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::FSIN:
556   case ISD::FTRUNC:
557   case ISD::FRINT:
558   case ISD::FNEARBYINT:
559   case ISD::FCANONICALIZE:
560   case AMDGPUISD::RCP:
561   case AMDGPUISD::RCP_LEGACY:
562   case AMDGPUISD::RCP_IFLAG:
563   case AMDGPUISD::SIN_HW:
564   case AMDGPUISD::FMUL_LEGACY:
565   case AMDGPUISD::FMIN_LEGACY:
566   case AMDGPUISD::FMAX_LEGACY:
567   case AMDGPUISD::FMED3:
568     return true;
569   default:
570     return false;
571   }
572 }
573 
574 /// \p returns true if the operation will definitely need to use a 64-bit
575 /// encoding, and thus will use a VOP3 encoding regardless of the source
576 /// modifiers.
577 LLVM_READONLY
578 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
579   return N->getNumOperands() > 2 || VT == MVT::f64;
580 }
581 
582 // Most FP instructions support source modifiers, but this could be refined
583 // slightly.
584 LLVM_READONLY
585 static bool hasSourceMods(const SDNode *N) {
586   if (isa<MemSDNode>(N))
587     return false;
588 
589   switch (N->getOpcode()) {
590   case ISD::CopyToReg:
591   case ISD::SELECT:
592   case ISD::FDIV:
593   case ISD::FREM:
594   case ISD::INLINEASM:
595   case AMDGPUISD::INTERP_P1:
596   case AMDGPUISD::INTERP_P2:
597   case AMDGPUISD::DIV_SCALE:
598 
599   // TODO: Should really be looking at the users of the bitcast. These are
600   // problematic because bitcasts are used to legalize all stores to integer
601   // types.
602   case ISD::BITCAST:
603     return false;
604   default:
605     return true;
606   }
607 }
608 
609 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
610                                                  unsigned CostThreshold) {
611   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
612   // it is truly free to use a source modifier in all cases. If there are
613   // multiple users but for each one will necessitate using VOP3, there will be
614   // a code size increase. Try to avoid increasing code size unless we know it
615   // will save on the instruction count.
616   unsigned NumMayIncreaseSize = 0;
617   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
618 
619   // XXX - Should this limit number of uses to check?
620   for (const SDNode *U : N->uses()) {
621     if (!hasSourceMods(U))
622       return false;
623 
624     if (!opMustUseVOP3Encoding(U, VT)) {
625       if (++NumMayIncreaseSize > CostThreshold)
626         return false;
627     }
628   }
629 
630   return true;
631 }
632 
633 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
634   return MVT::i32;
635 }
636 
637 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
638   return true;
639 }
640 
641 // The backend supports 32 and 64 bit floating point immediates.
642 // FIXME: Why are we reporting vectors of FP immediates as legal?
643 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
644   EVT ScalarVT = VT.getScalarType();
645   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
646          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
647 }
648 
649 // We don't want to shrink f64 / f32 constants.
650 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
651   EVT ScalarVT = VT.getScalarType();
652   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
653 }
654 
655 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
656                                                  ISD::LoadExtType,
657                                                  EVT NewVT) const {
658 
659   unsigned NewSize = NewVT.getStoreSizeInBits();
660 
661   // If we are reducing to a 32-bit load, this is always better.
662   if (NewSize == 32)
663     return true;
664 
665   EVT OldVT = N->getValueType(0);
666   unsigned OldSize = OldVT.getStoreSizeInBits();
667 
668   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
669   // extloads, so doing one requires using a buffer_load. In cases where we
670   // still couldn't use a scalar load, using the wider load shouldn't really
671   // hurt anything.
672 
673   // If the old size already had to be an extload, there's no harm in continuing
674   // to reduce the width.
675   return (OldSize < 32);
676 }
677 
678 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy,
679                                                    EVT CastTy) const {
680 
681   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
682 
683   if (LoadTy.getScalarType() == MVT::i32)
684     return false;
685 
686   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
687   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
688 
689   return (LScalarSize < CastScalarSize) ||
690          (CastScalarSize >= 32);
691 }
692 
693 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
694 // profitable with the expansion for 64-bit since it's generally good to
695 // speculate things.
696 // FIXME: These should really have the size as a parameter.
697 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
698   return true;
699 }
700 
701 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
702   return true;
703 }
704 
705 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode * N) const {
706   switch (N->getOpcode()) {
707     default:
708     return false;
709     case ISD::EntryToken:
710     case ISD::TokenFactor:
711       return true;
712     case ISD::INTRINSIC_WO_CHAIN:
713     {
714       unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
715       switch (IntrID) {
716         default:
717         return false;
718         case Intrinsic::amdgcn_readfirstlane:
719         case Intrinsic::amdgcn_readlane:
720           return true;
721       }
722     }
723     break;
724     case ISD::LOAD:
725     {
726       const LoadSDNode * L = dyn_cast<LoadSDNode>(N);
727       if (L->getMemOperand()->getAddrSpace()
728       == AMDGPUAS::CONSTANT_ADDRESS_32BIT)
729         return true;
730       return false;
731     }
732     break;
733   }
734 }
735 
736 //===---------------------------------------------------------------------===//
737 // Target Properties
738 //===---------------------------------------------------------------------===//
739 
740 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
741   assert(VT.isFloatingPoint());
742 
743   // Packed operations do not have a fabs modifier.
744   return VT == MVT::f32 || VT == MVT::f64 ||
745          (Subtarget->has16BitInsts() && VT == MVT::f16);
746 }
747 
748 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
749   assert(VT.isFloatingPoint());
750   return VT == MVT::f32 || VT == MVT::f64 ||
751          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
752          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
753 }
754 
755 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
756                                                          unsigned NumElem,
757                                                          unsigned AS) const {
758   return true;
759 }
760 
761 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
762   // There are few operations which truly have vector input operands. Any vector
763   // operation is going to involve operations on each component, and a
764   // build_vector will be a copy per element, so it always makes sense to use a
765   // build_vector input in place of the extracted element to avoid a copy into a
766   // super register.
767   //
768   // We should probably only do this if all users are extracts only, but this
769   // should be the common case.
770   return true;
771 }
772 
773 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
774   // Truncate is just accessing a subregister.
775 
776   unsigned SrcSize = Source.getSizeInBits();
777   unsigned DestSize = Dest.getSizeInBits();
778 
779   return DestSize < SrcSize && DestSize % 32 == 0 ;
780 }
781 
782 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
783   // Truncate is just accessing a subregister.
784 
785   unsigned SrcSize = Source->getScalarSizeInBits();
786   unsigned DestSize = Dest->getScalarSizeInBits();
787 
788   if (DestSize== 16 && Subtarget->has16BitInsts())
789     return SrcSize >= 32;
790 
791   return DestSize < SrcSize && DestSize % 32 == 0;
792 }
793 
794 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
795   unsigned SrcSize = Src->getScalarSizeInBits();
796   unsigned DestSize = Dest->getScalarSizeInBits();
797 
798   if (SrcSize == 16 && Subtarget->has16BitInsts())
799     return DestSize >= 32;
800 
801   return SrcSize == 32 && DestSize == 64;
802 }
803 
804 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
805   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
806   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
807   // this will enable reducing 64-bit operations the 32-bit, which is always
808   // good.
809 
810   if (Src == MVT::i16)
811     return Dest == MVT::i32 ||Dest == MVT::i64 ;
812 
813   return Src == MVT::i32 && Dest == MVT::i64;
814 }
815 
816 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
817   return isZExtFree(Val.getValueType(), VT2);
818 }
819 
820 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
821   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
822   // limited number of native 64-bit operations. Shrinking an operation to fit
823   // in a single 32-bit register should always be helpful. As currently used,
824   // this is much less general than the name suggests, and is only used in
825   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
826   // not profitable, and may actually be harmful.
827   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
828 }
829 
830 //===---------------------------------------------------------------------===//
831 // TargetLowering Callbacks
832 //===---------------------------------------------------------------------===//
833 
834 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
835                                                   bool IsVarArg) {
836   switch (CC) {
837   case CallingConv::AMDGPU_KERNEL:
838   case CallingConv::SPIR_KERNEL:
839     llvm_unreachable("kernels should not be handled here");
840   case CallingConv::AMDGPU_VS:
841   case CallingConv::AMDGPU_GS:
842   case CallingConv::AMDGPU_PS:
843   case CallingConv::AMDGPU_CS:
844   case CallingConv::AMDGPU_HS:
845   case CallingConv::AMDGPU_ES:
846   case CallingConv::AMDGPU_LS:
847     return CC_AMDGPU;
848   case CallingConv::C:
849   case CallingConv::Fast:
850   case CallingConv::Cold:
851     return CC_AMDGPU_Func;
852   default:
853     report_fatal_error("Unsupported calling convention.");
854   }
855 }
856 
857 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
858                                                     bool IsVarArg) {
859   switch (CC) {
860   case CallingConv::AMDGPU_KERNEL:
861   case CallingConv::SPIR_KERNEL:
862     llvm_unreachable("kernels should not be handled here");
863   case CallingConv::AMDGPU_VS:
864   case CallingConv::AMDGPU_GS:
865   case CallingConv::AMDGPU_PS:
866   case CallingConv::AMDGPU_CS:
867   case CallingConv::AMDGPU_HS:
868   case CallingConv::AMDGPU_ES:
869   case CallingConv::AMDGPU_LS:
870     return RetCC_SI_Shader;
871   case CallingConv::C:
872   case CallingConv::Fast:
873   case CallingConv::Cold:
874     return RetCC_AMDGPU_Func;
875   default:
876     report_fatal_error("Unsupported calling convention.");
877   }
878 }
879 
880 /// The SelectionDAGBuilder will automatically promote function arguments
881 /// with illegal types.  However, this does not work for the AMDGPU targets
882 /// since the function arguments are stored in memory as these illegal types.
883 /// In order to handle this properly we need to get the original types sizes
884 /// from the LLVM IR Function and fixup the ISD:InputArg values before
885 /// passing them to AnalyzeFormalArguments()
886 
887 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
888 /// input values across multiple registers.  Each item in the Ins array
889 /// represents a single value that will be stored in registers.  Ins[x].VT is
890 /// the value type of the value that will be stored in the register, so
891 /// whatever SDNode we lower the argument to needs to be this type.
892 ///
893 /// In order to correctly lower the arguments we need to know the size of each
894 /// argument.  Since Ins[x].VT gives us the size of the register that will
895 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
896 /// for the orignal function argument so that we can deduce the correct memory
897 /// type to use for Ins[x].  In most cases the correct memory type will be
898 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
899 /// we have a kernel argument of type v8i8, this argument will be split into
900 /// 8 parts and each part will be represented by its own item in the Ins array.
901 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
902 /// the argument before it was split.  From this, we deduce that the memory type
903 /// for each individual part is i8.  We pass the memory type as LocVT to the
904 /// calling convention analysis function and the register type (Ins[x].VT) as
905 /// the ValVT.
906 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(
907   CCState &State,
908   const SmallVectorImpl<ISD::InputArg> &Ins) const {
909   const MachineFunction &MF = State.getMachineFunction();
910   const Function &Fn = MF.getFunction();
911   LLVMContext &Ctx = Fn.getParent()->getContext();
912   const AMDGPUSubtarget &ST = AMDGPUSubtarget::get(MF);
913   const unsigned ExplicitOffset = ST.getExplicitKernelArgOffset(Fn);
914   CallingConv::ID CC = Fn.getCallingConv();
915 
916   unsigned MaxAlign = 1;
917   uint64_t ExplicitArgOffset = 0;
918   const DataLayout &DL = Fn.getParent()->getDataLayout();
919 
920   unsigned InIndex = 0;
921 
922   for (const Argument &Arg : Fn.args()) {
923     Type *BaseArgTy = Arg.getType();
924     unsigned Align = DL.getABITypeAlignment(BaseArgTy);
925     MaxAlign = std::max(Align, MaxAlign);
926     unsigned AllocSize = DL.getTypeAllocSize(BaseArgTy);
927 
928     uint64_t ArgOffset = alignTo(ExplicitArgOffset, Align) + ExplicitOffset;
929     ExplicitArgOffset = alignTo(ExplicitArgOffset, Align) + AllocSize;
930 
931     // We're basically throwing away everything passed into us and starting over
932     // to get accurate in-memory offsets. The "PartOffset" is completely useless
933     // to us as computed in Ins.
934     //
935     // We also need to figure out what type legalization is trying to do to get
936     // the correct memory offsets.
937 
938     SmallVector<EVT, 16> ValueVTs;
939     SmallVector<uint64_t, 16> Offsets;
940     ComputeValueVTs(*this, DL, BaseArgTy, ValueVTs, &Offsets, ArgOffset);
941 
942     for (unsigned Value = 0, NumValues = ValueVTs.size();
943          Value != NumValues; ++Value) {
944       uint64_t BasePartOffset = Offsets[Value];
945 
946       EVT ArgVT = ValueVTs[Value];
947       EVT MemVT = ArgVT;
948       MVT RegisterVT = getRegisterTypeForCallingConv(Ctx, CC, ArgVT);
949       unsigned NumRegs = getNumRegistersForCallingConv(Ctx, CC, ArgVT);
950 
951       if (NumRegs == 1) {
952         // This argument is not split, so the IR type is the memory type.
953         if (ArgVT.isExtended()) {
954           // We have an extended type, like i24, so we should just use the
955           // register type.
956           MemVT = RegisterVT;
957         } else {
958           MemVT = ArgVT;
959         }
960       } else if (ArgVT.isVector() && RegisterVT.isVector() &&
961                  ArgVT.getScalarType() == RegisterVT.getScalarType()) {
962         assert(ArgVT.getVectorNumElements() > RegisterVT.getVectorNumElements());
963         // We have a vector value which has been split into a vector with
964         // the same scalar type, but fewer elements.  This should handle
965         // all the floating-point vector types.
966         MemVT = RegisterVT;
967       } else if (ArgVT.isVector() &&
968                  ArgVT.getVectorNumElements() == NumRegs) {
969         // This arg has been split so that each element is stored in a separate
970         // register.
971         MemVT = ArgVT.getScalarType();
972       } else if (ArgVT.isExtended()) {
973         // We have an extended type, like i65.
974         MemVT = RegisterVT;
975       } else {
976         unsigned MemoryBits = ArgVT.getStoreSizeInBits() / NumRegs;
977         assert(ArgVT.getStoreSizeInBits() % NumRegs == 0);
978         if (RegisterVT.isInteger()) {
979           MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
980         } else if (RegisterVT.isVector()) {
981           assert(!RegisterVT.getScalarType().isFloatingPoint());
982           unsigned NumElements = RegisterVT.getVectorNumElements();
983           assert(MemoryBits % NumElements == 0);
984           // This vector type has been split into another vector type with
985           // a different elements size.
