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Stub out rewriting on exception paths for WinEH #106

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Oct 21, 2015
Merged

Stub out rewriting on exception paths for WinEH #106

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30 changes: 17 additions & 13 deletions include/llvm/IR/Statepoint.h
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Original file line number Diff line number Diff line change
Expand Up @@ -397,19 +397,23 @@ StatepointBase<FunTy, InstructionTy, ValueTy, CallSiteTy>::getRelocates()
return Result;

// We need to scan thorough exceptional relocations if it is invoke statepoint
LandingPadInst *LandingPad =
cast<InvokeInst>(getInstruction())->getLandingPadInst();

// Search for extract value from landingpad instruction to which
// gc relocates will be attached
for (const User *LandingPadUser : LandingPad->users()) {
if (!isa<ExtractValueInst>(LandingPadUser))
continue;

// gc relocates should be attached to this extract value
for (const User *U : LandingPadUser->users())
if (isGCRelocate(U))
Result.push_back(GCRelocateOperands(U));
const InvokeInst *Invoke = cast<InvokeInst>(getInstruction());

// FIXME: Getting relocates on WinEH invokes needs to work too.
if (Invoke->getUnwindDest()->isLandingPad()) {
LandingPadInst *LandingPad = Invoke->getLandingPadInst();

// Search for extract value from landingpad instruction to which
// gc relocates will be attached
for (const User *LandingPadUser : LandingPad->users()) {
if (!isa<ExtractValueInst>(LandingPadUser))
continue;

// gc relocates should be attached to this extract value
for (const User *U : LandingPadUser->users())
if (isGCRelocate(U))
Result.push_back(GCRelocateOperands(U));
}
}
return Result;
}
Expand Down
89 changes: 53 additions & 36 deletions lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1600,25 +1600,28 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */

Token = Invoke;

// Generate gc relocates in exceptional path
BasicBlock *UnwindBlock = ToReplace->getUnwindDest();
assert(!isa<PHINode>(UnwindBlock->begin()) &&
UnwindBlock->getUniquePredecessor() &&
"can't safely insert in this block!");

Builder.SetInsertPoint(&*UnwindBlock->getFirstInsertionPt());
Builder.SetCurrentDebugLocation(ToReplace->getDebugLoc());

// Extract second element from landingpad return value. We will attach
// exceptional gc relocates to it.
Instruction *ExceptionalToken =
cast<Instruction>(Builder.CreateExtractValue(
UnwindBlock->getLandingPadInst(), 1, "relocate_token"));
Result.UnwindToken = ExceptionalToken;

const unsigned LiveStartIdx = Statepoint(Token).gcArgsStartIdx();
CreateGCRelocates(LiveVariables, LiveStartIdx, BasePtrs, ExceptionalToken,
Builder);
// FIXME: Inserting relocates on WinEH invokes needs to work too.
if (Invoke->getUnwindDest()->isLandingPad()) {
// Generate gc relocates in exceptional path
BasicBlock *UnwindBlock = ToReplace->getUnwindDest();
assert(!isa<PHINode>(UnwindBlock->begin()) &&
UnwindBlock->getUniquePredecessor() &&
"can't safely insert in this block!");

Builder.SetInsertPoint(&*UnwindBlock->getFirstInsertionPt());
Builder.SetCurrentDebugLocation(ToReplace->getDebugLoc());

// Extract second element from landingpad return value. We will attach
// exceptional gc relocates to it.
Instruction *ExceptionalToken =
cast<Instruction>(Builder.CreateExtractValue(
UnwindBlock->getLandingPadInst(), 1, "relocate_token"));
Result.UnwindToken = ExceptionalToken;

const unsigned LiveStartIdx = Statepoint(Token).gcArgsStartIdx();
CreateGCRelocates(LiveVariables, LiveStartIdx, BasePtrs, ExceptionalToken,
Builder);
}

// Generate gc relocates and returns for normal block
BasicBlock *NormalDest = ToReplace->getNormalDest();
Expand Down Expand Up @@ -1876,7 +1879,9 @@ static void relocationViaAlloca(

