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1 //===-- AMDGPUISelLowering.cpp - AMDGPU Common DAG lowering functions -----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 /// \file
10 /// This is the parent TargetLowering class for hardware code gen
11 /// targets.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "AMDGPUISelLowering.h"
16 #include "AMDGPU.h"
17 #include "AMDGPUCallLowering.h"
18 #include "AMDGPUFrameLowering.h"
19 #include "AMDGPURegisterInfo.h"
20 #include "AMDGPUSubtarget.h"
21 #include "AMDGPUTargetMachine.h"
22 #include "Utils/AMDGPUBaseInfo.h"
23 #include "R600MachineFunctionInfo.h"
24 #include "SIInstrInfo.h"
25 #include "SIMachineFunctionInfo.h"
26 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
27 #include "llvm/CodeGen/Analysis.h"
28 #include "llvm/CodeGen/CallingConvLower.h"
29 #include "llvm/CodeGen/MachineFunction.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/CodeGen/SelectionDAG.h"
32 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
33 #include "llvm/IR/DataLayout.h"
34 #include "llvm/IR/DiagnosticInfo.h"
35 #include "llvm/Support/KnownBits.h"
36 #include "llvm/Support/MathExtras.h"
37 using namespace llvm;
38 
39 #include "AMDGPUGenCallingConv.inc"
40 
41 // Find a larger type to do a load / store of a vector with.
getEquivalentMemType(LLVMContext & Ctx,EVT VT)42 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
43   unsigned StoreSize = VT.getStoreSizeInBits();
44   if (StoreSize <= 32)
45     return EVT::getIntegerVT(Ctx, StoreSize);
46 
47   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
48   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
49 }
50 
numBitsUnsigned(SDValue Op,SelectionDAG & DAG)51 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
52   EVT VT = Op.getValueType();
53   KnownBits Known = DAG.computeKnownBits(Op);
54   return VT.getSizeInBits() - Known.countMinLeadingZeros();
55 }
56 
numBitsSigned(SDValue Op,SelectionDAG & DAG)57 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
58   EVT VT = Op.getValueType();
59 
60   // In order for this to be a signed 24-bit value, bit 23, must
61   // be a sign bit.
62   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
63 }
64 
AMDGPUTargetLowering(const TargetMachine & TM,const AMDGPUSubtarget & STI)65 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
66                                            const AMDGPUSubtarget &STI)
67     : TargetLowering(TM), Subtarget(&STI) {
68   // Lower floating point store/load to integer store/load to reduce the number
69   // of patterns in tablegen.
70   setOperationAction(ISD::LOAD, MVT::f32, Promote);
71   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
72 
73   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
74   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
75 
76   setOperationAction(ISD::LOAD, MVT::v3f32, Promote);
77   AddPromotedToType(ISD::LOAD, MVT::v3f32, MVT::v3i32);
78 
79   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
80   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
81 
82   setOperationAction(ISD::LOAD, MVT::v5f32, Promote);
83   AddPromotedToType(ISD::LOAD, MVT::v5f32, MVT::v5i32);
84 
85   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
86   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
87 
88   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
89   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
90 
91   setOperationAction(ISD::LOAD, MVT::v32f32, Promote);
92   AddPromotedToType(ISD::LOAD, MVT::v32f32, MVT::v32i32);
93 
94   setOperationAction(ISD::LOAD, MVT::i64, Promote);
95   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
96 
97   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
98   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
99 
100   setOperationAction(ISD::LOAD, MVT::f64, Promote);
101   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
102 
103   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
104   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
105 
106   // There are no 64-bit extloads. These should be done as a 32-bit extload and
107   // an extension to 64-bit.
108   for (MVT VT : MVT::integer_valuetypes()) {
109     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
110     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
111     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
112   }
113 
114   for (MVT VT : MVT::integer_valuetypes()) {
115     if (VT == MVT::i64)
116       continue;
117 
118     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
119     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
120     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
121     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
122 
123     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
124     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
125     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
126     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
127 
128     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
129     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
130     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
131     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
132   }
133 
134   for (MVT VT : MVT::integer_fixedlen_vector_valuetypes()) {
135     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
136     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
137     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
138     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
139     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
140     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
141     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
142     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
143     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
144     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v3i16, Expand);
145     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v3i16, Expand);
146     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v3i16, Expand);
147     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
148     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
149     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
150   }
151 
152   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
153   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
154   setLoadExtAction(ISD::EXTLOAD, MVT::v3f32, MVT::v3f16, Expand);
155   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
156   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
157   setLoadExtAction(ISD::EXTLOAD, MVT::v16f32, MVT::v16f16, Expand);
158   setLoadExtAction(ISD::EXTLOAD, MVT::v32f32, MVT::v32f16, Expand);
159 
160   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
161   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
162   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
163   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
164 
165   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
166   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
167   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
168   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
169 
170   setOperationAction(ISD::STORE, MVT::f32, Promote);
171   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
172 
173   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
174   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
175 
176   setOperationAction(ISD::STORE, MVT::v3f32, Promote);
177   AddPromotedToType(ISD::STORE, MVT::v3f32, MVT::v3i32);
178 
179   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
180   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
181 
182   setOperationAction(ISD::STORE, MVT::v5f32, Promote);
183   AddPromotedToType(ISD::STORE, MVT::v5f32, MVT::v5i32);
184 
185   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
186   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
187 
188   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
189   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
190 
191   setOperationAction(ISD::STORE, MVT::v32f32, Promote);
192   AddPromotedToType(ISD::STORE, MVT::v32f32, MVT::v32i32);
193 
194   setOperationAction(ISD::STORE, MVT::i64, Promote);
195   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
196 
197   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
198   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
199 
200   setOperationAction(ISD::STORE, MVT::f64, Promote);
201   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
202 
203   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
204   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
205 
206   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
207   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
208   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
209   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
210 
211   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
212   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
213   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
214   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
215 
216   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
217   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
218   setTruncStoreAction(MVT::v3f32, MVT::v3f16, Expand);
219   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
220   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
221   setTruncStoreAction(MVT::v16f32, MVT::v16f16, Expand);
222   setTruncStoreAction(MVT::v32f32, MVT::v32f16, Expand);
223 
224   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
225   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
226 
227   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
228   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
229 
230   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
231   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
232 
233   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
234   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
235 
236 
237   setOperationAction(ISD::Constant, MVT::i32, Legal);
238   setOperationAction(ISD::Constant, MVT::i64, Legal);
239   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
240   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
241 
242   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
243   setOperationAction(ISD::BRIND, MVT::Other, Expand);
244 
245   // This is totally unsupported, just custom lower to produce an error.
246   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
247 
248   // Library functions.  These default to Expand, but we have instructions
249   // for them.
250   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
251   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
252   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
253   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
254   setOperationAction(ISD::FABS,   MVT::f32, Legal);
255   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
256   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
257   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
258   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
259   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
260 
261   setOperationAction(ISD::FROUND, MVT::f32, Custom);
262   setOperationAction(ISD::FROUND, MVT::f64, Custom);
263 
264   setOperationAction(ISD::FLOG, MVT::f32, Custom);
265   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
266   setOperationAction(ISD::FEXP, MVT::f32, Custom);
267 
268 
269   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
270   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
271 
272   setOperationAction(ISD::FREM, MVT::f32, Custom);
273   setOperationAction(ISD::FREM, MVT::f64, Custom);
274 
275   // Expand to fneg + fadd.
276   setOperationAction(ISD::FSUB, MVT::f64, Expand);
277 
278   setOperationAction(ISD::CONCAT_VECTORS, MVT::v3i32, Custom);
279   setOperationAction(ISD::CONCAT_VECTORS, MVT::v3f32, Custom);
280   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
281   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
282   setOperationAction(ISD::CONCAT_VECTORS, MVT::v5i32, Custom);
283   setOperationAction(ISD::CONCAT_VECTORS, MVT::v5f32, Custom);
284   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
285   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
286   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
287   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
288   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v3f32, Custom);
289   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v3i32, Custom);
290   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
291   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
292   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v5f32, Custom);
293   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v5i32, Custom);
294   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
295   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
296   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16f32, Custom);
297   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16i32, Custom);
298   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v32f32, Custom);
299   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v32i32, Custom);
300 
301   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
302   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
303   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
304 
305   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
306   for (MVT VT : ScalarIntVTs) {
307     // These should use [SU]DIVREM, so set them to expand
308     setOperationAction(ISD::SDIV, VT, Expand);
309     setOperationAction(ISD::UDIV, VT, Expand);
310     setOperationAction(ISD::SREM, VT, Expand);
311     setOperationAction(ISD::UREM, VT, Expand);
312 
313     // GPU does not have divrem function for signed or unsigned.
314     setOperationAction(ISD::SDIVREM, VT, Custom);
315     setOperationAction(ISD::UDIVREM, VT, Custom);
316 
317     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
318     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
319     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
320 
321     setOperationAction(ISD::BSWAP, VT, Expand);
322     setOperationAction(ISD::CTTZ, VT, Expand);
323     setOperationAction(ISD::CTLZ, VT, Expand);
324 
325     // AMDGPU uses ADDC/SUBC/ADDE/SUBE
326     setOperationAction(ISD::ADDC, VT, Legal);
327     setOperationAction(ISD::SUBC, VT, Legal);
328     setOperationAction(ISD::ADDE, VT, Legal);
329     setOperationAction(ISD::SUBE, VT, Legal);
330   }
331 
332   // The hardware supports 32-bit ROTR, but not ROTL.
333   setOperationAction(ISD::ROTL, MVT::i32, Expand);
334   setOperationAction(ISD::ROTL, MVT::i64, Expand);
335   setOperationAction(ISD::ROTR, MVT::i64, Expand);
336 
337   setOperationAction(ISD::MUL, MVT::i64, Expand);
338   setOperationAction(ISD::MULHU, MVT::i64, Expand);
339   setOperationAction(ISD::MULHS, MVT::i64, Expand);
340   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
341   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
342   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
343   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
344   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
345 
346   setOperationAction(ISD::SMIN, MVT::i32, Legal);
347   setOperationAction(ISD::UMIN, MVT::i32, Legal);
348   setOperationAction(ISD::SMAX, MVT::i32, Legal);
349   setOperationAction(ISD::UMAX, MVT::i32, Legal);
350 
351   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
352   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
353   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
354   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
355 
356   static const MVT::SimpleValueType VectorIntTypes[] = {
357     MVT::v2i32, MVT::v3i32, MVT::v4i32, MVT::v5i32
358   };
359 
360   for (MVT VT : VectorIntTypes) {
361     // Expand the following operations for the current type by default.
362     setOperationAction(ISD::ADD,  VT, Expand);
363     setOperationAction(ISD::AND,  VT, Expand);
364     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
365     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
366     setOperationAction(ISD::MUL,  VT, Expand);
367     setOperationAction(ISD::MULHU, VT, Expand);
368     setOperationAction(ISD::MULHS, VT, Expand);
369     setOperationAction(ISD::OR,   VT, Expand);
370     setOperationAction(ISD::SHL,  VT, Expand);
371     setOperationAction(ISD::SRA,  VT, Expand);
372     setOperationAction(ISD::SRL,  VT, Expand);
373     setOperationAction(ISD::ROTL, VT, Expand);
374     setOperationAction(ISD::ROTR, VT, Expand);
375     setOperationAction(ISD::SUB,  VT, Expand);
376     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
377     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
378     setOperationAction(ISD::SDIV, VT, Expand);
379     setOperationAction(ISD::UDIV, VT, Expand);
380     setOperationAction(ISD::SREM, VT, Expand);
381     setOperationAction(ISD::UREM, VT, Expand);
382     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
383     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
384     setOperationAction(ISD::SDIVREM, VT, Custom);
385     setOperationAction(ISD::UDIVREM, VT, Expand);
386     setOperationAction(ISD::SELECT, VT, Expand);
387     setOperationAction(ISD::VSELECT, VT, Expand);
388     setOperationAction(ISD::SELECT_CC, VT, Expand);
389     setOperationAction(ISD::XOR,  VT, Expand);
390     setOperationAction(ISD::BSWAP, VT, Expand);
391     setOperationAction(ISD::CTPOP, VT, Expand);
392     setOperationAction(ISD::CTTZ, VT, Expand);
393     setOperationAction(ISD::CTLZ, VT, Expand);
394     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
395     setOperationAction(ISD::SETCC, VT, Expand);
396   }
397 
398   static const MVT::SimpleValueType FloatVectorTypes[] = {
399      MVT::v2f32, MVT::v3f32, MVT::v4f32, MVT::v5f32
400   };
401 
402   for (MVT VT : FloatVectorTypes) {
403     setOperationAction(ISD::FABS, VT, Expand);
404     setOperationAction(ISD::FMINNUM, VT, Expand);
405     setOperationAction(ISD::FMAXNUM, VT, Expand);
406     setOperationAction(ISD::FADD, VT, Expand);
407     setOperationAction(ISD::FCEIL, VT, Expand);
408     setOperationAction(ISD::FCOS, VT, Expand);
409     setOperationAction(ISD::FDIV, VT, Expand);
410     setOperationAction(ISD::FEXP2, VT, Expand);
411     setOperationAction(ISD::FEXP, VT, Expand);
412     setOperationAction(ISD::FLOG2, VT, Expand);
413     setOperationAction(ISD::FREM, VT, Expand);
414     setOperationAction(ISD::FLOG, VT, Expand);
415     setOperationAction(ISD::FLOG10, VT, Expand);
416     setOperationAction(ISD::FPOW, VT, Expand);
417     setOperationAction(ISD::FFLOOR, VT, Expand);
418     setOperationAction(ISD::FTRUNC, VT, Expand);
419     setOperationAction(ISD::FMUL, VT, Expand);
420     setOperationAction(ISD::FMA, VT, Expand);
421     setOperationAction(ISD::FRINT, VT, Expand);
422     setOperationAction(ISD::FNEARBYINT, VT, Expand);
423     setOperationAction(ISD::FSQRT, VT, Expand);
424     setOperationAction(ISD::FSIN, VT, Expand);
425     setOperationAction(ISD::FSUB, VT, Expand);
426     setOperationAction(ISD::FNEG, VT, Expand);
427     setOperationAction(ISD::VSELECT, VT, Expand);
428     setOperationAction(ISD::SELECT_CC, VT, Expand);
429     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
430     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
431     setOperationAction(ISD::SETCC, VT, Expand);
432     setOperationAction(ISD::FCANONICALIZE, VT, Expand);
433   }
434 
435   // This causes using an unrolled select operation rather than expansion with
436   // bit operations. This is in general better, but the alternative using BFI
437   // instructions may be better if the select sources are SGPRs.
438   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
439   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
440 
441   setOperationAction(ISD::SELECT, MVT::v3f32, Promote);
442   AddPromotedToType(ISD::SELECT, MVT::v3f32, MVT::v3i32);
443 
444   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
445   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
446 
447   setOperationAction(ISD::SELECT, MVT::v5f32, Promote);
448   AddPromotedToType(ISD::SELECT, MVT::v5f32, MVT::v5i32);
449 
450   // There are no libcalls of any kind.
451   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
452     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
453 
454   setSchedulingPreference(Sched::RegPressure);
455   setJumpIsExpensive(true);
456 
457   // FIXME: This is only partially true. If we have to do vector compares, any
458   // SGPR pair can be a condition register. If we have a uniform condition, we
459   // are better off doing SALU operations, where there is only one SCC. For now,
460   // we don't have a way of knowing during instruction selection if a condition
461   // will be uniform and we always use vector compares. Assume we are using
462   // vector compares until that is fixed.
463   setHasMultipleConditionRegisters(true);
464 
465   setMinCmpXchgSizeInBits(32);
466   setSupportsUnalignedAtomics(false);
467 
468   PredictableSelectIsExpensive = false;
469 
470   // We want to find all load dependencies for long chains of stores to enable
471   // merging into very wide vectors. The problem is with vectors with > 4
472   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
473   // vectors are a legal type, even though we have to split the loads
474   // usually. When we can more precisely specify load legality per address
475   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
476   // smarter so that they can figure out what to do in 2 iterations without all
477   // N > 4 stores on the same chain.
478   GatherAllAliasesMaxDepth = 16;
479 
480   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
481   // about these during lowering.
482   MaxStoresPerMemcpy  = 0xffffffff;
483   MaxStoresPerMemmove = 0xffffffff;
484   MaxStoresPerMemset  = 0xffffffff;
485 
486   setTargetDAGCombine(ISD::BITCAST);
487   setTargetDAGCombine(ISD::SHL);
488   setTargetDAGCombine(ISD::SRA);
489   setTargetDAGCombine(ISD::SRL);
490   setTargetDAGCombine(ISD::TRUNCATE);
491   setTargetDAGCombine(ISD::MUL);
492   setTargetDAGCombine(ISD::MULHU);
493   setTargetDAGCombine(ISD::MULHS);
494   setTargetDAGCombine(ISD::SELECT);
495   setTargetDAGCombine(ISD::SELECT_CC);
496   setTargetDAGCombine(ISD::STORE);
497   setTargetDAGCombine(ISD::FADD);
498   setTargetDAGCombine(ISD::FSUB);
499   setTargetDAGCombine(ISD::FNEG);
500   setTargetDAGCombine(ISD::FABS);
501   setTargetDAGCombine(ISD::AssertZext);
502   setTargetDAGCombine(ISD::AssertSext);
503   setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
504 }
505 
506 //===----------------------------------------------------------------------===//
507 // Target Information
508 //===----------------------------------------------------------------------===//
509 
510 LLVM_READNONE
fnegFoldsIntoOp(unsigned Opc)511 static bool fnegFoldsIntoOp(unsigned Opc) {
512   switch (Opc) {
513   case ISD::FADD:
514   case ISD::FSUB:
515   case ISD::FMUL:
516   case ISD::FMA:
517   case ISD::FMAD:
518   case ISD::FMINNUM:
519   case ISD::FMAXNUM:
520   case ISD::FMINNUM_IEEE:
521   case ISD::FMAXNUM_IEEE:
522   case ISD::FSIN:
523   case ISD::FTRUNC:
524   case ISD::FRINT:
525   case ISD::FNEARBYINT:
526   case ISD::FCANONICALIZE:
527   case AMDGPUISD::RCP:
528   case AMDGPUISD::RCP_LEGACY:
529   case AMDGPUISD::RCP_IFLAG:
530   case AMDGPUISD::SIN_HW:
531   case AMDGPUISD::FMUL_LEGACY:
532   case AMDGPUISD::FMIN_LEGACY:
533   case AMDGPUISD::FMAX_LEGACY:
534   case AMDGPUISD::FMED3:
535     return true;
536   default:
537     return false;
538   }
539 }
540 
541 /// \p returns true if the operation will definitely need to use a 64-bit
542 /// encoding, and thus will use a VOP3 encoding regardless of the source
543 /// modifiers.
544 LLVM_READONLY
opMustUseVOP3Encoding(const SDNode * N,MVT VT)545 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
546   return N->getNumOperands() > 2 || VT == MVT::f64;
547 }
548 
549 // Most FP instructions support source modifiers, but this could be refined
550 // slightly.
551 LLVM_READONLY
hasSourceMods(const SDNode * N)552 static bool hasSourceMods(const SDNode *N) {
553   if (isa<MemSDNode>(N))
554     return false;
555 
556   switch (N->getOpcode()) {
557   case ISD::CopyToReg:
558   case ISD::SELECT:
559   case ISD::FDIV:
560   case ISD::FREM:
561   case ISD::INLINEASM:
562   case ISD::INLINEASM_BR:
563   case AMDGPUISD::DIV_SCALE:
564   case ISD::INTRINSIC_W_CHAIN:
565 
566   // TODO: Should really be looking at the users of the bitcast. These are
567   // problematic because bitcasts are used to legalize all stores to integer
568   // types.
