[webkit-reviews] review granted: [Bug 88314] Improve Math.round and Math.floor intrinsic : [Attachment 145729] patch

[bugzilla-daemon at webkit.org]

Filip Pizlo <fpizlo at apple.com> has granted Yuqiang Xian
<yuqiang.xian at intel.com>'s request for review:
Bug 88314: Improve Math.round and Math.floor intrinsic
https://bugs.webkit.org/show_bug.cgi?id=88314

Attachment 145729: patch
https://bugs.webkit.org/attachment.cgi?id=145729&action=review

------- Additional Comments from Filip Pizlo <fpizlo at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=145729&action=review


This looks right.  I'm curious what your thoughts are about the comparing
against neg zero.  Maybe this code would work the same if you just used zero
instead of neg zero, which would be faster, since regular zero is easier to
load in SSE?

Not marking cq+ just because I want to give you an opportunity to respond.  But
I think the code is correct so if there's nothing that needs changing then I'm
fine with this being landed as-is.

> Source/JavaScriptCore/jit/ThunkGenerators.cpp:197
> +	   doubleResult.append(jit.branchDouble(MacroAssembler::DoubleEqual,
SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1));

Is this right?	Double equality has strange handling of zero.  0 == -0 for
example.