#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/Optional.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/AssumeBundleQueries.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/DomTreeUpdater.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LazyValueInfo.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/MemorySSAUpdater.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalObject.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.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/PatternMatch.h"
#include "llvm/IR/PseudoProbe.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include <algorithm>
#include <cassert>
#include <climits>
#include <cstdint>
#include <iterator>
#include <map>
#include <utility>

Macros
#define	DEBUG_TYPE "local"

Typedefs
using	PredBlockVector = SmallVector< BasicBlock *, 16 >

using	IncomingValueMap = DenseMap< BasicBlock , Value >

using	DbgValReplacement = Optional< DIExpression * >
	A replacement for a dbg.value expression. More...

Functions
	STATISTIC (NumRemoved, "Number of unreachable basic blocks removed")

	STATISTIC (NumPHICSEs, "Number of PHI's that got CSE'd")

static bool	areAllUsesEqual (Instruction *I)
	areAllUsesEqual - Check whether the uses of a value are all the same. More...

static bool	simplifyAndDCEInstruction (Instruction I, SmallSetVector< Instruction , 16 > &WorkList, const DataLayout &DL, const TargetLibraryInfo *TLI)

static bool	CanMergeValues (Value First, Value Second)
	Return true if we can choose one of these values to use in place of the other. More...

static bool	CanPropagatePredecessorsForPHIs (BasicBlock BB, BasicBlock Succ)
	Return true if we can fold BB, an almost-empty BB ending in an unconditional branch to Succ, into Succ. More...

static Value *	selectIncomingValueForBlock (Value OldVal, BasicBlock BB, IncomingValueMap &IncomingValues)
	Determines the value to use as the phi node input for a block. More...

static void	gatherIncomingValuesToPhi (PHINode *PN, IncomingValueMap &IncomingValues)
	Create a map from block to value for the operands of a given phi. More...

static void	replaceUndefValuesInPhi (PHINode *PN, const IncomingValueMap &IncomingValues)
	Replace the incoming undef values to a phi with the values from a block-to-value map. More...

static void	redirectValuesFromPredecessorsToPhi (BasicBlock BB, const PredBlockVector &BBPreds, PHINode PN)
	Replace a value flowing from a block to a phi with potentially multiple instances of that value flowing from the block's predecessors to the phi. More...

static bool	EliminateDuplicatePHINodesNaiveImpl (BasicBlock *BB)

static bool	EliminateDuplicatePHINodesSetBasedImpl (BasicBlock *BB)

static Align	tryEnforceAlignment (Value *V, Align PrefAlign, const DataLayout &DL)
	If the specified pointer points to an object that we control, try to modify the object's alignment to PrefAlign. More...

static bool	PhiHasDebugValue (DILocalVariable DIVar, DIExpression DIExpr, PHINode *APN)
	===------------------------------------------------------------------—===// Dbg Intrinsic utilities More...

static bool	valueCoversEntireFragment (Type ValTy, DbgVariableIntrinsic DII)
	Check if the alloc size of `ValTy` is large enough to cover the variable (or fragment of the variable) described by `DII`. More...

static DebugLoc	getDebugValueLoc (DbgVariableIntrinsic DII, Instruction Src)
	Produce a DebugLoc to use for each dbg.declare/inst pair that are promoted to a dbg.value. More...

static bool	isArray (AllocaInst *AI)
	Determine whether this alloca is either a VLA or an array. More...

static bool	isStructure (AllocaInst *AI)
	Determine whether this alloca is a structure. More...

static void	replaceOneDbgValueForAlloca (DbgValueInst DVI, Value NewAddress, DIBuilder &Builder, int Offset)

Value *	getSalvageOpsForGEP (GetElementPtrInst GEP, const DataLayout &DL, uint64_t CurrentLocOps, SmallVectorImpl< uint64_t > &Opcodes, SmallVectorImpl< Value > &AdditionalValues)

uint64_t	getDwarfOpForBinOp (Instruction::BinaryOps Opcode)

