diff options
Diffstat (limited to 'compiler/optimizing/intrinsics_arm.cc')
| -rw-r--r-- | compiler/optimizing/intrinsics_arm.cc | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/compiler/optimizing/intrinsics_arm.cc b/compiler/optimizing/intrinsics_arm.cc index e8181bbb06..4683aee603 100644 --- a/compiler/optimizing/intrinsics_arm.cc +++ b/compiler/optimizing/intrinsics_arm.cc @@ -825,8 +825,15 @@ static void GenCas(LocationSummary* locations, Primitive::Type type, CodeGenerat Label loop_head; __ Bind(&loop_head); + // TODO: When `type == Primitive::kPrimNot`, add a read barrier for + // the reference stored in the object before attempting the CAS, + // similar to the one in the art::Unsafe_compareAndSwapObject JNI + // implementation. + // + // Note that this code is not (yet) used when read barriers are + // enabled (see IntrinsicLocationsBuilderARM::VisitUnsafeCASObject). + DCHECK(!(type == Primitive::kPrimNot && kEmitCompilerReadBarrier)); __ ldrex(tmp_lo, tmp_ptr); - // TODO: Do we need a read barrier here when `type == Primitive::kPrimNot`? __ subs(tmp_lo, tmp_lo, ShifterOperand(expected_lo)); @@ -852,15 +859,17 @@ void IntrinsicLocationsBuilderARM::VisitUnsafeCASInt(HInvoke* invoke) { CreateIntIntIntIntIntToIntPlusTemps(arena_, invoke); } void IntrinsicLocationsBuilderARM::VisitUnsafeCASObject(HInvoke* invoke) { - // The UnsafeCASObject intrinsic does not always work when heap - // poisoning is enabled (it breaks run-test 004-UnsafeTest); turn it - // off temporarily as a quick fix. + // The UnsafeCASObject intrinsic is missing a read barrier, and + // therefore sometimes does not work as expected (b/25883050). + // Turn it off temporarily as a quick fix, until the read barrier is + // implemented (see TODO in GenCAS below). // - // TODO(rpl): Fix it and turn it back on. + // Also, the UnsafeCASObject intrinsic does not always work when heap + // poisoning is enabled (it breaks run-test 004-UnsafeTest); turn it + // off temporarily as a quick fix (b/26204023). // - // TODO(rpl): Also, we should investigate whether we need a read - // barrier in the generated code. - if (kPoisonHeapReferences) { + // TODO(rpl): Fix these two issues and re-enable this intrinsic. + if (kEmitCompilerReadBarrier || kPoisonHeapReferences) { return; } |