986           EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
987                                            MemoryBits / NumElements);
988           MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
989         } else {
990           llvm_unreachable("cannot deduce memory type.");
991         }
992       }
993 
994       // Convert one element vectors to scalar.
995       if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
996         MemVT = MemVT.getScalarType();
997 
998       if (MemVT.isExtended()) {
999         // This should really only happen if we have vec3 arguments
1000         assert(MemVT.isVector() && MemVT.getVectorNumElements() == 3);
1001         MemVT = MemVT.getPow2VectorType(State.getContext());
1002       }
1003 
1004       unsigned PartOffset = 0;
1005       for (unsigned i = 0; i != NumRegs; ++i) {
1006         State.addLoc(CCValAssign::getCustomMem(InIndex++, RegisterVT,
1007                                                BasePartOffset + PartOffset,
1008                                                MemVT.getSimpleVT(),
1009                                                CCValAssign::Full));
1010         PartOffset += MemVT.getStoreSize();
1011       }
1012     }
1013   }
1014 }
1015 
1016 SDValue AMDGPUTargetLowering::LowerReturn(
1017   SDValue Chain, CallingConv::ID CallConv,
1018   bool isVarArg,
1019   const SmallVectorImpl<ISD::OutputArg> &Outs,
1020   const SmallVectorImpl<SDValue> &OutVals,
1021   const SDLoc &DL, SelectionDAG &DAG) const {
1022   // FIXME: Fails for r600 tests
1023   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1024   // "wave terminate should not have return values");
1025   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1026 }
1027 
1028 //===---------------------------------------------------------------------===//
1029 // Target specific lowering
1030 //===---------------------------------------------------------------------===//
1031 
1032 /// Selects the correct CCAssignFn for a given CallingConvention value.
1033 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1034                                                     bool IsVarArg) {
1035   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1036 }
1037 
1038 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1039                                                       bool IsVarArg) {
1040   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1041 }
1042 
1043 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1044                                                   SelectionDAG &DAG,
1045                                                   MachineFrameInfo &MFI,
1046                                                   int ClobberedFI) const {
1047   SmallVector<SDValue, 8> ArgChains;
1048   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1049   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1050 
1051   // Include the original chain at the beginning of the list. When this is
1052   // used by target LowerCall hooks, this helps legalize find the
1053   // CALLSEQ_BEGIN node.
1054   ArgChains.push_back(Chain);
1055 
1056   // Add a chain value for each stack argument corresponding
1057   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1058                             UE = DAG.getEntryNode().getNode()->use_end();
1059        U != UE; ++U) {
1060     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1061       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1062         if (FI->getIndex() < 0) {
1063           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1064           int64_t InLastByte = InFirstByte;
1065           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1066 
1067           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1068               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1069             ArgChains.push_back(SDValue(L, 1));
1070         }
1071       }
1072     }
1073   }
1074 
1075   // Build a tokenfactor for all the chains.
1076   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1077 }
1078 
1079 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1080                                                  SmallVectorImpl<SDValue> &InVals,
1081                                                  StringRef Reason) const {
1082   SDValue Callee = CLI.Callee;
1083   SelectionDAG &DAG = CLI.DAG;
1084 
1085   const Function &Fn = DAG.getMachineFunction().getFunction();
1086 
1087   StringRef FuncName("<unknown>");
1088 
1089   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1090     FuncName = G->getSymbol();
1091   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1092     FuncName = G->getGlobal()->getName();
1093 
1094   DiagnosticInfoUnsupported NoCalls(
1095     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1096   DAG.getContext()->diagnose(NoCalls);
1097 
1098   if (!CLI.IsTailCall) {
1099     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1100       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1101   }
1102 
1103   return DAG.getEntryNode();
1104 }
1105 
1106 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1107                                         SmallVectorImpl<SDValue> &InVals) const {
1108   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1109 }
1110 
1111 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1112                                                       SelectionDAG &DAG) const {
1113   const Function &Fn = DAG.getMachineFunction().getFunction();
1114 
1115   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1116                                             SDLoc(Op).getDebugLoc());
1117   DAG.getContext()->diagnose(NoDynamicAlloca);
1118   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1119   return DAG.getMergeValues(Ops, SDLoc());
1120 }
1121 
1122 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1123                                              SelectionDAG &DAG) const {
1124   switch (Op.getOpcode()) {
1125   default:
1126     Op->print(errs(), &DAG);
1127     llvm_unreachable("Custom lowering code for this"
1128                      "instruction is not implemented yet!");
1129     break;
1130   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1131   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1132   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1133   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1134   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1135   case ISD::FREM: return LowerFREM(Op, DAG);
1136   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1137   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1138   case ISD::FRINT: return LowerFRINT(Op, DAG);
1139   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1140   case ISD::FROUND: return LowerFROUND(Op, DAG);
1141   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1142   case ISD::FLOG:
1143     return LowerFLOG(Op, DAG, 1 / AMDGPU_LOG2E_F);
1144   case ISD::FLOG10:
1145     return LowerFLOG(Op, DAG, AMDGPU_LN2_F / AMDGPU_LN10_F);
1146   case ISD::FEXP:
1147     return lowerFEXP(Op, DAG);
1148   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1149   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1150   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1151   case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
1152   case ISD::FP_TO_UINT: return LowerFP_TO_UINT(Op, DAG);
1153   case ISD::CTTZ:
1154   case ISD::CTTZ_ZERO_UNDEF:
1155   case ISD::CTLZ:
1156   case ISD::CTLZ_ZERO_UNDEF:
1157     return LowerCTLZ_CTTZ(Op, DAG);
1158   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1159   }
1160   return Op;
1161 }
1162 
1163 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1164                                               SmallVectorImpl<SDValue> &Results,
1165                                               SelectionDAG &DAG) const {
1166   switch (N->getOpcode()) {
1167   case ISD::SIGN_EXTEND_INREG:
1168     // Different parts of legalization seem to interpret which type of
1169     // sign_extend_inreg is the one to check for custom lowering. The extended
1170     // from type is what really matters, but some places check for custom
1171     // lowering of the result type. This results in trying to use
1172     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1173     // nothing here and let the illegal result integer be handled normally.
1174     return;
1175   default:
1176     return;
1177   }
1178 }
1179 
1180 static bool hasDefinedInitializer(const GlobalValue *GV) {
1181   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1182   if (!GVar || !GVar->hasInitializer())
1183     return false;
1184 
1185   return !isa<UndefValue>(GVar->getInitializer());
1186 }
1187 
1188 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1189                                                  SDValue Op,
1190                                                  SelectionDAG &DAG) const {
1191 
1192   const DataLayout &DL = DAG.getDataLayout();
1193   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1194   const GlobalValue *GV = G->getGlobal();
1195 
1196   if (G->getAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
1197       G->getAddressSpace() == AMDGPUAS::REGION_ADDRESS) {
1198     if (!MFI->isEntryFunction()) {
1199       const Function &Fn = DAG.getMachineFunction().getFunction();
1200       DiagnosticInfoUnsupported BadLDSDecl(
1201         Fn, "local memory global used by non-kernel function", SDLoc(Op).getDebugLoc());
1202       DAG.getContext()->diagnose(BadLDSDecl);
1203     }
1204 
1205     // XXX: What does the value of G->getOffset() mean?
1206     assert(G->getOffset() == 0 &&
1207          "Do not know what to do with an non-zero offset");
1208 
1209     // TODO: We could emit code to handle the initialization somewhere.
1210     if (!hasDefinedInitializer(GV)) {
1211       unsigned Offset = MFI->allocateLDSGlobal(DL, *GV);
1212       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1213     }
1214   }
1215 
1216   const Function &Fn = DAG.getMachineFunction().getFunction();
1217   DiagnosticInfoUnsupported BadInit(
1218       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1219   DAG.getContext()->diagnose(BadInit);
1220   return SDValue();
1221 }
1222 
1223 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1224                                                   SelectionDAG &DAG) const {
1225   SmallVector<SDValue, 8> Args;
1226 
1227   EVT VT = Op.getValueType();
1228   if (VT == MVT::v4i16 || VT == MVT::v4f16) {
1229     SDLoc SL(Op);
1230     SDValue Lo = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(0));
1231     SDValue Hi = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(1));
1232 
1233     SDValue BV = DAG.getBuildVector(MVT::v2i32, SL, { Lo, Hi });
1234     return DAG.getNode(ISD::BITCAST, SL, VT, BV);
1235   }
1236 
1237   for (const SDUse &U : Op->ops())
1238     DAG.ExtractVectorElements(U.get(), Args);
1239 
1240   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1241 }
1242 
1243 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1244                                                      SelectionDAG &DAG) const {
1245 
1246   SmallVector<SDValue, 8> Args;
1247   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1248   EVT VT = Op.getValueType();
1249   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1250                             VT.getVectorNumElements());
1251 
1252   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1253 }
1254 
1255 /// Generate Min/Max node
1256 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1257                                                    SDValue LHS, SDValue RHS,
1258                                                    SDValue True, SDValue False,
1259                                                    SDValue CC,
1260                                                    DAGCombinerInfo &DCI) const {
1261   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1262     return SDValue();
1263 
1264   SelectionDAG &DAG = DCI.DAG;
1265   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1266   switch (CCOpcode) {
1267   case ISD::SETOEQ:
1268   case ISD::SETONE:
1269   case ISD::SETUNE:
1270   case ISD::SETNE:
1271   case ISD::SETUEQ:
1272   case ISD::SETEQ:
1273   case ISD::SETFALSE:
1274   case ISD::SETFALSE2:
1275   case ISD::SETTRUE:
1276   case ISD::SETTRUE2:
1277   case ISD::SETUO:
1278   case ISD::SETO:
1279     break;
1280   case ISD::SETULE:
1281   case ISD::SETULT: {
1282     if (LHS == True)
1283       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1284     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1285   }
1286   case ISD::SETOLE:
1287   case ISD::SETOLT:
1288   case ISD::SETLE:
1289   case ISD::SETLT: {
1290     // Ordered. Assume ordered for undefined.
1291 
1292     // Only do this after legalization to avoid interfering with other combines
1293     // which might occur.
1294     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1295         !DCI.isCalledByLegalizer())
1296       return SDValue();
1297 
1298     // We need to permute the operands to get the correct NaN behavior. The
1299     // selected operand is the second one based on the failing compare with NaN,
1300     // so permute it based on the compare type the hardware uses.
1301     if (LHS == True)
1302       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1303     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1304   }
1305   case ISD::SETUGE:
1306   case ISD::SETUGT: {
1307     if (LHS == True)
1308       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1309     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1310   }
1311   case ISD::SETGT:
1312   case ISD::SETGE:
1313   case ISD::SETOGE:
1314   case ISD::SETOGT: {
1315     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1316         !DCI.isCalledByLegalizer())
1317       return SDValue();
1318 
1319     if (LHS == True)
1320       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1321     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1322   }
1323   case ISD::SETCC_INVALID:
1324     llvm_unreachable("Invalid setcc condcode!");
1325   }
1326   return SDValue();
1327 }
1328 
1329 std::pair<SDValue, SDValue>
1330 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1331   SDLoc SL(Op);
1332 
1333   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1334 
1335   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1336   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1337 
1338   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1339   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1340 
1341   return std::make_pair(Lo, Hi);
1342 }
1343 
1344 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1345   SDLoc SL(Op);
1346 
1347   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1348   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1349   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1350 }
1351 
1352 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1353   SDLoc SL(Op);
1354 
1355   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1356   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1357   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1358 }
1359 
1360 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1361                                               SelectionDAG &DAG) const {
1362   LoadSDNode *Load = cast<LoadSDNode>(Op);
1363   EVT VT = Op.getValueType();
1364 
1365 
1366   // If this is a 2 element vector, we really want to scalarize and not create
1367   // weird 1 element vectors.
1368   if (VT.getVectorNumElements() == 2)
1369     return scalarizeVectorLoad(Load, DAG);
1370 
1371   SDValue BasePtr = Load->getBasePtr();
1372   EVT MemVT = Load->getMemoryVT();
1373   SDLoc SL(Op);
1374 
1375   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1376 
1377   EVT LoVT, HiVT;
1378   EVT LoMemVT, HiMemVT;
1379   SDValue Lo, Hi;
1380 
1381   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1382   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1383   std::tie(Lo, Hi) = DAG.SplitVector(Op, SL, LoVT, HiVT);
1384 
1385   unsigned Size = LoMemVT.getStoreSize();
1386   unsigned BaseAlign = Load->getAlignment();
1387   unsigned HiAlign = MinAlign(BaseAlign, Size);
1388 
1389   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1390                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1391                                   BaseAlign, Load->getMemOperand()->getFlags());
1392   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, Size);
1393   SDValue HiLoad =
1394       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1395                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1396                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1397 
1398   SDValue Ops[] = {
1399     DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad),
1400     DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1401                 LoLoad.getValue(1), HiLoad.getValue(1))
1402   };
1403 
1404   return DAG.getMergeValues(Ops, SL);
1405 }
1406 
1407 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1408                                                SelectionDAG &DAG) const {
1409   StoreSDNode *Store = cast<StoreSDNode>(Op);
1410   SDValue Val = Store->getValue();
1411   EVT VT = Val.getValueType();
1412 
1413   // If this is a 2 element vector, we really want to scalarize and not create
1414   // weird 1 element vectors.
1415   if (VT.getVectorNumElements() == 2)
1416     return scalarizeVectorStore(Store, DAG);
1417 
1418   EVT MemVT = Store->getMemoryVT();
1419   SDValue Chain = Store->getChain();
1420   SDValue BasePtr = Store->getBasePtr();
1421   SDLoc SL(Op);
1422 
1423   EVT LoVT, HiVT;
1424   EVT LoMemVT, HiMemVT;
1425   SDValue Lo, Hi;
1426 
1427   std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);
1428   std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemVT);
1429   std::tie(Lo, Hi) = DAG.SplitVector(Val, SL, LoVT, HiVT);
1430 
1431   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1432 
1433   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1434   unsigned BaseAlign = Store->getAlignment();
1435   unsigned Size = LoMemVT.getStoreSize();
1436   unsigned HiAlign = MinAlign(BaseAlign, Size);
1437 
1438   SDValue LoStore =
1439       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1440                         Store->getMemOperand()->getFlags());
1441   SDValue HiStore =
1442       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1443                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1444 
1445   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1446 }
1447 
1448 // This is a shortcut for integer division because we have fast i32<->f32
1449 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1450 // float is enough to accurately represent up to a 24-bit signed integer.
