From: Bill Wendling Date: Thu, 29 Oct 2009 00:37:35 +0000 (+0000) Subject: Don't put in these EH changes. X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8bedf97f683bd5edb9308799a5e525de137d635c;p=oota-llvm.git Don't put in these EH changes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85460 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h index f753eecba2d..d0d610370bd 100644 --- a/include/llvm/CodeGen/Passes.h +++ b/include/llvm/CodeGen/Passes.h @@ -186,7 +186,7 @@ namespace llvm { /// createDwarfEHPass - This pass mulches exception handling code into a form /// adapted to code generation. Required if using dwarf exception handling. - FunctionPass *createDwarfEHPass(const TargetLowering *tli); + FunctionPass *createDwarfEHPass(const TargetLowering *tli, bool fast); /// createSjLjEHPass - This pass adapts exception handling code to use /// the GCC-style builtin setjmp/longjmp (sjlj) to handling EH control flow. diff --git a/include/llvm/IntrinsicInst.h b/include/llvm/IntrinsicInst.h index ee5f23a7511..6a8f3763926 100644 --- a/include/llvm/IntrinsicInst.h +++ b/include/llvm/IntrinsicInst.h @@ -307,19 +307,6 @@ namespace llvm { } }; - /// EHExceptionInst - This represents the llvm.eh.exception instruction. - /// - struct EHExceptionInst : public IntrinsicInst { - // Methods for support type inquiry through isa, cast, and dyn_cast: - static inline bool classof(const EHExceptionInst *) { return true; } - static inline bool classof(const IntrinsicInst *I) { - return I->getIntrinsicID() == Intrinsic::eh_exception; - } - static inline bool classof(const Value *V) { - return isa(V) && classof(cast(V)); - } - }; - /// EHSelectorInst - This represents the llvm.eh.selector instruction. /// struct EHSelectorInst : public IntrinsicInst { diff --git a/lib/CodeGen/DwarfEHPrepare.cpp b/lib/CodeGen/DwarfEHPrepare.cpp index cfaaa70b929..7fc62a9a96c 100644 --- a/lib/CodeGen/DwarfEHPrepare.cpp +++ b/lib/CodeGen/DwarfEHPrepare.cpp @@ -21,41 +21,27 @@ #include "llvm/IntrinsicInst.h" #include "llvm/Module.h" #include "llvm/Pass.h" -#include "llvm/Support/Compiler.h" -#include "llvm/Support/IRBuilder.h" #include "llvm/Target/TargetLowering.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/PromoteMemToReg.h" using namespace llvm; -STATISTIC(NumExceptionValuesMoved, "Number of eh.exception calls moved"); -STATISTIC(NumLonelyLandingPads, "Number of landing pads with no selector"); -STATISTIC(NumLonelySelectors, "Number of lonely selectors lowered"); STATISTIC(NumLandingPadsSplit, "Number of landing pads split"); -STATISTIC(NumSelectorsAdjusted, "Number of selector results adjusted"); -STATISTIC(NumSelectorsSimplified, "Number of selectors truncated"); -STATISTIC(NumStackTempsIntroduced, "Number of stack temporaries introduced"); STATISTIC(NumUnwindsLowered, "Number of unwind instructions lowered"); +STATISTIC(NumExceptionValuesMoved, "Number of eh.exception calls moved"); +STATISTIC(NumStackTempsIntroduced, "Number of stack temporaries introduced"); namespace { class DwarfEHPrepare : public FunctionPass { const TargetLowering *TLI; + bool CompileFast; // The eh.exception intrinsic. - Function *ExceptionIntrinsic; - - // The eh.selector intrinsic. - Function *SelectorIntrinsic; - - // The eh.typeid.for intrinsic. - Function *TypeIdIntrinsic; + Function *ExceptionValueIntrinsic; // _Unwind_Resume or the target equivalent. Constant *RewindFunction; - // _Unwind_RaiseException. - Constant *UnwindFunction; - // Dominator info is used when turning stack temporaries into registers. DominatorTree *DT; DominanceFrontier *DF; @@ -63,13 +49,6 @@ namespace { // The function we are running on. Function *F; - // The current context. - LLVMContext *Context; - - // The personality and catch-all value for this function. - Constant *Personality; - Constant *CatchAll; - // The landing pads for this function. typedef SmallPtrSet BBSet; BBSet LandingPads; @@ -79,10 +58,7 @@ namespace { bool NormalizeLandingPads(); bool LowerUnwinds(); - bool MoveSelectorCalls(); - bool RectifySelectorCalls(); bool MoveExceptionValueCalls(); - bool AddMissingSelectors(); bool FinishStackTemporaries(); bool PromoteStackTemporaries(); @@ -99,13 +75,22 @@ namespace { public: static char ID; // Pass identification, replacement for typeid. - DwarfEHPrepare(const TargetLowering *tli) : - FunctionPass(&ID), TLI(tli), ExceptionIntrinsic(0), - SelectorIntrinsic(0), TypeIdIntrinsic(0), RewindFunction(0), - UnwindFunction(0) {} + DwarfEHPrepare(const TargetLowering *tli, bool fast) : + FunctionPass(&ID), TLI(tli), CompileFast(fast), + ExceptionValueIntrinsic(0), RewindFunction(0) {} virtual bool runOnFunction(Function &Fn); + // getAnalysisUsage - We need dominance frontiers for memory promotion. + virtual void getAnalysisUsage(AnalysisUsage &AU) const { + if (!CompileFast) + AU.addRequired(); + AU.addPreserved(); + if (!CompileFast) + AU.addRequired(); + AU.addPreserved(); + } + const char *getPassName() const { return "Exception handling preparation"; } @@ -115,8 +100,8 @@ namespace { char DwarfEHPrepare::ID = 0; -FunctionPass *llvm::createDwarfEHPass(const TargetLowering *tli) { - return new DwarfEHPrepare(tli); +FunctionPass *llvm::createDwarfEHPass(const TargetLowering *tli, bool fast) { + return new DwarfEHPrepare(tli, fast); } /// NormalizeLandingPads - Normalize and discover landing pads, noting them @@ -159,7 +144,7 @@ bool DwarfEHPrepare::NormalizeLandingPads() { // edges to a new basic block which falls through into this one. // Create the new basic block. - BasicBlock *NewBB = BasicBlock::Create(*Context, + BasicBlock *NewBB = BasicBlock::Create(F->getContext(), LPad->getName() + "_unwind_edge"); // Insert it into the function right before the original landing pad. @@ -248,14 +233,17 @@ bool DwarfEHPrepare::LowerUnwinds() { // Find the rewind function if we didn't already. if (!RewindFunction) { + LLVMContext &Ctx = UnwindInsts[0]->getContext(); std::vector - Params(1, Type::getInt8PtrTy(*Context)); - FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Context), + Params(1, Type::getInt8PtrTy(Ctx)); + FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx), Params, false); const char *RewindName = TLI->getLibcallName(RTLIB::UNWIND_RESUME); RewindFunction = F->getParent()->getOrInsertFunction(RewindName, FTy); } + bool Changed = false; + for (SmallVectorImpl::iterator I = UnwindInsts.begin(), E = UnwindInsts.end(); I != E; ++I) { TerminatorInst *TI = *I; @@ -269,244 +257,11 @@ bool DwarfEHPrepare::LowerUnwinds() { "", TI); CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME)); // ...followed by an UnreachableInst. - new UnreachableInst(*Context, TI); + new UnreachableInst(TI->getContext(), TI); // Nuke the unwind instruction. TI->eraseFromParent(); ++NumUnwindsLowered; - } - - return true; -} - -/// MoveSelectorCalls - Make sure that every call to eh.selector occurs in its -/// own landing pad, the landing pad corresponding to the exception object. -bool DwarfEHPrepare::MoveSelectorCalls() { - // If the eh.selector intrinsic is not declared in the module then there is - // nothing to do. Speed up compilation by checking for this common case. - if (!F->getParent()->getFunction(Intrinsic::getName(Intrinsic::eh_selector))) - return false; - - // TODO: There is a lot of room for optimization here. - - bool Changed = false; - BasicBlock *UnrBB = 0; - - for (Function::iterator BB = F->begin(); BB != F->end(); ++BB) { - // If