569   case ISD::BITCAST:
570     return false;
571   case ISD::INTRINSIC_WO_CHAIN: {
572     switch (cast<ConstantSDNode>(N->getOperand(0))->getZExtValue()) {
573     case Intrinsic::amdgcn_interp_p1:
574     case Intrinsic::amdgcn_interp_p2:
575     case Intrinsic::amdgcn_interp_mov:
576     case Intrinsic::amdgcn_interp_p1_f16:
577     case Intrinsic::amdgcn_interp_p2_f16:
578       return false;
579     default:
580       return true;
581     }
582   }
583   default:
584     return true;
585   }
586 }
587 
allUsesHaveSourceMods(const SDNode * N,unsigned CostThreshold)588 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
589                                                  unsigned CostThreshold) {
590   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
591   // it is truly free to use a source modifier in all cases. If there are
592   // multiple users but for each one will necessitate using VOP3, there will be
593   // a code size increase. Try to avoid increasing code size unless we know it
594   // will save on the instruction count.
595   unsigned NumMayIncreaseSize = 0;
596   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
597 
598   // XXX - Should this limit number of uses to check?
599   for (const SDNode *U : N->uses()) {
600     if (!hasSourceMods(U))
601       return false;
602 
603     if (!opMustUseVOP3Encoding(U, VT)) {
604       if (++NumMayIncreaseSize > CostThreshold)
605         return false;
606     }
607   }
608 
609   return true;
610 }
611 
getVectorIdxTy(const DataLayout &) const612 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
613   return MVT::i32;
614 }
615 
isSelectSupported(SelectSupportKind SelType) const616 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
617   return true;
618 }
619 
620 // The backend supports 32 and 64 bit floating point immediates.
621 // FIXME: Why are we reporting vectors of FP immediates as legal?
isFPImmLegal(const APFloat & Imm,EVT VT,bool ForCodeSize) const622 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
623                                         bool ForCodeSize) const {
624   EVT ScalarVT = VT.getScalarType();
625   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
626          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
627 }
628 
629 // We don't want to shrink f64 / f32 constants.
ShouldShrinkFPConstant(EVT VT) const630 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
631   EVT ScalarVT = VT.getScalarType();
632   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
633 }
634 
shouldReduceLoadWidth(SDNode * N,ISD::LoadExtType ExtTy,EVT NewVT) const635 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
636                                                  ISD::LoadExtType ExtTy,
637                                                  EVT NewVT) const {
638   // TODO: This may be worth removing. Check regression tests for diffs.
639   if (!TargetLoweringBase::shouldReduceLoadWidth(N, ExtTy, NewVT))
640     return false;
641 
642   unsigned NewSize = NewVT.getStoreSizeInBits();
643 
644   // If we are reducing to a 32-bit load, this is always better.
645   if (NewSize == 32)
646     return true;
647 
648   EVT OldVT = N->getValueType(0);
649   unsigned OldSize = OldVT.getStoreSizeInBits();
650 
651   MemSDNode *MN = cast<MemSDNode>(N);
652   unsigned AS = MN->getAddressSpace();
653   // Do not shrink an aligned scalar load to sub-dword.
654   // Scalar engine cannot do sub-dword loads.
655   if (OldSize >= 32 && NewSize < 32 && MN->getAlignment() >= 4 &&
656       (AS == AMDGPUAS::CONSTANT_ADDRESS ||
657        AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT ||
658        (isa<LoadSDNode>(N) &&
659         AS == AMDGPUAS::GLOBAL_ADDRESS && MN->isInvariant())) &&
660       AMDGPUInstrInfo::isUniformMMO(MN->getMemOperand()))
661     return false;
662 
663   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
664   // extloads, so doing one requires using a buffer_load. In cases where we
665   // still couldn't use a scalar load, using the wider load shouldn't really
666   // hurt anything.
667 
668   // If the old size already had to be an extload, there's no harm in continuing
669   // to reduce the width.
670   return (OldSize < 32);
671 }
672 
isLoadBitCastBeneficial(EVT LoadTy,EVT CastTy,const SelectionDAG & DAG,const MachineMemOperand & MMO) const673 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy, EVT CastTy,
674                                                    const SelectionDAG &DAG,
675                                                    const MachineMemOperand &MMO) const {
676 
677   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
678 
679   if (LoadTy.getScalarType() == MVT::i32)
680     return false;
681 
682   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
683   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
684 
685   if ((LScalarSize >= CastScalarSize) && (CastScalarSize < 32))
686     return false;
687 
688   bool Fast = false;
689   return allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
690                                         CastTy, MMO, &Fast) &&
691          Fast;
692 }
693 
694 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
695 // profitable with the expansion for 64-bit since it's generally good to
696 // speculate things.
697 // FIXME: These should really have the size as a parameter.
isCheapToSpeculateCttz() const698 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
699   return true;
700 }
701 
isCheapToSpeculateCtlz() const702 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
703   return true;
704 }
705 
isSDNodeAlwaysUniform(const SDNode * N) const706 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
707   switch (N->getOpcode()) {
708     default:
709     return false;
710     case ISD::EntryToken:
711     case ISD::TokenFactor:
712       return true;
713     case ISD::INTRINSIC_WO_CHAIN:
714     {
715       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
716       switch (IntrID) {
717         default:
718         return false;
719         case Intrinsic::amdgcn_readfirstlane:
720         case Intrinsic::amdgcn_readlane:
721           return true;
722       }
723     }
724     break;
725     case ISD::LOAD:
726     {
727       if (cast<LoadSDNode>(N)->getMemOperand()->getAddrSpace() ==
728           AMDGPUAS::CONSTANT_ADDRESS_32BIT)
729         return true;
730       return false;
731     }
732     break;
733   }
734 }
735 
736 //===---------------------------------------------------------------------===//
737 // Target Properties
738 //===---------------------------------------------------------------------===//
739 
isFAbsFree(EVT VT) const740 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
741   assert(VT.isFloatingPoint());
742 
743   // Packed operations do not have a fabs modifier.
744   return VT == MVT::f32 || VT == MVT::f64 ||
745          (Subtarget->has16BitInsts() && VT == MVT::f16);
746 }
747 
isFNegFree(EVT VT) const748 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
749   assert(VT.isFloatingPoint());
750   return VT == MVT::f32 || VT == MVT::f64 ||
751          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
752          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
753 }
754 
storeOfVectorConstantIsCheap(EVT MemVT,unsigned NumElem,unsigned AS) const755 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
756                                                          unsigned NumElem,
757                                                          unsigned AS) const {
758   return true;
759 }
760 
aggressivelyPreferBuildVectorSources(EVT VecVT) const761 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
762   // There are few operations which truly have vector input operands. Any vector
763   // operation is going to involve operations on each component, and a
764   // build_vector will be a copy per element, so it always makes sense to use a
765   // build_vector input in place of the extracted element to avoid a copy into a
766   // super register.
767   //
768   // We should probably only do this if all users are extracts only, but this
769   // should be the common case.
770   return true;
771 }
772 
isTruncateFree(EVT Source,EVT Dest) const773 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
774   // Truncate is just accessing a subregister.
775 
776   unsigned SrcSize = Source.getSizeInBits();
777   unsigned DestSize = Dest.getSizeInBits();
778 
779   return DestSize < SrcSize && DestSize % 32 == 0 ;
780 }
781 
isTruncateFree(Type * Source,Type * Dest) const782 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
783   // Truncate is just accessing a subregister.
784 
785   unsigned SrcSize = Source->getScalarSizeInBits();
786   unsigned DestSize = Dest->getScalarSizeInBits();
787 
788   if (DestSize== 16 && Subtarget->has16BitInsts())
789     return SrcSize >= 32;
790 
791   return DestSize < SrcSize && DestSize % 32 == 0;
792 }
793 
isZExtFree(Type * Src,Type * Dest) const794 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
795   unsigned SrcSize = Src->getScalarSizeInBits();
796   unsigned DestSize = Dest->getScalarSizeInBits();
797 
798   if (SrcSize == 16 && Subtarget->has16BitInsts())
799     return DestSize >= 32;
800 
801   return SrcSize == 32 && DestSize == 64;
802 }
803 
isZExtFree(EVT Src,EVT Dest) const804 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
805   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
806   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
807   // this will enable reducing 64-bit operations the 32-bit, which is always
808   // good.
809 
810   if (Src == MVT::i16)
811     return Dest == MVT::i32 ||Dest == MVT::i64 ;
812 
813   return Src == MVT::i32 && Dest == MVT::i64;
814 }
815 
isZExtFree(SDValue Val,EVT VT2) const816 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
817   return isZExtFree(Val.getValueType(), VT2);
818 }
819 
isNarrowingProfitable(EVT SrcVT,EVT DestVT) const820 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
821   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
822   // limited number of native 64-bit operations. Shrinking an operation to fit
823   // in a single 32-bit register should always be helpful. As currently used,
824   // this is much less general than the name suggests, and is only used in
825   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
826   // not profitable, and may actually be harmful.
827   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
828 }
829 
830 //===---------------------------------------------------------------------===//
831 // TargetLowering Callbacks
832 //===---------------------------------------------------------------------===//
833 
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg)834 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
835                                                   bool IsVarArg) {
836   switch (CC) {
837   case CallingConv::AMDGPU_VS:
838   case CallingConv::AMDGPU_GS:
839   case CallingConv::AMDGPU_PS:
840   case CallingConv::AMDGPU_CS:
841   case CallingConv::AMDGPU_HS:
842   case CallingConv::AMDGPU_ES:
843   case CallingConv::AMDGPU_LS:
844     return CC_AMDGPU;
845   case CallingConv::C:
846   case CallingConv::Fast:
847   case CallingConv::Cold:
848     return CC_AMDGPU_Func;
849   case CallingConv::AMDGPU_KERNEL:
850   case CallingConv::SPIR_KERNEL:
851   default:
852     report_fatal_error("Unsupported calling convention for call");
853   }
854 }
855 
CCAssignFnForReturn(CallingConv::ID CC,bool IsVarArg)856 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
857                                                     bool IsVarArg) {
858   switch (CC) {
859   case CallingConv::AMDGPU_KERNEL:
860   case CallingConv::SPIR_KERNEL:
861     llvm_unreachable("kernels should not be handled here");
862   case CallingConv::AMDGPU_VS:
863   case CallingConv::AMDGPU_GS:
864   case CallingConv::AMDGPU_PS:
865   case CallingConv::AMDGPU_CS:
866   case CallingConv::AMDGPU_HS:
867   case CallingConv::AMDGPU_ES:
868   case CallingConv::AMDGPU_LS:
869     return RetCC_SI_Shader;
870   case CallingConv::C:
871   case CallingConv::Fast:
872   case CallingConv::Cold:
873     return RetCC_AMDGPU_Func;
874   default:
875     report_fatal_error("Unsupported calling convention.");
876   }
877 }
878 
879 /// The SelectionDAGBuilder will automatically promote function arguments
880 /// with illegal types.  However, this does not work for the AMDGPU targets
881 /// since the function arguments are stored in memory as these illegal types.
882 /// In order to handle this properly we need to get the original types sizes
883 /// from the LLVM IR Function and fixup the ISD:InputArg values before
884 /// passing them to AnalyzeFormalArguments()
885 
886 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
887 /// input values across multiple registers.  Each item in the Ins array
888 /// represents a single value that will be stored in registers.  Ins[x].VT is
889 /// the value type of the value that will be stored in the register, so
890 /// whatever SDNode we lower the argument to needs to be this type.
891 ///
892 /// In order to correctly lower the arguments we need to know the size of each
893 /// argument.  Since Ins[x].VT gives us the size of the register that will
894 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
895 /// for the orignal function argument so that we can deduce the correct memory
896 /// type to use for Ins[x].  In most cases the correct memory type will be
897 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
898 /// we have a kernel argument of type v8i8, this argument will be split into
899 /// 8 parts and each part will be represented by its own item in the Ins array.
900 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
901 /// the argument before it was split.  From this, we deduce that the memory type
902 /// for each individual part is i8.  We pass the memory type as LocVT to the
903 /// calling convention analysis function and the register type (Ins[x].VT) as
904 /// the ValVT.
analyzeFormalArgumentsCompute(CCState & State,const SmallVectorImpl<ISD::InputArg> & Ins) const905 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(
906   CCState &State,
907   const SmallVectorImpl<ISD::InputArg> &Ins) const {
908   const MachineFunction &MF = State.getMachineFunction();
909   const Function &Fn = MF.getFunction();
910   LLVMContext &Ctx = Fn.getParent()->getContext();
911   const AMDGPUSubtarget &ST = AMDGPUSubtarget::get(MF);
912   const unsigned ExplicitOffset = ST.getExplicitKernelArgOffset(Fn);
913   CallingConv::ID CC = Fn.getCallingConv();
914 
915   unsigned MaxAlign = 1;
916   uint64_t ExplicitArgOffset = 0;
917   const DataLayout &DL = Fn.getParent()->getDataLayout();
918 
919   unsigned InIndex = 0;
920 
921   for (const Argument &Arg : Fn.args()) {
922     Type *BaseArgTy = Arg.getType();
923     unsigned Align = DL.getABITypeAlignment(BaseArgTy);
924     MaxAlign = std::max(Align, MaxAlign);
925     unsigned AllocSize = DL.getTypeAllocSize(BaseArgTy);
926 
927     uint64_t ArgOffset = alignTo(ExplicitArgOffset, Align) + ExplicitOffset;
928     ExplicitArgOffset = alignTo(ExplicitArgOffset, Align) + AllocSize;
929 
930     // We're basically throwing away everything passed into us and starting over
931     // to get accurate in-memory offsets. The "PartOffset" is completely useless
932     // to us as computed in Ins.
933     //
934     // We also need to figure out what type legalization is trying to do to get
935     // the correct memory offsets.
936 
937     SmallVector<EVT, 16> ValueVTs;
938     SmallVector<uint64_t, 16> Offsets;
939     ComputeValueVTs(*this, DL, BaseArgTy, ValueVTs, &Offsets, ArgOffset);
940 
941     for (unsigned Value = 0, NumValues = ValueVTs.size();
942          Value != NumValues; ++Value) {
943       uint64_t BasePartOffset = Offsets[Value];
944 
945       EVT ArgVT = ValueVTs[Value];
946       EVT MemVT = ArgVT;
947       MVT RegisterVT = getRegisterTypeForCallingConv(Ctx, CC, ArgVT);
948       unsigned NumRegs = getNumRegistersForCallingConv(Ctx, CC, ArgVT);
949 
950       if (NumRegs == 1) {
951         // This argument is not split, so the IR type is the memory type.
952         if (ArgVT.isExtended()) {
953           // We have an extended type, like i24, so we should just use the
954           // register type.
955           MemVT = RegisterVT;
956         } else {
957           MemVT = ArgVT;
958         }
959       } else if (ArgVT.isVector() && RegisterVT.isVector() &&
960                  ArgVT.getScalarType() == RegisterVT.getScalarType()) {
961         assert(ArgVT.getVectorNumElements() > RegisterVT.getVectorNumElements());
962         // We have a vector value which has been split into a vector with
963         // the same scalar type, but fewer elements.  This should handle
964         // all the floating-point vector types.
965         MemVT = RegisterVT;
966       } else if (ArgVT.isVector() &&
967                  ArgVT.getVectorNumElements() == NumRegs) {
968         // This arg has been split so that each element is stored in a separate
969         // register.
970         MemVT = ArgVT.getScalarType();
971       } else if (ArgVT.isExtended()) {
972         // We have an extended type, like i65.
973         MemVT = RegisterVT;
974       } else {
975         unsigned MemoryBits = ArgVT.getStoreSizeInBits() / NumRegs;
976         assert(ArgVT.getStoreSizeInBits() % NumRegs == 0);
977         if (RegisterVT.isInteger()) {
978           MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
979         } else if (RegisterVT.isVector()) {
980           assert(!RegisterVT.getScalarType().isFloatingPoint());
981           unsigned NumElements = RegisterVT.getVectorNumElements();
982           assert(MemoryBits % NumElements == 0);
983           // This vector type has been split into another vector type with
984           // a different elements size.
985           EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
986                                            MemoryBits / NumElements);
987           MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
988         } else {
989           llvm_unreachable("cannot deduce memory type.");
990         }
991       }
992 
993       // Convert one element vectors to scalar.
994       if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
995         MemVT = MemVT.getScalarType();
996 
997       // Round up vec3/vec5 argument.
998       if (MemVT.isVector() && !MemVT.isPow2VectorType()) {
999         assert(MemVT.getVectorNumElements() == 3 ||
1000                MemVT.getVectorNumElements() == 5);
1001         MemVT = MemVT.getPow2VectorType(State.getContext());
1002       }
1003 
1004       unsigned PartOffset = 0;
1005       for (unsigned i = 0; i != NumRegs; ++i) {
1006         State.addLoc(CCValAssign::getCustomMem(InIndex++, RegisterVT,
1007                                                BasePartOffset + PartOffset,
1008                                                MemVT.getSimpleVT(),
1009                                                CCValAssign::Full));
1010         PartOffset += MemVT.getStoreSize();
1011       }
1012     }
1013   }
1014 }
1015 
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,const SDLoc & DL,SelectionDAG & DAG) const1016 SDValue AMDGPUTargetLowering::LowerReturn(
1017   SDValue Chain, CallingConv::ID CallConv,
1018   bool isVarArg,
1019   const SmallVectorImpl<ISD::OutputArg> &Outs,
1020   const SmallVectorImpl<SDValue> &OutVals,
1021   const SDLoc &DL, SelectionDAG &DAG) const {
1022   // FIXME: Fails for r600 tests
1023   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1024   // "wave terminate should not have return values");
1025   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1026 }
1027 
1028 //===---------------------------------------------------------------------===//
1029 // Target specific lowering
1030 //===---------------------------------------------------------------------===//
1031 
1032 /// Selects the correct CCAssignFn for a given CallingConvention value.
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg)1033 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1034                                                     bool IsVarArg) {
1035   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1036 }
1037 
CCAssignFnForReturn(CallingConv::ID CC,bool IsVarArg)1038 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1039                                                       bool IsVarArg) {
1040   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1041 }
1042 
addTokenForArgument(SDValue Chain,SelectionDAG & DAG,MachineFrameInfo & MFI,int ClobberedFI) const1043 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1044                                                   SelectionDAG &DAG,
1045                                                   MachineFrameInfo &MFI,
1046                                                   int ClobberedFI) const {
1047   SmallVector<SDValue, 8> ArgChains;
1048   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1049   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1050 
1051   // Include the original chain at the beginning of the list. When this is
1052   // used by target LowerCall hooks, this helps legalize find the
1053   // CALLSEQ_BEGIN node.
1054   ArgChains.push_back(Chain);
1055 
1056   // Add a chain value for each stack argument corresponding
1057   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1058                             UE = DAG.getEntryNode().getNode()->use_end();
1059        U != UE; ++U) {
1060     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1061       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1062         if (FI->getIndex() < 0) {
1063           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1064           int64_t InLastByte = InFirstByte;
1065           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1066 
1067           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1068               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1069             ArgChains.push_back(SDValue(L, 1));
1070         }
1071       }
1072     }
1073   }
1074 
1075   // Build a tokenfactor for all the chains.
