1 //===-- AMDGPUISelLowering.cpp - AMDGPU Common DAG lowering functions -----===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file
11 /// \brief This is the parent TargetLowering class for hardware code gen
12 /// targets.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #define AMDGPU_LOG2E_F     1.44269504088896340735992468100189214f
17 #define AMDGPU_LN2_F       0.693147180559945309417232121458176568f
18 #define AMDGPU_LN10_F      2.30258509299404568401799145468436421f
19 
20 #include "AMDGPUISelLowering.h"
21 #include "AMDGPU.h"
22 #include "AMDGPUCallLowering.h"
23 #include "AMDGPUFrameLowering.h"
24 #include "AMDGPUIntrinsicInfo.h"
25 #include "AMDGPURegisterInfo.h"
26 #include "AMDGPUSubtarget.h"
27 #include "AMDGPUTargetMachine.h"
28 #include "Utils/AMDGPUBaseInfo.h"
29 #include "R600MachineFunctionInfo.h"
30 #include "SIInstrInfo.h"
31 #include "SIMachineFunctionInfo.h"
32 #include "llvm/CodeGen/CallingConvLower.h"
33 #include "llvm/CodeGen/MachineFunction.h"
34 #include "llvm/CodeGen/MachineRegisterInfo.h"
35 #include "llvm/CodeGen/SelectionDAG.h"
36 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
37 #include "llvm/IR/DataLayout.h"
38 #include "llvm/IR/DiagnosticInfo.h"
39 #include "llvm/Support/KnownBits.h"
40 using namespace llvm;
41 
42 static bool allocateKernArg(unsigned ValNo, MVT ValVT, MVT LocVT,
43                             CCValAssign::LocInfo LocInfo,
44                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
45   MachineFunction &MF = State.getMachineFunction();
46   AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
47 
48   uint64_t Offset = MFI->allocateKernArg(LocVT.getStoreSize(),
49                                          ArgFlags.getOrigAlign());
50   State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, Offset, LocVT, LocInfo));
51   return true;
52 }
53 
54 static bool allocateCCRegs(unsigned ValNo, MVT ValVT, MVT LocVT,
55                            CCValAssign::LocInfo LocInfo,
56                            ISD::ArgFlagsTy ArgFlags, CCState &State,
57                            const TargetRegisterClass *RC,
58                            unsigned NumRegs) {
59   ArrayRef<MCPhysReg> RegList = makeArrayRef(RC->begin(), NumRegs);
60   unsigned RegResult = State.AllocateReg(RegList);
61   if (RegResult == AMDGPU::NoRegister)
62     return false;
63 
64   State.addLoc(CCValAssign::getReg(ValNo, ValVT, RegResult, LocVT, LocInfo));
65   return true;
66 }
67 
68 static bool allocateSGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
69                               CCValAssign::LocInfo LocInfo,
70                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
71   switch (LocVT.SimpleTy) {
72   case MVT::i64:
73   case MVT::f64:
74   case MVT::v2i32:
75   case MVT::v2f32: {
76     // Up to SGPR0-SGPR39
77     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
78                           &AMDGPU::SGPR_64RegClass, 20);
79   }
80   default:
81     return false;
82   }
83 }
84 
85 // Allocate up to VGPR31.
86 //
87 // TODO: Since there are no VGPR alignent requirements would it be better to
88 // split into individual scalar registers?
89 static bool allocateVGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
90                               CCValAssign::LocInfo LocInfo,
91                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
92   switch (LocVT.SimpleTy) {
93   case MVT::i64:
94   case MVT::f64:
95   case MVT::v2i32:
96   case MVT::v2f32: {
97     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
98                           &AMDGPU::VReg_64RegClass, 31);
99   }
100   case MVT::v4i32:
101   case MVT::v4f32:
102   case MVT::v2i64:
103   case MVT::v2f64: {
104     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
105                           &AMDGPU::VReg_128RegClass, 29);
106   }
107   case MVT::v8i32:
108   case MVT::v8f32: {
109     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
110                           &AMDGPU::VReg_256RegClass, 25);
111 
112   }
113   case MVT::v16i32:
114   case MVT::v16f32: {
115     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
116                           &AMDGPU::VReg_512RegClass, 17);
117 
118   }
119   default:
120     return false;
121   }
122 }
123 
124 #include "AMDGPUGenCallingConv.inc"
125 
126 // Find a larger type to do a load / store of a vector with.
127 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
128   unsigned StoreSize = VT.getStoreSizeInBits();
129   if (StoreSize <= 32)
130     return EVT::getIntegerVT(Ctx, StoreSize);
131 
132   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
133   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
134 }
135 
136 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
137   KnownBits Known;
138   EVT VT = Op.getValueType();
139   DAG.computeKnownBits(Op, Known);
140 
141   return VT.getSizeInBits() - Known.countMinLeadingZeros();
142 }
143 
144 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
145   EVT VT = Op.getValueType();
146 
147   // In order for this to be a signed 24-bit value, bit 23, must
148   // be a sign bit.
149   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
150 }
151 
152 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
153                                            const AMDGPUSubtarget &STI)
154     : TargetLowering(TM), Subtarget(&STI) {
155   AMDGPUASI = AMDGPU::getAMDGPUAS(TM);
156   // Lower floating point store/load to integer store/load to reduce the number
157   // of patterns in tablegen.
158   setOperationAction(ISD::LOAD, MVT::f32, Promote);
159   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
160 
161   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
162   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
163 
164   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
165   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
166 
167   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
168   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
169 
170   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
171   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
172 
173   setOperationAction(ISD::LOAD, MVT::i64, Promote);
174   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
175 
176   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
177   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
178 
179   setOperationAction(ISD::LOAD, MVT::f64, Promote);
180   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
181 
182   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
183   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
184 
185   // There are no 64-bit extloads. These should be done as a 32-bit extload and
186   // an extension to 64-bit.
187   for (MVT VT : MVT::integer_valuetypes()) {
188     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
189     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
190     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
191   }
192 
193   for (MVT VT : MVT::integer_valuetypes()) {
194     if (VT == MVT::i64)
195       continue;
196 
197     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
198     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
199     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
200     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
201 
202     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
203     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
204     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
205     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
206 
207     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
208     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
209     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
210     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
211   }
212 
213   for (MVT VT : MVT::integer_vector_valuetypes()) {
214     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
215     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
216     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
217     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
218     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
219     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
220     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
221     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
222     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
223     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
224     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
225     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
226   }
227 
228   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
229   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
230   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
231   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
232 
233   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
234   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
235   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
236   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
237 
238   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
239   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
240   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
241   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
242 
243   setOperationAction(ISD::STORE, MVT::f32, Promote);
244   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
245 
246   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
247   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
248 
249   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
250   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
251 
252   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
253   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
254 
255   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
256   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
257 
258   setOperationAction(ISD::STORE, MVT::i64, Promote);
259   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
260 
261   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
262   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
263 
264   setOperationAction(ISD::STORE, MVT::f64, Promote);
265   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
266 
267   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
268   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
269 
270   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
271   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
272   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
273   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
274 
275   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
276   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
277   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
278   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
279 
280   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
281   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
282   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
283   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
284 
285   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
286   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
287 
288   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
289   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
290 
291   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
292   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
293 
294   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
295   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
296 
297 
298   setOperationAction(ISD::Constant, MVT::i32, Legal);
299   setOperationAction(ISD::Constant, MVT::i64, Legal);
300   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
301   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
302 
303   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
304   setOperationAction(ISD::BRIND, MVT::Other, Expand);
305 
306   // This is totally unsupported, just custom lower to produce an error.
307   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
308 
309   // Library functions.  These default to Expand, but we have instructions
310   // for them.
311   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
312   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
313   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
314   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
315   setOperationAction(ISD::FABS,   MVT::f32, Legal);
316   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
317   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
318   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
319   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
320   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
321 
322   setOperationAction(ISD::FROUND, MVT::f32, Custom);
323   setOperationAction(ISD::FROUND, MVT::f64, Custom);
324 
325   setOperationAction(ISD::FLOG, MVT::f32, Custom);
326   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
327 
328   if (Subtarget->has16BitInsts()) {
329     setOperationAction(ISD::FLOG, MVT::f16, Custom);
330     setOperationAction(ISD::FLOG10, MVT::f16, Custom);
331   }
332 
333   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
334   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
335 
336   setOperationAction(ISD::FREM, MVT::f32, Custom);
337   setOperationAction(ISD::FREM, MVT::f64, Custom);
338 
339   // v_mad_f32 does not support denormals according to some sources.
340   if (!Subtarget->hasFP32Denormals())
341     setOperationAction(ISD::FMAD, MVT::f32, Legal);
342 
343   // Expand to fneg + fadd.
344   setOperationAction(ISD::FSUB, MVT::f64, Expand);
345 
346   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
347   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
348   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
349   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
350   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
351   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
352   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
353   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
354   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
355   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
356 
357   if (Subtarget->getGeneration() < AMDGPUSubtarget::SEA_ISLANDS) {
358     setOperationAction(ISD::FCEIL, MVT::f64, Custom);
359     setOperationAction(ISD::FTRUNC, MVT::f64, Custom);
360     setOperationAction(ISD::FRINT, MVT::f64, Custom);
361     setOperationAction(ISD::FFLOOR, MVT::f64, Custom);
362   }
363 
364   if (!Subtarget->hasBFI()) {
365     // fcopysign can be done in a single instruction with BFI.
366     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
367     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
368   }
369 
370   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
371   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
372   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
373 
374   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
375   for (MVT VT : ScalarIntVTs) {
376     // These should use [SU]DIVREM, so set them to expand
377     setOperationAction(ISD::SDIV, VT, Expand);
378     setOperationAction(ISD::UDIV, VT, Expand);
379     setOperationAction(ISD::SREM, VT, Expand);
380     setOperationAction(ISD::UREM, VT, Expand);
381 
382     // GPU does not have divrem function for signed or unsigned.
383     setOperationAction(ISD::SDIVREM, VT, Custom);
384     setOperationAction(ISD::UDIVREM, VT, Custom);
385 
386     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
387     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
388     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
389 
390     setOperationAction(ISD::BSWAP, VT, Expand);
391     setOperationAction(ISD::CTTZ, VT, Expand);
392     setOperationAction(ISD::CTLZ, VT, Expand);
393   }
394 
395   if (!Subtarget->hasBCNT(32))
396     setOperationAction(ISD::CTPOP, MVT::i32, Expand);
397 
398   if (!Subtarget->hasBCNT(64))
399     setOperationAction(ISD::CTPOP, MVT::i64, Expand);
400 
401   // The hardware supports 32-bit ROTR, but not ROTL.
402   setOperationAction(ISD::ROTL, MVT::i32, Expand);
403   setOperationAction(ISD::ROTL, MVT::i64, Expand);
404   setOperationAction(ISD::ROTR, MVT::i64, Expand);
405 
406   setOperationAction(ISD::MUL, MVT::i64, Expand);
407   setOperationAction(ISD::MULHU, MVT::i64, Expand);
408   setOperationAction(ISD::MULHS, MVT::i64, Expand);
409   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
410   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
411   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
412   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
413   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
414 
415   setOperationAction(ISD::SMIN, MVT::i32, Legal);
416   setOperationAction(ISD::UMIN, MVT::i32, Legal);
417   setOperationAction(ISD::SMAX, MVT::i32, Legal);
418   setOperationAction(ISD::UMAX, MVT::i32, Legal);
419 
420   if (Subtarget->hasFFBH())
421     setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Custom);
422 
423   if (Subtarget->hasFFBL())
424     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Custom);
425 
426   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
427   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
428   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
429   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
430 
431   // We only really have 32-bit BFE instructions (and 16-bit on VI).
432   //
433   // On SI+ there are 64-bit BFEs, but they are scalar only and there isn't any
434   // effort to match them now. We want this to be false for i64 cases when the
435   // extraction isn't restricted to the upper or lower half. Ideally we would
436   // have some pass reduce 64-bit extracts to 32-bit if possible. Extracts that
437   // span the midpoint are probably relatively rare, so don't worry about them
438   // for now.
439   if (Subtarget->hasBFE())
440     setHasExtractBitsInsn(true);
441 
442   static const MVT::SimpleValueType VectorIntTypes[] = {
443     MVT::v2i32, MVT::v4i32
444   };
445 
446   for (MVT VT : VectorIntTypes) {
447     // Expand the following operations for the current type by default.
448     setOperationAction(ISD::ADD,  VT, Expand);
449     setOperationAction(ISD::AND,  VT, Expand);
450     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
451     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
452     setOperationAction(ISD::MUL,  VT, Expand);
453     setOperationAction(ISD::MULHU, VT, Expand);
454     setOperationAction(ISD::MULHS, VT, Expand);
455     setOperationAction(ISD::OR,   VT, Expand);
456     setOperationAction(ISD::SHL,  VT, Expand);
457     setOperationAction(ISD::SRA,  VT, Expand);
458     setOperationAction(ISD::SRL,  VT, Expand);
459     setOperationAction(ISD::ROTL, VT, Expand);
460     setOperationAction(ISD::ROTR, VT, Expand);
461     setOperationAction(ISD::SUB,  VT, Expand);
462     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
463     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
464     setOperationAction(ISD::SDIV, VT, Expand);
465     setOperationAction(ISD::UDIV, VT, Expand);
466     setOperationAction(ISD::SREM, VT, Expand);
467     setOperationAction(ISD::UREM, VT, Expand);
468     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
469     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
470     setOperationAction(ISD::SDIVREM, VT, Custom);
471     setOperationAction(ISD::UDIVREM, VT, Expand);
472     setOperationAction(ISD::ADDC, VT, Expand);
473     setOperationAction(ISD::SUBC, VT, Expand);
474     setOperationAction(ISD::ADDE, VT, Expand);
475     setOperationAction(ISD::SUBE, VT, Expand);
476     setOperationAction(ISD::SELECT, VT, Expand);
477     setOperationAction(ISD::VSELECT, VT, Expand);
478     setOperationAction(ISD::SELECT_CC, VT, Expand);
479     setOperationAction(ISD::XOR,  VT, Expand);
480     setOperationAction(ISD::BSWAP, VT, Expand);
481     setOperationAction(ISD::CTPOP, VT, Expand);
482     setOperationAction(ISD::CTTZ, VT, Expand);
483     setOperationAction(ISD::CTLZ, VT, Expand);
484     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
485     setOperationAction(ISD::SETCC, VT, Expand);
486   }
487 
488   static const MVT::SimpleValueType FloatVectorTypes[] = {
489     MVT::v2f32, MVT::v4f32
490   };
491 
492   for (MVT VT : FloatVectorTypes) {
493     setOperationAction(ISD::FABS, VT, Expand);
494     setOperationAction(ISD::FMINNUM, VT, Expand);
495     setOperationAction(ISD::FMAXNUM, VT, Expand);
496     setOperationAction(ISD::FADD, VT, Expand);
497     setOperationAction(ISD::FCEIL, VT, Expand);
498     setOperationAction(ISD::FCOS, VT, Expand);
499     setOperationAction(ISD::FDIV, VT, Expand);
500     setOperationAction(ISD::FEXP2, VT, Expand);
501     setOperationAction(ISD::FLOG2, VT, Expand);
502     setOperationAction(ISD::FREM, VT, Expand);
503     setOperationAction(ISD::FLOG, VT, Expand);
504     setOperationAction(ISD::FLOG10, VT, Expand);
505     setOperationAction(ISD::FPOW, VT, Expand);
506     setOperationAction(ISD::FFLOOR, VT, Expand);
507     setOperationAction(ISD::FTRUNC, VT, Expand);
508     setOperationAction(ISD::FMUL, VT, Expand);
509     setOperationAction(ISD::FMA, VT, Expand);
510     setOperationAction(ISD::FRINT, VT, Expand);
511     setOperationAction(ISD::FNEARBYINT, VT, Expand);
512     setOperationAction(ISD::FSQRT, VT, Expand);
513     setOperationAction(ISD::FSIN, VT, Expand);
514     setOperationAction(ISD::FSUB, VT, Expand);
515     setOperationAction(ISD::FNEG, VT, Expand);
516     setOperationAction(ISD::VSELECT, VT, Expand);
517     setOperationAction(ISD::SELECT_CC, VT, Expand);
518     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
519     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
520     setOperationAction(ISD::SETCC, VT, Expand);
521   }
522 
523   // This causes using an unrolled select operation rather than expansion with
524   // bit operations. This is in general better, but the alternative using BFI
525   // instructions may be better if the select sources are SGPRs.