1451 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1452                                             bool Sign) const {
1453   SDLoc DL(Op);
1454   EVT VT = Op.getValueType();
1455   SDValue LHS = Op.getOperand(0);
1456   SDValue RHS = Op.getOperand(1);
1457   MVT IntVT = MVT::i32;
1458   MVT FltVT = MVT::f32;
1459 
1460   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1461   if (LHSSignBits < 9)
1462     return SDValue();
1463 
1464   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1465   if (RHSSignBits < 9)
1466     return SDValue();
1467 
1468   unsigned BitSize = VT.getSizeInBits();
1469   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1470   unsigned DivBits = BitSize - SignBits;
1471   if (Sign)
1472     ++DivBits;
1473 
1474   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1475   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1476 
1477   SDValue jq = DAG.getConstant(1, DL, IntVT);
1478 
1479   if (Sign) {
1480     // char|short jq = ia ^ ib;
1481     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1482 
1483     // jq = jq >> (bitsize - 2)
1484     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1485                      DAG.getConstant(BitSize - 2, DL, VT));
1486 
1487     // jq = jq | 0x1
1488     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1489   }
1490 
1491   // int ia = (int)LHS;
1492   SDValue ia = LHS;
1493 
1494   // int ib, (int)RHS;
1495   SDValue ib = RHS;
1496 
1497   // float fa = (float)ia;
1498   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1499 
1500   // float fb = (float)ib;
1501   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1502 
1503   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1504                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1505 
1506   // fq = trunc(fq);
1507   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1508 
1509   // float fqneg = -fq;
1510   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1511 
1512   // float fr = mad(fqneg, fb, fa);
1513   unsigned OpCode = Subtarget->hasFP32Denormals() ?
1514                     (unsigned)AMDGPUISD::FMAD_FTZ :
1515                     (unsigned)ISD::FMAD;
1516   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1517 
1518   // int iq = (int)fq;
1519   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1520 
1521   // fr = fabs(fr);
1522   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1523 
1524   // fb = fabs(fb);
1525   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1526 
1527   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1528 
1529   // int cv = fr >= fb;
1530   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1531 
1532   // jq = (cv ? jq : 0);
1533   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1534 
1535   // dst = iq + jq;
1536   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1537 
1538   // Rem needs compensation, it's easier to recompute it
1539   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1540   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1541 
1542   // Truncate to number of bits this divide really is.
1543   if (Sign) {
1544     SDValue InRegSize
1545       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1546     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1547     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1548   } else {
1549     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1550     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1551     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1552   }
1553 
1554   return DAG.getMergeValues({ Div, Rem }, DL);
1555 }
1556 
1557 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1558                                       SelectionDAG &DAG,
1559                                       SmallVectorImpl<SDValue> &Results) const {
1560   SDLoc DL(Op);
1561   EVT VT = Op.getValueType();
1562 
1563   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1564 
1565   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1566 
1567   SDValue One = DAG.getConstant(1, DL, HalfVT);
1568   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1569 
1570   //HiLo split
1571   SDValue LHS = Op.getOperand(0);
1572   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1573   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1574 
1575   SDValue RHS = Op.getOperand(1);
1576   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1577   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1578 
1579   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1580       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1581 
1582     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1583                               LHS_Lo, RHS_Lo);
1584 
1585     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1586     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1587 
1588     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1589     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1590     return;
1591   }
1592 
1593   if (isTypeLegal(MVT::i64)) {
1594     // Compute denominator reciprocal.
1595     unsigned FMAD = Subtarget->hasFP32Denormals() ?
1596                     (unsigned)AMDGPUISD::FMAD_FTZ :
1597                     (unsigned)ISD::FMAD;
1598 
1599     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1600     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1601     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1602       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1603       Cvt_Lo);
1604     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1605     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1606       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1607     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1608       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1609     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1610     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1611       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1612       Mul1);
1613     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1614     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1615     SDValue Rcp64 = DAG.getBitcast(VT,
1616                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1617 
1618     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1619     SDValue One64  = DAG.getConstant(1, DL, VT);
1620     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1621     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1622 
1623     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1624     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1625     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1626     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1627                                     Zero);
1628     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1629                                     One);
1630 
1631     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1632                                   Mulhi1_Lo, Zero1);
1633     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1634                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1635     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1636     SDValue Add1 = DAG.getBitcast(VT,
1637                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1638 
1639     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1640     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1641     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1642                                     Zero);
1643     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1644                                     One);
1645 
1646     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1647                                   Mulhi2_Lo, Zero1);
1648     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1649                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1650     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1651                                   Zero, Add2_Lo.getValue(1));
1652     SDValue Add2 = DAG.getBitcast(VT,
1653                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1654     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1655 
1656     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1657 
1658     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1659     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1660     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1661                                   Mul3_Lo, Zero1);
1662     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1663                                   Mul3_Hi, Sub1_Lo.getValue(1));
1664     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1665     SDValue Sub1 = DAG.getBitcast(VT,
1666                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1667 
1668     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1669     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1670                                  ISD::SETUGE);
1671     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1672                                  ISD::SETUGE);
1673     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1674 
1675     // TODO: Here and below portions of the code can be enclosed into if/endif.
1676     // Currently control flow is unconditional and we have 4 selects after
1677     // potential endif to substitute PHIs.
1678 
1679     // if C3 != 0 ...
1680     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1681                                   RHS_Lo, Zero1);
1682     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1683                                   RHS_Hi, Sub1_Lo.getValue(1));
1684     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1685                                   Zero, Sub2_Lo.getValue(1));
1686     SDValue Sub2 = DAG.getBitcast(VT,
1687                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1688 
1689     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1690 
1691     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1692                                  ISD::SETUGE);
1693     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1694                                  ISD::SETUGE);
1695     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1696 
1697     // if (C6 != 0)
1698     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1699 
1700     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1701                                   RHS_Lo, Zero1);
1702     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1703                                   RHS_Hi, Sub2_Lo.getValue(1));
1704     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1705                                   Zero, Sub3_Lo.getValue(1));
1706     SDValue Sub3 = DAG.getBitcast(VT,
1707                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1708 
1709     // endif C6
1710     // endif C3
1711 
1712     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1713     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1714 
1715     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1716     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1717 
1718     Results.push_back(Div);
1719     Results.push_back(Rem);
1720 
1721     return;
1722   }
1723 
1724   // r600 expandion.
1725   // Get Speculative values
1726   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1727   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1728 
1729   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1730   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1731   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1732 
1733   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1734   SDValue DIV_Lo = Zero;
1735 
1736   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1737 
1738   for (unsigned i = 0; i < halfBitWidth; ++i) {
1739     const unsigned bitPos = halfBitWidth - i - 1;
1740     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1741     // Get value of high bit
1742     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1743     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1744     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1745 
1746     // Shift
1747     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1748     // Add LHS high bit
1749     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1750 
1751     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1752     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1753 
1754     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1755 
1756     // Update REM
1757     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1758     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1759   }
1760 
1761   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1762   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1763   Results.push_back(DIV);
1764   Results.push_back(REM);
1765 }
1766 
1767 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1768                                            SelectionDAG &DAG) const {
1769   SDLoc DL(Op);
1770   EVT VT = Op.getValueType();
1771 
1772   if (VT == MVT::i64) {
1773     SmallVector<SDValue, 2> Results;
1774     LowerUDIVREM64(Op, DAG, Results);
1775     return DAG.getMergeValues(Results, DL);
1776   }
1777 
1778   if (VT == MVT::i32) {
1779     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1780       return Res;
1781   }
1782 
1783   SDValue Num = Op.getOperand(0);
1784   SDValue Den = Op.getOperand(1);
1785 
1786   // RCP =  URECIP(Den) = 2^32 / Den + e
1787   // e is rounding error.
1788   SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den);
1789 
1790   // RCP_LO = mul(RCP, Den) */
1791   SDValue RCP_LO = DAG.getNode(ISD::MUL, DL, VT, RCP, Den);
1792 
1793   // RCP_HI = mulhu (RCP, Den) */
1794   SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den);
1795 
1796   // NEG_RCP_LO = -RCP_LO
1797   SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
1798                                                      RCP_LO);
1799 
1800   // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO)
1801   SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1802                                            NEG_RCP_LO, RCP_LO,
1803                                            ISD::SETEQ);
1804   // Calculate the rounding error from the URECIP instruction
1805   // E = mulhu(ABS_RCP_LO, RCP)
1806   SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP);
1807 
1808   // RCP_A_E = RCP + E
1809   SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E);
1810 
1811   // RCP_S_E = RCP - E
1812   SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E);
1813 
1814   // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E)
1815   SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, DL, VT),
1816                                      RCP_A_E, RCP_S_E,
1817                                      ISD::SETEQ);
1818   // Quotient = mulhu(Tmp0, Num)
1819   SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num);
1820 
1821   // Num_S_Remainder = Quotient * Den
1822   SDValue Num_S_Remainder = DAG.getNode(ISD::MUL, DL, VT, Quotient, Den);
1823 
1824   // Remainder = Num - Num_S_Remainder
1825   SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder);
1826 
1827   // Remainder_GE_Den = (Remainder >= Den ? -1 : 0)
1828   SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den,
1829                                                  DAG.getConstant(-1, DL, VT),
1830                                                  DAG.getConstant(0, DL, VT),
1831                                                  ISD::SETUGE);
1832   // Remainder_GE_Zero = (Num >= Num_S_Remainder ? -1 : 0)
1833   SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Num,
1834                                                   Num_S_Remainder,
1835                                                   DAG.getConstant(-1, DL, VT),
1836                                                   DAG.getConstant(0, DL, VT),
1837                                                   ISD::SETUGE);
1838   // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero
1839   SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den,
1840                                                Remainder_GE_Zero);
1841 
1842   // Calculate Division result:
1843 
1844   // Quotient_A_One = Quotient + 1
1845   SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient,
1846                                        DAG.getConstant(1, DL, VT));
1847 
1848   // Quotient_S_One = Quotient - 1
1849   SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient,
1850                                        DAG.getConstant(1, DL, VT));
1851 
1852   // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One)
1853   SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1854                                      Quotient, Quotient_A_One, ISD::SETEQ);
1855 
1856   // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div)
1857   Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1858                             Quotient_S_One, Div, ISD::SETEQ);
1859 
1860   // Calculate Rem result:
1861 
1862   // Remainder_S_Den = Remainder - Den
1863   SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den);
1864 
1865   // Remainder_A_Den = Remainder + Den
1866   SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den);
1867 
1868   // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den)
1869   SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, DL, VT),
1870                                     Remainder, Remainder_S_Den, ISD::SETEQ);
1871 
1872   // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem)
1873   Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, DL, VT),
1874                             Remainder_A_Den, Rem, ISD::SETEQ);
1875   SDValue Ops[2] = {
1876     Div,
1877     Rem
1878   };
1879   return DAG.getMergeValues(Ops, DL);
1880 }
1881 
1882 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
1883                                            SelectionDAG &DAG) const {
1884   SDLoc DL(Op);
1885   EVT VT = Op.getValueType();
1886 
1887   SDValue LHS = Op.getOperand(0);
1888   SDValue RHS = Op.getOperand(1);
1889 
1890   SDValue Zero = DAG.getConstant(0, DL, VT);
1891   SDValue NegOne = DAG.getConstant(-1, DL, VT);
1892 
1893   if (VT == MVT::i32) {
1894     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
1895       return Res;
1896   }
1897 
1898   if (VT == MVT::i64 &&
1899       DAG.ComputeNumSignBits(LHS) > 32 &&
1900       DAG.ComputeNumSignBits(RHS) > 32) {
1901     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1902 
1903     //HiLo split
1904     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1905     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1906     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1907                                  LHS_Lo, RHS_Lo);
1908     SDValue Res[2] = {
1909       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
1910       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
1911     };
1912     return DAG.getMergeValues(Res, DL);
1913   }
1914 
1915   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
1916   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
1917   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
1918   SDValue RSign = LHSign; // Remainder sign is the same as LHS
1919 
1920   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
1921   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
1922 
1923   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
1924   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
1925 
1926   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
1927   SDValue Rem = Div.getValue(1);
1928 
1929   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
1930   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
1931 
1932   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
1933   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
1934 
1935   SDValue Res[2] = {
1936     Div,
1937     Rem
1938   };
1939   return DAG.getMergeValues(Res, DL);
1940 }
1941 
1942 // (frem x, y) -> (fsub x, (fmul (ftrunc (fdiv x, y)), y))
1943 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
1944   SDLoc SL(Op);
1945   EVT VT = Op.getValueType();
1946   SDValue X = Op.getOperand(0);
1947   SDValue Y = Op.getOperand(1);
1948 
1949   // TODO: Should this propagate fast-math-flags?
1950 
1951   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y);
1952   SDValue Floor = DAG.getNode(ISD::FTRUNC, SL, VT, Div);
1953   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Floor, Y);
1954 
1955   return DAG.getNode(ISD::FSUB, SL, VT, X, Mul);
1956 }
1957 
1958 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
1959   SDLoc SL(Op);
1960   SDValue Src = Op.getOperand(0);
1961 
1962   // result = trunc(src)
1963   // if (src > 0.0 && src != result)
1964   //   result += 1.0
1965 
1966   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
1967 
1968   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
1969   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
1970 
1971   EVT SetCCVT =
1972       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
1973 
1974   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
1975   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
1976   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
1977 
1978   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
1979   // TODO: Should this propagate fast-math-flags?
1980   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
1981 }
1982 
1983 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
1984                                   SelectionDAG &DAG) {
1985   const unsigned FractBits = 52;
1986   const unsigned ExpBits = 11;
1987 
1988   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
1989                                 Hi,
1990                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
1991                                 DAG.getConstant(ExpBits, SL, MVT::i32));
1992   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
1993                             DAG.getConstant(1023, SL, MVT::i32));
1994 
1995   return Exp;
1996 }
1997 
1998 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
1999   SDLoc SL(Op);
2000   SDValue Src = Op.getOperand(0);
2001 
2002   assert(Op.getValueType() == MVT::f64);
2003 
2004   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2005   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2006 
2007   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2008 
2009   // Extract the upper half, since this is where we will find the sign and
2010   // exponent.
2011   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2012 
2013   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2014 
2015   const unsigned FractBits = 52;
2016 
2017   // Extract the sign bit.
2018   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2019   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2020 
2021   // Extend back to 64-bits.
2022   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2023   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2024 
2025   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2026   const SDValue FractMask
2027     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2028 
2029   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2030   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2031   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2032 
2033   EVT SetCCVT =
2034       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2035 
2036   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2037 
2038   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2039   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2040 
2041   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2042   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2043 
2044   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2045 }
2046 
2047 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2048   SDLoc SL(Op);
2049   SDValue Src = Op.getOperand(0);
2050 
2051   assert(Op.getValueType() == MVT::f64);
2052 
2053   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2054   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2055   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2056 
2057   // TODO: Should this propagate fast-math-flags?
2058 
2059   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2060   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2061 
2062   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2063 
2064   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2065   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2066 
2067   EVT SetCCVT =
2068       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2069   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2070 
2071   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2072 }
2073 
2074 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2075   // FNEARBYINT and FRINT are the same, except in their handling of FP
2076   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2077   // rint, so just treat them as equivalent.
2078   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2079 }
2080 
2081 // XXX - May require not supporting f32 denormals?
2082 
2083 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2084 // compare and vselect end up producing worse code than scalarizing the whole
2085 // operation.
