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[clang][CodeGen][OpenMP] Fix casting of atomic update of ptr types #88215

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Merged
merged 1 commit into from
Apr 12, 2024
Merged

[clang][CodeGen][OpenMP] Fix casting of atomic update of ptr types #88215

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6 changes: 5 additions & 1 deletion clang/lib/CodeGen/CGAtomic.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1806,7 +1806,11 @@ void AtomicInfo::EmitAtomicUpdateOp(
/*NumReservedValues=*/2);
PHI->addIncoming(OldVal, CurBB);
Address NewAtomicAddr = CreateTempAlloca();
Address NewAtomicIntAddr = castToAtomicIntPointer(NewAtomicAddr);
Address NewAtomicIntAddr =
shouldCastToInt(NewAtomicAddr.getElementType(), /*CmpXchg=*/true)
? castToAtomicIntPointer(NewAtomicAddr)
: NewAtomicAddr;

if ((LVal.isBitField() && BFI.Size != ValueSizeInBits) ||
requiresMemSetZero(getAtomicAddress().getElementType())) {
CGF.Builder.CreateStore(PHI, NewAtomicIntAddr);
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11 changes: 11 additions & 0 deletions clang/test/OpenMP/atomic_update_codegen.cpp
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Expand Up @@ -27,6 +27,7 @@ long double ldv, ldx;
_Complex int civ, cix;
_Complex float cfv, cfx;
_Complex double cdv, cdx;
char *cpx;

typedef int int4 __attribute__((__vector_size__(16)));
int4 int4x;
Expand Down Expand Up @@ -851,6 +852,16 @@ int main(void) {
// CHECK: call{{.*}} @__kmpc_flush(
#pragma omp atomic seq_cst
rix = dv / rix;

// CHECK: [[LD_CPX:%.+]] = load atomic ptr, ptr @cpx monotonic
// CHECK: br label %[[CONT:.+]]
// CHECK: [[CONT]]
// CHECK: [[PHI:%.+]] = phi ptr
// CHECK: [[RES:%.+]] = cmpxchg ptr @cpx,
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Do we really end up emitting a cmpxchg in the frontend just because atomicrmw doesn't have pointer typed add? This is horrible

// CHECK: br i1 %{{.+}}, label %[[EXIT:.+]], label %[[CONT]]
#pragma omp atomic update
cpx += 1;

return 0;
}

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