xref: /freebsd/contrib/llvm-project/llvm/lib/Target/X86/X86TargetTransformInfo.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===-- X86TargetTransformInfo.h - X86 specific TTI -------------*- 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 /// \file
9 /// This file a TargetTransformInfo::Concept conforming object specific to the
10 /// X86 target machine. It uses the target's detailed information to
11 /// provide more precise answers to certain TTI queries, while letting the
12 /// target independent and default TTI implementations handle the rest.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_LIB_TARGET_X86_X86TARGETTRANSFORMINFO_H
17 #define LLVM_LIB_TARGET_X86_X86TARGETTRANSFORMINFO_H
18 
19 #include "X86TargetMachine.h"
20 #include "llvm/Analysis/TargetTransformInfo.h"
21 #include "llvm/CodeGen/BasicTTIImpl.h"
22 #include <optional>
23 
24 namespace llvm {
25 
26 class InstCombiner;
27 
28 class X86TTIImpl : public BasicTTIImplBase<X86TTIImpl> {
29   typedef BasicTTIImplBase<X86TTIImpl> BaseT;
30   typedef TargetTransformInfo TTI;
31   friend BaseT;
32 
33   const X86Subtarget *ST;
34   const X86TargetLowering *TLI;
35 
getST()36   const X86Subtarget *getST() const { return ST; }
getTLI()37   const X86TargetLowering *getTLI() const { return TLI; }
38 
39   const FeatureBitset InlineFeatureIgnoreList = {
40       // This indicates the CPU is 64 bit capable not that we are in 64-bit
41       // mode.
42       X86::FeatureX86_64,
43 
44       // These features don't have any intrinsics or ABI effect.
45       X86::FeatureNOPL,
46       X86::FeatureCX16,
47       X86::FeatureLAHFSAHF64,
48 
49       // Some older targets can be setup to fold unaligned loads.
50       X86::FeatureSSEUnalignedMem,
51 
52       // Codegen control options.
53       X86::TuningFast11ByteNOP,
54       X86::TuningFast15ByteNOP,
55       X86::TuningFastBEXTR,
56       X86::TuningFastHorizontalOps,
57       X86::TuningFastLZCNT,
58       X86::TuningFastScalarFSQRT,
59       X86::TuningFastSHLDRotate,
60       X86::TuningFastScalarShiftMasks,
61       X86::TuningFastVectorShiftMasks,
62       X86::TuningFastVariableCrossLaneShuffle,
63       X86::TuningFastVariablePerLaneShuffle,
64       X86::TuningFastVectorFSQRT,
65       X86::TuningLEAForSP,
66       X86::TuningLEAUsesAG,
67       X86::TuningLZCNTFalseDeps,
68       X86::TuningBranchFusion,
69       X86::TuningMacroFusion,
70       X86::TuningPadShortFunctions,
71       X86::TuningPOPCNTFalseDeps,
72       X86::TuningMULCFalseDeps,
73       X86::TuningPERMFalseDeps,
74       X86::TuningRANGEFalseDeps,
75       X86::TuningGETMANTFalseDeps,
76       X86::TuningMULLQFalseDeps,
77       X86::TuningSlow3OpsLEA,
78       X86::TuningSlowDivide32,
79       X86::TuningSlowDivide64,
80       X86::TuningSlowIncDec,
81       X86::TuningSlowLEA,
82       X86::TuningSlowPMADDWD,
83       X86::TuningSlowPMULLD,
84       X86::TuningSlowSHLD,
85       X86::TuningSlowTwoMemOps,
86       X86::TuningSlowUAMem16,
87       X86::TuningPreferMaskRegisters,
88       X86::TuningInsertVZEROUPPER,
89       X86::TuningUseSLMArithCosts,
90       X86::TuningUseGLMDivSqrtCosts,
91       X86::TuningNoDomainDelay,
92       X86::TuningNoDomainDelayMov,
93       X86::TuningNoDomainDelayShuffle,
94       X86::TuningNoDomainDelayBlend,
95       X86::TuningPreferShiftShuffle,
96       X86::TuningFastImmVectorShift,
97       X86::TuningFastDPWSSD,
98 
99       // Perf-tuning flags.