2086 SDValue AMDGPUTargetLowering::LowerFROUND32_16(SDValue Op, SelectionDAG &DAG) const {
2087   SDLoc SL(Op);
2088   SDValue X = Op.getOperand(0);
2089   EVT VT = Op.getValueType();
2090 
2091   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2092 
2093   // TODO: Should this propagate fast-math-flags?
2094 
2095   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2096 
2097   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2098 
2099   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2100   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2101   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2102 
2103   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2104 
2105   EVT SetCCVT =
2106       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2107 
2108   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2109 
2110   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2111 
2112   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2113 }
2114 
2115 SDValue AMDGPUTargetLowering::LowerFROUND64(SDValue Op, SelectionDAG &DAG) const {
2116   SDLoc SL(Op);
2117   SDValue X = Op.getOperand(0);
2118 
2119   SDValue L = DAG.getNode(ISD::BITCAST, SL, MVT::i64, X);
2120 
2121   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2122   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2123   const SDValue NegOne = DAG.getConstant(-1, SL, MVT::i32);
2124   const SDValue FiftyOne = DAG.getConstant(51, SL, MVT::i32);
2125   EVT SetCCVT =
2126       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2127 
2128   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, X);
2129 
2130   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC, One);
2131 
2132   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2133 
2134   const SDValue Mask = DAG.getConstant(INT64_C(0x000fffffffffffff), SL,
2135                                        MVT::i64);
2136 
2137   SDValue M = DAG.getNode(ISD::SRA, SL, MVT::i64, Mask, Exp);
2138   SDValue D = DAG.getNode(ISD::SRA, SL, MVT::i64,
2139                           DAG.getConstant(INT64_C(0x0008000000000000), SL,
2140                                           MVT::i64),
2141                           Exp);
2142 
2143   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, L, M);
2144   SDValue Tmp1 = DAG.getSetCC(SL, SetCCVT,
2145                               DAG.getConstant(0, SL, MVT::i64), Tmp0,
2146                               ISD::SETNE);
2147 
2148   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, Tmp1,
2149                              D, DAG.getConstant(0, SL, MVT::i64));
2150   SDValue K = DAG.getNode(ISD::ADD, SL, MVT::i64, L, Tmp2);
2151 
2152   K = DAG.getNode(ISD::AND, SL, MVT::i64, K, DAG.getNOT(SL, M, MVT::i64));
2153   K = DAG.getNode(ISD::BITCAST, SL, MVT::f64, K);
2154 
2155   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2156   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2157   SDValue ExpEqNegOne = DAG.getSetCC(SL, SetCCVT, NegOne, Exp, ISD::SETEQ);
2158 
2159   SDValue Mag = DAG.getNode(ISD::SELECT, SL, MVT::f64,
2160                             ExpEqNegOne,
2161                             DAG.getConstantFP(1.0, SL, MVT::f64),
2162                             DAG.getConstantFP(0.0, SL, MVT::f64));
2163 
2164   SDValue S = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, Mag, X);
2165 
2166   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpLt0, S, K);
2167   K = DAG.getNode(ISD::SELECT, SL, MVT::f64, ExpGt51, X, K);
2168 
2169   return K;
2170 }
2171 
2172 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2173   EVT VT = Op.getValueType();
2174 
2175   if (VT == MVT::f32 || VT == MVT::f16)
2176     return LowerFROUND32_16(Op, DAG);
2177 
2178   if (VT == MVT::f64)
2179     return LowerFROUND64(Op, DAG);
2180 
2181   llvm_unreachable("unhandled type");
2182 }
2183 
2184 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2185   SDLoc SL(Op);
2186   SDValue Src = Op.getOperand(0);
2187 
2188   // result = trunc(src);
2189   // if (src < 0.0 && src != result)
2190   //   result += -1.0.
2191 
2192   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2193 
2194   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2195   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2196 
2197   EVT SetCCVT =
2198       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2199 
2200   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2201   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2202   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2203 
2204   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2205   // TODO: Should this propagate fast-math-flags?
2206   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2207 }
2208 
2209 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2210                                         double Log2BaseInverted) const {
2211   EVT VT = Op.getValueType();
2212 
2213   SDLoc SL(Op);
2214   SDValue Operand = Op.getOperand(0);
2215   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2216   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2217 
2218   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2219 }
2220 
2221 // Return M_LOG2E of appropriate type
2222 static SDValue getLog2EVal(SelectionDAG &DAG, const SDLoc &SL, EVT VT) {
2223   switch (VT.getScalarType().getSimpleVT().SimpleTy) {
2224   case MVT::f32:
2225     return DAG.getConstantFP(1.44269504088896340735992468100189214f, SL, VT);
2226   case MVT::f16:
2227     return DAG.getConstantFP(
2228       APFloat(APFloat::IEEEhalf(), "1.44269504088896340735992468100189214"),
2229       SL, VT);
2230   case MVT::f64:
2231     return DAG.getConstantFP(
2232       APFloat(APFloat::IEEEdouble(), "0x1.71547652b82fep+0"), SL, VT);
2233   default:
2234     llvm_unreachable("unsupported fp type");
2235   }
2236 }
2237 
2238 // exp2(M_LOG2E_F * f);
2239 SDValue AMDGPUTargetLowering::lowerFEXP(SDValue Op, SelectionDAG &DAG) const {
2240   EVT VT = Op.getValueType();
2241   SDLoc SL(Op);
2242   SDValue Src = Op.getOperand(0);
2243 
2244   const SDValue K = getLog2EVal(DAG, SL, VT);
2245   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Src, K, Op->getFlags());
2246   return DAG.getNode(ISD::FEXP2, SL, VT, Mul, Op->getFlags());
2247 }
2248 
2249 static bool isCtlzOpc(unsigned Opc) {
2250   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2251 }
2252 
2253 static bool isCttzOpc(unsigned Opc) {
2254   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2255 }
2256 
2257 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2258   SDLoc SL(Op);
2259   SDValue Src = Op.getOperand(0);
2260   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2261                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2262 
2263   unsigned ISDOpc, NewOpc;
2264   if (isCtlzOpc(Op.getOpcode())) {
2265     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2266     NewOpc = AMDGPUISD::FFBH_U32;
2267   } else if (isCttzOpc(Op.getOpcode())) {
2268     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2269     NewOpc = AMDGPUISD::FFBL_B32;
2270   } else
2271     llvm_unreachable("Unexpected OPCode!!!");
2272 
2273 
2274   if (ZeroUndef && Src.getValueType() == MVT::i32)
2275     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2276 
2277   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2278 
2279   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2280   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2281 
2282   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2283   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2284 
2285   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2286                                    *DAG.getContext(), MVT::i32);
2287 
2288   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2289   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2290 
2291   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2292   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2293 
2294   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2295   SDValue Add, NewOpr;
2296   if (isCtlzOpc(Op.getOpcode())) {
2297     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2298     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2299     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2300   } else {
2301     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2302     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2303     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2304   }
2305 
2306   if (!ZeroUndef) {
2307     // Test if the full 64-bit input is zero.
2308 
2309     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2310     // which we probably don't want.
2311     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2312     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2313     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2314 
2315     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2316     // with the same cycles, otherwise it is slower.
2317     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2318     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2319 
2320     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2321 
2322     // The instruction returns -1 for 0 input, but the defined intrinsic
2323     // behavior is to return the number of bits.
2324     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2325                          SrcIsZero, Bits32, NewOpr);
2326   }
2327 
2328   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2329 }
2330 
2331 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2332                                                bool Signed) const {
2333   // Unsigned
2334   // cul2f(ulong u)
2335   //{
2336   //  uint lz = clz(u);
2337   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2338   //  u = (u << lz) & 0x7fffffffffffffffUL;
2339   //  ulong t = u & 0xffffffffffUL;
2340   //  uint v = (e << 23) | (uint)(u >> 40);
2341   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2342   //  return as_float(v + r);
2343   //}
2344   // Signed
2345   // cl2f(long l)
2346   //{
2347   //  long s = l >> 63;
2348   //  float r = cul2f((l + s) ^ s);
2349   //  return s ? -r : r;
2350   //}
2351 
2352   SDLoc SL(Op);
2353   SDValue Src = Op.getOperand(0);
2354   SDValue L = Src;
2355 
2356   SDValue S;
2357   if (Signed) {
2358     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2359     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2360 
2361     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2362     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2363   }
2364 
2365   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2366                                    *DAG.getContext(), MVT::f32);
2367 
2368 
2369   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2370   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2371   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2372   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2373 
2374   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2375   SDValue E = DAG.getSelect(SL, MVT::i32,
2376     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2377     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2378     ZeroI32);
2379 
2380   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2381     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2382     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2383 
2384   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2385                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2386 
2387   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2388                              U, DAG.getConstant(40, SL, MVT::i64));
2389 
2390   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2391     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2392     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2393 
2394   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2395   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2396   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2397 
2398   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2399 
2400   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2401 
2402   SDValue R = DAG.getSelect(SL, MVT::i32,
2403     RCmp,
2404     One,
2405     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2406   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2407   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2408 
2409   if (!Signed)
2410     return R;
2411 
2412   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2413   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2414 }
2415 
2416 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2417                                                bool Signed) const {
2418   SDLoc SL(Op);
2419   SDValue Src = Op.getOperand(0);
2420 
2421   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2422 
2423   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2424                            DAG.getConstant(0, SL, MVT::i32));
2425   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2426                            DAG.getConstant(1, SL, MVT::i32));
2427 
2428   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2429                               SL, MVT::f64, Hi);
2430 
2431   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2432 
2433   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2434                               DAG.getConstant(32, SL, MVT::i32));
2435   // TODO: Should this propagate fast-math-flags?
2436   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2437 }
2438 
2439 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2440                                                SelectionDAG &DAG) const {
2441   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2442          "operation should be legal");
2443 
2444   // TODO: Factor out code common with LowerSINT_TO_FP.
2445 
2446   EVT DestVT = Op.getValueType();
2447   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2448     SDLoc DL(Op);
2449     SDValue Src = Op.getOperand(0);
2450 
2451     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2452     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2453     SDValue FPRound =
2454         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2455 
2456     return FPRound;
2457   }
2458 
2459   if (DestVT == MVT::f32)
2460     return LowerINT_TO_FP32(Op, DAG, false);
2461 
2462   assert(DestVT == MVT::f64);
2463   return LowerINT_TO_FP64(Op, DAG, false);
2464 }
2465 
2466 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2467                                               SelectionDAG &DAG) const {
2468   assert(Op.getOperand(0).getValueType() == MVT::i64 &&
2469          "operation should be legal");
2470 
2471   // TODO: Factor out code common with LowerUINT_TO_FP.
2472 
2473   EVT DestVT = Op.getValueType();
2474   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2475     SDLoc DL(Op);
2476     SDValue Src = Op.getOperand(0);
2477 
2478     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2479     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2480     SDValue FPRound =
2481         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2482 
2483     return FPRound;
2484   }
2485 
2486   if (DestVT == MVT::f32)
2487     return LowerINT_TO_FP32(Op, DAG, true);
2488 
2489   assert(DestVT == MVT::f64);
2490   return LowerINT_TO_FP64(Op, DAG, true);
2491 }
2492 
2493 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2494                                                bool Signed) const {
2495   SDLoc SL(Op);
2496 
2497   SDValue Src = Op.getOperand(0);
2498 
2499   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2500 
2501   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2502                                  MVT::f64);
2503   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2504                                  MVT::f64);
2505   // TODO: Should this propagate fast-math-flags?
2506   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2507 
2508   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2509 
2510 
2511   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2512 
2513   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2514                            MVT::i32, FloorMul);
2515   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2516 
2517   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2518 
2519   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2520 }
2521 
2522 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2523   SDLoc DL(Op);
2524   SDValue N0 = Op.getOperand(0);
2525 
2526   // Convert to target node to get known bits
2527   if (N0.getValueType() == MVT::f32)
2528     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2529 
2530   if (getTargetMachine().Options.UnsafeFPMath) {
2531     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2532     return SDValue();
2533   }
2534 
2535   assert(N0.getSimpleValueType() == MVT::f64);
2536 
2537   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2538   const unsigned ExpMask = 0x7ff;
2539   const unsigned ExpBiasf64 = 1023;
2540   const unsigned ExpBiasf16 = 15;
2541   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2542   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2543   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2544   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2545                            DAG.getConstant(32, DL, MVT::i64));
2546   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2547   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2548   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2549                           DAG.getConstant(20, DL, MVT::i64));
2550   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2551                   DAG.getConstant(ExpMask, DL, MVT::i32));
2552   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2553   // add the f16 bias (15) to get the biased exponent for the f16 format.
2554   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2555                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2556 
2557   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2558                           DAG.getConstant(8, DL, MVT::i32));
2559   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2560                   DAG.getConstant(0xffe, DL, MVT::i32));
2561 
2562   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2563                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2564   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2565 
2566   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2567   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2568 
2569   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2570   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2571       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2572                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2573 
2574   // N = M | (E << 12);
2575   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2576       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2577                   DAG.getConstant(12, DL, MVT::i32)));
2578 
2579   // B = clamp(1-E, 0, 13);
2580   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2581                                   One, E);
2582   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2583   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2584                   DAG.getConstant(13, DL, MVT::i32));
2585 
2586   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2587                                    DAG.getConstant(0x1000, DL, MVT::i32));
2588 
2589   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2590   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2591   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2592   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2593 
2594   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2595   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2596                               DAG.getConstant(0x7, DL, MVT::i32));
2597   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2598                   DAG.getConstant(2, DL, MVT::i32));
2599   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2600                                One, Zero, ISD::SETEQ);
2601   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2602                                One, Zero, ISD::SETGT);
2603   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2604   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2605 
2606   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2607                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2608   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2609                       I, V, ISD::SETEQ);
2610 
2611   // Extract the sign bit.
2612   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2613                             DAG.getConstant(16, DL, MVT::i32));
2614   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2615                      DAG.getConstant(0x8000, DL, MVT::i32));
2616 
2617   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2618   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2619 }
2620 
2621 SDValue AMDGPUTargetLowering::LowerFP_TO_SINT(SDValue Op,
2622                                               SelectionDAG &DAG) const {
2623   SDValue Src = Op.getOperand(0);
2624 
2625   // TODO: Factor out code common with LowerFP_TO_UINT.
2626 
2627   EVT SrcVT = Src.getValueType();
2628   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2629     SDLoc DL(Op);
2630 
2631     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2632     SDValue FpToInt32 =
2633         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2634 
2635     return FpToInt32;
2636   }
2637 
2638   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2639     return LowerFP64_TO_INT(Op, DAG, true);
2640 
2641   return SDValue();
2642 }
2643 
2644 SDValue AMDGPUTargetLowering::LowerFP_TO_UINT(SDValue Op,
2645                                               SelectionDAG &DAG) const {
2646   SDValue Src = Op.getOperand(0);
2647 
2648   // TODO: Factor out code common with LowerFP_TO_SINT.
