diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/SjLjEHPrepare.cpp | 594 |
1 files changed, 10 insertions, 584 deletions
diff --git a/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/llvm/lib/CodeGen/SjLjEHPrepare.cpp index e5cb1bb6ea2..ac88441bf9a 100644 --- a/llvm/lib/CodeGen/SjLjEHPrepare.cpp +++ b/llvm/lib/CodeGen/SjLjEHPrepare.cpp @@ -30,17 +30,13 @@ #include "llvm/Support/Debug.h" #include "llvm/Support/IRBuilder.h" #include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/Statistic.h" #include <set> using namespace llvm; -static cl::opt<bool> DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden, - cl::init(true), - cl::desc("Disable the old SjLj EH preparation pass")); - STATISTIC(NumInvokes, "Number of invokes replaced"); -STATISTIC(NumUnwinds, "Number of unwinds replaced"); STATISTIC(NumSpilled, "Number of registers live across unwind edges"); namespace { @@ -52,16 +48,12 @@ namespace { Constant *BuiltinSetjmpFn; Constant *FrameAddrFn; Constant *StackAddrFn; - Constant *StackRestoreFn; Constant *LSDAAddrFn; Value *PersonalityFn; - Constant *SelectorFn; - Constant *ExceptionFn; Constant *CallSiteFn; Constant *DispatchSetupFn; Constant *FuncCtxFn; Value *CallSite; - DenseMap<InvokeInst*, BasicBlock*> LPadSuccMap; public: static char ID; // Pass identification, replacement for typeid explicit SjLjEHPass(const TargetLowering *tli = NULL) @@ -79,13 +71,7 @@ namespace { Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads); void lowerIncomingArguments(Function &F); void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes); - void insertCallSiteStore(Instruction *I, int Number, Value *CallSite); - void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, - SwitchInst *CatchSwitch); - void splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes); - void splitLandingPad(InvokeInst *II); - bool insertSjLjEHSupport(Function &F); }; } // end anonymous namespace @@ -121,11 +107,8 @@ bool SjLjEHPass::doInitialization(Module &M) { (Type *)0); 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); LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); - SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector); - ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception); CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite); DispatchSetupFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup); @@ -145,572 +128,16 @@ void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number, new StoreInst(CallSiteNoC, CallSite, true, I); // volatile } -/// splitLandingPad - Split a landing pad. This takes considerable care because -/// of PHIs and other nasties. The problem is that the jump table needs to jump -/// to the landing pad block. However, the landing pad block can be jumped to -/// only by an invoke instruction. So we clone the landingpad instruction into -/// its own basic block, have the invoke jump to there. The landingpad -/// instruction's basic block's successor is now the target for the jump table. -/// -/// But because of PHI nodes, we need to create another basic block for the jump -/// table to jump to. This is definitely a hack, because the values for the PHI -/// nodes may not be defined on the edge from the jump table. But that's okay, -/// because the jump table is simply a construct to mimic what is happening in -/// the CFG. So the values are mysteriously there, even though there is no value -/// for the PHI from the jump table's edge (hence calling this a hack). -void SjLjEHPass::splitLandingPad(InvokeInst *II) { - SmallVector<BasicBlock*, 2> NewBBs; - SplitLandingPadPredecessors(II->getUnwindDest(), II->getParent(), - ".1", ".2", this, NewBBs); - - // Create an empty block so that the jump table has something to jump to - // which doesn't have any PHI nodes. - BasicBlock *LPad = NewBBs[0]; - BasicBlock *Succ = *succ_begin(LPad); - BasicBlock *JumpTo = BasicBlock::Create(II->getContext(), "jt.land", - LPad->getParent(), Succ); - LPad->getTerminator()->eraseFromParent(); - BranchInst::Create(JumpTo, LPad); - BranchInst::Create(Succ, JumpTo); - LPadSuccMap[II] = JumpTo; - - for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) { - PHINode *PN = cast<PHINode>(I); - Value *Val = PN->removeIncomingValue(LPad, false); - PN->addIncoming(Val, JumpTo); - } -} - -/// markInvokeCallSite - Insert code to mark the call_site for this invoke -void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo, - Value *CallSite, - SwitchInst *CatchSwitch) { - ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()), - InvokeNo); - // The runtime comes back to the dispatcher with the call_site - 1 in - // the context. Odd, but there it is. - ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()), - InvokeNo - 1); - - // If the unwind edge has phi nodes, split the edge. - if (isa<PHINode>(II->getUnwindDest()->begin())) { - // FIXME: New EH - This if-condition will be always