we can't do a match,
3860   // but allow it at the lowest weight.
3861   if (!CallOperandVal)
3862     return CW_Default;
3863   Type *type = CallOperandVal->getType();
3864   // Look at the constraint type.
3865   switch (*constraint) {
3866   default:
3867     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3868     break;
3869   case 'x':
3870   case 'w':
3871     if (type->isFloatingPointTy() || type->isVectorTy())
3872       weight = CW_Register;
3873     break;
3874   case 'z':
3875     weight = CW_Constant;
3876     break;
3877   }
3878   return weight;
3879 }
3880 
3881 std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const std::string & Constraint,MVT VT) const3882 AArch64TargetLowering::getRegForInlineAsmConstraint(
3883     const std::string &Constraint, MVT VT) const {
3884   if (Constraint.size() == 1) {
3885     switch (Constraint[0]) {
3886     case 'r':
3887       if (VT.getSizeInBits() == 64)
3888         return std::make_pair(0U, &AArch64::GPR64commonRegClass);
3889       return std::make_pair(0U, &AArch64::GPR32commonRegClass);
3890     case 'w':
3891       if (VT == MVT::f32)
3892         return std::make_pair(0U, &AArch64::FPR32RegClass);
3893       if (VT.getSizeInBits() == 64)
3894         return std::make_pair(0U, &AArch64::FPR64RegClass);
3895       if (VT.getSizeInBits() == 128)
3896         return std::make_pair(0U, &AArch64::FPR128RegClass);
3897       break;
3898     // The instructions that this constraint is designed for can
3899     // only take 128-bit registers so just use that regclass.
3900     case 'x':
3901       if (VT.getSizeInBits() == 128)
3902         return std::make_pair(0U, &AArch64::FPR128_loRegClass);
3903       break;
3904     }
3905   }
3906   if (StringRef("{cc}").equals_lower(Constraint))
3907     return std::make_pair(unsigned(AArch64::NZCV), &AArch64::CCRRegClass);
3908 
3909   // Use the default implementation in TargetLowering to convert the register
3910   // constraint into a member of a register class.
3911   std::pair<unsigned, const TargetRegisterClass *> Res;
3912   Res = TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
3913 
3914   // Not found as a standard register?
3915   if (!Res.second) {
3916     unsigned Size = Constraint.size();
3917     if ((Size == 4 || Size == 5) && Constraint[0] == '{' &&
3918         tolower(Constraint[1]) == 'v' && Constraint[Size - 1] == '}') {
3919       const std::string Reg =
3920           std::string(&Constraint[2], &Constraint[Size - 1]);
3921       int RegNo = atoi(Reg.c_str());
3922       if (RegNo >= 0 && RegNo <= 31) {
3923         // v0 - v31 are aliases of q0 - q31.
3924         // By default we'll emit v0-v31 for this unless there's a modifier where
3925         // we'll emit the correct register as well.
3926         Res.first = AArch64::FPR128RegClass.getRegister(RegNo);
3927         Res.second = &AArch64::FPR128RegClass;
3928       }
3929     }
3930   }
3931 
3932   return Res;
3933 }
3934 
3935 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3936 /// vector.  If it is invalid, don't add anything to Ops.
LowerAsmOperandForConstraint(SDValue Op,std::string & Constraint,std::vector<SDValue> & Ops,SelectionDAG & DAG) const3937 void AArch64TargetLowering::LowerAsmOperandForConstraint(
3938     SDValue Op, std::string &Constraint, std::vector<SDValue> &Ops,
3939     SelectionDAG &DAG) const {
3940   SDValue Result;
3941 
3942   // Currently only support length 1 constraints.
3943   if (Constraint.length() != 1)
3944     return;
3945 
3946   char ConstraintLetter = Constraint[0];
3947   switch (ConstraintLetter) {
3948   default:
3949     break;
3950 
3951   // This set of constraints deal with valid constants for various instructions.
3952   // Validate and return a target constant for them if we can.
3953   case 'z': {
3954     // 'z' maps to xzr or wzr so it needs an input of 0.
3955     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
3956     if (!C || C->getZExtValue() != 0)
3957       return;
3958 
3959     if (Op.getValueType() == MVT::i64)
3960       Result = DAG.getRegister(AArch64::XZR, MVT::i64);
3961     else
3962       Result = DAG.getRegister(AArch64::WZR, MVT::i32);
3963     break;
3964   }
3965 
3966   case 'I':
3967   case 'J':
3968   case 'K':
3969   case 'L':
3970   case 'M':
3971   case 'N':
3972     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
3973     if (!C)
3974       return;
3975 
3976     // Grab the value and do some validation.
3977     uint64_t CVal = C->getZExtValue();
3978     switch (ConstraintLetter) {
3979     // The I constraint applies only to simple ADD or SUB immediate operands:
3980     // i.e. 0 to 4095 with optional shift by 12
3981     // The J constraint applies only to ADD or SUB immediates that would be
3982     // valid when negated, i.e. if [an add pattern] were to be output as a SUB
3983     // instruction [or vice versa], in other words -1 to -4095 with optional
3984     // left shift by 12.
3985     case 'I':
3986       if (isUInt<12>(CVal) || isShiftedUInt<12, 12>(CVal))
3987         break;
3988       return;
3989     case 'J': {
3990       uint64_t NVal = -C->getSExtValue();
3991       if (isUInt<12>(NVal) || isShiftedUInt<12, 12>(NVal))
3992         break;
3993       return;
3994     }
3995     // The K and L constraints apply *only* to logical immediates, including
3996     // what used to be the MOVI alias for ORR (though the MOVI alias has now
3997     // been removed and MOV should be used). So these constraints have to
3998     // distinguish between bit patterns that are valid 32-bit or 64-bit
3999     // "bitmask immediates": for example 0xaaaaaaaa is a valid bimm32 (K), but
4000     // not a valid bimm64 (L) where 0xaaaaaaaaaaaaaaaa would be valid, and vice
4001     // versa.
4002     case 'K':
4003       if (AArch64_AM::isLogicalImmediate(CVal, 32))
4004         break;
4005       return;
4006     case 'L':
4007       if (AArch64_AM::isLogicalImmediate(CVal, 64))
4008         break;
4009       return;
4010     // The M and N constraints are a superset of K and L respectively, for use
4011     // with the MOV (immediate) alias. As well as the logical immediates they
4012     // also match 32 or 64-bit immediates that can be loaded either using a
4013     // *single* MOVZ or MOVN , such as 32-bit 0x12340000, 0x00001234, 0xffffedca
4014     // (M) or 64-bit 0x1234000000000000 (N) etc.
4015     // As a note some of this code is liberally stolen from the asm parser.
4016     case 'M': {
4017       if (!isUInt<32>(CVal))
4018         return;
4019       if (AArch64_AM::isLogicalImmediate(CVal, 32))
4020         break;
4021       if ((CVal & 0xFFFF) == CVal)
4022         break;
4023       if ((CVal & 0xFFFF0000ULL) == CVal)
4024         break;
4025       uint64_t NCVal = ~(uint32_t)CVal;
4026       if ((NCVal & 0xFFFFULL) == NCVal)
4027         break;
4028       if ((NCVal & 0xFFFF0000ULL) == NCVal)
4029         break;
4030       return;
4031     }
4032     case 'N': {
4033       if (AArch64_AM::isLogicalImmediate(CVal, 64))
4034         break;
4035       if ((CVal & 0xFFFFULL) == CVal)
4036         break;
4037       if ((CVal & 0xFFFF0000ULL) == CVal)
4038         break;
4039       if ((CVal & 0xFFFF00000000ULL) == CVal)
4040         break;
4041       if ((CVal & 0xFFFF000000000000ULL) == CVal)
4042         break;
4043       uint64_t NCVal = ~CVal;
4044       if ((NCVal & 0xFFFFULL) == NCVal)
4045         break;
4046       if ((NCVal & 0xFFFF0000ULL) == NCVal)
4047         break;
4048       if ((NCVal & 0xFFFF00000000ULL) == NCVal)
4049         break;
4050       if ((NCVal & 0xFFFF000000000000ULL) == NCVal)
4051         break;
4052       return;
4053     }
4054     default:
4055       return;
4056     }
4057 
4058     // All assembler immediates are 64-bit integers.
4059     Result = DAG.getTargetConstant(CVal, MVT::i64);
4060     break;
4061   }
4062 
4063   if (Result.getNode()) {
4064     Ops.push_back(Result);
4065     return;
4066   }
4067 
4068   return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4069 }
4070 
4071 //===----------------------------------------------------------------------===//
4072 //                     AArch64 Advanced SIMD Support
4073 //===----------------------------------------------------------------------===//
4074 
4075 /// WidenVector - Given a value in the V64 register class, produce the
4076 /// equivalent value in the V128 register class.
WidenVector(SDValue V64Reg,SelectionDAG & DAG)4077 static SDValue WidenVector(SDValue V64Reg, SelectionDAG &DAG) {
4078   EVT VT = V64Reg.getValueType();
4079   unsigned NarrowSize = VT.getVectorNumElements();
4080   MVT EltTy = VT.getVectorElementType().getSimpleVT();
4081   MVT WideTy = MVT::getVectorVT(EltTy, 2 * NarrowSize);
4082   SDLoc DL(V64Reg);
4083 
4084   return DAG.getNode(ISD::INSERT_SUBVECTOR, DL, WideTy, DAG.getUNDEF(WideTy),
4085                      V64Reg, DAG.getConstant(0, MVT::i32));
4086 }
4087 
4088 /// getExtFactor - Determine the adjustment factor for the position when
4089 /// generating an "extract from vector registers" instruction.
getExtFactor(SDValue & V)4090 static unsigned getExtFactor(SDValue &V) {
4091   EVT EltType = V.getValueType().getVectorElementType();
4092   return EltType.getSizeInBits() / 8;
4093 }
4094 
4095 /// NarrowVector - Given a value in the V128 register class, produce the
4096 /// equivalent value in the V64 register class.
NarrowVector(SDValue V128Reg,SelectionDAG & DAG)4097 static SDValue NarrowVector(SDValue V128Reg, SelectionDAG &DAG) {
4098   EVT VT = V128Reg.getValueType();
4099   unsigned WideSize = VT.getVectorNumElements();
4100   MVT EltTy = VT.getVectorElementType().getSimpleVT();
4101   MVT NarrowTy = MVT::getVectorVT(EltTy, WideSize / 2);
4102   SDLoc DL(V128Reg);
4103 
4104   return DAG.getTargetExtractSubreg(AArch64::dsub, DL, NarrowTy, V128Reg);
4105 }
4106 
4107 // Gather data to see if the operation can be modelled as a
4108 // shuffle in combination with VEXTs.
ReconstructShuffle(SDValue Op,SelectionDAG & DAG) const4109 SDValue AArch64TargetLowering::ReconstructShuffle(SDValue Op,
4110                                                   SelectionDAG &DAG) const {
4111   assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
4112   SDLoc dl(Op);
4113   EVT VT = Op.getValueType();
4114   unsigned NumElts = VT.getVectorNumElements();
4115 
4116   SmallVector<SDValue, 2> SourceVecs;
4117   SmallVector<unsigned, 2> MinElts;
4118   SmallVector<unsigned, 2> MaxElts;
4119 
4120   for (unsigned i = 0; i < NumElts; ++i) {
4121     SDValue V = Op.getOperand(i);
4122     if (V.getOpcode() == ISD::UNDEF)
4123       continue;
4124     else if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT) {
4125       // A shuffle can only come from building a vector from various
4126       // elements of other vectors.
4127       return SDValue();
4128     }
4129 
4130     // Record this extraction against the appropriate vector if possible...
4131     SDValue SourceVec = V.getOperand(0);
4132     unsigned EltNo = cast<ConstantSDNode>(V.getOperand(1))->getZExtValue();
4133     bool FoundSource = false;
4134     for (unsigned j = 0; j < SourceVecs.size(); ++j) {
4135       if (SourceVecs[j] == SourceVec) {
4136         if (MinElts[j] > EltNo)
4137           MinElts[j] = EltNo;
4138         if (MaxElts[j] < EltNo)
4139           MaxElts[j] = EltNo;
4140         FoundSource = true;
4141         break;
4142       }
4143     }
4144 
4145     // Or record a new source if not...
4146     if (!FoundSource) {
4147       SourceVecs.push_back(SourceVec);
4148       MinElts.push_back(EltNo);
4149       MaxElts.push_back(EltNo);
4150     }
4151   }
4152 
4153   // Currently only do something sane when at most two source vectors
4154   // involved.
4155   if (SourceVecs.size() > 2)
4156     return SDValue();
4157 
4158   SDValue ShuffleSrcs[2] = { DAG.getUNDEF(VT), DAG.getUNDEF(VT) };
4159   int VEXTOffsets[2] = { 0, 0 };
4160   int OffsetMultipliers[2] = { 1, 1 };
4161 
4162   // This loop extracts the usage patterns of the source vectors
4163   // and prepares appropriate SDValues for a shuffle if possible.
4164   for (unsigned i = 0; i < SourceVecs.size(); ++i) {
4165     unsigned NumSrcElts = SourceVecs[i].getValueType().getVectorNumElements();
4166     SDValue CurSource = SourceVecs[i];
4167     if (SourceVecs[i].getValueType().getVectorElementType() !=
4168         VT.getVectorElementType()) {
4169       // It may hit this case if SourceVecs[i] is AssertSext/AssertZext.
4170       // Then bitcast it to the vector which holds asserted element type,
4171       // and record the multiplier of element width between SourceVecs and
4172       // Build_vector which is needed to extract the correct lanes later.
4173       EVT CastVT =
4174           EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(),
4175                            SourceVecs[i].getValueSizeInBits() /
4176                                VT.getVectorElementType().getSizeInBits());
4177 
4178       CurSource = DAG.getNode(ISD::BITCAST, dl, CastVT, SourceVecs[i]);
4179       OffsetMultipliers[i] = CastVT.getVectorNumElements() / NumSrcElts;
4180       NumSrcElts *= OffsetMultipliers[i];
4181       MaxElts[i] *= OffsetMultipliers[i];
4182       MinElts[i] *= OffsetMultipliers[i];
4183     }
4184 
4185     if (CurSource.getValueType() == VT) {
4186       // No VEXT necessary
4187       ShuffleSrcs[i] = CurSource;
4188       VEXTOffsets[i] = 0;
4189       continue;
4190     } else if (NumSrcElts < NumElts) {
4191       // We can pad out the smaller vector for free, so if it's part of a
4192       // shuffle...
4193       ShuffleSrcs[i] = DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, CurSource,
4194                                    DAG.getUNDEF(CurSource.getValueType()));
4195       continue;
4196     }
4197 
4198     // Since only 64-bit and 128-bit vectors are legal on ARM and
4199     // we've eliminated the other cases...
4200     assert(NumSrcElts == 2 * NumElts &&
4201            "unexpected vector sizes in ReconstructShuffle");
4202 
4203     if (MaxElts[i] - MinElts[i] >= NumElts) {
4204       // Span too large for a VEXT to cope
4205       return SDValue();
4206     }
4207 
4208     if (MinElts[i] >= NumElts) {
4209       // The extraction can just take the second half
4210       VEXTOffsets[i] = NumElts;
4211       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4212                                    DAG.getIntPtrConstant(NumElts));
4213     } else if (MaxElts[i] < NumElts) {
4214       // The extraction can just take the first half
4215       VEXTOffsets[i] = 0;
4216       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4217                                    DAG.getIntPtrConstant(0));
4218     } else {
4219       // An actual VEXT is needed
4220       VEXTOffsets[i] = MinElts[i];
4221       SDValue VEXTSrc1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4222                                      DAG.getIntPtrConstant(0));
4223       SDValue VEXTSrc2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, CurSource,
4224                                      DAG.getIntPtrConstant(NumElts));
4225       unsigned Imm = VEXTOffsets[i] * getExtFactor(VEXTSrc1);
4226       ShuffleSrcs[i] = DAG.getNode(AArch64ISD::EXT, dl, VT, VEXTSrc1, VEXTSrc2,
4227                                    DAG.getConstant(Imm, MVT::i32));
4228     }
4229   }
4230 
4231   SmallVector<int, 8> Mask;
4232 
4233   for (unsigned i = 0; i < NumElts; ++i) {
4234     SDValue Entry = Op.getOperand(i);
4235     if (Entry.getOpcode() == ISD::UNDEF) {
4236       Mask.push_back(-1);
4237       continue;
4238     }
4239 
4240     SDValue ExtractVec = Entry.getOperand(0);
4241     int ExtractElt =
4242         cast<ConstantSDNode>(Op.getOperand(i).getOperand(1))->getSExtValue();
4243     if (ExtractVec == SourceVecs[0]) {
4244       Mask.push_back(ExtractElt * OffsetMultipliers[0] - VEXTOffsets[0]);
4245     } else {
4246       Mask.push_back(ExtractElt * OffsetMultipliers[1] + NumElts -
4247                      VEXTOffsets[1]);
4248     }
4249   }
4250 
4251   // Final check before we try to produce nonsense...
4252   if (isShuffleMaskLegal(Mask, VT))
4253     return DAG.getVectorShuffle(VT, dl, ShuffleSrcs[0], ShuffleSrcs[1],
4254                                 &Mask[0]);
4255 
4256   return SDValue();
4257 }
4258 
4259 // check if an EXT instruction can handle the shuffle mask when the
4260 // vector sources of the shuffle are the same.
isSingletonEXTMask(ArrayRef<int> M,EVT VT,unsigned & Imm)4261 static bool isSingletonEXTMask(ArrayRef<int> M, EVT VT, unsigned &Imm) {
4262   unsigned NumElts = VT.getVectorNumElements();
4263 
4264   // Assume that the first shuffle index is not UNDEF.  Fail if it is.
4265   if (M[0] < 0)
4266     return false;
4267 
4268   Imm = M[0];
4269 
4270   // If this is a VEXT shuffle, the immediate value is the index of the first
4271   // element.  The other shuffle indices must be the successive elements after
4272   // the first one.
4273   unsigned ExpectedElt = Imm;
4274   for (unsigned i = 1; i < NumElts; ++i) {
4275     // Increment the expected index.  If it wraps around, just follow it
4276     // back to index zero and keep going.
4277     ++ExpectedElt;
4278     if (ExpectedElt == NumElts)
4279       ExpectedElt = 0;
4280 
4281     if (M[i] < 0)
4282       continue; // ignore UNDEF indices
4283     if (ExpectedElt != static_cast<unsigned>(M[i]))
4284       return false;
4285   }
4286 
4287   return true;
4288 }
4289 
4290 // check if an EXT instruction can handle the shuffle mask when the
4291 // vector sources of the shuffle are different.
isEXTMask(ArrayRef<int> M,EVT VT,bool & ReverseEXT,unsigned & Imm)4292 static bool isEXTMask(ArrayRef<int> M, EVT VT, bool &ReverseEXT,
4293                       unsigned &Imm) {
4294   // Look for the first non-undef element.
4295   const int *FirstRealElt = std::find_if(M.begin(), M.end(),
4296       [](int Elt) {return Elt >= 0;});
4297 
4298   // Benefit form APInt to handle overflow when calculating expected element.
4299   unsigned NumElts = VT.getVectorNumElements();
4300   unsigned MaskBits = APInt(32, NumElts * 2).logBase2();
4301   APInt ExpectedElt = APInt(MaskBits, *FirstRealElt + 1);
4302   // The following shuffle indices must be the successive elements after the
4303   // first real element.
4304   const int *FirstWrongElt = std::find_if(FirstRealElt + 1, M.end(),
4305       [&](int Elt) {return Elt != ExpectedElt++ && Elt != -1;});
4306   if (FirstWrongElt != M.end())
4307     return false;
4308 
4309   // The index of an EXT is the first element if it is not UNDEF.
4310   // Watch out for the beginning UNDEFs. The EXT index should be the expected
4311   // value of the first element.  E.g.
4312   // <-1, -1, 3, ...> is treated as <1, 2, 3, ...>.
4313   // <-1, -1, 0, 1, ...> is treated as <2*NumElts-2, 2*NumElts-1, 0, 1, ...>.
4314   // ExpectedElt is the last mask index plus 1.
4315   Imm = ExpectedElt.getZExtValue();
4316 
4317   // There are two difference cases requiring to reverse input vectors.
4318   // For example, for vector <4 x i32> we have the following cases,
4319   // Case 1: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, -1, 0>)
4320   // Case 2: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, 7, 0>)
4321   // For both cases, we finally use mask <5, 6, 7, 0>, which requires
4322   // to reverse two input vectors.
4323   if (Imm < NumElts)
4324     ReverseEXT = true;
4325   else
4326     Imm -= NumElts;
4327 
4328   return true;
4329 }
4330 
4331 /// isREVMask - Check if a vector shuffle corresponds to a REV
4332 /// instruction with the specified blocksize.  (The order of the elements
4333 /// within each block of the vector is reversed.)
isREVMask(ArrayRef<int> M,EVT VT,unsigned BlockSize)4334 static bool isREVMask(ArrayRef<int> M, EVT VT, unsigned BlockSize) {
4335   assert((BlockSize == 16 || BlockSize == 32 || BlockSize == 64) &&
4336          "Only possible block sizes for REV are: 16, 32, 64");
4337 
4338   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
4339   if (EltSz == 64)
4340     return false;
4341 
4342   unsigned NumElts = VT.getVectorNumElements();
4343   unsigned BlockElts = M[0] + 1;
4344   // If the first shuffle index is UNDEF, be optimistic.
