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/Analysis.h"
34 #include "llvm/CodeGen/CallingConvLower.h"
35 #include "llvm/CodeGen/MachineFunction.h"
36 #include "llvm/CodeGen/MachineRegisterInfo.h"
37 #include "llvm/CodeGen/SelectionDAG.h"
38 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
39 #include "llvm/IR/DataLayout.h"
40 #include "llvm/IR/DiagnosticInfo.h"
41 #include "llvm/Support/KnownBits.h"
42 using namespace llvm;
43 
44 static bool allocateCCRegs(unsigned ValNo, MVT ValVT, MVT LocVT,
45                            CCValAssign::LocInfo LocInfo,
46                            ISD::ArgFlagsTy ArgFlags, CCState &State,
47                            const TargetRegisterClass *RC,
48                            unsigned NumRegs) {
49   ArrayRef<MCPhysReg> RegList = makeArrayRef(RC->begin(), NumRegs);
50   unsigned RegResult = State.AllocateReg(RegList);
51   if (RegResult == AMDGPU::NoRegister)
52     return false;
53 
54   State.addLoc(CCValAssign::getReg(ValNo, ValVT, RegResult, LocVT, LocInfo));
55   return true;
56 }
57 
58 static bool allocateSGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
59                               CCValAssign::LocInfo LocInfo,
60                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
61   switch (LocVT.SimpleTy) {
62   case MVT::i64:
63   case MVT::f64:
64   case MVT::v2i32:
65   case MVT::v2f32:
66   case MVT::v4i16:
67   case MVT::v4f16: {
68     // Up to SGPR0-SGPR39
69     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
70                           &AMDGPU::SGPR_64RegClass, 20);
71   }
72   default:
73     return false;
74   }
75 }
76 
77 // Allocate up to VGPR31.
78 //
79 // TODO: Since there are no VGPR alignent requirements would it be better to
80 // split into individual scalar registers?
81 static bool allocateVGPRTuple(unsigned ValNo, MVT ValVT, MVT LocVT,
82                               CCValAssign::LocInfo LocInfo,
83                               ISD::ArgFlagsTy ArgFlags, CCState &State) {
84   switch (LocVT.SimpleTy) {
85   case MVT::i64:
86   case MVT::f64:
87   case MVT::v2i32:
88   case MVT::v2f32:
89   case MVT::v4i16:
90   case MVT::v4f16: {
91     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
92                           &AMDGPU::VReg_64RegClass, 31);
93   }
94   case MVT::v4i32:
95   case MVT::v4f32:
96   case MVT::v2i64:
97   case MVT::v2f64: {
98     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
99                           &AMDGPU::VReg_128RegClass, 29);
100   }
101   case MVT::v8i32:
102   case MVT::v8f32: {
103     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
104                           &AMDGPU::VReg_256RegClass, 25);
105 
106   }
107   case MVT::v16i32:
108   case MVT::v16f32: {
109     return allocateCCRegs(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State,
110                           &AMDGPU::VReg_512RegClass, 17);
111 
112   }
113   default:
114     return false;
115   }
116 }
117 
118 #include "AMDGPUGenCallingConv.inc"
119 
120 // Find a larger type to do a load / store of a vector with.
121 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
122   unsigned StoreSize = VT.getStoreSizeInBits();
123   if (StoreSize <= 32)
124     return EVT::getIntegerVT(Ctx, StoreSize);
125 
126   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
127   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
128 }
129 
130 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
131   KnownBits Known;
132   EVT VT = Op.getValueType();
133   DAG.computeKnownBits(Op, Known);
134 
135   return VT.getSizeInBits() - Known.countMinLeadingZeros();
136 }
137 
138 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
139   EVT VT = Op.getValueType();
140 
141   // In order for this to be a signed 24-bit value, bit 23, must
142   // be a sign bit.
143   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
144 }
145 
146 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
147                                            const AMDGPUSubtarget &STI)
148     : TargetLowering(TM), Subtarget(&STI) {
149   // Lower floating point store/load to integer store/load to reduce the number
150   // of patterns in tablegen.
151   setOperationAction(ISD::LOAD, MVT::f32, Promote);
152   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
153 
154   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
155   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
156 
157   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
158   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
159 
160   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
161   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
162 
163   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
164   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
165 
166   setOperationAction(ISD::LOAD, MVT::i64, Promote);
167   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
168 
169   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
170   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
171 
172   setOperationAction(ISD::LOAD, MVT::f64, Promote);
173   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
174 
175   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
176   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
177 
178   // There are no 64-bit extloads. These should be done as a 32-bit extload and
179   // an extension to 64-bit.
180   for (MVT VT : MVT::integer_valuetypes()) {
181     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
182     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
183     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
184   }
185 
186   for (MVT VT : MVT::integer_valuetypes()) {
187     if (VT == MVT::i64)
188       continue;
189 
190     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
191     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
192     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
193     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
194 
195     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
196     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
197     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
198     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
199 
200     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
201     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
202     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
203     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
204   }
205 
206   for (MVT VT : MVT::integer_vector_valuetypes()) {
207     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
208     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
209     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
210     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
211     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
212     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
213     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
214     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
215     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
216     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
217     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
218     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
219   }
220 
221   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
222   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
223   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
224   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
225 
226   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
227   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
228   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
229   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
230 
231   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
232   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
233   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
234   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
235 
236   setOperationAction(ISD::STORE, MVT::f32, Promote);
237   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
238 
239   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
240   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
241 
242   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
243   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
244 
245   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
246   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
247 
248   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
249   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
250 
251   setOperationAction(ISD::STORE, MVT::i64, Promote);
252   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
253 
254   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
255   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
256 
257   setOperationAction(ISD::STORE, MVT::f64, Promote);
258   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
259 
260   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
261   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
262 
263   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
264   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
265   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
266   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
267 
268   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
269   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
270   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
271   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
272 
273   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
274   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
275   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
276   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
277 
278   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
279   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
280 
281   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
282   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
283 
284   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
285   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
286 
287   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
288   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
289 
290 
291   setOperationAction(ISD::Constant, MVT::i32, Legal);
292   setOperationAction(ISD::Constant, MVT::i64, Legal);
293   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
294   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
295 
296   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
297   setOperationAction(ISD::BRIND, MVT::Other, Expand);
298 
299   // This is totally unsupported, just custom lower to produce an error.
300   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
301 
302   // Library functions.  These default to Expand, but we have instructions
303   // for them.
304   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
305   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
306   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
307   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
308   setOperationAction(ISD::FABS,   MVT::f32, Legal);
309   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
310   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
311   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
312   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
313   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
314 
315   setOperationAction(ISD::FROUND, MVT::f32, Custom);
316   setOperationAction(ISD::FROUND, MVT::f64, Custom);
317 
318   setOperationAction(ISD::FLOG, MVT::f32, Custom);
319   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
320   setOperationAction(ISD::FEXP, MVT::f32, Custom);
321 
322 
323   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
324   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
325 
326   setOperationAction(ISD::FREM, MVT::f32, Custom);
327   setOperationAction(ISD::FREM, MVT::f64, Custom);
328 
329   // Expand to fneg + fadd.
330   setOperationAction(ISD::FSUB, MVT::f64, Expand);
331 
332   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
333   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
334   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
335   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
336   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
337   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
338   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
339   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
340   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
341   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
342 
343   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
344   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
345   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
346 
347   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
348   for (MVT VT : ScalarIntVTs) {
349     // These should use [SU]DIVREM, so set them to expand
350     setOperationAction(ISD::SDIV, VT, Expand);
351     setOperationAction(ISD::UDIV, VT, Expand);
352     setOperationAction(ISD::SREM, VT, Expand);
353     setOperationAction(ISD::UREM, VT, Expand);
354 
355     // GPU does not have divrem function for signed or unsigned.
356     setOperationAction(ISD::SDIVREM, VT, Custom);
357     setOperationAction(ISD::UDIVREM, VT, Custom);
358 
359     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
360     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
361     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
362 
363     setOperationAction(ISD::BSWAP, VT, Expand);
364     setOperationAction(ISD::CTTZ, VT, Expand);
365     setOperationAction(ISD::CTLZ, VT, Expand);
366 
367     // AMDGPU uses ADDC/SUBC/ADDE/SUBE
368     setOperationAction(ISD::ADDC, VT, Legal);
369     setOperationAction(ISD::SUBC, VT, Legal);
370     setOperationAction(ISD::ADDE, VT, Legal);
371     setOperationAction(ISD::SUBE, VT, Legal);
372   }
373 
374   // The hardware supports 32-bit ROTR, but not ROTL.
375   setOperationAction(ISD::ROTL, MVT::i32, Expand);
376   setOperationAction(ISD::ROTL, MVT::i64, Expand);
377   setOperationAction(ISD::ROTR, MVT::i64, Expand);
378 
379   setOperationAction(ISD::MUL, MVT::i64, Expand);
380   setOperationAction(ISD::MULHU, MVT::i64, Expand);
381   setOperationAction(ISD::MULHS, MVT::i64, Expand);
382   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
383   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
384   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
385   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
386   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
387 
388   setOperationAction(ISD::SMIN, MVT::i32, Legal);
389   setOperationAction(ISD::UMIN, MVT::i32, Legal);
390   setOperationAction(ISD::SMAX, MVT::i32, Legal);
391   setOperationAction(ISD::UMAX, MVT::i32, Legal);
392 
393   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
394   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
395   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
396   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
397 
398   static const MVT::SimpleValueType VectorIntTypes[] = {
399     MVT::v2i32, MVT::v4i32
400   };
401 
402   for (MVT VT : VectorIntTypes) {
403     // Expand the following operations for the current type by default.
404     setOperationAction(ISD::ADD,  VT, Expand);
405     setOperationAction(ISD::AND,  VT, Expand);
406     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
407     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
408     setOperationAction(ISD::MUL,  VT, Expand);
409     setOperationAction(ISD::MULHU, VT, Expand);
410     setOperationAction(ISD::MULHS, VT, Expand);
411     setOperationAction(ISD::OR,   VT, Expand);
412     setOperationAction(ISD::SHL,  VT, Expand);
413     setOperationAction(ISD::SRA,  VT, Expand);
414     setOperationAction(ISD::SRL,  VT, Expand);
415     setOperationAction(ISD::ROTL, VT, Expand);
416     setOperationAction(ISD::ROTR, VT, Expand);
417     setOperationAction(ISD::SUB,  VT, Expand);
418     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
419     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
420     setOperationAction(ISD::SDIV, VT, Expand);
421     setOperationAction(ISD::UDIV, VT, Expand);
422     setOperationAction(ISD::SREM, VT, Expand);
423     setOperationAction(ISD::UREM, VT, Expand);
424     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
425     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
426     setOperationAction(ISD::SDIVREM, VT, Custom);
427     setOperationAction(ISD::UDIVREM, VT, Expand);
428     setOperationAction(ISD::SELECT, VT, Expand);
429     setOperationAction(ISD::VSELECT, VT, Expand);
430     setOperationAction(ISD::SELECT_CC, VT, Expand);
431     setOperationAction(ISD::XOR,  VT, Expand);
432     setOperationAction(ISD::BSWAP, VT, Expand);
433     setOperationAction(ISD::CTPOP, VT, Expand);
434     setOperationAction(ISD::CTTZ, VT, Expand);
435     setOperationAction(ISD::CTLZ, VT, Expand);
436     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
437     setOperationAction(ISD::SETCC, VT, Expand);
438   }
439 
440   static const MVT::SimpleValueType FloatVectorTypes[] = {
441     MVT::v2f32, MVT::v4f32
442   };
443 
444   for (MVT VT : FloatVectorTypes) {
445     setOperationAction(ISD::FABS, VT, Expand);
446     setOperationAction(ISD::FMINNUM, VT, Expand);
447     setOperationAction(ISD::FMAXNUM, VT, Expand);
448     setOperationAction(ISD::FADD, VT, Expand);
449     setOperationAction(ISD::FCEIL, VT, Expand);
450     setOperationAction(ISD::FCOS, VT, Expand);
451     setOperationAction(ISD::FDIV, VT, Expand);
452     setOperationAction(ISD::FEXP2, VT, Expand);
453     setOperationAction(ISD::FEXP, VT, Expand);
454     setOperationAction(ISD::FLOG2, VT, Expand);
455     setOperationAction(ISD::FREM, VT, Expand);
456     setOperationAction(ISD::FLOG, VT, Expand);
457     setOperationAction(ISD::FLOG10, VT, Expand);
458     setOperationAction(ISD::FPOW, VT, Expand);
459     setOperationAction(ISD::FFLOOR, VT, Expand);
460     setOperationAction(ISD::FTRUNC, VT, Expand);
461     setOperationAction(ISD::FMUL, VT, Expand);
462     setOperationAction(ISD::FMA, VT, Expand);
463     setOperationAction(ISD::FRINT, VT, Expand);
464     setOperationAction(ISD::FNEARBYINT, VT, Expand);
465     setOperationAction(ISD::FSQRT, VT, Expand);
466     setOperationAction(ISD::FSIN, VT, Expand);
467     setOperationAction(ISD::FSUB, VT, Expand);
468     setOperationAction(ISD::FNEG, VT, Expand);
469     setOperationAction(ISD::VSELECT, VT, Expand);
470     setOperationAction(ISD::SELECT_CC, VT, Expand);
471     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
472     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
473     setOperationAction(ISD::SETCC, VT, Expand);
474     setOperationAction(ISD::FCANONICALIZE, VT, Expand);
475   }
476 
477   // This causes using an unrolled select operation rather than expansion with
478   // bit operations. This is in general better, but the alternative using BFI
479   // instructions may be better if the select sources are SGPRs.
480   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
481   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
482 
483   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
484   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
485 
486   // There are no libcalls of any kind.
487   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
488     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
489 
490   setBooleanContents(ZeroOrNegativeOneBooleanContent);
491   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
492 
493   setSchedulingPreference(Sched::RegPressure);
494   setJumpIsExpensive(true);
495 
496   // FIXME: This is only partially true. If we have to do vector compares, any
497   // SGPR pair can be a condition register. If we have a uniform condition, we
498   // are better off doing SALU operations, where there is only one SCC. For now,
499   // we don't have a way of knowing during instruction selection if a condition
500   // will be uniform and we always use vector compares. Assume we are using
501   // vector compares until that is fixed.
502   setHasMultipleConditionRegisters(true);
503 
504   PredictableSelectIsExpensive = false;
505 
506   // We want to find all load dependencies for long chains of stores to enable
507   // merging into very wide vectors. The problem is with vectors with > 4
508   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
509   // vectors are a legal type, even though we have to split the loads
510   // usually. When we can more precisely specify load legality per address
511   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
512   // smarter so that they can figure out what to do in 2 iterations without all
513   // N > 4 stores on the same chain.
514   GatherAllAliasesMaxDepth = 16;
515 
516   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
517   // about these during lowering.
