1 //===- TargetTransformInfoImpl.h --------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 /// This file provides helpers for the implementation of
11 /// a TargetTransformInfo-conforming class.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
16 #define LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
18 #include "llvm/Analysis/TargetTransformInfo.h"
19 #include "llvm/IR/CallSite.h"
20 #include "llvm/IR/DataLayout.h"
21 #include "llvm/IR/Function.h"
22 #include "llvm/IR/GetElementPtrTypeIterator.h"
23 #include "llvm/IR/Operator.h"
24 #include "llvm/IR/Type.h"
25 #include "llvm/Analysis/VectorUtils.h"
29 /// \brief Base class for use as a mix-in that aids implementing
30 /// a TargetTransformInfo-compatible class.
31 class TargetTransformInfoImplBase {
33 typedef TargetTransformInfo TTI;
37 explicit TargetTransformInfoImplBase(const DataLayout &DL) : DL(DL) {}
40 // Provide value semantics. MSVC requires that we spell all of these out.
41 TargetTransformInfoImplBase(const TargetTransformInfoImplBase &Arg)
43 TargetTransformInfoImplBase(TargetTransformInfoImplBase &&Arg) : DL(Arg.DL) {}
45 const DataLayout &getDataLayout() const { return DL; }
47 unsigned getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) {
50 // By default, just classify everything as 'basic'.
51 return TTI::TCC_Basic;
53 case Instruction::GetElementPtr:
54 llvm_unreachable("Use getGEPCost for GEP operations!");
56 case Instruction::BitCast:
57 assert(OpTy && "Cast instructions must provide the operand type");
58 if (Ty == OpTy || (Ty->isPointerTy() && OpTy->isPointerTy()))
59 // Identity and pointer-to-pointer casts are free.
62 // Otherwise, the default basic cost is used.
63 return TTI::TCC_Basic;
65 case Instruction::FDiv:
66 case Instruction::FRem:
67 case Instruction::SDiv:
68 case Instruction::SRem:
69 case Instruction::UDiv:
70 case Instruction::URem:
71 return TTI::TCC_Expensive;
73 case Instruction::IntToPtr: {
74 // An inttoptr cast is free so long as the input is a legal integer type
75 // which doesn't contain values outside the range of a pointer.
76 unsigned OpSize = OpTy->getScalarSizeInBits();
77 if (DL.isLegalInteger(OpSize) &&
78 OpSize <= DL.getPointerTypeSizeInBits(Ty))
81 // Otherwise it's not a no-op.
82 return TTI::TCC_Basic;
84 case Instruction::PtrToInt: {
85 // A ptrtoint cast is free so long as the result is large enough to store
86 // the pointer, and a legal integer type.
87 unsigned DestSize = Ty->getScalarSizeInBits();
88 if (DL.isLegalInteger(DestSize) &&
89 DestSize >= DL.getPointerTypeSizeInBits(OpTy))
92 // Otherwise it's not a no-op.
93 return TTI::TCC_Basic;
95 case Instruction::Trunc:
96 // trunc to a native type is free (assuming the target has compare and
97 // shift-right of the same width).
98 if (DL.isLegalInteger(DL.getTypeSizeInBits(Ty)))
101 return TTI::TCC_Basic;
105 int getGEPCost(Type *PointeeType, const Value *Ptr,
106 ArrayRef<const Value *> Operands) {
107 // In the basic model, we just assume that all-constant GEPs will be folded
108 // into their uses via addressing modes.
109 for (unsigned Idx = 0, Size = Operands.size(); Idx != Size; ++Idx)
110 if (!isa<Constant>(Operands[Idx]))
111 return TTI::TCC_Basic;
113 return TTI::TCC_Free;
116 unsigned getCallCost(FunctionType *FTy, int NumArgs) {
117 assert(FTy && "FunctionType must be provided to this routine.");
119 // The target-independent implementation just measures the size of the
120 // function by approximating that each argument will take on average one
121 // instruction to prepare.
