LoopPredication.cpp File Reference

#include "llvm/Transforms/Scalar/LoopPredication.h"
#include "ScalarOptions.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/GuardUtils.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/MemorySSA.h"
#include "llvm/Analysis/MemorySSAUpdater.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/ProfDataUtils.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/GuardUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
#include <optional>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "loop-predication"

Functions
	STATISTIC (TotalConsidered, "Number of guards considered")
	STATISTIC (TotalWidened, "Number of checks widened")
static bool	isSafeToTruncateWideIVType (const ScalarOptions &Opts, const DataLayout &DL, ScalarEvolution &SE, const LoopICmp LatchCheck, Type *RangeCheckType)
static std::optional< LoopICmp >	generateLoopLatchCheck (const ScalarOptions &Opts, const DataLayout &DL, ScalarEvolution &SE, const LoopICmp LatchCheck, Type *RangeCheckType)
static void	normalizePredicate (ScalarEvolution *SE, Loop *L, LoopICmp &RC)
static CondBrInst *	FindWidenableTerminatorAboveLoop (Loop *L, LoopInfo &LI)
	If we can (cheaply) find a widenable branch which controls entry into the loop, return it.
static const SCEV *	getMinAnalyzeableBackedgeTakenCount (ScalarEvolution &SE, DominatorTree &DT, Loop *L)
	Return the minimum of all analyzeable exit counts.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "loop-predication"

Definition at line 205 of file LoopPredication.cpp.

Function Documentation

FindWidenableTerminatorAboveLoop()

CondBrInst * FindWidenableTerminatorAboveLoop ( Loop * L, LoopInfo & LI )

static

If we can (cheaply) find a widenable branch which controls entry into the loop, return it.

Definition at line 947 of file LoopPredication.cpp.

References llvm::dyn_cast(), llvm::BasicBlock::getSinglePredecessor(), llvm::BasicBlock::getSingleSuccessor(), llvm::CondBrInst::getSuccessor(), and llvm::isWidenableBranch().

generateLoopLatchCheck()

std::optional< LoopICmp > generateLoopLatchCheck ( const ScalarOptions & Opts, const DataLayout & DL, ScalarEvolution & SE, const LoopICmp LatchCheck, Type * RangeCheckType )

static

Definition at line 417 of file LoopPredication.cpp.

References llvm::dbgs(), DL, llvm::dyn_cast(), llvm::ScalarEvolution::getTruncateExpr(), llvm::SCEV::getType(), isSafeToTruncateWideIVType(), and LLVM_DEBUG.

getMinAnalyzeableBackedgeTakenCount()

const SCEV * getMinAnalyzeableBackedgeTakenCount ( ScalarEvolution & SE, DominatorTree & DT, Loop * L )

static

Return the minimum of all analyzeable exit counts.

This is an upper bound on the actual exit count. If there are not at least two analyzeable exits, returns SCEVCouldNotCompute.

Definition at line 977 of file LoopPredication.cpp.

References assert(), llvm::DominatorTree::dominates(), llvm::ScalarEvolution::getCouldNotCompute(), llvm::ScalarEvolution::getExitCount(), llvm::ScalarEvolution::getUMinFromMismatchedTypes(), llvm::isa(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::SmallVectorTemplateCommon< T, typename >::size().

isSafeToTruncateWideIVType()

bool isSafeToTruncateWideIVType ( const ScalarOptions & Opts, const DataLayout & DL, ScalarEvolution & SE, const LoopICmp LatchCheck, Type * RangeCheckType )

static

Definition at line 382 of file LoopPredication.cpp.

References assert(), DL, llvm::dyn_cast(), llvm::ScalarEvolution::getMonotonicPredicateType(), llvm::SCEVAddRecExpr::getStart(), and llvm::SCEV::getType().

Referenced by generateLoopLatchCheck().

normalizePredicate()

void normalizePredicate ( ScalarEvolution * SE, Loop * L, LoopICmp & RC )

static

Definition at line 611 of file LoopPredication.cpp.

References llvm::SCEVAddRecExpr::getStart(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::ICmpInst::isEquality(), llvm::ScalarEvolution::isKnownPredicate(), and llvm::SCEV::isOne().

STATISTIC() [1/2]

STATISTIC	(	TotalConsidered	,
		"Number of guards considered"	)

STATISTIC() [2/2]

STATISTIC	(	TotalWidened	,
		"Number of checks widened"	)

References IV.