include/llvm/Analysis/TargetTransformInfoImpl.h - llvm - Git at Google

 //===- TargetTransformInfoImpl.h --------------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 /// \file
 /// This file provides helpers for the implementation of
 /// a TargetTransformInfo-conforming class.
 ///
 //===----------------------------------------------------------------------===//

 #ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
 #define LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H

 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/IR/Type.h"

 namespace llvm {

 /// \brief Base class for use as a mix-in that aids implementing
 /// a TargetTransformInfo-compatible class.
 class TargetTransformInfoImplBase {
 protected:
   typedef TargetTransformInfo TTI;

   const DataLayout &DL;

   explicit TargetTransformInfoImplBase(const DataLayout &DL) : DL(DL) {}

 public:
   // Provide value semantics. MSVC requires that we spell all of these out.
   TargetTransformInfoImplBase(const TargetTransformInfoImplBase &Arg)
       : DL(Arg.DL) {}
   TargetTransformInfoImplBase(TargetTransformInfoImplBase &&Arg) : DL(Arg.DL) {}

   const DataLayout &getDataLayout() const { return DL; }

   unsigned getOperationCost(unsigned Opcode, Type *Ty, Type *OpTy) {
     switch (Opcode) {
     default:
       // By default, just classify everything as 'basic'.
       return TTI::TCC_Basic;

     case Instruction::GetElementPtr:
       llvm_unreachable("Use getGEPCost for GEP operations!");

     case Instruction::BitCast:
       assert(OpTy && "Cast instructions must provide the operand type");
       if (Ty == OpTy || (Ty->isPointerTy() && OpTy->isPointerTy()))
         // Identity and pointer-to-pointer casts are free.
         return TTI::TCC_Free;

       // Otherwise, the default basic cost is used.
       return TTI::TCC_Basic;

     case Instruction::IntToPtr: {
       // An inttoptr cast is free so long as the input is a legal integer type
       // which doesn't contain values outside the range of a pointer.
       unsigned OpSize = OpTy->getScalarSizeInBits();
       if (DL.isLegalInteger(OpSize) &&
           OpSize <= DL.getPointerTypeSizeInBits(Ty))
         return TTI::TCC_Free;

       // Otherwise it's not a no-op.
       return TTI::TCC_Basic;
     }
     case Instruction::PtrToInt: {
       // A ptrtoint cast is free so long as the result is large enough to store
       // the pointer, and a legal integer type.
       unsigned DestSize = Ty->getScalarSizeInBits();
       if (DL.isLegalInteger(DestSize) &&
           DestSize >= DL.getPointerTypeSizeInBits(OpTy))
         return TTI::TCC_Free;

       // Otherwise it's not a no-op.
       return TTI::TCC_Basic;
     }
     case Instruction::Trunc:
       // trunc to a native type is free (assuming the target has compare and
       // shift-right of the same width).
       if (DL.isLegalInteger(DL.getTypeSizeInBits(Ty)))
         return TTI::TCC_Free;

       return TTI::TCC_Basic;
     }
   }

   unsigned getGEPCost(const Value *Ptr, ArrayRef<const Value *> Operands) {
     // In the basic model, we just assume that all-constant GEPs will be folded
     // into their uses via addressing modes.
     for (unsigned Idx = 0, Size = Operands.size(); Idx != Size; ++Idx)
       if (!isa<Constant>(Operands[Idx]))
         return TTI::TCC_Basic;

     return TTI::TCC_Free;
   }

   unsigned getCallCost(FunctionType *FTy, int NumArgs) {
     assert(FTy && "FunctionType must be provided to this routine.");

     // The target-independent implementation just measures the size of the
     // function by approximating that each argument will take on average one
     // instruction to prepare.