100       X86::TuningFastGather,
101       X86::TuningSlowUAMem32,
102       X86::TuningAllowLight256Bit,
103 
104       // Based on whether user set the -mprefer-vector-width command line.
105       X86::TuningPrefer128Bit,
106       X86::TuningPrefer256Bit,
107 
108       // CPU name enums. These just follow CPU string.
109       X86::ProcIntelAtom
110   };
111 
112 public:
X86TTIImpl(const X86TargetMachine * TM,const Function & F)113   explicit X86TTIImpl(const X86TargetMachine *TM, const Function &F)
114       : BaseT(TM, F.getDataLayout()), ST(TM->getSubtargetImpl(F)),
115         TLI(ST->getTargetLowering()) {}
116 
117   /// \name Scalar TTI Implementations
118   /// @{
119   TTI::PopcntSupportKind getPopcntSupport(unsigned TyWidth);
120 
121   /// @}
122 
123   /// \name Cache TTI Implementation
124   /// @{
125   std::optional<unsigned> getCacheSize(
126     TargetTransformInfo::CacheLevel Level) const override;
127   std::optional<unsigned> getCacheAssociativity(
128     TargetTransformInfo::CacheLevel Level) const override;
129   /// @}
130 
131   /// \name Vector TTI Implementations
132   /// @{
133 
134   unsigned getNumberOfRegisters(unsigned ClassID) const;
135   bool hasConditionalLoadStoreForType(Type *Ty = nullptr) const;
136   TypeSize getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const;
137   unsigned getLoadStoreVecRegBitWidth(unsigned AS) const;
138   unsigned getMaxInterleaveFactor(ElementCount VF);
139   InstructionCost getArithmeticInstrCost(
140       unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
141       TTI::OperandValueInfo Op1Info = {TTI::OK_AnyValue, TTI::OP_None},
142       TTI::OperandValueInfo Op2Info = {TTI::OK_AnyValue, TTI::OP_None},
143       ArrayRef<const Value *> Args = std::nullopt,
144       const Instruction *CxtI = nullptr);
145   InstructionCost getAltInstrCost(VectorType *VecTy, unsigned Opcode0,
146                                   unsigned Opcode1,
147                                   const SmallBitVector &OpcodeMask,
148                                   TTI::TargetCostKind CostKind) const;
149 
150   InstructionCost getShuffleCost(TTI::ShuffleKind Kind, VectorType *Tp,
151                                  ArrayRef<int> Mask,
152                                  TTI::TargetCostKind CostKind, int Index,
153                                  VectorType *SubTp,
154                                  ArrayRef<const Value *> Args = std::nullopt,
155                                  const Instruction *CxtI = nullptr);
156   InstructionCost getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src,
157                                    TTI::CastContextHint CCH,
158                                    TTI::TargetCostKind CostKind,
159                                    const Instruction *I = nullptr);
160   InstructionCost getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy,
161                                      CmpInst::Predicate VecPred,
162                                      TTI::TargetCostKind CostKind,
163                                      const Instruction *I = nullptr);
164   using BaseT::getVectorInstrCost;
165   InstructionCost getVectorInstrCost(unsigned Opcode, Type *Val,
166                                      TTI::TargetCostKind CostKind,
167                                      unsigned Index, Value *Op0, Value *Op1);
168   InstructionCost getScalarizationOverhead(VectorType *Ty,
169                                            const APInt &DemandedElts,
170                                            bool Insert, bool Extract,
171                                            TTI::TargetCostKind CostKind);
172   InstructionCost getReplicationShuffleCost(Type *EltTy, int ReplicationFactor,
173                                             int VF,
174                                             const APInt &DemandedDstElts,
175                                             TTI::TargetCostKind CostKind);
176   InstructionCost
177   getMemoryOpCost(unsigned Opcode, Type *Src, MaybeAlign Alignment,
178                   unsigned AddressSpace, TTI::TargetCostKind CostKind,
179                   TTI::OperandValueInfo OpInfo = {TTI::OK_AnyValue, TTI::OP_None},
180                   const Instruction *I = nullptr);