this basic block is not a landing pad then synthesize a landing pad - // for every selector in it. - bool SynthesizeLandingPad = !LandingPads.count(BB); - - for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE; ++II) { - EHSelectorInst *SI = dyn_cast(II); - // Only interested in eh.selector calls. - if (!SI) - continue; - - // Note the personality and catch-all for later use. - Personality = cast(SI->getOperand(2)); - CatchAll = cast(SI->getOperand(SI->getNumOperands() - 1) - ->stripPointerCasts()); - - // The exception object. - Value *Exception = SI->getOperand(1); - - if (!SynthesizeLandingPad) { - // Did the exception come from unwinding to this landing pad or another? - // If it comes from a different landing pad then we need to synthesize a - // new landing pad for the selector. - EHExceptionInst *EI = dyn_cast(Exception); - SynthesizeLandingPad = !EI || EI->getParent() != BB; - } - - if (!SynthesizeLandingPad) { - // This is the first selector in this landing pad, and it is the landing - // pad corresponding to the exception object. No need to do anything to - // this selector, but any subsequent selectors in this landing pad will - // need their own invoke in order to make them independent of this one. - SynthesizeLandingPad = true; - continue; - } - - // Rethrow the exception and catch it again, generating a landing pad for - // this selector to live in. - - // Find _Unwind_RaiseException if we didn't already. - if (!UnwindFunction) { - std::vector ArgTys(1, Type::getInt8PtrTy(*Context)); - const FunctionType *FTy = - FunctionType::get(Type::getInt32Ty(*Context), ArgTys, true); - - const char *Name = "_Unwind_RaiseException"; - UnwindFunction = F->getParent()->getOrInsertFunction(Name, FTy); - } - - // Create a basic block containing only an unreachable instruction if we - // didn't already. - if (!UnrBB) { - UnrBB = BasicBlock::Create(*Context, "unreachable", F); - new UnreachableInst(*Context, UnrBB); - } - - // Split the basic block before the selector. - BasicBlock *NewBB = SplitBlock(BB, SI, this); - - // Replace the terminator with an invoke of _Unwind_RaiseException. - BB->getTerminator()->eraseFromParent(); - InvokeInst::Create(UnwindFunction, UnrBB, NewBB, &Exception, - 1 + &Exception, "", BB); - - // The split off basic block is now a landing pad. - LandingPads.insert(NewBB); - - // Replace the exception argument in the selector call with a call to - // eh.exception. This is not really necessary but it makes things more - // regular. - Exception = CreateExceptionValueCall(NewBB); - SI->setOperand(1, Exception); - - ++NumLonelySelectors; - Changed = true; - - // All instructions still in the original basic block have been scanned. - // Move on to the next basic block. - break; - } - } - - return Changed; -} - -/// RectifySelectorCalls - Remove useless catch-all clauses from the ends of -/// selectors, or correct the selector result for the presence of the catch-all -/// if it is really needed. -bool DwarfEHPrepare::RectifySelectorCalls() { - // If the eh.selector intrinsic is not declared in the module then there is - // nothing to do. Speed up compilation by checking for this common case. - if (!F->getParent()->getFunction(Intrinsic::getName(Intrinsic::eh_selector))) - return false; - - bool Changed = false; - - for (BBSet::iterator I = LandingPads.begin(), E = LandingPads.end(); I != E; - ++I) - for (BasicBlock::iterator II = (*I)->begin(), IE = (*I)->end(); II != IE; ) - if (EHSelectorInst *SI = dyn_cast(II++)) { - // Found a call to eh.selector. Check whether it has a catch-all in the - // middle. - unsigned LastIndex = 0; - for (unsigned i = 3, e = SI->getNumOperands() - 1; i < e; ++i) { - Value *V = SI->getOperand(i); - if (V->stripPointerCasts() == CatchAll) { - // A catch-all. The catch-all at the end was not needed. - LastIndex = i; - break; - } else if (ConstantInt *FilterLength = dyn_cast(V)) { - // A cleanup or a filter. - unsigned Length = FilterLength->getZExtValue(); - if (Length == 0) - // A cleanup - skip it. - continue; - if (Length == 1) { - // A catch-all filter. Drop everything that follows. - LastIndex = i; - break; - } - // A filter, skip over the typeinfos. - i += Length - 1; - } - } - - if (LastIndex) { - // Drop the pointless catch-all from the end. In fact drop everything - // after LastIndex as an optimization. - SmallVector Args; - Args.reserve(LastIndex); - for (unsigned i = 1; i <= LastIndex; ++i) - Args.push_back(SI->getOperand(i)); - CallInst *CI = CallInst::Create(SI->getOperand(0), Args.begin(), - Args.end(), "", SI); - CI->takeName(SI); - SI->replaceAllUsesWith(CI); - SI->eraseFromParent(); - ++NumSelectorsSimplified; - } else if (!isa(CatchAll) && // Not a cleanup. - !SI->use_empty()) { - // Correct the selector value to return zero if the catch-all matches. - Constant *Zero = ConstantInt::getNullValue(Type::getInt32Ty(*Context)); - - // Create the new selector value, with placeholders instead of the - // real operands and make everyone use it. The reason for this round - // about approach is that the computation of the new value makes use - // of the old value, so we can't just compute it then do RAUW. - SelectInst *S = SelectInst::Create(ConstantInt::getFalse(*Context), - Zero, Zero, "", II); - SI->replaceAllUsesWith(S); - - // Now calculate the operands of the select. - IRBuilder<> Builder(*I, S); - - // Find the eh.typeid.for intrinsic if we didn't already. - if (!TypeIdIntrinsic) - TypeIdIntrinsic = Intrinsic::getDeclaration(F->getParent(), - Intrinsic::eh_typeid_for); - - // Obtain the id of the catch-all. - Value *CatchAllId = Builder.CreateCall(TypeIdIntrinsic, - ConstantExpr::getBitCast(CatchAll, Type::getInt8PtrTy(*Context))); - - // Compare it with the original selector result. If it matched then - // the selector result is zero, otherwise it is the original selector. - Value *MatchesCatchAll = Builder.CreateICmpEQ(SI, CatchAllId); - S->setOperand(0, MatchesCatchAll); - S->setOperand(2, SI); - ++NumSelectorsAdjusted; - } - - Changed = true; - break; - } - - return Changed; -} - -/// Make sure every landing pad has a selector in it. -bool DwarfEHPrepare::AddMissingSelectors() { - if (!Personality) - // We only know how to codegen invokes if there is a personality. - // FIXME: This results in wrong code. - return false; - - bool Changed = false; - - for (BBSet::iterator I = LandingPads.begin(), E = LandingPads.end(); I != E; - ++I) { - bool FoundSelector = false; - - // Check whether the landing pad already contains a call to eh.selector. - for (BasicBlock::iterator II = (*I)->begin(), IE = (*I)->end(); II != IE; - ++II) - if (isa(II)) { - FoundSelector = true; - break; - } - - if (FoundSelector) - continue; - - // Find the eh.selector intrinsic if we didn't already. - if (!SelectorIntrinsic) - SelectorIntrinsic = Intrinsic::getDeclaration(F->getParent(), - Intrinsic::eh_selector); - - // Get the exception object. - Instruction *Exception = CreateExceptionValueCall(*I); - - Value *Args[3] = { Exception, Personality, CatchAll }; - CallInst *Selector = CallInst::Create(SelectorIntrinsic, Args, Args + 3); - Selector->insertAfter(Exception); - - ++NumLonelyLandingPads; Changed = true; } @@ -520,7 +275,7 @@ bool DwarfEHPrepare::AddMissingSelectors() { bool DwarfEHPrepare::MoveExceptionValueCalls() { // If the eh.exception intrinsic is not declared in the module then there is // nothing to do. Speed