526   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
527   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
528 
529   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
530   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
531 
532   // There are no libcalls of any kind.
533   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
534     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
535 
536   setBooleanContents(ZeroOrNegativeOneBooleanContent);
537   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
538 
539   setSchedulingPreference(Sched::RegPressure);
540   setJumpIsExpensive(true);
541 
542   // FIXME: This is only partially true. If we have to do vector compares, any
543   // SGPR pair can be a condition register. If we have a uniform condition, we
544   // are better off doing SALU operations, where there is only one SCC. For now,
545   // we don't have a way of knowing during instruction selection if a condition
546   // will be uniform and we always use vector compares. Assume we are using
547   // vector compares until that is fixed.
548   setHasMultipleConditionRegisters(true);
549 
550   // SI at least has hardware support for floating point exceptions, but no way
551   // of using or handling them is implemented. They are also optional in OpenCL
552   // (Section 7.3)
553   setHasFloatingPointExceptions(Subtarget->hasFPExceptions());
554 
555   PredictableSelectIsExpensive = false;
556 
557   // We want to find all load dependencies for long chains of stores to enable
558   // merging into very wide vectors. The problem is with vectors with > 4
559   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
560   // vectors are a legal type, even though we have to split the loads
561   // usually. When we can more precisely specify load legality per address
562   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
563   // smarter so that they can figure out what to do in 2 iterations without all
564   // N > 4 stores on the same chain.
565   GatherAllAliasesMaxDepth = 16;
566 
567   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
568   // about these during lowering.
569   MaxStoresPerMemcpy  = 0xffffffff;
570   MaxStoresPerMemmove = 0xffffffff;
571   MaxStoresPerMemset  = 0xffffffff;
572 
573   setTargetDAGCombine(ISD::BITCAST);
574   setTargetDAGCombine(ISD::SHL);
575   setTargetDAGCombine(ISD::SRA);
576   setTargetDAGCombine(ISD::SRL);
577   setTargetDAGCombine(ISD::MUL);
578   setTargetDAGCombine(ISD::MULHU);
579   setTargetDAGCombine(ISD::MULHS);
580   setTargetDAGCombine(ISD::SELECT);
581   setTargetDAGCombine(ISD::SELECT_CC);
582   setTargetDAGCombine(ISD::STORE);
583   setTargetDAGCombine(ISD::FADD);
584   setTargetDAGCombine(ISD::FSUB);
585   setTargetDAGCombine(ISD::FNEG);
586   setTargetDAGCombine(ISD::FABS);
587   setTargetDAGCombine(ISD::AssertZext);
588   setTargetDAGCombine(ISD::AssertSext);
589 }
590 
591 //===----------------------------------------------------------------------===//
592 // Target Information
593 //===----------------------------------------------------------------------===//
594 
595 LLVM_READNONE
596 static bool fnegFoldsIntoOp(unsigned Opc) {
597   switch (Opc) {
598   case ISD::FADD:
599   case ISD::FSUB:
600   case ISD::FMUL:
601   case ISD::FMA:
602   case ISD::FMAD:
603   case ISD::FMINNUM:
604   case ISD::FMAXNUM:
605   case ISD::FSIN:
606   case ISD::FTRUNC:
607   case ISD::FRINT:
608   case ISD::FNEARBYINT:
609   case AMDGPUISD::RCP:
610   case AMDGPUISD::RCP_LEGACY:
611   case AMDGPUISD::SIN_HW:
612   case AMDGPUISD::FMUL_LEGACY:
613   case AMDGPUISD::FMIN_LEGACY:
614   case AMDGPUISD::FMAX_LEGACY:
615     return true;
616   default:
617     return false;
618   }
619 }
620 
621 /// \p returns true if the operation will definitely need to use a 64-bit
622 /// encoding, and thus will use a VOP3 encoding regardless of the source
623 /// modifiers.
624 LLVM_READONLY
625 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
626   return N->getNumOperands() > 2 || VT == MVT::f64;
627 }
628 
629 // Most FP instructions support source modifiers, but this could be refined
630 // slightly.
631 LLVM_READONLY
632 static bool hasSourceMods(const SDNode *N) {
633   if (isa<MemSDNode>(N))
634     return false;
635 
636   switch (N->getOpcode()) {
637   case ISD::CopyToReg:
638   case ISD::SELECT:
639   case ISD::FDIV:
640   case ISD::FREM:
641   case ISD::INLINEASM:
642   case AMDGPUISD::INTERP_P1:
643   case AMDGPUISD::INTERP_P2:
644   case AMDGPUISD::DIV_SCALE:
645 
646   // TODO: Should really be looking at the users of the bitcast. These are
647   // problematic because bitcasts are used to legalize all stores to integer
648   // types.
649   case ISD::BITCAST:
650     return false;
651   default:
652     return true;
653   }
654 }
655 
656 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
657                                                  unsigned CostThreshold) {
658   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
659   // it is truly free to use a source modifier in all cases. If there are
660   // multiple users but for each one will necessitate using VOP3, there will be
661   // a code size increase. Try to avoid increasing code size unless we know it
662   // will save on the instruction count.
663   unsigned NumMayIncreaseSize = 0;
664   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
665 
666   // XXX - Should this limit number of uses to check?
667   for (const SDNode *U : N->uses()) {
668     if (!hasSourceMods(U))
669       return false;
670 
671     if (!opMustUseVOP3Encoding(U, VT)) {
672       if (++NumMayIncreaseSize > CostThreshold)
673         return false;
674     }
675   }
676 
677   return true;
678 }
679 
680 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
681   return MVT::i32;
682 }
683 
684 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
685   return true;
686 }
687 
688 // The backend supports 32 and 64 bit floating point immediates.
689 // FIXME: Why are we reporting vectors of FP immediates as legal?
690 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
691   EVT ScalarVT = VT.getScalarType();
692   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
693          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
694 }
695 
696 // We don't want to shrink f64 / f32 constants.
697 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
698   EVT ScalarVT = VT.getScalarType();
699   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
700 }
701 
702 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
703                                                  ISD::LoadExtType,
704                                                  EVT NewVT) const {
705 
706   unsigned NewSize = NewVT.getStoreSizeInBits();
707 
708   // If we are reducing to a 32-bit load, this is always better.
709   if (NewSize == 32)
710     return true;
711 
712   EVT OldVT = N->getValueType(0);
713   unsigned OldSize = OldVT.getStoreSizeInBits();
714 
715   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
716   // extloads, so doing one requires using a buffer_load. In cases where we
717   // still couldn't use a scalar load, using the wider load shouldn't really
718   // hurt anything.
719 
720   // If the old size already had to be an extload, there's no harm in continuing
721   // to reduce the width.
722   return (OldSize < 32);
723 }
724 
725 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy,
726                                                    EVT CastTy) const {
727 
728   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
729 
730   if (LoadTy.getScalarType() == MVT::i32)
731     return false;
732 
733   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
734   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
735 
736   return (LScalarSize < CastScalarSize) ||
737          (CastScalarSize >= 32);
738 }
739 
740 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
741 // profitable with the expansion for 64-bit since it's generally good to
742 // speculate things.
743 // FIXME: These should really have the size as a parameter.
744 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
745   return true;
746 }
747 
748 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
749   return true;
750 }
751 
752 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
753   switch (N->getOpcode()) {
754     default:
755     return false;
756     case ISD::EntryToken:
757     case ISD::TokenFactor:
758       return true;
759     case ISD::INTRINSIC_WO_CHAIN:
760     {
761       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
762       switch (IntrID) {
763         default:
764         return false;
765         case Intrinsic::amdgcn_readfirstlane:
766         case Intrinsic::amdgcn_readlane:
767           return true;
768       }
769     }
770     break;
771     case ISD::LOAD:
772     {
773       const LoadSDNode * L = dyn_cast<LoadSDNode>(N);
774       if (L->getMemOperand()->getAddrSpace()
775       == Subtarget->getAMDGPUAS().CONSTANT_ADDRESS_32BIT)
776         return true;
777       return false;
778     }
779     break;
780   }
781 }
782 
783 bool AMDGPUTargetLowering::isSDNodeSourceOfDivergence(const SDNode * N,
784   FunctionLoweringInfo * FLI, DivergenceAnalysis * DA) const
785 {
786   switch (N->getOpcode()) {
787     case ISD::Register:
788     case ISD::CopyFromReg:
789     {
790       const RegisterSDNode *R = nullptr;
791       if (N->getOpcode() == ISD::Register) {
792         R = dyn_cast<RegisterSDNode>(N);
793       }
794       else {
795         R = dyn_cast<RegisterSDNode>(N->getOperand(1));
796       }
797       if (R)
798       {
799         const MachineFunction * MF = FLI->MF;
800         const SISubtarget &ST = MF->getSubtarget<SISubtarget>();
801         const MachineRegisterInfo &MRI = MF->getRegInfo();
802         const SIRegisterInfo &TRI = ST.getInstrInfo()->getRegisterInfo();
803         unsigned Reg = R->getReg();
804         if (TRI.isPhysicalRegister(Reg))
805           return TRI.isVGPR(MRI, Reg);
806 
807         if (MRI.isLiveIn(Reg)) {
808           // workitem.id.x workitem.id.y workitem.id.z
809           // Any VGPR formal argument is also considered divergent
810           if ((MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_X) ||
811               (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Y) ||
812               (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Z) ||
813               (TRI.isVGPR(MRI, Reg)))
814               return true;
815           // Formal arguments of non-entry functions
816           // are conservatively considered divergent
817           else if (!AMDGPU::isEntryFunctionCC(FLI->Fn->getCallingConv()))
818             return true;
819         }
820         return !DA || DA->isDivergent(FLI->getValueFromVirtualReg(Reg));
821       }
822     }
823     break;
824     case ISD::LOAD: {
825       const LoadSDNode *L = dyn_cast<LoadSDNode>(N);
826       if (L->getMemOperand()->getAddrSpace() ==
827           Subtarget->getAMDGPUAS().PRIVATE_ADDRESS)
828         return true;
829     } break;
830     case ISD::CALLSEQ_END:
831     return true;
832     break;
833     case ISD::INTRINSIC_WO_CHAIN:
834     {
835 
836     }
837       return AMDGPU::isIntrinsicSourceOfDivergence(
838       cast<ConstantSDNode>(N->getOperand(0))->getZExtValue());
839     case ISD::INTRINSIC_W_CHAIN:
840       return AMDGPU::isIntrinsicSourceOfDivergence(
841       cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
842     // In some cases intrinsics that are a source of divergence have been
843     // lowered to AMDGPUISD so we also need to check those too.
844     case AMDGPUISD::INTERP_MOV:
845     case AMDGPUISD::INTERP_P1:
846     case AMDGPUISD::INTERP_P2:
847       return true;
848   }
849   return false;
850 }
851 
852 //===---------------------------------------------------------------------===//
853 // Target Properties
854 //===---------------------------------------------------------------------===//
855 
856 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
857   assert(VT.isFloatingPoint());
858 
859   // Packed operations do not have a fabs modifier.
860   return VT == MVT::f32 || VT == MVT::f64 ||
861          (Subtarget->has16BitInsts() && VT == MVT::f16);
862 }
863 
864 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
865   assert(VT.isFloatingPoint());
866   return VT == MVT::f32 || VT == MVT::f64 ||
867          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
868          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
869 }
870 
871 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
872                                                          unsigned NumElem,
873                                                          unsigned AS) const {
874   return true;
875 }
876 
877 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
878   // There are few operations which truly have vector input operands. Any vector
879   // operation is going to involve operations on each component, and a
880   // build_vector will be a copy per element, so it always makes sense to use a
881   // build_vector input in place of the extracted element to avoid a copy into a
882   // super register.
883   //
884   // We should probably only do this if all users are extracts only, but this
885   // should be the common case.
886   return true;
887 }
888 
889 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
890   // Truncate is just accessing a subregister.
891 
892   unsigned SrcSize = Source.getSizeInBits();
893   unsigned DestSize = Dest.getSizeInBits();
894 
895   return DestSize < SrcSize && DestSize % 32 == 0 ;
896 }
897 
898 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
899   // Truncate is just accessing a subregister.
900 
901   unsigned SrcSize = Source->getScalarSizeInBits();
902   unsigned DestSize = Dest->getScalarSizeInBits();
903 
904   if (DestSize== 16 && Subtarget->has16BitInsts())
905     return SrcSize >= 32;
906 
907   return DestSize < SrcSize && DestSize % 32 == 0;
908 }
909 
910 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
911   unsigned SrcSize = Src->getScalarSizeInBits();
912   unsigned DestSize = Dest->getScalarSizeInBits();
913 
914   if (SrcSize == 16 && Subtarget->has16BitInsts())
915     return DestSize >= 32;
916 
917   return SrcSize == 32 && DestSize == 64;
918 }
919 
920 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
921   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
922   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
923   // this will enable reducing 64-bit operations the 32-bit, which is always
924   // good.
925 
926   if (Src == MVT::i16)
927     return Dest == MVT::i32 ||Dest == MVT::i64 ;
928 
929   return Src == MVT::i32 && Dest == MVT::i64;
930 }
931 
932 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
933   return isZExtFree(Val.getValueType(), VT2);
934 }
935 
936 // v_mad_mix* support a conversion from f16 to f32.
937 //
938 // There is only one special case when denormals are enabled we don't currently,
939 // where this is OK to use.
940 bool AMDGPUTargetLowering::isFPExtFoldable(unsigned Opcode,
941                                            EVT DestVT, EVT SrcVT) const {
942   return Opcode == ISD::FMAD && Subtarget->hasMadMixInsts() &&
943          DestVT.getScalarType() == MVT::f32 && !Subtarget->hasFP32Denormals() &&
944          SrcVT.getScalarType() == MVT::f16;
945 }
946 
947 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
948   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
949   // limited number of native 64-bit operations. Shrinking an operation to fit
950   // in a single 32-bit register should always be helpful. As currently used,
951   // this is much less general than the name suggests, and is only used in
952   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
953   // not profitable, and may actually be harmful.
954   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
955 }
956 
957 //===---------------------------------------------------------------------===//
958 // TargetLowering Callbacks
959 //===---------------------------------------------------------------------===//
960 
961 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
962                                                   bool IsVarArg) {
963   switch (CC) {
964   case CallingConv::AMDGPU_KERNEL:
965   case CallingConv::SPIR_KERNEL:
966     return CC_AMDGPU_Kernel;
967   case CallingConv::AMDGPU_VS:
968   case CallingConv::AMDGPU_GS:
969   case CallingConv::AMDGPU_PS:
970   case CallingConv::AMDGPU_CS:
971   case CallingConv::AMDGPU_HS:
972   case CallingConv::AMDGPU_ES:
973   case CallingConv::AMDGPU_LS:
974     return CC_AMDGPU;
975   case CallingConv::C:
976   case CallingConv::Fast:
977   case CallingConv::Cold:
978     return CC_AMDGPU_Func;
979   default:
980     report_fatal_error("Unsupported calling convention.");
981   }
982 }
983 
984 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
985                                                     bool IsVarArg) {
986   switch (CC) {
987   case CallingConv::AMDGPU_KERNEL:
988   case CallingConv::SPIR_KERNEL:
989     return CC_AMDGPU_Kernel;
990   case CallingConv::AMDGPU_VS:
991   case CallingConv::AMDGPU_GS:
992   case CallingConv::AMDGPU_PS:
993   case CallingConv::AMDGPU_CS:
994   case CallingConv::AMDGPU_HS:
995   case CallingConv::AMDGPU_ES:
996   case CallingConv::AMDGPU_LS:
997     return RetCC_SI_Shader;
998   case CallingConv::C:
999   case CallingConv::Fast:
1000   case CallingConv::Cold:
1001     return RetCC_AMDGPU_Func;
1002   default:
1003     report_fatal_error("Unsupported calling convention.");
1004   }
1005 }
1006 
1007 /// The SelectionDAGBuilder will automatically promote function arguments
1008 /// with illegal types.  However, this does not work for the AMDGPU targets
1009 /// since the function arguments are stored in memory as these illegal types.
