1 //===- llvm/Analysis/TargetTransformInfo.cpp ------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Analysis/TargetTransformInfo.h"
11 #include "llvm/IR/CallSite.h"
12 #include "llvm/IR/DataLayout.h"
13 #include "llvm/IR/Instruction.h"
14 #include "llvm/IR/Instructions.h"
15 #include "llvm/IR/IntrinsicInst.h"
16 #include "llvm/IR/Operator.h"
17 #include "llvm/Support/ErrorHandling.h"
18 
19 using namespace llvm;
20 
21 #define DEBUG_TYPE "tti"
22 
23 // Setup the analysis group to manage the TargetTransformInfo passes.
24 INITIALIZE_ANALYSIS_GROUP(TargetTransformInfo, "Target Information", NoTTI)
25 char TargetTransformInfo::ID = 0;
26 
27 TargetTransformInfo::~TargetTransformInfo() {
28 }
29 
30 void TargetTransformInfo::pushTTIStack(Pass *P) {
31   TopTTI = this;
32   PrevTTI = &P->getAnalysis<TargetTransformInfo>();
33 
34   // Walk up the chain and update the top TTI pointer.
35   for (TargetTransformInfo *PTTI = PrevTTI; PTTI; PTTI = PTTI->PrevTTI)
36     PTTI->TopTTI = this;
37 }
38 
39 void TargetTransformInfo::getAnalysisUsage(AnalysisUsage &AU) const {
40   AU.addRequired<TargetTransformInfo>();
41 }
42 
43 unsigned TargetTransformInfo::getOperationCost(unsigned Opcode, Type *Ty,
44                                                Type *OpTy) const {
45   return PrevTTI->getOperationCost(Opcode, Ty, OpTy);
46 }
47 
48 unsigned TargetTransformInfo::getGEPCost(
49     const Value *Ptr, ArrayRef<const Value *> Operands) const {
50   return PrevTTI->getGEPCost(Ptr, Operands);
51 }
52 
53 unsigned TargetTransformInfo::getCallCost(FunctionType *FTy,
54                                           int NumArgs) const {
55   return PrevTTI->getCallCost(FTy, NumArgs);
56 }
57 
58 unsigned TargetTransformInfo::getCallCost(const Function *F,
59                                           int NumArgs) const {
60   return PrevTTI->getCallCost(F, NumArgs);
61 }
62 
63 unsigned TargetTransformInfo::getCallCost(
64     const Function *F, ArrayRef<const Value *> Arguments) const {
65   return PrevTTI->getCallCost(F, Arguments);
66 }
67 
68 unsigned TargetTransformInfo::getIntrinsicCost(
69     Intrinsic::ID IID, Type *RetTy, ArrayRef<Type *> ParamTys) const {
70   return PrevTTI->getIntrinsicCost(IID, RetTy, ParamTys);
71 }
72 
73 unsigned TargetTransformInfo::getIntrinsicCost(
74     Intrinsic::ID IID, Type *RetTy, ArrayRef<const Value *> Arguments) const {
75   return PrevTTI->getIntrinsicCost(IID, RetTy, Arguments);
76 }
77 
78 unsigned TargetTransformInfo::getUserCost(const User *U) const {
79   return PrevTTI->getUserCost(U);
80 }
81 
82 bool TargetTransformInfo::hasBranchDivergence() const {
83   return PrevTTI->hasBranchDivergence();
84 }
85 
86 bool TargetTransformInfo::isLoweredToCall(const Function *F) const {
87   return PrevTTI->isLoweredToCall(F);
88 }
89 
90 void
91 TargetTransformInfo::getUnrollingPreferences(const Function *F, Loop *L,
92                                              UnrollingPreferences &UP) const {
93   PrevTTI->getUnrollingPreferences(F, L, UP);
94 }
95 
96 bool TargetTransformInfo::isLegalAddImmediate(int64_t Imm) const {
97   return PrevTTI->isLegalAddImmediate(Imm);
98 }
99 
100 bool TargetTransformInfo::isLegalICmpImmediate(int64_t Imm) const {
101   return PrevTTI->isLegalICmpImmediate(Imm);
102 }
103 
104 bool TargetTransformInfo::isLegalMaskedLoad(Type *DataType,
105                                             int Consecutive) const {
106   return false;
107 }
108 
109 bool TargetTransformInfo::isLegalMaskedStore(Type *DataType,
110                                              int Consecutive) const {
111   return false;
112 }
113 
114 
