X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSjLjEHPrepare.cpp;h=e1f242a08de155d448489855b94fa7b3a38fcde6;hb=94d0a9154e9ec3df3398f11649c024ef8378b9c8;hp=5ac0c09ded9990c9dac8987eadf1c7d4df839371;hpb=30442f95573d7e0f505c573bd7462b77769010fa;p=oota-llvm.git diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index 5ac0c09ded9..e1f242a08de 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -12,83 +12,81 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "sjljehprepare" -#include "llvm/Transforms/Scalar.h" -#include "llvm/Constants.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Instructions.h" -#include "llvm/Intrinsics.h" -#include "llvm/LLVMContext.h" -#include "llvm/Module.h" -#include "llvm/Pass.h" -#include "llvm/Analysis/Verifier.h" #include "llvm/CodeGen/Passes.h" -#include "llvm/Target/TargetData.h" -#include "llvm/Target/TargetLowering.h" -#include "llvm/Transforms/Utils/BasicBlockUtils.h" -#include "llvm/Transforms/Utils/Local.h" -#include "llvm/Support/CommandLine.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/IRBuilder.h" -#include "llvm/Support/raw_ostream.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SetVector.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/Statistic.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/Pass.h" +#include "llvm/Support/CommandLine.h" +#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 TargetLowering *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 TargetLowering *tli = NULL) - : FunctionPass(ID), TLI(tli) {} - bool doInitialization(Module &M); - bool runOnFunction(Function &F); - - virtual void getAnalysisUsage(AnalysisUsage &AU) const { - FunctionPass::getAnalysisUsage(AU); - } - const char *getPassName() const { - return "SJLJ Exception Handling preparation"; - } +class SjLjEHPrepare : public FunctionPass { + Type *doubleUnderDataTy; + Type *doubleUnderJBufTy; + Type *FunctionContextTy; + Constant *RegisterFn; + Constant *UnregisterFn; + Constant *BuiltinSetupDispatchFn; + 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() : FunctionPass(ID) {} + 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; +INITIALIZE_PASS(SjLjEHPrepare, "sjljehprepare", "Prepare SjLj exceptions", + false, false) // Public Interface To the SjLjEHPrepare pass. -FunctionPass *llvm::createSjLjEHPreparePass(const TargetLowering *TLI) { - return new SjLjEHPrepare(TLI); -} +FunctionPass *llvm::createSjLjEHPreparePass() { return new SjLjEHPrepare(); } // doInitialization - Set up decalarations and types needed to process // exceptions. bool SjLjEHPrepare::doInitialization(Module &M) { @@ -96,31 +94,30 @@ 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); + doubleUnderDataTy = ArrayType::get(Int32Ty, 4); + doubleUnderJBufTy = ArrayType::get(VoidPtrTy, 5); + FunctionContextTy = StructType::get(VoidPtrTy, // __prev + Int32Ty, // call_site + doubleUnderDataTy, // __data + VoidPtrTy, // __personality + VoidPtrTy, // __lsda + doubleUnderJBufTy, // __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); - BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp); + BuiltinSetupDispatchFn = + Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setup_dispatch); 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; } @@ -135,46 +132,38 @@ void SjLjEHPrepare::insertCallSiteStore(Instruction *I, int Number) { Value *Zero = ConstantInt::get(Int32Ty, 0); Value *One = ConstantInt::get(Int32Ty, 1); Value *Idxs[2] = { Zero, One }; - Value *CallSite = Builder.CreateGEP(FuncCtx, Idxs, "call_site"); + Value *CallSite = + Builder.CreateGEP(FunctionContextTy, 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 +/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until /// we reach blocks we've already seen. -static void markBlocksLiveIn(BasicBlock *BB, Instruction *Inst, - SmallPtrSet &LiveBBs, - SmallPtrSet &InvokesCrossed, - bool &FoundDef) { - if (!LiveBBs.insert(BB)) return; // Already been here. - if (BB == Inst->getParent()) { - FoundDef = true; - return; - } +static void MarkBlocksLiveIn(BasicBlock *BB, + 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) { - BasicBlock *Pred = *PI; - if (BB->isLandingPad() && BB != Inst->getParent()) { - InvokesCrossed.insert(Pred); - continue; - } - markBlocksLiveIn(Pred, Inst, LiveBBs, InvokesCrossed, FoundDef); - } + for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) + MarkBlocksLiveIn(*PI, LiveBBs); } /// substituteLPadValues - Substitute the values returned by the landingpad /// 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) @@ -183,14 +172,15 @@ 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)))); + auto *SelI = cast(SelVal); + IRBuilder<> Builder(SelI->getParent(), std::next(SelI->getIterator())); LPadVal = Builder.CreateInsertValue(LPadVal, ExnVal, 0, "lpad.val"); LPadVal = Builder.CreateInsertValue(LPadVal, SelVal, 1, "lpad.val"); @@ -199,66 +189,56 @@ 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) { - BasicBlock *EntryBB = F.begin(); +Value *SjLjEHPrepare::setupFunctionContext(Function &F, + ArrayRef LPads) { + BasicBlock *EntryBB = &F.front(); // 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. - unsigned Align = - TLI->getTargetData()->getPrefTypeAlignment(FunctionContextTy); - FuncCtx = - new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin()); + auto &DL = F.getParent()->getDataLayout(); + unsigned Align = DL.getPrefTypeAlignment(FunctionContextTy); + FuncCtx = new AllocaInst(FunctionContextTy, nullptr, Align, "fn_context", + &EntryBB->front()); // Fill in the function context structure. - Type *Int32Ty = Type::getInt32Ty(F.getContext()); - Value *Zero = ConstantInt::get(Int32Ty, 0); - Value *One = ConstantInt::get(Int32Ty, 1); - Value *Two = ConstantInt::get(Int32Ty, 2); - Value *Three = ConstantInt::get(Int32Ty, 3); - Value *Four = ConstantInt::get(Int32Ty, 4); - - Value *Idxs[2] = { Zero, 0 }; - for (unsigned I = 0, E = LPads.size(); I != E; ++I) { LandingPadInst *LPI = LPads[I]; - IRBuilder<> Builder(LPI->getParent()->getFirstInsertionPt()); + IRBuilder<> Builder(LPI->getParent(), + LPI->getParent()->getFirstInsertionPt()); // Reference the __data field. - Idxs[1] = Two; - Value *FCData = Builder.CreateGEP(FuncCtx, Idxs, "__data"); + Value *FCData = + Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 2, "__data"); // The exception values come back in context->__data[0]. - Idxs[1] = Zero; - Value *ExceptionAddr = Builder.CreateGEP(FCData, Idxs, "exception_gep"); + Value *ExceptionAddr = Builder.CreateConstGEP2_32(doubleUnderDataTy, FCData, + 0, 0, "exception_gep"); Value *ExnVal = Builder.CreateLoad(ExceptionAddr, true, "exn_val"); - ExnVal = Builder.CreateIntToPtr(ExnVal, Type::getInt8PtrTy(F.getContext())); + ExnVal = Builder.CreateIntToPtr(ExnVal, Builder.getInt8PtrTy()); - Idxs[1] = One; - Value *SelectorAddr = Builder.CreateGEP(FCData, Idxs, "exn_selector_gep"); + Value *SelectorAddr = Builder.CreateConstGEP2_32(doubleUnderDataTy, FCData, + 0, 1, "exn_selector_gep"); Value *SelVal = Builder.CreateLoad(SelectorAddr, true, "exn_selector_val"); substituteLPadValues(LPI, ExnVal, SelVal); } // Personality function - Idxs[1] = Three; + IRBuilder<> Builder(EntryBB->getTerminator()); if (!PersonalityFn) - PersonalityFn = LPads[0]->getPersonalityFn(); - Value *PersonalityFieldPtr = - GetElementPtrInst::Create(FuncCtx, Idxs, "pers_fn_gep", - EntryBB->getTerminator()); - new StoreInst(PersonalityFn, PersonalityFieldPtr, true, - EntryBB->getTerminator()); + PersonalityFn = F.getPersonalityFn(); + Value *PersonalityFieldPtr = Builder.CreateConstGEP2_32( + FunctionContextTy, FuncCtx, 0, 3, "pers_fn_gep"); + Builder.CreateStore( + Builder.CreateBitCast(PersonalityFn, Builder.getInt8PtrTy()), + PersonalityFieldPtr, /*isVolatile=*/true); // LSDA address - Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr", - EntryBB->getTerminator()); - Idxs[1] = Four; - Value *LSDAFieldPtr = GetElementPtrInst::Create(FuncCtx, Idxs, "lsda_gep", - EntryBB->getTerminator()); - new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator()); + Value *LSDA = Builder.CreateCall(LSDAAddrFn, {}, "lsda_addr"); + Value *LSDAFieldPtr = + Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 4, "lsda_gep"); + Builder.CreateStore(LSDA, LSDAFieldPtr, /*isVolatile=*/true); return FuncCtx; } @@ -272,63 +252,41 @@ void SjLjEHPrepare::lowerIncomingArguments(Function &F) { while (isa(AfterAllocaInsPt) && isa(cast(AfterAllocaInsPt)->getArraySize())) ++AfterAllocaInsPt; + assert(AfterAllocaInsPt != F.front().end()); - 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); - } + for (auto &AI : F.args()) { + Type *Ty = AI.getType(); + + // 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) { - SmallVector, 