xref: /freebsd-src/contrib/llvm-project/llvm/lib/Target/AMDGPU/SIISelLowering.h (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
1 //===-- SIISelLowering.h - SI DAG Lowering Interface ------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 /// \file
10 /// SI DAG Lowering interface definition
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_AMDGPU_SIISELLOWERING_H
15 #define LLVM_LIB_TARGET_AMDGPU_SIISELLOWERING_H
16 
17 #include "AMDGPUISelLowering.h"
18 #include "AMDGPUArgumentUsageInfo.h"
19 #include "SIInstrInfo.h"
20 
21 namespace llvm {
22 
23 class SITargetLowering final : public AMDGPUTargetLowering {
24 private:
25   const GCNSubtarget *Subtarget;
26 
27 public:
28   MVT getRegisterTypeForCallingConv(LLVMContext &Context,
29                                     CallingConv::ID CC,
30                                     EVT VT) const override;
31   unsigned getNumRegistersForCallingConv(LLVMContext &Context,
32                                          CallingConv::ID CC,
33                                          EVT VT) const override;
34 
35   unsigned getVectorTypeBreakdownForCallingConv(
36     LLVMContext &Context, CallingConv::ID CC, EVT VT, EVT &IntermediateVT,
37     unsigned &NumIntermediates, MVT &RegisterVT) const override;
38 
39 private:
40   SDValue lowerKernArgParameterPtr(SelectionDAG &DAG, const SDLoc &SL,
41                                    SDValue Chain, uint64_t Offset) const;
42   SDValue getImplicitArgPtr(SelectionDAG &DAG, const SDLoc &SL) const;
43   SDValue lowerKernargMemParameter(SelectionDAG &DAG, EVT VT, EVT MemVT,
44                                    const SDLoc &SL, SDValue Chain,
45                                    uint64_t Offset, unsigned Align, bool Signed,
46                                    const ISD::InputArg *Arg = nullptr) const;
47 
48   SDValue lowerStackParameter(SelectionDAG &DAG, CCValAssign &VA,
49                               const SDLoc &SL, SDValue Chain,
50                               const ISD::InputArg &Arg) const;
51   SDValue getPreloadedValue(SelectionDAG &DAG,
52                             const SIMachineFunctionInfo &MFI,
53                             EVT VT,
54                             AMDGPUFunctionArgInfo::PreloadedValue) const;
55 
56   SDValue LowerGlobalAddress(AMDGPUMachineFunction *MFI, SDValue Op,
57                              SelectionDAG &DAG) const override;
58   SDValue lowerImplicitZextParam(SelectionDAG &DAG, SDValue Op,
59                                  MVT VT, unsigned Offset) const;
60   SDValue lowerImage(SDValue Op, const AMDGPU::ImageDimIntrinsicInfo *Intr,
61                      SelectionDAG &DAG) const;
62   SDValue lowerSBuffer(EVT VT, SDLoc DL, SDValue Rsrc, SDValue Offset,
63                        SDValue GLC, SDValue DLC, SelectionDAG &DAG) const;
64 
65   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
66   SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, SelectionDAG &DAG) const;
67   SDValue LowerINTRINSIC_VOID(SDValue Op, SelectionDAG &DAG) const;
68 
69   // The raw.tbuffer and struct.tbuffer intrinsics have two offset args: offset
70   // (the offset that is included in bounds checking and swizzling, to be split
71   // between the instruction's voffset and immoffset fields) and soffset (the
72   // offset that is excluded from bounds checking and swizzling, to go in the
73   // instruction's soffset field).  This function takes the first kind of
74   // offset and figures out how to split it between voffset and immoffset.