true in the new scheme. - if (II->getUnwindDest()->isLandingPad()) - splitLandingPad(II); - else - SplitCriticalEdge(II, 1, this); - - // If there are any phi nodes left, they must have a single predecessor. - while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) { - PN->replaceAllUsesWith(PN->getIncomingValue(0)); - PN->eraseFromParent(); - } - } - - // Insert the store of the call site value - insertCallSiteStore(II, InvokeNo, CallSite); - - // Record the call site value for the back end so it stays associated with - // the invoke. - CallInst::Create(CallSiteFn, CallSiteNoC, "", II); - - // Add a switch case to our unwind block. - if (BasicBlock *SuccBB = LPadSuccMap[II]) { - CatchSwitch->addCase(SwitchValC, SuccBB); - } else { - CatchSwitch->addCase(SwitchValC, II->getUnwindDest()); - } - - // We still want this to look like an invoke so we emit the LSDA properly, - // so we don't transform the invoke into a call here. -} - /// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until /// we reach blocks we've already seen. -static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) { - if (!LiveBBs.insert(BB).second) return; // already been here. +static void MarkBlocksLiveIn(BasicBlock *BB, + SmallPtrSet<BasicBlock*, 64> &LiveBBs) { + if (!LiveBBs.insert(BB)) return; // already been here. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) MarkBlocksLiveIn(*PI, LiveBBs); } -/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge -/// we spill into a stack location, guaranteeing that there is nothing live -/// across the unwind edge. This process also splits all critical edges -/// coming out of invoke's. -/// FIXME: Move this function to a common utility file (Local.cpp?) so -/// both SjLj and LowerInvoke can use it. -void SjLjEHPass:: -splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) { - // First step, split all critical edges from invoke instructions. - for (unsigned i = 0, e = Invokes.size(); i != e; ++i) { - InvokeInst *II = Invokes[i]; - SplitCriticalEdge(II, 0, this); - - // FIXME: New EH - This if-condition will be always true in the new scheme. - if (II->getUnwindDest()->isLandingPad()) - splitLandingPad(II); - else - SplitCriticalEdge(II, 1, this); - - assert(!isa<PHINode>(II->getNormalDest()) && - !isa<PHINode>(II->getUnwindDest()) && - "Critical edge splitting left single entry phi nodes?"); - } - - Function *F = Invokes.back()->getParent()->getParent(); - - // To avoid having to handle incoming arguments specially, we lower each arg - // to a copy instruction in the entry block. This ensures that the argument - // value itself cannot be live across the entry block. - BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin(); - while (isa<AllocaInst>(AfterAllocaInsertPt) && - isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize())) - ++AfterAllocaInsertPt; - for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end(); - AI != E; ++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<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) { - Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt); - 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", AfterAllocaInsertPt); - 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); - } - } - - // Finally, scan the code looking for instructions with bad live ranges. - for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) - for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++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->hasOneUse() && - cast<Instruction>(Inst->use_back())->getParent() == BB && - !isa<PHINode>(Inst->use_back())) continue; - - // If this is an alloca in the entry block, it's not a real register - // value. - if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst)) - if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin()) - continue; - - // Avoid iterator invalidation by copying users to a temporary vector. - SmallVector<Instruction*,16> Users; - for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end(); - UI != E; ++UI) { - Instruction *User = cast<Instruction>(*UI); - if (User->getParent() != BB || isa<PHINode>(User)) - Users.push_back(User); - } - - // Find all of the blocks that this value is live in. - std::set<BasicBlock*> LiveBBs; - LiveBBs.insert(Inst->getParent()); - while (!Users.empty()) { - Instruction *U = Users.back(); - Users.pop_back(); - - if (!isa<PHINode>(U)) { - MarkBlocksLiveIn(U->getParent(), LiveBBs); - } else { - // Uses for a PHI node occur in their predecessor block. - PHINode *PN = cast<PHINode>(U); - for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) - if (PN->getIncomingValue(i) == Inst) - MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs); - } - } - - // 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)) - NeedsSpill = true; - } - - // 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) { - ++NumSpilled; - DemoteRegToStack(*Inst, true); - } - } -} - -/// CreateLandingPadLoad - Load the exception handling values and insert them -/// into a structure. -static Instruction *CreateLandingPadLoad(Function &F, Value *ExnAddr, - Value *SelAddr, - BasicBlock::iterator InsertPt) { - Value *Exn = new LoadInst(ExnAddr, "exn", false, - InsertPt); - Type *Ty = Type::getInt8PtrTy(F.getContext()); - Exn = CastInst::Create(Instruction::IntToPtr, Exn, Ty, "", InsertPt); - Value *Sel = new LoadInst(SelAddr, "sel", false, InsertPt); - - Ty = StructType::get(Exn->getType(), Sel->getType(), NULL); - InsertValueInst *LPadVal = InsertValueInst::Create(llvm::UndefValue::get(Ty), - Exn, 0, - "lpad.val", InsertPt); - return InsertValueInst::Create(LPadVal, Sel, 1, "lpad.val", InsertPt); -} - -/// ReplaceLandingPadVal - Replace the landingpad instruction's value with a -/// load from the stored values (via CreateLandingPadLoad). This looks through -/// PHI nodes, and removes them if they are dead. -static void ReplaceLandingPadVal(Function &F, Instruction *Inst, Value *ExnAddr, - Value *SelAddr) { - if (Inst->use_empty()) return; - - while (!Inst->use_empty()) { - Instruction *I = cast<Instruction>(Inst->use_back()); - - if (PHINode *PN = dyn_cast<PHINode>(I)) { - ReplaceLandingPadVal(F, PN, ExnAddr, SelAddr); - if (PN->use_empty()) PN->eraseFromParent(); - continue; - } - - I->replaceUsesOfWith(Inst, CreateLandingPadLoad(F, ExnAddr, SelAddr, I)); - } -} - -bool SjLjEHPass::insertSjLjEHSupport(Function &F) { - SmallVector<ReturnInst*,16> Returns; - SmallVector<UnwindInst*,16> Unwinds; - SmallVector<InvokeInst*,16> Invokes; - - // Look through the terminators of the basic blocks to find invokes, returns - // and unwinds. - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { - if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) { - // Remember all return instructions in case we insert an invoke into this - // function. - Returns.push_back(RI); - } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) { - Invokes.push_back(II); - } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) { - Unwinds.push_back(UI); - } - } - - NumInvokes += Invokes.size(); - NumUnwinds += Unwinds.size(); - - // If we don't have any invokes, there's nothing to do. - if (Invokes.empty()) return false; - - // Find the eh.selector.*, eh.exception and alloca calls. - // - // Remember any allocas() that aren't in the entry block, as the - // jmpbuf saved SP will need to be updated for them. - // - // We'll use the first eh.selector to determine the right personality - // function to use. For SJLJ, we always use the same personality for the - // whole function, not on a per-selector basis. - // FIXME: That's a bit ugly. Better way? - SmallVector<CallInst*,16> EH_Selectors; - SmallVector<CallInst*,16> EH_Exceptions; - SmallVector<Instruction*,16> JmpbufUpdatePoints; - - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { - // Note: Skip the entry block since there's nothing there that interests - // us. eh.selector and eh.exception shouldn't ever be there, and we - // want to disregard any allocas that are there. - // - // FIXME: This is awkward. The new EH scheme won't need to skip the entry - // block. - if (BB == F.begin()) { - if (InvokeInst *II = dyn_cast<InvokeInst>(F.begin()->getTerminator())) { - // FIXME: This will be always non-NULL in the new EH. - if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst()) - if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn(); - } - - continue; - } - - for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { - if (CallInst *CI = dyn_cast<CallInst>(I)) { - if (CI->getCalledFunction() == SelectorFn) { - if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1); - EH_Selectors.push_back(CI); - } else if (CI->getCalledFunction() == ExceptionFn) { - EH_Exceptions.push_back(CI); - } else if (CI->getCalledFunction() == StackRestoreFn) { - JmpbufUpdatePoints.push_back(CI); - } - } else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) { - JmpbufUpdatePoints.push_back(AI); - } else if (InvokeInst *II = dyn_cast<InvokeInst>(I)) { - // FIXME: This will be always non-NULL in the new EH. - if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst()) - if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn(); - } - } - } - - // If we don't have any eh.selector calls, we can't determine the personality - // function. Without a personality function, we can't process exceptions. - if (!PersonalityFn) return false; - - // We have invokes, so we need to add register/unregister calls to get this - // function onto the global unwind stack. - // - // First thing we need to do is scan the whole function for values that are - // live across unwind edges. Each value that is live across an unwind edge we - // spill into a stack location, guaranteeing that there is nothing live across - // the unwind edge. This process also splits all critical edges