181   InstructionCost getMaskedMemoryOpCost(unsigned Opcode, Type *Src,
182                                         Align Alignment, unsigned AddressSpace,
183                                         TTI::TargetCostKind CostKind);
184   InstructionCost getGatherScatterOpCost(unsigned Opcode, Type *DataTy,
185                                          const Value *Ptr, bool VariableMask,
186                                          Align Alignment,
187                                          TTI::TargetCostKind CostKind,
188                                          const Instruction *I);
189   InstructionCost getPointersChainCost(ArrayRef<const Value *> Ptrs,
190                                        const Value *Base,
191                                        const TTI::PointersChainInfo &Info,
192                                        Type *AccessTy,
193                                        TTI::TargetCostKind CostKind);
194   InstructionCost getAddressComputationCost(Type *PtrTy, ScalarEvolution *SE,
195                                             const SCEV *Ptr);
196 
197   std::optional<Instruction *> instCombineIntrinsic(InstCombiner &IC,
198                                                     IntrinsicInst &II) const;
199   std::optional<Value *>
200   simplifyDemandedUseBitsIntrinsic(InstCombiner &IC, IntrinsicInst &II,
201                                    APInt DemandedMask, KnownBits &Known,
202                                    bool &KnownBitsComputed) const;
203   std::optional<Value *> simplifyDemandedVectorEltsIntrinsic(
204       InstCombiner &IC, IntrinsicInst &II, APInt DemandedElts, APInt &UndefElts,
205       APInt &UndefElts2, APInt &UndefElts3,
206       std::function<void(Instruction *, unsigned, APInt, APInt &)>
207           SimplifyAndSetOp) const;
208 
209   unsigned getAtomicMemIntrinsicMaxElementSize() const;
210 
211   InstructionCost getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
212                                         TTI::TargetCostKind CostKind);
213 
214   InstructionCost getArithmeticReductionCost(unsigned Opcode, VectorType *Ty,
215                                              std::optional<FastMathFlags> FMF,
216                                              TTI::TargetCostKind CostKind);
217 
218   InstructionCost getMinMaxCost(Intrinsic::ID IID, Type *Ty,
219                                 TTI::TargetCostKind CostKind,
220                                 FastMathFlags FMF);
221 
222   InstructionCost getMinMaxReductionCost(Intrinsic::ID IID, VectorType *Ty,
223                                          FastMathFlags FMF,
224                                          TTI::TargetCostKind CostKind);
225 
226   InstructionCost getInterleavedMemoryOpCost(
227       unsigned Opcode, Type *VecTy, unsigned Factor, ArrayRef<unsigned> Indices,
228       Align Alignment, unsigned AddressSpace, TTI::TargetCostKind CostKind,
229       bool UseMaskForCond = false, bool UseMaskForGaps = false);
230   InstructionCost getInterleavedMemoryOpCostAVX512(
231       unsigned Opcode, FixedVectorType *VecTy, unsigned Factor,
232       ArrayRef<unsigned> Indices, Align Alignment, unsigned AddressSpace,
233       TTI::TargetCostKind CostKind, bool UseMaskForCond = false,
234       bool UseMaskForGaps = false);
235 
236   InstructionCost getIntImmCost(int64_t);
237 
238   InstructionCost getIntImmCost(const APInt &Imm, Type *Ty,
239                                 TTI::TargetCostKind CostKind);
240 
241   InstructionCost getCFInstrCost(unsigned Opcode, TTI::TargetCostKind CostKind,
242                                  const Instruction *I = nullptr);
243 
244   InstructionCost getIntImmCostInst(unsigned Opcode, unsigned Idx,
245                                     const APInt &Imm, Type *Ty,
246                                     TTI::TargetCostKind CostKind,
247                                     Instruction *Inst = nullptr);
248   InstructionCost getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
249                                       const APInt &Imm, Type *Ty,
250                                       TTI::TargetCostKind CostKind);
251   /// Return the cost of the scaling factor used in the addressing
252   /// mode represented by AM for this target, for a load/store
253   /// of the specified type.
