#include "llvm/Support/CallSite.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/PromoteMemToReg.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
using namespace llvm;
STATISTIC(NumLandingPadsSplit, "Number of landing pads split");
STATISTIC(NumUnwindsLowered, "Number of unwind instructions lowered");
+STATISTIC(NumResumesLowered, "Number of eh.resume calls lowered");
STATISTIC(NumExceptionValuesMoved, "Number of eh.exception calls moved");
-STATISTIC(NumStackTempsIntroduced, "Number of stack temporaries introduced");
namespace {
class DwarfEHPrepare : public FunctionPass {
const TargetMachine *TM;
const TargetLowering *TLI;
- bool CompileFast;
// The eh.exception intrinsic.
Function *ExceptionValueIntrinsic;
// The eh.selector intrinsic.
Function *SelectorIntrinsic;
- // _Unwind_Resume_or_Rethrow call.
+ // _Unwind_Resume_or_Rethrow or _Unwind_SjLj_Resume call.
Constant *URoR;
// The EH language-specific catch-all type.
// _Unwind_Resume or the target equivalent.
Constant *RewindFunction;
- // Dominator info is used when turning stack temporaries into registers.
+ // We both use and preserve dominator info.
DominatorTree *DT;
- DominanceFrontier *DF;
// The function we are running on.
Function *F;
typedef SmallPtrSet<BasicBlock*, 8> BBSet;
BBSet LandingPads;
- // Stack temporary used to hold eh.exception values.
- AllocaInst *ExceptionValueVar;
-
bool NormalizeLandingPads();
- bool LowerUnwinds();
+ bool LowerUnwindsAndResumes();
bool MoveExceptionValueCalls();
- bool FinishStackTemporaries();
- bool PromoteStackTemporaries();
Instruction *CreateExceptionValueCall(BasicBlock *BB);
- Instruction *CreateValueLoad(BasicBlock *BB);
-
- /// CreateReadOfExceptionValue - Return the result of the eh.exception
- /// intrinsic by calling the intrinsic if in a landing pad, or loading it
- /// from the exception value variable otherwise.
- Instruction *CreateReadOfExceptionValue(BasicBlock *BB) {
- return LandingPads.count(BB) ?
- CreateExceptionValueCall(BB) : CreateValueLoad(BB);
- }
/// CleanupSelectors - Any remaining eh.selector intrinsic calls which still
- /// use the ".llvm.eh.catch.all.value" call need to convert to using its
+ /// use the "llvm.eh.catch.all.value" call need to convert to using its
/// initializer instead.
bool CleanupSelectors(SmallPtrSet<IntrinsicInst*, 32> &Sels);
/// FindAllURoRInvokes - Find all URoR invokes in the function.
void FindAllURoRInvokes(SmallPtrSet<InvokeInst*, 32> &URoRInvokes);
- /// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow"
- /// calls. The "unwind" part of these invokes jump to a landing pad within
- /// the current function. This is a candidate to merge the selector
- /// associated with the URoR invoke with the one from the URoR's landing
- /// pad.
+ /// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow" or
+ /// "_Unwind_SjLj_Resume" calls. The "unwind" part of these invokes jump to
+ /// a landing pad within the current function. This is a candidate to merge
+ /// the selector associated with the URoR invoke with the one from the
+ /// URoR's landing pad.
bool HandleURoRInvokes();
/// FindSelectorAndURoR - Find the eh.selector call and URoR call associated
/// with the eh.exception call. This recursively looks past instructions
/// which don't change the EH pointer value, like casts or PHI nodes.
bool FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
- SmallPtrSet<IntrinsicInst*, 8> &SelCalls);
+ SmallPtrSet<IntrinsicInst*, 8> &SelCalls,
+ SmallPtrSet<PHINode*, 32> &SeenPHIs);
- /// DoMem2RegPromotion - Take an alloca call and promote it from memory to a
- /// register.
- bool DoMem2RegPromotion(Value *V) {
- AllocaInst *AI = dyn_cast<AllocaInst>(V);
- if (!AI || !isAllocaPromotable(AI)) return false;
-
- // Turn the alloca into a register.
- std::vector<AllocaInst*> Allocas(1, AI);
- PromoteMemToReg(Allocas, *DT, *DF);
- return true;
- }
-
- /// PromoteStoreInst - Perform Mem2Reg on a StoreInst.
