InstCombineSimplifyDemanded.cpp File Reference

#include "InstCombineInternal.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "instcombine"

Functions
static bool	ShrinkDemandedConstant (Instruction *I, unsigned OpNo, const APInt &Demanded)
	Check to see if the specified operand of the specified instruction is a constant integer.
static unsigned	getBitWidth (Type *Ty, const DataLayout &DL)
	Returns the bitwidth of the given scalar or pointer type.

Variables
static cl::opt< bool >	VerifyKnownBits ("instcombine-verify-known-bits", cl::desc("Verify that computeKnownBits() and " "SimplifyDemandedBits() are consistent"), cl::Hidden, cl::init(false))

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "instcombine"

Definition at line 25 of file InstCombineSimplifyDemanded.cpp.

Function Documentation

getBitWidth()

static unsigned getBitWidth ( Type *  Ty, const DataLayout &  DL  )

static

Returns the bitwidth of the given scalar or pointer type.

For vector types, returns the element type's bitwidth.

Definition at line 59 of file InstCombineSimplifyDemanded.cpp.

References llvm::BitWidth, DL, and llvm::Type::getScalarSizeInBits().

ShrinkDemandedConstant()

static bool ShrinkDemandedConstant ( Instruction *  I, unsigned  OpNo, const APInt &  Demanded  )

static

Check to see if the specified operand of the specified instruction is a constant integer.

If so, check to see if there are any bits set in the constant that are not demanded. If so, shrink the constant and return true.

Definition at line 36 of file InstCombineSimplifyDemanded.cpp.

References assert(), llvm::CallingConv::C, llvm::ConstantInt::get(), I, llvm::PatternMatch::m_APInt(), and llvm::PatternMatch::match().

Referenced by llvm::TargetLowering::ShrinkDemandedConstant(), llvm::TargetLowering::SimplifyDemandedBits(), and llvm::InstCombinerImpl::SimplifyDemandedUseBits().

Variable Documentation

VerifyKnownBits

cl::opt< bool > VerifyKnownBits("instcombine-verify-known-bits", cl::desc("Verify that computeKnownBits() and " "SimplifyDemandedBits() are consistent"), cl::Hidden, cl::init(false)) ( "instcombine-verify-known-bits"  , cl::desc("Verify that computeKnownBits() and " "SimplifyDemandedBits() are consistent")  , cl::Hidden  , cl::init(false)    )

static

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