#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/NoFolder.h"
#include "llvm/Support/PatternMatch.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include <algorithm>
#include <map>
#include <set>

Include dependency graph for SimplifyCFG.cpp:

Macros
#define	DEBUG_TYPE "simplifycfg"

Functions
	STATISTIC (NumBitMaps,"Number of switch instructions turned into bitmaps")

	STATISTIC (NumLookupTables,"Number of switch instructions turned into lookup tables")

	STATISTIC (NumSinkCommons,"Number of common instructions sunk down to the end block")

	STATISTIC (NumSpeculations,"Number of speculative executed instructions")

static bool	SafeToMergeTerminators (TerminatorInst SI1, TerminatorInst SI2)

static bool	isProfitableToFoldUnconditional (BranchInst SI1, BranchInst SI2, Instruction Cond, SmallVectorImpl< PHINode > &PhiNodes)

static void	AddPredecessorToBlock (BasicBlock Succ, BasicBlock NewPred, BasicBlock *ExistPred)

static unsigned	ComputeSpeculationCost (const User *I)

static bool	DominatesMergePoint (Value V, BasicBlock BB, SmallPtrSet< Instruction , 4 > AggressiveInsts, unsigned &CostRemaining)

static ConstantInt *	GetConstantInt (Value V, const DataLayout TD)

static Value *	GatherConstantCompares (Value V, std::vector< ConstantInt > &Vals, Value &Extra, const DataLayout TD, bool isEQ, unsigned &UsedICmps)

static void	EraseTerminatorInstAndDCECond (TerminatorInst *TI)

static void	EliminateBlockCases (BasicBlock *BB, std::vector< ValueEqualityComparisonCase > &Cases)

static bool	ValuesOverlap (std::vector< ValueEqualityComparisonCase > &C1, std::vector< ValueEqualityComparisonCase > &C2)

static int	ConstantIntSortPredicate (ConstantInt const P1, ConstantInt const P2)

static bool	HasBranchWeights (const Instruction *I)

static void	GetBranchWeights (TerminatorInst *TI, SmallVectorImpl< uint64_t > &Weights)

static void	FitWeights (MutableArrayRef< uint64_t > Weights)

static bool	isSafeToHoistInvoke (BasicBlock BB1, BasicBlock BB2, Instruction I1, Instruction I2)

static bool	HoistThenElseCodeToIf (BranchInst *BI)

static bool	SinkThenElseCodeToEnd (BranchInst *BI1)

static Value *	isSafeToSpeculateStore (Instruction I, BasicBlock BrBB, BasicBlock StoreBB, BasicBlock EndBB)
	Determine if we can hoist sink a sole store instruction out of a conditional block. More...

static bool	SpeculativelyExecuteBB (BranchInst BI, BasicBlock ThenBB)
	Speculate a conditional basic block flattening the CFG. More...

static bool	HasNoDuplicateCall (const BasicBlock *BB)

static bool	BlockIsSimpleEnoughToThreadThrough (BasicBlock *BB)

static bool	FoldCondBranchOnPHI (BranchInst BI, const DataLayout TD)

static bool	FoldTwoEntryPHINode (PHINode PN, const DataLayout TD)

static bool	SimplifyCondBranchToTwoReturns (BranchInst *BI, IRBuilder<> &Builder)

static bool	ExtractBranchMetadata (BranchInst *BI, uint64_t &ProbTrue, uint64_t &ProbFalse)

static bool	checkCSEInPredecessor (Instruction Inst, BasicBlock PB)

static bool	SimplifyCondBranchToCondBranch (BranchInst PBI, BranchInst BI)

static bool	SimplifyTerminatorOnSelect (TerminatorInst OldTerm, Value Cond, BasicBlock TrueBB, BasicBlock FalseBB, uint32_t TrueWeight, uint32_t FalseWeight)

static bool	SimplifySwitchOnSelect (SwitchInst SI, SelectInst Select)

static bool	SimplifyIndirectBrOnSelect (IndirectBrInst IBI, SelectInst SI)

static bool	TryToSimplifyUncondBranchWithICmpInIt (ICmpInst ICI, IRBuilder<> &Builder, const TargetTransformInfo &TTI, const DataLayout TD)

static bool	SimplifyBranchOnICmpChain (BranchInst BI, const DataLayout TD, IRBuilder<> &Builder)

static bool	TurnSwitchRangeIntoICmp (SwitchInst *SI, IRBuilder<> &Builder)

static bool	EliminateDeadSwitchCases (SwitchInst *SI)

static PHINode *	FindPHIForConditionForwarding (ConstantInt CaseValue, BasicBlock BB, int *PhiIndex)

static bool	ForwardSwitchConditionToPHI (SwitchInst *SI)

static bool	ValidLookupTableConstant (Constant *C)

static Constant *	LookupConstant (Value V, const SmallDenseMap< Value , Constant * > &ConstantPool)

static Constant *	ConstantFold (Instruction I, const SmallDenseMap< Value , Constant * > &ConstantPool, const DataLayout *DL)

static bool	GetCaseResults (SwitchInst SI, ConstantInt CaseVal, BasicBlock CaseDest, BasicBlock CommonDest, SmallVectorImpl< std::pair< PHINode , Constant * > > &Res, const DataLayout *DL)

static bool	ShouldBuildLookupTable (SwitchInst SI, uint64_t TableSize, const TargetTransformInfo &TTI, const DataLayout TD, const SmallDenseMap< PHINode , Type > &ResultTypes)

static bool	SwitchToLookupTable (SwitchInst SI, IRBuilder<> &Builder, const TargetTransformInfo &TTI, const DataLayout TD)

static bool	passingValueIsAlwaysUndefined (Value V, Instruction I)
	Check if passing a value to an instruction will cause undefined behavior. More...

static bool	removeUndefIntroducingPredecessor (BasicBlock *BB)

Variables
static cl::opt< unsigned >	PHINodeFoldingThreshold ("phi-node-folding-threshold", cl::Hidden, cl::init(1), cl::desc("Control the amount of phi node folding to perform (default = 1)"))

static cl::opt< bool >	DupRet ("simplifycfg-dup-ret", cl::Hidden, cl::init(false), cl::desc("Duplicate return instructions into unconditional branches"))

static cl::opt< bool >	SinkCommon ("simplifycfg-sink-common", cl::Hidden, cl::init(true), cl::desc("Sink common instructions down to the end block"))

static cl::opt< bool >	HoistCondStores ("simplifycfg-hoist-cond-stores", cl::Hidden, cl::init(true), cl::desc("Hoist conditional stores if an unconditional store preceeds"))

Macro Definition Documentation

#define DEBUG_TYPE "simplifycfg"

Definition at line 14 of file SimplifyCFG.cpp.