// In case if it was invoke statepoint
// we will insert stores for exceptional path gc relocates.
if (isa<InvokeInst>(Statepoint)) {
// FIXME: This needs to work for WinEH invokes too.
if (isa<InvokeInst>(Statepoint) &&
cast<InvokeInst>(Statepoint)->getUnwindDest()->isLandingPad()) {
insertRelocationStores(Info.UnwindToken->users(), AllocaMap,
VisitedLiveValues);
}
Expand Down Expand Up @@ -1917,7 +1922,9 @@ static void relocationViaAlloca(
// gc.results and gc.relocates, but that's fine.
if (auto II = dyn_cast<InvokeInst>(Statepoint)) {
InsertClobbersAt(&*II->getNormalDest()->getFirstInsertionPt());
InsertClobbersAt(&*II->getUnwindDest()->getFirstInsertionPt());
// FIXME: Need to be able to clobber WinEH invokes too.
if (II->getUnwindDest()->isLandingPad())
InsertClobbersAt(&*II->getUnwindDest()->getFirstInsertionPt());
} else {
InsertClobbersAt(cast<Instruction>(Statepoint)->getNextNode());
}
Expand Down Expand Up @@ -2036,8 +2043,10 @@ static void insertUseHolderAfter(CallSite &CS, const ArrayRef<Value *> Values,
auto *II = cast<InvokeInst>(CS.getInstruction());
Holders.push_back(CallInst::Create(
Func, Values, "", &*II->getNormalDest()->getFirstInsertionPt()));
Holders.push_back(CallInst::Create(
Func, Values, "", &*II->getUnwindDest()->getFirstInsertionPt()));
// FIXME: Statepoint rewriting on WinEH invokes needs to work too.
if (II->getUnwindDest()->isLandingPad())
Holders.push_back(CallInst::Create(
Func, Values, "", &*II->getUnwindDest()->getFirstInsertionPt()));
}

static void findLiveReferences(
Expand Down Expand Up @@ -2111,13 +2120,17 @@ static void splitVectorValues(Instruction *StatepointInst,
// blocks
BasicBlock *NormalDest = Invoke->getNormalDest();
assert(!isa<PHINode>(NormalDest->begin()));
BasicBlock *UnwindDest = Invoke->getUnwindDest();
assert(!isa<PHINode>(UnwindDest->begin()));
// Insert insert element sequences in both successors
Instruction *IP = &*(NormalDest->getFirstInsertionPt());
Replacements[V].first = InsertVectorReform(IP);
IP = &*(UnwindDest->getFirstInsertionPt());
Replacements[V].second = InsertVectorReform(IP);

BasicBlock *UnwindDest = Invoke->getUnwindDest();
// FIXME: need to be able to insert replacements for WinEH invokes too.
if (UnwindDest->isLandingPad()) {
assert(!isa<PHINode>(UnwindDest->begin()));
Replacements[V].first = InsertVectorReform(IP);
IP = &*(UnwindDest->getFirstInsertionPt());
Replacements[V].second = InsertVectorReform(IP);
}
}
}

Expand Down Expand Up @@ -2361,16 +2374,18 @@ static void rematerializeLiveValues(CallSite CS,

Instruction *NormalInsertBefore =
&*Invoke->getNormalDest()->getFirstInsertionPt();
Instruction *UnwindInsertBefore =
&*Invoke->getUnwindDest()->getFirstInsertionPt();

Instruction *NormalRematerializedValue =
rematerializeChain(NormalInsertBefore);
Instruction *UnwindRematerializedValue =
rematerializeChain(UnwindInsertBefore);

Info.RematerializedValues[NormalRematerializedValue] = LiveValue;
Info.RematerializedValues[UnwindRematerializedValue] = LiveValue;

// FIXME: rematerialization needs to work for WinEH invokes too.
if (Invoke->getUnwindDest()->isLandingPad()) {
Instruction *UnwindInsertBefore =
&*Invoke->getUnwindDest()->getFirstInsertionPt();
Instruction *UnwindRematerializedValue =
rematerializeChain(UnwindInsertBefore);
Info.RematerializedValues[UnwindRematerializedValue] = LiveValue;
}
}
}

Expand Down Expand Up @@ -2404,7 +2419,9 @@ static bool insertParsePoints(Function &F, DominatorTree &DT, Pass *P,
continue;
auto *II = cast<InvokeInst>(CS.getInstruction());
normalizeForInvokeSafepoint(II->getNormalDest(), II->getParent(), DT);
normalizeForInvokeSafepoint(II->getUnwindDest(), II->getParent(), DT);
// FIXME: Inserting statepoints on WinEH invokes needs to work too.
if (II->getUnwindDest()->isLandingPad())
normalizeForInvokeSafepoint(II->getUnwindDest(), II->getParent(), DT);
}

// A list of dummy calls added to the IR to keep various values obviously
Expand Down