2649 
2650   EVT SrcVT = Src.getValueType();
2651   if (Subtarget->has16BitInsts() && SrcVT == MVT::f16) {
2652     SDLoc DL(Op);
2653 
2654     SDValue FPExtend = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Src);
2655     SDValue FpToInt32 =
2656         DAG.getNode(Op.getOpcode(), DL, MVT::i64, FPExtend);
2657 
2658     return FpToInt32;
2659   }
2660 
2661   if (Op.getValueType() == MVT::i64 && Src.getValueType() == MVT::f64)
2662     return LowerFP64_TO_INT(Op, DAG, false);
2663 
2664   return SDValue();
2665 }
2666 
2667 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2668                                                      SelectionDAG &DAG) const {
2669   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2670   MVT VT = Op.getSimpleValueType();
2671   MVT ScalarVT = VT.getScalarType();
2672 
2673   assert(VT.isVector());
2674 
2675   SDValue Src = Op.getOperand(0);
2676   SDLoc DL(Op);
2677 
2678   // TODO: Don't scalarize on Evergreen?
2679   unsigned NElts = VT.getVectorNumElements();
2680   SmallVector<SDValue, 8> Args;
2681   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2682 
2683   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2684   for (unsigned I = 0; I < NElts; ++I)
2685     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2686 
2687   return DAG.getBuildVector(VT, DL, Args);
2688 }
2689 
2690 //===----------------------------------------------------------------------===//
2691 // Custom DAG optimizations
2692 //===----------------------------------------------------------------------===//
2693 
2694 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2695   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2696 }
2697 
2698 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2699   EVT VT = Op.getValueType();
2700   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2701                                      // as unsigned 24-bit values.
2702     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2703 }
2704 
2705 static bool simplifyI24(SDNode *Node24, unsigned OpIdx,
2706                         TargetLowering::DAGCombinerInfo &DCI) {
2707 
2708   SelectionDAG &DAG = DCI.DAG;
2709   SDValue Op = Node24->getOperand(OpIdx);
2710   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2711   EVT VT = Op.getValueType();
2712 
2713   APInt Demanded = APInt::getLowBitsSet(VT.getSizeInBits(), 24);
2714   APInt KnownZero, KnownOne;
2715   TargetLowering::TargetLoweringOpt TLO(DAG, true, true);
2716   if (TLI.SimplifyDemandedBits(Node24, OpIdx, Demanded, DCI, TLO))
2717     return true;
2718 
2719   return false;
2720 }
2721 
2722 template <typename IntTy>
2723 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2724                                uint32_t Width, const SDLoc &DL) {
2725   if (Width + Offset < 32) {
2726     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2727     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2728     return DAG.getConstant(Result, DL, MVT::i32);
2729   }
2730 
2731   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2732 }
2733 
2734 static bool hasVolatileUser(SDNode *Val) {
2735   for (SDNode *U : Val->uses()) {
2736     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2737       if (M->isVolatile())
2738         return true;
2739     }
2740   }
2741 
2742   return false;
2743 }
2744 
2745 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2746   // i32 vectors are the canonical memory type.
2747   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2748     return false;
2749 
2750   if (!VT.isByteSized())
2751     return false;
2752 
2753   unsigned Size = VT.getStoreSize();
2754 
2755   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2756     return false;
2757 
2758   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2759     return false;
2760 
2761   return true;
2762 }
2763 
2764 // Replace load of an illegal type with a store of a bitcast to a friendlier
2765 // type.
2766 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2767                                                  DAGCombinerInfo &DCI) const {
2768   if (!DCI.isBeforeLegalize())
2769     return SDValue();
2770 
2771   LoadSDNode *LN = cast<LoadSDNode>(N);
2772   if (LN->isVolatile() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2773     return SDValue();
2774 
2775   SDLoc SL(N);
2776   SelectionDAG &DAG = DCI.DAG;
2777   EVT VT = LN->getMemoryVT();
2778 
2779   unsigned Size = VT.getStoreSize();
2780   unsigned Align = LN->getAlignment();
2781   if (Align < Size && isTypeLegal(VT)) {
2782     bool IsFast;
2783     unsigned AS = LN->getAddressSpace();
2784 
2785     // Expand unaligned loads earlier than legalization. Due to visitation order
2786     // problems during legalization, the emitted instructions to pack and unpack
2787     // the bytes again are not eliminated in the case of an unaligned copy.
2788     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2789       if (VT.isVector())
2790         return scalarizeVectorLoad(LN, DAG);
2791 
2792       SDValue Ops[2];
2793       std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2794       return DAG.getMergeValues(Ops, SDLoc(N));
2795     }
2796 
2797     if (!IsFast)
2798       return SDValue();
2799   }
2800 
2801   if (!shouldCombineMemoryType(VT))
2802     return SDValue();
2803 
2804   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2805 
2806   SDValue NewLoad
2807     = DAG.getLoad(NewVT, SL, LN->getChain(),
2808                   LN->getBasePtr(), LN->getMemOperand());
2809 
2810   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2811   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2812   return SDValue(N, 0);
2813 }
2814 
2815 // Replace store of an illegal type with a store of a bitcast to a friendlier
2816 // type.
2817 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2818                                                   DAGCombinerInfo &DCI) const {
2819   if (!DCI.isBeforeLegalize())
2820     return SDValue();
2821 
2822   StoreSDNode *SN = cast<StoreSDNode>(N);
2823   if (SN->isVolatile() || !ISD::isNormalStore(SN))
2824     return SDValue();
2825 
2826   EVT VT = SN->getMemoryVT();
2827   unsigned Size = VT.getStoreSize();
2828 
2829   SDLoc SL(N);
2830   SelectionDAG &DAG = DCI.DAG;
2831   unsigned Align = SN->getAlignment();
2832   if (Align < Size && isTypeLegal(VT)) {
2833     bool IsFast;
2834     unsigned AS = SN->getAddressSpace();
2835 
2836     // Expand unaligned stores earlier than legalization. Due to visitation
2837     // order problems during legalization, the emitted instructions to pack and
2838     // unpack the bytes again are not eliminated in the case of an unaligned
2839     // copy.
2840     if (!allowsMisalignedMemoryAccesses(VT, AS, Align, &IsFast)) {
2841       if (VT.isVector())
2842         return scalarizeVectorStore(SN, DAG);
2843 
2844       return expandUnalignedStore(SN, DAG);
2845     }
2846 
2847     if (!IsFast)
2848       return SDValue();
2849   }
2850 
2851   if (!shouldCombineMemoryType(VT))
2852     return SDValue();
2853 
2854   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2855   SDValue Val = SN->getValue();
2856 
2857   //DCI.AddToWorklist(Val.getNode());
2858 
2859   bool OtherUses = !Val.hasOneUse();
2860   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2861   if (OtherUses) {
2862     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2863     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2864   }
2865 
2866   return DAG.getStore(SN->getChain(), SL, CastVal,
2867                       SN->getBasePtr(), SN->getMemOperand());
2868 }
2869 
2870 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2871 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2872 // issues.
2873 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2874                                                         DAGCombinerInfo &DCI) const {
2875   SelectionDAG &DAG = DCI.DAG;
2876   SDValue N0 = N->getOperand(0);
2877 
2878   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2879   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2880   if (N0.getOpcode() == ISD::TRUNCATE) {
2881     SDValue N1 = N->getOperand(1);
2882     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2883     SDLoc SL(N);
2884 
2885     SDValue Src = N0.getOperand(0);
2886     EVT SrcVT = Src.getValueType();
2887     if (SrcVT.bitsGE(ExtVT)) {
2888       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2889       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2890     }
2891   }
2892 
2893   return SDValue();
2894 }
2895 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
2896 /// binary operation \p Opc to it with the corresponding constant operands.
2897 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
2898   DAGCombinerInfo &DCI, const SDLoc &SL,
2899   unsigned Opc, SDValue LHS,
2900   uint32_t ValLo, uint32_t ValHi) const {
2901   SelectionDAG &DAG = DCI.DAG;
2902   SDValue Lo, Hi;
2903   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
2904 
2905   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
2906   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
2907 
2908   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
2909   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
2910 
2911   // Re-visit the ands. It's possible we eliminated one of them and it could
2912   // simplify the vector.
2913   DCI.AddToWorklist(Lo.getNode());
2914   DCI.AddToWorklist(Hi.getNode());
2915 
2916   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
2917   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2918 }
2919 
2920 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
2921                                                 DAGCombinerInfo &DCI) const {
2922   EVT VT = N->getValueType(0);
2923 
2924   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2925   if (!RHS)
2926     return SDValue();
2927 
2928   SDValue LHS = N->getOperand(0);
2929   unsigned RHSVal = RHS->getZExtValue();
2930   if (!RHSVal)
2931     return LHS;
2932 
2933   SDLoc SL(N);
2934   SelectionDAG &DAG = DCI.DAG;
2935 
2936   switch (LHS->getOpcode()) {
2937   default:
2938     break;
2939   case ISD::ZERO_EXTEND:
2940   case ISD::SIGN_EXTEND:
2941   case ISD::ANY_EXTEND: {
2942     SDValue X = LHS->getOperand(0);
2943 
2944     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
2945         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
2946       // Prefer build_vector as the canonical form if packed types are legal.
2947       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
2948       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
2949        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
2950       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
2951     }
2952 
2953     // shl (ext x) => zext (shl x), if shift does not overflow int
2954     if (VT != MVT::i64)
2955       break;
2956     KnownBits Known;
2957     DAG.computeKnownBits(X, Known);
2958     unsigned LZ = Known.countMinLeadingZeros();
2959     if (LZ < RHSVal)
2960       break;
2961     EVT XVT = X.getValueType();
2962     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
2963     return DAG.getZExtOrTrunc(Shl, SL, VT);
2964   }
2965   }
2966 
2967   if (VT != MVT::i64)
2968     return SDValue();
2969 
2970   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
2971 
2972   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
2973   // common case, splitting this into a move and a 32-bit shift is faster and
2974   // the same code size.
2975   if (RHSVal < 32)
2976     return SDValue();
2977 
2978   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
2979 
2980   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
2981   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
2982 
2983   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2984 
2985   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
2986   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
2987 }
2988 
2989 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
2990                                                 DAGCombinerInfo &DCI) const {
2991   if (N->getValueType(0) != MVT::i64)
2992     return SDValue();
2993 
2994   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
2995   if (!RHS)
2996     return SDValue();
2997 
2998   SelectionDAG &DAG = DCI.DAG;
2999   SDLoc SL(N);
3000   unsigned RHSVal = RHS->getZExtValue();
3001 
3002   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3003   if (RHSVal == 32) {
3004     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3005     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3006                                    DAG.getConstant(31, SL, MVT::i32));
3007 
3008     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3009     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3010   }
3011 
3012   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3013   if (RHSVal == 63) {
3014     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3015     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3016                                    DAG.getConstant(31, SL, MVT::i32));
3017     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3018     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3019   }
3020 
3021   return SDValue();
3022 }
3023 
3024 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3025                                                 DAGCombinerInfo &DCI) const {
3026   if (N->getValueType(0) != MVT::i64)
3027     return SDValue();
3028 
3029   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3030   if (!RHS)
3031     return SDValue();
3032 
3033   unsigned ShiftAmt = RHS->getZExtValue();
3034   if (ShiftAmt < 32)
3035     return SDValue();
3036 
3037   // srl i64:x, C for C >= 32
3038   // =>
3039   //   build_pair (srl hi_32(x), C - 32), 0
3040 
3041   SelectionDAG &DAG = DCI.DAG;
3042   SDLoc SL(N);
3043 
3044   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3045   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3046 
3047   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, N->getOperand(0));
3048   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32,
3049                            VecOp, One);
3050 
3051   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3052   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3053 
3054   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3055 
3056   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3057 }
3058 
3059 SDValue AMDGPUTargetLowering::performTruncateCombine(
3060   SDNode *N, DAGCombinerInfo &DCI) const {
3061   SDLoc SL(N);
3062   SelectionDAG &DAG = DCI.DAG;
3063   EVT VT = N->getValueType(0);
3064   SDValue Src = N->getOperand(0);
3065 
3066   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3067   if (Src.getOpcode() == ISD::BITCAST) {
3068     SDValue Vec = Src.getOperand(0);
3069     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3070       SDValue Elt0 = Vec.getOperand(0);
3071       EVT EltVT = Elt0.getValueType();
3072       if (VT.getSizeInBits() <= EltVT.getSizeInBits()) {
3073         if (EltVT.isFloatingPoint()) {
3074           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3075                              EltVT.changeTypeToInteger(), Elt0);
3076         }
3077 
3078         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3079       }
3080     }
3081   }
3082 
3083   // Equivalent of above for accessing the high element of a vector as an
3084   // integer operation.
3085   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3086   if (Src.getOpcode() == ISD::SRL && !VT.isVector()) {
3087     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3088       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3089         SDValue BV = stripBitcast(Src.getOperand(0));
3090         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3091             BV.getValueType().getVectorNumElements() == 2) {
3092           SDValue SrcElt = BV.getOperand(1);
3093           EVT SrcEltVT = SrcElt.getValueType();
3094           if (SrcEltVT.isFloatingPoint()) {
3095             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3096                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3097           }
3098 
3099           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3100         }
3101       }
3102     }
3103   }
3104 
3105   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3106   //
3107   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3108   //     i16 (trunc (srl (i32 (trunc x), K)))
3109   if (VT.getScalarSizeInBits() < 32) {
3110     EVT SrcVT = Src.getValueType();
3111     if (SrcVT.getScalarSizeInBits() > 32 &&
3112         (Src.getOpcode() == ISD::SRL ||
3113          Src.getOpcode() == ISD::SRA ||
3114          Src.getOpcode() == ISD::SHL)) {
3115       SDValue Amt = Src.getOperand(1);
3116       KnownBits Known;
3117       DAG.computeKnownBits(Amt, Known);
3118       unsigned Size = VT.getScalarSizeInBits();
3119       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3120           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3121         EVT MidVT = VT.isVector() ?
3122           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3123                            VT.getVectorNumElements()) : MVT::i32;
3124 
3125         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3126         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3127                                     Src.getOperand(0));
3128         DCI.AddToWorklist(Trunc.getNode());
3129 
3130         if (Amt.getValueType() != NewShiftVT) {
3131           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3132           DCI.AddToWorklist(Amt.getNode());
3133         }
3134 
3135         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3136                                           Trunc, Amt);
3137         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3138       }
3139     }
3140   }
3141 
3142   return SDValue();
3143 }
3144 
3145 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3146 // instructions. If we only match on the legalized i64 mul expansion,
3147 // SimplifyDemandedBits will be unable to remove them because there will be
3148 // multiple uses due to the separate mul + mulh[su].
