X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSjLjEHPrepare.cpp;h=35e4292eea883a026ea20548a8a91671a812aeef;hb=8143b4da3f8df2506d768f2833a2888545489853;hp=b58bb85e49e0459216b78b4927060e91b3ae6dd5;hpb=69e42dbd006c0afb732067ece7327988b1e24c01;p=oota-llvm.git diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index b58bb85e49e..35e4292eea8 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -12,7 +12,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "sjljehprepare" #include "llvm/CodeGen/Passes.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SetVector.h" @@ -32,58 +31,60 @@ #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetSubtargetInfo.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/Local.h" #include using namespace llvm; +#define DEBUG_TYPE "sjljehprepare" + STATISTIC(NumInvokes, "Number of invokes replaced"); STATISTIC(NumSpilled, "Number of registers live across unwind edges"); namespace { - class SjLjEHPrepare : public FunctionPass { - const TargetLoweringBase *TLI; - Type *FunctionContextTy; - Constant *RegisterFn; - Constant *UnregisterFn; - Constant *BuiltinSetjmpFn; - Constant *FrameAddrFn; - Constant *StackAddrFn; - Constant *StackRestoreFn; - Constant *LSDAAddrFn; - Value *PersonalityFn; - Constant *CallSiteFn; - Constant *FuncCtxFn; - AllocaInst *FuncCtx; - public: - static char ID; // Pass identification, replacement for typeid - explicit SjLjEHPrepare(const TargetLoweringBase *tli = NULL) - : FunctionPass(ID), TLI(tli) { } - bool doInitialization(Module &M); - bool runOnFunction(Function &F); - - virtual void getAnalysisUsage(AnalysisUsage &AU) const {} - const char *getPassName() const { - return "SJLJ Exception Handling preparation"; - } +class SjLjEHPrepare : public FunctionPass { + const TargetMachine *TM; + Type *FunctionContextTy; + Constant *RegisterFn; + Constant *UnregisterFn; + Constant *BuiltinSetjmpFn; + Constant *FrameAddrFn; + Constant *StackAddrFn; + Constant *StackRestoreFn; + Constant *LSDAAddrFn; + Value *PersonalityFn; + Constant *CallSiteFn; + Constant *FuncCtxFn; + AllocaInst *FuncCtx; + +public: + static char ID; // Pass identification, replacement for typeid + explicit SjLjEHPrepare(const TargetMachine *TM) : FunctionPass(ID), TM(TM) {} + bool doInitialization(Module &M) override; + bool runOnFunction(Function &F) override; + + void getAnalysisUsage(AnalysisUsage &AU) const override {} + const char *getPassName() const override { + return "SJLJ Exception Handling preparation"; + } - private: - bool setupEntryBlockAndCallSites(Function &F); - void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, - Value *SelVal); - Value *setupFunctionContext(Function &F, ArrayRef LPads); - void lowerIncomingArguments(Function &F); - void lowerAcrossUnwindEdges(Function &F, ArrayRef Invokes); - void insertCallSiteStore(Instruction *I, int Number); - }; +private: + bool setupEntryBlockAndCallSites(Function &F); + void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, Value *SelVal); + Value *setupFunctionContext(Function &F, ArrayRef LPads); + void lowerIncomingArguments(Function &F); + void lowerAcrossUnwindEdges(Function &F, ArrayRef Invokes); + void insertCallSiteStore(Instruction *I, int Number); +}; } // end anonymous namespace char SjLjEHPrepare::ID = 0; // Public Interface To the SjLjEHPrepare pass. -FunctionPass *llvm::createSjLjEHPreparePass(const TargetLoweringBase *TLI) { - return new SjLjEHPrepare(TLI); +FunctionPass *llvm::createSjLjEHPreparePass(const TargetMachine *TM) { + return new SjLjEHPrepare(TM); } // doInitialization - Set up decalarations and types needed to process // exceptions. @@ -92,23 +93,19 @@ bool SjLjEHPrepare::doInitialization(Module &M) { // builtin_setjmp uses a five word jbuf Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext()); Type *Int32Ty = Type::getInt32Ty(M.getContext()); - FunctionContextTy = - StructType::get(VoidPtrTy, // __prev - Int32Ty, // call_site - ArrayType::get(Int32Ty, 4), // __data - VoidPtrTy, // __personality - VoidPtrTy, // __lsda - ArrayType::get(VoidPtrTy, 5), // __jbuf - NULL); - RegisterFn = M.getOrInsertFunction("_Unwind_SjLj_Register", - Type::getVoidTy(M.getContext()), - PointerType::getUnqual(FunctionContextTy), - (Type *)0); - UnregisterFn = - M.getOrInsertFunction("_Unwind_SjLj_Unregister", - Type::getVoidTy(M.getContext()), - PointerType::getUnqual(FunctionContextTy), - (Type *)0); + FunctionContextTy = StructType::get(VoidPtrTy, // __prev + Int32Ty, // call_site + ArrayType::get(Int32Ty, 4), // __data + VoidPtrTy, // __personality + VoidPtrTy, // __lsda + ArrayType::get(VoidPtrTy, 5), // __jbuf + nullptr); + RegisterFn = M.getOrInsertFunction( + "_Unwind_SjLj_Register", Type::getVoidTy(M.getContext()), + PointerType::getUnqual(FunctionContextTy), (Type *)nullptr); + UnregisterFn = M.getOrInsertFunction( + "_Unwind_SjLj_Unregister", Type::getVoidTy(M.getContext()), + PointerType::getUnqual(FunctionContextTy), (Type *)nullptr); FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress); StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave); StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore); @@ -116,7 +113,7 @@ bool SjLjEHPrepare::doInitialization(Module &M) { LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite); FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext); - PersonalityFn = 0; + PersonalityFn = nullptr; return true; } @@ -134,16 +131,17 @@ void SjLjEHPrepare::insertCallSiteStore(Instruction *I, int Number) { Value *CallSite = Builder.CreateGEP(FuncCtx, Idxs, "call_site"); // Insert a store of the call-site number - ConstantInt *CallSiteNoC = ConstantInt::get(Type::getInt32Ty(I->getContext()), - Number); - Builder.CreateStore(CallSiteNoC, CallSite, true/*volatile*/); + ConstantInt *CallSiteNoC = + ConstantInt::get(Type::getInt32Ty(I->getContext()), Number); + Builder.CreateStore(CallSiteNoC, CallSite, true /*volatile*/); } /// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until /// we reach blocks we've already seen. static void MarkBlocksLiveIn(BasicBlock *BB, - SmallPtrSet &LiveBBs) { - if (!LiveBBs.insert(BB)) return; // already been here. + SmallPtrSetImpl &LiveBBs) { + if (!LiveBBs.insert(BB).second) + return; // already been here. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) MarkBlocksLiveIn(*PI, LiveBBs); @@ -153,12 +151,14 @@ static void MarkBlocksLiveIn(BasicBlock *BB, /// instruction with those returned by the personality function. void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, Value *SelVal) { - SmallVector UseWorkList(LPI->use_begin(), LPI->use_end()); + SmallVector UseWorkList(LPI->user_begin(), LPI->user_end()); while (!UseWorkList.empty()) { Value *Val = UseWorkList.pop_back_val(); ExtractValueInst *EVI = dyn_cast(Val); - if (!EVI) continue; - if (EVI->getNumIndices() != 1) continue; + if (!EVI) + continue; + if (EVI->getNumIndices() != 1) + continue; if (*EVI->idx_begin() == 0) EVI->replaceAllUsesWith(ExnVal); else if (*EVI->idx_begin() == 1) @@ -167,14 +167,15 @@ void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, EVI->eraseFromParent(); } - if (LPI->getNumUses() == 0) return; + if (LPI->getNumUses() == 0) + return; // There are still some uses of LPI. Construct an aggregate with the exception // values and replace the LPI with that aggregate. Type *LPadType = LPI->getType(); Value *LPadVal = UndefValue::get(LPadType); - IRBuilder<> - Builder(llvm::next(BasicBlock::iterator(cast(SelVal)))); + IRBuilder<> Builder( + std::next(BasicBlock::iterator(cast(SelVal)))); LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val"); LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val"); @@ -183,17 +184,18 @@ void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, /// setupFunctionContext - Allocate the function context on the stack and fill /// it with all of the data that we know at this point. -Value *SjLjEHPrepare:: -setupFunctionContext(Function &F, ArrayRef LPads) { +Value *SjLjEHPrepare::setupFunctionContext(Function &F, + ArrayRef LPads) { BasicBlock *EntryBB = F.begin(); // Create an alloca for the incoming jump buffer ptr and the new jump buffer // that needs to be restored on all exits from the function. This is an alloca // because the value needs to be added to the global context list. + const TargetLowering *TLI = TM->getSubtargetImpl(F)->getTargetLowering(); unsigned Align = - TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy); - FuncCtx = - new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin()); + TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy); + FuncCtx = new AllocaInst(FunctionContextTy, nullptr, Align, "fn_context", + EntryBB->begin()); // Fill in the function context