518   MaxStoresPerMemcpy  = 0xffffffff;
519   MaxStoresPerMemmove = 0xffffffff;
520   MaxStoresPerMemset  = 0xffffffff;
521 
522   setTargetDAGCombine(ISD::BITCAST);
523   setTargetDAGCombine(ISD::SHL);
524   setTargetDAGCombine(ISD::SRA);
525   setTargetDAGCombine(ISD::SRL);
526   setTargetDAGCombine(ISD::TRUNCATE);
527   setTargetDAGCombine(ISD::MUL);
528   setTargetDAGCombine(ISD::MULHU);
529   setTargetDAGCombine(ISD::MULHS);
530   setTargetDAGCombine(ISD::SELECT);
531   setTargetDAGCombine(ISD::SELECT_CC);
532   setTargetDAGCombine(ISD::STORE);
533   setTargetDAGCombine(ISD::FADD);
534   setTargetDAGCombine(ISD::FSUB);
535   setTargetDAGCombine(ISD::FNEG);
536   setTargetDAGCombine(ISD::FABS);
537   setTargetDAGCombine(ISD::AssertZext);
538   setTargetDAGCombine(ISD::AssertSext);
539 }
540 
541 //===----------------------------------------------------------------------===//
542 // Target Information
543 //===----------------------------------------------------------------------===//
544 
545 LLVM_READNONE
546 static bool fnegFoldsIntoOp(unsigned Opc) {
547   switch (Opc) {
548   case ISD::FADD:
549   case ISD::FSUB:
550   case ISD::FMUL:
551   case ISD::FMA:
552   case ISD::FMAD:
553   case ISD::FMINNUM:
554   case ISD::FMAXNUM:
555   case ISD::FMINNUM_IEEE:
556   case ISD::FMAXNUM_IEEE:
557   case ISD::FSIN:
558   case ISD::FTRUNC:
559   case ISD::FRINT:
560   case ISD::FNEARBYINT:
561   case ISD::FCANONICALIZE:
562   case AMDGPUISD::RCP:
563   case AMDGPUISD::RCP_LEGACY:
564   case AMDGPUISD::RCP_IFLAG:
565   case AMDGPUISD::SIN_HW:
566   case AMDGPUISD::FMUL_LEGACY:
567   case AMDGPUISD::FMIN_LEGACY:
568   case AMDGPUISD::FMAX_LEGACY:
569   case AMDGPUISD::FMED3:
570     return true;
571   default:
572     return false;
573   }
574 }
575 
576 /// \p returns true if the operation will definitely need to use a 64-bit
577 /// encoding, and thus will use a VOP3 encoding regardless of the source
578 /// modifiers.
579 LLVM_READONLY
580 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
581   return N->getNumOperands() > 2 || VT == MVT::f64;
582 }
583 
584 // Most FP instructions support source modifiers, but this could be refined
585 // slightly.
586 LLVM_READONLY
587 static bool hasSourceMods(const SDNode *N) {
588   if (isa<MemSDNode>(N))
589     return false;
590 
591   switch (N->getOpcode()) {
592   case ISD::CopyToReg:
593   case ISD::SELECT:
594   case ISD::FDIV:
595   case ISD::FREM:
596   case ISD::INLINEASM:
597   case AMDGPUISD::INTERP_P1:
598   case AMDGPUISD::INTERP_P2:
599   case AMDGPUISD::DIV_SCALE:
600 
601   // TODO: Should really be looking at the users of the bitcast. These are
602   // problematic because bitcasts are used to legalize all stores to integer
603   // types.
604   case ISD::BITCAST:
605     return false;
606   default:
607     return true;
608   }
609 }
610 
611 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
612                                                  unsigned CostThreshold) {
613   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
614   // it is truly free to use a source modifier in all cases. If there are
615   // multiple users but for each one will necessitate using VOP3, there will be
616   // a code size increase. Try to avoid increasing code size unless we know it
617   // will save on the instruction count.
618   unsigned NumMayIncreaseSize = 0;
619   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
620 
621   // XXX - Should this limit number of uses to check?
622   for (const SDNode *U : N->uses()) {
623     if (!hasSourceMods(U))
624       return false;
625 
626     if (!opMustUseVOP3Encoding(U, VT)) {
627       if (++NumMayIncreaseSize > CostThreshold)
628         return false;
629     }
630   }
631 
632   return true;
633 }
634 
635 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
636   return MVT::i32;
637 }
638 
639 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
640   return true;
641 }
642 
643 // The backend supports 32 and 64 bit floating point immediates.
644 // FIXME: Why are we reporting vectors of FP immediates as legal?
645 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
646   EVT ScalarVT = VT.getScalarType();
647   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
648          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
649 }
650 
651 // We don't want to shrink f64 / f32 constants.
652 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
653   EVT ScalarVT = VT.getScalarType();
654   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
655 }
656 
657 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
658                                                  ISD::LoadExtType ExtTy,
659                                                  EVT NewVT) const {
660   // TODO: This may be worth removing. Check regression tests for diffs.
661   if (!TargetLoweringBase::shouldReduceLoadWidth(N, ExtTy, NewVT))
662     return false;
663 
664   unsigned NewSize = NewVT.getStoreSizeInBits();
665 
666   // If we are reducing to a 32-bit load, this is always better.
667   if (NewSize == 32)
668     return true;
669 
670   EVT OldVT = N->getValueType(0);
671   unsigned OldSize = OldVT.getStoreSizeInBits();
672 
673   MemSDNode *MN = cast<MemSDNode>(N);
674   unsigned AS = MN->getAddressSpace();
675   // Do not shrink an aligned scalar load to sub-dword.
676   // Scalar engine cannot do sub-dword loads.
677   if (OldSize >= 32 && NewSize < 32 && MN->getAlignment() >= 4 &&
678       (AS == AMDGPUAS::CONSTANT_ADDRESS ||
679        AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT ||
680        (isa<LoadSDNode>(N) &&
681         AS == AMDGPUAS::GLOBAL_ADDRESS && MN->isInvariant())) &&
682       AMDGPUInstrInfo::isUniformMMO(MN->getMemOperand()))
683     return false;
684 
685   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
686   // extloads, so doing one requires using a buffer_load. In cases where we
687   // still couldn't use a scalar load, using the wider load shouldn't really
688   // hurt anything.
689 
690   // If the old size already had to be an extload, there's no harm in continuing
691   // to reduce the width.
692   return (OldSize < 32);
693 }
694 
695 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy,
696                                                    EVT CastTy) const {
697 
698   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
699 
700   if (LoadTy.getScalarType() == MVT::i32)
701     return false;
702 
703   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
704   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
705 
706   return (LScalarSize < CastScalarSize) ||
707          (CastScalarSize >= 32);
708 }
709 
710 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
711 // profitable with the expansion for 64-bit since it's generally good to
712 // speculate things.
713 // FIXME: These should really have the size as a parameter.
714 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
715   return true;
716 }
717 
718 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
719   return true;
720 }
721 
722 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
723   switch (N->getOpcode()) {
724     default:
725     return false;
726     case ISD::EntryToken:
727     case ISD::TokenFactor:
728       return true;
729     case ISD::INTRINSIC_WO_CHAIN:
730     {
731       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
732       switch (IntrID) {
733         default:
734         return false;
735         case Intrinsic::amdgcn_readfirstlane:
736         case Intrinsic::amdgcn_readlane:
737           return true;
738       }
739     }
740     break;
741     case ISD::LOAD:
742     {
743       const LoadSDNode * L = dyn_cast<LoadSDNode>(N);
744       if (L->getMemOperand()->getAddrSpace()
745       == AMDGPUAS::CONSTANT_ADDRESS_32BIT)
746         return true;
747       return false;
748     }
749     break;
750   }
751 }
752 
753 //===---------------------------------------------------------------------===//
754 // Target Properties
755 //===---------------------------------------------------------------------===//
756 
757 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
758   assert(VT.isFloatingPoint());
759 
760   // Packed operations do not have a fabs modifier.
761   return VT == MVT::f32 || VT == MVT::f64 ||
762          (Subtarget->has16BitInsts() && VT == MVT::f16);
763 }
764 
765 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
766   assert(VT.isFloatingPoint());
767   return VT == MVT::f32 || VT == MVT::f64 ||
768          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
769          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
770 }
771 
772 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
773                                                          unsigned NumElem,
774                                                          unsigned AS) const {
775   return true;
776 }
777 
778 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
779   // There are few operations which truly have vector input operands. Any vector
780   // operation is going to involve operations on each component, and a
781   // build_vector will be a copy per element, so it always makes sense to use a
782   // build_vector input in place of the extracted element to avoid a copy into a
783   // super register.
784   //
785   // We should probably only do this if all users are extracts only, but this
786   // should be the common case.
787   return true;
788 }
789 
790 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
791   // Truncate is just accessing a subregister.
792 
793   unsigned SrcSize = Source.getSizeInBits();
794   unsigned DestSize = Dest.getSizeInBits();
795 
796   return DestSize < SrcSize && DestSize % 32 == 0 ;
797 }
798 
799 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
800   // Truncate is just accessing a subregister.
801 
802   unsigned SrcSize = Source->getScalarSizeInBits();
803   unsigned DestSize = Dest->getScalarSizeInBits();
804 
805   if (DestSize== 16 && Subtarget->has16BitInsts())
806     return SrcSize >= 32;
807 
808   return DestSize < SrcSize && DestSize % 32 == 0;
809 }
810 
811 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
812   unsigned SrcSize = Src->getScalarSizeInBits();
813   unsigned DestSize = Dest->getScalarSizeInBits();
814 
815   if (SrcSize == 16 && Subtarget->has16BitInsts())
816     return DestSize >= 32;
817 
818   return SrcSize == 32 && DestSize == 64;
819 }
820 
821 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
822   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
823   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
824   // this will enable reducing 64-bit operations the 32-bit, which is always
825   // good.
826 
827   if (Src == MVT::i16)
828     return Dest == MVT::i32 ||Dest == MVT::i64 ;
829 
830   return Src == MVT::i32 && Dest == MVT::i64;
831 }
832 
833 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
834   return isZExtFree(Val.getValueType(), VT2);
835 }
836 
837 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
838   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
839   // limited number of native 64-bit operations. Shrinking an operation to fit
840   // in a single 32-bit register should always be helpful. As currently used,
841   // this is much less general than the name suggests, and is only used in
842   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
843   // not profitable, and may actually be harmful.
844   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
845 }
846 
847 //===---------------------------------------------------------------------===//
848 // TargetLowering Callbacks
849 //===---------------------------------------------------------------------===//
850 
851 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
852                                                   bool IsVarArg) {
853   switch (CC) {
854   case CallingConv::AMDGPU_KERNEL:
855   case CallingConv::SPIR_KERNEL:
856     llvm_unreachable("kernels should not be handled here");
857   case CallingConv::AMDGPU_VS:
858   case CallingConv::AMDGPU_GS:
859   case CallingConv::AMDGPU_PS:
860   case CallingConv::AMDGPU_CS:
861   case CallingConv::AMDGPU_HS:
862   case CallingConv::AMDGPU_ES:
863   case CallingConv::AMDGPU_LS:
864     return CC_AMDGPU;
865   case CallingConv::C:
866   case CallingConv::Fast:
867   case CallingConv::Cold:
868     return CC_AMDGPU_Func;
869   default:
870     report_fatal_error("Unsupported calling convention.");
871   }
872 }
873 
874 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
875                                                     bool IsVarArg) {
876   switch (CC) {
877   case CallingConv::AMDGPU_KERNEL:
878   case CallingConv::SPIR_KERNEL:
879     llvm_unreachable("kernels should not be handled here");
880   case CallingConv::AMDGPU_VS:
881   case CallingConv::AMDGPU_GS:
882   case CallingConv::AMDGPU_PS:
883   case CallingConv::AMDGPU_CS:
884   case CallingConv::AMDGPU_HS:
885   case CallingConv::AMDGPU_ES:
886   case CallingConv::AMDGPU_LS:
887     return RetCC_SI_Shader;
888   case CallingConv::C:
889   case CallingConv::Fast:
890   case CallingConv::Cold:
891     return RetCC_AMDGPU_Func;
892   default:
893     report_fatal_error("Unsupported calling convention.");
894   }
895 }
896 
897 /// The SelectionDAGBuilder will automatically promote function arguments
898 /// with illegal types.  However, this does not work for the AMDGPU targets
899 /// since the function arguments are stored in memory as these illegal types.
900 /// In order to handle this properly we need to get the original types sizes
901 /// from the LLVM IR Function and fixup the ISD:InputArg values before
902 /// passing them to AnalyzeFormalArguments()
903 
904 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
905 /// input values across multiple registers.  Each item in the Ins array
906 /// represents a single value that will be stored in registers.  Ins[x].VT is
907 /// the value type of the value that will be stored in the register, so
908 /// whatever SDNode we lower the argument to needs to be this type.
909 ///
910 /// In order to correctly lower the arguments we need to know the size of each
911 /// argument.  Since Ins[x].VT gives us the size of the register that will
912 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
913 /// for the orignal function argument so that we can deduce the correct memory
914 /// type to use for Ins[x].  In most cases the correct memory type will be
915 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
916 /// we have a kernel argument of type v8i8, this argument will be split into
917 /// 8 parts and each part will be represented by its own item in the Ins array.
918 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
919 /// the argument before it was split.  From this, we deduce that the memory type
920 /// for each individual part is i8.  We pass the memory type as LocVT to the
921 /// calling convention analysis function and the register type (Ins[x].VT) as
922 /// the ValVT.
923 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(
924   CCState &State,
925   const SmallVectorImpl<ISD::InputArg> &Ins) const {
926   const MachineFunction &MF = State.getMachineFunction();
927   const Function &Fn = MF.getFunction();
928   LLVMContext &Ctx = Fn.getParent()->getContext();
929   const AMDGPUSubtarget &ST = AMDGPUSubtarget::get(MF);
930   const unsigned ExplicitOffset = ST.getExplicitKernelArgOffset(Fn);
931   CallingConv::ID CC = Fn.getCallingConv();
932 
933   unsigned MaxAlign = 1;
934   uint64_t ExplicitArgOffset = 0;
935   const DataLayout &DL = Fn.getParent()->getDataLayout();
936 
937   unsigned InIndex = 0;
938 
939   for (const Argument &Arg : Fn.args()) {
940     Type *BaseArgTy = Arg.getType();
941     unsigned Align = DL.getABITypeAlignment(BaseArgTy);
942     MaxAlign = std::max(Align, MaxAlign);
943     unsigned AllocSize = DL.getTypeAllocSize(BaseArgTy);
944 
945     uint64_t ArgOffset = alignTo(ExplicitArgOffset, Align) + ExplicitOffset;
946     ExplicitArgOffset = alignTo(ExplicitArgOffset, Align) + AllocSize;
947 
948     // We're basically throwing away everything passed into us and starting over
949     // to get accurate in-memory offsets. The "PartOffset" is completely useless
950     // to us as computed in Ins.
951     //
952     // We also need to figure out what type legalization is trying to do to get
953     // the correct memory offsets.
954 
955     SmallVector<EVT, 16> ValueVTs;
956     SmallVector<uint64_t, 16> Offsets;
957     ComputeValueVTs(*this, DL, BaseArgTy, ValueVTs, &Offsets, ArgOffset);
958 
959     for (unsigned Value = 0, NumValues = ValueVTs.size();
960          Value != NumValues; ++Value) {
961       uint64_t BasePartOffset = Offsets[Value];
962 
963       EVT ArgVT = ValueVTs[Value];
964       EVT MemVT = ArgVT;
965       MVT RegisterVT = getRegisterTypeForCallingConv(Ctx, CC, ArgVT);
966       unsigned NumRegs = getNumRegistersForCallingConv(Ctx, CC, ArgVT);
967 
968       if (NumRegs == 1) {
969         // This argument is not split, so the IR type is the memory type.
970         if (ArgVT.isExtended()) {
971           // We have an extended type, like i24, so we should just use the
972           // register type.
973           MemVT = RegisterVT;
974         } else {
975           MemVT = ArgVT;
976         }
977       } else if (ArgVT.isVector() && RegisterVT.isVector() &&
978                  ArgVT.getScalarType() == RegisterVT.getScalarType()) {
979         assert(ArgVT.getVectorNumElements() > RegisterVT.getVectorNumElements());
980         // We have a vector value which has been split into a vector with
981         // the same scalar type, but fewer elements.  This should handle
982         // all the floating-point vector types.
983         MemVT = RegisterVT;
984       } else if (ArgVT.isVector() &&
985                  ArgVT.getVectorNumElements() == NumRegs) {
986         // This arg has been split so that each element is stored in a separate
987         // register.
988         MemVT = ArgVT.getScalarType();
989       } else if (ArgVT.isExtended()) {
990         // We have an extended type, like i65.
991         MemVT = RegisterVT;
992       } else {
993         unsigned MemoryBits = ArgVT.getStoreSizeInBits() / NumRegs;
994         assert(ArgVT.getStoreSizeInBits() % NumRegs == 0);
995         if (RegisterVT.isInteger()) {
996           MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
997         } else if (RegisterVT.isVector()) {
998           assert(!RegisterVT.getScalarType().isFloatingPoint());
999           unsigned NumElements = RegisterVT.getVectorNumElements();
1000           assert(MemoryBits % NumElements == 0);
1001           // This vector type has been split into another vector type with
1002           // a different elements size.
