Bug 63662

Summary:

DFG JIT does not do put_by_id transition caching.

Product:

WebKit

Reporter:

Filip Pizlo <fpizlo>

Component:

JavaScriptCore

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

barraclough, webkit.review.bot

Priority:

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Attachments:

Description	Flags
the patch	none

Description Filip Pizlo 2011-06-29 15:14:35 PDT

The baseline JIT emits a stub specialized for put_by_id transitions (i.e. setting a property that did not previous exist in the object, thereby resulting in a structure transition).  The DFG JIT emits a slow C call.  The DFG JIT should really be emitting an optimized stub, like the baseline JIT.

Comment 1 Filip Pizlo 2011-06-29 15:37:33 PDT

Created attachment 99161 [details]
the patch

This patch takes us from a 20% slow-down in v8-raytrace to a 4% speed-up on v8-raytrace.  We no longer have large regressions on any v8 benchmark (all v8 benchmarks are now speed-ups, no effect, or <5% slowdowns).

Comment 2 WebKit Review Bot 2011-06-29 16:45:40 PDT

Comment on attachment 99161 [details]
the patch

Clearing flags on attachment: 99161

Committed r90063: <http://trac.webkit.org/changeset/90063>

Comment 3 WebKit Review Bot 2011-06-29 16:45:45 PDT

All reviewed patches have been landed.  Closing bug.