75   std::pair<SDValue, SDValue> splitBufferOffsets(SDValue Offset,
76                                                  SelectionDAG &DAG) const;
77 
78   SDValue widenLoad(LoadSDNode *Ld, DAGCombinerInfo &DCI) const;
79   SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
80   SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
81   SDValue lowerFastUnsafeFDIV(SDValue Op, SelectionDAG &DAG) const;
82   SDValue lowerFDIV_FAST(SDValue Op, SelectionDAG &DAG) const;
83   SDValue LowerFDIV16(SDValue Op, SelectionDAG &DAG) const;
84   SDValue LowerFDIV32(SDValue Op, SelectionDAG &DAG) const;
85   SDValue LowerFDIV64(SDValue Op, SelectionDAG &DAG) const;
86   SDValue LowerFDIV(SDValue Op, SelectionDAG &DAG) const;
87   SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG, bool Signed) const;
88   SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG) const;
89   SDValue LowerTrig(SDValue Op, SelectionDAG &DAG) const;
90   SDValue LowerATOMIC_CMP_SWAP(SDValue Op, SelectionDAG &DAG) const;
91   SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
92   SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
93   SDValue adjustLoadValueType(unsigned Opcode, MemSDNode *M,
94                               SelectionDAG &DAG, ArrayRef<SDValue> Ops,
95                               bool IsIntrinsic = false) const;
96 
97   SDValue lowerIntrinsicLoad(MemSDNode *M, bool IsFormat, SelectionDAG &DAG,
98                              ArrayRef<SDValue> Ops) const;
99 
100   // Call DAG.getMemIntrinsicNode for a load, but first widen a dwordx3 type to
101   // dwordx4 if on SI.
102   SDValue getMemIntrinsicNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList,
103                               ArrayRef<SDValue> Ops, EVT MemVT,
104                               MachineMemOperand *MMO, SelectionDAG &DAG) const;
105 
106   SDValue handleD16VData(SDValue VData, SelectionDAG &DAG) const;
107 
108   /// Converts \p Op, which must be of floating point type, to the
109   /// floating point type \p VT, by either extending or truncating it.
110   SDValue getFPExtOrFPTrunc(SelectionDAG &DAG,
111                             SDValue Op,
112                             const SDLoc &DL,
113                             EVT VT) const;
114 
115   SDValue convertArgType(
116     SelectionDAG &DAG, EVT VT, EVT MemVT, const SDLoc &SL, SDValue Val,
117     bool Signed, const ISD::InputArg *Arg = nullptr) const;
118 
119   /// Custom lowering for ISD::FP_ROUND for MVT::f16.
120   SDValue lowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const;
121   SDValue lowerFMINNUM_FMAXNUM(SDValue Op, SelectionDAG &DAG) const;
122 
123   SDValue getSegmentAperture(unsigned AS, const SDLoc &DL,
124                              SelectionDAG &DAG) const;
125 
126   SDValue lowerADDRSPACECAST(SDValue Op, SelectionDAG &DAG) const;
127   SDValue lowerINSERT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
128   SDValue lowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
129   SDValue lowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
130   SDValue lowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
131   SDValue lowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
132   SDValue lowerTRAP(SDValue Op, SelectionDAG &DAG) const;
133   SDValue lowerDEBUGTRAP(SDValue Op, SelectionDAG &DAG) const;
134 
135   SDNode *adjustWritemask(MachineSDNode *&N, SelectionDAG &DAG) const;
136 
137   SDValue performUCharToFloatCombine(SDNode *N,
138                                      DAGCombinerInfo &DCI) const;
139   SDValue performSHLPtrCombine(SDNode *N,
140                                unsigned AS,
141                                EVT MemVT,
142                                DAGCombinerInfo &DCI) const;
