ConstraintElimination.cpp File Reference

#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/Dominators.h"
#include "llvm/IR/Function.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 <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 SmallVector< std::pair< int64_t, Value * >, 4 >	decompose (Value *V, SmallVector< PreconditionTy, 4 > &Preconditions, bool IsSigned)
static ConstraintTy	getConstraint (CmpInst::Predicate Pred, Value *Op0, Value *Op1, const DenseMap< Value *, unsigned > &Value2Index, DenseMap< Value *, unsigned > &NewIndices)
	Turn a condition CmpI into a vector of constraints, using indices from Value2Index. More...
static ConstraintTy	getConstraint (CmpInst *Cmp, ConstraintInfo &Info, DenseMap< Value *, unsigned > &NewIndices)
static void	dumpWithNames (ConstraintTy &C, DenseMap< Value *, unsigned > &Value2Index)
static void	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 39 of file ConstraintElimination.cpp.

Function Documentation

DEBUG_COUNTER()

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

decompose()

static SmallVector<std::pair<int64_t, Value *>, 4> decompose ( Value *  V, SmallVector< PreconditionTy, 4 > &  Preconditions, bool  IsSigned  )

static

Definition at line 144 of file ConstraintElimination.cpp.

References llvm::SmallVectorImpl< T >::emplace_back(), GEP, llvm::ConstantInt::get(), llvm::ConstantInt::getSExtValue(), llvm::Value::getType(), llvm::ConstantInt::getZExtValue(), llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_UGE, llvm::ConstantInt::isNegative(), llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_ConstantInt(), llvm::PatternMatch::m_NSWAdd(), llvm::PatternMatch::m_NUWAdd(), llvm::PatternMatch::m_NUWShl(), llvm::PatternMatch::m_NUWSub(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::m_ZExt(), llvm::PatternMatch::match(), MaxConstraintValue, MinSignedConstraintValue, llvm::APInt::sgt(), llvm::APInt::slt(), and llvm::ConstantInt::uge().

Referenced by getConstraint().

dumpWithNames()

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

static

Definition at line 434 of file ConstraintElimination.cpp.

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

Referenced by eliminateConstraints().

eliminateConstraints()

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

static

Definition at line 570 of file ConstraintElimination.cpp.

References assert(), B, BB, llvm::count_if(), llvm::dbgs(), dumpWithNames(), E, llvm::SmallVectorImpl< T >::emplace_back(), F, getConstraint(), llvm::ConstantInt::getFalse(), llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), llvm::ConstantInt::getTrue(), I, Info, llvm::CmpInst::isSigned(), LLVM_DEBUG, llvm::make_early_inc_range(), llvm::make_scope_exit(), llvm::ConstraintSystem::negate(), llvm::reverse(), S, llvm::DebugCounter::shouldExecute(), llvm::sort(), ToRemove, tryToSimplifyOverflowMath(), and llvm::DominatorTreeBase< NodeT, IsPostDom >::updateDFSNumbers().

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

getConstraint() [1/2]

static ConstraintTy getConstraint ( CmpInst *  Cmp, ConstraintInfo &  Info, DenseMap< Value *, unsigned > &  NewIndices  )

static

Definition at line 345 of file ConstraintElimination.cpp.

References getConstraint(), Info, and llvm::CmpInst::isSigned().

getConstraint() [2/2]

static ConstraintTy getConstraint ( CmpInst::Predicate  Pred, Value *  Op0, Value *  Op1, const DenseMap< Value *, unsigned > &  Value2Index, DenseMap< Value *, unsigned > &  NewIndices  )

static

Turn a condition CmpI into a vector of constraints, using indices from Value2Index.

Additional indices for newly discovered values are added to NewIndices.

Definition at line 246 of file ConstraintElimination.cpp.

References decompose(), llvm::drop_begin(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::CmpInst::getSwappedPredicate(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, Insert, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::CmpInst::isSigned(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::size(), llvm::Value::stripPointerCastsSameRepresentation(), and std::swap().

Referenced by eliminateConstraints(), getConstraint(), and tryToSimplifyOverflowMath().

INITIALIZE_PASS_BEGIN()

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

STATISTIC()

STATISTIC	(	NumCondsRemoved	,
		"Number of instructions removed"
	)

tryToSimplifyOverflowMath()

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

static

Definition at line 522 of file ConstraintElimination.cpp.

References B, Builder, llvm::Instruction::eraseFromParent(), llvm::ConstantInt::get(), llvm::PoisonValue::get(), llvm::CallBase::getArgOperand(), getConstraint(), llvm::IntrinsicInst::getIntrinsicID(), llvm::ilist_node_impl< OptionsT >::getIterator(), llvm::Instruction::getParent(), llvm::Value::getType(), I, llvm::CmpInst::ICMP_SGE, Info, llvm::CmpInst::isSigned(), llvm::PatternMatch::m_Value(), llvm::make_early_inc_range(), llvm::PatternMatch::match(), ToRemove, llvm::Value::use_empty(), and llvm::Value::users().

Referenced by eliminateConstraints().

Variable Documentation

elimination

constraint elimination

Definition at line 806 of file ConstraintElimination.cpp.

Elimination

constraint Constraint Elimination

Definition at line 807 of file ConstraintElimination.cpp.

false

constraint Constraint false

Definition at line 807 of file ConstraintElimination.cpp.

MaxConstraintValue

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

static

Definition at line 45 of file ConstraintElimination.cpp.

Referenced by decompose().

MinSignedConstraintValue

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

static

Definition at line 46 of file ConstraintElimination.cpp.

Referenced by decompose().