3149 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3150                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3151   if (Size <= 32) {
3152     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3153     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3154   }
3155 
3156   // Because we want to eliminate extension instructions before the
3157   // operation, we need to create a single user here (i.e. not the separate
3158   // mul_lo + mul_hi) so that SimplifyDemandedBits will deal with it.
3159 
3160   unsigned MulOpc = Signed ? AMDGPUISD::MUL_LOHI_I24 : AMDGPUISD::MUL_LOHI_U24;
3161 
3162   SDValue Mul = DAG.getNode(MulOpc, SL,
3163                             DAG.getVTList(MVT::i32, MVT::i32), N0, N1);
3164 
3165   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64,
3166                      Mul.getValue(0), Mul.getValue(1));
3167 }
3168 
3169 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3170                                                 DAGCombinerInfo &DCI) const {
3171   EVT VT = N->getValueType(0);
3172 
3173   unsigned Size = VT.getSizeInBits();
3174   if (VT.isVector() || Size > 64)
3175     return SDValue();
3176 
3177   // There are i16 integer mul/mad.
3178   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3179     return SDValue();
3180 
3181   SelectionDAG &DAG = DCI.DAG;
3182   SDLoc DL(N);
3183 
3184   SDValue N0 = N->getOperand(0);
3185   SDValue N1 = N->getOperand(1);
3186 
3187   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3188   // in the source into any_extends if the result of the mul is truncated. Since
3189   // we can assume the high bits are whatever we want, use the underlying value
3190   // to avoid the unknown high bits from interfering.
3191   if (N0.getOpcode() == ISD::ANY_EXTEND)
3192     N0 = N0.getOperand(0);
3193 
3194   if (N1.getOpcode() == ISD::ANY_EXTEND)
3195     N1 = N1.getOperand(0);
3196 
3197   SDValue Mul;
3198 
3199   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3200     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3201     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3202     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3203   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3204     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3205     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3206     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3207   } else {
3208     return SDValue();
3209   }
3210 
3211   // We need to use sext even for MUL_U24, because MUL_U24 is used
3212   // for signed multiply of 8 and 16-bit types.
3213   return DAG.getSExtOrTrunc(Mul, DL, VT);
3214 }
3215 
3216 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3217                                                   DAGCombinerInfo &DCI) const {
3218   EVT VT = N->getValueType(0);
3219 
3220   if (!Subtarget->hasMulI24() || VT.isVector())
3221     return SDValue();
3222 
3223   SelectionDAG &DAG = DCI.DAG;
3224   SDLoc DL(N);
3225 
3226   SDValue N0 = N->getOperand(0);
3227   SDValue N1 = N->getOperand(1);
3228 
3229   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3230     return SDValue();
3231 
3232   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3233   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3234 
3235   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3236   DCI.AddToWorklist(Mulhi.getNode());
3237   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3238 }
3239 
3240 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3241                                                   DAGCombinerInfo &DCI) const {
3242   EVT VT = N->getValueType(0);
3243 
3244   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3245     return SDValue();
3246 
3247   SelectionDAG &DAG = DCI.DAG;
3248   SDLoc DL(N);
3249 
3250   SDValue N0 = N->getOperand(0);
3251   SDValue N1 = N->getOperand(1);
3252 
3253   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3254     return SDValue();
3255 
3256   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3257   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3258 
3259   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3260   DCI.AddToWorklist(Mulhi.getNode());
3261   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3262 }
3263 
3264 SDValue AMDGPUTargetLowering::performMulLoHi24Combine(
3265   SDNode *N, DAGCombinerInfo &DCI) const {
3266   SelectionDAG &DAG = DCI.DAG;
3267 
3268   // Simplify demanded bits before splitting into multiple users.
3269   if (simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI))
3270     return SDValue();
3271 
3272   SDValue N0 = N->getOperand(0);
3273   SDValue N1 = N->getOperand(1);
3274 
3275   bool Signed = (N->getOpcode() == AMDGPUISD::MUL_LOHI_I24);
3276 
3277   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3278   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3279 
3280   SDLoc SL(N);
3281 
3282   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3283   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3284   return DAG.getMergeValues({ MulLo, MulHi }, SL);
3285 }
3286 
3287 static bool isNegativeOne(SDValue Val) {
3288   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3289     return C->isAllOnesValue();
3290   return false;
3291 }
3292 
3293 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3294                                           SDValue Op,
3295                                           const SDLoc &DL,
3296                                           unsigned Opc) const {
3297   EVT VT = Op.getValueType();
3298   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3299   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3300                               LegalVT != MVT::i16))
3301     return SDValue();
3302 
3303   if (VT != MVT::i32)
3304     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3305 
3306   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3307   if (VT != MVT::i32)
3308     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3309 
3310   return FFBX;
3311 }
3312 
3313 // The native instructions return -1 on 0 input. Optimize out a select that
3314 // produces -1 on 0.
3315 //
3316 // TODO: If zero is not undef, we could also do this if the output is compared
3317 // against the bitwidth.
3318 //
3319 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
3320 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3321                                                  SDValue LHS, SDValue RHS,
3322                                                  DAGCombinerInfo &DCI) const {
3323   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3324   if (!CmpRhs || !CmpRhs->isNullValue())
3325     return SDValue();
3326 
3327   SelectionDAG &DAG = DCI.DAG;
3328   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3329   SDValue CmpLHS = Cond.getOperand(0);
3330 
3331   unsigned Opc = isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 :
3332                                            AMDGPUISD::FFBH_U32;
3333 
3334   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3335   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3336   if (CCOpcode == ISD::SETEQ &&
3337       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3338       RHS.getOperand(0) == CmpLHS &&
3339       isNegativeOne(LHS)) {
3340     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3341   }
3342 
3343   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3344   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3345   if (CCOpcode == ISD::SETNE &&
3346       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3347       LHS.getOperand(0) == CmpLHS &&
3348       isNegativeOne(RHS)) {
3349     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3350   }
3351 
3352   return SDValue();
3353 }
3354 
3355 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3356                                          unsigned Op,
3357                                          const SDLoc &SL,
3358                                          SDValue Cond,
3359                                          SDValue N1,
3360                                          SDValue N2) {
3361   SelectionDAG &DAG = DCI.DAG;
3362   EVT VT = N1.getValueType();
3363 
3364   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3365                                   N1.getOperand(0), N2.getOperand(0));
3366   DCI.AddToWorklist(NewSelect.getNode());
3367   return DAG.getNode(Op, SL, VT, NewSelect);
3368 }
3369 
3370 // Pull a free FP operation out of a select so it may fold into uses.
3371 //
3372 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3373 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3374 //
3375 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3376 // select c, (fabs x), +k -> fabs (select c, x, k)
3377 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3378                                     SDValue N) {
3379   SelectionDAG &DAG = DCI.DAG;
3380   SDValue Cond = N.getOperand(0);
3381   SDValue LHS = N.getOperand(1);
3382   SDValue RHS = N.getOperand(2);
3383 
3384   EVT VT = N.getValueType();
3385   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3386       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3387     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3388                                      SDLoc(N), Cond, LHS, RHS);
3389   }
3390 
3391   bool Inv = false;
3392   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3393     std::swap(LHS, RHS);
3394     Inv = true;
3395   }
3396 
3397   // TODO: Support vector constants.
3398   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3399   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3400     SDLoc SL(N);
3401     // If one side is an fneg/fabs and the other is a constant, we can push the
3402     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3403     SDValue NewLHS = LHS.getOperand(0);
3404     SDValue NewRHS = RHS;
3405 
3406     // Careful: if the neg can be folded up, don't try to pull it back down.
3407     bool ShouldFoldNeg = true;
3408 
3409     if (NewLHS.hasOneUse()) {
3410       unsigned Opc = NewLHS.getOpcode();
3411       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3412         ShouldFoldNeg = false;
3413       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3414         ShouldFoldNeg = false;
3415     }
3416 
3417     if (ShouldFoldNeg) {
3418       if (LHS.getOpcode() == ISD::FNEG)
3419         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3420       else if (CRHS->isNegative())
3421         return SDValue();
3422 
3423       if (Inv)
3424         std::swap(NewLHS, NewRHS);
3425 
3426       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3427                                       Cond, NewLHS, NewRHS);
3428       DCI.AddToWorklist(NewSelect.getNode());
3429       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3430     }
3431   }
3432 
3433   return SDValue();
3434 }
3435 
3436 
3437 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3438                                                    DAGCombinerInfo &DCI) const {
3439   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3440     return Folded;
3441 
3442   SDValue Cond = N->getOperand(0);
3443   if (Cond.getOpcode() != ISD::SETCC)
3444     return SDValue();
3445 
3446   EVT VT = N->getValueType(0);
3447   SDValue LHS = Cond.getOperand(0);
3448   SDValue RHS = Cond.getOperand(1);
3449   SDValue CC = Cond.getOperand(2);
3450 
3451   SDValue True = N->getOperand(1);
3452   SDValue False = N->getOperand(2);
3453 
3454   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3455     SelectionDAG &DAG = DCI.DAG;
3456     if ((DAG.isConstantValueOfAnyType(True) ||
3457          DAG.isConstantValueOfAnyType(True)) &&
3458         (!DAG.isConstantValueOfAnyType(False) &&
3459          !DAG.isConstantValueOfAnyType(False))) {
3460       // Swap cmp + select pair to move constant to false input.
3461       // This will allow using VOPC cndmasks more often.
3462       // select (setcc x, y), k, x -> select (setcc y, x) x, x
3463 
3464       SDLoc SL(N);
3465       ISD::CondCode NewCC = getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
3466                                             LHS.getValueType().isInteger());
3467 
3468       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3469       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3470     }
3471 
3472     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3473       SDValue MinMax
3474         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3475       // Revisit this node so we can catch min3/max3/med3 patterns.
3476       //DCI.AddToWorklist(MinMax.getNode());
3477       return MinMax;
3478     }
3479   }
3480 
3481   // There's no reason to not do this if the condition has other uses.
3482   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3483 }
3484 
3485 static bool isInv2Pi(const APFloat &APF) {
3486   static const APFloat KF16(APFloat::IEEEhalf(), APInt(16, 0x3118));
3487   static const APFloat KF32(APFloat::IEEEsingle(), APInt(32, 0x3e22f983));
3488   static const APFloat KF64(APFloat::IEEEdouble(), APInt(64, 0x3fc45f306dc9c882));
3489 
3490   return APF.bitwiseIsEqual(KF16) ||
3491          APF.bitwiseIsEqual(KF32) ||
3492          APF.bitwiseIsEqual(KF64);
3493 }
3494 
3495 // 0 and 1.0 / (0.5 * pi) do not have inline immmediates, so there is an
3496 // additional cost to negate them.
3497 bool AMDGPUTargetLowering::isConstantCostlierToNegate(SDValue N) const {
3498   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N)) {
3499     if (C->isZero() && !C->isNegative())
3500       return true;
3501 
3502     if (Subtarget->hasInv2PiInlineImm() && isInv2Pi(C->getValueAPF()))
3503       return true;
3504   }
3505 
3506   return false;
3507 }
3508 
3509 static unsigned inverseMinMax(unsigned Opc) {
3510   switch (Opc) {
3511   case ISD::FMAXNUM:
3512     return ISD::FMINNUM;
3513   case ISD::FMINNUM:
3514     return ISD::FMAXNUM;
3515   case AMDGPUISD::FMAX_LEGACY:
3516     return AMDGPUISD::FMIN_LEGACY;
3517   case AMDGPUISD::FMIN_LEGACY:
3518     return  AMDGPUISD::FMAX_LEGACY;
3519   default:
3520     llvm_unreachable("invalid min/max opcode");
3521   }
3522 }
3523 
3524 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3525                                                  DAGCombinerInfo &DCI) const {
3526   SelectionDAG &DAG = DCI.DAG;
3527   SDValue N0 = N->getOperand(0);
3528   EVT VT = N->getValueType(0);
3529 
3530   unsigned Opc = N0.getOpcode();
3531 
3532   // If the input has multiple uses and we can either fold the negate down, or
3533   // the other uses cannot, give up. This both prevents unprofitable
3534   // transformations and infinite loops: we won't repeatedly try to fold around
3535   // a negate that has no 'good' form.
3536   if (N0.hasOneUse()) {
3537     // This may be able to fold into the source, but at a code size cost. Don't
3538     // fold if the fold into the user is free.
3539     if (allUsesHaveSourceMods(N, 0))
3540       return SDValue();
3541   } else {
3542     if (fnegFoldsIntoOp(Opc) &&
3543         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3544       return SDValue();
3545   }
3546 
3547   SDLoc SL(N);
3548   switch (Opc) {
3549   case ISD::FADD: {
3550     if (!mayIgnoreSignedZero(N0))
3551       return SDValue();
3552 
3553     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3554     SDValue LHS = N0.getOperand(0);
3555     SDValue RHS = N0.getOperand(1);
3556 
3557     if (LHS.getOpcode() != ISD::FNEG)
3558       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3559     else
3560       LHS = LHS.getOperand(0);
3561 
3562     if (RHS.getOpcode() != ISD::FNEG)
3563       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3564     else
3565       RHS = RHS.getOperand(0);
3566 
3567     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3568     if (!N0.hasOneUse())
3569       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3570     return Res;
3571   }
3572   case ISD::FMUL:
3573   case AMDGPUISD::FMUL_LEGACY: {
3574     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3575     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3576     SDValue LHS = N0.getOperand(0);
3577     SDValue RHS = N0.getOperand(1);
3578 
3579     if (LHS.getOpcode() == ISD::FNEG)
3580       LHS = LHS.getOperand(0);
3581     else if (RHS.getOpcode() == ISD::FNEG)
3582       RHS = RHS.getOperand(0);
3583     else
3584       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3585 
3586     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3587     if (!N0.hasOneUse())
3588       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3589     return Res;
3590   }
3591   case ISD::FMA:
3592   case ISD::FMAD: {
3593     if (!mayIgnoreSignedZero(N0))
3594       return SDValue();
3595 
3596     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3597     SDValue LHS = N0.getOperand(0);
3598     SDValue MHS = N0.getOperand(1);
3599     SDValue RHS = N0.getOperand(2);
3600 
3601     if (LHS.getOpcode() == ISD::FNEG)
3602       LHS = LHS.getOperand(0);
3603     else if (MHS.getOpcode() == ISD::FNEG)
3604       MHS = MHS.getOperand(0);
3605     else
3606       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3607 
3608     if (RHS.getOpcode() != ISD::FNEG)
3609       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3610     else
3611       RHS = RHS.getOperand(0);
3612 
3613     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3614     if (!N0.hasOneUse())
3615       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3616     return Res;
3617   }
3618   case ISD::FMAXNUM:
3619   case ISD::FMINNUM:
3620   case AMDGPUISD::FMAX_LEGACY:
3621   case AMDGPUISD::FMIN_LEGACY: {
3622     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3623     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3624     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3625     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3626 
3627     SDValue LHS = N0.getOperand(0);
3628     SDValue RHS = N0.getOperand(1);
3629 
3630     // 0 doesn't have a negated inline immediate.