     if (NumArgs < 0)
       // Set the argument number to the number of explicit arguments in the
       // function.
       NumArgs = FTy->getNumParams();

     return TTI::TCC_Basic * (NumArgs + 1);
   }

   unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
                             ArrayRef<Type *> ParamTys) {
     switch (IID) {
     default:
       // Intrinsics rarely (if ever) have normal argument setup constraints.
       // Model them as having a basic instruction cost.
       // FIXME: This is wrong for libc intrinsics.
       return TTI::TCC_Basic;

     case Intrinsic::annotation:
     case Intrinsic::assume:
     case Intrinsic::dbg_declare:
     case Intrinsic::dbg_value:
     case Intrinsic::invariant_start:
     case Intrinsic::invariant_end:
     case Intrinsic::lifetime_start:
     case Intrinsic::lifetime_end:
     case Intrinsic::objectsize:
     case Intrinsic::ptr_annotation:
     case Intrinsic::var_annotation:
     case Intrinsic::experimental_gc_result_int:
     case Intrinsic::experimental_gc_result_float:
     case Intrinsic::experimental_gc_result_ptr:
     case Intrinsic::experimental_gc_result:
     case Intrinsic::experimental_gc_relocate:
       // These intrinsics don't actually represent code after lowering.
       return TTI::TCC_Free;
     }
   }

   bool hasBranchDivergence() { return false; }

   bool isSourceOfDivergence(const Value *V) { return false; }

   bool isLoweredToCall(const Function *F) {
     // FIXME: These should almost certainly not be handled here, and instead
     // handled with the help of TLI or the target itself. This was largely
     // ported from existing analysis heuristics here so that such refactorings
     // can take place in the future.

     if (F->isIntrinsic())
       return false;

     if (F->hasLocalLinkage() || !F->hasName())
       return true;

     StringRef Name = F->getName();

     // These will all likely lower to a single selection DAG node.
     if (Name == "copysign" || Name == "copysignf" || Name == "copysignl" ||
         Name == "fabs" || Name == "fabsf" || Name == "fabsl" || Name == "sin" ||
         Name == "fmin" || Name == "fminf" || Name == "fminl" ||
         Name == "fmax" || Name == "fmaxf" || Name == "fmaxl" ||
         Name == "sinf" || Name == "sinl" || Name == "cos" || Name == "cosf" ||
         Name == "cosl" || Name == "sqrt" || Name == "sqrtf" || Name == "sqrtl")
       return false;

     // These are all likely to be optimized into something smaller.
     if (Name == "pow" || Name == "powf" || Name == "powl" || Name == "exp2" ||
         Name == "exp2l" || Name == "exp2f" || Name == "floor" ||
         Name == "floorf" || Name == "ceil" || Name == "round" ||
         Name == "ffs" || Name == "ffsl" || Name == "abs" || Name == "labs" ||
         Name == "llabs")
       return false;

     return true;
   }

   void getUnrollingPreferences(Loop *, TTI::UnrollingPreferences &) {}

   bool isLegalAddImmediate(int64_t Imm) { return false; }

   bool isLegalICmpImmediate(int64_t Imm) { return false; }

   bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
                              bool HasBaseReg, int64_t Scale,
                              unsigned AddrSpace) {
     // Guess that only reg and reg+reg addressing is allowed. This heuristic is
     // taken from the implementation of LSR.
     return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
   }

   bool isLegalMaskedStore(Type *DataType, int Consecutive) { return false; }

   bool isLegalMaskedLoad(Type *DataType, int Consecutive) { return false; }

   int getScalingFactorCost(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
                            bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
     // Guess that all legal addressing mode are free.
     if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
                               Scale, AddrSpace))
       return 0;
     return -1;
   }

   bool isTruncateFree(Type *Ty1, Type *Ty2) { return false; }

   bool isProfitableToHoist(Instruction *I) { return true; }

   bool isTypeLegal(Type *Ty) { return false; }

   unsigned getJumpBufAlignment() { return 0; }

   unsigned getJumpBufSize() { return 0; }

   bool shouldBuildLookupTables() { return true; }

   bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }

   TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
     return TTI::PSK_Software;
   }

   bool haveFastSqrt(Type *Ty) { return false; }

   unsigned getFPOpCost(Type *Ty) { return TargetTransformInfo::TCC_Basic; }

   unsigned getIntImmCost(const APInt &Imm, Type *Ty) { return TTI::TCC_Basic; }

   unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
                          Type *Ty) {
     return TTI::TCC_Free;
   }

   unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
                          Type *Ty) {
     return TTI::TCC_Free;
   }

   unsigned getNumberOfRegisters(bool Vector) { return 8; }

   unsigned getRegisterBitWidth(bool Vector) { return 32; }

   unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }

   unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
                                   TTI::OperandValueKind Opd1Info,
                                   TTI::OperandValueKind Opd2Info,
                                   TTI::OperandValueProperties Opd1PropInfo,
                                   TTI::OperandValueProperties Opd2PropInfo) {
     return 1;
   }

   unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Ty, int Index,
                           Type *SubTp) {
     return 1;
   }

   unsigned getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) { return 1; }

   unsigned getCFInstrCost(unsigned Opcode) { return 1; }

   unsigned getCmpSelInstrCost(unsigned Opcode, Type *ValTy, Type *CondTy) {
     return 1;
   }

   unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
     return 1;
   }

   unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
                            unsigned AddressSpace) {
     return 1;
   }

   unsigned getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
                                  unsigned AddressSpace) {
     return 1;
   }

   unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
                                       unsigned Factor,
                                       ArrayRef<unsigned> Indices,
                                       unsigned Alignment,
                                       unsigned AddressSpace) {
     return 1;
   }

   unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
                                  ArrayRef<Type *> Tys) {
     return 1;
   }

   unsigned getCallInstrCost(Function *F, Type *RetTy, ArrayRef<Type *> Tys) {
     return 1;
   }

   unsigned getNumberOfParts(Type *Tp) { return 0; }

   unsigned getAddressComputationCost(Type *Tp, bool) { return 0; }

   unsigned getReductionCost(unsigned, Type *, bool) { return 1; }

   unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) { return 0; }

   bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) {
     return false;
   }

   Value *getOrCreateResultFromMemIntrinsic(IntrinsicInst *Inst,
                                            Type *ExpectedType) {
     return nullptr;
   }

   bool hasCompatibleFunctionAttributes(const Function *Caller,
                                        const Function *Callee) const {
     return (Caller->getFnAttribute("target-cpu") ==
             Callee->getFnAttribute("target-cpu")) &&
            (Caller->getFnAttribute("target-features") ==
             Callee->getFnAttribute("target-features"));
   }
 };

 /// \brief CRTP base class for use as a mix-in that aids implementing
 /// a TargetTransformInfo-compatible class.
 template <typename T>
 class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
 private:
   typedef TargetTransformInfoImplBase BaseT;

 protected:
   explicit TargetTransformInfoImplCRTPBase(const DataLayout &DL) : BaseT(DL) {}

 public:
   // Provide value semantics. MSVC requires that we spell all of these out.
   TargetTransformInfoImplCRTPBase(const TargetTransformInfoImplCRTPBase &Arg)
       : BaseT(static_cast<const BaseT &>(Arg)) {}
   TargetTransformInfoImplCRTPBase(TargetTransformInfoImplCRTPBase &&Arg)
       : BaseT(std::move(static_cast<BaseT &>(Arg))) {}

   using BaseT::getCallCost;

   unsigned getCallCost(const Function *F, int NumArgs) {
     assert(F && "A concrete function must be provided to this routine.");

     if (NumArgs < 0)
       // Set the argument number to the number of explicit arguments in the
       // function.
       NumArgs = F->arg_size();

     if (Intrinsic::ID IID = F->getIntrinsicID()) {
       FunctionType *FTy = F->getFunctionType();
       SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
       return static_cast<T *>(this)
           ->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
     }

     if (!static_cast<T *>(this)->isLoweredToCall(F))
       return TTI::TCC_Basic; // Give a basic cost if it will be lowered
                              // directly.

     return static_cast<T *>(this)->getCallCost(F->getFunctionType(), NumArgs);
   }

   unsigned getCallCost(const Function *F, ArrayRef<const Value *> Arguments) {
     // Simply delegate to generic handling of the call.
     // FIXME: We should use instsimplify or something else to catch calls which
     // will constant fold with these arguments.
     return static_cast<T *>(this)->getCallCost(F, Arguments.size());
   }

   using BaseT::getIntrinsicCost;

   unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
                             ArrayRef<const Value *> Arguments) {
     // Delegate to the generic intrinsic handling code. This mostly provides an
     // opportunity for targets to (for example) special case the cost of
     // certain intrinsics based on constants used as arguments.
     SmallVector<Type *, 8> ParamTys;
     ParamTys.reserve(Arguments.size());
     for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
       ParamTys.push_back(Arguments[Idx]->getType());
     return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
   }

   unsigned getUserCost(const User *U) {
     if (isa<PHINode>(U))
       return TTI::TCC_Free; // Model all PHI nodes as free.

