[webkit-reviews] review requested: [Bug 19180] speed up SunSpider by optimizing immediate number cases : [Attachment 21398] Patch for >>, >>>, ==, ===, !=, !==

[bugzilla-daemon at webkit.org]

Alexey Proskuryakov <ap at webkit.org> has asked  for review:
Bug 19180: speed up SunSpider by optimizing immediate number cases
http://bugs.webkit.org/show_bug.cgi?id=19180

Attachment 21398: Patch for >>, >>>, ==, ===, !=, !==
http://bugs.webkit.org/attachment.cgi?id=21398&action=edit

------- Additional Comments from Alexey Proskuryakov <ap at webkit.org>
Removed the fast path for >>> for now, as it was quite incorrect for negative
numbers, and fixing this results in rather mixed performance changes.

(In reply to comment #21)
> Does this do the correct thing on numbers that have low bits set? 

As far as I can tell, it does.

> What about a 1 shifted right by 1?

That's (7 >> (7 >> 2)) | 3 == (7 >> 1) | 3 == 3, which is correct.