coming out of - // invoke's. - splitLiveRangesAcrossInvokes(Invokes); - - - SmallVector<LandingPadInst*, 16> LandingPads; - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { - if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) - // FIXME: This will be always non-NULL in the new EH. - if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst()) - LandingPads.push_back(LPI); - } - - - 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. - unsigned Align = 4; // FIXME: Should be a TLI check? - AllocaInst *FunctionContext = - new AllocaInst(FunctionContextTy, 0, Align, - "fcn_context", F.begin()->begin()); - - Value *Idxs[2]; - Type *Int32Ty = Type::getInt32Ty(F.getContext()); - Value *Zero = ConstantInt::get(Int32Ty, 0); - // We need to also keep around a reference to the call_site field - Idxs[0] = Zero; - Idxs[1] = ConstantInt::get(Int32Ty, 1); - CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, "call_site", - EntryBB->getTerminator()); - - // The exception selector comes back in context->data[1] - Idxs[1] = ConstantInt::get(Int32Ty, 2); - Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, "fc_data", - EntryBB->getTerminator()); - Idxs[1] = ConstantInt::get(Int32Ty, 1); - Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs, - "exc_selector_gep", - EntryBB->getTerminator()); - // The exception value comes back in context->data[0] - Idxs[1] = Zero; - Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs, - "exception_gep", - EntryBB->getTerminator()); - - // The result of the eh.selector call will be replaced with a a reference to - // the selector value returned in the function context. We leave the selector - // itself so the EH analysis later can use it. - for (int i = 0, e = EH_Selectors.size(); i < e; ++i) { - CallInst *I = EH_Selectors[i]; - Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I); - I->replaceAllUsesWith(SelectorVal); - } - - // eh.exception calls are replaced with references to the proper location in - // the context. Unlike eh.selector, the eh.exception calls are removed - // entirely. - for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) { - CallInst *I = EH_Exceptions[i]; - // Possible for there to be duplicates, so check to make sure the - // instruction hasn't already been removed. - if (!I->getParent()) continue; - Value *Val = new LoadInst(ExceptionAddr, "exception", true, I); - Type *Ty = Type::getInt8PtrTy(F.getContext()); - Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I); - - I->replaceAllUsesWith(Val); - I->eraseFromParent(); - } - - for (unsigned i = 0, e = LandingPads.size(); i != e; ++i) - ReplaceLandingPadVal(F, LandingPads[i], ExceptionAddr, SelectorAddr); - - // The entry block changes to have the eh.sjlj.setjmp, with a conditional - // branch to a dispatch block for non-zero returns. If we return normally, - // we're not handling an exception and just register the function context and - // continue. - - // Create the dispatch block. The dispatch block is basically a big switch - // statement that goes to all of the invoke landing pads. - BasicBlock *DispatchBlock = - BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F); - - // Insert a load of the callsite in the dispatch block, and a switch on its - // value. By default, we issue a trap statement. - BasicBlock *TrapBlock = - BasicBlock::Create(F.getContext(), "trapbb", &F); - CallInst::Create(Intrinsic::getDeclaration(F.getParent(), Intrinsic::trap), - "", TrapBlock); - new UnreachableInst(F.getContext(), TrapBlock); - - Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true, - DispatchBlock); - SwitchInst *DispatchSwitch = - SwitchInst::Create(DispatchLoad, TrapBlock, Invokes.size(), - DispatchBlock); - // Split the entry block to insert the conditional branch for the setjmp. - BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(), - "eh.sjlj.setjmp.cont"); - - // Populate the Function Context - // 1. LSDA address - // 2. Personality function address - // 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp) - - // LSDA address - Idxs[0] = Zero; - Idxs[1] = ConstantInt::get(Int32Ty, 4); - Value *LSDAFieldPtr = - GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep", - EntryBB->getTerminator()); - Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr", - EntryBB->getTerminator()); - new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator()); - - Idxs[1] = ConstantInt::get(Int32Ty, 3); - Value *PersonalityFieldPtr = - GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep", - EntryBB->getTerminator()); - new StoreInst(PersonalityFn, PersonalityFieldPtr, true, - EntryBB->getTerminator()); - - // Save the frame pointer. - Idxs[1] = ConstantInt::get(Int32Ty, 5); - Value *JBufPtr - = GetElementPtrInst::Create(FunctionContext, Idxs, "jbuf_gep", - EntryBB->getTerminator()); - Idxs[1] = ConstantInt::get(Int32Ty, 0); - Value *FramePtr = - GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_fp_gep", - EntryBB->getTerminator()); - - Value *Val = CallInst::Create(FrameAddrFn, - ConstantInt::get(Int32Ty, 0), - "fp", - EntryBB->getTerminator()); - new StoreInst(Val, FramePtr, true, EntryBB->getTerminator()); - - // Save the stack pointer. - Idxs[1] = ConstantInt::get(Int32Ty, 2); - Value *StackPtr = - GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_sp_gep", - EntryBB->getTerminator()); - - Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator()); - new StoreInst(Val, StackPtr, true, EntryBB->getTerminator()); - - // 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()); - Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg, - "", - EntryBB->getTerminator()); - - // Add a call to dispatch_setup after the setjmp call. This is expanded to any - // target-specific setup that needs to be done. - CallInst::Create(DispatchSetupFn, DispatchVal, "", EntryBB->getTerminator()); - - // check the return value of the setjmp. non-zero goes to dispatcher. - Value *IsNormal = new ICmpInst(EntryBB->getTerminator(), - ICmpInst::ICMP_EQ, DispatchVal, Zero, - "notunwind"); - // Nuke the uncond branch. - EntryBB->getTerminator()->eraseFromParent(); - - // Put in a new condbranch in its place. - BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB); - - // Register the function context and make sure it's known to not throw - CallInst *Register = - CallInst::Create(RegisterFn, FunctionContext, "", - ContBlock->getTerminator()); - Register->setDoesNotThrow(); - - // At this point, we are all set up, update the invoke instructions to mark - // their call_site values, and fill in the dispatch switch accordingly. - for (unsigned i = 0, e = Invokes.size(); i != e; ++i) - markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); - - // Mark call instructions that aren't nounwind as no-action (call_site == - // -1). Skip the entry block, as prior to then, no function context has been - // created for this function and any unexpected exceptions thrown will go - // directly to the caller's context, which is what we want anyway, so no need - // to do anything here. - for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { - for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I) - if (CallInst *CI = dyn_cast<CallInst>(I)) { - // Ignore calls to the EH builtins (eh.selector, eh.exception) - Constant *Callee = CI->getCalledFunction(); - if (Callee != SelectorFn && Callee != ExceptionFn - && !CI->doesNotThrow()) - insertCallSiteStore(CI, -1, CallSite); - } else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) { - insertCallSiteStore(RI, -1, CallSite); - } - } - - // Replace all unwinds with a branch to the unwind handler. - // ??? Should this ever happen with sjlj exceptions? - for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) { - BranchInst::Create(TrapBlock, Unwinds[i]); - Unwinds[i]->eraseFromParent(); - } - - // Following any allocas not in the entry block, update the saved SP in the - // jmpbuf to the new value. - for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) { - Instruction *AI = JmpbufUpdatePoints[i]; - Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp"); - StackAddr->insertAfter(AI); - Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true); - StoreStackAddr->insertAfter(StackAddr); - } - - // Finally, for any returns from this function, if this function contains an - // invoke, add a call to unregister the function context. - for (unsigned i = 0, e = Returns.size(); i != e; ++i) - CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]); - - return true; -} - /// setupFunctionContext - Allocate the function context on the stack and fill /// it with all of the data that we know at this point. Value *SjLjEHPass:: @@ -871,7 +298,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, } // Find all of the blocks that this value is live in. - std::set<BasicBlock*> LiveBBs; + SmallPtrSet<BasicBlock*, 64> LiveBBs; LiveBBs.insert(Inst->getParent()); while (!Users.empty()) { Instruction *U = Users.back(); @@ -895,6 +322,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest(); if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) { NeedsSpill = true; + break; } } @@ -903,8 +331,8 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F, // 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) { - ++NumSpilled; DemoteRegToStack(*Inst, true); + ++NumSpilled; } } } @@ -950,6 +378,8 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) { if (Invokes.empty()) return false; + NumInvokes += Invokes.size(); + lowerIncomingArguments(F); lowerAcrossUnwindEdges(F, Invokes); @@ -1039,10 +469,6 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) { } bool SjLjEHPass::runOnFunction(Function &F) { - bool Res = false; - if (!DisableOldSjLjEH) - Res = insertSjLjEHSupport(F); - else - Res = setupEntryBlockAndCallSites(F); + bool Res = setupEntryBlockAndCallSites(F); return Res; } |