Function Documentation

static void AddPredecessorToBlock	(	BasicBlock *	Succ,
		BasicBlock *	NewPred,
		BasicBlock *	ExistPred
	)

static

AddPredecessorToBlock - Update PHI nodes in Succ to indicate that there will now be entries in it from the 'NewPred' block. The values that will be flowing into the PHI nodes will be the same as those coming in from ExistPred, an existing predecessor of Succ.

Definition at line 189 of file SimplifyCFG.cpp.

References llvm::PHINode::addIncoming(), llvm::BasicBlock::begin(), llvm::dyn_cast(), llvm::PHINode::getIncomingValueForBlock(), and I.

Referenced by llvm::FoldBranchToCommonDest(), FoldCondBranchOnPHI(), HoistThenElseCodeToIf(), SimplifyBranchOnICmpChain(), and SimplifyCondBranchToCondBranch().

static bool BlockIsSimpleEnoughToThreadThrough ( BasicBlock * BB )

static

BlockIsSimpleEnoughToThreadThrough - Return true if we can thread a branch across this block.

Definition at line 1580 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::Instruction::getParent(), and llvm::BasicBlock::getTerminator().

Referenced by FoldCondBranchOnPHI(), and SimplifyCondBranchToCondBranch().

static bool checkCSEInPredecessor	(	Instruction *	Inst,
		BasicBlock *	PB
	)

static

checkCSEInPredecessor - Return true if the given instruction is available in its predecessor block. If yes, the instruction will be removed.

Definition at line 1949 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::BasicBlock::end(), llvm::Instruction::eraseFromParent(), I, llvm::Instruction::isIdenticalTo(), and llvm::Value::replaceAllUsesWith().

Referenced by llvm::FoldBranchToCommonDest().

static unsigned ComputeSpeculationCost ( const User * I )

static

ComputeSpeculationCost - Compute an abstract "cost" of speculating the given instruction, which is assumed to be safe to speculate. 1 means cheap, 2 means less cheap, and UINT_MAX means prohibitively expensive.

Definition at line 202 of file SimplifyCFG.cpp.

References llvm::APIntOps::And(), llvm::Call, llvm::Operator::getOpcode(), llvm::isSafeToSpeculativelyExecute(), llvm::SPII::Load, llvm::APIntOps::Or(), llvm::MCID::Select, and llvm::APIntOps::Xor().

Referenced by DominatesMergePoint(), and SpeculativelyExecuteBB().

static Constant* ConstantFold	(	Instruction *	I,
		const SmallDenseMap< Value , Constant > &	ConstantPool,
		const DataLayout *	DL
	)

static

ConstantFold - Try to fold instruction I into a constant. This works for simple instructions such as binary operations where both operands are constant or can be replaced by constants from the ConstantPool. Returns the resulting constant on success, 0 otherwise.

Definition at line 3333 of file SimplifyCFG.cpp.

References llvm::ARM_PROC::A, llvm::ConstantFoldCompareInstOperands(), llvm::ConstantFoldInstOperands(), llvm::ISD::ConstantPool, llvm::User::getNumOperands(), llvm::Instruction::getOpcode(), llvm::User::getOperand(), llvm::Value::getType(), llvm::Constant::isAllOnesValue(), llvm::Constant::isNullValue(), LookupConstant(), N, llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), and llvm::MCID::Select.

Referenced by GetCaseResults().

static int ConstantIntSortPredicate	(	ConstantInt const	P1,
		ConstantInt const	P2
	)

static

Definition at line 707 of file SimplifyCFG.cpp.

References llvm::ConstantInt::getValue(), and llvm::APInt::ult().

Referenced by SimplifyBranchOnICmpChain(), and TurnSwitchRangeIntoICmp().

static bool DominatesMergePoint	(	Value *	V,
		BasicBlock *	BB,
		SmallPtrSet< Instruction , 4 >	AggressiveInsts,
		unsigned &	CostRemaining
	)

static

DominatesMergePoint - If we have a merge point of an "if condition" as accepted above, return true if the specified value dominates the block. We don't handle the true generality of domination here, just a special case which works well enough for us.

If AggressiveInsts is non-null, and if V does not dominate BB, we check to see if V (which must be an instruction) and its recursive operands that do not dominate BB have a combined cost lower than CostRemaining and are non-trapping. If both are true, the instruction is inserted into the set and true is returned.

The cost for most non-trapping instructions is defined as 1 except for Select whose cost is 2.

After this function returns, CostRemaining is decreased by the cost of V plus its non-dominating operands. If that cost is greater than CostRemaining, false is returned and CostRemaining is undefined.

Definition at line 252 of file SimplifyCFG.cpp.

References llvm::CallingConv::C, ComputeSpeculationCost(), llvm::SmallPtrSet< PtrType, SmallSize >::count(), llvm::dyn_cast(), llvm::Instruction::getParent(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), I, llvm::SmallPtrSet< PtrType, SmallSize >::insert(), llvm::BranchInst::isConditional(), llvm::isSafeToSpeculativelyExecute(), llvm::User::op_begin(), and llvm::User::op_end().

