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 /// 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 "MCTargetDesc/AMDGPUMCTargetDesc.h"
33 #include "llvm/CodeGen/CallingConvLower.h"
34 #include "llvm/CodeGen/MachineFunction.h"
35 #include "llvm/CodeGen/MachineRegisterInfo.h"
36 #include "llvm/CodeGen/SelectionDAG.h"
37 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
38 #include "llvm/IR/DataLayout.h"
39 #include "llvm/IR/DiagnosticInfo.h"
40 #include "llvm/Support/KnownBits.h"
41 using namespace llvm;
42 
43 static bool allocateKernArg(unsigned ValNo, MVT ValVT, MVT LocVT,
44                             CCValAssign::LocInfo LocInfo,
45                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
46   MachineFunction &MF = State.getMachineFunction();
47   AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
48 
49   uint64_t Offset = MFI->allocateKernArg(LocVT.getStoreSize(),
50                                          ArgFlags.getOrigAlign());
51   State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, Offset, LocVT, LocInfo));
52   return true;
53 }
54 
55 static bool allocateCCRegs(unsigned ValNo, MVT ValVT, MVT LocVT,
56                            CCValAssign::LocInfo LocInfo,
57                            ISD::ArgFlagsTy ArgFlags, CCState &State,
58                            const TargetRegisterClass *RC,
59                            unsigned NumRegs) {
60   ArrayRef<MCPhysReg> RegList = makeArrayRef(RC->begin(), NumRegs);
61   unsigned RegResult = State.AllocateReg(RegList);
62   if (RegResult == AMDGPU::NoRegister)
63     return false;
64 
65   State.addLoc(CCValAssign::getReg(ValNo, ValVT, RegResult, LocVT, LocInfo));
66   return true;
67 }
68 
69 static bool allocateSGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
70                               CCValAssign::LocInfo LocInfo,
71                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
72   switch (LocVT.SimpleTy) {
73   case MVT::i64:
74   case MVT::f64:
75   case MVT::v2i32:
76   case MVT::v2f32: {
77     // Up to SGPR0-SGPR39
78     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
79                           &AMDGPU::SGPR_64RegClass, 20);
80   }
81   default:
82     return false;
83   }
84 }
85 
86 // Allocate up to VGPR31.
87 //
88 // TODO: Since there are no VGPR alignent requirements would it be better to
89 // split into individual scalar registers?
90 static bool allocateVGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
91                               CCValAssign::LocInfo LocInfo,
92                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
93   switch (LocVT.SimpleTy) {
94   case MVT::i64:
95   case MVT::f64:
96   case MVT::v2i32:
97   case MVT::v2f32: {
98     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
99                           &AMDGPU::VReg_64RegClass, 31);
100   }
101   case MVT::v4i32:
102   case MVT::v4f32:
103   case MVT::v2i64:
104   case MVT::v2f64: {
105     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
106                           &AMDGPU::VReg_128RegClass, 29);
107   }
108   case MVT::v8i32:
109   case MVT::v8f32: {
110     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
111                           &AMDGPU::VReg_256RegClass, 25);
112 
113   }
114   case MVT::v16i32:
115   case MVT::v16f32: {
116     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
117                           &AMDGPU::VReg_512RegClass, 17);
118 
119   }
120   default:
121     return false;
122   }
123 }
124 
125 #include "AMDGPUGenCallingConv.inc"
126 
127 // Find a larger type to do a load / store of a vector with.
128 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
129   unsigned StoreSize = VT.getStoreSizeInBits();
130   if (StoreSize <= 32)
131     return EVT::getIntegerVT(Ctx, StoreSize);
132 
133   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
134   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
135 }
136 
137 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
138   KnownBits Known;
139   EVT VT = Op.getValueType();
140   DAG.computeKnownBits(Op, Known);
141 
142   return VT.getSizeInBits() - Known.countMinLeadingZeros();
143 }
144 
145 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
146   EVT VT = Op.getValueType();
147 
148   // In order for this to be a signed 24-bit value, bit 23, must
149   // be a sign bit.
150   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
151 }
152 
153 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
154                                            const AMDGPUSubtarget &STI)
155     : TargetLowering(TM), Subtarget(&STI) {
156   AMDGPUASI = AMDGPU::getAMDGPUAS(TM);
157   // Lower floating point store/load to integer store/load to reduce the number
158   // of patterns in tablegen.
159   setOperationAction(ISD::LOAD, MVT::f32, Promote);
160   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
161 
162   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
163   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
164 
165   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
166   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
167 
168   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
169   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
170 
171   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
172   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
173 
174   setOperationAction(ISD::LOAD, MVT::i64, Promote);
175   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
176 
177   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
178   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
179 
180   setOperationAction(ISD::LOAD, MVT::f64, Promote);
181   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
182 
183   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
184   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
185 
186   // There are no 64-bit extloads. These should be done as a 32-bit extload and
187   // an extension to 64-bit.
188   for (MVT VT : MVT::integer_valuetypes()) {
189     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
190     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
191     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
192   }
193 
194   for (MVT VT : MVT::integer_valuetypes()) {
195     if (VT == MVT::i64)
196       continue;
197 
198     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
199     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
200     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
201     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
202 
203     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
204     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
205     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
206     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
207 
208     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
209     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
210     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
211     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
212   }
213 
214   for (MVT VT : MVT::integer_vector_valuetypes()) {
215     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
216     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
217     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
218     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
219     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
220     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
221     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
222     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
223     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
224     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
225     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
226     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
227   }
228 
229   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
230   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
231   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
232   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
233 
234   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
235   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
236   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
237   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
238 
239   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
240   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
241   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
242   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
243 
244   setOperationAction(ISD::STORE, MVT::f32, Promote);
245   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
246 
247   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
248   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
249 
250   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
251   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
252 
253   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
254   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
255 
256   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
257   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
258 
259   setOperationAction(ISD::STORE, MVT::i64, Promote);
260   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
261 
262   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
263   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
264 
265   setOperationAction(ISD::STORE, MVT::f64, Promote);
266   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
267 
268   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
269   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
270 
271   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
272   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
273   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
274   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
275 
276   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
277   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
278   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
279   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
280 
281   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
282   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
283   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
284   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
285 
286   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
287   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
288 
289   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
290   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
291 
292   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
293   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
294 
295   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
296   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
297 
298 
299   setOperationAction(ISD::Constant, MVT::i32, Legal);
300   setOperationAction(ISD::Constant, MVT::i64, Legal);
301   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
302   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
303 
304   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
305   setOperationAction(ISD::BRIND, MVT::Other, Expand);
306 
307   // This is totally unsupported, just custom lower to produce an error.
308   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
309 
310   // Library functions.  These default to Expand, but we have instructions
311   // for them.
312   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
313   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
314   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
315   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
316   setOperationAction(ISD::FABS,   MVT::f32, Legal);
317   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
318   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
319   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
320   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
321   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
322 
323   setOperationAction(ISD::FROUND, MVT::f32, Custom);
324   setOperationAction(ISD::FROUND, MVT::f64, Custom);
325 
326   setOperationAction(ISD::FLOG, MVT::f32, Custom);
327   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
328 
329   if (Subtarget->has16BitInsts()) {
330     setOperationAction(ISD::FLOG, MVT::f16, Custom);
331     setOperationAction(ISD::FLOG10, MVT::f16, Custom);
332   }
333 
334   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
335   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
336 
337   setOperationAction(ISD::FREM, MVT::f32, Custom);
338   setOperationAction(ISD::FREM, MVT::f64, Custom);
339 
340   // v_mad_f32 does not support denormals according to some sources.
341   if (!Subtarget->hasFP32Denormals())
342     setOperationAction(ISD::FMAD, MVT::f32, Legal);
343 
344   // Expand to fneg + fadd.
345   setOperationAction(ISD::FSUB, MVT::f64, Expand);
346 
347   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
348   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
349   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
350   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
351   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
352   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
353   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
354   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
355   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
356   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
357 
358   if (Subtarget->getGeneration() < AMDGPUSubtarget::SEA_ISLANDS) {
359     setOperationAction(ISD::FCEIL, MVT::f64, Custom);
360     setOperationAction(ISD::FTRUNC, MVT::f64, Custom);
361     setOperationAction(ISD::FRINT, MVT::f64, Custom);
362     setOperationAction(ISD::FFLOOR, MVT::f64, Custom);
363   }
364 
365   if (!Subtarget->hasBFI()) {
366     // fcopysign can be done in a single instruction with BFI.
367     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
368     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
369   }
370 
371   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
372   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
373   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
374 
375   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
376   for (MVT VT : ScalarIntVTs) {
377     // These should use [SU]DIVREM, so set them to expand
378     setOperationAction(ISD::SDIV, VT, Expand);
379     setOperationAction(ISD::UDIV, VT, Expand);
380     setOperationAction(ISD::SREM, VT, Expand);
381     setOperationAction(ISD::UREM, VT, Expand);
382 
383     // GPU does not have divrem function for signed or unsigned.
384     setOperationAction(ISD::SDIVREM, VT, Custom);
385     setOperationAction(ISD::UDIVREM, VT, Custom);
386 
387     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
388     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
389     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
390 
391     setOperationAction(ISD::BSWAP, VT, Expand);
392     setOperationAction(ISD::CTTZ, VT, Expand);
393     setOperationAction(ISD::CTLZ, VT, Expand);
394 
395     // AMDGPU uses ADDC/SUBC/ADDE/SUBE
396     setOperationAction(ISD::ADDC, VT, Legal);
397     setOperationAction(ISD::SUBC, VT, Legal);
398     setOperationAction(ISD::ADDE, VT, Legal);
399     setOperationAction(ISD::SUBE, VT, Legal);
400   }
401 
402   if (!Subtarget->hasBCNT(32))
403     setOperationAction(ISD::CTPOP, MVT::i32, Expand);
404 
405   if (!Subtarget->hasBCNT(64))
406     setOperationAction(ISD::CTPOP, MVT::i64, Expand);
407 
408   // The hardware supports 32-bit ROTR, but not ROTL.
409   setOperationAction(ISD::ROTL, MVT::i32, Expand);
410   setOperationAction(ISD::ROTL, MVT::i64, Expand);
411   setOperationAction(ISD::ROTR, MVT::i64, Expand);
412 
413   setOperationAction(ISD::MUL, MVT::i64, Expand);
414   setOperationAction(ISD::MULHU, MVT::i64, Expand);
415   setOperationAction(ISD::MULHS, MVT::i64, Expand);
416   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
417   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
418   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
419   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
420   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
421 
422   setOperationAction(ISD::SMIN, MVT::i32, Legal);
423   setOperationAction(ISD::UMIN, MVT::i32, Legal);
424   setOperationAction(ISD::SMAX, MVT::i32, Legal);
425   setOperationAction(ISD::UMAX, MVT::i32, Legal);
426 
427   if (Subtarget->hasFFBH())
428     setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Custom);
429 
430   if (Subtarget->hasFFBL())
431     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Custom);
432 
433   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
434   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
435   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
436   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
437 
438   // We only really have 32-bit BFE instructions (and 16-bit on VI).
439   //
440   // On SI+ there are 64-bit BFEs, but they are scalar only and there isn't any
441   // effort to match them now. We want this to be false for i64 cases when the
442   // extraction isn't restricted to the upper or lower half. Ideally we would
443   // have some pass reduce 64-bit extracts to 32-bit if possible. Extracts that
444   // span the midpoint are probably relatively rare, so don't worry about them
445   // for now.
446   if (Subtarget->hasBFE())
447     setHasExtractBitsInsn(true);
448 
449   static const MVT::SimpleValueType VectorIntTypes[] = {
450     MVT::v2i32, MVT::v4i32
451   };
452 
453   for (MVT VT : VectorIntTypes) {
454     // Expand the following operations for the current type by default.
455     setOperationAction(ISD::ADD,  VT, Expand);
456     setOperationAction(ISD::AND,  VT, Expand);
457     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
458     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
459     setOperationAction(ISD::MUL,  VT, Expand);
460     setOperationAction(ISD::MULHU, VT, Expand);
461     setOperationAction(ISD::MULHS, VT, Expand);
462     setOperationAction(ISD::OR,   VT, Expand);
463     setOperationAction(ISD::SHL,  VT, Expand);
464     setOperationAction(ISD::SRA,  VT, Expand);
465     setOperationAction(ISD::SRL,  VT, Expand);
466     setOperationAction(ISD::ROTL, VT, Expand);
467     setOperationAction(ISD::ROTR, VT, Expand);
468     setOperationAction(ISD::SUB,  VT, Expand);
469     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
470     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
471     setOperationAction(ISD::SDIV, VT, Expand);
472     setOperationAction(ISD::UDIV, VT, Expand);
473     setOperationAction(ISD::SREM, VT, Expand);
474     setOperationAction(ISD::UREM, VT, Expand);
475     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
476     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
477     setOperationAction(ISD::SDIVREM, VT, Custom);
478     setOperationAction(ISD::UDIVREM, VT, Expand);
479     setOperationAction(ISD::SELECT, VT, Expand);
480     setOperationAction(ISD::VSELECT, VT, Expand);
481     setOperationAction(ISD::SELECT_CC, VT, Expand);
482     setOperationAction(ISD::XOR,  VT, Expand);
483     setOperationAction(ISD::BSWAP, VT, Expand);
484     setOperationAction(ISD::CTPOP, VT, Expand);
485     setOperationAction(ISD::CTTZ, VT, Expand);
486     setOperationAction(ISD::CTLZ, VT, Expand);
487     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
488     setOperationAction(ISD::SETCC, VT, Expand);
489   }
490 
491   static const MVT::SimpleValueType FloatVectorTypes[] = {
492     MVT::v2f32, MVT::v4f32
493   };
494 
495   for (MVT VT : FloatVectorTypes) {
496     setOperationAction(ISD::FABS, VT, Expand);
497     setOperationAction(ISD::FMINNUM, VT, Expand);
498     setOperationAction(ISD::FMAXNUM, VT, Expand);
499     setOperationAction(ISD::FADD, VT, Expand);
500     setOperationAction(ISD::FCEIL, VT, Expand);
501     setOperationAction(ISD::FCOS, VT, Expand);
502     setOperationAction(ISD::FDIV, VT, Expand);
503     setOperationAction(ISD::FEXP2, VT, Expand);
504     setOperationAction(ISD::FLOG2, VT, Expand);
505     setOperationAction(ISD::FREM, VT, Expand);
506     setOperationAction(ISD::FLOG, VT, Expand);
507     setOperationAction(ISD::FLOG10, VT, Expand);
508     setOperationAction(ISD::FPOW, VT, Expand);
509     setOperationAction(ISD::FFLOOR, VT, Expand);
510     setOperationAction(ISD::FTRUNC, VT, Expand);
511     setOperationAction(ISD::FMUL, VT, Expand);
512     setOperationAction(ISD::FMA, VT, Expand);
513     setOperationAction(ISD::FRINT, VT, Expand);
514     setOperationAction(ISD::FNEARBYINT, VT, Expand);
515     setOperationAction(ISD::FSQRT, VT, Expand);
516     setOperationAction(ISD::FSIN, VT, Expand);
517     setOperationAction(ISD::FSUB, VT, Expand);
518     setOperationAction(ISD::FNEG, VT, Expand);
519     setOperationAction(ISD::VSELECT, VT, Expand);
520     setOperationAction(ISD::SELECT_CC, VT, Expand);
521     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
522     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
523     setOperationAction(ISD::SETCC, VT, Expand);
524   }
525 
526   // This causes using an unrolled select operation rather than expansion with
527   // bit operations. This is in general better, but the alternative using BFI
528   // instructions may be better if the select sources are SGPRs.
529   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
530   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
531 
532   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
533   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
534 
535   // There are no libcalls of any kind.
536   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
537     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
538 
539   setBooleanContents(ZeroOrNegativeOneBooleanContent);
540   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
541 
542   setSchedulingPreference(Sched::RegPressure);
543   setJumpIsExpensive(true);
544 
545   // FIXME: This is only partially true. If we have to do vector compares, any
546   // SGPR pair can be a condition register. If we have a uniform condition, we
547   // are better off doing SALU operations, where there is only one SCC. For now,
548   // we don't have a way of knowing during instruction selection if a condition
549   // will be uniform and we always use vector compares. Assume we are using
550   // vector compares until that is fixed.