32> ReloadUsers; - DenseMap, AllocaInst*> AllocaMap; - + 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; + Instruction *Inst = &*II; + 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. @@ -337,146 +295,73 @@ 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. - std::map > InvokesCrossed; - std::map > LiveBBs; - bool FoundDef = false; + SmallPtrSet LiveBBs; + LiveBBs.insert(Inst->getParent()); while (!Users.empty()) { - Instruction *U = Users.pop_back_val(); + Instruction *U = Users.back(); + Users.pop_back(); - if (PHINode *PN = dyn_cast(U)) { + if (!isa(U)) { + MarkBlocksLiveIn(U->getParent(), LiveBBs); + } else { // Uses for a PHI node occur in their predecessor block. + PHINode *PN = cast(U); for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) if (PN->getIncomingValue(i) == Inst) - markBlocksLiveIn(PN->getIncomingBlock(i), Inst, LiveBBs[U], - InvokesCrossed[U], FoundDef); - } else { - markBlocksLiveIn(U->getParent(), Inst, LiveBBs[U], - InvokesCrossed[U], FoundDef); + MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs); } } - // If we hit the definition, resort to the dump-this-value-everywhere - // method. - if (FoundDef) { - // Now that we know all of the blocks that this thing is live in, see if - // it includes any of the unwind locations. - bool NeedsSpill = false; - for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { - BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); - if (UnwindBlock == BB) continue; - - for (std::map >::iterator - MI = LiveBBs.begin(), ME = LiveBBs.end(); MI != ME; ++MI) { - if (MI->second.count(UnwindBlock)) { - DEBUG({ - dbgs() << "SJLJ Spill: " << *Inst << " around " - << UnwindBlock->getName() << "\n"; - }); - NeedsSpill = true; - break; - } - } - - // If we decided we need a spill, do it. - if (NeedsSpill) { - DemoteRegToStack(*Inst, true); - ++NumSpilled; - } + // Now that we know all of the blocks that this thing is live in, see if + // it includes any of the unwind locations. + bool NeedsSpill = false; + for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { + BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); + if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) { + DEBUG(dbgs() << "SJLJ Spill: " << *Inst << " around " + << UnwindBlock->getName() << "\n"); + NeedsSpill = true; + break; } - - // We don't need this map anymore. - InvokesCrossed.clear(); } - // Go through the invokes the value crosses and insert a spill right - // before the invoke. - for (std::map >::iterator - MI = InvokesCrossed.begin(), ME = InvokesCrossed.end(); - MI != ME; ++MI) { - Instruction *User = MI->first; - SmallPtrSet &Crossings = MI->second; - if (Crossings.empty()) continue; - - ReloadUsers.push_back(std::make_pair(Inst, User)); - - AllocaInst *&Slot = AllocaMap[std::make_pair(Inst, User)]; - if (!Slot) - Slot = new AllocaInst(Inst->getType(), 0, - Inst->getName() + ".reg2mem", - F.getEntryBlock().begin()); - - for (SmallPtrSet::iterator - CI = Crossings.begin(), CE = Crossings.end(); CI != CE; ++CI) { - new StoreInst(Inst, Slot, (*CI)->getTerminator()); - ++NumSpilled; - } + // If we decided we need a spill, do it. + // FIXME: Spilling this way is overkill, as it forces all uses of + // the value to be reloaded from the stack slot, even those that aren't + // in the unwind blocks. We should be more selective. + if (NeedsSpill) { + DemoteRegToStack(*Inst, true); + ++NumSpilled; } } } - // Now go through the instructions which were spilled and replace their uses - // after a crossed invoke with a reload instruction. - for (SmallVectorImpl >::iterator - I = ReloadUsers.begin(), E = ReloadUsers.end(); I != E; ++I) { - Instruction *User = I->second; - AllocaInst *Slot = AllocaMap[*I]; - assert(Slot && "A spill slot hasn't been allocated yet!"); - - if (PHINode *PN = dyn_cast(User)) { - // If this is a PHI node, we can't insert a load of the value before the - // use. Instead insert the load in the predecessor block corresponding to - // the incoming value. - // - // Note that if there are multiple edges from a basic block to this PHI - // node that we cannot have multiple loads. The problem is that the - // resulting PHI node will have multiple values (from each load) coming in - // from the same block, which is illegal SSA form. For this reason, we - // keep track of and reuse loads we insert. - DenseMap