1010 /// In order to handle this properly we need to get the original types sizes
1011 /// from the LLVM IR Function and fixup the ISD:InputArg values before
1012 /// passing them to AnalyzeFormalArguments()
1013 
1014 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
1015 /// input values across multiple registers.  Each item in the Ins array
1016 /// represents a single value that will be stored in registers.  Ins[x].VT is
1017 /// the value type of the value that will be stored in the register, so
1018 /// whatever SDNode we lower the argument to needs to be this type.
1019 ///
1020 /// In order to correctly lower the arguments we need to know the size of each
1021 /// argument.  Since Ins[x].VT gives us the size of the register that will
1022 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
1023 /// for the orignal function argument so that we can deduce the correct memory
1024 /// type to use for Ins[x].  In most cases the correct memory type will be
1025 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
1026 /// we have a kernel argument of type v8i8, this argument will be split into
1027 /// 8 parts and each part will be represented by its own item in the Ins array.
1028 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
1029 /// the argument before it was split.  From this, we deduce that the memory type
1030 /// for each individual part is i8.  We pass the memory type as LocVT to the
1031 /// calling convention analysis function and the register type (Ins[x].VT) as
1032 /// the ValVT.
1033 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(CCState &State,
1034                              const SmallVectorImpl<ISD::InputArg> &Ins) const {
1035   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
1036     const ISD::InputArg &In = Ins[i];
1037     EVT MemVT;
1038 
1039     unsigned NumRegs = getNumRegisters(State.getContext(), In.ArgVT);
1040 
1041     if (!Subtarget->isAmdHsaOS() &&
1042         (In.ArgVT == MVT::i16 || In.ArgVT == MVT::i8 || In.ArgVT == MVT::f16)) {
1043       // The ABI says the caller will extend these values to 32-bits.
1044       MemVT = In.ArgVT.isInteger() ? MVT::i32 : MVT::f32;
1045     } else if (NumRegs == 1) {
1046       // This argument is not split, so the IR type is the memory type.
1047       assert(!In.Flags.isSplit());
1048       if (In.ArgVT.isExtended()) {
1049         // We have an extended type, like i24, so we should just use the register type
1050         MemVT = In.VT;
1051       } else {
1052         MemVT = In.ArgVT;
1053       }
1054     } else if (In.ArgVT.isVector() && In.VT.isVector() &&
1055                In.ArgVT.getScalarType() == In.VT.getScalarType()) {
1056       assert(In.ArgVT.getVectorNumElements() > In.VT.getVectorNumElements());
1057       // We have a vector value which has been split into a vector with
1058       // the same scalar type, but fewer elements.  This should handle
1059       // all the floating-point vector types.
1060       MemVT = In.VT;
1061     } else if (In.ArgVT.isVector() &&
1062                In.ArgVT.getVectorNumElements() == NumRegs) {
1063       // This arg has been split so that each element is stored in a separate
1064       // register.
1065       MemVT = In.ArgVT.getScalarType();
1066     } else if (In.ArgVT.isExtended()) {
1067       // We have an extended type, like i65.
1068       MemVT = In.VT;
1069     } else {
1070       unsigned MemoryBits = In.ArgVT.getStoreSizeInBits() / NumRegs;
1071       assert(In.ArgVT.getStoreSizeInBits() % NumRegs == 0);
1072       if (In.VT.isInteger()) {
1073         MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
1074       } else if (In.VT.isVector()) {
1075         assert(!In.VT.getScalarType().isFloatingPoint());
1076         unsigned NumElements = In.VT.getVectorNumElements();
1077         assert(MemoryBits % NumElements == 0);
1078         // This vector type has been split into another vector type with
1079         // a different elements size.
1080         EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
1081                                          MemoryBits / NumElements);
1082         MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
1083       } else {
1084         llvm_unreachable("cannot deduce memory type.");
1085       }
1086     }
1087 
1088     // Convert one element vectors to scalar.
1089     if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
1090       MemVT = MemVT.getScalarType();
1091 
1092     if (MemVT.isExtended()) {
1093       // This should really only happen if we have vec3 arguments
1094       assert(MemVT.isVector() && MemVT.getVectorNumElements() == 3);
1095       MemVT = MemVT.getPow2VectorType(State.getContext());
1096     }
1097 
1098     assert(MemVT.isSimple());
1099     allocateKernArg(i, In.VT, MemVT.getSimpleVT(), CCValAssign::Full, In.Flags,
1100                     State);
1101   }
1102 }
1103 
1104 SDValue AMDGPUTargetLowering::LowerReturn(
1105   SDValue Chain, CallingConv::ID CallConv,
1106   bool isVarArg,
1107   const SmallVectorImpl<ISD::OutputArg> &Outs,
1108   const SmallVectorImpl<SDValue> &OutVals,
1109   const SDLoc &DL, SelectionDAG &DAG) const {
1110   // FIXME: Fails for r600 tests
1111   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1112   // "wave terminate should not have return values");
1113   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1114 }
1115 
1116 //===---------------------------------------------------------------------===//
1117 // Target specific lowering
1118 //===---------------------------------------------------------------------===//
1119 
1120 /// Selects the correct CCAssignFn for a given CallingConvention value.
1121 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1122                                                     bool IsVarArg) {
1123   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1124 }
1125 
1126 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1127                                                       bool IsVarArg) {
1128   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1129 }
1130 
1131 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1132                                                   SelectionDAG &DAG,
1133                                                   MachineFrameInfo &MFI,
1134                                                   int ClobberedFI) const {
1135   SmallVector<SDValue, 8> ArgChains;
1136   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1137   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1138 
1139   // Include the original chain at the beginning of the list. When this is
1140   // used by target LowerCall hooks, this helps legalize find the
1141   // CALLSEQ_BEGIN node.
1142   ArgChains.push_back(Chain);
1143 
1144   // Add a chain value for each stack argument corresponding
1145   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1146                             UE = DAG.getEntryNode().getNode()->use_end();
1147        U != UE; ++U) {
1148     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1149       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1150         if (FI->getIndex() < 0) {
1151           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1152           int64_t InLastByte = InFirstByte;
1153           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1154 
1155           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1156               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1157             ArgChains.push_back(SDValue(L, 1));
1158         }
1159       }
1160     }
1161   }
1162 
1163   // Build a tokenfactor for all the chains.
1164   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1165 }
1166 
1167 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1168                                                  SmallVectorImpl<SDValue> &InVals,
1169                                                  StringRef Reason) const {
1170   SDValue Callee = CLI.Callee;
1171   SelectionDAG &DAG = CLI.DAG;
1172 
1173   const Function &Fn = DAG.getMachineFunction().getFunction();
1174 
1175   StringRef FuncName("<unknown>");
1176 
1177   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1178     FuncName = G->getSymbol();
1179   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1180     FuncName = G->getGlobal()->getName();
1181 
1182   DiagnosticInfoUnsupported NoCalls(
1183     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1184   DAG.getContext()->diagnose(NoCalls);
1185 
1186   if (!CLI.IsTailCall) {
1187     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1188       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1189   }
1190 
1191   return DAG.getEntryNode();
1192 }
1193 
1194 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1195                                         SmallVectorImpl<SDValue> &InVals) const {
1196   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1197 }
1198 
1199 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1200                                                       SelectionDAG &DAG) const {
1201   const Function &Fn = DAG.getMachineFunction().getFunction();
1202 
1203   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1204                                             SDLoc(Op).getDebugLoc());
1205   DAG.getContext()->diagnose(NoDynamicAlloca);
1206   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1207   return DAG.getMergeValues(Ops, SDLoc());
1208 }
1209 
1210 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1211                                              SelectionDAG &DAG) const {
1212   switch (Op.getOpcode()) {
1213   default:
1214     Op->print(errs(), &DAG);
1215     llvm_unreachable("Custom lowering code for this"
1216                      "instruction is not implemented yet!");
1217     break;
1218   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1219   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1220   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1221   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1222   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1223   case ISD::FREM: return LowerFREM(Op, DAG);
1224   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1225   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1226   case ISD::FRINT: return LowerFRINT(Op, DAG);
1227   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1228   case ISD::FROUND: return LowerFROUND(Op, DAG);
1229   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1230   case ISD::FLOG:
1231     return LowerFLOG(Op, DAG, 1 / AMDGPU_LOG2E_F);
1232   case ISD::FLOG10:
1233     return LowerFLOG(Op, DAG, AMDGPU_LN2_F / AMDGPU_LN10_F);
1234   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1235   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1236   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1237   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1238   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1239   case ISD::CTTZ:
1240   case ISD::CTTZ_ZERO_UNDEF:
1241   case ISD::CTLZ:
1242   case ISD::CTLZ_ZERO_UNDEF:
1243     return LowerCTLZ_CTTZ(Op, DAG);
1244   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1245   }
1246   return Op;
1247 }
1248 
1249 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1250                                               SmallVectorImpl<SDValue> &Results,
1251                                               SelectionDAG &DAG) const {
1252   switch (N->getOpcode()) {
1253   case ISD::SIGN_EXTEND_INREG:
1254     // Different parts of legalization seem to interpret which type of
1255     // sign_extend_inreg is the one to check for custom lowering. The extended
1256     // from type is what really matters, but some places check for custom
1257     // lowering of the result type. This results in trying to use
1258     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1259     // nothing here and let the illegal result integer be handled normally.
1260     return;
1261   default:
1262     return;
1263   }
1264 }
1265 
1266 static bool hasDefinedInitializer(const GlobalValue *GV) {
1267   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1268   if (!GVar || !GVar->hasInitializer())
1269     return false;
1270 
1271   return !isa<UndefValue>(GVar->getInitializer());
1272 }
1273 
1274 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1275                                                  SDValue Op,
1276                                                  SelectionDAG &DAG) const {
1277 
1278   const DataLayout &DL = DAG.getDataLayout();
1279   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1280   const GlobalValue *GV = G->getGlobal();
1281 
1282   if  (G->getAddressSpace() == AMDGPUASI.LOCAL_ADDRESS) {
1283     // XXX: What does the value of G->getOffset() mean?
1284     assert(G->getOffset() == 0 &&
1285          "Do not know what to do with an non-zero offset");
1286 
1287     // TODO: We could emit code to handle the initialization somewhere.
1288     if (!hasDefinedInitializer(GV)) {
1289       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1290       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1291     }
1292   }
1293 
1294   const Function &Fn = DAG.getMachineFunction().getFunction();
1295   DiagnosticInfoUnsupported BadInit(
1296       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1297   DAG.getContext()->diagnose(BadInit);
1298   return SDValue();
1299 }
1300 
1301 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1302                                                   SelectionDAG &DAG) const {
1303   SmallVector<SDValue, 8> Args;
1304 
1305   for (const SDUse &U : Op->ops())
1306     DAG.ExtractVectorElements(U.get(), Args);
1307 
1308   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1309 }
1310 
1311 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1312                                                      SelectionDAG &DAG) const {
1313 
1314   SmallVector<SDValue, 8> Args;
1315   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1316   EVT VT = Op.getValueType();
1317   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1318                             VT.getVectorNumElements());
1319 
1320   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1321 }
1322 
1323 /// \brief Generate Min/Max node
1324 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1325                                                    SDValue LHS, SDValue RHS,
1326                                                    SDValue True, SDValue False,
1327                                                    SDValue CC,
1328                                                    DAGCombinerInfo &DCI) const {
1329   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1330     return SDValue();
1331 
1332   SelectionDAG &DAG = DCI.DAG;
1333   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1334   switch (CCOpcode) {
1335   case ISD::SETOEQ:
1336   case ISD::SETONE:
1337   case ISD::SETUNE:
1338   case ISD::SETNE:
1339   case ISD::SETUEQ:
1340   case ISD::SETEQ:
1341   case ISD::SETFALSE:
1342   case ISD::SETFALSE2:
1343   case ISD::SETTRUE:
1344   case ISD::SETTRUE2:
1345   case ISD::SETUO:
1346   case ISD::SETO:
1347     break;
1348   case ISD::SETULE:
1349   case ISD::SETULT: {
1350     if (LHS == True)
1351       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1352     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1353   }
1354   case ISD::SETOLE:
1355   case ISD::SETOLT:
1356   case ISD::SETLE:
1357   case ISD::SETLT: {
1358     // Ordered. Assume ordered for undefined.
1359 
1360     // Only do this after legalization to avoid interfering with other combines
1361     // which might occur.
1362     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1363         !DCI.isCalledByLegalizer())
1364       return SDValue();
1365 
1366     // We need to permute the operands to get the correct NaN behavior. The
1367     // selected operand is the second one based on the failing compare with NaN,
1368     // so permute it based on the compare type the hardware uses.
1369     if (LHS == True)
1370       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1371     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1372   }
1373   case ISD::SETUGE:
1374   case ISD::SETUGT: {
1375     if (LHS == True)
1376       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1377     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1378   }
1379   case ISD::SETGT:
1380   case ISD::SETGE:
1381   case ISD::SETOGE:
1382   case ISD::SETOGT: {
1383     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1384         !DCI.isCalledByLegalizer())
1385       return SDValue();
1386 
1387     if (LHS == True)
1388       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1389     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1390   }
1391   case ISD::SETCC_INVALID:
1392     llvm_unreachable("Invalid setcc condcode!");
1393   }
1394   return SDValue();
1395 }
1396 
1397 std::pair<SDValue, SDValue>
1398 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1399   SDLoc SL(Op);
1400 
1401   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1402 
1403   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1404   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1405 
1406   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1407   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1408 
1409   return std::make_pair(Lo, Hi);
1410 }
1411 
1412 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1413   SDLoc SL(Op);
1414 
1415   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1416   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1417   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1418 }
1419 
1420 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1421   SDLoc SL(Op);
1422 
1423   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1424   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1425   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1426 }
1427 
1428 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1429                                               SelectionDAG &DAG) const {
1430   LoadSDNode *Load = cast<LoadSDNode>(Op);
1431   EVT VT = Op.getValueType();
1432 
1433 
1434   // If this is a 2 element vector, we really want to scalarize and not create
1435   // weird 1 element vectors.
1436   if (VT.getVectorNumElements() == 2)
1437     return scalarizeVectorLoad(Load, DAG);
1438 
1439   SDValue BasePtr = Load->getBasePtr();
1440   EVT MemVT = Load->getMemoryVT();
1441   SDLoc SL(Op);
1442 
1443   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1444 
1445   EVT LoVT, HiVT;
1446   EVT LoMemVT, HiMemVT;
1447   SDValue Lo, Hi;
1448 
1449   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1450   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1451   std::tie(Lo, Hi) = DAG.SplitVector(Op, SL, LoVT, HiVT);
1452 
1453   unsigned Size = LoMemVT.getStoreSize();
1454   unsigned BaseAlign = Load->getAlignment();
1455   unsigned HiAlign = MinAlign(BaseAlign, Size);
1456 
1457   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1458                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1459                                   BaseAlign, Load->getMemOperand()->getFlags());
1460   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1461   SDValue HiLoad =
1462       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1463                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1464                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1465 
1466   SDValue Ops[] = {
1467     DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad),
1468     DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1469                 LoLoad.getValue(1), HiLoad.getValue(1))
1470   };
1471 
1472   return DAG.getMergeValues(Ops, SL);
1473 }
1474 
1475 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1476                                                SelectionDAG &DAG) const {
1477   StoreSDNode *Store = cast<StoreSDNode>(Op);
1478   SDValue Val = Store->getValue();
1479   EVT VT = Val.getValueType();
1480 
1481   // If this is a 2 element vector, we really want to scalarize and not create
1482   // weird 1 element vectors.
1483   if (VT.getVectorNumElements() == 2)
1484     return scalarizeVectorStore(Store, DAG);
1485 
1486   EVT MemVT = Store->getMemoryVT();
1487   SDValue Chain = Store->getChain();
1488   SDValue BasePtr = Store->getBasePtr();
1489   SDLoc SL(Op);
1490 
1491   EVT LoVT, HiVT;
1492   EVT LoMemVT, HiMemVT;
1493   SDValue Lo, Hi;
1494 
1495   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1496   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1497   std::tie(Lo, Hi) = DAG.SplitVector(Val, SL, LoVT, HiVT);
1498 
1499   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1500 
1501   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1502   unsigned BaseAlign = Store->getAlignment();
1503   unsigned Size = LoMemVT.getStoreSize();
1504   unsigned HiAlign = MinAlign(BaseAlign, Size);
1505 
1506   SDValue LoStore =
1507       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1508                         Store->getMemOperand()->getFlags());
1509   SDValue HiStore =
1510       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1511                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1512 
1513   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1514 }
1515 
1516 // This is a shortcut for integer division because we have fast i32<->f32
1517 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1518 // float is enough to accurately represent up to a 24-bit signed integer.