4345   if (M[0] < 0)
4346     BlockElts = BlockSize / EltSz;
4347 
4348   if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
4349     return false;
4350 
4351   for (unsigned i = 0; i < NumElts; ++i) {
4352     if (M[i] < 0)
4353       continue; // ignore UNDEF indices
4354     if ((unsigned)M[i] != (i - i % BlockElts) + (BlockElts - 1 - i % BlockElts))
4355       return false;
4356   }
4357 
4358   return true;
4359 }
4360 
isZIPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4361 static bool isZIPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4362   unsigned NumElts = VT.getVectorNumElements();
4363   WhichResult = (M[0] == 0 ? 0 : 1);
4364   unsigned Idx = WhichResult * NumElts / 2;
4365   for (unsigned i = 0; i != NumElts; i += 2) {
4366     if ((M[i] >= 0 && (unsigned)M[i] != Idx) ||
4367         (M[i + 1] >= 0 && (unsigned)M[i + 1] != Idx + NumElts))
4368       return false;
4369     Idx += 1;
4370   }
4371 
4372   return true;
4373 }
4374 
isUZPMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4375 static bool isUZPMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4376   unsigned NumElts = VT.getVectorNumElements();
4377   WhichResult = (M[0] == 0 ? 0 : 1);
4378   for (unsigned i = 0; i != NumElts; ++i) {
4379     if (M[i] < 0)
4380       continue; // ignore UNDEF indices
4381     if ((unsigned)M[i] != 2 * i + WhichResult)
4382       return false;
4383   }
4384 
4385   return true;
4386 }
4387 
isTRNMask(ArrayRef<int> M,EVT VT,unsigned & WhichResult)4388 static bool isTRNMask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4389   unsigned NumElts = VT.getVectorNumElements();
4390   WhichResult = (M[0] == 0 ? 0 : 1);
4391   for (unsigned i = 0; i < NumElts; i += 2) {
4392     if ((M[i] >= 0 && (unsigned)M[i] != i + WhichResult) ||
4393         (M[i + 1] >= 0 && (unsigned)M[i + 1] != i + NumElts + WhichResult))
4394       return false;
4395   }
4396   return true;
4397 }
4398 
4399 /// isZIP_v_undef_Mask - Special case of isZIPMask for canonical form of
4400 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4401 /// 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)4402 static bool isZIP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4403   unsigned NumElts = VT.getVectorNumElements();
4404   WhichResult = (M[0] == 0 ? 0 : 1);
4405   unsigned Idx = WhichResult * NumElts / 2;
4406   for (unsigned i = 0; i != NumElts; i += 2) {
4407     if ((M[i] >= 0 && (unsigned)M[i] != Idx) ||
4408         (M[i + 1] >= 0 && (unsigned)M[i + 1] != Idx))
4409       return false;
4410     Idx += 1;
4411   }
4412 
4413   return true;
4414 }
4415 
4416 /// isUZP_v_undef_Mask - Special case of isUZPMask for canonical form of
4417 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4418 /// 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)4419 static bool isUZP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4420   unsigned Half = VT.getVectorNumElements() / 2;
4421   WhichResult = (M[0] == 0 ? 0 : 1);
4422   for (unsigned j = 0; j != 2; ++j) {
4423     unsigned Idx = WhichResult;
4424     for (unsigned i = 0; i != Half; ++i) {
4425       int MIdx = M[i + j * Half];
4426       if (MIdx >= 0 && (unsigned)MIdx != Idx)
4427         return false;
4428       Idx += 2;
4429     }
4430   }
4431 
4432   return true;
4433 }
4434 
4435 /// isTRN_v_undef_Mask - Special case of isTRNMask for canonical form of
4436 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
4437 /// 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)4438 static bool isTRN_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
4439   unsigned NumElts = VT.getVectorNumElements();
4440   WhichResult = (M[0] == 0 ? 0 : 1);
4441   for (unsigned i = 0; i < NumElts; i += 2) {
4442     if ((M[i] >= 0 && (unsigned)M[i] != i + WhichResult) ||
4443         (M[i + 1] >= 0 && (unsigned)M[i + 1] != i + WhichResult))
4444       return false;
4445   }
4446   return true;
4447 }
4448 
isINSMask(ArrayRef<int> M,int NumInputElements,bool & DstIsLeft,int & Anomaly)4449 static bool isINSMask(ArrayRef<int> M, int NumInputElements,
4450                       bool &DstIsLeft, int &Anomaly) {
4451   if (M.size() != static_cast<size_t>(NumInputElements))
4452     return false;
4453 
4454   int NumLHSMatch = 0, NumRHSMatch = 0;
4455   int LastLHSMismatch = -1, LastRHSMismatch = -1;
4456 
4457   for (int i = 0; i < NumInputElements; ++i) {
4458     if (M[i] == -1) {
4459       ++NumLHSMatch;
4460       ++NumRHSMatch;
4461       continue;
4462     }
4463 
4464     if (M[i] == i)
4465       ++NumLHSMatch;
4466     else
4467       LastLHSMismatch = i;
4468 
4469     if (M[i] == i + NumInputElements)
4470       ++NumRHSMatch;
4471     else
4472       LastRHSMismatch = i;
4473   }
4474 
4475   if (NumLHSMatch == NumInputElements - 1) {
4476     DstIsLeft = true;
4477     Anomaly = LastLHSMismatch;
4478     return true;
4479   } else if (NumRHSMatch == NumInputElements - 1) {
4480     DstIsLeft = false;
4481     Anomaly = LastRHSMismatch;
4482     return true;
4483   }
4484 
4485   return false;
4486 }
4487 
isConcatMask(ArrayRef<int> Mask,EVT VT,bool SplitLHS)4488 static bool isConcatMask(ArrayRef<int> Mask, EVT VT, bool SplitLHS) {
4489   if (VT.getSizeInBits() != 128)
4490     return false;
4491 
4492   unsigned NumElts = VT.getVectorNumElements();
4493 
4494   for (int I = 0, E = NumElts / 2; I != E; I++) {
4495     if (Mask[I] != I)
4496       return false;
4497   }
4498 
4499   int Offset = NumElts / 2;
4500   for (int I = NumElts / 2, E = NumElts; I != E; I++) {
4501     if (Mask[I] != I + SplitLHS * Offset)
4502       return false;
4503   }
4504 
4505   return true;
4506 }
4507 
tryFormConcatFromShuffle(SDValue Op,SelectionDAG & DAG)4508 static SDValue tryFormConcatFromShuffle(SDValue Op, SelectionDAG &DAG) {
4509   SDLoc DL(Op);
4510   EVT VT = Op.getValueType();
4511   SDValue V0 = Op.getOperand(0);
4512   SDValue V1 = Op.getOperand(1);
4513   ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Op)->getMask();
4514 
4515   if (VT.getVectorElementType() != V0.getValueType().getVectorElementType() ||
4516       VT.getVectorElementType() != V1.getValueType().getVectorElementType())
4517     return SDValue();
4518 
4519   bool SplitV0 = V0.getValueType().getSizeInBits() == 128;
4520 
4521   if (!isConcatMask(Mask, VT, SplitV0))
4522     return SDValue();
4523 
4524   EVT CastVT = EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(),
4525                                 VT.getVectorNumElements() / 2);
4526   if (SplitV0) {
4527     V0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V0,
4528                      DAG.getConstant(0, MVT::i64));
4529   }
4530   if (V1.getValueType().getSizeInBits() == 128) {
4531     V1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V1,
4532                      DAG.getConstant(0, MVT::i64));
4533   }
4534   return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, V0, V1);
4535 }
4536 
4537 /// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
4538 /// the specified operations to build the shuffle.
GeneratePerfectShuffle(unsigned PFEntry,SDValue LHS,SDValue RHS,SelectionDAG & DAG,SDLoc dl)4539 static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
4540                                       SDValue RHS, SelectionDAG &DAG,
4541                                       SDLoc dl) {
4542   unsigned OpNum = (PFEntry >> 26) & 0x0F;
4543   unsigned LHSID = (PFEntry >> 13) & ((1 << 13) - 1);
4544   unsigned RHSID = (PFEntry >> 0) & ((1 << 13) - 1);
4545 
4546   enum {
4547     OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
4548     OP_VREV,
4549     OP_VDUP0,
4550     OP_VDUP1,
4551     OP_VDUP2,
4552     OP_VDUP3,
4553     OP_VEXT1,
4554     OP_VEXT2,
4555     OP_VEXT3,
4556     OP_VUZPL, // VUZP, left result
4557     OP_VUZPR, // VUZP, right result
4558     OP_VZIPL, // VZIP, left result
4559     OP_VZIPR, // VZIP, right result
4560     OP_VTRNL, // VTRN, left result
4561     OP_VTRNR  // VTRN, right result
4562   };
4563 
4564   if (OpNum == OP_COPY) {
4565     if (LHSID == (1 * 9 + 2) * 9 + 3)
4566       return LHS;
4567     assert(LHSID == ((4 * 9 + 5) * 9 + 6) * 9 + 7 && "Illegal OP_COPY!");
4568     return RHS;
4569   }
4570 
4571   SDValue OpLHS, OpRHS;
4572   OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
4573   OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
4574   EVT VT = OpLHS.getValueType();
4575 
4576   switch (OpNum) {
4577   default:
4578     llvm_unreachable("Unknown shuffle opcode!");
4579   case OP_VREV:
4580     // VREV divides the vector in half and swaps within the half.
4581     if (VT.getVectorElementType() == MVT::i32 ||
4582         VT.getVectorElementType() == MVT::f32)
4583       return DAG.getNode(AArch64ISD::REV64, dl, VT, OpLHS);
4584     // vrev <4 x i16> -> REV32
4585     if (VT.getVectorElementType() == MVT::i16)
4586       return DAG.getNode(AArch64ISD::REV32, dl, VT, OpLHS);
4587     // vrev <4 x i8> -> REV16
4588     assert(VT.getVectorElementType() == MVT::i8);
4589     return DAG.getNode(AArch64ISD::REV16, dl, VT, OpLHS);
4590   case OP_VDUP0:
4591   case OP_VDUP1:
4592   case OP_VDUP2:
4593   case OP_VDUP3: {
4594     EVT EltTy = VT.getVectorElementType();
4595     unsigned Opcode;
4596     if (EltTy == MVT::i8)
4597       Opcode = AArch64ISD::DUPLANE8;
4598     else if (EltTy == MVT::i16)
4599       Opcode = AArch64ISD::DUPLANE16;
4600     else if (EltTy == MVT::i32 || EltTy == MVT::f32)
4601       Opcode = AArch64ISD::DUPLANE32;
4602     else if (EltTy == MVT::i64 || EltTy == MVT::f64)
4603       Opcode = AArch64ISD::DUPLANE64;
4604     else
4605       llvm_unreachable("Invalid vector element type?");
4606 
4607     if (VT.getSizeInBits() == 64)
4608       OpLHS = WidenVector(OpLHS, DAG);
4609     SDValue Lane = DAG.getConstant(OpNum - OP_VDUP0, MVT::i64);
4610     return DAG.getNode(Opcode, dl, VT, OpLHS, Lane);
4611   }
4612   case OP_VEXT1:
4613   case OP_VEXT2:
4614   case OP_VEXT3: {
4615     unsigned Imm = (OpNum - OP_VEXT1 + 1) * getExtFactor(OpLHS);
4616     return DAG.getNode(AArch64ISD::EXT, dl, VT, OpLHS, OpRHS,
4617                        DAG.getConstant(Imm, MVT::i32));
4618   }
4619   case OP_VUZPL:
4620     return DAG.getNode(AArch64ISD::UZP1, dl, DAG.getVTList(VT, VT), OpLHS,
4621                        OpRHS);
4622   case OP_VUZPR:
4623     return DAG.getNode(AArch64ISD::UZP2, dl, DAG.getVTList(VT, VT), OpLHS,
4624                        OpRHS);
4625   case OP_VZIPL:
4626     return DAG.getNode(AArch64ISD::ZIP1, dl, DAG.getVTList(VT, VT), OpLHS,
4627                        OpRHS);
4628   case OP_VZIPR:
4629     return DAG.getNode(AArch64ISD::ZIP2, dl, DAG.getVTList(VT, VT), OpLHS,
4630                        OpRHS);
4631   case OP_VTRNL:
4632     return DAG.getNode(AArch64ISD::TRN1, dl, DAG.getVTList(VT, VT), OpLHS,
4633                        OpRHS);
4634   case OP_VTRNR:
4635     return DAG.getNode(AArch64ISD::TRN2, dl, DAG.getVTList(VT, VT), OpLHS,
4636                        OpRHS);
4637   }
4638 }
4639 
GenerateTBL(SDValue Op,ArrayRef<int> ShuffleMask,SelectionDAG & DAG)4640 static SDValue GenerateTBL(SDValue Op, ArrayRef<int> ShuffleMask,
4641                            SelectionDAG &DAG) {
4642   // Check to see if we can use the TBL instruction.
4643   SDValue V1 = Op.getOperand(0);
4644   SDValue V2 = Op.getOperand(1);
4645   SDLoc DL(Op);
4646 
4647   EVT EltVT = Op.getValueType().getVectorElementType();
4648   unsigned BytesPerElt = EltVT.getSizeInBits() / 8;
4649 
4650   SmallVector<SDValue, 8> TBLMask;
4651   for (int Val : ShuffleMask) {
4652     for (unsigned Byte = 0; Byte < BytesPerElt; ++Byte) {
4653       unsigned Offset = Byte + Val * BytesPerElt;
4654       TBLMask.push_back(DAG.getConstant(Offset, MVT::i32));
4655     }
4656   }
4657 
4658   MVT IndexVT = MVT::v8i8;
4659   unsigned IndexLen = 8;
4660   if (Op.getValueType().getSizeInBits() == 128) {
4661     IndexVT = MVT::v16i8;
4662     IndexLen = 16;
4663   }
4664 
4665   SDValue V1Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V1);
4666   SDValue V2Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V2);
4667 
4668   SDValue Shuffle;
4669   if (V2.getNode()->getOpcode() == ISD::UNDEF) {
4670     if (IndexLen == 8)
4671       V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V1Cst);
4672     Shuffle = DAG.getNode(
4673         ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4674         DAG.getConstant(Intrinsic::aarch64_neon_tbl1, MVT::i32), V1Cst,
4675         DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4676                     makeArrayRef(TBLMask.data(), IndexLen)));
4677   } else {
4678     if (IndexLen == 8) {
4679       V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V2Cst);
4680       Shuffle = DAG.getNode(
4681           ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4682           DAG.getConstant(Intrinsic::aarch64_neon_tbl1, MVT::i32), V1Cst,
4683           DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4684                       makeArrayRef(TBLMask.data(), IndexLen)));
4685     } else {
4686       // FIXME: We cannot, for the moment, emit a TBL2 instruction because we
4687       // cannot currently represent the register constraints on the input
4688       // table registers.
4689       //  Shuffle = DAG.getNode(AArch64ISD::TBL2, DL, IndexVT, V1Cst, V2Cst,
4690       //                   DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4691       //                               &TBLMask[0], IndexLen));
4692       Shuffle = DAG.getNode(
4693           ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
4694           DAG.getConstant(Intrinsic::aarch64_neon_tbl2, MVT::i32), V1Cst, V2Cst,
4695           DAG.getNode(ISD::BUILD_VECTOR, DL, IndexVT,
4696                       makeArrayRef(TBLMask.data(), IndexLen)));
4697     }
4698   }
4699   return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Shuffle);
4700 }
4701 
getDUPLANEOp(EVT EltType)4702 static unsigned getDUPLANEOp(EVT EltType) {
4703   if (EltType == MVT::i8)
4704     return AArch64ISD::DUPLANE8;
4705   if (EltType == MVT::i16)
4706     return AArch64ISD::DUPLANE16;
4707   if (EltType == MVT::i32 || EltType == MVT::f32)
4708     return AArch64ISD::DUPLANE32;
4709   if (EltType == MVT::i64 || EltType == MVT::f64)
4710     return AArch64ISD::DUPLANE64;
4711 
4712   llvm_unreachable("Invalid vector element type?");
4713 }
4714 
LowerVECTOR_SHUFFLE(SDValue Op,SelectionDAG & DAG) const4715 SDValue AArch64TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op,
4716                                                    SelectionDAG &DAG) const {
4717   SDLoc dl(Op);
4718   EVT VT = Op.getValueType();
4719 
4720   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
4721 
4722   // Convert shuffles that are directly supported on NEON to target-specific
4723   // DAG nodes, instead of keeping them as shuffles and matching them again
4724   // during code selection.  This is more efficient and avoids the possibility
4725   // of inconsistencies between legalization and selection.
4726   ArrayRef<int> ShuffleMask = SVN->getMask();
4727 
4728   SDValue V1 = Op.getOperand(0);
4729   SDValue V2 = Op.getOperand(1);
4730 
4731   if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0],
4732                                        V1.getValueType().getSimpleVT())) {
4733     int Lane = SVN->getSplatIndex();
4734     // If this is undef splat, generate it via "just" vdup, if possible.
4735     if (Lane == -1)
4736       Lane = 0;
4737 
4738     if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR)
4739       return DAG.getNode(AArch64ISD::DUP, dl, V1.getValueType(),
4740                          V1.getOperand(0));
4741     // Test if V1 is a BUILD_VECTOR and the lane being referenced is a non-
4742     // constant. If so, we can just reference the lane's definition directly.
4743     if (V1.getOpcode() == ISD::BUILD_VECTOR &&
4744         !isa<ConstantSDNode>(V1.getOperand(Lane)))
4745       return DAG.getNode(AArch64ISD::DUP, dl, VT, V1.getOperand(Lane));
4746 
4747     // Otherwise, duplicate from the lane of the input vector.
4748     unsigned Opcode = getDUPLANEOp(V1.getValueType().getVectorElementType());
4749 
4750     // SelectionDAGBuilder may have "helpfully" already extracted or conatenated
4751     // to make a vector of the same size as this SHUFFLE. We can ignore the
4752     // extract entirely, and canonicalise the concat using WidenVector.
4753     if (V1.getOpcode() == ISD::EXTRACT_SUBVECTOR) {
4754       Lane += cast<ConstantSDNode>(V1.getOperand(1))->getZExtValue();
4755       V1 = V1.getOperand(0);
4756     } else if (V1.getOpcode() == ISD::CONCAT_VECTORS) {
4757       unsigned Idx = Lane >= (int)VT.getVectorNumElements() / 2;
4758       Lane -= Idx * VT.getVectorNumElements() / 2;
4759       V1 = WidenVector(V1.getOperand(Idx), DAG);
4760     } else if (VT.getSizeInBits() == 64)
4761       V1 = WidenVector(V1, DAG);
4762 
4763     return DAG.getNode(Opcode, dl, VT, V1, DAG.getConstant(Lane, MVT::i64));
4764   }
4765 
4766   if (isREVMask(ShuffleMask, VT, 64))
4767     return DAG.getNode(AArch64ISD::REV64, dl, V1.getValueType(), V1, V2);
4768   if (isREVMask(ShuffleMask, VT, 32))
4769     return DAG.getNode(AArch64ISD::REV32, dl, V1.getValueType(), V1, V2);
4770   if (isREVMask(ShuffleMask, VT, 16))
4771     return DAG.getNode(AArch64ISD::REV16, dl, V1.getValueType(), V1, V2);
4772 
4773   bool ReverseEXT = false;
4774   unsigned Imm;
4775   if (isEXTMask(ShuffleMask, VT, ReverseEXT, Imm)) {
4776     if (ReverseEXT)
4777       std::swap(V1, V2);
4778     Imm *= getExtFactor(V1);
4779     return DAG.getNode(AArch64ISD::EXT, dl, V1.getValueType(), V1, V2,
4780                        DAG.getConstant(Imm, MVT::i32));
4781   } else if (V2->getOpcode() == ISD::UNDEF &&
4782              isSingletonEXTMask(ShuffleMask, VT, Imm)) {
4783     Imm *= getExtFactor(V1);
4784     return DAG.getNode(AArch64ISD::EXT, dl, V1.getValueType(), V1, V1,
4785                        DAG.getConstant(Imm, MVT::i32));
4786   }
4787 
4788   unsigned WhichResult;
4789   if (isZIPMask(ShuffleMask, VT, WhichResult)) {
4790     unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
4791     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4792   }
4793   if (isUZPMask(ShuffleMask, VT, WhichResult)) {
4794     unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
4795     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4796   }
4797   if (isTRNMask(ShuffleMask, VT, WhichResult)) {
4798     unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
4799     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V2);
4800   }
4801 
4802   if (isZIP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4803     unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
4804     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4805   }
4806   if (isUZP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4807     unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
4808     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4809   }
4810   if (isTRN_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
4811     unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
4812     return DAG.getNode(Opc, dl, V1.getValueType(), V1, V1);
4813   }
4814 
4815   SDValue Concat = tryFormConcatFromShuffle(Op, DAG);
4816   if (Concat.getNode())
4817     return Concat;
4818 
4819   bool DstIsLeft;
4820   int Anomaly;
4821   int NumInputElements = V1.getValueType().getVectorNumElements();
4822   if (isINSMask(ShuffleMask, NumInputElements, DstIsLeft, Anomaly)) {
4823     SDValue DstVec = DstIsLeft ? V1 : V2;
4824     SDValue DstLaneV = DAG.getConstant(Anomaly, MVT::i64);
4825 
4826     SDValue SrcVec = V1;
4827     int SrcLane = ShuffleMask[Anomaly];
4828     if (SrcLane >= NumInputElements) {
4829       SrcVec = V2;
4830       SrcLane -= VT.getVectorNumElements();
4831     }
4832     SDValue SrcLaneV = DAG.getConstant(SrcLane, MVT::i64);
4833 
4834     EVT ScalarVT = VT.getVectorElementType();
4835     if (ScalarVT.getSizeInBits() < 32)
4836       ScalarVT = MVT::i32;
4837 
4838     return DAG.getNode(
4839         ISD::INSERT_VECTOR_ELT, dl, VT, DstVec,
4840         DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ScalarVT, SrcVec, SrcLaneV),
4841         DstLaneV);
4842   }
4843 
4844   // If the shuffle is not directly supported and it has 4 elements, use
4845   // the PerfectShuffle-generated table to synthesize it from other shuffles.
4846   unsigned NumElts = VT.getVectorNumElements();
4847   if (NumElts == 4) {
4848     unsigned PFIndexes[4];
4849     for (unsigned i = 0; i != 4; ++i) {
4850       if (ShuffleMask[i] < 0)
4851         PFIndexes[i] = 8;
4852       else
4853         PFIndexes[i] = ShuffleMask[i];
4854     }
4855 
4856     // Compute the index in the perfect shuffle table.
4857     unsigned PFTableIndex = PFIndexes[0] * 9 * 9 * 9 + PFIndexes[1] * 9 * 9 +
4858                             PFIndexes[2] * 9 + PFIndexes[3];
4859     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
4860     unsigned Cost = (PFEntry >> 30);
4861 
4862     if (Cost <= 4)
4863       return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
4864   }
4865 
4866   return GenerateTBL(Op, ShuffleMask, DAG);
4867 }
4868 
resolveBuildVector(BuildVectorSDNode * BVN,APInt & CnstBits,APInt & UndefBits)4869 static bool resolveBuildVector(BuildVectorSDNode *BVN, APInt &CnstBits,
4870                                APInt &UndefBits) {
4871   EVT VT = BVN->getValueType(0);
4872   APInt SplatBits, SplatUndef;
4873   unsigned SplatBitSize;
4874   bool HasAnyUndefs;
4875   if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
4876     unsigned NumSplats = VT.getSizeInBits() / SplatBitSize;
4877 
4878     for (unsigned i = 0; i < NumSplats; ++i) {
4879       CnstBits <<= SplatBitSize;
4880       UndefBits <<= SplatBitSize;
4881       CnstBits |= SplatBits.zextOrTrunc(VT.getSizeInBits());
4882       UndefBits |= (SplatBits ^ SplatUndef).zextOrTrunc(VT.getSizeInBits());
4883     }
4884 
4885     return true;
4886   }
4887 
4888   return false;
4889 }
4890 
LowerVectorAND(SDValue Op,SelectionDAG & DAG) const4891 SDValue AArch64TargetLowering::LowerVectorAND(SDValue Op,
4892                                               SelectionDAG &DAG) const {
4893   BuildVectorSDNode *BVN =
4894       dyn_cast<BuildVectorSDNode>(Op.getOperand(1).getNode());
4895   SDValue LHS = Op.getOperand(0);
4896   SDLoc dl(Op);
4897   EVT VT = Op.getValueType();
4898 
4899   if (!BVN)
4900     return Op;
4901 
4902   APInt CnstBits(VT.getSizeInBits(), 0);
4903   APInt UndefBits(VT.getSizeInBits(), 0);
4904   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
4905     // We only have BIC vector immediate instruction, which is and-not.
4906     CnstBits = ~CnstBits;
4907 
4908     // We make use of a little bit of goto ickiness in order to avoid having to
4909     // duplicate the immediate matching logic for the undef toggled case.
4910     bool SecondTry = false;
4911   AttemptModImm:
4912 
4913     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
4914       CnstBits = CnstBits.zextOrTrunc(64);
4915       uint64_t CnstVal = CnstBits.getZExtValue();
4916 
4917       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
4918         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
4919         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4920         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4921                                   DAG.getConstant(CnstVal, MVT::i32),
4922                                   DAG.getConstant(0, MVT::i32));
4923         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4924       }
4925 
4926       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
4927         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
4928         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4929         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4930                                   DAG.getConstant(CnstVal, MVT::i32),
4931                                   DAG.getConstant(8, MVT::i32));
4932         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4933       }
4934 
4935       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
4936         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
4937         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4938         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4939                                   DAG.getConstant(CnstVal, MVT::i32),
4940                                   DAG.getConstant(16, MVT::i32));
4941         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4942       }
4943 
4944       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
4945         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
4946         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
4947         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4948                                   DAG.getConstant(CnstVal, MVT::i32),
4949                                   DAG.getConstant(24, MVT::i32));
4950         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4951       }
4952 
4953       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
4954         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
4955         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
4956         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4957                                   DAG.getConstant(CnstVal, MVT::i32),
4958                                   DAG.getConstant(0, MVT::i32));
4959         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4960       }
4961 
4962       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
4963         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
4964         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
4965         SDValue Mov = DAG.getNode(AArch64ISD::BICi, dl, MovTy, LHS,
4966                                   DAG.getConstant(CnstVal, MVT::i32),
4967                                   DAG.getConstant(8, MVT::i32));
4968         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
4969       }
4970     }
4971 
4972     if (SecondTry)
4973       goto FailedModImm;
4974     SecondTry = true;
4975     CnstBits = ~UndefBits;
4976     goto AttemptModImm;
4977   }
4978 
4979 // We can always fall back to a non-immediate AND.