1003           EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
1004                                            MemoryBits / NumElements);
1005           MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
1006         } else {
1007           llvm_unreachable("cannot deduce memory type.");
1008         }
1009       }
1010 
1011       // Convert one element vectors to scalar.
1012       if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
1013         MemVT = MemVT.getScalarType();
1014 
1015       if (MemVT.isExtended()) {
1016         // This should really only happen if we have vec3 arguments
1017         assert(MemVT.isVector() && MemVT.getVectorNumElements() == 3);
1018         MemVT = MemVT.getPow2VectorType(State.getContext());
1019       }
1020 
1021       unsigned PartOffset = 0;
1022       for (unsigned i = 0; i != NumRegs; ++i) {
1023         State.addLoc(CCValAssign::getCustomMem(InIndex++, RegisterVT,
1024                                                BasePartOffset + PartOffset,
1025                                                MemVT.getSimpleVT(),
1026                                                CCValAssign::Full));
1027         PartOffset += MemVT.getStoreSize();
1028       }
1029     }
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::FEXP:
1164     return lowerFEXP(Op, DAG);
1165   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1166   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1167   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1168   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1169   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1170   case ISD::CTTZ:
1171   case ISD::CTTZ_ZERO_UNDEF:
1172   case ISD::CTLZ:
1173   case ISD::CTLZ_ZERO_UNDEF:
1174     return LowerCTLZ_CTTZ(Op, DAG);
1175   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1176   }
1177   return Op;
1178 }
1179 
1180 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1181                                               SmallVectorImpl<SDValue> &Results,
1182                                               SelectionDAG &DAG) const {
1183   switch (N->getOpcode()) {
1184   case ISD::SIGN_EXTEND_INREG:
1185     // Different parts of legalization seem to interpret which type of
1186     // sign_extend_inreg is the one to check for custom lowering. The extended
1187     // from type is what really matters, but some places check for custom
1188     // lowering of the result type. This results in trying to use
1189     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1190     // nothing here and let the illegal result integer be handled normally.
1191     return;
1192   default:
1193     return;
1194   }
1195 }
1196 
1197 static bool hasDefinedInitializer(const GlobalValue *GV) {
1198   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1199   if (!GVar || !GVar->hasInitializer())
1200     return false;
1201 
1202   return !isa<UndefValue>(GVar->getInitializer());
1203 }
1204 
1205 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1206                                                  SDValue Op,
1207                                                  SelectionDAG &DAG) const {
1208 
1209   const DataLayout &DL = DAG.getDataLayout();
1210   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1211   const GlobalValue *GV = G->getGlobal();
1212 
1213   if (G->getAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
1214       G->getAddressSpace() == AMDGPUAS::REGION_ADDRESS) {
1215     if (!MFI->isEntryFunction()) {
1216       const Function &Fn = DAG.getMachineFunction().getFunction();
1217       DiagnosticInfoUnsupported BadLDSDecl(
1218         Fn, "local memory global used by non-kernel function", SDLoc(Op).getDebugLoc());
1219       DAG.getContext()->diagnose(BadLDSDecl);
1220     }
1221 
1222     // XXX: What does the value of G->getOffset() mean?
1223     assert(G->getOffset() == 0 &&
1224          "Do not know what to do with an non-zero offset");
1225 
1226     // TODO: We could emit code to handle the initialization somewhere.
1227     if (!hasDefinedInitializer(GV)) {
1228       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1229       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1230     }
1231   }
1232 
1233   const Function &Fn = DAG.getMachineFunction().getFunction();
1234   DiagnosticInfoUnsupported BadInit(
1235       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1236   DAG.getContext()->diagnose(BadInit);
1237   return SDValue();
1238 }
1239 
1240 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1241                                                   SelectionDAG &DAG) const {
1242   SmallVector<SDValue, 8> Args;
1243 
1244   EVT VT = Op.getValueType();
1245   if (VT == MVT::v4i16 || VT == MVT::v4f16) {
1246     SDLoc SL(Op);
1247     SDValue Lo = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(0));
1248     SDValue Hi = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(1));
1249 
1250     SDValue BV = DAG.getBuildVector(MVT::v2i32, SL, { Lo, Hi });
1251     return DAG.getNode(ISD::BITCAST, SL, VT, BV);
1252   }
1253 
1254   for (const SDUse &U : Op->ops())
1255     DAG.ExtractVectorElements(U.get(), Args);
1256 
1257   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1258 }
1259 
1260 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1261                                                      SelectionDAG &DAG) const {
1262 
1263   SmallVector<SDValue, 8> Args;
1264   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1265   EVT VT = Op.getValueType();
1266   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1267                             VT.getVectorNumElements());
1268 
1269   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1270 }
1271 
1272 /// Generate Min/Max node
1273 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1274                                                    SDValue LHS, SDValue RHS,
1275                                                    SDValue True, SDValue False,
1276                                                    SDValue CC,
1277                                                    DAGCombinerInfo &DCI) const {
1278   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1279     return SDValue();
1280 
1281   SelectionDAG &DAG = DCI.DAG;
1282   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1283   switch (CCOpcode) {
1284   case ISD::SETOEQ:
1285   case ISD::SETONE:
1286   case ISD::SETUNE:
1287   case ISD::SETNE:
1288   case ISD::SETUEQ:
1289   case ISD::SETEQ:
1290   case ISD::SETFALSE:
1291   case ISD::SETFALSE2:
1292   case ISD::SETTRUE:
1293   case ISD::SETTRUE2:
1294   case ISD::SETUO:
1295   case ISD::SETO:
1296     break;
1297   case ISD::SETULE:
1298   case ISD::SETULT: {
1299     if (LHS == True)
1300       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1301     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1302   }
1303   case ISD::SETOLE:
1304   case ISD::SETOLT:
1305   case ISD::SETLE:
1306   case ISD::SETLT: {
1307     // Ordered. Assume ordered for undefined.
1308 
1309     // Only do this after legalization to avoid interfering with other combines
1310     // which might occur.
1311     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1312         !DCI.isCalledByLegalizer())
1313       return SDValue();
1314 
1315     // We need to permute the operands to get the correct NaN behavior. The
1316     // selected operand is the second one based on the failing compare with NaN,
1317     // so permute it based on the compare type the hardware uses.
1318     if (LHS == True)
1319       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1320     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1321   }
1322   case ISD::SETUGE:
1323   case ISD::SETUGT: {
1324     if (LHS == True)
1325       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1326     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1327   }
1328   case ISD::SETGT:
1329   case ISD::SETGE:
1330   case ISD::SETOGE:
1331   case ISD::SETOGT: {
1332     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1333         !DCI.isCalledByLegalizer())
1334       return SDValue();
1335 
1336     if (LHS == True)
1337       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1338     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1339   }
1340   case ISD::SETCC_INVALID:
1341     llvm_unreachable("Invalid setcc condcode!");
1342   }
1343   return SDValue();
1344 }
1345 
1346 std::pair<SDValue, SDValue>
1347 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1348   SDLoc SL(Op);
1349 
1350   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1351 
1352   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1353   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1354 
1355   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1356   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1357 
1358   return std::make_pair(Lo, Hi);
1359 }
1360 
1361 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1362   SDLoc SL(Op);
1363 
1364   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1365   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1366   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1367 }
1368 
1369 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1370   SDLoc SL(Op);
1371 
1372   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1373   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1374   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1375 }
1376 
1377 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1378                                               SelectionDAG &DAG) const {
1379   LoadSDNode *Load = cast<LoadSDNode>(Op);
1380   EVT VT = Op.getValueType();
1381 
1382 
1383   // If this is a 2 element vector, we really want to scalarize and not create
1384   // weird 1 element vectors.
1385   if (VT.getVectorNumElements() == 2)
1386     return scalarizeVectorLoad(Load, DAG);
1387 
1388   SDValue BasePtr = Load->getBasePtr();
1389   EVT MemVT = Load->getMemoryVT();
1390   SDLoc SL(Op);
1391 
1392   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1393 
1394   EVT LoVT, HiVT;
1395   EVT LoMemVT, HiMemVT;
1396   SDValue Lo, Hi;
1397 
1398   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1399   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1400   std::tie(Lo, Hi) = DAG.SplitVector(Op, SL, LoVT, HiVT);
1401 
1402   unsigned Size = LoMemVT.getStoreSize();
1403   unsigned BaseAlign = Load->getAlignment();
1404   unsigned HiAlign = MinAlign(BaseAlign, Size);
1405 
1406   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1407                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1408                                   BaseAlign, Load->getMemOperand()->getFlags());
1409   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1410   SDValue HiLoad =
1411       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1412                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1413                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1414 
1415   SDValue Ops[] = {
1416     DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad),
1417     DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1418                 LoLoad.getValue(1), HiLoad.getValue(1))
1419   };
1420 
1421   return DAG.getMergeValues(Ops, SL);
1422 }
1423 
1424 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1425                                                SelectionDAG &DAG) const {
1426   StoreSDNode *Store = cast<StoreSDNode>(Op);
1427   SDValue Val = Store->getValue();
1428   EVT VT = Val.getValueType();
1429 
1430   // If this is a 2 element vector, we really want to scalarize and not create
1431   // weird 1 element vectors.
1432   if (VT.getVectorNumElements() == 2)
1433     return scalarizeVectorStore(Store, DAG);
1434 
1435   EVT MemVT = Store->getMemoryVT();
1436   SDValue Chain = Store->getChain();
1437   SDValue BasePtr = Store->getBasePtr();
1438   SDLoc SL(Op);
1439 
1440   EVT LoVT, HiVT;
1441   EVT LoMemVT, HiMemVT;
1442   SDValue Lo, Hi;
1443 
1444   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1445   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1446   std::tie(Lo, Hi) = DAG.SplitVector(Val, SL, LoVT, HiVT);
1447 
1448   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1449 
1450   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1451   unsigned BaseAlign = Store->getAlignment();
1452   unsigned Size = LoMemVT.getStoreSize();
1453   unsigned HiAlign = MinAlign(BaseAlign, Size);
1454 
1455   SDValue LoStore =
1456       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1457                         Store->getMemOperand()->getFlags());
1458   SDValue HiStore =
1459       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1460                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1461 
1462   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1463 }
1464 
1465 // This is a shortcut for integer division because we have fast i32<->f32
1466 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1467 // float is enough to accurately represent up to a 24-bit signed integer.
1468 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1469                                             bool Sign) const {
1470   SDLoc DL(Op);
1471   EVT VT = Op.getValueType();
1472   SDValue LHS = Op.getOperand(0);
1473   SDValue RHS = Op.getOperand(1);
1474   MVT IntVT = MVT::i32;
1475   MVT FltVT = MVT::f32;
1476 
1477   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1478   if (LHSSignBits < 9)
1479     return SDValue();
1480 
1481   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1482   if (RHSSignBits < 9)
1483     return SDValue();
1484 
1485   unsigned BitSize = VT.getSizeInBits();
1486   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1487   unsigned DivBits = BitSize - SignBits;
1488   if (Sign)
1489     ++DivBits;
1490 
1491   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1492   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1493 
1494   SDValue jq = DAG.getConstant(1, DL, IntVT);
1495 
1496   if (Sign) {
1497     // char|short jq = ia ^ ib;
1498     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1499 
1500     // jq = jq >> (bitsize - 2)
1501     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1502                      DAG.getConstant(BitSize - 2, DL, VT));
1503 
1504     // jq = jq | 0x1
1505     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1506   }
1507 
1508   // int ia = (int)LHS;
1509   SDValue ia = LHS;
1510 
1511   // int ib, (int)RHS;
1512   SDValue ib = RHS;
1513 
1514   // float fa = (float)ia;
1515   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1516 
1517   // float fb = (float)ib;
1518   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1519 
1520   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1521                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1522 
1523   // fq = trunc(fq);
1524   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1525 
1526   // float fqneg = -fq;
1527   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1528 
1529   // float fr = mad(fqneg, fb, fa);
1530   unsigned OpCode = Subtarget->hasFP32Denormals() ?
1531                     (unsigned)AMDGPUISD::FMAD_FTZ :
1532                     (unsigned)ISD::FMAD;
1533   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1534 
1535   // int iq = (int)fq;
1536   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1537 
1538   // fr = fabs(fr);
1539   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1540 
1541   // fb = fabs(fb);
1542   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1543 
1544   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1545 
1546   // int cv = fr >= fb;
1547   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1548 
1549   // jq = (cv ? jq : 0);
1550   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1551 
1552   // dst = iq + jq;
1553   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1554 
1555   // Rem needs compensation, it's easier to recompute it
1556   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1557   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1558 
1559   // Truncate to number of bits this divide really is.
1560   if (Sign) {
1561     SDValue InRegSize
1562       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1563     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1564     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1565   } else {
1566     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1567     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1568     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1569   }
1570 
1571   return DAG.getMergeValues({ Div, Rem }, DL);
1572 }
1573 
1574 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1575                                       SelectionDAG &DAG,
1576                                       SmallVectorImpl<SDValue> &Results) const {
1577   SDLoc DL(Op);
1578   EVT VT = Op.getValueType();
1579 
1580   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1581 
1582   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1583 
1584   SDValue One = DAG.getConstant(1, DL, HalfVT);
1585   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1586 
1587   //HiLo split
1588   SDValue LHS = Op.getOperand(0);
1589   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1590   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1591 
1592   SDValue RHS = Op.getOperand(1);
1593   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1594   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1595 
1596   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1597       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1598 
1599     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1600                               LHS_Lo, RHS_Lo);
1601 
1602     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1603     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1604 
1605     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1606     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1607     return;
1608   }
1609 
1610   if (isTypeLegal(MVT::i64)) {
1611     // Compute denominator reciprocal.
1612     unsigned FMAD = Subtarget->hasFP32Denormals() ?
1613                     (unsigned)AMDGPUISD::FMAD_FTZ :
1614                     (unsigned)ISD::FMAD;
1615 
1616     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1617     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1618     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1619       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1620       Cvt_Lo);
1621     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1622     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1623       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1624     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1625       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1626     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1627     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1628       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1629       Mul1);
1630     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1631     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1632     SDValue Rcp64 = DAG.getBitcast(VT,
1633                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1634 
1635     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1636     SDValue One64  = DAG.getConstant(1, DL, VT);
1637     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1638     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1639 
1640     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1641     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1642     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1643     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1644                                     Zero);
1645     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1646                                     One);
1647 
1648     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1649                                   Mulhi1_Lo, Zero1);
1650     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1651                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1652     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1653     SDValue Add1 = DAG.getBitcast(VT,
1654                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1655 
1656     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1657     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1658     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1659                                     Zero);
1660     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1661                                     One);
1662 
1663     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1664                                   Mulhi2_Lo, Zero1);
1665     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1666                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1667     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1668                                   Zero, Add2_Lo.getValue(1));
1669     SDValue Add2 = DAG.getBitcast(VT,
1670                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1671     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1672 
1673     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1674 
1675     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1676     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1677     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1678                                   Mul3_Lo, Zero1);
1679     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1680                                   Mul3_Hi, Sub1_Lo.getValue(1));
1681     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1682     SDValue Sub1 = DAG.getBitcast(VT,
1683                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1684 
1685     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1686     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1687                                  ISD::SETUGE);
1688     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1689                                  ISD::SETUGE);
1690     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1691 
1692     // TODO: Here and below portions of the code can be enclosed into if/endif.
1693     // Currently control flow is unconditional and we have 4 selects after
1694     // potential endif to substitute PHIs.
1695 
1696     // if C3 != 0 ...