143 
144   SDValue performMemSDNodeCombine(MemSDNode *N, DAGCombinerInfo &DCI) const;
145 
146   SDValue splitBinaryBitConstantOp(DAGCombinerInfo &DCI, const SDLoc &SL,
147                                    unsigned Opc, SDValue LHS,
148                                    const ConstantSDNode *CRHS) const;
149 
150   SDValue performAndCombine(SDNode *N, DAGCombinerInfo &DCI) const;
151   SDValue performOrCombine(SDNode *N, DAGCombinerInfo &DCI) const;
152   SDValue performXorCombine(SDNode *N, DAGCombinerInfo &DCI) const;
153   SDValue performZeroExtendCombine(SDNode *N, DAGCombinerInfo &DCI) const;
154   SDValue performSignExtendInRegCombine(SDNode *N, DAGCombinerInfo &DCI) const;
155   SDValue performClassCombine(SDNode *N, DAGCombinerInfo &DCI) const;
156   SDValue getCanonicalConstantFP(SelectionDAG &DAG, const SDLoc &SL, EVT VT,
157                                  const APFloat &C) const;
158   SDValue performFCanonicalizeCombine(SDNode *N, DAGCombinerInfo &DCI) const;
159 
160   SDValue performFPMed3ImmCombine(SelectionDAG &DAG, const SDLoc &SL,
161                                   SDValue Op0, SDValue Op1) const;
162   SDValue performIntMed3ImmCombine(SelectionDAG &DAG, const SDLoc &SL,
163                                    SDValue Op0, SDValue Op1, bool Signed) const;
164   SDValue performMinMaxCombine(SDNode *N, DAGCombinerInfo &DCI) const;
165   SDValue performFMed3Combine(SDNode *N, DAGCombinerInfo &DCI) const;
166   SDValue performCvtPkRTZCombine(SDNode *N, DAGCombinerInfo &DCI) const;
167   SDValue performExtractVectorEltCombine(SDNode *N, DAGCombinerInfo &DCI) const;
168   SDValue performInsertVectorEltCombine(SDNode *N, DAGCombinerInfo &DCI) const;
169 
170   SDValue reassociateScalarOps(SDNode *N, SelectionDAG &DAG) const;
171   unsigned getFusedOpcode(const SelectionDAG &DAG,
172                           const SDNode *N0, const SDNode *N1) const;
173   SDValue performAddCombine(SDNode *N, DAGCombinerInfo &DCI) const;
174   SDValue performAddCarrySubCarryCombine(SDNode *N, DAGCombinerInfo &DCI) const;
175   SDValue performSubCombine(SDNode *N, DAGCombinerInfo &DCI) const;
176   SDValue performFAddCombine(SDNode *N, DAGCombinerInfo &DCI) const;
177   SDValue performFSubCombine(SDNode *N, DAGCombinerInfo &DCI) const;
178   SDValue performFMACombine(SDNode *N, DAGCombinerInfo &DCI) const;
179   SDValue performSetCCCombine(SDNode *N, DAGCombinerInfo &DCI) const;
180   SDValue performCvtF32UByteNCombine(SDNode *N, DAGCombinerInfo &DCI) const;
181   SDValue performClampCombine(SDNode *N, DAGCombinerInfo &DCI) const;
182   SDValue performRcpCombine(SDNode *N, DAGCombinerInfo &DCI) const;
183 
184   bool isLegalFlatAddressingMode(const AddrMode &AM) const;
185   bool isLegalMUBUFAddressingMode(const AddrMode &AM) const;
186 
187   unsigned isCFIntrinsic(const SDNode *Intr) const;
188 
189 public:
190   /// \returns True if fixup needs to be emitted for given global value \p GV,
191   /// false otherwise.
192   bool shouldEmitFixup(const GlobalValue *GV) const;
193 
194   /// \returns True if GOT relocation needs to be emitted for given global value
195   /// \p GV, false otherwise.
196   bool shouldEmitGOTReloc(const GlobalValue *GV) const;
197 
198   /// \returns True if PC-relative relocation needs to be emitted for given
199   /// global value \p GV, false otherwise.
200   bool shouldEmitPCReloc(const GlobalValue *GV) const;
201 
202 private:
203   // Analyze a combined offset from an amdgcn_buffer_ intrinsic and store the
204   // three offsets (voffset, soffset and instoffset) into the SDValue[3] array
205   // pointed to by Offsets.
206   /// \returns 0 If there is a non-constant offset or if the offset is 0.
207   /// Otherwise returns the constant offset.