4980 FailedModImm:
4981   return Op;
4982 }
4983 
4984 // Specialized code to quickly find if PotentialBVec is a BuildVector that
4985 // consists of only the same constant int value, returned in reference arg
4986 // ConstVal
isAllConstantBuildVector(const SDValue & PotentialBVec,uint64_t & ConstVal)4987 static bool isAllConstantBuildVector(const SDValue &PotentialBVec,
4988                                      uint64_t &ConstVal) {
4989   BuildVectorSDNode *Bvec = dyn_cast<BuildVectorSDNode>(PotentialBVec);
4990   if (!Bvec)
4991     return false;
4992   ConstantSDNode *FirstElt = dyn_cast<ConstantSDNode>(Bvec->getOperand(0));
4993   if (!FirstElt)
4994     return false;
4995   EVT VT = Bvec->getValueType(0);
4996   unsigned NumElts = VT.getVectorNumElements();
4997   for (unsigned i = 1; i < NumElts; ++i)
4998     if (dyn_cast<ConstantSDNode>(Bvec->getOperand(i)) != FirstElt)
4999       return false;
5000   ConstVal = FirstElt->getZExtValue();
5001   return true;
5002 }
5003 
getIntrinsicID(const SDNode * N)5004 static unsigned getIntrinsicID(const SDNode *N) {
5005   unsigned Opcode = N->getOpcode();
5006   switch (Opcode) {
5007   default:
5008     return Intrinsic::not_intrinsic;
5009   case ISD::INTRINSIC_WO_CHAIN: {
5010     unsigned IID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
5011     if (IID < Intrinsic::num_intrinsics)
5012       return IID;
5013     return Intrinsic::not_intrinsic;
5014   }
5015   }
5016 }
5017 
5018 // Attempt to form a vector S[LR]I from (or (and X, BvecC1), (lsl Y, C2)),
5019 // to (SLI X, Y, C2), where X and Y have matching vector types, BvecC1 is a
5020 // BUILD_VECTORs with constant element C1, C2 is a constant, and C1 == ~C2.
5021 // Also, logical shift right -> sri, with the same structure.
tryLowerToSLI(SDNode * N,SelectionDAG & DAG)5022 static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
5023   EVT VT = N->getValueType(0);
5024 
5025   if (!VT.isVector())
5026     return SDValue();
5027 
5028   SDLoc DL(N);
5029 
5030   // Is the first op an AND?
5031   const SDValue And = N->getOperand(0);
5032   if (And.getOpcode() != ISD::AND)
5033     return SDValue();
5034 
5035   // Is the second op an shl or lshr?
5036   SDValue Shift = N->getOperand(1);
5037   // This will have been turned into: AArch64ISD::VSHL vector, #shift
5038   // or AArch64ISD::VLSHR vector, #shift
5039   unsigned ShiftOpc = Shift.getOpcode();
5040   if ((ShiftOpc != AArch64ISD::VSHL && ShiftOpc != AArch64ISD::VLSHR))
5041     return SDValue();
5042   bool IsShiftRight = ShiftOpc == AArch64ISD::VLSHR;
5043 
5044   // Is the shift amount constant?
5045   ConstantSDNode *C2node = dyn_cast<ConstantSDNode>(Shift.getOperand(1));
5046   if (!C2node)
5047     return SDValue();
5048 
5049   // Is the and mask vector all constant?
5050   uint64_t C1;
5051   if (!isAllConstantBuildVector(And.getOperand(1), C1))
5052     return SDValue();
5053 
5054   // Is C1 == ~C2, taking into account how much one can shift elements of a
5055   // particular size?
5056   uint64_t C2 = C2node->getZExtValue();
5057   unsigned ElemSizeInBits = VT.getVectorElementType().getSizeInBits();
5058   if (C2 > ElemSizeInBits)
5059     return SDValue();
5060   unsigned ElemMask = (1 << ElemSizeInBits) - 1;
5061   if ((C1 & ElemMask) != (~C2 & ElemMask))
5062     return SDValue();
5063 
5064   SDValue X = And.getOperand(0);
5065   SDValue Y = Shift.getOperand(0);
5066 
5067   unsigned Intrin =
5068       IsShiftRight ? Intrinsic::aarch64_neon_vsri : Intrinsic::aarch64_neon_vsli;
5069   SDValue ResultSLI =
5070       DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5071                   DAG.getConstant(Intrin, MVT::i32), X, Y, Shift.getOperand(1));
5072 
5073   DEBUG(dbgs() << "aarch64-lower: transformed: \n");
5074   DEBUG(N->dump(&DAG));
5075   DEBUG(dbgs() << "into: \n");
5076   DEBUG(ResultSLI->dump(&DAG));
5077 
5078   ++NumShiftInserts;
5079   return ResultSLI;
5080 }
5081 
LowerVectorOR(SDValue Op,SelectionDAG & DAG) const5082 SDValue AArch64TargetLowering::LowerVectorOR(SDValue Op,
5083                                              SelectionDAG &DAG) const {
5084   // Attempt to form a vector S[LR]I from (or (and X, C1), (lsl Y, C2))
5085   if (EnableAArch64SlrGeneration) {
5086     SDValue Res = tryLowerToSLI(Op.getNode(), DAG);
5087     if (Res.getNode())
5088       return Res;
5089   }
5090 
5091   BuildVectorSDNode *BVN =
5092       dyn_cast<BuildVectorSDNode>(Op.getOperand(0).getNode());
5093   SDValue LHS = Op.getOperand(1);
5094   SDLoc dl(Op);
5095   EVT VT = Op.getValueType();
5096 
5097   // OR commutes, so try swapping the operands.
5098   if (!BVN) {
5099     LHS = Op.getOperand(0);
5100     BVN = dyn_cast<BuildVectorSDNode>(Op.getOperand(1).getNode());
5101   }
5102   if (!BVN)
5103     return Op;
5104 
5105   APInt CnstBits(VT.getSizeInBits(), 0);
5106   APInt UndefBits(VT.getSizeInBits(), 0);
5107   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
5108     // We make use of a little bit of goto ickiness in order to avoid having to
5109     // duplicate the immediate matching logic for the undef toggled case.
5110     bool SecondTry = false;
5111   AttemptModImm:
5112 
5113     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
5114       CnstBits = CnstBits.zextOrTrunc(64);
5115       uint64_t CnstVal = CnstBits.getZExtValue();
5116 
5117       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5118         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5119         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5120         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5121                                   DAG.getConstant(CnstVal, MVT::i32),
5122                                   DAG.getConstant(0, MVT::i32));
5123         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5124       }
5125 
5126       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5127         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5128         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5129         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5130                                   DAG.getConstant(CnstVal, MVT::i32),
5131                                   DAG.getConstant(8, MVT::i32));
5132         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5133       }
5134 
5135       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5136         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5137         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5138         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5139                                   DAG.getConstant(CnstVal, MVT::i32),
5140                                   DAG.getConstant(16, MVT::i32));
5141         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5142       }
5143 
5144       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5145         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5146         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5147         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5148                                   DAG.getConstant(CnstVal, MVT::i32),
5149                                   DAG.getConstant(24, MVT::i32));
5150         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5151       }
5152 
5153       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5154         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5155         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5156         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5157                                   DAG.getConstant(CnstVal, MVT::i32),
5158                                   DAG.getConstant(0, MVT::i32));
5159         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5160       }
5161 
5162       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5163         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5164         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5165         SDValue Mov = DAG.getNode(AArch64ISD::ORRi, dl, MovTy, LHS,
5166                                   DAG.getConstant(CnstVal, MVT::i32),
5167                                   DAG.getConstant(8, MVT::i32));
5168         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5169       }
5170     }
5171 
5172     if (SecondTry)
5173       goto FailedModImm;
5174     SecondTry = true;
5175     CnstBits = UndefBits;
5176     goto AttemptModImm;
5177   }
5178 
5179 // We can always fall back to a non-immediate OR.
5180 FailedModImm:
5181   return Op;
5182 }
5183 
5184 // Normalize the operands of BUILD_VECTOR. The value of constant operands will
5185 // be truncated to fit element width.
NormalizeBuildVector(SDValue Op,SelectionDAG & DAG)5186 static SDValue NormalizeBuildVector(SDValue Op,
5187                                     SelectionDAG &DAG) {
5188   assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
5189   SDLoc dl(Op);
5190   EVT VT = Op.getValueType();
5191   EVT EltTy= VT.getVectorElementType();
5192 
5193   if (EltTy.isFloatingPoint() || EltTy.getSizeInBits() > 16)
5194     return Op;
5195 
5196   SmallVector<SDValue, 16> Ops;
5197   for (unsigned I = 0, E = VT.getVectorNumElements(); I != E; ++I) {
5198     SDValue Lane = Op.getOperand(I);
5199     if (Lane.getOpcode() == ISD::Constant) {
5200       APInt LowBits(EltTy.getSizeInBits(),
5201                     cast<ConstantSDNode>(Lane)->getZExtValue());
5202       Lane = DAG.getConstant(LowBits.getZExtValue(), MVT::i32);
5203     }
5204     Ops.push_back(Lane);
5205   }
5206   return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
5207 }
5208 
LowerBUILD_VECTOR(SDValue Op,SelectionDAG & DAG) const5209 SDValue AArch64TargetLowering::LowerBUILD_VECTOR(SDValue Op,
5210                                                  SelectionDAG &DAG) const {
5211   SDLoc dl(Op);
5212   EVT VT = Op.getValueType();
5213   Op = NormalizeBuildVector(Op, DAG);
5214   BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
5215 
5216   APInt CnstBits(VT.getSizeInBits(), 0);
5217   APInt UndefBits(VT.getSizeInBits(), 0);
5218   if (resolveBuildVector(BVN, CnstBits, UndefBits)) {
5219     // We make use of a little bit of goto ickiness in order to avoid having to
5220     // duplicate the immediate matching logic for the undef toggled case.
5221     bool SecondTry = false;
5222   AttemptModImm:
5223 
5224     if (CnstBits.getHiBits(64) == CnstBits.getLoBits(64)) {
5225       CnstBits = CnstBits.zextOrTrunc(64);
5226       uint64_t CnstVal = CnstBits.getZExtValue();
5227 
5228       // Certain magic vector constants (used to express things like NOT
5229       // and NEG) are passed through unmodified.  This allows codegen patterns
5230       // for these operations to match.  Special-purpose patterns will lower
5231       // these immediates to MOVIs if it proves necessary.
5232       if (VT.isInteger() && (CnstVal == 0 || CnstVal == ~0ULL))
5233         return Op;
5234 
5235       // The many faces of MOVI...
5236       if (AArch64_AM::isAdvSIMDModImmType10(CnstVal)) {
5237         CnstVal = AArch64_AM::encodeAdvSIMDModImmType10(CnstVal);
5238         if (VT.getSizeInBits() == 128) {
5239           SDValue Mov = DAG.getNode(AArch64ISD::MOVIedit, dl, MVT::v2i64,
5240                                     DAG.getConstant(CnstVal, MVT::i32));
5241           return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5242         }
5243 
5244         // Support the V64 version via subregister insertion.
5245         SDValue Mov = DAG.getNode(AArch64ISD::MOVIedit, dl, MVT::f64,
5246                                   DAG.getConstant(CnstVal, MVT::i32));
5247         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5248       }
5249 
5250       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5251         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5252         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5253         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5254                                   DAG.getConstant(CnstVal, MVT::i32),
5255                                   DAG.getConstant(0, MVT::i32));
5256         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5257       }
5258 
5259       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5260         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5261         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5262         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5263                                   DAG.getConstant(CnstVal, MVT::i32),
5264                                   DAG.getConstant(8, MVT::i32));
5265         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5266       }
5267 
5268       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5269         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5270         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5271         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5272                                   DAG.getConstant(CnstVal, MVT::i32),
5273                                   DAG.getConstant(16, MVT::i32));
5274         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5275       }
5276 
5277       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5278         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5279         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5280         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5281                                   DAG.getConstant(CnstVal, MVT::i32),
5282                                   DAG.getConstant(24, MVT::i32));
5283         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5284       }
5285 
5286       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5287         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5288         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5289         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5290                                   DAG.getConstant(CnstVal, MVT::i32),
5291                                   DAG.getConstant(0, MVT::i32));
5292         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5293       }
5294 
5295       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5296         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5297         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5298         SDValue Mov = DAG.getNode(AArch64ISD::MOVIshift, dl, MovTy,
5299                                   DAG.getConstant(CnstVal, MVT::i32),
5300                                   DAG.getConstant(8, MVT::i32));
5301         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5302       }
5303 
5304       if (AArch64_AM::isAdvSIMDModImmType7(CnstVal)) {
5305         CnstVal = AArch64_AM::encodeAdvSIMDModImmType7(CnstVal);
5306         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5307         SDValue Mov = DAG.getNode(AArch64ISD::MOVImsl, dl, MovTy,
5308                                   DAG.getConstant(CnstVal, MVT::i32),
5309                                   DAG.getConstant(264, MVT::i32));
5310         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5311       }
5312 
5313       if (AArch64_AM::isAdvSIMDModImmType8(CnstVal)) {
5314         CnstVal = AArch64_AM::encodeAdvSIMDModImmType8(CnstVal);
5315         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5316         SDValue Mov = DAG.getNode(AArch64ISD::MOVImsl, dl, MovTy,
5317                                   DAG.getConstant(CnstVal, MVT::i32),
5318                                   DAG.getConstant(272, MVT::i32));
5319         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5320       }
5321 
5322       if (AArch64_AM::isAdvSIMDModImmType9(CnstVal)) {
5323         CnstVal = AArch64_AM::encodeAdvSIMDModImmType9(CnstVal);
5324         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v16i8 : MVT::v8i8;
5325         SDValue Mov = DAG.getNode(AArch64ISD::MOVI, dl, MovTy,
5326                                   DAG.getConstant(CnstVal, MVT::i32));
5327         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5328       }
5329 
5330       // The few faces of FMOV...
5331       if (AArch64_AM::isAdvSIMDModImmType11(CnstVal)) {
5332         CnstVal = AArch64_AM::encodeAdvSIMDModImmType11(CnstVal);
5333         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4f32 : MVT::v2f32;
5334         SDValue Mov = DAG.getNode(AArch64ISD::FMOV, dl, MovTy,
5335                                   DAG.getConstant(CnstVal, MVT::i32));
5336         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5337       }
5338 
5339       if (AArch64_AM::isAdvSIMDModImmType12(CnstVal) &&
5340           VT.getSizeInBits() == 128) {
5341         CnstVal = AArch64_AM::encodeAdvSIMDModImmType12(CnstVal);
5342         SDValue Mov = DAG.getNode(AArch64ISD::FMOV, dl, MVT::v2f64,
5343                                   DAG.getConstant(CnstVal, MVT::i32));
5344         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5345       }
5346 
5347       // The many faces of MVNI...
5348       CnstVal = ~CnstVal;
5349       if (AArch64_AM::isAdvSIMDModImmType1(CnstVal)) {
5350         CnstVal = AArch64_AM::encodeAdvSIMDModImmType1(CnstVal);
5351         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5352         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5353                                   DAG.getConstant(CnstVal, MVT::i32),
5354                                   DAG.getConstant(0, MVT::i32));
5355         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5356       }
5357 
5358       if (AArch64_AM::isAdvSIMDModImmType2(CnstVal)) {
5359         CnstVal = AArch64_AM::encodeAdvSIMDModImmType2(CnstVal);
5360         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5361         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5362                                   DAG.getConstant(CnstVal, MVT::i32),
5363                                   DAG.getConstant(8, MVT::i32));
5364         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5365       }
5366 
5367       if (AArch64_AM::isAdvSIMDModImmType3(CnstVal)) {
5368         CnstVal = AArch64_AM::encodeAdvSIMDModImmType3(CnstVal);
5369         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5370         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5371                                   DAG.getConstant(CnstVal, MVT::i32),
5372                                   DAG.getConstant(16, MVT::i32));
5373         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5374       }
5375 
5376       if (AArch64_AM::isAdvSIMDModImmType4(CnstVal)) {
5377         CnstVal = AArch64_AM::encodeAdvSIMDModImmType4(CnstVal);
5378         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5379         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5380                                   DAG.getConstant(CnstVal, MVT::i32),
5381                                   DAG.getConstant(24, MVT::i32));
5382         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5383       }
5384 
5385       if (AArch64_AM::isAdvSIMDModImmType5(CnstVal)) {
5386         CnstVal = AArch64_AM::encodeAdvSIMDModImmType5(CnstVal);
5387         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5388         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5389                                   DAG.getConstant(CnstVal, MVT::i32),
5390                                   DAG.getConstant(0, MVT::i32));
5391         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5392       }
5393 
5394       if (AArch64_AM::isAdvSIMDModImmType6(CnstVal)) {
5395         CnstVal = AArch64_AM::encodeAdvSIMDModImmType6(CnstVal);
5396         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
5397         SDValue Mov = DAG.getNode(AArch64ISD::MVNIshift, dl, MovTy,
5398                                   DAG.getConstant(CnstVal, MVT::i32),
5399                                   DAG.getConstant(8, MVT::i32));
5400         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5401       }
5402 
5403       if (AArch64_AM::isAdvSIMDModImmType7(CnstVal)) {
5404         CnstVal = AArch64_AM::encodeAdvSIMDModImmType7(CnstVal);
5405         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5406         SDValue Mov = DAG.getNode(AArch64ISD::MVNImsl, dl, MovTy,
5407                                   DAG.getConstant(CnstVal, MVT::i32),
5408                                   DAG.getConstant(264, MVT::i32));
5409         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5410       }
5411 
5412       if (AArch64_AM::isAdvSIMDModImmType8(CnstVal)) {
5413         CnstVal = AArch64_AM::encodeAdvSIMDModImmType8(CnstVal);
5414         MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
5415         SDValue Mov = DAG.getNode(AArch64ISD::MVNImsl, dl, MovTy,
5416                                   DAG.getConstant(CnstVal, MVT::i32),
5417                                   DAG.getConstant(272, MVT::i32));
5418         return DAG.getNode(ISD::BITCAST, dl, VT, Mov);
5419       }
5420     }
5421 
5422     if (SecondTry)
5423       goto FailedModImm;
5424     SecondTry = true;
5425     CnstBits = UndefBits;
5426     goto AttemptModImm;
5427   }
5428 FailedModImm:
5429 
5430   // Scan through the operands to find some interesting properties we can
5431   // exploit:
5432   //   1) If only one value is used, we can use a DUP, or
5433   //   2) if only the low element is not undef, we can just insert that, or
5434   //   3) if only one constant value is used (w/ some non-constant lanes),
5435   //      we can splat the constant value into the whole vector then fill
5436   //      in the non-constant lanes.
5437   //   4) FIXME: If different constant values are used, but we can intelligently
5438   //             select the values we'll be overwriting for the non-constant
5439   //             lanes such that we can directly materialize the vector
5440   //             some other way (MOVI, e.g.), we can be sneaky.
5441   unsigned NumElts = VT.getVectorNumElements();
5442   bool isOnlyLowElement = true;
5443   bool usesOnlyOneValue = true;
5444   bool usesOnlyOneConstantValue = true;
5445   bool isConstant = true;
5446   unsigned NumConstantLanes = 0;
5447   SDValue Value;
5448   SDValue ConstantValue;
5449   for (unsigned i = 0; i < NumElts; ++i) {
5450     SDValue V = Op.getOperand(i);
5451     if (V.getOpcode() == ISD::UNDEF)
5452       continue;
5453     if (i > 0)
5454       isOnlyLowElement = false;
5455     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
5456       isConstant = false;
5457 
5458     if (isa<ConstantSDNode>(V) || isa<ConstantFPSDNode>(V)) {
5459       ++NumConstantLanes;
5460       if (!ConstantValue.getNode())
5461         ConstantValue = V;
5462       else if (ConstantValue != V)
5463         usesOnlyOneConstantValue = false;
5464     }
5465 
5466     if (!Value.getNode())
5467       Value = V;
5468     else if (V != Value)
5469       usesOnlyOneValue = false;
5470   }
5471 
5472   if (!Value.getNode())
5473     return DAG.getUNDEF(VT);
5474 
5475   if (isOnlyLowElement)
5476     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
5477 
5478   // Use DUP for non-constant splats.  For f32 constant splats, reduce to
5479   // i32 and try again.
5480   if (usesOnlyOneValue) {
5481     if (!isConstant) {
5482       if (Value.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
5483           Value.getValueType() != VT)
5484         return DAG.getNode(AArch64ISD::DUP, dl, VT, Value);
5485 
5486       // This is actually a DUPLANExx operation, which keeps everything vectory.
5487 
5488       // DUPLANE works on 128-bit vectors, widen it if necessary.
5489       SDValue Lane = Value.getOperand(1);
5490       Value = Value.getOperand(0);
5491       if (Value.getValueType().getSizeInBits() == 64)
5492         Value = WidenVector(Value, DAG);
5493 
5494       unsigned Opcode = getDUPLANEOp(VT.getVectorElementType());
5495       return DAG.getNode(Opcode, dl, VT, Value, Lane);
5496     }
5497 
5498     if (VT.getVectorElementType().isFloatingPoint()) {
5499       SmallVector<SDValue, 8> Ops;
5500       MVT NewType =
5501           (VT.getVectorElementType() == MVT::f32) ? MVT::i32 : MVT::i64;
5502       for (unsigned i = 0; i < NumElts; ++i)
5503         Ops.push_back(DAG.getNode(ISD::BITCAST, dl, NewType, Op.getOperand(i)));
5504       EVT VecVT = EVT::getVectorVT(*DAG.getContext(), NewType, NumElts);
5505       SDValue Val = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, Ops);
5506       Val = LowerBUILD_VECTOR(Val, DAG);
5507       if (Val.getNode())
5508         return DAG.getNode(ISD::BITCAST, dl, VT, Val);
5509     }
5510   }
5511 
5512   // If there was only one constant value used and for more than one lane,
5513   // start by splatting that value, then replace the non-constant lanes. This
5514   // is better than the default, which will perform a separate initialization
5515   // for each lane.
5516   if (NumConstantLanes > 0 && usesOnlyOneConstantValue) {
5517     SDValue Val = DAG.getNode(AArch64ISD::DUP, dl, VT, ConstantValue);
5518     // Now insert the non-constant lanes.
5519     for (unsigned i = 0; i < NumElts; ++i) {
5520       SDValue V = Op.getOperand(i);
5521       SDValue LaneIdx = DAG.getConstant(i, MVT::i64);
5522       if (!isa<ConstantSDNode>(V) && !isa<ConstantFPSDNode>(V)) {
5523         // Note that type legalization likely mucked about with the VT of the
5524         // source operand, so we may have to convert it here before inserting.
5525         Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Val, V, LaneIdx);
5526       }
5527     }
5528     return Val;
5529   }
5530 
5531   // If all elements are constants and the case above didn't get hit, fall back
5532   // to the default expansion, which will generate a load from the constant
5533   // pool.
5534   if (isConstant)
5535     return SDValue();
5536 
5537   // Empirical tests suggest this is rarely worth it for vectors of length <= 2.
5538   if (NumElts >= 4) {
5539     SDValue shuffle = ReconstructShuffle(Op, DAG);
5540     if (shuffle != SDValue())
5541       return shuffle;
5542   }
5543 
5544   // If all else fails, just use a sequence of INSERT_VECTOR_ELT when we
5545   // know the default expansion would otherwise fall back on something even
5546   // worse. For a vector with one or two non-undef values, that's
5547   // scalar_to_vector for the elements followed by a shuffle (provided the
5548   // shuffle is valid for the target) and materialization element by element
5549   // on the stack followed by a load for everything else.
5550   if (!isConstant && !usesOnlyOneValue) {
5551     SDValue Vec = DAG.getUNDEF(VT);
5552     SDValue Op0 = Op.getOperand(0);
5553     unsigned ElemSize = VT.getVectorElementType().getSizeInBits();
5554     unsigned i = 0;
5555     // For 32 and 64 bit types, use INSERT_SUBREG for lane zero to
5556     // a) Avoid a RMW dependency on the full vector register, and
5557     // b) Allow the register coalescer to fold away the copy if the
5558     //    value is already in an S or D register.
