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[clang codegen] Delete unnecessary GEP cleanup code. #90303

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Merged
merged 2 commits into from
May 29, 2024
Merged

[clang codegen] Delete unnecessary GEP cleanup code. #90303

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4a3612b
[clang codegen] Delete unnecessary GEP cleanup code.
efriedma-quic Apr 26, 2024
0753489
Merge branch 'main' into clang-no-gep-cleanup
efriedma-quic May 28, 2024
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10 changes: 0 additions & 10 deletions clang/lib/CodeGen/CGExprAgg.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1789,25 +1789,15 @@ void AggExprEmitter::VisitCXXParenListOrInitListExpr(
// Push a destructor if necessary.
// FIXME: if we have an array of structures, all explicitly
// initialized, we can end up pushing a linear number of cleanups.
bool pushedCleanup = false;
if (QualType::DestructionKind dtorKind
= field->getType().isDestructedType()) {
assert(LV.isSimple());
if (dtorKind) {
CGF.pushDestroyAndDeferDeactivation(NormalAndEHCleanup, LV.getAddress(),
field->getType(),
CGF.getDestroyer(dtorKind), false);
pushedCleanup = true;
}
}

// If the GEP didn't get used because of a dead zero init or something
// else, clean it up for -O0 builds and general tidiness.
if (!pushedCleanup && LV.isSimple())
if (llvm::GetElementPtrInst *GEP =
dyn_cast<llvm::GetElementPtrInst>(LV.emitRawPointer(CGF)))
if (GEP->use_empty())
GEP->eraseFromParent();
}
}

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25 changes: 25 additions & 0 deletions clang/test/CodeGenCXX/no-unique-address.cpp
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Expand Up @@ -101,3 +101,28 @@ struct HasZeroSizedFieldWithNonTrivialInit {
HasZeroSizedFieldWithNonTrivialInit testHasZeroSizedFieldWithNonTrivialInit = {.a = 1};
// CHECK-LABEL: define {{.*}}cxx_global_var_init
// CHECK: call {{.*}}@_ZN14NonTrivialInitC1Ev({{.*}}@testHasZeroSizedFieldWithNonTrivialInit

void *operator new(unsigned long, void *);
template <class Ty>
struct _box {
[[no_unique_address]] Ty _value;
};
// Make sure this doesn't crash.
// CHECK-LABEL: define {{.*}}placement_new_struct
void placement_new_struct() {
struct set_value_t {};

// GH88077
struct _tuple : _box<set_value_t>, _box<int> {};

int _storage[1];
new (_storage) _tuple{};

// GH89547
struct _tuple2 {
_box<set_value_t> a;
};

int _storage2[1];
new (_storage2) _tuple2{};
}