1697     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1698                                   RHS_Lo, Zero1);
1699     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1700                                   RHS_Hi, Sub1_Lo.getValue(1));
1701     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1702                                   Zero, Sub2_Lo.getValue(1));
1703     SDValue Sub2 = DAG.getBitcast(VT,
1704                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1705 
1706     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1707 
1708     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1709                                  ISD::SETUGE);
1710     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1711                                  ISD::SETUGE);
1712     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1713 
1714     // if (C6 != 0)
1715     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1716 
1717     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1718                                   RHS_Lo, Zero1);
1719     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1720                                   RHS_Hi, Sub2_Lo.getValue(1));
1721     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1722                                   Zero, Sub3_Lo.getValue(1));
1723     SDValue Sub3 = DAG.getBitcast(VT,
1724                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1725 
1726     // endif C6
1727     // endif C3
1728 
1729     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1730     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1731 
1732     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1733     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1734 
1735     Results.push_back(Div);
1736     Results.push_back(Rem);
1737 
1738     return;
1739   }
1740 
1741   // r600 expandion.
1742   // Get Speculative values
1743   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1744   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1745 
1746   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1747   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1748   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1749 
1750   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1751   SDValue DIV_Lo = Zero;
1752 
1753   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1754 
1755   for (unsigned i = 0; i < halfBitWidth; ++i) {
1756     const unsigned bitPos = halfBitWidth - i - 1;
1757     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1758     // Get value of high bit
1759     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1760     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1761     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1762 
1763     // Shift
1764     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1765     // Add LHS high bit
1766     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1767 
1768     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1769     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1770 
1771     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1772 
1773     // Update REM
1774     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1775     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1776   }
1777 
1778   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1779   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1780   Results.push_back(DIV);
1781   Results.push_back(REM);
1782 }
1783 
1784 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1785                                            SelectionDAG &DAG) const {
1786   SDLoc DL(Op);
1787   EVT VT = Op.getValueType();
1788 
1789   if (VT == MVT::i64) {
1790     SmallVector<SDValue, 2> Results;
1791     LowerUDIVREM64(Op, DAG, Results);
1792     return DAG.getMergeValues(Results, DL);
1793   }
1794 
1795   if (VT == MVT::i32) {
1796     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1797       return Res;
1798   }
1799 
1800   SDValue Num = Op.getOperand(0);
1801   SDValue Den = Op.getOperand(1);
1802 
1803   // RCP =  URECIP(Den) = 2^32 / Den + e
1804   // e is rounding error.
1805   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1806 
1807   // RCP_LO = mul(RCP, Den) */
1808   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1809 
1810   // RCP_HI = mulhu (RCP, Den) */
1811   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1812 
1813   // NEG_RCP_LO = -RCP_LO
1814   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1815                                                      RCP_LO);
1816 
1817   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1818   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1819                                            NEG_RCP_LO, RCP_LO,
1820                                            ISD::SETEQ);
1821   // Calculate the rounding error from the URECIP instruction
1822   // E = mulhu(ABS_RCP_LO, RCP)
1823   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1824 
1825   // RCP_A_E = RCP + E
1826   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1827 
1828   // RCP_S_E = RCP - E
1829   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1830 
1831   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1832   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1833                                      RCP_A_E, RCP_S_E,
1834                                      ISD::SETEQ);
1835   // Quotient = mulhu(Tmp0, Num)
1836   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1837 
1838   // Num_S_Remainder = Quotient * Den
1839   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1840 
1841   // Remainder = Num - Num_S_Remainder
1842   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1843 
1844   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1845   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1846                                                  DAG.getConstant(-1, DL, VT),
1847                                                  DAG.getConstant(0, DL, VT),
1848                                                  ISD::SETUGE);
1849   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1850   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1851                                                   Num_S_Remainder,
1852                                                   DAG.getConstant(-1, DL, VT),
1853                                                   DAG.getConstant(0, DL, VT),
1854                                                   ISD::SETUGE);
1855   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1856   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1857                                                Remainder_GE_Zero);
1858 
1859   // Calculate Division result:
1860 
1861   // Quotient_A_One = Quotient + 1
1862   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1863                                        DAG.getConstant(1, DL, VT));
1864 
1865   // Quotient_S_One = Quotient - 1
1866   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1867                                        DAG.getConstant(1, DL, VT));
1868 
1869   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1870   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1871                                      Quotient, Quotient_A_One, ISD::SETEQ);
1872 
1873   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1874   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1875                             Quotient_S_One, Div, ISD::SETEQ);
1876 
1877   // Calculate Rem result:
1878 
1879   // Remainder_S_Den = Remainder - Den
1880   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1881 
1882   // Remainder_A_Den = Remainder + Den
1883   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1884 
1885   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1886   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1887                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1888 
1889   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1890   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1891                             Remainder_A_Den, Rem, ISD::SETEQ);
1892   SDValue Ops[2] = {
1893     Div,
1894     Rem
1895   };
1896   return DAG.getMergeValues(Ops, DL);
1897 }
1898 
1899 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1900                                            SelectionDAG &DAG) const {
1901   SDLoc DL(Op);
1902   EVT VT = Op.getValueType();
1903 
1904   SDValue LHS = Op.getOperand(0);
1905   SDValue RHS = Op.getOperand(1);
1906 
1907   SDValue Zero = DAG.getConstant(0, DL, VT);
1908   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1909 
1910   if (VT == MVT::i32) {
1911     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1912       return Res;
1913   }
1914 
1915   if (VT == MVT::i64 &&
1916       DAG.ComputeNumSignBits(LHS) > 32 &&
1917       DAG.ComputeNumSignBits(RHS) > 32) {
1918     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1919 
1920     //HiLo split
1921     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1922     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1923     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1924                                  LHS_Lo, RHS_Lo);
1925     SDValue Res[2] = {
1926       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1927       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1928     };
1929     return DAG.getMergeValues(Res, DL);
1930   }
1931 
1932   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1933   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1934   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1935   SDValue RSign = LHSign; // Remainder sign is the same as LHS
1936 
1937   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
1938   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
1939 
1940   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
1941   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
1942 
1943   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
1944   SDValue Rem = Div.getValue(1);
1945 
1946   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
1947   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
1948 
1949   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
1950   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
1951 
1952   SDValue Res[2] = {
1953     Div,
1954     Rem
1955   };
1956   return DAG.getMergeValues(Res, DL);
1957 }
1958 
1959 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
1960 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
1961   SDLoc SL(Op);
1962   EVT VT = Op.getValueType();
1963   SDValue X = Op.getOperand(0);
1964   SDValue Y = Op.getOperand(1);
1965 
1966   // TODO: Should this propagate fast-math-flags?
1967 
1968   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
1969   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
1970   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
1971 
1972   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
1973 }
1974 
1975 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
1976   SDLoc SL(Op);
1977   SDValue Src = Op.getOperand(0);
1978 
1979   // result = trunc(src)
1980   // if (src > 0.0 && src != result)
1981   //   result += 1.0
1982 
1983   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
1984 
1985   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
1986   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
1987 
1988   EVT SetCCVT =
1989       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
1990 
1991   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
1992   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
1993   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
1994 
1995   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
1996   // TODO: Should this propagate fast-math-flags?
1997   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
1998 }
1999 
2000 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
2001                                   SelectionDAG &DAG) {
2002   const unsigned FractBits = 52;
2003   const unsigned ExpBits = 11;
2004 
2005   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2006                                 Hi,
2007                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2008                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2009   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2010                             DAG.getConstant(1023, SL, MVT::i32));
2011 
2012   return Exp;
2013 }
2014 
2015 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2016   SDLoc SL(Op);
2017   SDValue Src = Op.getOperand(0);
2018 
2019   assert(Op.getValueType() == MVT::f64);
2020 
2021   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2022   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2023 
2024   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2025 
2026   // Extract the upper half, since this is where we will find the sign and
2027   // exponent.
2028   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2029 
2030   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2031 
2032   const unsigned FractBits = 52;
2033 
2034   // Extract the sign bit.
2035   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2036   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2037 
2038   // Extend back to 64-bits.
2039   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2040   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2041 
2042   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2043   const SDValue FractMask
2044     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2045 
2046   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2047   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2048   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2049 
2050   EVT SetCCVT =
2051       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2052 
2053   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2054 
2055   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2056   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2057 
2058   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2059   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2060 
2061   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2062 }
2063 
2064 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2065   SDLoc SL(Op);
2066   SDValue Src = Op.getOperand(0);
2067 
2068   assert(Op.getValueType() == MVT::f64);
2069 
2070   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2071   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2072   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2073 
2074   // TODO: Should this propagate fast-math-flags?
2075 
2076   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2077   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2078 
2079   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2080 
2081   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2082   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2083 
2084   EVT SetCCVT =
2085       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2086   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2087 
2088   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2089 }
2090 
2091 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2092   // FNEARBYINT and FRINT are the same, except in their handling of FP
2093   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2094   // rint, so just treat them as equivalent.
2095   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2096 }
2097 
2098 // XXX - May require not supporting f32 denormals?
2099 
2100 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2101 // compare and vselect end up producing worse code than scalarizing the whole
2102 // operation.
2103 SDValue AMDGPUTargetLowering::LowerFROUND32_16(SDValue Op, SelectionDAG &DAG) const {
2104   SDLoc SL(Op);
2105   SDValue X = Op.getOperand(0);
2106   EVT VT = Op.getValueType();
2107 
2108   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2109 
2110   // TODO: Should this propagate fast-math-flags?
2111 
2112   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2113 
2114   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2115 
2116   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2117   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2118   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2119 
2120   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2121 
2122   EVT SetCCVT =
2123       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2124 
2125   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2126 
2127   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2128 
2129   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2130 }
2131 
2132 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2133   SDLoc SL(Op);
2134   SDValue X = Op.getOperand(0);
2135 
2136   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2137 
2138   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2139   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2140   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2141   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2142   EVT SetCCVT =
2143       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2144 
2145   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2146 
2147   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2148 
2149   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2150 
2151   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2152                                        MVT::i64);
2153 
2154   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2155   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2156                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2157                                           MVT::i64),
2158                           Exp);
2159 
2160   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2161   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2162                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2163                               ISD::SETNE);
2164 
2165   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2166                              D, DAG.getConstant(0, SL, MVT::i64));
2167   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2168 
2169   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2170   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2171 
2172   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2173   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2174   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2175 
2176   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2177                             ExpEqNegOne,
2178                             DAG.getConstantFP(1.0, SL, MVT::f64),
2179                             DAG.getConstantFP(0.0, SL, MVT::f64));
2180 
2181   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2182 
2183   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2184   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2185 
2186   return K;
2187 }
2188 
2189 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2190   EVT VT = Op.getValueType();
2191 
2192   if (VT == MVT::f32 || VT == MVT::f16)
2193     return LowerFROUND32_16(Op, DAG);
2194 
2195   if (VT == MVT::f64)
2196     return LowerFROUND64(Op, DAG);
2197 
2198   llvm_unreachable("unhandled type");
2199 }
2200 
2201 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2202   SDLoc SL(Op);
2203   SDValue Src = Op.getOperand(0);
2204 
2205   // result = trunc(src);
2206   // if (src < 0.0 && src != result)
2207   //   result += -1.0.
2208 
2209   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2210 
2211   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2212   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2213 
2214   EVT SetCCVT =
2215       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2216 
2217   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2218   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2219   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2220 
2221   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2222   // TODO: Should this propagate fast-math-flags?
2223   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2224 }
2225 
2226 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2227                                         double Log2BaseInverted) const {
2228   EVT VT = Op.getValueType();
2229 
2230   SDLoc SL(Op);
2231   SDValue Operand = Op.getOperand(0);
2232   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2233   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2234 
2235   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2236 }
2237 
2238 // Return M_LOG2E of appropriate type
2239 static SDValue getLog2EVal(SelectionDAG &DAG, const SDLoc &SL, EVT VT) {
2240   switch (VT.getScalarType().getSimpleVT().SimpleTy) {
2241   case MVT::f32:
2242     return DAG.getConstantFP(1.44269504088896340735992468100189214f, SL, VT);
2243   case MVT::f16:
2244     return DAG.getConstantFP(
2245       APFloat(APFloat::IEEEhalf(), "1.44269504088896340735992468100189214"),
2246       SL, VT);
2247   case MVT::f64:
2248     return DAG.getConstantFP(
2249       APFloat(APFloat::IEEEdouble(), "0x1.71547652b82fep+0"), SL, VT);
2250   default:
2251     llvm_unreachable("unsupported fp type");
2252   }
2253 }
2254 
2255 // exp2(M_LOG2E_F * f);
2256 SDValue AMDGPUTargetLowering::lowerFEXP(SDValue Op, SelectionDAG &DAG) const {
2257   EVT VT = Op.getValueType();
2258   SDLoc SL(Op);
2259   SDValue Src = Op.getOperand(0);
2260 
2261   const SDValue K = getLog2EVal(DAG, SL, VT);
2262   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Src, K, Op->getFlags());
2263   return DAG.getNode(ISD::FEXP2, SL, VT, Mul, Op->getFlags());
2264 }
2265 
2266 static bool isCtlzOpc(unsigned Opc) {
2267   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2268 }
2269 
2270 static bool isCttzOpc(unsigned Opc) {
2271   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2272 }
2273 
2274 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2275   SDLoc SL(Op);
2276   SDValue Src = Op.getOperand(0);
2277   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2278                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2279 
2280   unsigned ISDOpc, NewOpc;
2281   if (isCtlzOpc(Op.getOpcode())) {
2282     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2283     NewOpc = AMDGPUISD::FFBH_U32;
2284   } else if (isCttzOpc(Op.getOpcode())) {
2285     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2286     NewOpc = AMDGPUISD::FFBL_B32;
2287   } else
2288     llvm_unreachable("Unexpected OPCode!!!");
2289 
2290 
2291   if (ZeroUndef && Src.getValueType() == MVT::i32)
2292     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2293 
2294   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2295 
2296   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2297   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2298 
2299   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2300   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2301 
2302   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2303                                    *DAG.getContext(), MVT::i32);
2304 
2305   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2306   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2307 
2308   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2309   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2310 
2311   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2312   SDValue Add, NewOpr;
2313   if (isCtlzOpc(Op.getOpcode())) {
2314     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2315     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2316     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2317   } else {
2318     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2319     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2320     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2321   }
2322 
2323   if (!ZeroUndef) {
2324     // Test if the full 64-bit input is zero.
2325 
2326     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2327     // which we probably don't want.
2328     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2329     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2330     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2331 
2332     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2333     // with the same cycles, otherwise it is slower.
2334     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2335     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2336 
2337     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2338 
2339     // The instruction returns -1 for 0 input, but the defined intrinsic
2340     // behavior is to return the number of bits.
2341     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2342                          SrcIsZero, Bits32, NewOpr);
2343   }
2344 
2345   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2346 }
2347 
2348 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2349                                                bool Signed) const {
2350   // Unsigned
2351   // cul2f(ulong u)
2352   //{
2353   //  uint lz = clz(u);
2354   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2355   //  u = (u << lz) & 0x7fffffffffffffffUL;
2356   //  ulong t = u & 0xffffffffffUL;
2357   //  uint v = (e << 23) | (uint)(u >> 40);
2358   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2359   //  return as_float(v + r);
2360   //}
2361   // Signed
2362   // cl2f(long l)
2363   //{
2364   //  long s = l >> 63;
2365   //  float r = cul2f((l + s) ^ s);
2366   //  return s ? -r : r;
2367   //}
2368 
2369   SDLoc SL(Op);
2370   SDValue Src = Op.getOperand(0);
2371   SDValue L = Src;
2372 
2373   SDValue S;
2374   if (Signed) {
2375     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2376     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2377 
2378     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2379     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2380   }
2381 
2382   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2383                                    *DAG.getContext(), MVT::f32);
2384 
2385 
2386   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2387   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2388   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2389   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2390 
2391   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2392   SDValue E = DAG.getSelect(SL, MVT::i32,
2393     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2394     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2395     ZeroI32);
2396 
2397   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2398     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2399     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2400 
2401   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2402                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2403 
2404   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2405                              U, DAG.getConstant(40, SL, MVT::i64));
2406 
2407   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2408     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2409     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2410 
2411   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2412   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2413   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2414 
2415   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2416 
2417   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2418 
2419   SDValue R = DAG.getSelect(SL, MVT::i32,
2420     RCmp,
2421     One,
2422     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2423   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2424   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2425 
2426   if (!Signed)
2427     return R;
2428 
2429   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2430   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2431 }
2432 
2433 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2434                                                bool Signed) const {
2435   SDLoc SL(Op);
2436   SDValue Src = Op.getOperand(0);
2437 
2438   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2439 
2440   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2441                            DAG.getConstant(0, SL, MVT::i32));
2442   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2443                            DAG.getConstant(1, SL, MVT::i32));
2444 
2445   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2446                               SL, MVT::f64, Hi);
2447 
2448   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2449 
2450   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2451                               DAG.getConstant(32, SL, MVT::i32));
2452   // TODO: Should this propagate fast-math-flags?
