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Diffstat (limited to 'lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp')
| -rw-r--r-- | lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp b/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp deleted file mode 100644 index 3893aab76b2a..000000000000 --- a/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.cpp +++ /dev/null @@ -1,168 +0,0 @@ -//===- ObjCARCAliasAnalysis.cpp - ObjC ARC Optimization -------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -/// \file -/// This file defines a simple ARC-aware AliasAnalysis using special knowledge -/// of Objective C to enhance other optimization passes which rely on the Alias -/// Analysis infrastructure. -/// -/// 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. -/// -//===----------------------------------------------------------------------===// - -#include "ObjCARC.h" -#include "ObjCARCAliasAnalysis.h" -#include "llvm/IR/Instruction.h" -#include "llvm/InitializePasses.h" -#include "llvm/PassAnalysisSupport.h" -#include "llvm/PassSupport.h" - -#define DEBUG_TYPE "objc-arc-aa" - -namespace llvm { - class Function; - class Value; -} - -using namespace llvm; -using namespace llvm::objcarc; - -// Register this pass... -char ObjCARCAliasAnalysis::ID = 0; -INITIALIZE_AG_PASS(ObjCARCAliasAnalysis, AliasAnalysis, "objc-arc-aa", - "ObjC-ARC-Based Alias Analysis", false, true, false) - -ImmutablePass *llvm::createObjCARCAliasAnalysisPass() { - return new ObjCARCAliasAnalysis(); -} - -bool ObjCARCAliasAnalysis::doInitialization(Module &M) { - InitializeAliasAnalysis(this, &M.getDataLayout()); - return true; -} - -void -ObjCARCAliasAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { - AU.setPreservesAll(); - AliasAnalysis::getAnalysisUsage(AU); -} - -AliasResult ObjCARCAliasAnalysis::alias(const MemoryLocation &LocA, - const MemoryLocation &LocB) { - if (!EnableARCOpts) - return AliasAnalysis::alias(LocA, LocB); - - // First, strip off no-ops, including ObjC-specific no-ops, and try making a - // precise alias query. - const Value *SA = GetRCIdentityRoot(LocA.Ptr); - const Value *SB = GetRCIdentityRoot(LocB.Ptr); - AliasResult Result = - AliasAnalysis::alias(MemoryLocation(SA, LocA.Size, LocA.AATags), - MemoryLocation(SB, LocB.Size, LocB.AATags)); - if (Result != MayAlias) - return Result; - - // If that failed, climb to the underlying object, including climbing through - // ObjC-specific no-ops, and try making an imprecise alias query. - const Value *UA = GetUnderlyingObjCPtr(SA, *DL); - const Value *UB = GetUnderlyingObjCPtr(SB, *DL); - if (UA != SA || UB != SB) { - Result = AliasAnalysis::alias(MemoryLocation(UA), MemoryLocation(UB)); - // We can't use MustAlias or PartialAlias results here because - // GetUnderlyingObjCPtr may return an offsetted pointer value. - if (Result == NoAlias) - return NoAlias; - } - - // If that failed, fail. We don't need to chain here, since that's covered - // by the earlier precise query. - return MayAlias; -} - -bool ObjCARCAliasAnalysis::pointsToConstantMemory(const MemoryLocation &Loc, - bool OrLocal) { - if (!EnableARCOpts) - return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal); - - // First, strip off no-ops, including ObjC-specific no-ops, and try making - // a precise alias query. - const Value *S = GetRCIdentityRoot(Loc.Ptr); - if (AliasAnalysis::pointsToConstantMemory( - MemoryLocation(S, Loc.Size, Loc.AATags), OrLocal)) - return true; - - // If that failed, climb to the underlying object, including climbing through - // ObjC-specific no-ops, and try making an imprecise alias query. - const Value *U = GetUnderlyingObjCPtr(S, *DL); - if (U != S) - return AliasAnalysis::pointsToConstantMemory(MemoryLocation(U), OrLocal); - - // If that failed, fail. We don't need to chain here, since that's covered - // by the earlier precise query. - return false; -} - -AliasAnalysis::ModRefBehavior -ObjCARCAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) { - // We have nothing to do. Just chain to the next AliasAnalysis. - return AliasAnalysis::getModRefBehavior(CS); -} - -AliasAnalysis::ModRefBehavior -ObjCARCAliasAnalysis::getModRefBehavior(const Function *F) { - if (!EnableARCOpts) - return AliasAnalysis::getModRefBehavior(F); - - switch (GetFunctionClass(F)) { - case ARCInstKind::NoopCast: - return DoesNotAccessMemory; - default: - break; - } - - return AliasAnalysis::getModRefBehavior(F); -} - -AliasAnalysis::ModRefResult -ObjCARCAliasAnalysis::getModRefInfo(ImmutableCallSite CS, - const MemoryLocation &Loc) { - if (!EnableARCOpts) - return AliasAnalysis::getModRefInfo(CS, Loc); - - switch (GetBasicARCInstKind(CS.getInstruction())) { - case ARCInstKind::Retain: - case ARCInstKind::RetainRV: - case ARCInstKind::Autorelease: - case ARCInstKind::AutoreleaseRV: - case ARCInstKind::NoopCast: - case ARCInstKind::AutoreleasepoolPush: - case ARCInstKind::FusedRetainAutorelease: - case ARCInstKind::FusedRetainAutoreleaseRV: - // These functions don't access any memory visible to the compiler. - // Note that this doesn't include objc_retainBlock, because it updates - // pointers when it copies block data. - return NoModRef; - default: - break; - } - - return AliasAnalysis::getModRefInfo(CS, Loc); -} - -AliasAnalysis::ModRefResult -ObjCARCAliasAnalysis::getModRefInfo(ImmutableCallSite CS1, - ImmutableCallSite CS2) { - // TODO: Theoretically we could check for dependencies between objc_* calls - // and OnlyAccessesArgumentPointees calls or other well-behaved calls. - return AliasAnalysis::getModRefInfo(CS1, CS2); -} |