115 bool TargetTransformInfo::isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
116                                                 int64_t BaseOffset,
117                                                 bool HasBaseReg,
118                                                 int64_t Scale) const {
119   return PrevTTI->isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
120                                         Scale);
121 }
122 
123 int TargetTransformInfo::getScalingFactorCost(Type *Ty, GlobalValue *BaseGV,
124                                               int64_t BaseOffset,
125                                               bool HasBaseReg,
126                                               int64_t Scale) const {
127   return PrevTTI->getScalingFactorCost(Ty, BaseGV, BaseOffset, HasBaseReg,
128                                        Scale);
129 }
130 
131 bool TargetTransformInfo::isTruncateFree(Type *Ty1, Type *Ty2) const {
132   return PrevTTI->isTruncateFree(Ty1, Ty2);
133 }
134 
135 bool TargetTransformInfo::isTypeLegal(Type *Ty) const {
136   return PrevTTI->isTypeLegal(Ty);
137 }
138 
139 unsigned TargetTransformInfo::getJumpBufAlignment() const {
140   return PrevTTI->getJumpBufAlignment();
141 }
142 
143 unsigned TargetTransformInfo::getJumpBufSize() const {
144   return PrevTTI->getJumpBufSize();
145 }
146 
147 bool TargetTransformInfo::shouldBuildLookupTables() const {
148   return PrevTTI->shouldBuildLookupTables();
149 }
150 
151 TargetTransformInfo::PopcntSupportKind
152 TargetTransformInfo::getPopcntSupport(unsigned IntTyWidthInBit) const {
153   return PrevTTI->getPopcntSupport(IntTyWidthInBit);
154 }
155 
156 bool TargetTransformInfo::haveFastSqrt(Type *Ty) const {
157   return PrevTTI->haveFastSqrt(Ty);
158 }
159 
160 unsigned TargetTransformInfo::getIntImmCost(const APInt &Imm, Type *Ty) const {
161   return PrevTTI->getIntImmCost(Imm, Ty);
162 }
163 
164 unsigned TargetTransformInfo::getIntImmCost(unsigned Opc, unsigned Idx,
165                                             const APInt &Imm, Type *Ty) const {
166   return PrevTTI->getIntImmCost(Opc, Idx, Imm, Ty);
167 }
168 
169 unsigned TargetTransformInfo::getIntImmCost(Intrinsic::ID IID, unsigned Idx,
170                                             const APInt &Imm, Type *Ty) const {
171   return PrevTTI->getIntImmCost(IID, Idx, Imm, Ty);
172 }
173 
174 unsigned TargetTransformInfo::getNumberOfRegisters(bool Vector) const {
175   return PrevTTI->getNumberOfRegisters(Vector);
176 }
177 
178 unsigned TargetTransformInfo::getRegisterBitWidth(bool Vector) const {
179   return PrevTTI->getRegisterBitWidth(Vector);
180 }
181 
182 unsigned TargetTransformInfo::getMaxInterleaveFactor() const {
183   return PrevTTI->getMaxInterleaveFactor();
184 }
185 
186 unsigned TargetTransformInfo::getArithmeticInstrCost(
187     unsigned Opcode, Type *Ty, OperandValueKind Op1Info,
188     OperandValueKind Op2Info, OperandValueProperties Opd1PropInfo,
189     OperandValueProperties Opd2PropInfo) const {
190   return PrevTTI->getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info,
191                                          Opd1PropInfo, Opd2PropInfo);
192 }
193 
194 unsigned TargetTransformInfo::getShuffleCost(ShuffleKind Kind, Type *Tp,
195                                              int Index, Type *SubTp) const {
196   return PrevTTI->getShuffleCost(Kind, Tp, Index, SubTp);
197 }
198 
199 unsigned TargetTransformInfo::getCastInstrCost(unsigned Opcode, Type *Dst,
200                                                Type *Src) const {
201   return PrevTTI->getCastInstrCost(Opcode, Dst, Src);
202 }
203 
