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   case MVT::v4i16:
78   case MVT::v4f16: {
79     // Up to SGPR0-SGPR39
80     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
81                           &AMDGPU::SGPR_64RegClass, 20);
82   }
83   default:
84     return false;
85   }
86 }
87 
88 // Allocate up to VGPR31.
89 //
90 // TODO: Since there are no VGPR alignent requirements would it be better to
91 // split into individual scalar registers?
92 static bool allocateVGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
93                               CCValAssign::LocInfo LocInfo,
94                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
95   switch (LocVT.SimpleTy) {
96   case MVT::i64:
97   case MVT::f64:
98   case MVT::v2i32:
99   case MVT::v2f32:
100   case MVT::v4i16:
101   case MVT::v4f16: {
102     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
103                           &AMDGPU::VReg_64RegClass, 31);
104   }
105   case MVT::v4i32:
106   case MVT::v4f32:
107   case MVT::v2i64:
108   case MVT::v2f64: {
109     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
110                           &AMDGPU::VReg_128RegClass, 29);
111   }
112   case MVT::v8i32:
113   case MVT::v8f32: {
114     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
115                           &AMDGPU::VReg_256RegClass, 25);
116 
117   }
118   case MVT::v16i32:
119   case MVT::v16f32: {
120     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
121                           &AMDGPU::VReg_512RegClass, 17);
122 
123   }
124   default:
125     return false;
126   }
127 }
128 
129 #include "AMDGPUGenCallingConv.inc"
130 
131 // Find a larger type to do a load / store of a vector with.
132 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
133   unsigned StoreSize = VT.getStoreSizeInBits();
134   if (StoreSize <= 32)
135     return EVT::getIntegerVT(Ctx, StoreSize);
136 
137   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
138   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
139 }
140 
141 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
142   KnownBits Known;
143   EVT VT = Op.getValueType();
144   DAG.computeKnownBits(Op, Known);
145 
146   return VT.getSizeInBits() - Known.countMinLeadingZeros();
147 }
148 
149 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
150   EVT VT = Op.getValueType();
151 
152   // In order for this to be a signed 24-bit value, bit 23, must
153   // be a sign bit.
154   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
155 }
156 
157 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
158                                            const AMDGPUSubtarget &STI)
159     : TargetLowering(TM), Subtarget(&STI) {
160   AMDGPUASI = AMDGPU::getAMDGPUAS(TM);
161   // Lower floating point store/load to integer store/load to reduce the number
162   // of patterns in tablegen.
163   setOperationAction(ISD::LOAD, MVT::f32, Promote);
164   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
165 
166   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
167   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
168 
169   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
170   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
171 
172   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
173   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
174 
175   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
176   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
177 
178   setOperationAction(ISD::LOAD, MVT::i64, Promote);
179   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
180 
181   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
182   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
183 
184   setOperationAction(ISD::LOAD, MVT::f64, Promote);
185   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
186 
187   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
188   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
189 
190   // There are no 64-bit extloads. These should be done as a 32-bit extload and
191   // an extension to 64-bit.
192   for (MVT VT : MVT::integer_valuetypes()) {
193     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
194     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
195     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
196   }
197 
198   for (MVT VT : MVT::integer_valuetypes()) {
199     if (VT == MVT::i64)
200       continue;
201 
202     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
203     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
204     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
205     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
206 
207     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
208     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
209     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
210     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
211 
212     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
213     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
214     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
215     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
216   }
217 
218   for (MVT VT : MVT::integer_vector_valuetypes()) {
219     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
220     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
221     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
222     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
223     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
224     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
225     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
226     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
227     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
228     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
229     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
230     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
231   }
232 
233   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
234   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
235   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
236   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
237 
238   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
239   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
240   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
241   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
242 
243   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
244   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
245   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
246   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
247 
248   setOperationAction(ISD::STORE, MVT::f32, Promote);
249   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
250 
251   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
252   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
253 
254   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
255   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
256 
257   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
258   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
259 
260   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
261   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
262 
263   setOperationAction(ISD::STORE, MVT::i64, Promote);
264   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
265 
266   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
267   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
268 
269   setOperationAction(ISD::STORE, MVT::f64, Promote);
270   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
271 
272   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
273   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
274 
275   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
276   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
277   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
278   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
279 
280   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
281   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
282   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
283   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
284 
285   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
286   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
287   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
288   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
289 
290   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
291   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
292 
293   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
294   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
295 
296   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
297   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
298 
299   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
300   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
301 
302 
303   setOperationAction(ISD::Constant, MVT::i32, Legal);
304   setOperationAction(ISD::Constant, MVT::i64, Legal);
305   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
306   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
307 
308   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
309   setOperationAction(ISD::BRIND, MVT::Other, Expand);
310 
311   // This is totally unsupported, just custom lower to produce an error.
312   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
313 
314   // Library functions.  These default to Expand, but we have instructions
315   // for them.
316   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
317   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
318   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
319   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
320   setOperationAction(ISD::FABS,   MVT::f32, Legal);
321   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
322   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
323   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
324   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
325   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
326 
327   setOperationAction(ISD::FROUND, MVT::f32, Custom);
328   setOperationAction(ISD::FROUND, MVT::f64, Custom);
329 
330   setOperationAction(ISD::FLOG, MVT::f32, Custom);
331   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
332 
333   if (Subtarget->has16BitInsts()) {
334     setOperationAction(ISD::FLOG, MVT::f16, Custom);
335     setOperationAction(ISD::FLOG10, MVT::f16, Custom);
336   }
337 
338   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
339   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
340 
341   setOperationAction(ISD::FREM, MVT::f32, Custom);
342   setOperationAction(ISD::FREM, MVT::f64, Custom);
343 
344   // v_mad_f32 does not support denormals according to some sources.
345   if (!Subtarget->hasFP32Denormals())
346     setOperationAction(ISD::FMAD, MVT::f32, Legal);
347 
348   // Expand to fneg + fadd.
349   setOperationAction(ISD::FSUB, MVT::f64, Expand);
350 
351   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
352   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
353   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
354   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
355   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
356   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
357   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
358   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
359   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
360   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
361 
362   if (Subtarget->getGeneration() < AMDGPUSubtarget::SEA_ISLANDS) {
363     setOperationAction(ISD::FCEIL, MVT::f64, Custom);
364     setOperationAction(ISD::FTRUNC, MVT::f64, Custom);
365     setOperationAction(ISD::FRINT, MVT::f64, Custom);
366     setOperationAction(ISD::FFLOOR, MVT::f64, Custom);
367   }
368 
369   if (!Subtarget->hasBFI()) {
370     // fcopysign can be done in a single instruction with BFI.
371     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
372     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
373   }
374 
375   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
376   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
377   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
378 
379   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
380   for (MVT VT : ScalarIntVTs) {
381     // These should use [SU]DIVREM, so set them to expand
382     setOperationAction(ISD::SDIV, VT, Expand);
383     setOperationAction(ISD::UDIV, VT, Expand);
384     setOperationAction(ISD::SREM, VT, Expand);
385     setOperationAction(ISD::UREM, VT, Expand);
386 
387     // GPU does not have divrem function for signed or unsigned.
388     setOperationAction(ISD::SDIVREM, VT, Custom);
389     setOperationAction(ISD::UDIVREM, VT, Custom);
390 
391     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
392     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
393     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
394 
395     setOperationAction(ISD::BSWAP, VT, Expand);
396     setOperationAction(ISD::CTTZ, VT, Expand);
397     setOperationAction(ISD::CTLZ, VT, Expand);
398 
399     // AMDGPU uses ADDC/SUBC/ADDE/SUBE
400     setOperationAction(ISD::ADDC, VT, Legal);
401     setOperationAction(ISD::SUBC, VT, Legal);
402     setOperationAction(ISD::ADDE, VT, Legal);
403     setOperationAction(ISD::SUBE, VT, Legal);
404   }
405 
406   if (!Subtarget->hasBCNT(32))
407     setOperationAction(ISD::CTPOP, MVT::i32, Expand);
408 
409   if (!Subtarget->hasBCNT(64))
410     setOperationAction(ISD::CTPOP, MVT::i64, Expand);
411 
412   // The hardware supports 32-bit ROTR, but not ROTL.
413   setOperationAction(ISD::ROTL, MVT::i32, Expand);
414   setOperationAction(ISD::ROTL, MVT::i64, Expand);
415   setOperationAction(ISD::ROTR, MVT::i64, Expand);
416 
417   setOperationAction(ISD::MUL, MVT::i64, Expand);
418   setOperationAction(ISD::MULHU, MVT::i64, Expand);
419   setOperationAction(ISD::MULHS, MVT::i64, Expand);
420   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
421   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
422   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
423   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
424   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
425 
426   setOperationAction(ISD::SMIN, MVT::i32, Legal);
427   setOperationAction(ISD::UMIN, MVT::i32, Legal);
428   setOperationAction(ISD::SMAX, MVT::i32, Legal);
429   setOperationAction(ISD::UMAX, MVT::i32, Legal);
430 
431   if (Subtarget->hasFFBH())
432     setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Custom);
433 
434   if (Subtarget->hasFFBL())
435     setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Custom);
436 
437   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
438   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
439   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
440   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
441 
442   // We only really have 32-bit BFE instructions (and 16-bit on VI).
443   //
444   // On SI+ there are 64-bit BFEs, but they are scalar only and there isn't any
445   // effort to match them now. We want this to be false for i64 cases when the
446   // extraction isn't restricted to the upper or lower half. Ideally we would
447   // have some pass reduce 64-bit extracts to 32-bit if possible. Extracts that
448   // span the midpoint are probably relatively rare, so don't worry about them
449   // for now.
450   if (Subtarget->hasBFE())
451     setHasExtractBitsInsn(true);
452 
453   static const MVT::SimpleValueType VectorIntTypes[] = {
454     MVT::v2i32, MVT::v4i32
455   };
456 
457   for (MVT VT : VectorIntTypes) {
458     // Expand the following operations for the current type by default.
459     setOperationAction(ISD::ADD,  VT, Expand);
460     setOperationAction(ISD::AND,  VT, Expand);
461     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
462     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
463     setOperationAction(ISD::MUL,  VT, Expand);
464     setOperationAction(ISD::MULHU, VT, Expand);
465     setOperationAction(ISD::MULHS, VT, Expand);
466     setOperationAction(ISD::OR,   VT, Expand);
467     setOperationAction(ISD::SHL,  VT, Expand);
468     setOperationAction(ISD::SRA,  VT, Expand);
469     setOperationAction(ISD::SRL,  VT, Expand);
470     setOperationAction(ISD::ROTL, VT, Expand);
471     setOperationAction(ISD::ROTR, VT, Expand);
472     setOperationAction(ISD::SUB,  VT, Expand);
473     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
474     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
475     setOperationAction(ISD::SDIV, VT, Expand);
476     setOperationAction(ISD::UDIV, VT, Expand);
477     setOperationAction(ISD::SREM, VT, Expand);
478     setOperationAction(ISD::UREM, VT, Expand);
479     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
480     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
481     setOperationAction(ISD::SDIVREM, VT, Custom);
482     setOperationAction(ISD::UDIVREM, VT, Expand);
483     setOperationAction(ISD::SELECT, VT, Expand);
484     setOperationAction(ISD::VSELECT, VT, Expand);
485     setOperationAction(ISD::SELECT_CC, VT, Expand);
486     setOperationAction(ISD::XOR,  VT, Expand);
487     setOperationAction(ISD::BSWAP, VT, Expand);
488     setOperationAction(ISD::CTPOP, VT, Expand);
489     setOperationAction(ISD::CTTZ, VT, Expand);
490     setOperationAction(ISD::CTLZ, VT, Expand);
491     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
492     setOperationAction(ISD::SETCC, VT, Expand);
493   }
494 
495   static const MVT::SimpleValueType FloatVectorTypes[] = {
496     MVT::v2f32, MVT::v4f32
497   };
498 
499   for (MVT VT : FloatVectorTypes) {
500     setOperationAction(ISD::FABS, VT, Expand);
501     setOperationAction(ISD::FMINNUM, VT, Expand);
502     setOperationAction(ISD::FMAXNUM, VT, Expand);
503     setOperationAction(ISD::FADD, VT, Expand);
504     setOperationAction(ISD::FCEIL, VT, Expand);
505     setOperationAction(ISD::FCOS, VT, Expand);
506     setOperationAction(ISD::FDIV, VT, Expand);
507     setOperationAction(ISD::FEXP2, VT, Expand);
508     setOperationAction(ISD::FLOG2, VT, Expand);
509     setOperationAction(ISD::FREM, VT, Expand);
510     setOperationAction(ISD::FLOG, VT, Expand);
511     setOperationAction(ISD::FLOG10, VT, Expand);
512     setOperationAction(ISD::FPOW, VT, Expand);
513     setOperationAction(ISD::FFLOOR, VT, Expand);
514     setOperationAction(ISD::FTRUNC, VT, Expand);
515     setOperationAction(ISD::FMUL, VT, Expand);
516     setOperationAction(ISD::FMA, VT, Expand);
517     setOperationAction(ISD::FRINT, VT, Expand);
518     setOperationAction(ISD::FNEARBYINT, VT, Expand);
519     setOperationAction(ISD::FSQRT, VT, Expand);
520     setOperationAction(ISD::FSIN, VT, Expand);
521     setOperationAction(ISD::FSUB, VT, Expand);
522     setOperationAction(ISD::FNEG, VT, Expand);
523     setOperationAction(ISD::VSELECT, VT, Expand);
524     setOperationAction(ISD::SELECT_CC, VT, Expand);
525     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
526     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
527     setOperationAction(ISD::SETCC, VT, Expand);
528   }
529 
530   // This causes using an unrolled select operation rather than expansion with
531   // bit operations. This is in general better, but the alternative using BFI
532   // instructions may be better if the select sources are SGPRs.
533   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
534   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
535 
536   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
537   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
538 
539   // There are no libcalls of any kind.
540   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
541     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
542 
543   setBooleanContents(ZeroOrNegativeOneBooleanContent);
544   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
545 
546   setSchedulingPreference(Sched::RegPressure);
547   setJumpIsExpensive(true);
548 
549   // FIXME: This is only partially true. If we have to do vector compares, any
550   // SGPR pair can be a condition register. If we have a uniform condition, we
551   // are better off doing SALU operations, where there is only one SCC. For now,
552   // we don't have a way of knowing during instruction selection if a condition
553   // will be uniform and we always use vector compares. Assume we are using
554   // vector compares until that is fixed.
555   setHasMultipleConditionRegisters(true);
556 
557   // SI at least has hardware support for floating point exceptions, but no way
558   // of using or handling them is implemented. They are also optional in OpenCL
559   // (Section 7.3)
560   setHasFloatingPointExceptions(Subtarget->hasFPExceptions());
561 
562   PredictableSelectIsExpensive = false;
563 
564   // We want to find all load dependencies for long chains of stores to enable
565   // merging into very wide vectors. The problem is with vectors with > 4
566   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
567   // vectors are a legal type, even though we have to split the loads
568   // usually. When we can more precisely specify load legality per address
569   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
570   // smarter so that they can figure out what to do in 2 iterations without all
571   // N > 4 stores on the same chain.
572   GatherAllAliasesMaxDepth = 16;
573 
574   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
575   // about these during lowering.
