This file implements interprocedural passes which walk the call-graph deducing and/or propagating function attributes. More...

#include "llvm/Transforms/IPO/FunctionAttrs.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SCCIterator.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/CGSCCPassManager.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/LazyCallGraph.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Utils/Local.h"
#include <cassert>
#include <iterator>
#include <map>
#include <optional>
#include <vector>

Classes
struct	llvm::GraphTraits< ArgumentGraphNode * >

struct	llvm::GraphTraits< ArgumentGraph * >

Namespaces
namespace	llvm
	This is an optimization pass for GlobalISel generic memory operations.

Macros
#define	DEBUG_TYPE "function-attrs"

Functions
	STATISTIC (NumMemoryAttr, "Number of functions with improved memory attribute")

	STATISTIC (NumNoCapture, "Number of arguments marked nocapture")

	STATISTIC (NumReturned, "Number of arguments marked returned")

	STATISTIC (NumReadNoneArg, "Number of arguments marked readnone")

	STATISTIC (NumReadOnlyArg, "Number of arguments marked readonly")

	STATISTIC (NumWriteOnlyArg, "Number of arguments marked writeonly")

	STATISTIC (NumNoAlias, "Number of function returns marked noalias")

	STATISTIC (NumNonNullReturn, "Number of function returns marked nonnull")

	STATISTIC (NumNoRecurse, "Number of functions marked as norecurse")

	STATISTIC (NumNoUnwind, "Number of functions marked as nounwind")

	STATISTIC (NumNoFree, "Number of functions marked as nofree")

	STATISTIC (NumWillReturn, "Number of functions marked as willreturn")

	STATISTIC (NumNoSync, "Number of functions marked as nosync")

	STATISTIC (NumThinLinkNoRecurse, "Number of functions marked as norecurse during thinlink")

	STATISTIC (NumThinLinkNoUnwind, "Number of functions marked as nounwind during thinlink")

static MemoryEffects	checkFunctionMemoryAccess (Function &F, bool ThisBody, AAResults &AAR, const SCCNodeSet &SCCNodes)
	Returns the memory access attribute for function F using AAR for AA results, where SCCNodes is the current SCC.

template<typename AARGetterT >
static void	addMemoryAttrs (const SCCNodeSet &SCCNodes, AARGetterT &&AARGetter, SmallSet< Function *, 8 > &Changed)
	Deduce readonly/readnone/writeonly attributes for the SCC.

static FunctionSummary *	calculatePrevailingSummary (ValueInfo VI, DenseMap< ValueInfo, FunctionSummary * > &CachedPrevailingSummary, function_ref< bool(GlobalValue::GUID, const GlobalValueSummary *)> IsPrevailing)

static Attribute::AttrKind	determinePointerAccessAttrs (Argument A, const SmallPtrSet< Argument , 8 > &SCCNodes)
	Returns Attribute::None, Attribute::ReadOnly or Attribute::ReadNone.

static void	addArgumentReturnedAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Deduce returned attributes for the SCC.

static bool	addArgumentAttrsFromCallsites (Function &F)
	If a callsite has arguments that are also arguments to the parent function, try to propagate attributes from the callsite's arguments to the parent's arguments.

static bool	addAccessAttr (Argument *A, Attribute::AttrKind R)

static void	addArgumentAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Deduce nocapture attributes for the SCC.

static bool	isFunctionMallocLike (Function *F, const SCCNodeSet &SCCNodes)
	Tests whether a function is "malloc-like".

static void	addNoAliasAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Deduce noalias attributes for the SCC.

static bool	isReturnNonNull (Function *F, const SCCNodeSet &SCCNodes, bool &Speculative)
	Tests whether this function is known to not return null.

static void	addNonNullAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Deduce nonnull attributes for the SCC.

static bool	InstrBreaksNonConvergent (Instruction &I, const SCCNodeSet &SCCNodes)
	Helper for non-Convergent inference predicate InstrBreaksAttribute.

static bool	InstrBreaksNonThrowing (Instruction &I, const SCCNodeSet &SCCNodes)
	Helper for NoUnwind inference predicate InstrBreaksAttribute.

static bool	InstrBreaksNoFree (Instruction &I, const SCCNodeSet &SCCNodes)
	Helper for NoFree inference predicate InstrBreaksAttribute.

static bool	isOrderedAtomic (Instruction *I)

static bool	InstrBreaksNoSync (Instruction &I, const SCCNodeSet &SCCNodes)

static void	inferConvergent (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Attempt to remove convergent function attribute when possible.

static void	inferAttrsFromFunctionBodies (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)
	Infer attributes from all functions in the SCC by scanning every instruction for compliance to the attribute assumptions.

static void	addNoRecurseAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)

static bool	instructionDoesNotReturn (Instruction &I)

static bool	basicBlockCanReturn (BasicBlock &BB)

static bool	canReturn (Function &F)

static void	addNoReturnAttrs (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)

static bool	functionWillReturn (const Function &F)

static void	addWillReturn (const SCCNodeSet &SCCNodes, SmallSet< Function *, 8 > &Changed)

static SCCNodesResult	createSCCNodeSet (ArrayRef< Function * > Functions)

template<typename AARGetterT >
static SmallSet< Function *, 8 >	deriveAttrsInPostOrder (ArrayRef< Function * > Functions, AARGetterT &&AARGetter)

template<typename AARGetterT >
static bool	runImpl (CallGraphSCC &SCC, AARGetterT AARGetter)

static bool	addNoRecurseAttrsTopDown (Function &F)

static bool	deduceFunctionAttributeInRPO (Module &M, LazyCallGraph &CG)

Variables
static cl::opt< bool >	EnableNonnullArgPropagation ("enable-nonnull-arg-prop", cl::init(true), cl::Hidden, cl::desc("Try to propagate nonnull argument attributes from callsites to " "caller functions."))

static cl::opt< bool >	DisableNoUnwindInference ("disable-nounwind-inference", cl::Hidden, cl::desc("Stop inferring nounwind attribute during function-attrs pass"))

static cl::opt< bool >	DisableNoFreeInference ("disable-nofree-inference", cl::Hidden, cl::desc("Stop inferring nofree attribute during function-attrs pass"))

static cl::opt< bool >	DisableThinLTOPropagation ("disable-thinlto-funcattrs", cl::init(true), cl::Hidden, cl::desc("Don't propagate function-attrs in thinLTO"))

Detailed Description

This file implements interprocedural passes which walk the call-graph deducing and/or propagating function attributes.

Definition in file FunctionAttrs.cpp.

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "function-attrs"

Definition at line 71 of file FunctionAttrs.cpp.

Function Documentation

◆ addAccessAttr()

static bool addAccessAttr	(	Argument *	A,
		Attribute::AttrKind	R
	)

static

Definition at line 800 of file FunctionAttrs.cpp.

References A, and assert().

Referenced by addArgumentAttrs().

◆ addArgumentAttrs()

static void addArgumentAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Deduce nocapture attributes for the SCC.

Definition at line 826 of file FunctionAttrs.cpp.

References A, addAccessAttr(), addArgumentAttrsFromCallsites(), B, llvm::SmallPtrSetImpl< PtrType >::count(), determinePointerAccessAttrs(), F, I, llvm::SmallSet< T, N, C >::insert(), llvm::SmallPtrSetImpl< PtrType >::insert(), N, llvm::Attribute::None, llvm::PointerMayBeCaptured(), llvm::scc_begin(), and Uses.

Referenced by deriveAttrsInPostOrder().

◆ addArgumentAttrsFromCallsites()

static bool addArgumentAttrsFromCallsites ( Function & F )

static

If a callsite has arguments that are also arguments to the parent function, try to propagate attributes from the callsite's arguments to the parent's arguments.

This may be important because inlining can cause information loss when attribute knowledge disappears with the inlined call.

Definition at line 761 of file FunctionAttrs.cpp.

References EnableNonnullArgPropagation, F, llvm::CallBase::getArgOperand(), llvm::CallBase::getCalledFunction(), I, and llvm::isGuaranteedToTransferExecutionToSuccessor().

Referenced by addArgumentAttrs().

◆ addArgumentReturnedAttrs()

static void addArgumentReturnedAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Deduce returned attributes for the SCC.

Definition at line 712 of file FunctionAttrs.cpp.

References llvm::Argument::addAttr(), F, and llvm::SmallSet< T, N, C >::insert().

Referenced by deriveAttrsInPostOrder().

◆ addMemoryAttrs()

template<typename AARGetterT >

static void addMemoryAttrs	(	const SCCNodeSet &	SCCNodes,
		AARGetterT &&	AARGetter,
		SmallSet< Function *, 8 > &	Changed
	)

static

Deduce readonly/readnone/writeonly attributes for the SCC.

Definition at line 240 of file FunctionAttrs.cpp.

References checkFunctionMemoryAccess(), F, llvm::SmallSet< T, N, C >::insert(), llvm::MemoryEffects::none(), and llvm::MemoryEffects::unknown().

Referenced by deriveAttrsInPostOrder().

◆ addNoAliasAttrs()

static void addNoAliasAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Deduce noalias attributes for the SCC.

Definition at line 1075 of file FunctionAttrs.cpp.

References F, llvm::SmallSet< T, N, C >::insert(), and isFunctionMallocLike().

Referenced by deriveAttrsInPostOrder().

◆ addNonNullAttrs()

static void addNonNullAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Deduce nonnull attributes for the SCC.

Definition at line 1183 of file FunctionAttrs.cpp.

References llvm::dbgs(), F, llvm::SmallSet< T, N, C >::insert(), isReturnNonNull(), and LLVM_DEBUG.

Referenced by deriveAttrsInPostOrder().

◆ addNoRecurseAttrs()

static void addNoRecurseAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Definition at line 1570 of file FunctionAttrs.cpp.

References Callee, F, llvm::CallBase::getCalledFunction(), I, and llvm::SmallSet< T, N, C >::insert().

Referenced by deriveAttrsInPostOrder().

◆ addNoRecurseAttrsTopDown()

static bool addNoRecurseAttrsTopDown ( Function & F )

static

Definition at line 1836 of file FunctionAttrs.cpp.

References assert(), llvm::Function::doesNotRecurse(), F, llvm::BasicBlock::getParent(), llvm::Instruction::getParent(), I, and llvm::CallBase::isCallee().

Referenced by deduceFunctionAttributeInRPO().

◆ addNoReturnAttrs()

static void addNoReturnAttrs	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Definition at line 1637 of file FunctionAttrs.cpp.

References canReturn(), F, and llvm::SmallSet< T, N, C >::insert().

Referenced by deriveAttrsInPostOrder().

◆ addWillReturn()

static void addWillReturn	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Definition at line 1681 of file FunctionAttrs.cpp.

References F, functionWillReturn(), and llvm::SmallSet< T, N, C >::insert().

Referenced by deriveAttrsInPostOrder().

◆ basicBlockCanReturn()

static bool basicBlockCanReturn ( BasicBlock & BB )

static

Definition at line 1610 of file FunctionAttrs.cpp.

References llvm::BasicBlock::getTerminator(), instructionDoesNotReturn(), and llvm::none_of().

Referenced by canReturn().

◆ calculatePrevailingSummary()

static FunctionSummary * calculatePrevailingSummary	(	ValueInfo	VI,
		DenseMap< ValueInfo, FunctionSummary * > &	CachedPrevailingSummary,
		function_ref< bool(GlobalValue::GUID, const GlobalValueSummary *)>	IsPrevailing
	)

static

At this point, prevailing symbols have been resolved. The following leads to returning a conservative result:

Multiple instances with local linkage. Normally local linkage would be unique per module as the GUID includes the module path. We could have a guid alias if there wasn't any distinguishing path when each file was compiled, but that should be rare so we'll punt on those.

These next 2 cases should not happen and will assert:

Multiple instances with external linkage. This should be caught in symbol resolution
Non-existent FunctionSummary for Aliasee. This presents a hole in our knowledge meaning we have to go conservative.

Otherwise, we calculate attributes for a function as:

If we have a local linkage, take its attributes. If there's somehow multiple, bail and go conservative.
If we have an external/WeakODR/LinkOnceODR linkage check that it is prevailing, take its attributes.
If we have a Weak/LinkOnce linkage the copies can have semantic differences. However, if the prevailing copy is known it will be used so take its attributes. If the prevailing copy is in a native file all IR copies will be dead and propagation will go conservative.
AvailableExternally summaries without a prevailing copy are known to occur in a couple of circumstances: a. An internal function gets imported due to its caller getting imported, it becomes AvailableExternally but no prevailing definition exists. Because it has to get imported along with its caller the attributes will be captured by propagating on its caller. b. C++11 [temp.explicit]p10 can generate AvailableExternally definitions of explicitly instanced template declarations for inlining which are ultimately dropped from the TU. Since this is localized to the TU the attributes will have already made it to the callers. These are edge cases and already captured by their callers so we ignore these for now. If they become relevant to optimize in the future this can be revisited.
Otherwise, go conservative.

Definition at line 268 of file FunctionAttrs.cpp.

References assert(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::dbgs(), llvm::GlobalValue::isAvailableExternallyLinkage(), llvm::GlobalValue::isExternalLinkage(), llvm::GlobalValue::isLinkOnceAnyLinkage(), llvm::GlobalValue::isLinkOnceODRLinkage(), llvm::GlobalValue::isLocalLinkage(), llvm::GlobalValue::isWeakAnyLinkage(), llvm::GlobalValue::isWeakODRLinkage(), LLVM_DEBUG, and VI.

Referenced by llvm::thinLTOPropagateFunctionAttrs().

◆ canReturn()

static bool canReturn ( Function & F )

static

Definition at line 1617 of file FunctionAttrs.cpp.

References basicBlockCanReturn(), llvm::SmallVectorBase< Size_T >::empty(), F, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::successors().

Referenced by addNoReturnAttrs().

◆ checkFunctionMemoryAccess()

static MemoryEffects checkFunctionMemoryAccess	(	Function &	F,
		bool	ThisBody,
		AAResults &	AAR,
		const SCCNodeSet &	SCCNodes
	)

static

Returns the memory access attribute for function F using AAR for AA results, where SCCNodes is the current SCC.

If ThisBody is true, this function may examine the function body and will return a result pertaining to this copy of the function. If it is false, the result will be based only on AA results for the function declaration; it will be assumed that some other (perhaps less optimized) version of the function may be selected at link time.

Definition at line 123 of file FunctionAttrs.cpp.

Referenced by addMemoryAttrs(), and llvm::computeFunctionBodyMemoryAccess().

◆ createSCCNodeSet()

static SCCNodesResult createSCCNodeSet ( ArrayRef< Function * > Functions )

static

Definition at line 1693 of file FunctionAttrs.cpp.

References F, llvm::CallBase::getCalledFunction(), I, and instructions.

Referenced by deriveAttrsInPostOrder().

◆ deduceFunctionAttributeInRPO()

static bool deduceFunctionAttributeInRPO	(	Module &	M,
		LazyCallGraph &	CG
	)

static

Definition at line 1868 of file FunctionAttrs.cpp.

References addNoRecurseAttrsTopDown(), llvm::LazyCallGraph::buildRefSCCs(), F, llvm::LazyCallGraph::postorder_ref_sccs(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::reverse().

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

◆ deriveAttrsInPostOrder()

template<typename AARGetterT >

static SmallSet< Function *, 8 > deriveAttrsInPostOrder	(	ArrayRef< Function * >	Functions,
		AARGetterT &&	AARGetter
	)

static

Definition at line 1725 of file FunctionAttrs.cpp.

References addArgumentAttrs(), addArgumentReturnedAttrs(), addMemoryAttrs(), addNoAliasAttrs(), addNonNullAttrs(), addNoRecurseAttrs(), addNoReturnAttrs(), addWillReturn(), createSCCNodeSet(), F, llvm::inferAttributesFromOthers(), inferAttrsFromFunctionBodies(), inferConvergent(), and llvm::SmallSet< T, N, C >::insert().

Referenced by llvm::PostOrderFunctionAttrsPass::run(), and runImpl().

◆ determinePointerAccessAttrs()

static Attribute::AttrKind determinePointerAccessAttrs	(	Argument *	A,
		const SmallPtrSet< Argument *, 8 > &	SCCNodes
	)

static

Returns Attribute::None, Attribute::ReadOnly or Attribute::ReadNone.

Definition at line 579 of file FunctionAttrs.cpp.

References A, llvm::SmallPtrSetImpl< PtrType >::count(), llvm::CallBase::dataOperandHasImpliedAttr(), llvm::CallBase::doesNotAccessMemory(), llvm::CallBase::doesNotCapture(), llvm::SmallVectorBase< Size_T >::empty(), F, llvm::CallBase::getCalledFunction(), llvm::CallBase::getDataOperandNo(), llvm::CallBase::hasFnAttr(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::CallBase::isArgOperand(), llvm::CallBase::isCallee(), llvm::Attribute::None, llvm::CallBase::onlyReadsMemory(), llvm::SmallVectorImpl< T >::pop_back_val(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by addArgumentAttrs().

◆ functionWillReturn()

static bool functionWillReturn ( const Function & F )

static

Definition at line 1651 of file FunctionAttrs.cpp.

References llvm::all_of(), llvm::SmallVectorBase< Size_T >::empty(), F, llvm::FindFunctionBackedges(), I, and instructions.

Referenced by addWillReturn().

◆ inferAttrsFromFunctionBodies()

static void inferAttrsFromFunctionBodies	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Infer attributes from all functions in the SCC by scanning every instruction for compliance to the attribute assumptions.

Returns true if any changes to function attributes were made.

Definition at line 1501 of file FunctionAttrs.cpp.

References llvm::dbgs(), DisableNoFreeInference, DisableNoUnwindInference, F, I, InstrBreaksNoFree(), InstrBreaksNonThrowing(), InstrBreaksNoSync(), and LLVM_DEBUG.

Referenced by deriveAttrsInPostOrder().

◆ inferConvergent()

static void inferConvergent	(	const SCCNodeSet &	SCCNodes,
		SmallSet< Function *, 8 > &	Changed
	)

static

Attempt to remove convergent function attribute when possible.

Returns true if any changes to function attributes were made.

Definition at line 1470 of file FunctionAttrs.cpp.

References llvm::dbgs(), F, I, InstrBreaksNonConvergent(), and LLVM_DEBUG.

Referenced by deriveAttrsInPostOrder().

◆ InstrBreaksNoFree()

static bool InstrBreaksNoFree	(	Instruction &	I,
		const SCCNodeSet &	SCCNodes
	)

static

Helper for NoFree inference predicate InstrBreaksAttribute.

Definition at line 1396 of file FunctionAttrs.cpp.

References Callee, llvm::CallBase::getCalledFunction(), llvm::CallBase::hasFnAttr(), and I.

Referenced by inferAttrsFromFunctionBodies().

◆ InstrBreaksNonConvergent()

static bool InstrBreaksNonConvergent	(	Instruction &	I,
		const SCCNodeSet &	SCCNodes
	)

static

Helper for non-Convergent inference predicate InstrBreaksAttribute.

Definition at line 1370 of file FunctionAttrs.cpp.

References llvm::CallBase::getCalledFunction(), I, and llvm::CallBase::isConvergent().

Referenced by inferConvergent().

◆ InstrBreaksNonThrowing()

static bool InstrBreaksNonThrowing	(	Instruction &	I,
		const SCCNodeSet &	SCCNodes
	)

static

Helper for NoUnwind inference predicate InstrBreaksAttribute.

Definition at line 1380 of file FunctionAttrs.cpp.

References Callee, and I.

Referenced by inferAttrsFromFunctionBodies().

◆ InstrBreaksNoSync()

static bool InstrBreaksNoSync	(	Instruction &	I,
		const SCCNodeSet &	SCCNodes
	)

static

Definition at line 1435 of file FunctionAttrs.cpp.

References Callee, llvm::CallBase::getCalledFunction(), llvm::CallBase::hasFnAttr(), I, isOrderedAtomic(), and MI.

Referenced by inferAttrsFromFunctionBodies().

◆ instructionDoesNotReturn()

static bool instructionDoesNotReturn ( Instruction & I )

static

Definition at line 1602 of file FunctionAttrs.cpp.

References llvm::CallBase::hasFnAttr(), and I.

Referenced by basicBlockCanReturn().

◆ isFunctionMallocLike()

static bool isFunctionMallocLike	(	Function *	F,
		const SCCNodeSet &	SCCNodes
	)

static

Tests whether a function is "malloc-like".

A function is "malloc-like" if it returns either null or a pointer that doesn't alias any other pointer visible to the caller.

Definition at line 1011 of file FunctionAttrs.cpp.

References llvm::CallingConv::C, F, llvm::CallBase::getCalledFunction(), llvm::CallBase::hasRetAttr(), llvm::PHINode::incoming_values(), llvm::SetVector< T, Vector, Set >::insert(), llvm::PointerMayBeCaptured(), SI, and llvm::SetVector< T, Vector, Set >::size().

Referenced by addNoAliasAttrs().

◆ isOrderedAtomic()

static bool isOrderedAtomic ( Instruction * I )

static

Definition at line 1417 of file FunctionAttrs.cpp.

References I, llvm_unreachable, SI, and llvm::SyncScope::SingleThread.

Referenced by InstrBreaksNoSync().

◆ isReturnNonNull()

static bool isReturnNonNull	(	Function *	F,
		const SCCNodeSet &	SCCNodes,
		bool &	Speculative
	)

static

Tests whether this function is known to not return null.

Requires that the function returns a pointer.

Returns true if it believes the function will not return a null, and sets Speculative based on whether the returned conclusion is a speculative conclusion due to SCC calls.

Definition at line 1117 of file FunctionAttrs.cpp.

References assert(), Callee, DL, F, llvm::CallBase::getCalledFunction(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), llvm::Instruction::getOpcode(), llvm::User::getOperand(), llvm::SetVector< T, Vector, Set >::insert(), llvm::isKnownNonZero(), llvm_unreachable, SI, and llvm::SetVector< T, Vector, Set >::size().

Referenced by addNonNullAttrs().

◆ runImpl()

template<typename AARGetterT >

static bool runImpl	(	CallGraphSCC &	SCC,
		AARGetterT	AARGetter
	)

static

Definition at line 1827 of file FunctionAttrs.cpp.

References deriveAttrsInPostOrder(), I, and llvm::SmallVectorTemplateBase< T, bool >::push_back().

◆ STATISTIC() [1/15]

STATISTIC	(	NumMemoryAttr	,
		"Number of functions with improved memory attribute"
	)

◆ STATISTIC() [2/15]

STATISTIC	(	NumNoAlias	,
		"Number of function returns marked noalias"
	)

◆ STATISTIC() [3/15]

STATISTIC	(	NumNoCapture	,
		"Number of arguments marked nocapture"
	)

◆ STATISTIC() [4/15]

STATISTIC	(	NumNoFree	,
		"Number of functions marked as nofree"
	)

◆ STATISTIC() [5/15]

STATISTIC	(	NumNonNullReturn	,
		"Number of function returns marked nonnull"
	)

◆ STATISTIC() [6/15]

STATISTIC	(	NumNoRecurse	,
		"Number of functions marked as norecurse"
	)

◆ STATISTIC() [7/15]

STATISTIC	(	NumNoSync	,
		"Number of functions marked as nosync"
	)

◆ STATISTIC() [8/15]

STATISTIC	(	NumNoUnwind	,
		"Number of functions marked as nounwind"
	)

◆ STATISTIC() [9/15]

STATISTIC	(	NumReadNoneArg	,
		"Number of arguments marked readnone"
	)

◆ STATISTIC() [10/15]

STATISTIC	(	NumReadOnlyArg	,
		"Number of arguments marked readonly"
	)

◆ STATISTIC() [11/15]

STATISTIC	(	NumReturned	,
		"Number of arguments marked returned"
	)

◆ STATISTIC() [12/15]

STATISTIC	(	NumThinLinkNoRecurse	,
		"Number of functions marked as norecurse during thinlink"
	)

◆ STATISTIC() [13/15]

STATISTIC	(	NumThinLinkNoUnwind	,
		"Number of functions marked as nounwind during thinlink"
	)

◆ STATISTIC() [14/15]

STATISTIC	(	NumWillReturn	,
		"Number of functions marked as willreturn"
	)

◆ STATISTIC() [15/15]

STATISTIC	(	NumWriteOnlyArg	,
		"Number of arguments marked writeonly"
	)

Variable Documentation

◆ DisableNoFreeInference

cl::opt< bool > DisableNoFreeInference("disable-nofree-inference", cl::Hidden, cl::desc("Stop inferring nofree attribute during function-attrs pass"))	(	"disable-nofree-inference"	,
		cl::Hidden	,
		cl::desc("Stop inferring nofree attribute during function-attrs pass")
	)

static

Referenced by inferAttrsFromFunctionBodies().

◆ DisableNoUnwindInference

cl::opt< bool > DisableNoUnwindInference("disable-nounwind-inference", cl::Hidden, cl::desc("Stop inferring nounwind attribute during function-attrs pass"))	(	"disable-nounwind-inference"	,
		cl::Hidden	,
		cl::desc("Stop inferring nounwind attribute during function-attrs pass")
	)

static

Referenced by inferAttrsFromFunctionBodies().

◆ DisableThinLTOPropagation

cl::opt< bool > DisableThinLTOPropagation("disable-thinlto-funcattrs", cl::init(true), cl::Hidden, cl::desc("Don't propagate function-attrs in thinLTO"))	(	"disable-thinlto-funcattrs"	,
		cl::init(true)	,
		cl::Hidden	,
		cl::desc("Don't propagate function-attrs in thinLTO")
	)

static

Referenced by llvm::thinLTOPropagateFunctionAttrs().

◆ EnableNonnullArgPropagation

cl::opt< bool > EnableNonnullArgPropagation("enable-nonnull-arg-prop", cl::init(true), cl::Hidden, cl::desc("Try to propagate nonnull argument attributes from callsites to " "caller functions."))	(	"enable-nonnull-arg-prop"	,
		cl::init(true)	,
		cl::Hidden	,
		cl::desc("Try to propagate nonnull argument attributes from callsites to " "caller functions.")
	)

static

Referenced by addArgumentAttrsFromCallsites().

Classes

Namespaces

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DEBUG_TYPE

Function Documentation

◆ addAccessAttr()

◆ addArgumentAttrs()

◆ addArgumentAttrsFromCallsites()

◆ addArgumentReturnedAttrs()

◆ addMemoryAttrs()

◆ addNoAliasAttrs()

◆ addNonNullAttrs()

◆ addNoRecurseAttrs()

◆ addNoRecurseAttrsTopDown()

◆ addNoReturnAttrs()

◆ addWillReturn()

◆ basicBlockCanReturn()

◆ calculatePrevailingSummary()

◆ canReturn()

◆ checkFunctionMemoryAccess()

◆ createSCCNodeSet()

◆ deduceFunctionAttributeInRPO()

◆ deriveAttrsInPostOrder()

◆ determinePointerAccessAttrs()

◆ functionWillReturn()

◆ inferAttrsFromFunctionBodies()

◆ inferConvergent()

◆ InstrBreaksNoFree()

◆ InstrBreaksNonConvergent()

◆ InstrBreaksNonThrowing()

◆ InstrBreaksNoSync()

◆ instructionDoesNotReturn()

◆ isFunctionMallocLike()

◆ isOrderedAtomic()

◆ isReturnNonNull()

◆ runImpl()

◆ STATISTIC() [1/15]

◆ STATISTIC() [2/15]

◆ STATISTIC() [3/15]

◆ STATISTIC() [4/15]

◆ STATISTIC() [5/15]

◆ STATISTIC() [6/15]

◆ STATISTIC() [7/15]

◆ STATISTIC() [8/15]

◆ STATISTIC() [9/15]

◆ STATISTIC() [10/15]

◆ STATISTIC() [11/15]

◆ STATISTIC() [12/15]

◆ STATISTIC() [13/15]

◆ STATISTIC() [14/15]

◆ STATISTIC() [15/15]

Variable Documentation

◆ DisableNoFreeInference

◆ DisableNoUnwindInference

◆ DisableThinLTOPropagation

◆ EnableNonnullArgPropagation