1 //===- BasicTargetTransformInfo.cpp - Basic target-independent TTI impl ---===//
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 the implementation of a basic TargetTransformInfo pass
11 /// predicated on the target abstractions present in the target independent
12 /// code generator. It uses these (primarily TargetLowering) to model as much
13 /// of the TTI query interface as possible. It is included by most targets so
14 /// that they can specialize only a small subset of the query space.
16 //===----------------------------------------------------------------------===//
18 #define DEBUG_TYPE "basictti"
19 #include "llvm/CodeGen/Passes.h"
20 #include "llvm/Analysis/TargetTransformInfo.h"
21 #include "llvm/Target/TargetLowering.h"
28 class BasicTTI : public ImmutablePass, public TargetTransformInfo {
29 const TargetLoweringBase *TLI;
31 /// Estimate the overhead of scalarizing an instruction. Insert and Extract
32 /// are set if the result needs to be inserted and/or extracted from vectors.
33 unsigned getScalarizationOverhead(Type *Ty, bool Insert, bool Extract) const;
36 BasicTTI() : ImmutablePass(ID), TLI(0) {
37 llvm_unreachable("This pass cannot be directly constructed");
40 BasicTTI(const TargetLoweringBase *TLI) : ImmutablePass(ID), TLI(TLI) {
41 initializeBasicTTIPass(*PassRegistry::getPassRegistry());
44 virtual void initializePass() {
48 virtual void finalizePass() {
52 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
53 TargetTransformInfo::getAnalysisUsage(AU);
56 /// Pass identification.
59 /// Provide necessary pointer adjustments for the two base classes.
60 virtual void *getAdjustedAnalysisPointer(const void *ID) {
61 if (ID == &TargetTransformInfo::ID)
62 return (TargetTransformInfo*)this;
66 /// \name Scalar TTI Implementations
69 virtual bool isLegalAddImmediate(int64_t imm) const;
70 virtual bool isLegalICmpImmediate(int64_t imm) const;
71 virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
72 int64_t BaseOffset, bool HasBaseReg,
74 virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
75 virtual bool isTypeLegal(Type *Ty) const;
76 virtual unsigned getJumpBufAlignment() const;
77 virtual unsigned getJumpBufSize() const;
78 virtual bool shouldBuildLookupTables() const;
82 /// \name Vector TTI Implementations
85 virtual unsigned getNumberOfRegisters(bool Vector) const;
86 virtual unsigned getMaximumUnrollFactor() const;
87 virtual unsigned getRegisterBitWidth(bool Vector) const;
88 virtual unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty) const;
89 virtual unsigned getShuffleCost(ShuffleKind Kind, Type *Tp,
90 int Index, Type *SubTp) const;
91 virtual unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
93 virtual unsigned getCFInstrCost(unsigned Opcode) const;
94 virtual unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
96 virtual unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
97 unsigned Index) const;
98 virtual unsigned getMemoryOpCost(unsigned Opcode, Type *Src,
100 unsigned AddressSpace) const;
101 virtual unsigned getIntrinsicInstrCost(Intrinsic::ID, Type *RetTy,
102 ArrayRef<Type*> Tys) const;
103 virtual unsigned getNumberOfParts(Type *Tp) const;
104 virtual unsigned getAddressComputationCost(Type *Ty) const;
111 INITIALIZE_AG_PASS(BasicTTI, TargetTransformInfo, "basictti",
112 "Target independent code generator's TTI", true, true, false)
113 char BasicTTI::ID = 0;
116 llvm::createBasicTargetTransformInfoPass(const TargetLoweringBase *TLI) {
117 return new BasicTTI(TLI);
121 bool BasicTTI::isLegalAddImmediate(int64_t imm) const {
122 return TLI->isLegalAddImmediate(imm);
125 bool BasicTTI::isLegalICmpImmediate(int64_t imm) const {
126 return TLI->isLegalICmpImmediate(imm);
129 bool BasicTTI::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
130 int64_t BaseOffset, bool HasBaseReg,
131 int64_t Scale) const {
132 TargetLoweringBase::AddrMode AM;
134 AM.BaseOffs = BaseOffset;
135 AM.HasBaseReg = HasBaseReg;
137 return TLI->isLegalAddressingMode(AM, Ty);
140 bool BasicTTI::isTruncateFree(Type *Ty1, Type *Ty2) const {
141 return TLI->isTruncateFree(Ty1, Ty2);
144 bool BasicTTI::isTypeLegal(Type *Ty) const {
145 EVT T = TLI->getValueType(Ty);
146 return TLI->isTypeLegal(T);
149 unsigned BasicTTI::getJumpBufAlignment() const {
150 return TLI->getJumpBufAlignment();
153 unsigned BasicTTI::getJumpBufSize() const {
154 return TLI->getJumpBufSize();
157 bool BasicTTI::shouldBuildLookupTables() const {
158 return TLI->supportJumpTables() &&
159 (TLI->isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
160 TLI->isOperationLegalOrCustom(ISD::BRIND, MVT::Other));
163 //===----------------------------------------------------------------------===//
165 // Calls used by the vectorizers.