5559     if (Op0.getOpcode() != ISD::UNDEF && (ElemSize == 32 || ElemSize == 64)) {
5560       unsigned SubIdx = ElemSize == 32 ? AArch64::ssub : AArch64::dsub;
5561       MachineSDNode *N =
5562           DAG.getMachineNode(TargetOpcode::INSERT_SUBREG, dl, VT, Vec, Op0,
5563                              DAG.getTargetConstant(SubIdx, MVT::i32));
5564       Vec = SDValue(N, 0);
5565       ++i;
5566     }
5567     for (; i < NumElts; ++i) {
5568       SDValue V = Op.getOperand(i);
5569       if (V.getOpcode() == ISD::UNDEF)
5570         continue;
5571       SDValue LaneIdx = DAG.getConstant(i, MVT::i64);
5572       Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, VT, Vec, V, LaneIdx);
5573     }
5574     return Vec;
5575   }
5576 
5577   // Just use the default expansion. We failed to find a better alternative.
5578   return SDValue();
5579 }
5580 
LowerINSERT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG) const5581 SDValue AArch64TargetLowering::LowerINSERT_VECTOR_ELT(SDValue Op,
5582                                                       SelectionDAG &DAG) const {
5583   assert(Op.getOpcode() == ISD::INSERT_VECTOR_ELT && "Unknown opcode!");
5584 
5585   // Check for non-constant lane.
5586   if (!isa<ConstantSDNode>(Op.getOperand(2)))
5587     return SDValue();
5588 
5589   EVT VT = Op.getOperand(0).getValueType();
5590 
5591   // Insertion/extraction are legal for V128 types.
5592   if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32 ||
5593       VT == MVT::v2i64 || VT == MVT::v4f32 || VT == MVT::v2f64)
5594     return Op;
5595 
5596   if (VT != MVT::v8i8 && VT != MVT::v4i16 && VT != MVT::v2i32 &&
5597       VT != MVT::v1i64 && VT != MVT::v2f32)
5598     return SDValue();
5599 
5600   // For V64 types, we perform insertion by expanding the value
5601   // to a V128 type and perform the insertion on that.
5602   SDLoc DL(Op);
5603   SDValue WideVec = WidenVector(Op.getOperand(0), DAG);
5604   EVT WideTy = WideVec.getValueType();
5605 
5606   SDValue Node = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, WideTy, WideVec,
5607                              Op.getOperand(1), Op.getOperand(2));
5608   // Re-narrow the resultant vector.
5609   return NarrowVector(Node, DAG);
5610 }
5611 
5612 SDValue
LowerEXTRACT_VECTOR_ELT(SDValue Op,SelectionDAG & DAG) const5613 AArch64TargetLowering::LowerEXTRACT_VECTOR_ELT(SDValue Op,
5614                                                SelectionDAG &DAG) const {
5615   assert(Op.getOpcode() == ISD::EXTRACT_VECTOR_ELT && "Unknown opcode!");
5616 
5617   // Check for non-constant lane.
5618   if (!isa<ConstantSDNode>(Op.getOperand(1)))
5619     return SDValue();
5620 
5621   EVT VT = Op.getOperand(0).getValueType();
5622 
5623   // Insertion/extraction are legal for V128 types.
5624   if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32 ||
5625       VT == MVT::v2i64 || VT == MVT::v4f32 || VT == MVT::v2f64)
5626     return Op;
5627 
5628   if (VT != MVT::v8i8 && VT != MVT::v4i16 && VT != MVT::v2i32 &&
5629       VT != MVT::v1i64 && VT != MVT::v2f32)
5630     return SDValue();
5631 
5632   // For V64 types, we perform extraction by expanding the value
5633   // to a V128 type and perform the extraction on that.
5634   SDLoc DL(Op);
5635   SDValue WideVec = WidenVector(Op.getOperand(0), DAG);
5636   EVT WideTy = WideVec.getValueType();
5637 
5638   EVT ExtrTy = WideTy.getVectorElementType();
5639   if (ExtrTy == MVT::i16 || ExtrTy == MVT::i8)
5640     ExtrTy = MVT::i32;
5641 
5642   // For extractions, we just return the result directly.
5643   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ExtrTy, WideVec,
5644                      Op.getOperand(1));
5645 }
5646 
LowerEXTRACT_SUBVECTOR(SDValue Op,SelectionDAG & DAG) const5647 SDValue AArch64TargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
5648                                                       SelectionDAG &DAG) const {
5649   EVT VT = Op.getOperand(0).getValueType();
5650   SDLoc dl(Op);
5651   // Just in case...
5652   if (!VT.isVector())
5653     return SDValue();
5654 
5655   ConstantSDNode *Cst = dyn_cast<ConstantSDNode>(Op.getOperand(1));
5656   if (!Cst)
5657     return SDValue();
5658   unsigned Val = Cst->getZExtValue();
5659 
5660   unsigned Size = Op.getValueType().getSizeInBits();
5661   if (Val == 0) {
5662     switch (Size) {
5663     case 8:
5664       return DAG.getTargetExtractSubreg(AArch64::bsub, dl, Op.getValueType(),
5665                                         Op.getOperand(0));
5666     case 16:
5667       return DAG.getTargetExtractSubreg(AArch64::hsub, dl, Op.getValueType(),
5668                                         Op.getOperand(0));
5669     case 32:
5670       return DAG.getTargetExtractSubreg(AArch64::ssub, dl, Op.getValueType(),
5671                                         Op.getOperand(0));
5672     case 64:
5673       return DAG.getTargetExtractSubreg(AArch64::dsub, dl, Op.getValueType(),
5674                                         Op.getOperand(0));
5675     default:
5676       llvm_unreachable("Unexpected vector type in extract_subvector!");
5677     }
5678   }
5679   // If this is extracting the upper 64-bits of a 128-bit vector, we match
5680   // that directly.
5681   if (Size == 64 && Val * VT.getVectorElementType().getSizeInBits() == 64)
5682     return Op;
5683 
5684   return SDValue();
5685 }
5686 
isShuffleMaskLegal(const SmallVectorImpl<int> & M,EVT VT) const5687 bool AArch64TargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
5688                                                EVT VT) const {
5689   if (VT.getVectorNumElements() == 4 &&
5690       (VT.is128BitVector() || VT.is64BitVector())) {
5691     unsigned PFIndexes[4];
5692     for (unsigned i = 0; i != 4; ++i) {
5693       if (M[i] < 0)
5694         PFIndexes[i] = 8;
5695       else
5696         PFIndexes[i] = M[i];
5697     }
5698 
5699     // Compute the index in the perfect shuffle table.
5700     unsigned PFTableIndex = PFIndexes[0] * 9 * 9 * 9 + PFIndexes[1] * 9 * 9 +
5701                             PFIndexes[2] * 9 + PFIndexes[3];
5702     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
5703     unsigned Cost = (PFEntry >> 30);
5704 
5705     if (Cost <= 4)
5706       return true;
5707   }
5708 
5709   bool DummyBool;
5710   int DummyInt;
5711   unsigned DummyUnsigned;
5712 
5713   return (ShuffleVectorSDNode::isSplatMask(&M[0], VT) || isREVMask(M, VT, 64) ||
5714           isREVMask(M, VT, 32) || isREVMask(M, VT, 16) ||
5715           isEXTMask(M, VT, DummyBool, DummyUnsigned) ||
5716           // isTBLMask(M, VT) || // FIXME: Port TBL support from ARM.
5717           isTRNMask(M, VT, DummyUnsigned) || isUZPMask(M, VT, DummyUnsigned) ||
5718           isZIPMask(M, VT, DummyUnsigned) ||
5719           isTRN_v_undef_Mask(M, VT, DummyUnsigned) ||
5720           isUZP_v_undef_Mask(M, VT, DummyUnsigned) ||
5721           isZIP_v_undef_Mask(M, VT, DummyUnsigned) ||
5722           isINSMask(M, VT.getVectorNumElements(), DummyBool, DummyInt) ||
5723           isConcatMask(M, VT, VT.getSizeInBits() == 128));
5724 }
5725 
5726 /// getVShiftImm - Check if this is a valid build_vector for the immediate
5727 /// operand of a vector shift operation, where all the elements of the
5728 /// build_vector must have the same constant integer value.
getVShiftImm(SDValue Op,unsigned ElementBits,int64_t & Cnt)5729 static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
5730   // Ignore bit_converts.
5731   while (Op.getOpcode() == ISD::BITCAST)
5732     Op = Op.getOperand(0);
5733   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
5734   APInt SplatBits, SplatUndef;
5735   unsigned SplatBitSize;
5736   bool HasAnyUndefs;
5737   if (!BVN || !BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
5738                                     HasAnyUndefs, ElementBits) ||
5739       SplatBitSize > ElementBits)
5740     return false;
5741   Cnt = SplatBits.getSExtValue();
5742   return true;
5743 }
5744 
5745 /// isVShiftLImm - Check if this is a valid build_vector for the immediate
5746 /// operand of a vector shift left operation.  That value must be in the range:
5747 ///   0 <= Value < ElementBits for a left shift; or
5748 ///   0 <= Value <= ElementBits for a long left shift.
isVShiftLImm(SDValue Op,EVT VT,bool isLong,int64_t & Cnt)5749 static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
5750   assert(VT.isVector() && "vector shift count is not a vector type");
5751   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
5752   if (!getVShiftImm(Op, ElementBits, Cnt))
5753     return false;
5754   return (Cnt >= 0 && (isLong ? Cnt - 1 : Cnt) < ElementBits);
5755 }
5756 
5757 /// isVShiftRImm - Check if this is a valid build_vector for the immediate
5758 /// operand of a vector shift right operation.  For a shift opcode, the value
5759 /// is positive, but for an intrinsic the value count must be negative. The
5760 /// absolute value must be in the range:
5761 ///   1 <= |Value| <= ElementBits for a right shift; or
5762 ///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
isVShiftRImm(SDValue Op,EVT VT,bool isNarrow,bool isIntrinsic,int64_t & Cnt)5763 static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
5764                          int64_t &Cnt) {
5765   assert(VT.isVector() && "vector shift count is not a vector type");
5766   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
5767   if (!getVShiftImm(Op, ElementBits, Cnt))
5768     return false;
5769   if (isIntrinsic)
5770     Cnt = -Cnt;
5771   return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits / 2 : ElementBits));
5772 }
5773 
LowerVectorSRA_SRL_SHL(SDValue Op,SelectionDAG & DAG) const5774 SDValue AArch64TargetLowering::LowerVectorSRA_SRL_SHL(SDValue Op,
5775                                                       SelectionDAG &DAG) const {
5776   EVT VT = Op.getValueType();
5777   SDLoc DL(Op);
5778   int64_t Cnt;
5779 
5780   if (!Op.getOperand(1).getValueType().isVector())
5781     return Op;
5782   unsigned EltSize = VT.getVectorElementType().getSizeInBits();
5783 
5784   switch (Op.getOpcode()) {
5785   default:
5786     llvm_unreachable("unexpected shift opcode");
5787 
5788   case ISD::SHL:
5789     if (isVShiftLImm(Op.getOperand(1), VT, false, Cnt) && Cnt < EltSize)
5790       return DAG.getNode(AArch64ISD::VSHL, SDLoc(Op), VT, Op.getOperand(0),
5791                          DAG.getConstant(Cnt, MVT::i32));
5792     return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5793                        DAG.getConstant(Intrinsic::aarch64_neon_ushl, MVT::i32),
5794                        Op.getOperand(0), Op.getOperand(1));
5795   case ISD::SRA:
5796   case ISD::SRL:
5797     // Right shift immediate
5798     if (isVShiftRImm(Op.getOperand(1), VT, false, false, Cnt) &&
5799         Cnt < EltSize) {
5800       unsigned Opc =
5801           (Op.getOpcode() == ISD::SRA) ? AArch64ISD::VASHR : AArch64ISD::VLSHR;
5802       return DAG.getNode(Opc, SDLoc(Op), VT, Op.getOperand(0),
5803                          DAG.getConstant(Cnt, MVT::i32));
5804     }
5805 
5806     // Right shift register.  Note, there is not a shift right register
5807     // instruction, but the shift left register instruction takes a signed
5808     // value, where negative numbers specify a right shift.
5809     unsigned Opc = (Op.getOpcode() == ISD::SRA) ? Intrinsic::aarch64_neon_sshl
5810                                                 : Intrinsic::aarch64_neon_ushl;
5811     // negate the shift amount
5812     SDValue NegShift = DAG.getNode(AArch64ISD::NEG, DL, VT, Op.getOperand(1));
5813     SDValue NegShiftLeft =
5814         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
5815                     DAG.getConstant(Opc, MVT::i32), Op.getOperand(0), NegShift);
5816     return NegShiftLeft;
5817   }
5818 
5819   return SDValue();
5820 }
5821 
EmitVectorComparison(SDValue LHS,SDValue RHS,AArch64CC::CondCode CC,bool NoNans,EVT VT,SDLoc dl,SelectionDAG & DAG)5822 static SDValue EmitVectorComparison(SDValue LHS, SDValue RHS,
5823                                     AArch64CC::CondCode CC, bool NoNans, EVT VT,
5824                                     SDLoc dl, SelectionDAG &DAG) {
5825   EVT SrcVT = LHS.getValueType();
5826 
5827   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(RHS.getNode());
5828   APInt CnstBits(VT.getSizeInBits(), 0);
5829   APInt UndefBits(VT.getSizeInBits(), 0);
5830   bool IsCnst = BVN && resolveBuildVector(BVN, CnstBits, UndefBits);
5831   bool IsZero = IsCnst && (CnstBits == 0);
5832 
5833   if (SrcVT.getVectorElementType().isFloatingPoint()) {
5834     switch (CC) {
5835     default:
5836       return SDValue();
5837     case AArch64CC::NE: {
5838       SDValue Fcmeq;
5839       if (IsZero)
5840         Fcmeq = DAG.getNode(AArch64ISD::FCMEQz, dl, VT, LHS);
5841       else
5842         Fcmeq = DAG.getNode(AArch64ISD::FCMEQ, dl, VT, LHS, RHS);
5843       return DAG.getNode(AArch64ISD::NOT, dl, VT, Fcmeq);
5844     }
5845     case AArch64CC::EQ:
5846       if (IsZero)
5847         return DAG.getNode(AArch64ISD::FCMEQz, dl, VT, LHS);
5848       return DAG.getNode(AArch64ISD::FCMEQ, dl, VT, LHS, RHS);
5849     case AArch64CC::GE:
5850       if (IsZero)
5851         return DAG.getNode(AArch64ISD::FCMGEz, dl, VT, LHS);
5852       return DAG.getNode(AArch64ISD::FCMGE, dl, VT, LHS, RHS);
5853     case AArch64CC::GT:
5854       if (IsZero)
5855         return DAG.getNode(AArch64ISD::FCMGTz, dl, VT, LHS);
5856       return DAG.getNode(AArch64ISD::FCMGT, dl, VT, LHS, RHS);
5857     case AArch64CC::LS:
5858       if (IsZero)
5859         return DAG.getNode(AArch64ISD::FCMLEz, dl, VT, LHS);
5860       return DAG.getNode(AArch64ISD::FCMGE, dl, VT, RHS, LHS);
5861     case AArch64CC::LT:
5862       if (!NoNans)
5863         return SDValue();
5864     // If we ignore NaNs then we can use to the MI implementation.
5865     // Fallthrough.
5866     case AArch64CC::MI:
5867       if (IsZero)
5868         return DAG.getNode(AArch64ISD::FCMLTz, dl, VT, LHS);
5869       return DAG.getNode(AArch64ISD::FCMGT, dl, VT, RHS, LHS);
5870     }
5871   }
5872 
5873   switch (CC) {
5874   default:
5875     return SDValue();
5876   case AArch64CC::NE: {
5877     SDValue Cmeq;
5878     if (IsZero)
5879       Cmeq = DAG.getNode(AArch64ISD::CMEQz, dl, VT, LHS);
5880     else
5881       Cmeq = DAG.getNode(AArch64ISD::CMEQ, dl, VT, LHS, RHS);
5882     return DAG.getNode(AArch64ISD::NOT, dl, VT, Cmeq);
5883   }
5884   case AArch64CC::EQ:
5885     if (IsZero)
5886       return DAG.getNode(AArch64ISD::CMEQz, dl, VT, LHS);
5887     return DAG.getNode(AArch64ISD::CMEQ, dl, VT, LHS, RHS);
5888   case AArch64CC::GE:
5889     if (IsZero)
5890       return DAG.getNode(AArch64ISD::CMGEz, dl, VT, LHS);
5891     return DAG.getNode(AArch64ISD::CMGE, dl, VT, LHS, RHS);
5892   case AArch64CC::GT:
5893     if (IsZero)
5894       return DAG.getNode(AArch64ISD::CMGTz, dl, VT, LHS);
5895     return DAG.getNode(AArch64ISD::CMGT, dl, VT, LHS, RHS);
5896   case AArch64CC::LE:
5897     if (IsZero)
5898       return DAG.getNode(AArch64ISD::CMLEz, dl, VT, LHS);
5899     return DAG.getNode(AArch64ISD::CMGE, dl, VT, RHS, LHS);
5900   case AArch64CC::LS:
5901     return DAG.getNode(AArch64ISD::CMHS, dl, VT, RHS, LHS);
5902   case AArch64CC::LO:
5903     return DAG.getNode(AArch64ISD::CMHI, dl, VT, RHS, LHS);
5904   case AArch64CC::LT:
5905     if (IsZero)
5906       return DAG.getNode(AArch64ISD::CMLTz, dl, VT, LHS);
5907     return DAG.getNode(AArch64ISD::CMGT, dl, VT, RHS, LHS);
5908   case AArch64CC::HI:
5909     return DAG.getNode(AArch64ISD::CMHI, dl, VT, LHS, RHS);
5910   case AArch64CC::HS:
5911     return DAG.getNode(AArch64ISD::CMHS, dl, VT, LHS, RHS);
5912   }
5913 }
5914 
LowerVSETCC(SDValue Op,SelectionDAG & DAG) const5915 SDValue AArch64TargetLowering::LowerVSETCC(SDValue Op,
5916                                            SelectionDAG &DAG) const {
5917   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
5918   SDValue LHS = Op.getOperand(0);
5919   SDValue RHS = Op.getOperand(1);
5920   SDLoc dl(Op);
5921 
5922   if (LHS.getValueType().getVectorElementType().isInteger()) {
5923     assert(LHS.getValueType() == RHS.getValueType());
5924     AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
5925     return EmitVectorComparison(LHS, RHS, AArch64CC, false, Op.getValueType(),
5926                                 dl, DAG);
5927   }
5928 
5929   assert(LHS.getValueType().getVectorElementType() == MVT::f32 ||
5930          LHS.getValueType().getVectorElementType() == MVT::f64);
5931 
5932   // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
5933   // clean.  Some of them require two branches to implement.
5934   AArch64CC::CondCode CC1, CC2;
5935   bool ShouldInvert;
5936   changeVectorFPCCToAArch64CC(CC, CC1, CC2, ShouldInvert);
5937 
5938   bool NoNaNs = getTargetMachine().Options.NoNaNsFPMath;
5939   SDValue Cmp =
5940       EmitVectorComparison(LHS, RHS, CC1, NoNaNs, Op.getValueType(), dl, DAG);
5941   if (!Cmp.getNode())
5942     return SDValue();
5943 
5944   if (CC2 != AArch64CC::AL) {
5945     SDValue Cmp2 =
5946         EmitVectorComparison(LHS, RHS, CC2, NoNaNs, Op.getValueType(), dl, DAG);
5947     if (!Cmp2.getNode())
5948       return SDValue();
5949 
5950     Cmp = DAG.getNode(ISD::OR, dl, Cmp.getValueType(), Cmp, Cmp2);
5951   }
5952 
5953   if (ShouldInvert)
5954     return Cmp = DAG.getNOT(dl, Cmp, Cmp.getValueType());
5955 
5956   return Cmp;
5957 }
5958 
5959 /// getTgtMemIntrinsic - Represent NEON load and store intrinsics as
5960 /// MemIntrinsicNodes.  The associated MachineMemOperands record the alignment
5961 /// specified in the intrinsic calls.
getTgtMemIntrinsic(IntrinsicInfo & Info,const CallInst & I,unsigned Intrinsic) const5962 bool AArch64TargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
5963                                                const CallInst &I,
5964                                                unsigned Intrinsic) const {
5965   switch (Intrinsic) {
5966   case Intrinsic::aarch64_neon_ld2:
5967   case Intrinsic::aarch64_neon_ld3:
5968   case Intrinsic::aarch64_neon_ld4:
5969   case Intrinsic::aarch64_neon_ld1x2:
5970   case Intrinsic::aarch64_neon_ld1x3:
5971   case Intrinsic::aarch64_neon_ld1x4:
5972   case Intrinsic::aarch64_neon_ld2lane:
5973   case Intrinsic::aarch64_neon_ld3lane:
5974   case Intrinsic::aarch64_neon_ld4lane:
5975   case Intrinsic::aarch64_neon_ld2r:
5976   case Intrinsic::aarch64_neon_ld3r:
5977   case Intrinsic::aarch64_neon_ld4r: {
5978     Info.opc = ISD::INTRINSIC_W_CHAIN;
5979     // Conservatively set memVT to the entire set of vectors loaded.
5980     uint64_t NumElts = getDataLayout()->getTypeAllocSize(I.getType()) / 8;
5981     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
5982     Info.ptrVal = I.getArgOperand(I.getNumArgOperands() - 1);
5983     Info.offset = 0;
5984     Info.align = 0;
5985     Info.vol = false; // volatile loads with NEON intrinsics not supported
5986     Info.readMem = true;
5987     Info.writeMem = false;
5988     return true;
5989   }
5990   case Intrinsic::aarch64_neon_st2:
5991   case Intrinsic::aarch64_neon_st3:
5992   case Intrinsic::aarch64_neon_st4:
5993   case Intrinsic::aarch64_neon_st1x2:
5994   case Intrinsic::aarch64_neon_st1x3:
5995   case Intrinsic::aarch64_neon_st1x4:
5996   case Intrinsic::aarch64_neon_st2lane:
5997   case Intrinsic::aarch64_neon_st3lane:
5998   case Intrinsic::aarch64_neon_st4lane: {
5999     Info.opc = ISD::INTRINSIC_VOID;
6000     // Conservatively set memVT to the entire set of vectors stored.
