diff options
Diffstat (limited to 'compiler/optimizing/intrinsics_arm64.cc')
| -rw-r--r-- | compiler/optimizing/intrinsics_arm64.cc | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/compiler/optimizing/intrinsics_arm64.cc b/compiler/optimizing/intrinsics_arm64.cc index 6b34daadf0..9f6863cf6e 100644 --- a/compiler/optimizing/intrinsics_arm64.cc +++ b/compiler/optimizing/intrinsics_arm64.cc @@ -1031,10 +1031,15 @@ static void GenCas(LocationSummary* locations, Primitive::Type type, CodeGenerat } else { __ Dmb(InnerShareable, BarrierWrites); __ Bind(&loop_head); - __ Ldxr(tmp_value, MemOperand(tmp_ptr)); - // TODO: Do we need a read barrier here when `type == Primitive::kPrimNot`? + // 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 IntrinsicLocationsBuilderARM64::VisitUnsafeCASObject). + DCHECK(!(type == Primitive::kPrimNot && kEmitCompilerReadBarrier)); + __ Ldxr(tmp_value, MemOperand(tmp_ptr)); __ Cmp(tmp_value, expected); __ B(&exit_loop, ne); __ Stxr(tmp_32, value, MemOperand(tmp_ptr)); @@ -1057,15 +1062,17 @@ void IntrinsicLocationsBuilderARM64::VisitUnsafeCASLong(HInvoke* invoke) { CreateIntIntIntIntIntToInt(arena_, invoke); } void IntrinsicLocationsBuilderARM64::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; } |