1519 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1520                                             bool Sign) const {
1521   SDLoc DL(Op);
1522   EVT VT = Op.getValueType();
1523   SDValue LHS = Op.getOperand(0);
1524   SDValue RHS = Op.getOperand(1);
1525   MVT IntVT = MVT::i32;
1526   MVT FltVT = MVT::f32;
1527 
1528   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1529   if (LHSSignBits < 9)
1530     return SDValue();
1531 
1532   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1533   if (RHSSignBits < 9)
1534     return SDValue();
1535 
1536   unsigned BitSize = VT.getSizeInBits();
1537   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1538   unsigned DivBits = BitSize - SignBits;
1539   if (Sign)
1540     ++DivBits;
1541 
1542   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1543   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1544 
1545   SDValue jq = DAG.getConstant(1, DL, IntVT);
1546 
1547   if (Sign) {
1548     // char|short jq = ia ^ ib;
1549     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1550 
1551     // jq = jq >> (bitsize - 2)
1552     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1553                      DAG.getConstant(BitSize - 2, DL, VT));
1554 
1555     // jq = jq | 0x1
1556     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1557   }
1558 
1559   // int ia = (int)LHS;
1560   SDValue ia = LHS;
1561 
1562   // int ib, (int)RHS;
1563   SDValue ib = RHS;
1564 
1565   // float fa = (float)ia;
1566   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1567 
1568   // float fb = (float)ib;
1569   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1570 
1571   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1572                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1573 
1574   // fq = trunc(fq);
1575   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1576 
1577   // float fqneg = -fq;
1578   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1579 
1580   // float fr = mad(fqneg, fb, fa);
1581   unsigned OpCode = Subtarget->hasFP32Denormals() ?
1582                     (unsigned)AMDGPUISD::FMAD_FTZ :
1583                     (unsigned)ISD::FMAD;
1584   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1585 
1586   // int iq = (int)fq;
1587   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1588 
1589   // fr = fabs(fr);
1590   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1591 
1592   // fb = fabs(fb);
1593   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1594 
1595   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1596 
1597   // int cv = fr >= fb;
1598   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1599 
1600   // jq = (cv ? jq : 0);
1601   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1602 
1603   // dst = iq + jq;
1604   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1605 
1606   // Rem needs compensation, it's easier to recompute it
1607   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1608   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1609 
1610   // Truncate to number of bits this divide really is.
1611   if (Sign) {
1612     SDValue InRegSize
1613       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1614     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1615     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1616   } else {
1617     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1618     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1619     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1620   }
1621 
1622   return DAG.getMergeValues({ Div, Rem }, DL);
1623 }
1624 
1625 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1626                                       SelectionDAG &DAG,
1627                                       SmallVectorImpl<SDValue> &Results) const {
1628   SDLoc DL(Op);
1629   EVT VT = Op.getValueType();
1630 
1631   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1632 
1633   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1634 
1635   SDValue One = DAG.getConstant(1, DL, HalfVT);
1636   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1637 
1638   //HiLo split
1639   SDValue LHS = Op.getOperand(0);
1640   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1641   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1642 
1643   SDValue RHS = Op.getOperand(1);
1644   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1645   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1646 
1647   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1648       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1649 
1650     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1651                               LHS_Lo, RHS_Lo);
1652 
1653     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1654     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1655 
1656     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1657     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1658     return;
1659   }
1660 
1661   if (isTypeLegal(MVT::i64)) {
1662     // Compute denominator reciprocal.
1663     unsigned FMAD = Subtarget->hasFP32Denormals() ?
1664                     (unsigned)AMDGPUISD::FMAD_FTZ :
1665                     (unsigned)ISD::FMAD;
1666 
1667     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1668     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1669     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1670       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1671       Cvt_Lo);
1672     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1673     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1674       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1675     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1676       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1677     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1678     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1679       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1680       Mul1);
1681     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1682     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1683     SDValue Rcp64 = DAG.getBitcast(VT,
1684                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1685 
1686     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1687     SDValue One64  = DAG.getConstant(1, DL, VT);
1688     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1689     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1690 
1691     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1692     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1693     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1694     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1695                                     Zero);
1696     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1697                                     One);
1698 
1699     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1700                                   Mulhi1_Lo, Zero1);
1701     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1702                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1703     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1704     SDValue Add1 = DAG.getBitcast(VT,
1705                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1706 
1707     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1708     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1709     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1710                                     Zero);
1711     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1712                                     One);
1713 
1714     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1715                                   Mulhi2_Lo, Zero1);
1716     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1717                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1718     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1719                                   Zero, Add2_Lo.getValue(1));
1720     SDValue Add2 = DAG.getBitcast(VT,
1721                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1722     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1723 
1724     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1725 
1726     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1727     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1728     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1729                                   Mul3_Lo, Zero1);
1730     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1731                                   Mul3_Hi, Sub1_Lo.getValue(1));
1732     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1733     SDValue Sub1 = DAG.getBitcast(VT,
1734                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1735 
1736     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1737     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1738                                  ISD::SETUGE);
1739     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1740                                  ISD::SETUGE);
1741     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1742 
1743     // TODO: Here and below portions of the code can be enclosed into if/endif.
1744     // Currently control flow is unconditional and we have 4 selects after
1745     // potential endif to substitute PHIs.
1746 
1747     // if C3 != 0 ...
1748     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1749                                   RHS_Lo, Zero1);
1750     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1751                                   RHS_Hi, Sub1_Lo.getValue(1));
1752     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1753                                   Zero, Sub2_Lo.getValue(1));
1754     SDValue Sub2 = DAG.getBitcast(VT,
1755                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1756 
1757     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1758 
1759     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1760                                  ISD::SETUGE);
1761     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1762                                  ISD::SETUGE);
1763     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1764 
1765     // if (C6 != 0)
1766     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1767 
1768     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1769                                   RHS_Lo, Zero1);
1770     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1771                                   RHS_Hi, Sub2_Lo.getValue(1));
1772     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1773                                   Zero, Sub3_Lo.getValue(1));
1774     SDValue Sub3 = DAG.getBitcast(VT,
1775                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1776 
1777     // endif C6
1778     // endif C3
1779 
1780     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1781     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1782 
1783     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1784     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1785 
1786     Results.push_back(Div);
1787     Results.push_back(Rem);
1788 
1789     return;
1790   }
1791 
1792   // r600 expandion.
1793   // Get Speculative values
1794   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1795   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1796 
1797   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1798   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1799   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1800 
1801   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1802   SDValue DIV_Lo = Zero;
1803 
1804   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1805 
1806   for (unsigned i = 0; i < halfBitWidth; ++i) {
1807     const unsigned bitPos = halfBitWidth - i - 1;
1808     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1809     // Get value of high bit
1810     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1811     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1812     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1813 
1814     // Shift
1815     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1816     // Add LHS high bit
1817     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1818 
1819     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1820     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1821 
1822     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1823 
1824     // Update REM
1825     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1826     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1827   }
1828 
1829   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1830   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1831   Results.push_back(DIV);
1832   Results.push_back(REM);
1833 }
1834 
1835 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1836                                            SelectionDAG &DAG) const {
1837   SDLoc DL(Op);
1838   EVT VT = Op.getValueType();
1839 
1840   if (VT == MVT::i64) {
1841     SmallVector<SDValue, 2> Results;
1842     LowerUDIVREM64(Op, DAG, Results);
1843     return DAG.getMergeValues(Results, DL);
1844   }
1845 
1846   if (VT == MVT::i32) {
1847     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1848       return Res;
1849   }
1850 
1851   SDValue Num = Op.getOperand(0);
1852   SDValue Den = Op.getOperand(1);
1853 
1854   // RCP =  URECIP(Den) = 2^32 / Den + e
1855   // e is rounding error.
1856   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1857 
1858   // RCP_LO = mul(RCP, Den) */
1859   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1860 
1861   // RCP_HI = mulhu (RCP, Den) */
1862   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1863 
1864   // NEG_RCP_LO = -RCP_LO
1865   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1866                                                      RCP_LO);
1867 
1868   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1869   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1870                                            NEG_RCP_LO, RCP_LO,
1871                                            ISD::SETEQ);
1872   // Calculate the rounding error from the URECIP instruction
1873   // E = mulhu(ABS_RCP_LO, RCP)
1874   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1875 
1876   // RCP_A_E = RCP + E
1877   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1878 
1879   // RCP_S_E = RCP - E
1880   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1881 
1882   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1883   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1884                                      RCP_A_E, RCP_S_E,
1885                                      ISD::SETEQ);
1886   // Quotient = mulhu(Tmp0, Num)
1887   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1888 
1889   // Num_S_Remainder = Quotient * Den
1890   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1891 
1892   // Remainder = Num - Num_S_Remainder
1893   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1894 
1895   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1896   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1897                                                  DAG.getConstant(-1, DL, VT),
1898                                                  DAG.getConstant(0, DL, VT),
1899                                                  ISD::SETUGE);
1900   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1901   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1902                                                   Num_S_Remainder,
1903                                                   DAG.getConstant(-1, DL, VT),
1904                                                   DAG.getConstant(0, DL, VT),
1905                                                   ISD::SETUGE);
1906   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1907   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1908                                                Remainder_GE_Zero);
1909 
1910   // Calculate Division result:
1911 
1912   // Quotient_A_One = Quotient + 1
1913   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1914                                        DAG.getConstant(1, DL, VT));
1915 
1916   // Quotient_S_One = Quotient - 1
1917   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1918                                        DAG.getConstant(1, DL, VT));
1919 
1920   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1921   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1922                                      Quotient, Quotient_A_One, ISD::SETEQ);
1923 
1924   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1925   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1926                             Quotient_S_One, Div, ISD::SETEQ);
1927 
1928   // Calculate Rem result:
1929 
1930   // Remainder_S_Den = Remainder - Den
1931   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1932 
1933   // Remainder_A_Den = Remainder + Den
1934   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1935 
1936   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1937   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1938                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1939 
1940   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1941   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1942                             Remainder_A_Den, Rem, ISD::SETEQ);
1943   SDValue Ops[2] = {
1944     Div,
1945     Rem
1946   };
1947   return DAG.getMergeValues(Ops, DL);
1948 }
1949 
1950 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1951                                            SelectionDAG &DAG) const {
1952   SDLoc DL(Op);
1953   EVT VT = Op.getValueType();
1954 
1955   SDValue LHS = Op.getOperand(0);
1956   SDValue RHS = Op.getOperand(1);
1957 
1958   SDValue Zero = DAG.getConstant(0, DL, VT);
1959   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1960 
1961   if (VT == MVT::i32) {
1962     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1963       return Res;
1964   }
1965 
1966   if (VT == MVT::i64 &&
1967       DAG.ComputeNumSignBits(LHS) > 32 &&
1968       DAG.ComputeNumSignBits(RHS) > 32) {
1969     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1970 
1971     //HiLo split
1972     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1973     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1974     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1975                                  LHS_Lo, RHS_Lo);
1976     SDValue Res[2] = {
1977       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1978       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1979     };
1980     return DAG.getMergeValues(Res, DL);
1981   }
1982 
1983   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1984   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1985   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1986   SDValue RSign = LHSign; // Remainder sign is the same as LHS
1987 
1988   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
1989   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
1990 
1991   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
1992   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
1993 
1994   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
1995   SDValue Rem = Div.getValue(1);
1996 
1997   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
1998   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
1999 
2000   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
2001   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
2002 
2003   SDValue Res[2] = {
2004     Div,
2005     Rem
2006   };
2007   return DAG.getMergeValues(Res, DL);
2008 }
2009 
2010 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
2011 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
2012   SDLoc SL(Op);
2013   EVT VT = Op.getValueType();
2014   SDValue X = Op.getOperand(0);
2015   SDValue Y = Op.getOperand(1);
2016 
2017   // TODO: Should this propagate fast-math-flags?
2018 
2019   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
2020   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
2021   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
2022 
2023   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
2024 }
2025 
2026 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
2027   SDLoc SL(Op);
2028   SDValue Src = Op.getOperand(0);
2029 
2030   // result = trunc(src)
2031   // if (src > 0.0 && src != result)
2032   //   result += 1.0
2033 
2034   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2035 
2036   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2037   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
2038 
2039   EVT SetCCVT =
2040       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2041 
2042   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
2043   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2044   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2045 
2046   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
2047   // TODO: Should this propagate fast-math-flags?
2048   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2049 }
2050 
2051 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
2052                                   SelectionDAG &DAG) {
2053   const unsigned FractBits = 52;
2054   const unsigned ExpBits = 11;
2055 
2056   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2057                                 Hi,
2058                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2059                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2060   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2061                             DAG.getConstant(1023, SL, MVT::i32));
2062 
2063   return Exp;
2064 }
2065 
2066 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2067   SDLoc SL(Op);
2068   SDValue Src = Op.getOperand(0);
2069 
2070   assert(Op.getValueType() == MVT::f64);
2071 
2072   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2073   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2074 
2075   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2076 
2077   // Extract the upper half, since this is where we will find the sign and
2078   // exponent.
2079   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2080 
2081   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2082 
2083   const unsigned FractBits = 52;
2084 
2085   // Extract the sign bit.
2086   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2087   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2088 
2089   // Extend back to 64-bits.
2090   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2091   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2092 
2093   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2094   const SDValue FractMask
2095     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2096 
2097   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2098   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2099   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2100 
2101   EVT SetCCVT =
2102       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2103 
2104   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2105 
2106   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2107   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2108 
2109   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2110   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2111 
2112   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2113 }
2114 
2115 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2116   SDLoc SL(Op);
2117   SDValue Src = Op.getOperand(0);
2118 
2119   assert(Op.getValueType() == MVT::f64);
2120 
2121   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2122   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2123   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2124 
2125   // TODO: Should this propagate fast-math-flags?
2126 
2127   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2128   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2129 
2130   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2131 
2132   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2133   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2134 
2135   EVT SetCCVT =
2136       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2137   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2138 
2139   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2140 }
2141 
2142 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2143   // FNEARBYINT and FRINT are the same, except in their handling of FP
2144   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2145   // rint, so just treat them as equivalent.
2146   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2147 }
2148 
2149 // XXX - May require not supporting f32 denormals?
2150 
2151 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2152 // compare and vselect end up producing worse code than scalarizing the whole
2153 // operation.
2154 SDValue AMDGPUTargetLowering::LowerFROUND32_16(SDValue Op, SelectionDAG &DAG) const {
2155   SDLoc SL(Op);
2156   SDValue X = Op.getOperand(0);
2157   EVT VT = Op.getValueType();
2158 
2159   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2160 
2161   // TODO: Should this propagate fast-math-flags?
2162 
2163   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2164 
2165   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2166 
2167   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2168   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2169   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2170 
2171   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2172 
2173   EVT SetCCVT =
2174       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2175 
2176   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2177 
2178   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2179 
2180   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2181 }
2182 
2183 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2184   SDLoc SL(Op);
2185   SDValue X = Op.getOperand(0);
2186 
2187   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2188 
2189   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2190   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2191   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2192   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2193   EVT SetCCVT =
2194       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2195 
2196   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2197 
2198   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2199 
2200   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2201 
2202   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2203                                        MVT::i64);
2204 
2205   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2206   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2207                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2208                                           MVT::i64),
2209                           Exp);
2210 
2211   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2212   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2213                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2214                               ISD::SETNE);
2215 
2216   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2217                              D, DAG.getConstant(0, SL, MVT::i64));
2218   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2219 
2220   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2221   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2222 
2223   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2224   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2225   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2226 
2227   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2228                             ExpEqNegOne,
2229                             DAG.getConstantFP(1.0, SL, MVT::f64),
2230                             DAG.getConstantFP(0.0, SL, MVT::f64));
2231 
2232   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2233 
2234   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2235   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2236 
2237   return K;
2238 }
2239 
2240 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2241   EVT VT = Op.getValueType();
2242 
2243   if (VT == MVT::f32 || VT == MVT::f16)
2244     return LowerFROUND32_16(Op, DAG);
2245 
2246   if (VT == MVT::f64)
2247     return LowerFROUND64(Op, DAG);
2248 
2249   llvm_unreachable("unhandled type");
2250 }
2251 
2252 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2253   SDLoc SL(Op);
2254   SDValue Src = Op.getOperand(0);
2255 
2256   // result = trunc(src);
2257   // if (src < 0.0 && src != result)
2258   //   result += -1.0.