551   setHasMultipleConditionRegisters(true);
552 
553   // SI at least has hardware support for floating point exceptions, but no way
554   // of using or handling them is implemented. They are also optional in OpenCL
555   // (Section 7.3)
556   setHasFloatingPointExceptions(Subtarget->hasFPExceptions());
557 
558   PredictableSelectIsExpensive = false;
559 
560   // We want to find all load dependencies for long chains of stores to enable
561   // merging into very wide vectors. The problem is with vectors with > 4
562   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
563   // vectors are a legal type, even though we have to split the loads
564   // usually. When we can more precisely specify load legality per address
565   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
566   // smarter so that they can figure out what to do in 2 iterations without all
567   // N > 4 stores on the same chain.
568   GatherAllAliasesMaxDepth = 16;
569 
570   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
571   // about these during lowering.
572   MaxStoresPerMemcpy  = 0xffffffff;
573   MaxStoresPerMemmove = 0xffffffff;
574   MaxStoresPerMemset  = 0xffffffff;
575 
576   setTargetDAGCombine(ISD::BITCAST);
577   setTargetDAGCombine(ISD::SHL);
578   setTargetDAGCombine(ISD::SRA);
579   setTargetDAGCombine(ISD::SRL);
580   setTargetDAGCombine(ISD::TRUNCATE);
581   setTargetDAGCombine(ISD::MUL);
582   setTargetDAGCombine(ISD::MULHU);
583   setTargetDAGCombine(ISD::MULHS);
584   setTargetDAGCombine(ISD::SELECT);
585   setTargetDAGCombine(ISD::SELECT_CC);
586   setTargetDAGCombine(ISD::STORE);
587   setTargetDAGCombine(ISD::FADD);
588   setTargetDAGCombine(ISD::FSUB);
589   setTargetDAGCombine(ISD::FNEG);
590   setTargetDAGCombine(ISD::FABS);
591   setTargetDAGCombine(ISD::AssertZext);
592   setTargetDAGCombine(ISD::AssertSext);
593 }
594 
595 //===----------------------------------------------------------------------===//
596 // Target Information
597 //===----------------------------------------------------------------------===//
598 
599 LLVM_READNONE
600 static bool fnegFoldsIntoOp(unsigned Opc) {
601   switch (Opc) {
602   case ISD::FADD:
603   case ISD::FSUB:
604   case ISD::FMUL:
605   case ISD::FMA:
606   case ISD::FMAD:
607   case ISD::FMINNUM:
608   case ISD::FMAXNUM:
609   case ISD::FSIN:
610   case ISD::FTRUNC:
611   case ISD::FRINT:
612   case ISD::FNEARBYINT:
613   case AMDGPUISD::RCP:
614   case AMDGPUISD::RCP_LEGACY:
615   case AMDGPUISD::SIN_HW:
616   case AMDGPUISD::FMUL_LEGACY:
617   case AMDGPUISD::FMIN_LEGACY:
618   case AMDGPUISD::FMAX_LEGACY:
619     return true;
620   default:
621     return false;
622   }
623 }
624 
625 /// \p returns true if the operation will definitely need to use a 64-bit
626 /// encoding, and thus will use a VOP3 encoding regardless of the source
627 /// modifiers.
628 LLVM_READONLY
629 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
630   return N->getNumOperands() > 2 || VT == MVT::f64;
631 }
632 
633 // Most FP instructions support source modifiers, but this could be refined
634 // slightly.
635 LLVM_READONLY
636 static bool hasSourceMods(const SDNode *N) {
637   if (isa<MemSDNode>(N))
638     return false;
639 
640   switch (N->getOpcode()) {
641   case ISD::CopyToReg:
642   case ISD::SELECT:
643   case ISD::FDIV:
644   case ISD::FREM:
645   case ISD::INLINEASM:
646   case AMDGPUISD::INTERP_P1:
647   case AMDGPUISD::INTERP_P2:
648   case AMDGPUISD::DIV_SCALE:
649 
650   // TODO: Should really be looking at the users of the bitcast. These are
651   // problematic because bitcasts are used to legalize all stores to integer
652   // types.
653   case ISD::BITCAST:
654     return false;
655   default:
656     return true;
657   }
658 }
659 
660 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
661                                                  unsigned CostThreshold) {
662   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
663   // it is truly free to use a source modifier in all cases. If there are
664   // multiple users but for each one will necessitate using VOP3, there will be
665   // a code size increase. Try to avoid increasing code size unless we know it
666   // will save on the instruction count.
667   unsigned NumMayIncreaseSize = 0;
668   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
669 
670   // XXX - Should this limit number of uses to check?
671   for (const SDNode *U : N->uses()) {
672     if (!hasSourceMods(U))
673       return false;
674 
675     if (!opMustUseVOP3Encoding(U, VT)) {
676       if (++NumMayIncreaseSize > CostThreshold)
677         return false;
678     }
679   }
680 
681   return true;
682 }
683 
684 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
685   return MVT::i32;
686 }
687 
688 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
689   return true;
690 }
691 
692 // The backend supports 32 and 64 bit floating point immediates.
693 // FIXME: Why are we reporting vectors of FP immediates as legal?
694 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
695   EVT ScalarVT = VT.getScalarType();
696   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
697          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
698 }
699 
700 // We don't want to shrink f64 / f32 constants.
701 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
702   EVT ScalarVT = VT.getScalarType();
703   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
704 }
705 
706 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
707                                                  ISD::LoadExtType,
708                                                  EVT NewVT) const {
709 
710   unsigned NewSize = NewVT.getStoreSizeInBits();
711 
712   // If we are reducing to a 32-bit load, this is always better.
713   if (NewSize == 32)
714     return true;
715 
716   EVT OldVT = N->getValueType(0);
717   unsigned OldSize = OldVT.getStoreSizeInBits();
718 
719   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
720   // extloads, so doing one requires using a buffer_load. In cases where we
721   // still couldn't use a scalar load, using the wider load shouldn't really
722   // hurt anything.
723 
724   // If the old size already had to be an extload, there's no harm in continuing
725   // to reduce the width.
726   return (OldSize < 32);
727 }
728 
729 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy,
730                                                    EVT CastTy) const {
731 
732   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
733 
734   if (LoadTy.getScalarType() == MVT::i32)
735     return false;
736 
737   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
738   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
739 
740   return (LScalarSize < CastScalarSize) ||
741          (CastScalarSize >= 32);
742 }
743 
744 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
745 // profitable with the expansion for 64-bit since it's generally good to
746 // speculate things.
747 // FIXME: These should really have the size as a parameter.
748 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
749   return true;
750 }
751 
752 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
753   return true;
754 }
755 
756 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
757   switch (N->getOpcode()) {
758     default:
759     return false;
760     case ISD::EntryToken:
761     case ISD::TokenFactor:
762       return true;
763     case ISD::INTRINSIC_WO_CHAIN:
764     {
765       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
766       switch (IntrID) {
767         default:
768         return false;
769         case Intrinsic::amdgcn_readfirstlane:
770         case Intrinsic::amdgcn_readlane:
771           return true;
772       }
773     }
774     break;
775     case ISD::LOAD:
776     {
777       const LoadSDNode * L = dyn_cast<LoadSDNode>(N);
778       if (L->getMemOperand()->getAddrSpace()
779       == Subtarget->getAMDGPUAS().CONSTANT_ADDRESS_32BIT)
780         return true;
781       return false;
782     }
783     break;
784   }
785 }
786 
787 bool AMDGPUTargetLowering::isSDNodeSourceOfDivergence(const SDNode * N,
788   FunctionLoweringInfo * FLI, DivergenceAnalysis * DA) const
789 {
790   switch (N->getOpcode()) {
791     case ISD::Register:
792     case ISD::CopyFromReg:
793     {
794       const RegisterSDNode *R = nullptr;
795       if (N->getOpcode() == ISD::Register) {
796         R = dyn_cast<RegisterSDNode>(N);
797       }
798       else {
799         R = dyn_cast<RegisterSDNode>(N->getOperand(1));
800       }
801       if (R)
802       {
803         const MachineFunction * MF = FLI->MF;
804         const SISubtarget &ST = MF->getSubtarget<SISubtarget>();
805         const MachineRegisterInfo &MRI = MF->getRegInfo();
806         const SIRegisterInfo &TRI = ST.getInstrInfo()->getRegisterInfo();
807         unsigned Reg = R->getReg();
808         if (TRI.isPhysicalRegister(Reg))
809           return TRI.isVGPR(MRI, Reg);
810 
811         if (MRI.isLiveIn(Reg)) {
812           // workitem.id.x workitem.id.y workitem.id.z
813           // Any VGPR formal argument is also considered divergent
814           if ((MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_X) ||
815               (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Y) ||
816               (MRI.getLiveInPhysReg(Reg) == AMDGPU::T0_Z) ||
817               (TRI.isVGPR(MRI, Reg)))
818               return true;
819           // Formal arguments of non-entry functions
820           // are conservatively considered divergent
821           else if (!AMDGPU::isEntryFunctionCC(FLI->Fn->getCallingConv()))
822             return true;
823         }
824         return !DA || DA->isDivergent(FLI->getValueFromVirtualReg(Reg));
825       }
826     }
827     break;
828     case ISD::LOAD: {
829       const LoadSDNode *L = dyn_cast<LoadSDNode>(N);
830       if (L->getMemOperand()->getAddrSpace() ==
831           Subtarget->getAMDGPUAS().PRIVATE_ADDRESS)
832         return true;
833     } break;
834     case ISD::CALLSEQ_END:
835     return true;
836     break;
837     case ISD::INTRINSIC_WO_CHAIN:
838     {
839 
840     }
841       return AMDGPU::isIntrinsicSourceOfDivergence(
842       cast<ConstantSDNode>(N->getOperand(0))->getZExtValue());
843     case ISD::INTRINSIC_W_CHAIN:
844       return AMDGPU::isIntrinsicSourceOfDivergence(
845       cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
846     // In some cases intrinsics that are a source of divergence have been
847     // lowered to AMDGPUISD so we also need to check those too.
848     case AMDGPUISD::INTERP_MOV:
849     case AMDGPUISD::INTERP_P1:
850     case AMDGPUISD::INTERP_P2:
851       return true;
852   }
853   return false;
854 }
855 
856 //===---------------------------------------------------------------------===//
857 // Target Properties
858 //===---------------------------------------------------------------------===//
859 
860 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
861   assert(VT.isFloatingPoint());
862 
863   // Packed operations do not have a fabs modifier.
864   return VT == MVT::f32 || VT == MVT::f64 ||
865          (Subtarget->has16BitInsts() && VT == MVT::f16);
866 }
867 
868 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
869   assert(VT.isFloatingPoint());
870   return VT == MVT::f32 || VT == MVT::f64 ||
871          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
872          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
873 }
874 
875 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
876                                                          unsigned NumElem,
877                                                          unsigned AS) const {
878   return true;
879 }
880 
881 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
882   // There are few operations which truly have vector input operands. Any vector
883   // operation is going to involve operations on each component, and a
884   // build_vector will be a copy per element, so it always makes sense to use a
885   // build_vector input in place of the extracted element to avoid a copy into a
886   // super register.
887   //
888   // We should probably only do this if all users are extracts only, but this
889   // should be the common case.
890   return true;
891 }
892 
893 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
894   // Truncate is just accessing a subregister.
895 
896   unsigned SrcSize = Source.getSizeInBits();
897   unsigned DestSize = Dest.getSizeInBits();
898 
899   return DestSize < SrcSize && DestSize % 32 == 0 ;
900 }
901 
902 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
903   // Truncate is just accessing a subregister.
904 
905   unsigned SrcSize = Source->getScalarSizeInBits();
906   unsigned DestSize = Dest->getScalarSizeInBits();
907 
908   if (DestSize== 16 && Subtarget->has16BitInsts())
909     return SrcSize >= 32;
910 
911   return DestSize < SrcSize && DestSize % 32 == 0;
912 }
913 
914 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
915   unsigned SrcSize = Src->getScalarSizeInBits();
916   unsigned DestSize = Dest->getScalarSizeInBits();
917 
918   if (SrcSize == 16 && Subtarget->has16BitInsts())
919     return DestSize >= 32;
920 
921   return SrcSize == 32 && DestSize == 64;
922 }
923 
924 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
925   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
926   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
927   // this will enable reducing 64-bit operations the 32-bit, which is always
928   // good.
929 
930   if (Src == MVT::i16)
931     return Dest == MVT::i32 ||Dest == MVT::i64 ;
932 
933   return Src == MVT::i32 && Dest == MVT::i64;
934 }
935 
936 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
937   return isZExtFree(Val.getValueType(), VT2);
938 }
939 
940 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
941   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
942   // limited number of native 64-bit operations. Shrinking an operation to fit
943   // in a single 32-bit register should always be helpful. As currently used,
944   // this is much less general than the name suggests, and is only used in
945   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
946   // not profitable, and may actually be harmful.
947   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
948 }
949 
950 //===---------------------------------------------------------------------===//
951 // TargetLowering Callbacks
952 //===---------------------------------------------------------------------===//
953 
954 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
955                                                   bool IsVarArg) {
956   switch (CC) {
957   case CallingConv::AMDGPU_KERNEL:
958   case CallingConv::SPIR_KERNEL:
959     return CC_AMDGPU_Kernel;
960   case CallingConv::AMDGPU_VS:
961   case CallingConv::AMDGPU_GS:
962   case CallingConv::AMDGPU_PS:
963   case CallingConv::AMDGPU_CS:
964   case CallingConv::AMDGPU_HS:
965   case CallingConv::AMDGPU_ES:
966   case CallingConv::AMDGPU_LS:
967     return CC_AMDGPU;
968   case CallingConv::C:
969   case CallingConv::Fast:
970   case CallingConv::Cold:
971     return CC_AMDGPU_Func;
972   default:
973     report_fatal_error("Unsupported calling convention.");
974   }
975 }
976 
977 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
978                                                     bool IsVarArg) {
979   switch (CC) {
980   case CallingConv::AMDGPU_KERNEL:
981   case CallingConv::SPIR_KERNEL:
982     return CC_AMDGPU_Kernel;
983   case CallingConv::AMDGPU_VS:
984   case CallingConv::AMDGPU_GS:
985   case CallingConv::AMDGPU_PS:
986   case CallingConv::AMDGPU_CS:
987   case CallingConv::AMDGPU_HS:
988   case CallingConv::AMDGPU_ES:
989   case CallingConv::AMDGPU_LS:
990     return RetCC_SI_Shader;
991   case CallingConv::C:
992   case CallingConv::Fast:
993   case CallingConv::Cold:
994     return RetCC_AMDGPU_Func;
995   default:
996     report_fatal_error("Unsupported calling convention.");
997   }
998 }
999 
1000 /// The SelectionDAGBuilder will automatically promote function arguments
1001 /// with illegal types.  However, this does not work for the AMDGPU targets
1002 /// since the function arguments are stored in memory as these illegal types.
1003 /// In order to handle this properly we need to get the original types sizes
1004 /// from the LLVM IR Function and fixup the ISD:InputArg values before
1005 /// passing them to AnalyzeFormalArguments()
1006 
1007 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
1008 /// input values across multiple registers.  Each item in the Ins array
1009 /// represents a single value that will be stored in registers.  Ins[x].VT is
1010 /// the value type of the value that will be stored in the register, so
1011 /// whatever SDNode we lower the argument to needs to be this type.
1012 ///
1013 /// In order to correctly lower the arguments we need to know the size of each
1014 /// argument.  Since Ins[x].VT gives us the size of the register that will
1015 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
1016 /// for the orignal function argument so that we can deduce the correct memory
1017 /// type to use for Ins[x].  In most cases the correct memory type will be
1018 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
1019 /// we have a kernel argument of type v8i8, this argument will be split into
1020 /// 8 parts and each part will be represented by its own item in the Ins array.
1021 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
1022 /// the argument before it was split.  From this, we deduce that the memory type
1023 /// for each individual part is i8.  We pass the memory type as LocVT to the
1024 /// calling convention analysis function and the register type (Ins[x].VT) as
1025 /// the ValVT.
1026 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(CCState &State,
1027                              const SmallVectorImpl<ISD::InputArg> &Ins) const {
1028   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
1029     const ISD::InputArg &In = Ins[i];
1030     EVT MemVT;
1031 
1032     unsigned NumRegs = getNumRegisters(State.getContext(), In.ArgVT);
1033 
1034     if (!Subtarget->isAmdHsaOS() &&
1035         (In.ArgVT == MVT::i16 || In.ArgVT == MVT::i8 || In.ArgVT == MVT::f16)) {
1036       // The ABI says the caller will extend these values to 32-bits.
