AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

[builtins] Save one word in contexts for Promise.all.

Browse Source 
In the contexts for the resolver closures used in Promise.all we can
save the "already visited" cell, by just setting the index slot to a
negative value, which then indicates that this element was already
done.

Bug: v8:7253
Change-Id: I1296a2216eac3b51368c1e7795dbcd2c80cc430a
Reviewed-on: https://chromium-review.googlesource.com/903928
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51125}
This commit is contained in:
Benedikt Meurer 2018-02-06 12:54:44 +01:00 committed by Commit Bot
parent d468ff4e1f
commit 7632da067b
2 changed files with 7 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/builtins/builtins-promise-gen.cc
View File

@ -1703,9 +1703,6 @@ Node* PromiseBuiltinsAssembler::PerformPromiseAll(
// Promise.all Resolve Element Functions.
Node* const resolve_context =
CreatePromiseContext(native_context, kPromiseAllResolveElementLength);
StoreContextElementNoWriteBarrier(
resolve_context, kPromiseAllResolveElementAlreadyVisitedSlot,
SmiConstant(0));
StoreContextElementNoWriteBarrier(
resolve_context, kPromiseAllResolveElementIndexSlot, var_index.value());
StoreContextElementNoWriteBarrier(
@ -1890,19 +1887,16 @@ TF_BUILTIN(PromiseAllResolveElementClosure, PromiseBuiltinsAssembler) {
CSA_ASSERT(this, SmiEqual(LoadFixedArrayBaseLength(context),
SmiConstant(kPromiseAllResolveElementLength)));
Label already_called(this), resolve_promise(this);
GotoIf(SmiEqual(LoadContextElement(
context, kPromiseAllResolveElementAlreadyVisitedSlot),
SmiConstant(1)),
&already_called);
StoreContextElementNoWriteBarrier(
context, kPromiseAllResolveElementAlreadyVisitedSlot, SmiConstant(1));
Node* const index =
LoadContextElement(context, kPromiseAllResolveElementIndexSlot);
Node* const values_array =
LoadContextElement(context, kPromiseAllResolveElementValuesArraySlot);
Label already_called(this, Label::kDeferred), resolve_promise(this);
GotoIf(SmiLessThan(index, SmiConstant(Smi::kZero)), &already_called);
StoreContextElementNoWriteBarrier(context, kPromiseAllResolveElementIndexSlot,
SmiConstant(-1));
// Set element in FixedArray
Label runtime_set_element(this), did_set_element(this);
GotoIfNot(TaggedIsPositiveSmi(index), &runtime_set_element);

7
src/builtins/builtins-promise-gen.h
View File

@ -29,11 +29,8 @@ class PromiseBuiltinsAssembler : public CodeStubAssembler {
protected:
enum PromiseAllResolveElementContextSlots {
// Whether the resolve callback was already called.
kPromiseAllResolveElementAlreadyVisitedSlot = Context::MIN_CONTEXT_SLOTS,
// Index into the values array
kPromiseAllResolveElementIndexSlot,
// Index into the values array, or -1 if the callback was already called
kPromiseAllResolveElementIndexSlot = Context::MIN_CONTEXT_SLOTS,
// Remaining elements count (mutable HeapNumber)
kPromiseAllResolveElementRemainingElementsSlot,