[webkit-reviews] review granted: [Bug 206571] [JSC] Add CheckArrayOrEmpty to handle the case when hoisting CheckArray for places where input can be empty : [Attachment 388398] Patch

[bugzilla-daemon at webkit.org]

Saam Barati <sbarati at apple.com> has granted Yusuke Suzuki <ysuzuki at apple.com>'s
request for review:
Bug 206571: [JSC] Add CheckArrayOrEmpty to handle the case when hoisting
CheckArray for places where input can be empty
https://bugs.webkit.org/show_bug.cgi?id=206571

Attachment 388398: Patch

https://bugs.webkit.org/attachment.cgi?id=388398&action=review




--- Comment #3 from Saam Barati <sbarati at apple.com> ---
Comment on attachment 388398
  --> https://bugs.webkit.org/attachment.cgi?id=388398
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=388398&action=review

> Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp:287
> +		   // check just remains, and it works as CheckArrayOrEmpty
without ArrayMode checking.

Seems like we should also have an assert here like
speculatedTypeForUseKind(node->child1().useKind()) & SpecEmpty

> Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:832
> +	   // We can purge Empty check completely in this case of
CheckArrayOrEmpty since CellUse only accepts SpecCell | SpecEmpty.

Ditto