2259 
2260   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2261 
2262   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2263   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2264 
2265   EVT SetCCVT =
2266       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2267 
2268   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2269   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2270   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2271 
2272   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2273   // TODO: Should this propagate fast-math-flags?
2274   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2275 }
2276 
2277 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2278                                         double Log2BaseInverted) const {
2279   EVT VT = Op.getValueType();
2280 
2281   SDLoc SL(Op);
2282   SDValue Operand = Op.getOperand(0);
2283   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2284   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2285 
2286   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2287 }
2288 
2289 static bool isCtlzOpc(unsigned Opc) {
2290   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2291 }
2292 
2293 static bool isCttzOpc(unsigned Opc) {
2294   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2295 }
2296 
2297 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2298   SDLoc SL(Op);
2299   SDValue Src = Op.getOperand(0);
2300   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2301                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2302 
2303   unsigned ISDOpc, NewOpc;
2304   if (isCtlzOpc(Op.getOpcode())) {
2305     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2306     NewOpc = AMDGPUISD::FFBH_U32;
2307   } else if (isCttzOpc(Op.getOpcode())) {
2308     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2309     NewOpc = AMDGPUISD::FFBL_B32;
2310   } else
2311     llvm_unreachable("Unexpected OPCode!!!");
2312 
2313 
2314   if (ZeroUndef && Src.getValueType() == MVT::i32)
2315     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2316 
2317   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2318 
2319   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2320   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2321 
2322   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2323   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2324 
2325   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2326                                    *DAG.getContext(), MVT::i32);
2327 
2328   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2329   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2330 
2331   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2332   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2333 
2334   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2335   SDValue Add, NewOpr;
2336   if (isCtlzOpc(Op.getOpcode())) {
2337     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2338     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2339     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2340   } else {
2341     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2342     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2343     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2344   }
2345 
2346   if (!ZeroUndef) {
2347     // Test if the full 64-bit input is zero.
2348 
2349     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2350     // which we probably don't want.
2351     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2352     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2353     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2354 
2355     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2356     // with the same cycles, otherwise it is slower.
2357     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2358     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2359 
2360     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2361 
2362     // The instruction returns -1 for 0 input, but the defined intrinsic
2363     // behavior is to return the number of bits.
2364     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2365                          SrcIsZero, Bits32, NewOpr);
2366   }
2367 
2368   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2369 }
2370 
2371 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2372                                                bool Signed) const {
2373   // Unsigned
2374   // cul2f(ulong u)
2375   //{
2376   //  uint lz = clz(u);
2377   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2378   //  u = (u << lz) & 0x7fffffffffffffffUL;
2379   //  ulong t = u & 0xffffffffffUL;
2380   //  uint v = (e << 23) | (uint)(u >> 40);
2381   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2382   //  return as_float(v + r);
2383   //}
2384   // Signed
2385   // cl2f(long l)
2386   //{
2387   //  long s = l >> 63;
2388   //  float r = cul2f((l + s) ^ s);
2389   //  return s ? -r : r;
2390   //}
2391 
2392   SDLoc SL(Op);
2393   SDValue Src = Op.getOperand(0);
2394   SDValue L = Src;
2395 
2396   SDValue S;
2397   if (Signed) {
2398     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2399     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2400 
2401     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2402     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2403   }
2404 
2405   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2406                                    *DAG.getContext(), MVT::f32);
2407 
2408 
2409   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2410   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2411   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2412   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2413 
2414   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2415   SDValue E = DAG.getSelect(SL, MVT::i32,
2416     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2417     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2418     ZeroI32);
2419 
2420   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2421     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2422     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2423 
2424   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2425                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2426 
2427   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2428                              U, DAG.getConstant(40, SL, MVT::i64));
2429 
2430   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2431     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2432     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2433 
2434   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2435   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2436   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2437 
2438   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2439 
2440   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2441 
2442   SDValue R = DAG.getSelect(SL, MVT::i32,
2443     RCmp,
2444     One,
2445     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2446   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2447   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2448 
2449   if (!Signed)
2450     return R;
2451 
2452   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2453   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2454 }
2455 
2456 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2457                                                bool Signed) const {
2458   SDLoc SL(Op);
2459   SDValue Src = Op.getOperand(0);
2460 
2461   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2462 
2463   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2464                            DAG.getConstant(0, SL, MVT::i32));
2465   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2466                            DAG.getConstant(1, SL, MVT::i32));
2467 
2468   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2469                               SL, MVT::f64, Hi);
2470 
2471   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2472 
2473   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2474                               DAG.getConstant(32, SL, MVT::i32));
2475   // TODO: Should this propagate fast-math-flags?
2476   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2477 }
2478 
2479 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2480                                                SelectionDAG &DAG) const {
2481   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2482          "operation should be legal");
2483 
2484   // TODO: Factor out code common with LowerSINT_TO_FP.
2485 
2486   EVT DestVT = Op.getValueType();
2487   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2488     SDLoc DL(Op);
2489     SDValue Src = Op.getOperand(0);
2490 
2491     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2492     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2493     SDValue FPRound =
2494         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2495 
2496     return FPRound;
2497   }
2498 
2499   if (DestVT == MVT::f32)
2500     return LowerINT_TO_FP32(Op, DAG, false);
2501 
2502   assert(DestVT == MVT::f64);
2503   return LowerINT_TO_FP64(Op, DAG, false);
2504 }
2505 
2506 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2507                                               SelectionDAG &DAG) const {
2508   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2509          "operation should be legal");
2510 
2511   // TODO: Factor out code common with LowerUINT_TO_FP.
2512 
2513   EVT DestVT = Op.getValueType();
2514   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2515     SDLoc DL(Op);
2516     SDValue Src = Op.getOperand(0);
2517 
2518     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2519     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2520     SDValue FPRound =
2521         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2522 
2523     return FPRound;
2524   }
2525 
2526   if (DestVT == MVT::f32)
2527     return LowerINT_TO_FP32(Op, DAG, true);
2528 
2529   assert(DestVT == MVT::f64);
2530   return LowerINT_TO_FP64(Op, DAG, true);
2531 }
2532 
2533 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2534                                                bool Signed) const {
2535   SDLoc SL(Op);
2536 
2537   SDValue Src = Op.getOperand(0);
2538 
2539   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2540 
2541   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2542                                  MVT::f64);
2543   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2544                                  MVT::f64);
2545   // TODO: Should this propagate fast-math-flags?
2546   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2547 
2548   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2549 
2550 
2551   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2552 
2553   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2554                            MVT::i32, FloorMul);
2555   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2556 
2557   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2558 
2559   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2560 }
2561 
2562 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2563   SDLoc DL(Op);
2564   SDValue N0 = Op.getOperand(0);
2565 
2566   // Convert to target node to get known bits
2567   if (N0.getValueType() == MVT::f32)
2568     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2569 
2570   if (getTargetMachine().Options.UnsafeFPMath) {
2571     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2572     return SDValue();
2573   }
2574 
2575   assert(N0.getSimpleValueType() == MVT::f64);
2576 
2577   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2578   const unsigned ExpMask = 0x7ff;
2579   const unsigned ExpBiasf64 = 1023;
2580   const unsigned ExpBiasf16 = 15;
2581   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2582   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2583   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2584   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2585                            DAG.getConstant(32, DL, MVT::i64));
2586   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2587   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2588   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2589                           DAG.getConstant(20, DL, MVT::i64));
2590   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2591                   DAG.getConstant(ExpMask, DL, MVT::i32));
2592   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2593   // add the f16 bias (15) to get the biased exponent for the f16 format.
2594   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2595                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2596 
2597   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2598                           DAG.getConstant(8, DL, MVT::i32));
2599   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2600                   DAG.getConstant(0xffe, DL, MVT::i32));
2601 
2602   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2603                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2604   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2605 
2606   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2607   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2608 
2609   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2610   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2611       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2612                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2613 
2614   // N = M | (E << 12);
2615   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2616       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2617                   DAG.getConstant(12, DL, MVT::i32)));
2618 
2619   // B = clamp(1-E, 0, 13);
2620   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2621                                   One, E);
2622   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2623   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2624                   DAG.getConstant(13, DL, MVT::i32));
2625 
2626   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2627                                    DAG.getConstant(0x1000, DL, MVT::i32));
2628 
2629   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2630   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2631   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2632   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2633 
2634   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2635   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2636                               DAG.getConstant(0x7, DL, MVT::i32));
2637   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2638                   DAG.getConstant(2, DL, MVT::i32));
2639   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2640                                One, Zero, ISD::SETEQ);
2641   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2642                                One, Zero, ISD::SETGT);
2643   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2644   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2645 
2646   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2647                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2648   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2649                       I, V, ISD::SETEQ);
2650 
2651   // Extract the sign bit.
2652   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2653                             DAG.getConstant(16, DL, MVT::i32));
2654   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2655                      DAG.getConstant(0x8000, DL, MVT::i32));
2656 
2657   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2658   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2659 }
2660 
2661 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2662                                               SelectionDAG &DAG) const {
2663   SDValue Src = Op.getOperand(0);
2664 
2665   // TODO: Factor out code common with LowerFP_TO_UINT.
2666 
2667   EVT SrcVT = Src.getValueType();
2668   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2669     SDLoc DL(Op);
2670 
2671     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2672     SDValue FpToInt32 =
2673         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2674 
2675     return FpToInt32;
2676   }
2677 
2678   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2679     return LowerFP64_TO_INT(Op, DAG, true);
2680 
2681   return SDValue();
2682 }
2683 
2684 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2685                                               SelectionDAG &DAG) const {
2686   SDValue Src = Op.getOperand(0);
2687 
2688   // TODO: Factor out code common with LowerFP_TO_SINT.
2689 
2690   EVT SrcVT = Src.getValueType();
2691   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2692     SDLoc DL(Op);
2693 
2694     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2695     SDValue FpToInt32 =
2696         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2697 
2698     return FpToInt32;
2699   }
2700 
2701   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2702     return LowerFP64_TO_INT(Op, DAG, false);
2703 
2704   return SDValue();
2705 }
2706 
2707 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2708                                                      SelectionDAG &DAG) const {
2709   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2710   MVT VT = Op.getSimpleValueType();
2711   MVT ScalarVT = VT.getScalarType();
2712 
2713   assert(VT.isVector());
2714 
2715   SDValue Src = Op.getOperand(0);
2716   SDLoc DL(Op);
2717 
2718   // TODO: Don't scalarize on Evergreen?
2719   unsigned NElts = VT.getVectorNumElements();
2720   SmallVector<SDValue, 8> Args;
2721   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2722 
2723   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2724   for (unsigned I = 0; I < NElts; ++I)
2725     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2726 
2727   return DAG.getBuildVector(VT, DL, Args);
2728 }
2729 
2730 //===----------------------------------------------------------------------===//
2731 // Custom DAG optimizations
2732 //===----------------------------------------------------------------------===//
2733 
2734 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2735   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2736 }
2737 
2738 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2739   EVT VT = Op.getValueType();
2740   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2741                                      // as unsigned 24-bit values.
2742     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2743 }
2744 
2745 static bool simplifyI24(SDNode *Node24, unsigned OpIdx,
2746                         TargetLowering::DAGCombinerInfo &DCI) {
2747 
2748   SelectionDAG &DAG = DCI.DAG;
2749   SDValue Op = Node24->getOperand(OpIdx);
2750   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2751   EVT VT = Op.getValueType();
2752 
2753   APInt Demanded = APInt::getLowBitsSet(VT.getSizeInBits(), 24);
2754   APInt KnownZero, KnownOne;
2755   TargetLowering::TargetLoweringOpt TLO(DAG, true, true);
2756   if (TLI.SimplifyDemandedBits(Node24, OpIdx, Demanded, DCI, TLO))
2757     return true;
2758 
2759   return false;
2760 }
2761 
2762 template <typename IntTy>
2763 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2764                                uint32_t Width, const SDLoc &DL) {
2765   if (Width + Offset < 32) {
2766     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2767     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2768     return DAG.getConstant(Result, DL, MVT::i32);
2769   }
2770 
2771   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2772 }
2773 
2774 static bool hasVolatileUser(SDNode *Val) {
2775   for (SDNode *U : Val->uses()) {
2776     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2777       if (M->isVolatile())
2778         return true;
2779     }
2780   }
2781 
2782   return false;
2783 }
2784 
2785 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2786   // i32 vectors are the canonical memory type.
2787   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2788     return false;
2789 
2790   if (!VT.isByteSized())
2791     return false;
2792 
2793   unsigned Size = VT.getStoreSize();
2794 
2795   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2796     return false;
2797 
2798   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2799     return false;
2800 
2801   return true;
2802 }
2803 
2804 // Replace load of an illegal type with a store of a bitcast to a friendlier
2805 // type.
2806 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2807                                                  DAGCombinerInfo &DCI) const {
2808   if (!DCI.isBeforeLegalize())
2809     return SDValue();
2810 
2811   LoadSDNode *LN = cast<LoadSDNode>(N);
2812   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2813     return SDValue();
2814 
2815   SDLoc SL(N);
2816   SelectionDAG &DAG = DCI.DAG;
2817   EVT VT = LN->getMemoryVT();
2818 
2819   unsigned Size = VT.getStoreSize();
2820   unsigned Align = LN->getAlignment();
2821   if (Align < Size && isTypeLegal(VT)) {
2822     bool IsFast;
2823     unsigned AS = LN->getAddressSpace();
2824 
2825     // Expand unaligned loads earlier than legalization. Due to visitation order
2826     // problems during legalization, the emitted instructions to pack and unpack
2827     // the bytes again are not eliminated in the case of an unaligned copy.
2828     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2829       if (VT.isVector())
2830         return scalarizeVectorLoad(LN, DAG);
2831 
2832       SDValue Ops[2];
2833       std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2834       return DAG.getMergeValues(Ops, SDLoc(N));
2835     }
2836 
2837     if (!IsFast)
2838       return SDValue();
2839   }
2840 
2841   if (!shouldCombineMemoryType(VT))
2842     return SDValue();
2843 
2844   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2845 
2846   SDValue NewLoad
2847     = DAG.getLoad(NewVT, SL, LN->getChain(),
2848                   LN->getBasePtr(), LN->getMemOperand());
2849 
2850   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2851   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2852   return SDValue(N, 0);
2853 }
2854 
2855 // Replace store of an illegal type with a store of a bitcast to a friendlier
2856 // type.
2857 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2858                                                   DAGCombinerInfo &DCI) const {
2859   if (!DCI.isBeforeLegalize())
2860     return SDValue();
2861 
2862   StoreSDNode *SN = cast<StoreSDNode>(N);
2863   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2864     return SDValue();
2865 
2866   EVT VT = SN->getMemoryVT();
2867   unsigned Size = VT.getStoreSize();
2868 
2869   SDLoc SL(N);
2870   SelectionDAG &DAG = DCI.DAG;
2871   unsigned Align = SN->getAlignment();
2872   if (Align < Size && isTypeLegal(VT)) {
2873     bool IsFast;
2874     unsigned AS = SN->getAddressSpace();
2875 
2876     // Expand unaligned stores earlier than legalization. Due to visitation
2877     // order problems during legalization, the emitted instructions to pack and
2878     // unpack the bytes again are not eliminated in the case of an unaligned
2879     // copy.
