LoopConstrainer.cpp File Reference

#include "llvm/Transforms/Utils/LoopConstrainer.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/IR/Dominators.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/LoopSimplify.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "loop-constrainer"

Functions
static bool	isLoopEntryGuardedByCond (ScalarEvolution &SE, Loop *L, ICmpInst::Predicate Pred, const SCEV *Start, const SCEV *Bound)
static bool	isSafeDecreasingBound (const SCEV *Start, const SCEV *BoundSCEV, const SCEV *Step, ICmpInst::Predicate Pred, unsigned LatchBrExitIdx, Loop *L, ScalarEvolution &SE)
	Given a loop with an deccreasing induction variable, is it possible to safely calculate the bounds of a new loop using the given Predicate.
static bool	isSafeIncreasingBound (const SCEV *Start, const SCEV *BoundSCEV, const SCEV *Step, ICmpInst::Predicate Pred, unsigned LatchBrExitIdx, Loop *L, ScalarEvolution &SE)
	Given a loop with an increasing induction variable, is it possible to safely calculate the bounds of a new loop using the given Predicate.
static const SCEV *	getNarrowestLatchMaxTakenCountEstimate (ScalarEvolution &SE, const Loop &L)
	Returns estimate for max latch taken count of the loop of the narrowest available type.
static void	DisableAllLoopOptsOnLoop (Loop &L)

Variables
static const char *	ClonedLoopTag = "loop_constrainer.loop.clone"

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "loop-constrainer"

Definition at line 15 of file LoopConstrainer.cpp.

Function Documentation

DisableAllLoopOptsOnLoop()

void DisableAllLoopOptsOnLoop ( Loop & L )

static

Definition at line 439 of file LoopConstrainer.cpp.

References llvm::ConstantAsMetadata::get(), llvm::MDNode::get(), llvm::MDString::get(), llvm::Type::getInt1Ty(), and llvm::MDNode::replaceOperandWith().

Referenced by llvm::LoopConstrainer::run().

getNarrowestLatchMaxTakenCountEstimate()

const SCEV * getNarrowestLatchMaxTakenCountEstimate ( ScalarEvolution & SE, const Loop & L )

static

Returns estimate for max latch taken count of the loop of the narrowest available type.

If the latch block has such estimate, it is returned. Otherwise, we use max exit count of whole loop (that is potentially of wider type than latch check itself), which is still better than no estimate.

Definition at line 121 of file LoopConstrainer.cpp.

References llvm::ScalarEvolution::getExitCount(), llvm::ScalarEvolution::getSymbolicMaxBackedgeTakenCount(), llvm::isa(), and llvm::ScalarEvolution::SymbolicMaximum.

Referenced by llvm::LoopStructure::parseLoopStructure().

isLoopEntryGuardedByCond()

bool isLoopEntryGuardedByCond ( ScalarEvolution & SE, Loop * L, ICmpInst::Predicate Pred, const SCEV * Start, const SCEV * Bound )

static

Definition at line 17 of file LoopConstrainer.cpp.

References llvm::ScalarEvolution::applyLoopGuards(), and llvm::ScalarEvolution::isLoopEntryGuardedByCond().

Referenced by isSafeDecreasingBound(), and isSafeIncreasingBound().

isSafeDecreasingBound()

bool isSafeDecreasingBound ( const SCEV * Start, const SCEV * BoundSCEV, const SCEV * Step, ICmpInst::Predicate Pred, unsigned LatchBrExitIdx, Loop * L, ScalarEvolution & SE )

static

Given a loop with an deccreasing induction variable, is it possible to safely calculate the bounds of a new loop using the given Predicate.

Definition at line 31 of file LoopConstrainer.cpp.

References assert(), llvm::BitWidth, llvm::cast(), llvm::dbgs(), llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getConstant(), llvm::ScalarEvolution::getMinusSCEV(), llvm::APInt::getMinValue(), llvm::ScalarEvolution::getOne(), llvm::APInt::getSignedMinValue(), llvm::SCEV::getType(), llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::ScalarEvolution::isAvailableAtLoopEntry(), llvm::ScalarEvolution::isKnownNegative(), isLoopEntryGuardedByCond(), llvm::CmpInst::isSigned(), and LLVM_DEBUG.

Referenced by llvm::LoopStructure::parseLoopStructure().

isSafeIncreasingBound()

bool isSafeIncreasingBound ( const SCEV * Start, const SCEV * BoundSCEV, const SCEV * Step, ICmpInst::Predicate Pred, unsigned LatchBrExitIdx, Loop * L, ScalarEvolution & SE )

static

Given a loop with an increasing induction variable, is it possible to safely calculate the bounds of a new loop using the given Predicate.

Definition at line 77 of file LoopConstrainer.cpp.

References assert(), llvm::BitWidth, llvm::cast(), llvm::dbgs(), llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getConstant(), llvm::APInt::getMaxValue(), llvm::ScalarEvolution::getMinusSCEV(), llvm::ScalarEvolution::getOne(), llvm::APInt::getSignedMaxValue(), llvm::SCEV::getType(), llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULT, llvm::ScalarEvolution::isAvailableAtLoopEntry(), isLoopEntryGuardedByCond(), llvm::CmpInst::isSigned(), and LLVM_DEBUG.

Referenced by llvm::LoopStructure::parseLoopStructure().

Variable Documentation

ClonedLoopTag

const char* ClonedLoopTag = "loop_constrainer.loop.clone"

static

Definition at line 13 of file LoopConstrainer.cpp.

Referenced by llvm::LoopStructure::parseLoopStructure().