576   MaxStoresPerMemcpy  = 0xffffffff;
577   MaxStoresPerMemmove = 0xffffffff;
578   MaxStoresPerMemset  = 0xffffffff;
579 
580   setTargetDAGCombine(ISD::BITCAST);
581   setTargetDAGCombine(ISD::SHL);
582   setTargetDAGCombine(ISD::SRA);
583   setTargetDAGCombine(ISD::SRL);
584   setTargetDAGCombine(ISD::TRUNCATE);
585   setTargetDAGCombine(ISD::MUL);
586   setTargetDAGCombine(ISD::MULHU);
587   setTargetDAGCombine(ISD::MULHS);
588   setTargetDAGCombine(ISD::SELECT);
589   setTargetDAGCombine(ISD::SELECT_CC);
590   setTargetDAGCombine(ISD::STORE);
591   setTargetDAGCombine(ISD::FADD);
592   setTargetDAGCombine(ISD::FSUB);
593   setTargetDAGCombine(ISD::FNEG);
594   setTargetDAGCombine(ISD::FABS);
595   setTargetDAGCombine(ISD::AssertZext);
596   setTargetDAGCombine(ISD::AssertSext);
597 }
598 
599 //===----------------------------------------------------------------------===//
600 // Target Information
601 //===----------------------------------------------------------------------===//
602 
603 LLVM_READNONE
604 static bool fnegFoldsIntoOp(unsigned Opc) {
605   switch (Opc) {
606   case ISD::FADD:
607   case ISD::FSUB:
608   case ISD::FMUL:
609   case ISD::FMA:
610   case ISD::FMAD:
611   case ISD::FMINNUM:
612   case ISD::FMAXNUM:
613   case ISD::FSIN:
614   case ISD::FTRUNC:
615   case ISD::FRINT:
616   case ISD::FNEARBYINT:
617   case AMDGPUISD::RCP:
618   case AMDGPUISD::RCP_LEGACY:
619   case AMDGPUISD::RCP_IFLAG:
620   case AMDGPUISD::SIN_HW:
621   case AMDGPUISD::FMUL_LEGACY:
622   case AMDGPUISD::FMIN_LEGACY:
623   case AMDGPUISD::FMAX_LEGACY:
624     return true;
625   default:
626     return false;
627   }
628 }
629 
630 /// \p returns true if the operation will definitely need to use a 64-bit
631 /// encoding, and thus will use a VOP3 encoding regardless of the source
632 /// modifiers.
633 LLVM_READONLY
634 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
635   return N->getNumOperands() > 2 || VT == MVT::f64;
636 }
637 
638 // Most FP instructions support source modifiers, but this could be refined
639 // slightly.
640 LLVM_READONLY
641 static bool hasSourceMods(const SDNode *N) {
642   if (isa<MemSDNode>(N))
643     return false;
644 
645   switch (N->getOpcode()) {
646   case ISD::CopyToReg:
647   case ISD::SELECT:
648   case ISD::FDIV:
649   case ISD::FREM:
650   case ISD::INLINEASM:
651   case AMDGPUISD::INTERP_P1:
652   case AMDGPUISD::INTERP_P2:
653   case AMDGPUISD::DIV_SCALE:
654 
655   // TODO: Should really be looking at the users of the bitcast. These are
656   // problematic because bitcasts are used to legalize all stores to integer
657   // types.
658   case ISD::BITCAST:
659     return false;
660   default:
661     return true;
662   }
663 }
664 
665 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
666                                                  unsigned CostThreshold) {
667   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
668   // it is truly free to use a source modifier in all cases. If there are
669   // multiple users but for each one will necessitate using VOP3, there will be
670   // a code size increase. Try to avoid increasing code size unless we know it
671   // will save on the instruction count.
672   unsigned NumMayIncreaseSize = 0;
673   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
674 
675   // XXX - Should this limit number of uses to check?
676   for (const SDNode *U : N->uses()) {
677     if (!hasSourceMods(U))
678       return false;
679 
680     if (!opMustUseVOP3Encoding(U, VT)) {
681       if (++NumMayIncreaseSize > CostThreshold)
682         return false;
683     }
684   }
685 
686   return true;
687 }
688 
689 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
690   return MVT::i32;
691 }
692 
693 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
694   return true;
695 }
696 
697 // The backend supports 32 and 64 bit floating point immediates.
698 // FIXME: Why are we reporting vectors of FP immediates as legal?
699 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
700   EVT ScalarVT = VT.getScalarType();
701   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
702          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
703 }
704 
705 // We don't want to shrink f64 / f32 constants.
706 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
707   EVT ScalarVT = VT.getScalarType();
708   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
709 }
710 
711 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
712                                                  ISD::LoadExtType,
713                                                  EVT NewVT) const {
714 
715   unsigned NewSize = NewVT.getStoreSizeInBits();
716 
717   // If we are reducing to a 32-bit load, this is always better.
718   if (NewSize == 32)
719     return true;
720 
721   EVT OldVT = N->getValueType(0);
722   unsigned OldSize = OldVT.getStoreSizeInBits();
723 
724   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
725   // extloads, so doing one requires using a buffer_load. In cases where we
726   // still couldn't use a scalar load, using the wider load shouldn't really
727   // hurt anything.
728 
729   // If the old size already had to be an extload, there's no harm in continuing
730   // to reduce the width.
731   return (OldSize < 32);
732 }
733 
734 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy,
735                                                    EVT CastTy) const {
736 
737   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
738 
739   if (LoadTy.getScalarType() == MVT::i32)
740     return false;
741 
742   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
743   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
744 
745   return (LScalarSize < CastScalarSize) ||
746          (CastScalarSize >= 32);
747 }
748 
749 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
750 // profitable with the expansion for 64-bit since it's generally good to
751 // speculate things.
752 // FIXME: These should really have the size as a parameter.
753 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
754   return true;
755 }
756 
757 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
758   return true;
759 }
760 
761 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
762   switch (N->getOpcode()) {
763     default:
764     return false;
765     case ISD::EntryToken:
766     case ISD::TokenFactor:
767       return true;
768     case ISD::INTRINSIC_WO_CHAIN:
769     {
770       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
771       switch (IntrID) {
772         default:
773         return false;
774         case Intrinsic::amdgcn_readfirstlane:
775         case Intrinsic::amdgcn_readlane:
776           return true;
777       }
778     }
779     break;
780     case ISD::LOAD:
781     {
782       const LoadSDNode * L = dyn_cast<LoadSDNode>(N);
783       if (L->getMemOperand()->getAddrSpace()
784       == Subtarget->getAMDGPUAS().CONSTANT_ADDRESS_32BIT)
785         return true;
786       return false;
787     }
788     break;
789   }
790 }
791 
792 //===---------------------------------------------------------------------===//
793 // Target Properties
794 //===---------------------------------------------------------------------===//
795 
796 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
797   assert(VT.isFloatingPoint());
798 
799   // Packed operations do not have a fabs modifier.
800   return VT == MVT::f32 || VT == MVT::f64 ||
801          (Subtarget->has16BitInsts() && VT == MVT::f16);
802 }
803 
804 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
805   assert(VT.isFloatingPoint());
806   return VT == MVT::f32 || VT == MVT::f64 ||
807          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
808          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
809 }
810 
811 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
812                                                          unsigned NumElem,
813                                                          unsigned AS) const {
814   return true;
815 }
816 
817 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
818   // There are few operations which truly have vector input operands. Any vector
819   // operation is going to involve operations on each component, and a
820   // build_vector will be a copy per element, so it always makes sense to use a
821   // build_vector input in place of the extracted element to avoid a copy into a
822   // super register.
823   //
824   // We should probably only do this if all users are extracts only, but this
825   // should be the common case.
826   return true;
827 }
828 
829 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
830   // Truncate is just accessing a subregister.
831 
832   unsigned SrcSize = Source.getSizeInBits();
833   unsigned DestSize = Dest.getSizeInBits();
834 
835   return DestSize < SrcSize && DestSize % 32 == 0 ;
836 }
837 
838 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
839   // Truncate is just accessing a subregister.
840 
841   unsigned SrcSize = Source->getScalarSizeInBits();
842   unsigned DestSize = Dest->getScalarSizeInBits();
843 
844   if (DestSize== 16 && Subtarget->has16BitInsts())
845     return SrcSize >= 32;
846 
847   return DestSize < SrcSize && DestSize % 32 == 0;
848 }
849 
850 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
851   unsigned SrcSize = Src->getScalarSizeInBits();
852   unsigned DestSize = Dest->getScalarSizeInBits();
853 
854   if (SrcSize == 16 && Subtarget->has16BitInsts())
855     return DestSize >= 32;
856 
857   return SrcSize == 32 && DestSize == 64;
858 }
859 
860 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
861   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
862   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
863   // this will enable reducing 64-bit operations the 32-bit, which is always
864   // good.
865 
866   if (Src == MVT::i16)
867     return Dest == MVT::i32 ||Dest == MVT::i64 ;
868 
869   return Src == MVT::i32 && Dest == MVT::i64;
870 }
871 
872 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
873   return isZExtFree(Val.getValueType(), VT2);
874 }
875 
876 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
877   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
878   // limited number of native 64-bit operations. Shrinking an operation to fit
879   // in a single 32-bit register should always be helpful. As currently used,
880   // this is much less general than the name suggests, and is only used in
881   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
882   // not profitable, and may actually be harmful.
883   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
884 }
885 
886 //===---------------------------------------------------------------------===//
887 // TargetLowering Callbacks
888 //===---------------------------------------------------------------------===//
889 
890 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
891                                                   bool IsVarArg) {
892   switch (CC) {
893   case CallingConv::AMDGPU_KERNEL:
894   case CallingConv::SPIR_KERNEL:
895     return CC_AMDGPU_Kernel;
896   case CallingConv::AMDGPU_VS:
897   case CallingConv::AMDGPU_GS:
898   case CallingConv::AMDGPU_PS:
899   case CallingConv::AMDGPU_CS:
900   case CallingConv::AMDGPU_HS:
901   case CallingConv::AMDGPU_ES:
902   case CallingConv::AMDGPU_LS:
903     return CC_AMDGPU;
904   case CallingConv::C:
905   case CallingConv::Fast:
906   case CallingConv::Cold:
907     return CC_AMDGPU_Func;
908   default:
909     report_fatal_error("Unsupported calling convention.");
910   }
911 }
912 
913 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
914                                                     bool IsVarArg) {
915   switch (CC) {
916   case CallingConv::AMDGPU_KERNEL:
917   case CallingConv::SPIR_KERNEL:
918     return CC_AMDGPU_Kernel;
919   case CallingConv::AMDGPU_VS:
920   case CallingConv::AMDGPU_GS:
921   case CallingConv::AMDGPU_PS:
922   case CallingConv::AMDGPU_CS:
923   case CallingConv::AMDGPU_HS:
924   case CallingConv::AMDGPU_ES:
925   case CallingConv::AMDGPU_LS:
926     return RetCC_SI_Shader;
927   case CallingConv::C:
928   case CallingConv::Fast:
929   case CallingConv::Cold:
930     return RetCC_AMDGPU_Func;
931   default:
932     report_fatal_error("Unsupported calling convention.");
933   }
934 }
935 
936 /// The SelectionDAGBuilder will automatically promote function arguments
937 /// with illegal types.  However, this does not work for the AMDGPU targets
938 /// since the function arguments are stored in memory as these illegal types.
939 /// In order to handle this properly we need to get the original types sizes
940 /// from the LLVM IR Function and fixup the ISD:InputArg values before
941 /// passing them to AnalyzeFormalArguments()
942 
943 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
944 /// input values across multiple registers.  Each item in the Ins array
945 /// represents a single value that will be stored in registers.  Ins[x].VT is
946 /// the value type of the value that will be stored in the register, so
947 /// whatever SDNode we lower the argument to needs to be this type.
948 ///
949 /// In order to correctly lower the arguments we need to know the size of each
950 /// argument.  Since Ins[x].VT gives us the size of the register that will
951 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
952 /// for the orignal function argument so that we can deduce the correct memory
953 /// type to use for Ins[x].  In most cases the correct memory type will be
954 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
955 /// we have a kernel argument of type v8i8, this argument will be split into
956 /// 8 parts and each part will be represented by its own item in the Ins array.
957 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
958 /// the argument before it was split.  From this, we deduce that the memory type
959 /// for each individual part is i8.  We pass the memory type as LocVT to the
960 /// calling convention analysis function and the register type (Ins[x].VT) as
961 /// the ValVT.
962 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(CCState &State,
963                              const SmallVectorImpl<ISD::InputArg> &Ins) const {
964   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
965     const ISD::InputArg &In = Ins[i];
966     EVT MemVT;
967 
968     unsigned NumRegs = getNumRegisters(State.getContext(), In.ArgVT);
969 
970     if (!Subtarget->isAmdHsaOS() &&
971         (In.ArgVT == MVT::i16 || In.ArgVT == MVT::i8 || In.ArgVT == MVT::f16)) {
972       // The ABI says the caller will extend these values to 32-bits.
973       MemVT = In.ArgVT.isInteger() ? MVT::i32 : MVT::f32;
974     } else if (NumRegs == 1) {
975       // This argument is not split, so the IR type is the memory type.
976       assert(!In.Flags.isSplit());
977       if (In.ArgVT.isExtended()) {
978         // We have an extended type, like i24, so we should just use the register type
979         MemVT = In.VT;
980       } else {
981         MemVT = In.ArgVT;
982       }
983     } else if (In.ArgVT.isVector() && In.VT.isVector() &&
984                In.ArgVT.getScalarType() == In.VT.getScalarType()) {
985       assert(In.ArgVT.getVectorNumElements() > In.VT.getVectorNumElements());
986       // We have a vector value which has been split into a vector with
987       // the same scalar type, but fewer elements.  This should handle
988       // all the floating-point vector types.
989       MemVT = In.VT;
990     } else if (In.ArgVT.isVector() &&
991                In.ArgVT.getVectorNumElements() == NumRegs) {
992       // This arg has been split so that each element is stored in a separate
993       // register.
994       MemVT = In.ArgVT.getScalarType();
995     } else if (In.ArgVT.isExtended()) {
996       // We have an extended type, like i65.
997       MemVT = In.VT;
998     } else {
999       unsigned MemoryBits = In.ArgVT.getStoreSizeInBits() / NumRegs;
1000       assert(In.ArgVT.getStoreSizeInBits() % NumRegs == 0);
1001       if (In.VT.isInteger()) {
1002         MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
1003       } else if (In.VT.isVector()) {
1004         assert(!In.VT.getScalarType().isFloatingPoint());
1005         unsigned NumElements = In.VT.getVectorNumElements();
1006         assert(MemoryBits % NumElements == 0);
1007         // This vector type has been split into another vector type with
1008         // a different elements size.
1009         EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
1010                                          MemoryBits / NumElements);
1011         MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
1012       } else {
1013         llvm_unreachable("cannot deduce memory type.");
1014       }
1015     }
1016 
1017     // Convert one element vectors to scalar.