208   unsigned setBufferOffsets(SDValue CombinedOffset, SelectionDAG &DAG,
209                            SDValue *Offsets, unsigned Align = 4) const;
210 
211   // Handle 8 bit and 16 bit buffer loads
212   SDValue handleByteShortBufferLoads(SelectionDAG &DAG, EVT LoadVT, SDLoc DL,
213                                      ArrayRef<SDValue> Ops, MemSDNode *M) const;
214 
215   // Handle 8 bit and 16 bit buffer stores
216   SDValue handleByteShortBufferStores(SelectionDAG &DAG, EVT VDataType,
217                                       SDLoc DL, SDValue Ops[],
218                                       MemSDNode *M) const;
219 
220 public:
221   SITargetLowering(const TargetMachine &tm, const GCNSubtarget &STI);
222 
223   const GCNSubtarget *getSubtarget() const;
224 
225   bool isFPExtFoldable(unsigned Opcode, EVT DestVT, EVT SrcVT) const override;
226 
227   bool isShuffleMaskLegal(ArrayRef<int> /*Mask*/, EVT /*VT*/) const override;
228 
229   bool getTgtMemIntrinsic(IntrinsicInfo &, const CallInst &,
230                           MachineFunction &MF,
231                           unsigned IntrinsicID) const override;
232 
233   bool getAddrModeArguments(IntrinsicInst * /*I*/,
234                             SmallVectorImpl<Value*> &/*Ops*/,
235                             Type *&/*AccessTy*/) const override;
236 
237   bool isLegalGlobalAddressingMode(const AddrMode &AM) const;
238   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
239                              unsigned AS,
240                              Instruction *I = nullptr) const override;
241 
242   bool canMergeStoresTo(unsigned AS, EVT MemVT,
243                         const SelectionDAG &DAG) const override;
244 
245   bool allowsMisalignedMemoryAccessesImpl(
246       unsigned Size, unsigned AS, unsigned Align,
247       MachineMemOperand::Flags Flags = MachineMemOperand::MONone,
248       bool *IsFast = nullptr) const;
249 
250   bool allowsMisalignedMemoryAccesses(
251       EVT VT, unsigned AS, unsigned Align,
252       MachineMemOperand::Flags Flags = MachineMemOperand::MONone,
253       bool *IsFast = nullptr) const override;
254 
255   EVT getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
256                           unsigned SrcAlign, bool IsMemset,
257                           bool ZeroMemset,
258                           bool MemcpyStrSrc,
259                           const AttributeList &FuncAttributes) const override;
260 
261   bool isMemOpUniform(const SDNode *N) const;
262   bool isMemOpHasNoClobberedMemOperand(const SDNode *N) const;
263   bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override;
264   bool isFreeAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override;
265 
266   TargetLoweringBase::LegalizeTypeAction
267   getPreferredVectorAction(MVT VT) const override;
268 
269   bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
270                                         Type *Ty) const override;
271 
272   bool isTypeDesirableForOp(unsigned Op, EVT VT) const override;
273 
274   bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
275 
276   bool supportSplitCSR(MachineFunction *MF) const override;
277   void initializeSplitCSR(MachineBasicBlock *Entry) const override;
278   void insertCopiesSplitCSR(
279     MachineBasicBlock *Entry,
280     const SmallVectorImpl<MachineBasicBlock *> &Exits) const override;
281 
282   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
283                                bool isVarArg,
284                                const SmallVectorImpl<ISD::InputArg> &Ins,
285                                const SDLoc &DL, SelectionDAG &DAG,
286                                SmallVectorImpl<SDValue> &InVals) const override;
287 
288   bool CanLowerReturn(CallingConv::ID CallConv,
289                       MachineFunction &MF, bool isVarArg,
290                       const SmallVectorImpl<ISD::OutputArg> &Outs,
291                       LLVMContext &Context) const override;
292 
293   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
294                       const SmallVectorImpl<ISD::OutputArg> &Outs,
295                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &DL,
296                       SelectionDAG &DAG) const override;
297 
298   void passSpecialInputs(
299     CallLoweringInfo &CLI,
300     CCState &CCInfo,
301     const SIMachineFunctionInfo &Info,
302     SmallVectorImpl<std::pair<unsigned, SDValue>> &RegsToPass,
303     SmallVectorImpl<SDValue> &MemOpChains,
304     SDValue Chain) const;
305 
306   SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
307                           CallingConv::ID CallConv, bool isVarArg,
308                           const SmallVectorImpl<ISD::InputArg> &Ins,
309                           const SDLoc &DL, SelectionDAG &DAG,
310                           SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
311                           SDValue ThisVal) const;
312 
313   bool mayBeEmittedAsTailCall(const CallInst *) const override;
314 
315   bool isEligibleForTailCallOptimization(
316     SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg,
317     const SmallVectorImpl<ISD::OutputArg> &Outs,
318     const SmallVectorImpl<SDValue> &OutVals,