up compilation by checking for this common case. - if (!ExceptionIntrinsic && + if (!ExceptionValueIntrinsic && !F->getParent()->getFunction(Intrinsic::getName(Intrinsic::eh_exception))) return false; @@ -577,7 +332,7 @@ bool DwarfEHPrepare::PromoteStackTemporaries() { if (ExceptionValueVar && DT && DF && isAllocaPromotable(ExceptionValueVar)) { // Turn the exception temporary into registers and phi nodes if possible. std::vector Allocas(1, ExceptionValueVar); - PromoteMemToReg(Allocas, *DT, *DF, *Context); + PromoteMemToReg(Allocas, *DT, *DF, ExceptionValueVar->getContext()); return true; } return false; @@ -595,12 +350,12 @@ Instruction *DwarfEHPrepare::CreateExceptionValueCall(BasicBlock *BB) { return Start; // Find the eh.exception intrinsic if we didn't already. - if (!ExceptionIntrinsic) - ExceptionIntrinsic = Intrinsic::getDeclaration(F->getParent(), + if (!ExceptionValueIntrinsic) + ExceptionValueIntrinsic = Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_exception); // Create the call. - return CallInst::Create(ExceptionIntrinsic, "eh.value.call", Start); + return CallInst::Create(ExceptionValueIntrinsic, "eh.value.call", Start); } /// CreateValueLoad - Insert a load of the exception value stack variable @@ -618,7 +373,7 @@ Instruction *DwarfEHPrepare::CreateValueLoad(BasicBlock *BB) { // Create the temporary if we didn't already. if (!ExceptionValueVar) { ExceptionValueVar = new AllocaInst(PointerType::getUnqual( - Type::getInt8Ty(*Context)), "eh.value", F->begin()->begin()); + Type::getInt8Ty(BB->getContext())), "eh.value", F->begin()->begin()); ++NumStackTempsIntroduced; } @@ -633,9 +388,6 @@ bool DwarfEHPrepare::runOnFunction(Function &Fn) { DT = getAnalysisIfAvailable(); DF = getAnalysisIfAvailable(); ExceptionValueVar = 0; - Personality = 0; - CatchAll = 0; - Context = &Fn.getContext(); F = &Fn; // Ensure that only unwind edges end at landing pads (a landing pad is a @@ -645,15 +397,7 @@ bool DwarfEHPrepare::runOnFunction(Function &Fn) { // Turn unwind instructions into libcalls. Changed |= LowerUnwinds(); - // Make sure that every call to eh.selector occurs in its own landing pad. - Changed |= MoveSelectorCalls(); - - // Remove useless catch-all clauses from the ends of selectors, or correct the - // selector result for the presence of the catch-all if it is really needed. - Changed |= RectifySelectorCalls(); - - // Make sure every landing pad has a selector in it. - Changed |= AddMissingSelectors(); + // TODO: Move eh.selector calls to landing pads and combine them. // Move eh.exception calls to landing pads. Changed |= MoveExceptionValueCalls(); @@ -662,8 +406,8 @@ bool DwarfEHPrepare::runOnFunction(Function &Fn) { Changed |= FinishStackTemporaries(); // Turn any stack temporaries into registers if possible. -//TODO if (!CompileFast) -//TODO Changed |= PromoteStackTemporaries(); + if (!CompileFast) + Changed |= PromoteStackTemporaries(); LandingPads.clear(); diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp index 1000b2e3809..e58a9ca82c6 100644 --- a/lib/CodeGen/LLVMTargetMachine.cpp +++ b/lib/CodeGen/LLVMTargetMachine.cpp @@ -239,11 +239,11 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, { case ExceptionHandling::SjLj: // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both - PM.add(createDwarfEHPass(getTargetLowering())); + PM.add(createDwarfEHPass(getTargetLowering(), OptLevel==CodeGenOpt::None)); PM.add(createSjLjEHPass(getTargetLowering())); break; case ExceptionHandling::Dwarf: - PM.add(createDwarfEHPass(getTargetLowering())); + PM.add(createDwarfEHPass(getTargetLowering(), OptLevel==CodeGenOpt::None)); break; case ExceptionHandling::None: PM.add(createLowerInvokePass(getTargetLowering()));