124 // Set the argument number to the number of explicit arguments in the
126 NumArgs = FTy->getNumParams();
128 return TTI::TCC_Basic * (NumArgs + 1);
131 unsigned getInliningThresholdMultiplier() { return 1; }
133 unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
134 ArrayRef<Type *> ParamTys) {
137 // Intrinsics rarely (if ever) have normal argument setup constraints.
138 // Model them as having a basic instruction cost.
139 // FIXME: This is wrong for libc intrinsics.
140 return TTI::TCC_Basic;
142 case Intrinsic::annotation:
143 case Intrinsic::assume:
144 case Intrinsic::dbg_declare:
145 case Intrinsic::dbg_value:
146 case Intrinsic::invariant_start:
147 case Intrinsic::invariant_end:
148 case Intrinsic::lifetime_start:
149 case Intrinsic::lifetime_end:
150 case Intrinsic::objectsize:
151 case Intrinsic::ptr_annotation:
152 case Intrinsic::var_annotation:
153 case Intrinsic::experimental_gc_result:
154 case Intrinsic::experimental_gc_relocate:
155 // These intrinsics don't actually represent code after lowering.
156 return TTI::TCC_Free;
160 bool hasBranchDivergence() { return false; }
162 bool isSourceOfDivergence(const Value *V) { return false; }
164 bool isLoweredToCall(const Function *F) {
165 // FIXME: These should almost certainly not be handled here, and instead
166 // handled with the help of TLI or the target itself. This was largely
167 // ported from existing analysis heuristics here so that such refactorings
168 // can take place in the future.
170 if (F->isIntrinsic())
173 if (F->hasLocalLinkage() || !F->hasName())
176 StringRef Name = F->getName();
178 // These will all likely lower to a single selection DAG node.
179 if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
180 Name == "fabs" || Name == "fabsf" || Name == "fabsl" || Name == "sin" ||
181 Name == "fmin" || Name == "fminf" || Name == "fminl" ||
182 Name == "fmax" || Name == "fmaxf" || Name == "fmaxl" ||
183 Name == "sinf" || Name == "sinl" || Name == "cos" || Name == "cosf" ||
184 Name == "cosl" || Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl")
187 // These are all likely to be optimized into something smaller.
188 if (Name == "pow" || Name == "powf" || Name == "powl" || Name == "exp2" ||
189 Name == "exp2l" || Name == "exp2f" || Name == "floor" ||
190 Name == "floorf" || Name == "ceil" || Name == "round" ||
191 Name == "ffs" || Name == "ffsl" || Name == "abs" || Name == "labs" ||
198 void getUnrollingPreferences(Loop *, TTI::UnrollingPreferences &) {}
200 bool isLegalAddImmediate(int64_t Imm) { return false; }
202 bool isLegalICmpImmediate(int64_t Imm) { return false; }
204 bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
205 bool HasBaseReg, int64_t Scale,
206 unsigned AddrSpace) {
207 // Guess that only reg and reg+reg addressing is allowed. This heuristic is
208 // taken from the implementation of LSR.
209 return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
212 bool isLegalMaskedStore(Type *DataType) { return false; }
214 bool isLegalMaskedLoad(Type *DataType) { return false; }
216 bool isLegalMaskedScatter(Type *DataType) { return false; }
218 bool isLegalMaskedGather(Type *DataType) { return false; }
220 int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
221 bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
222 // Guess that all legal addressing mode are free.