1076   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1077 }
1078 
lowerUnhandledCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals,StringRef Reason) const1079 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1080                                                  SmallVectorImpl<SDValue> &InVals,
1081                                                  StringRef Reason) const {
1082   SDValue Callee = CLI.Callee;
1083   SelectionDAG &DAG = CLI.DAG;
1084 
1085   const Function &Fn = DAG.getMachineFunction().getFunction();
1086 
1087   StringRef FuncName("<unknown>");
1088 
1089   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1090     FuncName = G->getSymbol();
1091   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1092     FuncName = G->getGlobal()->getName();
1093 
1094   DiagnosticInfoUnsupported NoCalls(
1095     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1096   DAG.getContext()->diagnose(NoCalls);
1097 
1098   if (!CLI.IsTailCall) {
1099     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1100       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1101   }
1102 
1103   return DAG.getEntryNode();
1104 }
1105 
LowerCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const1106 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1107                                         SmallVectorImpl<SDValue> &InVals) const {
1108   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1109 }
1110 
LowerDYNAMIC_STACKALLOC(SDValue Op,SelectionDAG & DAG) const1111 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1112                                                       SelectionDAG &DAG) const {
1113   const Function &Fn = DAG.getMachineFunction().getFunction();
1114 
1115   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1116                                             SDLoc(Op).getDebugLoc());
1117   DAG.getContext()->diagnose(NoDynamicAlloca);
1118   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1119   return DAG.getMergeValues(Ops, SDLoc());
1120 }
1121 
LowerOperation(SDValue Op,SelectionDAG & DAG) const1122 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1123                                              SelectionDAG &DAG) const {
1124   switch (Op.getOpcode()) {
1125   default:
1126     Op->print(errs(), &DAG);
1127     llvm_unreachable("Custom lowering code for this"
1128                      "instruction is not implemented yet!");
1129     break;
1130   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1131   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1132   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1133   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1134   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1135   case ISD::FREM: return LowerFREM(Op, DAG);
1136   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1137   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1138   case ISD::FRINT: return LowerFRINT(Op, DAG);
1139   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1140   case ISD::FROUND: return LowerFROUND(Op, DAG);
1141   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1142   case ISD::FLOG:
1143     return LowerFLOG(Op, DAG, 1.0F / numbers::log2ef);
1144   case ISD::FLOG10:
1145     return LowerFLOG(Op, DAG, numbers::ln2f / numbers::ln10f);
1146   case ISD::FEXP:
1147     return lowerFEXP(Op, DAG);
1148   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1149   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1150   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1151   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1152   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1153   case ISD::CTTZ:
1154   case ISD::CTTZ_ZERO_UNDEF:
1155   case ISD::CTLZ:
1156   case ISD::CTLZ_ZERO_UNDEF:
1157     return LowerCTLZ_CTTZ(Op, DAG);
1158   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1159   }
1160   return Op;
1161 }
1162 
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const1163 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1164                                               SmallVectorImpl<SDValue> &Results,
1165                                               SelectionDAG &DAG) const {
1166   switch (N->getOpcode()) {
1167   case ISD::SIGN_EXTEND_INREG:
1168     // Different parts of legalization seem to interpret which type of
1169     // sign_extend_inreg is the one to check for custom lowering. The extended
1170     // from type is what really matters, but some places check for custom
1171     // lowering of the result type. This results in trying to use
1172     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1173     // nothing here and let the illegal result integer be handled normally.
1174     return;
1175   default:
1176     return;
1177   }
1178 }
1179 
hasDefinedInitializer(const GlobalValue * GV)1180 bool AMDGPUTargetLowering::hasDefinedInitializer(const GlobalValue *GV) {
1181   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1182   if (!GVar || !GVar->hasInitializer())
1183     return false;
1184 
1185   return !isa<UndefValue>(GVar->getInitializer());
1186 }
1187 
LowerGlobalAddress(AMDGPUMachineFunction * MFI,SDValue Op,SelectionDAG & DAG) const1188 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1189                                                  SDValue Op,
1190                                                  SelectionDAG &DAG) const {
1191 
1192   const DataLayout &DL = DAG.getDataLayout();
1193   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1194   const GlobalValue *GV = G->getGlobal();
1195 
1196   if (G->getAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
1197       G->getAddressSpace() == AMDGPUAS::REGION_ADDRESS) {
1198     if (!MFI->isEntryFunction()) {
1199       const Function &Fn = DAG.getMachineFunction().getFunction();
1200       DiagnosticInfoUnsupported BadLDSDecl(
1201         Fn, "local memory global used by non-kernel function", SDLoc(Op).getDebugLoc());
1202       DAG.getContext()->diagnose(BadLDSDecl);
1203     }
1204 
1205     // XXX: What does the value of G->getOffset() mean?
1206     assert(G->getOffset() == 0 &&
1207          "Do not know what to do with an non-zero offset");
1208 
1209     // TODO: We could emit code to handle the initialization somewhere.
1210     if (!hasDefinedInitializer(GV)) {
1211       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1212       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1213     }
1214   }
1215 
1216   const Function &Fn = DAG.getMachineFunction().getFunction();
1217   DiagnosticInfoUnsupported BadInit(
1218       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1219   DAG.getContext()->diagnose(BadInit);
1220   return SDValue();
1221 }
1222 
LowerCONCAT_VECTORS(SDValue Op,SelectionDAG & DAG) const1223 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1224                                                   SelectionDAG &DAG) const {
1225   SmallVector<SDValue, 8> Args;
1226 
1227   EVT VT = Op.getValueType();
1228   if (VT == MVT::v4i16 || VT == MVT::v4f16) {
1229     SDLoc SL(Op);
1230     SDValue Lo = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(0));
1231     SDValue Hi = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(1));
1232 
1233     SDValue BV = DAG.getBuildVector(MVT::v2i32, SL, { Lo, Hi });
1234     return DAG.getNode(ISD::BITCAST, SL, VT, BV);
1235   }
1236 
1237   for (const SDUse &U : Op->ops())
1238     DAG.ExtractVectorElements(U.get(), Args);
1239 
1240   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1241 }
1242 
LowerEXTRACT_SUBVECTOR(SDValue Op,SelectionDAG & DAG) const1243 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1244                                                      SelectionDAG &DAG) const {
1245 
1246   SmallVector<SDValue, 8> Args;
1247   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1248   EVT VT = Op.getValueType();
1249   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1250                             VT.getVectorNumElements());
1251 
1252   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1253 }
1254 
1255 /// Generate Min/Max node
combineFMinMaxLegacy(const SDLoc & DL,EVT VT,SDValue LHS,SDValue RHS,SDValue True,SDValue False,SDValue CC,DAGCombinerInfo & DCI) const1256 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1257                                                    SDValue LHS, SDValue RHS,
1258                                                    SDValue True, SDValue False,
1259                                                    SDValue CC,
1260                                                    DAGCombinerInfo &DCI) const {
1261   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1262     return SDValue();
1263 
1264   SelectionDAG &DAG = DCI.DAG;
1265   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1266   switch (CCOpcode) {
1267   case ISD::SETOEQ:
1268   case ISD::SETONE:
1269   case ISD::SETUNE:
1270   case ISD::SETNE:
1271   case ISD::SETUEQ:
1272   case ISD::SETEQ:
1273   case ISD::SETFALSE:
1274   case ISD::SETFALSE2:
1275   case ISD::SETTRUE:
1276   case ISD::SETTRUE2:
1277   case ISD::SETUO:
1278   case ISD::SETO:
1279     break;
1280   case ISD::SETULE:
1281   case ISD::SETULT: {
1282     if (LHS == True)
1283       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1284     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1285   }
1286   case ISD::SETOLE:
1287   case ISD::SETOLT:
1288   case ISD::SETLE:
1289   case ISD::SETLT: {
1290     // Ordered. Assume ordered for undefined.
1291 
1292     // Only do this after legalization to avoid interfering with other combines
1293     // which might occur.
1294     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1295         !DCI.isCalledByLegalizer())
1296       return SDValue();
1297 
1298     // We need to permute the operands to get the correct NaN behavior. The
1299     // selected operand is the second one based on the failing compare with NaN,
1300     // so permute it based on the compare type the hardware uses.
1301     if (LHS == True)
1302       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1303     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1304   }
1305   case ISD::SETUGE:
1306   case ISD::SETUGT: {
1307     if (LHS == True)
1308       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1309     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1310   }
1311   case ISD::SETGT:
1312   case ISD::SETGE:
1313   case ISD::SETOGE:
1314   case ISD::SETOGT: {
1315     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1316         !DCI.isCalledByLegalizer())
1317       return SDValue();
1318 
1319     if (LHS == True)
1320       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1321     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1322   }
1323   case ISD::SETCC_INVALID:
1324     llvm_unreachable("Invalid setcc condcode!");
1325   }
1326   return SDValue();
1327 }
1328 
1329 std::pair<SDValue, SDValue>
split64BitValue(SDValue Op,SelectionDAG & DAG) const1330 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1331   SDLoc SL(Op);
1332 
1333   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1334 
1335   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1336   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1337 
1338   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1339   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1340 
1341   return std::make_pair(Lo, Hi);
1342 }
1343 
getLoHalf64(SDValue Op,SelectionDAG & DAG) const1344 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1345   SDLoc SL(Op);
1346 
1347   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1348   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1349   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1350 }
1351 
getHiHalf64(SDValue Op,SelectionDAG & DAG) const1352 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1353   SDLoc SL(Op);
1354 
1355   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1356   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1357   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1358 }
1359 
1360 // Split a vector type into two parts. The first part is a power of two vector.
1361 // The second part is whatever is left over, and is a scalar if it would
1362 // otherwise be a 1-vector.
1363 std::pair<EVT, EVT>
getSplitDestVTs(const EVT & VT,SelectionDAG & DAG) const1364 AMDGPUTargetLowering::getSplitDestVTs(const EVT &VT, SelectionDAG &DAG) const {
1365   EVT LoVT, HiVT;
1366   EVT EltVT = VT.getVectorElementType();
1367   unsigned NumElts = VT.getVectorNumElements();
1368   unsigned LoNumElts = PowerOf2Ceil((NumElts + 1) / 2);
1369   LoVT = EVT::getVectorVT(*DAG.getContext(), EltVT, LoNumElts);
1370   HiVT = NumElts - LoNumElts == 1
1371              ? EltVT
1372              : EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts - LoNumElts);
1373   return std::make_pair(LoVT, HiVT);
1374 }
1375 
1376 // Split a vector value into two parts of types LoVT and HiVT. HiVT could be
1377 // scalar.
1378 std::pair<SDValue, SDValue>
splitVector(const SDValue & N,const SDLoc & DL,const EVT & LoVT,const EVT & HiVT,SelectionDAG & DAG) const1379 AMDGPUTargetLowering::splitVector(const SDValue &N, const SDLoc &DL,
1380                                   const EVT &LoVT, const EVT &HiVT,
1381                                   SelectionDAG &DAG) const {
1382   assert(LoVT.getVectorNumElements() +
1383                  (HiVT.isVector() ? HiVT.getVectorNumElements() : 1) <=
1384              N.getValueType().getVectorNumElements() &&
1385          "More vector elements requested than available!");
1386   auto IdxTy = getVectorIdxTy(DAG.getDataLayout());
1387   SDValue Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, LoVT, N,
1388                            DAG.getConstant(0, DL, IdxTy));
1389   SDValue Hi = DAG.getNode(
1390       HiVT.isVector() ? ISD::EXTRACT_SUBVECTOR : ISD::EXTRACT_VECTOR_ELT, DL,
1391       HiVT, N, DAG.getConstant(LoVT.getVectorNumElements(), DL, IdxTy));
1392   return std::make_pair(Lo, Hi);
1393 }
1394 
SplitVectorLoad(const SDValue Op,SelectionDAG & DAG) const1395 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1396                                               SelectionDAG &DAG) const {
1397   LoadSDNode *Load = cast<LoadSDNode>(Op);
1398   EVT VT = Op.getValueType();
1399   SDLoc SL(Op);
1400 
1401 
1402   // If this is a 2 element vector, we really want to scalarize and not create
1403   // weird 1 element vectors.
1404   if (VT.getVectorNumElements() == 2) {
1405     SDValue Ops[2];
1406     std::tie(Ops[0], Ops[1]) = scalarizeVectorLoad(Load, DAG);
1407     return DAG.getMergeValues(Ops, SL);
1408   }
1409 
1410   SDValue BasePtr = Load->getBasePtr();
1411   EVT MemVT = Load->getMemoryVT();
1412 
1413   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1414 
1415   EVT LoVT, HiVT;
1416   EVT LoMemVT, HiMemVT;
1417   SDValue Lo, Hi;
1418 
1419   std::tie(LoVT, HiVT) = getSplitDestVTs(VT, DAG);
1420   std::tie(LoMemVT, HiMemVT) = getSplitDestVTs(MemVT, DAG);
1421   std::tie(Lo, Hi) = splitVector(Op, SL, LoVT, HiVT, DAG);
1422 
1423   unsigned Size = LoMemVT.getStoreSize();
1424   unsigned BaseAlign = Load->getAlignment();
1425   unsigned HiAlign = MinAlign(BaseAlign, Size);
1426 
1427   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1428                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1429                                   BaseAlign, Load->getMemOperand()->getFlags());
1430   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1431   SDValue HiLoad =
1432       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1433                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1434                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1435 
1436   auto IdxTy = getVectorIdxTy(DAG.getDataLayout());
1437   SDValue Join;
1438   if (LoVT == HiVT) {
1439     // This is the case that the vector is power of two so was evenly split.
1440     Join = DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad);
1441   } else {
1442     Join = DAG.getNode(ISD::INSERT_SUBVECTOR, SL, VT, DAG.getUNDEF(VT), LoLoad,
1443                        DAG.getConstant(0, SL, IdxTy));
1444     Join = DAG.getNode(HiVT.isVector() ? ISD::INSERT_SUBVECTOR
1445                                        : ISD::INSERT_VECTOR_ELT,
1446                        SL, VT, Join, HiLoad,
1447                        DAG.getConstant(LoVT.getVectorNumElements(), SL, IdxTy));
1448   }
1449 
1450   SDValue Ops[] = {Join, DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1451                                      LoLoad.getValue(1), HiLoad.getValue(1))};
1452 
1453   return DAG.getMergeValues(Ops, SL);
1454 }
1455 
1456 // Widen a vector load from vec3 to vec4.
WidenVectorLoad(SDValue Op,SelectionDAG & DAG) const1457 SDValue AMDGPUTargetLowering::WidenVectorLoad(SDValue Op,
1458                                               SelectionDAG &DAG) const {
1459   LoadSDNode *Load = cast<LoadSDNode>(Op);
1460   EVT VT = Op.getValueType();
1461   assert(VT.getVectorNumElements() == 3);
1462   SDValue BasePtr = Load->getBasePtr();
1463   EVT MemVT = Load->getMemoryVT();
1464   SDLoc SL(Op);
1465   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1466   unsigned BaseAlign = Load->getAlignment();
1467 
1468   EVT WideVT =
1469       EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(), 4);
1470   EVT WideMemVT =
1471       EVT::getVectorVT(*DAG.getContext(), MemVT.getVectorElementType(), 4);
1472   SDValue WideLoad = DAG.getExtLoad(
1473       Load->getExtensionType(), SL, WideVT, Load->getChain(), BasePtr, SrcValue,
1474       WideMemVT, BaseAlign, Load->getMemOperand()->getFlags());
1475   return DAG.getMergeValues(
1476       {DAG.getNode(ISD::EXTRACT_SUBVECTOR, SL, VT, WideLoad,
1477                    DAG.getConstant(0, SL, getVectorIdxTy(DAG.getDataLayout()))),
1478        WideLoad.getValue(1)},
1479       SL);
1480 }
1481 
SplitVectorStore(SDValue Op,SelectionDAG & DAG) const1482 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1483                                                SelectionDAG &DAG) const {
1484   StoreSDNode *Store = cast<StoreSDNode>(Op);
1485   SDValue Val = Store->getValue();
1486   EVT VT = Val.getValueType();
1487 
1488   // If this is a 2 element vector, we really want to scalarize and not create
1489   // weird 1 element vectors.
1490   if (VT.getVectorNumElements() == 2)
1491     return scalarizeVectorStore(Store, DAG);
1492 
1493   EVT MemVT = Store->getMemoryVT();
1494   SDValue Chain = Store->getChain();
1495   SDValue BasePtr = Store->getBasePtr();
1496   SDLoc SL(Op);
1497 
1498   EVT LoVT, HiVT;
1499   EVT LoMemVT, HiMemVT;
1500   SDValue Lo, Hi;
1501 
1502   std::tie(LoVT, HiVT) = getSplitDestVTs(VT, DAG);
1503   std::tie(LoMemVT, HiMemVT) = getSplitDestVTs(MemVT, DAG);
1504   std::tie(Lo, Hi) = splitVector(Val, SL, LoVT, HiVT, DAG);
1505 
1506   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1507 
1508   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1509   unsigned BaseAlign = Store->getAlignment();
1510   unsigned Size = LoMemVT.getStoreSize();
1511   unsigned HiAlign = MinAlign(BaseAlign, Size);
1512 
1513   SDValue LoStore =
1514       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1515                         Store->getMemOperand()->getFlags());
1516   SDValue HiStore =
1517       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1518                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1519 
1520   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1521 }
1522 
1523 // This is a shortcut for integer division because we have fast i32<->f32
1524 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1525 // float is enough to accurately represent up to a 24-bit signed integer.
LowerDIVREM24(SDValue Op,SelectionDAG & DAG,bool Sign) const1526 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1527                                             bool Sign) const {
1528   SDLoc DL(Op);
1529   EVT VT = Op.getValueType();
1530   SDValue LHS = Op.getOperand(0);
1531   SDValue RHS = Op.getOperand(1);
1532   MVT IntVT = MVT::i32;
1533   MVT FltVT = MVT::f32;
1534 
1535   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1536   if (LHSSignBits < 9)
1537     return SDValue();
1538 
1539   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1540   if (RHSSignBits < 9)
1541     return SDValue();
1542 
1543   unsigned BitSize = VT.getSizeInBits();
1544   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1545   unsigned DivBits = BitSize - SignBits;
1546   if (Sign)
1547     ++DivBits;
1548 
1549   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1550   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1551 
1552   SDValue jq = DAG.getConstant(1, DL, IntVT);
1553 
1554   if (Sign) {
1555     // char|short jq = ia ^ ib;
1556     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1557 
1558     // jq = jq >> (bitsize - 2)
1559     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1560                      DAG.getConstant(BitSize - 2, DL, VT));
1561 
1562     // jq = jq | 0x1
1563     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1564   }
1565 
1566   // int ia = (int)LHS;
1567   SDValue ia = LHS;
1568 
1569   // int ib, (int)RHS;
1570   SDValue ib = RHS;
1571 
1572   // float fa = (float)ia;
1573   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1574 
1575   // float fb = (float)ib;
1576   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1577 
1578   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1579                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1580 
1581   // fq = trunc(fq);
1582   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1583 
1584   // float fqneg = -fq;
1585   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1586 
1587   MachineFunction &MF = DAG.getMachineFunction();
1588   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
1589 
1590   // float fr = mad(fqneg, fb, fa);
1591   unsigned OpCode = MFI->getMode().FP32Denormals ?
1592                     (unsigned)AMDGPUISD::FMAD_FTZ :
1593                     (unsigned)ISD::FMAD;
1594   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1595 
1596   // int iq = (int)fq;
1597   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1598 
1599   // fr = fabs(fr);
1600   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1601 
1602   // fb = fabs(fb);
1603   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1604 
1605   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1606 
1607   // int cv = fr >= fb;
1608   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1609 
1610   // jq = (cv ? jq : 0);
1611   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1612 
1613   // dst = iq + jq;
1614   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1615 
1616   // Rem needs compensation, it's easier to recompute it
1617   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1618   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1619 
1620   // Truncate to number of bits this divide really is.
