20814 2008-09-12 16:20:25 -0700 V8 tests spend fair amount of time in property lookup cache misses 2012-09-23 16:31:33 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) Mac OS X 10.5 RESOLVED WONTFIX P2 Normal --- 20813 1 mjs webkit-unassigned barraclough webmaster oldest_to_newest 90984 0 mjs 2008-09-12 16:20:25 -0700 A number of the V8 tests spend significant time in cti_op_get_by_id_generic, indicating misses of the polymorphic inline cache. Some of the causes include: - Math object properties being accessed in a pattern that makes the structure ID change (since the function properties are created on demand). We might want to pre-populate all at once, perhaps, or at least prebuild the structure ID and leave "placeholder" values of some kind. - Legitimate polymorphism, which we could handle either by making the generic case faster, or by making the polymorphic inline cache truly polymorphic up to some limit. - Unknown causes perhaps due to bugs in our cache logic. This most heavily affects DeltaBlue (to the tune of 23.2%) but Richards (6.4%), Raytrace (3.2%), and Crypto(1.9%) are also somewhat affected. See bug 20813 for profiles. 572620 1 barraclough 2012-03-07 00:05:10 -0800 *** Bug 20813 has been marked as a duplicate of this bug. *** 726313 2 barraclough 2012-09-23 16:31:33 -0700 Our caching has improved a lot in the last 4 years, I don't think this bug is still tracking useful work (which is not to say our caching in v8 is perfect yet!).