1037       MemVT = In.ArgVT.isInteger() ? MVT::i32 : MVT::f32;
1038     } else if (NumRegs == 1) {
1039       // This argument is not split, so the IR type is the memory type.
1040       assert(!In.Flags.isSplit());
1041       if (In.ArgVT.isExtended()) {
1042         // We have an extended type, like i24, so we should just use the register type
1043         MemVT = In.VT;
1044       } else {
1045         MemVT = In.ArgVT;
1046       }
1047     } else if (In.ArgVT.isVector() && In.VT.isVector() &&
1048                In.ArgVT.getScalarType() == In.VT.getScalarType()) {
1049       assert(In.ArgVT.getVectorNumElements() > In.VT.getVectorNumElements());
1050       // We have a vector value which has been split into a vector with
1051       // the same scalar type, but fewer elements.  This should handle
1052       // all the floating-point vector types.
1053       MemVT = In.VT;
1054     } else if (In.ArgVT.isVector() &&
1055                In.ArgVT.getVectorNumElements() == NumRegs) {
1056       // This arg has been split so that each element is stored in a separate
1057       // register.
1058       MemVT = In.ArgVT.getScalarType();
1059     } else if (In.ArgVT.isExtended()) {
1060       // We have an extended type, like i65.
1061       MemVT = In.VT;
1062     } else {
1063       unsigned MemoryBits = In.ArgVT.getStoreSizeInBits() / NumRegs;
1064       assert(In.ArgVT.getStoreSizeInBits() % NumRegs == 0);
1065       if (In.VT.isInteger()) {
1066         MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
1067       } else if (In.VT.isVector()) {
1068         assert(!In.VT.getScalarType().isFloatingPoint());
1069         unsigned NumElements = In.VT.getVectorNumElements();
1070         assert(MemoryBits % NumElements == 0);
1071         // This vector type has been split into another vector type with
1072         // a different elements size.
1073         EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
1074                                          MemoryBits / NumElements);
1075         MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
1076       } else {
1077         llvm_unreachable("cannot deduce memory type.");
1078       }
1079     }
1080 
1081     // Convert one element vectors to scalar.
1082     if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
1083       MemVT = MemVT.getScalarType();
1084 
1085     if (MemVT.isExtended()) {
1086       // This should really only happen if we have vec3 arguments
1087       assert(MemVT.isVector() && MemVT.getVectorNumElements() == 3);
1088       MemVT = MemVT.getPow2VectorType(State.getContext());
1089     }
1090 
1091     assert(MemVT.isSimple());
1092     allocateKernArg(i, In.VT, MemVT.getSimpleVT(), CCValAssign::Full, In.Flags,
1093                     State);
1094   }
1095 }
1096 
1097 SDValue AMDGPUTargetLowering::LowerReturn(
1098   SDValue Chain, CallingConv::ID CallConv,
1099   bool isVarArg,
1100   const SmallVectorImpl<ISD::OutputArg> &Outs,
1101   const SmallVectorImpl<SDValue> &OutVals,
1102   const SDLoc &DL, SelectionDAG &DAG) const {
1103   // FIXME: Fails for r600 tests
1104   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1105   // "wave terminate should not have return values");
1106   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1107 }
1108 
1109 //===---------------------------------------------------------------------===//
1110 // Target specific lowering
1111 //===---------------------------------------------------------------------===//
1112 
1113 /// Selects the correct CCAssignFn for a given CallingConvention value.
1114 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1115                                                     bool IsVarArg) {
1116   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1117 }
1118 
1119 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1120                                                       bool IsVarArg) {
1121   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1122 }
1123 
1124 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1125                                                   SelectionDAG &DAG,
1126                                                   MachineFrameInfo &MFI,
1127                                                   int ClobberedFI) const {
1128   SmallVector<SDValue, 8> ArgChains;
1129   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1130   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1131 
1132   // Include the original chain at the beginning of the list. When this is
1133   // used by target LowerCall hooks, this helps legalize find the
1134   // CALLSEQ_BEGIN node.
1135   ArgChains.push_back(Chain);
1136 
1137   // Add a chain value for each stack argument corresponding
1138   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1139                             UE = DAG.getEntryNode().getNode()->use_end();
1140        U != UE; ++U) {
1141     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1142       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1143         if (FI->getIndex() < 0) {
1144           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1145           int64_t InLastByte = InFirstByte;
1146           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1147 
1148           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1149               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1150             ArgChains.push_back(SDValue(L, 1));
1151         }
1152       }
1153     }
1154   }
1155 
1156   // Build a tokenfactor for all the chains.
1157   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1158 }
1159 
1160 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1161                                                  SmallVectorImpl<SDValue> &InVals,
1162                                                  StringRef Reason) const {
1163   SDValue Callee = CLI.Callee;
1164   SelectionDAG &DAG = CLI.DAG;
1165 
1166   const Function &Fn = DAG.getMachineFunction().getFunction();
1167 
1168   StringRef FuncName("<unknown>");
1169 
1170   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1171     FuncName = G->getSymbol();
1172   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1173     FuncName = G->getGlobal()->getName();
1174 
1175   DiagnosticInfoUnsupported NoCalls(
1176     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1177   DAG.getContext()->diagnose(NoCalls);
1178 
1179   if (!CLI.IsTailCall) {
1180     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1181       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1182   }
1183 
1184   return DAG.getEntryNode();
1185 }
1186 
1187 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1188                                         SmallVectorImpl<SDValue> &InVals) const {
1189   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1190 }
1191 
1192 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1193                                                       SelectionDAG &DAG) const {
1194   const Function &Fn = DAG.getMachineFunction().getFunction();
1195 
1196   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1197                                             SDLoc(Op).getDebugLoc());
1198   DAG.getContext()->diagnose(NoDynamicAlloca);
1199   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1200   return DAG.getMergeValues(Ops, SDLoc());
1201 }
1202 
1203 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1204                                              SelectionDAG &DAG) const {
1205   switch (Op.getOpcode()) {
1206   default:
1207     Op->print(errs(), &DAG);
1208     llvm_unreachable("Custom lowering code for this"
1209                      "instruction is not implemented yet!");
1210     break;
1211   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1212   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1213   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1214   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1215   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1216   case ISD::FREM: return LowerFREM(Op, DAG);
1217   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1218   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1219   case ISD::FRINT: return LowerFRINT(Op, DAG);
1220   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1221   case ISD::FROUND: return LowerFROUND(Op, DAG);
1222   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1223   case ISD::FLOG:
1224     return LowerFLOG(Op, DAG, 1 / AMDGPU_LOG2E_F);
1225   case ISD::FLOG10:
1226     return LowerFLOG(Op, DAG, AMDGPU_LN2_F / AMDGPU_LN10_F);
1227   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1228   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1229   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1230   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1231   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1232   case ISD::CTTZ:
1233   case ISD::CTTZ_ZERO_UNDEF:
1234   case ISD::CTLZ:
1235   case ISD::CTLZ_ZERO_UNDEF:
1236     return LowerCTLZ_CTTZ(Op, DAG);
1237   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1238   }
1239   return Op;
1240 }
1241 
1242 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1243                                               SmallVectorImpl<SDValue> &Results,
1244                                               SelectionDAG &DAG) const {
1245   switch (N->getOpcode()) {
1246   case ISD::SIGN_EXTEND_INREG:
1247     // Different parts of legalization seem to interpret which type of
1248     // sign_extend_inreg is the one to check for custom lowering. The extended
1249     // from type is what really matters, but some places check for custom
1250     // lowering of the result type. This results in trying to use
1251     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1252     // nothing here and let the illegal result integer be handled normally.
1253     return;
1254   default:
1255     return;
1256   }
1257 }
1258 
1259 static bool hasDefinedInitializer(const GlobalValue *GV) {
1260   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1261   if (!GVar || !GVar->hasInitializer())
1262     return false;
1263 
1264   return !isa<UndefValue>(GVar->getInitializer());
1265 }
1266 
1267 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1268                                                  SDValue Op,
1269                                                  SelectionDAG &DAG) const {
1270 
1271   const DataLayout &DL = DAG.getDataLayout();
1272   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1273   const GlobalValue *GV = G->getGlobal();
1274 
1275   if  (G->getAddressSpace() == AMDGPUASI.LOCAL_ADDRESS) {
1276     // XXX: What does the value of G->getOffset() mean?
1277     assert(G->getOffset() == 0 &&
1278          "Do not know what to do with an non-zero offset");
1279 
1280     // TODO: We could emit code to handle the initialization somewhere.
1281     if (!hasDefinedInitializer(GV)) {
1282       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1283       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1284     }
1285   }
1286 
1287   const Function &Fn = DAG.getMachineFunction().getFunction();
1288   DiagnosticInfoUnsupported BadInit(
1289       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1290   DAG.getContext()->diagnose(BadInit);
1291   return SDValue();
1292 }
1293 
1294 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1295                                                   SelectionDAG &DAG) const {
1296   SmallVector<SDValue, 8> Args;
1297 
1298   for (const SDUse &U : Op->ops())
1299     DAG.ExtractVectorElements(U.get(), Args);
1300 
1301   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1302 }
1303 
1304 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1305                                                      SelectionDAG &DAG) const {
1306 
1307   SmallVector<SDValue, 8> Args;
1308   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1309   EVT VT = Op.getValueType();
1310   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1311                             VT.getVectorNumElements());
1312 
1313   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1314 }
1315 
1316 /// Generate Min/Max node
1317 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1318                                                    SDValue LHS, SDValue RHS,
1319                                                    SDValue True, SDValue False,
1320                                                    SDValue CC,
1321                                                    DAGCombinerInfo &DCI) const {
1322   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1323     return SDValue();
1324 
1325   SelectionDAG &DAG = DCI.DAG;
1326   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1327   switch (CCOpcode) {
1328   case ISD::SETOEQ:
1329   case ISD::SETONE:
1330   case ISD::SETUNE:
1331   case ISD::SETNE:
1332   case ISD::SETUEQ:
1333   case ISD::SETEQ:
1334   case ISD::SETFALSE:
1335   case ISD::SETFALSE2:
1336   case ISD::SETTRUE:
1337   case ISD::SETTRUE2:
1338   case ISD::SETUO:
1339   case ISD::SETO:
1340     break;
1341   case ISD::SETULE:
1342   case ISD::SETULT: {
1343     if (LHS == True)
1344       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1345     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1346   }
1347   case ISD::SETOLE:
1348   case ISD::SETOLT:
1349   case ISD::SETLE:
1350   case ISD::SETLT: {
1351     // Ordered. Assume ordered for undefined.
1352 
1353     // Only do this after legalization to avoid interfering with other combines
1354     // which might occur.
1355     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1356         !DCI.isCalledByLegalizer())
1357       return SDValue();
1358 
1359     // We need to permute the operands to get the correct NaN behavior. The
1360     // selected operand is the second one based on the failing compare with NaN,
1361     // so permute it based on the compare type the hardware uses.
1362     if (LHS == True)
1363       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1364     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1365   }
1366   case ISD::SETUGE:
1367   case ISD::SETUGT: {
1368     if (LHS == True)
1369       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1370     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1371   }
1372   case ISD::SETGT:
1373   case ISD::SETGE:
1374   case ISD::SETOGE:
1375   case ISD::SETOGT: {
1376     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1377         !DCI.isCalledByLegalizer())
1378       return SDValue();
1379 
1380     if (LHS == True)
1381       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1382     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1383   }
1384   case ISD::SETCC_INVALID:
1385     llvm_unreachable("Invalid setcc condcode!");
1386   }
1387   return SDValue();
1388 }
1389 
1390 std::pair<SDValue, SDValue>
1391 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1392   SDLoc SL(Op);
1393 
1394   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1395 
1396   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1397   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1398 
1399   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1400   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1401 
1402   return std::make_pair(Lo, Hi);
1403 }
1404 
1405 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1406   SDLoc SL(Op);
1407 
1408   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1409   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1410   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1411 }
1412 
1413 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1414   SDLoc SL(Op);
1415 
1416   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1417   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1418   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1419 }
1420 
1421 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1422                                               SelectionDAG &DAG) const {
1423   LoadSDNode *Load = cast<LoadSDNode>(Op);
1424   EVT VT = Op.getValueType();
1425 
1426 
1427   // If this is a 2 element vector, we really want to scalarize and not create
1428   // weird 1 element vectors.
1429   if (VT.getVectorNumElements() == 2)
1430     return scalarizeVectorLoad(Load, DAG);
1431 
1432   SDValue BasePtr = Load->getBasePtr();
1433   EVT MemVT = Load->getMemoryVT();
1434   SDLoc SL(Op);
1435 
1436   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1437 
1438   EVT LoVT, HiVT;
1439   EVT LoMemVT, HiMemVT;
1440   SDValue Lo, Hi;
1441 
1442   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1443   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1444   std::tie(Lo, Hi) = DAG.SplitVector(Op, SL, LoVT, HiVT);
1445 
1446   unsigned Size = LoMemVT.getStoreSize();
1447   unsigned BaseAlign = Load->getAlignment();
1448   unsigned HiAlign = MinAlign(BaseAlign, Size);
1449 
1450   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1451                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1452                                   BaseAlign, Load->getMemOperand()->getFlags());
1453   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1454   SDValue HiLoad =
1455       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1456                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1457                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1458 
1459   SDValue Ops[] = {
1460     DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad),
1461     DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1462                 LoLoad.getValue(1), HiLoad.getValue(1))
1463   };
1464 
1465   return DAG.getMergeValues(Ops, SL);
1466 }
1467 
1468 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1469                                                SelectionDAG &DAG) const {
1470   StoreSDNode *Store = cast<StoreSDNode>(Op);
1471   SDValue Val = Store->getValue();
1472   EVT VT = Val.getValueType();
1473 
1474   // If this is a 2 element vector, we really want to scalarize and not create
1475   // weird 1 element vectors.
1476   if (VT.getVectorNumElements() == 2)
1477     return scalarizeVectorStore(Store, DAG);
1478 
1479   EVT MemVT = Store->getMemoryVT();
1480   SDValue Chain = Store->getChain();
1481   SDValue BasePtr = Store->getBasePtr();
1482   SDLoc SL(Op);
1483 
1484   EVT LoVT, HiVT;
1485   EVT LoMemVT, HiMemVT;
1486   SDValue Lo, Hi;
1487 
1488   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1489   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1490   std::tie(Lo, Hi) = DAG.SplitVector(Val, SL, LoVT, HiVT);
1491 
1492   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1493 
1494   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1495   unsigned BaseAlign = Store->getAlignment();
1496   unsigned Size = LoMemVT.getStoreSize();
1497   unsigned HiAlign = MinAlign(BaseAlign, Size);
1498 
1499   SDValue LoStore =
1500       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1501                         Store->getMemOperand()->getFlags());
1502   SDValue HiStore =
1503       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1504                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1505 
1506   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1507 }
1508 
1509 // This is a shortcut for integer division because we have fast i32<->f32
1510 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1511 // float is enough to accurately represent up to a 24-bit signed integer.
1512 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1513                                             bool Sign) const {
1514   SDLoc DL(Op);
1515   EVT VT = Op.getValueType();
1516   SDValue LHS = Op.getOperand(0);
1517   SDValue RHS = Op.getOperand(1);
1518   MVT IntVT = MVT::i32;
1519   MVT FltVT = MVT::f32;
1520 
1521   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1522   if (LHSSignBits < 9)
1523     return SDValue();
1524 
1525   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1526   if (RHSSignBits < 9)
1527     return SDValue();
1528 
1529   unsigned BitSize = VT.getSizeInBits();
1530   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1531   unsigned DivBits = BitSize - SignBits;
1532   if (Sign)
1533     ++DivBits;
1534 
1535   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1536   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1537 
1538   SDValue jq = DAG.getConstant(1, DL, IntVT);
1539 
1540   if (Sign) {
1541     // char|short jq = ia ^ ib;
1542     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1543 
1544     // jq = jq >> (bitsize - 2)
1545     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1546                      DAG.getConstant(BitSize - 2, DL, VT));
1547 
1548     // jq = jq | 0x1
1549     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1550   }
1551 
1552   // int ia = (int)LHS;
1553   SDValue ia = LHS;
1554 
1555   // int ib, (int)RHS;
1556   SDValue ib = RHS;
1557 
1558   // float fa = (float)ia;
1559   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1560 
1561   // float fb = (float)ib;
1562   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1563 
1564   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1565                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1566 
1567   // fq = trunc(fq);
1568   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1569 
1570   // float fqneg = -fq;
1571   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1572 
1573   // float fr = mad(fqneg, fb, fa);
1574   unsigned OpCode = Subtarget->hasFP32Denormals() ?