1621   if (Sign) {
1622     SDValue InRegSize
1623       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1624     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1625     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1626   } else {
1627     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1628     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1629     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1630   }
1631 
1632   return DAG.getMergeValues({ Div, Rem }, DL);
1633 }
1634 
LowerUDIVREM64(SDValue Op,SelectionDAG & DAG,SmallVectorImpl<SDValue> & Results) const1635 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1636                                       SelectionDAG &DAG,
1637                                       SmallVectorImpl<SDValue> &Results) const {
1638   SDLoc DL(Op);
1639   EVT VT = Op.getValueType();
1640 
1641   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1642 
1643   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1644 
1645   SDValue One = DAG.getConstant(1, DL, HalfVT);
1646   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1647 
1648   //HiLo split
1649   SDValue LHS = Op.getOperand(0);
1650   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1651   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1652 
1653   SDValue RHS = Op.getOperand(1);
1654   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1655   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1656 
1657   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1658       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1659 
1660     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1661                               LHS_Lo, RHS_Lo);
1662 
1663     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1664     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1665 
1666     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1667     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1668     return;
1669   }
1670 
1671   if (isTypeLegal(MVT::i64)) {
1672     MachineFunction &MF = DAG.getMachineFunction();
1673     const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
1674 
1675     // Compute denominator reciprocal.
1676     unsigned FMAD = MFI->getMode().FP32Denormals ?
1677                     (unsigned)AMDGPUISD::FMAD_FTZ :
1678                     (unsigned)ISD::FMAD;
1679 
1680     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1681     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1682     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1683       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1684       Cvt_Lo);
1685     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1686     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1687       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1688     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1689       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1690     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1691     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1692       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1693       Mul1);
1694     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1695     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1696     SDValue Rcp64 = DAG.getBitcast(VT,
1697                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1698 
1699     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1700     SDValue One64  = DAG.getConstant(1, DL, VT);
1701     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1702     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1703 
1704     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1705     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1706     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1707     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1708                                     Zero);
1709     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1710                                     One);
1711 
1712     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1713                                   Mulhi1_Lo, Zero1);
1714     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1715                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1716     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1717     SDValue Add1 = DAG.getBitcast(VT,
1718                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1719 
1720     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1721     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1722     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1723                                     Zero);
1724     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1725                                     One);
1726 
1727     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1728                                   Mulhi2_Lo, Zero1);
1729     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1730                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1731     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1732                                   Zero, Add2_Lo.getValue(1));
1733     SDValue Add2 = DAG.getBitcast(VT,
1734                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1735     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1736 
1737     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1738 
1739     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1740     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1741     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1742                                   Mul3_Lo, Zero1);
1743     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1744                                   Mul3_Hi, Sub1_Lo.getValue(1));
1745     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1746     SDValue Sub1 = DAG.getBitcast(VT,
1747                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1748 
1749     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1750     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1751                                  ISD::SETUGE);
1752     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1753                                  ISD::SETUGE);
1754     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1755 
1756     // TODO: Here and below portions of the code can be enclosed into if/endif.
1757     // Currently control flow is unconditional and we have 4 selects after
1758     // potential endif to substitute PHIs.
1759 
1760     // if C3 != 0 ...
1761     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1762                                   RHS_Lo, Zero1);
1763     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1764                                   RHS_Hi, Sub1_Lo.getValue(1));
1765     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1766                                   Zero, Sub2_Lo.getValue(1));
1767     SDValue Sub2 = DAG.getBitcast(VT,
1768                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1769 
1770     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1771 
1772     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1773                                  ISD::SETUGE);
1774     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1775                                  ISD::SETUGE);
1776     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1777 
1778     // if (C6 != 0)
1779     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1780 
1781     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1782                                   RHS_Lo, Zero1);
1783     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1784                                   RHS_Hi, Sub2_Lo.getValue(1));
1785     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1786                                   Zero, Sub3_Lo.getValue(1));
1787     SDValue Sub3 = DAG.getBitcast(VT,
1788                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1789 
1790     // endif C6
1791     // endif C3
1792 
1793     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1794     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1795 
1796     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1797     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1798 
1799     Results.push_back(Div);
1800     Results.push_back(Rem);
1801 
1802     return;
1803   }
1804 
1805   // r600 expandion.
1806   // Get Speculative values
1807   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1808   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1809 
1810   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1811   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1812   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1813 
1814   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1815   SDValue DIV_Lo = Zero;
1816 
1817   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1818 
1819   for (unsigned i = 0; i < halfBitWidth; ++i) {
1820     const unsigned bitPos = halfBitWidth - i - 1;
1821     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1822     // Get value of high bit
1823     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1824     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1825     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1826 
1827     // Shift
1828     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1829     // Add LHS high bit
1830     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1831 
1832     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1833     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1834 
1835     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1836 
1837     // Update REM
1838     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1839     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1840   }
1841 
1842   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1843   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1844   Results.push_back(DIV);
1845   Results.push_back(REM);
1846 }
1847 
LowerUDIVREM(SDValue Op,SelectionDAG & DAG) const1848 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1849                                            SelectionDAG &DAG) const {
1850   SDLoc DL(Op);
1851   EVT VT = Op.getValueType();
1852 
1853   if (VT == MVT::i64) {
1854     SmallVector<SDValue, 2> Results;
1855     LowerUDIVREM64(Op, DAG, Results);
1856     return DAG.getMergeValues(Results, DL);
1857   }
1858 
1859   if (VT == MVT::i32) {
1860     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1861       return Res;
1862   }
1863 
1864   SDValue Num = Op.getOperand(0);
1865   SDValue Den = Op.getOperand(1);
1866 
1867   // RCP =  URECIP(Den) = 2^32 / Den + e
1868   // e is rounding error.
1869   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1870 
1871   // RCP_LO = mul(RCP, Den) */
1872   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1873 
1874   // RCP_HI = mulhu (RCP, Den) */
1875   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1876 
1877   // NEG_RCP_LO = -RCP_LO
1878   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1879                                                      RCP_LO);
1880 
1881   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1882   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1883                                            NEG_RCP_LO, RCP_LO,
1884                                            ISD::SETEQ);
1885   // Calculate the rounding error from the URECIP instruction
1886   // E = mulhu(ABS_RCP_LO, RCP)
1887   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1888 
1889   // RCP_A_E = RCP + E
1890   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1891 
1892   // RCP_S_E = RCP - E
1893   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1894 
1895   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1896   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1897                                      RCP_A_E, RCP_S_E,
1898                                      ISD::SETEQ);
1899   // Quotient = mulhu(Tmp0, Num)
1900   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1901 
1902   // Num_S_Remainder = Quotient * Den
1903   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1904 
1905   // Remainder = Num - Num_S_Remainder
1906   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1907 
1908   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1909   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1910                                                  DAG.getConstant(-1, DL, VT),
1911                                                  DAG.getConstant(0, DL, VT),
1912                                                  ISD::SETUGE);
1913   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1914   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1915                                                   Num_S_Remainder,
1916                                                   DAG.getConstant(-1, DL, VT),
1917                                                   DAG.getConstant(0, DL, VT),
1918                                                   ISD::SETUGE);
1919   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1920   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1921                                                Remainder_GE_Zero);
1922 
1923   // Calculate Division result:
1924 
1925   // Quotient_A_One = Quotient + 1
1926   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1927                                        DAG.getConstant(1, DL, VT));
1928 
1929   // Quotient_S_One = Quotient - 1
1930   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1931                                        DAG.getConstant(1, DL, VT));
1932 
1933   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1934   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1935                                      Quotient, Quotient_A_One, ISD::SETEQ);
1936 
1937   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1938   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1939                             Quotient_S_One, Div, ISD::SETEQ);
1940 
1941   // Calculate Rem result:
1942 
1943   // Remainder_S_Den = Remainder - Den
1944   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1945 
1946   // Remainder_A_Den = Remainder + Den
1947   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1948 
1949   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1950   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1951                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1952 
1953   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1954   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1955                             Remainder_A_Den, Rem, ISD::SETEQ);
1956   SDValue Ops[2] = {
1957     Div,
1958     Rem
1959   };
1960   return DAG.getMergeValues(Ops, DL);
1961 }
1962 
LowerSDIVREM(SDValue Op,SelectionDAG & DAG) const1963 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1964                                            SelectionDAG &DAG) const {
1965   SDLoc DL(Op);
1966   EVT VT = Op.getValueType();
1967 
1968   SDValue LHS = Op.getOperand(0);
1969   SDValue RHS = Op.getOperand(1);
1970 
1971   SDValue Zero = DAG.getConstant(0, DL, VT);
1972   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1973 
1974   if (VT == MVT::i32) {
1975     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1976       return Res;
1977   }
1978 
1979   if (VT == MVT::i64 &&
1980       DAG.ComputeNumSignBits(LHS) > 32 &&
1981       DAG.ComputeNumSignBits(RHS) > 32) {
1982     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1983 
1984     //HiLo split
1985     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1986     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1987     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1988                                  LHS_Lo, RHS_Lo);
1989     SDValue Res[2] = {
1990       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1991       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1992     };
1993     return DAG.getMergeValues(Res, DL);
1994   }
1995 
1996   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1997   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1998   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1999   SDValue RSign = LHSign; // Remainder sign is the same as LHS
2000 
2001   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
2002   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
2003 
2004   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
2005   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
2006 
2007   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
2008   SDValue Rem = Div.getValue(1);
2009 
2010   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
2011   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
2012 
2013   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
2014   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
2015 
2016   SDValue Res[2] = {
2017     Div,
2018     Rem
2019   };
2020   return DAG.getMergeValues(Res, DL);
2021 }
2022 
2023 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
LowerFREM(SDValue Op,SelectionDAG & DAG) const2024 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
2025   SDLoc SL(Op);
2026   EVT VT = Op.getValueType();
2027   SDValue X = Op.getOperand(0);
2028   SDValue Y = Op.getOperand(1);
2029 
2030   // TODO: Should this propagate fast-math-flags?
2031 
2032   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
2033   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
2034   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
2035 
2036   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
2037 }
2038 
LowerFCEIL(SDValue Op,SelectionDAG & DAG) const2039 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
2040   SDLoc SL(Op);
2041   SDValue Src = Op.getOperand(0);
2042 
2043   // result = trunc(src)
2044   // if (src > 0.0 && src != result)
2045   //   result += 1.0
2046 
2047   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2048 
2049   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2050   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
2051 
2052   EVT SetCCVT =
2053       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2054 
2055   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
2056   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2057   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2058 
2059   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
2060   // TODO: Should this propagate fast-math-flags?
2061   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2062 }
2063 
extractF64Exponent(SDValue Hi,const SDLoc & SL,SelectionDAG & DAG)2064 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
2065                                   SelectionDAG &DAG) {
2066   const unsigned FractBits = 52;
2067   const unsigned ExpBits = 11;
2068 
2069   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2070                                 Hi,
2071                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2072                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2073   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2074                             DAG.getConstant(1023, SL, MVT::i32));
2075 
2076   return Exp;
2077 }
2078 
LowerFTRUNC(SDValue Op,SelectionDAG & DAG) const2079 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2080   SDLoc SL(Op);
2081   SDValue Src = Op.getOperand(0);
2082 
2083   assert(Op.getValueType() == MVT::f64);
2084 
2085   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2086   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2087 
2088   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2089 
2090   // Extract the upper half, since this is where we will find the sign and
2091   // exponent.
2092   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2093 
2094   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2095 
2096   const unsigned FractBits = 52;
2097 
2098   // Extract the sign bit.
2099   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2100   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2101 
2102   // Extend back to 64-bits.
2103   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2104   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2105 
2106   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2107   const SDValue FractMask
2108     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2109 
2110   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2111   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2112   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2113 
2114   EVT SetCCVT =
2115       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2116 
2117   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2118 
2119   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2120   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2121 
2122   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2123   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2124 
2125   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2126 }
2127 
LowerFRINT(SDValue Op,SelectionDAG & DAG) const2128 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2129   SDLoc SL(Op);
2130   SDValue Src = Op.getOperand(0);
2131 
2132   assert(Op.getValueType() == MVT::f64);
2133 
2134   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2135   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2136   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2137 
2138   // TODO: Should this propagate fast-math-flags?
2139 
2140   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2141   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2142 
2143   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2144 
2145   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2146   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2147 
2148   EVT SetCCVT =
2149       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2150   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2151 
2152   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2153 }
2154 
LowerFNEARBYINT(SDValue Op,SelectionDAG & DAG) const2155 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2156   // FNEARBYINT and FRINT are the same, except in their handling of FP
2157   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2158   // rint, so just treat them as equivalent.
2159   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2160 }
2161 
2162 // XXX - May require not supporting f32 denormals?
2163 
2164 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2165 // compare and vselect end up producing worse code than scalarizing the whole
2166 // operation.
LowerFROUND_LegalFTRUNC(SDValue Op,SelectionDAG & DAG) const2167 SDValue AMDGPUTargetLowering::LowerFROUND_LegalFTRUNC(SDValue Op,
2168                                                       SelectionDAG &DAG) const {
2169   SDLoc SL(Op);
2170   SDValue X = Op.getOperand(0);
2171   EVT VT = Op.getValueType();
2172 
2173   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2174 
2175   // TODO: Should this propagate fast-math-flags?
2176 
2177   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2178 
2179   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2180 
2181   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2182   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2183   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2184 
2185   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2186 
2187   EVT SetCCVT =
2188       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2189 
2190   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2191 
2192   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2193 
2194   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2195 }
2196 
LowerFROUND64(SDValue Op,SelectionDAG & DAG) const2197 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2198   SDLoc SL(Op);
2199   SDValue X = Op.getOperand(0);
2200 
2201   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2202 
2203   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2204   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2205   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2206   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2207   EVT SetCCVT =
2208       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2209 
2210   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2211 
2212   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2213 
2214   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2215 
2216   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2217                                        MVT::i64);
2218 
2219   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2220   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2221                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2222                                           MVT::i64),
2223                           Exp);
2224 
2225   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2226   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2227                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2228                               ISD::SETNE);
2229 
2230   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2231                              D, DAG.getConstant(0, SL, MVT::i64));
2232   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2233 
2234   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2235   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2236 
2237   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2238   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2239   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2240 
2241   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2242                             ExpEqNegOne,
2243                             DAG.getConstantFP(1.0, SL, MVT::f64),
2244                             DAG.getConstantFP(0.0, SL, MVT::f64));
2245 
2246   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2247 
2248   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2249   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2250 
2251   return K;
2252 }
2253 
LowerFROUND(SDValue Op,SelectionDAG & DAG) const2254 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2255   EVT VT = Op.getValueType();
2256 
2257   if (isOperationLegal(ISD::FTRUNC, VT))
2258     return LowerFROUND_LegalFTRUNC(Op, DAG);
2259 
2260   if (VT == MVT::f64)
2261     return LowerFROUND64(Op, DAG);
2262 
2263   llvm_unreachable("unhandled type");
2264 }
2265 
LowerFFLOOR(SDValue Op,SelectionDAG & DAG) const2266 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2267   SDLoc SL(Op);
2268   SDValue Src = Op.getOperand(0);
2269 
2270   // result = trunc(src);
2271   // if (src < 0.0 && src != result)
2272   //   result += -1.0.
2273 
2274   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2275 
2276   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2277   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2278 
2279   EVT SetCCVT =
2280       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2281 
2282   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2283   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2284   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2285 
2286   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2287   // TODO: Should this propagate fast-math-flags?
2288   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2289 }
2290 
LowerFLOG(SDValue Op,SelectionDAG & DAG,double Log2BaseInverted) const2291 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2292                                         double Log2BaseInverted) const {
2293   EVT VT = Op.getValueType();
2294 
2295   SDLoc SL(Op);
2296   SDValue Operand = Op.getOperand(0);
2297   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2298   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2299 
2300   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2301 }
2302 
2303 // exp2(M_LOG2E_F * f);
lowerFEXP(SDValue Op,SelectionDAG & DAG) const2304 SDValue AMDGPUTargetLowering::lowerFEXP(SDValue Op, SelectionDAG &DAG) const {
2305   EVT VT = Op.getValueType();
2306   SDLoc SL(Op);
2307   SDValue Src = Op.getOperand(0);
2308 
2309   const SDValue K = DAG.getConstantFP(numbers::log2e, SL, VT);
2310   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Src, K, Op->getFlags());
2311   return DAG.getNode(ISD::FEXP2, SL, VT, Mul, Op->getFlags());
2312 }
2313 
isCtlzOpc(unsigned Opc)2314 static bool isCtlzOpc(unsigned Opc) {
2315   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2316 }
2317 
isCttzOpc(unsigned Opc)2318 static bool isCttzOpc(unsigned Opc) {
2319   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2320 }
2321 
LowerCTLZ_CTTZ(SDValue Op,SelectionDAG & DAG) const2322 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2323   SDLoc SL(Op);
2324   SDValue Src = Op.getOperand(0);
2325   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2326                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2327 
2328   unsigned ISDOpc, NewOpc;
2329   if (isCtlzOpc(Op.getOpcode())) {
2330     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2331     NewOpc = AMDGPUISD::FFBH_U32;
2332   } else if (isCttzOpc(Op.getOpcode())) {
2333     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2334     NewOpc = AMDGPUISD::FFBL_B32;
2335   } else
2336     llvm_unreachable("Unexpected OPCode!!!");
2337 
2338 
2339   if (ZeroUndef && Src.getValueType() == MVT::i32)
2340     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2341 
2342   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2343 
2344   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2345   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2346 
2347   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2348   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2349 
2350   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2351                                    *DAG.getContext(), MVT::i32);
2352 
2353   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2354   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2355 
2356   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2357   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2358 
2359   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2360   SDValue Add, NewOpr;
2361   if (isCtlzOpc(Op.getOpcode())) {
2362     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2363     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2364     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2365   } else {
2366     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2367     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2368     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2369   }
2370 
2371   if (!ZeroUndef) {
2372     // Test if the full 64-bit input is zero.
2373 
2374     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2375     // which we probably don't want.
2376     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2377     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2378     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2379 
2380     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2381     // with the same cycles, otherwise it is slower.
2382     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2383     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2384 
2385     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2386 
2387     // The instruction returns -1 for 0 input, but the defined intrinsic
2388     // behavior is to return the number of bits.