- bool PromoteStoreInst(StoreInst *SI) {
- if (!SI || !DT || !DF) return false;
- if (DoMem2RegPromotion(SI->getOperand(1)))
- return true;
- return false;
- }
-
- /// PromoteEHPtrStore - Promote the storing of an EH pointer into a
- /// register. This should get rid of the store and subsequent loads.
- bool PromoteEHPtrStore(IntrinsicInst *II) {
- if (!DT || !DF) return false;
-
- bool Changed = false;
- StoreInst *SI;
-
- while (1) {
- SI = 0;
- for (Value::use_iterator
- I = II->use_begin(), E = II->use_end(); I != E; ++I) {
- SI = dyn_cast<StoreInst>(I);
- if (SI) break;
- }
-
- if (!PromoteStoreInst(SI))
- break;
-
- Changed = true;
- }
-
- return Changed;
- }
-
public:
static char ID; // Pass identification, replacement for typeid.
- DwarfEHPrepare(const TargetMachine *tm, bool fast) :
- FunctionPass(&ID), TM(tm), TLI(TM->getTargetLowering()),
- CompileFast(fast),
+ DwarfEHPrepare(const TargetMachine *tm) :
+ FunctionPass(ID), TM(tm), TLI(TM->getTargetLowering()),
ExceptionValueIntrinsic(0), SelectorIntrinsic(0),
- URoR(0), EHCatchAllValue(0), RewindFunction(0) {}
+ URoR(0), EHCatchAllValue(0), RewindFunction(0) {
+ initializeDominatorTreePass(*PassRegistry::getPassRegistry());
+ }
virtual bool runOnFunction(Function &Fn);
- // getAnalysisUsage - We need dominance frontiers for memory promotion.
+ // getAnalysisUsage - We need the dominator tree for handling URoR.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- if (!CompileFast)
- AU.addRequired<DominatorTree>();
+ AU.addRequired<DominatorTree>();
AU.addPreserved<DominatorTree>();
- if (!CompileFast)
- AU.addRequired<DominanceFrontier>();
- AU.addPreserved<DominanceFrontier>();
}
const char *getPassName() const {
char DwarfEHPrepare::ID = 0;
-FunctionPass *llvm::createDwarfEHPass(const TargetMachine *tm, bool fast) {
- return new DwarfEHPrepare(tm, fast);
+FunctionPass *llvm::createDwarfEHPass(const TargetMachine *tm) {
+ return new DwarfEHPrepare(tm);
}
/// HasCatchAllInSelector - Return true if the intrinsic instruction has a
for (Value::use_iterator
I = SelectorIntrinsic->use_begin(),
E = SelectorIntrinsic->use_end(); I != E; ++I) {
- IntrinsicInst *II = cast<IntrinsicInst>(I);
+ IntrinsicInst *II = cast<IntrinsicInst>(*I);
if (II->getParent()->getParent() != F)
continue;
for (Value::use_iterator
I = URoR->use_begin(),
E = URoR->use_end(); I != E; ++I) {
- if (InvokeInst *II = dyn_cast<InvokeInst>(I))
+ if (InvokeInst *II = dyn_cast<InvokeInst>(*I))
URoRInvokes.insert(II);
}
}
/// CleanupSelectors - Any remaining eh.selector intrinsic calls which still use
-/// the ".llvm.eh.catch.all.value" call need to convert to using its
+/// the "llvm.eh.catch.all.value" call need to convert to using its
/// initializer instead.
bool DwarfEHPrepare::CleanupSelectors(SmallPtrSet<IntrinsicInst*, 32> &Sels) {
if (!EHCatchAllValue) return false;
I = Sels.begin(), E = Sels.end(); I != E; ++I) {
IntrinsicInst *Sel = *I;
- // Index of the ".llvm.eh.catch.all.value" variable.
+ // Index of the "llvm.eh.catch.all.value" variable.
unsigned OpIdx = Sel->getNumArgOperands() - 1;
GlobalVariable *GV = dyn_cast<GlobalVariable>(Sel->getArgOperand(OpIdx));
if (GV != EHCatchAllValue) continue;
/// change the EH pointer value, like casts or PHI nodes.