Value *	getSalvageOpsForBinOp (BinaryOperator BI, uint64_t CurrentLocOps, SmallVectorImpl< uint64_t > &Opcodes, SmallVectorImpl< Value > &AdditionalValues)

static bool	rewriteDebugUsers (Instruction &From, Value &To, Instruction &DomPoint, DominatorTree &DT, function_ref< DbgValReplacement(DbgVariableIntrinsic &DII)> RewriteExpr)
	Point debug users of `From` to `To` using exprs given by `RewriteExpr`, possibly moving/undefing users to prevent use-before-def. More...

static bool	isBitCastSemanticsPreserving (const DataLayout &DL, Type FromTy, Type ToTy)
	Check if a bitcast between a value of type `FromTy` to type `ToTy` would losslessly preserve the bits and semantics of the value. More...

static bool	markAliveBlocks (Function &F, SmallPtrSetImpl< BasicBlock * > &Reachable, DomTreeUpdater *DTU=nullptr)

template<typename RootType , typename DominatesFn >
static unsigned	replaceDominatedUsesWith (Value From, Value To, const RootType &Root, const DominatesFn &Dominates)

static const Optional< BitPart > &	collectBitParts (Value V, bool MatchBSwaps, bool MatchBitReversals, std::map< Value , Optional< BitPart >> &BPS, int Depth, bool &FoundRoot)
	Analyze the specified subexpression and see if it is capable of providing pieces of a bswap or bitreverse. More...

static bool	bitTransformIsCorrectForBSwap (unsigned From, unsigned To, unsigned BitWidth)

static bool	bitTransformIsCorrectForBitReverse (unsigned From, unsigned To, unsigned BitWidth)

Variables
static cl::opt< bool >	PHICSEDebugHash ("phicse-debug-hash", cl::init(false), cl::Hidden, cl::desc("Perform extra assertion checking to verify that PHINodes's hash " "function is well-behaved w.r.t. its isEqual predicate"))

static cl::opt< unsigned >	PHICSENumPHISmallSize ("phicse-num-phi-smallsize", cl::init(32), cl::Hidden, cl::desc("When the basic block contains not more than this number of PHI nodes, " "perform a (faster!) exhaustive search instead of set-driven one."))

static const unsigned	BitPartRecursionMaxDepth = 48

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "local"

Definition at line 91 of file Local.cpp.

Typedef Documentation

◆ DbgValReplacement

using DbgValReplacement = Optional<DIExpression *>

A replacement for a dbg.value expression.

Definition at line 1937 of file Local.cpp.

◆ IncomingValueMap

using IncomingValueMap = DenseMap<BasicBlock *, Value *>

Definition at line 889 of file Local.cpp.

◆ PredBlockVector

using PredBlockVector = SmallVector<BasicBlock *, 16>

Definition at line 888 of file Local.cpp.

Function Documentation

◆ areAllUsesEqual()

static bool areAllUsesEqual ( Instruction * I )

static

areAllUsesEqual - Check whether the uses of a value are all the same.

This is similar to Instruction::hasOneUse() except this will also return true when there are no uses or multiple uses that all refer to the same value.

Definition at line 602 of file Local.cpp.

References I.

Referenced by llvm::RecursivelyDeleteDeadPHINode().

◆ bitTransformIsCorrectForBitReverse()

static bool bitTransformIsCorrectForBitReverse	(	unsigned	From,
		unsigned	To,
		unsigned	BitWidth
	)

static

Definition at line 3125 of file Local.cpp.

References llvm::BitWidth, and From.

Referenced by llvm::recognizeBSwapOrBitReverseIdiom().

◆ bitTransformIsCorrectForBSwap()

static bool bitTransformIsCorrectForBSwap	(	unsigned	From,
		unsigned	To,
		unsigned	BitWidth
	)

static

Definition at line 3114 of file Local.cpp.

References llvm::BitWidth, and From.

Referenced by llvm::recognizeBSwapOrBitReverseIdiom().

◆ CanMergeValues()

static bool CanMergeValues	(	Value *	First,
		Value *	Second
	)

static

Return true if we can choose one of these values to use in place of the other.

Note that we will always choose the non-undef value to keep.

Definition at line 823 of file Local.cpp.

References First.

Referenced by CanPropagatePredecessorsForPHIs().