2453   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2454 }
2455 
2456 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2457                                                SelectionDAG &DAG) const {
2458   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2459          "operation should be legal");
2460 
2461   // TODO: Factor out code common with LowerSINT_TO_FP.
2462 
2463   EVT DestVT = Op.getValueType();
2464   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2465     SDLoc DL(Op);
2466     SDValue Src = Op.getOperand(0);
2467 
2468     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2469     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2470     SDValue FPRound =
2471         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2472 
2473     return FPRound;
2474   }
2475 
2476   if (DestVT == MVT::f32)
2477     return LowerINT_TO_FP32(Op, DAG, false);
2478 
2479   assert(DestVT == MVT::f64);
2480   return LowerINT_TO_FP64(Op, DAG, false);
2481 }
2482 
2483 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2484                                               SelectionDAG &DAG) const {
2485   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2486          "operation should be legal");
2487 
2488   // TODO: Factor out code common with LowerUINT_TO_FP.
2489 
2490   EVT DestVT = Op.getValueType();
2491   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2492     SDLoc DL(Op);
2493     SDValue Src = Op.getOperand(0);
2494 
2495     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2496     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2497     SDValue FPRound =
2498         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2499 
2500     return FPRound;
2501   }
2502 
2503   if (DestVT == MVT::f32)
2504     return LowerINT_TO_FP32(Op, DAG, true);
2505 
2506   assert(DestVT == MVT::f64);
2507   return LowerINT_TO_FP64(Op, DAG, true);
2508 }
2509 
2510 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2511                                                bool Signed) const {
2512   SDLoc SL(Op);
2513 
2514   SDValue Src = Op.getOperand(0);
2515 
2516   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2517 
2518   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2519                                  MVT::f64);
2520   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2521                                  MVT::f64);
2522   // TODO: Should this propagate fast-math-flags?
2523   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2524 
2525   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2526 
2527 
2528   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2529 
2530   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2531                            MVT::i32, FloorMul);
2532   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2533 
2534   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2535 
2536   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2537 }
2538 
2539 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2540   SDLoc DL(Op);
2541   SDValue N0 = Op.getOperand(0);
2542 
2543   // Convert to target node to get known bits
2544   if (N0.getValueType() == MVT::f32)
2545     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2546 
2547   if (getTargetMachine().Options.UnsafeFPMath) {
2548     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2549     return SDValue();
2550   }
2551 
2552   assert(N0.getSimpleValueType() == MVT::f64);
2553 
2554   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2555   const unsigned ExpMask = 0x7ff;
2556   const unsigned ExpBiasf64 = 1023;
2557   const unsigned ExpBiasf16 = 15;
2558   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2559   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2560   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2561   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2562                            DAG.getConstant(32, DL, MVT::i64));
2563   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2564   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2565   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2566                           DAG.getConstant(20, DL, MVT::i64));
2567   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2568                   DAG.getConstant(ExpMask, DL, MVT::i32));
2569   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2570   // add the f16 bias (15) to get the biased exponent for the f16 format.
2571   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2572                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2573 
2574   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2575                           DAG.getConstant(8, DL, MVT::i32));
2576   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2577                   DAG.getConstant(0xffe, DL, MVT::i32));
2578 
2579   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2580                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2581   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2582 
2583   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2584   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2585 
2586   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2587   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2588       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2589                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2590 
2591   // N = M | (E << 12);
2592   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2593       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2594                   DAG.getConstant(12, DL, MVT::i32)));
2595 
2596   // B = clamp(1-E, 0, 13);
2597   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2598                                   One, E);
2599   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2600   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2601                   DAG.getConstant(13, DL, MVT::i32));
2602 
2603   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2604                                    DAG.getConstant(0x1000, DL, MVT::i32));
2605 
2606   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2607   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2608   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2609   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2610 
2611   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2612   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2613                               DAG.getConstant(0x7, DL, MVT::i32));
2614   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2615                   DAG.getConstant(2, DL, MVT::i32));
2616   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2617                                One, Zero, ISD::SETEQ);
2618   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2619                                One, Zero, ISD::SETGT);
2620   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2621   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2622 
2623   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2624                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2625   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2626                       I, V, ISD::SETEQ);
2627 
2628   // Extract the sign bit.
2629   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2630                             DAG.getConstant(16, DL, MVT::i32));
2631   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2632                      DAG.getConstant(0x8000, DL, MVT::i32));
2633 
2634   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2635   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2636 }
2637 
2638 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2639                                               SelectionDAG &DAG) const {
2640   SDValue Src = Op.getOperand(0);
2641 
2642   // TODO: Factor out code common with LowerFP_TO_UINT.
2643 
2644   EVT SrcVT = Src.getValueType();
2645   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2646     SDLoc DL(Op);
2647 
2648     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2649     SDValue FpToInt32 =
2650         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2651 
2652     return FpToInt32;
2653   }
2654 
2655   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2656     return LowerFP64_TO_INT(Op, DAG, true);
2657 
2658   return SDValue();
2659 }
2660 
2661 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2662                                               SelectionDAG &DAG) const {
2663   SDValue Src = Op.getOperand(0);
2664 
2665   // TODO: Factor out code common with LowerFP_TO_SINT.
2666 
2667   EVT SrcVT = Src.getValueType();
2668   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2669     SDLoc DL(Op);
2670 
2671     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2672     SDValue FpToInt32 =
2673         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2674 
2675     return FpToInt32;
2676   }
2677 
2678   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2679     return LowerFP64_TO_INT(Op, DAG, false);
2680 
2681   return SDValue();
2682 }
2683 
2684 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2685                                                      SelectionDAG &DAG) const {
2686   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2687   MVT VT = Op.getSimpleValueType();
2688   MVT ScalarVT = VT.getScalarType();
2689 
2690   assert(VT.isVector());
2691 
2692   SDValue Src = Op.getOperand(0);
2693   SDLoc DL(Op);
2694 
2695   // TODO: Don't scalarize on Evergreen?
2696   unsigned NElts = VT.getVectorNumElements();
2697   SmallVector<SDValue, 8> Args;
2698   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2699 
2700   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2701   for (unsigned I = 0; I < NElts; ++I)
2702     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2703 
2704   return DAG.getBuildVector(VT, DL, Args);
2705 }
2706 
2707 //===----------------------------------------------------------------------===//
2708 // Custom DAG optimizations
2709 //===----------------------------------------------------------------------===//
2710 
2711 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2712   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2713 }
2714 
2715 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2716   EVT VT = Op.getValueType();
2717   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2718                                      // as unsigned 24-bit values.
2719     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2720 }
2721 
2722 static bool simplifyI24(SDNode *Node24, unsigned OpIdx,
2723                         TargetLowering::DAGCombinerInfo &DCI) {
2724 
2725   SelectionDAG &DAG = DCI.DAG;
2726   SDValue Op = Node24->getOperand(OpIdx);
2727   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2728   EVT VT = Op.getValueType();
2729 
2730   APInt Demanded = APInt::getLowBitsSet(VT.getSizeInBits(), 24);
2731   APInt KnownZero, KnownOne;
2732   TargetLowering::TargetLoweringOpt TLO(DAG, true, true);
2733   if (TLI.SimplifyDemandedBits(Node24, OpIdx, Demanded, DCI, TLO))
2734     return true;
2735 
2736   return false;
2737 }
2738 
2739 template <typename IntTy>
2740 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2741                                uint32_t Width, const SDLoc &DL) {
2742   if (Width + Offset < 32) {
2743     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2744     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2745     return DAG.getConstant(Result, DL, MVT::i32);
2746   }
2747 
2748   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2749 }
2750 
2751 static bool hasVolatileUser(SDNode *Val) {
2752   for (SDNode *U : Val->uses()) {
2753     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2754       if (M->isVolatile())
2755         return true;
2756     }
2757   }
2758 
2759   return false;
2760 }
2761 
2762 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2763   // i32 vectors are the canonical memory type.
2764   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2765     return false;
2766 
2767   if (!VT.isByteSized())
2768     return false;
2769 
2770   unsigned Size = VT.getStoreSize();
2771 
2772   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2773     return false;
2774 
2775   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2776     return false;
2777 
2778   return true;
2779 }
2780 
2781 // Replace load of an illegal type with a store of a bitcast to a friendlier
2782 // type.
2783 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2784                                                  DAGCombinerInfo &DCI) const {
2785   if (!DCI.isBeforeLegalize())
2786     return SDValue();
2787 
2788   LoadSDNode *LN = cast<LoadSDNode>(N);
2789   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2790     return SDValue();
2791 
2792   SDLoc SL(N);
2793   SelectionDAG &DAG = DCI.DAG;
2794   EVT VT = LN->getMemoryVT();
2795 
2796   unsigned Size = VT.getStoreSize();
2797   unsigned Align = LN->getAlignment();
2798   if (Align < Size && isTypeLegal(VT)) {
2799     bool IsFast;
2800     unsigned AS = LN->getAddressSpace();
2801 
2802     // Expand unaligned loads earlier than legalization. Due to visitation order
2803     // problems during legalization, the emitted instructions to pack and unpack
2804     // the bytes again are not eliminated in the case of an unaligned copy.
2805     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2806       if (VT.isVector())
2807         return scalarizeVectorLoad(LN, DAG);
2808 
2809       SDValue Ops[2];
2810       std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2811       return DAG.getMergeValues(Ops, SDLoc(N));
2812     }
2813 
2814     if (!IsFast)
2815       return SDValue();
2816   }
2817 
2818   if (!shouldCombineMemoryType(VT))
2819     return SDValue();
2820 
2821   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2822 
2823   SDValue NewLoad
2824     = DAG.getLoad(NewVT, SL, LN->getChain(),
2825                   LN->getBasePtr(), LN->getMemOperand());
2826 
2827   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2828   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2829   return SDValue(N, 0);
2830 }
2831 
2832 // Replace store of an illegal type with a store of a bitcast to a friendlier
2833 // type.
2834 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2835                                                   DAGCombinerInfo &DCI) const {
2836   if (!DCI.isBeforeLegalize())
2837     return SDValue();
2838 
2839   StoreSDNode *SN = cast<StoreSDNode>(N);
2840   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2841     return SDValue();
2842 
2843   EVT VT = SN->getMemoryVT();
2844   unsigned Size = VT.getStoreSize();
2845 
2846   SDLoc SL(N);
2847   SelectionDAG &DAG = DCI.DAG;
2848   unsigned Align = SN->getAlignment();
2849   if (Align < Size && isTypeLegal(VT)) {
2850     bool IsFast;
2851     unsigned AS = SN->getAddressSpace();
2852 
2853     // Expand unaligned stores earlier than legalization. Due to visitation
2854     // order problems during legalization, the emitted instructions to pack and
2855     // unpack the bytes again are not eliminated in the case of an unaligned
2856     // copy.
2857     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2858       if (VT.isVector())
2859         return scalarizeVectorStore(SN, DAG);
2860 
2861       return expandUnalignedStore(SN, DAG);
2862     }
2863 
2864     if (!IsFast)
2865       return SDValue();
2866   }
2867 
2868   if (!shouldCombineMemoryType(VT))
2869     return SDValue();
2870 
2871   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2872   SDValue Val = SN->getValue();
2873 
2874   //DCI.AddToWorklist(Val.getNode());
2875 
2876   bool OtherUses = !Val.hasOneUse();
2877   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2878   if (OtherUses) {
2879     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2880     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2881   }
2882 
2883   return DAG.getStore(SN->getChain(), SL, CastVal,
2884                       SN->getBasePtr(), SN->getMemOperand());
2885 }
2886 
2887 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2888 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2889 // issues.
2890 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2891                                                         DAGCombinerInfo &DCI) const {
2892   SelectionDAG &DAG = DCI.DAG;
2893   SDValue N0 = N->getOperand(0);
2894 
2895   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2896   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2897   if (N0.getOpcode() == ISD::TRUNCATE) {
2898     SDValue N1 = N->getOperand(1);
2899     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2900     SDLoc SL(N);
2901 
2902     SDValue Src = N0.getOperand(0);
2903     EVT SrcVT = Src.getValueType();
2904     if (SrcVT.bitsGE(ExtVT)) {
2905       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2906       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2907     }
2908   }
2909 
2910   return SDValue();
2911 }
2912 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
2913 /// binary operation \p Opc to it with the corresponding constant operands.
2914 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
2915   DAGCombinerInfo &DCI, const SDLoc &SL,
2916   unsigned Opc, SDValue LHS,
2917   uint32_t ValLo, uint32_t ValHi) const {
2918   SelectionDAG &DAG = DCI.DAG;
2919   SDValue Lo, Hi;
2920   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
2921 
2922   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
2923   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
2924 
2925   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
2926   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
2927 
2928   // Re-visit the ands. It's possible we eliminated one of them and it could
2929   // simplify the vector.
2930   DCI.AddToWorklist(Lo.getNode());
2931   DCI.AddToWorklist(Hi.getNode());
2932 
2933   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
2934   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2935 }
2936 
2937 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
2938                                                 DAGCombinerInfo &DCI) const {
2939   EVT VT = N->getValueType(0);
2940 
2941   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2942   if (!RHS)
2943     return SDValue();
2944 
2945   SDValue LHS = N->getOperand(0);
2946   unsigned RHSVal = RHS->getZExtValue();
2947   if (!RHSVal)
2948     return LHS;
2949 
2950   SDLoc SL(N);
2951   SelectionDAG &DAG = DCI.DAG;
2952 
2953   switch (LHS->getOpcode()) {
2954   default:
2955     break;
2956   case ISD::ZERO_EXTEND:
2957   case ISD::SIGN_EXTEND:
2958   case ISD::ANY_EXTEND: {
2959     SDValue X = LHS->getOperand(0);
2960 
2961     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
2962         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
2963       // Prefer build_vector as the canonical form if packed types are legal.
2964       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
2965       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
2966        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
2967       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
2968     }
2969 
2970     // shl (ext x) => zext (shl x), if shift does not overflow int
2971     if (VT != MVT::i64)
2972       break;
2973     KnownBits Known;
2974     DAG.computeKnownBits(X, Known);
2975     unsigned LZ = Known.countMinLeadingZeros();
2976     if (LZ < RHSVal)
2977       break;
2978     EVT XVT = X.getValueType();
2979     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
2980     return DAG.getZExtOrTrunc(Shl, SL, VT);
2981   }
2982   }
2983 
2984   if (VT != MVT::i64)
2985     return SDValue();
2986 
2987   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
2988 
2989   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
2990   // common case, splitting this into a move and a 32-bit shift is faster and
2991   // the same code size.