6001     unsigned NumElts = 0;
6002     for (unsigned ArgI = 1, ArgE = I.getNumArgOperands(); ArgI < ArgE; ++ArgI) {
6003       Type *ArgTy = I.getArgOperand(ArgI)->getType();
6004       if (!ArgTy->isVectorTy())
6005         break;
6006       NumElts += getDataLayout()->getTypeAllocSize(ArgTy) / 8;
6007     }
6008     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
6009     Info.ptrVal = I.getArgOperand(I.getNumArgOperands() - 1);
6010     Info.offset = 0;
6011     Info.align = 0;
6012     Info.vol = false; // volatile stores with NEON intrinsics not supported
6013     Info.readMem = false;
6014     Info.writeMem = true;
6015     return true;
6016   }
6017   case Intrinsic::aarch64_ldaxr:
6018   case Intrinsic::aarch64_ldxr: {
6019     PointerType *PtrTy = cast<PointerType>(I.getArgOperand(0)->getType());
6020     Info.opc = ISD::INTRINSIC_W_CHAIN;
6021     Info.memVT = MVT::getVT(PtrTy->getElementType());
6022     Info.ptrVal = I.getArgOperand(0);
6023     Info.offset = 0;
6024     Info.align = getDataLayout()->getABITypeAlignment(PtrTy->getElementType());
6025     Info.vol = true;
6026     Info.readMem = true;
6027     Info.writeMem = false;
6028     return true;
6029   }
6030   case Intrinsic::aarch64_stlxr:
6031   case Intrinsic::aarch64_stxr: {
6032     PointerType *PtrTy = cast<PointerType>(I.getArgOperand(1)->getType());
6033     Info.opc = ISD::INTRINSIC_W_CHAIN;
6034     Info.memVT = MVT::getVT(PtrTy->getElementType());
6035     Info.ptrVal = I.getArgOperand(1);
6036     Info.offset = 0;
6037     Info.align = getDataLayout()->getABITypeAlignment(PtrTy->getElementType());
6038     Info.vol = true;
6039     Info.readMem = false;
6040     Info.writeMem = true;
6041     return true;
6042   }
6043   case Intrinsic::aarch64_ldaxp:
6044   case Intrinsic::aarch64_ldxp: {
6045     Info.opc = ISD::INTRINSIC_W_CHAIN;
6046     Info.memVT = MVT::i128;
6047     Info.ptrVal = I.getArgOperand(0);
6048     Info.offset = 0;
6049     Info.align = 16;
6050     Info.vol = true;
6051     Info.readMem = true;
6052     Info.writeMem = false;
6053     return true;
6054   }
6055   case Intrinsic::aarch64_stlxp:
6056   case Intrinsic::aarch64_stxp: {
6057     Info.opc = ISD::INTRINSIC_W_CHAIN;
6058     Info.memVT = MVT::i128;
6059     Info.ptrVal = I.getArgOperand(2);
6060     Info.offset = 0;
6061     Info.align = 16;
6062     Info.vol = true;
6063     Info.readMem = false;
6064     Info.writeMem = true;
6065     return true;
6066   }
6067   default:
6068     break;
6069   }
6070 
6071   return false;
6072 }
6073 
6074 // Truncations from 64-bit GPR to 32-bit GPR is free.
isTruncateFree(Type * Ty1,Type * Ty2) const6075 bool AArch64TargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const {
6076   if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
6077     return false;
6078   unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
6079   unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
6080   return NumBits1 > NumBits2;
6081 }
isTruncateFree(EVT VT1,EVT VT2) const6082 bool AArch64TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
6083   if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
6084     return false;
6085   unsigned NumBits1 = VT1.getSizeInBits();
6086   unsigned NumBits2 = VT2.getSizeInBits();
6087   return NumBits1 > NumBits2;
6088 }
6089 
6090 // All 32-bit GPR operations implicitly zero the high-half of the corresponding
6091 // 64-bit GPR.
isZExtFree(Type * Ty1,Type * Ty2) const6092 bool AArch64TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
6093   if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
6094     return false;
6095   unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
6096   unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
6097   return NumBits1 == 32 && NumBits2 == 64;
6098 }
isZExtFree(EVT VT1,EVT VT2) const6099 bool AArch64TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
6100   if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
6101     return false;
6102   unsigned NumBits1 = VT1.getSizeInBits();
6103   unsigned NumBits2 = VT2.getSizeInBits();
6104   return NumBits1 == 32 && NumBits2 == 64;
6105 }
6106 
isZExtFree(SDValue Val,EVT VT2) const6107 bool AArch64TargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
6108   EVT VT1 = Val.getValueType();
6109   if (isZExtFree(VT1, VT2)) {
6110     return true;
6111   }
6112 
6113   if (Val.getOpcode() != ISD::LOAD)
6114     return false;
6115 
6116   // 8-, 16-, and 32-bit integer loads all implicitly zero-extend.
6117   return (VT1.isSimple() && !VT1.isVector() && VT1.isInteger() &&
6118           VT2.isSimple() && !VT2.isVector() && VT2.isInteger() &&
6119           VT1.getSizeInBits() <= 32);
6120 }
6121 
hasPairedLoad(Type * LoadedType,unsigned & RequiredAligment) const6122 bool AArch64TargetLowering::hasPairedLoad(Type *LoadedType,
6123                                           unsigned &RequiredAligment) const {
6124   if (!LoadedType->isIntegerTy() && !LoadedType->isFloatTy())
6125     return false;
6126   // Cyclone supports unaligned accesses.
6127   RequiredAligment = 0;
6128   unsigned NumBits = LoadedType->getPrimitiveSizeInBits();
6129   return NumBits == 32 || NumBits == 64;
6130 }
6131 
hasPairedLoad(EVT LoadedType,unsigned & RequiredAligment) const6132 bool AArch64TargetLowering::hasPairedLoad(EVT LoadedType,
6133                                           unsigned &RequiredAligment) const {
6134   if (!LoadedType.isSimple() ||
6135       (!LoadedType.isInteger() && !LoadedType.isFloatingPoint()))
6136     return false;
6137   // Cyclone supports unaligned accesses.
6138   RequiredAligment = 0;
6139   unsigned NumBits = LoadedType.getSizeInBits();
6140   return NumBits == 32 || NumBits == 64;
6141 }
6142 
memOpAlign(unsigned DstAlign,unsigned SrcAlign,unsigned AlignCheck)6143 static bool memOpAlign(unsigned DstAlign, unsigned SrcAlign,
6144                        unsigned AlignCheck) {
6145   return ((SrcAlign == 0 || SrcAlign % AlignCheck == 0) &&
6146           (DstAlign == 0 || DstAlign % AlignCheck == 0));
6147 }
6148 
getOptimalMemOpType(uint64_t Size,unsigned DstAlign,unsigned SrcAlign,bool IsMemset,bool ZeroMemset,bool MemcpyStrSrc,MachineFunction & MF) const6149 EVT AArch64TargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
6150                                                unsigned SrcAlign, bool IsMemset,
6151                                                bool ZeroMemset,
6152                                                bool MemcpyStrSrc,
6153                                                MachineFunction &MF) const {
6154   // Don't use AdvSIMD to implement 16-byte memset. It would have taken one
6155   // instruction to materialize the v2i64 zero and one store (with restrictive
6156   // addressing mode). Just do two i64 store of zero-registers.
6157   bool Fast;
6158   const Function *F = MF.getFunction();
6159   if (Subtarget->hasFPARMv8() && !IsMemset && Size >= 16 &&
6160       !F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
6161                                        Attribute::NoImplicitFloat) &&
6162       (memOpAlign(SrcAlign, DstAlign, 16) ||
6163        (allowsUnalignedMemoryAccesses(MVT::f128, 0, &Fast) && Fast)))
6164     return MVT::f128;
6165 
6166   return Size >= 8 ? MVT::i64 : MVT::i32;
6167 }
6168 
6169 // 12-bit optionally shifted immediates are legal for adds.
isLegalAddImmediate(int64_t Immed) const6170 bool AArch64TargetLowering::isLegalAddImmediate(int64_t Immed) const {
6171   if ((Immed >> 12) == 0 || ((Immed & 0xfff) == 0 && Immed >> 24 == 0))
6172     return true;
6173   return false;
6174 }
6175 
6176 // Integer comparisons are implemented with ADDS/SUBS, so the range of valid
6177 // immediates is the same as for an add or a sub.
isLegalICmpImmediate(int64_t Immed) const6178 bool AArch64TargetLowering::isLegalICmpImmediate(int64_t Immed) const {
6179   if (Immed < 0)
6180     Immed *= -1;
6181   return isLegalAddImmediate(Immed);
6182 }
6183 
6184 /// isLegalAddressingMode - Return true if the addressing mode represented
6185 /// by AM is legal for this target, for a load/store of the specified type.
isLegalAddressingMode(const AddrMode & AM,Type * Ty) const6186 bool AArch64TargetLowering::isLegalAddressingMode(const AddrMode &AM,
6187                                                   Type *Ty) const {
6188   // AArch64 has five basic addressing modes:
6189   //  reg
6190   //  reg + 9-bit signed offset
6191   //  reg + SIZE_IN_BYTES * 12-bit unsigned offset
6192   //  reg1 + reg2
6193   //  reg + SIZE_IN_BYTES * reg
6194 
6195   // No global is ever allowed as a base.
6196   if (AM.BaseGV)
6197     return false;
6198 
6199   // No reg+reg+imm addressing.
6200   if (AM.HasBaseReg && AM.BaseOffs && AM.Scale)
6201     return false;
6202 
6203   // check reg + imm case:
6204   // i.e., reg + 0, reg + imm9, reg + SIZE_IN_BYTES * uimm12
6205   uint64_t NumBytes = 0;
6206   if (Ty->isSized()) {
6207     uint64_t NumBits = getDataLayout()->getTypeSizeInBits(Ty);
6208     NumBytes = NumBits / 8;
6209     if (!isPowerOf2_64(NumBits))
6210       NumBytes = 0;
6211   }
6212 
6213   if (!AM.Scale) {
6214     int64_t Offset = AM.BaseOffs;
6215 
6216     // 9-bit signed offset
6217     if (Offset >= -(1LL << 9) && Offset <= (1LL << 9) - 1)
6218       return true;
6219 
6220     // 12-bit unsigned offset
6221     unsigned shift = Log2_64(NumBytes);
6222     if (NumBytes && Offset > 0 && (Offset / NumBytes) <= (1LL << 12) - 1 &&
6223         // Must be a multiple of NumBytes (NumBytes is a power of 2)
6224         (Offset >> shift) << shift == Offset)
6225       return true;
6226     return false;
6227   }
6228 
6229   // Check reg1 + SIZE_IN_BYTES * reg2 and reg1 + reg2
6230 
6231   if (!AM.Scale || AM.Scale == 1 ||
6232       (AM.Scale > 0 && (uint64_t)AM.Scale == NumBytes))
6233     return true;
6234   return false;
6235 }
6236 
getScalingFactorCost(const AddrMode & AM,Type * Ty) const6237 int AArch64TargetLowering::getScalingFactorCost(const AddrMode &AM,
6238                                                 Type *Ty) const {
6239   // Scaling factors are not free at all.
6240   // Operands                     | Rt Latency
6241   // -------------------------------------------
6242   // Rt, [Xn, Xm]                 | 4
6243   // -------------------------------------------
6244   // Rt, [Xn, Xm, lsl #imm]       | Rn: 4 Rm: 5
6245   // Rt, [Xn, Wm, <extend> #imm]  |
6246   if (isLegalAddressingMode(AM, Ty))
6247     // Scale represents reg2 * scale, thus account for 1 if
6248     // it is not equal to 0 or 1.
6249     return AM.Scale != 0 && AM.Scale != 1;
6250   return -1;
6251 }
6252 
isFMAFasterThanFMulAndFAdd(EVT VT) const6253 bool AArch64TargetLowering::isFMAFasterThanFMulAndFAdd(EVT VT) const {
6254   VT = VT.getScalarType();
6255 
6256   if (!VT.isSimple())
6257     return false;
6258 
6259   switch (VT.getSimpleVT().SimpleTy) {
6260   case MVT::f32:
6261   case MVT::f64:
6262     return true;
6263   default:
6264     break;
6265   }
6266 
6267   return false;
6268 }
6269 
6270 const MCPhysReg *
getScratchRegisters(CallingConv::ID) const6271 AArch64TargetLowering::getScratchRegisters(CallingConv::ID) const {
6272   // LR is a callee-save register, but we must treat it as clobbered by any call
6273   // site. Hence we include LR in the scratch registers, which are in turn added
6274   // as implicit-defs for stackmaps and patchpoints.
6275   static const MCPhysReg ScratchRegs[] = {
6276     AArch64::X16, AArch64::X17, AArch64::LR, 0
6277   };
6278   return ScratchRegs;
6279 }
6280 
6281 bool
isDesirableToCommuteWithShift(const SDNode * N) const6282 AArch64TargetLowering::isDesirableToCommuteWithShift(const SDNode *N) const {
6283   EVT VT = N->getValueType(0);
6284     // If N is unsigned bit extraction: ((x >> C) & mask), then do not combine
6285     // it with shift to let it be lowered to UBFX.
6286   if (N->getOpcode() == ISD::AND && (VT == MVT::i32 || VT == MVT::i64) &&
6287       isa<ConstantSDNode>(N->getOperand(1))) {
6288     uint64_t TruncMask = N->getConstantOperandVal(1);
6289     if (isMask_64(TruncMask) &&
6290       N->getOperand(0).getOpcode() == ISD::SRL &&
6291       isa<ConstantSDNode>(N->getOperand(0)->getOperand(1)))
6292       return false;
6293   }
6294   return true;
6295 }
6296 
shouldConvertConstantLoadToIntImm(const APInt & Imm,Type * Ty) const6297 bool AArch64TargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
6298                                                               Type *Ty) const {
6299   assert(Ty->isIntegerTy());
6300 
6301   unsigned BitSize = Ty->getPrimitiveSizeInBits();
6302   if (BitSize == 0)
6303     return false;
6304 
6305   int64_t Val = Imm.getSExtValue();
6306   if (Val == 0 || AArch64_AM::isLogicalImmediate(Val, BitSize))
6307     return true;
6308 
6309   if ((int64_t)Val < 0)
6310     Val = ~Val;
6311   if (BitSize == 32)
6312     Val &= (1LL << 32) - 1;
6313 
6314   unsigned LZ = countLeadingZeros((uint64_t)Val);
6315   unsigned Shift = (63 - LZ) / 16;
6316   // MOVZ is free so return true for one or fewer MOVK.
6317   return (Shift < 3) ? true : false;
6318 }
6319 
6320 // Generate SUBS and CSEL for integer abs.
performIntegerAbsCombine(SDNode * N,SelectionDAG & DAG)6321 static SDValue performIntegerAbsCombine(SDNode *N, SelectionDAG &DAG) {
6322   EVT VT = N->getValueType(0);
6323 
6324   SDValue N0 = N->getOperand(0);
6325   SDValue N1 = N->getOperand(1);
6326   SDLoc DL(N);
6327 
6328   // Check pattern of XOR(ADD(X,Y), Y) where Y is SRA(X, size(X)-1)
6329   // and change it to SUB and CSEL.
6330   if (VT.isInteger() && N->getOpcode() == ISD::XOR &&
6331       N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1 &&
6332       N1.getOpcode() == ISD::SRA && N1.getOperand(0) == N0.getOperand(0))
6333     if (ConstantSDNode *Y1C = dyn_cast<ConstantSDNode>(N1.getOperand(1)))
6334       if (Y1C->getAPIntValue() == VT.getSizeInBits() - 1) {
6335         SDValue Neg = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT),
6336                                   N0.getOperand(0));
6337         // Generate SUBS & CSEL.
6338         SDValue Cmp =
6339             DAG.getNode(AArch64ISD::SUBS, DL, DAG.getVTList(VT, MVT::i32),
6340                         N0.getOperand(0), DAG.getConstant(0, VT));
6341         return DAG.getNode(AArch64ISD::CSEL, DL, VT, N0.getOperand(0), Neg,
6342                            DAG.getConstant(AArch64CC::PL, MVT::i32),
6343                            SDValue(Cmp.getNode(), 1));
6344       }
6345   return SDValue();
6346 }
6347 
6348 // performXorCombine - Attempts to handle integer ABS.
performXorCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6349 static SDValue performXorCombine(SDNode *N, SelectionDAG &DAG,
6350                                  TargetLowering::DAGCombinerInfo &DCI,
6351                                  const AArch64Subtarget *Subtarget) {
6352   if (DCI.isBeforeLegalizeOps())
6353     return SDValue();
6354 
6355   return performIntegerAbsCombine(N, DAG);
6356 }
6357 
performMulCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6358 static SDValue performMulCombine(SDNode *N, SelectionDAG &DAG,
6359                                  TargetLowering::DAGCombinerInfo &DCI,
6360                                  const AArch64Subtarget *Subtarget) {
6361   if (DCI.isBeforeLegalizeOps())
6362     return SDValue();
6363 
6364   // Multiplication of a power of two plus/minus one can be done more
6365   // cheaply as as shift+add/sub. For now, this is true unilaterally. If
6366   // future CPUs have a cheaper MADD instruction, this may need to be
6367   // gated on a subtarget feature. For Cyclone, 32-bit MADD is 4 cycles and
6368   // 64-bit is 5 cycles, so this is always a win.
6369   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
6370     APInt Value = C->getAPIntValue();
6371     EVT VT = N->getValueType(0);
6372     if (Value.isNonNegative()) {
6373       // (mul x, 2^N + 1) => (add (shl x, N), x)
6374       APInt VM1 = Value - 1;
6375       if (VM1.isPowerOf2()) {
6376         SDValue ShiftedVal =
6377             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6378                         DAG.getConstant(VM1.logBase2(), MVT::i64));
6379         return DAG.getNode(ISD::ADD, SDLoc(N), VT, ShiftedVal,
6380                            N->getOperand(0));
6381       }
6382       // (mul x, 2^N - 1) => (sub (shl x, N), x)
6383       APInt VP1 = Value + 1;
6384       if (VP1.isPowerOf2()) {
6385         SDValue ShiftedVal =
6386             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6387                         DAG.getConstant(VP1.logBase2(), MVT::i64));
6388         return DAG.getNode(ISD::SUB, SDLoc(N), VT, ShiftedVal,
6389                            N->getOperand(0));
6390       }
6391     } else {
6392       // (mul x, -(2^N + 1)) => - (add (shl x, N), x)
6393       APInt VNM1 = -Value - 1;
6394       if (VNM1.isPowerOf2()) {
6395         SDValue ShiftedVal =
6396             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6397                         DAG.getConstant(VNM1.logBase2(), MVT::i64));
6398         SDValue Add =
6399             DAG.getNode(ISD::ADD, SDLoc(N), VT, ShiftedVal, N->getOperand(0));
6400         return DAG.getNode(ISD::SUB, SDLoc(N), VT, DAG.getConstant(0, VT), Add);
6401       }
6402       // (mul x, -(2^N - 1)) => (sub x, (shl x, N))
6403       APInt VNP1 = -Value + 1;
6404       if (VNP1.isPowerOf2()) {
6405         SDValue ShiftedVal =
6406             DAG.getNode(ISD::SHL, SDLoc(N), VT, N->getOperand(0),
6407                         DAG.getConstant(VNP1.logBase2(), MVT::i64));
6408         return DAG.getNode(ISD::SUB, SDLoc(N), VT, N->getOperand(0),
6409                            ShiftedVal);
6410       }
6411     }
6412   }
6413   return SDValue();
6414 }
6415 
performIntToFpCombine(SDNode * N,SelectionDAG & DAG)6416 static SDValue performIntToFpCombine(SDNode *N, SelectionDAG &DAG) {
6417   EVT VT = N->getValueType(0);
6418   if (VT != MVT::f32 && VT != MVT::f64)
6419     return SDValue();
6420   // Only optimize when the source and destination types have the same width.
6421   if (VT.getSizeInBits() != N->getOperand(0).getValueType().getSizeInBits())
6422     return SDValue();
6423 
6424   // If the result of an integer load is only used by an integer-to-float
6425   // conversion, use a fp load instead and a AdvSIMD scalar {S|U}CVTF instead.
6426   // This eliminates an "integer-to-vector-move UOP and improve throughput.
6427   SDValue N0 = N->getOperand(0);
6428   if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
6429       // Do not change the width of a volatile load.
6430       !cast<LoadSDNode>(N0)->isVolatile()) {
6431     LoadSDNode *LN0 = cast<LoadSDNode>(N0);
6432     SDValue Load = DAG.getLoad(VT, SDLoc(N), LN0->getChain(), LN0->getBasePtr(),
6433                                LN0->getPointerInfo(), LN0->isVolatile(),
6434                                LN0->isNonTemporal(), LN0->isInvariant(),
6435                                LN0->getAlignment());
6436 
6437     // Make sure successors of the original load stay after it by updating them
6438     // to use the new Chain.
6439     DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), Load.getValue(1));
6440 
6441     unsigned Opcode =
6442         (N->getOpcode() == ISD::SINT_TO_FP) ? AArch64ISD::SITOF : AArch64ISD::UITOF;
6443     return DAG.getNode(Opcode, SDLoc(N), VT, Load);
6444   }
6445 
6446   return SDValue();
6447 }
6448 
6449 /// An EXTR instruction is made up of two shifts, ORed together. This helper
6450 /// searches for and classifies those shifts.
findEXTRHalf(SDValue N,SDValue & Src,uint32_t & ShiftAmount,bool & FromHi)6451 static bool findEXTRHalf(SDValue N, SDValue &Src, uint32_t &ShiftAmount,
6452                          bool &FromHi) {
6453   if (N.getOpcode() == ISD::SHL)
6454     FromHi = false;
6455   else if (N.getOpcode() == ISD::SRL)
6456     FromHi = true;
6457   else
6458     return false;
6459 
6460   if (!isa<ConstantSDNode>(N.getOperand(1)))
6461     return false;
6462 
6463   ShiftAmount = N->getConstantOperandVal(1);
6464   Src = N->getOperand(0);
6465   return true;
6466 }
6467 
6468 /// EXTR instruction extracts a contiguous chunk of bits from two existing
6469 /// registers viewed as a high/low pair. This function looks for the pattern:
6470 /// (or (shl VAL1, #N), (srl VAL2, #RegWidth-N)) and replaces it with an
6471 /// EXTR. Can't quite be done in TableGen because the two immediates aren't
6472 /// independent.
tryCombineToEXTR(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)6473 static SDValue tryCombineToEXTR(SDNode *N,
6474                                 TargetLowering::DAGCombinerInfo &DCI) {
6475   SelectionDAG &DAG = DCI.DAG;
6476   SDLoc DL(N);
6477   EVT VT = N->getValueType(0);
6478 
6479   assert(N->getOpcode() == ISD::OR && "Unexpected root");
6480 
6481   if (VT != MVT::i32 && VT != MVT::i64)
6482     return SDValue();
6483 
6484   SDValue LHS;
6485   uint32_t ShiftLHS = 0;
6486   bool LHSFromHi = 0;
6487   if (!findEXTRHalf(N->getOperand(0), LHS, ShiftLHS, LHSFromHi))
6488     return SDValue();
6489 
6490   SDValue RHS;
6491   uint32_t ShiftRHS = 0;
6492   bool RHSFromHi = 0;
6493   if (!findEXTRHalf(N->getOperand(1), RHS, ShiftRHS, RHSFromHi))
6494     return SDValue();
6495 
6496   // If they're both trying to come from the high part of the register, they're
6497   // not really an EXTR.
6498   if (LHSFromHi == RHSFromHi)
6499     return SDValue();
6500 
6501   if (ShiftLHS + ShiftRHS != VT.getSizeInBits())
6502     return SDValue();
6503 
6504   if (LHSFromHi) {
6505     std::swap(LHS, RHS);
6506     std::swap(ShiftLHS, ShiftRHS);
6507   }
6508 
6509   return DAG.getNode(AArch64ISD::EXTR, DL, VT, LHS, RHS,
6510                      DAG.getConstant(ShiftRHS, MVT::i64));
6511 }
6512 
tryCombineToBSL(SDNode * N,TargetLowering::DAGCombinerInfo & DCI)6513 static SDValue tryCombineToBSL(SDNode *N,
6514                                 TargetLowering::DAGCombinerInfo &DCI) {
6515   EVT VT = N->getValueType(0);
6516   SelectionDAG &DAG = DCI.DAG;
6517   SDLoc DL(N);
6518 
6519   if (!VT.isVector())
6520     return SDValue();
6521 
6522   SDValue N0 = N->getOperand(0);
6523   if (N0.getOpcode() != ISD::AND)
6524     return SDValue();
6525 
6526   SDValue N1 = N->getOperand(1);
6527   if (N1.getOpcode() != ISD::AND)
6528     return SDValue();
6529 
6530   // We only have to look for constant vectors here since the general, variable
6531   // case can be handled in TableGen.