bool
DwarfEHPrepare::FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
- SmallPtrSet<IntrinsicInst*, 8> &SelCalls) {
- SmallPtrSet<PHINode*, 32> SeenPHIs;
+ SmallPtrSet<IntrinsicInst*, 8> &SelCalls,
+ SmallPtrSet<PHINode*, 32> &SeenPHIs) {
bool Changed = false;
- restart:
for (Value::use_iterator
I = Inst->use_begin(), E = Inst->use_end(); I != E; ++I) {
- Instruction *II = dyn_cast<Instruction>(I);
+ Instruction *II = dyn_cast<Instruction>(*I);
if (!II || II->getParent()->getParent() != F) continue;
if (IntrinsicInst *Sel = dyn_cast<IntrinsicInst>(II)) {
if (Invoke->getCalledFunction() == URoR)
URoRInvoke = true;
} else if (CastInst *CI = dyn_cast<CastInst>(II)) {
- Changed |= FindSelectorAndURoR(CI, URoRInvoke, SelCalls);
- } else if (StoreInst *SI = dyn_cast<StoreInst>(II)) {
- if (!PromoteStoreInst(SI)) continue;
- Changed = true;
- SeenPHIs.clear();
- goto restart; // Uses may have changed, restart loop.
+ Changed |= FindSelectorAndURoR(CI, URoRInvoke, SelCalls, SeenPHIs);
} else if (PHINode *PN = dyn_cast<PHINode>(II)) {
if (SeenPHIs.insert(PN))
// Don't process a PHI node more than once.
- Changed |= FindSelectorAndURoR(PN, URoRInvoke, SelCalls);
+ Changed |= FindSelectorAndURoR(PN, URoRInvoke, SelCalls, SeenPHIs);
}
}
return Changed;
}
-/// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow" calls. The
-/// "unwind" part of these invokes jump to a landing pad within the current
-/// function. This is a candidate to merge the selector associated with the URoR
-/// invoke with the one from the URoR's landing pad.
+/// HandleURoRInvokes - Handle invokes of "_Unwind_Resume_or_Rethrow" or
+/// "_Unwind_SjLj_Resume" calls. The "unwind" part of these invokes jump to a
+/// landing pad within the current function. This is a candidate to merge the
+/// selector associated with the URoR invoke with the one from the URoR's
+/// landing pad.
bool DwarfEHPrepare::HandleURoRInvokes() {
if (!EHCatchAllValue) {
EHCatchAllValue =
- F->getParent()->getNamedGlobal(".llvm.eh.catch.all.value");
+ F->getParent()->getNamedGlobal("llvm.eh.catch.all.value");
if (!EHCatchAllValue) return false;
}
SmallPtrSet<IntrinsicInst*, 32> CatchAllSels;
FindAllCleanupSelectors(Sels, CatchAllSels);
- if (!DT)
- // We require DominatorTree information.
- return CleanupSelectors(CatchAllSels);
-
if (!URoR) {
URoR = F->getParent()->getFunction("_Unwind_Resume_or_Rethrow");
if (!URoR) return CleanupSelectors(CatchAllSels);
for (SmallPtrSet<InvokeInst*, 32>::iterator
UI = URoRInvokes.begin(), UE = URoRInvokes.end(); UI != UE; ++UI) {
const BasicBlock *URoRBB = (*UI)->getParent();
- if (SelBB == URoRBB || DT->dominates(SelBB, URoRBB)) {
+ if (DT->dominates(SelBB, URoRBB)) {
SelsToConvert.insert(*SI);
break;
}
for (Value::use_iterator
I = ExceptionValueIntrinsic->use_begin(),
E = ExceptionValueIntrinsic->use_end(); I != E; ++I) {
- IntrinsicInst *EHPtr = dyn_cast<IntrinsicInst>(I);
+ IntrinsicInst *EHPtr = dyn_cast<IntrinsicInst>(*I);
if (!EHPtr || EHPtr->getParent()->getParent() != F) continue;
- Changed |= PromoteEHPtrStore(EHPtr);
-
bool URoRInvoke = false;
SmallPtrSet<IntrinsicInst*, 8> SelCalls;
- Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls);
+ SmallPtrSet<PHINode*, 32> SeenPHIs;
+ Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls, SeenPHIs);
if (URoRInvoke) {
// This EH pointer is being used by an invoke of an URoR instruction and
Args.push_back(EHCatchAllValue->getInitializer()); // Catch-all indicator.
CallInst *NewSelector =
- CallInst::Create(SelectorIntrinsic, Args.begin(), Args.end(),
- "eh.sel.catch.all", II);
+ CallInst::Create(SelectorIntrinsic, Args, "eh.sel.catch.all", II);
NewSelector->setTailCall(II->isTailCall());
NewSelector->setAttributes(II->getAttributes());
if (InVal == 0) {
// Different unwind edges have different values. Create a new PHI node
// in NewBB.