◆ CanPropagatePredecessorsForPHIs()

static bool CanPropagatePredecessorsForPHIs	(	BasicBlock *	BB,
		BasicBlock *	Succ
	)

static

Return true if we can fold BB, an almost-empty BB ending in an unconditional branch to Succ, into Succ.

Assumption: Succ is the single successor for BB.

Definition at line 831 of file Local.cpp.

References assert(), BB, llvm::BasicBlock::begin(), CanMergeValues(), llvm::SmallPtrSetImpl< PtrType >::count(), llvm::dbgs(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getIncomingValueForBlock(), llvm::Value::getName(), llvm::PHINode::getNumIncomingValues(), llvm::Instruction::getParent(), llvm::BasicBlock::getSinglePredecessor(), I, LLVM_DEBUG, llvm::pred_begin(), llvm::pred_end(), and llvm::succ_begin().

Referenced by llvm::TryToSimplifyUncondBranchFromEmptyBlock().

◆ collectBitParts()

static const Optional<BitPart>& collectBitParts	(	Value *	V,
		bool	MatchBSwaps,
		bool	MatchBitReversals,
		std::map< Value *, Optional< BitPart >> &	BPS,
		int	Depth,
		bool &	FoundRoot
	)

static

Analyze the specified subexpression and see if it is capable of providing pieces of a bswap or bitreverse.

The subexpression provides a potential piece of a bswap or bitreverse if it can be proved that each non-zero bit in the output of the expression came from a corresponding bit in some other value. This function is recursive, and the end result is a mapping of bitnumber to bitnumber. It is the caller's responsibility to validate that the bitnumber to bitnumber mapping is correct for a bswap or bitreverse.

For example, if the current subexpression if "(shl i32 %X, 24)" then we know that the expression deposits the low byte of X into the high byte of the result and that all other bits are zero. This expression is accepted and a BitPart is returned with Provider set to X and Provenance[24-31] set to [0-7].

For vector types, all analysis is performed at the per-element level. No cross-element analysis is supported (shuffle/insertion/reduction), and all constant masks must be splatted across all elements.

To avoid revisiting values, the BitPart results are memoized into the provided map. To avoid unnecessary copying of BitParts, BitParts are constructed in-place in the BPS map. Because of this BPS needs to store BitParts objects, not pointers. As we need the concept of a nullptr BitParts (Value has been analyzed and the analysis failed), we an Optional type instead to provide the same functionality.

Because we pass around references into BPS, we must use a container that does not invalidate internal references (std::map instead of DenseMap).

Definition at line 2894 of file Local.cpp.

Referenced by llvm::recognizeBSwapOrBitReverseIdiom().

◆ EliminateDuplicatePHINodesNaiveImpl()

static bool EliminateDuplicatePHINodesNaiveImpl ( BasicBlock * BB )

static

Definition at line 1170 of file Local.cpp.

References BB, llvm::Instruction::eraseFromParent(), I, llvm::Instruction::isIdenticalToWhenDefined(), and llvm::Value::replaceAllUsesWith().

Referenced by llvm::EliminateDuplicatePHINodes().

◆ EliminateDuplicatePHINodesSetBasedImpl()

static bool EliminateDuplicatePHINodesSetBasedImpl ( BasicBlock * BB )

static

Definition at line 1202 of file Local.cpp.

References assert(), BB, llvm::PHINode::block_begin(), llvm::PHINode::block_end(), llvm::detail::DenseSetImpl< ValueT, DenseMap< ValueT, detail::DenseSetEmpty, DenseMapInfo< ValueT >, detail::DenseSetPair< ValueT > >, DenseMapInfo< ValueT > >::clear(), getHashValueImpl(), llvm::hash_combine(), llvm::hash_combine_range(), I, llvm::detail::DenseSetImpl< ValueT, DenseMap< ValueT, detail::DenseSetEmpty, DenseMapInfo< ValueT >, detail::DenseSetPair< ValueT > >, DenseMapInfo< ValueT > >::insert(), llvm::isEqual(), isEqualImpl(), llvm::Instruction::isIdenticalTo(), isSentinel(), PHICSEDebugHash, PHICSENumPHISmallSize, llvm::detail::DenseSetImpl< ValueT, DenseMap< ValueT, detail::DenseSetEmpty, DenseMapInfo< ValueT >, detail::DenseSetPair< ValueT > >, DenseMapInfo< ValueT > >::reserve(), llvm::User::value_op_begin(), and llvm::User::value_op_end().