6532   unsigned Bits = VT.getVectorElementType().getSizeInBits();
6533   uint64_t BitMask = Bits == 64 ? -1ULL : ((1ULL << Bits) - 1);
6534   for (int i = 1; i >= 0; --i)
6535     for (int j = 1; j >= 0; --j) {
6536       BuildVectorSDNode *BVN0 = dyn_cast<BuildVectorSDNode>(N0->getOperand(i));
6537       BuildVectorSDNode *BVN1 = dyn_cast<BuildVectorSDNode>(N1->getOperand(j));
6538       if (!BVN0 || !BVN1)
6539         continue;
6540 
6541       bool FoundMatch = true;
6542       for (unsigned k = 0; k < VT.getVectorNumElements(); ++k) {
6543         ConstantSDNode *CN0 = dyn_cast<ConstantSDNode>(BVN0->getOperand(k));
6544         ConstantSDNode *CN1 = dyn_cast<ConstantSDNode>(BVN1->getOperand(k));
6545         if (!CN0 || !CN1 ||
6546             CN0->getZExtValue() != (BitMask & ~CN1->getZExtValue())) {
6547           FoundMatch = false;
6548           break;
6549         }
6550       }
6551 
6552       if (FoundMatch)
6553         return DAG.getNode(AArch64ISD::BSL, DL, VT, SDValue(BVN0, 0),
6554                            N0->getOperand(1 - i), N1->getOperand(1 - j));
6555     }
6556 
6557   return SDValue();
6558 }
6559 
performORCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)6560 static SDValue performORCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
6561                                 const AArch64Subtarget *Subtarget) {
6562   // Attempt to form an EXTR from (or (shl VAL1, #N), (srl VAL2, #RegWidth-N))
6563   if (!EnableAArch64ExtrGeneration)
6564     return SDValue();
6565   SelectionDAG &DAG = DCI.DAG;
6566   EVT VT = N->getValueType(0);
6567 
6568   if (!DAG.getTargetLoweringInfo().isTypeLegal(VT))
6569     return SDValue();
6570 
6571   SDValue Res = tryCombineToEXTR(N, DCI);
6572   if (Res.getNode())
6573     return Res;
6574 
6575   Res = tryCombineToBSL(N, DCI);
6576   if (Res.getNode())
6577     return Res;
6578 
6579   return SDValue();
6580 }
6581 
performBitcastCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6582 static SDValue performBitcastCombine(SDNode *N,
6583                                      TargetLowering::DAGCombinerInfo &DCI,
6584                                      SelectionDAG &DAG) {
6585   // Wait 'til after everything is legalized to try this. That way we have
6586   // legal vector types and such.
6587   if (DCI.isBeforeLegalizeOps())
6588     return SDValue();
6589 
6590   // Remove extraneous bitcasts around an extract_subvector.
6591   // For example,
6592   //    (v4i16 (bitconvert
6593   //             (extract_subvector (v2i64 (bitconvert (v8i16 ...)), (i64 1)))))
6594   //  becomes
6595   //    (extract_subvector ((v8i16 ...), (i64 4)))
6596 
6597   // Only interested in 64-bit vectors as the ultimate result.
6598   EVT VT = N->getValueType(0);
6599   if (!VT.isVector())
6600     return SDValue();
6601   if (VT.getSimpleVT().getSizeInBits() != 64)
6602     return SDValue();
6603   // Is the operand an extract_subvector starting at the beginning or halfway
6604   // point of the vector? A low half may also come through as an
6605   // EXTRACT_SUBREG, so look for that, too.
6606   SDValue Op0 = N->getOperand(0);
6607   if (Op0->getOpcode() != ISD::EXTRACT_SUBVECTOR &&
6608       !(Op0->isMachineOpcode() &&
6609         Op0->getMachineOpcode() == AArch64::EXTRACT_SUBREG))
6610     return SDValue();
6611   uint64_t idx = cast<ConstantSDNode>(Op0->getOperand(1))->getZExtValue();
6612   if (Op0->getOpcode() == ISD::EXTRACT_SUBVECTOR) {
6613     if (Op0->getValueType(0).getVectorNumElements() != idx && idx != 0)
6614       return SDValue();
6615   } else if (Op0->getMachineOpcode() == AArch64::EXTRACT_SUBREG) {
6616     if (idx != AArch64::dsub)
6617       return SDValue();
6618     // The dsub reference is equivalent to a lane zero subvector reference.
6619     idx = 0;
6620   }
6621   // Look through the bitcast of the input to the extract.
6622   if (Op0->getOperand(0)->getOpcode() != ISD::BITCAST)
6623     return SDValue();
6624   SDValue Source = Op0->getOperand(0)->getOperand(0);
6625   // If the source type has twice the number of elements as our destination
6626   // type, we know this is an extract of the high or low half of the vector.
6627   EVT SVT = Source->getValueType(0);
6628   if (SVT.getVectorNumElements() != VT.getVectorNumElements() * 2)
6629     return SDValue();
6630 
6631   DEBUG(dbgs() << "aarch64-lower: bitcast extract_subvector simplification\n");
6632 
6633   // Create the simplified form to just extract the low or high half of the
6634   // vector directly rather than bothering with the bitcasts.
6635   SDLoc dl(N);
6636   unsigned NumElements = VT.getVectorNumElements();
6637   if (idx) {
6638     SDValue HalfIdx = DAG.getConstant(NumElements, MVT::i64);
6639     return DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT, Source, HalfIdx);
6640   } else {
6641     SDValue SubReg = DAG.getTargetConstant(AArch64::dsub, MVT::i32);
6642     return SDValue(DAG.getMachineNode(TargetOpcode::EXTRACT_SUBREG, dl, VT,
6643                                       Source, SubReg),
6644                    0);
6645   }
6646 }
6647 
performConcatVectorsCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6648 static SDValue performConcatVectorsCombine(SDNode *N,
6649                                            TargetLowering::DAGCombinerInfo &DCI,
6650                                            SelectionDAG &DAG) {
6651   // Wait 'til after everything is legalized to try this. That way we have
6652   // legal vector types and such.
6653   if (DCI.isBeforeLegalizeOps())
6654     return SDValue();
6655 
6656   SDLoc dl(N);
6657   EVT VT = N->getValueType(0);
6658 
6659   // If we see a (concat_vectors (v1x64 A), (v1x64 A)) it's really a vector
6660   // splat. The indexed instructions are going to be expecting a DUPLANE64, so
6661   // canonicalise to that.
6662   if (N->getOperand(0) == N->getOperand(1) && VT.getVectorNumElements() == 2) {
6663     assert(VT.getVectorElementType().getSizeInBits() == 64);
6664     return DAG.getNode(AArch64ISD::DUPLANE64, dl, VT,
6665                        WidenVector(N->getOperand(0), DAG),
6666                        DAG.getConstant(0, MVT::i64));
6667   }
6668 
6669   // Canonicalise concat_vectors so that the right-hand vector has as few
6670   // bit-casts as possible before its real operation. The primary matching
6671   // destination for these operations will be the narrowing "2" instructions,
6672   // which depend on the operation being performed on this right-hand vector.
6673   // For example,
6674   //    (concat_vectors LHS,  (v1i64 (bitconvert (v4i16 RHS))))
6675   // becomes
6676   //    (bitconvert (concat_vectors (v4i16 (bitconvert LHS)), RHS))
6677 
6678   SDValue Op1 = N->getOperand(1);
6679   if (Op1->getOpcode() != ISD::BITCAST)
6680     return SDValue();
6681   SDValue RHS = Op1->getOperand(0);
6682   MVT RHSTy = RHS.getValueType().getSimpleVT();
6683   // If the RHS is not a vector, this is not the pattern we're looking for.
6684   if (!RHSTy.isVector())
6685     return SDValue();
6686 
6687   DEBUG(dbgs() << "aarch64-lower: concat_vectors bitcast simplification\n");
6688 
6689   MVT ConcatTy = MVT::getVectorVT(RHSTy.getVectorElementType(),
6690                                   RHSTy.getVectorNumElements() * 2);
6691   return DAG.getNode(
6692       ISD::BITCAST, dl, VT,
6693       DAG.getNode(ISD::CONCAT_VECTORS, dl, ConcatTy,
6694                   DAG.getNode(ISD::BITCAST, dl, RHSTy, N->getOperand(0)), RHS));
6695 }
6696 
tryCombineFixedPointConvert(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6697 static SDValue tryCombineFixedPointConvert(SDNode *N,
6698                                            TargetLowering::DAGCombinerInfo &DCI,
6699                                            SelectionDAG &DAG) {
6700   // Wait 'til after everything is legalized to try this. That way we have
6701   // legal vector types and such.
6702   if (DCI.isBeforeLegalizeOps())
6703     return SDValue();
6704   // Transform a scalar conversion of a value from a lane extract into a
6705   // lane extract of a vector conversion. E.g., from foo1 to foo2:
6706   // double foo1(int64x2_t a) { return vcvtd_n_f64_s64(a[1], 9); }
6707   // double foo2(int64x2_t a) { return vcvtq_n_f64_s64(a, 9)[1]; }
6708   //
6709   // The second form interacts better with instruction selection and the
6710   // register allocator to avoid cross-class register copies that aren't
6711   // coalescable due to a lane reference.
6712 
6713   // Check the operand and see if it originates from a lane extract.
6714   SDValue Op1 = N->getOperand(1);
6715   if (Op1.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
6716     // Yep, no additional predication needed. Perform the transform.
6717     SDValue IID = N->getOperand(0);
6718     SDValue Shift = N->getOperand(2);
6719     SDValue Vec = Op1.getOperand(0);
6720     SDValue Lane = Op1.getOperand(1);
6721     EVT ResTy = N->getValueType(0);
6722     EVT VecResTy;
6723     SDLoc DL(N);
6724 
6725     // The vector width should be 128 bits by the time we get here, even
6726     // if it started as 64 bits (the extract_vector handling will have
6727     // done so).
6728     assert(Vec.getValueType().getSizeInBits() == 128 &&
6729            "unexpected vector size on extract_vector_elt!");
6730     if (Vec.getValueType() == MVT::v4i32)
6731       VecResTy = MVT::v4f32;
6732     else if (Vec.getValueType() == MVT::v2i64)
6733       VecResTy = MVT::v2f64;
6734     else
6735       llvm_unreachable("unexpected vector type!");
6736 
6737     SDValue Convert =
6738         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VecResTy, IID, Vec, Shift);
6739     return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ResTy, Convert, Lane);
6740   }
6741   return SDValue();
6742 }
6743 
6744 // AArch64 high-vector "long" operations are formed by performing the non-high
6745 // version on an extract_subvector of each operand which gets the high half:
6746 //
6747 //  (longop2 LHS, RHS) == (longop (extract_high LHS), (extract_high RHS))
6748 //
6749 // However, there are cases which don't have an extract_high explicitly, but
6750 // have another operation that can be made compatible with one for free. For
6751 // example:
6752 //
6753 //  (dupv64 scalar) --> (extract_high (dup128 scalar))
6754 //
6755 // This routine does the actual conversion of such DUPs, once outer routines
6756 // have determined that everything else is in order.
tryExtendDUPToExtractHigh(SDValue N,SelectionDAG & DAG)6757 static SDValue tryExtendDUPToExtractHigh(SDValue N, SelectionDAG &DAG) {
6758   // We can handle most types of duplicate, but the lane ones have an extra
6759   // operand saying *which* lane, so we need to know.
6760   bool IsDUPLANE;
6761   switch (N.getOpcode()) {
6762   case AArch64ISD::DUP:
6763     IsDUPLANE = false;
6764     break;
6765   case AArch64ISD::DUPLANE8:
6766   case AArch64ISD::DUPLANE16:
6767   case AArch64ISD::DUPLANE32:
6768   case AArch64ISD::DUPLANE64:
6769     IsDUPLANE = true;
6770     break;
6771   default:
6772     return SDValue();
6773   }
6774 
6775   MVT NarrowTy = N.getSimpleValueType();
6776   if (!NarrowTy.is64BitVector())
6777     return SDValue();
6778 
6779   MVT ElementTy = NarrowTy.getVectorElementType();
6780   unsigned NumElems = NarrowTy.getVectorNumElements();
6781   MVT NewDUPVT = MVT::getVectorVT(ElementTy, NumElems * 2);
6782 
6783   SDValue NewDUP;
6784   if (IsDUPLANE)
6785     NewDUP = DAG.getNode(N.getOpcode(), SDLoc(N), NewDUPVT, N.getOperand(0),
6786                          N.getOperand(1));
6787   else
6788     NewDUP = DAG.getNode(AArch64ISD::DUP, SDLoc(N), NewDUPVT, N.getOperand(0));
6789 
6790   return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(N.getNode()), NarrowTy,
6791                      NewDUP, DAG.getConstant(NumElems, MVT::i64));
6792 }
6793 
isEssentiallyExtractSubvector(SDValue N)6794 static bool isEssentiallyExtractSubvector(SDValue N) {
6795   if (N.getOpcode() == ISD::EXTRACT_SUBVECTOR)
6796     return true;
6797 
6798   return N.getOpcode() == ISD::BITCAST &&
6799          N.getOperand(0).getOpcode() == ISD::EXTRACT_SUBVECTOR;
6800 }
6801 
6802 /// \brief Helper structure to keep track of ISD::SET_CC operands.
6803 struct GenericSetCCInfo {
6804   const SDValue *Opnd0;
6805   const SDValue *Opnd1;
6806   ISD::CondCode CC;
6807 };
6808 
6809 /// \brief Helper structure to keep track of a SET_CC lowered into AArch64 code.
6810 struct AArch64SetCCInfo {
6811   const SDValue *Cmp;
6812   AArch64CC::CondCode CC;
6813 };
6814 
6815 /// \brief Helper structure to keep track of SetCC information.
6816 union SetCCInfo {
6817   GenericSetCCInfo Generic;
6818   AArch64SetCCInfo AArch64;
6819 };
6820 
6821 /// \brief Helper structure to be able to read SetCC information.  If set to
6822 /// true, IsAArch64 field, Info is a AArch64SetCCInfo, otherwise Info is a
6823 /// GenericSetCCInfo.
6824 struct SetCCInfoAndKind {
6825   SetCCInfo Info;
6826   bool IsAArch64;
6827 };
6828 
6829 /// \brief Check whether or not \p Op is a SET_CC operation, either a generic or
6830 /// an
6831 /// AArch64 lowered one.
6832 /// \p SetCCInfo is filled accordingly.
6833 /// \post SetCCInfo is meanginfull only when this function returns true.
6834 /// \return True when Op is a kind of SET_CC operation.
isSetCC(SDValue Op,SetCCInfoAndKind & SetCCInfo)6835 static bool isSetCC(SDValue Op, SetCCInfoAndKind &SetCCInfo) {
6836   // If this is a setcc, this is straight forward.
6837   if (Op.getOpcode() == ISD::SETCC) {
6838     SetCCInfo.Info.Generic.Opnd0 = &Op.getOperand(0);
6839     SetCCInfo.Info.Generic.Opnd1 = &Op.getOperand(1);
6840     SetCCInfo.Info.Generic.CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
6841     SetCCInfo.IsAArch64 = false;
6842     return true;
6843   }
6844   // Otherwise, check if this is a matching csel instruction.
6845   // In other words:
6846   // - csel 1, 0, cc
6847   // - csel 0, 1, !cc
6848   if (Op.getOpcode() != AArch64ISD::CSEL)
6849     return false;
6850   // Set the information about the operands.
6851   // TODO: we want the operands of the Cmp not the csel
6852   SetCCInfo.Info.AArch64.Cmp = &Op.getOperand(3);
6853   SetCCInfo.IsAArch64 = true;
6854   SetCCInfo.Info.AArch64.CC = static_cast<AArch64CC::CondCode>(
6855       cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue());
6856 
6857   // Check that the operands matches the constraints:
6858   // (1) Both operands must be constants.
6859   // (2) One must be 1 and the other must be 0.
6860   ConstantSDNode *TValue = dyn_cast<ConstantSDNode>(Op.getOperand(0));
6861   ConstantSDNode *FValue = dyn_cast<ConstantSDNode>(Op.getOperand(1));
6862 
6863   // Check (1).
6864   if (!TValue || !FValue)
6865     return false;
6866 
6867   // Check (2).
6868   if (!TValue->isOne()) {
6869     // Update the comparison when we are interested in !cc.
6870     std::swap(TValue, FValue);
6871     SetCCInfo.Info.AArch64.CC =
6872         AArch64CC::getInvertedCondCode(SetCCInfo.Info.AArch64.CC);
6873   }
6874   return TValue->isOne() && FValue->isNullValue();
6875 }
6876 
6877 // Returns true if Op is setcc or zext of setcc.
isSetCCOrZExtSetCC(const SDValue & Op,SetCCInfoAndKind & Info)6878 static bool isSetCCOrZExtSetCC(const SDValue& Op, SetCCInfoAndKind &Info) {
6879   if (isSetCC(Op, Info))
6880     return true;
6881   return ((Op.getOpcode() == ISD::ZERO_EXTEND) &&
6882     isSetCC(Op->getOperand(0), Info));
6883 }
6884 
6885 // The folding we want to perform is:
6886 // (add x, [zext] (setcc cc ...) )
6887 //   -->
6888 // (csel x, (add x, 1), !cc ...)
6889 //
6890 // The latter will get matched to a CSINC instruction.
performSetccAddFolding(SDNode * Op,SelectionDAG & DAG)6891 static SDValue performSetccAddFolding(SDNode *Op, SelectionDAG &DAG) {
6892   assert(Op && Op->getOpcode() == ISD::ADD && "Unexpected operation!");
6893   SDValue LHS = Op->getOperand(0);
6894   SDValue RHS = Op->getOperand(1);
6895   SetCCInfoAndKind InfoAndKind;
6896 
6897   // If neither operand is a SET_CC, give up.
6898   if (!isSetCCOrZExtSetCC(LHS, InfoAndKind)) {
6899     std::swap(LHS, RHS);
6900     if (!isSetCCOrZExtSetCC(LHS, InfoAndKind))
6901       return SDValue();
6902   }
6903 
6904   // FIXME: This could be generatized to work for FP comparisons.
6905   EVT CmpVT = InfoAndKind.IsAArch64
6906                   ? InfoAndKind.Info.AArch64.Cmp->getOperand(0).getValueType()
6907                   : InfoAndKind.Info.Generic.Opnd0->getValueType();
6908   if (CmpVT != MVT::i32 && CmpVT != MVT::i64)
6909     return SDValue();
6910 
6911   SDValue CCVal;
6912   SDValue Cmp;
6913   SDLoc dl(Op);
6914   if (InfoAndKind.IsAArch64) {
6915     CCVal = DAG.getConstant(
6916         AArch64CC::getInvertedCondCode(InfoAndKind.Info.AArch64.CC), MVT::i32);
6917     Cmp = *InfoAndKind.Info.AArch64.Cmp;
6918   } else
6919     Cmp = getAArch64Cmp(*InfoAndKind.Info.Generic.Opnd0,
6920                       *InfoAndKind.Info.Generic.Opnd1,
6921                       ISD::getSetCCInverse(InfoAndKind.Info.Generic.CC, true),
6922                       CCVal, DAG, dl);
6923 
6924   EVT VT = Op->getValueType(0);
6925   LHS = DAG.getNode(ISD::ADD, dl, VT, RHS, DAG.getConstant(1, VT));
6926   return DAG.getNode(AArch64ISD::CSEL, dl, VT, RHS, LHS, CCVal, Cmp);
6927 }
6928 
6929 // The basic add/sub long vector instructions have variants with "2" on the end
6930 // which act on the high-half of their inputs. They are normally matched by
6931 // patterns like:
6932 //
6933 // (add (zeroext (extract_high LHS)),
6934 //      (zeroext (extract_high RHS)))
6935 // -> uaddl2 vD, vN, vM
6936 //
6937 // However, if one of the extracts is something like a duplicate, this
6938 // instruction can still be used profitably. This function puts the DAG into a
6939 // more appropriate form for those patterns to trigger.
performAddSubLongCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6940 static SDValue performAddSubLongCombine(SDNode *N,
6941                                         TargetLowering::DAGCombinerInfo &DCI,
6942                                         SelectionDAG &DAG) {
6943   if (DCI.isBeforeLegalizeOps())
6944     return SDValue();
6945 
6946   MVT VT = N->getSimpleValueType(0);
6947   if (!VT.is128BitVector()) {
6948     if (N->getOpcode() == ISD::ADD)
6949       return performSetccAddFolding(N, DAG);
6950     return SDValue();
6951   }
6952 
6953   // Make sure both branches are extended in the same way.
6954   SDValue LHS = N->getOperand(0);
6955   SDValue RHS = N->getOperand(1);
6956   if ((LHS.getOpcode() != ISD::ZERO_EXTEND &&
6957        LHS.getOpcode() != ISD::SIGN_EXTEND) ||
6958       LHS.getOpcode() != RHS.getOpcode())
6959     return SDValue();
6960 
6961   unsigned ExtType = LHS.getOpcode();
6962 
6963   // It's not worth doing if at least one of the inputs isn't already an
6964   // extract, but we don't know which it'll be so we have to try both.
6965   if (isEssentiallyExtractSubvector(LHS.getOperand(0))) {
6966     RHS = tryExtendDUPToExtractHigh(RHS.getOperand(0), DAG);
6967     if (!RHS.getNode())
6968       return SDValue();
6969 
6970     RHS = DAG.getNode(ExtType, SDLoc(N), VT, RHS);
6971   } else if (isEssentiallyExtractSubvector(RHS.getOperand(0))) {
6972     LHS = tryExtendDUPToExtractHigh(LHS.getOperand(0), DAG);
6973     if (!LHS.getNode())
6974       return SDValue();
6975 
6976     LHS = DAG.getNode(ExtType, SDLoc(N), VT, LHS);
6977   }
6978 
6979   return DAG.getNode(N->getOpcode(), SDLoc(N), VT, LHS, RHS);
6980 }
6981 
6982 // Massage DAGs which we can use the high-half "long" operations on into
6983 // something isel will recognize better. E.g.
6984 //
6985 // (aarch64_neon_umull (extract_high vec) (dupv64 scalar)) -->
6986 //   (aarch64_neon_umull (extract_high (v2i64 vec)))
6987 //                     (extract_high (v2i64 (dup128 scalar)))))
6988 //
tryCombineLongOpWithDup(unsigned IID,SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)6989 static SDValue tryCombineLongOpWithDup(unsigned IID, SDNode *N,
6990                                        TargetLowering::DAGCombinerInfo &DCI,
6991                                        SelectionDAG &DAG) {
6992   if (DCI.isBeforeLegalizeOps())
6993     return SDValue();
6994 
6995   SDValue LHS = N->getOperand(1);
6996   SDValue RHS = N->getOperand(2);
6997   assert(LHS.getValueType().is64BitVector() &&
6998          RHS.getValueType().is64BitVector() &&
6999          "unexpected shape for long operation");
7000 
7001   // Either node could be a DUP, but it's not worth doing both of them (you'd
7002   // just as well use the non-high version) so look for a corresponding extract
7003   // operation on the other "wing".
