-//===- SjLjEHPass.cpp - Eliminate Invoke & Unwind instructions -----------===//
+//===- SjLjEHPrepare.cpp - Eliminate Invoke & Unwind instructions ---------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
-#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 <set>
using namespace llvm;
+#define DEBUG_TYPE "sjljehprepare"
+
STATISTIC(NumInvokes, "Number of invokes replaced");
STATISTIC(NumSpilled, "Number of registers live across unwind edges");
namespace {
- class SjLjEHPass : 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 SjLjEHPass(const TargetLowering *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 {
+ 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<LandingPadInst*> LPads);
- void lowerIncomingArguments(Function &F);
- void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> 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<LandingPadInst *> LPads);
+ void lowerIncomingArguments(Function &F);
+ void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst *> Invokes);
+ void insertCallSiteStore(Instruction *I, int Number);
+};
} // end anonymous namespace
-char SjLjEHPass::ID = 0;
+char SjLjEHPrepare::ID = 0;
+INITIALIZE_PASS(SjLjEHPrepare, "sjljehprepare", "Prepare SjLj exceptions",
+ false, false)
-// 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() { return new SjLjEHPrepare(); }
// 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());
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;
}
/// 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.
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<BasicBlock*, 64> &LiveBBs,
- SmallPtrSet<BasicBlock*, 4> &InvokesCrossed) {
- 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);
- }
+static void MarkBlocksLiveIn(BasicBlock *BB,
+ SmallPtrSetImpl<BasicBlock *> &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);
}
/// 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) {
- SmallVector<Value*, 8> UseWorkList(LPI->use_begin(), LPI->use_end());
+void SjLjEHPrepare::substituteLPadValues(LandingPadInst *LPI, Value *ExnVal,
+ Value *SelVal) {
+ SmallVector<Value *, 8> UseWorkList(LPI->user_begin(), LPI->user_end());
while (!UseWorkList.empty()) {
Value *Val = UseWorkList.pop_back_val();
ExtractValueInst *EVI = dyn_cast<ExtractValueInst>(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)
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<Instruction>(SelVal))));
+ auto *SelI = cast<Instruction>(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");
/// setupFunctionContext - Allocate the function context on the stack and fill
/// it with all of the data that we know at this point.
-Value *SjLjEHPass::
-setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads) {
- BasicBlock *EntryBB = F.begin();
+Value *SjLjEHPrepare::setupFunctionContext(Function &F,
+ ArrayRef<LandingPadInst *> 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;
}
/// 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<AllocaInst>(AfterAllocaInsPt) &&
isa<ConstantInt>(cast<AllocaInst>(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<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(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 SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
- ArrayRef<InvokeInst*> Invokes) {
- SmallVector<std::pair<Instruction*, Instruction*>, 32> ReloadUsers;
- DenseMap<std::pair<Instruction*, Instruction*>, AllocaInst*> AllocaMap;
-
+void SjLjEHPrepare::lowerAcrossUnwindEdges(Function &F,
+ ArrayRef<InvokeInst *> 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<Instruction>(Inst->use_back())->getParent() == BB &&
- !isa<PHINode>(Inst->use_back())) continue;
+ cast<Instruction>(Inst->user_back())->getParent() == BB &&
+ !isa<PHINode>(Inst->user_back()))
+ continue;
// If this is an alloca in the entry block, it's not a real register
// value.
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);
+ SmallVector<Instruction *, 16> Users;
+ for (User *U : Inst->users()) {
+ Instruction *UI = cast<Instruction>(U);
+ if (UI->getParent() != BB || isa<PHINode>(UI))
+ Users.push_back(UI);
}
// Find all of the blocks that this value is live in.
- std::map<Instruction*, SmallPtrSet<BasicBlock*, 4> > InvokesCrossed;
- std::map<Instruction*, SmallPtrSet<BasicBlock*, 64> > LiveBBs;
+ SmallPtrSet<BasicBlock *, 64> 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<PHINode>(U)) {
+ 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), 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<Instruction*, SmallPtrSet<BasicBlock*, 4> >::iterator
- MI = InvokesCrossed.begin(), ME = InvokesCrossed.end();
- MI != ME; ++MI) {
- Instruction *User = MI->first;
- SmallPtrSet<BasicBlock*, 4> &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<BasicBlock*, 4>::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<std::pair<Instruction*, Instruction*> >::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<PHINode>(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<BasicBlock*, Value*> 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;
+ }
}
}
LandingPadInst *LPI = UnwindBlock->getLandingPadInst();
// Place PHIs into a set to avoid invalidating the iterator.
- SmallPtrSet<PHINode*, 8> PHIsToDemote;
- for (BasicBlock::iterator
- PN = UnwindBlock->begin(); isa<PHINode>(PN); ++PN)
+ SmallPtrSet<PHINode *, 8> PHIsToDemote;
+ for (BasicBlock::iterator PN = UnwindBlock->begin(); isa<PHINode>(PN); ++PN)
PHIsToDemote.insert(cast<PHINode>(PN));
- if (PHIsToDemote.empty()) continue;
+ if (PHIsToDemote.empty())
+ continue;
// Demote the PHIs to the stack.
- for (SmallPtrSet<PHINode*, 8>::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());
}
}
/// 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<ReturnInst*, 16> Returns;
- SmallVector<InvokeInst*, 16> Invokes;
- SmallSetVector<LandingPadInst*, 16> LPads;
+bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) {
+ SmallVector<ReturnInst *, 16> Returns;
+ SmallVector<InvokeInst *, 16> Invokes;
+ SmallSetVector<LandingPadInst *, 16> 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<InvokeInst>(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<ReturnInst>(BB->getTerminator())) {
Returns.push_back(RI);
}
- if (Invokes.empty()) return false;
+ if (Invokes.empty())
+ return false;
NumInvokes += Invokes.size();
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.
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.
}
// 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
continue;
}
Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
- StackAddr->insertAfter(I);
+ StackAddr->insertAfter(&*I);
Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
StoreStackAddr->insertAfter(StackAddr);
}
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;
}