Referenced by FoldTwoEntryPHINode().

static void EliminateBlockCases	(	BasicBlock *	BB,
		std::vector< ValueEqualityComparisonCase > &	Cases
	)

static

EliminateBlockCases - Given a vector of bb/value pairs, remove any entries in the list that match the specified block.

Definition at line 515 of file SimplifyCFG.cpp.

References llvm::LibFunc::remove.

static bool EliminateDeadSwitchCases ( SwitchInst * SI )

static

EliminateDeadSwitchCases - Compute masked bits for the condition of a switch and use it to remove dead cases.

Definition at line 3187 of file SimplifyCFG.cpp.

static void EraseTerminatorInstAndDCECond ( TerminatorInst * TI )

static

Definition at line 447 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), and llvm::RecursivelyDeleteTriviallyDeadInstructions().

Referenced by llvm::FoldBranchToCommonDest(), HoistThenElseCodeToIf(), SimplifyBranchOnICmpChain(), SimplifyCondBranchToTwoReturns(), and SimplifyTerminatorOnSelect().

static bool ExtractBranchMetadata	(	BranchInst *	BI,
		uint64_t &	ProbTrue,
		uint64_t &	ProbFalse
	)

static

ExtractBranchMetadata - Given a conditional BranchInstruction, retrieve the probabilities of the branch taking each edge. Fills in the two APInt parameters and return true, or returns false if no or invalid metadata was found.

Definition at line 1932 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::Instruction::getMetadata(), llvm::ConstantInt::getValue(), llvm::APInt::getZExtValue(), llvm::BranchInst::isConditional(), and llvm::LLVMContext::MD_prof.

Referenced by llvm::FoldBranchToCommonDest(), and SimplifyCondBranchToCondBranch().

static PHINode* FindPHIForConditionForwarding	(	ConstantInt *	CaseValue,
		BasicBlock *	BB,
		int *	PhiIndex
	)

static

FindPHIForConditionForwarding - If BB would be eligible for simplification by TryToSimplifyUncondBranchFromEmptyBlock (i.e. it is empty and terminated by an unconditional branch), look at the phi node for BB in the successor block and see if the incoming value is equal to CaseValue. If so, return the phi node, and set PhiIndex to BB's index in the phi node.

Definition at line 3240 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::MCID::Branch, llvm::dyn_cast(), llvm::BasicBlock::getFirstNonPHIOrDbg(), llvm::BasicBlock::getSinglePredecessor(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::BranchInst::isUnconditional(), and llvm::TargetOpcode::PHI.

Referenced by ForwardSwitchConditionToPHI().

static void FitWeights ( MutableArrayRef< uint64_t > Weights )

static

Sees if any of the weights are too big for a uint32_t, and halves all the weights if any are.

Definition at line 753 of file SimplifyCFG.cpp.

References llvm::ArrayRef< T >::size().

Referenced by llvm::FoldBranchToCommonDest(), and SimplifyCondBranchToCondBranch().

static bool FoldCondBranchOnPHI	(	BranchInst *	BI,
		const DataLayout *	TD
	)

static

FoldCondBranchOnPHI - If we have a conditional branch on a PHI node value that is defined in the same block as the branch and if any PHI entries are constants, thread edges corresponding to that entry to be branches to their ultimate destination.

Definition at line 1608 of file SimplifyCFG.cpp.

References AddPredecessorToBlock(), llvm::BasicBlock::begin(), BlockIsSimpleEnoughToThreadThrough(), llvm::BasicBlock::Create(), llvm::BranchInst::Create(), llvm::dyn_cast(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT >, KeyT, ValueT, KeyInfoT >::end(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT >, KeyT, ValueT, KeyInfoT >::find(), llvm::FoldSingleEntryPHINodes(), llvm::BranchInst::getCondition(), llvm::BasicBlock::getContext(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getIncomingValueForBlock(), llvm::BasicBlock::getInstList(), llvm::Value::getName(), llvm::PHINode::getNumIncomingValues(), llvm::TerminatorInst::getNumSuccessors(), llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), llvm::TerminatorInst::getSuccessor(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::ConstantInt::getType(), llvm::ConstantInt::getZExtValue(), HasNoDuplicateCall(), llvm::Value::hasOneUse(), llvm::iplist< NodeTy, Traits >::insert(), llvm::Type::isIntegerTy(), N, llvm::User::op_begin(), llvm::User::op_end(), llvm::BasicBlock::removePredecessor(), llvm::Value::setName(), llvm::TerminatorInst::setSuccessor(), and llvm::SimplifyInstruction().

static bool FoldTwoEntryPHINode	(	PHINode *	PN,
		const DataLayout *	TD
	)

static

FoldTwoEntryPHINode - Given a BB that starts with the specified two-entry PHI node, see if we can eliminate it.

Definition at line 1706 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::SmallPtrSet< PtrType, SmallSize >::count(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSelect(), llvm::dbgs(), DEBUG, DominatesMergePoint(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::GetIfCondition(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::BasicBlock::getInstList(), llvm::Value::getName(), llvm::Instruction::getParent(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), I, llvm::Type::isIntegerTy(), llvm::A64CC::NV, PHINodeFoldingThreshold, llvm::pred_begin(), llvm::Value::replaceAllUsesWith(), llvm::IRBuilderBase::SetInsertPoint(), llvm::SimplifyInstruction(), llvm::iplist< NodeTy, Traits >::splice(), and llvm::Value::takeName().

static bool ForwardSwitchConditionToPHI ( SwitchInst * SI )

static

ForwardSwitchConditionToPHI - Try to forward the condition of a switch instruction to a phi node dominated by the switch, if that would mean that some of the destination blocks of the switch can be folded away. Returns true if a change is made.

Definition at line 3273 of file SimplifyCFG.cpp.

