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Fix a globalvariable initializer bug in LLVMSwiftARC #4453

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Merged
merged 1 commit into from
Aug 22, 2016
Merged

Fix a globalvariable initializer bug in LLVMSwiftARC #4453

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4 changes: 3 additions & 1 deletion lib/LLVMPasses/LLVMARCOpts.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -545,8 +545,10 @@ static DtorKind analyzeDestructor(Value *P) {

// We have to have a known heap metadata value, reject dynamically computed
// ones, or places
// Also, make sure we have a definitive initializer for the global.
GlobalVariable *GV = dyn_cast<GlobalVariable>(P->stripPointerCasts());
if (GV == 0 || GV->mayBeOverridden()) return DtorKind::Unknown;
if (GV == 0 || !GV->hasDefinitiveInitializer())
return DtorKind::Unknown;

ConstantStruct *CS = dyn_cast_or_null<ConstantStruct>(GV->getInitializer());
if (CS == 0 || CS->getNumOperands() == 0) return DtorKind::Unknown;
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15 changes: 15 additions & 0 deletions test/LLVMPasses/allocation-deletion.ll
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Expand Up @@ -81,4 +81,19 @@ entry:
; CHECK-NEXT: ret void


; external_dtor_alloc_eliminate - Make sure we can not eliminate the allocation
; because we know nothing about the type of the allocation.
@external_dtor_metadata = external global %swift.heapmetadata, align 8
define void @external_dtor_alloc_eliminate() nounwind {
entry:
%0 = tail call noalias %swift.refcounted* @swift_allocObject(%swift.heapmetadata* nonnull @external_dtor_metadata, i64 24, i64 8) nounwind
tail call void @swift_release(%swift.refcounted* %0) nounwind
ret void
}

; CHECK: @external_dtor_alloc_eliminate
; CHECK-NEXT: entry:
; CHECK-NEXT: swift_allocObject
; CHECK-NEXT: swift_release
; CHECK-NEXT: ret void