7004   if (isEssentiallyExtractSubvector(LHS)) {
7005     RHS = tryExtendDUPToExtractHigh(RHS, DAG);
7006     if (!RHS.getNode())
7007       return SDValue();
7008   } else if (isEssentiallyExtractSubvector(RHS)) {
7009     LHS = tryExtendDUPToExtractHigh(LHS, DAG);
7010     if (!LHS.getNode())
7011       return SDValue();
7012   }
7013 
7014   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, SDLoc(N), N->getValueType(0),
7015                      N->getOperand(0), LHS, RHS);
7016 }
7017 
tryCombineShiftImm(unsigned IID,SDNode * N,SelectionDAG & DAG)7018 static SDValue tryCombineShiftImm(unsigned IID, SDNode *N, SelectionDAG &DAG) {
7019   MVT ElemTy = N->getSimpleValueType(0).getScalarType();
7020   unsigned ElemBits = ElemTy.getSizeInBits();
7021 
7022   int64_t ShiftAmount;
7023   if (BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(2))) {
7024     APInt SplatValue, SplatUndef;
7025     unsigned SplatBitSize;
7026     bool HasAnyUndefs;
7027     if (!BVN->isConstantSplat(SplatValue, SplatUndef, SplatBitSize,
7028                               HasAnyUndefs, ElemBits) ||
7029         SplatBitSize != ElemBits)
7030       return SDValue();
7031 
7032     ShiftAmount = SplatValue.getSExtValue();
7033   } else if (ConstantSDNode *CVN = dyn_cast<ConstantSDNode>(N->getOperand(2))) {
7034     ShiftAmount = CVN->getSExtValue();
7035   } else
7036     return SDValue();
7037 
7038   unsigned Opcode;
7039   bool IsRightShift;
7040   switch (IID) {
7041   default:
7042     llvm_unreachable("Unknown shift intrinsic");
7043   case Intrinsic::aarch64_neon_sqshl:
7044     Opcode = AArch64ISD::SQSHL_I;
7045     IsRightShift = false;
7046     break;
7047   case Intrinsic::aarch64_neon_uqshl:
7048     Opcode = AArch64ISD::UQSHL_I;
7049     IsRightShift = false;
7050     break;
7051   case Intrinsic::aarch64_neon_srshl:
7052     Opcode = AArch64ISD::SRSHR_I;
7053     IsRightShift = true;
7054     break;
7055   case Intrinsic::aarch64_neon_urshl:
7056     Opcode = AArch64ISD::URSHR_I;
7057     IsRightShift = true;
7058     break;
7059   case Intrinsic::aarch64_neon_sqshlu:
7060     Opcode = AArch64ISD::SQSHLU_I;
7061     IsRightShift = false;
7062     break;
7063   }
7064 
7065   if (IsRightShift && ShiftAmount <= -1 && ShiftAmount >= -(int)ElemBits)
7066     return DAG.getNode(Opcode, SDLoc(N), N->getValueType(0), N->getOperand(1),
7067                        DAG.getConstant(-ShiftAmount, MVT::i32));
7068   else if (!IsRightShift && ShiftAmount >= 0 && ShiftAmount < ElemBits)
7069     return DAG.getNode(Opcode, SDLoc(N), N->getValueType(0), N->getOperand(1),
7070                        DAG.getConstant(ShiftAmount, MVT::i32));
7071 
7072   return SDValue();
7073 }
7074 
7075 // The CRC32[BH] instructions ignore the high bits of their data operand. Since
7076 // the intrinsics must be legal and take an i32, this means there's almost
7077 // certainly going to be a zext in the DAG which we can eliminate.
tryCombineCRC32(unsigned Mask,SDNode * N,SelectionDAG & DAG)7078 static SDValue tryCombineCRC32(unsigned Mask, SDNode *N, SelectionDAG &DAG) {
7079   SDValue AndN = N->getOperand(2);
7080   if (AndN.getOpcode() != ISD::AND)
7081     return SDValue();
7082 
7083   ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(AndN.getOperand(1));
7084   if (!CMask || CMask->getZExtValue() != Mask)
7085     return SDValue();
7086 
7087   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, SDLoc(N), MVT::i32,
7088                      N->getOperand(0), N->getOperand(1), AndN.getOperand(0));
7089 }
7090 
performIntrinsicCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,const AArch64Subtarget * Subtarget)7091 static SDValue performIntrinsicCombine(SDNode *N,
7092                                        TargetLowering::DAGCombinerInfo &DCI,
7093                                        const AArch64Subtarget *Subtarget) {
7094   SelectionDAG &DAG = DCI.DAG;
7095   unsigned IID = getIntrinsicID(N);
7096   switch (IID) {
7097   default:
7098     break;
7099   case Intrinsic::aarch64_neon_vcvtfxs2fp:
7100   case Intrinsic::aarch64_neon_vcvtfxu2fp:
7101     return tryCombineFixedPointConvert(N, DCI, DAG);
7102     break;
7103   case Intrinsic::aarch64_neon_fmax:
7104     return DAG.getNode(AArch64ISD::FMAX, SDLoc(N), N->getValueType(0),
7105                        N->getOperand(1), N->getOperand(2));
7106   case Intrinsic::aarch64_neon_fmin:
7107     return DAG.getNode(AArch64ISD::FMIN, SDLoc(N), N->getValueType(0),
7108                        N->getOperand(1), N->getOperand(2));
7109   case Intrinsic::aarch64_neon_smull:
7110   case Intrinsic::aarch64_neon_umull:
7111   case Intrinsic::aarch64_neon_pmull:
7112   case Intrinsic::aarch64_neon_sqdmull:
7113     return tryCombineLongOpWithDup(IID, N, DCI, DAG);
7114   case Intrinsic::aarch64_neon_sqshl:
7115   case Intrinsic::aarch64_neon_uqshl:
7116   case Intrinsic::aarch64_neon_sqshlu:
7117   case Intrinsic::aarch64_neon_srshl:
7118   case Intrinsic::aarch64_neon_urshl:
7119     return tryCombineShiftImm(IID, N, DAG);
7120   case Intrinsic::aarch64_crc32b:
7121   case Intrinsic::aarch64_crc32cb:
7122     return tryCombineCRC32(0xff, N, DAG);
7123   case Intrinsic::aarch64_crc32h:
7124   case Intrinsic::aarch64_crc32ch:
7125     return tryCombineCRC32(0xffff, N, DAG);
7126   }
7127   return SDValue();
7128 }
7129 
performExtendCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7130 static SDValue performExtendCombine(SDNode *N,
7131                                     TargetLowering::DAGCombinerInfo &DCI,
7132                                     SelectionDAG &DAG) {
7133   // If we see something like (zext (sabd (extract_high ...), (DUP ...))) then
7134   // we can convert that DUP into another extract_high (of a bigger DUP), which
7135   // helps the backend to decide that an sabdl2 would be useful, saving a real
7136   // extract_high operation.
7137   if (!DCI.isBeforeLegalizeOps() && N->getOpcode() == ISD::ZERO_EXTEND &&
7138       N->getOperand(0).getOpcode() == ISD::INTRINSIC_WO_CHAIN) {
7139     SDNode *ABDNode = N->getOperand(0).getNode();
7140     unsigned IID = getIntrinsicID(ABDNode);
7141     if (IID == Intrinsic::aarch64_neon_sabd ||
7142         IID == Intrinsic::aarch64_neon_uabd) {
7143       SDValue NewABD = tryCombineLongOpWithDup(IID, ABDNode, DCI, DAG);
7144       if (!NewABD.getNode())
7145         return SDValue();
7146 
7147       return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), N->getValueType(0),
7148                          NewABD);
7149     }
7150   }
7151 
7152   // This is effectively a custom type legalization for AArch64.
7153   //
7154   // Type legalization will split an extend of a small, legal, type to a larger
7155   // illegal type by first splitting the destination type, often creating
7156   // illegal source types, which then get legalized in isel-confusing ways,
7157   // leading to really terrible codegen. E.g.,
7158   //   %result = v8i32 sext v8i8 %value
7159   // becomes
7160   //   %losrc = extract_subreg %value, ...
7161   //   %hisrc = extract_subreg %value, ...
7162   //   %lo = v4i32 sext v4i8 %losrc
7163   //   %hi = v4i32 sext v4i8 %hisrc
7164   // Things go rapidly downhill from there.
7165   //
7166   // For AArch64, the [sz]ext vector instructions can only go up one element
7167   // size, so we can, e.g., extend from i8 to i16, but to go from i8 to i32
7168   // take two instructions.
7169   //
7170   // This implies that the most efficient way to do the extend from v8i8
7171   // to two v4i32 values is to first extend the v8i8 to v8i16, then do
7172   // the normal splitting to happen for the v8i16->v8i32.
7173 
7174   // This is pre-legalization to catch some cases where the default
7175   // type legalization will create ill-tempered code.
7176   if (!DCI.isBeforeLegalizeOps())
7177     return SDValue();
7178 
7179   // We're only interested in cleaning things up for non-legal vector types
7180   // here. If both the source and destination are legal, things will just
7181   // work naturally without any fiddling.
7182   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
7183   EVT ResVT = N->getValueType(0);
7184   if (!ResVT.isVector() || TLI.isTypeLegal(ResVT))
7185     return SDValue();
7186   // If the vector type isn't a simple VT, it's beyond the scope of what
7187   // we're  worried about here. Let legalization do its thing and hope for
7188   // the best.
7189   if (!ResVT.isSimple())
7190     return SDValue();
7191 
7192   SDValue Src = N->getOperand(0);
7193   MVT SrcVT = Src->getValueType(0).getSimpleVT();
7194   // If the source VT is a 64-bit vector, we can play games and get the
7195   // better results we want.
7196   if (SrcVT.getSizeInBits() != 64)
7197     return SDValue();
7198 
7199   unsigned SrcEltSize = SrcVT.getVectorElementType().getSizeInBits();
7200   unsigned ElementCount = SrcVT.getVectorNumElements();
7201   SrcVT = MVT::getVectorVT(MVT::getIntegerVT(SrcEltSize * 2), ElementCount);
7202   SDLoc DL(N);
7203   Src = DAG.getNode(N->getOpcode(), DL, SrcVT, Src);
7204 
7205   // Now split the rest of the operation into two halves, each with a 64
7206   // bit source.
7207   EVT LoVT, HiVT;
7208   SDValue Lo, Hi;
7209   unsigned NumElements = ResVT.getVectorNumElements();
7210   assert(!(NumElements & 1) && "Splitting vector, but not in half!");
7211   LoVT = HiVT = EVT::getVectorVT(*DAG.getContext(),
7212                                  ResVT.getVectorElementType(), NumElements / 2);
7213 
7214   EVT InNVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getVectorElementType(),
7215                                LoVT.getVectorNumElements());
7216   Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InNVT, Src,
7217                    DAG.getIntPtrConstant(0));
7218   Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, InNVT, Src,
7219                    DAG.getIntPtrConstant(InNVT.getVectorNumElements()));
7220   Lo = DAG.getNode(N->getOpcode(), DL, LoVT, Lo);
7221   Hi = DAG.getNode(N->getOpcode(), DL, HiVT, Hi);
7222 
7223   // Now combine the parts back together so we still have a single result
7224   // like the combiner expects.
7225   return DAG.getNode(ISD::CONCAT_VECTORS, DL, ResVT, Lo, Hi);
7226 }
7227 
7228 /// Replace a splat of a scalar to a vector store by scalar stores of the scalar
7229 /// value. The load store optimizer pass will merge them to store pair stores.
7230 /// This has better performance than a splat of the scalar followed by a split
7231 /// vector store. Even if the stores are not merged it is four stores vs a dup,
7232 /// followed by an ext.b and two stores.
replaceSplatVectorStore(SelectionDAG & DAG,StoreSDNode * St)7233 static SDValue replaceSplatVectorStore(SelectionDAG &DAG, StoreSDNode *St) {
7234   SDValue StVal = St->getValue();
7235   EVT VT = StVal.getValueType();
7236 
7237   // Don't replace floating point stores, they possibly won't be transformed to
7238   // stp because of the store pair suppress pass.
7239   if (VT.isFloatingPoint())
7240     return SDValue();
7241 
7242   // Check for insert vector elements.
7243   if (StVal.getOpcode() != ISD::INSERT_VECTOR_ELT)
7244     return SDValue();
7245 
7246   // We can express a splat as store pair(s) for 2 or 4 elements.
7247   unsigned NumVecElts = VT.getVectorNumElements();
7248   if (NumVecElts != 4 && NumVecElts != 2)
7249     return SDValue();
7250   SDValue SplatVal = StVal.getOperand(1);
7251   unsigned RemainInsertElts = NumVecElts - 1;
7252 
7253   // Check that this is a splat.
7254   while (--RemainInsertElts) {
7255     SDValue NextInsertElt = StVal.getOperand(0);
7256     if (NextInsertElt.getOpcode() != ISD::INSERT_VECTOR_ELT)
7257       return SDValue();
7258     if (NextInsertElt.getOperand(1) != SplatVal)
7259       return SDValue();
7260     StVal = NextInsertElt;
7261   }
7262   unsigned OrigAlignment = St->getAlignment();
7263   unsigned EltOffset = NumVecElts == 4 ? 4 : 8;
7264   unsigned Alignment = std::min(OrigAlignment, EltOffset);
7265 
7266   // Create scalar stores. This is at least as good as the code sequence for a
7267   // split unaligned store wich is a dup.s, ext.b, and two stores.
7268   // Most of the time the three stores should be replaced by store pair
7269   // instructions (stp).
7270   SDLoc DL(St);
7271   SDValue BasePtr = St->getBasePtr();
7272   SDValue NewST1 =
7273       DAG.getStore(St->getChain(), DL, SplatVal, BasePtr, St->getPointerInfo(),
7274                    St->isVolatile(), St->isNonTemporal(), St->getAlignment());
7275 
7276   unsigned Offset = EltOffset;
7277   while (--NumVecElts) {
7278     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i64, BasePtr,
7279                                     DAG.getConstant(Offset, MVT::i64));
7280     NewST1 = DAG.getStore(NewST1.getValue(0), DL, SplatVal, OffsetPtr,
7281                           St->getPointerInfo(), St->isVolatile(),
7282                           St->isNonTemporal(), Alignment);
7283     Offset += EltOffset;
7284   }
7285   return NewST1;
7286 }
7287 
performSTORECombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG,const AArch64Subtarget * Subtarget)7288 static SDValue performSTORECombine(SDNode *N,
7289                                    TargetLowering::DAGCombinerInfo &DCI,
7290                                    SelectionDAG &DAG,
7291                                    const AArch64Subtarget *Subtarget) {
7292   if (!DCI.isBeforeLegalize())
7293     return SDValue();
7294 
7295   StoreSDNode *S = cast<StoreSDNode>(N);
7296   if (S->isVolatile())
7297     return SDValue();
7298 
7299   // Cyclone has bad performance on unaligned 16B stores when crossing line and
7300   // page boundries. We want to split such stores.
7301   if (!Subtarget->isCyclone())
7302     return SDValue();
7303 
7304   // Don't split at Oz.
7305   MachineFunction &MF = DAG.getMachineFunction();
7306   bool IsMinSize = MF.getFunction()->getAttributes().hasAttribute(
7307       AttributeSet::FunctionIndex, Attribute::MinSize);
7308   if (IsMinSize)
7309     return SDValue();
7310 
7311   SDValue StVal = S->getValue();
7312   EVT VT = StVal.getValueType();
7313 
7314   // Don't split v2i64 vectors. Memcpy lowering produces those and splitting
7315   // those up regresses performance on micro-benchmarks and olden/bh.
7316   if (!VT.isVector() || VT.getVectorNumElements() < 2 || VT == MVT::v2i64)
7317     return SDValue();
7318 
7319   // Split unaligned 16B stores. They are terrible for performance.
7320   // Don't split stores with alignment of 1 or 2. Code that uses clang vector
7321   // extensions can use this to mark that it does not want splitting to happen
7322   // (by underspecifying alignment to be 1 or 2). Furthermore, the chance of
7323   // eliminating alignment hazards is only 1 in 8 for alignment of 2.
7324   if (VT.getSizeInBits() != 128 || S->getAlignment() >= 16 ||
7325       S->getAlignment() <= 2)
7326     return SDValue();
7327 
7328   // If we get a splat of a scalar convert this vector store to a store of
7329   // scalars. They will be merged into store pairs thereby removing two
7330   // instructions.
7331   SDValue ReplacedSplat = replaceSplatVectorStore(DAG, S);
7332   if (ReplacedSplat != SDValue())
7333     return ReplacedSplat;
7334 
7335   SDLoc DL(S);
7336   unsigned NumElts = VT.getVectorNumElements() / 2;
7337   // Split VT into two.
7338   EVT HalfVT =
7339       EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(), NumElts);
7340   SDValue SubVector0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, StVal,
7341                                    DAG.getIntPtrConstant(0));
7342   SDValue SubVector1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, StVal,
7343                                    DAG.getIntPtrConstant(NumElts));
7344   SDValue BasePtr = S->getBasePtr();
7345   SDValue NewST1 =
7346       DAG.getStore(S->getChain(), DL, SubVector0, BasePtr, S->getPointerInfo(),
7347                    S->isVolatile(), S->isNonTemporal(), S->getAlignment());
7348   SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i64, BasePtr,
7349                                   DAG.getConstant(8, MVT::i64));
7350   return DAG.getStore(NewST1.getValue(0), DL, SubVector1, OffsetPtr,
7351                       S->getPointerInfo(), S->isVolatile(), S->isNonTemporal(),
7352                       S->getAlignment());
7353 }
7354 
7355 /// Target-specific DAG combine function for post-increment LD1 (lane) and
7356 /// post-increment LD1R.
performPostLD1Combine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,bool IsLaneOp)7357 static SDValue performPostLD1Combine(SDNode *N,
7358                                      TargetLowering::DAGCombinerInfo &DCI,
7359                                      bool IsLaneOp) {
7360   if (DCI.isBeforeLegalizeOps())
7361     return SDValue();
7362 
7363   SelectionDAG &DAG = DCI.DAG;
7364   EVT VT = N->getValueType(0);
7365 
7366   unsigned LoadIdx = IsLaneOp ? 1 : 0;
7367   SDNode *LD = N->getOperand(LoadIdx).getNode();
7368   // If it is not LOAD, can not do such combine.
7369   if (LD->getOpcode() != ISD::LOAD)
7370     return SDValue();
7371 
7372   LoadSDNode *LoadSDN = cast<LoadSDNode>(LD);
7373   EVT MemVT = LoadSDN->getMemoryVT();
7374   // Check if memory operand is the same type as the vector element.
7375   if (MemVT != VT.getVectorElementType())
7376     return SDValue();
7377 
7378   // Check if there are other uses. If so, do not combine as it will introduce
7379   // an extra load.
7380   for (SDNode::use_iterator UI = LD->use_begin(), UE = LD->use_end(); UI != UE;
7381        ++UI) {
7382     if (UI.getUse().getResNo() == 1) // Ignore uses of the chain result.
7383       continue;
7384     if (*UI != N)
7385       return SDValue();
7386   }
7387 
7388   SDValue Addr = LD->getOperand(1);
7389   SDValue Vector = N->getOperand(0);
7390   // Search for a use of the address operand that is an increment.
7391   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(), UE =
7392        Addr.getNode()->use_end(); UI != UE; ++UI) {
7393     SDNode *User = *UI;
7394     if (User->getOpcode() != ISD::ADD
7395         || UI.getUse().getResNo() != Addr.getResNo())
7396       continue;
7397 
7398     // Check that the add is independent of the load.  Otherwise, folding it
7399     // would create a cycle.
7400     if (User->isPredecessorOf(LD) || LD->isPredecessorOf(User))
7401       continue;
7402     // Also check that add is not used in the vector operand.  This would also
7403     // create a cycle.
7404     if (User->isPredecessorOf(Vector.getNode()))
7405       continue;
7406 
7407     // If the increment is a constant, it must match the memory ref size.
7408     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
7409     if (ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode())) {
7410       uint32_t IncVal = CInc->getZExtValue();
7411       unsigned NumBytes = VT.getScalarSizeInBits() / 8;
7412       if (IncVal != NumBytes)
7413         continue;
7414       Inc = DAG.getRegister(AArch64::XZR, MVT::i64);
7415     }
7416 
7417     SmallVector<SDValue, 8> Ops;
7418     Ops.push_back(LD->getOperand(0));  // Chain
7419     if (IsLaneOp) {
7420       Ops.push_back(Vector);           // The vector to be inserted
7421       Ops.push_back(N->getOperand(2)); // The lane to be inserted in the vector
7422     }
7423     Ops.push_back(Addr);
7424     Ops.push_back(Inc);
7425 
7426     EVT Tys[3] = { VT, MVT::i64, MVT::Other };
7427     SDVTList SDTys = DAG.getVTList(ArrayRef<EVT>(Tys, 3));
7428     unsigned NewOp = IsLaneOp ? AArch64ISD::LD1LANEpost : AArch64ISD::LD1DUPpost;
7429     SDValue UpdN = DAG.getMemIntrinsicNode(NewOp, SDLoc(N), SDTys, Ops,
7430                                            MemVT,
7431                                            LoadSDN->getMemOperand());
7432 
7433     // Update the uses.
7434     std::vector<SDValue> NewResults;
7435     NewResults.push_back(SDValue(LD, 0));             // The result of load
7436     NewResults.push_back(SDValue(UpdN.getNode(), 2)); // Chain
7437     DCI.CombineTo(LD, NewResults);
7438     DCI.CombineTo(N, SDValue(UpdN.getNode(), 0));     // Dup/Inserted Result
7439     DCI.CombineTo(User, SDValue(UpdN.getNode(), 1));  // Write back register
7440 
7441     break;
7442   }
7443   return SDValue();
7444 }
7445 
7446 /// Target-specific DAG combine function for NEON load/store intrinsics
7447 /// to merge base address updates.
performNEONPostLDSTCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7448 static SDValue performNEONPostLDSTCombine(SDNode *N,
7449                                           TargetLowering::DAGCombinerInfo &DCI,
7450                                           SelectionDAG &DAG) {
7451   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
7452     return SDValue();
7453 
7454   unsigned AddrOpIdx = N->getNumOperands() - 1;
7455   SDValue Addr = N->getOperand(AddrOpIdx);
7456 
7457   // Search for a use of the address operand that is an increment.
7458   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(),
7459        UE = Addr.getNode()->use_end(); UI != UE; ++UI) {
7460     SDNode *User = *UI;
7461     if (User->getOpcode() != ISD::ADD ||
7462         UI.getUse().getResNo() != Addr.getResNo())
7463       continue;
7464 
7465     // Check that the add is independent of the load/store.  Otherwise, folding
7466     // it would create a cycle.
7467     if (User->isPredecessorOf(N) || N->isPredecessorOf(User))
7468       continue;
7469 
7470     // Find the new opcode for the updating load/store.
7471     bool IsStore = false;
7472     bool IsLaneOp = false;
7473     bool IsDupOp = false;
7474     unsigned NewOpc = 0;
7475     unsigned NumVecs = 0;
7476     unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
7477     switch (IntNo) {
7478     default: llvm_unreachable("unexpected intrinsic for Neon base update");
7479     case Intrinsic::aarch64_neon_ld2:       NewOpc = AArch64ISD::LD2post;
7480       NumVecs = 2; break;
7481     case Intrinsic::aarch64_neon_ld3:       NewOpc = AArch64ISD::LD3post;
7482       NumVecs = 3; break;
7483     case Intrinsic::aarch64_neon_ld4:       NewOpc = AArch64ISD::LD4post;
7484       NumVecs = 4; break;
7485     case Intrinsic::aarch64_neon_st2:       NewOpc = AArch64ISD::ST2post;
7486       NumVecs = 2; IsStore = true; break;
7487     case Intrinsic::aarch64_neon_st3:       NewOpc = AArch64ISD::ST3post;
7488       NumVecs = 3; IsStore = true; break;
7489     case Intrinsic::aarch64_neon_st4:       NewOpc = AArch64ISD::ST4post;
7490       NumVecs = 4; IsStore = true; break;
7491     case Intrinsic::aarch64_neon_ld1x2:     NewOpc = AArch64ISD::LD1x2post;
7492       NumVecs = 2; break;
7493     case Intrinsic::aarch64_neon_ld1x3:     NewOpc = AArch64ISD::LD1x3post;
7494       NumVecs = 3; break;
7495     case Intrinsic::aarch64_neon_ld1x4:     NewOpc = AArch64ISD::LD1x4post;
7496       NumVecs = 4; break;
7497     case Intrinsic::aarch64_neon_st1x2:     NewOpc = AArch64ISD::ST1x2post;
7498       NumVecs = 2; IsStore = true; break;
7499     case Intrinsic::aarch64_neon_st1x3:     NewOpc = AArch64ISD::ST1x3post;
7500       NumVecs = 3; IsStore = true; break;
7501     case Intrinsic::aarch64_neon_st1x4:     NewOpc = AArch64ISD::ST1x4post;
7502       NumVecs = 4; IsStore = true; break;
7503     case Intrinsic::aarch64_neon_ld2r:      NewOpc = AArch64ISD::LD2DUPpost;
7504       NumVecs = 2; IsDupOp = true; break;
7505     case Intrinsic::aarch64_neon_ld3r:      NewOpc = AArch64ISD::LD3DUPpost;
7506       NumVecs = 3; IsDupOp = true; break;
7507     case Intrinsic::aarch64_neon_ld4r:      NewOpc = AArch64ISD::LD4DUPpost;
7508       NumVecs = 4; IsDupOp = true; break;
7509     case Intrinsic::aarch64_neon_ld2lane:   NewOpc = AArch64ISD::LD2LANEpost;
7510       NumVecs = 2; IsLaneOp = true; break;
7511     case Intrinsic::aarch64_neon_ld3lane:   NewOpc = AArch64ISD::LD3LANEpost;
7512       NumVecs = 3; IsLaneOp = true; break;
7513     case Intrinsic::aarch64_neon_ld4lane:   NewOpc = AArch64ISD::LD4LANEpost;
7514       NumVecs = 4; IsLaneOp = true; break;
7515     case Intrinsic::aarch64_neon_st2lane:   NewOpc = AArch64ISD::ST2LANEpost;
7516       NumVecs = 2; IsStore = true; IsLaneOp = true; break;
7517     case Intrinsic::aarch64_neon_st3lane:   NewOpc = AArch64ISD::ST3LANEpost;
7518       NumVecs = 3; IsStore = true; IsLaneOp = true; break;
7519     case Intrinsic::aarch64_neon_st4lane:   NewOpc = AArch64ISD::ST4LANEpost;
7520       NumVecs = 4; IsStore = true; IsLaneOp = true; break;
7521     }
7522 
7523     EVT VecTy;
7524     if (IsStore)
7525       VecTy = N->getOperand(2).getValueType();
7526     else
7527       VecTy = N->getValueType(0);
7528 
7529     // If the increment is a constant, it must match the memory ref size.