References llvm::SwitchInst::case_begin(), llvm::SwitchInst::case_end(), FindPHIForConditionForwarding(), llvm::SwitchInst::getCondition(), I, llvm::TargetOpcode::PHI, llvm::PHINode::setIncomingValue(), and llvm::SmallVectorTemplateCommon< T, typename >::size().

static Value* GatherConstantCompares	(	Value *	V,
		std::vector< ConstantInt * > &	Vals,
		Value *&	Extra,
		const DataLayout *	TD,
		bool	isEQ,
		unsigned &	UsedICmps
	)

static

GatherConstantCompares - Given a potentially 'or'd or 'and'd together collection of icmp eq/ne instructions that compare a value against a constant, return the value being compared, and stick the constant into the Values vector.

Definition at line 342 of file SimplifyCFG.cpp.

References llvm::APIntOps::And(), llvm::CallingConv::C, llvm::dyn_cast(), llvm::ConstantInt::get(), GetConstantInt(), llvm::Value::getContext(), llvm::ConstantRange::getLower(), llvm::Instruction::getOpcode(), llvm::User::getOperand(), llvm::ConstantRange::getSetSize(), llvm::ConstantRange::getUpper(), llvm::ConstantInt::getValue(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::ConstantRange::inverse(), llvm::ConstantRange::isEmptySet(), llvm::APInt::isPowerOf2(), llvm::PatternMatch::m_Add(), llvm::PatternMatch::m_And(), llvm::PatternMatch::m_ConstantInt(), llvm::PatternMatch::m_Value(), llvm::ConstantRange::makeICmpRegion(), llvm::PatternMatch::match(), llvm::APIntOps::Not(), llvm::APIntOps::Or(), llvm::ConstantRange::subtract(), TD, and llvm::APInt::ugt().

Referenced by SimplifyBranchOnICmpChain().

static void GetBranchWeights	(	TerminatorInst *	TI,
		SmallVectorImpl< uint64_t > &	Weights
	)

static

Get Weights of a given TerminatorInst, the default weight is at the front of the vector. If TI is a conditional eq, we need to swap the branch-weight metadata.

Definition at line 730 of file SimplifyCFG.cpp.

References llvm::SmallVectorTemplateCommon< T >::back(), llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T >::front(), llvm::BranchInst::getCondition(), llvm::Instruction::getMetadata(), llvm::MDNode::getNumOperands(), llvm::MDNode::getOperand(), llvm::ConstantInt::getValue(), llvm::APInt::getZExtValue(), llvm::CmpInst::ICMP_EQ, llvm::LLVMContext::MD_prof, llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::SmallVectorTemplateCommon< T >::size(), and std::swap().

Referenced by EliminateDeadSwitchCases(), SimplifySwitchOnSelect(), TryToSimplifyUncondBranchWithICmpInIt(), and TurnSwitchRangeIntoICmp().

static bool GetCaseResults	(	SwitchInst *	SI,
		ConstantInt *	CaseVal,
		BasicBlock *	CaseDest,
		BasicBlock **	CommonDest,
		SmallVectorImpl< std::pair< PHINode , Constant > > &	Res,
		const DataLayout *	DL
	)

static

GetCaseResults - Try to determine the resulting constant values in phi nodes at the common destination basic block, *CommonDest, for one of the case destionations CaseDest corresponding to value CaseVal (0 for the default case), of a switch instruction SI.

Definition at line 3367 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::CallingConv::C, ConstantFold(), llvm::ISD::ConstantPool, llvm::BasicBlock::end(), llvm::SwitchInst::getCondition(), llvm::Instruction::getParent(), I, llvm::DenseMapBase< SmallDenseMap< KeyT, ValueT, InlineBuckets, KeyInfoT >, KeyT, ValueT, KeyInfoT >::insert(), LookupConstant(), llvm::TargetOpcode::PHI, and ValidLookupTableConstant().

Referenced by SwitchToLookupTable().

static ConstantInt* GetConstantInt	(	Value *	V,
		const DataLayout *	TD
	)

static

GetConstantInt - Extract ConstantInt from value, looking through IntToPtr and PointerNullValue. Return NULL if value is not a constant int.

Definition at line 309 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::ConstantInt::get(), llvm::ConstantExpr::getIntegerCast(), llvm::DataLayout::getIntPtrType(), llvm::Value::getType(), llvm::ConstantInt::getType(), and llvm::Type::isPointerTy().

Referenced by GatherConstantCompares().

static bool HasBranchWeights ( const Instruction * I )

inlinestatic

Definition at line 718 of file SimplifyCFG.cpp.

References llvm::Instruction::getMetadata(), llvm::MDNode::getOperand(), and llvm::LLVMContext::MD_prof.

Referenced by EliminateDeadSwitchCases(), SimplifySwitchOnSelect(), TryToSimplifyUncondBranchWithICmpInIt(), and TurnSwitchRangeIntoICmp().

static bool HasNoDuplicateCall ( const BasicBlock * BB )

static

Returns: True if this block contains a CallInst with the NoDuplicate attribute.

Definition at line 1567 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::CallInst::cannotDuplicate(), llvm::dyn_cast(), llvm::BasicBlock::end(), and I.

Referenced by FoldCondBranchOnPHI().

static bool HoistThenElseCodeToIf ( BranchInst * BI )

static

HoistThenElseCodeToIf - Given a conditional branch that goes to BB1 and BB2, hoist any common code in the two blocks up into the branch block. The caller of this function guarantees that BI's block dominates BB1 and BB2.

Definition at line 1002 of file SimplifyCFG.cpp.