2389     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2390                          SrcIsZero, Bits32, NewOpr);
2391   }
2392 
2393   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2394 }
2395 
LowerINT_TO_FP32(SDValue Op,SelectionDAG & DAG,bool Signed) const2396 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2397                                                bool Signed) const {
2398   // Unsigned
2399   // cul2f(ulong u)
2400   //{
2401   //  uint lz = clz(u);
2402   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2403   //  u = (u << lz) & 0x7fffffffffffffffUL;
2404   //  ulong t = u & 0xffffffffffUL;
2405   //  uint v = (e << 23) | (uint)(u >> 40);
2406   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2407   //  return as_float(v + r);
2408   //}
2409   // Signed
2410   // cl2f(long l)
2411   //{
2412   //  long s = l >> 63;
2413   //  float r = cul2f((l + s) ^ s);
2414   //  return s ? -r : r;
2415   //}
2416 
2417   SDLoc SL(Op);
2418   SDValue Src = Op.getOperand(0);
2419   SDValue L = Src;
2420 
2421   SDValue S;
2422   if (Signed) {
2423     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2424     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2425 
2426     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2427     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2428   }
2429 
2430   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2431                                    *DAG.getContext(), MVT::f32);
2432 
2433 
2434   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2435   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2436   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2437   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2438 
2439   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2440   SDValue E = DAG.getSelect(SL, MVT::i32,
2441     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2442     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2443     ZeroI32);
2444 
2445   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2446     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2447     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2448 
2449   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2450                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2451 
2452   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2453                              U, DAG.getConstant(40, SL, MVT::i64));
2454 
2455   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2456     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2457     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2458 
2459   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2460   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2461   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2462 
2463   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2464 
2465   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2466 
2467   SDValue R = DAG.getSelect(SL, MVT::i32,
2468     RCmp,
2469     One,
2470     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2471   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2472   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2473 
2474   if (!Signed)
2475     return R;
2476 
2477   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2478   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2479 }
2480 
LowerINT_TO_FP64(SDValue Op,SelectionDAG & DAG,bool Signed) const2481 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2482                                                bool Signed) const {
2483   SDLoc SL(Op);
2484   SDValue Src = Op.getOperand(0);
2485 
2486   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2487 
2488   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2489                            DAG.getConstant(0, SL, MVT::i32));
2490   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2491                            DAG.getConstant(1, SL, MVT::i32));
2492 
2493   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2494                               SL, MVT::f64, Hi);
2495 
2496   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2497 
2498   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2499                               DAG.getConstant(32, SL, MVT::i32));
2500   // TODO: Should this propagate fast-math-flags?
2501   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2502 }
2503 
LowerUINT_TO_FP(SDValue Op,SelectionDAG & DAG) const2504 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2505                                                SelectionDAG &DAG) const {
2506   // TODO: Factor out code common with LowerSINT_TO_FP.
2507   EVT DestVT = Op.getValueType();
2508   SDValue Src = Op.getOperand(0);
2509   EVT SrcVT = Src.getValueType();
2510 
2511   if (SrcVT == MVT::i16) {
2512     if (DestVT == MVT::f16)
2513       return Op;
2514     SDLoc DL(Op);
2515 
2516     // Promote src to i32
2517     SDValue Ext = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Src);
2518     return DAG.getNode(ISD::UINT_TO_FP, DL, DestVT, Ext);
2519   }
2520 
2521   assert(SrcVT == MVT::i64 && "operation should be legal");
2522 
2523   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2524     SDLoc DL(Op);
2525 
2526     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2527     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2528     SDValue FPRound =
2529         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2530 
2531     return FPRound;
2532   }
2533 
2534   if (DestVT == MVT::f32)
2535     return LowerINT_TO_FP32(Op, DAG, false);
2536 
2537   assert(DestVT == MVT::f64);
2538   return LowerINT_TO_FP64(Op, DAG, false);
2539 }
2540 
LowerSINT_TO_FP(SDValue Op,SelectionDAG & DAG) const2541 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2542                                               SelectionDAG &DAG) const {
2543   EVT DestVT = Op.getValueType();
2544 
2545   SDValue Src = Op.getOperand(0);
2546   EVT SrcVT = Src.getValueType();
2547 
2548   if (SrcVT == MVT::i16) {
2549     if (DestVT == MVT::f16)
2550       return Op;
2551 
2552     SDLoc DL(Op);
2553     // Promote src to i32
2554     SDValue Ext = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i32, Src);
2555     return DAG.getNode(ISD::SINT_TO_FP, DL, DestVT, Ext);
2556   }
2557 
2558   assert(SrcVT == MVT::i64 && "operation should be legal");
2559 
2560   // TODO: Factor out code common with LowerUINT_TO_FP.
2561 
2562   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2563     SDLoc DL(Op);
2564     SDValue Src = Op.getOperand(0);
2565 
2566     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2567     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2568     SDValue FPRound =
2569         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2570 
2571     return FPRound;
2572   }
2573 
2574   if (DestVT == MVT::f32)
2575     return LowerINT_TO_FP32(Op, DAG, true);
2576 
2577   assert(DestVT == MVT::f64);
2578   return LowerINT_TO_FP64(Op, DAG, true);
2579 }
2580 
LowerFP64_TO_INT(SDValue Op,SelectionDAG & DAG,bool Signed) const2581 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2582                                                bool Signed) const {
2583   SDLoc SL(Op);
2584 
2585   SDValue Src = Op.getOperand(0);
2586 
2587   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2588 
2589   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2590                                  MVT::f64);
2591   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2592                                  MVT::f64);
2593   // TODO: Should this propagate fast-math-flags?
2594   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2595 
2596   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2597 
2598 
2599   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2600 
2601   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2602                            MVT::i32, FloorMul);
2603   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2604 
2605   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2606 
2607   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2608 }
2609 
LowerFP_TO_FP16(SDValue Op,SelectionDAG & DAG) const2610 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2611   SDLoc DL(Op);
2612   SDValue N0 = Op.getOperand(0);
2613 
2614   // Convert to target node to get known bits
2615   if (N0.getValueType() == MVT::f32)
2616     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2617 
2618   if (getTargetMachine().Options.UnsafeFPMath) {
2619     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2620     return SDValue();
2621   }
2622 
2623   assert(N0.getSimpleValueType() == MVT::f64);
2624 
2625   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2626   const unsigned ExpMask = 0x7ff;
2627   const unsigned ExpBiasf64 = 1023;
2628   const unsigned ExpBiasf16 = 15;
2629   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2630   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2631   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2632   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2633                            DAG.getConstant(32, DL, MVT::i64));
2634   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2635   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2636   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2637                           DAG.getConstant(20, DL, MVT::i64));
2638   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2639                   DAG.getConstant(ExpMask, DL, MVT::i32));
2640   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2641   // add the f16 bias (15) to get the biased exponent for the f16 format.
2642   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2643                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2644 
2645   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2646                           DAG.getConstant(8, DL, MVT::i32));
2647   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2648                   DAG.getConstant(0xffe, DL, MVT::i32));
2649 
2650   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2651                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2652   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2653 
2654   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2655   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2656 
2657   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2658   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2659       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2660                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2661 
2662   // N = M | (E << 12);
2663   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2664       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2665                   DAG.getConstant(12, DL, MVT::i32)));
2666 
2667   // B = clamp(1-E, 0, 13);
2668   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2669                                   One, E);
2670   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2671   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2672                   DAG.getConstant(13, DL, MVT::i32));
2673 
2674   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2675                                    DAG.getConstant(0x1000, DL, MVT::i32));
2676 
2677   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2678   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2679   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2680   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2681 
2682   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2683   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2684                               DAG.getConstant(0x7, DL, MVT::i32));
2685   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2686                   DAG.getConstant(2, DL, MVT::i32));
2687   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2688                                One, Zero, ISD::SETEQ);
2689   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2690                                One, Zero, ISD::SETGT);
2691   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2692   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2693 
2694   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2695                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2696   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2697                       I, V, ISD::SETEQ);
2698 
2699   // Extract the sign bit.
2700   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2701                             DAG.getConstant(16, DL, MVT::i32));
2702   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2703                      DAG.getConstant(0x8000, DL, MVT::i32));
2704 
2705   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2706   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2707 }
2708 
LowerFP_TO_SINT(SDValue Op,SelectionDAG & DAG) const2709 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2710                                               SelectionDAG &DAG) const {
2711   SDValue Src = Op.getOperand(0);
2712 
2713   // TODO: Factor out code common with LowerFP_TO_UINT.
2714 
2715   EVT SrcVT = Src.getValueType();
2716   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2717     SDLoc DL(Op);
2718 
2719     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2720     SDValue FpToInt32 =
2721         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2722 
2723     return FpToInt32;
2724   }
2725 
2726   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2727     return LowerFP64_TO_INT(Op, DAG, true);
2728 
2729   return SDValue();
2730 }
2731 
LowerFP_TO_UINT(SDValue Op,SelectionDAG & DAG) const2732 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2733                                               SelectionDAG &DAG) const {
2734   SDValue Src = Op.getOperand(0);
2735 
2736   // TODO: Factor out code common with LowerFP_TO_SINT.
2737 
2738   EVT SrcVT = Src.getValueType();
2739   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2740     SDLoc DL(Op);
2741 
2742     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2743     SDValue FpToInt32 =
2744         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2745 
2746     return FpToInt32;
2747   }
2748 
2749   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2750     return LowerFP64_TO_INT(Op, DAG, false);
2751 
2752   return SDValue();
2753 }
2754 
LowerSIGN_EXTEND_INREG(SDValue Op,SelectionDAG & DAG) const2755 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2756                                                      SelectionDAG &DAG) const {
2757   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2758   MVT VT = Op.getSimpleValueType();
2759   MVT ScalarVT = VT.getScalarType();
2760 
2761   assert(VT.isVector());
2762 
2763   SDValue Src = Op.getOperand(0);
2764   SDLoc DL(Op);
2765 
2766   // TODO: Don't scalarize on Evergreen?
2767   unsigned NElts = VT.getVectorNumElements();
2768   SmallVector<SDValue, 8> Args;
2769   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2770 
2771   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2772   for (unsigned I = 0; I < NElts; ++I)
2773     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2774 
2775   return DAG.getBuildVector(VT, DL, Args);
2776 }
2777 
2778 //===----------------------------------------------------------------------===//
2779 // Custom DAG optimizations
2780 //===----------------------------------------------------------------------===//
2781 
isU24(SDValue Op,SelectionDAG & DAG)2782 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2783   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2784 }
2785 
isI24(SDValue Op,SelectionDAG & DAG)2786 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2787   EVT VT = Op.getValueType();
2788   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2789                                      // as unsigned 24-bit values.
2790     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2791 }
2792 
simplifyI24(SDNode * Node24,TargetLowering::DAGCombinerInfo & DCI)2793 static SDValue simplifyI24(SDNode *Node24,
2794                            TargetLowering::DAGCombinerInfo &DCI) {
2795   SelectionDAG &DAG = DCI.DAG;
2796   bool IsIntrin = Node24->getOpcode() == ISD::INTRINSIC_WO_CHAIN;
2797 
2798   SDValue LHS = IsIntrin ? Node24->getOperand(1) : Node24->getOperand(0);
2799   SDValue RHS = IsIntrin ? Node24->getOperand(2) : Node24->getOperand(1);
2800   unsigned NewOpcode = Node24->getOpcode();
2801   if (IsIntrin) {
2802     unsigned IID = cast<ConstantSDNode>(Node24->getOperand(0))->getZExtValue();
2803     NewOpcode = IID == Intrinsic::amdgcn_mul_i24 ?
2804       AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
2805   }
2806 
2807   APInt Demanded = APInt::getLowBitsSet(LHS.getValueSizeInBits(), 24);
2808 
2809   // First try to simplify using GetDemandedBits which allows the operands to
2810   // have other uses, but will only perform simplifications that involve
2811   // bypassing some nodes for this user.
2812   SDValue DemandedLHS = DAG.GetDemandedBits(LHS, Demanded);
2813   SDValue DemandedRHS = DAG.GetDemandedBits(RHS, Demanded);
2814   if (DemandedLHS || DemandedRHS)
2815     return DAG.getNode(NewOpcode, SDLoc(Node24), Node24->getVTList(),
2816                        DemandedLHS ? DemandedLHS : LHS,
2817                        DemandedRHS ? DemandedRHS : RHS);
2818 
2819   // Now try SimplifyDemandedBits which can simplify the nodes used by our
2820   // operands if this node is the only user.
2821   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2822   if (TLI.SimplifyDemandedBits(LHS, Demanded, DCI))
2823     return SDValue(Node24, 0);
2824   if (TLI.SimplifyDemandedBits(RHS, Demanded, DCI))
2825     return SDValue(Node24, 0);
2826 
2827   return SDValue();
2828 }
2829 
2830 template <typename IntTy>
constantFoldBFE(SelectionDAG & DAG,IntTy Src0,uint32_t Offset,uint32_t Width,const SDLoc & DL)2831 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2832                                uint32_t Width, const SDLoc &DL) {
2833   if (Width + Offset < 32) {
2834     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2835     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2836     return DAG.getConstant(Result, DL, MVT::i32);
2837   }
2838 
2839   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2840 }
2841 
hasVolatileUser(SDNode * Val)2842 static bool hasVolatileUser(SDNode *Val) {
2843   for (SDNode *U : Val->uses()) {
2844     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2845       if (M->isVolatile())
2846         return true;
2847     }
2848   }
2849 
2850   return false;
2851 }
2852 
shouldCombineMemoryType(EVT VT) const2853 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2854   // i32 vectors are the canonical memory type.
2855   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2856     return false;
2857 
2858   if (!VT.isByteSized())
2859     return false;
2860 
2861   unsigned Size = VT.getStoreSize();
2862 
2863   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2864     return false;
2865 
2866   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2867     return false;
2868 
2869   return true;
2870 }
2871 
2872 // Replace load of an illegal type with a store of a bitcast to a friendlier
2873 // type.
performLoadCombine(SDNode * N,DAGCombinerInfo & DCI) const2874 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2875                                                  DAGCombinerInfo &DCI) const {
2876   if (!DCI.isBeforeLegalize())
2877     return SDValue();
2878 
2879   LoadSDNode *LN = cast<LoadSDNode>(N);
2880   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2881     return SDValue();
2882 
2883   SDLoc SL(N);
2884   SelectionDAG &DAG = DCI.DAG;
2885   EVT VT = LN->getMemoryVT();
2886 
2887   unsigned Size = VT.getStoreSize();
2888   unsigned Align = LN->getAlignment();
2889   if (Align < Size && isTypeLegal(VT)) {
2890     bool IsFast;
2891     unsigned AS = LN->getAddressSpace();
2892 
2893     // Expand unaligned loads earlier than legalization. Due to visitation order
2894     // problems during legalization, the emitted instructions to pack and unpack
2895     // the bytes again are not eliminated in the case of an unaligned copy.
2896     if (!allowsMisalignedMemoryAccesses(
2897             VT, AS, Align, LN->getMemOperand()->getFlags(), &IsFast)) {
2898       SDValue Ops[2];
2899 
2900       if (VT.isVector())
2901         std::tie(Ops[0], Ops[1]) = scalarizeVectorLoad(LN, DAG);
2902       else
2903         std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2904 
2905       return DAG.getMergeValues(Ops, SDLoc(N));
2906     }
2907 
2908     if (!IsFast)
2909       return SDValue();
2910   }
2911 
2912   if (!shouldCombineMemoryType(VT))
2913     return SDValue();
2914 
2915   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2916 
2917   SDValue NewLoad
2918     = DAG.getLoad(NewVT, SL, LN->getChain(),
2919                   LN->getBasePtr(), LN->getMemOperand());
2920 
2921   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2922   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2923   return SDValue(N, 0);
2924 }
2925 
2926 // Replace store of an illegal type with a store of a bitcast to a friendlier
2927 // type.
performStoreCombine(SDNode * N,DAGCombinerInfo & DCI) const2928 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2929                                                   DAGCombinerInfo &DCI) const {
2930   if (!DCI.isBeforeLegalize())
2931     return SDValue();
2932 
2933   StoreSDNode *SN = cast<StoreSDNode>(N);
2934   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2935     return SDValue();
2936 
2937   EVT VT = SN->getMemoryVT();
2938   unsigned Size = VT.getStoreSize();
2939 
2940   SDLoc SL(N);
2941   SelectionDAG &DAG = DCI.DAG;
2942   unsigned Align = SN->getAlignment();
2943   if (Align < Size && isTypeLegal(VT)) {
2944     bool IsFast;
2945     unsigned AS = SN->getAddressSpace();
2946 
2947     // Expand unaligned stores earlier than legalization. Due to visitation
2948     // order problems during legalization, the emitted instructions to pack and
2949     // unpack the bytes again are not eliminated in the case of an unaligned
2950     // copy.
2951     if (!allowsMisalignedMemoryAccesses(
2952             VT, AS, Align, SN->getMemOperand()->getFlags(), &IsFast)) {
2953       if (VT.isVector())
2954         return scalarizeVectorStore(SN, DAG);
2955 
2956       return expandUnalignedStore(SN, DAG);
2957     }
2958 
2959     if (!IsFast)
2960       return SDValue();
2961   }
2962 
2963   if (!shouldCombineMemoryType(VT))
2964     return SDValue();
2965 
2966   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2967   SDValue Val = SN->getValue();
2968 
2969   //DCI.AddToWorklist(Val.getNode());
2970 
2971   bool OtherUses = !Val.hasOneUse();
2972   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2973   if (OtherUses) {
2974     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2975     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2976   }
2977 
2978   return DAG.getStore(SN->getChain(), SL, CastVal,
2979                       SN->getBasePtr(), SN->getMemOperand());
2980 }
2981 
2982 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2983 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2984 // issues.
performAssertSZExtCombine(SDNode * N,DAGCombinerInfo & DCI) const2985 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2986                                                         DAGCombinerInfo &DCI) const {
2987   SelectionDAG &DAG = DCI.DAG;
2988   SDValue N0 = N->getOperand(0);
2989 
2990   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2991   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2992   if (N0.getOpcode() == ISD::TRUNCATE) {
2993     SDValue N1 = N->getOperand(1);
2994     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2995     SDLoc SL(N);
2996 
2997     SDValue Src = N0.getOperand(0);
2998     EVT SrcVT = Src.getValueType();
2999     if (SrcVT.bitsGE(ExtVT)) {
3000       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
3001       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
3002     }
3003   }
3004 
3005   return SDValue();
3006 }
3007 
performIntrinsicWOChainCombine(SDNode * N,DAGCombinerInfo & DCI) const3008 SDValue AMDGPUTargetLowering::performIntrinsicWOChainCombine(
3009   SDNode *N, DAGCombinerInfo &DCI) const {
3010   unsigned IID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
3011   switch (IID) {
3012   case Intrinsic::amdgcn_mul_i24:
3013   case Intrinsic::amdgcn_mul_u24:
3014     return simplifyI24(N, DCI);
3015   default:
3016     return SDValue();
3017   }
3018 }
3019 
3020 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
3021 /// binary operation \p Opc to it with the corresponding constant operands.
splitBinaryBitConstantOpImpl(DAGCombinerInfo & DCI,const SDLoc & SL,unsigned Opc,SDValue LHS,uint32_t ValLo,uint32_t ValHi) const3022 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
3023   DAGCombinerInfo &DCI, const SDLoc &SL,
3024   unsigned Opc, SDValue LHS,
3025   uint32_t ValLo, uint32_t ValHi) const {
3026   SelectionDAG &DAG = DCI.DAG;
3027   SDValue Lo, Hi;
3028   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
3029 
3030   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
3031   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
3032 
3033   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
3034   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
3035 
3036   // Re-visit the ands. It's possible we eliminated one of them and it could
3037   // simplify the vector.
3038   DCI.AddToWorklist(Lo.getNode());
3039   DCI.AddToWorklist(Hi.getNode());
3040 
3041   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
3042   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3043 }
3044 
performShlCombine(SDNode * N,DAGCombinerInfo & DCI) const3045 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
3046                                                 DAGCombinerInfo &DCI) const {
3047   EVT VT = N->getValueType(0);
3048 
3049   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3050   if (!RHS)
3051     return SDValue();
3052 
3053   SDValue LHS = N->getOperand(0);
3054   unsigned RHSVal = RHS->getZExtValue();
3055   if (!RHSVal)
3056     return LHS;
3057 
3058   SDLoc SL(N);
3059   SelectionDAG &DAG = DCI.DAG;
3060 
3061   switch (LHS->getOpcode()) {
3062   default:
3063     break;
3064   case ISD::ZERO_EXTEND:
3065   case ISD::SIGN_EXTEND:
3066   case ISD::ANY_EXTEND: {
3067     SDValue X = LHS->getOperand(0);
3068 
3069     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
3070         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
3071       // Prefer build_vector as the canonical form if packed types are legal.