204 unsigned TargetTransformInfo::getCFInstrCost(unsigned Opcode) const {
205   return PrevTTI->getCFInstrCost(Opcode);
206 }
207 
208 unsigned TargetTransformInfo::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
209                                                  Type *CondTy) const {
210   return PrevTTI->getCmpSelInstrCost(Opcode, ValTy, CondTy);
211 }
212 
213 unsigned TargetTransformInfo::getVectorInstrCost(unsigned Opcode, Type *Val,
214                                                  unsigned Index) const {
215   return PrevTTI->getVectorInstrCost(Opcode, Val, Index);
216 }
217 
218 unsigned TargetTransformInfo::getMemoryOpCost(unsigned Opcode, Type *Src,
219                                               unsigned Alignment,
220                                               unsigned AddressSpace) const {
221   return PrevTTI->getMemoryOpCost(Opcode, Src, Alignment, AddressSpace);
222   ;
223 }
224 
225 unsigned
226 TargetTransformInfo::getIntrinsicInstrCost(Intrinsic::ID ID,
227                                            Type *RetTy,
228                                            ArrayRef<Type *> Tys) const {
229   return PrevTTI->getIntrinsicInstrCost(ID, RetTy, Tys);
230 }
231 
232 unsigned TargetTransformInfo::getNumberOfParts(Type *Tp) const {
233   return PrevTTI->getNumberOfParts(Tp);
234 }
235 
236 unsigned TargetTransformInfo::getAddressComputationCost(Type *Tp,
237                                                         bool IsComplex) const {
238   return PrevTTI->getAddressComputationCost(Tp, IsComplex);
239 }
240 
241 unsigned TargetTransformInfo::getReductionCost(unsigned Opcode, Type *Ty,
242                                                bool IsPairwise) const {
243   return PrevTTI->getReductionCost(Opcode, Ty, IsPairwise);
244 }
245 
246 unsigned TargetTransformInfo::getCostOfKeepingLiveOverCall(ArrayRef<Type*> Tys)
247   const {
248   return PrevTTI->getCostOfKeepingLiveOverCall(Tys);
249 }
250 
251 namespace {
252 
253 struct NoTTI final : ImmutablePass, TargetTransformInfo {
254   const DataLayout *DL;
255 
256   NoTTI() : ImmutablePass(ID), DL(nullptr) {
257     initializeNoTTIPass(*PassRegistry::getPassRegistry());
258   }
259 
260   void initializePass() override {
261     // Note that this subclass is special, and must *not* call initializeTTI as
262     // it does not chain.
263     TopTTI = this;
264     PrevTTI = nullptr;
265     DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
266     DL = DLP ? &DLP->getDataLayout() : nullptr;
267   }
268 
269   void getAnalysisUsage(AnalysisUsage &AU) const override {
270     // Note that this subclass is special, and must *not* call
271     // TTI::getAnalysisUsage as it breaks the recursion.
272   }
273 
274   /// Pass identification.
275   static char ID;
276 
277   /// Provide necessary pointer adjustments for the two base classes.
278   void *getAdjustedAnalysisPointer(const void *ID) override {
279     if (ID == &TargetTransformInfo::ID)
280       return (TargetTransformInfo*)this;
281     return this;
282   }
283 
284   unsigned getOperationCost(unsigned Opcode, Type *Ty,
285                             Type *OpTy) const override {
286     switch (Opcode) {
287     default:
288       // By default, just classify everything as 'basic'.
289       return TCC_Basic;
290 
291     case Instruction::GetElementPtr:
292       llvm_unreachable("Use getGEPCost for GEP operations!");
293 
294     case Instruction::BitCast:
295       assert(OpTy && "Cast instructions must provide the operand type");
296       if (Ty == OpTy || (Ty->isPointerTy() && OpTy->isPointerTy()))
297         // Identity and pointer-to-pointer casts are free.