2880     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2881       if (VT.isVector())
2882         return scalarizeVectorStore(SN, DAG);
2883 
2884       return expandUnalignedStore(SN, DAG);
2885     }
2886 
2887     if (!IsFast)
2888       return SDValue();
2889   }
2890 
2891   if (!shouldCombineMemoryType(VT))
2892     return SDValue();
2893 
2894   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2895   SDValue Val = SN->getValue();
2896 
2897   //DCI.AddToWorklist(Val.getNode());
2898 
2899   bool OtherUses = !Val.hasOneUse();
2900   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2901   if (OtherUses) {
2902     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2903     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2904   }
2905 
2906   return DAG.getStore(SN->getChain(), SL, CastVal,
2907                       SN->getBasePtr(), SN->getMemOperand());
2908 }
2909 
2910 SDValue AMDGPUTargetLowering::performClampCombine(SDNode *N,
2911                                                   DAGCombinerInfo &DCI) const {
2912   ConstantFPSDNode *CSrc = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
2913   if (!CSrc)
2914     return SDValue();
2915 
2916   const APFloat &F = CSrc->getValueAPF();
2917   APFloat Zero = APFloat::getZero(F.getSemantics());
2918   APFloat::cmpResult Cmp0 = F.compare(Zero);
2919   if (Cmp0 == APFloat::cmpLessThan ||
2920       (Cmp0 == APFloat::cmpUnordered && Subtarget->enableDX10Clamp())) {
2921     return DCI.DAG.getConstantFP(Zero, SDLoc(N), N->getValueType(0));
2922   }
2923 
2924   APFloat One(F.getSemantics(), "1.0");
2925   APFloat::cmpResult Cmp1 = F.compare(One);
2926   if (Cmp1 == APFloat::cmpGreaterThan)
2927     return DCI.DAG.getConstantFP(One, SDLoc(N), N->getValueType(0));
2928 
2929   return SDValue(CSrc, 0);
2930 }
2931 
2932 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2933 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2934 // issues.
2935 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2936                                                         DAGCombinerInfo &DCI) const {
2937   SelectionDAG &DAG = DCI.DAG;
2938   SDValue N0 = N->getOperand(0);
2939 
2940   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2941   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2942   if (N0.getOpcode() == ISD::TRUNCATE) {
2943     SDValue N1 = N->getOperand(1);
2944     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2945     SDLoc SL(N);
2946 
2947     SDValue Src = N0.getOperand(0);
2948     EVT SrcVT = Src.getValueType();
2949     if (SrcVT.bitsGE(ExtVT)) {
2950       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2951       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2952     }
2953   }
2954 
2955   return SDValue();
2956 }
2957 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
2958 /// binary operation \p Opc to it with the corresponding constant operands.
2959 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
2960   DAGCombinerInfo &DCI, const SDLoc &SL,
2961   unsigned Opc, SDValue LHS,
2962   uint32_t ValLo, uint32_t ValHi) const {
2963   SelectionDAG &DAG = DCI.DAG;
2964   SDValue Lo, Hi;
2965   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
2966 
2967   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
2968   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
2969 
2970   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
2971   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
2972 
2973   // Re-visit the ands. It's possible we eliminated one of them and it could
2974   // simplify the vector.
2975   DCI.AddToWorklist(Lo.getNode());
2976   DCI.AddToWorklist(Hi.getNode());
2977 
2978   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
2979   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2980 }
2981 
2982 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
2983                                                 DAGCombinerInfo &DCI) const {
2984   EVT VT = N->getValueType(0);
2985 
2986   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2987   if (!RHS)
2988     return SDValue();
2989 
2990   SDValue LHS = N->getOperand(0);
2991   unsigned RHSVal = RHS->getZExtValue();
2992   if (!RHSVal)
2993     return LHS;
2994 
2995   SDLoc SL(N);
2996   SelectionDAG &DAG = DCI.DAG;
2997 
2998   switch (LHS->getOpcode()) {
2999   default:
3000     break;
3001   case ISD::ZERO_EXTEND:
3002   case ISD::SIGN_EXTEND:
3003   case ISD::ANY_EXTEND: {
3004     SDValue X = LHS->getOperand(0);
3005 
3006     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
3007         isTypeLegal(MVT::v2i16)) {
3008       // Prefer build_vector as the canonical form if packed types are legal.
3009       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
3010       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
3011        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
3012       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
3013     }
3014 
3015     // shl (ext x) => zext (shl x), if shift does not overflow int
3016     if (VT != MVT::i64)
3017       break;
3018     KnownBits Known;
3019     DAG.computeKnownBits(X, Known);
3020     unsigned LZ = Known.countMinLeadingZeros();
3021     if (LZ < RHSVal)
3022       break;
3023     EVT XVT = X.getValueType();
3024     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
3025     return DAG.getZExtOrTrunc(Shl, SL, VT);
3026   }
3027   }
3028 
3029   if (VT != MVT::i64)
3030     return SDValue();
3031 
3032   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
3033 
3034   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
3035   // common case, splitting this into a move and a 32-bit shift is faster and
3036   // the same code size.
3037   if (RHSVal < 32)
3038     return SDValue();
3039 
3040   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
3041 
3042   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
3043   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
3044 
3045   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3046 
3047   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
3048   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3049 }
3050 
3051 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
3052                                                 DAGCombinerInfo &DCI) const {
3053   if (N->getValueType(0) != MVT::i64)
3054     return SDValue();
3055 
3056   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3057   if (!RHS)
3058     return SDValue();
3059 
3060   SelectionDAG &DAG = DCI.DAG;
3061   SDLoc SL(N);
3062   unsigned RHSVal = RHS->getZExtValue();
3063 
3064   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3065   if (RHSVal == 32) {
3066     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3067     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3068                                    DAG.getConstant(31, SL, MVT::i32));
3069 
3070     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3071     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3072   }
3073 
3074   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3075   if (RHSVal == 63) {
3076     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3077     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3078                                    DAG.getConstant(31, SL, MVT::i32));
3079     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3080     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3081   }
3082 
3083   return SDValue();
3084 }
3085 
3086 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3087                                                 DAGCombinerInfo &DCI) const {
3088   if (N->getValueType(0) != MVT::i64)
3089     return SDValue();
3090 
3091   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3092   if (!RHS)
3093     return SDValue();
3094 
3095   unsigned ShiftAmt = RHS->getZExtValue();
3096   if (ShiftAmt < 32)
3097     return SDValue();
3098 
3099   // srl i64:x, C for C >= 32
3100   // =>
3101   //   build_pair (srl hi_32(x), C - 32), 0
3102 
3103   SelectionDAG &DAG = DCI.DAG;
3104   SDLoc SL(N);
3105 
3106   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3107   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3108 
3109   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, N->getOperand(0));
3110   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32,
3111                            VecOp, One);
3112 
3113   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3114   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3115 
3116   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3117 
3118   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3119 }
3120 
3121 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3122 // instructions. If we only match on the legalized i64 mul expansion,
3123 // SimplifyDemandedBits will be unable to remove them because there will be
3124 // multiple uses due to the separate mul + mulh[su].
3125 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3126                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3127   if (Size <= 32) {
3128     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3129     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3130   }
3131 
3132   // Because we want to eliminate extension instructions before the
3133   // operation, we need to create a single user here (i.e. not the separate
3134   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3135 
3136   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3137 
3138   SDValue Mul = DAG.getNode(MulOpc, SL,
3139                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3140 
3141   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3142                      Mul.getValue(0), Mul.getValue(1));
3143 }
3144 
3145 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3146                                                 DAGCombinerInfo &DCI) const {
3147   EVT VT = N->getValueType(0);
3148 
3149   unsigned Size = VT.getSizeInBits();
3150   if (VT.isVector() || Size > 64)
3151     return SDValue();
3152 
3153   // There are i16 integer mul/mad.
3154   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3155     return SDValue();
3156 
3157   SelectionDAG &DAG = DCI.DAG;
3158   SDLoc DL(N);
3159 
3160   SDValue N0 = N->getOperand(0);
3161   SDValue N1 = N->getOperand(1);
3162   SDValue Mul;
3163 
3164   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3165     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3166     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3167     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3168   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3169     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3170     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3171     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3172   } else {
3173     return SDValue();
3174   }
3175 
3176   // We need to use sext even for MUL_U24, because MUL_U24 is used
3177   // for signed multiply of 8 and 16-bit types.
3178   return DAG.getSExtOrTrunc(Mul, DL, VT);
3179 }
3180 
3181 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3182                                                   DAGCombinerInfo &DCI) const {
3183   EVT VT = N->getValueType(0);
3184 
3185   if (!Subtarget->hasMulI24() || VT.isVector())
3186     return SDValue();
3187 
3188   SelectionDAG &DAG = DCI.DAG;
3189   SDLoc DL(N);
3190 
3191   SDValue N0 = N->getOperand(0);
3192   SDValue N1 = N->getOperand(1);
3193 
3194   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3195     return SDValue();
3196 
3197   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3198   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3199 
3200   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3201   DCI.AddToWorklist(Mulhi.getNode());
3202   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3203 }
3204 
3205 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3206                                                   DAGCombinerInfo &DCI) const {
3207   EVT VT = N->getValueType(0);
3208 
3209   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3210     return SDValue();
3211 
3212   SelectionDAG &DAG = DCI.DAG;
3213   SDLoc DL(N);
3214 
3215   SDValue N0 = N->getOperand(0);
3216   SDValue N1 = N->getOperand(1);
3217 
3218   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3219     return SDValue();
3220 
3221   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3222   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3223 
3224   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3225   DCI.AddToWorklist(Mulhi.getNode());
3226   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3227 }
3228 
3229 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3230   SDNode *N, DAGCombinerInfo &DCI) const {
3231   SelectionDAG &DAG = DCI.DAG;
3232 
3233   // Simplify demanded bits before splitting into multiple users.
3234   if (simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI))
3235     return SDValue();
3236 
3237   SDValue N0 = N->getOperand(0);
3238   SDValue N1 = N->getOperand(1);
3239 
3240   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3241 
3242   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3243   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3244 
3245   SDLoc SL(N);
3246 
3247   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3248   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3249   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3250 }
3251 
3252 static bool isNegativeOne(SDValue Val) {
3253   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3254     return C->isAllOnesValue();
3255   return false;
3256 }
3257 
3258 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3259                                           SDValue Op,
3260                                           const SDLoc &DL,
3261                                           unsigned Opc) const {
3262   EVT VT = Op.getValueType();
3263   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3264   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3265                               LegalVT != MVT::i16))
3266     return SDValue();
3267 
3268   if (VT != MVT::i32)
3269     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3270 
3271   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3272   if (VT != MVT::i32)
3273     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3274 
3275   return FFBX;
3276 }
3277 
3278 // The native instructions return -1 on 0 input. Optimize out a select that
3279 // produces -1 on 0.
3280 //
3281 // TODO: If zero is not undef, we could also do this if the output is compared
3282 // against the bitwidth.
3283 //
3284 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
3285 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3286                                                  SDValue LHS, SDValue RHS,
3287                                                  DAGCombinerInfo &DCI) const {
3288   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3289   if (!CmpRhs || !CmpRhs->isNullValue())
3290     return SDValue();
3291 
3292   SelectionDAG &DAG = DCI.DAG;
3293   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3294   SDValue CmpLHS = Cond.getOperand(0);
3295 
3296   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3297                                            AMDGPUISD::FFBH_U32;
3298 
3299   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3300   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3301   if (CCOpcode == ISD::SETEQ &&
3302       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3303       RHS.getOperand(0) == CmpLHS &&
3304       isNegativeOne(LHS)) {
3305     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3306   }
3307 
3308   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3309   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3310   if (CCOpcode == ISD::SETNE &&
3311       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3312       LHS.getOperand(0) == CmpLHS &&
3313       isNegativeOne(RHS)) {
3314     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3315   }
3316 
3317   return SDValue();
3318 }
3319 
3320 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3321                                          unsigned Op,
3322                                          const SDLoc &SL,
3323                                          SDValue Cond,
3324                                          SDValue N1,
3325                                          SDValue N2) {
3326   SelectionDAG &DAG = DCI.DAG;
3327   EVT VT = N1.getValueType();
3328 
3329   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3330                                   N1.getOperand(0), N2.getOperand(0));
3331   DCI.AddToWorklist(NewSelect.getNode());
3332   return DAG.getNode(Op, SL, VT, NewSelect);
3333 }
3334 
3335 // Pull a free FP operation out of a select so it may fold into uses.
3336 //
3337 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3338 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3339 //
3340 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3341 // select c, (fabs x), +k -> fabs (select c, x, k)
3342 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3343                                     SDValue N) {
3344   SelectionDAG &DAG = DCI.DAG;
3345   SDValue Cond = N.getOperand(0);
3346   SDValue LHS = N.getOperand(1);
3347   SDValue RHS = N.getOperand(2);
3348 
3349   EVT VT = N.getValueType();
3350   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3351       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3352     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3353                                      SDLoc(N), Cond, LHS, RHS);
3354   }
3355 
3356   bool Inv = false;
3357   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3358     std::swap(LHS, RHS);
3359     Inv = true;
3360   }
3361 
3362   // TODO: Support vector constants.
3363   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3364   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3365     SDLoc SL(N);
3366     // If one side is an fneg/fabs and the other is a constant, we can push the
3367     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3368     SDValue NewLHS = LHS.getOperand(0);
3369     SDValue NewRHS = RHS;
3370 
3371     // Careful: if the neg can be folded up, don't try to pull it back down.
3372     bool ShouldFoldNeg = true;
3373 
3374     if (NewLHS.hasOneUse()) {
3375       unsigned Opc = NewLHS.getOpcode();
3376       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3377         ShouldFoldNeg = false;
3378       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3379         ShouldFoldNeg = false;
3380     }
3381 
3382     if (ShouldFoldNeg) {
3383       if (LHS.getOpcode() == ISD::FNEG)
3384         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3385       else if (CRHS->isNegative())
3386         return SDValue();
3387 
3388       if (Inv)
3389         std::swap(NewLHS, NewRHS);
3390 
3391       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3392                                       Cond, NewLHS, NewRHS);
3393       DCI.AddToWorklist(NewSelect.getNode());
3394       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3395     }
3396   }
3397 
3398   return SDValue();
3399 }
3400 
3401 
3402 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3403                                                    DAGCombinerInfo &DCI) const {
3404   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3405     return Folded;
3406 
3407   SDValue Cond = N->getOperand(0);
3408   if (Cond.getOpcode() != ISD::SETCC)
3409     return SDValue();
3410 
3411   EVT VT = N->getValueType(0);
3412   SDValue LHS = Cond.getOperand(0);
3413   SDValue RHS = Cond.getOperand(1);
3414   SDValue CC = Cond.getOperand(2);
3415 
3416   SDValue True = N->getOperand(1);
3417   SDValue False = N->getOperand(2);
3418 
3419   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3420     SelectionDAG &DAG = DCI.DAG;
3421     if ((DAG.isConstantValueOfAnyType(True) ||
3422          DAG.isConstantValueOfAnyType(True)) &&
3423         (!DAG.isConstantValueOfAnyType(False) &&
3424          !DAG.isConstantValueOfAnyType(False))) {
3425       // Swap cmp + select pair to move constant to false input.
3426       // This will allow using VOPC cndmasks more often.
3427       // select (setcc x, y), k, x -> select (setcc y, x) x, x
3428 
3429       SDLoc SL(N);
3430       ISD::CondCode NewCC = getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3431                                             LHS.getValueType().isInteger());
3432 
3433       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3434       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3435     }
3436 
3437     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3438       SDValue MinMax
3439         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3440       // Revisit this node so we can catch min3/max3/med3 patterns.
3441       //DCI.AddToWorklist(MinMax.getNode());
3442       return MinMax;
3443     }
3444   }
3445 
3446   // There's no reason to not do this if the condition has other uses.