3072       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
3073       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
3074        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
3075       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
3076     }
3077 
3078     // shl (ext x) => zext (shl x), if shift does not overflow int
3079     if (VT != MVT::i64)
3080       break;
3081     KnownBits Known = DAG.computeKnownBits(X);
3082     unsigned LZ = Known.countMinLeadingZeros();
3083     if (LZ < RHSVal)
3084       break;
3085     EVT XVT = X.getValueType();
3086     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
3087     return DAG.getZExtOrTrunc(Shl, SL, VT);
3088   }
3089   }
3090 
3091   if (VT != MVT::i64)
3092     return SDValue();
3093 
3094   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
3095 
3096   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
3097   // common case, splitting this into a move and a 32-bit shift is faster and
3098   // the same code size.
3099   if (RHSVal < 32)
3100     return SDValue();
3101 
3102   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
3103 
3104   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
3105   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
3106 
3107   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3108 
3109   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
3110   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3111 }
3112 
performSraCombine(SDNode * N,DAGCombinerInfo & DCI) const3113 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
3114                                                 DAGCombinerInfo &DCI) const {
3115   if (N->getValueType(0) != MVT::i64)
3116     return SDValue();
3117 
3118   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3119   if (!RHS)
3120     return SDValue();
3121 
3122   SelectionDAG &DAG = DCI.DAG;
3123   SDLoc SL(N);
3124   unsigned RHSVal = RHS->getZExtValue();
3125 
3126   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3127   if (RHSVal == 32) {
3128     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3129     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3130                                    DAG.getConstant(31, SL, MVT::i32));
3131 
3132     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3133     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3134   }
3135 
3136   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3137   if (RHSVal == 63) {
3138     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3139     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3140                                    DAG.getConstant(31, SL, MVT::i32));
3141     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3142     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3143   }
3144 
3145   return SDValue();
3146 }
3147 
performSrlCombine(SDNode * N,DAGCombinerInfo & DCI) const3148 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3149                                                 DAGCombinerInfo &DCI) const {
3150   auto *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3151   if (!RHS)
3152     return SDValue();
3153 
3154   EVT VT = N->getValueType(0);
3155   SDValue LHS = N->getOperand(0);
3156   unsigned ShiftAmt = RHS->getZExtValue();
3157   SelectionDAG &DAG = DCI.DAG;
3158   SDLoc SL(N);
3159 
3160   // fold (srl (and x, c1 << c2), c2) -> (and (srl(x, c2), c1)
3161   // this improves the ability to match BFE patterns in isel.
3162   if (LHS.getOpcode() == ISD::AND) {
3163     if (auto *Mask = dyn_cast<ConstantSDNode>(LHS.getOperand(1))) {
3164       if (Mask->getAPIntValue().isShiftedMask() &&
3165           Mask->getAPIntValue().countTrailingZeros() == ShiftAmt) {
3166         return DAG.getNode(
3167             ISD::AND, SL, VT,
3168             DAG.getNode(ISD::SRL, SL, VT, LHS.getOperand(0), N->getOperand(1)),
3169             DAG.getNode(ISD::SRL, SL, VT, LHS.getOperand(1), N->getOperand(1)));
3170       }
3171     }
3172   }
3173 
3174   if (VT != MVT::i64)
3175     return SDValue();
3176 
3177   if (ShiftAmt < 32)
3178     return SDValue();
3179 
3180   // srl i64:x, C for C >= 32
3181   // =>
3182   //   build_pair (srl hi_32(x), C - 32), 0
3183   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3184   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3185 
3186   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, LHS);
3187   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecOp, One);
3188 
3189   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3190   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3191 
3192   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3193 
3194   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3195 }
3196 
performTruncateCombine(SDNode * N,DAGCombinerInfo & DCI) const3197 SDValue AMDGPUTargetLowering::performTruncateCombine(
3198   SDNode *N, DAGCombinerInfo &DCI) const {
3199   SDLoc SL(N);
3200   SelectionDAG &DAG = DCI.DAG;
3201   EVT VT = N->getValueType(0);
3202   SDValue Src = N->getOperand(0);
3203 
3204   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3205   if (Src.getOpcode() == ISD::BITCAST && !VT.isVector()) {
3206     SDValue Vec = Src.getOperand(0);
3207     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3208       SDValue Elt0 = Vec.getOperand(0);
3209       EVT EltVT = Elt0.getValueType();
3210       if (VT.getSizeInBits() <= EltVT.getSizeInBits()) {
3211         if (EltVT.isFloatingPoint()) {
3212           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3213                              EltVT.changeTypeToInteger(), Elt0);
3214         }
3215 
3216         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3217       }
3218     }
3219   }
3220 
3221   // Equivalent of above for accessing the high element of a vector as an
3222   // integer operation.
3223   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3224   if (Src.getOpcode() == ISD::SRL && !VT.isVector()) {
3225     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3226       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3227         SDValue BV = stripBitcast(Src.getOperand(0));
3228         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3229             BV.getValueType().getVectorNumElements() == 2) {
3230           SDValue SrcElt = BV.getOperand(1);
3231           EVT SrcEltVT = SrcElt.getValueType();
3232           if (SrcEltVT.isFloatingPoint()) {
3233             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3234                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3235           }
3236 
3237           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3238         }
3239       }
3240     }
3241   }
3242 
3243   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3244   //
3245   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3246   //     i16 (trunc (srl (i32 (trunc x), K)))
3247   if (VT.getScalarSizeInBits() < 32) {
3248     EVT SrcVT = Src.getValueType();
3249     if (SrcVT.getScalarSizeInBits() > 32 &&
3250         (Src.getOpcode() == ISD::SRL ||
3251          Src.getOpcode() == ISD::SRA ||
3252          Src.getOpcode() == ISD::SHL)) {
3253       SDValue Amt = Src.getOperand(1);
3254       KnownBits Known = DAG.computeKnownBits(Amt);
3255       unsigned Size = VT.getScalarSizeInBits();
3256       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3257           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3258         EVT MidVT = VT.isVector() ?
3259           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3260                            VT.getVectorNumElements()) : MVT::i32;
3261 
3262         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3263         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3264                                     Src.getOperand(0));
3265         DCI.AddToWorklist(Trunc.getNode());
3266 
3267         if (Amt.getValueType() != NewShiftVT) {
3268           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3269           DCI.AddToWorklist(Amt.getNode());
3270         }
3271 
3272         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3273                                           Trunc, Amt);
3274         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3275       }
3276     }
3277   }
3278 
3279   return SDValue();
3280 }
3281 
3282 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3283 // instructions. If we only match on the legalized i64 mul expansion,
3284 // SimplifyDemandedBits will be unable to remove them because there will be
3285 // multiple uses due to the separate mul + mulh[su].
getMul24(SelectionDAG & DAG,const SDLoc & SL,SDValue N0,SDValue N1,unsigned Size,bool Signed)3286 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3287                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3288   if (Size <= 32) {
3289     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3290     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3291   }
3292 
3293   // Because we want to eliminate extension instructions before the
3294   // operation, we need to create a single user here (i.e. not the separate
3295   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3296 
3297   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3298 
3299   SDValue Mul = DAG.getNode(MulOpc, SL,
3300                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3301 
3302   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3303                      Mul.getValue(0), Mul.getValue(1));
3304 }
3305 
performMulCombine(SDNode * N,DAGCombinerInfo & DCI) const3306 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3307                                                 DAGCombinerInfo &DCI) const {
3308   EVT VT = N->getValueType(0);
3309 
3310   unsigned Size = VT.getSizeInBits();
3311   if (VT.isVector() || Size > 64)
3312     return SDValue();
3313 
3314   // There are i16 integer mul/mad.
3315   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3316     return SDValue();
3317 
3318   SelectionDAG &DAG = DCI.DAG;
3319   SDLoc DL(N);
3320 
3321   SDValue N0 = N->getOperand(0);
3322   SDValue N1 = N->getOperand(1);
3323 
3324   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3325   // in the source into any_extends if the result of the mul is truncated. Since
3326   // we can assume the high bits are whatever we want, use the underlying value
3327   // to avoid the unknown high bits from interfering.
3328   if (N0.getOpcode() == ISD::ANY_EXTEND)
3329     N0 = N0.getOperand(0);
3330 
3331   if (N1.getOpcode() == ISD::ANY_EXTEND)
3332     N1 = N1.getOperand(0);
3333 
3334   SDValue Mul;
3335 
3336   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3337     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3338     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3339     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3340   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3341     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3342     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3343     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3344   } else {
3345     return SDValue();
3346   }
3347 
3348   // We need to use sext even for MUL_U24, because MUL_U24 is used
3349   // for signed multiply of 8 and 16-bit types.
3350   return DAG.getSExtOrTrunc(Mul, DL, VT);
3351 }
3352 
performMulhsCombine(SDNode * N,DAGCombinerInfo & DCI) const3353 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3354                                                   DAGCombinerInfo &DCI) const {
3355   EVT VT = N->getValueType(0);
3356 
3357   if (!Subtarget->hasMulI24() || VT.isVector())
3358     return SDValue();
3359 
3360   SelectionDAG &DAG = DCI.DAG;
3361   SDLoc DL(N);
3362 
3363   SDValue N0 = N->getOperand(0);
3364   SDValue N1 = N->getOperand(1);
3365 
3366   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3367     return SDValue();
3368 
3369   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3370   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3371 
3372   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3373   DCI.AddToWorklist(Mulhi.getNode());
3374   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3375 }
3376 
performMulhuCombine(SDNode * N,DAGCombinerInfo & DCI) const3377 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3378                                                   DAGCombinerInfo &DCI) const {
3379   EVT VT = N->getValueType(0);
3380 
3381   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3382     return SDValue();
3383 
3384   SelectionDAG &DAG = DCI.DAG;
3385   SDLoc DL(N);
3386 
3387   SDValue N0 = N->getOperand(0);
3388   SDValue N1 = N->getOperand(1);
3389 
3390   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3391     return SDValue();
3392 
3393   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3394   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3395 
3396   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3397   DCI.AddToWorklist(Mulhi.getNode());
3398   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3399 }
3400 
performMulLoHi24Combine(SDNode * N,DAGCombinerInfo & DCI) const3401 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3402   SDNode *N, DAGCombinerInfo &DCI) const {
3403   SelectionDAG &DAG = DCI.DAG;
3404 
3405   // Simplify demanded bits before splitting into multiple users.
3406   if (SDValue V = simplifyI24(N, DCI))
3407     return V;
3408 
3409   SDValue N0 = N->getOperand(0);
3410   SDValue N1 = N->getOperand(1);
3411 
3412   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3413 
3414   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3415   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3416 
3417   SDLoc SL(N);
3418 
3419   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3420   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3421   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3422 }
3423 
isNegativeOne(SDValue Val)3424 static bool isNegativeOne(SDValue Val) {
3425   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3426     return C->isAllOnesValue();
3427   return false;
3428 }
3429 
getFFBX_U32(SelectionDAG & DAG,SDValue Op,const SDLoc & DL,unsigned Opc) const3430 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3431                                           SDValue Op,
3432                                           const SDLoc &DL,
3433                                           unsigned Opc) const {
3434   EVT VT = Op.getValueType();
3435   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3436   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3437                               LegalVT != MVT::i16))
3438     return SDValue();
3439 
3440   if (VT != MVT::i32)
3441     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3442 
3443   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3444   if (VT != MVT::i32)
3445     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3446 
3447   return FFBX;
3448 }
3449 
3450 // The native instructions return -1 on 0 input. Optimize out a select that
3451 // produces -1 on 0.
3452 //
3453 // TODO: If zero is not undef, we could also do this if the output is compared
3454 // against the bitwidth.
3455 //
3456 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
performCtlz_CttzCombine(const SDLoc & SL,SDValue Cond,SDValue LHS,SDValue RHS,DAGCombinerInfo & DCI) const3457 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3458                                                  SDValue LHS, SDValue RHS,
3459                                                  DAGCombinerInfo &DCI) const {
3460   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3461   if (!CmpRhs || !CmpRhs->isNullValue())
3462     return SDValue();
3463 
3464   SelectionDAG &DAG = DCI.DAG;
3465   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3466   SDValue CmpLHS = Cond.getOperand(0);
3467 
3468   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3469                                            AMDGPUISD::FFBH_U32;
3470 
3471   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3472   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3473   if (CCOpcode == ISD::SETEQ &&
3474       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3475       RHS.getOperand(0) == CmpLHS &&
3476       isNegativeOne(LHS)) {
3477     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3478   }
3479 
3480   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3481   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3482   if (CCOpcode == ISD::SETNE &&
3483       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3484       LHS.getOperand(0) == CmpLHS &&
3485       isNegativeOne(RHS)) {
3486     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3487   }
3488 
3489   return SDValue();
3490 }
3491 
distributeOpThroughSelect(TargetLowering::DAGCombinerInfo & DCI,unsigned Op,const SDLoc & SL,SDValue Cond,SDValue N1,SDValue N2)3492 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3493                                          unsigned Op,
3494                                          const SDLoc &SL,
3495                                          SDValue Cond,
3496                                          SDValue N1,
3497                                          SDValue N2) {
3498   SelectionDAG &DAG = DCI.DAG;
3499   EVT VT = N1.getValueType();
3500 
3501   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3502                                   N1.getOperand(0), N2.getOperand(0));
3503   DCI.AddToWorklist(NewSelect.getNode());
3504   return DAG.getNode(Op, SL, VT, NewSelect);
3505 }
3506 
3507 // Pull a free FP operation out of a select so it may fold into uses.
3508 //
3509 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3510 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3511 //
3512 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3513 // select c, (fabs x), +k -> fabs (select c, x, k)
foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo & DCI,SDValue N)3514 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3515                                     SDValue N) {
3516   SelectionDAG &DAG = DCI.DAG;
3517   SDValue Cond = N.getOperand(0);
3518   SDValue LHS = N.getOperand(1);
3519   SDValue RHS = N.getOperand(2);
3520 
3521   EVT VT = N.getValueType();
3522   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3523       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3524     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3525                                      SDLoc(N), Cond, LHS, RHS);
3526   }
3527 
3528   bool Inv = false;
3529   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3530     std::swap(LHS, RHS);
3531     Inv = true;
3532   }
3533 
3534   // TODO: Support vector constants.
3535   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3536   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3537     SDLoc SL(N);
3538     // If one side is an fneg/fabs and the other is a constant, we can push the
3539     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3540     SDValue NewLHS = LHS.getOperand(0);
3541     SDValue NewRHS = RHS;
3542 
3543     // Careful: if the neg can be folded up, don't try to pull it back down.
3544     bool ShouldFoldNeg = true;
3545 
3546     if (NewLHS.hasOneUse()) {
3547       unsigned Opc = NewLHS.getOpcode();
3548       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3549         ShouldFoldNeg = false;
3550       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3551         ShouldFoldNeg = false;
3552     }
3553 
3554     if (ShouldFoldNeg) {
3555       if (LHS.getOpcode() == ISD::FNEG)
3556         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3557       else if (CRHS->isNegative())
3558         return SDValue();
3559 
3560       if (Inv)
3561         std::swap(NewLHS, NewRHS);
3562 
3563       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3564                                       Cond, NewLHS, NewRHS);
3565       DCI.AddToWorklist(NewSelect.getNode());
3566       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3567     }
3568   }
3569 
3570   return SDValue();
3571 }
3572 
3573 
performSelectCombine(SDNode * N,DAGCombinerInfo & DCI) const3574 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3575                                                    DAGCombinerInfo &DCI) const {
3576   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3577     return Folded;
3578 
3579   SDValue Cond = N->getOperand(0);
3580   if (Cond.getOpcode() != ISD::SETCC)
3581     return SDValue();
3582 
3583   EVT VT = N->getValueType(0);
3584   SDValue LHS = Cond.getOperand(0);
3585   SDValue RHS = Cond.getOperand(1);
3586   SDValue CC = Cond.getOperand(2);
3587 
3588   SDValue True = N->getOperand(1);
3589   SDValue False = N->getOperand(2);
3590 
3591   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3592     SelectionDAG &DAG = DCI.DAG;
3593     if (DAG.isConstantValueOfAnyType(True) &&
3594         !DAG.isConstantValueOfAnyType(False)) {
3595       // Swap cmp + select pair to move constant to false input.
3596       // This will allow using VOPC cndmasks more often.
3597       // select (setcc x, y), k, x -> select (setccinv x, y), x, k
3598 
3599       SDLoc SL(N);
3600       ISD::CondCode NewCC =
3601           getSetCCInverse(cast<CondCodeSDNode>(CC)->get(), LHS.getValueType());
3602 
3603       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3604       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3605     }
3606 
3607     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3608       SDValue MinMax
3609         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3610       // Revisit this node so we can catch min3/max3/med3 patterns.
3611       //DCI.AddToWorklist(MinMax.getNode());
3612       return MinMax;
3613     }
3614   }
3615 
3616   // There's no reason to not do this if the condition has other uses.
3617   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3618 }
3619 
isInv2Pi(const APFloat & APF)3620 static bool isInv2Pi(const APFloat &APF) {
3621   static const APFloat KF16(APFloat::IEEEhalf(), APInt(16, 0x3118));
3622   static const APFloat KF32(APFloat::IEEEsingle(), APInt(32, 0x3e22f983));
3623   static const APFloat KF64(APFloat::IEEEdouble(), APInt(64, 0x3fc45f306dc9c882));
3624 
3625   return APF.bitwiseIsEqual(KF16) ||
3626          APF.bitwiseIsEqual(KF32) ||
3627          APF.bitwiseIsEqual(KF64);
3628 }
3629 
3630 // 0 and 1.0 / (0.5 * pi) do not have inline immmediates, so there is an
3631 // additional cost to negate them.
isConstantCostlierToNegate(SDValue N) const3632 bool AMDGPUTargetLowering::isConstantCostlierToNegate(SDValue N) const {
3633   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N)) {
3634     if (C->isZero() && !C->isNegative())
3635       return true;
3636 
3637     if (Subtarget->hasInv2PiInlineImm() && isInv2Pi(C->getValueAPF()))
3638       return true;
3639   }
3640 
3641   return false;
3642 }
3643 
inverseMinMax(unsigned Opc)3644 static unsigned inverseMinMax(unsigned Opc) {
3645   switch (Opc) {
3646   case ISD::FMAXNUM:
3647     return ISD::FMINNUM;
3648   case ISD::FMINNUM:
3649     return ISD::FMAXNUM;
3650   case ISD::FMAXNUM_IEEE:
3651     return ISD::FMINNUM_IEEE;
3652   case ISD::FMINNUM_IEEE:
3653     return ISD::FMAXNUM_IEEE;
3654   case AMDGPUISD::FMAX_LEGACY:
3655     return AMDGPUISD::FMIN_LEGACY;
3656   case AMDGPUISD::FMIN_LEGACY:
3657     return  AMDGPUISD::FMAX_LEGACY;
3658   default:
3659     llvm_unreachable("invalid min/max opcode");
3660   }
3661 }
3662 
performFNegCombine(SDNode * N,DAGCombinerInfo & DCI) const3663 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3664                                                  DAGCombinerInfo &DCI) const {
3665   SelectionDAG &DAG = DCI.DAG;
3666   SDValue N0 = N->getOperand(0);
3667   EVT VT = N->getValueType(0);
3668 
3669   unsigned Opc = N0.getOpcode();
3670 
3671   // If the input has multiple uses and we can either fold the negate down, or
3672   // the other uses cannot, give up. This both prevents unprofitable
3673   // transformations and infinite loops: we won't repeatedly try to fold around
3674   // a negate that has no 'good' form.