298         return TCC_Free;
299 
300       // Otherwise, the default basic cost is used.
301       return TCC_Basic;
302 
303     case Instruction::IntToPtr: {
304       if (!DL)
305         return TCC_Basic;
306 
307       // An inttoptr cast is free so long as the input is a legal integer type
308       // which doesn't contain values outside the range of a pointer.
309       unsigned OpSize = OpTy->getScalarSizeInBits();
310       if (DL->isLegalInteger(OpSize) &&
311           OpSize <= DL->getPointerTypeSizeInBits(Ty))
312         return TCC_Free;
313 
314       // Otherwise it's not a no-op.
315       return TCC_Basic;
316     }
317     case Instruction::PtrToInt: {
318       if (!DL)
319         return TCC_Basic;
320 
321       // A ptrtoint cast is free so long as the result is large enough to store
322       // the pointer, and a legal integer type.
323       unsigned DestSize = Ty->getScalarSizeInBits();
324       if (DL->isLegalInteger(DestSize) &&
325           DestSize >= DL->getPointerTypeSizeInBits(OpTy))
326         return TCC_Free;
327 
328       // Otherwise it's not a no-op.
329       return TCC_Basic;
330     }
331     case Instruction::Trunc:
332       // trunc to a native type is free (assuming the target has compare and
333       // shift-right of the same width).
334       if (DL && DL->isLegalInteger(DL->getTypeSizeInBits(Ty)))
335         return TCC_Free;
336 
337       return TCC_Basic;
338     }
339   }
340 
341   unsigned getGEPCost(const Value *Ptr,
342                       ArrayRef<const Value *> Operands) const override {
343     // In the basic model, we just assume that all-constant GEPs will be folded
344     // into their uses via addressing modes.
345     for (unsigned Idx = 0, Size = Operands.size(); Idx != Size; ++Idx)
346       if (!isa<Constant>(Operands[Idx]))
347         return TCC_Basic;
348 
349     return TCC_Free;
350   }
351 
352   unsigned getCallCost(FunctionType *FTy, int NumArgs = -1) const override
353   {
354     assert(FTy && "FunctionType must be provided to this routine.");
355 
356     // The target-independent implementation just measures the size of the
357     // function by approximating that each argument will take on average one
358     // instruction to prepare.
359 
360     if (NumArgs < 0)
361       // Set the argument number to the number of explicit arguments in the
362       // function.
363       NumArgs = FTy->getNumParams();
364 
365     return TCC_Basic * (NumArgs + 1);
366   }
367 
368   unsigned getCallCost(const Function *F, int NumArgs = -1) const override
369   {
370     assert(F && "A concrete function must be provided to this routine.");
371 
372     if (NumArgs < 0)
373       // Set the argument number to the number of explicit arguments in the
374       // function.
375       NumArgs = F->arg_size();
376 
377     if (Intrinsic::ID IID = (Intrinsic::ID)F->getIntrinsicID()) {
378       FunctionType *FTy = F->getFunctionType();
379       SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
380       return TopTTI->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
381     }
382 
383     if (!TopTTI->isLoweredToCall(F))
384       return TCC_Basic; // Give a basic cost if it will be lowered directly.
385 
386     return TopTTI->getCallCost(F->getFunctionType(), NumArgs);
387   }
388 
389   unsigned getCallCost(const Function *F,
390                        ArrayRef<const Value *> Arguments) const override {
391     // Simply delegate to generic handling of the call.
392     // FIXME: We should use instsimplify or something else to catch calls which
393     // will constant fold with these arguments.
394     return TopTTI->getCallCost(F, Arguments.size());
395   }
396 
397   unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
398                             ArrayRef<Type *> ParamTys) const override {
399     switch (IID) {
400     default:
401       // Intrinsics rarely (if ever) have normal argument setup constraints.
402       // Model them as having a basic instruction cost.