References AddPredecessorToBlock(), llvm::BasicBlock::begin(), llvm::Instruction::clone(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSelect(), llvm::dyn_cast(), EraseTerminatorInstAndDCECond(), llvm::BranchInst::getCondition(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValueForBlock(), llvm::BasicBlock::getInstList(), llvm::Value::getName(), llvm::PHINode::getNumIncomingValues(), llvm::Instruction::getParent(), llvm::BranchInst::getSuccessor(), llvm::Value::getType(), llvm::iplist< NodeTy, Traits >::insert(), llvm::Value::intersectOptionalDataWith(), llvm::Instruction::isIdenticalToWhenDefined(), isSafeToHoistInvoke(), llvm::isSafeToSpeculativelyExecute(), llvm::Type::isVoidTy(), llvm::Value::replaceAllUsesWith(), llvm::PHINode::setIncomingValue(), llvm::iplist< NodeTy, Traits >::splice(), llvm::succ_begin(), llvm::succ_end(), and llvm::Value::takeName().

static bool isProfitableToFoldUnconditional	(	BranchInst *	SI1,
		BranchInst *	SI2,
		Instruction *	Cond,
		SmallVectorImpl< PHINode * > &	PhiNodes
	)

static

isProfitableToFoldUnconditional - Return true if it is safe and profitable to merge these two terminator instructions together, where SI1 is an unconditional branch. PhiNodes will store all PHI nodes in common successors.

Definition at line 149 of file SimplifyCFG.cpp.

References llvm::SmallPtrSet< PtrType, SmallSize >::count(), llvm::dyn_cast(), llvm::BranchInst::getCondition(), llvm::PHINode::getIncomingValueForBlock(), llvm::User::getOperand(), llvm::Instruction::getParent(), I, llvm::BranchInst::isConditional(), llvm::BranchInst::isUnconditional(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::succ_begin(), and llvm::succ_end().

Referenced by llvm::FoldBranchToCommonDest().

static bool isSafeToHoistInvoke	(	BasicBlock *	BB1,
		BasicBlock *	BB2,
		Instruction *	I1,
		Instruction *	I2
	)

static

Definition at line 983 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::PHINode::getIncomingValueForBlock(), llvm::succ_begin(), and llvm::succ_end().

Referenced by HoistThenElseCodeToIf().

static Value* isSafeToSpeculateStore	(	Instruction *	I,
		BasicBlock *	BrBB,
		BasicBlock *	StoreBB,
		BasicBlock *	EndBB
	)

static

Determine if we can hoist sink a sole store instruction out of a conditional block.

We are looking for code like the following: BrBB: store i32 add, i32* arrayidx2 ... // No other stores or function calls (we could be calling a memory ... // function). cmp = icmp ult x, y br i1 cmp, label EndBB, label ThenBB ThenBB: store i32 add5, i32* arrayidx2 br label EndBB EndBB: ... We are going to transform this into: BrBB: store i32 add, i32* arrayidx2 ... // cmp = icmp ult x, y add.add5 = select i1 cmp, i32 add, add5 store i32 add.add5, i32* arrayidx2 ...

Returns: The pointer to the value of the previous store if the store can be hoisted into the predecessor block. 0 otherwise.

Definition at line 1324 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::StoreInst::getPointerOperand(), llvm::StoreInst::getValueOperand(), I, llvm::StoreInst::isSimple(), llvm::Instruction::mayHaveSideEffects(), llvm::BasicBlock::rbegin(), and llvm::BasicBlock::rend().

Referenced by SpeculativelyExecuteBB().

static Constant* LookupConstant	(	Value *	V,
		const SmallDenseMap< Value , Constant > &	ConstantPool
	)

static

LookupConstant - If V is a Constant, return it. Otherwise, try to look up its constant value in ConstantPool, returning 0 if it's not there.

Definition at line 3321 of file SimplifyCFG.cpp.

References llvm::CallingConv::C, and llvm::DenseMapBase< SmallDenseMap< KeyT, ValueT, InlineBuckets, KeyInfoT >, KeyT, ValueT, KeyInfoT >::lookup().

Referenced by ConstantFold(), and GetCaseResults().

static bool passingValueIsAlwaysUndefined	(	Value *	V,
		Instruction *	I
	)

static

Check if passing a value to an instruction will cause undefined behavior.

Definition at line 4016 of file SimplifyCFG.cpp.

References llvm::CallingConv::C, llvm::dyn_cast(), llvm::BasicBlock::end(), llvm::Instruction::getParent(), I, llvm::Constant::isNullValue(), LI, llvm::Value::use_begin(), and llvm::Value::use_empty().

Referenced by removeUndefIntroducingPredecessor().

static bool removeUndefIntroducingPredecessor ( BasicBlock * BB )

static

If BB has an incoming value that will always trigger undefined behavior (eg. null pointer dereference), remove the branch leading here.

Definition at line 4058 of file SimplifyCFG.cpp.

References llvm::BasicBlock::begin(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateUnreachable(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::BranchInst::isUnconditional(), passingValueIsAlwaysUndefined(), llvm::TargetOpcode::PHI, and llvm::BasicBlock::removePredecessor().

static bool SafeToMergeTerminators	(	TerminatorInst *	SI1,
		TerminatorInst *	SI2
	)

static

SafeToMergeTerminators - Return true if it is safe to merge these two terminator instructions together.

Definition at line 121 of file SimplifyCFG.cpp.

References llvm::SmallPtrSet< PtrType, SmallSize >::count(), llvm::PHINode::getIncomingValueForBlock(), llvm::Instruction::getParent(), I, llvm::succ_begin(), and llvm::succ_end().

Referenced by llvm::FoldBranchToCommonDest().

static bool ShouldBuildLookupTable	(	SwitchInst *	SI,
		uint64_t	TableSize,
		const TargetTransformInfo &	TTI,
		const DataLayout *	TD,
		const SmallDenseMap< PHINode , Type > &	ResultTypes
	)

static

ShouldBuildLookupTable - Determine whether a lookup table should be built for this switch, based on the number of cases, size of the table and the types of the results.

Definition at line 3621 of file SimplifyCFG.cpp.