167 //===----------------------------------------------------------------------===//
169 unsigned BasicTTI::getScalarizationOverhead(Type *Ty, bool Insert,
170 bool Extract) const {
171 assert (Ty->isVectorTy() && "Can only scalarize vectors");
174 for (int i = 0, e = Ty->getVectorNumElements(); i < e; ++i) {
176 Cost += TopTTI->getVectorInstrCost(Instruction::InsertElement, Ty, i);
178 Cost += TopTTI->getVectorInstrCost(Instruction::ExtractElement, Ty, i);
184 unsigned BasicTTI::getNumberOfRegisters(bool Vector) const {
188 unsigned BasicTTI::getRegisterBitWidth(bool Vector) const {
192 unsigned BasicTTI::getMaximumUnrollFactor() const {
196 unsigned BasicTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty) const {
197 // Check if any of the operands are vector operands.
198 int ISD = TLI->InstructionOpcodeToISD(Opcode);
199 assert(ISD && "Invalid opcode");
201 std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Ty);
203 if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
204 // The operation is legal. Assume it costs 1.
205 // If the type is split to multiple registers, assume that thre is some
207 // TODO: Once we have extract/insert subvector cost we need to use them.
213 if (!TLI->isOperationExpand(ISD, LT.second)) {
214 // If the operation is custom lowered then assume
215 // thare the code is twice as expensive.
219 // Else, assume that we need to scalarize this op.
220 if (Ty->isVectorTy()) {
221 unsigned Num = Ty->getVectorNumElements();
222 unsigned Cost = TopTTI->getArithmeticInstrCost(Opcode, Ty->getScalarType());
223 // return the cost of multiple scalar invocation plus the cost of inserting
224 // and extracting the values.
225 return getScalarizationOverhead(Ty, true, true) + Num * Cost;
228 // We don't know anything about this scalar instruction.
232 unsigned BasicTTI::getShuffleCost(ShuffleKind Kind, Type *Tp, int Index,
237 unsigned BasicTTI::getCastInstrCost(unsigned Opcode, Type *Dst,
239 int ISD = TLI->InstructionOpcodeToISD(Opcode);
240 assert(ISD && "Invalid opcode");
242 std::pair<unsigned, MVT> SrcLT = TLI->getTypeLegalizationCost(Src);
243 std::pair<unsigned, MVT> DstLT = TLI->getTypeLegalizationCost(Dst);
245 // Check for NOOP conversions.
246 if (SrcLT.first == DstLT.first &&
247 SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
249 // Bitcast between types that are legalized to the same type are free.
250 if (Opcode == Instruction::BitCast || Opcode == Instruction::Trunc)
254 if (Opcode == Instruction::Trunc &&
255 TLI->isTruncateFree(SrcLT.second, DstLT.second))
258 if (Opcode == Instruction::ZExt &&
259 TLI->isZExtFree(SrcLT.second, DstLT.second))
262 // If the cast is marked as legal (or promote) then assume low cost.
263 if (TLI->isOperationLegalOrPromote(ISD, DstLT.second))
266 // Handle scalar conversions.
267 if (!Src->isVectorTy() && !Dst->isVectorTy()) {
269 // Scalar bitcasts are usually free.
270 if (Opcode == Instruction::BitCast)
273 // Just check the op cost. If the operation is legal then assume it costs 1.
274 if (!TLI->isOperationExpand(ISD, DstLT.second))
277 // Assume that illegal scalar instruction are expensive.
281 // Check vector-to-vector casts.
282 if (Dst->isVectorTy() && Src->isVectorTy()) {
284 // If the cast is between same-sized registers, then the check is simple.
285 if (SrcLT.first == DstLT.first &&
286 SrcLT.second.getSizeInBits() == DstLT.second.getSizeInBits()) {
288 // Assume that Zext is done using AND.
289 if (Opcode == Instruction::ZExt)
292 // Assume that sext is done using SHL and SRA.
293 if (Opcode == Instruction::SExt)
296 // Just check the op cost. If the operation is legal then assume it costs
297 // 1 and multiply by the type-legalization overhead.
298 if (!TLI->isOperationExpand(ISD, DstLT.second))
299 return SrcLT.first * 1;
302 // If we are converting vectors and the operation is illegal, or
303 // if the vectors are legalized to different types, estimate the
304 // scalarization costs.
305 unsigned Num = Dst->getVectorNumElements();
306 unsigned Cost = TopTTI->getCastInstrCost(Opcode, Dst->getScalarType(),
307 Src->getScalarType());
309 // Return the cost of multiple scalar invocation plus the cost of
310 // inserting and extracting the values.
311 return getScalarizationOverhead(Dst, true, true) + Num * Cost;
314 // We already handled vector-to-vector and scalar-to-scalar conversions. This
315 // is where we handle bitcast between vectors and scalars. We need to assume
316 // that the conversion is scalarized in one way or another.
317 if (Opcode == Instruction::BitCast)
318 // Illegal bitcasts are done by storing and loading from a stack slot.