1575                     (unsigned)AMDGPUISD::FMAD_FTZ :
1576                     (unsigned)ISD::FMAD;
1577   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1578 
1579   // int iq = (int)fq;
1580   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1581 
1582   // fr = fabs(fr);
1583   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1584 
1585   // fb = fabs(fb);
1586   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1587 
1588   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1589 
1590   // int cv = fr >= fb;
1591   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1592 
1593   // jq = (cv ? jq : 0);
1594   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1595 
1596   // dst = iq + jq;
1597   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1598 
1599   // Rem needs compensation, it's easier to recompute it
1600   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1601   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1602 
1603   // Truncate to number of bits this divide really is.
1604   if (Sign) {
1605     SDValue InRegSize
1606       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1607     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1608     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1609   } else {
1610     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1611     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1612     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1613   }
1614 
1615   return DAG.getMergeValues({ Div, Rem }, DL);
1616 }
1617 
1618 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1619                                       SelectionDAG &DAG,
1620                                       SmallVectorImpl<SDValue> &Results) const {
1621   SDLoc DL(Op);
1622   EVT VT = Op.getValueType();
1623 
1624   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1625 
1626   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1627 
1628   SDValue One = DAG.getConstant(1, DL, HalfVT);
1629   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1630 
1631   //HiLo split
1632   SDValue LHS = Op.getOperand(0);
1633   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1634   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1635 
1636   SDValue RHS = Op.getOperand(1);
1637   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1638   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1639 
1640   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1641       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1642 
1643     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1644                               LHS_Lo, RHS_Lo);
1645 
1646     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1647     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1648 
1649     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1650     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1651     return;
1652   }
1653 
1654   if (isTypeLegal(MVT::i64)) {
1655     // Compute denominator reciprocal.
1656     unsigned FMAD = Subtarget->hasFP32Denormals() ?
1657                     (unsigned)AMDGPUISD::FMAD_FTZ :
1658                     (unsigned)ISD::FMAD;
1659 
1660     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1661     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1662     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1663       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1664       Cvt_Lo);
1665     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1666     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1667       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1668     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1669       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1670     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1671     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1672       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1673       Mul1);
1674     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1675     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1676     SDValue Rcp64 = DAG.getBitcast(VT,
1677                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1678 
1679     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1680     SDValue One64  = DAG.getConstant(1, DL, VT);
1681     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1682     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1683 
1684     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1685     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1686     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1687     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1688                                     Zero);
1689     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1690                                     One);
1691 
1692     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1693                                   Mulhi1_Lo, Zero1);
1694     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1695                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1696     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1697     SDValue Add1 = DAG.getBitcast(VT,
1698                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1699 
1700     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1701     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1702     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1703                                     Zero);
1704     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1705                                     One);
1706 
1707     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1708                                   Mulhi2_Lo, Zero1);
1709     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1710                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1711     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1712                                   Zero, Add2_Lo.getValue(1));
1713     SDValue Add2 = DAG.getBitcast(VT,
1714                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1715     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1716 
1717     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1718 
1719     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1720     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1721     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1722                                   Mul3_Lo, Zero1);
1723     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1724                                   Mul3_Hi, Sub1_Lo.getValue(1));
1725     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1726     SDValue Sub1 = DAG.getBitcast(VT,
1727                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1728 
1729     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1730     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1731                                  ISD::SETUGE);
1732     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1733                                  ISD::SETUGE);
1734     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1735 
1736     // TODO: Here and below portions of the code can be enclosed into if/endif.
1737     // Currently control flow is unconditional and we have 4 selects after
1738     // potential endif to substitute PHIs.
1739 
1740     // if C3 != 0 ...
1741     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1742                                   RHS_Lo, Zero1);
1743     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1744                                   RHS_Hi, Sub1_Lo.getValue(1));
1745     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1746                                   Zero, Sub2_Lo.getValue(1));
1747     SDValue Sub2 = DAG.getBitcast(VT,
1748                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1749 
1750     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1751 
1752     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1753                                  ISD::SETUGE);
1754     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1755                                  ISD::SETUGE);
1756     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1757 
1758     // if (C6 != 0)
1759     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1760 
1761     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1762                                   RHS_Lo, Zero1);
1763     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1764                                   RHS_Hi, Sub2_Lo.getValue(1));
1765     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1766                                   Zero, Sub3_Lo.getValue(1));
1767     SDValue Sub3 = DAG.getBitcast(VT,
1768                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1769 
1770     // endif C6
1771     // endif C3
1772 
1773     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1774     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1775 
1776     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1777     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1778 
1779     Results.push_back(Div);
1780     Results.push_back(Rem);
1781 
1782     return;
1783   }
1784 
1785   // r600 expandion.
1786   // Get Speculative values
1787   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1788   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1789 
1790   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1791   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1792   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1793 
1794   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1795   SDValue DIV_Lo = Zero;
1796 
1797   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1798 
1799   for (unsigned i = 0; i < halfBitWidth; ++i) {
1800     const unsigned bitPos = halfBitWidth - i - 1;
1801     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1802     // Get value of high bit
1803     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1804     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1805     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1806 
1807     // Shift
1808     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1809     // Add LHS high bit
1810     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1811 
1812     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1813     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1814 
1815     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1816 
1817     // Update REM
1818     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1819     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1820   }
1821 
1822   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1823   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1824   Results.push_back(DIV);
1825   Results.push_back(REM);
1826 }
1827 
1828 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1829                                            SelectionDAG &DAG) const {
1830   SDLoc DL(Op);
1831   EVT VT = Op.getValueType();
1832 
1833   if (VT == MVT::i64) {
1834     SmallVector<SDValue, 2> Results;
1835     LowerUDIVREM64(Op, DAG, Results);
1836     return DAG.getMergeValues(Results, DL);
1837   }
1838 
1839   if (VT == MVT::i32) {
1840     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1841       return Res;
1842   }
1843 
1844   SDValue Num = Op.getOperand(0);
1845   SDValue Den = Op.getOperand(1);
1846 
1847   // RCP =  URECIP(Den) = 2^32 / Den + e
1848   // e is rounding error.
1849   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1850 
1851   // RCP_LO = mul(RCP, Den) */
1852   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1853 
1854   // RCP_HI = mulhu (RCP, Den) */
1855   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1856 
1857   // NEG_RCP_LO = -RCP_LO
1858   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1859                                                      RCP_LO);
1860 
1861   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1862   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1863                                            NEG_RCP_LO, RCP_LO,
1864                                            ISD::SETEQ);
1865   // Calculate the rounding error from the URECIP instruction
1866   // E = mulhu(ABS_RCP_LO, RCP)
1867   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1868 
1869   // RCP_A_E = RCP + E
1870   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1871 
1872   // RCP_S_E = RCP - E
1873   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1874 
1875   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1876   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1877                                      RCP_A_E, RCP_S_E,
1878                                      ISD::SETEQ);
1879   // Quotient = mulhu(Tmp0, Num)
1880   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1881 
1882   // Num_S_Remainder = Quotient * Den
1883   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1884 
1885   // Remainder = Num - Num_S_Remainder
1886   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1887 
1888   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1889   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1890                                                  DAG.getConstant(-1, DL, VT),
1891                                                  DAG.getConstant(0, DL, VT),
1892                                                  ISD::SETUGE);
1893   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1894   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1895                                                   Num_S_Remainder,
1896                                                   DAG.getConstant(-1, DL, VT),
1897                                                   DAG.getConstant(0, DL, VT),
1898                                                   ISD::SETUGE);
1899   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1900   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1901                                                Remainder_GE_Zero);
1902 
1903   // Calculate Division result:
1904 
1905   // Quotient_A_One = Quotient + 1
1906   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1907                                        DAG.getConstant(1, DL, VT));
1908 
1909   // Quotient_S_One = Quotient - 1
1910   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1911                                        DAG.getConstant(1, DL, VT));
1912 
1913   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1914   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1915                                      Quotient, Quotient_A_One, ISD::SETEQ);
1916 
1917   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1918   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1919                             Quotient_S_One, Div, ISD::SETEQ);
1920 
1921   // Calculate Rem result:
1922 
1923   // Remainder_S_Den = Remainder - Den
1924   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1925 
1926   // Remainder_A_Den = Remainder + Den
1927   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1928 
1929   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1930   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1931                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1932 
1933   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1934   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1935                             Remainder_A_Den, Rem, ISD::SETEQ);
1936   SDValue Ops[2] = {
1937     Div,
1938     Rem
1939   };
1940   return DAG.getMergeValues(Ops, DL);
1941 }
1942 
1943 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1944                                            SelectionDAG &DAG) const {
1945   SDLoc DL(Op);
1946   EVT VT = Op.getValueType();
1947 
1948   SDValue LHS = Op.getOperand(0);
1949   SDValue RHS = Op.getOperand(1);
1950 
1951   SDValue Zero = DAG.getConstant(0, DL, VT);
1952   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1953 
1954   if (VT == MVT::i32) {
1955     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1956       return Res;
1957   }
1958 
1959   if (VT == MVT::i64 &&
1960       DAG.ComputeNumSignBits(LHS) > 32 &&
1961       DAG.ComputeNumSignBits(RHS) > 32) {
1962     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1963 
1964     //HiLo split
1965     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1966     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1967     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1968                                  LHS_Lo, RHS_Lo);
1969     SDValue Res[2] = {
1970       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1971       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1972     };
1973     return DAG.getMergeValues(Res, DL);
1974   }
1975 
1976   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1977   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1978   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1979   SDValue RSign = LHSign; // Remainder sign is the same as LHS
1980 
1981   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
1982   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
1983 
1984   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
1985   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
1986 
1987   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
1988   SDValue Rem = Div.getValue(1);
1989 
1990   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
1991   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
1992 
1993   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
1994   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
1995 
1996   SDValue Res[2] = {
1997     Div,
1998     Rem
1999   };
2000   return DAG.getMergeValues(Res, DL);
2001 }
2002 
2003 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
2004 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
2005   SDLoc SL(Op);
2006   EVT VT = Op.getValueType();
2007   SDValue X = Op.getOperand(0);
2008   SDValue Y = Op.getOperand(1);
2009 
2010   // TODO: Should this propagate fast-math-flags?
2011 
2012   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
2013   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
2014   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
2015 
2016   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
2017 }
2018 
2019 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
2020   SDLoc SL(Op);
2021   SDValue Src = Op.getOperand(0);
2022 
2023   // result = trunc(src)
2024   // if (src > 0.0 && src != result)
2025   //   result += 1.0
2026 
2027   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2028 
2029   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2030   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
2031 
2032   EVT SetCCVT =
2033       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2034 
2035   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
2036   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2037   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2038 
2039   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
2040   // TODO: Should this propagate fast-math-flags?
2041   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2042 }
2043 
2044 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
2045                                   SelectionDAG &DAG) {
2046   const unsigned FractBits = 52;
2047   const unsigned ExpBits = 11;
2048 
2049   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2050                                 Hi,
2051                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2052                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2053   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2054                             DAG.getConstant(1023, SL, MVT::i32));
2055 
2056   return Exp;
2057 }
2058 
2059 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2060   SDLoc SL(Op);
2061   SDValue Src = Op.getOperand(0);
2062 
2063   assert(Op.getValueType() == MVT::f64);
2064 
2065   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2066   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2067 
2068   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2069 
2070   // Extract the upper half, since this is where we will find the sign and
2071   // exponent.
2072   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2073 
2074   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2075 
2076   const unsigned FractBits = 52;
2077 
2078   // Extract the sign bit.
2079   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2080   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2081 
2082   // Extend back to 64-bits.
2083   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2084   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2085 
2086   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2087   const SDValue FractMask
2088     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2089 
2090   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2091   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2092   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2093 
2094   EVT SetCCVT =
2095       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2096 
2097   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2098 
2099   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2100   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2101 
2102   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2103   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2104 
2105   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2106 }
2107 
2108 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2109   SDLoc SL(Op);
2110   SDValue Src = Op.getOperand(0);
2111 
2112   assert(Op.getValueType() == MVT::f64);
2113 
2114   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2115   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2116   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2117 
2118   // TODO: Should this propagate fast-math-flags?
2119 
2120   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2121   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2122 
2123   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2124 
2125   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2126   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2127 
2128   EVT SetCCVT =
2129       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2130   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2131 
2132   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2133 }
2134 
2135 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2136   // FNEARBYINT and FRINT are the same, except in their handling of FP
2137   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2138   // rint, so just treat them as equivalent.
2139   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2140 }
2141 
2142 // XXX - May require not supporting f32 denormals?
2143 
2144 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2145 // compare and vselect end up producing worse code than scalarizing the whole
2146 // operation.
2147 SDValue AMDGPUTargetLowering::LowerFROUND32_16(SDValue Op, SelectionDAG &DAG) const {
2148   SDLoc SL(Op);
2149   SDValue X = Op.getOperand(0);
2150   EVT VT = Op.getValueType();
2151 
2152   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2153 
2154   // TODO: Should this propagate fast-math-flags?
2155 
2156   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2157 
2158   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2159 
2160   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2161   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2162   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2163 
2164   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2165 
2166   EVT SetCCVT =
2167       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2168 
2169   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2170 
2171   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2172 
2173   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2174 }
2175 
2176 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2177   SDLoc SL(Op);
2178   SDValue X = Op.getOperand(0);
2179 
2180   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2181 
2182   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2183   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2184   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2185   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2186   EVT SetCCVT =
2187       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2188 
2189   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2190 
2191   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2192 
2193   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2194 
2195   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2196                                        MVT::i64);
2197 
2198   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2199   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2200                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2201                                           MVT::i64),
2202                           Exp);
2203 
2204   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2205   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2206                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2207                               ISD::SETNE);
2208 
2209   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2210                              D, DAG.getConstant(0, SL, MVT::i64));
2211   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2212 
2213   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2214   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2215 
2216   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2217   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2218   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2219 
2220   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2221                             ExpEqNegOne,
2222                             DAG.getConstantFP(1.0, SL, MVT::f64),
2223                             DAG.getConstantFP(0.0, SL, MVT::f64));
2224 
2225   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2226 
2227   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2228   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2229 
2230   return K;
2231 }
2232 
2233 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2234   EVT VT = Op.getValueType();
2235 
2236   if (VT == MVT::f32 || VT == MVT::f16)
2237     return LowerFROUND32_16(Op, DAG);
2238 
2239   if (VT == MVT::f64)
2240     return LowerFROUND64(Op, DAG);
2241 
2242   llvm_unreachable("unhandled type");
2243 }
2244 
2245 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2246   SDLoc SL(Op);
2247   SDValue Src = Op.getOperand(0);
2248 
2249   // result = trunc(src);
2250   // if (src < 0.0 && src != result)
2251   //   result += -1.0.
2252 
2253   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2254 
2255   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2256   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2257 
2258   EVT SetCCVT =
2259       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2260 
2261   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2262   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2263   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2264 
2265   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2266   // TODO: Should this propagate fast-math-flags?
2267   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2268 }
2269 
2270 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2271                                         double Log2BaseInverted) const {
2272   EVT VT = Op.getValueType();
2273 
2274   SDLoc SL(Op);
2275   SDValue Operand = Op.getOperand(0);
2276   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2277   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2278 
2279   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2280 }
2281 
2282 static bool isCtlzOpc(unsigned Opc) {
2283   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2284 }
2285 
2286 static bool isCttzOpc(unsigned Opc) {
2287   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2288 }
2289 
2290 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2291   SDLoc SL(Op);
2292   SDValue Src = Op.getOperand(0);
2293   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2294                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2295 
2296   unsigned ISDOpc, NewOpc;
2297   if (isCtlzOpc(Op.getOpcode())) {
2298     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2299     NewOpc = AMDGPUISD::FFBH_U32;
2300   } else if (isCttzOpc(Op.getOpcode())) {
2301     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2302     NewOpc = AMDGPUISD::FFBL_B32;
2303   } else
2304     llvm_unreachable("Unexpected OPCode!!!");
2305 
2306 
2307   if (ZeroUndef && Src.getValueType() == MVT::i32)
2308     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2309 
2310   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2311 
2312   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2313   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2314 
2315   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2316   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2317 
2318   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2319                                    *DAG.getContext(), MVT::i32);
2320 
2321   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2322   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2323 
2324   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2325   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2326 
2327   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2328   SDValue Add, NewOpr;
2329   if (isCtlzOpc(Op.getOpcode())) {
2330     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2331     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2332     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2333   } else {
2334     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2335     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2336     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2337   }
2338 
2339   if (!ZeroUndef) {
2340     // Test if the full 64-bit input is zero.