223 if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
229 bool isTruncateFree(Type *Ty1, Type *Ty2) { return false; }
231 bool isProfitableToHoist(Instruction *I) { return true; }
233 bool isTypeLegal(Type *Ty) { return false; }
235 unsigned getJumpBufAlignment() { return 0; }
237 unsigned getJumpBufSize() { return 0; }
239 bool shouldBuildLookupTables() { return true; }
241 bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }
243 bool enableInterleavedAccessVectorization() { return false; }
245 bool isFPVectorizationPotentiallyUnsafe() { return false; }
247 bool allowsMisalignedMemoryAccesses(unsigned BitWidth,
248 unsigned AddressSpace,
250 bool *Fast) { return false; }
252 TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
253 return TTI::PSK_Software;
256 bool haveFastSqrt(Type *Ty) { return false; }
258 unsigned getFPOpCost(Type *Ty) { return TargetTransformInfo::TCC_Basic; }
260 int getIntImmCodeSizeCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
265 unsigned getIntImmCost(const APInt &Imm, Type *Ty) { return TTI::TCC_Basic; }
267 unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
269 return TTI::TCC_Free;
272 unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
274 return TTI::TCC_Free;
277 unsigned getNumberOfRegisters(bool Vector) { return 8; }
279 unsigned getRegisterBitWidth(bool Vector) { return 32; }
281 unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) { return 128; }
283 unsigned getCacheLineSize() { return 0; }
285 unsigned getPrefetchDistance() { return 0; }
287 unsigned getMinPrefetchStride() { return 1; }
289 unsigned getMaxPrefetchIterationsAhead() { return UINT_MAX; }
291 unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }
293 unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
294 TTI::OperandValueKind Opd1Info,
295 TTI::OperandValueKind Opd2Info,
296 TTI::OperandValueProperties Opd1PropInfo,
297 TTI::OperandValueProperties Opd2PropInfo) {
301 unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Ty, int Index,
306 unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) { return 1; }
308 unsigned getExtractWithExtendCost(unsigned Opcode, Type *Dst,
309 VectorType *VecTy, unsigned Index) {
313 unsigned getCFInstrCost(unsigned Opcode) { return 1; }
315 unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) {
319 unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
323 unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
324 unsigned AddressSpace) {
328 unsigned getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
329 unsigned AddressSpace) {
333 unsigned getGatherScatterOpCost(unsigned Opcode, Type *DataTy, Value *Ptr,
335 unsigned Alignment) {
339 unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
341 ArrayRef<unsigned> Indices,
343 unsigned AddressSpace) {
347 unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
348 ArrayRef<Type *> Tys, FastMathFlags FMF) {
351 unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
352 ArrayRef<Value *> Args, FastMathFlags FMF) {
356 unsigned getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) {
360 unsigned getNumberOfParts(Type *Tp) { return 0; }
362 unsigned getAddressComputationCost(Type *Tp, bool) { return 0; }
364 unsigned getReductionCost(unsigned, Type *, bool) { return 1; }
366 unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) { return 0; }
368 bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) {
372 Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
373 Type *ExpectedType) {
377 bool areInlineCompatible(const Function *Caller,
378 const Function *Callee) const {
379 return (Caller->getFnAttribute("target-cpu") ==
380 Callee->getFnAttribute("target-cpu")) &&
381 (Caller->getFnAttribute("target-features") ==
382 Callee->getFnAttribute("target-features"));
386 /// \brief CRTP base class for use as a mix-in that aids implementing
387 /// a TargetTransformInfo-compatible class.
388 template <typename T>
389 class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
391 typedef TargetTransformInfoImplBase BaseT;
394 explicit TargetTransformInfoImplCRTPBase(const DataLayout &DL) : BaseT(DL) {}
397 // Provide value semantics. MSVC requires that we spell all of these out.
398 TargetTransformInfoImplCRTPBase(const TargetTransformInfoImplCRTPBase &Arg)
399 : BaseT(static_cast<const BaseT &>(Arg)) {}
400 TargetTransformInfoImplCRTPBase(TargetTransformInfoImplCRTPBase &&Arg)
401 : BaseT(std::move(static_cast<BaseT &>(Arg))) {}
403 using BaseT::getCallCost;
405 unsigned getCallCost(const Function *F, int NumArgs) {
406 assert(F && "A concrete function must be provided to this routine.");
409 // Set the argument number to the number of explicit arguments in the
411 NumArgs = F->arg_size();
413 if (Intrinsic::ID IID = F->getIntrinsicID()) {
414 FunctionType *FTy = F->getFunctionType();
415 SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
416 return static_cast<T *>(this)
417 ->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
420 if (!static_cast<T *>(this)->isLoweredToCall(F))
421 return TTI::TCC_Basic; // Give a basic cost if it will be lowered
424 return static_cast<T *>(this)->getCallCost(F->getFunctionType(), NumArgs);
427 unsigned getCallCost(const Function *F, ArrayRef<const Value *> Arguments) {
428 // Simply delegate to generic handling of the call.
