Index: src/hydrogen.cc |
diff --git a/src/hydrogen.cc b/src/hydrogen.cc |
index 142c92171048e44b92b22998da9be366c4ae9cec..58b2d790adbaa6c5ccd6adfe145ff862cdd83700 100644 |
--- a/src/hydrogen.cc |
+++ b/src/hydrogen.cc |
@@ -7632,19 +7632,29 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinMethodCall( |
Drop(expr->arguments()->length()); |
HValue* result; |
- HValue* checked_object; |
HValue* reduced_length; |
HValue* receiver = Pop(); |
+ |
+ HValue* checked_object = AddCheckMap(receiver, receiver_map); |
+ HValue* length = Add<HLoadNamedField>( |
+ checked_object, HObjectAccess::ForArrayLength(elements_kind)); |
+ |
{ NoObservableSideEffectsScope scope(this); |
- checked_object = AddCheckMap(receiver, receiver_map); |
+ IfBuilder length_checker(this); |
+ |
+ length_checker.If<HCompareNumericAndBranch>( |
+ length, graph()->GetConstant0(), Token::EQ); |
+ length_checker.Then(); |
+ |
+ Push(graph()->GetConstantUndefined()); |
+ |
+ length_checker.Else(); |
HValue* elements = AddLoadElements(checked_object); |
// Ensure that we aren't popping from a copy-on-write array. |
if (IsFastSmiOrObjectElementsKind(elements_kind)) { |
- Add<HCheckMaps>( |
- elements, isolate()->factory()->fixed_array_map(), top_info()); |
+ elements = BuildCopyElementsOnWrite(checked_object, elements, |
+ elements_kind, length); |
} |
- HValue* length = Add<HLoadNamedField>( |
- checked_object, HObjectAccess::ForArrayLength(elements_kind)); |
reduced_length = AddUncasted<HSub>(length, graph()->GetConstant1()); |
HValue* bounds_check = Add<HBoundsCheck>( |
graph()->GetConstant0(), length); |
@@ -7660,13 +7670,18 @@ bool HOptimizedGraphBuilder::TryInlineBuiltinMethodCall( |
} |
AddElementAccess( |
elements, reduced_length, hole, bounds_check, elements_kind, true); |
+ Add<HStoreNamedField>( |
+ checked_object, HObjectAccess::ForArrayLength(elements_kind), |
+ reduced_length); |
mvstanton
2014/01/29 10:16:09
I just don't understand why storing the reduced le
|
+ |
+ Push(result); |
+ |
+ length_checker.End(); |
} |
- Add<HStoreNamedField>( |
- checked_object, HObjectAccess::ForArrayLength(elements_kind), |
- reduced_length); |
- if (!ast_context()->IsEffect()) Push(result); |
+ result = ast_context()->IsEffect() ? Pop() : Top(); |
Add<HSimulate>(expr->id(), REMOVABLE_SIMULATE); |
if (!ast_context()->IsEffect()) Drop(1); |
+ |
ast_context()->ReturnValue(result); |
return true; |
} |