1018     if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
1019       MemVT = MemVT.getScalarType();
1020 
1021     if (MemVT.isExtended()) {
1022       // This should really only happen if we have vec3 arguments
1023       assert(MemVT.isVector() && MemVT.getVectorNumElements() == 3);
1024       MemVT = MemVT.getPow2VectorType(State.getContext());
1025     }
1026 
1027     assert(MemVT.isSimple());
1028     allocateKernArg(i, In.VT, MemVT.getSimpleVT(), CCValAssign::Full, In.Flags,
1029                     State);
1030   }
1031 }
1032 
1033 SDValue AMDGPUTargetLowering::LowerReturn(
1034   SDValue Chain, CallingConv::ID CallConv,
1035   bool isVarArg,
1036   const SmallVectorImpl<ISD::OutputArg> &Outs,
1037   const SmallVectorImpl<SDValue> &OutVals,
1038   const SDLoc &DL, SelectionDAG &DAG) const {
1039   // FIXME: Fails for r600 tests
1040   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1041   // "wave terminate should not have return values");
1042   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1043 }
1044 
1045 //===---------------------------------------------------------------------===//
1046 // Target specific lowering
1047 //===---------------------------------------------------------------------===//
1048 
1049 /// Selects the correct CCAssignFn for a given CallingConvention value.
1050 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1051                                                     bool IsVarArg) {
1052   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1053 }
1054 
1055 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1056                                                       bool IsVarArg) {
1057   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1058 }
1059 
1060 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1061                                                   SelectionDAG &DAG,
1062                                                   MachineFrameInfo &MFI,
1063                                                   int ClobberedFI) const {
1064   SmallVector<SDValue, 8> ArgChains;
1065   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1066   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1067 
1068   // Include the original chain at the beginning of the list. When this is
1069   // used by target LowerCall hooks, this helps legalize find the
1070   // CALLSEQ_BEGIN node.
1071   ArgChains.push_back(Chain);
1072 
1073   // Add a chain value for each stack argument corresponding
1074   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1075                             UE = DAG.getEntryNode().getNode()->use_end();
1076        U != UE; ++U) {
1077     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1078       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1079         if (FI->getIndex() < 0) {
1080           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1081           int64_t InLastByte = InFirstByte;
1082           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1083 
1084           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1085               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1086             ArgChains.push_back(SDValue(L, 1));
1087         }
1088       }
1089     }
1090   }
1091 
1092   // Build a tokenfactor for all the chains.
1093   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1094 }
1095 
1096 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1097                                                  SmallVectorImpl<SDValue> &InVals,
1098                                                  StringRef Reason) const {
1099   SDValue Callee = CLI.Callee;
1100   SelectionDAG &DAG = CLI.DAG;
1101 
1102   const Function &Fn = DAG.getMachineFunction().getFunction();
1103 
1104   StringRef FuncName("<unknown>");
1105 
1106   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1107     FuncName = G->getSymbol();
1108   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1109     FuncName = G->getGlobal()->getName();
1110 
1111   DiagnosticInfoUnsupported NoCalls(
1112     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1113   DAG.getContext()->diagnose(NoCalls);
1114 
1115   if (!CLI.IsTailCall) {
1116     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1117       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1118   }
1119 
1120   return DAG.getEntryNode();
1121 }
1122 
1123 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1124                                         SmallVectorImpl<SDValue> &InVals) const {
1125   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1126 }
1127 
1128 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1129                                                       SelectionDAG &DAG) const {
1130   const Function &Fn = DAG.getMachineFunction().getFunction();
1131 
1132   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1133                                             SDLoc(Op).getDebugLoc());
1134   DAG.getContext()->diagnose(NoDynamicAlloca);
1135   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1136   return DAG.getMergeValues(Ops, SDLoc());
1137 }
1138 
1139 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1140                                              SelectionDAG &DAG) const {
1141   switch (Op.getOpcode()) {
1142   default:
1143     Op->print(errs(), &DAG);
1144     llvm_unreachable("Custom lowering code for this"
1145                      "instruction is not implemented yet!");
1146     break;
1147   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1148   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1149   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1150   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1151   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1152   case ISD::FREM: return LowerFREM(Op, DAG);
1153   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1154   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1155   case ISD::FRINT: return LowerFRINT(Op, DAG);
1156   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1157   case ISD::FROUND: return LowerFROUND(Op, DAG);
1158   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1159   case ISD::FLOG:
1160     return LowerFLOG(Op, DAG, 1 / AMDGPU_LOG2E_F);
1161   case ISD::FLOG10:
1162     return LowerFLOG(Op, DAG, AMDGPU_LN2_F / AMDGPU_LN10_F);
1163   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1164   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1165   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1166   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1167   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1168   case ISD::CTTZ:
1169   case ISD::CTTZ_ZERO_UNDEF:
1170   case ISD::CTLZ:
1171   case ISD::CTLZ_ZERO_UNDEF:
1172     return LowerCTLZ_CTTZ(Op, DAG);
1173   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1174   }
1175   return Op;
1176 }
1177 
1178 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1179                                               SmallVectorImpl<SDValue> &Results,
1180                                               SelectionDAG &DAG) const {
1181   switch (N->getOpcode()) {
1182   case ISD::SIGN_EXTEND_INREG:
1183     // Different parts of legalization seem to interpret which type of
1184     // sign_extend_inreg is the one to check for custom lowering. The extended
1185     // from type is what really matters, but some places check for custom
1186     // lowering of the result type. This results in trying to use
1187     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1188     // nothing here and let the illegal result integer be handled normally.
1189     return;
1190   default:
1191     return;
1192   }
1193 }
1194 
1195 static bool hasDefinedInitializer(const GlobalValue *GV) {
1196   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1197   if (!GVar || !GVar->hasInitializer())
1198     return false;
1199 
1200   return !isa<UndefValue>(GVar->getInitializer());
1201 }
1202 
1203 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1204                                                  SDValue Op,
1205                                                  SelectionDAG &DAG) const {
1206 
1207   const DataLayout &DL = DAG.getDataLayout();
1208   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1209   const GlobalValue *GV = G->getGlobal();
1210 
1211   if (G->getAddressSpace() == AMDGPUASI.LOCAL_ADDRESS ||
1212       G->getAddressSpace() == AMDGPUASI.REGION_ADDRESS) {
1213     if (!MFI->isEntryFunction()) {
1214       const Function &Fn = DAG.getMachineFunction().getFunction();
1215       DiagnosticInfoUnsupported BadLDSDecl(
1216         Fn, "local memory global used by non-kernel function", SDLoc(Op).getDebugLoc());
1217       DAG.getContext()->diagnose(BadLDSDecl);
1218     }
1219 
1220     // XXX: What does the value of G->getOffset() mean?
1221     assert(G->getOffset() == 0 &&
1222          "Do not know what to do with an non-zero offset");
1223 
1224     // TODO: We could emit code to handle the initialization somewhere.
1225     if (!hasDefinedInitializer(GV)) {
1226       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1227       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1228     }
1229   }
1230 
1231   const Function &Fn = DAG.getMachineFunction().getFunction();
1232   DiagnosticInfoUnsupported BadInit(
1233       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1234   DAG.getContext()->diagnose(BadInit);
1235   return SDValue();
1236 }
1237 
1238 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1239                                                   SelectionDAG &DAG) const {
1240   SmallVector<SDValue, 8> Args;
1241 
1242   EVT VT = Op.getValueType();
1243   if (VT == MVT::v4i16 || VT == MVT::v4f16) {
1244     SDLoc SL(Op);
1245     SDValue Lo = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(0));
1246     SDValue Hi = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(1));
1247 
1248     SDValue BV = DAG.getBuildVector(MVT::v2i32, SL, { Lo, Hi });
1249     return DAG.getNode(ISD::BITCAST, SL, VT, BV);
1250   }
1251 
1252   for (const SDUse &U : Op->ops())
1253     DAG.ExtractVectorElements(U.get(), Args);
1254 
1255   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1256 }
1257 
1258 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1259                                                      SelectionDAG &DAG) const {
1260 
1261   SmallVector<SDValue, 8> Args;
1262   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1263   EVT VT = Op.getValueType();
1264   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1265                             VT.getVectorNumElements());
1266 
1267   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1268 }
1269 
1270 /// Generate Min/Max node
1271 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1272                                                    SDValue LHS, SDValue RHS,
1273                                                    SDValue True, SDValue False,
1274                                                    SDValue CC,
1275                                                    DAGCombinerInfo &DCI) const {
1276   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1277     return SDValue();
1278 
1279   SelectionDAG &DAG = DCI.DAG;
1280   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1281   switch (CCOpcode) {
1282   case ISD::SETOEQ:
1283   case ISD::SETONE:
1284   case ISD::SETUNE:
1285   case ISD::SETNE:
1286   case ISD::SETUEQ:
1287   case ISD::SETEQ:
1288   case ISD::SETFALSE:
1289   case ISD::SETFALSE2:
1290   case ISD::SETTRUE:
1291   case ISD::SETTRUE2:
1292   case ISD::SETUO:
1293   case ISD::SETO:
1294     break;
1295   case ISD::SETULE:
1296   case ISD::SETULT: {
1297     if (LHS == True)
1298       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1299     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1300   }
1301   case ISD::SETOLE:
1302   case ISD::SETOLT:
1303   case ISD::SETLE:
1304   case ISD::SETLT: {
1305     // Ordered. Assume ordered for undefined.
1306 
1307     // Only do this after legalization to avoid interfering with other combines
1308     // which might occur.
1309     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1310         !DCI.isCalledByLegalizer())
1311       return SDValue();
1312 
1313     // We need to permute the operands to get the correct NaN behavior. The
1314     // selected operand is the second one based on the failing compare with NaN,
1315     // so permute it based on the compare type the hardware uses.
1316     if (LHS == True)
1317       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1318     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1319   }
1320   case ISD::SETUGE:
1321   case ISD::SETUGT: {
1322     if (LHS == True)
1323       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1324     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1325   }
1326   case ISD::SETGT:
1327   case ISD::SETGE:
1328   case ISD::SETOGE:
1329   case ISD::SETOGT: {
1330     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1331         !DCI.isCalledByLegalizer())
1332       return SDValue();
1333 
1334     if (LHS == True)
1335       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1336     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1337   }
1338   case ISD::SETCC_INVALID:
1339     llvm_unreachable("Invalid setcc condcode!");
1340   }
1341   return SDValue();
1342 }
1343 
1344 std::pair<SDValue, SDValue>
1345 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1346   SDLoc SL(Op);
1347 
1348   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1349 
1350   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1351   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1352 
1353   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1354   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1355 
1356   return std::make_pair(Lo, Hi);
1357 }
1358 
1359 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1360   SDLoc SL(Op);
1361 
1362   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1363   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1364   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1365 }
1366 
1367 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1368   SDLoc SL(Op);
1369 
1370   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1371   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1372   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1373 }
1374 
1375 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1376                                               SelectionDAG &DAG) const {
1377   LoadSDNode *Load = cast<LoadSDNode>(Op);
1378   EVT VT = Op.getValueType();
1379 
1380 
1381   // If this is a 2 element vector, we really want to scalarize and not create
1382   // weird 1 element vectors.
1383   if (VT.getVectorNumElements() == 2)
1384     return scalarizeVectorLoad(Load, DAG);
1385 
1386   SDValue BasePtr = Load->getBasePtr();
1387   EVT MemVT = Load->getMemoryVT();
1388   SDLoc SL(Op);
1389 
1390   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1391 
1392   EVT LoVT, HiVT;
1393   EVT LoMemVT, HiMemVT;
1394   SDValue Lo, Hi;
1395 
1396   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1397   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1398   std::tie(Lo, Hi) = DAG.SplitVector(Op, SL, LoVT, HiVT);
1399 
1400   unsigned Size = LoMemVT.getStoreSize();
1401   unsigned BaseAlign = Load->getAlignment();
1402   unsigned HiAlign = MinAlign(BaseAlign, Size);
1403 
1404   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1405                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1406                                   BaseAlign, Load->getMemOperand()->getFlags());
1407   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1408   SDValue HiLoad =
1409       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1410                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1411                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1412 
1413   SDValue Ops[] = {
1414     DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad),
1415     DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1416                 LoLoad.getValue(1), HiLoad.getValue(1))
1417   };
1418 
1419   return DAG.getMergeValues(Ops, SL);
1420 }
1421 
1422 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1423                                                SelectionDAG &DAG) const {
1424   StoreSDNode *Store = cast<StoreSDNode>(Op);
1425   SDValue Val = Store->getValue();
1426   EVT VT = Val.getValueType();
1427 
1428   // If this is a 2 element vector, we really want to scalarize and not create
1429   // weird 1 element vectors.
1430   if (VT.getVectorNumElements() == 2)
1431     return scalarizeVectorStore(Store, DAG);
1432 
1433   EVT MemVT = Store->getMemoryVT();
1434   SDValue Chain = Store->getChain();
1435   SDValue BasePtr = Store->getBasePtr();
1436   SDLoc SL(Op);
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(Val, SL, LoVT, HiVT);
1445 
1446   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1447 
1448   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1449   unsigned BaseAlign = Store->getAlignment();
1450   unsigned Size = LoMemVT.getStoreSize();
1451   unsigned HiAlign = MinAlign(BaseAlign, Size);
1452 
1453   SDValue LoStore =
1454       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1455                         Store->getMemOperand()->getFlags());
1456   SDValue HiStore =
1457       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1458                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1459 
1460   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1461 }
1462 
1463 // This is a shortcut for integer division because we have fast i32<->f32
1464 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1465 // float is enough to accurately represent up to a 24-bit signed integer.
1466 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1467                                             bool Sign) const {
1468   SDLoc DL(Op);
1469   EVT VT = Op.getValueType();
1470   SDValue LHS = Op.getOperand(0);
1471   SDValue RHS = Op.getOperand(1);
1472   MVT IntVT = MVT::i32;
1473   MVT FltVT = MVT::f32;
1474 
1475   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1476   if (LHSSignBits < 9)
1477     return SDValue();
1478 
1479   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1480   if (RHSSignBits < 9)
1481     return SDValue();
1482 
1483   unsigned BitSize = VT.getSizeInBits();
1484   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1485   unsigned DivBits = BitSize - SignBits;
1486   if (Sign)
1487     ++DivBits;
1488 
1489   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1490   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1491 
1492   SDValue jq = DAG.getConstant(1, DL, IntVT);
1493 
1494   if (Sign) {
1495     // char|short jq = ia ^ ib;
1496     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1497 
1498     // jq = jq >> (bitsize - 2)
1499     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1500                      DAG.getConstant(BitSize - 2, DL, VT));
1501 
1502     // jq = jq | 0x1
1503     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1504   }
1505 
1506   // int ia = (int)LHS;
1507   SDValue ia = LHS;
1508 
1509   // int ib, (int)RHS;
1510   SDValue ib = RHS;
1511 
1512   // float fa = (float)ia;
1513   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1514 
1515   // float fb = (float)ib;
1516   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1517 
1518   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1519                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1520 
1521   // fq = trunc(fq);
1522   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1523 
1524   // float fqneg = -fq;
1525   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1526 
1527   // float fr = mad(fqneg, fb, fa);
1528   unsigned OpCode = Subtarget->hasFP32Denormals() ?
1529                     (unsigned)AMDGPUISD::FMAD_FTZ :
1530                     (unsigned)ISD::FMAD;
1531   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1532 
1533   // int iq = (int)fq;
1534   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1535 
1536   // fr = fabs(fr);
1537   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1538 
1539   // fb = fabs(fb);
1540   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1541 
1542   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1543 
1544   // int cv = fr >= fb;
1545   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1546 
1547   // jq = (cv ? jq : 0);
1548   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1549 
1550   // dst = iq + jq;
1551   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1552 
1553   // Rem needs compensation, it's easier to recompute it
1554   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1555   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1556 
1557   // Truncate to number of bits this divide really is.
