LLVM API Documentation

 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
Functions
InstCombineSelect.cpp File Reference
#include "InstCombine.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Support/PatternMatch.h"
Include dependency graph for InstCombineSelect.cpp:

Go to the source code of this file.

Functions

static SelectPatternFlavor MatchSelectPattern (Value *V, Value *&LHS, Value *&RHS)
 
static unsigned GetSelectFoldableOperands (Instruction *I)
 
static ConstantGetSelectFoldableConstant (Instruction *I)
 
static bool isSelect01 (Constant *C1, Constant *C2)
 
static ValueSimplifyWithOpReplaced (Value *V, Value *Op, Value *RepOp, const DataLayout *TD, const TargetLibraryInfo *TLI)
 
static ValuefoldSelectICmpAndOr (const SelectInst &SI, Value *TrueVal, Value *FalseVal, InstCombiner::BuilderTy *Builder)
 
static bool CanSelectOperandBeMappingIntoPredBlock (const Value *V, const SelectInst &SI)
 
static ValuefoldSelectICmpAnd (const SelectInst &SI, ConstantInt *TrueVal, ConstantInt *FalseVal, InstCombiner::BuilderTy *Builder)
 

Function Documentation

static bool CanSelectOperandBeMappingIntoPredBlock ( const Value V,
const SelectInst SI 
)
static

CanSelectOperandBeMappingIntoPredBlock - SI is a select whose condition is a PHI node (but the two may be in different blocks). See if the true/false values (V) are live in all of the predecessor blocks of the PHI. For example, cases like this cannot be mapped:

X = phi [ C1, BB1], [C2, BB2] Y = add Z = select X, Y, 0

because Y is not live in BB1/BB2.

Definition at line 604 of file InstCombineSelect.cpp.

References llvm::dyn_cast(), llvm::SelectInst::getCondition(), llvm::Instruction::getParent(), and I.

Referenced by llvm::InstCombiner::visitSelectInst().

static Value* foldSelectICmpAnd ( const SelectInst SI,
ConstantInt TrueVal,
ConstantInt FalseVal,
InstCombiner::BuilderTy Builder 
)
static
static Value* foldSelectICmpAndOr ( const SelectInst SI,
Value TrueVal,
Value FalseVal,
InstCombiner::BuilderTy Builder 
)
static
static Constant* GetSelectFoldableConstant ( Instruction I)
static

GetSelectFoldableConstant - For the same transformation as the previous function, return the identity constant that goes into the select.

Definition at line 104 of file InstCombineSelect.cpp.

References llvm::APIntOps::And(), llvm::ConstantInt::get(), llvm::Constant::getAllOnesValue(), llvm::Constant::getNullValue(), llvm::Instruction::getOpcode(), llvm::Value::getType(), llvm_unreachable, llvm::APIntOps::Or(), and llvm::APIntOps::Xor().

Referenced by llvm::InstCombiner::FoldSelectIntoOp().

static unsigned GetSelectFoldableOperands ( Instruction I)
static

GetSelectFoldableOperands - We want to turn code that looks like this: C = or A, B D = select cond, C, A into: C = select cond, B, 0 D = or A, C

Assuming that the specified instruction is an operand to the select, return a bitmask indicating which operands of this instruction are foldable if they equal the other incoming value of the select.

Definition at line 84 of file InstCombineSelect.cpp.

References llvm::APIntOps::And(), llvm::Instruction::getOpcode(), llvm::APIntOps::Or(), and llvm::APIntOps::Xor().

Referenced by llvm::InstCombiner::FoldSelectIntoOp().

static bool isSelect01 ( Constant C1,
Constant C2 
)
static
static SelectPatternFlavor MatchSelectPattern ( Value V,
Value *&  LHS,
Value *&  RHS 
)
static
static Value* SimplifyWithOpReplaced ( Value V,
Value Op,
Value RepOp,
const DataLayout TD,
const TargetLibraryInfo TLI 
)
static