3631     // TODO: This constant check should be generalized to other operations.
3632     if (isConstantCostlierToNegate(RHS))
3633       return SDValue();
3634 
3635     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3636     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3637     unsigned Opposite = inverseMinMax(Opc);
3638 
3639     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3640     if (!N0.hasOneUse())
3641       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3642     return Res;
3643   }
3644   case AMDGPUISD::FMED3: {
3645     SDValue Ops[3];
3646     for (unsigned I = 0; I < 3; ++I)
3647       Ops[I] = DAG.getNode(ISD::FNEG, SL, VT, N0->getOperand(I), N0->getFlags());
3648 
3649     SDValue Res = DAG.getNode(AMDGPUISD::FMED3, SL, VT, Ops, N0->getFlags());
3650     if (!N0.hasOneUse())
3651       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3652     return Res;
3653   }
3654   case ISD::FP_EXTEND:
3655   case ISD::FTRUNC:
3656   case ISD::FRINT:
3657   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3658   case ISD::FSIN:
3659   case ISD::FCANONICALIZE:
3660   case AMDGPUISD::RCP:
3661   case AMDGPUISD::RCP_LEGACY:
3662   case AMDGPUISD::RCP_IFLAG:
3663   case AMDGPUISD::SIN_HW: {
3664     SDValue CvtSrc = N0.getOperand(0);
3665     if (CvtSrc.getOpcode() == ISD::FNEG) {
3666       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3667       // (fneg (rcp (fneg x))) -> (rcp x)
3668       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3669     }
3670 
3671     if (!N0.hasOneUse())
3672       return SDValue();
3673 
3674     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3675     // (fneg (rcp x)) -> (rcp (fneg x))
3676     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3677     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3678   }
3679   case ISD::FP_ROUND: {
3680     SDValue CvtSrc = N0.getOperand(0);
3681 
3682     if (CvtSrc.getOpcode() == ISD::FNEG) {
3683       // (fneg (fp_round (fneg x))) -> (fp_round x)
3684       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3685                          CvtSrc.getOperand(0), N0.getOperand(1));
3686     }
3687 
3688     if (!N0.hasOneUse())
3689       return SDValue();
3690 
3691     // (fneg (fp_round x)) -> (fp_round (fneg x))
3692     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3693     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3694   }
3695   case ISD::FP16_TO_FP: {
3696     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3697     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3698     // Put the fneg back as a legal source operation that can be matched later.
3699     SDLoc SL(N);
3700 
3701     SDValue Src = N0.getOperand(0);
3702     EVT SrcVT = Src.getValueType();
3703 
3704     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3705     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3706                                   DAG.getConstant(0x8000, SL, SrcVT));
3707     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3708   }
3709   default:
3710     return SDValue();
3711   }
3712 }
3713 
3714 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3715                                                  DAGCombinerInfo &DCI) const {
3716   SelectionDAG &DAG = DCI.DAG;
3717   SDValue N0 = N->getOperand(0);
3718 
3719   if (!N0.hasOneUse())
3720     return SDValue();
3721 
3722   switch (N0.getOpcode()) {
3723   case ISD::FP16_TO_FP: {
3724     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3725     SDLoc SL(N);
3726     SDValue Src = N0.getOperand(0);
3727     EVT SrcVT = Src.getValueType();
3728 
3729     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3730     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3731                                   DAG.getConstant(0x7fff, SL, SrcVT));
3732     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3733   }
3734   default:
3735     return SDValue();
3736   }
3737 }
3738 
3739 SDValue AMDGPUTargetLowering::performRcpCombine(SDNode *N,
3740                                                 DAGCombinerInfo &DCI) const {
3741   const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
3742   if (!CFP)
3743     return SDValue();
3744 
3745   // XXX - Should this flush denormals?
3746   const APFloat &Val = CFP->getValueAPF();
3747   APFloat One(Val.getSemantics(), "1.0");
3748   return DCI.DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3749 }
3750 
3751 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3752                                                 DAGCombinerInfo &DCI) const {
3753   SelectionDAG &DAG = DCI.DAG;
3754   SDLoc DL(N);
3755 
3756   switch(N->getOpcode()) {
3757   default:
3758     break;
3759   case ISD::BITCAST: {
3760     EVT DestVT = N->getValueType(0);
3761 
3762     // Push casts through vector builds. This helps avoid emitting a large
3763     // number of copies when materializing floating point vector constants.
3764     //
3765     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3766     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3767     if (DestVT.isVector()) {
3768       SDValue Src = N->getOperand(0);
3769       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3770         EVT SrcVT = Src.getValueType();
3771         unsigned NElts = DestVT.getVectorNumElements();
3772 
3773         if (SrcVT.getVectorNumElements() == NElts) {
3774           EVT DestEltVT = DestVT.getVectorElementType();
3775 
3776           SmallVector<SDValue, 8> CastedElts;
3777           SDLoc SL(N);
3778           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3779             SDValue Elt = Src.getOperand(I);
3780             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3781           }
3782 
3783           return DAG.getBuildVector(DestVT, SL, CastedElts);
3784         }
3785       }
3786     }
3787 
3788     if (DestVT.getSizeInBits() != 64 && !DestVT.isVector())
3789       break;
3790 
3791     // Fold bitcasts of constants.
3792     //
3793     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3794     // TODO: Generalize and move to DAGCombiner
3795     SDValue Src = N->getOperand(0);
3796     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3797       if (Src.getValueType() == MVT::i64) {
3798         SDLoc SL(N);
3799         uint64_t CVal = C->getZExtValue();
3800         return DAG.getNode(ISD::BUILD_VECTOR, SL, DestVT,
3801                            DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3802                            DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3803       }
3804     }
3805 
3806     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3807       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3808       SDLoc SL(N);
3809       uint64_t CVal = Val.getZExtValue();
3810       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3811                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3812                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3813 
3814       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3815     }
3816 
3817     break;
3818   }
3819   case ISD::SHL: {
3820     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3821       break;
3822 
3823     return performShlCombine(N, DCI);
3824   }
3825   case ISD::SRL: {
3826     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3827       break;
3828 
3829     return performSrlCombine(N, DCI);
3830   }
3831   case ISD::SRA: {
3832     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3833       break;
3834 
3835     return performSraCombine(N, DCI);
3836   }
3837   case ISD::TRUNCATE:
3838     return performTruncateCombine(N, DCI);
3839   case ISD::MUL:
3840     return performMulCombine(N, DCI);
3841   case ISD::MULHS:
3842     return performMulhsCombine(N, DCI);
3843   case ISD::MULHU:
3844     return performMulhuCombine(N, DCI);
3845   case AMDGPUISD::MUL_I24:
3846   case AMDGPUISD::MUL_U24:
3847   case AMDGPUISD::MULHI_I24:
3848   case AMDGPUISD::MULHI_U24: {
3849     // If the first call to simplify is successfull, then N may end up being
3850     // deleted, so we shouldn't call simplifyI24 again.
3851     simplifyI24(N, 0, DCI) || simplifyI24(N, 1, DCI);
3852     return SDValue();
3853   }
3854   case AMDGPUISD::MUL_LOHI_I24:
3855   case AMDGPUISD::MUL_LOHI_U24:
3856     return performMulLoHi24Combine(N, DCI);
3857   case ISD::SELECT:
3858     return performSelectCombine(N, DCI);
3859   case ISD::FNEG:
3860     return performFNegCombine(N, DCI);
3861   case ISD::FABS:
3862     return performFAbsCombine(N, DCI);
3863   case AMDGPUISD::BFE_I32:
3864   case AMDGPUISD::BFE_U32: {
3865     assert(!N->getValueType(0).isVector() &&
3866            "Vector handling of BFE not implemented");
3867     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
3868     if (!Width)
3869       break;
3870 
3871     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
3872     if (WidthVal == 0)
3873       return DAG.getConstant(0, DL, MVT::i32);
3874 
3875     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
3876     if (!Offset)
3877       break;
3878 
3879     SDValue BitsFrom = N->getOperand(0);
3880     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
3881 
3882     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
3883 
3884     if (OffsetVal == 0) {
3885       // This is already sign / zero extended, so try to fold away extra BFEs.
3886       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
3887 
3888       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
3889       if (OpSignBits >= SignBits)
3890         return BitsFrom;
3891 
3892       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
3893       if (Signed) {
3894         // This is a sign_extend_inreg. Replace it to take advantage of existing
3895         // DAG Combines. If not eliminated, we will match back to BFE during
3896         // selection.
3897 
3898         // TODO: The sext_inreg of extended types ends, although we can could
3899         // handle them in a single BFE.
3900         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
3901                            DAG.getValueType(SmallVT));
3902       }
3903 
3904       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
3905     }
3906 
3907     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
3908       if (Signed) {
3909         return constantFoldBFE<int32_t>(DAG,
3910                                         CVal->getSExtValue(),
3911                                         OffsetVal,
3912                                         WidthVal,
3913                                         DL);
3914       }
3915 
3916       return constantFoldBFE<uint32_t>(DAG,
3917                                        CVal->getZExtValue(),
3918                                        OffsetVal,
3919                                        WidthVal,
3920                                        DL);
3921     }
3922 
3923     if ((OffsetVal + WidthVal) >= 32 &&
3924         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
3925       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
3926       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
3927                          BitsFrom, ShiftVal);
3928     }
3929 
3930     if (BitsFrom.hasOneUse()) {
3931       APInt Demanded = APInt::getBitsSet(32,
3932                                          OffsetVal,
3933                                          OffsetVal + WidthVal);
3934 
3935       KnownBits Known;
3936       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
3937                                             !DCI.isBeforeLegalizeOps());
3938       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
3939       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
3940           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
3941         DCI.CommitTargetLoweringOpt(TLO);
3942       }
3943     }
3944 
3945     break;
3946   }
3947   case ISD::LOAD:
3948     return performLoadCombine(N, DCI);
3949   case ISD::STORE:
3950     return performStoreCombine(N, DCI);
3951   case AMDGPUISD::RCP:
3952   case AMDGPUISD::RCP_IFLAG:
3953     return performRcpCombine(N, DCI);
3954   case ISD::AssertZext:
3955   case ISD::AssertSext:
3956     return performAssertSZExtCombine(N, DCI);
3957   }
3958   return SDValue();
3959 }
3960 
3961 //===----------------------------------------------------------------------===//
3962 // Helper functions
3963 //===----------------------------------------------------------------------===//
3964 
3965 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
3966                                                    const TargetRegisterClass *RC,
3967                                                    unsigned Reg, EVT VT,
3968                                                    const SDLoc &SL,
3969                                                    bool RawReg) const {
3970   MachineFunction &MF = DAG.getMachineFunction();
3971   MachineRegisterInfo &MRI = MF.getRegInfo();
3972   unsigned VReg;
3973 
3974   if (!MRI.isLiveIn(Reg)) {
3975     VReg = MRI.createVirtualRegister(RC);
3976     MRI.addLiveIn(Reg, VReg);
3977   } else {
3978     VReg = MRI.getLiveInVirtReg(Reg);
3979   }
3980 
3981   if (RawReg)
3982     return DAG.getRegister(VReg, VT);
3983 
3984   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
3985 }
3986 
3987 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
3988                                                   EVT VT,
3989                                                   const SDLoc &SL,
3990                                                   int64_t Offset) const {
3991   MachineFunction &MF = DAG.getMachineFunction();
3992   MachineFrameInfo &MFI = MF.getFrameInfo();
3993 
3994   int FI = MFI.CreateFixedObject(VT.getStoreSize(), Offset, true);
3995   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
3996   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
3997 
3998   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, 4,
3999                      MachineMemOperand::MODereferenceable |
4000                      MachineMemOperand::MOInvariant);
4001 }
4002 
4003 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
4004                                                    const SDLoc &SL,
4005                                                    SDValue Chain,
4006                                                    SDValue ArgVal,
4007                                                    int64_t Offset) const {
4008   MachineFunction &MF = DAG.getMachineFunction();
4009   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
4010 
4011   SDValue Ptr = DAG.getConstant(Offset, SL, MVT::i32);
4012   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, 4,
4013                                MachineMemOperand::MODereferenceable);
4014   return Store;
4015 }
4016 
4017 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
4018                                              const TargetRegisterClass *RC,
4019                                              EVT VT, const SDLoc &SL,
4020                                              const ArgDescriptor &Arg) const {
4021   assert(Arg && "Attempting to load missing argument");
4022 
4023   if (Arg.isRegister())
4024     return CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL);
4025   return loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
4026 }
4027 
4028 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
4029     const MachineFunction &MF, const ImplicitParameter Param) const {
4030   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
4031   const AMDGPUSubtarget &ST =
4032       AMDGPUSubtarget::get(getTargetMachine(), MF.getFunction());
4033   unsigned ExplicitArgOffset = ST.getExplicitKernelArgOffset(MF.getFunction());