     if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
       SmallVector<const Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
       return static_cast<T *>(this)
           ->getGEPCost(GEP->getPointerOperand(), Indices);
     }

     if (auto CS = ImmutableCallSite(U)) {
       const Function *F = CS.getCalledFunction();
       if (!F) {
         // Just use the called value type.
         Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
         return static_cast<T *>(this)
             ->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
       }

       SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
       return static_cast<T *>(this)->getCallCost(F, Arguments);
     }

     if (const CastInst *CI = dyn_cast<CastInst>(U)) {
       // Result of a cmp instruction is often extended (to be used by other
       // cmp instructions, logical or return instructions). These are usually
       // nop on most sane targets.
       if (isa<CmpInst>(CI->getOperand(0)))
         return TTI::TCC_Free;
     }

     return static_cast<T *>(this)->getOperationCost(
         Operator::getOpcode(U), U->getType(),
         U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr);
   }
 };
 }

 #endif
	//===- TargetTransformInfoImpl.h --------------------------------- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	/// \file
	/// This file provides helpers for the implementation of
	/// a TargetTransformInfo-conforming class.
	///
	//===----------------------------------------------------------------------===//

	#ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H
	#define LLVM_ANALYSIS_TARGETTRANSFORMINFOIMPL_H

	#include "llvm/Analysis/TargetTransformInfo.h"
	#include "llvm/IR/CallSite.h"
	#include "llvm/IR/DataLayout.h"
	#include "llvm/IR/Function.h"
	#include "llvm/IR/Operator.h"
	#include "llvm/IR/Type.h"

	namespace llvm {

	/// \brief Base class for use as a mix-in that aids implementing
	/// a TargetTransformInfo-compatible class.
	class TargetTransformInfoImplBase {
	protected:
	typedef TargetTransformInfo TTI;

	const DataLayout &DL;

	explicit TargetTransformInfoImplBase(const DataLayout &DL) : DL(DL) {}

	public:
	// Provide value semantics. MSVC requires that we spell all of these out.
	TargetTransformInfoImplBase(const TargetTransformInfoImplBase &Arg)
	: DL(Arg.DL) {}
	TargetTransformInfoImplBase(TargetTransformInfoImplBase &&Arg) : DL(Arg.DL) {}

	const DataLayout &getDataLayout() const { return DL; }

	unsigned getOperationCost(unsigned Opcode, Type Ty, Type OpTy) {
	switch (Opcode) {
	default:
	// By default, just classify everything as 'basic'.
	return TTI::TCC_Basic;

	case Instruction::GetElementPtr:
	llvm_unreachable("Use getGEPCost for GEP operations!");

	case Instruction::BitCast:
	assert(OpTy && "Cast instructions must provide the operand type");
	if (Ty == OpTy \|\| (Ty->isPointerTy() && OpTy->isPointerTy()))
	// Identity and pointer-to-pointer casts are free.
	return TTI::TCC_Free;

	// Otherwise, the default basic cost is used.
	return TTI::TCC_Basic;

	case Instruction::IntToPtr: {
	// An inttoptr cast is free so long as the input is a legal integer type
	// which doesn't contain values outside the range of a pointer.
	unsigned OpSize = OpTy->getScalarSizeInBits();
	if (DL.isLegalInteger(OpSize) &&
	OpSize <= DL.getPointerTypeSizeInBits(Ty))
	return TTI::TCC_Free;

	// Otherwise it's not a no-op.
	return TTI::TCC_Basic;
	}
	case Instruction::PtrToInt: {
	// A ptrtoint cast is free so long as the result is large enough to store
	// the pointer, and a legal integer type.
	unsigned DestSize = Ty->getScalarSizeInBits();
	if (DL.isLegalInteger(DestSize) &&
	DestSize >= DL.getPointerTypeSizeInBits(OpTy))
	return TTI::TCC_Free;