References llvm::DenseMapBase< SmallDenseMap< KeyT, ValueT, InlineBuckets, KeyInfoT >, KeyT, ValueT, KeyInfoT >::begin(), llvm::DenseMapBase< SmallDenseMap< KeyT, ValueT, InlineBuckets, KeyInfoT >, KeyT, ValueT, KeyInfoT >::end(), llvm::SwitchInst::getNumCases(), I, and llvm::TargetTransformInfo::isTypeLegal().

Referenced by SwitchToLookupTable().

static bool SimplifyBranchOnICmpChain	(	BranchInst *	BI,
		const DataLayout *	TD,
		IRBuilder<> &	Builder
	)

static

SimplifyBranchOnICmpChain - The specified branch is a conditional branch. Check to see if it is branching on an or/and chain of icmp instructions, and fold it into a switch instruction if so.

Definition at line 2733 of file SimplifyCFG.cpp.

References llvm::SwitchInst::addCase(), llvm::PHINode::addIncoming(), AddPredecessorToBlock(), llvm::APIntOps::And(), llvm::array_pod_sort(), llvm::BasicBlock::begin(), ConstantIntSortPredicate(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateCondBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreatePtrToInt(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSwitch(), llvm::dbgs(), DEBUG, llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), EraseTerminatorInstAndDCECond(), GatherConstantCompares(), llvm::BranchInst::getCondition(), llvm::PHINode::getIncomingValueForBlock(), llvm::DataLayout::getIntPtrType(), llvm::Instruction::getOpcode(), llvm::Instruction::getParent(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), llvm::Type::isPointerTy(), llvm::APIntOps::Or(), llvm::IRBuilderBase::SetInsertPoint(), llvm::BasicBlock::size(), llvm::BasicBlock::splitBasicBlock(), and std::swap().

static bool SimplifyCondBranchToCondBranch	(	BranchInst *	PBI,
		BranchInst *	BI
	)

static

SimplifyCondBranchToCondBranch - If we have a conditional branch as a predecessor of another block, this function tries to simplify it. We know that PBI and BI are both conditional branches, and BI is in one of the successor blocks of PBI - PBI branches to BI.

Definition at line 2290 of file SimplifyCFG.cpp.

References llvm::PHINode::addIncoming(), AddPredecessorToBlock(), llvm::StringRef::begin(), llvm::SmallVectorTemplateCommon< T >::begin(), llvm::BasicBlock::begin(), BlockIsSimpleEnoughToThreadThrough(), llvm::BasicBlock::Create(), llvm::PHINode::Create(), llvm::BranchInst::Create(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateNot(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateOr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSelect(), llvm::dbgs(), DEBUG, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T >::end(), ExtractBranchMetadata(), FitWeights(), llvm::ConstantInt::get(), llvm::BranchInst::getCondition(), llvm::Value::getContext(), llvm::PHINode::getIncomingValueForBlock(), llvm::Type::getInt1Ty(), llvm::Value::getName(), llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::BranchInst::isConditional(), llvm::LLVMContext::MD_prof, llvm::A64CC::NV, P, llvm::pred_begin(), llvm::pred_end(), llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::BranchInst::setCondition(), llvm::Instruction::setMetadata(), and llvm::BranchInst::setSuccessor().

static bool SimplifyCondBranchToTwoReturns	(	BranchInst *	BI,
		IRBuilder<> &	Builder
	)

static

SimplifyCondBranchToTwoReturns - If we found a conditional branch that goes to two returning blocks, try to merge them together into one return, introducing a select if the return values disagree.

Definition at line 1843 of file SimplifyCFG.cpp.

References llvm::IRBuilder< preserveNames, T, Inserter >::CreateRet(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateRetVoid(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSelect(), llvm::dbgs(), DEBUG, EraseTerminatorInstAndDCECond(), llvm::BranchInst::getCondition(), llvm::BasicBlock::getFirstNonPHIOrDbg(), llvm::Instruction::getParent(), llvm::ReturnInst::getReturnValue(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::BranchInst::isConditional(), llvm::Instruction::isTerminator(), llvm::BasicBlock::removePredecessor(), and llvm::IRBuilderBase::SetInsertPoint().

static bool SimplifyIndirectBrOnSelect	(	IndirectBrInst *	IBI,
		SelectInst *	SI
	)

static

Definition at line 2593 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::BlockAddress::getBasicBlock(), llvm::SelectInst::getCondition(), llvm::SelectInst::getFalseValue(), llvm::SelectInst::getTrueValue(), and SimplifyTerminatorOnSelect().

static bool SimplifySwitchOnSelect	(	SwitchInst *	SI,
		SelectInst *	Select
	)

static

Definition at line 2557 of file SimplifyCFG.cpp.

References llvm::dyn_cast(), llvm::SwitchInst::findCaseValue(), GetBranchWeights(), llvm::SwitchInst::CaseIteratorT< SwitchInstTy, ConstantIntTy, BasicBlockTy >::getCaseSuccessor(), llvm::SelectInst::getCondition(), llvm::SelectInst::getFalseValue(), llvm::SwitchInst::getNumCases(), llvm::SelectInst::getTrueValue(), HasBranchWeights(), SimplifyTerminatorOnSelect(), and llvm::SmallVectorTemplateCommon< T >::size().

static bool SimplifyTerminatorOnSelect	(	TerminatorInst *	OldTerm,
		Value *	Cond,
		BasicBlock *	TrueBB,
		BasicBlock *	FalseBB,
		uint32_t	TrueWeight,
		uint32_t	FalseWeight
	)

static

Definition at line 2492 of file SimplifyCFG.cpp.

References llvm::IRBuilder< preserveNames, T, Inserter >::CreateBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateCondBr(), EraseTerminatorInstAndDCECond(), llvm::Value::getContext(), llvm::Instruction::getDebugLoc(), llvm::TerminatorInst::getNumSuccessors(), llvm::Instruction::getParent(), llvm::TerminatorInst::getSuccessor(), I, llvm::LLVMContext::MD_prof, llvm::BasicBlock::removePredecessor(), llvm::IRBuilderBase::SetCurrentDebugLocation(), and llvm::Instruction::setMetadata().