2341 
2342     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2343     // which we probably don't want.
2344     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2345     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2346     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2347 
2348     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2349     // with the same cycles, otherwise it is slower.
2350     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2351     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2352 
2353     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2354 
2355     // The instruction returns -1 for 0 input, but the defined intrinsic
2356     // behavior is to return the number of bits.
2357     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2358                          SrcIsZero, Bits32, NewOpr);
2359   }
2360 
2361   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2362 }
2363 
2364 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2365                                                bool Signed) const {
2366   // Unsigned
2367   // cul2f(ulong u)
2368   //{
2369   //  uint lz = clz(u);
2370   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2371   //  u = (u << lz) & 0x7fffffffffffffffUL;
2372   //  ulong t = u & 0xffffffffffUL;
2373   //  uint v = (e << 23) | (uint)(u >> 40);
2374   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2375   //  return as_float(v + r);
2376   //}
2377   // Signed
2378   // cl2f(long l)
2379   //{
2380   //  long s = l >> 63;
2381   //  float r = cul2f((l + s) ^ s);
2382   //  return s ? -r : r;
2383   //}
2384 
2385   SDLoc SL(Op);
2386   SDValue Src = Op.getOperand(0);
2387   SDValue L = Src;
2388 
2389   SDValue S;
2390   if (Signed) {
2391     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2392     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2393 
2394     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2395     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2396   }
2397 
2398   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2399                                    *DAG.getContext(), MVT::f32);
2400 
2401 
2402   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2403   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2404   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2405   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2406 
2407   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2408   SDValue E = DAG.getSelect(SL, MVT::i32,
2409     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2410     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2411     ZeroI32);
2412 
2413   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2414     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2415     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2416 
2417   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2418                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2419 
2420   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2421                              U, DAG.getConstant(40, SL, MVT::i64));
2422 
2423   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2424     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2425     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2426 
2427   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2428   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2429   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2430 
2431   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2432 
2433   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2434 
2435   SDValue R = DAG.getSelect(SL, MVT::i32,
2436     RCmp,
2437     One,
2438     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2439   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2440   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2441 
2442   if (!Signed)
2443     return R;
2444 
2445   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2446   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2447 }
2448 
2449 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2450                                                bool Signed) const {
2451   SDLoc SL(Op);
2452   SDValue Src = Op.getOperand(0);
2453 
2454   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2455 
2456   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2457                            DAG.getConstant(0, SL, MVT::i32));
2458   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2459                            DAG.getConstant(1, SL, MVT::i32));
2460 
2461   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2462                               SL, MVT::f64, Hi);
2463 
2464   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2465 
2466   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2467                               DAG.getConstant(32, SL, MVT::i32));
2468   // TODO: Should this propagate fast-math-flags?
2469   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2470 }
2471 
2472 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2473                                                SelectionDAG &DAG) const {
2474   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2475          "operation should be legal");
2476 
2477   // TODO: Factor out code common with LowerSINT_TO_FP.
2478 
2479   EVT DestVT = Op.getValueType();
2480   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2481     SDLoc DL(Op);
2482     SDValue Src = Op.getOperand(0);
2483 
2484     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2485     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2486     SDValue FPRound =
2487         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2488 
2489     return FPRound;
2490   }
2491 
2492   if (DestVT == MVT::f32)
2493     return LowerINT_TO_FP32(Op, DAG, false);
2494 
2495   assert(DestVT == MVT::f64);
2496   return LowerINT_TO_FP64(Op, DAG, false);
2497 }
2498 
2499 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2500                                               SelectionDAG &DAG) const {
2501   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2502          "operation should be legal");
2503 
2504   // TODO: Factor out code common with LowerUINT_TO_FP.
2505 
2506   EVT DestVT = Op.getValueType();
2507   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2508     SDLoc DL(Op);
2509     SDValue Src = Op.getOperand(0);
2510 
2511     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2512     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2513     SDValue FPRound =
2514         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2515 
2516     return FPRound;
2517   }
2518 
2519   if (DestVT == MVT::f32)
2520     return LowerINT_TO_FP32(Op, DAG, true);
2521 
2522   assert(DestVT == MVT::f64);
2523   return LowerINT_TO_FP64(Op, DAG, true);
2524 }
2525 
2526 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2527                                                bool Signed) const {
2528   SDLoc SL(Op);
2529 
2530   SDValue Src = Op.getOperand(0);
2531 
2532   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2533 
2534   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2535                                  MVT::f64);
2536   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2537                                  MVT::f64);
2538   // TODO: Should this propagate fast-math-flags?
2539   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2540 
2541   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2542 
2543 
2544   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2545 
2546   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2547                            MVT::i32, FloorMul);
2548   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2549 
2550   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2551 
2552   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2553 }
2554 
2555 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2556   SDLoc DL(Op);
2557   SDValue N0 = Op.getOperand(0);
2558 
2559   // Convert to target node to get known bits
2560   if (N0.getValueType() == MVT::f32)
2561     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2562 
2563   if (getTargetMachine().Options.UnsafeFPMath) {
2564     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2565     return SDValue();
2566   }
2567 
2568   assert(N0.getSimpleValueType() == MVT::f64);
2569 
2570   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2571   const unsigned ExpMask = 0x7ff;
2572   const unsigned ExpBiasf64 = 1023;
2573   const unsigned ExpBiasf16 = 15;
2574   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2575   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2576   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2577   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2578                            DAG.getConstant(32, DL, MVT::i64));
2579   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2580   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2581   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2582                           DAG.getConstant(20, DL, MVT::i64));
2583   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2584                   DAG.getConstant(ExpMask, DL, MVT::i32));
2585   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2586   // add the f16 bias (15) to get the biased exponent for the f16 format.
2587   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2588                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2589 
2590   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2591                           DAG.getConstant(8, DL, MVT::i32));
2592   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2593                   DAG.getConstant(0xffe, DL, MVT::i32));
2594 
2595   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2596                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2597   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2598 
2599   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2600   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2601 
2602   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2603   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2604       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2605                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2606 
2607   // N = M | (E << 12);
2608   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2609       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2610                   DAG.getConstant(12, DL, MVT::i32)));
2611 
2612   // B = clamp(1-E, 0, 13);
2613   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2614                                   One, E);
2615   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2616   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2617                   DAG.getConstant(13, DL, MVT::i32));
2618 
2619   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2620                                    DAG.getConstant(0x1000, DL, MVT::i32));
2621 
2622   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2623   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2624   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2625   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2626 
2627   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2628   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2629                               DAG.getConstant(0x7, DL, MVT::i32));
2630   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2631                   DAG.getConstant(2, DL, MVT::i32));
2632   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2633                                One, Zero, ISD::SETEQ);
2634   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2635                                One, Zero, ISD::SETGT);
2636   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2637   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2638 
2639   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2640                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2641   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2642                       I, V, ISD::SETEQ);
2643 
2644   // Extract the sign bit.
2645   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2646                             DAG.getConstant(16, DL, MVT::i32));
2647   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2648                      DAG.getConstant(0x8000, DL, MVT::i32));
2649 
2650   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2651   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2652 }
2653 
2654 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2655                                               SelectionDAG &DAG) const {
2656   SDValue Src = Op.getOperand(0);
2657 
2658   // TODO: Factor out code common with LowerFP_TO_UINT.
2659 
2660   EVT SrcVT = Src.getValueType();
2661   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2662     SDLoc DL(Op);
2663 
2664     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2665     SDValue FpToInt32 =
2666         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2667 
2668     return FpToInt32;
2669   }
2670 
2671   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2672     return LowerFP64_TO_INT(Op, DAG, true);
2673 
2674   return SDValue();
2675 }
2676 
2677 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2678                                               SelectionDAG &DAG) const {
2679   SDValue Src = Op.getOperand(0);
2680 
2681   // TODO: Factor out code common with LowerFP_TO_SINT.
2682 
2683   EVT SrcVT = Src.getValueType();
2684   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2685     SDLoc DL(Op);
2686 
2687     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2688     SDValue FpToInt32 =
2689         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2690 
2691     return FpToInt32;
2692   }
2693 
2694   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2695     return LowerFP64_TO_INT(Op, DAG, false);
2696 
2697   return SDValue();
2698 }
2699 
2700 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2701                                                      SelectionDAG &DAG) const {
2702   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2703   MVT VT = Op.getSimpleValueType();
2704   MVT ScalarVT = VT.getScalarType();
2705 
2706   assert(VT.isVector());
2707 
2708   SDValue Src = Op.getOperand(0);
2709   SDLoc DL(Op);
2710 
2711   // TODO: Don't scalarize on Evergreen?
2712   unsigned NElts = VT.getVectorNumElements();
2713   SmallVector<SDValue, 8> Args;
2714   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2715 
2716   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2717   for (unsigned I = 0; I < NElts; ++I)
2718     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2719 
2720   return DAG.getBuildVector(VT, DL, Args);
2721 }
2722 
2723 //===----------------------------------------------------------------------===//
2724 // Custom DAG optimizations
2725 //===----------------------------------------------------------------------===//
2726 
2727 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2728   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2729 }
2730 
2731 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2732   EVT VT = Op.getValueType();
2733   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2734                                      // as unsigned 24-bit values.
2735     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2736 }
2737 
2738 static bool simplifyI24(SDNode *Node24, unsigned OpIdx,
2739                         TargetLowering::DAGCombinerInfo &DCI) {
2740 
2741   SelectionDAG &DAG = DCI.DAG;
2742   SDValue Op = Node24->getOperand(OpIdx);
2743   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2744   EVT VT = Op.getValueType();
2745 
2746   APInt Demanded = APInt::getLowBitsSet(VT.getSizeInBits(), 24);
2747   APInt KnownZero, KnownOne;
2748   TargetLowering::TargetLoweringOpt TLO(DAG, true, true);
2749   if (TLI.SimplifyDemandedBits(Node24, OpIdx, Demanded, DCI, TLO))
2750     return true;
2751 
2752   return false;
2753 }
2754 
2755 template <typename IntTy>
2756 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2757                                uint32_t Width, const SDLoc &DL) {
2758   if (Width + Offset < 32) {
2759     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2760     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2761     return DAG.getConstant(Result, DL, MVT::i32);
2762   }
2763 
2764   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2765 }
2766 
2767 static bool hasVolatileUser(SDNode *Val) {
2768   for (SDNode *U : Val->uses()) {
2769     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2770       if (M->isVolatile())
2771         return true;
2772     }
2773   }
2774 
2775   return false;
2776 }
2777 
2778 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2779   // i32 vectors are the canonical memory type.
2780   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2781     return false;
2782 
2783   if (!VT.isByteSized())
2784     return false;
2785 
2786   unsigned Size = VT.getStoreSize();
2787 
2788   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2789     return false;
2790 
2791   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2792     return false;
2793 
2794   return true;
2795 }
2796 
2797 // Replace load of an illegal type with a store of a bitcast to a friendlier
2798 // type.
2799 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2800                                                  DAGCombinerInfo &DCI) const {
2801   if (!DCI.isBeforeLegalize())
2802     return SDValue();
2803 
2804   LoadSDNode *LN = cast<LoadSDNode>(N);
2805   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2806     return SDValue();
2807 
2808   SDLoc SL(N);
2809   SelectionDAG &DAG = DCI.DAG;
2810   EVT VT = LN->getMemoryVT();
2811 
2812   unsigned Size = VT.getStoreSize();
2813   unsigned Align = LN->getAlignment();
2814   if (Align < Size && isTypeLegal(VT)) {
2815     bool IsFast;
2816     unsigned AS = LN->getAddressSpace();
2817 
2818     // Expand unaligned loads earlier than legalization. Due to visitation order
2819     // problems during legalization, the emitted instructions to pack and unpack
2820     // the bytes again are not eliminated in the case of an unaligned copy.
2821     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2822       if (VT.isVector())
2823         return scalarizeVectorLoad(LN, DAG);
2824 
2825       SDValue Ops[2];
2826       std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2827       return DAG.getMergeValues(Ops, SDLoc(N));
2828     }
2829 
2830     if (!IsFast)
2831       return SDValue();
2832   }
2833 
2834   if (!shouldCombineMemoryType(VT))
2835     return SDValue();
2836 
2837   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2838 
2839   SDValue NewLoad
2840     = DAG.getLoad(NewVT, SL, LN->getChain(),
2841                   LN->getBasePtr(), LN->getMemOperand());
2842 
2843   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2844   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2845   return SDValue(N, 0);
2846 }
2847 
2848 // Replace store of an illegal type with a store of a bitcast to a friendlier
2849 // type.
2850 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2851                                                   DAGCombinerInfo &DCI) const {
2852   if (!DCI.isBeforeLegalize())
2853     return SDValue();
2854 
2855   StoreSDNode *SN = cast<StoreSDNode>(N);
2856   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2857     return SDValue();
2858 
2859   EVT VT = SN->getMemoryVT();
2860   unsigned Size = VT.getStoreSize();
2861 
2862   SDLoc SL(N);
2863   SelectionDAG &DAG = DCI.DAG;
2864   unsigned Align = SN->getAlignment();
2865   if (Align < Size && isTypeLegal(VT)) {
2866     bool IsFast;
2867     unsigned AS = SN->getAddressSpace();
2868 
2869     // Expand unaligned stores earlier than legalization. Due to visitation
2870     // order problems during legalization, the emitted instructions to pack and
2871     // unpack the bytes again are not eliminated in the case of an unaligned
2872     // copy.
2873     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2874       if (VT.isVector())
2875         return scalarizeVectorStore(SN, DAG);
2876 
2877       return expandUnalignedStore(SN, DAG);
2878     }
2879 
2880     if (!IsFast)
2881       return SDValue();
2882   }
2883 
2884   if (!shouldCombineMemoryType(VT))
2885     return SDValue();
2886 
2887   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2888   SDValue Val = SN->getValue();
2889 
2890   //DCI.AddToWorklist(Val.getNode());
2891 
2892   bool OtherUses = !Val.hasOneUse();
2893   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2894   if (OtherUses) {
2895     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2896     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2897   }
2898 
2899   return DAG.getStore(SN->getChain(), SL, CastVal,
2900                       SN->getBasePtr(), SN->getMemOperand());
2901 }
2902 
2903 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2904 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2905 // issues.
2906 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2907                                                         DAGCombinerInfo &DCI) const {
2908   SelectionDAG &DAG = DCI.DAG;
2909   SDValue N0 = N->getOperand(0);
2910 
2911   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2912   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2913   if (N0.getOpcode() == ISD::TRUNCATE) {
2914     SDValue N1 = N->getOperand(1);
2915     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2916     SDLoc SL(N);
2917 
2918     SDValue Src = N0.getOperand(0);
2919     EVT SrcVT = Src.getValueType();
2920     if (SrcVT.bitsGE(ExtVT)) {
2921       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2922       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2923     }
2924   }
2925 
2926   return SDValue();
2927 }
2928 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
2929 /// binary operation \p Opc to it with the corresponding constant operands.
2930 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
2931   DAGCombinerInfo &DCI, const SDLoc &SL,
2932   unsigned Opc, SDValue LHS,
2933   uint32_t ValLo, uint32_t ValHi) const {
2934   SelectionDAG &DAG = DCI.DAG;
2935   SDValue Lo, Hi;
2936   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
2937 
2938   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
2939   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
2940 
2941   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
2942   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
2943 
2944   // Re-visit the ands. It's possible we eliminated one of them and it could
2945   // simplify the vector.