403       // FIXME: This is wrong for libc intrinsics.
404       return TCC_Basic;
405 
406     case Intrinsic::annotation:
407     case Intrinsic::assume:
408     case Intrinsic::dbg_declare:
409     case Intrinsic::dbg_value:
410     case Intrinsic::invariant_start:
411     case Intrinsic::invariant_end:
412     case Intrinsic::lifetime_start:
413     case Intrinsic::lifetime_end:
414     case Intrinsic::objectsize:
415     case Intrinsic::ptr_annotation:
416     case Intrinsic::var_annotation:
417     case Intrinsic::experimental_gc_result_int:
418     case Intrinsic::experimental_gc_result_float:
419     case Intrinsic::experimental_gc_result_ptr:
420     case Intrinsic::experimental_gc_relocate:
421       // These intrinsics don't actually represent code after lowering.
422       return TCC_Free;
423     }
424   }
425 
426   unsigned
427   getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
428                    ArrayRef<const Value *> Arguments) const override {
429     // Delegate to the generic intrinsic handling code. This mostly provides an
430     // opportunity for targets to (for example) special case the cost of
431     // certain intrinsics based on constants used as arguments.
432     SmallVector<Type *, 8> ParamTys;
433     ParamTys.reserve(Arguments.size());
434     for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
435       ParamTys.push_back(Arguments[Idx]->getType());
436     return TopTTI->getIntrinsicCost(IID, RetTy, ParamTys);
437   }
438 
439   unsigned getUserCost(const User *U) const override {
440     if (isa<PHINode>(U))
441       return TCC_Free; // Model all PHI nodes as free.
442 
443     if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
444       SmallVector<const Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
445       return TopTTI->getGEPCost(GEP->getPointerOperand(), Indices);
446     }
447 
448     if (ImmutableCallSite CS = U) {
449       const Function *F = CS.getCalledFunction();
450       if (!F) {
451         // Just use the called value type.
452         Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
453         return TopTTI->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
454       }
455 
456       SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
457       return TopTTI->getCallCost(F, Arguments);
458     }
459 
460     if (const CastInst *CI = dyn_cast<CastInst>(U)) {
461       // Result of a cmp instruction is often extended (to be used by other
462       // cmp instructions, logical or return instructions). These are usually
463       // nop on most sane targets.
464       if (isa<CmpInst>(CI->getOperand(0)))
465         return TCC_Free;
466     }
467 
468     // Otherwise delegate to the fully generic implementations.
469     return getOperationCost(Operator::getOpcode(U), U->getType(),
470                             U->getNumOperands() == 1 ?
471                                 U->getOperand(0)->getType() : nullptr);
472   }
473 
474   bool hasBranchDivergence() const override { return false; }
475 
476   bool isLoweredToCall(const Function *F) const override {
477     // FIXME: These should almost certainly not be handled here, and instead
478     // handled with the help of TLI or the target itself. This was largely
479     // ported from existing analysis heuristics here so that such refactorings
480     // can take place in the future.
481 
482     if (F->isIntrinsic())
483       return false;
484 
485     if (F->hasLocalLinkage() || !F->hasName())
486       return true;
487 
488     StringRef Name = F->getName();
489 
490     // These will all likely lower to a single selection DAG node.
491     if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
492         Name == "fabs" || Name == "fabsf" || Name == "fabsl" || Name == "sin" ||
493         Name == "fmin" || Name == "fminf" || Name == "fminl" ||
494         Name == "fmax" || Name == "fmaxf" || Name == "fmaxl" ||
495         Name == "sinf" || Name == "sinl" || Name == "cos" || Name == "cosf" ||
496         Name == "cosl" || Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl")
497       return false;
498 
499     // These are all likely to be optimized into something smaller.