Referenced by SimplifyIndirectBrOnSelect(), and SimplifySwitchOnSelect().

static bool SinkThenElseCodeToEnd ( BranchInst * BI1 )

static

SinkThenElseCodeToEnd - Given an unconditional branch that goes to BBEnd, check whether BBEnd has only two predecessors and the other predecessor ends with an unconditional branch. If it is true, sink any common code in the two predecessors to BBEnd.

Definition at line 1133 of file SimplifyCFG.cpp.

References llvm::PHINode::addIncoming(), llvm::BasicBlock::begin(), llvm::PHINode::Create(), llvm::dbgs(), DEBUG, llvm::dyn_cast(), llvm::BasicBlock::end(), llvm::Instruction::eraseFromParent(), llvm::BasicBlock::getInstList(), llvm::Value::getName(), llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::Instruction::getParent(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), llvm::Value::hasOneUse(), I, llvm::Value::intersectOptionalDataWith(), llvm::Instruction::isSameOperationAs(), llvm::BranchInst::isUnconditional(), llvm::Instruction::mayHaveSideEffects(), llvm::Instruction::mayReadOrWriteMemory(), llvm::pred_begin(), llvm::pred_end(), llvm::iplist< NodeTy, Traits >::rbegin(), llvm::iplist< NodeTy, Traits >::rend(), llvm::Value::replaceAllUsesWith(), llvm::User::setOperand(), llvm::iplist< NodeTy, Traits >::splice(), and llvm::Value::use_empty().

static bool SpeculativelyExecuteBB	(	BranchInst *	BI,
		BasicBlock *	ThenBB
	)

static

Speculate a conditional basic block flattening the CFG.

Note that this is a very risky transform currently. Speculating instructions like this is most often not desirable. Instead, there is an MI pass which can do it with full awareness of the resource constraints. However, some cases are "obvious" and we should do directly. An example of this is speculating a single, reasonably cheap instruction.

There is only one distinct advantage to flattening the CFG at the IR level: it makes very common but simplistic optimizations such as are common in instcombine and the DAG combiner more powerful by removing CFG edges and modeling their effects with easier to reason about SSA value graphs.

An illustration of this transform is turning this IR:

BB:
  %cmp = icmp ult %x, %y
  br i1 %cmp, label %EndBB, label %ThenBB
ThenBB:
  %sub = sub %x, %y
  br label BB2
EndBB:
  %phi = phi [ %sub, %ThenBB ], [ 0, %EndBB ]
  ...

Into this IR:

BB:
  %cmp = icmp ult %x, %y
  %sub = sub %x, %y
  %cond = select i1 %cmp, 0, %sub
  ...

Returns: true if the conditional block is removed.

Definition at line 1395 of file SimplifyCFG.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT >::begin(), llvm::BasicBlock::begin(), ComputeSpeculationCost(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSelect(), llvm::dbgs(), DEBUG, llvm::dyn_cast(), llvm::BasicBlock::end(), llvm::PHINode::getBasicBlockIndex(), llvm::BranchInst::getCondition(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getIncomingValueForBlock(), llvm::BasicBlock::getInstList(), llvm::Value::getName(), llvm::Instruction::getParent(), llvm::TerminatorInst::getSuccessor(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::StoreInst::getValueOperand(), HoistCondStores, I, isSafeToSpeculateStore(), llvm::isSafeToSpeculativelyExecute(), llvm::Instruction::mayHaveSideEffects(), llvm::User::op_begin(), llvm::User::op_end(), PHINodeFoldingThreshold, llvm::prior(), llvm::PHINode::setIncomingValue(), llvm::User::setOperand(), llvm::iplist< NodeTy, Traits >::splice(), and std::swap().

STATISTIC	(	NumBitMaps	,
		"Number of switch instructions turned into bitmaps"
	)

STATISTIC	(	NumLookupTables	,
		"Number of switch instructions turned into lookup tables"
	)

STATISTIC	(	NumSinkCommons	,
		"Number of common instructions sunk down to the end block"
	)

STATISTIC	(	NumSpeculations	,
		"Number of speculative executed instructions"
	)

static bool SwitchToLookupTable	(	SwitchInst *	SI,
		IRBuilder<> &	Builder,
		const TargetTransformInfo &	TTI,
		const DataLayout *	TD
	)

static

SwitchToLookupTable - If the switch is only used to initialize one or more phi nodes in a common successor block with different constant values, replace the switch with lookup tables.

Definition at line 3666 of file SimplifyCFG.cpp.

References llvm::SwitchInst::case_begin(), llvm::SwitchInst::case_end(), llvm::DenseMapBase< SmallDenseMap< KeyT, ValueT, InlineBuckets, KeyInfoT >, KeyT, ValueT, KeyInfoT >::count(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateCondBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateICmpULT(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateRet(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateSub(), llvm::Instruction::eraseFromParent(), GetCaseResults(), llvm::SwitchInst::getCondition(), llvm::Module::getContext(), llvm::SwitchInst::getDefaultDest(), llvm::BasicBlock::getFirstNonPHIOrDbg(), llvm::APInt::getLimitedValue(), llvm::SwitchInst::getNumCases(), llvm::SwitchInst::getNumSuccessors(), llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), llvm::GlobalValue::getParent(), llvm::Type::getPrimitiveSizeInBits(), llvm::SwitchInst::getSuccessor(), llvm::Value::getType(), llvm::ConstantInt::getType(), llvm::ConstantInt::getValue(), I, llvm::TargetOpcode::PHI, llvm::SmallVectorTemplateBase< T, isPodLike< T >::value >::push_back(), llvm::BasicBlock::removePredecessor(), llvm::IRBuilderBase::SetInsertPoint(), llvm::APInt::sgt(), ShouldBuildLookupTable(), llvm::TargetTransformInfo::shouldBuildLookupTables(), llvm::SmallVectorTemplateCommon< T >::size(), llvm::APInt::slt(), and TD.

