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[compiler] Set/Get the Map's inobject properties start non-atomically

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The property kInObjectPropertiesStartOrConstructorFunctionIndexOffset
was set as relaxed due to races with the layout_descriptor
(https://chromium-review.googlesource.com/c/v8/v8/+/555210/). The
layout_descriptor was removed with the removal of double field unboxing.

We are able to turn those property's accessors into non-atomic ones
since they are set at construction time.

Bug: v8:7790
Change-Id: I25c53f0e00718cca72ba86f8475af9ecefb7ba3d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2843359
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74174}
This commit is contained in:
Santiago Aboy Solanes 2021-04-26 09:23:29 +01:00 committed by Commit Bot
parent 84e144fe71
commit 8e73532460
2 changed files with 7 additions and 8 deletions
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6
src/compiler/heap-refs.cc
View File

@ -3109,7 +3109,7 @@ FieldIndex MapRef::GetFieldIndexFor(InternalIndex descriptor_index) const {
}
int MapRef::GetInObjectPropertyOffset(int i) const {
if (data_->should_access_heap()) {
if (data_->should_access_heap() || broker()->is_concurrent_inlining()) {
return object()->GetInObjectPropertyOffset(i);
}
return (GetInObjectPropertiesStartInWords() + i) * kTaggedSize;
@ -3699,7 +3699,7 @@ bool MapRef::IsInobjectSlackTrackingInProgress() const {
}
int MapRef::constructor_function_index() const {
IF_ACCESS_FROM_HEAP_C(GetConstructorFunctionIndex);
IF_ACCESS_FROM_HEAP_WITH_FLAG_C(GetConstructorFunctionIndex);
CHECK(IsPrimitiveMap());
return data()->AsMap()->constructor_function_index();
}
@ -3721,7 +3721,7 @@ bool MapRef::CanTransition() const {
}
int MapRef::GetInObjectPropertiesStartInWords() const {
IF_ACCESS_FROM_HEAP_C(GetInObjectPropertiesStartInWords);
IF_ACCESS_FROM_HEAP_WITH_FLAG_C(GetInObjectPropertiesStartInWords);
return data()->AsMap()->in_object_properties_start_in_words();
}

7
src/objects/map-inl.h
View File

@ -277,15 +277,14 @@ void Map::set_instance_size(int value) {
}
int Map::inobject_properties_start_or_constructor_function_index() const {
return RELAXED_READ_BYTE_FIELD(
*this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset);
return ReadField<byte>(
kInObjectPropertiesStartOrConstructorFunctionIndexOffset);
}
void Map::set_inobject_properties_start_or_constructor_function_index(
int value) {
CHECK_LT(static_cast<unsigned>(value), 256);
RELAXED_WRITE_BYTE_FIELD(
*this, kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
WriteField<byte>(kInObjectPropertiesStartOrConstructorFunctionIndexOffset,
static_cast<byte>(value));
}