[webkit-reviews] review granted: [Bug 79899] DFG BasicBlocks should not require that their nodes have contiguous indices in the graph : [Attachment 129627] patch updated

[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 79899: DFG BasicBlocks should not require that their nodes have contiguous
indices in the graph
https://bugs.webkit.org/show_bug.cgi?id=79899

Attachment 129627: patch updated
https://bugs.webkit.org/attachment.cgi?id=129627&action=review

------- Additional Comments from Filip Pizlo <fpizlo at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=129627&action=review


Awesome!

Question: does this mean that the start index performance hack is no longer in
effect at all?	I.e. you're not even stopping the CSE when it gets to the
earliest possible child of the node being replaced?  That's not a problem - in
fact it's great if that's true.  I had added that optimization prematurely and
it's somewhat comforting to know that it isn't necessary.

R=me.

> Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp:616
> +	   block->prepend(resultIndex);

Ha!  I find it to be quite awesome that we see no regression even though
prepend is an O(n) operation.  Or am I missing something?