- PHINode *NewPN = PHINode::Create(PN->getType(), PN->getName()+".unwind",
- NewBB);
+ PHINode *NewPN = PHINode::Create(PN->getType(),
+ PN->getNumIncomingValues(),
+ PN->getName()+".unwind", NewBB);
// Add an entry for each unwind edge, using the value from the old PHI.
for (pred_iterator PI = PB; PI != PE; ++PI)
NewPN->addIncoming(PN->getIncomingValueForBlock(*PI), *PI);
// Add a fallthrough from NewBB to the original landing pad.
BranchInst::Create(LPad, NewBB);
- // Now update DominatorTree and DominanceFrontier analysis information.
- if (DT)
- DT->splitBlock(NewBB);
- if (DF)
- DF->splitBlock(NewBB);
+ // Now update DominatorTree analysis information.
+ DT->splitBlock(NewBB);
// Remember the newly constructed landing pad. The original landing pad
// LPad is no longer a landing pad now that all unwind edges have been
/// rethrowing any previously caught exception. This will crash horribly
/// at runtime if there is no such exception: using unwind to throw a new
/// exception is currently not supported.
-bool DwarfEHPrepare::LowerUnwinds() {
- SmallVector<TerminatorInst*, 16> UnwindInsts;
-
- for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
- TerminatorInst *TI = I->getTerminator();
- if (isa<UnwindInst>(TI))
- UnwindInsts.push_back(TI);
+bool DwarfEHPrepare::LowerUnwindsAndResumes() {
+ SmallVector<Instruction*, 16> ResumeInsts;
+
+ for (Function::iterator fi = F->begin(), fe = F->end(); fi != fe; ++fi) {
+ for (BasicBlock::iterator bi = fi->begin(), be = fi->end(); bi != be; ++bi){
+ if (isa<UnwindInst>(bi))
+ ResumeInsts.push_back(bi);
+ else if (CallInst *call = dyn_cast<CallInst>(bi))
+ if (Function *fn = dyn_cast<Function>(call->getCalledValue()))
+ if (fn->getName() == "llvm.eh.resume")
+ ResumeInsts.push_back(bi);
+ }
}
- if (UnwindInsts.empty()) return false;
+ if (ResumeInsts.empty()) return false;
// Find the rewind function if we didn't already.
if (!RewindFunction) {
- LLVMContext &Ctx = UnwindInsts[0]->getContext();
- std::vector<const Type*>
- Params(1, Type::getInt8PtrTy(Ctx));
+ LLVMContext &Ctx = ResumeInsts[0]->getContext();
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
- Params, false);
+ Type::getInt8PtrTy(Ctx), false);
const char *RewindName = TLI->getLibcallName(RTLIB::UNWIND_RESUME);
RewindFunction = F->getParent()->getOrInsertFunction(RewindName, FTy);
}
bool Changed = false;
- for (SmallVectorImpl<TerminatorInst*>::iterator
- I = UnwindInsts.begin(), E = UnwindInsts.end(); I != E; ++I) {
- TerminatorInst *TI = *I;
+ for (SmallVectorImpl<Instruction*>::iterator
+ I = ResumeInsts.begin(), E = ResumeInsts.end(); I != E; ++I) {
+ Instruction *RI = *I;
- // Replace the unwind instruction with a call to _Unwind_Resume (or the
- // appropriate target equivalent) followed by an UnreachableInst.
+ // Replace the resuming instruction with a call to _Unwind_Resume (or the
+ // appropriate target equivalent).
+
+ llvm::Value *ExnValue;
+ if (isa<UnwindInst>(RI))
+ ExnValue = CreateExceptionValueCall(RI->getParent());
+ else
+ ExnValue = cast<CallInst>(RI)->getArgOperand(0);
// Create the call...
- CallInst *CI = CallInst::Create(RewindFunction,
- CreateReadOfExceptionValue(TI->getParent()),
- "", TI);
+ CallInst *CI = CallInst::Create(RewindFunction, ExnValue, "", RI);
CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
- // ...followed by an UnreachableInst.
- new UnreachableInst(TI->getContext(), TI);
- // Nuke the unwind instruction.
- TI->eraseFromParent();
- ++NumUnwindsLowered;
+ // ...followed by an UnreachableInst, if it was an unwind.
