LLVM: lib/Transforms/Scalar/ConstraintElimination.cpp File Reference

LLVM 16.0.0git

#include "llvm/Transforms/Scalar/ConstraintElimination.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstraintSystem.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/DebugCounter.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Transforms/Scalar.h"
#include <cmath>
#include <string>

Include dependency graph for ConstraintElimination.cpp:

Go to the source code of this file.

Macros
#define	DEBUG_TYPE "constraint-elimination"

Functions
	STATISTIC (NumCondsRemoved, "Number of instructions removed")

	DEBUG_COUNTER (EliminatedCounter, "conds-eliminated", "Controls which conditions are eliminated")

static int64_t	multiplyWithOverflow (int64_t A, int64_t B)

static int64_t	addWithOverflow (int64_t A, int64_t B)

static Decomposition	decompose (Value *V, SmallVectorImpl< PreconditionTy > &Preconditions, bool IsSigned, const DataLayout &DL)

static bool	canUseSExt (ConstantInt *CI)

static Decomposition	decomposeGEP (GetElementPtrInst &GEP, SmallVectorImpl< PreconditionTy > &Preconditions, bool IsSigned, const DataLayout &DL)

static void	dumpWithNames (const ConstraintSystem &CS, DenseMap< Value *, unsigned > &Value2Index)

static void	dumpWithNames (ArrayRef< int64_t > C, DenseMap< Value *, unsigned > &Value2Index)

static bool	checkAndReplaceCondition (CmpInst *Cmp, ConstraintInfo &Info)

static bool	replaceSubOverflowUses (IntrinsicInst II, Value A, Value B, SmallVectorImpl< Instruction > &ToRemove)

static bool	tryToSimplifyOverflowMath (IntrinsicInst II, ConstraintInfo &Info, SmallVectorImpl< Instruction > &ToRemove)

static bool	eliminateConstraints (Function &F, DominatorTree &DT)

	INITIALIZE_PASS_BEGIN (ConstraintElimination, "constraint-elimination", "Constraint Elimination", false, false) INITIALIZE_PASS_END(ConstraintElimination

Variables
static int64_t	MaxConstraintValue = std::numeric_limits<int64_t>::max()

static int64_t	MinSignedConstraintValue = std::numeric_limits<int64_t>::min()

constraint	elimination

constraint Constraint	Elimination

constraint Constraint	false

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "constraint-elimination"

Definition at line 42 of file ConstraintElimination.cpp.

Function Documentation

◆ addWithOverflow()

static int64_t addWithOverflow	(	int64_t	A,
		int64_t	B
	)

static

Definition at line 59 of file ConstraintElimination.cpp.

References llvm::AddOverflow(), and B.

◆ canUseSExt()

static bool canUseSExt ( ConstantInt * CI )

static

Definition at line 229 of file ConstraintElimination.cpp.

References llvm::ConstantInt::getValue(), MaxConstraintValue, MinSignedConstraintValue, llvm::APInt::sgt(), and llvm::APInt::slt().

Referenced by decompose().

◆ checkAndReplaceCondition()

static bool checkAndReplaceCondition	(	CmpInst *	Cmp,
		ConstraintInfo &	Info
	)

static

Definition at line 740 of file ConstraintElimination.cpp.

References B, llvm::dbgs(), dumpWithNames(), llvm::ConstantInt::getFalse(), llvm::ConstantInt::getTrue(), llvm::Use::getUser(), I, Info, LLVM_DEBUG, llvm::make_scope_exit(), llvm::CmpInst::makeCmpResultType(), llvm::ConstraintSystem::negate(), and llvm::DebugCounter::shouldExecute().

◆ DEBUG_COUNTER()

DEBUG_COUNTER	(	EliminatedCounter	,
		"conds-eliminated"	,
		"Controls which conditions are eliminated"
	)

◆ decompose()

static Decomposition decompose	(	Value *	V,
		SmallVectorImpl< PreconditionTy > &	Preconditions,
		bool	IsSigned,
		const DataLayout &	DL
	)

static

◆ decomposeGEP()

static Decomposition decomposeGEP	(	GetElementPtrInst &	GEP,
		SmallVectorImpl< PreconditionTy > &	Preconditions,
		bool	IsSigned,
		const DataLayout &	DL
	)

static

Definition at line 235 of file ConstraintElimination.cpp.

