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[ObjCARC] Account for funclet token in storeStrong transform 

When creating a call to storeStrong in ObjCARCContract, ensure the call
gets the correct funclet token, otherwise WinEHPrepare will turn the
call (and all subsequent instructions) into unreachable.

We already have logic to do this for the ARC autorelease elision marker;
factor that out into a common function that's used for both. These are
the only two places in this transform that create call instructions.

Differential Revision: https://reviews.llvm.org/D45857

llvm-svn: 330487
This commit is contained in:
Shoaib Meenai 2018-04-20 22:11:03 +00:00
parent 1803bfb75f
commit d64b83266b
2 changed files with 64 additions and 16 deletions
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43
llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp
View File

@ -91,8 +91,9 @@ namespace {
SmallPtrSetImpl<Instruction *> &DependingInstructions,
SmallPtrSetImpl<const BasicBlock *> &Visited);
void tryToContractReleaseIntoStoreStrong(Instruction *Release,
inst_iterator &Iter);
void tryToContractReleaseIntoStoreStrong(
Instruction *Release, inst_iterator &Iter,
const DenseMap<BasicBlock *, ColorVector> &BlockColors);
void getAnalysisUsage(AnalysisUsage &AU) const override;
bool doInitialization(Module &M) override;
@ -306,6 +307,24 @@ findRetainForStoreStrongContraction(Value *New, StoreInst *Store,
return Retain;
}
/// Create a call instruction with the correct funclet token. Should be used
/// instead of calling CallInst::Create directly.
static CallInst *
createCallInst(Value *Func, ArrayRef<Value *> Args, const Twine &NameStr,
Instruction *InsertBefore,
const DenseMap<BasicBlock *, ColorVector> &BlockColors) {
SmallVector<OperandBundleDef, 1> OpBundles;
if (!BlockColors.empty()) {
const ColorVector &CV = BlockColors.find(InsertBefore->getParent())->second;
assert(CV.size() == 1 && "non-unique color for block!");
Instruction *EHPad = CV.front()->getFirstNonPHI();
if (EHPad->isEHPad())
OpBundles.emplace_back("funclet", EHPad);
}
return CallInst::Create(Func, Args, OpBundles, NameStr, InsertBefore);
}
/// Attempt to merge an objc_release with a store, load, and objc_retain to form
/// an objc_storeStrong. An objc_storeStrong:
///
@ -333,8 +352,9 @@ findRetainForStoreStrongContraction(Value *New, StoreInst *Store,
/// (4).
/// 2. We need to make sure that any re-orderings of (1), (2), (3), (4) are
/// safe.
void ObjCARCContract::tryToContractReleaseIntoStoreStrong(Instruction *Release,
inst_iterator &Iter) {
void ObjCARCContract::tryToContractReleaseIntoStoreStrong(
Instruction *Release, inst_iterator &Iter,
const DenseMap<BasicBlock *, ColorVector> &BlockColors) {
// See if we are releasing something that we just loaded.
auto *Load = dyn_cast<LoadInst>(GetArgRCIdentityRoot(Release));
if (!Load || !Load->isSimple())
@ -386,7 +406,7 @@ void ObjCARCContract::tryToContractReleaseIntoStoreStrong(Instruction *Release,
if (Args[1]->getType() != I8X)
Args[1] = new BitCastInst(Args[1], I8X, "", Store);
Constant *Decl = EP.get(ARCRuntimeEntryPointKind::StoreStrong);
CallInst *StoreStrong = CallInst::Create(Decl, Args, "", Store);
CallInst *StoreStrong = createCallInst(Decl, Args, "", Store, BlockColors);
StoreStrong->setDoesNotThrow();
StoreStrong->setDebugLoc(Store->getDebugLoc());
@ -462,16 +482,7 @@ bool ObjCARCContract::tryToPeepholeInstruction(
RVInstMarker->getString(),
/*Constraints=*/"", /*hasSideEffects=*/true);
SmallVector<OperandBundleDef, 1> OpBundles;
if (!BlockColors.empty()) {
const ColorVector &CV = BlockColors.find(Inst->getParent())->second;
assert(CV.size() == 1 && "non-unique color for block!");
Instruction *EHPad = CV.front()->getFirstNonPHI();
if (EHPad->isEHPad())
OpBundles.emplace_back("funclet", EHPad);
}
CallInst::Create(IA, None, OpBundles, "", Inst);
createCallInst(IA, None, "", Inst, BlockColors);
}
decline_rv_optimization:
return false;
@ -496,7 +507,7 @@ bool ObjCARCContract::tryToPeepholeInstruction(
case ARCInstKind::Release:
// Try to form an objc store strong from our release. If we fail, there is
// nothing further to do below, so continue.
tryToContractReleaseIntoStoreStrong(Inst, Iter);
tryToContractReleaseIntoStoreStrong(Inst, Iter, BlockColors);
return true;
case ARCInstKind::User:
// Be conservative if the function has any alloca instructions.

37
llvm/test/Transforms/ObjCARC/contract-storestrong-funclet.ll Normal file
View File

@ -0,0 +1,37 @@
; RUN: opt -mtriple=i686-unknown-windows-msvc -objc-arc-contract -S -o - %s | FileCheck %s
declare void @f()
declare i32 @__CxxFrameHandler3(...)
declare dllimport i8* @objc_retain(i8*)
declare dllimport i8* @objc_retainAutoreleasedReturnValue(i8*)
declare dllimport void @objc_release(i8*)
@x = external global i8*
define void @g(i8* %p) personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
invoke void @f() to label %invoke.cont unwind label %ehcleanup
invoke.cont:
%call = tail call i8* @objc_retain(i8* %p) nounwind
%tmp = load i8*, i8** @x, align 4
store i8* %call, i8** @x, align 4
tail call void @objc_release(i8* %tmp) nounwind
ret void
ehcleanup:
%1 = cleanuppad within none []
%call1 = tail call i8* @objc_retain(i8* %p) nounwind [ "funclet"(token %1) ]
%tmp1 = load i8*, i8** @x, align 4
store i8* %call1, i8** @x, align 4
tail call void @objc_release(i8* %tmp1) nounwind [ "funclet"(token %1) ]
cleanupret from %1 unwind to caller
}
; CHECK-LABEL: invoke.cont:
; CHECK: tail call void @objc_storeStrong(i8** @x, i8* %p) #0{{$}}
; CHECK: ret void
; CHECK-LABEL: ehcleanup:
; CHECK: %1 = cleanuppad within none []
; CHECK: tail call void @objc_storeStrong(i8** @x, i8* %p) #0 [ "funclet"(token %1) ]
; CHECK: cleanupret from %1 unwind to caller