Loads; - for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) - if (PN->getIncomingValue(i) == I->first) { - Value *&V = Loads[PN->getIncomingBlock(i)]; - if (V == 0) - // Insert the load into the predecessor block - V = new LoadInst(Slot, I->first->getName() + ".reload", true, - PN->getIncomingBlock(i)->getTerminator()); - - PN->setIncomingValue(i, V); - } - } else { - LoadInst *Reload = new LoadInst(Slot, Slot->getName() + ".reload", User); - User->replaceUsesOfWith(I->first, Reload); - } - } - // Go through the landing pads and remove any PHIs there. for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); 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()); + LPI->moveBefore(&UnwindBlock->front()); } } @@ -484,20 +369,30 @@ 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(); @@ -505,50 +400,35 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { lowerAcrossUnwindEdges(F, Invokes); Value *FuncCtx = - setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end())); - BasicBlock *EntryBB = F.begin(); - Type *Int32Ty = Type::getInt32Ty(F.getContext()); - - Value *Idxs[2] = { - ConstantInt::get(Int32Ty, 0), 0 - }; + setupFunctionContext(F, makeArrayRef(LPads.begin(), LPads.end())); + BasicBlock *EntryBB = &F.front(); + IRBuilder<> Builder(EntryBB->getTerminator()); // Get a reference to the jump buffer. - Idxs[1] = ConstantInt::get(Int32Ty, 5); - Value *JBufPtr = GetElementPtrInst::Create(FuncCtx, Idxs, "jbuf_gep", - EntryBB->getTerminator()); + Value *JBufPtr = + Builder.CreateConstGEP2_32(FunctionContextTy, FuncCtx, 0, 5, "jbuf_gep"); // Save the frame pointer. - Idxs[1] = ConstantInt::get(Int32Ty, 0); - Value *FramePtr = GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_fp_gep", - EntryBB->getTerminator()); + Value *FramePtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 0, + "jbuf_fp_gep"); - Value *Val = CallInst::Create(FrameAddrFn, - ConstantInt::get(Int32Ty, 0), - "fp", - EntryBB->getTerminator()); - new StoreInst(Val, FramePtr, true, EntryBB->getTerminator()); + Value *Val = Builder.CreateCall(FrameAddrFn, Builder.getInt32(0), "fp"); + Builder.CreateStore(Val, FramePtr, /*isVolatile=*/true); // Save the stack pointer. - Idxs[1] = ConstantInt::get(Int32Ty, 2); - Value *StackPtr = GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_sp_gep", - EntryBB->getTerminator()); + Value *StackPtr = Builder.CreateConstGEP2_32(doubleUnderJBufTy, JBufPtr, 0, 2, + "jbuf_sp_gep"); - Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator()); - new StoreInst(Val, StackPtr, true, EntryBB->getTerminator()); + Val = Builder.CreateCall(StackAddrFn, {}, "sp"); + Builder.CreateStore(Val, StackPtr, /*isVolatile=*/true); - // Call the setjmp instrinsic. It fills in the rest of the jmpbuf. - Value *SetjmpArg = CastInst::Create(Instruction::BitCast, JBufPtr, - Type::getInt8PtrTy(F.getContext()), "", - EntryBB->getTerminator()); - CallInst::Create(BuiltinSetjmpFn, SetjmpArg, "", EntryBB->getTerminator()); + // Call the setup_dispatch instrinsic. It fills in the rest of the jmpbuf. + Builder.CreateCall(BuiltinSetupDispatchFn, {}); // Store a pointer to the function context so that the back-end will know // where to look for it. - Value *FuncCtxArg = CastInst::Create(Instruction::BitCast, FuncCtx, - Type::getInt8PtrTy(F.getContext()), "", - EntryBB->getTerminator()); - CallInst::Create(FuncCtxFn, FuncCtxArg, "", EntryBB->getTerminator()); + Value *FuncCtxArg = Builder.CreateBitCast(FuncCtx, Builder.getInt8PtrTy()); + Builder.CreateCall(FuncCtxFn, FuncCtxArg); // At this point, we are all set up, update the invoke instructions to mark // their call_site values. @@ -556,7 +436,7 @@ 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. @@ -578,8 +458,8 @@ 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 @@ -595,7 +475,7 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { continue; } Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp"); - StackAddr->insertAfter(I); + StackAddr->insertAfter(&*I); Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true); StoreStackAddr->insertAfter(StackAddr); } @@ -611,9 +491,5 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { bool SjLjEHPrepare::runOnFunction(Function &F) { bool Res = setupEntryBlockAndCallSites(F); - DEBUG({ - if (verifyFunction(F)) - report_fatal_error("verifyFunction failed!"); - }); return Res; }