254   /// If the AM is supported, the return value must be >= 0.
255   /// If the AM is not supported, it returns a negative value.
256   InstructionCost getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
257                                        StackOffset BaseOffset, bool HasBaseReg,
258                                        int64_t Scale, unsigned AddrSpace) const;
259 
260   bool isLSRCostLess(const TargetTransformInfo::LSRCost &C1,
261                      const TargetTransformInfo::LSRCost &C2);
262   bool canMacroFuseCmp();
263   bool isLegalMaskedLoad(Type *DataType, Align Alignment);
264   bool isLegalMaskedStore(Type *DataType, Align Alignment);
265   bool isLegalNTLoad(Type *DataType, Align Alignment);
266   bool isLegalNTStore(Type *DataType, Align Alignment);
267   bool isLegalBroadcastLoad(Type *ElementTy, ElementCount NumElements) const;
268   bool forceScalarizeMaskedGather(VectorType *VTy, Align Alignment);
forceScalarizeMaskedScatter(VectorType * VTy,Align Alignment)269   bool forceScalarizeMaskedScatter(VectorType *VTy, Align Alignment) {
270     return forceScalarizeMaskedGather(VTy, Alignment);
271   }
272   bool isLegalMaskedGatherScatter(Type *DataType, Align Alignment);
273   bool isLegalMaskedGather(Type *DataType, Align Alignment);
274   bool isLegalMaskedScatter(Type *DataType, Align Alignment);
275   bool isLegalMaskedExpandLoad(Type *DataType, Align Alignment);
276   bool isLegalMaskedCompressStore(Type *DataType, Align Alignment);
277   bool isLegalAltInstr(VectorType *VecTy, unsigned Opcode0, unsigned Opcode1,
278                        const SmallBitVector &OpcodeMask) const;
279   bool hasDivRemOp(Type *DataType, bool IsSigned);
280   bool isExpensiveToSpeculativelyExecute(const Instruction *I);
281   bool isFCmpOrdCheaperThanFCmpZero(Type *Ty);
282   bool areInlineCompatible(const Function *Caller,
283                            const Function *Callee) const;
284   bool areTypesABICompatible(const Function *Caller, const Function *Callee,
285                              const ArrayRef<Type *> &Type) const;
286 
getMaxMemIntrinsicInlineSizeThreshold()287   uint64_t getMaxMemIntrinsicInlineSizeThreshold() const {
288     return ST->getMaxInlineSizeThreshold();
289   }
290 
291   TTI::MemCmpExpansionOptions enableMemCmpExpansion(bool OptSize,
292                                                     bool IsZeroCmp) const;
293   bool prefersVectorizedAddressing() const;
294   bool supportsEfficientVectorElementLoadStore() const;
295   bool enableInterleavedAccessVectorization();
296 
297   InstructionCost getBranchMispredictPenalty() const;
298 
299 private:
300   bool supportsGather() const;
301   InstructionCost getGSVectorCost(unsigned Opcode, TTI::TargetCostKind CostKind,
302                                   Type *DataTy, const Value *Ptr,
303                                   Align Alignment, unsigned AddressSpace);
304 
305   int getGatherOverhead() const;
306   int getScatterOverhead() const;
307 
308   /// @}
309 };
310 
311 } // end namespace llvm
312 
313 #endif
314