RESOLVED FIXED191729
KnownCellUse should also have SpecCellCheck as its type filter 
https://bugs.webkit.org/show_bug.cgi?id=191729
Summary KnownCellUse should also have SpecCellCheck as its type filter
Saam Barati
Reported 2018-11-15 17:53:18 PST
We write transformations in the compiler like this where we emit edges with KnownCellUse if we know we're inserting code at a point where we're dominated by a Cell check: a: SomeValue b: Something(Cell:@a) c: SomethingElse(@b) d: CheckNotEmpty(@a) => a: SomeValue b: Something(Cell:@a) e: RandomOtherThing(KnownCellUse:@a) c: SomethingElse(@b) d: CheckNotEmpty(@a) However, doing this may lead to subtly incorrect programs since KnownCellUse doesn't allow the empty value to flow through it. We end up deleting @d in the above program, which is wrong. We need to have KnownCellUse allow the empty value to flow through.
Attachments
patch (3.57 KB, patch)
2018-11-15 17:59 PST, Saam Barati 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Saam Barati
Comment 1 2018-11-15 17:53:53 PST
<rdar://problem/45872852>
Saam Barati
Comment 2 2018-11-15 17:59:35 PST
Created attachment 355005 [details] patch
WebKit Commit Bot
Comment 3 2018-11-16 12:43:01 PST
Comment on attachment 355005 [details] patch Clearing flags on attachment: 355005 Committed r238297: <https://trac.webkit.org/changeset/238297>
WebKit Commit Bot
Comment 4 2018-11-16 12:43:03 PST
All reviewed patches have been landed. Closing bug.
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