319     const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const;
320 
321   SDValue LowerCall(CallLoweringInfo &CLI,
322                     SmallVectorImpl<SDValue> &InVals) const override;
323 
324   Register getRegisterByName(const char* RegName, EVT VT,
325                              const MachineFunction &MF) const override;
326 
327   MachineBasicBlock *splitKillBlock(MachineInstr &MI,
328                                     MachineBasicBlock *BB) const;
329 
330   void bundleInstWithWaitcnt(MachineInstr &MI) const;
331   MachineBasicBlock *emitGWSMemViolTestLoop(MachineInstr &MI,
332                                             MachineBasicBlock *BB) const;
333 
334   MachineBasicBlock *
335   EmitInstrWithCustomInserter(MachineInstr &MI,
336                               MachineBasicBlock *BB) const override;
337 
338   bool hasBitPreservingFPLogic(EVT VT) const override;
339   bool enableAggressiveFMAFusion(EVT VT) const override;
340   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
341                          EVT VT) const override;
342   MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override;
343   bool isFMAFasterThanFMulAndFAdd(EVT VT) const override;
344   SDValue splitUnaryVectorOp(SDValue Op, SelectionDAG &DAG) const;
345   SDValue splitBinaryVectorOp(SDValue Op, SelectionDAG &DAG) const;
346   SDValue splitTernaryVectorOp(SDValue Op, SelectionDAG &DAG) const;
347   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
348 
349   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
350                           SelectionDAG &DAG) const override;
351 
352   SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
353   SDNode *PostISelFolding(MachineSDNode *N, SelectionDAG &DAG) const override;
354   void AdjustInstrPostInstrSelection(MachineInstr &MI,
355                                      SDNode *Node) const override;
356 
357   SDNode *legalizeTargetIndependentNode(SDNode *Node, SelectionDAG &DAG) const;
358 
359   MachineSDNode *wrapAddr64Rsrc(SelectionDAG &DAG, const SDLoc &DL,
360                                 SDValue Ptr) const;
361   MachineSDNode *buildRSRC(SelectionDAG &DAG, const SDLoc &DL, SDValue Ptr,
362                            uint32_t RsrcDword1, uint64_t RsrcDword2And3) const;
363   std::pair<unsigned, const TargetRegisterClass *>
364   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
365                                StringRef Constraint, MVT VT) const override;
366   ConstraintType getConstraintType(StringRef Constraint) const override;
367   SDValue copyToM0(SelectionDAG &DAG, SDValue Chain, const SDLoc &DL,
368                    SDValue V) const;
369 
370   void finalizeLowering(MachineFunction &MF) const override;
371 
372   void computeKnownBitsForFrameIndex(const SDValue Op,
373                                      KnownBits &Known,
374                                      const APInt &DemandedElts,
375                                      const SelectionDAG &DAG,
376                                      unsigned Depth = 0) const override;
377 
378   bool isSDNodeSourceOfDivergence(const SDNode *N,
379     FunctionLoweringInfo *FLI, LegacyDivergenceAnalysis *DA) const override;
380 
381   bool isCanonicalized(SelectionDAG &DAG, SDValue Op,
382                        unsigned MaxDepth = 5) const;
383   bool denormalsEnabledForType(EVT VT) const;
384 
385   bool isKnownNeverNaNForTargetNode(SDValue Op,
386                                     const SelectionDAG &DAG,
387                                     bool SNaN = false,
388                                     unsigned Depth = 0) const override;
389   AtomicExpansionKind shouldExpandAtomicRMWInIR(AtomicRMWInst *) const override;
390 
391   virtual const TargetRegisterClass *
392   getRegClassFor(MVT VT, bool isDivergent) const override;
393   virtual bool requiresUniformRegister(MachineFunction &MF,
394                                        const Value *V) const override;
395   Align getPrefLoopAlignment(MachineLoop *ML) const override;
396 
397   void allocateHSAUserSGPRs(CCState &CCInfo,
398                             MachineFunction &MF,
399                             const SIRegisterInfo &TRI,
400                             SIMachineFunctionInfo &Info) const;
401 
402   void allocateSystemSGPRs(CCState &CCInfo,
403                            MachineFunction &MF,
404                            SIMachineFunctionInfo &Info,
405                            CallingConv::ID CallConv,
406                            bool IsShader) const;
407 
408   void allocateSpecialEntryInputVGPRs(CCState &CCInfo,
409                                       MachineFunction &MF,
410                                       const SIRegisterInfo &TRI,
411                                       SIMachineFunctionInfo &Info) const;
412   void allocateSpecialInputSGPRs(
413     CCState &CCInfo,
414     MachineFunction &MF,
415     const SIRegisterInfo &TRI,
416     SIMachineFunctionInfo &Info) const;
417 
418   void allocateSpecialInputVGPRs(CCState &CCInfo,
419                                  MachineFunction &MF,
420                                  const SIRegisterInfo &TRI,
421                                  SIMachineFunctionInfo &Info) const;
422 };
423 
424 } // End namespace llvm
425 
426 #endif
427