InstCombineMulDivRem.cpp File Reference

#include "InstCombineInternal.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include <cassert>
#include "llvm/Transforms/Utils/InstructionWorklist.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "instcombine"

Functions
static Value *	simplifyValueKnownNonZero (Value *V, InstCombinerImpl &IC, Instruction &CxtI)
	The specific integer value is used in a context where it is known to be non-zero.
static Value *	foldMulSelectToNegate (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Value *	foldMulShl1 (BinaryOperator &Mul, bool CommuteOperands, InstCombiner::BuilderTy &Builder)
	Reduce integer multiplication patterns that contain a (+/-1 << Z) factor.
static bool	getFSqrtDivOptPattern (Instruction *Div, SmallPtrSetImpl< Instruction * > &R1, SmallPtrSetImpl< Instruction * > &R2)
static bool	isFSqrtDivToFMulLegal (Instruction *X, SmallPtrSetImpl< Instruction * > &R1, SmallPtrSetImpl< Instruction * > &R2)
static bool	multiplyOverflows (const APInt &C1, const APInt &C2, APInt &Product, bool IsSigned)
	True if the multiply can not be expressed in an int this size.
static bool	isMultiple (const APInt &C1, const APInt &C2, APInt &Quotient, bool IsSigned)
	True if C1 is a multiple of C2. Quotient contains C1/C2.
static Value *	foldIDivShl (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Instruction *	narrowUDivURem (BinaryOperator &I, InstCombinerImpl &IC)
	If we have zero-extended operands of an unsigned div or rem, we may be able to narrow the operation (sink the zext below the math).
static Instruction *	foldFDivConstantDividend (BinaryOperator &I)
	Remove negation and try to reassociate constant math.
static Instruction *	foldFDivPowDivisor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Negate the exponent of pow/exp to fold division-by-pow() into multiply.
static Instruction *	foldFDivSqrtDivisor (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Convert div to mul if we have an sqrt divisor iff sqrt's operand is a fdiv instruction.
static Instruction *	convertFSqrtDivIntoFMul (CallInst *CI, Instruction *X, const SmallPtrSetImpl< Instruction * > &R1, const SmallPtrSetImpl< Instruction * > &R2, InstCombiner::BuilderTy &B, InstCombinerImpl *IC)
static Instruction *	simplifyIRemMulShl (BinaryOperator &I, InstCombinerImpl &IC)

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "instcombine"

Definition at line 38 of file InstCombineMulDivRem.cpp.

Function Documentation

convertFSqrtDivIntoFMul()

static Instruction * convertFSqrtDivIntoFMul ( CallInst *  CI, Instruction *  X, const SmallPtrSetImpl< Instruction * > &  R1, const SmallPtrSetImpl< Instruction * > &  R2, InstCombiner::BuilderTy &  B, InstCombinerImpl *  IC  )

static

Definition at line 2019 of file InstCombineMulDivRem.cpp.

References B, llvm::SmallPtrSetImpl< PtrType >::begin(), llvm::Instruction::clone(), llvm::InstCombinerImpl::eraseInstFromFunction(), llvm::FMul, llvm::CallBase::getArgOperand(), llvm::MDNode::getMostGenericFPMath(), I, llvm::FastMathFlags::intersectRewrite(), llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_SpecificFP(), llvm::PatternMatch::match(), llvm::Mul, R2, llvm::InstCombiner::replaceInstUsesWith(), llvm::Instruction::setMetadata(), llvm::FastMathFlags::unionValue(), and X.

Referenced by llvm::InstCombinerImpl::visitFDiv().

foldFDivConstantDividend()

static Instruction * foldFDivConstantDividend ( BinaryOperator &  I )

static

Remove negation and try to reassociate constant math.

Definition at line 1898 of file InstCombineMulDivRem.cpp.

References llvm::CallingConv::C, llvm::ConstantFoldBinaryOpOperands(), llvm::ConstantFoldUnaryOpOperand(), llvm::BinaryOperator::CreateFDivFMF(), DL, I, llvm::Constant::isNormalFP(), llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_FMul(), llvm::PatternMatch::m_FNeg(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and X.

Referenced by llvm::InstCombinerImpl::visitFDiv().

foldFDivPowDivisor()

static Instruction * foldFDivPowDivisor ( BinaryOperator &  I, InstCombiner::BuilderTy &  Builder  )

static

Negate the exponent of pow/exp to fold division-by-pow() into multiply.

Definition at line 1933 of file InstCombineMulDivRem.cpp.

References llvm::BinaryOperator::CreateFMulFMF(), llvm::IRBuilderBase::CreateFNegFMF(), llvm::IRBuilderBase::CreateIntrinsic(), llvm::IRBuilderBase::CreateNeg(), I, and II.

Referenced by llvm::InstCombinerImpl::visitFDiv().

foldFDivSqrtDivisor()

static Instruction * foldFDivSqrtDivisor ( BinaryOperator &  I, InstCombiner::BuilderTy &  Builder  )

static

Convert div to mul if we have an sqrt divisor iff sqrt's operand is a fdiv instruction.

Definition at line 1979 of file InstCombineMulDivRem.cpp.

References llvm::IRBuilderBase::CreateFDivFMF(), llvm::BinaryOperator::CreateFMulFMF(), llvm::IRBuilderBase::CreateUnaryIntrinsic(), I, II, llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), and Y.

Referenced by llvm::InstCombinerImpl::visitFDiv().

foldIDivShl()

static Value * foldIDivShl ( BinaryOperator &  I, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 1151 of file InstCombineMulDivRem.cpp.

References assert(), llvm::IRBuilderBase::CreateLShr(), llvm::IRBuilderBase::CreateSDiv(), llvm::IRBuilderBase::CreateShl(), llvm::IRBuilderBase::CreateUDiv(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_c_Mul(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::Mul, X, and Y.

Referenced by llvm::InstCombinerImpl::commonIDivTransforms().

foldMulSelectToNegate()

static Value * foldMulSelectToNegate ( BinaryOperator &  I, InstCombiner::BuilderTy &  Builder  )

static

Definition at line 100 of file InstCombineMulDivRem.cpp.

References Cond, llvm::IRBuilderBase::CreateFNegFMF(), llvm::IRBuilderBase::CreateNeg(), llvm::IRBuilderBase::CreateSelect(), llvm::IRBuilderBase::CreateSelectFMF(), I, llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_c_FMul(), llvm::PatternMatch::m_c_Mul(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Select(), llvm::PatternMatch::m_SpecificFP(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

Referenced by llvm::InstCombinerImpl::visitFMul(), and llvm::InstCombinerImpl::visitMul().

foldMulShl1()

static Value * foldMulShl1 ( BinaryOperator &  Mul, bool  CommuteOperands, InstCombiner::BuilderTy &  Builder  )

static

Reduce integer multiplication patterns that contain a (+/-1 << Z) factor.

Callers are expected to call this twice to handle commuted patterns.

Definition at line 142 of file InstCombineMulDivRem.cpp.

References llvm::IRBuilderBase::CreateAdd(), llvm::IRBuilderBase::CreateFreeze(), llvm::IRBuilderBase::CreateShl(), llvm::IRBuilderBase::CreateSub(), llvm::Value::getName(), llvm::User::getOperand(), llvm::Instruction::hasNoSignedWrap(), llvm::Instruction::hasNoUnsignedWrap(), llvm::isGuaranteedNotToBeUndef(), llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_BinOp(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), Mul, std::swap(), X, and Y.

Referenced by llvm::InstCombinerImpl::visitMul().

getFSqrtDivOptPattern()

static bool getFSqrtDivOptPattern ( Instruction *  Div, SmallPtrSetImpl< Instruction * > &  R1, SmallPtrSetImpl< Instruction * > &  R2  )

static

Definition at line 666 of file InstCombineMulDivRem.cpp.

References A, llvm::SmallPtrSetImplBase::empty(), llvm::User::getOperand(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_FMul(), llvm::PatternMatch::m_FPOne(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_SpecificFP(), llvm::PatternMatch::m_Sqrt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), R2, and llvm::Value::users().

Referenced by isFSqrtDivToFMulLegal().

isFSqrtDivToFMulLegal()

static bool isFSqrtDivToFMulLegal ( Instruction *  X, SmallPtrSetImpl< Instruction * > &  R1, SmallPtrSetImpl< Instruction * > &  R2  )

static

Definition at line 699 of file InstCombineMulDivRem.cpp.

References llvm::all_of(), llvm::any_of(), llvm::SmallPtrSetImpl< PtrType >::begin(), getFSqrtDivOptPattern(), getParent(), llvm::Instruction::hasAllowReassoc(), llvm::Instruction::hasNoInfs(), llvm::Instruction::hasNoNaNs(), llvm::Instruction::hasNoSignedZeros(), I, R2, and X.

Referenced by llvm::InstCombinerImpl::visitFDiv().

isMultiple()

static bool isMultiple ( const APInt &  C1, const APInt &  C2, APInt &  Quotient, bool  IsSigned  )

static

True if C1 is a multiple of C2. Quotient contains C1/C2.

Definition at line 1130 of file InstCombineMulDivRem.cpp.

References assert(), llvm::APInt::getBitWidth(), llvm::APInt::isAllOnes(), llvm::APInt::isMinSignedValue(), llvm::APInt::isMinValue(), llvm::APInt::isZero(), llvm::APInt::sdivrem(), and llvm::APInt::udivrem().

Referenced by llvm::InstCombinerImpl::commonIDivTransforms().

multiplyOverflows()

static bool multiplyOverflows ( const APInt &  C1, const APInt &  C2, APInt &  Product, bool  IsSigned  )

static

True if the multiply can not be expressed in an int this size.

Definition at line 1122 of file InstCombineMulDivRem.cpp.

References llvm::APInt::smul_ov(), and llvm::APInt::umul_ov().

Referenced by llvm::InstCombinerImpl::commonIDivTransforms().

narrowUDivURem()

static Instruction * narrowUDivURem ( BinaryOperator &  I, InstCombinerImpl &  IC  )

static

If we have zero-extended operands of an unsigned div or rem, we may be able to narrow the operation (sink the zext below the math).

Definition at line 1591 of file InstCombineMulDivRem.cpp.

References llvm::InstCombiner::Builder, llvm::CallingConv::C, llvm::IRBuilderBase::CreateBinOp(), D, llvm::InstCombinerImpl::getLosslessUnsignedTrunc(), I, llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZExt(), llvm::PatternMatch::match(), N, X, and Y.

Referenced by llvm::InstCombinerImpl::visitUDiv(), and llvm::InstCombinerImpl::visitURem().

simplifyIRemMulShl()

static Instruction * simplifyIRemMulShl ( BinaryOperator &  I, InstCombinerImpl &  IC  )

static

Definition at line 2223 of file InstCombineMulDivRem.cpp.

References llvm::CallingConv::C, llvm::APInt::getBitWidth(), llvm::Constant::getNullValue(), llvm::OverflowingBinaryOperator::hasNoSignedWrap(), llvm::OverflowingBinaryOperator::hasNoUnsignedWrap(), I, llvm::APInt::isZero(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_Mul(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::InstCombiner::replaceInstUsesWith(), llvm::Instruction::setHasNoSignedWrap(), llvm::Instruction::setHasNoUnsignedWrap(), llvm::APInt::ult(), X, and Y.

Referenced by llvm::InstCombinerImpl::commonIRemTransforms().

simplifyValueKnownNonZero()

static Value * simplifyValueKnownNonZero ( Value *  V, InstCombinerImpl &  IC, Instruction &  CxtI  )

static

The specific integer value is used in a context where it is known to be non-zero.

If this allows us to simplify the computation, do so and return the new operand, otherwise return null.

Definition at line 47 of file InstCombineMulDivRem.cpp.

References A, B, llvm::InstCombiner::Builder, llvm::IRBuilderBase::CreateShl(), llvm::IRBuilderBase::CreateSub(), I, llvm::InstCombiner::isKnownToBeAPowerOfTwo(), llvm::PatternMatch::m_LShr(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::InstCombiner::replaceOperand(), and simplifyValueKnownNonZero().

Referenced by llvm::InstCombinerImpl::commonIDivRemTransforms(), and simplifyValueKnownNonZero().