Referenced by llvm::EliminateDuplicatePHINodes().

◆ gatherIncomingValuesToPhi()

static void gatherIncomingValuesToPhi	(	PHINode *	PN,
		IncomingValueMap &	IncomingValues
	)

static

Create a map from block to value for the operands of a given phi.

Create a map from block to value for each non-undef value flowing into PN.

Parameters

PN	The phi we are collecting the map for.
IncomingValues	[out] The map from block to value for this phi.

Definition at line 928 of file Local.cpp.

References BB, llvm::numbers::e, llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), i, and llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert().

Referenced by redirectValuesFromPredecessorsToPhi().

◆ getDebugValueLoc()

static DebugLoc getDebugValueLoc	(	DbgVariableIntrinsic *	DII,
		Instruction *	Src
	)

static

Produce a DebugLoc to use for each dbg.declare/inst pair that are promoted to a dbg.value.

Because no machine insts can come from debug intrinsics, only the scope and inlinedAt is significant. Zero line numbers are used in case this DebugLoc leaks into any adjacent instructions.

Definition at line 1430 of file Local.cpp.

References llvm::MDNode::get(), llvm::Value::getContext(), llvm::Instruction::getDebugLoc(), llvm::DebugLoc::getInlinedAt(), and llvm::DebugLoc::getScope().

Referenced by llvm::ConvertDebugDeclareToDebugValue(), and llvm::LowerDbgDeclare().

◆ getDwarfOpForBinOp()

uint64_t getDwarfOpForBinOp ( Instruction::BinaryOps Opcode )

Definition at line 1828 of file Local.cpp.

References llvm::MCID::Add.

Referenced by getSalvageOpsForBinOp().

◆ getSalvageOpsForBinOp()

Value* getSalvageOpsForBinOp	(	BinaryOperator *	BI,
		uint64_t	CurrentLocOps,
		SmallVectorImpl< uint64_t > &	Opcodes,
		SmallVectorImpl< Value * > &	AdditionalValues
	)

Definition at line 1858 of file Local.cpp.

References llvm::MCID::Add, llvm::SmallVectorImpl< T >::append(), llvm::DIExpression::appendOffset(), llvm::dwarf::DW_OP_LLVM_arg, getDwarfOpForBinOp(), llvm::BinaryOperator::getOpcode(), llvm::User::getOperand(), and Offset.

Referenced by llvm::salvageDebugInfoImpl().

◆ getSalvageOpsForGEP()

Value* getSalvageOpsForGEP	(	GetElementPtrInst *	GEP,
		const DataLayout &	DL,
		uint64_t	CurrentLocOps,
		SmallVectorImpl< uint64_t > &	Opcodes,
		SmallVectorImpl< Value * > &	AdditionalValues
	)

Definition at line 1802 of file Local.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::DIExpression::appendOffset(), assert(), llvm::BitWidth, DL, llvm::dwarf::DW_OP_LLVM_arg, llvm::MapVector< KeyT, ValueT, MapType, VectorType >::empty(), GEP, llvm::APInt::getSExtValue(), llvm::SmallVectorImpl< T >::insert(), and Offset.

Referenced by llvm::salvageDebugInfoImpl().

◆ isArray()

static bool isArray ( AllocaInst * AI )

static

Determine whether this alloca is either a VLA or an array.

Definition at line 1528 of file Local.cpp.

References llvm::AllocaInst::getAllocatedType(), llvm::AllocaInst::isArrayAllocation(), and llvm::Type::isArrayTy().

Referenced by llvm::LowerDbgDeclare().

◆ isBitCastSemanticsPreserving()

static bool isBitCastSemanticsPreserving	(	const DataLayout &	DL,
		Type *	FromTy,
		Type *	ToTy
	)

static

Check if a bitcast between a value of type FromTy to type ToTy would losslessly preserve the bits and semantics of the value.

This predicate is symmetric, i.e swapping FromTy and ToTy should give the same result.

Note that Type::canLosslesslyBitCastTo is not suitable here because it allows semantically unequivalent bitcasts, such as <2 x i64> -> <4 x i32>, and also does not allow lossless pointer <-> integer conversions.

Definition at line 2004 of file Local.cpp.

References DL, and llvm::Type::isIntOrPtrTy().

Referenced by llvm::replaceAllDbgUsesWith().

◆ isStructure()

static bool isStructure ( AllocaInst * AI )

static

Determine whether this alloca is a structure.

Definition at line 1534 of file Local.cpp.

References llvm::AllocaInst::getAllocatedType(), and llvm::Type::isStructTy().

Referenced by llvm::LowerDbgDeclare().

◆ markAliveBlocks()

static bool markAliveBlocks	(	Function &	F,
		SmallPtrSetImpl< BasicBlock * > &	Reachable,
		DomTreeUpdater *	DTU = `nullptr`
	)

static

Definition at line 2247 of file Local.cpp.

References BB, Callee, llvm::canSimplifyInvokeNoUnwind(), llvm::changeToCall(), llvm::changeToUnreachable(), llvm::ConstantFoldTerminator(), llvm::BranchInst::Create(), llvm::DominatorTreeBase< BasicBlock, false >::Delete, E, F, llvm::BasicBlock::getFirstNonPHI(), llvm::hash_combine_range(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::isEqual(), llvm::Instruction::isIdenticalTo(), llvm::PatternMatch::m_CombineOr(), llvm::PatternMatch::m_Undef(), llvm::PatternMatch::m_Zero(), llvm::PatternMatch::match(), llvm::NullPointerIsDefined(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::BasicBlock::removePredecessor(), SI, llvm::Successor, llvm::successors(), llvm::MCID::Terminator, llvm::User::value_op_begin(), and llvm::User::value_op_end().

Referenced by llvm::removeUnreachableBlocks().

◆ PhiHasDebugValue()

static bool PhiHasDebugValue	(	DILocalVariable *	DIVar,
		DIExpression *	DIExpr,
		PHINode *	APN
	)

static

===------------------------------------------------------------------—===// Dbg Intrinsic utilities

See if there is a dbg.value intrinsic for DIVar for the PHI node.

Definition at line 1373 of file Local.cpp.

References assert(), llvm::findDbgValues(), and llvm::is_contained().

Referenced by llvm::ConvertDebugDeclareToDebugValue().

◆ redirectValuesFromPredecessorsToPhi()

static void redirectValuesFromPredecessorsToPhi	(	BasicBlock *	BB,
		const PredBlockVector &	BBPreds,
		PHINode *	PN
	)

static

Replace a value flowing from a block to a phi with potentially multiple instances of that value flowing from the block's predecessors to the phi.

Parameters

BB	The block with the value flowing into the phi.
BBPreds	The predecessors of BB.
PN	The phi that we are updating.

Definition at line 988 of file Local.cpp.

References llvm::PHINode::addIncoming(), assert(), BB, llvm::numbers::e, gatherIncomingValuesToPhi(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), getParent(), i, llvm::PHINode::removeIncomingValue(), replaceUndefValuesInPhi(), and selectIncomingValueForBlock().

Referenced by llvm::TryToSimplifyUncondBranchFromEmptyBlock().

◆ replaceDominatedUsesWith()

template<typename RootType , typename DominatesFn >

static unsigned replaceDominatedUsesWith	(	Value *	From,
		Value *	To,
		const RootType &	Root,
		const DominatesFn &	Dominates
	)

static

Definition at line 2674 of file Local.cpp.

References assert(), llvm::dbgs(), From, llvm::Value::getType(), LLVM_DEBUG, and llvm::make_early_inc_range().

Referenced by llvm::replaceDominatedUsesWith().

◆ replaceOneDbgValueForAlloca()

static void replaceOneDbgValueForAlloca	(	DbgValueInst *	DVI,
		Value *	NewAddress,
		DIBuilder &	Builder,
		int	Offset
	)

static

Definition at line 1694 of file Local.cpp.

References assert(), Builder, llvm::Instruction::eraseFromParent(), llvm::Instruction::getDebugLoc(), llvm::DbgVariableIntrinsic::getExpression(), llvm::DbgVariableIntrinsic::getVariable(), Offset, and llvm::DIExpression::prepend().

Referenced by llvm::replaceDbgValueForAlloca().

◆ replaceUndefValuesInPhi()

static void replaceUndefValuesInPhi	(	PHINode *	PN,
		const IncomingValueMap &	IncomingValues
	)

static

Replace the incoming undef values to a phi with the values from a block-to-value map.

Parameters

PN	The phi we are replacing the undefs in.
IncomingValues	A map from block to value.

Definition at line 944 of file Local.cpp.

References BB, llvm::count_if(), llvm::numbers::e, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::UndefValue::get(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), llvm::Value::getType(), i, and llvm::PHINode::setIncomingValue().

Referenced by redirectValuesFromPredecessorsToPhi().

◆ rewriteDebugUsers()

static bool rewriteDebugUsers	(	Instruction &	From,
		Value &	To,
		Instruction &	DomPoint,
		DominatorTree &	DT,
		function_ref< DbgValReplacement(DbgVariableIntrinsic &DII)>	RewriteExpr
	)

static

Point debug users of From to To using exprs given by RewriteExpr, possibly moving/undefing users to prevent use-before-def.

Returns true if changes are made.

Definition at line 1942 of file Local.cpp.

References llvm::SmallPtrSetImpl< PtrType >::count(), llvm::dbgs(), llvm::DominatorTree::dominates(), llvm::SmallPtrSetImplBase::empty(), llvm::findDbgUsers(), From, llvm::Instruction::getNextNonDebugInstruction(), llvm::SmallPtrSetImpl< PtrType >::insert(), LLVM_DEBUG, llvm::Instruction::moveAfter(), llvm::DbgVariableIntrinsic::replaceVariableLocationOp(), llvm::salvageDebugInfo(), llvm::DbgVariableIntrinsic::setExpression(), and Users.

Referenced by llvm::replaceAllDbgUsesWith().

◆ selectIncomingValueForBlock()

static Value* selectIncomingValueForBlock	(	Value *	OldVal,
		BasicBlock *	BB,
		IncomingValueMap &	IncomingValues
	)

static

Determines the value to use as the phi node input for a block.

Select between OldVal any value that we know flows from BB to a particular phi on the basis of which one (if either) is not undef. Update IncomingValues based on the selected value.

Parameters

OldVal	The value we are considering selecting.
BB	The block that the value flows in from.
IncomingValues	A map from block-to-value for other phi inputs that we have examined.

Returns: the selected value.

Definition at line 903 of file Local.cpp.

References assert(), BB, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), and llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert().

Referenced by redirectValuesFromPredecessorsToPhi().

◆ simplifyAndDCEInstruction()

static bool simplifyAndDCEInstruction	(	Instruction *	I,
		SmallSetVector< Instruction *, 16 > &	WorkList,
		const DataLayout &	DL,
		const TargetLibraryInfo *	TLI
	)

static

Definition at line 643 of file Local.cpp.

References DL, llvm::numbers::e, i, I, llvm::SetVector< T, SmallVector< T, N >, SmallDenseSet< T, N > >::insert(), llvm::isInstructionTriviallyDead(), llvm::salvageDebugInfo(), llvm::SimplifyInstruction(), and llvm::Value::use_empty().

Referenced by llvm::SimplifyInstructionsInBlock().

◆ STATISTIC() [1/2]

STATISTIC	(	NumPHICSEs	,
		"Number of PHI's that got CSE'd"
	)

◆ STATISTIC() [2/2]

STATISTIC	(	NumRemoved	,
		"Number of unreachable basic blocks removed"
	)

◆ tryEnforceAlignment()

static Align tryEnforceAlignment	(	Value *	V,
		Align	PrefAlign,
		const DataLayout &	DL
	)

static

If the specified pointer points to an object that we control, try to modify the object's alignment to PrefAlign.

Returns a minimum known alignment of the value after the operation, which may be lower than PrefAlign.

Increating value alignment isn't often possible though. If alignment is important, a more reliable approach is to simply align all global variables and allocation instructions to their preferred alignment from the beginning.

Definition at line 1301 of file Local.cpp.

References Align, DL, and llvm::Value::stripPointerCasts().

Referenced by llvm::getOrEnforceKnownAlignment().

◆ valueCoversEntireFragment()

static bool valueCoversEntireFragment	(	Type *	ValTy,
		DbgVariableIntrinsic *	DII
	)

static

Check if the alloc size of ValTy is large enough to cover the variable (or fragment of the variable) described by DII.

This is primarily intended as a helper for the different ConvertDebugDeclareToDebugValue functions. The dbg.declare/dbg.addr that is converted describes an alloca'd variable, so we need to use the alloc size of the value when doing the comparison. E.g. an i1 value will be identified as covering an n-bit fragment, if the store size of i1 is at least n bits.

Definition at line 1398 of file Local.cpp.

References assert(), DL, llvm::Module::getDataLayout(), llvm::TypeSize::getFixedSize(), llvm::DbgVariableIntrinsic::getFragmentSizeInBits(), llvm::Instruction::getModule(), llvm::DbgVariableIntrinsic::getNumVariableLocationOps(), llvm::DbgVariableIntrinsic::getVariableLocationOp(), llvm::DbgVariableIntrinsic::isAddressOfVariable(), llvm::LinearPolySize< TypeSize >::isKnownGE(), and llvm::LinearPolySize< LeafTy >::isScalable().

Referenced by llvm::ConvertDebugDeclareToDebugValue().

Variable Documentation

◆ BitPartRecursionMaxDepth

const unsigned BitPartRecursionMaxDepth = 48

static

Definition at line 115 of file Local.cpp.

Referenced by collectBitParts().

◆ PHICSEDebugHash

cl::opt<bool> PHICSEDebugHash("phicse-debug-hash", cl::init(false), cl::Hidden, cl::desc("Perform extra assertion checking to verify that PHINodes's hash " "function is well-behaved w.r.t. its isEqual predicate"))

static

Referenced by llvm::EliminateDuplicatePHINodes(), and EliminateDuplicatePHINodesSetBasedImpl().

◆ PHICSENumPHISmallSize

cl::opt<unsigned> PHICSENumPHISmallSize("phicse-num-phi-smallsize", cl::init(32), cl::Hidden, cl::desc( "When the basic block contains not more than this number of PHI nodes, " "perform a (faster!) exhaustive search instead of set-driven one."))

static

Referenced by llvm::EliminateDuplicatePHINodes(), and EliminateDuplicatePHINodesSetBasedImpl().

Macros

Typedefs

Functions

Variables

Macro Definition Documentation

◆ DEBUG_TYPE

Typedef Documentation

◆ DbgValReplacement

◆ IncomingValueMap

◆ PredBlockVector

Function Documentation

◆ areAllUsesEqual()

◆ bitTransformIsCorrectForBitReverse()

◆ bitTransformIsCorrectForBSwap()

◆ CanMergeValues()

◆ CanPropagatePredecessorsForPHIs()

◆ collectBitParts()

◆ EliminateDuplicatePHINodesNaiveImpl()

◆ EliminateDuplicatePHINodesSetBasedImpl()

◆ gatherIncomingValuesToPhi()

◆ getDebugValueLoc()

◆ getDwarfOpForBinOp()

◆ getSalvageOpsForBinOp()

◆ getSalvageOpsForGEP()

◆ isArray()

◆ isBitCastSemanticsPreserving()

◆ isStructure()

◆ markAliveBlocks()

◆ PhiHasDebugValue()

◆ redirectValuesFromPredecessorsToPhi()

◆ replaceDominatedUsesWith()

◆ replaceOneDbgValueForAlloca()

◆ replaceUndefValuesInPhi()

◆ rewriteDebugUsers()

◆ selectIncomingValueForBlock()

◆ simplifyAndDCEInstruction()

◆ STATISTIC() [1/2]

◆ STATISTIC() [2/2]

◆ tryEnforceAlignment()

◆ valueCoversEntireFragment()

Variable Documentation

◆ BitPartRecursionMaxDepth

◆ PHICSEDebugHash

◆ PHICSENumPHISmallSize