#include "llvm/Analysis/DemandedBits.h"

Public Member Functions
	DemandedBits (Function &F, AssumptionCache &AC, DominatorTree &DT)

APInt	getDemandedBits (Instruction *I)
	Return the bits demanded from instruction I. More...

bool	isInstructionDead (Instruction *I)
	Return true if, during analysis, I could not be reached. More...

bool	isUseDead (Use *U)
	Return whether this use is dead by means of not having any demanded bits. More...

void	print (raw_ostream &OS)

Detailed Description

Definition at line 41 of file DemandedBits.h.

Constructor & Destructor Documentation

◆ DemandedBits()

llvm::DemandedBits::DemandedBits	(	Function &	F,
		AssumptionCache &	AC,
		DominatorTree &	DT
	)

inline

Definition at line 43 of file DemandedBits.h.

References getDemandedBits(), I, isInstructionDead(), isUseDead(), and print().

Member Function Documentation

◆ getDemandedBits()

APInt DemandedBits::getDemandedBits ( Instruction * I )

Return the bits demanded from instruction I.

For vector instructions individual vector elements are not distinguished: A bit is demanded if it is demanded for any of the vector elements. The size of the return value corresponds to the type size in bits of the scalar type.

Instructions that do not have integer or vector of integer type are accepted, but will always produce a mask with all bits set.

Definition at line 424 of file DemandedBits.cpp.

References llvm::APInt::getAllOnesValue(), llvm::Module::getDataLayout(), llvm::Instruction::getModule(), llvm::Type::getScalarType(), and llvm::Value::getType().

Referenced by bitTrackingDCE(), clearAssumptionsOfUsers(), llvm::computeMinimumValueSizes(), computeRecurrenceType(), and DemandedBits().