References llvm::BitWidth, decompose(), DL, llvm::SmallVectorImpl< T >::emplace_back(), GEP, llvm::gep_type_begin(), llvm::ConstantInt::get(), llvm::APInt::getSExtValue(), llvm::CmpInst::ICMP_SGE, llvm::isKnownNonNegative(), llvm::MaxAnalysisRecursionDepth, and multiplyWithOverflow().

Referenced by decompose().

◆ dumpWithNames() [1/2]

static void dumpWithNames	(	ArrayRef< int64_t >	C,
		DenseMap< Value *, unsigned > &	Value2Index
	)

static

Definition at line 643 of file ConstraintElimination.cpp.

References llvm::ConstraintSystem::addVariableRowFill(), and dumpWithNames().

◆ dumpWithNames() [2/2]

static void dumpWithNames	(	const ConstraintSystem &	CS,
		DenseMap< Value *, unsigned > &	Value2Index
	)

static

Definition at line 634 of file ConstraintElimination.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::size().

Referenced by checkAndReplaceCondition(), and dumpWithNames().

◆ eliminateConstraints()

static bool eliminateConstraints	(	Function &	F,
		DominatorTree &	DT
	)

static

Definition at line 912 of file ConstraintElimination.cpp.

References B, BB, F, llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), Info, S, llvm::stable_sort(), and llvm::DominatorTreeBase< NodeT, IsPostDom >::updateDFSNumbers().

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

◆ INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	ConstraintElimination	,
		"constraint-elimination"	,
		"Constraint Elimination"	,
		false	,
		false
	)

◆ multiplyWithOverflow()

static int64_t multiplyWithOverflow	(	int64_t	A,
		int64_t	B
	)

static

Definition at line 52 of file ConstraintElimination.cpp.

References B, and llvm::MulOverflow().

Referenced by decomposeGEP().

◆ replaceSubOverflowUses()

static bool replaceSubOverflowUses	(	IntrinsicInst *	II,
		Value *	A,
		Value *	B,
		SmallVectorImpl< Instruction * > &	ToRemove
	)

static

Definition at line 852 of file ConstraintElimination.cpp.

References B, Builder, llvm::Instruction::eraseFromParent(), llvm::PoisonValue::get(), llvm::ilist_node_impl< OptionsT >::getIterator(), llvm::Instruction::getParent(), llvm::Value::getType(), I, llvm::PatternMatch::m_Value(), llvm::make_early_inc_range(), llvm::PatternMatch::match(), ToRemove, llvm::Value::use_empty(), and llvm::Value::users().

Referenced by tryToSimplifyOverflowMath().

◆ STATISTIC()

STATISTIC	(	NumCondsRemoved	,
		"Number of instructions removed"
	)

◆ tryToSimplifyOverflowMath()

static bool tryToSimplifyOverflowMath	(	IntrinsicInst *	II,
		ConstraintInfo &	Info,
		SmallVectorImpl< Instruction * > &	ToRemove
	)

static

Definition at line 885 of file ConstraintElimination.cpp.

References B, llvm::ConstantInt::get(), llvm::CallBase::getArgOperand(), llvm::IntrinsicInst::getIntrinsicID(), llvm::CmpInst::ICMP_SGE, Info, replaceSubOverflowUses(), and ToRemove.

Variable Documentation

◆ elimination

constraint elimination

Definition at line 1071 of file ConstraintElimination.cpp.

◆ Elimination

constraint Constraint Elimination

Definition at line 1072 of file ConstraintElimination.cpp.

◆ false

constraint Constraint false

Definition at line 1072 of file ConstraintElimination.cpp.

◆ MaxConstraintValue

int64_t MaxConstraintValue = std::numeric_limits<int64_t>::max()

static

Definition at line 48 of file ConstraintElimination.cpp.

Referenced by canUseSExt(), and decompose().

◆ MinSignedConstraintValue

int64_t MinSignedConstraintValue = std::numeric_limits<int64_t>::min()

static

Definition at line 49 of file ConstraintElimination.cpp.

Referenced by canUseSExt().