diff options
| -rw-r--r-- | llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp | 178 |
1 files changed, 88 insertions, 90 deletions
diff --git a/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp b/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp index ff07cfe00d4..906425d229a 100644 --- a/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp +++ b/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp @@ -439,102 +439,100 @@ void ObjCARCContract::tryToContractReleaseIntoStoreStrong( } bool ObjCARCContract::tryToPeepholeInstruction( - Function &F, Instruction *Inst, inst_iterator &Iter, - SmallPtrSetImpl<Instruction *> &DependingInsts, - SmallPtrSetImpl<const BasicBlock *> &Visited, - bool &TailOkForStoreStrongs, - const DenseMap<BasicBlock *, ColorVector> &BlockColors) { - // Only these library routines return their argument. In particular, - // objc_retainBlock does not necessarily return its argument. + Function &F, Instruction *Inst, inst_iterator &Iter, + SmallPtrSetImpl<Instruction *> &DependingInsts, + SmallPtrSetImpl<const BasicBlock *> &Visited, bool &TailOkForStoreStrongs, + const DenseMap<BasicBlock *, ColorVector> &BlockColors) { + // Only these library routines return their argument. In particular, + // objc_retainBlock does not necessarily return its argument. ARCInstKind Class = GetBasicARCInstKind(Inst); - switch (Class) { - case ARCInstKind::FusedRetainAutorelease: - case ARCInstKind::FusedRetainAutoreleaseRV: + switch (Class) { + case ARCInstKind::FusedRetainAutorelease: + case ARCInstKind::FusedRetainAutoreleaseRV: + return false; + case ARCInstKind::Autorelease: + case ARCInstKind::AutoreleaseRV: + return contractAutorelease(F, Inst, Class, DependingInsts, Visited); + case ARCInstKind::Retain: + // Attempt to convert retains to retainrvs if they are next to function + // calls. + if (!optimizeRetainCall(F, Inst)) return false; - case ARCInstKind::Autorelease: - case ARCInstKind::AutoreleaseRV: - return contractAutorelease(F, Inst, Class, DependingInsts, Visited); - case ARCInstKind::Retain: - // Attempt to convert retains to retainrvs if they are next to function - // calls. - if (!optimizeRetainCall(F, Inst)) - return false; - // If we succeed in our optimization, fall through. - LLVM_FALLTHROUGH; - case ARCInstKind::RetainRV: - case ARCInstKind::ClaimRV: { - // If we're compiling for a target which needs a special inline-asm - // marker to do the return value optimization, insert it now. - if (!RVInstMarker) - return false; - BasicBlock::iterator BBI = Inst->getIterator(); - BasicBlock *InstParent = Inst->getParent(); - - // Step up to see if the call immediately precedes the RV call. - // If it's an invoke, we have to cross a block boundary. And we have - // to carefully dodge no-op instructions. - do { - if (BBI == InstParent->begin()) { - BasicBlock *Pred = InstParent->getSinglePredecessor(); - if (!Pred) - goto decline_rv_optimization; - BBI = Pred->getTerminator()->getIterator(); - break; - } - --BBI; - } while (IsNoopInstruction(&*BBI)); - - if (&*BBI == GetArgRCIdentityRoot(Inst)) { - LLVM_DEBUG(dbgs() << "Adding inline asm marker for the return value " - "optimization.\n"); - Changed = true; - InlineAsm *IA = InlineAsm::get( - FunctionType::get(Type::getVoidTy(Inst->getContext()), - /*isVarArg=*/false), - RVInstMarker->getString(), - /*Constraints=*/"", /*hasSideEffects=*/true); - - createCallInst(IA, None, "", Inst, BlockColors); - } - decline_rv_optimization: + // If we succeed in our optimization, fall through. + LLVM_FALLTHROUGH; + case ARCInstKind::RetainRV: + case ARCInstKind::ClaimRV: { + // If we're compiling for a target which needs a special inline-asm + // marker to do the return value optimization, insert it now. + if (!RVInstMarker) return false; - } - case ARCInstKind::InitWeak: { - // objc_initWeak(p, null) => *p = null - CallInst *CI = cast<CallInst>(Inst); - if (IsNullOrUndef(CI->getArgOperand(1))) { - Value *Null = - ConstantPointerNull::get(cast<PointerType>(CI->getType())); - Changed = true; - new StoreInst(Null, CI->getArgOperand(0), CI); - - LLVM_DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n" - << " New = " << *Null << "\n"); - - CI->replaceAllUsesWith(Null); - CI->eraseFromParent(); + BasicBlock::iterator BBI = Inst->getIterator(); + BasicBlock *InstParent = Inst->getParent(); + + // Step up to see if the call immediately precedes the RV call. + // If it's an invoke, we have to cross a block boundary. And we have + // to carefully dodge no-op instructions. + do { + if (BBI == InstParent->begin()) { + BasicBlock *Pred = InstParent->getSinglePredecessor(); + if (!Pred) + goto decline_rv_optimization; + BBI = Pred->getTerminator()->getIterator(); + break; } - return true; + --BBI; + } while (IsNoopInstruction(&*BBI)); + + if (&*BBI == GetArgRCIdentityRoot(Inst)) { + LLVM_DEBUG(dbgs() << "Adding inline asm marker for the return value " + "optimization.\n"); + Changed = true; + InlineAsm *IA = + InlineAsm::get(FunctionType::get(Type::getVoidTy(Inst->getContext()), + /*isVarArg=*/false), + RVInstMarker->getString(), + /*Constraints=*/"", /*hasSideEffects=*/true); + + createCallInst(IA, None, "", Inst, BlockColors); } - case ARCInstKind::Release: - // Try to form an objc store strong from our release. If we fail, there is - // nothing further to do below, so continue. - tryToContractReleaseIntoStoreStrong(Inst, Iter, BlockColors); - return true; - case ARCInstKind::User: - // Be conservative if the function has any alloca instructions. - // Technically we only care about escaping alloca instructions, - // but this is sufficient to handle some interesting cases. - if (isa<AllocaInst>(Inst)) - TailOkForStoreStrongs = false; - return true; - case ARCInstKind::IntrinsicUser: - // Remove calls to @llvm.objc.clang.arc.use(...). - Inst->eraseFromParent(); - return true; - default: - return true; + decline_rv_optimization: + return false; + } + case ARCInstKind::InitWeak: { + // objc_initWeak(p, null) => *p = null + CallInst *CI = cast<CallInst>(Inst); + if (IsNullOrUndef(CI->getArgOperand(1))) { + Value *Null = ConstantPointerNull::get(cast<PointerType>(CI->getType())); + Changed = true; + new StoreInst(Null, CI->getArgOperand(0), CI); + + LLVM_DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n" + << " New = " << *Null << "\n"); + + CI->replaceAllUsesWith(Null); + CI->eraseFromParent(); } + return true; + } + case ARCInstKind::Release: + // Try to form an objc store strong from our release. If we fail, there is + // nothing further to do below, so continue. + tryToContractReleaseIntoStoreStrong(Inst, Iter, BlockColors); + return true; + case ARCInstKind::User: + // Be conservative if the function has any alloca instructions. + // Technically we only care about escaping alloca instructions, + // but this is sufficient to handle some interesting cases. + if (isa<AllocaInst>(Inst)) + TailOkForStoreStrongs = false; + return true; + case ARCInstKind::IntrinsicUser: + // Remove calls to @llvm.objc.clang.arc.use(...). + Inst->eraseFromParent(); + return true; + default: + return true; + } } //===----------------------------------------------------------------------===// |