	// Otherwise it's not a no-op.
	return TTI::TCC_Basic;
	}
	case Instruction::Trunc:
	// trunc to a native type is free (assuming the target has compare and
	// shift-right of the same width).
	if (DL.isLegalInteger(DL.getTypeSizeInBits(Ty)))
	return TTI::TCC_Free;

	return TTI::TCC_Basic;
	}
	}

	unsigned getGEPCost(const Value Ptr, ArrayRef<const Value > Operands) {
	// In the basic model, we just assume that all-constant GEPs will be folded
	// into their uses via addressing modes.
	for (unsigned Idx = 0, Size = Operands.size(); Idx != Size; ++Idx)
	if (!isa<Constant>(Operands[Idx]))
	return TTI::TCC_Basic;

	return TTI::TCC_Free;
	}

	unsigned getCallCost(FunctionType *FTy, int NumArgs) {
	assert(FTy && "FunctionType must be provided to this routine.");

	// The target-independent implementation just measures the size of the
	// function by approximating that each argument will take on average one
	// instruction to prepare.

	if (NumArgs < 0)
	// Set the argument number to the number of explicit arguments in the
	// function.
	NumArgs = FTy->getNumParams();

	return TTI::TCC_Basic * (NumArgs + 1);
	}

	unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
	ArrayRef<Type *> ParamTys) {
	switch (IID) {
	default:
	// Intrinsics rarely (if ever) have normal argument setup constraints.
	// Model them as having a basic instruction cost.
	// FIXME: This is wrong for libc intrinsics.
	return TTI::TCC_Basic;

	case Intrinsic::annotation:
	case Intrinsic::assume:
	case Intrinsic::dbg_declare:
	case Intrinsic::dbg_value:
	case Intrinsic::invariant_start:
	case Intrinsic::invariant_end:
	case Intrinsic::lifetime_start:
	case Intrinsic::lifetime_end:
	case Intrinsic::objectsize:
	case Intrinsic::ptr_annotation:
	case Intrinsic::var_annotation:
	case Intrinsic::experimental_gc_result_int:
	case Intrinsic::experimental_gc_result_float:
	case Intrinsic::experimental_gc_result_ptr:
	case Intrinsic::experimental_gc_result:
	case Intrinsic::experimental_gc_relocate:
	// These intrinsics don't actually represent code after lowering.
	return TTI::TCC_Free;
	}
	}

	bool hasBranchDivergence() { return false; }

	bool isSourceOfDivergence(const Value *V) { return false; }

	bool isLoweredToCall(const Function *F) {
	// FIXME: These should almost certainly not be handled here, and instead
	// handled with the help of TLI or the target itself. This was largely
	// ported from existing analysis heuristics here so that such refactorings
	// can take place in the future.

	if (F->isIntrinsic())
	return false;

	if (F->hasLocalLinkage() \|\| !F->hasName())
	return true;

	StringRef Name = F->getName();

	// These will all likely lower to a single selection DAG node.
	if (Name == "copysign" \|\| Name == "copysignf" \|\| Name == "copysignl" \|\|
	Name == "fabs" \|\| Name == "fabsf" \|\| Name == "fabsl" \|\| Name == "sin" \|\|
	Name == "fmin" \|\| Name == "fminf" \|\| Name == "fminl" \|\|
	Name == "fmax" \|\| Name == "fmaxf" \|\| Name == "fmaxl" \|\|
	Name == "sinf" \|\| Name == "sinl" \|\| Name == "cos" \|\| Name == "cosf" \|\|
	Name == "cosl" \|\| Name == "sqrt" \|\| Name == "sqrtf" \|\| Name == "sqrtl")
	return false;

	// These are all likely to be optimized into something smaller.
	if (Name == "pow" \|\| Name == "powf" \|\| Name == "powl" \|\| Name == "exp2" \|\|
	Name == "exp2l" \|\| Name == "exp2f" \|\| Name == "floor" \|\|
	Name == "floorf" \|\| Name == "ceil" \|\| Name == "round" \|\|
	Name == "ffs" \|\| Name == "ffsl" \|\| Name == "abs" \|\| Name == "labs" \|\|
	Name == "llabs")
	return false;

	return true;
	}

	void getUnrollingPreferences(Loop *, TTI::UnrollingPreferences &) {}

	bool isLegalAddImmediate(int64_t Imm) { return false; }

	bool isLegalICmpImmediate(int64_t Imm) { return false; }

	bool isLegalAddressingMode(Type Ty, GlobalValue BaseGV, int64_t BaseOffset,
	bool HasBaseReg, int64_t Scale,
	unsigned AddrSpace) {
	// Guess that only reg and reg+reg addressing is allowed. This heuristic is
	// taken from the implementation of LSR.
	return !BaseGV && BaseOffset == 0 && (Scale == 0 \|\| Scale == 1);
	}