500     if (Name == "pow" || Name == "powf" || Name == "powl" || Name == "exp2" ||
501         Name == "exp2l" || Name == "exp2f" || Name == "floor" || Name ==
502         "floorf" || Name == "ceil" || Name == "round" || Name == "ffs" ||
503         Name == "ffsl" || Name == "abs" || Name == "labs" || Name == "llabs")
504       return false;
505 
506     return true;
507   }
508 
509   void getUnrollingPreferences(const Function *, Loop *,
510                                UnrollingPreferences &) const override {}
511 
512   bool isLegalAddImmediate(int64_t Imm) const override {
513     return false;
514   }
515 
516   bool isLegalICmpImmediate(int64_t Imm) const override {
517     return false;
518   }
519 
520   bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
521                              bool HasBaseReg, int64_t Scale) const override
522   {
523     // Guess that reg+reg addressing is allowed. This heuristic is taken from
524     // the implementation of LSR.
525     return !BaseGV && BaseOffset == 0 && Scale <= 1;
526   }
527 
528   int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
529                            bool HasBaseReg, int64_t Scale) const override {
530     // Guess that all legal addressing mode are free.
531     if(isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg, Scale))
532       return 0;
533     return -1;
534   }
535 
536   bool isTruncateFree(Type *Ty1, Type *Ty2) const override {
537     return false;
538   }
539 
540   bool isTypeLegal(Type *Ty) const override {
541     return false;
542   }
543 
544   unsigned getJumpBufAlignment() const override {
545     return 0;
546   }
547 
548   unsigned getJumpBufSize() const override {
549     return 0;
550   }
551 
552   bool shouldBuildLookupTables() const override {
553     return true;
554   }
555 
556   PopcntSupportKind
557   getPopcntSupport(unsigned IntTyWidthInBit) const override {
558     return PSK_Software;
559   }
560 
561   bool haveFastSqrt(Type *Ty) const override {
562     return false;
563   }
564 
565   unsigned getIntImmCost(const APInt &Imm, Type *Ty) const override {
566     return TCC_Basic;
567   }
568 
569   unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
570                          Type *Ty) const override {
571     return TCC_Free;
572   }
573 
574   unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
575                          Type *Ty) const override {
576     return TCC_Free;
577   }
578 
579   unsigned getNumberOfRegisters(bool Vector) const override {
580     return 8;
581   }
582 
583   unsigned  getRegisterBitWidth(bool Vector) const override {
584     return 32;
585   }
586 
587   unsigned getMaxInterleaveFactor() const override {
588     return 1;
589   }
590 
591   unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueKind,
592                                   OperandValueKind, OperandValueProperties,
593                                   OperandValueProperties) const override {
594     return 1;
595   }
596 
597   unsigned getShuffleCost(ShuffleKind Kind, Type *Ty,
598                           int Index = 0, Type *SubTp = nullptr) const override {
599     return 1;
600   }
601 
602   unsigned getCastInstrCost(unsigned Opcode, Type *Dst,
603                             Type *Src) const override {
604     return 1;
605   }
606 
607   unsigned getCFInstrCost(unsigned Opcode) const override {
608     return 1;
609   }
610 
611   unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
612                               Type *CondTy = nullptr) const override {
613     return 1;
614   }
615 
616   unsigned getVectorInstrCost(unsigned Opcode, Type *Val,
617                               unsigned Index = -1) const override {
618     return 1;
619   }
620 
621   unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
622                            unsigned AddressSpace) const override {
623     return 1;
624   }
625 
626   unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
627                                  ArrayRef<Type*> Tys) const override {
628     return 1;
629   }
630 
631   unsigned getNumberOfParts(Type *Tp) const override {
632     return 0;
633   }
634 
635   unsigned getAddressComputationCost(Type *Tp, bool) const override {
636     return 0;
637   }
638 
639   unsigned getReductionCost(unsigned, Type *, bool) const override {
640     return 1;
641   }
642 
643   unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type*> Tys) const override {
644     return 0;
645   }
646 
647 };
648 
649 } // end anonymous namespace
650 
651 INITIALIZE_AG_PASS(NoTTI, TargetTransformInfo, "notti",
652                    "No target information", true, true, true)
653 char NoTTI::ID = 0;
654 
655 ImmutablePass *llvm::createNoTargetTransformInfoPass() {
656   return new NoTTI();
657 }
658