1558   if (Sign) {
1559     SDValue InRegSize
1560       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1561     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1562     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1563   } else {
1564     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1565     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1566     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1567   }
1568 
1569   return DAG.getMergeValues({ Div, Rem }, DL);
1570 }
1571 
1572 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1573                                       SelectionDAG &DAG,
1574                                       SmallVectorImpl<SDValue> &Results) const {
1575   SDLoc DL(Op);
1576   EVT VT = Op.getValueType();
1577 
1578   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1579 
1580   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1581 
1582   SDValue One = DAG.getConstant(1, DL, HalfVT);
1583   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1584 
1585   //HiLo split
1586   SDValue LHS = Op.getOperand(0);
1587   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1588   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1589 
1590   SDValue RHS = Op.getOperand(1);
1591   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1592   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1593 
1594   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1595       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1596 
1597     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1598                               LHS_Lo, RHS_Lo);
1599 
1600     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1601     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1602 
1603     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1604     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1605     return;
1606   }
1607 
1608   if (isTypeLegal(MVT::i64)) {
1609     // Compute denominator reciprocal.
1610     unsigned FMAD = Subtarget->hasFP32Denormals() ?
1611                     (unsigned)AMDGPUISD::FMAD_FTZ :
1612                     (unsigned)ISD::FMAD;
1613 
1614     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1615     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1616     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1617       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1618       Cvt_Lo);
1619     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1620     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1621       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1622     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1623       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1624     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1625     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1626       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1627       Mul1);
1628     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1629     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1630     SDValue Rcp64 = DAG.getBitcast(VT,
1631                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1632 
1633     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1634     SDValue One64  = DAG.getConstant(1, DL, VT);
1635     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1636     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1637 
1638     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1639     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1640     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1641     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1642                                     Zero);
1643     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1644                                     One);
1645 
1646     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1647                                   Mulhi1_Lo, Zero1);
1648     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1649                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1650     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1651     SDValue Add1 = DAG.getBitcast(VT,
1652                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1653 
1654     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1655     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1656     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1657                                     Zero);
1658     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1659                                     One);
1660 
1661     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1662                                   Mulhi2_Lo, Zero1);
1663     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1664                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1665     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1666                                   Zero, Add2_Lo.getValue(1));
1667     SDValue Add2 = DAG.getBitcast(VT,
1668                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1669     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1670 
1671     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1672 
1673     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1674     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1675     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1676                                   Mul3_Lo, Zero1);
1677     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1678                                   Mul3_Hi, Sub1_Lo.getValue(1));
1679     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1680     SDValue Sub1 = DAG.getBitcast(VT,
1681                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1682 
1683     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1684     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1685                                  ISD::SETUGE);
1686     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1687                                  ISD::SETUGE);
1688     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1689 
1690     // TODO: Here and below portions of the code can be enclosed into if/endif.
1691     // Currently control flow is unconditional and we have 4 selects after
1692     // potential endif to substitute PHIs.
1693 
1694     // if C3 != 0 ...
1695     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1696                                   RHS_Lo, Zero1);
1697     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1698                                   RHS_Hi, Sub1_Lo.getValue(1));
1699     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1700                                   Zero, Sub2_Lo.getValue(1));
1701     SDValue Sub2 = DAG.getBitcast(VT,
1702                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1703 
1704     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1705 
1706     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1707                                  ISD::SETUGE);
1708     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1709                                  ISD::SETUGE);
1710     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1711 
1712     // if (C6 != 0)
1713     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1714 
1715     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1716                                   RHS_Lo, Zero1);
1717     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1718                                   RHS_Hi, Sub2_Lo.getValue(1));
1719     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1720                                   Zero, Sub3_Lo.getValue(1));
1721     SDValue Sub3 = DAG.getBitcast(VT,
1722                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1723 
1724     // endif C6
1725     // endif C3
1726 
1727     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1728     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1729 
1730     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1731     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1732 
1733     Results.push_back(Div);
1734     Results.push_back(Rem);
1735 
1736     return;
1737   }
1738 
1739   // r600 expandion.
1740   // Get Speculative values
1741   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1742   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1743 
1744   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1745   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1746   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1747 
1748   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1749   SDValue DIV_Lo = Zero;
1750 
1751   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1752 
1753   for (unsigned i = 0; i < halfBitWidth; ++i) {
1754     const unsigned bitPos = halfBitWidth - i - 1;
1755     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1756     // Get value of high bit
1757     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1758     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1759     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1760 
1761     // Shift
1762     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1763     // Add LHS high bit
1764     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1765 
1766     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1767     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1768 
1769     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1770 
1771     // Update REM
1772     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1773     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1774   }
1775 
1776   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1777   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1778   Results.push_back(DIV);
1779   Results.push_back(REM);
1780 }
1781 
1782 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1783                                            SelectionDAG &DAG) const {
1784   SDLoc DL(Op);
1785   EVT VT = Op.getValueType();
1786 
1787   if (VT == MVT::i64) {
1788     SmallVector<SDValue, 2> Results;
1789     LowerUDIVREM64(Op, DAG, Results);
1790     return DAG.getMergeValues(Results, DL);
1791   }
1792 
1793   if (VT == MVT::i32) {
1794     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1795       return Res;
1796   }
1797 
1798   SDValue Num = Op.getOperand(0);
1799   SDValue Den = Op.getOperand(1);
1800 
1801   // RCP =  URECIP(Den) = 2^32 / Den + e
1802   // e is rounding error.
1803   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1804 
1805   // RCP_LO = mul(RCP, Den) */
1806   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1807 
1808   // RCP_HI = mulhu (RCP, Den) */
1809   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1810 
1811   // NEG_RCP_LO = -RCP_LO
1812   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1813                                                      RCP_LO);
1814 
1815   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1816   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1817                                            NEG_RCP_LO, RCP_LO,
1818                                            ISD::SETEQ);
1819   // Calculate the rounding error from the URECIP instruction
1820   // E = mulhu(ABS_RCP_LO, RCP)
1821   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1822 
1823   // RCP_A_E = RCP + E
1824   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1825 
1826   // RCP_S_E = RCP - E
1827   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1828 
1829   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1830   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1831                                      RCP_A_E, RCP_S_E,
1832                                      ISD::SETEQ);
1833   // Quotient = mulhu(Tmp0, Num)
1834   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1835 
1836   // Num_S_Remainder = Quotient * Den
1837   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1838 
1839   // Remainder = Num - Num_S_Remainder
1840   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1841 
1842   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1843   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1844                                                  DAG.getConstant(-1, DL, VT),
1845                                                  DAG.getConstant(0, DL, VT),
1846                                                  ISD::SETUGE);
1847   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1848   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1849                                                   Num_S_Remainder,
1850                                                   DAG.getConstant(-1, DL, VT),
1851                                                   DAG.getConstant(0, DL, VT),
1852                                                   ISD::SETUGE);
1853   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1854   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1855                                                Remainder_GE_Zero);
1856 
1857   // Calculate Division result:
1858 
1859   // Quotient_A_One = Quotient + 1
1860   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1861                                        DAG.getConstant(1, DL, VT));
1862 
1863   // Quotient_S_One = Quotient - 1
1864   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1865                                        DAG.getConstant(1, DL, VT));
1866 
1867   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1868   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1869                                      Quotient, Quotient_A_One, ISD::SETEQ);
1870 
1871   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1872   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1873                             Quotient_S_One, Div, ISD::SETEQ);
1874 
1875   // Calculate Rem result:
1876 
1877   // Remainder_S_Den = Remainder - Den
1878   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1879 
1880   // Remainder_A_Den = Remainder + Den
1881   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1882 
1883   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1884   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1885                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1886 
1887   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1888   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1889                             Remainder_A_Den, Rem, ISD::SETEQ);
1890   SDValue Ops[2] = {
1891     Div,
1892     Rem
1893   };
1894   return DAG.getMergeValues(Ops, DL);
1895 }
1896 
1897 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1898                                            SelectionDAG &DAG) const {
1899   SDLoc DL(Op);
1900   EVT VT = Op.getValueType();
1901 
1902   SDValue LHS = Op.getOperand(0);
1903   SDValue RHS = Op.getOperand(1);
1904 
1905   SDValue Zero = DAG.getConstant(0, DL, VT);
1906   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1907 
1908   if (VT == MVT::i32) {
1909     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1910       return Res;
1911   }
1912 
1913   if (VT == MVT::i64 &&
1914       DAG.ComputeNumSignBits(LHS) > 32 &&
1915       DAG.ComputeNumSignBits(RHS) > 32) {
1916     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1917 
1918     //HiLo split
1919     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1920     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1921     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1922                                  LHS_Lo, RHS_Lo);
1923     SDValue Res[2] = {
1924       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1925       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1926     };
1927     return DAG.getMergeValues(Res, DL);
1928   }
1929 
1930   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1931   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1932   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1933   SDValue RSign = LHSign; // Remainder sign is the same as LHS
1934 
1935   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
1936   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
1937 
1938   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
1939   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
1940 
1941   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
1942   SDValue Rem = Div.getValue(1);
1943 
1944   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
1945   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
1946 
1947   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
1948   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
1949 
1950   SDValue Res[2] = {
1951     Div,
1952     Rem
1953   };
1954   return DAG.getMergeValues(Res, DL);
1955 }
1956 
1957 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
1958 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
1959   SDLoc SL(Op);
1960   EVT VT = Op.getValueType();
1961   SDValue X = Op.getOperand(0);
1962   SDValue Y = Op.getOperand(1);
1963 
1964   // TODO: Should this propagate fast-math-flags?
1965 
1966   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
1967   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
1968   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
1969 
1970   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
1971 }
1972 
1973 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
1974   SDLoc SL(Op);
1975   SDValue Src = Op.getOperand(0);
1976 
1977   // result = trunc(src)
1978   // if (src > 0.0 && src != result)
1979   //   result += 1.0
1980 
1981   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
1982 
1983   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
1984   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
1985 
1986   EVT SetCCVT =
1987       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
1988 
1989   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
1990   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
1991   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
1992 
1993   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
1994   // TODO: Should this propagate fast-math-flags?
1995   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
1996 }
1997 
1998 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
1999                                   SelectionDAG &DAG) {
2000   const unsigned FractBits = 52;
2001   const unsigned ExpBits = 11;
2002 
2003   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2004                                 Hi,
2005                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2006                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2007   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2008                             DAG.getConstant(1023, SL, MVT::i32));
2009 
2010   return Exp;
2011 }
2012 
2013 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2014   SDLoc SL(Op);
2015   SDValue Src = Op.getOperand(0);
2016 
2017   assert(Op.getValueType() == MVT::f64);
2018 
2019   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2020   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2021 
2022   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2023 
2024   // Extract the upper half, since this is where we will find the sign and
2025   // exponent.
2026   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2027 
2028   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2029 
2030   const unsigned FractBits = 52;
2031 
2032   // Extract the sign bit.
2033   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2034   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2035 
2036   // Extend back to 64-bits.
2037   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2038   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2039 
2040   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2041   const SDValue FractMask
2042     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2043 
2044   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2045   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2046   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2047 
2048   EVT SetCCVT =
2049       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2050 
2051   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2052 
2053   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2054   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2055 
2056   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2057   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2058 
2059   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2060 }
2061 
2062 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2063   SDLoc SL(Op);
2064   SDValue Src = Op.getOperand(0);
2065 
2066   assert(Op.getValueType() == MVT::f64);
2067 
2068   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2069   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2070   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2071 
2072   // TODO: Should this propagate fast-math-flags?
2073 
2074   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2075   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2076 
2077   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2078 
2079   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2080   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2081 
2082   EVT SetCCVT =
2083       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2084   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2085 
2086   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2087 }
2088 
2089 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2090   // FNEARBYINT and FRINT are the same, except in their handling of FP
2091   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2092   // rint, so just treat them as equivalent.
2093   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2094 }
2095 
2096 // XXX - May require not supporting f32 denormals?
2097 
2098 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2099 // compare and vselect end up producing worse code than scalarizing the whole
2100 // operation.
2101 SDValue AMDGPUTargetLowering::LowerFROUND32_16(SDValue Op, SelectionDAG &DAG) const {
2102   SDLoc SL(Op);
2103   SDValue X = Op.getOperand(0);
2104   EVT VT = Op.getValueType();
2105 
2106   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2107 
2108   // TODO: Should this propagate fast-math-flags?
2109 
2110   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2111 
2112   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2113 
2114   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2115   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2116   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2117 
2118   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2119 
2120   EVT SetCCVT =
2121       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2122 
2123   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2124 
2125   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2126 
2127   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2128 }
2129 
2130 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2131   SDLoc SL(Op);
2132   SDValue X = Op.getOperand(0);
2133 
2134   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2135 
2136   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2137   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2138   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2139   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2140   EVT SetCCVT =
2141       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2142 
2143   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2144 
2145   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2146 
2147   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2148 
2149   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2150                                        MVT::i64);
2151 
2152   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2153   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2154                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2155                                           MVT::i64),
2156                           Exp);
2157 
2158   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2159   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2160                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2161                               ISD::SETNE);
2162 
2163   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2164                              D, DAG.getConstant(0, SL, MVT::i64));
2165   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2166 
2167   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2168   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2169 
2170   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2171   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2172   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2173 
2174   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2175                             ExpEqNegOne,
2176                             DAG.getConstantFP(1.0, SL, MVT::f64),
2177                             DAG.getConstantFP(0.0, SL, MVT::f64));
2178 
2179   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2180 
2181   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2182   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2183 
2184   return K;
2185 }
2186 
2187 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2188   EVT VT = Op.getValueType();
2189 
2190   if (VT == MVT::f32 || VT == MVT::f16)
2191     return LowerFROUND32_16(Op, DAG);
2192 
2193   if (VT == MVT::f64)
2194     return LowerFROUND64(Op, DAG);
2195 
2196   llvm_unreachable("unhandled type");
2197 }
2198 
2199 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2200   SDLoc SL(Op);
2201   SDValue Src = Op.getOperand(0);
2202 
2203   // result = trunc(src);
2204   // if (src < 0.0 && src != result)
2205   //   result += -1.0.
2206 
2207   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2208 
2209   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2210   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2211 
2212   EVT SetCCVT =
2213       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2214 
2215   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2216   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2217   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2218 
2219   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2220   // TODO: Should this propagate fast-math-flags?
2221   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2222 }
2223 
2224 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2225                                         double Log2BaseInverted) const {
2226   EVT VT = Op.getValueType();
2227 
2228   SDLoc SL(Op);
2229   SDValue Operand = Op.getOperand(0);
2230   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2231   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2232 
2233   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2234 }
2235 
2236 static bool isCtlzOpc(unsigned Opc) {
2237   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2238 }
2239 
2240 static bool isCttzOpc(unsigned Opc) {
2241   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2242 }
2243 
2244 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2245   SDLoc SL(Op);
2246   SDValue Src = Op.getOperand(0);
2247   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2248                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2249 
2250   unsigned ISDOpc, NewOpc;
2251   if (isCtlzOpc(Op.getOpcode())) {
2252     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2253     NewOpc = AMDGPUISD::FFBH_U32;
2254   } else if (isCttzOpc(Op.getOpcode())) {
2255     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2256     NewOpc = AMDGPUISD::FFBL_B32;
2257   } else
2258     llvm_unreachable("Unexpected OPCode!!!");
2259 
2260 
2261   if (ZeroUndef && Src.getValueType() == MVT::i32)
2262     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2263 
2264   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2265 
2266   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2267   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2268 
2269   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2270   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2271 
2272   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2273                                    *DAG.getContext(), MVT::i32);
2274 
2275   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2276   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2277 
2278   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2279   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2280 
2281   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2282   SDValue Add, NewOpr;
2283   if (isCtlzOpc(Op.getOpcode())) {
2284     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2285     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2286     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2287   } else {
2288     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2289     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2290     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2291   }
2292 
2293   if (!ZeroUndef) {
2294     // Test if the full 64-bit input is zero.
