LLVM  3.7.0
Namespaces | Functions
ScalarEvolutionExpander.cpp File Reference
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
Include dependency graph for ScalarEvolutionExpander.cpp:

Go to the source code of this file.

Namespaces

 llvm
 Compute iterated dominance frontiers using a linear time algorithm.
 

Functions

static bool FactorOutConstant (const SCEV *&S, const SCEV *&Remainder, const SCEV *Factor, ScalarEvolution &SE, const DataLayout &DL)
 FactorOutConstant - Test if S is divisible by Factor, using signed division. More...
 
static void SimplifyAddOperands (SmallVectorImpl< const SCEV * > &Ops, Type *Ty, ScalarEvolution &SE)
 SimplifyAddOperands - Sort and simplify a list of add operands. More...
 
static void SplitAddRecs (SmallVectorImpl< const SCEV * > &Ops, Type *Ty, ScalarEvolution &SE)
 SplitAddRecs - Flatten a list of add operands, moving addrec start values out to the top level. More...
 
static const LoopPickMostRelevantLoop (const Loop *A, const Loop *B, DominatorTree &DT)
 PickMostRelevantLoop - Given two loops pick the one that's most relevant for SCEV expansion. More...
 
static void ExposePointerBase (const SCEV *&Base, const SCEV *&Rest, ScalarEvolution &SE)
 Move parts of Base into Rest to leave Base with the minimal expression that provides a pointer operand suitable for a GEP expansion. More...
 
static void hoistBeforePos (DominatorTree *DT, Instruction *InstToHoist, Instruction *Pos, PHINode *LoopPhi)
 Hoist the addrec instruction chain rooted in the loop phi above the position. More...
 
static bool canBeCheaplyTransformed (ScalarEvolution &SE, const SCEVAddRecExpr *Phi, const SCEVAddRecExpr *Requested, bool &InvertStep)
 Check whether we can cheaply express the requested SCEV in terms of the available PHI SCEV by truncation and/or invertion of the step. More...
 
static bool IsIncrementNSW (ScalarEvolution &SE, const SCEVAddRecExpr *AR)
 
static bool IsIncrementNUW (ScalarEvolution &SE, const SCEVAddRecExpr *AR)
 
bool llvm::isSafeToExpand (const SCEV *S, ScalarEvolution &SE)
 Return true if the given expression is safe to expand in the sense that all materialized values are safe to speculate. More...
 

Function Documentation

static bool canBeCheaplyTransformed ( ScalarEvolution SE,
const SCEVAddRecExpr Phi,
const SCEVAddRecExpr Requested,
bool InvertStep 
)
static
static void ExposePointerBase ( const SCEV *&  Base,
const SCEV *&  Rest,
ScalarEvolution SE 
)
static

Move parts of Base into Rest to leave Base with the minimal expression that provides a pointer operand suitable for a GEP expansion.

Definition at line 804 of file ScalarEvolutionExpander.cpp.

References llvm::ARM_PROC::A, llvm::SmallVectorTemplateCommon< T, typename >::back(), llvm::SCEV::FlagNW, llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getAddRecExpr(), and llvm::ScalarEvolution::getConstant().

static bool FactorOutConstant ( const SCEV *&  S,
const SCEV *&  Remainder,
const SCEV Factor,
ScalarEvolution SE,
const DataLayout DL 
)
static

FactorOutConstant - Test if S is divisible by Factor, using signed division.

If so, update S with Factor divided out and return true. S need not be evenly divisible if a reasonable remainder can be computed. TODO: When ScalarEvolution gets a SCEVSDivExpr, this can be made unnecessary; in its place, just signed-divide Ops[i] by the scale and check to see if the divide was folded.

Definition at line 211 of file ScalarEvolutionExpander.cpp.

References llvm::ARM_PROC::A, R600_InstFlag::FC, llvm::SCEV::FlagNW, llvm::ConstantInt::get(), llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getAddRecExpr(), llvm::ScalarEvolution::getConstant(), llvm::ScalarEvolution::getContext(), llvm::ScalarEvolution::getMulExpr(), llvm::SCEV::getType(), llvm::SCEVConstant::getValue(), llvm::ConstantInt::getValue(), llvm::SCEV::isOne(), llvm::SCEV::isZero(), and llvm::ConstantInt::isZero().

static void hoistBeforePos ( DominatorTree DT,
Instruction InstToHoist,
Instruction Pos,
PHINode LoopPhi 
)
static

Hoist the addrec instruction chain rooted in the loop phi above the position.

This routine assumes that this is possible (has been checked).

Definition at line 991 of file ScalarEvolutionExpander.cpp.

References llvm::DominatorTree::dominates(), llvm::User::getOperand(), and llvm::Instruction::moveBefore().

static bool IsIncrementNSW ( ScalarEvolution SE,
const SCEVAddRecExpr AR 
)
static
static bool IsIncrementNUW ( ScalarEvolution SE,
const SCEVAddRecExpr AR 
)
static
static const Loop* PickMostRelevantLoop ( const Loop A,
const Loop B,
DominatorTree DT 
)
static

PickMostRelevantLoop - Given two loops pick the one that's most relevant for SCEV expansion.

If they are nested, this is the most nested. If they are neighboring, pick the later.

Definition at line 581 of file ScalarEvolutionExpander.cpp.

References llvm::ARM_PROC::A, llvm::LoopBase< N, M >::contains(), llvm::DominatorTree::dominates(), and llvm::LoopBase< N, M >::getHeader().

static void SimplifyAddOperands ( SmallVectorImpl< const SCEV * > &  Ops,
Type Ty,
ScalarEvolution SE 
)
static
static void SplitAddRecs ( SmallVectorImpl< const SCEV * > &  Ops,
Type Ty,
ScalarEvolution SE 
)
static

SplitAddRecs - Flatten a list of add operands, moving addrec start values out to the top level.

For example, convert {a + b,+,c} to a, b, {0,+,d}. This helps expose more opportunities for folding parts of the expressions into GEP indices.

Definition at line 318 of file ScalarEvolutionExpander.cpp.

References llvm::ARM_PROC::A, llvm::SmallVectorImpl< T >::append(), llvm::SmallVectorTemplateCommon< T >::begin(), llvm::SmallVectorBase::empty(), llvm::SmallVectorTemplateCommon< T >::end(), llvm::SCEV::FlagNW, llvm::ScalarEvolution::getAddRecExpr(), llvm::ScalarEvolution::getConstant(), llvm::SCEV::isZero(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), SimplifyAddOperands(), and llvm::SmallVectorTemplateCommon< T >::size().