static bool TryToSimplifyUncondBranchWithICmpInIt	(	ICmpInst *	ICI,
		IRBuilder<> &	Builder,
		const TargetTransformInfo &	TTI,
		const DataLayout *	TD
	)

static

TryToSimplifyUncondBranchWithICmpInIt - This is called when we find an icmp instruction (a seteq/setne with a constant) as the only instruction in a block that ends with an uncond branch. We are looking for a very specific pattern that occurs when "A == 1 || A == 2 || A == 3" gets simplified. In this case, we merge the first two "or's of icmp" into a switch, but then the default value goes to an uncond block with a seteq in it, we get something like:

switch i8 A, label DEFAULT [ i8 1, label end i8 2, label end ] DEFAULT: tmp = icmp eq i8 A, 92 br label end end: ... = phi i1 [ true, entry ], [ tmp, DEFAULT ], [ true, entry ]

We prefer to split the edge to 'end' so that there is a true/false entry to the PHI, merging the third icmp into the switch.

Definition at line 2626 of file SimplifyCFG.cpp.

References llvm::SwitchInst::addCase(), llvm::PHINode::addIncoming(), llvm::BasicBlock::begin(), llvm::SwitchInst::case_default(), llvm::BasicBlock::Create(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateBr(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::SwitchInst::findCaseDest(), llvm::SwitchInst::findCaseValue(), llvm::BasicBlock::front(), GetBranchWeights(), llvm::SwitchInst::getCondition(), llvm::BasicBlock::getContext(), llvm::Value::getContext(), llvm::Instruction::getDebugLoc(), llvm::SwitchInst::getDefaultDest(), llvm::ConstantInt::getFalse(), llvm::SwitchInst::getNumCases(), llvm::User::getOperand(), llvm::Instruction::getParent(), llvm::BasicBlock::getParent(), llvm::CmpInst::getPredicate(), llvm::BasicBlock::getSinglePredecessor(), llvm::TerminatorInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::ConstantInt::getTrue(), HasBranchWeights(), llvm::Value::hasOneUse(), llvm::CmpInst::ICMP_EQ, llvm::LLVMContext::MD_prof, llvm::Value::replaceAllUsesWith(), llvm::IRBuilderBase::SetCurrentDebugLocation(), llvm::IRBuilderBase::SetInsertPoint(), llvm::Instruction::setMetadata(), llvm::User::setOperand(), llvm::SimplifyCFG(), llvm::SimplifyInstruction(), std::swap(), and llvm::Instruction::use_back().

static bool TurnSwitchRangeIntoICmp	(	SwitchInst *	SI,
		IRBuilder<> &	Builder
	)

static

TurnSwitchRangeIntoICmp - Turns a switch with that contains only a integer range comparison into a sub, an icmp and a branch.

Definition at line 3118 of file SimplifyCFG.cpp.

References llvm::array_pod_sort(), llvm::BasicBlock::begin(), llvm::SwitchInst::case_begin(), llvm::SwitchInst::case_end(), ConstantIntSortPredicate(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateAdd(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateCondBr(), llvm::IRBuilder< preserveNames, T, Inserter >::CreateICmpULT(), llvm::Instruction::eraseFromParent(), llvm::ConstantInt::get(), GetBranchWeights(), llvm::SwitchInst::CaseIteratorT< SwitchInstTy, ConstantIntTy, BasicBlockTy >::getCaseSuccessor(), llvm::SwitchInst::CaseIteratorT< SwitchInstTy, ConstantIntTy, BasicBlockTy >::getCaseValue(), llvm::SwitchInst::getCondition(), llvm::Value::getContext(), llvm::SwitchInst::getDefaultDest(), llvm::Value::getName(), llvm::ConstantExpr::getNeg(), llvm::SwitchInst::getNumCases(), llvm::Instruction::getParent(), llvm::ConstantInt::getTrue(), llvm::Value::getType(), HasBranchWeights(), I, llvm::Constant::isNullValue(), llvm::LLVMContext::MD_prof, llvm::Instruction::setMetadata(), and llvm::SmallVectorTemplateCommon< T >::size().

static bool ValidLookupTableConstant ( Constant * C )

static

ValidLookupTableConstant - Return true if the backend will be able to handle initializing an array of constants like C.

Definition at line 3308 of file SimplifyCFG.cpp.

References llvm::CallingConv::C.

Referenced by GetCaseResults().

static bool ValuesOverlap	(	std::vector< ValueEqualityComparisonCase > &	C1,
		std::vector< ValueEqualityComparisonCase > &	C2
	)

static

ValuesOverlap - Return true if there are any keys in C1 that exist in C2 as well.

Definition at line 523 of file SimplifyCFG.cpp.

References llvm::array_pod_sort(), std::swap(), llvm::NVPTX::PTXLdStInstCode::V2, and llvm::Value::Value().

Variable Documentation

cl::opt<bool> DupRet("simplifycfg-dup-ret", cl::Hidden, cl::init(false), cl::desc("Duplicate return instructions into unconditional branches"))

static

cl::opt<bool> HoistCondStores("simplifycfg-hoist-cond-stores", cl::Hidden, cl::init(true), cl::desc("Hoist conditional stores if an unconditional store preceeds"))

static

Referenced by SpeculativelyExecuteBB().

cl::opt<unsigned> PHINodeFoldingThreshold("phi-node-folding-threshold", cl::Hidden, cl::init(1), cl::desc("Control the amount of phi node folding to perform (default = 1)"))

static

Referenced by FoldTwoEntryPHINode(), and SpeculativelyExecuteBB().

cl::opt<bool> SinkCommon("simplifycfg-sink-common", cl::Hidden, cl::init(true), cl::desc("Sink common instructions down to the end block"))

static

Macros

Functions

Variables

Macro Definition Documentation

Function Documentation

Variable Documentation