2946   DCI.AddToWorklist(Lo.getNode());
2947   DCI.AddToWorklist(Hi.getNode());
2948 
2949   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
2950   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2951 }
2952 
2953 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
2954                                                 DAGCombinerInfo &DCI) const {
2955   EVT VT = N->getValueType(0);
2956 
2957   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2958   if (!RHS)
2959     return SDValue();
2960 
2961   SDValue LHS = N->getOperand(0);
2962   unsigned RHSVal = RHS->getZExtValue();
2963   if (!RHSVal)
2964     return LHS;
2965 
2966   SDLoc SL(N);
2967   SelectionDAG &DAG = DCI.DAG;
2968 
2969   switch (LHS->getOpcode()) {
2970   default:
2971     break;
2972   case ISD::ZERO_EXTEND:
2973   case ISD::SIGN_EXTEND:
2974   case ISD::ANY_EXTEND: {
2975     SDValue X = LHS->getOperand(0);
2976 
2977     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
2978         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
2979       // Prefer build_vector as the canonical form if packed types are legal.
2980       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
2981       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
2982        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
2983       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
2984     }
2985 
2986     // shl (ext x) => zext (shl x), if shift does not overflow int
2987     if (VT != MVT::i64)
2988       break;
2989     KnownBits Known;
2990     DAG.computeKnownBits(X, Known);
2991     unsigned LZ = Known.countMinLeadingZeros();
2992     if (LZ < RHSVal)
2993       break;
2994     EVT XVT = X.getValueType();
2995     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
2996     return DAG.getZExtOrTrunc(Shl, SL, VT);
2997   }
2998   }
2999 
3000   if (VT != MVT::i64)
3001     return SDValue();
3002 
3003   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
3004 
3005   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
3006   // common case, splitting this into a move and a 32-bit shift is faster and
3007   // the same code size.
3008   if (RHSVal < 32)
3009     return SDValue();
3010 
3011   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
3012 
3013   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
3014   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
3015 
3016   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3017 
3018   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
3019   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3020 }
3021 
3022 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
3023                                                 DAGCombinerInfo &DCI) const {
3024   if (N->getValueType(0) != MVT::i64)
3025     return SDValue();
3026 
3027   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3028   if (!RHS)
3029     return SDValue();
3030 
3031   SelectionDAG &DAG = DCI.DAG;
3032   SDLoc SL(N);
3033   unsigned RHSVal = RHS->getZExtValue();
3034 
3035   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3036   if (RHSVal == 32) {
3037     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3038     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3039                                    DAG.getConstant(31, SL, MVT::i32));
3040 
3041     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3042     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3043   }
3044 
3045   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3046   if (RHSVal == 63) {
3047     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3048     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3049                                    DAG.getConstant(31, SL, MVT::i32));
3050     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3051     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3052   }
3053 
3054   return SDValue();
3055 }
3056 
3057 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3058                                                 DAGCombinerInfo &DCI) const {
3059   if (N->getValueType(0) != MVT::i64)
3060     return SDValue();
3061 
3062   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3063   if (!RHS)
3064     return SDValue();
3065 
3066   unsigned ShiftAmt = RHS->getZExtValue();
3067   if (ShiftAmt < 32)
3068     return SDValue();
3069 
3070   // srl i64:x, C for C >= 32
3071   // =>
3072   //   build_pair (srl hi_32(x), C - 32), 0
3073 
3074   SelectionDAG &DAG = DCI.DAG;
3075   SDLoc SL(N);
3076 
3077   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3078   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3079 
3080   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, N->getOperand(0));
3081   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32,
3082                            VecOp, One);
3083 
3084   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3085   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3086 
3087   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3088 
3089   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3090 }
3091 
3092 SDValue AMDGPUTargetLowering::performTruncateCombine(
3093   SDNode *N, DAGCombinerInfo &DCI) const {
3094   SDLoc SL(N);
3095   SelectionDAG &DAG = DCI.DAG;
3096   EVT VT = N->getValueType(0);
3097   SDValue Src = N->getOperand(0);
3098 
3099   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3100   if (Src.getOpcode() == ISD::BITCAST) {
3101     SDValue Vec = Src.getOperand(0);
3102     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3103       SDValue Elt0 = Vec.getOperand(0);
3104       EVT EltVT = Elt0.getValueType();
3105       if (VT.getSizeInBits() <= EltVT.getSizeInBits()) {
3106         if (EltVT.isFloatingPoint()) {
3107           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3108                              EltVT.changeTypeToInteger(), Elt0);
3109         }
3110 
3111         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3112       }
3113     }
3114   }
3115 
3116   // Equivalent of above for accessing the high element of a vector as an
3117   // integer operation.
3118   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3119   if (Src.getOpcode() == ISD::SRL) {
3120     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3121       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3122         SDValue BV = stripBitcast(Src.getOperand(0));
3123         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3124             BV.getValueType().getVectorNumElements() == 2) {
3125           SDValue SrcElt = BV.getOperand(1);
3126           EVT SrcEltVT = SrcElt.getValueType();
3127           if (SrcEltVT.isFloatingPoint()) {
3128             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3129                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3130           }
3131 
3132           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3133         }
3134       }
3135     }
3136   }
3137 
3138   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3139   //
3140   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3141   //     i16 (trunc (srl (i32 (trunc x), K)))
3142   if (VT.getScalarSizeInBits() < 32) {
3143     EVT SrcVT = Src.getValueType();
3144     if (SrcVT.getScalarSizeInBits() > 32 &&
3145         (Src.getOpcode() == ISD::SRL ||
3146          Src.getOpcode() == ISD::SRA ||
3147          Src.getOpcode() == ISD::SHL)) {
3148       SDValue Amt = Src.getOperand(1);
3149       KnownBits Known;
3150       DAG.computeKnownBits(Amt, Known);
3151       unsigned Size = VT.getScalarSizeInBits();
3152       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3153           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3154         EVT MidVT = VT.isVector() ?
3155           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3156                            VT.getVectorNumElements()) : MVT::i32;
3157 
3158         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3159         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3160                                     Src.getOperand(0));
3161         DCI.AddToWorklist(Trunc.getNode());
3162 
3163         if (Amt.getValueType() != NewShiftVT) {
3164           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3165           DCI.AddToWorklist(Amt.getNode());
3166         }
3167 
3168         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3169                                           Trunc, Amt);
3170         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3171       }
3172     }
3173   }
3174 
3175   return SDValue();
3176 }
3177 
3178 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3179 // instructions. If we only match on the legalized i64 mul expansion,
3180 // SimplifyDemandedBits will be unable to remove them because there will be
3181 // multiple uses due to the separate mul + mulh[su].
3182 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3183                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3184   if (Size <= 32) {
3185     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3186     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3187   }
3188 
3189   // Because we want to eliminate extension instructions before the
3190   // operation, we need to create a single user here (i.e. not the separate
3191   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3192 
3193   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3194 
3195   SDValue Mul = DAG.getNode(MulOpc, SL,
3196                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3197 
3198   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3199                      Mul.getValue(0), Mul.getValue(1));
3200 }
3201 
3202 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3203                                                 DAGCombinerInfo &DCI) const {
3204   EVT VT = N->getValueType(0);
3205 
3206   unsigned Size = VT.getSizeInBits();
3207   if (VT.isVector() || Size > 64)
3208     return SDValue();
3209 
3210   // There are i16 integer mul/mad.
3211   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3212     return SDValue();
3213 
3214   SelectionDAG &DAG = DCI.DAG;
3215   SDLoc DL(N);
3216 
3217   SDValue N0 = N->getOperand(0);
3218   SDValue N1 = N->getOperand(1);
3219 
3220   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3221   // in the source into any_extends if the result of the mul is truncated. Since
3222   // we can assume the high bits are whatever we want, use the underlying value
3223   // to avoid the unknown high bits from interfering.
3224   if (N0.getOpcode() == ISD::ANY_EXTEND)
3225     N0 = N0.getOperand(0);
3226 
3227   if (N1.getOpcode() == ISD::ANY_EXTEND)
3228     N1 = N1.getOperand(0);
3229 
3230   SDValue Mul;
3231 
3232   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3233     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3234     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3235     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3236   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3237     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3238     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3239     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3240   } else {
3241     return SDValue();
3242   }
3243 
3244   // We need to use sext even for MUL_U24, because MUL_U24 is used
3245   // for signed multiply of 8 and 16-bit types.
3246   return DAG.getSExtOrTrunc(Mul, DL, VT);
3247 }
3248 
3249 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3250                                                   DAGCombinerInfo &DCI) const {
3251   EVT VT = N->getValueType(0);
3252 
3253   if (!Subtarget->hasMulI24() || VT.isVector())
3254     return SDValue();
3255 
3256   SelectionDAG &DAG = DCI.DAG;
3257   SDLoc DL(N);
3258 
3259   SDValue N0 = N->getOperand(0);
3260   SDValue N1 = N->getOperand(1);
3261 
3262   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3263     return SDValue();
3264 
3265   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3266   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3267 
3268   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3269   DCI.AddToWorklist(Mulhi.getNode());
3270   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3271 }
3272 
3273 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3274                                                   DAGCombinerInfo &DCI) const {
3275   EVT VT = N->getValueType(0);
3276 
3277   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3278     return SDValue();
3279 
3280   SelectionDAG &DAG = DCI.DAG;
3281   SDLoc DL(N);
3282 
3283   SDValue N0 = N->getOperand(0);
3284   SDValue N1 = N->getOperand(1);
3285 
3286   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3287     return SDValue();
3288 
3289   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3290   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3291 
3292   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3293   DCI.AddToWorklist(Mulhi.getNode());
3294   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3295 }
3296 
3297 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3298   SDNode *N, DAGCombinerInfo &DCI) const {
3299   SelectionDAG &DAG = DCI.DAG;
3300 
3301   // Simplify demanded bits before splitting into multiple users.
3302   if (simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI))
3303     return SDValue();
3304 
3305   SDValue N0 = N->getOperand(0);
3306   SDValue N1 = N->getOperand(1);
3307 
3308   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3309 
3310   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3311   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3312 
3313   SDLoc SL(N);
3314 
3315   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3316   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3317   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3318 }
3319 
3320 static bool isNegativeOne(SDValue Val) {
3321   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3322     return C->isAllOnesValue();
3323   return false;
3324 }
3325 
3326 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3327                                           SDValue Op,
3328                                           const SDLoc &DL,
3329                                           unsigned Opc) const {
3330   EVT VT = Op.getValueType();
3331   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3332   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3333                               LegalVT != MVT::i16))
3334     return SDValue();
3335 
3336   if (VT != MVT::i32)
3337     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3338 
3339   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3340   if (VT != MVT::i32)
3341     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3342 
3343   return FFBX;
3344 }
3345 
3346 // The native instructions return -1 on 0 input. Optimize out a select that
3347 // produces -1 on 0.
3348 //
3349 // TODO: If zero is not undef, we could also do this if the output is compared
3350 // against the bitwidth.
3351 //
3352 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
3353 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3354                                                  SDValue LHS, SDValue RHS,
3355                                                  DAGCombinerInfo &DCI) const {
3356   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3357   if (!CmpRhs || !CmpRhs->isNullValue())
3358     return SDValue();
3359 
3360   SelectionDAG &DAG = DCI.DAG;
3361   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3362   SDValue CmpLHS = Cond.getOperand(0);
3363 
3364   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3365                                            AMDGPUISD::FFBH_U32;
3366 
3367   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3368   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3369   if (CCOpcode == ISD::SETEQ &&
3370       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3371       RHS.getOperand(0) == CmpLHS &&
3372       isNegativeOne(LHS)) {
3373     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3374   }
3375 
3376   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3377   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3378   if (CCOpcode == ISD::SETNE &&
3379       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3380       LHS.getOperand(0) == CmpLHS &&
3381       isNegativeOne(RHS)) {
3382     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3383   }
3384 
3385   return SDValue();
3386 }
3387 
3388 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3389                                          unsigned Op,
3390                                          const SDLoc &SL,
3391                                          SDValue Cond,
3392                                          SDValue N1,
3393                                          SDValue N2) {
3394   SelectionDAG &DAG = DCI.DAG;
3395   EVT VT = N1.getValueType();
3396 
3397   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3398                                   N1.getOperand(0), N2.getOperand(0));
3399   DCI.AddToWorklist(NewSelect.getNode());
3400   return DAG.getNode(Op, SL, VT, NewSelect);
3401 }
3402 
3403 // Pull a free FP operation out of a select so it may fold into uses.
3404 //
3405 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3406 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3407 //
3408 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3409 // select c, (fabs x), +k -> fabs (select c, x, k)
3410 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3411                                     SDValue N) {
3412   SelectionDAG &DAG = DCI.DAG;
3413   SDValue Cond = N.getOperand(0);
3414   SDValue LHS = N.getOperand(1);
3415   SDValue RHS = N.getOperand(2);
3416 
3417   EVT VT = N.getValueType();
3418   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3419       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3420     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3421                                      SDLoc(N), Cond, LHS, RHS);
3422   }
3423 
3424   bool Inv = false;
3425   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3426     std::swap(LHS, RHS);
3427     Inv = true;
3428   }
3429 
3430   // TODO: Support vector constants.
3431   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3432   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3433     SDLoc SL(N);
3434     // If one side is an fneg/fabs and the other is a constant, we can push the
3435     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3436     SDValue NewLHS = LHS.getOperand(0);
3437     SDValue NewRHS = RHS;
3438 
3439     // Careful: if the neg can be folded up, don't try to pull it back down.
3440     bool ShouldFoldNeg = true;
3441 
3442     if (NewLHS.hasOneUse()) {
3443       unsigned Opc = NewLHS.getOpcode();
3444       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3445         ShouldFoldNeg = false;
3446       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3447         ShouldFoldNeg = false;
3448     }
3449 
3450     if (ShouldFoldNeg) {
3451       if (LHS.getOpcode() == ISD::FNEG)
3452         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3453       else if (CRHS->isNegative())
3454         return SDValue();
3455 
3456       if (Inv)
3457         std::swap(NewLHS, NewRHS);
3458 
3459       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3460                                       Cond, NewLHS, NewRHS);
3461       DCI.AddToWorklist(NewSelect.getNode());
3462       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3463     }
3464   }
3465 
3466   return SDValue();
3467 }
3468 
3469 
3470 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3471                                                    DAGCombinerInfo &DCI) const {
3472   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3473     return Folded;
3474 
3475   SDValue Cond = N->getOperand(0);
3476   if (Cond.getOpcode() != ISD::SETCC)
3477     return SDValue();
3478 
3479   EVT VT = N->getValueType(0);
3480   SDValue LHS = Cond.getOperand(0);
3481   SDValue RHS = Cond.getOperand(1);
3482   SDValue CC = Cond.getOperand(2);
3483 
3484   SDValue True = N->getOperand(1);
3485   SDValue False = N->getOperand(2);
3486 
3487   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3488     SelectionDAG &DAG = DCI.DAG;
3489     if ((DAG.isConstantValueOfAnyType(True) ||
3490          DAG.isConstantValueOfAnyType(True)) &&
3491         (!DAG.isConstantValueOfAnyType(False) &&
3492          !DAG.isConstantValueOfAnyType(False))) {
3493       // Swap cmp + select pair to move constant to false input.
3494       // This will allow using VOPC cndmasks more often.
3495       // select (setcc x, y), k, x -> select (setcc y, x) x, x
3496 
3497       SDLoc SL(N);
3498       ISD::CondCode NewCC = getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3499                                             LHS.getValueType().isInteger());
3500 
3501       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3502       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3503     }
3504 
3505     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3506       SDValue MinMax
3507         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3508       // Revisit this node so we can catch min3/max3/med3 patterns.
3509       //DCI.AddToWorklist(MinMax.getNode());
3510       return MinMax;
3511     }
3512   }
3513 
3514   // There's no reason to not do this if the condition has other uses.