3447   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3448 }
3449 
3450 static bool isConstantFPZero(SDValue N) {
3451   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N))
3452     return C->isZero() && !C->isNegative();
3453   return false;
3454 }
3455 
3456 static unsigned inverseMinMax(unsigned Opc) {
3457   switch (Opc) {
3458   case ISD::FMAXNUM:
3459     return ISD::FMINNUM;
3460   case ISD::FMINNUM:
3461     return ISD::FMAXNUM;
3462   case AMDGPUISD::FMAX_LEGACY:
3463     return AMDGPUISD::FMIN_LEGACY;
3464   case AMDGPUISD::FMIN_LEGACY:
3465     return  AMDGPUISD::FMAX_LEGACY;
3466   default:
3467     llvm_unreachable("invalid min/max opcode");
3468   }
3469 }
3470 
3471 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3472                                                  DAGCombinerInfo &DCI) const {
3473   SelectionDAG &DAG = DCI.DAG;
3474   SDValue N0 = N->getOperand(0);
3475   EVT VT = N->getValueType(0);
3476 
3477   unsigned Opc = N0.getOpcode();
3478 
3479   // If the input has multiple uses and we can either fold the negate down, or
3480   // the other uses cannot, give up. This both prevents unprofitable
3481   // transformations and infinite loops: we won't repeatedly try to fold around
3482   // a negate that has no 'good' form.
3483   if (N0.hasOneUse()) {
3484     // This may be able to fold into the source, but at a code size cost. Don't
3485     // fold if the fold into the user is free.
3486     if (allUsesHaveSourceMods(N, 0))
3487       return SDValue();
3488   } else {
3489     if (fnegFoldsIntoOp(Opc) &&
3490         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3491       return SDValue();
3492   }
3493 
3494   SDLoc SL(N);
3495   switch (Opc) {
3496   case ISD::FADD: {
3497     if (!mayIgnoreSignedZero(N0))
3498       return SDValue();
3499 
3500     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3501     SDValue LHS = N0.getOperand(0);
3502     SDValue RHS = N0.getOperand(1);
3503 
3504     if (LHS.getOpcode() != ISD::FNEG)
3505       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3506     else
3507       LHS = LHS.getOperand(0);
3508 
3509     if (RHS.getOpcode() != ISD::FNEG)
3510       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3511     else
3512       RHS = RHS.getOperand(0);
3513 
3514     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3515     if (!N0.hasOneUse())
3516       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3517     return Res;
3518   }
3519   case ISD::FMUL:
3520   case AMDGPUISD::FMUL_LEGACY: {
3521     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3522     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3523     SDValue LHS = N0.getOperand(0);
3524     SDValue RHS = N0.getOperand(1);
3525 
3526     if (LHS.getOpcode() == ISD::FNEG)
3527       LHS = LHS.getOperand(0);
3528     else if (RHS.getOpcode() == ISD::FNEG)
3529       RHS = RHS.getOperand(0);
3530     else
3531       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3532 
3533     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3534     if (!N0.hasOneUse())
3535       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3536     return Res;
3537   }
3538   case ISD::FMA:
3539   case ISD::FMAD: {
3540     if (!mayIgnoreSignedZero(N0))
3541       return SDValue();
3542 
3543     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3544     SDValue LHS = N0.getOperand(0);
3545     SDValue MHS = N0.getOperand(1);
3546     SDValue RHS = N0.getOperand(2);
3547 
3548     if (LHS.getOpcode() == ISD::FNEG)
3549       LHS = LHS.getOperand(0);
3550     else if (MHS.getOpcode() == ISD::FNEG)
3551       MHS = MHS.getOperand(0);
3552     else
3553       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3554 
3555     if (RHS.getOpcode() != ISD::FNEG)
3556       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3557     else
3558       RHS = RHS.getOperand(0);
3559 
3560     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3561     if (!N0.hasOneUse())
3562       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3563     return Res;
3564   }
3565   case ISD::FMAXNUM:
3566   case ISD::FMINNUM:
3567   case AMDGPUISD::FMAX_LEGACY:
3568   case AMDGPUISD::FMIN_LEGACY: {
3569     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3570     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3571     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3572     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3573 
3574     SDValue LHS = N0.getOperand(0);
3575     SDValue RHS = N0.getOperand(1);
3576 
3577     // 0 doesn't have a negated inline immediate.
3578     // TODO: Shouldn't fold 1/2pi either, and should be generalized to other
3579     // operations.
3580     if (isConstantFPZero(RHS))
3581       return SDValue();
3582 
3583     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3584     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3585     unsigned Opposite = inverseMinMax(Opc);
3586 
3587     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3588     if (!N0.hasOneUse())
3589       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3590     return Res;
3591   }
3592   case ISD::FP_EXTEND:
3593   case ISD::FTRUNC:
3594   case ISD::FRINT:
3595   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3596   case ISD::FSIN:
3597   case AMDGPUISD::RCP:
3598   case AMDGPUISD::RCP_LEGACY:
3599   case AMDGPUISD::SIN_HW: {
3600     SDValue CvtSrc = N0.getOperand(0);
3601     if (CvtSrc.getOpcode() == ISD::FNEG) {
3602       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3603       // (fneg (rcp (fneg x))) -> (rcp x)
3604       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3605     }
3606 
3607     if (!N0.hasOneUse())
3608       return SDValue();
3609 
3610     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3611     // (fneg (rcp x)) -> (rcp (fneg x))
3612     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3613     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3614   }
3615   case ISD::FP_ROUND: {
3616     SDValue CvtSrc = N0.getOperand(0);
3617 
3618     if (CvtSrc.getOpcode() == ISD::FNEG) {
3619       // (fneg (fp_round (fneg x))) -> (fp_round x)
3620       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3621                          CvtSrc.getOperand(0), N0.getOperand(1));
3622     }
3623 
3624     if (!N0.hasOneUse())
3625       return SDValue();
3626 
3627     // (fneg (fp_round x)) -> (fp_round (fneg x))
3628     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3629     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3630   }
3631   case ISD::FP16_TO_FP: {
3632     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3633     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3634     // Put the fneg back as a legal source operation that can be matched later.
3635     SDLoc SL(N);
3636 
3637     SDValue Src = N0.getOperand(0);
3638     EVT SrcVT = Src.getValueType();
3639 
3640     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3641     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3642                                   DAG.getConstant(0x8000, SL, SrcVT));
3643     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3644   }
3645   default:
3646     return SDValue();
3647   }
3648 }
3649 
3650 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3651                                                  DAGCombinerInfo &DCI) const {
3652   SelectionDAG &DAG = DCI.DAG;
3653   SDValue N0 = N->getOperand(0);
3654 
3655   if (!N0.hasOneUse())
3656     return SDValue();
3657 
3658   switch (N0.getOpcode()) {
3659   case ISD::FP16_TO_FP: {
3660     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3661     SDLoc SL(N);
3662     SDValue Src = N0.getOperand(0);
3663     EVT SrcVT = Src.getValueType();
3664 
3665     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3666     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3667                                   DAG.getConstant(0x7fff, SL, SrcVT));
3668     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3669   }
3670   default:
3671     return SDValue();
3672   }
3673 }
3674 
3675 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3676                                                 DAGCombinerInfo &DCI) const {
3677   SelectionDAG &DAG = DCI.DAG;
3678   SDLoc DL(N);
3679 
3680   switch(N->getOpcode()) {
3681   default:
3682     break;
3683   case ISD::BITCAST: {
3684     EVT DestVT = N->getValueType(0);
3685 
3686     // Push casts through vector builds. This helps avoid emitting a large
3687     // number of copies when materializing floating point vector constants.
3688     //
3689     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3690     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3691     if (DestVT.isVector()) {
3692       SDValue Src = N->getOperand(0);
3693       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3694         EVT SrcVT = Src.getValueType();
3695         unsigned NElts = DestVT.getVectorNumElements();
3696 
3697         if (SrcVT.getVectorNumElements() == NElts) {
3698           EVT DestEltVT = DestVT.getVectorElementType();
3699 
3700           SmallVector<SDValue, 8> CastedElts;
3701           SDLoc SL(N);
3702           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3703             SDValue Elt = Src.getOperand(I);
3704             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3705           }
3706 
3707           return DAG.getBuildVector(DestVT, SL, CastedElts);
3708         }
3709       }
3710     }
3711 
3712     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3713       break;
3714 
3715     // Fold bitcasts of constants.
3716     //
3717     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3718     // TODO: Generalize and move to DAGCombiner
3719     SDValue Src = N->getOperand(0);
3720     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3721       assert(Src.getValueType() == MVT::i64);
3722       SDLoc SL(N);
3723       uint64_t CVal = C->getZExtValue();
3724       return DAG.getNode(ISD::BUILD_VECTOR, SL, DestVT,
3725                          DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3726                          DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3727     }
3728 
3729     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3730       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3731       SDLoc SL(N);
3732       uint64_t CVal = Val.getZExtValue();
3733       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3734                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3735                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3736 
3737       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3738     }
3739 
3740     break;
3741   }
3742   case ISD::SHL: {
3743     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3744       break;
3745 
3746     return performShlCombine(N, DCI);
3747   }
3748   case ISD::SRL: {
3749     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3750       break;
3751 
3752     return performSrlCombine(N, DCI);
3753   }
3754   case ISD::SRA: {
3755     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3756       break;
3757 
3758     return performSraCombine(N, DCI);
3759   }
3760   case ISD::MUL:
3761     return performMulCombine(N, DCI);
3762   case ISD::MULHS:
3763     return performMulhsCombine(N, DCI);
3764   case ISD::MULHU:
3765     return performMulhuCombine(N, DCI);
3766   case AMDGPUISD::MUL_I24:
3767   case AMDGPUISD::MUL_U24:
3768   case AMDGPUISD::MULHI_I24:
3769   case AMDGPUISD::MULHI_U24: {
3770     // If the first call to simplify is successfull, then N may end up being
3771     // deleted, so we shouldn't call simplifyI24 again.
3772     simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI);
3773     return SDValue();
3774   }
3775   case AMDGPUISD::MUL_LOHI_I24:
3776   case AMDGPUISD::MUL_LOHI_U24:
3777     return performMulLoHi24Combine(N, DCI);
3778   case ISD::SELECT:
3779     return performSelectCombine(N, DCI);
3780   case ISD::FNEG:
3781     return performFNegCombine(N, DCI);
3782   case ISD::FABS:
3783     return performFAbsCombine(N, DCI);
3784   case AMDGPUISD::BFE_I32:
3785   case AMDGPUISD::BFE_U32: {
3786     assert(!N->getValueType(0).isVector() &&
3787            "Vector handling of BFE not implemented");
3788     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
3789     if (!Width)
3790       break;
3791 
3792     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
3793     if (WidthVal == 0)
3794       return DAG.getConstant(0, DL, MVT::i32);
3795 
3796     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
3797     if (!Offset)
3798       break;
3799 
3800     SDValue BitsFrom = N->getOperand(0);
3801     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
3802 
3803     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
3804 
3805     if (OffsetVal == 0) {
3806       // This is already sign / zero extended, so try to fold away extra BFEs.
3807       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
3808 
3809       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
3810       if (OpSignBits >= SignBits)
3811         return BitsFrom;
3812 
3813       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
3814       if (Signed) {
3815         // This is a sign_extend_inreg. Replace it to take advantage of existing
3816         // DAG Combines. If not eliminated, we will match back to BFE during
3817         // selection.
3818 
3819         // TODO: The sext_inreg of extended types ends, although we can could
3820         // handle them in a single BFE.
3821         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
3822                            DAG.getValueType(SmallVT));
3823       }
3824 
3825       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
3826     }
3827 
3828     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
3829       if (Signed) {
3830         return constantFoldBFE<int32_t>(DAG,
3831                                         CVal->getSExtValue(),
3832                                         OffsetVal,
3833                                         WidthVal,
3834                                         DL);
3835       }
3836 
3837       return constantFoldBFE<uint32_t>(DAG,
3838                                        CVal->getZExtValue(),
3839                                        OffsetVal,
3840                                        WidthVal,
3841                                        DL);
3842     }
3843 
3844     if ((OffsetVal + WidthVal) >= 32 &&
3845         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
3846       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
3847       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
3848                          BitsFrom, ShiftVal);
3849     }
3850 
3851     if (BitsFrom.hasOneUse()) {
3852       APInt Demanded = APInt::getBitsSet(32,
3853                                          OffsetVal,
3854                                          OffsetVal + WidthVal);
3855 
3856       KnownBits Known;
3857       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
3858                                             !DCI.isBeforeLegalizeOps());
3859       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3860       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
3861           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
3862         DCI.CommitTargetLoweringOpt(TLO);
3863       }
3864     }
3865 
3866     break;
3867   }
3868   case ISD::LOAD:
3869     return performLoadCombine(N, DCI);
3870   case ISD::STORE:
3871     return performStoreCombine(N, DCI);
3872   case AMDGPUISD::CLAMP:
3873     return performClampCombine(N, DCI);
3874   case AMDGPUISD::RCP: {
3875     if (const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0))) {
3876       // XXX - Should this flush denormals?