2295 
2296     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2297     // which we probably don't want.
2298     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2299     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2300     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2301 
2302     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2303     // with the same cycles, otherwise it is slower.
2304     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2305     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2306 
2307     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2308 
2309     // The instruction returns -1 for 0 input, but the defined intrinsic
2310     // behavior is to return the number of bits.
2311     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2312                          SrcIsZero, Bits32, NewOpr);
2313   }
2314 
2315   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2316 }
2317 
2318 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2319                                                bool Signed) const {
2320   // Unsigned
2321   // cul2f(ulong u)
2322   //{
2323   //  uint lz = clz(u);
2324   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2325   //  u = (u << lz) & 0x7fffffffffffffffUL;
2326   //  ulong t = u & 0xffffffffffUL;
2327   //  uint v = (e << 23) | (uint)(u >> 40);
2328   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2329   //  return as_float(v + r);
2330   //}
2331   // Signed
2332   // cl2f(long l)
2333   //{
2334   //  long s = l >> 63;
2335   //  float r = cul2f((l + s) ^ s);
2336   //  return s ? -r : r;
2337   //}
2338 
2339   SDLoc SL(Op);
2340   SDValue Src = Op.getOperand(0);
2341   SDValue L = Src;
2342 
2343   SDValue S;
2344   if (Signed) {
2345     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2346     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2347 
2348     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2349     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2350   }
2351 
2352   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2353                                    *DAG.getContext(), MVT::f32);
2354 
2355 
2356   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2357   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2358   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2359   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2360 
2361   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2362   SDValue E = DAG.getSelect(SL, MVT::i32,
2363     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2364     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2365     ZeroI32);
2366 
2367   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2368     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2369     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2370 
2371   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2372                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2373 
2374   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2375                              U, DAG.getConstant(40, SL, MVT::i64));
2376 
2377   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2378     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2379     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2380 
2381   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2382   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2383   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2384 
2385   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2386 
2387   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2388 
2389   SDValue R = DAG.getSelect(SL, MVT::i32,
2390     RCmp,
2391     One,
2392     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2393   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2394   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2395 
2396   if (!Signed)
2397     return R;
2398 
2399   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2400   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2401 }
2402 
2403 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2404                                                bool Signed) const {
2405   SDLoc SL(Op);
2406   SDValue Src = Op.getOperand(0);
2407 
2408   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2409 
2410   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2411                            DAG.getConstant(0, SL, MVT::i32));
2412   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2413                            DAG.getConstant(1, SL, MVT::i32));
2414 
2415   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2416                               SL, MVT::f64, Hi);
2417 
2418   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2419 
2420   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2421                               DAG.getConstant(32, SL, MVT::i32));
2422   // TODO: Should this propagate fast-math-flags?
2423   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2424 }
2425 
2426 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2427                                                SelectionDAG &DAG) const {
2428   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2429          "operation should be legal");
2430 
2431   // TODO: Factor out code common with LowerSINT_TO_FP.
2432 
2433   EVT DestVT = Op.getValueType();
2434   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2435     SDLoc DL(Op);
2436     SDValue Src = Op.getOperand(0);
2437 
2438     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2439     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2440     SDValue FPRound =
2441         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2442 
2443     return FPRound;
2444   }
2445 
2446   if (DestVT == MVT::f32)
2447     return LowerINT_TO_FP32(Op, DAG, false);
2448 
2449   assert(DestVT == MVT::f64);
2450   return LowerINT_TO_FP64(Op, DAG, false);
2451 }
2452 
2453 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2454                                               SelectionDAG &DAG) const {
2455   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2456          "operation should be legal");
2457 
2458   // TODO: Factor out code common with LowerUINT_TO_FP.
2459 
2460   EVT DestVT = Op.getValueType();
2461   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2462     SDLoc DL(Op);
2463     SDValue Src = Op.getOperand(0);
2464 
2465     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2466     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2467     SDValue FPRound =
2468         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2469 
2470     return FPRound;
2471   }
2472 
2473   if (DestVT == MVT::f32)
2474     return LowerINT_TO_FP32(Op, DAG, true);
2475 
2476   assert(DestVT == MVT::f64);
2477   return LowerINT_TO_FP64(Op, DAG, true);
2478 }
2479 
2480 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2481                                                bool Signed) const {
2482   SDLoc SL(Op);
2483 
2484   SDValue Src = Op.getOperand(0);
2485 
2486   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2487 
2488   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2489                                  MVT::f64);
2490   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2491                                  MVT::f64);
2492   // TODO: Should this propagate fast-math-flags?
2493   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2494 
2495   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2496 
2497 
2498   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2499 
2500   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2501                            MVT::i32, FloorMul);
2502   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2503 
2504   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2505 
2506   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2507 }
2508 
2509 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2510   SDLoc DL(Op);
2511   SDValue N0 = Op.getOperand(0);
2512 
2513   // Convert to target node to get known bits
2514   if (N0.getValueType() == MVT::f32)
2515     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2516 
2517   if (getTargetMachine().Options.UnsafeFPMath) {
2518     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2519     return SDValue();
2520   }
2521 
2522   assert(N0.getSimpleValueType() == MVT::f64);
2523 
2524   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2525   const unsigned ExpMask = 0x7ff;
2526   const unsigned ExpBiasf64 = 1023;
2527   const unsigned ExpBiasf16 = 15;
2528   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2529   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2530   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2531   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2532                            DAG.getConstant(32, DL, MVT::i64));
2533   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2534   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2535   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2536                           DAG.getConstant(20, DL, MVT::i64));
2537   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2538                   DAG.getConstant(ExpMask, DL, MVT::i32));
2539   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2540   // add the f16 bias (15) to get the biased exponent for the f16 format.
2541   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2542                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2543 
2544   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2545                           DAG.getConstant(8, DL, MVT::i32));
2546   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2547                   DAG.getConstant(0xffe, DL, MVT::i32));
2548 
2549   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2550                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2551   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2552 
2553   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2554   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2555 
2556   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2557   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2558       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2559                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2560 
2561   // N = M | (E << 12);
2562   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2563       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2564                   DAG.getConstant(12, DL, MVT::i32)));
2565 
2566   // B = clamp(1-E, 0, 13);
2567   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2568                                   One, E);
2569   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2570   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2571                   DAG.getConstant(13, DL, MVT::i32));
2572 
2573   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2574                                    DAG.getConstant(0x1000, DL, MVT::i32));
2575 
2576   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2577   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2578   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2579   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2580 
2581   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2582   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2583                               DAG.getConstant(0x7, DL, MVT::i32));
2584   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2585                   DAG.getConstant(2, DL, MVT::i32));
2586   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2587                                One, Zero, ISD::SETEQ);
2588   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2589                                One, Zero, ISD::SETGT);
2590   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2591   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2592 
2593   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2594                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2595   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2596                       I, V, ISD::SETEQ);
2597 
2598   // Extract the sign bit.
2599   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2600                             DAG.getConstant(16, DL, MVT::i32));
2601   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2602                      DAG.getConstant(0x8000, DL, MVT::i32));
2603 
2604   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2605   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2606 }
2607 
2608 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2609                                               SelectionDAG &DAG) const {
2610   SDValue Src = Op.getOperand(0);
2611 
2612   // TODO: Factor out code common with LowerFP_TO_UINT.
2613 
2614   EVT SrcVT = Src.getValueType();
2615   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2616     SDLoc DL(Op);
2617 
2618     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2619     SDValue FpToInt32 =
2620         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2621 
2622     return FpToInt32;
2623   }
2624 
2625   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2626     return LowerFP64_TO_INT(Op, DAG, true);
2627 
2628   return SDValue();
2629 }
2630 
2631 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2632                                               SelectionDAG &DAG) const {
2633   SDValue Src = Op.getOperand(0);
2634 
2635   // TODO: Factor out code common with LowerFP_TO_SINT.
2636 
2637   EVT SrcVT = Src.getValueType();
2638   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2639     SDLoc DL(Op);
2640 
2641     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2642     SDValue FpToInt32 =
2643         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2644 
2645     return FpToInt32;
2646   }
2647 
2648   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2649     return LowerFP64_TO_INT(Op, DAG, false);
2650 
2651   return SDValue();
2652 }
2653 
2654 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2655                                                      SelectionDAG &DAG) const {
2656   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2657   MVT VT = Op.getSimpleValueType();
2658   MVT ScalarVT = VT.getScalarType();
2659 
2660   assert(VT.isVector());
2661 
2662   SDValue Src = Op.getOperand(0);
2663   SDLoc DL(Op);
2664 
2665   // TODO: Don't scalarize on Evergreen?
2666   unsigned NElts = VT.getVectorNumElements();
2667   SmallVector<SDValue, 8> Args;
2668   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2669 
2670   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2671   for (unsigned I = 0; I < NElts; ++I)
2672     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2673 
2674   return DAG.getBuildVector(VT, DL, Args);
2675 }
2676 
2677 //===----------------------------------------------------------------------===//
2678 // Custom DAG optimizations
2679 //===----------------------------------------------------------------------===//
2680 
2681 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2682   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2683 }
2684 
2685 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2686   EVT VT = Op.getValueType();
2687   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2688                                      // as unsigned 24-bit values.
2689     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2690 }
2691 
2692 static bool simplifyI24(SDNode *Node24, unsigned OpIdx,
2693                         TargetLowering::DAGCombinerInfo &DCI) {
2694 
2695   SelectionDAG &DAG = DCI.DAG;
2696   SDValue Op = Node24->getOperand(OpIdx);
2697   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2698   EVT VT = Op.getValueType();
2699 
2700   APInt Demanded = APInt::getLowBitsSet(VT.getSizeInBits(), 24);
2701   APInt KnownZero, KnownOne;
2702   TargetLowering::TargetLoweringOpt TLO(DAG, true, true);
2703   if (TLI.SimplifyDemandedBits(Node24, OpIdx, Demanded, DCI, TLO))
2704     return true;
2705 
2706   return false;
2707 }
2708 
2709 template <typename IntTy>
2710 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2711                                uint32_t Width, const SDLoc &DL) {
2712   if (Width + Offset < 32) {
2713     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2714     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2715     return DAG.getConstant(Result, DL, MVT::i32);
2716   }
2717 
2718   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2719 }
2720 
2721 static bool hasVolatileUser(SDNode *Val) {
2722   for (SDNode *U : Val->uses()) {
2723     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2724       if (M->isVolatile())
2725         return true;
2726     }
2727   }
2728 
2729   return false;
2730 }
2731 
2732 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2733   // i32 vectors are the canonical memory type.
2734   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2735     return false;
2736 
2737   if (!VT.isByteSized())
2738     return false;
2739 
2740   unsigned Size = VT.getStoreSize();
2741 
2742   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2743     return false;
2744 
2745   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2746     return false;
2747 
2748   return true;
2749 }
2750 
2751 // Replace load of an illegal type with a store of a bitcast to a friendlier
2752 // type.
2753 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2754                                                  DAGCombinerInfo &DCI) const {
2755   if (!DCI.isBeforeLegalize())
2756     return SDValue();
2757 
2758   LoadSDNode *LN = cast<LoadSDNode>(N);
2759   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2760     return SDValue();
2761 
2762   SDLoc SL(N);
2763   SelectionDAG &DAG = DCI.DAG;
2764   EVT VT = LN->getMemoryVT();
2765 
2766   unsigned Size = VT.getStoreSize();
2767   unsigned Align = LN->getAlignment();
2768   if (Align < Size && isTypeLegal(VT)) {
2769     bool IsFast;
2770     unsigned AS = LN->getAddressSpace();
2771 
2772     // Expand unaligned loads earlier than legalization. Due to visitation order
2773     // problems during legalization, the emitted instructions to pack and unpack
2774     // the bytes again are not eliminated in the case of an unaligned copy.
2775     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2776       if (VT.isVector())
2777         return scalarizeVectorLoad(LN, DAG);
2778 
2779       SDValue Ops[2];
2780       std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2781       return DAG.getMergeValues(Ops, SDLoc(N));
2782     }
2783 
2784     if (!IsFast)
2785       return SDValue();
2786   }
2787 
2788   if (!shouldCombineMemoryType(VT))
2789     return SDValue();
2790 
2791   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2792 
2793   SDValue NewLoad
2794     = DAG.getLoad(NewVT, SL, LN->getChain(),
2795                   LN->getBasePtr(), LN->getMemOperand());
2796 
2797   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2798   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2799   return SDValue(N, 0);
2800 }
2801 
2802 // Replace store of an illegal type with a store of a bitcast to a friendlier
2803 // type.
2804 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2805                                                   DAGCombinerInfo &DCI) const {
2806   if (!DCI.isBeforeLegalize())
2807     return SDValue();
2808 
2809   StoreSDNode *SN = cast<StoreSDNode>(N);
2810   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2811     return SDValue();
2812 
2813   EVT VT = SN->getMemoryVT();
2814   unsigned Size = VT.getStoreSize();
2815 
2816   SDLoc SL(N);
2817   SelectionDAG &DAG = DCI.DAG;
2818   unsigned Align = SN->getAlignment();
2819   if (Align < Size && isTypeLegal(VT)) {
2820     bool IsFast;
2821     unsigned AS = SN->getAddressSpace();
2822 
2823     // Expand unaligned stores earlier than legalization. Due to visitation
2824     // order problems during legalization, the emitted instructions to pack and
2825     // unpack the bytes again are not eliminated in the case of an unaligned
2826     // copy.
2827     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2828       if (VT.isVector())
2829         return scalarizeVectorStore(SN, DAG);
2830 
2831       return expandUnalignedStore(SN, DAG);
2832     }
2833 
2834     if (!IsFast)
2835       return SDValue();
2836   }
2837 
2838   if (!shouldCombineMemoryType(VT))
2839     return SDValue();
2840 
2841   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2842   SDValue Val = SN->getValue();
2843 
2844   //DCI.AddToWorklist(Val.getNode());
2845 
2846   bool OtherUses = !Val.hasOneUse();
2847   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2848   if (OtherUses) {
2849     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2850     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2851   }
2852 
2853   return DAG.getStore(SN->getChain(), SL, CastVal,
2854                       SN->getBasePtr(), SN->getMemOperand());
2855 }
2856 
2857 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2858 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2859 // issues.
2860 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2861                                                         DAGCombinerInfo &DCI) const {
2862   SelectionDAG &DAG = DCI.DAG;
2863   SDValue N0 = N->getOperand(0);
2864 
2865   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2866   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2867   if (N0.getOpcode() == ISD::TRUNCATE) {
2868     SDValue N1 = N->getOperand(1);
2869     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2870     SDLoc SL(N);
2871 
2872     SDValue Src = N0.getOperand(0);
2873     EVT SrcVT = Src.getValueType();
2874     if (SrcVT.bitsGE(ExtVT)) {
2875       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2876       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2877     }
2878   }
2879 
2880   return SDValue();
2881 }
2882 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
2883 /// binary operation \p Opc to it with the corresponding constant operands.