3515   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3516 }
3517 
3518 static bool isConstantFPZero(SDValue N) {
3519   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N))
3520     return C->isZero() && !C->isNegative();
3521   return false;
3522 }
3523 
3524 static unsigned inverseMinMax(unsigned Opc) {
3525   switch (Opc) {
3526   case ISD::FMAXNUM:
3527     return ISD::FMINNUM;
3528   case ISD::FMINNUM:
3529     return ISD::FMAXNUM;
3530   case AMDGPUISD::FMAX_LEGACY:
3531     return AMDGPUISD::FMIN_LEGACY;
3532   case AMDGPUISD::FMIN_LEGACY:
3533     return  AMDGPUISD::FMAX_LEGACY;
3534   default:
3535     llvm_unreachable("invalid min/max opcode");
3536   }
3537 }
3538 
3539 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3540                                                  DAGCombinerInfo &DCI) const {
3541   SelectionDAG &DAG = DCI.DAG;
3542   SDValue N0 = N->getOperand(0);
3543   EVT VT = N->getValueType(0);
3544 
3545   unsigned Opc = N0.getOpcode();
3546 
3547   // If the input has multiple uses and we can either fold the negate down, or
3548   // the other uses cannot, give up. This both prevents unprofitable
3549   // transformations and infinite loops: we won't repeatedly try to fold around
3550   // a negate that has no 'good' form.
3551   if (N0.hasOneUse()) {
3552     // This may be able to fold into the source, but at a code size cost. Don't
3553     // fold if the fold into the user is free.
3554     if (allUsesHaveSourceMods(N, 0))
3555       return SDValue();
3556   } else {
3557     if (fnegFoldsIntoOp(Opc) &&
3558         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3559       return SDValue();
3560   }
3561 
3562   SDLoc SL(N);
3563   switch (Opc) {
3564   case ISD::FADD: {
3565     if (!mayIgnoreSignedZero(N0))
3566       return SDValue();
3567 
3568     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3569     SDValue LHS = N0.getOperand(0);
3570     SDValue RHS = N0.getOperand(1);
3571 
3572     if (LHS.getOpcode() != ISD::FNEG)
3573       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3574     else
3575       LHS = LHS.getOperand(0);
3576 
3577     if (RHS.getOpcode() != ISD::FNEG)
3578       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3579     else
3580       RHS = RHS.getOperand(0);
3581 
3582     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3583     if (!N0.hasOneUse())
3584       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3585     return Res;
3586   }
3587   case ISD::FMUL:
3588   case AMDGPUISD::FMUL_LEGACY: {
3589     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3590     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3591     SDValue LHS = N0.getOperand(0);
3592     SDValue RHS = N0.getOperand(1);
3593 
3594     if (LHS.getOpcode() == ISD::FNEG)
3595       LHS = LHS.getOperand(0);
3596     else if (RHS.getOpcode() == ISD::FNEG)
3597       RHS = RHS.getOperand(0);
3598     else
3599       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3600 
3601     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3602     if (!N0.hasOneUse())
3603       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3604     return Res;
3605   }
3606   case ISD::FMA:
3607   case ISD::FMAD: {
3608     if (!mayIgnoreSignedZero(N0))
3609       return SDValue();
3610 
3611     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3612     SDValue LHS = N0.getOperand(0);
3613     SDValue MHS = N0.getOperand(1);
3614     SDValue RHS = N0.getOperand(2);
3615 
3616     if (LHS.getOpcode() == ISD::FNEG)
3617       LHS = LHS.getOperand(0);
3618     else if (MHS.getOpcode() == ISD::FNEG)
3619       MHS = MHS.getOperand(0);
3620     else
3621       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3622 
3623     if (RHS.getOpcode() != ISD::FNEG)
3624       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3625     else
3626       RHS = RHS.getOperand(0);
3627 
3628     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3629     if (!N0.hasOneUse())
3630       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3631     return Res;
3632   }
3633   case ISD::FMAXNUM:
3634   case ISD::FMINNUM:
3635   case AMDGPUISD::FMAX_LEGACY:
3636   case AMDGPUISD::FMIN_LEGACY: {
3637     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3638     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3639     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3640     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3641 
3642     SDValue LHS = N0.getOperand(0);
3643     SDValue RHS = N0.getOperand(1);
3644 
3645     // 0 doesn't have a negated inline immediate.
3646     // TODO: Shouldn't fold 1/2pi either, and should be generalized to other
3647     // operations.
3648     if (isConstantFPZero(RHS))
3649       return SDValue();
3650 
3651     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3652     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3653     unsigned Opposite = inverseMinMax(Opc);
3654 
3655     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3656     if (!N0.hasOneUse())
3657       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3658     return Res;
3659   }
3660   case ISD::FP_EXTEND:
3661   case ISD::FTRUNC:
3662   case ISD::FRINT:
3663   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3664   case ISD::FSIN:
3665   case AMDGPUISD::RCP:
3666   case AMDGPUISD::RCP_LEGACY:
3667   case AMDGPUISD::SIN_HW: {
3668     SDValue CvtSrc = N0.getOperand(0);
3669     if (CvtSrc.getOpcode() == ISD::FNEG) {
3670       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3671       // (fneg (rcp (fneg x))) -> (rcp x)
3672       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3673     }
3674 
3675     if (!N0.hasOneUse())
3676       return SDValue();
3677 
3678     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3679     // (fneg (rcp x)) -> (rcp (fneg x))
3680     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3681     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3682   }
3683   case ISD::FP_ROUND: {
3684     SDValue CvtSrc = N0.getOperand(0);
3685 
3686     if (CvtSrc.getOpcode() == ISD::FNEG) {
3687       // (fneg (fp_round (fneg x))) -> (fp_round x)
3688       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3689                          CvtSrc.getOperand(0), N0.getOperand(1));
3690     }
3691 
3692     if (!N0.hasOneUse())
3693       return SDValue();
3694 
3695     // (fneg (fp_round x)) -> (fp_round (fneg x))
3696     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3697     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3698   }
3699   case ISD::FP16_TO_FP: {
3700     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3701     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3702     // Put the fneg back as a legal source operation that can be matched later.
3703     SDLoc SL(N);
3704 
3705     SDValue Src = N0.getOperand(0);
3706     EVT SrcVT = Src.getValueType();
3707 
3708     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3709     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3710                                   DAG.getConstant(0x8000, SL, SrcVT));
3711     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3712   }
3713   default:
3714     return SDValue();
3715   }
3716 }
3717 
3718 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3719                                                  DAGCombinerInfo &DCI) const {
3720   SelectionDAG &DAG = DCI.DAG;
3721   SDValue N0 = N->getOperand(0);
3722 
3723   if (!N0.hasOneUse())
3724     return SDValue();
3725 
3726   switch (N0.getOpcode()) {
3727   case ISD::FP16_TO_FP: {
3728     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3729     SDLoc SL(N);
3730     SDValue Src = N0.getOperand(0);
3731     EVT SrcVT = Src.getValueType();
3732 
3733     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3734     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3735                                   DAG.getConstant(0x7fff, SL, SrcVT));
3736     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3737   }
3738   default:
3739     return SDValue();
3740   }
3741 }
3742 
3743 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3744                                                 DAGCombinerInfo &DCI) const {
3745   SelectionDAG &DAG = DCI.DAG;
3746   SDLoc DL(N);
3747 
3748   switch(N->getOpcode()) {
3749   default:
3750     break;
3751   case ISD::BITCAST: {
3752     EVT DestVT = N->getValueType(0);
3753 
3754     // Push casts through vector builds. This helps avoid emitting a large
3755     // number of copies when materializing floating point vector constants.
3756     //
3757     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3758     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3759     if (DestVT.isVector()) {
3760       SDValue Src = N->getOperand(0);
3761       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3762         EVT SrcVT = Src.getValueType();
3763         unsigned NElts = DestVT.getVectorNumElements();
3764 
3765         if (SrcVT.getVectorNumElements() == NElts) {
3766           EVT DestEltVT = DestVT.getVectorElementType();
3767 
3768           SmallVector<SDValue, 8> CastedElts;
3769           SDLoc SL(N);
3770           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3771             SDValue Elt = Src.getOperand(I);
3772             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3773           }
3774 
3775           return DAG.getBuildVector(DestVT, SL, CastedElts);
3776         }
3777       }
3778     }
3779 
3780     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3781       break;
3782 
3783     // Fold bitcasts of constants.
3784     //
3785     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3786     // TODO: Generalize and move to DAGCombiner
3787     SDValue Src = N->getOperand(0);
3788     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3789       if (Src.getValueType() == MVT::i64) {
3790         SDLoc SL(N);
3791         uint64_t CVal = C->getZExtValue();
3792         return DAG.getNode(ISD::BUILD_VECTOR, SL, DestVT,
3793                            DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3794                            DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3795       }
3796     }
3797 
3798     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3799       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3800       SDLoc SL(N);
3801       uint64_t CVal = Val.getZExtValue();
3802       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3803                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3804                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3805 
3806       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3807     }
3808 
3809     break;
3810   }
3811   case ISD::SHL: {
3812     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3813       break;
3814 
3815     return performShlCombine(N, DCI);
3816   }
3817   case ISD::SRL: {
3818     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3819       break;
3820 
3821     return performSrlCombine(N, DCI);
3822   }
3823   case ISD::SRA: {
3824     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3825       break;
3826 
3827     return performSraCombine(N, DCI);
3828   }
3829   case ISD::TRUNCATE:
3830     return performTruncateCombine(N, DCI);
3831   case ISD::MUL:
3832     return performMulCombine(N, DCI);
3833   case ISD::MULHS:
3834     return performMulhsCombine(N, DCI);
3835   case ISD::MULHU:
3836     return performMulhuCombine(N, DCI);
3837   case AMDGPUISD::MUL_I24:
3838   case AMDGPUISD::MUL_U24:
3839   case AMDGPUISD::MULHI_I24:
3840   case AMDGPUISD::MULHI_U24: {
3841     // If the first call to simplify is successfull, then N may end up being
3842     // deleted, so we shouldn't call simplifyI24 again.
3843     simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI);
3844     return SDValue();
3845   }
3846   case AMDGPUISD::MUL_LOHI_I24:
3847   case AMDGPUISD::MUL_LOHI_U24:
3848     return performMulLoHi24Combine(N, DCI);
3849   case ISD::SELECT:
3850     return performSelectCombine(N, DCI);
3851   case ISD::FNEG:
3852     return performFNegCombine(N, DCI);
3853   case ISD::FABS:
3854     return performFAbsCombine(N, DCI);
3855   case AMDGPUISD::BFE_I32:
3856   case AMDGPUISD::BFE_U32: {
3857     assert(!N->getValueType(0).isVector() &&
3858            "Vector handling of BFE not implemented");
3859     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
3860     if (!Width)
3861       break;
3862 
3863     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
3864     if (WidthVal == 0)
3865       return DAG.getConstant(0, DL, MVT::i32);
3866 
3867     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
3868     if (!Offset)
3869       break;
3870 
3871     SDValue BitsFrom = N->getOperand(0);
3872     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
3873 
3874     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
3875 
3876     if (OffsetVal == 0) {
3877       // This is already sign / zero extended, so try to fold away extra BFEs.
3878       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
3879 
3880       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
3881       if (OpSignBits >= SignBits)
3882         return BitsFrom;
3883 
3884       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
3885       if (Signed) {
3886         // This is a sign_extend_inreg. Replace it to take advantage of existing
3887         // DAG Combines. If not eliminated, we will match back to BFE during
3888         // selection.
3889 
3890         // TODO: The sext_inreg of extended types ends, although we can could
3891         // handle them in a single BFE.
3892         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
3893                            DAG.getValueType(SmallVT));
3894       }
3895 
3896       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
3897     }
3898 
3899     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
3900       if (Signed) {
3901         return constantFoldBFE<int32_t>(DAG,
3902                                         CVal->getSExtValue(),
3903                                         OffsetVal,
3904                                         WidthVal,
3905                                         DL);
3906       }
3907 
3908       return constantFoldBFE<uint32_t>(DAG,
3909                                        CVal->getZExtValue(),
3910                                        OffsetVal,
3911                                        WidthVal,
3912                                        DL);
3913     }
3914 
3915     if ((OffsetVal + WidthVal) >= 32 &&
3916         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
3917       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
3918       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
3919                          BitsFrom, ShiftVal);
3920     }
3921 
3922     if (BitsFrom.hasOneUse()) {
3923       APInt Demanded = APInt::getBitsSet(32,
3924                                          OffsetVal,
3925                                          OffsetVal + WidthVal);
3926 
3927       KnownBits Known;
3928       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
3929                                             !DCI.isBeforeLegalizeOps());
3930       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3931       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
3932           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
3933         DCI.CommitTargetLoweringOpt(TLO);
3934       }
3935     }
3936 
3937     break;
3938   }
3939   case ISD::LOAD:
3940     return performLoadCombine(N, DCI);
3941   case ISD::STORE:
3942     return performStoreCombine(N, DCI);
3943   case AMDGPUISD::RCP: {
3944     if (const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0))) {
3945       // XXX - Should this flush denormals?
