Bug 69291

Summary: DFG backends don't have access to per-node predictions from the propagator
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Description Flags
the patch oliver: review+

Description Filip Pizlo 2011-10-03 13:50:46 PDT
The DFG propagator has complete knowledge of how each node in the data flow graph is predicted.  But this knowledge is lost when going to the backend.  The backends try to reinfer this, but do so poorly (for example the backend has no idea how to predict a ConvertThis node, while the propagator knows exactly how to predict it).
Comment 1 Filip Pizlo 2011-10-03 14:01:46 PDT
Created attachment 109527 [details]
the patch
Comment 2 Oliver Hunt 2011-10-03 17:35:12 PDT
Comment on attachment 109527 [details]
the patch

Comment 3 Filip Pizlo 2011-10-03 18:05:26 PDT
Landed in r96562.