2992   if (RHSVal < 32)
2993     return SDValue();
2994 
2995   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
2996 
2997   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
2998   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
2999 
3000   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3001 
3002   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
3003   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3004 }
3005 
3006 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
3007                                                 DAGCombinerInfo &DCI) const {
3008   if (N->getValueType(0) != MVT::i64)
3009     return SDValue();
3010 
3011   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3012   if (!RHS)
3013     return SDValue();
3014 
3015   SelectionDAG &DAG = DCI.DAG;
3016   SDLoc SL(N);
3017   unsigned RHSVal = RHS->getZExtValue();
3018 
3019   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3020   if (RHSVal == 32) {
3021     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3022     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3023                                    DAG.getConstant(31, SL, MVT::i32));
3024 
3025     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3026     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3027   }
3028 
3029   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3030   if (RHSVal == 63) {
3031     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3032     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3033                                    DAG.getConstant(31, SL, MVT::i32));
3034     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3035     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3036   }
3037 
3038   return SDValue();
3039 }
3040 
3041 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3042                                                 DAGCombinerInfo &DCI) const {
3043   if (N->getValueType(0) != MVT::i64)
3044     return SDValue();
3045 
3046   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3047   if (!RHS)
3048     return SDValue();
3049 
3050   unsigned ShiftAmt = RHS->getZExtValue();
3051   if (ShiftAmt < 32)
3052     return SDValue();
3053 
3054   // srl i64:x, C for C >= 32
3055   // =>
3056   //   build_pair (srl hi_32(x), C - 32), 0
3057 
3058   SelectionDAG &DAG = DCI.DAG;
3059   SDLoc SL(N);
3060 
3061   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3062   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3063 
3064   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, N->getOperand(0));
3065   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32,
3066                            VecOp, One);
3067 
3068   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3069   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3070 
3071   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3072 
3073   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3074 }
3075 
3076 SDValue AMDGPUTargetLowering::performTruncateCombine(
3077   SDNode *N, DAGCombinerInfo &DCI) const {
3078   SDLoc SL(N);
3079   SelectionDAG &DAG = DCI.DAG;
3080   EVT VT = N->getValueType(0);
3081   SDValue Src = N->getOperand(0);
3082 
3083   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3084   if (Src.getOpcode() == ISD::BITCAST) {
3085     SDValue Vec = Src.getOperand(0);
3086     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3087       SDValue Elt0 = Vec.getOperand(0);
3088       EVT EltVT = Elt0.getValueType();
3089       if (VT.getSizeInBits() <= EltVT.getSizeInBits()) {
3090         if (EltVT.isFloatingPoint()) {
3091           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3092                              EltVT.changeTypeToInteger(), Elt0);
3093         }
3094 
3095         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3096       }
3097     }
3098   }
3099 
3100   // Equivalent of above for accessing the high element of a vector as an
3101   // integer operation.
3102   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3103   if (Src.getOpcode() == ISD::SRL && !VT.isVector()) {
3104     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3105       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3106         SDValue BV = stripBitcast(Src.getOperand(0));
3107         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3108             BV.getValueType().getVectorNumElements() == 2) {
3109           SDValue SrcElt = BV.getOperand(1);
3110           EVT SrcEltVT = SrcElt.getValueType();
3111           if (SrcEltVT.isFloatingPoint()) {
3112             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3113                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3114           }
3115 
3116           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3117         }
3118       }
3119     }
3120   }
3121 
3122   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3123   //
3124   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3125   //     i16 (trunc (srl (i32 (trunc x), K)))
3126   if (VT.getScalarSizeInBits() < 32) {
3127     EVT SrcVT = Src.getValueType();
3128     if (SrcVT.getScalarSizeInBits() > 32 &&
3129         (Src.getOpcode() == ISD::SRL ||
3130          Src.getOpcode() == ISD::SRA ||
3131          Src.getOpcode() == ISD::SHL)) {
3132       SDValue Amt = Src.getOperand(1);
3133       KnownBits Known;
3134       DAG.computeKnownBits(Amt, Known);
3135       unsigned Size = VT.getScalarSizeInBits();
3136       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3137           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3138         EVT MidVT = VT.isVector() ?
3139           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3140                            VT.getVectorNumElements()) : MVT::i32;
3141 
3142         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3143         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3144                                     Src.getOperand(0));
3145         DCI.AddToWorklist(Trunc.getNode());
3146 
3147         if (Amt.getValueType() != NewShiftVT) {
3148           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3149           DCI.AddToWorklist(Amt.getNode());
3150         }
3151 
3152         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3153                                           Trunc, Amt);
3154         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3155       }
3156     }
3157   }
3158 
3159   return SDValue();
3160 }
3161 
3162 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3163 // instructions. If we only match on the legalized i64 mul expansion,
3164 // SimplifyDemandedBits will be unable to remove them because there will be
3165 // multiple uses due to the separate mul + mulh[su].
3166 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3167                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3168   if (Size <= 32) {
3169     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3170     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3171   }
3172 
3173   // Because we want to eliminate extension instructions before the
3174   // operation, we need to create a single user here (i.e. not the separate
3175   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3176 
3177   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3178 
3179   SDValue Mul = DAG.getNode(MulOpc, SL,
3180                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3181 
3182   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3183                      Mul.getValue(0), Mul.getValue(1));
3184 }
3185 
3186 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3187                                                 DAGCombinerInfo &DCI) const {
3188   EVT VT = N->getValueType(0);
3189 
3190   unsigned Size = VT.getSizeInBits();
3191   if (VT.isVector() || Size > 64)
3192     return SDValue();
3193 
3194   // There are i16 integer mul/mad.
3195   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3196     return SDValue();
3197 
3198   SelectionDAG &DAG = DCI.DAG;
3199   SDLoc DL(N);
3200 
3201   SDValue N0 = N->getOperand(0);
3202   SDValue N1 = N->getOperand(1);
3203 
3204   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3205   // in the source into any_extends if the result of the mul is truncated. Since
3206   // we can assume the high bits are whatever we want, use the underlying value
3207   // to avoid the unknown high bits from interfering.
3208   if (N0.getOpcode() == ISD::ANY_EXTEND)
3209     N0 = N0.getOperand(0);
3210 
3211   if (N1.getOpcode() == ISD::ANY_EXTEND)
3212     N1 = N1.getOperand(0);
3213 
3214   SDValue Mul;
3215 
3216   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3217     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3218     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3219     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3220   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3221     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3222     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3223     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3224   } else {
3225     return SDValue();
3226   }
3227 
3228   // We need to use sext even for MUL_U24, because MUL_U24 is used
3229   // for signed multiply of 8 and 16-bit types.
3230   return DAG.getSExtOrTrunc(Mul, DL, VT);
3231 }
3232 
3233 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3234                                                   DAGCombinerInfo &DCI) const {
3235   EVT VT = N->getValueType(0);
3236 
3237   if (!Subtarget->hasMulI24() || VT.isVector())
3238     return SDValue();
3239 
3240   SelectionDAG &DAG = DCI.DAG;
3241   SDLoc DL(N);
3242 
3243   SDValue N0 = N->getOperand(0);
3244   SDValue N1 = N->getOperand(1);
3245 
3246   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3247     return SDValue();
3248 
3249   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3250   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3251 
3252   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3253   DCI.AddToWorklist(Mulhi.getNode());
3254   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3255 }
3256 
3257 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3258                                                   DAGCombinerInfo &DCI) const {
3259   EVT VT = N->getValueType(0);
3260 
3261   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3262     return SDValue();
3263 
3264   SelectionDAG &DAG = DCI.DAG;
3265   SDLoc DL(N);
3266 
3267   SDValue N0 = N->getOperand(0);
3268   SDValue N1 = N->getOperand(1);
3269 
3270   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3271     return SDValue();
3272 
3273   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3274   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3275 
3276   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3277   DCI.AddToWorklist(Mulhi.getNode());
3278   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3279 }
3280 
3281 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3282   SDNode *N, DAGCombinerInfo &DCI) const {
3283   SelectionDAG &DAG = DCI.DAG;
3284 
3285   // Simplify demanded bits before splitting into multiple users.
3286   if (simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI))
3287     return SDValue();
3288 
3289   SDValue N0 = N->getOperand(0);
3290   SDValue N1 = N->getOperand(1);
3291 
3292   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3293 
3294   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3295   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3296 
3297   SDLoc SL(N);
3298 
3299   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3300   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3301   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3302 }
3303 
3304 static bool isNegativeOne(SDValue Val) {
3305   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3306     return C->isAllOnesValue();
3307   return false;
3308 }
3309 
3310 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3311                                           SDValue Op,
3312                                           const SDLoc &DL,
3313                                           unsigned Opc) const {
3314   EVT VT = Op.getValueType();
3315   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3316   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3317                               LegalVT != MVT::i16))
3318     return SDValue();
3319 
3320   if (VT != MVT::i32)
3321     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3322 
3323   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3324   if (VT != MVT::i32)
3325     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3326 
3327   return FFBX;
3328 }
3329 
3330 // The native instructions return -1 on 0 input. Optimize out a select that
3331 // produces -1 on 0.
3332 //
3333 // TODO: If zero is not undef, we could also do this if the output is compared
3334 // against the bitwidth.
3335 //
3336 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
3337 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3338                                                  SDValue LHS, SDValue RHS,
3339                                                  DAGCombinerInfo &DCI) const {
3340   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3341   if (!CmpRhs || !CmpRhs->isNullValue())
3342     return SDValue();
3343 
3344   SelectionDAG &DAG = DCI.DAG;
3345   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3346   SDValue CmpLHS = Cond.getOperand(0);
3347 
3348   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3349                                            AMDGPUISD::FFBH_U32;
3350 
3351   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3352   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3353   if (CCOpcode == ISD::SETEQ &&
3354       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3355       RHS.getOperand(0) == CmpLHS &&
3356       isNegativeOne(LHS)) {
3357     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3358   }
3359 
3360   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3361   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3362   if (CCOpcode == ISD::SETNE &&
3363       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3364       LHS.getOperand(0) == CmpLHS &&
3365       isNegativeOne(RHS)) {
3366     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3367   }
3368 
3369   return SDValue();
3370 }
3371 
3372 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3373                                          unsigned Op,
3374                                          const SDLoc &SL,
3375                                          SDValue Cond,
3376                                          SDValue N1,
3377                                          SDValue N2) {
3378   SelectionDAG &DAG = DCI.DAG;
3379   EVT VT = N1.getValueType();
3380 
3381   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3382                                   N1.getOperand(0), N2.getOperand(0));
3383   DCI.AddToWorklist(NewSelect.getNode());
3384   return DAG.getNode(Op, SL, VT, NewSelect);
3385 }
3386 
3387 // Pull a free FP operation out of a select so it may fold into uses.
3388 //
3389 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3390 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3391 //
3392 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3393 // select c, (fabs x), +k -> fabs (select c, x, k)
3394 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3395                                     SDValue N) {
3396   SelectionDAG &DAG = DCI.DAG;
3397   SDValue Cond = N.getOperand(0);
3398   SDValue LHS = N.getOperand(1);
3399   SDValue RHS = N.getOperand(2);
3400 
3401   EVT VT = N.getValueType();
3402   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3403       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3404     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3405                                      SDLoc(N), Cond, LHS, RHS);
3406   }
3407 
3408   bool Inv = false;
3409   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3410     std::swap(LHS, RHS);
3411     Inv = true;
3412   }
3413 
3414   // TODO: Support vector constants.
3415   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3416   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3417     SDLoc SL(N);
3418     // If one side is an fneg/fabs and the other is a constant, we can push the
3419     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3420     SDValue NewLHS = LHS.getOperand(0);
3421     SDValue NewRHS = RHS;
3422 
3423     // Careful: if the neg can be folded up, don't try to pull it back down.
3424     bool ShouldFoldNeg = true;
3425 
3426     if (NewLHS.hasOneUse()) {
3427       unsigned Opc = NewLHS.getOpcode();
3428       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3429         ShouldFoldNeg = false;
3430       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3431         ShouldFoldNeg = false;
3432     }
3433 
3434     if (ShouldFoldNeg) {
3435       if (LHS.getOpcode() == ISD::FNEG)
3436         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3437       else if (CRHS->isNegative())
3438         return SDValue();
3439 
3440       if (Inv)
3441         std::swap(NewLHS, NewRHS);
3442 
3443       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3444                                       Cond, NewLHS, NewRHS);
3445       DCI.AddToWorklist(NewSelect.getNode());
3446       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3447     }
3448   }
3449 
3450   return SDValue();
3451 }
3452 
3453 
3454 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3455                                                    DAGCombinerInfo &DCI) const {
3456   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3457     return Folded;
3458 
3459   SDValue Cond = N->getOperand(0);
3460   if (Cond.getOpcode() != ISD::SETCC)
3461     return SDValue();
3462 
3463   EVT VT = N->getValueType(0);
3464   SDValue LHS = Cond.getOperand(0);
3465   SDValue RHS = Cond.getOperand(1);
3466   SDValue CC = Cond.getOperand(2);
3467 
3468   SDValue True = N->getOperand(1);
3469   SDValue False = N->getOperand(2);
3470 
3471   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3472     SelectionDAG &DAG = DCI.DAG;
3473     if ((DAG.isConstantValueOfAnyType(True) ||
3474          DAG.isConstantValueOfAnyType(True)) &&
3475         (!DAG.isConstantValueOfAnyType(False) &&
3476          !DAG.isConstantValueOfAnyType(False))) {
3477       // Swap cmp + select pair to move constant to false input.
3478       // This will allow using VOPC cndmasks more often.
3479       // select (setcc x, y), k, x -> select (setcc y, x) x, x
3480 
3481       SDLoc SL(N);
3482       ISD::CondCode NewCC = getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3483                                             LHS.getValueType().isInteger());
3484 
3485       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3486       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3487     }
3488 
3489     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3490       SDValue MinMax
3491         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3492       // Revisit this node so we can catch min3/max3/med3 patterns.
3493       //DCI.AddToWorklist(MinMax.getNode());
3494       return MinMax;
3495     }
3496   }
3497 
3498   // There's no reason to not do this if the condition has other uses.
3499   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3500 }
3501 
3502 static bool isInv2Pi(const APFloat &APF) {
3503   static const APFloat KF16(APFloat::IEEEhalf(), APInt(16, 0x3118));
3504   static const APFloat KF32(APFloat::IEEEsingle(), APInt(32, 0x3e22f983));
3505   static const APFloat KF64(APFloat::IEEEdouble(), APInt(64, 0x3fc45f306dc9c882));
3506 
3507   return APF.bitwiseIsEqual(KF16) ||
3508          APF.bitwiseIsEqual(KF32) ||
3509          APF.bitwiseIsEqual(KF64);
3510 }
3511 
3512 // 0 and 1.0 / (0.5 * pi) do not have inline immmediates, so there is an
3513 // additional cost to negate them.
3514 bool AMDGPUTargetLowering::isConstantCostlierToNegate(SDValue N) const {
3515   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N)) {
3516     if (C->isZero() && !C->isNegative())
3517       return true;
3518 
3519     if (Subtarget->hasInv2PiInlineImm() && isInv2Pi(C->getValueAPF()))
3520       return true;
3521   }
3522 
3523   return false;
3524 }
3525 
3526 static unsigned inverseMinMax(unsigned Opc) {
3527   switch (Opc) {
3528   case ISD::FMAXNUM:
3529     return ISD::FMINNUM;
3530   case ISD::FMINNUM:
3531     return ISD::FMAXNUM;
3532   case ISD::FMAXNUM_IEEE:
3533     return ISD::FMINNUM_IEEE;
3534   case ISD::FMINNUM_IEEE:
3535     return ISD::FMAXNUM_IEEE;
3536   case AMDGPUISD::FMAX_LEGACY:
3537     return AMDGPUISD::FMIN_LEGACY;
3538   case AMDGPUISD::FMIN_LEGACY:
3539     return  AMDGPUISD::FMAX_LEGACY;
3540   default:
3541     llvm_unreachable("invalid min/max opcode");
3542   }
3543 }
3544 
3545 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3546                                                  DAGCombinerInfo &DCI) const {
3547   SelectionDAG &DAG = DCI.DAG;
3548   SDValue N0 = N->getOperand(0);
3549   EVT VT = N->getValueType(0);
3550 
3551   unsigned Opc = N0.getOpcode();
3552 
3553   // If the input has multiple uses and we can either fold the negate down, or
3554   // the other uses cannot, give up. This both prevents unprofitable
3555   // transformations and infinite loops: we won't repeatedly try to fold around
3556   // a negate that has no 'good' form.
3557   if (N0.hasOneUse()) {
3558     // This may be able to fold into the source, but at a code size cost. Don't
3559     // fold if the fold into the user is free.