4034   unsigned Alignment = ST.getAlignmentForImplicitArgPtr();
4035   uint64_t ArgOffset = alignTo(MFI->getExplicitKernArgSize(), Alignment) +
4036                        ExplicitArgOffset;
4037   switch (Param) {
4038   case GRID_DIM:
4039     return ArgOffset;
4040   case GRID_OFFSET:
4041     return ArgOffset + 4;
4042   }
4043   llvm_unreachable("unexpected implicit parameter type");
4044 }
4045 
4046 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4047 
4048 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4049   switch ((AMDGPUISD::NodeType)Opcode) {
4050   case AMDGPUISD::FIRST_NUMBER: break;
4051   // AMDIL DAG nodes
4052   NODE_NAME_CASE(UMUL);
4053   NODE_NAME_CASE(BRANCH_COND);
4054 
4055   // AMDGPU DAG nodes
4056   NODE_NAME_CASE(IF)
4057   NODE_NAME_CASE(ELSE)
4058   NODE_NAME_CASE(LOOP)
4059   NODE_NAME_CASE(CALL)
4060   NODE_NAME_CASE(TC_RETURN)
4061   NODE_NAME_CASE(TRAP)
4062   NODE_NAME_CASE(RET_FLAG)
4063   NODE_NAME_CASE(RETURN_TO_EPILOG)
4064   NODE_NAME_CASE(ENDPGM)
4065   NODE_NAME_CASE(DWORDADDR)
4066   NODE_NAME_CASE(FRACT)
4067   NODE_NAME_CASE(SETCC)
4068   NODE_NAME_CASE(SETREG)
4069   NODE_NAME_CASE(FMA_W_CHAIN)
4070   NODE_NAME_CASE(FMUL_W_CHAIN)
4071   NODE_NAME_CASE(CLAMP)
4072   NODE_NAME_CASE(COS_HW)
4073   NODE_NAME_CASE(SIN_HW)
4074   NODE_NAME_CASE(FMAX_LEGACY)
4075   NODE_NAME_CASE(FMIN_LEGACY)
4076   NODE_NAME_CASE(FMAX3)
4077   NODE_NAME_CASE(SMAX3)
4078   NODE_NAME_CASE(UMAX3)
4079   NODE_NAME_CASE(FMIN3)
4080   NODE_NAME_CASE(SMIN3)
4081   NODE_NAME_CASE(UMIN3)
4082   NODE_NAME_CASE(FMED3)
4083   NODE_NAME_CASE(SMED3)
4084   NODE_NAME_CASE(UMED3)
4085   NODE_NAME_CASE(FDOT2)
4086   NODE_NAME_CASE(URECIP)
4087   NODE_NAME_CASE(DIV_SCALE)
4088   NODE_NAME_CASE(DIV_FMAS)
4089   NODE_NAME_CASE(DIV_FIXUP)
4090   NODE_NAME_CASE(FMAD_FTZ)
4091   NODE_NAME_CASE(TRIG_PREOP)
4092   NODE_NAME_CASE(RCP)
4093   NODE_NAME_CASE(RSQ)
4094   NODE_NAME_CASE(RCP_LEGACY)
4095   NODE_NAME_CASE(RSQ_LEGACY)
4096   NODE_NAME_CASE(RCP_IFLAG)
4097   NODE_NAME_CASE(FMUL_LEGACY)
4098   NODE_NAME_CASE(RSQ_CLAMP)
4099   NODE_NAME_CASE(LDEXP)
4100   NODE_NAME_CASE(FP_CLASS)
4101   NODE_NAME_CASE(DOT4)
4102   NODE_NAME_CASE(CARRY)
4103   NODE_NAME_CASE(BORROW)
4104   NODE_NAME_CASE(BFE_U32)
4105   NODE_NAME_CASE(BFE_I32)
4106   NODE_NAME_CASE(BFI)
4107   NODE_NAME_CASE(BFM)
4108   NODE_NAME_CASE(FFBH_U32)
4109   NODE_NAME_CASE(FFBH_I32)
4110   NODE_NAME_CASE(FFBL_B32)
4111   NODE_NAME_CASE(MUL_U24)
4112   NODE_NAME_CASE(MUL_I24)
4113   NODE_NAME_CASE(MULHI_U24)
4114   NODE_NAME_CASE(MULHI_I24)
4115   NODE_NAME_CASE(MUL_LOHI_U24)
4116   NODE_NAME_CASE(MUL_LOHI_I24)
4117   NODE_NAME_CASE(MAD_U24)
4118   NODE_NAME_CASE(MAD_I24)
4119   NODE_NAME_CASE(MAD_I64_I32)
4120   NODE_NAME_CASE(MAD_U64_U32)
4121   NODE_NAME_CASE(PERM)
4122   NODE_NAME_CASE(TEXTURE_FETCH)
4123   NODE_NAME_CASE(EXPORT)
4124   NODE_NAME_CASE(EXPORT_DONE)
4125   NODE_NAME_CASE(R600_EXPORT)
4126   NODE_NAME_CASE(CONST_ADDRESS)
4127   NODE_NAME_CASE(REGISTER_LOAD)
4128   NODE_NAME_CASE(REGISTER_STORE)
4129   NODE_NAME_CASE(SAMPLE)
4130   NODE_NAME_CASE(SAMPLEB)
4131   NODE_NAME_CASE(SAMPLED)
4132   NODE_NAME_CASE(SAMPLEL)
4133   NODE_NAME_CASE(CVT_F32_UBYTE0)
4134   NODE_NAME_CASE(CVT_F32_UBYTE1)
4135   NODE_NAME_CASE(CVT_F32_UBYTE2)
4136   NODE_NAME_CASE(CVT_F32_UBYTE3)
4137   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4138   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4139   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4140   NODE_NAME_CASE(CVT_PK_I16_I32)
4141   NODE_NAME_CASE(CVT_PK_U16_U32)
4142   NODE_NAME_CASE(FP_TO_FP16)
4143   NODE_NAME_CASE(FP16_ZEXT)
4144   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4145   NODE_NAME_CASE(CONST_DATA_PTR)
4146   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4147   NODE_NAME_CASE(KILL)
4148   NODE_NAME_CASE(DUMMY_CHAIN)
4149   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4150   NODE_NAME_CASE(INIT_EXEC)
4151   NODE_NAME_CASE(INIT_EXEC_FROM_INPUT)
4152   NODE_NAME_CASE(SENDMSG)
4153   NODE_NAME_CASE(SENDMSGHALT)
4154   NODE_NAME_CASE(INTERP_MOV)
4155   NODE_NAME_CASE(INTERP_P1)
4156   NODE_NAME_CASE(INTERP_P2)
4157   NODE_NAME_CASE(STORE_MSKOR)
4158   NODE_NAME_CASE(LOAD_CONSTANT)
4159   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4160   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_X3)
4161   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4162   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4163   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4164   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4165   NODE_NAME_CASE(ATOMIC_INC)
4166   NODE_NAME_CASE(ATOMIC_DEC)
4167   NODE_NAME_CASE(ATOMIC_LOAD_FADD)
4168   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4169   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4170   NODE_NAME_CASE(BUFFER_LOAD)
4171   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4172   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4173   NODE_NAME_CASE(SBUFFER_LOAD)
4174   NODE_NAME_CASE(BUFFER_STORE)
4175   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4176   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4177   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4178   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4179   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4180   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4181   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4182   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4183   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4184   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4185   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4186   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4187   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4188 
4189   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4190   }
4191   return nullptr;
4192 }
4193 
4194 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4195                                               SelectionDAG &DAG, int Enabled,
4196                                               int &RefinementSteps,
4197                                               bool &UseOneConstNR,
4198                                               bool Reciprocal) const {
4199   EVT VT = Operand.getValueType();
4200 
4201   if (VT == MVT::f32) {
4202     RefinementSteps = 0;
4203     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4204   }
4205 
4206   // TODO: There is also f64 rsq instruction, but the documentation is less
4207   // clear on its precision.
4208 
4209   return SDValue();
4210 }
4211 
4212 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4213                                                SelectionDAG &DAG, int Enabled,
4214                                                int &RefinementSteps) const {
4215   EVT VT = Operand.getValueType();
4216 
4217   if (VT == MVT::f32) {
4218     // Reciprocal, < 1 ulp error.
4219     //
4220     // This reciprocal approximation converges to < 0.5 ulp error with one
4221     // newton rhapson performed with two fused multiple adds (FMAs).
4222 
4223     RefinementSteps = 0;
4224     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4225   }
4226 
4227   // TODO: There is also f64 rcp instruction, but the documentation is less
4228   // clear on its precision.
4229 
4230   return SDValue();
4231 }
4232 
4233 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4234     const SDValue Op, KnownBits &Known,
4235     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4236 
4237   Known.resetAll(); // Don't know anything.
4238 
4239   unsigned Opc = Op.getOpcode();
4240 
4241   switch (Opc) {
4242   default:
4243     break;
4244   case AMDGPUISD::CARRY:
4245   case AMDGPUISD::BORROW: {
4246     Known.Zero = APInt::getHighBitsSet(32, 31);
4247     break;
4248   }
4249 
4250   case AMDGPUISD::BFE_I32:
4251   case AMDGPUISD::BFE_U32: {
4252     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4253     if (!CWidth)
4254       return;
4255 
4256     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4257 
4258     if (Opc == AMDGPUISD::BFE_U32)
4259       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4260 
4261     break;
4262   }
4263   case AMDGPUISD::FP_TO_FP16:
4264   case AMDGPUISD::FP16_ZEXT: {
4265     unsigned BitWidth = Known.getBitWidth();
4266 
4267     // High bits are zero.
4268     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4269     break;
4270   }
4271   case AMDGPUISD::MUL_U24:
4272   case AMDGPUISD::MUL_I24: {
4273     KnownBits LHSKnown, RHSKnown;
4274     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4275     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4276 
4277     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4278                       RHSKnown.countMinTrailingZeros();
4279     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4280 
4281     unsigned LHSValBits = 32 - std::max(LHSKnown.countMinSignBits(), 8u);
4282     unsigned RHSValBits = 32 - std::max(RHSKnown.countMinSignBits(), 8u);
4283     unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4284     if (MaxValBits >= 32)
4285       break;
4286     bool Negative = false;
4287     if (Opc == AMDGPUISD::MUL_I24) {
4288       bool LHSNegative = !!(LHSKnown.One  & (1 << 23));
4289       bool LHSPositive = !!(LHSKnown.Zero & (1 << 23));
4290       bool RHSNegative = !!(RHSKnown.One  & (1 << 23));
4291       bool RHSPositive = !!(RHSKnown.Zero & (1 << 23));
4292       if ((!LHSNegative && !LHSPositive) || (!RHSNegative && !RHSPositive))
4293         break;
4294       Negative = (LHSNegative && RHSPositive) || (LHSPositive && RHSNegative);
4295     }
4296     if (Negative)
4297       Known.One.setHighBits(32 - MaxValBits);
4298     else
4299       Known.Zero.setHighBits(32 - MaxValBits);
4300     break;
4301   }
4302   case AMDGPUISD::PERM: {
4303     ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4304     if (!CMask)
4305       return;
4306 
4307     KnownBits LHSKnown, RHSKnown;
4308     DAG.computeKnownBits(Op.getOperand(0), LHSKnown, Depth + 1);
4309     DAG.computeKnownBits(Op.getOperand(1), RHSKnown, Depth + 1);
4310     unsigned Sel = CMask->getZExtValue();
4311 
4312     for (unsigned I = 0; I < 32; I += 8) {
4313       unsigned SelBits = Sel & 0xff;
4314       if (SelBits < 4) {
4315         SelBits *= 8;
4316         Known.One |= ((RHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4317         Known.Zero |= ((RHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4318       } else if (SelBits < 7) {
4319         SelBits = (SelBits & 3) * 8;
4320         Known.One |= ((LHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4321         Known.Zero |= ((LHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4322       } else if (SelBits == 0x0c) {
4323         Known.Zero |= 0xff << I;
4324       } else if (SelBits > 0x0c) {
4325         Known.One |= 0xff << I;
4326       }
4327       Sel >>= 8;
4328     }
4329     break;
4330   }
4331   case ISD::INTRINSIC_WO_CHAIN: {
4332     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4333     switch (IID) {
4334     case Intrinsic::amdgcn_mbcnt_lo:
4335     case Intrinsic::amdgcn_mbcnt_hi: {
4336       const GCNSubtarget &ST =
4337           DAG.getMachineFunction().getSubtarget<GCNSubtarget>();
4338       // These return at most the wavefront size - 1.
4339       unsigned Size = Op.getValueType().getSizeInBits();
4340       Known.Zero.setHighBits(Size - ST.getWavefrontSizeLog2());
4341       break;
4342     }
4343     default:
4344       break;
4345     }
4346   }
4347   }
4348 }
4349 
4350 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4351     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4352     unsigned Depth) const {
4353   switch (Op.getOpcode()) {
4354   case AMDGPUISD::BFE_I32: {
4355     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4356     if (!Width)
4357       return 1;
4358 
4359     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4360     if (!isNullConstant(Op.getOperand(1)))
4361       return SignBits;
4362 
4363     // TODO: Could probably figure something out with non-0 offsets.
4364     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4365     return std::max(SignBits, Op0SignBits);
4366   }
4367 
4368   case AMDGPUISD::BFE_U32: {
4369     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4370     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4371   }
4372 
4373   case AMDGPUISD::CARRY:
4374   case AMDGPUISD::BORROW:
4375     return 31;
4376   case AMDGPUISD::FP_TO_FP16:
4377   case AMDGPUISD::FP16_ZEXT:
4378     return 16;
4379   default:
4380     return 1;
4381   }
4382 }
4383 
4384 bool AMDGPUTargetLowering::isKnownNeverNaNForTargetNode(SDValue Op,
4385                                                         const SelectionDAG &DAG,
4386                                                         bool SNaN,
4387                                                         unsigned Depth) const {
4388   unsigned Opcode = Op.getOpcode();
4389   switch (Opcode) {
4390   case AMDGPUISD::FMIN_LEGACY:
4391   case AMDGPUISD::FMAX_LEGACY: {
4392     if (SNaN)
4393       return true;
4394 
4395     // TODO: Can check no nans on one of the operands for each one, but which
4396     // one?
4397     return false;
4398   }
4399   case AMDGPUISD::FMUL_LEGACY:
4400   case AMDGPUISD::CVT_PKRTZ_F16_F32: {
4401     if (SNaN)
4402       return true;
4403     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4404            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4405   }
4406   case AMDGPUISD::FMED3:
4407   case AMDGPUISD::FMIN3:
4408   case AMDGPUISD::FMAX3:
4409   case AMDGPUISD::FMAD_FTZ: {
4410     if (SNaN)
4411       return true;
4412     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4413            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4414            DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4415   }
4416   case AMDGPUISD::CVT_F32_UBYTE0:
4417   case AMDGPUISD::CVT_F32_UBYTE1:
4418   case AMDGPUISD::CVT_F32_UBYTE2:
4419   case AMDGPUISD::CVT_F32_UBYTE3:
4420     return true;
4421 
4422   case AMDGPUISD::RCP:
4423   case AMDGPUISD::RSQ:
4424   case AMDGPUISD::RCP_LEGACY:
4425   case AMDGPUISD::RSQ_LEGACY:
4426   case AMDGPUISD::RSQ_CLAMP: {
4427     if (SNaN)
4428       return true;
4429 
4430     // TODO: Need is known positive check.
4431     return false;
4432   }
4433   case AMDGPUISD::LDEXP:
4434   case AMDGPUISD::FRACT: {
4435     if (SNaN)
4436       return true;
4437     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1);
4438   }
4439   case AMDGPUISD::DIV_SCALE:
4440   case AMDGPUISD::DIV_FMAS:
4441   case AMDGPUISD::DIV_FIXUP:
4442   case AMDGPUISD::TRIG_PREOP:
4443     // TODO: Refine on operands.
4444     return SNaN;
4445   case AMDGPUISD::SIN_HW:
4446   case AMDGPUISD::COS_HW: {
4447     // TODO: Need check for infinity
4448     return SNaN;
4449   }
4450   case ISD::INTRINSIC_WO_CHAIN: {
4451     unsigned IntrinsicID
4452       = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4453     // TODO: Handle more intrinsics
4454     switch (IntrinsicID) {
4455     case Intrinsic::amdgcn_cubeid:
4456       return true;
4457 
4458     case Intrinsic::amdgcn_frexp_mant: {
4459       if (SNaN)
4460         return true;
4461       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4462     }
4463     case Intrinsic::amdgcn_cvt_pkrtz: {
4464       if (SNaN)
4465         return true;
4466       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4467              DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4468     }
4469     case Intrinsic::amdgcn_fdot2:
4470       // TODO: Refine on operand
4471       return SNaN;
4472     default:
4473       return false;
4474     }
4475   }
4476   default:
4477     return false;
4478   }
4479 }
4480