7530     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
7531     if (ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode())) {
7532       uint32_t IncVal = CInc->getZExtValue();
7533       unsigned NumBytes = NumVecs * VecTy.getSizeInBits() / 8;
7534       if (IsLaneOp || IsDupOp)
7535         NumBytes /= VecTy.getVectorNumElements();
7536       if (IncVal != NumBytes)
7537         continue;
7538       Inc = DAG.getRegister(AArch64::XZR, MVT::i64);
7539     }
7540     SmallVector<SDValue, 8> Ops;
7541     Ops.push_back(N->getOperand(0)); // Incoming chain
7542     // Load lane and store have vector list as input.
7543     if (IsLaneOp || IsStore)
7544       for (unsigned i = 2; i < AddrOpIdx; ++i)
7545         Ops.push_back(N->getOperand(i));
7546     Ops.push_back(Addr); // Base register
7547     Ops.push_back(Inc);
7548 
7549     // Return Types.
7550     EVT Tys[6];
7551     unsigned NumResultVecs = (IsStore ? 0 : NumVecs);
7552     unsigned n;
7553     for (n = 0; n < NumResultVecs; ++n)
7554       Tys[n] = VecTy;
7555     Tys[n++] = MVT::i64;  // Type of write back register
7556     Tys[n] = MVT::Other;  // Type of the chain
7557     SDVTList SDTys = DAG.getVTList(ArrayRef<EVT>(Tys, NumResultVecs + 2));
7558 
7559     MemIntrinsicSDNode *MemInt = cast<MemIntrinsicSDNode>(N);
7560     SDValue UpdN = DAG.getMemIntrinsicNode(NewOpc, SDLoc(N), SDTys, Ops,
7561                                            MemInt->getMemoryVT(),
7562                                            MemInt->getMemOperand());
7563 
7564     // Update the uses.
7565     std::vector<SDValue> NewResults;
7566     for (unsigned i = 0; i < NumResultVecs; ++i) {
7567       NewResults.push_back(SDValue(UpdN.getNode(), i));
7568     }
7569     NewResults.push_back(SDValue(UpdN.getNode(), NumResultVecs + 1));
7570     DCI.CombineTo(N, NewResults);
7571     DCI.CombineTo(User, SDValue(UpdN.getNode(), NumResultVecs));
7572 
7573     break;
7574   }
7575   return SDValue();
7576 }
7577 
7578 // Optimize compare with zero and branch.
performBRCONDCombine(SDNode * N,TargetLowering::DAGCombinerInfo & DCI,SelectionDAG & DAG)7579 static SDValue performBRCONDCombine(SDNode *N,
7580                                     TargetLowering::DAGCombinerInfo &DCI,
7581                                     SelectionDAG &DAG) {
7582   SDValue Chain = N->getOperand(0);
7583   SDValue Dest = N->getOperand(1);
7584   SDValue CCVal = N->getOperand(2);
7585   SDValue Cmp = N->getOperand(3);
7586 
7587   assert(isa<ConstantSDNode>(CCVal) && "Expected a ConstantSDNode here!");
7588   unsigned CC = cast<ConstantSDNode>(CCVal)->getZExtValue();
7589   if (CC != AArch64CC::EQ && CC != AArch64CC::NE)
7590     return SDValue();
7591 
7592   unsigned CmpOpc = Cmp.getOpcode();
7593   if (CmpOpc != AArch64ISD::ADDS && CmpOpc != AArch64ISD::SUBS)
7594     return SDValue();
7595 
7596   // Only attempt folding if there is only one use of the flag and no use of the
7597   // value.
7598   if (!Cmp->hasNUsesOfValue(0, 0) || !Cmp->hasNUsesOfValue(1, 1))
7599     return SDValue();
7600 
7601   SDValue LHS = Cmp.getOperand(0);
7602   SDValue RHS = Cmp.getOperand(1);
7603 
7604   assert(LHS.getValueType() == RHS.getValueType() &&
7605          "Expected the value type to be the same for both operands!");
7606   if (LHS.getValueType() != MVT::i32 && LHS.getValueType() != MVT::i64)
7607     return SDValue();
7608 
7609   if (isa<ConstantSDNode>(LHS) && cast<ConstantSDNode>(LHS)->isNullValue())
7610     std::swap(LHS, RHS);
7611 
7612   if (!isa<ConstantSDNode>(RHS) || !cast<ConstantSDNode>(RHS)->isNullValue())
7613     return SDValue();
7614 
7615   if (LHS.getOpcode() == ISD::SHL || LHS.getOpcode() == ISD::SRA ||
7616       LHS.getOpcode() == ISD::SRL)
7617     return SDValue();
7618 
7619   // Fold the compare into the branch instruction.
7620   SDValue BR;
7621   if (CC == AArch64CC::EQ)
7622     BR = DAG.getNode(AArch64ISD::CBZ, SDLoc(N), MVT::Other, Chain, LHS, Dest);
7623   else
7624     BR = DAG.getNode(AArch64ISD::CBNZ, SDLoc(N), MVT::Other, Chain, LHS, Dest);
7625 
7626   // Do not add new nodes to DAG combiner worklist.
7627   DCI.CombineTo(N, BR, false);
7628 
7629   return SDValue();
7630 }
7631 
7632 // vselect (v1i1 setcc) ->
7633 //     vselect (v1iXX setcc)  (XX is the size of the compared operand type)
7634 // FIXME: Currently the type legalizer can't handle VSELECT having v1i1 as
7635 // condition. If it can legalize "VSELECT v1i1" correctly, no need to combine
7636 // such VSELECT.
performVSelectCombine(SDNode * N,SelectionDAG & DAG)7637 static SDValue performVSelectCombine(SDNode *N, SelectionDAG &DAG) {
7638   SDValue N0 = N->getOperand(0);
7639   EVT CCVT = N0.getValueType();
7640 
7641   if (N0.getOpcode() != ISD::SETCC || CCVT.getVectorNumElements() != 1 ||
7642       CCVT.getVectorElementType() != MVT::i1)
7643     return SDValue();
7644 
7645   EVT ResVT = N->getValueType(0);
7646   EVT CmpVT = N0.getOperand(0).getValueType();
7647   // Only combine when the result type is of the same size as the compared
7648   // operands.
7649   if (ResVT.getSizeInBits() != CmpVT.getSizeInBits())
7650     return SDValue();
7651 
7652   SDValue IfTrue = N->getOperand(1);
7653   SDValue IfFalse = N->getOperand(2);
7654   SDValue SetCC =
7655       DAG.getSetCC(SDLoc(N), CmpVT.changeVectorElementTypeToInteger(),
7656                    N0.getOperand(0), N0.getOperand(1),
7657                    cast<CondCodeSDNode>(N0.getOperand(2))->get());
7658   return DAG.getNode(ISD::VSELECT, SDLoc(N), ResVT, SetCC,
7659                      IfTrue, IfFalse);
7660 }
7661 
7662 /// A vector select: "(select vL, vR, (setcc LHS, RHS))" is best performed with
7663 /// the compare-mask instructions rather than going via NZCV, even if LHS and
7664 /// RHS are really scalar. This replaces any scalar setcc in the above pattern
7665 /// with a vector one followed by a DUP shuffle on the result.
performSelectCombine(SDNode * N,SelectionDAG & DAG)7666 static SDValue performSelectCombine(SDNode *N, SelectionDAG &DAG) {
7667   SDValue N0 = N->getOperand(0);
7668   EVT ResVT = N->getValueType(0);
7669 
7670   if (!N->getOperand(1).getValueType().isVector())
7671     return SDValue();
7672 
7673   if (N0.getOpcode() != ISD::SETCC || N0.getValueType() != MVT::i1)
7674     return SDValue();
7675 
7676   SDLoc DL(N0);
7677 
7678   EVT SrcVT = N0.getOperand(0).getValueType();
7679   SrcVT = EVT::getVectorVT(*DAG.getContext(), SrcVT,
7680                            ResVT.getSizeInBits() / SrcVT.getSizeInBits());
7681   EVT CCVT = SrcVT.changeVectorElementTypeToInteger();
7682 
7683   // First perform a vector comparison, where lane 0 is the one we're interested
7684   // in.
7685   SDValue LHS =
7686       DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, SrcVT, N0.getOperand(0));
7687   SDValue RHS =
7688       DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, SrcVT, N0.getOperand(1));
7689   SDValue SetCC = DAG.getNode(ISD::SETCC, DL, CCVT, LHS, RHS, N0.getOperand(2));
7690 
7691   // Now duplicate the comparison mask we want across all other lanes.
7692   SmallVector<int, 8> DUPMask(CCVT.getVectorNumElements(), 0);
7693   SDValue Mask = DAG.getVectorShuffle(CCVT, DL, SetCC, SetCC, DUPMask.data());
7694   Mask = DAG.getNode(ISD::BITCAST, DL, ResVT.changeVectorElementTypeToInteger(),
7695                      Mask);
7696 
7697   return DAG.getSelect(DL, ResVT, Mask, N->getOperand(1), N->getOperand(2));
7698 }
7699 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const7700 SDValue AArch64TargetLowering::PerformDAGCombine(SDNode *N,
7701                                                  DAGCombinerInfo &DCI) const {
7702   SelectionDAG &DAG = DCI.DAG;
7703   switch (N->getOpcode()) {
7704   default:
7705     break;
7706   case ISD::ADD:
7707   case ISD::SUB:
7708     return performAddSubLongCombine(N, DCI, DAG);
7709   case ISD::XOR:
7710     return performXorCombine(N, DAG, DCI, Subtarget);
7711   case ISD::MUL:
7712     return performMulCombine(N, DAG, DCI, Subtarget);
7713   case ISD::SINT_TO_FP:
7714   case ISD::UINT_TO_FP:
7715     return performIntToFpCombine(N, DAG);
7716   case ISD::OR:
7717     return performORCombine(N, DCI, Subtarget);
7718   case ISD::INTRINSIC_WO_CHAIN:
7719     return performIntrinsicCombine(N, DCI, Subtarget);
7720   case ISD::ANY_EXTEND:
7721   case ISD::ZERO_EXTEND:
7722   case ISD::SIGN_EXTEND:
7723     return performExtendCombine(N, DCI, DAG);
7724   case ISD::BITCAST:
7725     return performBitcastCombine(N, DCI, DAG);
7726   case ISD::CONCAT_VECTORS:
7727     return performConcatVectorsCombine(N, DCI, DAG);
7728   case ISD::SELECT:
7729     return performSelectCombine(N, DAG);
7730   case ISD::VSELECT:
7731     return performVSelectCombine(N, DCI.DAG);
7732   case ISD::STORE:
7733     return performSTORECombine(N, DCI, DAG, Subtarget);
7734   case AArch64ISD::BRCOND:
7735     return performBRCONDCombine(N, DCI, DAG);
7736   case AArch64ISD::DUP:
7737     return performPostLD1Combine(N, DCI, false);
7738   case ISD::INSERT_VECTOR_ELT:
7739     return performPostLD1Combine(N, DCI, true);
7740   case ISD::INTRINSIC_VOID:
7741   case ISD::INTRINSIC_W_CHAIN:
7742     switch (cast<ConstantSDNode>(N->getOperand(1))->getZExtValue()) {
7743     case Intrinsic::aarch64_neon_ld2:
7744     case Intrinsic::aarch64_neon_ld3:
7745     case Intrinsic::aarch64_neon_ld4:
7746     case Intrinsic::aarch64_neon_ld1x2:
7747     case Intrinsic::aarch64_neon_ld1x3:
7748     case Intrinsic::aarch64_neon_ld1x4:
7749     case Intrinsic::aarch64_neon_ld2lane:
7750     case Intrinsic::aarch64_neon_ld3lane:
7751     case Intrinsic::aarch64_neon_ld4lane:
7752     case Intrinsic::aarch64_neon_ld2r:
7753     case Intrinsic::aarch64_neon_ld3r:
7754     case Intrinsic::aarch64_neon_ld4r:
7755     case Intrinsic::aarch64_neon_st2:
7756     case Intrinsic::aarch64_neon_st3:
7757     case Intrinsic::aarch64_neon_st4:
7758     case Intrinsic::aarch64_neon_st1x2:
7759     case Intrinsic::aarch64_neon_st1x3:
7760     case Intrinsic::aarch64_neon_st1x4:
7761     case Intrinsic::aarch64_neon_st2lane:
7762     case Intrinsic::aarch64_neon_st3lane:
7763     case Intrinsic::aarch64_neon_st4lane:
7764       return performNEONPostLDSTCombine(N, DCI, DAG);
7765     default:
7766       break;
7767     }
7768   }
7769   return SDValue();
7770 }
7771 
7772 // Check if the return value is used as only a return value, as otherwise
7773 // we can't perform a tail-call. In particular, we need to check for
7774 // target ISD nodes that are returns and any other "odd" constructs
7775 // that the generic analysis code won't necessarily catch.
isUsedByReturnOnly(SDNode * N,SDValue & Chain) const7776 bool AArch64TargetLowering::isUsedByReturnOnly(SDNode *N,
7777                                                SDValue &Chain) const {
7778   if (N->getNumValues() != 1)
7779     return false;
7780   if (!N->hasNUsesOfValue(1, 0))
7781     return false;
7782 
7783   SDValue TCChain = Chain;
7784   SDNode *Copy = *N->use_begin();
7785   if (Copy->getOpcode() == ISD::CopyToReg) {
7786     // If the copy has a glue operand, we conservatively assume it isn't safe to
7787     // perform a tail call.
7788     if (Copy->getOperand(Copy->getNumOperands() - 1).getValueType() ==
7789         MVT::Glue)
7790       return false;
7791     TCChain = Copy->getOperand(0);
7792   } else if (Copy->getOpcode() != ISD::FP_EXTEND)
7793     return false;
7794 
7795   bool HasRet = false;
7796   for (SDNode *Node : Copy->uses()) {
7797     if (Node->getOpcode() != AArch64ISD::RET_FLAG)
7798       return false;
7799     HasRet = true;
7800   }
7801 
7802   if (!HasRet)
7803     return false;
7804 
7805   Chain = TCChain;
7806   return true;
7807 }
7808 
7809 // Return whether the an instruction can potentially be optimized to a tail
7810 // call. This will cause the optimizers to attempt to move, or duplicate,
7811 // return instructions to help enable tail call optimizations for this
7812 // instruction.
mayBeEmittedAsTailCall(CallInst * CI) const7813 bool AArch64TargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
7814   if (!CI->isTailCall())
7815     return false;
7816 
7817   return true;
7818 }
7819 
getIndexedAddressParts(SDNode * Op,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,bool & IsInc,SelectionDAG & DAG) const7820 bool AArch64TargetLowering::getIndexedAddressParts(SDNode *Op, SDValue &Base,
7821                                                    SDValue &Offset,
7822                                                    ISD::MemIndexedMode &AM,
7823                                                    bool &IsInc,
7824                                                    SelectionDAG &DAG) const {
7825   if (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB)
7826     return false;
7827 
7828   Base = Op->getOperand(0);
7829   // All of the indexed addressing mode instructions take a signed
7830   // 9 bit immediate offset.
7831   if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Op->getOperand(1))) {
7832     int64_t RHSC = (int64_t)RHS->getZExtValue();
7833     if (RHSC >= 256 || RHSC <= -256)
7834       return false;
7835     IsInc = (Op->getOpcode() == ISD::ADD);
7836     Offset = Op->getOperand(1);
7837     return true;
7838   }
7839   return false;
7840 }
7841 
getPreIndexedAddressParts(SDNode * N,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const7842 bool AArch64TargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
7843                                                       SDValue &Offset,
7844                                                       ISD::MemIndexedMode &AM,
7845                                                       SelectionDAG &DAG) const {
7846   EVT VT;
7847   SDValue Ptr;
7848   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7849     VT = LD->getMemoryVT();
7850     Ptr = LD->getBasePtr();
7851   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7852     VT = ST->getMemoryVT();
7853     Ptr = ST->getBasePtr();
7854   } else
7855     return false;
7856 
7857   bool IsInc;
7858   if (!getIndexedAddressParts(Ptr.getNode(), Base, Offset, AM, IsInc, DAG))
7859     return false;
7860   AM = IsInc ? ISD::PRE_INC : ISD::PRE_DEC;
7861   return true;
7862 }
7863 
getPostIndexedAddressParts(SDNode * N,SDNode * Op,SDValue & Base,SDValue & Offset,ISD::MemIndexedMode & AM,SelectionDAG & DAG) const7864 bool AArch64TargetLowering::getPostIndexedAddressParts(
7865     SDNode *N, SDNode *Op, SDValue &Base, SDValue &Offset,
7866     ISD::MemIndexedMode &AM, SelectionDAG &DAG) const {
7867   EVT VT;
7868   SDValue Ptr;
7869   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
7870     VT = LD->getMemoryVT();
7871     Ptr = LD->getBasePtr();
7872   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
7873     VT = ST->getMemoryVT();
7874     Ptr = ST->getBasePtr();
7875   } else
7876     return false;
7877 
7878   bool IsInc;
7879   if (!getIndexedAddressParts(Op, Base, Offset, AM, IsInc, DAG))
7880     return false;
7881   // Post-indexing updates the base, so it's not a valid transform
7882   // if that's not the same as the load's pointer.
7883   if (Ptr != Base)
7884     return false;
7885   AM = IsInc ? ISD::POST_INC : ISD::POST_DEC;
7886   return true;
7887 }
7888 
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const7889 void AArch64TargetLowering::ReplaceNodeResults(
7890     SDNode *N, SmallVectorImpl<SDValue> &Results, SelectionDAG &DAG) const {
7891   switch (N->getOpcode()) {
7892   default:
7893     llvm_unreachable("Don't know how to custom expand this");
7894   case ISD::FP_TO_UINT:
7895   case ISD::FP_TO_SINT:
7896     assert(N->getValueType(0) == MVT::i128 && "unexpected illegal conversion");
7897     // Let normal code take care of it by not adding anything to Results.
7898     return;
7899   }
7900 }
7901 
shouldExpandAtomicInIR(Instruction * Inst) const7902 bool AArch64TargetLowering::shouldExpandAtomicInIR(Instruction *Inst) const {
7903   // Loads and stores less than 128-bits are already atomic; ones above that
7904   // are doomed anyway, so defer to the default libcall and blame the OS when
7905   // things go wrong:
7906   if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
7907     return SI->getValueOperand()->getType()->getPrimitiveSizeInBits() == 128;
7908   else if (LoadInst *LI = dyn_cast<LoadInst>(Inst))
7909     return LI->getType()->getPrimitiveSizeInBits() == 128;
7910 
7911   // For the real atomic operations, we have ldxr/stxr up to 128 bits.
7912   return Inst->getType()->getPrimitiveSizeInBits() <= 128;
7913 }
7914 
7915 TargetLoweringBase::LegalizeTypeAction
getPreferredVectorAction(EVT VT) const7916 AArch64TargetLowering::getPreferredVectorAction(EVT VT) const {
7917   MVT SVT = VT.getSimpleVT();
7918   // During type legalization, we prefer to widen v1i8, v1i16, v1i32  to v8i8,
7919   // v4i16, v2i32 instead of to promote.
7920   if (SVT == MVT::v1i8 || SVT == MVT::v1i16 || SVT == MVT::v1i32
7921       || SVT == MVT::v1f32)
7922     return TypeWidenVector;
7923 
7924   return TargetLoweringBase::getPreferredVectorAction(VT);
7925 }
7926 
emitLoadLinked(IRBuilder<> & Builder,Value * Addr,AtomicOrdering Ord) const7927 Value *AArch64TargetLowering::emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
7928                                              AtomicOrdering Ord) const {
7929   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
7930   Type *ValTy = cast<PointerType>(Addr->getType())->getElementType();
7931   bool IsAcquire =
7932       Ord == Acquire || Ord == AcquireRelease || Ord == SequentiallyConsistent;
7933 
7934   // Since i128 isn't legal and intrinsics don't get type-lowered, the ldrexd
7935   // intrinsic must return {i64, i64} and we have to recombine them into a
7936   // single i128 here.
7937   if (ValTy->getPrimitiveSizeInBits() == 128) {
7938     Intrinsic::ID Int =
7939         IsAcquire ? Intrinsic::aarch64_ldaxp : Intrinsic::aarch64_ldxp;
7940     Function *Ldxr = llvm::Intrinsic::getDeclaration(M, Int);
7941 
7942     Addr = Builder.CreateBitCast(Addr, Type::getInt8PtrTy(M->getContext()));
7943     Value *LoHi = Builder.CreateCall(Ldxr, Addr, "lohi");
7944 
7945     Value *Lo = Builder.CreateExtractValue(LoHi, 0, "lo");
7946     Value *Hi = Builder.CreateExtractValue(LoHi, 1, "hi");
7947     Lo = Builder.CreateZExt(Lo, ValTy, "lo64");
7948     Hi = Builder.CreateZExt(Hi, ValTy, "hi64");
7949     return Builder.CreateOr(
7950         Lo, Builder.CreateShl(Hi, ConstantInt::get(ValTy, 64)), "val64");
7951   }
7952 
7953   Type *Tys[] = { Addr->getType() };
7954   Intrinsic::ID Int =
7955       IsAcquire ? Intrinsic::aarch64_ldaxr : Intrinsic::aarch64_ldxr;
7956   Function *Ldxr = llvm::Intrinsic::getDeclaration(M, Int, Tys);
7957 
7958   return Builder.CreateTruncOrBitCast(
7959       Builder.CreateCall(Ldxr, Addr),
7960       cast<PointerType>(Addr->getType())->getElementType());
7961 }
7962 
emitStoreConditional(IRBuilder<> & Builder,Value * Val,Value * Addr,AtomicOrdering Ord) const7963 Value *AArch64TargetLowering::emitStoreConditional(IRBuilder<> &Builder,
7964                                                    Value *Val, Value *Addr,
7965                                                    AtomicOrdering Ord) const {
7966   Module *M = Builder.GetInsertBlock()->getParent()->getParent();
7967   bool IsRelease =
7968       Ord == Release || Ord == AcquireRelease || Ord == SequentiallyConsistent;
7969 
7970   // Since the intrinsics must have legal type, the i128 intrinsics take two
7971   // parameters: "i64, i64". We must marshal Val into the appropriate form
7972   // before the call.
7973   if (Val->getType()->getPrimitiveSizeInBits() == 128) {
7974     Intrinsic::ID Int =
7975         IsRelease ? Intrinsic::aarch64_stlxp : Intrinsic::aarch64_stxp;
7976     Function *Stxr = Intrinsic::getDeclaration(M, Int);
7977     Type *Int64Ty = Type::getInt64Ty(M->getContext());
7978 
7979     Value *Lo = Builder.CreateTrunc(Val, Int64Ty, "lo");
7980     Value *Hi = Builder.CreateTrunc(Builder.CreateLShr(Val, 64), Int64Ty, "hi");
7981     Addr = Builder.CreateBitCast(Addr, Type::getInt8PtrTy(M->getContext()));
7982     return Builder.CreateCall3(Stxr, Lo, Hi, Addr);
7983   }
7984 
7985   Intrinsic::ID Int =
7986       IsRelease ? Intrinsic::aarch64_stlxr : Intrinsic::aarch64_stxr;
7987   Type *Tys[] = { Addr->getType() };
7988   Function *Stxr = Intrinsic::getDeclaration(M, Int, Tys);
7989 
7990   return Builder.CreateCall2(
7991       Stxr, Builder.CreateZExtOrBitCast(
7992                 Val, Stxr->getFunctionType()->getParamType(0)),
7993       Addr);
7994 }
7995