structure. for (unsigned I = 0, E = LPads.size(); I != E; ++I) { @@ -204,13 +206,13 @@ setupFunctionContext(Function &F, ArrayRef LPads) { Value *FCData = Builder.CreateConstGEP2_32(FuncCtx, 0, 2, "__data"); // The exception values come back in context->__data[0]. - Value *ExceptionAddr = Builder.CreateConstGEP2_32(FCData, 0, 0, - "exception_gep"); + Value *ExceptionAddr = + Builder.CreateConstGEP2_32(FCData, 0, 0, "exception_gep"); Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val"); ExnVal = Builder.CreateIntToPtr(ExnVal, Builder.getInt8PtrTy()); - Value *SelectorAddr = Builder.CreateConstGEP2_32(FCData, 0, 1, - "exn_selector_gep"); + Value *SelectorAddr = + Builder.CreateConstGEP2_32(FCData, 0, 1, "exn_selector_gep"); Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val"); substituteLPadValues(LPI, ExnVal, SelVal); @@ -220,9 +222,11 @@ setupFunctionContext(Function &F, ArrayRef LPads) { IRBuilder<> Builder(EntryBB->getTerminator()); if (!PersonalityFn) PersonalityFn = LPads[0]->getPersonalityFn(); - Value *PersonalityFieldPtr = Builder.CreateConstGEP2_32(FuncCtx, 0, 3, - "pers_fn_gep"); - Builder.CreateStore(PersonalityFn, PersonalityFieldPtr, /*isVolatile=*/true); + Value *PersonalityFieldPtr = + Builder.CreateConstGEP2_32(FuncCtx, 0, 3, "pers_fn_gep"); + Builder.CreateStore( + Builder.CreateBitCast(PersonalityFn, Builder.getInt8PtrTy()), + PersonalityFieldPtr, /*isVolatile=*/true); // LSDA address Value *LSDA = Builder.CreateCall(LSDAAddrFn, "lsda_addr"); @@ -242,59 +246,41 @@ void SjLjEHPrepare::lowerIncomingArguments(Function &F) { isa(cast(AfterAllocaInsPt)->getArraySize())) ++AfterAllocaInsPt; - for (Function::arg_iterator - AI = F.arg_begin(), AE = F.arg_end(); AI != AE; ++AI) { + for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); AI != AE; + ++AI) { Type *Ty = AI->getType(); - // Aggregate types can't be cast, but are legal argument types, so we have - // to handle them differently. We use an extract/insert pair as a - // lightweight method to achieve the same goal. - if (isa(Ty) || isa(Ty) || isa(Ty)) { - Instruction *EI = ExtractValueInst::Create(AI, 0, "", AfterAllocaInsPt); - Instruction *NI = InsertValueInst::Create(AI, EI, 0); - NI->insertAfter(EI); - AI->replaceAllUsesWith(NI); - - // Set the operand of the instructions back to the AllocaInst. - EI->setOperand(0, AI); - NI->setOperand(0, AI); - } else { - // This is always a no-op cast because we're casting AI to AI->getType() - // so src and destination types are identical. BitCast is the only - // possibility. - CastInst *NC = - new BitCastInst(AI, AI->getType(), AI->getName() + ".tmp", - AfterAllocaInsPt); - AI->replaceAllUsesWith(NC); - - // Set the operand of the cast instruction back to the AllocaInst. - // Normally it's forbidden to replace a CastInst's operand because it - // could cause the opcode to reflect an illegal conversion. However, we're - // replacing it here with the same value it was constructed with. We do - // this because the above replaceAllUsesWith() clobbered the operand, but - // we want this one to remain. - NC->setOperand(0, AI); - } + // Use 'select i8 true, %arg, undef' to simulate a 'no-op' instruction. + Value *TrueValue = ConstantInt::getTrue(F.getContext()); + Value *UndefValue = UndefValue::get(Ty); + Instruction *SI = SelectInst::Create(TrueValue, AI, UndefValue, + AI->getName() + ".tmp", + AfterAllocaInsPt); + AI->replaceAllUsesWith(SI); + + // Reset the operand, because it was clobbered by the RAUW above. + SI->setOperand(1, AI); } } /// lowerAcrossUnwindEdges - Find all variables which are alive across an unwind /// edge and spill them. void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, - ArrayRef Invokes) { + ArrayRef Invokes) { // Finally, scan the code looking for instructions with bad live ranges. - for (Function::iterator - BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) { - for (BasicBlock::iterator - II = BB->begin(), IIE = BB->end(); II != IIE; ++II) { + for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) { + for (BasicBlock::iterator II = BB->begin(), IIE = BB->end(); II != IIE; + ++II) { // Ignore obvious cases we don't have to handle. In particular, most // instructions either have no uses or only have a single use inside the // current block. Ignore them quickly. Instruction *Inst = II; - if (Inst->use_empty()) continue; + if (Inst->use_empty()) + continue; if (Inst->hasOneUse() && - cast(Inst->use_back())->getParent() == BB && - !isa(Inst->use_back())) continue; + cast(Inst->user_back())->getParent() == BB && + !isa(Inst->user_back())) + continue; // If this is an alloca in the entry block, it's not a real register // value. @@ -303,16 +289,15 @@ void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, continue; // Avoid iterator invalidation by copying users to a temporary vector. - SmallVector Users; - for (Value::use_iterator - UI = Inst->use_begin(), E = Inst->use_end(); UI != E; ++UI) { - Instruction *User = cast(*UI); - if (User->getParent() != BB || isa(User)) - Users.push_back(User); + SmallVector Users; + for (User *U : Inst->users()) { + Instruction *UI = cast(U); + if (UI->getParent() != BB || isa(UI)) + Users.push_back(UI); } // Find all of the blocks that this value is live in. - SmallPtrSet LiveBBs; + SmallPtrSet LiveBBs; LiveBBs.insert(Inst->getParent()); while (!Users.empty()) { Instruction *U = Users.back(); @@ -336,7 +321,7 @@ void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) { DEBUG(dbgs() << "SJLJ Spill: " << *Inst << " around " - << UnwindBlock->getName() << "\n"); + << UnwindBlock->getName() << "\n"); NeedsSpill = true; break; } @@ -359,16 +344,15 @@ void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, LandingPadInst *LPI = UnwindBlock->getLandingPadInst(); // Place PHIs into a set to avoid invalidating the iterator. - SmallPtrSet PHIsToDemote; - for (BasicBlock::iterator - PN = UnwindBlock->begin(); isa(PN); ++PN) + SmallPtrSet PHIsToDemote; + for (BasicBlock::iterator PN = UnwindBlock->begin(); isa(PN); ++PN) PHIsToDemote.insert(cast(PN)); - if (PHIsToDemote.empty()) continue; + if (PHIsToDemote.empty()) + continue; // Demote the PHIs to the stack. - for (SmallPtrSet::iterator - I = PHIsToDemote.begin(), E = PHIsToDemote.end(); I != E; ++I) - DemotePHIToStack(*I); + for (PHINode *PN : PHIsToDemote) + DemotePHIToStack(PN); // Move the landingpad instruction back to the top of the landing pad block. LPI->moveBefore(UnwindBlock->begin()); @@ -379,20 +363,30 @@ void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, /// the function context and marking the call sites with the appropriate /// values. These values are used by the DWARF EH emitter. bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { - SmallVector Returns; - SmallVector Invokes; - SmallSetVector LPads; + SmallVector Returns; + SmallVector Invokes; + SmallSetVector LPads; // Look through the terminators of the basic blocks to find invokes. for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) if (InvokeInst *II = dyn_cast(BB->getTerminator())) { + if (Function *Callee = II->getCalledFunction()) + if (Callee->isIntrinsic() && + Callee->getIntrinsicID() == Intrinsic::donothing) { + // Remove the NOP invoke. + BranchInst::Create(II->getNormalDest(), II); + II->eraseFromParent(); + continue; + } + Invokes.push_back(II); LPads.insert(II->getUnwindDest()->getLandingPadInst()); } else if (ReturnInst *RI = dyn_cast(BB->getTerminator())) { Returns.push_back(RI); } - if (Invokes.empty()) return false; + if (Invokes.empty()) + return false; NumInvokes += Invokes.size(); @@ -400,7 +394,7 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { lowerAcrossUnwindEdges(F, Invokes); Value *FuncCtx = - setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end())); + setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end())); BasicBlock *EntryBB = F.begin(); IRBuilder<> Builder(EntryBB->getTerminator()); @@ -434,7 +428,7 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { insertCallSiteStore(Invokes[I], I + 1); ConstantInt *CallSiteNum = - ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1); + ConstantInt::get(Type::getInt32Ty(F.getContext()), I + 1); // Record the call site value for the back end so it stays associated with // the invoke. @@ -456,8 +450,8 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { } // Register the function context and make sure it's known to not throw - CallInst *Register = CallInst::Create(RegisterFn, FuncCtx, "", - EntryBB->getTerminator()); + CallInst *Register = + CallInst::Create(RegisterFn, FuncCtx, "", EntryBB->getTerminator()); Register->setDoesNotThrow(); // Following any allocas not in the entry block, update the saved SP in the