319 return (Src->isVectorTy()? getScalarizationOverhead(Src, false, true):0) +
320 (Dst->isVectorTy()? getScalarizationOverhead(Dst, true, false):0);
322 llvm_unreachable("Unhandled cast");
325 unsigned BasicTTI::getCFInstrCost(unsigned Opcode) const {
326 // Branches are assumed to be predicted.
330 unsigned BasicTTI::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
331 Type *CondTy) const {
332 int ISD = TLI->InstructionOpcodeToISD(Opcode);
333 assert(ISD && "Invalid opcode");
335 // Selects on vectors are actually vector selects.
336 if (ISD == ISD::SELECT) {
337 assert(CondTy && "CondTy must exist");
338 if (CondTy->isVectorTy())
342 std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(ValTy);
344 if (!TLI->isOperationExpand(ISD, LT.second)) {
345 // The operation is legal. Assume it costs 1. Multiply
346 // by the type-legalization overhead.
350 // Otherwise, assume that the cast is scalarized.
351 if (ValTy->isVectorTy()) {
352 unsigned Num = ValTy->getVectorNumElements();
354 CondTy = CondTy->getScalarType();
355 unsigned Cost = TopTTI->getCmpSelInstrCost(Opcode, ValTy->getScalarType(),
358 // Return the cost of multiple scalar invocation plus the cost of inserting
359 // and extracting the values.
360 return getScalarizationOverhead(ValTy, true, false) + Num * Cost;
363 // Unknown scalar opcode.
367 unsigned BasicTTI::getVectorInstrCost(unsigned Opcode, Type *Val,
368 unsigned Index) const {
372 unsigned BasicTTI::getMemoryOpCost(unsigned Opcode, Type *Src,
374 unsigned AddressSpace) const {
375 assert(!Src->isVoidTy() && "Invalid type");
376 std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Src);
378 // Assume that all loads of legal types cost 1.
382 unsigned BasicTTI::getIntrinsicInstrCost(Intrinsic::ID IID, Type *RetTy,
383 ArrayRef<Type *> Tys) const {
387 // Assume that we need to scalarize this intrinsic.
388 unsigned ScalarizationCost = 0;
389 unsigned ScalarCalls = 1;
390 if (RetTy->isVectorTy()) {
391 ScalarizationCost = getScalarizationOverhead(RetTy, true, false);
392 ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
394 for (unsigned i = 0, ie = Tys.size(); i != ie; ++i) {
395 if (Tys[i]->isVectorTy()) {
396 ScalarizationCost += getScalarizationOverhead(Tys[i], false, true);
397 ScalarCalls = std::max(ScalarCalls, RetTy->getVectorNumElements());
401 return ScalarCalls + ScalarizationCost;
403 // Look for intrinsics that can be lowered directly or turned into a scalar
405 case Intrinsic::sqrt: ISD = ISD::FSQRT; break;
406 case Intrinsic::sin: ISD = ISD::FSIN; break;
407 case Intrinsic::cos: ISD = ISD::FCOS; break;
408 case Intrinsic::exp: ISD = ISD::FEXP; break;
409 case Intrinsic::exp2: ISD = ISD::FEXP2; break;
410 case Intrinsic::log: ISD = ISD::FLOG; break;
411 case Intrinsic::log10: ISD = ISD::FLOG10; break;
412 case Intrinsic::log2: ISD = ISD::FLOG2; break;
413 case Intrinsic::fabs: ISD = ISD::FABS; break;
414 case Intrinsic::floor: ISD = ISD::FFLOOR; break;
415 case Intrinsic::ceil: ISD = ISD::FCEIL; break;
416 case Intrinsic::trunc: ISD = ISD::FTRUNC; break;
417 case Intrinsic::rint: ISD = ISD::FRINT; break;
418 case Intrinsic::pow: ISD = ISD::FPOW; break;
419 case Intrinsic::fma: ISD = ISD::FMA; break;
420 case Intrinsic::fmuladd: ISD = ISD::FMA; break; // FIXME: mul + add?
423 std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(RetTy);
425 if (TLI->isOperationLegalOrPromote(ISD, LT.second)) {
426 // The operation is legal. Assume it costs 1.
427 // If the type is split to multiple registers, assume that thre is some
429 // TODO: Once we have extract/insert subvector cost we need to use them.
435 if (!TLI->isOperationExpand(ISD, LT.second)) {
436 // If the operation is custom lowered then assume
437 // thare the code is twice as expensive.
441 // Else, assume that we need to scalarize this intrinsic. For math builtins
442 // this will emit a costly libcall, adding call overhead and spills. Make it
444 if (RetTy->isVectorTy()) {
445 unsigned Num = RetTy->getVectorNumElements();
446 unsigned Cost = TopTTI->getIntrinsicInstrCost(IID, RetTy->getScalarType(),
448 return 10 * Cost * Num;
451 // This is going to be turned into a library call, make it expensive.
455 unsigned BasicTTI::getNumberOfParts(Type *Tp) const {
456 std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Tp);
460 unsigned BasicTTI::getAddressComputationCost(Type *Ty) const {