+ // Calls to llvm.eh.resume are typically already followed by this.
+ if (isa<UnwindInst>(RI))
+ new UnreachableInst(RI->getContext(), RI);
+
+ if (isa<UnwindInst>(RI))
+ ++NumUnwindsLowered;
+ else
+ ++NumResumesLowered;
+
+ // Nuke the resume instruction.
+ RI->eraseFromParent();
+
Changed = true;
}
}
/// MoveExceptionValueCalls - Ensure that eh.exception is only ever called from
-/// landing pads by replacing calls outside of landing pads with loads from a
-/// stack temporary. Move eh.exception calls inside landing pads to the start
-/// of the landing pad (optional, but may make things simpler for later passes).
+/// landing pads by replacing calls outside of landing pads with direct use of
+/// a register holding the appropriate value; this requires adding calls inside
+/// all landing pads to initialize the register. Also, move eh.exception calls
+/// inside landing pads to the start of the landing pad (optional, but may make
+/// things simpler for later passes).
bool DwarfEHPrepare::MoveExceptionValueCalls() {
// If the eh.exception intrinsic is not declared in the module then there is
// nothing to do. Speed up compilation by checking for this common case.
bool Changed = false;
- for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
- for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E;)
- if (IntrinsicInst *CI = dyn_cast<IntrinsicInst>(II++))
- if (CI->getIntrinsicID() == Intrinsic::eh_exception) {
- if (!CI->use_empty()) {
- Value *ExceptionValue = CreateReadOfExceptionValue(BB);
- if (CI == ExceptionValue) {
- // The call was at the start of a landing pad - leave it alone.
- assert(LandingPads.count(BB) &&
- "Created eh.exception call outside landing pad!");
- continue;
- }
- CI->replaceAllUsesWith(ExceptionValue);
- }
- CI->eraseFromParent();
- ++NumExceptionValuesMoved;
- Changed = true;
+ // Move calls to eh.exception that are inside a landing pad to the start of
+ // the landing pad.
+ for (BBSet::const_iterator LI = LandingPads.begin(), LE = LandingPads.end();
+ LI != LE; ++LI) {
+ BasicBlock *LP = *LI;
+ for (BasicBlock::iterator II = LP->getFirstNonPHIOrDbg(), IE = LP->end();
+ II != IE;)
+ if (EHExceptionInst *EI = dyn_cast<EHExceptionInst>(II++)) {
+ // Found a call to eh.exception.
+ if (!EI->use_empty()) {
+ // If there is already a call to eh.exception at the start of the
+ // landing pad, then get hold of it; otherwise create such a call.
+ Value *CallAtStart = CreateExceptionValueCall(LP);
+
+ // If the call was at the start of a landing pad then leave it alone.
+ if (EI == CallAtStart)
+ continue;
+ EI->replaceAllUsesWith(CallAtStart);
}
+ EI->eraseFromParent();
+ ++NumExceptionValuesMoved;
+ Changed = true;
+ }
}
- return Changed;
-}
-
-/// FinishStackTemporaries - If we introduced a stack variable to hold the
-/// exception value then initialize it in each landing pad.
-bool DwarfEHPrepare::FinishStackTemporaries() {
- if (!ExceptionValueVar)
- // Nothing to do.
- return false;
+ // Look for calls to eh.exception that are not in a landing pad. If one is
+ // found, then a register that holds the exception value will be created in
+ // each landing pad, and the SSAUpdater will be used to compute the values
+ // returned by eh.exception calls outside of landing pads.
+ SSAUpdater SSA;
+
+ // Remember where we found the eh.exception call, to avoid rescanning earlier
+ // basic blocks which we already know contain no eh.exception calls.
+ bool FoundCallOutsideLandingPad = false;
+ Function::iterator BB = F->begin();
+ for (Function::iterator BE = F->end(); BB != BE; ++BB) {
+ // Skip over landing pads.
+ if (LandingPads.count(BB))
+ continue;
- bool Changed = false;
+ for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
+ II != IE; ++II)
+ if (isa<EHExceptionInst>(II)) {
+ SSA.Initialize(II->getType(), II->getName());
+ FoundCallOutsideLandingPad = true;
+ break;
+ }
- // Make sure that there is a store of the exception value at the start of
- // each landing pad.