3560     if (allUsesHaveSourceMods(N, 0))
3561       return SDValue();
3562   } else {
3563     if (fnegFoldsIntoOp(Opc) &&
3564         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3565       return SDValue();
3566   }
3567 
3568   SDLoc SL(N);
3569   switch (Opc) {
3570   case ISD::FADD: {
3571     if (!mayIgnoreSignedZero(N0))
3572       return SDValue();
3573 
3574     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3575     SDValue LHS = N0.getOperand(0);
3576     SDValue RHS = N0.getOperand(1);
3577 
3578     if (LHS.getOpcode() != ISD::FNEG)
3579       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3580     else
3581       LHS = LHS.getOperand(0);
3582 
3583     if (RHS.getOpcode() != ISD::FNEG)
3584       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3585     else
3586       RHS = RHS.getOperand(0);
3587 
3588     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3589     if (!N0.hasOneUse())
3590       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3591     return Res;
3592   }
3593   case ISD::FMUL:
3594   case AMDGPUISD::FMUL_LEGACY: {
3595     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3596     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3597     SDValue LHS = N0.getOperand(0);
3598     SDValue RHS = N0.getOperand(1);
3599 
3600     if (LHS.getOpcode() == ISD::FNEG)
3601       LHS = LHS.getOperand(0);
3602     else if (RHS.getOpcode() == ISD::FNEG)
3603       RHS = RHS.getOperand(0);
3604     else
3605       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3606 
3607     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3608     if (!N0.hasOneUse())
3609       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3610     return Res;
3611   }
3612   case ISD::FMA:
3613   case ISD::FMAD: {
3614     if (!mayIgnoreSignedZero(N0))
3615       return SDValue();
3616 
3617     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3618     SDValue LHS = N0.getOperand(0);
3619     SDValue MHS = N0.getOperand(1);
3620     SDValue RHS = N0.getOperand(2);
3621 
3622     if (LHS.getOpcode() == ISD::FNEG)
3623       LHS = LHS.getOperand(0);
3624     else if (MHS.getOpcode() == ISD::FNEG)
3625       MHS = MHS.getOperand(0);
3626     else
3627       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3628 
3629     if (RHS.getOpcode() != ISD::FNEG)
3630       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3631     else
3632       RHS = RHS.getOperand(0);
3633 
3634     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3635     if (!N0.hasOneUse())
3636       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3637     return Res;
3638   }
3639   case ISD::FMAXNUM:
3640   case ISD::FMINNUM:
3641   case ISD::FMAXNUM_IEEE:
3642   case ISD::FMINNUM_IEEE:
3643   case AMDGPUISD::FMAX_LEGACY:
3644   case AMDGPUISD::FMIN_LEGACY: {
3645     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3646     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3647     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3648     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3649 
3650     SDValue LHS = N0.getOperand(0);
3651     SDValue RHS = N0.getOperand(1);
3652 
3653     // 0 doesn't have a negated inline immediate.
3654     // TODO: This constant check should be generalized to other operations.
3655     if (isConstantCostlierToNegate(RHS))
3656       return SDValue();
3657 
3658     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3659     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3660     unsigned Opposite = inverseMinMax(Opc);
3661 
3662     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3663     if (!N0.hasOneUse())
3664       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3665     return Res;
3666   }
3667   case AMDGPUISD::FMED3: {
3668     SDValue Ops[3];
3669     for (unsigned I = 0; I < 3; ++I)
3670       Ops[I] = DAG.getNode(ISD::FNEG, SL, VT, N0->getOperand(I), N0->getFlags());
3671 
3672     SDValue Res = DAG.getNode(AMDGPUISD::FMED3, SL, VT, Ops, N0->getFlags());
3673     if (!N0.hasOneUse())
3674       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3675     return Res;
3676   }
3677   case ISD::FP_EXTEND:
3678   case ISD::FTRUNC:
3679   case ISD::FRINT:
3680   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3681   case ISD::FSIN:
3682   case ISD::FCANONICALIZE:
3683   case AMDGPUISD::RCP:
3684   case AMDGPUISD::RCP_LEGACY:
3685   case AMDGPUISD::RCP_IFLAG:
3686   case AMDGPUISD::SIN_HW: {
3687     SDValue CvtSrc = N0.getOperand(0);
3688     if (CvtSrc.getOpcode() == ISD::FNEG) {
3689       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3690       // (fneg (rcp (fneg x))) -> (rcp x)
3691       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3692     }
3693 
3694     if (!N0.hasOneUse())
3695       return SDValue();
3696 
3697     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3698     // (fneg (rcp x)) -> (rcp (fneg x))
3699     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3700     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3701   }
3702   case ISD::FP_ROUND: {
3703     SDValue CvtSrc = N0.getOperand(0);
3704 
3705     if (CvtSrc.getOpcode() == ISD::FNEG) {
3706       // (fneg (fp_round (fneg x))) -> (fp_round x)
3707       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3708                          CvtSrc.getOperand(0), N0.getOperand(1));
3709     }
3710 
3711     if (!N0.hasOneUse())
3712       return SDValue();
3713 
3714     // (fneg (fp_round x)) -> (fp_round (fneg x))
3715     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3716     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3717   }
3718   case ISD::FP16_TO_FP: {
3719     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3720     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3721     // Put the fneg back as a legal source operation that can be matched later.
3722     SDLoc SL(N);
3723 
3724     SDValue Src = N0.getOperand(0);
3725     EVT SrcVT = Src.getValueType();
3726 
3727     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3728     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3729                                   DAG.getConstant(0x8000, SL, SrcVT));
3730     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3731   }
3732   default:
3733     return SDValue();
3734   }
3735 }
3736 
3737 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3738                                                  DAGCombinerInfo &DCI) const {
3739   SelectionDAG &DAG = DCI.DAG;
3740   SDValue N0 = N->getOperand(0);
3741 
3742   if (!N0.hasOneUse())
3743     return SDValue();
3744 
3745   switch (N0.getOpcode()) {
3746   case ISD::FP16_TO_FP: {
3747     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3748     SDLoc SL(N);
3749     SDValue Src = N0.getOperand(0);
3750     EVT SrcVT = Src.getValueType();
3751 
3752     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3753     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3754                                   DAG.getConstant(0x7fff, SL, SrcVT));
3755     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3756   }
3757   default:
3758     return SDValue();
3759   }
3760 }
3761 
3762 SDValue AMDGPUTargetLowering::performRcpCombine(SDNode *N,
3763                                                 DAGCombinerInfo &DCI) const {
3764   const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
3765   if (!CFP)
3766     return SDValue();
3767 
3768   // XXX - Should this flush denormals?
3769   const APFloat &Val = CFP->getValueAPF();
3770   APFloat One(Val.getSemantics(), "1.0");
3771   return DCI.DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3772 }
3773 
3774 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3775                                                 DAGCombinerInfo &DCI) const {
3776   SelectionDAG &DAG = DCI.DAG;
3777   SDLoc DL(N);
3778 
3779   switch(N->getOpcode()) {
3780   default:
3781     break;
3782   case ISD::BITCAST: {
3783     EVT DestVT = N->getValueType(0);
3784 
3785     // Push casts through vector builds. This helps avoid emitting a large
3786     // number of copies when materializing floating point vector constants.
3787     //
3788     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3789     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3790     if (DestVT.isVector()) {
3791       SDValue Src = N->getOperand(0);
3792       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3793         EVT SrcVT = Src.getValueType();
3794         unsigned NElts = DestVT.getVectorNumElements();
3795 
3796         if (SrcVT.getVectorNumElements() == NElts) {
3797           EVT DestEltVT = DestVT.getVectorElementType();
3798 
3799           SmallVector<SDValue, 8> CastedElts;
3800           SDLoc SL(N);
3801           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3802             SDValue Elt = Src.getOperand(I);
3803             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3804           }
3805 
3806           return DAG.getBuildVector(DestVT, SL, CastedElts);
3807         }
3808       }
3809     }
3810 
3811     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3812       break;
3813 
3814     // Fold bitcasts of constants.
3815     //
3816     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3817     // TODO: Generalize and move to DAGCombiner
3818     SDValue Src = N->getOperand(0);
3819     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3820       if (Src.getValueType() == MVT::i64) {
3821         SDLoc SL(N);
3822         uint64_t CVal = C->getZExtValue();
3823         SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3824                                  DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3825                                  DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3826         return DAG.getNode(ISD::BITCAST, SL, DestVT, BV);
3827       }
3828     }
3829 
3830     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3831       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3832       SDLoc SL(N);
3833       uint64_t CVal = Val.getZExtValue();
3834       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3835                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3836                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3837 
3838       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3839     }
3840 
3841     break;
3842   }
3843   case ISD::SHL: {
3844     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3845       break;
3846 
3847     return performShlCombine(N, DCI);
3848   }
3849   case ISD::SRL: {
3850     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3851       break;
3852 
3853     return performSrlCombine(N, DCI);
3854   }
3855   case ISD::SRA: {
3856     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3857       break;
3858 
3859     return performSraCombine(N, DCI);
3860   }
3861   case ISD::TRUNCATE:
3862     return performTruncateCombine(N, DCI);
3863   case ISD::MUL:
3864     return performMulCombine(N, DCI);
3865   case ISD::MULHS:
3866     return performMulhsCombine(N, DCI);
3867   case ISD::MULHU:
3868     return performMulhuCombine(N, DCI);
3869   case AMDGPUISD::MUL_I24:
3870   case AMDGPUISD::MUL_U24:
3871   case AMDGPUISD::MULHI_I24:
3872   case AMDGPUISD::MULHI_U24: {
3873     // If the first call to simplify is successfull, then N may end up being
3874     // deleted, so we shouldn't call simplifyI24 again.
3875     simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI);
3876     return SDValue();
3877   }
3878   case AMDGPUISD::MUL_LOHI_I24:
3879   case AMDGPUISD::MUL_LOHI_U24:
3880     return performMulLoHi24Combine(N, DCI);
3881   case ISD::SELECT:
3882     return performSelectCombine(N, DCI);
3883   case ISD::FNEG:
3884     return performFNegCombine(N, DCI);
3885   case ISD::FABS:
3886     return performFAbsCombine(N, DCI);
3887   case AMDGPUISD::BFE_I32:
3888   case AMDGPUISD::BFE_U32: {
3889     assert(!N->getValueType(0).isVector() &&
3890            "Vector handling of BFE not implemented");
3891     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
3892     if (!Width)
3893       break;
3894 
3895     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
3896     if (WidthVal == 0)
3897       return DAG.getConstant(0, DL, MVT::i32);
3898 
3899     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
3900     if (!Offset)
3901       break;
3902 
3903     SDValue BitsFrom = N->getOperand(0);
3904     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
3905 
3906     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
3907 
3908     if (OffsetVal == 0) {
3909       // This is already sign / zero extended, so try to fold away extra BFEs.
3910       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
3911 
3912       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
3913       if (OpSignBits >= SignBits)
3914         return BitsFrom;
3915 
3916       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
3917       if (Signed) {
3918         // This is a sign_extend_inreg. Replace it to take advantage of existing
3919         // DAG Combines. If not eliminated, we will match back to BFE during
3920         // selection.
3921 
3922         // TODO: The sext_inreg of extended types ends, although we can could
3923         // handle them in a single BFE.
3924         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
3925                            DAG.getValueType(SmallVT));
3926       }
3927 
3928       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
3929     }
3930 
3931     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
3932       if (Signed) {
3933         return constantFoldBFE<int32_t>(DAG,
3934                                         CVal->getSExtValue(),
3935                                         OffsetVal,
3936                                         WidthVal,
3937                                         DL);
3938       }
3939 
3940       return constantFoldBFE<uint32_t>(DAG,
3941                                        CVal->getZExtValue(),
3942                                        OffsetVal,
3943                                        WidthVal,
3944                                        DL);
3945     }
3946 
3947     if ((OffsetVal + WidthVal) >= 32 &&
3948         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
3949       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
3950       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
3951                          BitsFrom, ShiftVal);
3952     }
3953 
3954     if (BitsFrom.hasOneUse()) {
3955       APInt Demanded = APInt::getBitsSet(32,
3956                                          OffsetVal,
3957                                          OffsetVal + WidthVal);
3958 
3959       KnownBits Known;
3960       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
3961                                             !DCI.isBeforeLegalizeOps());
3962       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3963       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
3964           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
3965         DCI.CommitTargetLoweringOpt(TLO);
3966       }
3967     }
3968 
3969     break;
3970   }
3971   case ISD::LOAD:
3972     return performLoadCombine(N, DCI);
3973   case ISD::STORE:
3974     return performStoreCombine(N, DCI);
3975   case AMDGPUISD::RCP:
3976   case AMDGPUISD::RCP_IFLAG:
3977     return performRcpCombine(N, DCI);
3978   case ISD::AssertZext:
3979   case ISD::AssertSext:
3980     return performAssertSZExtCombine(N, DCI);
3981   }
3982   return SDValue();
3983 }
3984 
3985 //===----------------------------------------------------------------------===//
3986 // Helper functions
3987 //===----------------------------------------------------------------------===//
3988 
3989 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
3990                                                    const TargetRegisterClass *RC,
3991                                                    unsigned Reg, EVT VT,
3992                                                    const SDLoc &SL,
3993                                                    bool RawReg) const {
3994   MachineFunction &MF = DAG.getMachineFunction();
3995   MachineRegisterInfo &MRI = MF.getRegInfo();
3996   unsigned VReg;
3997 
3998   if (!MRI.isLiveIn(Reg)) {
3999     VReg = MRI.createVirtualRegister(RC);
4000     MRI.addLiveIn(Reg, VReg);
4001   } else {
4002     VReg = MRI.getLiveInVirtReg(Reg);
4003   }
4004 
4005   if (RawReg)
4006     return DAG.getRegister(VReg, VT);
4007 
4008   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
4009 }
4010 
4011 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
4012                                                   EVT VT,
4013                                                   const SDLoc &SL,
4014                                                   int64_t Offset) const {
4015   MachineFunction &MF = DAG.getMachineFunction();
4016   MachineFrameInfo &MFI = MF.getFrameInfo();
4017 
4018   int FI = MFI.CreateFixedObject(VT.getStoreSize(), Offset, true);
4019   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
4020   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
4021 
4022   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
4023                      MachineMemOperand::MODereferenceable |
4024                      MachineMemOperand::MOInvariant);
4025 }
4026 
4027 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
4028                                                    const SDLoc &SL,