3877       const APFloat &Val = CFP->getValueAPF();
3878       APFloat One(Val.getSemantics(), "1.0");
3879       return DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3880     }
3881 
3882     break;
3883   }
3884   case ISD::AssertZext:
3885   case ISD::AssertSext:
3886     return performAssertSZExtCombine(N, DCI);
3887   }
3888   return SDValue();
3889 }
3890 
3891 //===----------------------------------------------------------------------===//
3892 // Helper functions
3893 //===----------------------------------------------------------------------===//
3894 
3895 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
3896                                                    const TargetRegisterClass *RC,
3897                                                    unsigned Reg, EVT VT,
3898                                                    const SDLoc &SL,
3899                                                    bool RawReg) const {
3900   MachineFunction &MF = DAG.getMachineFunction();
3901   MachineRegisterInfo &MRI = MF.getRegInfo();
3902   unsigned VReg;
3903 
3904   if (!MRI.isLiveIn(Reg)) {
3905     VReg = MRI.createVirtualRegister(RC);
3906     MRI.addLiveIn(Reg, VReg);
3907   } else {
3908     VReg = MRI.getLiveInVirtReg(Reg);
3909   }
3910 
3911   if (RawReg)
3912     return DAG.getRegister(VReg, VT);
3913 
3914   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
3915 }
3916 
3917 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
3918                                                   EVT VT,
3919                                                   const SDLoc &SL,
3920                                                   int64_t Offset) const {
3921   MachineFunction &MF = DAG.getMachineFunction();
3922   MachineFrameInfo &MFI = MF.getFrameInfo();
3923 
3924   int FI = MFI.CreateFixedObject(VT.getStoreSize(), Offset, true);
3925   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
3926   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
3927 
3928   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
3929                      MachineMemOperand::MODereferenceable |
3930                      MachineMemOperand::MOInvariant);
3931 }
3932 
3933 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
3934                                                    const SDLoc &SL,
3935                                                    SDValue Chain,
3936                                                    SDValue StackPtr,
3937                                                    SDValue ArgVal,
3938                                                    int64_t Offset) const {
3939   MachineFunction &MF = DAG.getMachineFunction();
3940   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
3941 
3942   SDValue Ptr = DAG.getObjectPtrOffset(SL, StackPtr, Offset);
3943   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
3944                                MachineMemOperand::MODereferenceable);
3945   return Store;
3946 }
3947 
3948 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
3949                                              const TargetRegisterClass *RC,
3950                                              EVT VT, const SDLoc &SL,
3951                                              const ArgDescriptor &Arg) const {
3952   assert(Arg && "Attempting to load missing argument");
3953 
3954   if (Arg.isRegister())
3955     return CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL);
3956   return loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
3957 }
3958 
3959 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
3960     const AMDGPUMachineFunction *MFI, const ImplicitParameter Param) const {
3961   unsigned Alignment = Subtarget->getAlignmentForImplicitArgPtr();
3962   uint64_t ArgOffset = alignTo(MFI->getABIArgOffset(), Alignment);
3963   switch (Param) {
3964   case GRID_DIM:
3965     return ArgOffset;
3966   case GRID_OFFSET:
3967     return ArgOffset + 4;
3968   }
3969   llvm_unreachable("unexpected implicit parameter type");
3970 }
3971 
3972 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
3973 
3974 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
3975   switch ((AMDGPUISD::NodeType)Opcode) {
3976   case AMDGPUISD::FIRST_NUMBER: break;
3977   // AMDIL DAG nodes
3978   NODE_NAME_CASE(UMUL);
3979   NODE_NAME_CASE(BRANCH_COND);
3980 
3981   // AMDGPU DAG nodes
3982   NODE_NAME_CASE(IF)
3983   NODE_NAME_CASE(ELSE)
3984   NODE_NAME_CASE(LOOP)
3985   NODE_NAME_CASE(CALL)
3986   NODE_NAME_CASE(TC_RETURN)
3987   NODE_NAME_CASE(TRAP)
3988   NODE_NAME_CASE(RET_FLAG)
3989   NODE_NAME_CASE(RETURN_TO_EPILOG)
3990   NODE_NAME_CASE(ENDPGM)
3991   NODE_NAME_CASE(DWORDADDR)
3992   NODE_NAME_CASE(FRACT)
3993   NODE_NAME_CASE(SETCC)
3994   NODE_NAME_CASE(SETREG)
3995   NODE_NAME_CASE(FMA_W_CHAIN)
3996   NODE_NAME_CASE(FMUL_W_CHAIN)
3997   NODE_NAME_CASE(CLAMP)
3998   NODE_NAME_CASE(COS_HW)
3999   NODE_NAME_CASE(SIN_HW)
4000   NODE_NAME_CASE(FMAX_LEGACY)
4001   NODE_NAME_CASE(FMIN_LEGACY)
4002   NODE_NAME_CASE(FMAX3)
4003   NODE_NAME_CASE(SMAX3)
4004   NODE_NAME_CASE(UMAX3)
4005   NODE_NAME_CASE(FMIN3)
4006   NODE_NAME_CASE(SMIN3)
4007   NODE_NAME_CASE(UMIN3)
4008   NODE_NAME_CASE(FMED3)
4009   NODE_NAME_CASE(SMED3)
4010   NODE_NAME_CASE(UMED3)
4011   NODE_NAME_CASE(URECIP)
4012   NODE_NAME_CASE(DIV_SCALE)
4013   NODE_NAME_CASE(DIV_FMAS)
4014   NODE_NAME_CASE(DIV_FIXUP)
4015   NODE_NAME_CASE(FMAD_FTZ)
4016   NODE_NAME_CASE(TRIG_PREOP)
4017   NODE_NAME_CASE(RCP)
4018   NODE_NAME_CASE(RSQ)
4019   NODE_NAME_CASE(RCP_LEGACY)
4020   NODE_NAME_CASE(RSQ_LEGACY)
4021   NODE_NAME_CASE(FMUL_LEGACY)
4022   NODE_NAME_CASE(RSQ_CLAMP)
4023   NODE_NAME_CASE(LDEXP)
4024   NODE_NAME_CASE(FP_CLASS)
4025   NODE_NAME_CASE(DOT4)
4026   NODE_NAME_CASE(CARRY)
4027   NODE_NAME_CASE(BORROW)
4028   NODE_NAME_CASE(BFE_U32)
4029   NODE_NAME_CASE(BFE_I32)
4030   NODE_NAME_CASE(BFI)
4031   NODE_NAME_CASE(BFM)
4032   NODE_NAME_CASE(FFBH_U32)
4033   NODE_NAME_CASE(FFBH_I32)
4034   NODE_NAME_CASE(FFBL_B32)
4035   NODE_NAME_CASE(MUL_U24)
4036   NODE_NAME_CASE(MUL_I24)
4037   NODE_NAME_CASE(MULHI_U24)
4038   NODE_NAME_CASE(MULHI_I24)
4039   NODE_NAME_CASE(MUL_LOHI_U24)
4040   NODE_NAME_CASE(MUL_LOHI_I24)
4041   NODE_NAME_CASE(MAD_U24)
4042   NODE_NAME_CASE(MAD_I24)
4043   NODE_NAME_CASE(MAD_I64_I32)
4044   NODE_NAME_CASE(MAD_U64_U32)
4045   NODE_NAME_CASE(TEXTURE_FETCH)
4046   NODE_NAME_CASE(EXPORT)
4047   NODE_NAME_CASE(EXPORT_DONE)
4048   NODE_NAME_CASE(R600_EXPORT)
4049   NODE_NAME_CASE(CONST_ADDRESS)
4050   NODE_NAME_CASE(REGISTER_LOAD)
4051   NODE_NAME_CASE(REGISTER_STORE)
4052   NODE_NAME_CASE(SAMPLE)
4053   NODE_NAME_CASE(SAMPLEB)
4054   NODE_NAME_CASE(SAMPLED)
4055   NODE_NAME_CASE(SAMPLEL)
4056   NODE_NAME_CASE(CVT_F32_UBYTE0)
4057   NODE_NAME_CASE(CVT_F32_UBYTE1)
4058   NODE_NAME_CASE(CVT_F32_UBYTE2)
4059   NODE_NAME_CASE(CVT_F32_UBYTE3)
4060   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4061   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4062   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4063   NODE_NAME_CASE(CVT_PK_I16_I32)
4064   NODE_NAME_CASE(CVT_PK_U16_U32)
4065   NODE_NAME_CASE(FP_TO_FP16)
4066   NODE_NAME_CASE(FP16_ZEXT)
4067   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4068   NODE_NAME_CASE(CONST_DATA_PTR)
4069   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4070   NODE_NAME_CASE(KILL)
4071   NODE_NAME_CASE(DUMMY_CHAIN)
4072   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4073   NODE_NAME_CASE(INIT_EXEC)
4074   NODE_NAME_CASE(INIT_EXEC_FROM_INPUT)
4075   NODE_NAME_CASE(SENDMSG)
4076   NODE_NAME_CASE(SENDMSGHALT)
4077   NODE_NAME_CASE(INTERP_MOV)
4078   NODE_NAME_CASE(INTERP_P1)
4079   NODE_NAME_CASE(INTERP_P2)
4080   NODE_NAME_CASE(STORE_MSKOR)
4081   NODE_NAME_CASE(LOAD_CONSTANT)
4082   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4083   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_X3)
4084   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4085   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4086   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4087   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4088   NODE_NAME_CASE(ATOMIC_INC)
4089   NODE_NAME_CASE(ATOMIC_DEC)
4090   NODE_NAME_CASE(ATOMIC_LOAD_FADD)
4091   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4092   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4093   NODE_NAME_CASE(BUFFER_LOAD)
4094   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4095   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4096   NODE_NAME_CASE(BUFFER_STORE)
4097   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4098   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4099   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4100   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4101   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4102   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4103   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4104   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4105   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4106   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4107   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4108   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4109   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4110   NODE_NAME_CASE(IMAGE_LOAD)
4111   NODE_NAME_CASE(IMAGE_LOAD_MIP)
4112   NODE_NAME_CASE(IMAGE_STORE)
4113   NODE_NAME_CASE(IMAGE_STORE_MIP)
4114   // Basic sample.
4115   NODE_NAME_CASE(IMAGE_SAMPLE)
4116   NODE_NAME_CASE(IMAGE_SAMPLE_CL)
4117   NODE_NAME_CASE(IMAGE_SAMPLE_D)
4118   NODE_NAME_CASE(IMAGE_SAMPLE_D_CL)
4119   NODE_NAME_CASE(IMAGE_SAMPLE_L)
4120   NODE_NAME_CASE(IMAGE_SAMPLE_B)
4121   NODE_NAME_CASE(IMAGE_SAMPLE_B_CL)
4122   NODE_NAME_CASE(IMAGE_SAMPLE_LZ)
4123   NODE_NAME_CASE(IMAGE_SAMPLE_CD)
4124   NODE_NAME_CASE(IMAGE_SAMPLE_CD_CL)
4125   // Sample with comparison.
4126   NODE_NAME_CASE(IMAGE_SAMPLE_C)
4127   NODE_NAME_CASE(IMAGE_SAMPLE_C_CL)
4128   NODE_NAME_CASE(IMAGE_SAMPLE_C_D)
4129   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_CL)
4130   NODE_NAME_CASE(IMAGE_SAMPLE_C_L)
4131   NODE_NAME_CASE(IMAGE_SAMPLE_C_B)
4132   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_CL)
4133   NODE_NAME_CASE(IMAGE_SAMPLE_C_LZ)
4134   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD)
4135   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_CL)
4136   // Sample with offsets.
4137   NODE_NAME_CASE(IMAGE_SAMPLE_O)
4138   NODE_NAME_CASE(IMAGE_SAMPLE_CL_O)
4139   NODE_NAME_CASE(IMAGE_SAMPLE_D_O)
4140   NODE_NAME_CASE(IMAGE_SAMPLE_D_CL_O)
4141   NODE_NAME_CASE(IMAGE_SAMPLE_L_O)
4142   NODE_NAME_CASE(IMAGE_SAMPLE_B_O)
4143   NODE_NAME_CASE(IMAGE_SAMPLE_B_CL_O)
4144   NODE_NAME_CASE(IMAGE_SAMPLE_LZ_O)
4145   NODE_NAME_CASE(IMAGE_SAMPLE_CD_O)
4146   NODE_NAME_CASE(IMAGE_SAMPLE_CD_CL_O)
4147   // Sample with comparison and offsets.
4148   NODE_NAME_CASE(IMAGE_SAMPLE_C_O)
4149   NODE_NAME_CASE(IMAGE_SAMPLE_C_CL_O)
4150   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_O)
4151   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_CL_O)
4152   NODE_NAME_CASE(IMAGE_SAMPLE_C_L_O)
4153   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_O)
4154   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_CL_O)
4155   NODE_NAME_CASE(IMAGE_SAMPLE_C_LZ_O)
4156   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_O)
4157   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_CL_O)
4158   // Basic gather4.
4159   NODE_NAME_CASE(IMAGE_GATHER4)
4160   NODE_NAME_CASE(IMAGE_GATHER4_CL)
4161   NODE_NAME_CASE(IMAGE_GATHER4_L)
4162   NODE_NAME_CASE(IMAGE_GATHER4_B)
4163   NODE_NAME_CASE(IMAGE_GATHER4_B_CL)
4164   NODE_NAME_CASE(IMAGE_GATHER4_LZ)
4165   // Gather4 with comparison.
4166   NODE_NAME_CASE(IMAGE_GATHER4_C)
4167   NODE_NAME_CASE(IMAGE_GATHER4_C_CL)
4168   NODE_NAME_CASE(IMAGE_GATHER4_C_L)
4169   NODE_NAME_CASE(IMAGE_GATHER4_C_B)
4170   NODE_NAME_CASE(IMAGE_GATHER4_C_B_CL)
4171   NODE_NAME_CASE(IMAGE_GATHER4_C_LZ)
4172   // Gather4 with offsets.
4173   NODE_NAME_CASE(IMAGE_GATHER4_O)
4174   NODE_NAME_CASE(IMAGE_GATHER4_CL_O)
4175   NODE_NAME_CASE(IMAGE_GATHER4_L_O)
4176   NODE_NAME_CASE(IMAGE_GATHER4_B_O)
4177   NODE_NAME_CASE(IMAGE_GATHER4_B_CL_O)
4178   NODE_NAME_CASE(IMAGE_GATHER4_LZ_O)
4179   // Gather4 with comparison and offsets.
4180   NODE_NAME_CASE(IMAGE_GATHER4_C_O)
4181   NODE_NAME_CASE(IMAGE_GATHER4_C_CL_O)
4182   NODE_NAME_CASE(IMAGE_GATHER4_C_L_O)
4183   NODE_NAME_CASE(IMAGE_GATHER4_C_B_O)
4184   NODE_NAME_CASE(IMAGE_GATHER4_C_B_CL_O)
4185   NODE_NAME_CASE(IMAGE_GATHER4_C_LZ_O)
4186 
4187   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4188   }
4189   return nullptr;
4190 }
4191 
4192 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4193                                               SelectionDAG &DAG, int Enabled,
4194                                               int &RefinementSteps,
4195                                               bool &UseOneConstNR,
4196                                               bool Reciprocal) const {
4197   EVT VT = Operand.getValueType();
4198 
4199   if (VT == MVT::f32) {
4200     RefinementSteps = 0;
4201     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4202   }
4203 
4204   // TODO: There is also f64 rsq instruction, but the documentation is less
4205   // clear on its precision.
4206 
4207   return SDValue();
4208 }
4209 
4210 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4211                                                SelectionDAG &DAG, int Enabled,
4212                                                int &RefinementSteps) const {
4213   EVT VT = Operand.getValueType();
4214 
4215   if (VT == MVT::f32) {
4216     // Reciprocal, < 1 ulp error.
4217     //
4218     // This reciprocal approximation converges to < 0.5 ulp error with one
4219     // newton rhapson performed with two fused multiple adds (FMAs).
4220 
4221     RefinementSteps = 0;
4222     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4223   }
4224 
4225   // TODO: There is also f64 rcp instruction, but the documentation is less
4226   // clear on its precision.
4227 
4228   return SDValue();
4229 }
4230 
4231 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4232     const SDValue Op, KnownBits &Known,
4233     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4234 
4235   Known.resetAll(); // Don't know anything.
4236 
4237   unsigned Opc = Op.getOpcode();
4238 
4239   switch (Opc) {
4240   default:
4241     break;
4242   case AMDGPUISD::CARRY:
4243   case AMDGPUISD::BORROW: {
4244     Known.Zero = APInt::getHighBitsSet(32, 31);
4245     break;
4246   }
4247 
4248   case AMDGPUISD::BFE_I32:
4249   case AMDGPUISD::BFE_U32: {
4250     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4251     if (!CWidth)
4252       return;
4253 
4254     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4255 
4256     if (Opc == AMDGPUISD::BFE_U32)
4257       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4258 
4259     break;
4260   }
4261   case AMDGPUISD::FP_TO_FP16:
4262   case AMDGPUISD::FP16_ZEXT: {
4263     unsigned BitWidth = Known.getBitWidth();
4264 
4265     // High bits are zero.
4266     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4267     break;
4268   }
4269   case AMDGPUISD::MUL_U24:
4270   case AMDGPUISD::MUL_I24: {
4271     KnownBits LHSKnown, RHSKnown;
4272     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4273     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4274 
4275     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4276                       RHSKnown.countMinTrailingZeros();
4277     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4278 
4279     unsigned LHSValBits = 32 - std::max(LHSKnown.countMinSignBits(), 8u);
4280     unsigned RHSValBits = 32 - std::max(RHSKnown.countMinSignBits(), 8u);
4281     unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4282     if (MaxValBits >= 32)
4283       break;
4284     bool Negative = false;
4285     if (Opc == AMDGPUISD::MUL_I24) {
4286       bool LHSNegative = !!(LHSKnown.One  & (1 << 23));
4287       bool LHSPositive = !!(LHSKnown.Zero & (1 << 23));
4288       bool RHSNegative = !!(RHSKnown.One  & (1 << 23));
4289       bool RHSPositive = !!(RHSKnown.Zero & (1 << 23));
4290       if ((!LHSNegative && !LHSPositive) || (!RHSNegative && !RHSPositive))
4291         break;
4292       Negative = (LHSNegative && RHSPositive) || (LHSPositive && RHSNegative);
4293     }
4294     if (Negative)
4295       Known.One.setHighBits(32 - MaxValBits);
4296     else
4297       Known.Zero.setHighBits(32 - MaxValBits);
4298     break;
4299   }
4300   case ISD::INTRINSIC_WO_CHAIN: {
4301     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4302     switch (IID) {
4303     case Intrinsic::amdgcn_mbcnt_lo:
4304     case Intrinsic::amdgcn_mbcnt_hi: {
4305       // These return at most the wavefront size - 1.
4306       unsigned Size = Op.getValueType().getSizeInBits();
4307       Known.Zero.setHighBits(Size - Subtarget->getWavefrontSizeLog2());
4308       break;
4309     }
4310     default:
4311       break;
4312     }
4313   }
4314   }
4315 }
4316 
4317 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4318     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4319     unsigned Depth) const {
4320   switch (Op.getOpcode()) {
4321   case AMDGPUISD::BFE_I32: {
4322     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4323     if (!Width)
4324       return 1;
4325 
4326     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4327     if (!isNullConstant(Op.getOperand(1)))
4328       return SignBits;
4329 
4330     // TODO: Could probably figure something out with non-0 offsets.
4331     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4332     return std::max(SignBits, Op0SignBits);
4333   }
4334 
4335   case AMDGPUISD::BFE_U32: {
4336     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4337     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4338   }
4339 
4340   case AMDGPUISD::CARRY:
4341   case AMDGPUISD::BORROW:
4342     return 31;
4343   case AMDGPUISD::FP_TO_FP16:
4344   case AMDGPUISD::FP16_ZEXT:
4345     return 16;
4346   default:
4347     return 1;
4348   }
4349 }
4350