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 unsigned 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 getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
132 ArrayRef<Type *> ParamTys) {
135 // Intrinsics rarely (if ever) have normal argument setup constraints.
136 // Model them as having a basic instruction cost.
137 // FIXME: This is wrong for libc intrinsics.
138 return TTI::TCC_Basic;
140 case Intrinsic::annotation:
141 case Intrinsic::assume:
142 case Intrinsic::dbg_declare:
143 case Intrinsic::dbg_value:
144 case Intrinsic::invariant_start:
145 case Intrinsic::invariant_end:
146 case Intrinsic::lifetime_start:
147 case Intrinsic::lifetime_end:
148 case Intrinsic::objectsize:
149 case Intrinsic::ptr_annotation:
150 case Intrinsic::var_annotation:
151 case Intrinsic::experimental_gc_result:
152 case Intrinsic::experimental_gc_relocate:
153 // These intrinsics don't actually represent code after lowering.
154 return TTI::TCC_Free;
158 bool hasBranchDivergence() { return false; }
160 bool isSourceOfDivergence(const Value *V) { return false; }
162 bool isLoweredToCall(const Function *F) {
163 // FIXME: These should almost certainly not be handled here, and instead
164 // handled with the help of TLI or the target itself. This was largely
165 // ported from existing analysis heuristics here so that such refactorings
166 // can take place in the future.
168 if (F->isIntrinsic())
171 if (F->hasLocalLinkage() || !F->hasName())
174 StringRef Name = F->getName();
176 // These will all likely lower to a single selection DAG node.
177 if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
178 Name == "fabs" || Name == "fabsf" || Name == "fabsl" || Name == "sin" ||
179 Name == "fmin" || Name == "fminf" || Name == "fminl" ||
180 Name == "fmax" || Name == "fmaxf" || Name == "fmaxl" ||
181 Name == "sinf" || Name == "sinl" || Name == "cos" || Name == "cosf" ||
182 Name == "cosl" || Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl")
185 // These are all likely to be optimized into something smaller.
186 if (Name == "pow" || Name == "powf" || Name == "powl" || Name == "exp2" ||
187 Name == "exp2l" || Name == "exp2f" || Name == "floor" ||
188 Name == "floorf" || Name == "ceil" || Name == "round" ||
189 Name == "ffs" || Name == "ffsl" || Name == "abs" || Name == "labs" ||
196 void getUnrollingPreferences(Loop *, TTI::UnrollingPreferences &) {}
198 bool isLegalAddImmediate(int64_t Imm) { return false; }
200 bool isLegalICmpImmediate(int64_t Imm) { return false; }
202 bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
203 bool HasBaseReg, int64_t Scale,
204 unsigned AddrSpace) {
205 // Guess that only reg and reg+reg addressing is allowed. This heuristic is
206 // taken from the implementation of LSR.
207 return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
210 bool isLegalMaskedStore(Type *DataType) { return false; }
212 bool isLegalMaskedLoad(Type *DataType) { return false; }
214 bool isLegalMaskedScatter(Type *DataType) { return false; }
216 bool isLegalMaskedGather(Type *DataType) { return false; }
218 int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
219 bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
220 // Guess that all legal addressing mode are free.
221 if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
227 bool isTruncateFree(Type *Ty1, Type *Ty2) { return false; }
229 bool isProfitableToHoist(Instruction *I) { return true; }
231 bool isTypeLegal(Type *Ty) { return false; }
233 unsigned getJumpBufAlignment() { return 0; }
235 unsigned getJumpBufSize() { return 0; }
237 bool shouldBuildLookupTables() { return true; }
239 bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }
241 bool enableInterleavedAccessVectorization() { return false; }
243 TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
244 return TTI::PSK_Software;
247 bool haveFastSqrt(Type *Ty) { return false; }
249 unsigned getFPOpCost(Type *Ty) { return TargetTransformInfo::TCC_Basic; }
251 unsigned getIntImmCost(const APInt &Imm, Type *Ty) { return TTI::TCC_Basic; }
253 unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
255 return TTI::TCC_Free;
258 unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
260 return TTI::TCC_Free;
263 unsigned getNumberOfRegisters(bool Vector) { return 8; }
265 unsigned getRegisterBitWidth(bool Vector) { return 32; }
267 unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }
269 unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
270 TTI::OperandValueKind Opd1Info,
271 TTI::OperandValueKind Opd2Info,
272 TTI::OperandValueProperties Opd1PropInfo,
273 TTI::OperandValueProperties Opd2PropInfo) {
277 unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Ty, int Index,
282 unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) { return 1; }
284 unsigned getCFInstrCost(unsigned Opcode) { return 1; }
286 unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) {
290 unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
294 unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
295 unsigned AddressSpace) {
299 unsigned getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
300 unsigned AddressSpace) {
304 unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
306 ArrayRef<unsigned> Indices,
308 unsigned AddressSpace) {
312 unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
313 ArrayRef<Type *> Tys) {
317 unsigned getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) {
321 unsigned getNumberOfParts(Type *Tp) { return 0; }
323 unsigned getAddressComputationCost(Type *Tp, bool) { return 0; }
325 unsigned getReductionCost(unsigned, Type *, bool) { return 1; }
327 unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) { return 0; }
329 bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) {
333 Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
334 Type *ExpectedType) {
338 bool areInlineCompatible(const Function *Caller,
339 const Function *Callee) const {
340 return (Caller->getFnAttribute("target-cpu") ==
341 Callee->getFnAttribute("target-cpu")) &&
342 (Caller->getFnAttribute("target-features") ==
343 Callee->getFnAttribute("target-features"));
347 /// \brief CRTP base class for use as a mix-in that aids implementing
348 /// a TargetTransformInfo-compatible class.