2884 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
2885   DAGCombinerInfo &DCI, const SDLoc &SL,
2886   unsigned Opc, SDValue LHS,
2887   uint32_t ValLo, uint32_t ValHi) const {
2888   SelectionDAG &DAG = DCI.DAG;
2889   SDValue Lo, Hi;
2890   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
2891 
2892   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
2893   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
2894 
2895   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
2896   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
2897 
2898   // Re-visit the ands. It's possible we eliminated one of them and it could
2899   // simplify the vector.
2900   DCI.AddToWorklist(Lo.getNode());
2901   DCI.AddToWorklist(Hi.getNode());
2902 
2903   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
2904   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2905 }
2906 
2907 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
2908                                                 DAGCombinerInfo &DCI) const {
2909   EVT VT = N->getValueType(0);
2910 
2911   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2912   if (!RHS)
2913     return SDValue();
2914 
2915   SDValue LHS = N->getOperand(0);
2916   unsigned RHSVal = RHS->getZExtValue();
2917   if (!RHSVal)
2918     return LHS;
2919 
2920   SDLoc SL(N);
2921   SelectionDAG &DAG = DCI.DAG;
2922 
2923   switch (LHS->getOpcode()) {
2924   default:
2925     break;
2926   case ISD::ZERO_EXTEND:
2927   case ISD::SIGN_EXTEND:
2928   case ISD::ANY_EXTEND: {
2929     SDValue X = LHS->getOperand(0);
2930 
2931     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
2932         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
2933       // Prefer build_vector as the canonical form if packed types are legal.
2934       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
2935       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
2936        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
2937       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
2938     }
2939 
2940     // shl (ext x) => zext (shl x), if shift does not overflow int
2941     if (VT != MVT::i64)
2942       break;
2943     KnownBits Known;
2944     DAG.computeKnownBits(X, Known);
2945     unsigned LZ = Known.countMinLeadingZeros();
2946     if (LZ < RHSVal)
2947       break;
2948     EVT XVT = X.getValueType();
2949     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
2950     return DAG.getZExtOrTrunc(Shl, SL, VT);
2951   }
2952   }
2953 
2954   if (VT != MVT::i64)
2955     return SDValue();
2956 
2957   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
2958 
2959   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
2960   // common case, splitting this into a move and a 32-bit shift is faster and
2961   // the same code size.
2962   if (RHSVal < 32)
2963     return SDValue();
2964 
2965   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
2966 
2967   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
2968   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
2969 
2970   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2971 
2972   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
2973   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2974 }
2975 
2976 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
2977                                                 DAGCombinerInfo &DCI) const {
2978   if (N->getValueType(0) != MVT::i64)
2979     return SDValue();
2980 
2981   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2982   if (!RHS)
2983     return SDValue();
2984 
2985   SelectionDAG &DAG = DCI.DAG;
2986   SDLoc SL(N);
2987   unsigned RHSVal = RHS->getZExtValue();
2988 
2989   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
2990   if (RHSVal == 32) {
2991     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
2992     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
2993                                    DAG.getConstant(31, SL, MVT::i32));
2994 
2995     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
2996     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
2997   }
2998 
2999   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3000   if (RHSVal == 63) {
3001     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3002     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3003                                    DAG.getConstant(31, SL, MVT::i32));
3004     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3005     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3006   }
3007 
3008   return SDValue();
3009 }
3010 
3011 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3012                                                 DAGCombinerInfo &DCI) const {
3013   if (N->getValueType(0) != MVT::i64)
3014     return SDValue();
3015 
3016   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3017   if (!RHS)
3018     return SDValue();
3019 
3020   unsigned ShiftAmt = RHS->getZExtValue();
3021   if (ShiftAmt < 32)
3022     return SDValue();
3023 
3024   // srl i64:x, C for C >= 32
3025   // =>
3026   //   build_pair (srl hi_32(x), C - 32), 0
3027 
3028   SelectionDAG &DAG = DCI.DAG;
3029   SDLoc SL(N);
3030 
3031   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3032   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3033 
3034   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, N->getOperand(0));
3035   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32,
3036                            VecOp, One);
3037 
3038   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3039   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3040 
3041   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3042 
3043   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3044 }
3045 
3046 SDValue AMDGPUTargetLowering::performTruncateCombine(
3047   SDNode *N, DAGCombinerInfo &DCI) const {
3048   SDLoc SL(N);
3049   SelectionDAG &DAG = DCI.DAG;
3050   EVT VT = N->getValueType(0);
3051   SDValue Src = N->getOperand(0);
3052 
3053   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3054   if (Src.getOpcode() == ISD::BITCAST) {
3055     SDValue Vec = Src.getOperand(0);
3056     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3057       SDValue Elt0 = Vec.getOperand(0);
3058       EVT EltVT = Elt0.getValueType();
3059       if (VT.getSizeInBits() <= EltVT.getSizeInBits()) {
3060         if (EltVT.isFloatingPoint()) {
3061           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3062                              EltVT.changeTypeToInteger(), Elt0);
3063         }
3064 
3065         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3066       }
3067     }
3068   }
3069 
3070   // Equivalent of above for accessing the high element of a vector as an
3071   // integer operation.
3072   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3073   if (Src.getOpcode() == ISD::SRL) {
3074     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3075       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3076         SDValue BV = stripBitcast(Src.getOperand(0));
3077         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3078             BV.getValueType().getVectorNumElements() == 2) {
3079           SDValue SrcElt = BV.getOperand(1);
3080           EVT SrcEltVT = SrcElt.getValueType();
3081           if (SrcEltVT.isFloatingPoint()) {
3082             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3083                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3084           }
3085 
3086           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3087         }
3088       }
3089     }
3090   }
3091 
3092   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3093   //
3094   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3095   //     i16 (trunc (srl (i32 (trunc x), K)))
3096   if (VT.getScalarSizeInBits() < 32) {
3097     EVT SrcVT = Src.getValueType();
3098     if (SrcVT.getScalarSizeInBits() > 32 &&
3099         (Src.getOpcode() == ISD::SRL ||
3100          Src.getOpcode() == ISD::SRA ||
3101          Src.getOpcode() == ISD::SHL)) {
3102       SDValue Amt = Src.getOperand(1);
3103       KnownBits Known;
3104       DAG.computeKnownBits(Amt, Known);
3105       unsigned Size = VT.getScalarSizeInBits();
3106       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3107           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3108         EVT MidVT = VT.isVector() ?
3109           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3110                            VT.getVectorNumElements()) : MVT::i32;
3111 
3112         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3113         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3114                                     Src.getOperand(0));
3115         DCI.AddToWorklist(Trunc.getNode());
3116 
3117         if (Amt.getValueType() != NewShiftVT) {
3118           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3119           DCI.AddToWorklist(Amt.getNode());
3120         }
3121 
3122         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3123                                           Trunc, Amt);
3124         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3125       }
3126     }
3127   }
3128 
3129   return SDValue();
3130 }
3131 
3132 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3133 // instructions. If we only match on the legalized i64 mul expansion,
3134 // SimplifyDemandedBits will be unable to remove them because there will be
3135 // multiple uses due to the separate mul + mulh[su].
3136 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3137                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3138   if (Size <= 32) {
3139     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3140     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3141   }
3142 
3143   // Because we want to eliminate extension instructions before the
3144   // operation, we need to create a single user here (i.e. not the separate
3145   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3146 
3147   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3148 
3149   SDValue Mul = DAG.getNode(MulOpc, SL,
3150                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3151 
3152   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3153                      Mul.getValue(0), Mul.getValue(1));
3154 }
3155 
3156 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3157                                                 DAGCombinerInfo &DCI) const {
3158   EVT VT = N->getValueType(0);
3159 
3160   unsigned Size = VT.getSizeInBits();
3161   if (VT.isVector() || Size > 64)
3162     return SDValue();
3163 
3164   // There are i16 integer mul/mad.
3165   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3166     return SDValue();
3167 
3168   SelectionDAG &DAG = DCI.DAG;
3169   SDLoc DL(N);
3170 
3171   SDValue N0 = N->getOperand(0);
3172   SDValue N1 = N->getOperand(1);
3173 
3174   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3175   // in the source into any_extends if the result of the mul is truncated. Since
3176   // we can assume the high bits are whatever we want, use the underlying value
3177   // to avoid the unknown high bits from interfering.
3178   if (N0.getOpcode() == ISD::ANY_EXTEND)
3179     N0 = N0.getOperand(0);
3180 
3181   if (N1.getOpcode() == ISD::ANY_EXTEND)
3182     N1 = N1.getOperand(0);
3183 
3184   SDValue Mul;
3185 
3186   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3187     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3188     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3189     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3190   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3191     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3192     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3193     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3194   } else {
3195     return SDValue();
3196   }
3197 
3198   // We need to use sext even for MUL_U24, because MUL_U24 is used
3199   // for signed multiply of 8 and 16-bit types.
3200   return DAG.getSExtOrTrunc(Mul, DL, VT);
3201 }
3202 
3203 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3204                                                   DAGCombinerInfo &DCI) const {
3205   EVT VT = N->getValueType(0);
3206 
3207   if (!Subtarget->hasMulI24() || VT.isVector())
3208     return SDValue();
3209 
3210   SelectionDAG &DAG = DCI.DAG;
3211   SDLoc DL(N);
3212 
3213   SDValue N0 = N->getOperand(0);
3214   SDValue N1 = N->getOperand(1);
3215 
3216   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3217     return SDValue();
3218 
3219   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3220   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3221 
3222   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3223   DCI.AddToWorklist(Mulhi.getNode());
3224   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3225 }
3226 
3227 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3228                                                   DAGCombinerInfo &DCI) const {
3229   EVT VT = N->getValueType(0);
3230 
3231   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3232     return SDValue();
3233 
3234   SelectionDAG &DAG = DCI.DAG;
3235   SDLoc DL(N);
3236 
3237   SDValue N0 = N->getOperand(0);
3238   SDValue N1 = N->getOperand(1);
3239 
3240   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3241     return SDValue();
3242 
3243   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3244   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3245 
3246   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3247   DCI.AddToWorklist(Mulhi.getNode());
3248   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3249 }
3250 
3251 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3252   SDNode *N, DAGCombinerInfo &DCI) const {
3253   SelectionDAG &DAG = DCI.DAG;
3254 
3255   // Simplify demanded bits before splitting into multiple users.
3256   if (simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI))
3257     return SDValue();
3258 
3259   SDValue N0 = N->getOperand(0);
3260   SDValue N1 = N->getOperand(1);
3261 
3262   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3263 
3264   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3265   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3266 
3267   SDLoc SL(N);
3268 
3269   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3270   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3271   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3272 }
3273 
3274 static bool isNegativeOne(SDValue Val) {
3275   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3276     return C->isAllOnesValue();
3277   return false;
3278 }
3279 
3280 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3281                                           SDValue Op,
3282                                           const SDLoc &DL,
3283                                           unsigned Opc) const {
3284   EVT VT = Op.getValueType();
3285   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3286   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3287                               LegalVT != MVT::i16))
3288     return SDValue();
3289 
3290   if (VT != MVT::i32)
3291     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3292 
3293   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3294   if (VT != MVT::i32)
3295     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3296 
3297   return FFBX;
3298 }
3299 
3300 // The native instructions return -1 on 0 input. Optimize out a select that
3301 // produces -1 on 0.
3302 //
3303 // TODO: If zero is not undef, we could also do this if the output is compared
3304 // against the bitwidth.
3305 //
3306 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
3307 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3308                                                  SDValue LHS, SDValue RHS,
3309                                                  DAGCombinerInfo &DCI) const {
3310   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3311   if (!CmpRhs || !CmpRhs->isNullValue())
3312     return SDValue();
3313 
3314   SelectionDAG &DAG = DCI.DAG;
3315   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3316   SDValue CmpLHS = Cond.getOperand(0);
3317 
3318   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3319                                            AMDGPUISD::FFBH_U32;
3320 
3321   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3322   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3323   if (CCOpcode == ISD::SETEQ &&
3324       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3325       RHS.getOperand(0) == CmpLHS &&
3326       isNegativeOne(LHS)) {
3327     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3328   }
3329 
3330   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3331   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3332   if (CCOpcode == ISD::SETNE &&
3333       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3334       LHS.getOperand(0) == CmpLHS &&
3335       isNegativeOne(RHS)) {
3336     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3337   }
3338 
3339   return SDValue();
3340 }
3341 
3342 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3343                                          unsigned Op,
3344                                          const SDLoc &SL,
3345                                          SDValue Cond,
3346                                          SDValue N1,
3347                                          SDValue N2) {
3348   SelectionDAG &DAG = DCI.DAG;
3349   EVT VT = N1.getValueType();
3350 
3351   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3352                                   N1.getOperand(0), N2.getOperand(0));
3353   DCI.AddToWorklist(NewSelect.getNode());
3354   return DAG.getNode(Op, SL, VT, NewSelect);
3355 }
3356 
3357 // Pull a free FP operation out of a select so it may fold into uses.
3358 //
3359 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3360 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3361 //
3362 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3363 // select c, (fabs x), +k -> fabs (select c, x, k)
3364 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3365                                     SDValue N) {
3366   SelectionDAG &DAG = DCI.DAG;
3367   SDValue Cond = N.getOperand(0);
3368   SDValue LHS = N.getOperand(1);
3369   SDValue RHS = N.getOperand(2);
3370 
3371   EVT VT = N.getValueType();
3372   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3373       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3374     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3375                                      SDLoc(N), Cond, LHS, RHS);
3376   }
3377 
3378   bool Inv = false;
3379   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3380     std::swap(LHS, RHS);
3381     Inv = true;
3382   }
3383 
3384   // TODO: Support vector constants.
3385   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3386   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3387     SDLoc SL(N);
3388     // If one side is an fneg/fabs and the other is a constant, we can push the
3389     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3390     SDValue NewLHS = LHS.getOperand(0);
3391     SDValue NewRHS = RHS;
3392 
3393     // Careful: if the neg can be folded up, don't try to pull it back down.
3394     bool ShouldFoldNeg = true;
3395 
3396     if (NewLHS.hasOneUse()) {
3397       unsigned Opc = NewLHS.getOpcode();
3398       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3399         ShouldFoldNeg = false;
3400       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3401         ShouldFoldNeg = false;
3402     }
3403 
3404     if (ShouldFoldNeg) {
3405       if (LHS.getOpcode() == ISD::FNEG)
3406         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3407       else if (CRHS->isNegative())
3408         return SDValue();
3409 
3410       if (Inv)
3411         std::swap(NewLHS, NewRHS);
3412 
3413       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3414                                       Cond, NewLHS, NewRHS);
3415       DCI.AddToWorklist(NewSelect.getNode());
3416       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3417     }
3418   }
3419 
3420   return SDValue();
3421 }
3422 
3423 
3424 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3425                                                    DAGCombinerInfo &DCI) const {
3426   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3427     return Folded;
3428 
3429   SDValue Cond = N->getOperand(0);
3430   if (Cond.getOpcode() != ISD::SETCC)
3431     return SDValue();
3432 
3433   EVT VT = N->getValueType(0);
3434   SDValue LHS = Cond.getOperand(0);
3435   SDValue RHS = Cond.getOperand(1);
3436   SDValue CC = Cond.getOperand(2);
3437 
3438   SDValue True = N->getOperand(1);
3439   SDValue False = N->getOperand(2);
3440 
3441   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3442     SelectionDAG &DAG = DCI.DAG;
3443     if ((DAG.isConstantValueOfAnyType(True) ||
3444          DAG.isConstantValueOfAnyType(True)) &&
3445         (!DAG.isConstantValueOfAnyType(False) &&
3446          !DAG.isConstantValueOfAnyType(False))) {
3447       // Swap cmp + select pair to move constant to false input.
3448       // This will allow using VOPC cndmasks more often.
3449       // select (setcc x, y), k, x -> select (setcc y, x) x, x
3450 
3451       SDLoc SL(N);
3452       ISD::CondCode NewCC = getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3453                                             LHS.getValueType().isInteger());
3454 
3455       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3456       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3457     }
3458 
3459     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3460       SDValue MinMax
3461         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3462       // Revisit this node so we can catch min3/max3/med3 patterns.
3463       //DCI.AddToWorklist(MinMax.getNode());
3464       return MinMax;
3465     }
3466   }
3467 
3468   // There's no reason to not do this if the condition has other uses.
3469   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3470 }
3471 
3472 static bool isConstantFPZero(SDValue N) {
3473   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N))
3474     return C->isZero() && !C->isNegative();
3475   return false;
3476 }
3477 
3478 static unsigned inverseMinMax(unsigned Opc) {
3479   switch (Opc) {
3480   case ISD::FMAXNUM:
3481     return ISD::FMINNUM;
3482   case ISD::FMINNUM:
3483     return ISD::FMAXNUM;
3484   case AMDGPUISD::FMAX_LEGACY:
3485     return AMDGPUISD::FMIN_LEGACY;
3486   case AMDGPUISD::FMIN_LEGACY:
3487     return  AMDGPUISD::FMAX_LEGACY;
3488   default:
3489     llvm_unreachable("invalid min/max opcode");
3490   }
3491 }
3492 
3493 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3494                                                  DAGCombinerInfo &DCI) const {
3495   SelectionDAG &DAG = DCI.DAG;
3496   SDValue N0 = N->getOperand(0);
3497   EVT VT = N->getValueType(0);
3498 
3499   unsigned Opc = N0.getOpcode();
3500 
3501   // If the input has multiple uses and we can either fold the negate down, or
3502   // the other uses cannot, give up. This both prevents unprofitable
3503   // transformations and infinite loops: we won't repeatedly try to fold around
3504   // a negate that has no 'good' form.
3505   if (N0.hasOneUse()) {
3506     // This may be able to fold into the source, but at a code size cost. Don't
3507     // fold if the fold into the user is free.
3508     if (allUsesHaveSourceMods(N, 0))
3509       return SDValue();
3510   } else {
3511     if (fnegFoldsIntoOp(Opc) &&
3512         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3513       return SDValue();
3514   }
3515 
3516   SDLoc SL(N);
3517   switch (Opc) {
3518   case ISD::FADD: {
3519     if (!mayIgnoreSignedZero(N0))
3520       return SDValue();
3521 
3522     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3523     SDValue LHS = N0.getOperand(0);
3524     SDValue RHS = N0.getOperand(1);
3525 
3526     if (LHS.getOpcode() != ISD::FNEG)
3527       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3528     else
3529       LHS = LHS.getOperand(0);
3530 
3531     if (RHS.getOpcode() != ISD::FNEG)
3532       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3533     else
3534       RHS = RHS.getOperand(0);
3535 
3536     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3537     if (!N0.hasOneUse())
3538       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3539     return Res;
3540   }
3541   case ISD::FMUL:
3542   case AMDGPUISD::FMUL_LEGACY: {
3543     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3544     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3545     SDValue LHS = N0.getOperand(0);
3546     SDValue RHS = N0.getOperand(1);
3547 
3548     if (LHS.getOpcode() == ISD::FNEG)
3549       LHS = LHS.getOperand(0);
3550     else if (RHS.getOpcode() == ISD::FNEG)
3551       RHS = RHS.getOperand(0);
3552     else
3553       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3554 
3555     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3556     if (!N0.hasOneUse())
3557       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3558     return Res;
3559   }
3560   case ISD::FMA:
3561   case ISD::FMAD: {
3562     if (!mayIgnoreSignedZero(N0))
3563       return SDValue();
3564 
3565     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3566     SDValue LHS = N0.getOperand(0);
3567     SDValue MHS = N0.getOperand(1);
3568     SDValue RHS = N0.getOperand(2);
3569 
3570     if (LHS.getOpcode() == ISD::FNEG)
3571       LHS = LHS.getOperand(0);
3572     else if (MHS.getOpcode() == ISD::FNEG)
3573       MHS = MHS.getOperand(0);
3574     else
3575       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
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(Opc, SL, VT, LHS, MHS, RHS);
3583     if (!N0.hasOneUse())
3584       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3585     return Res;
3586   }
3587   case ISD::FMAXNUM:
3588   case ISD::FMINNUM:
3589   case AMDGPUISD::FMAX_LEGACY:
3590   case AMDGPUISD::FMIN_LEGACY: {
3591     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3592     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3593     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3594     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3595 
3596     SDValue LHS = N0.getOperand(0);
3597     SDValue RHS = N0.getOperand(1);
3598 
3599     // 0 doesn't have a negated inline immediate.
3600     // TODO: Shouldn't fold 1/2pi either, and should be generalized to other
3601     // operations.
3602     if (isConstantFPZero(RHS))
3603       return SDValue();
3604 
3605     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3606     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3607     unsigned Opposite = inverseMinMax(Opc);
3608 
3609     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3610     if (!N0.hasOneUse())
3611       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3612     return Res;
3613   }
3614   case ISD::FP_EXTEND:
3615   case ISD::FTRUNC:
3616   case ISD::FRINT:
3617   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3618   case ISD::FSIN:
3619   case AMDGPUISD::RCP:
3620   case AMDGPUISD::RCP_LEGACY:
3621   case AMDGPUISD::RCP_IFLAG:
3622   case AMDGPUISD::SIN_HW: {
3623     SDValue CvtSrc = N0.getOperand(0);
3624     if (CvtSrc.getOpcode() == ISD::FNEG) {
3625       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3626       // (fneg (rcp (fneg x))) -> (rcp x)
3627       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3628     }
3629 
3630     if (!N0.hasOneUse())
3631       return SDValue();
3632 
3633     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3634     // (fneg (rcp x)) -> (rcp (fneg x))
3635     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3636     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3637   }
3638   case ISD::FP_ROUND: {
3639     SDValue CvtSrc = N0.getOperand(0);
3640 
3641     if (CvtSrc.getOpcode() == ISD::FNEG) {
3642       // (fneg (fp_round (fneg x))) -> (fp_round x)
3643       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3644                          CvtSrc.getOperand(0), N0.getOperand(1));
3645     }
3646 
3647     if (!N0.hasOneUse())
3648       return SDValue();
3649 
3650     // (fneg (fp_round x)) -> (fp_round (fneg x))
3651     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3652     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3653   }
3654   case ISD::FP16_TO_FP: {
3655     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3656     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3657     // Put the fneg back as a legal source operation that can be matched later.
3658     SDLoc SL(N);
3659 
3660     SDValue Src = N0.getOperand(0);
3661     EVT SrcVT = Src.getValueType();
3662 
3663     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3664     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3665                                   DAG.getConstant(0x8000, SL, SrcVT));
3666     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3667   }
3668   default:
3669     return SDValue();
3670   }
3671 }
3672 
3673 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3674                                                  DAGCombinerInfo &DCI) const {
3675   SelectionDAG &DAG = DCI.DAG;
3676   SDValue N0 = N->getOperand(0);
3677 
3678   if (!N0.hasOneUse())
3679     return SDValue();
3680 
3681   switch (N0.getOpcode()) {
3682   case ISD::FP16_TO_FP: {
3683     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3684     SDLoc SL(N);
3685     SDValue Src = N0.getOperand(0);
3686     EVT SrcVT = Src.getValueType();
3687 
3688     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3689     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3690                                   DAG.getConstant(0x7fff, SL, SrcVT));
3691     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3692   }
3693   default:
3694     return SDValue();
3695   }
3696 }
3697 
3698 SDValue AMDGPUTargetLowering::performRcpCombine(SDNode *N,
3699                                                 DAGCombinerInfo &DCI) const {
3700   const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
3701   if (!CFP)
3702     return SDValue();
3703 
3704   // XXX - Should this flush denormals?
3705   const APFloat &Val = CFP->getValueAPF();
3706   APFloat One(Val.getSemantics(), "1.0");
3707   return DCI.DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3708 }
3709 
3710 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3711                                                 DAGCombinerInfo &DCI) const {
3712   SelectionDAG &DAG = DCI.DAG;
3713   SDLoc DL(N);
3714 
3715   switch(N->getOpcode()) {
3716   default:
3717     break;
3718   case ISD::BITCAST: {
3719     EVT DestVT = N->getValueType(0);
3720 
3721     // Push casts through vector builds. This helps avoid emitting a large
3722     // number of copies when materializing floating point vector constants.
3723     //
3724     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3725     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3726     if (DestVT.isVector()) {
3727       SDValue Src = N->getOperand(0);
3728       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3729         EVT SrcVT = Src.getValueType();
3730         unsigned NElts = DestVT.getVectorNumElements();
3731 
3732         if (SrcVT.getVectorNumElements() == NElts) {
3733           EVT DestEltVT = DestVT.getVectorElementType();
3734 
3735           SmallVector<SDValue, 8> CastedElts;
3736           SDLoc SL(N);
3737           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3738             SDValue Elt = Src.getOperand(I);
3739             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3740           }
3741 
3742           return DAG.getBuildVector(DestVT, SL, CastedElts);
3743         }
3744       }
3745     }
3746 
3747     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3748       break;
3749 
3750     // Fold bitcasts of constants.
3751     //
3752     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3753     // TODO: Generalize and move to DAGCombiner
3754     SDValue Src = N->getOperand(0);
3755     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3756       if (Src.getValueType() == MVT::i64) {
3757         SDLoc SL(N);
3758         uint64_t CVal = C->getZExtValue();
3759         return DAG.getNode(ISD::BUILD_VECTOR, SL, DestVT,
3760                            DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3761                            DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3762       }
3763     }
3764 
3765     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3766       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3767       SDLoc SL(N);
3768       uint64_t CVal = Val.getZExtValue();
3769       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3770                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3771                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3772 
3773       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3774     }
3775 
3776     break;
3777   }
3778   case ISD::SHL: {
3779     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3780       break;
3781 
3782     return performShlCombine(N, DCI);
3783   }
3784   case ISD::SRL: {
3785     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3786       break;
3787 
3788     return performSrlCombine(N, DCI);
3789   }
3790   case ISD::SRA: {
3791     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3792       break;
3793 
3794     return performSraCombine(N, DCI);
3795   }
3796   case ISD::TRUNCATE:
3797     return performTruncateCombine(N, DCI);
3798   case ISD::MUL:
3799     return performMulCombine(N, DCI);
3800   case ISD::MULHS:
3801     return performMulhsCombine(N, DCI);
3802   case ISD::MULHU:
3803     return performMulhuCombine(N, DCI);
3804   case AMDGPUISD::MUL_I24:
3805   case AMDGPUISD::MUL_U24:
3806   case AMDGPUISD::MULHI_I24:
3807   case AMDGPUISD::MULHI_U24: {
3808     // If the first call to simplify is successfull, then N may end up being
3809     // deleted, so we shouldn't call simplifyI24 again.
3810     simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI);
3811     return SDValue();
3812   }
3813   case AMDGPUISD::MUL_LOHI_I24:
3814   case AMDGPUISD::MUL_LOHI_U24:
3815     return performMulLoHi24Combine(N, DCI);
3816   case ISD::SELECT:
3817     return performSelectCombine(N, DCI);
3818   case ISD::FNEG:
3819     return performFNegCombine(N, DCI);
3820   case ISD::FABS:
3821     return performFAbsCombine(N, DCI);
3822   case AMDGPUISD::BFE_I32:
3823   case AMDGPUISD::BFE_U32: {
3824     assert(!N->getValueType(0).isVector() &&
3825            "Vector handling of BFE not implemented");
3826     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
3827     if (!Width)
3828       break;
3829 
3830     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
3831     if (WidthVal == 0)
3832       return DAG.getConstant(0, DL, MVT::i32);
3833 
3834     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
3835     if (!Offset)
3836       break;
3837 
3838     SDValue BitsFrom = N->getOperand(0);
3839     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
3840 
3841     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
3842 
3843     if (OffsetVal == 0) {
3844       // This is already sign / zero extended, so try to fold away extra BFEs.
3845       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
3846 
3847       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
3848       if (OpSignBits >= SignBits)
3849         return BitsFrom;
3850 
3851       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
3852       if (Signed) {
3853         // This is a sign_extend_inreg. Replace it to take advantage of existing
3854         // DAG Combines. If not eliminated, we will match back to BFE during
3855         // selection.
3856 
3857         // TODO: The sext_inreg of extended types ends, although we can could
3858         // handle them in a single BFE.