	bool isLegalMaskedStore(Type *DataType, int Consecutive) { return false; }

	bool isLegalMaskedLoad(Type *DataType, int Consecutive) { return false; }

	int getScalingFactorCost(Type Ty, GlobalValue BaseGV, int64_t BaseOffset,
	bool HasBaseReg, int64_t Scale, unsigned AddrSpace) {
	// Guess that all legal addressing mode are free.
	if (isLegalAddressingMode(Ty, BaseGV, BaseOffset, HasBaseReg,
	Scale, AddrSpace))
	return 0;
	return -1;
	}

	bool isTruncateFree(Type Ty1, Type Ty2) { return false; }

	bool isProfitableToHoist(Instruction *I) { return true; }

	bool isTypeLegal(Type *Ty) { return false; }

	unsigned getJumpBufAlignment() { return 0; }

	unsigned getJumpBufSize() { return 0; }

	bool shouldBuildLookupTables() { return true; }

	bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }

	TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
	return TTI::PSK_Software;
	}

	bool haveFastSqrt(Type *Ty) { return false; }

	unsigned getFPOpCost(Type *Ty) { return TargetTransformInfo::TCC_Basic; }

	unsigned getIntImmCost(const APInt &Imm, Type *Ty) { return TTI::TCC_Basic; }

	unsigned getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
	Type *Ty) {
	return TTI::TCC_Free;
	}

	unsigned getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
	Type *Ty) {
	return TTI::TCC_Free;
	}

	unsigned getNumberOfRegisters(bool Vector) { return 8; }

	unsigned getRegisterBitWidth(bool Vector) { return 32; }

	unsigned getMaxInterleaveFactor(unsigned VF) { return 1; }

	unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
	TTI::OperandValueKind Opd1Info,
	TTI::OperandValueKind Opd2Info,
	TTI::OperandValueProperties Opd1PropInfo,
	TTI::OperandValueProperties Opd2PropInfo) {
	return 1;
	}

	unsigned getShuffleCost(TTI::ShuffleKind Kind, Type *Ty, int Index,
	Type *SubTp) {
	return 1;
	}

	unsigned getCastInstrCost(unsigned Opcode, Type Dst, Type Src) { return 1; }

	unsigned getCFInstrCost(unsigned Opcode) { return 1; }

	unsigned getCmpSelInstrCost(unsigned Opcode, Type ValTy, Type CondTy) {
	return 1;
	}

	unsigned getVectorInstrCost(unsigned Opcode, Type *Val, unsigned Index) {
	return 1;
	}

	unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
	unsigned AddressSpace) {
	return 1;
	}

	unsigned getMaskedMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
	unsigned AddressSpace) {
	return 1;
	}

	unsigned getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
	unsigned Factor,
	ArrayRef<unsigned> Indices,
	unsigned Alignment,
	unsigned AddressSpace) {
	return 1;
	}

	unsigned getIntrinsicInstrCost(Intrinsic::ID ID, Type *RetTy,
	ArrayRef<Type *> Tys) {
	return 1;
	}

	unsigned getCallInstrCost(Function F, Type RetTy, ArrayRef<Type *> Tys) {
	return 1;
	}

	unsigned getNumberOfParts(Type *Tp) { return 0; }

	unsigned getAddressComputationCost(Type *Tp, bool) { return 0; }

	unsigned getReductionCost(unsigned, Type *, bool) { return 1; }

	unsigned getCostOfKeepingLiveOverCall(ArrayRef<Type *> Tys) { return 0; }

	bool getTgtMemIntrinsic(IntrinsicInst *Inst, MemIntrinsicInfo &Info) {
	return false;
	}

	Value getOrCreateResultFromMemIntrinsic(IntrinsicInst Inst,
	Type *ExpectedType) {
	return nullptr;
	}

	bool hasCompatibleFunctionAttributes(const Function *Caller,
	const Function *Callee) const {
	return (Caller->getFnAttribute("target-cpu") ==
	Callee->getFnAttribute("target-cpu")) &&
	(Caller->getFnAttribute("target-features") ==
	Callee->getFnAttribute("target-features"));
	}
	};

	/// \brief CRTP base class for use as a mix-in that aids implementing
	/// a TargetTransformInfo-compatible class.
	template <typename T>
	class TargetTransformInfoImplCRTPBase : public TargetTransformInfoImplBase {
	private:
	typedef TargetTransformInfoImplBase BaseT;

	protected:
	explicit TargetTransformInfoImplCRTPBase(const DataLayout &DL) : BaseT(DL) {}

	public:
	// Provide value semantics. MSVC requires that we spell all of these out.
	TargetTransformInfoImplCRTPBase(const TargetTransformInfoImplCRTPBase &Arg)
	: BaseT(static_cast<const BaseT &>(Arg)) {}
	TargetTransformInfoImplCRTPBase(TargetTransformInfoImplCRTPBase &&Arg)
	: BaseT(std::move(static_cast<BaseT &>(Arg))) {}

	using BaseT::getCallCost;

	unsigned getCallCost(const Function *F, int NumArgs) {
	assert(F && "A concrete function must be provided to this routine.");

	if (NumArgs < 0)
	// Set the argument number to the number of explicit arguments in the
	// function.
	NumArgs = F->arg_size();

	if (Intrinsic::ID IID = F->getIntrinsicID()) {
	FunctionType *FTy = F->getFunctionType();
	SmallVector<Type *, 8> ParamTys(FTy->param_begin(), FTy->param_end());
	return static_cast<T *>(this)
	->getIntrinsicCost(IID, FTy->getReturnType(), ParamTys);
	}

	if (!static_cast<T *>(this)->isLoweredToCall(F))
	return TTI::TCC_Basic; // Give a basic cost if it will be lowered
	// directly.

	return static_cast<T *>(this)->getCallCost(F->getFunctionType(), NumArgs);
	}

	unsigned getCallCost(const Function F, ArrayRef<const Value > Arguments) {
	// Simply delegate to generic handling of the call.
	// FIXME: We should use instsimplify or something else to catch calls which
	// will constant fold with these arguments.
	return static_cast<T *>(this)->getCallCost(F, Arguments.size());
	}

	using BaseT::getIntrinsicCost;

	unsigned getIntrinsicCost(Intrinsic::ID IID, Type *RetTy,
	ArrayRef<const Value *> Arguments) {
	// Delegate to the generic intrinsic handling code. This mostly provides an
	// opportunity for targets to (for example) special case the cost of
	// certain intrinsics based on constants used as arguments.
	SmallVector<Type *, 8> ParamTys;
	ParamTys.reserve(Arguments.size());
	for (unsigned Idx = 0, Size = Arguments.size(); Idx != Size; ++Idx)
	ParamTys.push_back(Arguments[Idx]->getType());
	return static_cast<T *>(this)->getIntrinsicCost(IID, RetTy, ParamTys);
	}

	unsigned getUserCost(const User *U) {
	if (isa<PHINode>(U))
	return TTI::TCC_Free; // Model all PHI nodes as free.

	if (const GEPOperator *GEP = dyn_cast<GEPOperator>(U)) {
	SmallVector<const Value *, 4> Indices(GEP->idx_begin(), GEP->idx_end());
	return static_cast<T *>(this)
	->getGEPCost(GEP->getPointerOperand(), Indices);
	}

	if (auto CS = ImmutableCallSite(U)) {
	const Function *F = CS.getCalledFunction();
	if (!F) {
	// Just use the called value type.
	Type *FTy = CS.getCalledValue()->getType()->getPointerElementType();
	return static_cast<T *>(this)
	->getCallCost(cast<FunctionType>(FTy), CS.arg_size());
	}

	SmallVector<const Value *, 8> Arguments(CS.arg_begin(), CS.arg_end());
	return static_cast<T *>(this)->getCallCost(F, Arguments);
	}

	if (const CastInst *CI = dyn_cast<CastInst>(U)) {
	// Result of a cmp instruction is often extended (to be used by other
	// cmp instructions, logical or return instructions). These are usually
	// nop on most sane targets.
	if (isa<CmpInst>(CI->getOperand(0)))
	return TTI::TCC_Free;
	}

	return static_cast<T *>(this)->getOperationCost(
	Operator::getOpcode(U), U->getType(),
	U->getNumOperands() == 1 ? U->getOperand(0)->getType() : nullptr);
	}
	};
	}

	#endif