4029                                                    SDValue Chain,
4030                                                    SDValue ArgVal,
4031                                                    int64_t Offset) const {
4032   MachineFunction &MF = DAG.getMachineFunction();
4033   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
4034 
4035   SDValue Ptr = DAG.getConstant(Offset, SL, MVT::i32);
4036   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
4037                                MachineMemOperand::MODereferenceable);
4038   return Store;
4039 }
4040 
4041 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
4042                                              const TargetRegisterClass *RC,
4043                                              EVT VT, const SDLoc &SL,
4044                                              const ArgDescriptor &Arg) const {
4045   assert(Arg && "Attempting to load missing argument");
4046 
4047   if (Arg.isRegister())
4048     return CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL);
4049   return loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
4050 }
4051 
4052 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
4053     const MachineFunction &MF, const ImplicitParameter Param) const {
4054   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
4055   const AMDGPUSubtarget &ST =
4056       AMDGPUSubtarget::get(getTargetMachine(), MF.getFunction());
4057   unsigned ExplicitArgOffset = ST.getExplicitKernelArgOffset(MF.getFunction());
4058   unsigned Alignment = ST.getAlignmentForImplicitArgPtr();
4059   uint64_t ArgOffset = alignTo(MFI->getExplicitKernArgSize(), Alignment) +
4060                        ExplicitArgOffset;
4061   switch (Param) {
4062   case GRID_DIM:
4063     return ArgOffset;
4064   case GRID_OFFSET:
4065     return ArgOffset + 4;
4066   }
4067   llvm_unreachable("unexpected implicit parameter type");
4068 }
4069 
4070 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4071 
4072 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4073   switch ((AMDGPUISD::NodeType)Opcode) {
4074   case AMDGPUISD::FIRST_NUMBER: break;
4075   // AMDIL DAG nodes
4076   NODE_NAME_CASE(UMUL);
4077   NODE_NAME_CASE(BRANCH_COND);
4078 
4079   // AMDGPU DAG nodes
4080   NODE_NAME_CASE(IF)
4081   NODE_NAME_CASE(ELSE)
4082   NODE_NAME_CASE(LOOP)
4083   NODE_NAME_CASE(CALL)
4084   NODE_NAME_CASE(TC_RETURN)
4085   NODE_NAME_CASE(TRAP)
4086   NODE_NAME_CASE(RET_FLAG)
4087   NODE_NAME_CASE(RETURN_TO_EPILOG)
4088   NODE_NAME_CASE(ENDPGM)
4089   NODE_NAME_CASE(DWORDADDR)
4090   NODE_NAME_CASE(FRACT)
4091   NODE_NAME_CASE(SETCC)
4092   NODE_NAME_CASE(SETREG)
4093   NODE_NAME_CASE(FMA_W_CHAIN)
4094   NODE_NAME_CASE(FMUL_W_CHAIN)
4095   NODE_NAME_CASE(CLAMP)
4096   NODE_NAME_CASE(COS_HW)
4097   NODE_NAME_CASE(SIN_HW)
4098   NODE_NAME_CASE(FMAX_LEGACY)
4099   NODE_NAME_CASE(FMIN_LEGACY)
4100   NODE_NAME_CASE(FMAX3)
4101   NODE_NAME_CASE(SMAX3)
4102   NODE_NAME_CASE(UMAX3)
4103   NODE_NAME_CASE(FMIN3)
4104   NODE_NAME_CASE(SMIN3)
4105   NODE_NAME_CASE(UMIN3)
4106   NODE_NAME_CASE(FMED3)
4107   NODE_NAME_CASE(SMED3)
4108   NODE_NAME_CASE(UMED3)
4109   NODE_NAME_CASE(FDOT2)
4110   NODE_NAME_CASE(URECIP)
4111   NODE_NAME_CASE(DIV_SCALE)
4112   NODE_NAME_CASE(DIV_FMAS)
4113   NODE_NAME_CASE(DIV_FIXUP)
4114   NODE_NAME_CASE(FMAD_FTZ)
4115   NODE_NAME_CASE(TRIG_PREOP)
4116   NODE_NAME_CASE(RCP)
4117   NODE_NAME_CASE(RSQ)
4118   NODE_NAME_CASE(RCP_LEGACY)
4119   NODE_NAME_CASE(RSQ_LEGACY)
4120   NODE_NAME_CASE(RCP_IFLAG)
4121   NODE_NAME_CASE(FMUL_LEGACY)
4122   NODE_NAME_CASE(RSQ_CLAMP)
4123   NODE_NAME_CASE(LDEXP)
4124   NODE_NAME_CASE(FP_CLASS)
4125   NODE_NAME_CASE(DOT4)
4126   NODE_NAME_CASE(CARRY)
4127   NODE_NAME_CASE(BORROW)
4128   NODE_NAME_CASE(BFE_U32)
4129   NODE_NAME_CASE(BFE_I32)
4130   NODE_NAME_CASE(BFI)
4131   NODE_NAME_CASE(BFM)
4132   NODE_NAME_CASE(FFBH_U32)
4133   NODE_NAME_CASE(FFBH_I32)
4134   NODE_NAME_CASE(FFBL_B32)
4135   NODE_NAME_CASE(MUL_U24)
4136   NODE_NAME_CASE(MUL_I24)
4137   NODE_NAME_CASE(MULHI_U24)
4138   NODE_NAME_CASE(MULHI_I24)
4139   NODE_NAME_CASE(MUL_LOHI_U24)
4140   NODE_NAME_CASE(MUL_LOHI_I24)
4141   NODE_NAME_CASE(MAD_U24)
4142   NODE_NAME_CASE(MAD_I24)
4143   NODE_NAME_CASE(MAD_I64_I32)
4144   NODE_NAME_CASE(MAD_U64_U32)
4145   NODE_NAME_CASE(PERM)
4146   NODE_NAME_CASE(TEXTURE_FETCH)
4147   NODE_NAME_CASE(EXPORT)
4148   NODE_NAME_CASE(EXPORT_DONE)
4149   NODE_NAME_CASE(R600_EXPORT)
4150   NODE_NAME_CASE(CONST_ADDRESS)
4151   NODE_NAME_CASE(REGISTER_LOAD)
4152   NODE_NAME_CASE(REGISTER_STORE)
4153   NODE_NAME_CASE(SAMPLE)
4154   NODE_NAME_CASE(SAMPLEB)
4155   NODE_NAME_CASE(SAMPLED)
4156   NODE_NAME_CASE(SAMPLEL)
4157   NODE_NAME_CASE(CVT_F32_UBYTE0)
4158   NODE_NAME_CASE(CVT_F32_UBYTE1)
4159   NODE_NAME_CASE(CVT_F32_UBYTE2)
4160   NODE_NAME_CASE(CVT_F32_UBYTE3)
4161   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4162   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4163   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4164   NODE_NAME_CASE(CVT_PK_I16_I32)
4165   NODE_NAME_CASE(CVT_PK_U16_U32)
4166   NODE_NAME_CASE(FP_TO_FP16)
4167   NODE_NAME_CASE(FP16_ZEXT)
4168   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4169   NODE_NAME_CASE(CONST_DATA_PTR)
4170   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4171   NODE_NAME_CASE(KILL)
4172   NODE_NAME_CASE(DUMMY_CHAIN)
4173   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4174   NODE_NAME_CASE(INIT_EXEC)
4175   NODE_NAME_CASE(INIT_EXEC_FROM_INPUT)
4176   NODE_NAME_CASE(SENDMSG)
4177   NODE_NAME_CASE(SENDMSGHALT)
4178   NODE_NAME_CASE(INTERP_MOV)
4179   NODE_NAME_CASE(INTERP_P1)
4180   NODE_NAME_CASE(INTERP_P2)
4181   NODE_NAME_CASE(STORE_MSKOR)
4182   NODE_NAME_CASE(LOAD_CONSTANT)
4183   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4184   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_X3)
4185   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4186   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4187   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4188   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4189   NODE_NAME_CASE(ATOMIC_INC)
4190   NODE_NAME_CASE(ATOMIC_DEC)
4191   NODE_NAME_CASE(ATOMIC_LOAD_FADD)
4192   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4193   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4194   NODE_NAME_CASE(BUFFER_LOAD)
4195   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4196   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4197   NODE_NAME_CASE(SBUFFER_LOAD)
4198   NODE_NAME_CASE(BUFFER_STORE)
4199   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4200   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4201   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4202   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4203   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4204   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4205   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4206   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4207   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4208   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4209   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4210   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4211   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4212 
4213   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4214   }
4215   return nullptr;
4216 }
4217 
4218 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4219                                               SelectionDAG &DAG, int Enabled,
4220                                               int &RefinementSteps,
4221                                               bool &UseOneConstNR,
4222                                               bool Reciprocal) const {
4223   EVT VT = Operand.getValueType();
4224 
4225   if (VT == MVT::f32) {
4226     RefinementSteps = 0;
4227     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4228   }
4229 
4230   // TODO: There is also f64 rsq instruction, but the documentation is less
4231   // clear on its precision.
4232 
4233   return SDValue();
4234 }
4235 
4236 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4237                                                SelectionDAG &DAG, int Enabled,
4238                                                int &RefinementSteps) const {
4239   EVT VT = Operand.getValueType();
4240 
4241   if (VT == MVT::f32) {
4242     // Reciprocal, < 1 ulp error.
4243     //
4244     // This reciprocal approximation converges to < 0.5 ulp error with one
4245     // newton rhapson performed with two fused multiple adds (FMAs).
4246 
4247     RefinementSteps = 0;
4248     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4249   }
4250 
4251   // TODO: There is also f64 rcp instruction, but the documentation is less
4252   // clear on its precision.
4253 
4254   return SDValue();
4255 }
4256 
4257 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4258     const SDValue Op, KnownBits &Known,
4259     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4260 
4261   Known.resetAll(); // Don't know anything.
4262 
4263   unsigned Opc = Op.getOpcode();
4264 
4265   switch (Opc) {
4266   default:
4267     break;
4268   case AMDGPUISD::CARRY:
4269   case AMDGPUISD::BORROW: {
4270     Known.Zero = APInt::getHighBitsSet(32, 31);
4271     break;
4272   }
4273 
4274   case AMDGPUISD::BFE_I32:
4275   case AMDGPUISD::BFE_U32: {
4276     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4277     if (!CWidth)
4278       return;
4279 
4280     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4281 
4282     if (Opc == AMDGPUISD::BFE_U32)
4283       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4284 
4285     break;
4286   }
4287   case AMDGPUISD::FP_TO_FP16:
4288   case AMDGPUISD::FP16_ZEXT: {
4289     unsigned BitWidth = Known.getBitWidth();
4290 
4291     // High bits are zero.
4292     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4293     break;
4294   }
4295   case AMDGPUISD::MUL_U24:
4296   case AMDGPUISD::MUL_I24: {
4297     KnownBits LHSKnown, RHSKnown;
4298     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4299     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4300 
4301     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4302                       RHSKnown.countMinTrailingZeros();
4303     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4304 
4305     unsigned LHSValBits = 32 - std::max(LHSKnown.countMinSignBits(), 8u);
4306     unsigned RHSValBits = 32 - std::max(RHSKnown.countMinSignBits(), 8u);
4307     unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4308     if (MaxValBits >= 32)
4309       break;
4310     bool Negative = false;
4311     if (Opc == AMDGPUISD::MUL_I24) {
4312       bool LHSNegative = !!(LHSKnown.One  & (1 << 23));
4313       bool LHSPositive = !!(LHSKnown.Zero & (1 << 23));
4314       bool RHSNegative = !!(RHSKnown.One  & (1 << 23));
4315       bool RHSPositive = !!(RHSKnown.Zero & (1 << 23));
4316       if ((!LHSNegative && !LHSPositive) || (!RHSNegative && !RHSPositive))
4317         break;
4318       Negative = (LHSNegative && RHSPositive) || (LHSPositive && RHSNegative);
4319     }
4320     if (Negative)
4321       Known.One.setHighBits(32 - MaxValBits);
4322     else
4323       Known.Zero.setHighBits(32 - MaxValBits);
4324     break;
4325   }
4326   case AMDGPUISD::PERM: {
4327     ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4328     if (!CMask)
4329       return;
4330 
4331     KnownBits LHSKnown, RHSKnown;
4332     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4333     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4334     unsigned Sel = CMask->getZExtValue();
4335 
4336     for (unsigned I = 0; I < 32; I += 8) {
4337       unsigned SelBits = Sel & 0xff;
4338       if (SelBits < 4) {
4339         SelBits *= 8;
4340         Known.One |= ((RHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4341         Known.Zero |= ((RHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4342       } else if (SelBits < 7) {
4343         SelBits = (SelBits & 3) * 8;
4344         Known.One |= ((LHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4345         Known.Zero |= ((LHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4346       } else if (SelBits == 0x0c) {
4347         Known.Zero |= 0xff << I;
4348       } else if (SelBits > 0x0c) {
4349         Known.One |= 0xff << I;
4350       }
4351       Sel >>= 8;
4352     }
4353     break;
4354   }
4355   case ISD::INTRINSIC_WO_CHAIN: {
4356     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4357     switch (IID) {
4358     case Intrinsic::amdgcn_mbcnt_lo:
4359     case Intrinsic::amdgcn_mbcnt_hi: {
4360       const GCNSubtarget &ST =
4361           DAG.getMachineFunction().getSubtarget<GCNSubtarget>();
4362       // These return at most the wavefront size - 1.
4363       unsigned Size = Op.getValueType().getSizeInBits();
4364       Known.Zero.setHighBits(Size - ST.getWavefrontSizeLog2());
4365       break;
4366     }
4367     default:
4368       break;
4369     }
4370   }
4371   }
4372 }
4373 
4374 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4375     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4376     unsigned Depth) const {
4377   switch (Op.getOpcode()) {
4378   case AMDGPUISD::BFE_I32: {
4379     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4380     if (!Width)
4381       return 1;
4382 
4383     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4384     if (!isNullConstant(Op.getOperand(1)))
4385       return SignBits;
4386 
4387     // TODO: Could probably figure something out with non-0 offsets.
4388     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4389     return std::max(SignBits, Op0SignBits);
4390   }
4391 
4392   case AMDGPUISD::BFE_U32: {
4393     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4394     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4395   }
4396 
4397   case AMDGPUISD::CARRY:
4398   case AMDGPUISD::BORROW:
4399     return 31;
4400   case AMDGPUISD::FP_TO_FP16:
4401   case AMDGPUISD::FP16_ZEXT:
4402     return 16;
4403   default:
4404     return 1;
4405   }
4406 }
4407 
4408 bool AMDGPUTargetLowering::isKnownNeverNaNForTargetNode(SDValue Op,
4409                                                         const SelectionDAG &DAG,
4410                                                         bool SNaN,
4411                                                         unsigned Depth) const {
4412   unsigned Opcode = Op.getOpcode();
4413   switch (Opcode) {
4414   case AMDGPUISD::FMIN_LEGACY:
4415   case AMDGPUISD::FMAX_LEGACY: {
4416     if (SNaN)
4417       return true;
4418 
4419     // TODO: Can check no nans on one of the operands for each one, but which
4420     // one?
4421     return false;
4422   }
4423   case AMDGPUISD::FMUL_LEGACY:
4424   case AMDGPUISD::CVT_PKRTZ_F16_F32: {
4425     if (SNaN)
4426       return true;
4427     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4428            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4429   }
4430   case AMDGPUISD::FMED3:
4431   case AMDGPUISD::FMIN3:
4432   case AMDGPUISD::FMAX3:
4433   case AMDGPUISD::FMAD_FTZ: {
4434     if (SNaN)
4435       return true;
4436     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4437            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4438            DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4439   }
4440   case AMDGPUISD::CVT_F32_UBYTE0:
4441   case AMDGPUISD::CVT_F32_UBYTE1:
4442   case AMDGPUISD::CVT_F32_UBYTE2:
4443   case AMDGPUISD::CVT_F32_UBYTE3:
4444     return true;
4445 
4446   case AMDGPUISD::RCP:
4447   case AMDGPUISD::RSQ:
4448   case AMDGPUISD::RCP_LEGACY:
4449   case AMDGPUISD::RSQ_LEGACY:
4450   case AMDGPUISD::RSQ_CLAMP: {
4451     if (SNaN)
4452       return true;
4453 
4454     // TODO: Need is known positive check.
4455     return false;
4456   }
4457   case AMDGPUISD::LDEXP:
4458   case AMDGPUISD::FRACT: {
4459     if (SNaN)
4460       return true;
4461     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1);
4462   }
4463   case AMDGPUISD::DIV_SCALE:
4464   case AMDGPUISD::DIV_FMAS:
4465   case AMDGPUISD::DIV_FIXUP:
4466   case AMDGPUISD::TRIG_PREOP:
4467     // TODO: Refine on operands.
4468     return SNaN;
4469   case AMDGPUISD::SIN_HW:
4470   case AMDGPUISD::COS_HW: {
4471     // TODO: Need check for infinity
4472     return SNaN;
4473   }
4474   case ISD::INTRINSIC_WO_CHAIN: {
4475     unsigned IntrinsicID
4476       = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4477     // TODO: Handle more intrinsics
4478     switch (IntrinsicID) {
4479     case Intrinsic::amdgcn_cubeid:
4480       return true;
4481 
4482     case Intrinsic::amdgcn_frexp_mant: {
4483       if (SNaN)
4484         return true;
4485       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4486     }
4487     case Intrinsic::amdgcn_cvt_pkrtz: {
4488       if (SNaN)
4489         return true;
4490       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4491              DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4492     }
4493     case Intrinsic::amdgcn_fdot2:
4494       // TODO: Refine on operand
4495       return SNaN;
4496     default:
4497       return false;
4498     }
4499   }
4500   default:
4501     return false;
4502   }
4503 }
4504 
4505 TargetLowering::AtomicExpansionKind
4506 AMDGPUTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *RMW) const {
4507   if (RMW->getOperation() == AtomicRMWInst::Nand)
4508     return AtomicExpansionKind::CmpXChg;
4509   return AtomicExpansionKind::None;
4510 }
4511