3946       const APFloat &Val = CFP->getValueAPF();
3947       APFloat One(Val.getSemantics(), "1.0");
3948       return DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3949     }
3950 
3951     break;
3952   }
3953   case ISD::AssertZext:
3954   case ISD::AssertSext:
3955     return performAssertSZExtCombine(N, DCI);
3956   }
3957   return SDValue();
3958 }
3959 
3960 //===----------------------------------------------------------------------===//
3961 // Helper functions
3962 //===----------------------------------------------------------------------===//
3963 
3964 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
3965                                                    const TargetRegisterClass *RC,
3966                                                    unsigned Reg, EVT VT,
3967                                                    const SDLoc &SL,
3968                                                    bool RawReg) const {
3969   MachineFunction &MF = DAG.getMachineFunction();
3970   MachineRegisterInfo &MRI = MF.getRegInfo();
3971   unsigned VReg;
3972 
3973   if (!MRI.isLiveIn(Reg)) {
3974     VReg = MRI.createVirtualRegister(RC);
3975     MRI.addLiveIn(Reg, VReg);
3976   } else {
3977     VReg = MRI.getLiveInVirtReg(Reg);
3978   }
3979 
3980   if (RawReg)
3981     return DAG.getRegister(VReg, VT);
3982 
3983   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
3984 }
3985 
3986 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
3987                                                   EVT VT,
3988                                                   const SDLoc &SL,
3989                                                   int64_t Offset) const {
3990   MachineFunction &MF = DAG.getMachineFunction();
3991   MachineFrameInfo &MFI = MF.getFrameInfo();
3992 
3993   int FI = MFI.CreateFixedObject(VT.getStoreSize(), Offset, true);
3994   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
3995   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
3996 
3997   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
3998                      MachineMemOperand::MODereferenceable |
3999                      MachineMemOperand::MOInvariant);
4000 }
4001 
4002 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
4003                                                    const SDLoc &SL,
4004                                                    SDValue Chain,
4005                                                    SDValue StackPtr,
4006                                                    SDValue ArgVal,
4007                                                    int64_t Offset) const {
4008   MachineFunction &MF = DAG.getMachineFunction();
4009   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
4010 
4011   SDValue Ptr = DAG.getObjectPtrOffset(SL, StackPtr, Offset);
4012   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
4013                                MachineMemOperand::MODereferenceable);
4014   return Store;
4015 }
4016 
4017 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
4018                                              const TargetRegisterClass *RC,
4019                                              EVT VT, const SDLoc &SL,
4020                                              const ArgDescriptor &Arg) const {
4021   assert(Arg && "Attempting to load missing argument");
4022 
4023   if (Arg.isRegister())
4024     return CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL);
4025   return loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
4026 }
4027 
4028 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
4029     const AMDGPUMachineFunction *MFI, const ImplicitParameter Param) const {
4030   unsigned Alignment = Subtarget->getAlignmentForImplicitArgPtr();
4031   uint64_t ArgOffset = alignTo(MFI->getABIArgOffset(), Alignment);
4032   switch (Param) {
4033   case GRID_DIM:
4034     return ArgOffset;
4035   case GRID_OFFSET:
4036     return ArgOffset + 4;
4037   }
4038   llvm_unreachable("unexpected implicit parameter type");
4039 }
4040 
4041 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4042 
4043 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4044   switch ((AMDGPUISD::NodeType)Opcode) {
4045   case AMDGPUISD::FIRST_NUMBER: break;
4046   // AMDIL DAG nodes
4047   NODE_NAME_CASE(UMUL);
4048   NODE_NAME_CASE(BRANCH_COND);
4049 
4050   // AMDGPU DAG nodes
4051   NODE_NAME_CASE(IF)
4052   NODE_NAME_CASE(ELSE)
4053   NODE_NAME_CASE(LOOP)
4054   NODE_NAME_CASE(CALL)
4055   NODE_NAME_CASE(TC_RETURN)
4056   NODE_NAME_CASE(TRAP)
4057   NODE_NAME_CASE(RET_FLAG)
4058   NODE_NAME_CASE(RETURN_TO_EPILOG)
4059   NODE_NAME_CASE(ENDPGM)
4060   NODE_NAME_CASE(DWORDADDR)
4061   NODE_NAME_CASE(FRACT)
4062   NODE_NAME_CASE(SETCC)
4063   NODE_NAME_CASE(SETREG)
4064   NODE_NAME_CASE(FMA_W_CHAIN)
4065   NODE_NAME_CASE(FMUL_W_CHAIN)
4066   NODE_NAME_CASE(CLAMP)
4067   NODE_NAME_CASE(COS_HW)
4068   NODE_NAME_CASE(SIN_HW)
4069   NODE_NAME_CASE(FMAX_LEGACY)
4070   NODE_NAME_CASE(FMIN_LEGACY)
4071   NODE_NAME_CASE(FMAX3)
4072   NODE_NAME_CASE(SMAX3)
4073   NODE_NAME_CASE(UMAX3)
4074   NODE_NAME_CASE(FMIN3)
4075   NODE_NAME_CASE(SMIN3)
4076   NODE_NAME_CASE(UMIN3)
4077   NODE_NAME_CASE(FMED3)
4078   NODE_NAME_CASE(SMED3)
4079   NODE_NAME_CASE(UMED3)
4080   NODE_NAME_CASE(URECIP)
4081   NODE_NAME_CASE(DIV_SCALE)
4082   NODE_NAME_CASE(DIV_FMAS)
4083   NODE_NAME_CASE(DIV_FIXUP)
4084   NODE_NAME_CASE(FMAD_FTZ)
4085   NODE_NAME_CASE(TRIG_PREOP)
4086   NODE_NAME_CASE(RCP)
4087   NODE_NAME_CASE(RSQ)
4088   NODE_NAME_CASE(RCP_LEGACY)
4089   NODE_NAME_CASE(RSQ_LEGACY)
4090   NODE_NAME_CASE(FMUL_LEGACY)
4091   NODE_NAME_CASE(RSQ_CLAMP)
4092   NODE_NAME_CASE(LDEXP)
4093   NODE_NAME_CASE(FP_CLASS)
4094   NODE_NAME_CASE(DOT4)
4095   NODE_NAME_CASE(CARRY)
4096   NODE_NAME_CASE(BORROW)
4097   NODE_NAME_CASE(BFE_U32)
4098   NODE_NAME_CASE(BFE_I32)
4099   NODE_NAME_CASE(BFI)
4100   NODE_NAME_CASE(BFM)
4101   NODE_NAME_CASE(FFBH_U32)
4102   NODE_NAME_CASE(FFBH_I32)
4103   NODE_NAME_CASE(FFBL_B32)
4104   NODE_NAME_CASE(MUL_U24)
4105   NODE_NAME_CASE(MUL_I24)
4106   NODE_NAME_CASE(MULHI_U24)
4107   NODE_NAME_CASE(MULHI_I24)
4108   NODE_NAME_CASE(MUL_LOHI_U24)
4109   NODE_NAME_CASE(MUL_LOHI_I24)
4110   NODE_NAME_CASE(MAD_U24)
4111   NODE_NAME_CASE(MAD_I24)
4112   NODE_NAME_CASE(MAD_I64_I32)
4113   NODE_NAME_CASE(MAD_U64_U32)
4114   NODE_NAME_CASE(TEXTURE_FETCH)
4115   NODE_NAME_CASE(EXPORT)
4116   NODE_NAME_CASE(EXPORT_DONE)
4117   NODE_NAME_CASE(R600_EXPORT)
4118   NODE_NAME_CASE(CONST_ADDRESS)
4119   NODE_NAME_CASE(REGISTER_LOAD)
4120   NODE_NAME_CASE(REGISTER_STORE)
4121   NODE_NAME_CASE(SAMPLE)
4122   NODE_NAME_CASE(SAMPLEB)
4123   NODE_NAME_CASE(SAMPLED)
4124   NODE_NAME_CASE(SAMPLEL)
4125   NODE_NAME_CASE(CVT_F32_UBYTE0)
4126   NODE_NAME_CASE(CVT_F32_UBYTE1)
4127   NODE_NAME_CASE(CVT_F32_UBYTE2)
4128   NODE_NAME_CASE(CVT_F32_UBYTE3)
4129   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4130   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4131   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4132   NODE_NAME_CASE(CVT_PK_I16_I32)
4133   NODE_NAME_CASE(CVT_PK_U16_U32)
4134   NODE_NAME_CASE(FP_TO_FP16)
4135   NODE_NAME_CASE(FP16_ZEXT)
4136   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4137   NODE_NAME_CASE(CONST_DATA_PTR)
4138   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4139   NODE_NAME_CASE(KILL)
4140   NODE_NAME_CASE(DUMMY_CHAIN)
4141   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4142   NODE_NAME_CASE(INIT_EXEC)
4143   NODE_NAME_CASE(INIT_EXEC_FROM_INPUT)
4144   NODE_NAME_CASE(SENDMSG)
4145   NODE_NAME_CASE(SENDMSGHALT)
4146   NODE_NAME_CASE(INTERP_MOV)
4147   NODE_NAME_CASE(INTERP_P1)
4148   NODE_NAME_CASE(INTERP_P2)
4149   NODE_NAME_CASE(STORE_MSKOR)
4150   NODE_NAME_CASE(LOAD_CONSTANT)
4151   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4152   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_X3)
4153   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4154   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4155   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4156   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4157   NODE_NAME_CASE(ATOMIC_INC)
4158   NODE_NAME_CASE(ATOMIC_DEC)
4159   NODE_NAME_CASE(ATOMIC_LOAD_FADD)
4160   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4161   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4162   NODE_NAME_CASE(BUFFER_LOAD)
4163   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4164   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4165   NODE_NAME_CASE(BUFFER_STORE)
4166   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4167   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4168   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4169   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4170   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4171   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4172   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4173   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4174   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4175   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4176   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4177   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4178   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4179   NODE_NAME_CASE(IMAGE_LOAD)
4180   NODE_NAME_CASE(IMAGE_LOAD_MIP)
4181   NODE_NAME_CASE(IMAGE_STORE)
4182   NODE_NAME_CASE(IMAGE_STORE_MIP)
4183   // Basic sample.
4184   NODE_NAME_CASE(IMAGE_SAMPLE)
4185   NODE_NAME_CASE(IMAGE_SAMPLE_CL)
4186   NODE_NAME_CASE(IMAGE_SAMPLE_D)
4187   NODE_NAME_CASE(IMAGE_SAMPLE_D_CL)
4188   NODE_NAME_CASE(IMAGE_SAMPLE_L)
4189   NODE_NAME_CASE(IMAGE_SAMPLE_B)
4190   NODE_NAME_CASE(IMAGE_SAMPLE_B_CL)
4191   NODE_NAME_CASE(IMAGE_SAMPLE_LZ)
4192   NODE_NAME_CASE(IMAGE_SAMPLE_CD)
4193   NODE_NAME_CASE(IMAGE_SAMPLE_CD_CL)
4194   // Sample with comparison.
4195   NODE_NAME_CASE(IMAGE_SAMPLE_C)
4196   NODE_NAME_CASE(IMAGE_SAMPLE_C_CL)
4197   NODE_NAME_CASE(IMAGE_SAMPLE_C_D)
4198   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_CL)
4199   NODE_NAME_CASE(IMAGE_SAMPLE_C_L)
4200   NODE_NAME_CASE(IMAGE_SAMPLE_C_B)
4201   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_CL)
4202   NODE_NAME_CASE(IMAGE_SAMPLE_C_LZ)
4203   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD)
4204   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_CL)
4205   // Sample with offsets.
4206   NODE_NAME_CASE(IMAGE_SAMPLE_O)
4207   NODE_NAME_CASE(IMAGE_SAMPLE_CL_O)
4208   NODE_NAME_CASE(IMAGE_SAMPLE_D_O)
4209   NODE_NAME_CASE(IMAGE_SAMPLE_D_CL_O)
4210   NODE_NAME_CASE(IMAGE_SAMPLE_L_O)
4211   NODE_NAME_CASE(IMAGE_SAMPLE_B_O)
4212   NODE_NAME_CASE(IMAGE_SAMPLE_B_CL_O)
4213   NODE_NAME_CASE(IMAGE_SAMPLE_LZ_O)
4214   NODE_NAME_CASE(IMAGE_SAMPLE_CD_O)
4215   NODE_NAME_CASE(IMAGE_SAMPLE_CD_CL_O)
4216   // Sample with comparison and offsets.
4217   NODE_NAME_CASE(IMAGE_SAMPLE_C_O)
4218   NODE_NAME_CASE(IMAGE_SAMPLE_C_CL_O)
4219   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_O)
4220   NODE_NAME_CASE(IMAGE_SAMPLE_C_D_CL_O)
4221   NODE_NAME_CASE(IMAGE_SAMPLE_C_L_O)
4222   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_O)
4223   NODE_NAME_CASE(IMAGE_SAMPLE_C_B_CL_O)
4224   NODE_NAME_CASE(IMAGE_SAMPLE_C_LZ_O)
4225   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_O)
4226   NODE_NAME_CASE(IMAGE_SAMPLE_C_CD_CL_O)
4227   // Basic gather4.
4228   NODE_NAME_CASE(IMAGE_GATHER4)
4229   NODE_NAME_CASE(IMAGE_GATHER4_CL)
4230   NODE_NAME_CASE(IMAGE_GATHER4_L)
4231   NODE_NAME_CASE(IMAGE_GATHER4_B)
4232   NODE_NAME_CASE(IMAGE_GATHER4_B_CL)
4233   NODE_NAME_CASE(IMAGE_GATHER4_LZ)
4234   // Gather4 with comparison.
4235   NODE_NAME_CASE(IMAGE_GATHER4_C)
4236   NODE_NAME_CASE(IMAGE_GATHER4_C_CL)
4237   NODE_NAME_CASE(IMAGE_GATHER4_C_L)
4238   NODE_NAME_CASE(IMAGE_GATHER4_C_B)
4239   NODE_NAME_CASE(IMAGE_GATHER4_C_B_CL)
4240   NODE_NAME_CASE(IMAGE_GATHER4_C_LZ)
4241   // Gather4 with offsets.
4242   NODE_NAME_CASE(IMAGE_GATHER4_O)
4243   NODE_NAME_CASE(IMAGE_GATHER4_CL_O)
4244   NODE_NAME_CASE(IMAGE_GATHER4_L_O)
4245   NODE_NAME_CASE(IMAGE_GATHER4_B_O)
4246   NODE_NAME_CASE(IMAGE_GATHER4_B_CL_O)
4247   NODE_NAME_CASE(IMAGE_GATHER4_LZ_O)
4248   // Gather4 with comparison and offsets.
4249   NODE_NAME_CASE(IMAGE_GATHER4_C_O)
4250   NODE_NAME_CASE(IMAGE_GATHER4_C_CL_O)
4251   NODE_NAME_CASE(IMAGE_GATHER4_C_L_O)
4252   NODE_NAME_CASE(IMAGE_GATHER4_C_B_O)
4253   NODE_NAME_CASE(IMAGE_GATHER4_C_B_CL_O)
4254   NODE_NAME_CASE(IMAGE_GATHER4_C_LZ_O)
4255 
4256   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4257   }
4258   return nullptr;
4259 }
4260 
4261 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4262                                               SelectionDAG &DAG, int Enabled,
4263                                               int &RefinementSteps,
4264                                               bool &UseOneConstNR,
4265                                               bool Reciprocal) const {
4266   EVT VT = Operand.getValueType();
4267 
4268   if (VT == MVT::f32) {
4269     RefinementSteps = 0;
4270     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4271   }
4272 
4273   // TODO: There is also f64 rsq instruction, but the documentation is less
4274   // clear on its precision.
4275 
4276   return SDValue();
4277 }
4278 
4279 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4280                                                SelectionDAG &DAG, int Enabled,
4281                                                int &RefinementSteps) const {
4282   EVT VT = Operand.getValueType();
4283 
4284   if (VT == MVT::f32) {
4285     // Reciprocal, < 1 ulp error.
4286     //
4287     // This reciprocal approximation converges to < 0.5 ulp error with one
4288     // newton rhapson performed with two fused multiple adds (FMAs).
4289 
4290     RefinementSteps = 0;
4291     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4292   }
4293 
4294   // TODO: There is also f64 rcp instruction, but the documentation is less
4295   // clear on its precision.
4296 
4297   return SDValue();
4298 }
4299 
4300 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4301     const SDValue Op, KnownBits &Known,
4302     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4303 
4304   Known.resetAll(); // Don't know anything.
4305 
4306   unsigned Opc = Op.getOpcode();
4307 
4308   switch (Opc) {
4309   default:
4310     break;
4311   case AMDGPUISD::CARRY:
4312   case AMDGPUISD::BORROW: {
4313     Known.Zero = APInt::getHighBitsSet(32, 31);
4314     break;
4315   }
4316 
4317   case AMDGPUISD::BFE_I32:
4318   case AMDGPUISD::BFE_U32: {
4319     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4320     if (!CWidth)
4321       return;
4322 
4323     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4324 
4325     if (Opc == AMDGPUISD::BFE_U32)
4326       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4327 
4328     break;
4329   }
4330   case AMDGPUISD::FP_TO_FP16:
4331   case AMDGPUISD::FP16_ZEXT: {
4332     unsigned BitWidth = Known.getBitWidth();
4333 
4334     // High bits are zero.
4335     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4336     break;
4337   }
4338   case AMDGPUISD::MUL_U24:
4339   case AMDGPUISD::MUL_I24: {
4340     KnownBits LHSKnown, RHSKnown;
4341     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4342     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4343 
4344     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4345                       RHSKnown.countMinTrailingZeros();
4346     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4347 
4348     unsigned LHSValBits = 32 - std::max(LHSKnown.countMinSignBits(), 8u);
4349     unsigned RHSValBits = 32 - std::max(RHSKnown.countMinSignBits(), 8u);
4350     unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4351     if (MaxValBits >= 32)
4352       break;
4353     bool Negative = false;
4354     if (Opc == AMDGPUISD::MUL_I24) {
4355       bool LHSNegative = !!(LHSKnown.One  & (1 << 23));
4356       bool LHSPositive = !!(LHSKnown.Zero & (1 << 23));
4357       bool RHSNegative = !!(RHSKnown.One  & (1 << 23));
4358       bool RHSPositive = !!(RHSKnown.Zero & (1 << 23));
4359       if ((!LHSNegative && !LHSPositive) || (!RHSNegative && !RHSPositive))
4360         break;
4361       Negative = (LHSNegative && RHSPositive) || (LHSPositive && RHSNegative);
4362     }
4363     if (Negative)
4364       Known.One.setHighBits(32 - MaxValBits);
4365     else
4366       Known.Zero.setHighBits(32 - MaxValBits);
4367     break;
4368   }
4369   case ISD::INTRINSIC_WO_CHAIN: {
4370     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4371     switch (IID) {
4372     case Intrinsic::amdgcn_mbcnt_lo:
4373     case Intrinsic::amdgcn_mbcnt_hi: {
4374       // These return at most the wavefront size - 1.
4375       unsigned Size = Op.getValueType().getSizeInBits();
4376       Known.Zero.setHighBits(Size - Subtarget->getWavefrontSizeLog2());
4377       break;
4378     }
4379     default:
4380       break;
4381     }
4382   }
4383   }
4384 }
4385 
4386 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4387     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4388     unsigned Depth) const {
4389   switch (Op.getOpcode()) {
4390   case AMDGPUISD::BFE_I32: {
4391     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4392     if (!Width)
4393       return 1;
4394 
4395     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4396     if (!isNullConstant(Op.getOperand(1)))
4397       return SignBits;
4398 
4399     // TODO: Could probably figure something out with non-0 offsets.
4400     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4401     return std::max(SignBits, Op0SignBits);
4402   }
4403 
4404   case AMDGPUISD::BFE_U32: {
4405     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4406     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4407   }
4408 
4409   case AMDGPUISD::CARRY:
4410   case AMDGPUISD::BORROW:
4411     return 31;
4412   case AMDGPUISD::FP_TO_FP16:
4413   case AMDGPUISD::FP16_ZEXT:
4414     return 16;
4415   default:
4416     return 1;
4417   }
4418 }
4419