3675   if (N0.hasOneUse()) {
3676     // This may be able to fold into the source, but at a code size cost. Don't
3677     // fold if the fold into the user is free.
3678     if (allUsesHaveSourceMods(N, 0))
3679       return SDValue();
3680   } else {
3681     if (fnegFoldsIntoOp(Opc) &&
3682         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3683       return SDValue();
3684   }
3685 
3686   SDLoc SL(N);
3687   switch (Opc) {
3688   case ISD::FADD: {
3689     if (!mayIgnoreSignedZero(N0))
3690       return SDValue();
3691 
3692     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3693     SDValue LHS = N0.getOperand(0);
3694     SDValue RHS = N0.getOperand(1);
3695 
3696     if (LHS.getOpcode() != ISD::FNEG)
3697       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3698     else
3699       LHS = LHS.getOperand(0);
3700 
3701     if (RHS.getOpcode() != ISD::FNEG)
3702       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3703     else
3704       RHS = RHS.getOperand(0);
3705 
3706     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3707     if (Res.getOpcode() != ISD::FADD)
3708       return SDValue(); // Op got folded away.
3709     if (!N0.hasOneUse())
3710       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3711     return Res;
3712   }
3713   case ISD::FMUL:
3714   case AMDGPUISD::FMUL_LEGACY: {
3715     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3716     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3717     SDValue LHS = N0.getOperand(0);
3718     SDValue RHS = N0.getOperand(1);
3719 
3720     if (LHS.getOpcode() == ISD::FNEG)
3721       LHS = LHS.getOperand(0);
3722     else if (RHS.getOpcode() == ISD::FNEG)
3723       RHS = RHS.getOperand(0);
3724     else
3725       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3726 
3727     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3728     if (Res.getOpcode() != Opc)
3729       return SDValue(); // Op got folded away.
3730     if (!N0.hasOneUse())
3731       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3732     return Res;
3733   }
3734   case ISD::FMA:
3735   case ISD::FMAD: {
3736     if (!mayIgnoreSignedZero(N0))
3737       return SDValue();
3738 
3739     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3740     SDValue LHS = N0.getOperand(0);
3741     SDValue MHS = N0.getOperand(1);
3742     SDValue RHS = N0.getOperand(2);
3743 
3744     if (LHS.getOpcode() == ISD::FNEG)
3745       LHS = LHS.getOperand(0);
3746     else if (MHS.getOpcode() == ISD::FNEG)
3747       MHS = MHS.getOperand(0);
3748     else
3749       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3750 
3751     if (RHS.getOpcode() != ISD::FNEG)
3752       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3753     else
3754       RHS = RHS.getOperand(0);
3755 
3756     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3757     if (Res.getOpcode() != Opc)
3758       return SDValue(); // Op got folded away.
3759     if (!N0.hasOneUse())
3760       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3761     return Res;
3762   }
3763   case ISD::FMAXNUM:
3764   case ISD::FMINNUM:
3765   case ISD::FMAXNUM_IEEE:
3766   case ISD::FMINNUM_IEEE:
3767   case AMDGPUISD::FMAX_LEGACY:
3768   case AMDGPUISD::FMIN_LEGACY: {
3769     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3770     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3771     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3772     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3773 
3774     SDValue LHS = N0.getOperand(0);
3775     SDValue RHS = N0.getOperand(1);
3776 
3777     // 0 doesn't have a negated inline immediate.
3778     // TODO: This constant check should be generalized to other operations.
3779     if (isConstantCostlierToNegate(RHS))
3780       return SDValue();
3781 
3782     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3783     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3784     unsigned Opposite = inverseMinMax(Opc);
3785 
3786     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3787     if (Res.getOpcode() != Opposite)
3788       return SDValue(); // Op got folded away.
3789     if (!N0.hasOneUse())
3790       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3791     return Res;
3792   }
3793   case AMDGPUISD::FMED3: {
3794     SDValue Ops[3];
3795     for (unsigned I = 0; I < 3; ++I)
3796       Ops[I] = DAG.getNode(ISD::FNEG, SL, VT, N0->getOperand(I), N0->getFlags());
3797 
3798     SDValue Res = DAG.getNode(AMDGPUISD::FMED3, SL, VT, Ops, N0->getFlags());
3799     if (Res.getOpcode() != AMDGPUISD::FMED3)
3800       return SDValue(); // Op got folded away.
3801     if (!N0.hasOneUse())
3802       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3803     return Res;
3804   }
3805   case ISD::FP_EXTEND:
3806   case ISD::FTRUNC:
3807   case ISD::FRINT:
3808   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3809   case ISD::FSIN:
3810   case ISD::FCANONICALIZE:
3811   case AMDGPUISD::RCP:
3812   case AMDGPUISD::RCP_LEGACY:
3813   case AMDGPUISD::RCP_IFLAG:
3814   case AMDGPUISD::SIN_HW: {
3815     SDValue CvtSrc = N0.getOperand(0);
3816     if (CvtSrc.getOpcode() == ISD::FNEG) {
3817       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3818       // (fneg (rcp (fneg x))) -> (rcp x)
3819       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3820     }
3821 
3822     if (!N0.hasOneUse())
3823       return SDValue();
3824 
3825     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3826     // (fneg (rcp x)) -> (rcp (fneg x))
3827     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3828     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3829   }
3830   case ISD::FP_ROUND: {
3831     SDValue CvtSrc = N0.getOperand(0);
3832 
3833     if (CvtSrc.getOpcode() == ISD::FNEG) {
3834       // (fneg (fp_round (fneg x))) -> (fp_round x)
3835       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3836                          CvtSrc.getOperand(0), N0.getOperand(1));
3837     }
3838 
3839     if (!N0.hasOneUse())
3840       return SDValue();
3841 
3842     // (fneg (fp_round x)) -> (fp_round (fneg x))
3843     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3844     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3845   }
3846   case ISD::FP16_TO_FP: {
3847     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3848     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3849     // Put the fneg back as a legal source operation that can be matched later.
3850     SDLoc SL(N);
3851 
3852     SDValue Src = N0.getOperand(0);
3853     EVT SrcVT = Src.getValueType();
3854 
3855     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3856     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3857                                   DAG.getConstant(0x8000, SL, SrcVT));
3858     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3859   }
3860   default:
3861     return SDValue();
3862   }
3863 }
3864 
performFAbsCombine(SDNode * N,DAGCombinerInfo & DCI) const3865 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3866                                                  DAGCombinerInfo &DCI) const {
3867   SelectionDAG &DAG = DCI.DAG;
3868   SDValue N0 = N->getOperand(0);
3869 
3870   if (!N0.hasOneUse())
3871     return SDValue();
3872 
3873   switch (N0.getOpcode()) {
3874   case ISD::FP16_TO_FP: {
3875     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3876     SDLoc SL(N);
3877     SDValue Src = N0.getOperand(0);
3878     EVT SrcVT = Src.getValueType();
3879 
3880     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3881     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3882                                   DAG.getConstant(0x7fff, SL, SrcVT));
3883     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3884   }
3885   default:
3886     return SDValue();
3887   }
3888 }
3889 
performRcpCombine(SDNode * N,DAGCombinerInfo & DCI) const3890 SDValue AMDGPUTargetLowering::performRcpCombine(SDNode *N,
3891                                                 DAGCombinerInfo &DCI) const {
3892   const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
3893   if (!CFP)
3894     return SDValue();
3895 
3896   // XXX - Should this flush denormals?
3897   const APFloat &Val = CFP->getValueAPF();
3898   APFloat One(Val.getSemantics(), "1.0");
3899   return DCI.DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3900 }
3901 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const3902 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3903                                                 DAGCombinerInfo &DCI) const {
3904   SelectionDAG &DAG = DCI.DAG;
3905   SDLoc DL(N);
3906 
3907   switch(N->getOpcode()) {
3908   default:
3909     break;
3910   case ISD::BITCAST: {
3911     EVT DestVT = N->getValueType(0);
3912 
3913     // Push casts through vector builds. This helps avoid emitting a large
3914     // number of copies when materializing floating point vector constants.
3915     //
3916     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3917     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3918     if (DestVT.isVector()) {
3919       SDValue Src = N->getOperand(0);
3920       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3921         EVT SrcVT = Src.getValueType();
3922         unsigned NElts = DestVT.getVectorNumElements();
3923 
3924         if (SrcVT.getVectorNumElements() == NElts) {
3925           EVT DestEltVT = DestVT.getVectorElementType();
3926 
3927           SmallVector<SDValue, 8> CastedElts;
3928           SDLoc SL(N);
3929           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3930             SDValue Elt = Src.getOperand(I);
3931             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3932           }
3933 
3934           return DAG.getBuildVector(DestVT, SL, CastedElts);
3935         }
3936       }
3937     }
3938 
3939     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3940       break;
3941 
3942     // Fold bitcasts of constants.
3943     //
3944     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3945     // TODO: Generalize and move to DAGCombiner
3946     SDValue Src = N->getOperand(0);
3947     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3948       if (Src.getValueType() == MVT::i64) {
3949         SDLoc SL(N);
3950         uint64_t CVal = C->getZExtValue();
3951         SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3952                                  DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3953                                  DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3954         return DAG.getNode(ISD::BITCAST, SL, DestVT, BV);
3955       }
3956     }
3957 
3958     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3959       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3960       SDLoc SL(N);
3961       uint64_t CVal = Val.getZExtValue();
3962       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3963                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3964                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3965 
3966       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3967     }
3968 
3969     break;
3970   }
3971   case ISD::SHL: {
3972     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3973       break;
3974 
3975     return performShlCombine(N, DCI);
3976   }
3977   case ISD::SRL: {
3978     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3979       break;
3980 
3981     return performSrlCombine(N, DCI);
3982   }
3983   case ISD::SRA: {
3984     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3985       break;
3986 
3987     return performSraCombine(N, DCI);
3988   }
3989   case ISD::TRUNCATE:
3990     return performTruncateCombine(N, DCI);
3991   case ISD::MUL:
3992     return performMulCombine(N, DCI);
3993   case ISD::MULHS:
3994     return performMulhsCombine(N, DCI);
3995   case ISD::MULHU:
3996     return performMulhuCombine(N, DCI);
3997   case AMDGPUISD::MUL_I24:
3998   case AMDGPUISD::MUL_U24:
3999   case AMDGPUISD::MULHI_I24:
4000   case AMDGPUISD::MULHI_U24: {
4001     if (SDValue V = simplifyI24(N, DCI))
4002       return V;
4003     return SDValue();
4004   }
4005   case AMDGPUISD::MUL_LOHI_I24:
4006   case AMDGPUISD::MUL_LOHI_U24:
4007     return performMulLoHi24Combine(N, DCI);
4008   case ISD::SELECT:
4009     return performSelectCombine(N, DCI);
4010   case ISD::FNEG:
4011     return performFNegCombine(N, DCI);
4012   case ISD::FABS:
4013     return performFAbsCombine(N, DCI);
4014   case AMDGPUISD::BFE_I32:
4015   case AMDGPUISD::BFE_U32: {
4016     assert(!N->getValueType(0).isVector() &&
4017            "Vector handling of BFE not implemented");
4018     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
4019     if (!Width)
4020       break;
4021 
4022     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
4023     if (WidthVal == 0)
4024       return DAG.getConstant(0, DL, MVT::i32);
4025 
4026     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
4027     if (!Offset)
4028       break;
4029 
4030     SDValue BitsFrom = N->getOperand(0);
4031     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
4032 
4033     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
4034 
4035     if (OffsetVal == 0) {
4036       // This is already sign / zero extended, so try to fold away extra BFEs.
4037       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
4038 
4039       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
4040       if (OpSignBits >= SignBits)
4041         return BitsFrom;
4042 
4043       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
4044       if (Signed) {
4045         // This is a sign_extend_inreg. Replace it to take advantage of existing
4046         // DAG Combines. If not eliminated, we will match back to BFE during
4047         // selection.
4048 
4049         // TODO: The sext_inreg of extended types ends, although we can could
4050         // handle them in a single BFE.
4051         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
4052                            DAG.getValueType(SmallVT));
4053       }
4054 
4055       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
4056     }
4057 
4058     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
4059       if (Signed) {
4060         return constantFoldBFE<int32_t>(DAG,
4061                                         CVal->getSExtValue(),
4062                                         OffsetVal,
4063                                         WidthVal,
4064                                         DL);
4065       }
4066 
4067       return constantFoldBFE<uint32_t>(DAG,
4068                                        CVal->getZExtValue(),
4069                                        OffsetVal,
4070                                        WidthVal,
4071                                        DL);
4072     }
4073 
4074     if ((OffsetVal + WidthVal) >= 32 &&
4075         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
4076       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
4077       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
4078                          BitsFrom, ShiftVal);
4079     }
4080 
4081     if (BitsFrom.hasOneUse()) {
4082       APInt Demanded = APInt::getBitsSet(32,
4083                                          OffsetVal,
4084                                          OffsetVal + WidthVal);
4085 
4086       KnownBits Known;
4087       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
4088                                             !DCI.isBeforeLegalizeOps());
4089       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
4090       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
4091           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
4092         DCI.CommitTargetLoweringOpt(TLO);
4093       }
4094     }
4095 
4096     break;
4097   }
4098   case ISD::LOAD:
4099     return performLoadCombine(N, DCI);
4100   case ISD::STORE:
4101     return performStoreCombine(N, DCI);
4102   case AMDGPUISD::RCP:
4103   case AMDGPUISD::RCP_IFLAG:
4104     return performRcpCombine(N, DCI);
4105   case ISD::AssertZext:
4106   case ISD::AssertSext:
4107     return performAssertSZExtCombine(N, DCI);
4108   case ISD::INTRINSIC_WO_CHAIN:
4109     return performIntrinsicWOChainCombine(N, DCI);
4110   }
4111   return SDValue();
4112 }
4113 
4114 //===----------------------------------------------------------------------===//
4115 // Helper functions
4116 //===----------------------------------------------------------------------===//
4117 
CreateLiveInRegister(SelectionDAG & DAG,const TargetRegisterClass * RC,unsigned Reg,EVT VT,const SDLoc & SL,bool RawReg) const4118 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
4119                                                    const TargetRegisterClass *RC,
4120                                                    unsigned Reg, EVT VT,
4121                                                    const SDLoc &SL,
4122                                                    bool RawReg) const {
4123   MachineFunction &MF = DAG.getMachineFunction();
4124   MachineRegisterInfo &MRI = MF.getRegInfo();
4125   unsigned VReg;
4126 
4127   if (!MRI.isLiveIn(Reg)) {
4128     VReg = MRI.createVirtualRegister(RC);
4129     MRI.addLiveIn(Reg, VReg);
4130   } else {
4131     VReg = MRI.getLiveInVirtReg(Reg);
4132   }
4133 
4134   if (RawReg)
4135     return DAG.getRegister(VReg, VT);
4136 
4137   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
4138 }
4139 
4140 // This may be called multiple times, and nothing prevents creating multiple
4141 // objects at the same offset. See if we already defined this object.
getOrCreateFixedStackObject(MachineFrameInfo & MFI,unsigned Size,int64_t Offset)4142 static int getOrCreateFixedStackObject(MachineFrameInfo &MFI, unsigned Size,
4143                                        int64_t Offset) {
4144   for (int I = MFI.getObjectIndexBegin(); I < 0; ++I) {
4145     if (MFI.getObjectOffset(I) == Offset) {
4146       assert(MFI.getObjectSize(I) == Size);
4147       return I;
4148     }
4149   }
4150 
4151   return MFI.CreateFixedObject(Size, Offset, true);
4152 }
4153 
loadStackInputValue(SelectionDAG & DAG,EVT VT,const SDLoc & SL,int64_t Offset) const4154 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
4155                                                   EVT VT,
4156                                                   const SDLoc &SL,
4157                                                   int64_t Offset) const {
4158   MachineFunction &MF = DAG.getMachineFunction();
4159   MachineFrameInfo &MFI = MF.getFrameInfo();
4160   int FI = getOrCreateFixedStackObject(MFI, VT.getStoreSize(), Offset);
4161 
4162   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
4163   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
4164 
4165   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
4166                      MachineMemOperand::MODereferenceable |
4167                      MachineMemOperand::MOInvariant);
4168 }
4169 
storeStackInputValue(SelectionDAG & DAG,const SDLoc & SL,SDValue Chain,SDValue ArgVal,int64_t Offset) const4170 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
4171                                                    const SDLoc &SL,
4172                                                    SDValue Chain,
4173                                                    SDValue ArgVal,
4174                                                    int64_t Offset) const {
4175   MachineFunction &MF = DAG.getMachineFunction();
4176   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
4177 
4178   SDValue Ptr = DAG.getConstant(Offset, SL, MVT::i32);
4179   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
4180                                MachineMemOperand::MODereferenceable);
4181   return Store;
4182 }
4183 
loadInputValue(SelectionDAG & DAG,const TargetRegisterClass * RC,EVT VT,const SDLoc & SL,const ArgDescriptor & Arg) const4184 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
4185                                              const TargetRegisterClass *RC,
4186                                              EVT VT, const SDLoc &SL,
4187                                              const ArgDescriptor &Arg) const {
4188   assert(Arg && "Attempting to load missing argument");
