Bug 121141 – Int32ToDouble should be predicted SpecInt48 and predictions should have nothing to do with constant folding

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Filip Pizlo]

Just changing Int32ToDouble to be predicted SpecInt48 breaks constant folding on that node because of soooper old code that prevented constant folding on mismatched predictions.  Kill that code.

[Filip Pizlo]

Created attachment 211282 [details]
the patch

[Geoffrey Garen]

Comment on attachment 211282 [details]
the patch

r=me

[Filip Pizlo]

Created attachment 211345 [details]
even better patch

Introduce setConstant(node, value) method that does both of these things:

forNode(node).set(m_graph, value)
m_state.setFoundConstants(true)

[Build Bot]

Comment on attachment 211345 [details]
even better patch

Attachment 211345 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.appspot.com/results/1738828

New failing tests:
js/dfg-constant-fold-misprediction.html

[Build Bot]

Created attachment 211347 [details]
Archive of layout-test-results from webkit-ews-10 for mac-mountainlion-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: webkit-ews-10  Port: mac-mountainlion-wk2  Platform: Mac OS X 10.8.4

[Filip Pizlo]

(In reply to comment #4)
> (From update of attachment 211345 [details])
> Attachment 211345 [details] did not pass mac-wk2-ews (mac-wk2):
> Output: http://webkit-queues.appspot.com/results/1738828
> 
> New failing tests:
> js/dfg-constant-fold-misprediction.html

Because I forgot to upload the test change with this patch like I did with the last one.

[Filip Pizlo]

Landed in http://trac.webkit.org/changeset/155567

[Antoine Quint]

I think this introduced a regression, see https://bugs.webkit.org/show_bug.cgi?id=123664.