[webkit-reviews] review granted: [Bug 234539] Expand the set of objects we take JSArray::fastSlice() path for : [Attachment 447749] Patch

[bugzilla-daemon at webkit.org]

Yusuke Suzuki <ysuzuki at apple.com> has granted Alexey Shvayka
<ashvayka at apple.com>'s request for review:
Bug 234539: Expand the set of objects we take JSArray::fastSlice() path for
https://bugs.webkit.org/show_bug.cgi?id=234539

Attachment 447749: Patch

https://bugs.webkit.org/attachment.cgi?id=447749&action=review




--- Comment #7 from Yusuke Suzuki <ysuzuki at apple.com> ---
Comment on attachment 447749
  --> https://bugs.webkit.org/attachment.cgi?id=447749
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=447749&action=review

r=me, nice.

> JSTests/microbenchmarks/array-slice-call-cloned-arguments.js:14
> +})();

Can we also have a test which performs,

array.slice(0, number-exceeding-length-of-array)

> Source/JavaScriptCore/runtime/JSArray.cpp:732
> +    source->ensureWritable(vm);

I think, in a subsequent patch, it is nice if we can avoid making the input as
non-CoW since we can create a slice of array from CoW array.
Can we have FIXME with bugzilla URL here?