429 // FIXME: We should use instsimplify or something else to catch calls which
430 // will constant fold with these arguments.
431 return static_cast<T *>(this)->getCallCost(F, Arguments.size());
434 using BaseT::getGEPCost;
436 int getGEPCost(Type *PointeeType, const Value *Ptr,
437 ArrayRef<const Value *> Operands) {
438 const GlobalValue *BaseGV = nullptr;
439 if (Ptr != nullptr) {
440 // TODO: will remove this when pointers have an opaque type.
441 assert(Ptr->getType()->getScalarType()->getPointerElementType() ==
443 "explicit pointee type doesn't match operand's pointee type");
444 BaseGV = dyn_cast<GlobalValue>(Ptr->stripPointerCasts());
446 bool HasBaseReg = (BaseGV == nullptr);
447 int64_t BaseOffset = 0;
450 // Assumes the address space is 0 when Ptr is nullptr.
452 (Ptr == nullptr ? 0 : Ptr->getType()->getPointerAddressSpace());
453 auto GTI = gep_type_begin(PointeeType, AS, Operands);
454 for (auto I = Operands.begin(); I != Operands.end(); ++I, ++GTI) {
455 // We assume that the cost of Scalar GEP with constant index and the
456 // cost of Vector GEP with splat constant index are the same.
457 const ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I);
459 if (auto Splat = getSplatValue(*I))
460 ConstIdx = dyn_cast<ConstantInt>(Splat);
461 if (isa<SequentialType>(*GTI)) {
462 int64_t ElementSize = DL.getTypeAllocSize(GTI.getIndexedType());
464 BaseOffset += ConstIdx->getSExtValue() * ElementSize;
466 // Needs scale register.
468 // No addressing mode takes two scale registers.
469 return TTI::TCC_Basic;
473 StructType *STy = cast<StructType>(*GTI);
474 // For structures the index is always splat or scalar constant
475 assert(ConstIdx && "Unexpected GEP index");
476 uint64_t Field = ConstIdx->getZExtValue();
477 BaseOffset += DL.getStructLayout(STy)->getElementOffset(Field);
481 if (static_cast<T *>(this)->isLegalAddressingMode(
482 PointerType::get(*GTI, AS), const_cast<GlobalValue *>(BaseGV),
483 BaseOffset, HasBaseReg, Scale, AS)) {
484 return TTI::TCC_Free;
486 return TTI::TCC_Basic;
489 using BaseT::getIntrinsicCost;
491 unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
492 ArrayRef<const Value *> Arguments) {
493 // Delegate to the generic intrinsic handling code. This mostly provides an
494 // opportunity for targets to (for example) special case the cost of
495 // certain intrinsics based on constants used as arguments.
496 SmallVector<Type *, 8> ParamTys;
497 ParamTys.reserve(Arguments.size());
498 for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
499 ParamTys.push_back(Arguments[Idx]->getType());
500 return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
503 unsigned getUserCost(const User *U) {
505 return TTI::TCC_Free; // Model all PHI nodes as free.
507 if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
508 SmallVector<Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
509 return static_cast<T *>(this)->getGEPCost(
510 GEP->getSourceElementType(), GEP->getPointerOperand(), Indices);
513 if (auto CS = ImmutableCallSite(U)) {
514 const Function *F = CS.getCalledFunction();
516 // Just use the called value type.
517 Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
518 return static_cast<T *>(this)
519 ->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
522 SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
523 return static_cast<T *>(this)->getCallCost(F, Arguments);
526 if (const CastInst *CI = dyn_cast<CastInst>(U)) {
527 // Result of a cmp instruction is often extended (to be used by other
528 // cmp instructions, logical or return instructions). These are usually
529 // nop on most sane targets.
530 if (isa<CmpInst>(CI->getOperand(0)))
531 return TTI::TCC_Free;
534 return static_cast<T *>(this)->getOperationCost(
535 Operator::getOpcode(U), U->getType(),
536 U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr);