ObjCARCContract.cpp File Reference

This file defines late ObjC ARC optimizations. More...

#include "ARCRuntimeEntryPoints.h"
#include "DependencyAnalysis.h"
#include "ObjCARC.h"
#include "ProvenanceAnalysis.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/ObjCARCUtil.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/EHPersonalities.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PassManager.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/ObjCARC.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "objc-arc-contract"

Functions
	STATISTIC (NumPeeps, "Number of calls peephole-optimized")
	STATISTIC (NumStoreStrongs, "Number objc_storeStrong calls formed")
static StoreInst *	findSafeStoreForStoreStrongContraction (LoadInst *Load, Instruction *Release, ProvenanceAnalysis &PA, AAResults *AA)
static Instruction *	findRetainForStoreStrongContraction (Value *New, StoreInst *Store, Instruction *Release, ProvenanceAnalysis &PA)
static bool	useClaimRuntimeCall (Module &M)
	Should we use objc_claimAutoreleasedReturnValue?
	INITIALIZE_PASS_BEGIN (ObjCARCContractLegacyPass, "objc-arc-contract", "ObjC ARC contraction", false, false) INITIALIZE_PASS_END(ObjCARCContractLegacyPass

Variables
static cl::opt< cl::boolOrDefault >	UseObjCClaimRV ("arc-contract-use-objc-claim-rv", cl::desc("Enable generation of calls to objc_claimAutoreleasedReturnValue"))
objc arc	contract
objc arc ObjC ARC	contraction
objc arc ObjC ARC	false

Detailed Description

This file defines late ObjC ARC optimizations.

ARC stands for Automatic Reference Counting and is a system for managing reference counts for objects in Objective C.

This specific file mainly deals with `‘contracting’' multiple lower level operations into singular higher level operations through pattern matching.

WARNING: This file knows about certain library functions. It recognizes them by name, and hardwires knowledge of their semantics.

WARNING: This file knows about how certain Objective-C library functions are used. Naive LLVM IR transformations which would otherwise be behavior-preserving may break these assumptions.

Definition in file ObjCARCContract.cpp.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "objc-arc-contract"

Definition at line 51 of file ObjCARCContract.cpp.

Function Documentation

findRetainForStoreStrongContraction()

Instruction * findRetainForStoreStrongContraction ( Value * New, StoreInst * Store, Instruction * Release, ProvenanceAnalysis & PA )

static

Definition at line 296 of file ObjCARCContract.cpp.

References llvm::objcarc::CanDecrementRefCount(), llvm::objcarc::GetArgRCIdentityRoot(), llvm::objcarc::GetBasicARCInstKind(), I, llvm::Release, llvm::objcarc::Retain, and Retain.

findSafeStoreForStoreStrongContraction()

StoreInst * findSafeStoreForStoreStrongContraction ( LoadInst * Load, Instruction * Release, ProvenanceAnalysis & PA, AAResults * AA )

static

Definition at line 206 of file ObjCARCContract.cpp.

References llvm::objcarc::CanUse(), llvm::dyn_cast(), E(), llvm::MemoryLocation::get(), llvm::objcarc::GetBasicARCInstKind(), I, llvm::isModSet(), llvm::objcarc::IsRetain(), and llvm::Release.

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	ObjCARCContractLegacyPass	,
		"objc-arc-contract"	,
		"ObjC ARC contraction"	,
		false	,
		false	)

References INITIALIZE_PASS_DEPENDENCY.

STATISTIC() [1/2]

STATISTIC	(	NumPeeps	,
		"Number of calls peephole-optimized"	)

STATISTIC() [2/2]

STATISTIC	(	NumStoreStrongs	,
		"Number objc_storeStrong calls formed"	)

useClaimRuntimeCall()

bool useClaimRuntimeCall ( Module & M )

static

Should we use objc_claimAutoreleasedReturnValue?

Definition at line 530 of file ObjCARCContract.cpp.

References llvm::cl::BOU_TRUE, llvm::cl::BOU_UNSET, llvm::Triple::BridgeOS, llvm::Triple::Darwin, llvm::Triple::IOS, llvm::Triple::MacOSX, llvm::Triple::TvOS, UseObjCClaimRV, and llvm::Triple::WatchOS.

Variable Documentation

contract

objc arc contract

Definition at line 754 of file ObjCARCContract.cpp.

contraction

objc arc ObjC ARC contraction

Definition at line 755 of file ObjCARCContract.cpp.

false

objc arc ObjC ARC false

Definition at line 755 of file ObjCARCContract.cpp.

UseObjCClaimRV

cl::opt< cl::boolOrDefault > UseObjCClaimRV("arc-contract-use-objc-claim-rv", cl::desc( "Enable generation of calls to objc_claimAutoreleasedReturnValue")) ( "arc-contract-use-objc-claim-rv" , cl::desc( "Enable generation of calls to objc_claimAutoreleasedReturnValue")  )

static

Referenced by useClaimRuntimeCall().