3859         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
3860                            DAG.getValueType(SmallVT));
3861       }
3862 
3863       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
3864     }
3865 
3866     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
3867       if (Signed) {
3868         return constantFoldBFE<int32_t>(DAG,
3869                                         CVal->getSExtValue(),
3870                                         OffsetVal,
3871                                         WidthVal,
3872                                         DL);
3873       }
3874 
3875       return constantFoldBFE<uint32_t>(DAG,
3876                                        CVal->getZExtValue(),
3877                                        OffsetVal,
3878                                        WidthVal,
3879                                        DL);
3880     }
3881 
3882     if ((OffsetVal + WidthVal) >= 32 &&
3883         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
3884       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
3885       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
3886                          BitsFrom, ShiftVal);
3887     }
3888 
3889     if (BitsFrom.hasOneUse()) {
3890       APInt Demanded = APInt::getBitsSet(32,
3891                                          OffsetVal,
3892                                          OffsetVal + WidthVal);
3893 
3894       KnownBits Known;
3895       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
3896                                             !DCI.isBeforeLegalizeOps());
3897       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3898       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
3899           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
3900         DCI.CommitTargetLoweringOpt(TLO);
3901       }
3902     }
3903 
3904     break;
3905   }
3906   case ISD::LOAD:
3907     return performLoadCombine(N, DCI);
3908   case ISD::STORE:
3909     return performStoreCombine(N, DCI);
3910   case AMDGPUISD::RCP:
3911   case AMDGPUISD::RCP_IFLAG:
3912     return performRcpCombine(N, DCI);
3913   case ISD::AssertZext:
3914   case ISD::AssertSext:
3915     return performAssertSZExtCombine(N, DCI);
3916   }
3917   return SDValue();
3918 }
3919 
3920 //===----------------------------------------------------------------------===//
3921 // Helper functions
3922 //===----------------------------------------------------------------------===//
3923 
3924 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
3925                                                    const TargetRegisterClass *RC,
3926                                                    unsigned Reg, EVT VT,
3927                                                    const SDLoc &SL,
3928                                                    bool RawReg) const {
3929   MachineFunction &MF = DAG.getMachineFunction();
3930   MachineRegisterInfo &MRI = MF.getRegInfo();
3931   unsigned VReg;
3932 
3933   if (!MRI.isLiveIn(Reg)) {
3934     VReg = MRI.createVirtualRegister(RC);
3935     MRI.addLiveIn(Reg, VReg);
3936   } else {
3937     VReg = MRI.getLiveInVirtReg(Reg);
3938   }
3939 
3940   if (RawReg)
3941     return DAG.getRegister(VReg, VT);
3942 
3943   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
3944 }
3945 
3946 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
3947                                                   EVT VT,
3948                                                   const SDLoc &SL,
3949                                                   int64_t Offset) const {
3950   MachineFunction &MF = DAG.getMachineFunction();
3951   MachineFrameInfo &MFI = MF.getFrameInfo();
3952 
3953   int FI = MFI.CreateFixedObject(VT.getStoreSize(), Offset, true);
3954   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
3955   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
3956 
3957   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
3958                      MachineMemOperand::MODereferenceable |
3959                      MachineMemOperand::MOInvariant);
3960 }
3961 
3962 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
3963                                                    const SDLoc &SL,
3964                                                    SDValue Chain,
3965                                                    SDValue StackPtr,
3966                                                    SDValue ArgVal,
3967                                                    int64_t Offset) const {
3968   MachineFunction &MF = DAG.getMachineFunction();
3969   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
3970 
3971   SDValue Ptr = DAG.getObjectPtrOffset(SL, StackPtr, Offset);
3972   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
3973                                MachineMemOperand::MODereferenceable);
3974   return Store;
3975 }
3976 
3977 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
3978                                              const TargetRegisterClass *RC,
3979                                              EVT VT, const SDLoc &SL,
3980                                              const ArgDescriptor &Arg) const {
3981   assert(Arg && "Attempting to load missing argument");
3982 
3983   if (Arg.isRegister())
3984     return CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL);
3985   return loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
3986 }
3987 
3988 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
3989     const AMDGPUMachineFunction *MFI, const ImplicitParameter Param) const {
3990   unsigned Alignment = Subtarget->getAlignmentForImplicitArgPtr();
3991   uint64_t ArgOffset = alignTo(MFI->getABIArgOffset(), Alignment);
3992   switch (Param) {
3993   case GRID_DIM:
3994     return ArgOffset;
3995   case GRID_OFFSET:
3996     return ArgOffset + 4;
3997   }
3998   llvm_unreachable("unexpected implicit parameter type");
3999 }
4000 
4001 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4002 
4003 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4004   switch ((AMDGPUISD::NodeType)Opcode) {
4005   case AMDGPUISD::FIRST_NUMBER: break;
4006   // AMDIL DAG nodes
4007   NODE_NAME_CASE(UMUL);
4008   NODE_NAME_CASE(BRANCH_COND);
4009 
4010   // AMDGPU DAG nodes
4011   NODE_NAME_CASE(IF)
4012   NODE_NAME_CASE(ELSE)
4013   NODE_NAME_CASE(LOOP)
4014   NODE_NAME_CASE(CALL)
4015   NODE_NAME_CASE(TC_RETURN)
4016   NODE_NAME_CASE(TRAP)
4017   NODE_NAME_CASE(RET_FLAG)
4018   NODE_NAME_CASE(RETURN_TO_EPILOG)
4019   NODE_NAME_CASE(ENDPGM)
4020   NODE_NAME_CASE(DWORDADDR)
4021   NODE_NAME_CASE(FRACT)
4022   NODE_NAME_CASE(SETCC)
4023   NODE_NAME_CASE(SETREG)
4024   NODE_NAME_CASE(FMA_W_CHAIN)
4025   NODE_NAME_CASE(FMUL_W_CHAIN)
4026   NODE_NAME_CASE(CLAMP)
4027   NODE_NAME_CASE(COS_HW)
4028   NODE_NAME_CASE(SIN_HW)
4029   NODE_NAME_CASE(FMAX_LEGACY)
4030   NODE_NAME_CASE(FMIN_LEGACY)
4031   NODE_NAME_CASE(FMAX3)
4032   NODE_NAME_CASE(SMAX3)
4033   NODE_NAME_CASE(UMAX3)
4034   NODE_NAME_CASE(FMIN3)
4035   NODE_NAME_CASE(SMIN3)
4036   NODE_NAME_CASE(UMIN3)
4037   NODE_NAME_CASE(FMED3)
4038   NODE_NAME_CASE(SMED3)
4039   NODE_NAME_CASE(UMED3)
4040   NODE_NAME_CASE(URECIP)
4041   NODE_NAME_CASE(DIV_SCALE)
4042   NODE_NAME_CASE(DIV_FMAS)
4043   NODE_NAME_CASE(DIV_FIXUP)
4044   NODE_NAME_CASE(FMAD_FTZ)
4045   NODE_NAME_CASE(TRIG_PREOP)
4046   NODE_NAME_CASE(RCP)
4047   NODE_NAME_CASE(RSQ)
4048   NODE_NAME_CASE(RCP_LEGACY)
4049   NODE_NAME_CASE(RSQ_LEGACY)
4050   NODE_NAME_CASE(RCP_IFLAG)
4051   NODE_NAME_CASE(FMUL_LEGACY)
4052   NODE_NAME_CASE(RSQ_CLAMP)
4053   NODE_NAME_CASE(LDEXP)
4054   NODE_NAME_CASE(FP_CLASS)
4055   NODE_NAME_CASE(DOT4)
4056   NODE_NAME_CASE(CARRY)
4057   NODE_NAME_CASE(BORROW)
4058   NODE_NAME_CASE(BFE_U32)
4059   NODE_NAME_CASE(BFE_I32)
4060   NODE_NAME_CASE(BFI)
4061   NODE_NAME_CASE(BFM)
4062   NODE_NAME_CASE(FFBH_U32)
4063   NODE_NAME_CASE(FFBH_I32)
4064   NODE_NAME_CASE(FFBL_B32)
4065   NODE_NAME_CASE(MUL_U24)
4066   NODE_NAME_CASE(MUL_I24)
4067   NODE_NAME_CASE(MULHI_U24)
4068   NODE_NAME_CASE(MULHI_I24)
4069   NODE_NAME_CASE(MUL_LOHI_U24)
4070   NODE_NAME_CASE(MUL_LOHI_I24)
4071   NODE_NAME_CASE(MAD_U24)
4072   NODE_NAME_CASE(MAD_I24)
4073   NODE_NAME_CASE(MAD_I64_I32)
4074   NODE_NAME_CASE(MAD_U64_U32)
4075   NODE_NAME_CASE(PERM)
4076   NODE_NAME_CASE(TEXTURE_FETCH)
4077   NODE_NAME_CASE(EXPORT)
4078   NODE_NAME_CASE(EXPORT_DONE)
4079   NODE_NAME_CASE(R600_EXPORT)
4080   NODE_NAME_CASE(CONST_ADDRESS)
4081   NODE_NAME_CASE(REGISTER_LOAD)
4082   NODE_NAME_CASE(REGISTER_STORE)
4083   NODE_NAME_CASE(SAMPLE)
4084   NODE_NAME_CASE(SAMPLEB)
4085   NODE_NAME_CASE(SAMPLED)
4086   NODE_NAME_CASE(SAMPLEL)
4087   NODE_NAME_CASE(CVT_F32_UBYTE0)
4088   NODE_NAME_CASE(CVT_F32_UBYTE1)
4089   NODE_NAME_CASE(CVT_F32_UBYTE2)
4090   NODE_NAME_CASE(CVT_F32_UBYTE3)
4091   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4092   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4093   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4094   NODE_NAME_CASE(CVT_PK_I16_I32)
4095   NODE_NAME_CASE(CVT_PK_U16_U32)
4096   NODE_NAME_CASE(FP_TO_FP16)
4097   NODE_NAME_CASE(FP16_ZEXT)
4098   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4099   NODE_NAME_CASE(CONST_DATA_PTR)
4100   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4101   NODE_NAME_CASE(KILL)
4102   NODE_NAME_CASE(DUMMY_CHAIN)
4103   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4104   NODE_NAME_CASE(INIT_EXEC)
4105   NODE_NAME_CASE(INIT_EXEC_FROM_INPUT)
4106   NODE_NAME_CASE(SENDMSG)
4107   NODE_NAME_CASE(SENDMSGHALT)
4108   NODE_NAME_CASE(INTERP_MOV)
4109   NODE_NAME_CASE(INTERP_P1)
4110   NODE_NAME_CASE(INTERP_P2)
4111   NODE_NAME_CASE(STORE_MSKOR)
4112   NODE_NAME_CASE(LOAD_CONSTANT)
4113   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4114   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_X3)
4115   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4116   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4117   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4118   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4119   NODE_NAME_CASE(ATOMIC_INC)
4120   NODE_NAME_CASE(ATOMIC_DEC)
4121   NODE_NAME_CASE(ATOMIC_LOAD_FADD)
4122   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4123   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4124   NODE_NAME_CASE(BUFFER_LOAD)
4125   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4126   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4127   NODE_NAME_CASE(BUFFER_STORE)
4128   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4129   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4130   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4131   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4132   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4133   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4134   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4135   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4136   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4137   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4138   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4139   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4140   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4141 
4142   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4143   }
4144   return nullptr;
4145 }
4146 
4147 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4148                                               SelectionDAG &DAG, int Enabled,
4149                                               int &RefinementSteps,
4150                                               bool &UseOneConstNR,
4151                                               bool Reciprocal) const {
4152   EVT VT = Operand.getValueType();
4153 
4154   if (VT == MVT::f32) {
4155     RefinementSteps = 0;
4156     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4157   }
4158 
4159   // TODO: There is also f64 rsq instruction, but the documentation is less
4160   // clear on its precision.
4161 
4162   return SDValue();
4163 }
4164 
4165 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4166                                                SelectionDAG &DAG, int Enabled,
4167                                                int &RefinementSteps) const {
4168   EVT VT = Operand.getValueType();
4169 
4170   if (VT == MVT::f32) {
4171     // Reciprocal, < 1 ulp error.
4172     //
4173     // This reciprocal approximation converges to < 0.5 ulp error with one
4174     // newton rhapson performed with two fused multiple adds (FMAs).
4175 
4176     RefinementSteps = 0;
4177     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4178   }
4179 
4180   // TODO: There is also f64 rcp instruction, but the documentation is less
4181   // clear on its precision.
4182 
4183   return SDValue();
4184 }
4185 
4186 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4187     const SDValue Op, KnownBits &Known,
4188     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4189 
4190   Known.resetAll(); // Don't know anything.
4191 
4192   unsigned Opc = Op.getOpcode();
4193 
4194   switch (Opc) {
4195   default:
4196     break;
4197   case AMDGPUISD::CARRY:
4198   case AMDGPUISD::BORROW: {
4199     Known.Zero = APInt::getHighBitsSet(32, 31);
4200     break;
4201   }
4202 
4203   case AMDGPUISD::BFE_I32:
4204   case AMDGPUISD::BFE_U32: {
4205     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4206     if (!CWidth)
4207       return;
4208 
4209     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4210 
4211     if (Opc == AMDGPUISD::BFE_U32)
4212       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4213 
4214     break;
4215   }
4216   case AMDGPUISD::FP_TO_FP16:
4217   case AMDGPUISD::FP16_ZEXT: {
4218     unsigned BitWidth = Known.getBitWidth();
4219 
4220     // High bits are zero.
4221     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4222     break;
4223   }
4224   case AMDGPUISD::MUL_U24:
4225   case AMDGPUISD::MUL_I24: {
4226     KnownBits LHSKnown, RHSKnown;
4227     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4228     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4229 
4230     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4231                       RHSKnown.countMinTrailingZeros();
4232     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4233 
4234     unsigned LHSValBits = 32 - std::max(LHSKnown.countMinSignBits(), 8u);
4235     unsigned RHSValBits = 32 - std::max(RHSKnown.countMinSignBits(), 8u);
4236     unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4237     if (MaxValBits >= 32)
4238       break;
4239     bool Negative = false;
4240     if (Opc == AMDGPUISD::MUL_I24) {
4241       bool LHSNegative = !!(LHSKnown.One  & (1 << 23));
4242       bool LHSPositive = !!(LHSKnown.Zero & (1 << 23));
4243       bool RHSNegative = !!(RHSKnown.One  & (1 << 23));
4244       bool RHSPositive = !!(RHSKnown.Zero & (1 << 23));
4245       if ((!LHSNegative && !LHSPositive) || (!RHSNegative && !RHSPositive))
4246         break;
4247       Negative = (LHSNegative && RHSPositive) || (LHSPositive && RHSNegative);
4248     }
4249     if (Negative)
4250       Known.One.setHighBits(32 - MaxValBits);
4251     else
4252       Known.Zero.setHighBits(32 - MaxValBits);
4253     break;
4254   }
4255   case AMDGPUISD::PERM: {
4256     ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4257     if (!CMask)
4258       return;
4259 
4260     KnownBits LHSKnown, RHSKnown;
4261     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4262     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4263     unsigned Sel = CMask->getZExtValue();
4264 
4265     for (unsigned I = 0; I < 32; I += 8) {
4266       unsigned SelBits = Sel & 0xff;
4267       if (SelBits < 4) {
4268         SelBits *= 8;
4269         Known.One |= ((RHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4270         Known.Zero |= ((RHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4271       } else if (SelBits < 7) {
4272         SelBits = (SelBits & 3) * 8;
4273         Known.One |= ((LHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4274         Known.Zero |= ((LHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4275       } else if (SelBits == 0x0c) {
4276         Known.Zero |= 0xff << I;
4277       } else if (SelBits > 0x0c) {
4278         Known.One |= 0xff << I;
4279       }
4280       Sel >>= 8;
4281     }
4282     break;
4283   }
4284   case ISD::INTRINSIC_WO_CHAIN: {
4285     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4286     switch (IID) {
4287     case Intrinsic::amdgcn_mbcnt_lo:
4288     case Intrinsic::amdgcn_mbcnt_hi: {
4289       // These return at most the wavefront size - 1.
4290       unsigned Size = Op.getValueType().getSizeInBits();
4291       Known.Zero.setHighBits(Size - Subtarget->getWavefrontSizeLog2());
4292       break;
4293     }
4294     default:
4295       break;
4296     }
4297   }
4298   }
4299 }
4300 
4301 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4302     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4303     unsigned Depth) const {
4304   switch (Op.getOpcode()) {
4305   case AMDGPUISD::BFE_I32: {
4306     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4307     if (!Width)
4308       return 1;
4309 
4310     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4311     if (!isNullConstant(Op.getOperand(1)))
4312       return SignBits;
4313 
4314     // TODO: Could probably figure something out with non-0 offsets.
4315     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4316     return std::max(SignBits, Op0SignBits);
4317   }
4318 
4319   case AMDGPUISD::BFE_U32: {
4320     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4321     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4322   }
4323 
4324   case AMDGPUISD::CARRY:
4325   case AMDGPUISD::BORROW:
4326     return 31;
4327   case AMDGPUISD::FP_TO_FP16:
4328   case AMDGPUISD::FP16_ZEXT:
4329     return 16;
4330   default:
4331     return 1;
4332   }
4333 }
4334