4189 
4190   SDValue V = Arg.isRegister() ?
4191     CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL) :
4192     loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
4193 
4194   if (!Arg.isMasked())
4195     return V;
4196 
4197   unsigned Mask = Arg.getMask();
4198   unsigned Shift = countTrailingZeros<unsigned>(Mask);
4199   V = DAG.getNode(ISD::SRL, SL, VT, V,
4200                   DAG.getShiftAmountConstant(Shift, VT, SL));
4201   return DAG.getNode(ISD::AND, SL, VT, V,
4202                      DAG.getConstant(Mask >> Shift, SL, VT));
4203 }
4204 
getImplicitParameterOffset(const MachineFunction & MF,const ImplicitParameter Param) const4205 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
4206     const MachineFunction &MF, const ImplicitParameter Param) const {
4207   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
4208   const AMDGPUSubtarget &ST =
4209       AMDGPUSubtarget::get(getTargetMachine(), MF.getFunction());
4210   unsigned ExplicitArgOffset = ST.getExplicitKernelArgOffset(MF.getFunction());
4211   const Align Alignment = ST.getAlignmentForImplicitArgPtr();
4212   uint64_t ArgOffset = alignTo(MFI->getExplicitKernArgSize(), Alignment) +
4213                        ExplicitArgOffset;
4214   switch (Param) {
4215   case GRID_DIM:
4216     return ArgOffset;
4217   case GRID_OFFSET:
4218     return ArgOffset + 4;
4219   }
4220   llvm_unreachable("unexpected implicit parameter type");
4221 }
4222 
4223 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4224 
getTargetNodeName(unsigned Opcode) const4225 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4226   switch ((AMDGPUISD::NodeType)Opcode) {
4227   case AMDGPUISD::FIRST_NUMBER: break;
4228   // AMDIL DAG nodes
4229   NODE_NAME_CASE(UMUL);
4230   NODE_NAME_CASE(BRANCH_COND);
4231 
4232   // AMDGPU DAG nodes
4233   NODE_NAME_CASE(IF)
4234   NODE_NAME_CASE(ELSE)
4235   NODE_NAME_CASE(LOOP)
4236   NODE_NAME_CASE(CALL)
4237   NODE_NAME_CASE(TC_RETURN)
4238   NODE_NAME_CASE(TRAP)
4239   NODE_NAME_CASE(RET_FLAG)
4240   NODE_NAME_CASE(RETURN_TO_EPILOG)
4241   NODE_NAME_CASE(ENDPGM)
4242   NODE_NAME_CASE(DWORDADDR)
4243   NODE_NAME_CASE(FRACT)
4244   NODE_NAME_CASE(SETCC)
4245   NODE_NAME_CASE(SETREG)
4246   NODE_NAME_CASE(DENORM_MODE)
4247   NODE_NAME_CASE(FMA_W_CHAIN)
4248   NODE_NAME_CASE(FMUL_W_CHAIN)
4249   NODE_NAME_CASE(CLAMP)
4250   NODE_NAME_CASE(COS_HW)
4251   NODE_NAME_CASE(SIN_HW)
4252   NODE_NAME_CASE(FMAX_LEGACY)
4253   NODE_NAME_CASE(FMIN_LEGACY)
4254   NODE_NAME_CASE(FMAX3)
4255   NODE_NAME_CASE(SMAX3)
4256   NODE_NAME_CASE(UMAX3)
4257   NODE_NAME_CASE(FMIN3)
4258   NODE_NAME_CASE(SMIN3)
4259   NODE_NAME_CASE(UMIN3)
4260   NODE_NAME_CASE(FMED3)
4261   NODE_NAME_CASE(SMED3)
4262   NODE_NAME_CASE(UMED3)
4263   NODE_NAME_CASE(FDOT2)
4264   NODE_NAME_CASE(URECIP)
4265   NODE_NAME_CASE(DIV_SCALE)
4266   NODE_NAME_CASE(DIV_FMAS)
4267   NODE_NAME_CASE(DIV_FIXUP)
4268   NODE_NAME_CASE(FMAD_FTZ)
4269   NODE_NAME_CASE(TRIG_PREOP)
4270   NODE_NAME_CASE(RCP)
4271   NODE_NAME_CASE(RSQ)
4272   NODE_NAME_CASE(RCP_LEGACY)
4273   NODE_NAME_CASE(RSQ_LEGACY)
4274   NODE_NAME_CASE(RCP_IFLAG)
4275   NODE_NAME_CASE(FMUL_LEGACY)
4276   NODE_NAME_CASE(RSQ_CLAMP)
4277   NODE_NAME_CASE(LDEXP)
4278   NODE_NAME_CASE(FP_CLASS)
4279   NODE_NAME_CASE(DOT4)
4280   NODE_NAME_CASE(CARRY)
4281   NODE_NAME_CASE(BORROW)
4282   NODE_NAME_CASE(BFE_U32)
4283   NODE_NAME_CASE(BFE_I32)
4284   NODE_NAME_CASE(BFI)
4285   NODE_NAME_CASE(BFM)
4286   NODE_NAME_CASE(FFBH_U32)
4287   NODE_NAME_CASE(FFBH_I32)
4288   NODE_NAME_CASE(FFBL_B32)
4289   NODE_NAME_CASE(MUL_U24)
4290   NODE_NAME_CASE(MUL_I24)
4291   NODE_NAME_CASE(MULHI_U24)
4292   NODE_NAME_CASE(MULHI_I24)
4293   NODE_NAME_CASE(MUL_LOHI_U24)
4294   NODE_NAME_CASE(MUL_LOHI_I24)
4295   NODE_NAME_CASE(MAD_U24)
4296   NODE_NAME_CASE(MAD_I24)
4297   NODE_NAME_CASE(MAD_I64_I32)
4298   NODE_NAME_CASE(MAD_U64_U32)
4299   NODE_NAME_CASE(PERM)
4300   NODE_NAME_CASE(TEXTURE_FETCH)
4301   NODE_NAME_CASE(EXPORT)
4302   NODE_NAME_CASE(EXPORT_DONE)
4303   NODE_NAME_CASE(R600_EXPORT)
4304   NODE_NAME_CASE(CONST_ADDRESS)
4305   NODE_NAME_CASE(REGISTER_LOAD)
4306   NODE_NAME_CASE(REGISTER_STORE)
4307   NODE_NAME_CASE(SAMPLE)
4308   NODE_NAME_CASE(SAMPLEB)
4309   NODE_NAME_CASE(SAMPLED)
4310   NODE_NAME_CASE(SAMPLEL)
4311   NODE_NAME_CASE(CVT_F32_UBYTE0)
4312   NODE_NAME_CASE(CVT_F32_UBYTE1)
4313   NODE_NAME_CASE(CVT_F32_UBYTE2)
4314   NODE_NAME_CASE(CVT_F32_UBYTE3)
4315   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4316   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4317   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4318   NODE_NAME_CASE(CVT_PK_I16_I32)
4319   NODE_NAME_CASE(CVT_PK_U16_U32)
4320   NODE_NAME_CASE(FP_TO_FP16)
4321   NODE_NAME_CASE(FP16_ZEXT)
4322   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4323   NODE_NAME_CASE(CONST_DATA_PTR)
4324   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4325   NODE_NAME_CASE(LDS)
4326   NODE_NAME_CASE(KILL)
4327   NODE_NAME_CASE(DUMMY_CHAIN)
4328   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4329   NODE_NAME_CASE(INTERP_P1LL_F16)
4330   NODE_NAME_CASE(INTERP_P1LV_F16)
4331   NODE_NAME_CASE(INTERP_P2_F16)
4332   NODE_NAME_CASE(LOAD_D16_HI)
4333   NODE_NAME_CASE(LOAD_D16_LO)
4334   NODE_NAME_CASE(LOAD_D16_HI_I8)
4335   NODE_NAME_CASE(LOAD_D16_HI_U8)
4336   NODE_NAME_CASE(LOAD_D16_LO_I8)
4337   NODE_NAME_CASE(LOAD_D16_LO_U8)
4338   NODE_NAME_CASE(STORE_MSKOR)
4339   NODE_NAME_CASE(LOAD_CONSTANT)
4340   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4341   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4342   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4343   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4344   NODE_NAME_CASE(DS_ORDERED_COUNT)
4345   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4346   NODE_NAME_CASE(ATOMIC_INC)
4347   NODE_NAME_CASE(ATOMIC_DEC)
4348   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4349   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4350   NODE_NAME_CASE(BUFFER_LOAD)
4351   NODE_NAME_CASE(BUFFER_LOAD_UBYTE)
4352   NODE_NAME_CASE(BUFFER_LOAD_USHORT)
4353   NODE_NAME_CASE(BUFFER_LOAD_BYTE)
4354   NODE_NAME_CASE(BUFFER_LOAD_SHORT)
4355   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4356   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4357   NODE_NAME_CASE(SBUFFER_LOAD)
4358   NODE_NAME_CASE(BUFFER_STORE)
4359   NODE_NAME_CASE(BUFFER_STORE_BYTE)
4360   NODE_NAME_CASE(BUFFER_STORE_SHORT)
4361   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4362   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4363   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4364   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4365   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4366   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4367   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4368   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4369   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4370   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4371   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4372   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4373   NODE_NAME_CASE(BUFFER_ATOMIC_INC)
4374   NODE_NAME_CASE(BUFFER_ATOMIC_DEC)
4375   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4376   NODE_NAME_CASE(BUFFER_ATOMIC_FADD)
4377   NODE_NAME_CASE(BUFFER_ATOMIC_PK_FADD)
4378   NODE_NAME_CASE(ATOMIC_PK_FADD)
4379 
4380   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4381   }
4382   return nullptr;
4383 }
4384 
getSqrtEstimate(SDValue Operand,SelectionDAG & DAG,int Enabled,int & RefinementSteps,bool & UseOneConstNR,bool Reciprocal) const4385 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4386                                               SelectionDAG &DAG, int Enabled,
4387                                               int &RefinementSteps,
4388                                               bool &UseOneConstNR,
4389                                               bool Reciprocal) const {
4390   EVT VT = Operand.getValueType();
4391 
4392   if (VT == MVT::f32) {
4393     RefinementSteps = 0;
4394     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4395   }
4396 
4397   // TODO: There is also f64 rsq instruction, but the documentation is less
4398   // clear on its precision.
4399 
4400   return SDValue();
4401 }
4402 
getRecipEstimate(SDValue Operand,SelectionDAG & DAG,int Enabled,int & RefinementSteps) const4403 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4404                                                SelectionDAG &DAG, int Enabled,
4405                                                int &RefinementSteps) const {
4406   EVT VT = Operand.getValueType();
4407 
4408   if (VT == MVT::f32) {
4409     // Reciprocal, < 1 ulp error.
4410     //
4411     // This reciprocal approximation converges to < 0.5 ulp error with one
4412     // newton rhapson performed with two fused multiple adds (FMAs).
4413 
4414     RefinementSteps = 0;
4415     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4416   }
4417 
4418   // TODO: There is also f64 rcp instruction, but the documentation is less
4419   // clear on its precision.
4420 
4421   return SDValue();
4422 }
4423 
computeKnownBitsForTargetNode(const SDValue Op,KnownBits & Known,const APInt & DemandedElts,const SelectionDAG & DAG,unsigned Depth) const4424 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4425     const SDValue Op, KnownBits &Known,
4426     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4427 
4428   Known.resetAll(); // Don't know anything.
4429 
4430   unsigned Opc = Op.getOpcode();
4431 
4432   switch (Opc) {
4433   default:
4434     break;
4435   case AMDGPUISD::CARRY:
4436   case AMDGPUISD::BORROW: {
4437     Known.Zero = APInt::getHighBitsSet(32, 31);
4438     break;
4439   }
4440 
4441   case AMDGPUISD::BFE_I32:
4442   case AMDGPUISD::BFE_U32: {
4443     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4444     if (!CWidth)
4445       return;
4446 
4447     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4448 
4449     if (Opc == AMDGPUISD::BFE_U32)
4450       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4451 
4452     break;
4453   }
4454   case AMDGPUISD::FP_TO_FP16:
4455   case AMDGPUISD::FP16_ZEXT: {
4456     unsigned BitWidth = Known.getBitWidth();
4457 
4458     // High bits are zero.
4459     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4460     break;
4461   }
4462   case AMDGPUISD::MUL_U24:
4463   case AMDGPUISD::MUL_I24: {
4464     KnownBits LHSKnown = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
4465     KnownBits RHSKnown = DAG.computeKnownBits(Op.getOperand(1), Depth + 1);
4466     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4467                       RHSKnown.countMinTrailingZeros();
4468     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4469     // Skip extra check if all bits are known zeros.
4470     if (TrailZ >= 32)
4471       break;
4472 
4473     // Truncate to 24 bits.
4474     LHSKnown = LHSKnown.trunc(24);
4475     RHSKnown = RHSKnown.trunc(24);
4476 
4477     if (Opc == AMDGPUISD::MUL_I24) {
4478       unsigned LHSValBits = 24 - LHSKnown.countMinSignBits();
4479       unsigned RHSValBits = 24 - RHSKnown.countMinSignBits();
4480       unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4481       if (MaxValBits >= 32)
4482         break;
4483       bool LHSNegative = LHSKnown.isNegative();
4484       bool LHSNonNegative = LHSKnown.isNonNegative();
4485       bool LHSPositive = LHSKnown.isStrictlyPositive();
4486       bool RHSNegative = RHSKnown.isNegative();
4487       bool RHSNonNegative = RHSKnown.isNonNegative();
4488       bool RHSPositive = RHSKnown.isStrictlyPositive();
4489 
4490       if ((LHSNonNegative && RHSNonNegative) || (LHSNegative && RHSNegative))
4491         Known.Zero.setHighBits(32 - MaxValBits);
4492       else if ((LHSNegative && RHSPositive) || (LHSPositive && RHSNegative))
4493         Known.One.setHighBits(32 - MaxValBits);
4494     } else {
4495       unsigned LHSValBits = 24 - LHSKnown.countMinLeadingZeros();
4496       unsigned RHSValBits = 24 - RHSKnown.countMinLeadingZeros();
4497       unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4498       if (MaxValBits >= 32)
4499         break;
4500       Known.Zero.setHighBits(32 - MaxValBits);
4501     }
4502     break;
4503   }
4504   case AMDGPUISD::PERM: {
4505     ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4506     if (!CMask)
4507       return;
4508 
4509     KnownBits LHSKnown = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
4510     KnownBits RHSKnown = DAG.computeKnownBits(Op.getOperand(1), Depth + 1);
4511     unsigned Sel = CMask->getZExtValue();
4512 
4513     for (unsigned I = 0; I < 32; I += 8) {
4514       unsigned SelBits = Sel & 0xff;
4515       if (SelBits < 4) {
4516         SelBits *= 8;
4517         Known.One |= ((RHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4518         Known.Zero |= ((RHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4519       } else if (SelBits < 7) {
4520         SelBits = (SelBits & 3) * 8;
4521         Known.One |= ((LHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4522         Known.Zero |= ((LHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4523       } else if (SelBits == 0x0c) {
4524         Known.Zero |= 0xFFull << I;
4525       } else if (SelBits > 0x0c) {
4526         Known.One |= 0xFFull << I;
4527       }
4528       Sel >>= 8;
4529     }
4530     break;
4531   }
4532   case AMDGPUISD::BUFFER_LOAD_UBYTE:  {
4533     Known.Zero.setHighBits(24);
4534     break;
4535   }
4536   case AMDGPUISD::BUFFER_LOAD_USHORT: {
4537     Known.Zero.setHighBits(16);
4538     break;
4539   }
4540   case AMDGPUISD::LDS: {
4541     auto GA = cast<GlobalAddressSDNode>(Op.getOperand(0).getNode());
4542     unsigned Align = GA->getGlobal()->getAlignment();
4543 
4544     Known.Zero.setHighBits(16);
4545     if (Align)
4546       Known.Zero.setLowBits(Log2_32(Align));
4547     break;
4548   }
4549   case ISD::INTRINSIC_WO_CHAIN: {
4550     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4551     switch (IID) {
4552     case Intrinsic::amdgcn_mbcnt_lo:
4553     case Intrinsic::amdgcn_mbcnt_hi: {
4554       const GCNSubtarget &ST =
4555           DAG.getMachineFunction().getSubtarget<GCNSubtarget>();
4556       // These return at most the wavefront size - 1.
4557       unsigned Size = Op.getValueType().getSizeInBits();
4558       Known.Zero.setHighBits(Size - ST.getWavefrontSizeLog2());
4559       break;
4560     }
4561     default:
4562       break;
4563     }
4564   }
4565   }
4566 }
4567 
ComputeNumSignBitsForTargetNode(SDValue Op,const APInt & DemandedElts,const SelectionDAG & DAG,unsigned Depth) const4568 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4569     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4570     unsigned Depth) const {
4571   switch (Op.getOpcode()) {
4572   case AMDGPUISD::BFE_I32: {
4573     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4574     if (!Width)
4575       return 1;
4576 
4577     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4578     if (!isNullConstant(Op.getOperand(1)))
4579       return SignBits;
4580 
4581     // TODO: Could probably figure something out with non-0 offsets.
4582     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4583     return std::max(SignBits, Op0SignBits);
4584   }
4585 
4586   case AMDGPUISD::BFE_U32: {
4587     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4588     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4589   }
4590 
4591   case AMDGPUISD::CARRY:
4592   case AMDGPUISD::BORROW:
4593     return 31;
4594   case AMDGPUISD::BUFFER_LOAD_BYTE:
4595     return 25;
4596   case AMDGPUISD::BUFFER_LOAD_SHORT:
4597     return 17;
4598   case AMDGPUISD::BUFFER_LOAD_UBYTE:
4599     return 24;
4600   case AMDGPUISD::BUFFER_LOAD_USHORT:
4601     return 16;
4602   case AMDGPUISD::FP_TO_FP16:
4603   case AMDGPUISD::FP16_ZEXT:
4604     return 16;
4605   default:
4606     return 1;
4607   }
4608 }
4609 
isKnownNeverNaNForTargetNode(SDValue Op,const SelectionDAG & DAG,bool SNaN,unsigned Depth) const4610 bool AMDGPUTargetLowering::isKnownNeverNaNForTargetNode(SDValue Op,
4611                                                         const SelectionDAG &DAG,
4612                                                         bool SNaN,
4613                                                         unsigned Depth) const {
4614   unsigned Opcode = Op.getOpcode();
4615   switch (Opcode) {
4616   case AMDGPUISD::FMIN_LEGACY:
4617   case AMDGPUISD::FMAX_LEGACY: {
4618     if (SNaN)
4619       return true;
4620 
4621     // TODO: Can check no nans on one of the operands for each one, but which
4622     // one?
4623     return false;
4624   }
4625   case AMDGPUISD::FMUL_LEGACY:
4626   case AMDGPUISD::CVT_PKRTZ_F16_F32: {
4627     if (SNaN)
4628       return true;
4629     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4630            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4631   }
4632   case AMDGPUISD::FMED3:
4633   case AMDGPUISD::FMIN3:
4634   case AMDGPUISD::FMAX3:
4635   case AMDGPUISD::FMAD_FTZ: {
4636     if (SNaN)
4637       return true;
4638     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4639            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4640            DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4641   }
4642   case AMDGPUISD::CVT_F32_UBYTE0:
4643   case AMDGPUISD::CVT_F32_UBYTE1:
4644   case AMDGPUISD::CVT_F32_UBYTE2:
4645   case AMDGPUISD::CVT_F32_UBYTE3:
4646     return true;
4647 
4648   case AMDGPUISD::RCP:
4649   case AMDGPUISD::RSQ:
4650   case AMDGPUISD::RCP_LEGACY:
4651   case AMDGPUISD::RSQ_LEGACY:
4652   case AMDGPUISD::RSQ_CLAMP: {
4653     if (SNaN)
4654       return true;
4655 
4656     // TODO: Need is known positive check.
4657     return false;
4658   }
4659   case AMDGPUISD::LDEXP:
4660   case AMDGPUISD::FRACT: {
4661     if (SNaN)
4662       return true;
4663     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1);
4664   }
4665   case AMDGPUISD::DIV_SCALE:
4666   case AMDGPUISD::DIV_FMAS:
4667   case AMDGPUISD::DIV_FIXUP:
4668   case AMDGPUISD::TRIG_PREOP:
4669     // TODO: Refine on operands.
4670     return SNaN;
4671   case AMDGPUISD::SIN_HW:
4672   case AMDGPUISD::COS_HW: {
4673     // TODO: Need check for infinity
4674     return SNaN;
4675   }
4676   case ISD::INTRINSIC_WO_CHAIN: {
4677     unsigned IntrinsicID
4678       = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4679     // TODO: Handle more intrinsics
4680     switch (IntrinsicID) {
4681     case Intrinsic::amdgcn_cubeid:
4682       return true;
4683 
4684     case Intrinsic::amdgcn_frexp_mant: {
4685       if (SNaN)
4686         return true;
4687       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4688     }
4689     case Intrinsic::amdgcn_cvt_pkrtz: {
4690       if (SNaN)
4691         return true;
4692       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4693              DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4694     }
4695     case Intrinsic::amdgcn_fdot2:
4696       // TODO: Refine on operand
4697       return SNaN;
4698     default:
4699       return false;
4700     }
4701   }
4702   default:
4703     return false;
4704   }
4705 }
4706 
4707 TargetLowering::AtomicExpansionKind
shouldExpandAtomicRMWInIR(AtomicRMWInst * RMW) const4708 AMDGPUTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *RMW) const {
4709   switch (RMW->getOperation()) {
4710   case AtomicRMWInst::Nand:
4711   case AtomicRMWInst::FAdd:
4712   case AtomicRMWInst::FSub:
4713     return AtomicExpansionKind::CmpXChg;
4714   default:
4715     return AtomicExpansionKind::None;
4716   }
4717 }
4718