349 template <typename T>
350 class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
352 typedef TargetTransformInfoImplBase BaseT;
355 explicit TargetTransformInfoImplCRTPBase(const DataLayout &DL) : BaseT(DL) {}
358 // Provide value semantics. MSVC requires that we spell all of these out.
359 TargetTransformInfoImplCRTPBase(const TargetTransformInfoImplCRTPBase &Arg)
360 : BaseT(static_cast<const BaseT &>(Arg)) {}
361 TargetTransformInfoImplCRTPBase(TargetTransformInfoImplCRTPBase &&Arg)
362 : BaseT(std::move(static_cast<BaseT &>(Arg))) {}
364 using BaseT::getCallCost;
366 unsigned getCallCost(const Function *F, int NumArgs) {
367 assert(F && "A concrete function must be provided to this routine.");
370 // Set the argument number to the number of explicit arguments in the
372 NumArgs = F->arg_size();
374 if (Intrinsic::ID IID = F->getIntrinsicID()) {
375 FunctionType *FTy = F->getFunctionType();
376 SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
377 return static_cast<T *>(this)
378 ->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
381 if (!static_cast<T *>(this)->isLoweredToCall(F))
382 return TTI::TCC_Basic; // Give a basic cost if it will be lowered
385 return static_cast<T *>(this)->getCallCost(F->getFunctionType(), NumArgs);
388 unsigned getCallCost(const Function *F, ArrayRef<const Value *> Arguments) {
389 // Simply delegate to generic handling of the call.
390 // FIXME: We should use instsimplify or something else to catch calls which
391 // will constant fold with these arguments.
392 return static_cast<T *>(this)->getCallCost(F, Arguments.size());
395 using BaseT::getGEPCost;
397 unsigned getGEPCost(Type *PointeeType, const Value *Ptr,
398 ArrayRef<const Value *> Operands) {
399 const GlobalValue *BaseGV = nullptr;
400 if (Ptr != nullptr) {
401 // TODO: will remove this when pointers have an opaque type.
402 assert(Ptr->getType()->getScalarType()->getPointerElementType() ==
404 "explicit pointee type doesn't match operand's pointee type");
405 BaseGV = dyn_cast<GlobalValue>(Ptr->stripPointerCasts());
407 bool HasBaseReg = (BaseGV == nullptr);
408 int64_t BaseOffset = 0;
411 // Assumes the address space is 0 when Ptr is nullptr.
413 (Ptr == nullptr ? 0 : Ptr->getType()->getPointerAddressSpace());
414 auto GTI = gep_type_begin(PointerType::get(PointeeType, AS), Operands);
415 for (auto I = Operands.begin(); I != Operands.end(); ++I, ++GTI) {
416 // We assume that the cost of Scalar GEP with constant index and the
417 // cost of Vector GEP with splat constant index are the same.
418 const ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I);
420 if (auto Splat = getSplatValue(*I))
421 ConstIdx = dyn_cast<ConstantInt>(Splat);
422 if (isa<SequentialType>(*GTI)) {
423 int64_t ElementSize = DL.getTypeAllocSize(GTI.getIndexedType());
425 BaseOffset += ConstIdx->getSExtValue() * ElementSize;
427 // Needs scale register.
429 // No addressing mode takes two scale registers.
430 return TTI::TCC_Basic;
434 StructType *STy = cast<StructType>(*GTI);
435 // For structures the index is always splat or scalar constant
436 assert(ConstIdx && "Unexpected GEP index");
437 uint64_t Field = ConstIdx->getZExtValue();
438 BaseOffset += DL.getStructLayout(STy)->getElementOffset(Field);
442 if (static_cast<T *>(this)->isLegalAddressingMode(
443 PointerType::get(*GTI, AS), const_cast<GlobalValue *>(BaseGV),
444 BaseOffset, HasBaseReg, Scale, AS)) {
445 return TTI::TCC_Free;
447 return TTI::TCC_Basic;
450 using BaseT::getIntrinsicCost;
452 unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
453 ArrayRef<const Value *> Arguments) {
454 // Delegate to the generic intrinsic handling code. This mostly provides an
455 // opportunity for targets to (for example) special case the cost of
456 // certain intrinsics based on constants used as arguments.
457 SmallVector<Type *, 8> ParamTys;
458 ParamTys.reserve(Arguments.size());
459 for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
460 ParamTys.push_back(Arguments[Idx]->getType());
461 return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
464 unsigned getUserCost(const User *U) {
466 return TTI::TCC_Free; // Model all PHI nodes as free.
468 if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
469 SmallVector<Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
470 return static_cast<T *>(this)->getGEPCost(
471 GEP->getSourceElementType(), GEP->getPointerOperand(), Indices);
474 if (auto CS = ImmutableCallSite(U)) {
475 const Function *F = CS.getCalledFunction();
477 // Just use the called value type.
478 Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
479 return static_cast<T *>(this)
480 ->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
483 SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
484 return static_cast<T *>(this)->getCallCost(F, Arguments);
487 if (const CastInst *CI = dyn_cast<CastInst>(U)) {
488 // Result of a cmp instruction is often extended (to be used by other
489 // cmp instructions, logical or return instructions). These are usually
490 // nop on most sane targets.
491 if (isa<CmpInst>(CI->getOperand(0)))
492 return TTI::TCC_Free;
495 return static_cast<T *>(this)->getOperationCost(
496 Operator::getOpcode(U), U->getType(),
497 U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr);