InstCombineAddSub.cpp File Reference

#include "InstCombineInternal.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/ValueTracking.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/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"
#include <cassert>
#include <utility>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "instcombine"

Functions
static Value *	checkForNegativeOperand (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Instruction *	foldNoWrapAdd (BinaryOperator &Add, InstCombiner::BuilderTy &Builder)
	Wrapping flags may allow combining constants separated by an extend.
template<bool FP, typename Mul2Rhs >
static bool	matchesSquareSum (BinaryOperator &I, Mul2Rhs M2Rhs, Value *&A, Value *&B)
static bool	MatchMul (Value *E, Value *&Op, APInt &C)
static bool	MatchRem (Value *E, Value *&Op, APInt &C, bool &IsSigned)
static bool	MatchDiv (Value *E, Value *&Op, APInt &C, bool IsSigned)
static bool	MulWillOverflow (APInt &C0, APInt &C1, bool IsSigned)
static Instruction *	canonicalizeLowbitMask (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Fold (1 << NBits) - 1 Into: ~(-(1 << NBits)) Because a 'not' is better for bit-tracking analysis and other transforms than an 'add'.
static Instruction *	foldToUnsignedSaturatedAdd (BinaryOperator &I)
static Instruction *	combineAddSubWithShlAddSub (InstCombiner::BuilderTy &Builder, const BinaryOperator &I)
static Instruction *	foldAddToAshr (BinaryOperator &Add)
	Try to reduce signed division by power-of-2 to an arithmetic shift right.
static Instruction *	factorizeMathWithShlOps (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	This is a specialization of a more general transform from foldUsingDistributiveLaws.
static Instruction *	foldBoxMultiply (BinaryOperator &I)
	Reduce a sequence of masked half-width multiplies to a single multiply.
static Instruction *	factorizeLerp (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Eliminate an op from a linear interpolation (lerp) pattern.
static Instruction *	factorizeFAddFSub (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
	Factor a common operand out of fadd/fsub of fmul/fdiv.
static Instruction *	foldSubOfMinMax (BinaryOperator &I, InstCombiner::BuilderTy &Builder)
static Instruction *	foldFNegIntoConstant (Instruction &I, const DataLayout &DL)
	This eliminates floating-point negation in either 'fneg(X)' or 'fsub(-0.0, X)' form by combining into a constant operand.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "instcombine"

Definition at line 39 of file InstCombineAddSub.cpp.

Function Documentation

canonicalizeLowbitMask()

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

static

Fold (1 << NBits) - 1 Into: ~(-(1 << NBits)) Because a 'not' is better for bit-tracking analysis and other transforms than an 'add'.

The new shl is always nsw, and is nuw if old and was.

Definition at line 1172 of file InstCombineAddSub.cpp.

References Builder, llvm::BinaryOperator::CreateNot(), llvm::Constant::getAllOnesValue(), llvm::Value::getType(), I, llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_AllOnes(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

checkForNegativeOperand()

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

static

Definition at line 752 of file InstCombineAddSub.cpp.

References Builder, llvm::APInt::countr_zero(), llvm::Value::hasOneUse(), I, LHS, llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_And(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_One(), llvm::PatternMatch::m_Or(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_Xor(), llvm::PatternMatch::match(), RHS, std::swap(), X, and Y.

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

combineAddSubWithShlAddSub()

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

static

Definition at line 1215 of file InstCombineAddSub.cpp.

References A, B, Builder, I, llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_Neg(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

factorizeFAddFSub()

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

static

Factor a common operand out of fadd/fsub of fmul/fdiv.

Definition at line 1728 of file InstCombineAddSub.cpp.

References assert(), Builder, llvm::CallingConv::C, llvm::BinaryOperator::CreateFDivFMF(), llvm::BinaryOperator::CreateFMulFMF(), factorizeLerp(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_APFloat(), llvm::PatternMatch::m_c_FMul(), llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_FMul(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

Referenced by llvm::InstCombinerImpl::visitFAdd(), and llvm::InstCombinerImpl::visitFSub().

factorizeLerp()

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

static

Eliminate an op from a linear interpolation (lerp) pattern.

Definition at line 1712 of file InstCombineAddSub.cpp.

References Builder, llvm::BinaryOperator::CreateFAddFMF(), I, llvm::PatternMatch::m_c_FAdd(), llvm::PatternMatch::m_c_FMul(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_FPOne(), llvm::PatternMatch::m_FSub(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

Referenced by factorizeFAddFSub().

factorizeMathWithShlOps()

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

static

This is a specialization of a more general transform from foldUsingDistributiveLaws.

If that code can be made to work optimally for multi-use cases or propagating nsw/nuw, then we would not need this.

Definition at line 1360 of file InstCombineAddSub.cpp.

References assert(), Builder, I, llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

Referenced by llvm::InstCombinerImpl::visitAdd(), and llvm::InstCombinerImpl::visitSub().

foldAddToAshr()

static Instruction * foldAddToAshr ( BinaryOperator &  Add )

static

Try to reduce signed division by power-of-2 to an arithmetic shift right.

Definition at line 1228 of file InstCombineAddSub.cpp.

References llvm::Add, llvm::APInt::exactLogBase2(), llvm::ConstantInt::get(), llvm::APInt::getSignedMinValue(), llvm::CmpInst::ICMP_UGT, llvm::APInt::isNegative(), llvm::PatternMatch::m_And(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_ICmp(), llvm::PatternMatch::m_Power2(), llvm::PatternMatch::m_SDiv(), llvm::PatternMatch::m_SExt(), llvm::PatternMatch::m_SignMask(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::SMin, and X.

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

foldBoxMultiply()

static Instruction * foldBoxMultiply ( BinaryOperator &  I )

static

Reduce a sequence of masked half-width multiplies to a single multiply.

((XLow * YHigh) + (YLow * XHigh)) << HalfBits) + (XLow * YLow) --> X * Y

Definition at line 1396 of file InstCombineAddSub.cpp.

References llvm::BitWidth, llvm::APInt::getMaxValue(), I, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_c_Mul(), llvm::PatternMatch::m_CombineOr(), llvm::PatternMatch::m_LShr(), llvm::PatternMatch::m_Mul(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_SpecificInt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

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

foldFNegIntoConstant()

static Instruction * foldFNegIntoConstant ( Instruction &  I, const DataLayout &  DL  )

static

This eliminates floating-point negation in either 'fneg(X)' or 'fsub(-0.0, X)' form by combining into a constant operand.

Definition at line 2569 of file InstCombineAddSub.cpp.

References llvm::CallingConv::C, llvm::ConstantFoldUnaryOpOperand(), llvm::BinaryOperator::CreateFDivFMF(), llvm::BinaryOperator::CreateFMulFMF(), llvm::BinaryOperator::CreateFSubFMF(), DL, llvm::Instruction::getFastMathFlags(), I, llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_FAdd(), llvm::PatternMatch::m_FDiv(), llvm::PatternMatch::m_FMul(), llvm::PatternMatch::m_FNeg(), llvm::PatternMatch::m_Instruction(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::FastMathFlags::noInfs(), llvm::FastMathFlags::noSignedZeros(), llvm::Instruction::setHasNoInfs(), llvm::Instruction::setHasNoSignedZeros(), and X.

Referenced by llvm::InstCombinerImpl::visitFNeg(), and llvm::InstCombinerImpl::visitFSub().

foldNoWrapAdd()

static Instruction * foldNoWrapAdd ( BinaryOperator &  Add, InstCombiner::BuilderTy &  Builder  )

static

Wrapping flags may allow combining constants separated by an extend.

Definition at line 809 of file InstCombineAddSub.cpp.

References llvm::Add, Builder, llvm::ConstantInt::get(), llvm::APInt::getBitWidth(), llvm::APInt::isNegative(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_Constant(), llvm::PatternMatch::m_NSWAdd(), llvm::PatternMatch::m_NUWAdd(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_SExt(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZExt(), llvm::PatternMatch::match(), llvm::APInt::sext(), llvm::APInt::sge(), llvm::APInt::trunc(), and X.

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

foldSubOfMinMax()

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

static

Definition at line 2018 of file InstCombineAddSub.cpp.

References Builder, llvm::CallInst::Create(), F, llvm::Intrinsic::getDeclaration(), llvm::getInverseMinMaxIntrinsic(), llvm::Value::hasOneUse(), I, llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_NSWSub(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_UMin(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZeroInt(), llvm::PatternMatch::match(), X, and Y.

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

foldToUnsignedSaturatedAdd()

static Instruction * foldToUnsignedSaturatedAdd ( BinaryOperator &  I )

static

Definition at line 1190 of file InstCombineAddSub.cpp.

References assert(), llvm::CallingConv::C, llvm::CallInst::Create(), llvm::ConstantInt::get(), llvm::Intrinsic::getDeclaration(), I, llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_c_UMin(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_Not(), llvm::PatternMatch::m_UMin(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), X, and Y.

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

MatchDiv()

static bool MatchDiv ( Value *  E, Value *&  Op, APInt &  C, bool  IsSigned  )

static

Definition at line 1104 of file InstCombineAddSub.cpp.

References llvm::CallingConv::C, E, llvm::APInt::getBitWidth(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_LShr(), llvm::PatternMatch::m_SDiv(), llvm::PatternMatch::m_UDiv(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

matchesSquareSum()

template<bool FP, typename Mul2Rhs >

static bool matchesSquareSum ( BinaryOperator &  I, Mul2Rhs  M2Rhs, Value *&  A, Value *&  B  )

static

Definition at line 1007 of file InstCombineAddSub.cpp.

References A, B, FP, I, llvm::PatternMatch::m_BinOp(), llvm::PatternMatch::m_c_BinOp(), llvm::PatternMatch::m_CombineOr(), llvm::PatternMatch::m_Deferred(), llvm::PatternMatch::m_OneUse(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

MatchMul()

static bool MatchMul ( Value *  E, Value *&  Op, APInt &  C  )

static

Definition at line 1064 of file InstCombineAddSub.cpp.

References llvm::CallingConv::C, E, llvm::APInt::getBitWidth(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_Mul(), llvm::PatternMatch::m_Shl(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

MatchRem()

static bool MatchRem ( Value *  E, Value *&  Op, APInt &  C, bool &  IsSigned  )

static

Definition at line 1082 of file InstCombineAddSub.cpp.

References llvm::CallingConv::C, E, llvm::PatternMatch::m_And(), llvm::PatternMatch::m_APInt(), llvm::PatternMatch::m_SRem(), llvm::PatternMatch::m_URem(), llvm::PatternMatch::m_Value(), and llvm::PatternMatch::match().

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

MulWillOverflow()

static bool MulWillOverflow ( APInt &  C0, APInt &  C1, bool  IsSigned  )

static

Definition at line 1125 of file InstCombineAddSub.cpp.

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

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