- for (BBSet::iterator LI = LandingPads.begin(), LE = LandingPads.end();
- LI != LE; ++LI) {
- Instruction *ExceptionValue = CreateReadOfExceptionValue(*LI);
- Instruction *Store = new StoreInst(ExceptionValue, ExceptionValueVar);
- Store->insertAfter(ExceptionValue);
- Changed = true;
+ if (FoundCallOutsideLandingPad)
+ break;
}
- return Changed;
-}
+ // If all calls to eh.exception are in landing pads then we are done.
+ if (!FoundCallOutsideLandingPad)
+ return Changed;
-/// PromoteStackTemporaries - Turn any stack temporaries we introduced into
-/// registers if possible.
-bool DwarfEHPrepare::PromoteStackTemporaries() {
- if (ExceptionValueVar && DT && DF && isAllocaPromotable(ExceptionValueVar)) {
- // Turn the exception temporary into registers and phi nodes if possible.
- std::vector<AllocaInst*> Allocas(1, ExceptionValueVar);
- PromoteMemToReg(Allocas, *DT, *DF);
- return true;
+ // Add a call to eh.exception at the start of each landing pad, and tell the
+ // SSAUpdater that this is the value produced by the landing pad.
+ for (BBSet::iterator LI = LandingPads.begin(), LE = LandingPads.end();
+ LI != LE; ++LI)
+ SSA.AddAvailableValue(*LI, CreateExceptionValueCall(*LI));
+
+ // Now turn all calls to eh.exception that are not in a landing pad into a use
+ // of the appropriate register.
+ for (Function::iterator BE = F->end(); BB != BE; ++BB) {
+ // Skip over landing pads.
+ if (LandingPads.count(BB))
+ continue;
+
+ for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
+ II != IE;)
+ if (EHExceptionInst *EI = dyn_cast<EHExceptionInst>(II++)) {
+ // Found a call to eh.exception, replace it with the value from any
+ // upstream landing pad(s).
+ EI->replaceAllUsesWith(SSA.GetValueAtEndOfBlock(BB));
+ EI->eraseFromParent();
+ ++NumExceptionValuesMoved;
+ }
}
- return false;
+
+ return true;
}
/// CreateExceptionValueCall - Insert a call to the eh.exception intrinsic at
return CallInst::Create(ExceptionValueIntrinsic, "eh.value.call", Start);
}
-/// CreateValueLoad - Insert a load of the exception value stack variable
-/// (creating it if necessary) at the start of the basic block (unless
-/// there already is a load, in which case the existing load is returned).
-Instruction *DwarfEHPrepare::CreateValueLoad(BasicBlock *BB) {
- Instruction *Start = BB->getFirstNonPHIOrDbg();
- // Is this a load of the exception temporary?
- if (ExceptionValueVar)
- if (LoadInst* LI = dyn_cast<LoadInst>(Start))
- if (LI->getPointerOperand() == ExceptionValueVar)
- // Reuse the existing load.
- return Start;
-
- // Create the temporary if we didn't already.
- if (!ExceptionValueVar) {
- ExceptionValueVar = new AllocaInst(PointerType::getUnqual(
- Type::getInt8Ty(BB->getContext())), "eh.value", F->begin()->begin());
- ++NumStackTempsIntroduced;
- }
-
- // Load the value.
- return new LoadInst(ExceptionValueVar, "eh.value.load", Start);
-}
-
bool DwarfEHPrepare::runOnFunction(Function &Fn) {
bool Changed = false;
// Initialize internal state.
- DT = getAnalysisIfAvailable<DominatorTree>();
- DF = getAnalysisIfAvailable<DominanceFrontier>();
- ExceptionValueVar = 0;
+ DT = &getAnalysis<DominatorTree>();
F = &Fn;
// Ensure that only unwind edges end at landing pads (a landing pad is a
// basic block where an invoke unwind edge ends).
Changed |= NormalizeLandingPads();
- // Turn unwind instructions into libcalls.
- Changed |= LowerUnwinds();
+ // Turn unwind instructions and eh.resume calls into libcalls.
+ Changed |= LowerUnwindsAndResumes();
// TODO: Move eh.selector calls to landing pads and combine them.
// Move eh.exception calls to landing pads.
Changed |= MoveExceptionValueCalls();
- // Initialize any stack temporaries we introduced.
- Changed |= FinishStackTemporaries();
-
- // Turn any stack temporaries into registers if possible.
- if (!CompileFast)
- Changed |= PromoteStackTemporaries();
-
Changed |= HandleURoRInvokes();
LandingPads.clear();
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