[webkit-reviews] review granted: [Bug 212032] Implement a faster findBitInWord() using the hardware ctz instruction. : [Attachment 399659] proposed patch.

[bugzilla-daemon at webkit.org]

Saam Barati <sbarati at apple.com> has granted Mark Lam <mark.lam at apple.com>'s
request for review:
Bug 212032: Implement a faster findBitInWord() using the hardware ctz
instruction.
https://bugs.webkit.org/show_bug.cgi?id=212032

Attachment 399659: proposed patch.

https://bugs.webkit.org/attachment.cgi?id=399659&action=review




--- Comment #3 from Saam Barati <sbarati at apple.com> ---
Comment on attachment 399659
  --> https://bugs.webkit.org/attachment.cgi?id=399659
proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=399659&action=review

r=me

> Source/bmalloc/bmalloc/Algorithm.h:239
> +    if ((index < endIndex) && word) {

I don't think we need the first (index < endIndex) check.

Also, I'd expect this algorithm below of ctz to just work on zero too, since
that'd put us past the endIndex.

however, as you said, maybe ctz doesn't do good things for zero? I just find
that very surprising

Ditto about WTF code.