X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSjLjEHPrepare.cpp;h=2fc8f46f48b1bf50110006cf9973a0018900df2b;hb=e2ff00e117ba9b758b298e671f65c0b002f8a52d;hp=a406f8e2426794bf5dc13494bfd1b3bc3d5d2961;hpb=fbf9ff462134a635eb0fc3bc86c70cc59fb065d1;p=oota-llvm.git diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index a406f8e2426..2fc8f46f48b 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -1,4 +1,4 @@ -//===- SjLjEHPass.cpp - Eliminate Invoke & Unwind instructions -----------===// +//===- SjLjEHPrepare.cpp - Eliminate Invoke & Unwind instructions ---------===// // // The LLVM Compiler Infrastructure // @@ -13,29 +13,28 @@ //===----------------------------------------------------------------------===// #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/Transforms/Scalar.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/Transforms/Utils/Local.h" #include using namespace llvm; @@ -43,8 +42,8 @@ STATISTIC(NumInvokes, "Number of invokes replaced"); STATISTIC(NumSpilled, "Number of registers live across unwind edges"); namespace { - class SjLjEHPass : public FunctionPass { - const TargetLowering *TLI; + class SjLjEHPrepare : public FunctionPass { + const TargetMachine *TM; Type *FunctionContextTy; Constant *RegisterFn; Constant *UnregisterFn; @@ -59,8 +58,8 @@ namespace { AllocaInst *FuncCtx; public: static char ID; // Pass identification, replacement for typeid - explicit SjLjEHPass(const TargetLowering *tli = NULL) - : FunctionPass(ID), TLI(tli) { } + explicit SjLjEHPrepare(const TargetMachine *TM) + : FunctionPass(ID), TM(TM) { } bool doInitialization(Module &M); bool runOnFunction(Function &F); @@ -80,15 +79,15 @@ namespace { }; } // end anonymous namespace -char SjLjEHPass::ID = 0; +char SjLjEHPrepare::ID = 0; -// Public Interface To the SjLjEHPass pass. -FunctionPass *llvm::createSjLjEHPass(const TargetLowering *TLI) { - return new SjLjEHPass(TLI); +// Public Interface To the SjLjEHPrepare pass. +FunctionPass *llvm::createSjLjEHPreparePass(const TargetMachine *TM) { + return new SjLjEHPrepare(TM); } // doInitialization - Set up decalarations and types needed to process // exceptions. -bool SjLjEHPass::doInitialization(Module &M) { +bool SjLjEHPrepare::doInitialization(Module &M) { // Build the function context structure. // builtin_setjmp uses a five word jbuf Type *VoidPtrTy = Type::getInt8PtrTy(M.getContext()); @@ -124,7 +123,7 @@ bool SjLjEHPass::doInitialization(Module &M) { /// insertCallSiteStore - Insert a store of the call-site value to the /// function context -void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number) { +void SjLjEHPrepare::insertCallSiteStore(Instruction *I, int Number) { IRBuilder<> Builder(I); // Get a reference to the call_site field. @@ -140,25 +139,20 @@ void SjLjEHPass::insertCallSiteStore(Instruction *I, int 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) { +static void MarkBlocksLiveIn(BasicBlock *BB, + SmallPtrSet &LiveBBs) { if (!LiveBBs.insert(BB)) 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); - markBlocksLiveIn(Pred, Inst, LiveBBs, InvokesCrossed); - } + 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 SjLjEHPass::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, - Value *SelVal) { +void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, + Value *SelVal) { SmallVector UseWorkList(LPI->use_begin(), LPI->use_end()); while (!UseWorkList.empty()) { Value *Val = UseWorkList.pop_back_val(); @@ -189,66 +183,54 @@ void SjLjEHPass::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 *SjLjEHPass:: +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->getTargetLowering(); unsigned Align = - TLI->getTargetData()->getPrefTypeAlignment(FunctionContextTy); + TLI->getDataLayout()->getPrefTypeAlignment(FunctionContextTy); FuncCtx = new AllocaInst(FunctionContextTy, 0, Align, "fn_context", EntryBB->begin()); // 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()); // Reference the __data field. - Idxs[1] = Two; - Value *FCData = Builder.CreateGEP(FuncCtx, Idxs, "__data"); + Value *FCData = Builder.CreateConstGEP2_32(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(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(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()); + 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 = 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(FuncCtx, 0, 4, "lsda_gep"); + Builder.CreateStore(LSDA, LSDAFieldPtr, /*isVolatile=*/true); return FuncCtx; } @@ -257,7 +239,7 @@ setupFunctionContext(Function &F, ArrayRef LPads) { /// specially, we lower each arg to a copy instruction in the entry block. This /// ensures that the argument value itself cannot be live out of the entry /// block. -void SjLjEHPass::lowerIncomingArguments(Function &F) { +void SjLjEHPrepare::lowerIncomingArguments(Function &F) { BasicBlock::iterator AfterAllocaInsPt = F.begin()->begin(); while (isa(AfterAllocaInsPt) && isa(cast(AfterAllocaInsPt)->getArraySize())) @@ -301,11 +283,8 @@ void SjLjEHPass::lowerIncomingArguments(Function &F) { /// lowerAcrossUnwindEdges - Find all variables which are alive across an unwind /// edge and spill them. -void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, - ArrayRef Invokes) { - SmallVector, 32> ReloadUsers; - DenseMap, AllocaInst*> AllocaMap; - +void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F, + 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) { @@ -336,81 +315,44 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, } // Find all of the blocks that this value is live in. - std::map > InvokesCrossed; - std::map > LiveBBs; + SmallPtrSet LiveBBs; + LiveBBs.insert(Inst->getParent()); while (!Users.empty()) { - Instruction *U = Users.pop_back_val(); - LiveBBs[U].insert(Inst->getParent()); + 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]); - } else { - markBlocksLiveIn(U->getParent(), Inst, LiveBBs[U], InvokesCrossed[U]); + MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs); } } - // 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; + // 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; } } - } - } - // 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); + // 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; + } } } @@ -439,14 +381,23 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, /// setupEntryBlockAndCallSites - Setup the entry block by creating and filling /// the function context and marking the call sites with the appropriate /// values. These values are used by the DWARF EH emitter. -bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) { - SmallVector Returns; - SmallVector Invokes; +bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { + 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())) { @@ -463,48 +414,31 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) { 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 - }; + 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(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(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(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()); + Value *SetjmpArg = Builder.CreateBitCast(JBufPtr, Builder.getInt8PtrTy()); + Builder.CreateCall(BuiltinSetjmpFn, SetjmpArg); // 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. @@ -565,11 +499,7 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) { return true; } -bool SjLjEHPass::runOnFunction(Function &F) { +bool SjLjEHPrepare::runOnFunction(Function &F) { bool Res = setupEntryBlockAndCallSites(F); - DEBUG({ - if (verifyFunction(F)) - report_fatal_error("verifyFunction failed!"); - }); return Res; }