Bug 154267 - FTL should support StringFromCharCode
Summary: FTL should support StringFromCharCode
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: WebKit Nightly Build
Hardware: All All
: P2 Normal
Assignee: Filip Pizlo
URL:
Keywords:
: 153069 (view as bug list)
Depends on:
Blocks: 154266
  Show dependency tree / graph
 
Reported: 2016-02-15 16:55 PST by Filip Pizlo
Modified: 2016-02-16 11:36 PST (History)
5 users (show)

See Also:

Attachments
the patch (9.61 KB, patch)
2016-02-15 16:58 PST, Filip Pizlo 		mark.lam: review+
Details | Formatted Diff | Diff
initial performance report (65.84 KB, text/plain)
2016-02-16 11:10 PST, Filip Pizlo 		no flags Details
View All Add an attachment (proposed patch, testcase, etc.)

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Description Filip Pizlo 2016-02-15 16:55:37 PST 
Patch forthcoming.
Comment 1 Filip Pizlo 2016-02-15 16:58:29 PST 
Created attachment 271391 [details]
the patch
Comment 2 Mark Lam 2016-02-15 17:02:12 PST 
Comment on attachment 271391 [details]
the patch

Do you have perf numbers?
Comment 3 Mark Lam 2016-02-15 17:08:44 PST 
Comment on attachment 271391 [details]
the patch

r=me if perf numbers are good.
Comment 4 Mark Lam 2016-02-16 09:36:52 PST 
*** Bug 153069 has been marked as a duplicate of this bug. ***
Comment 5 Filip Pizlo 2016-02-16 09:59:36 PST 
(In reply to comment #3)
> Comment on attachment 271391 [details]
> the patch
> 
> r=me if perf numbers are good.

Thanks!  I'm going to run them now.
Comment 6 Mark Lam 2016-02-16 10:10:20 PST 
<rdar://problem/24192536>
Comment 7 Filip Pizlo 2016-02-16 11:10:25 PST 
Created attachment 271442 [details]
initial performance report
Comment 8 Filip Pizlo 2016-02-16 11:11:04 PST 
Because string-from-char-code.js ran for much shorter than I wanted, I made it run 10x longer, and reran just those benchmarks.  Results:

                                       TipOfTree                FromCharCode                                   

string-from-char-code               16.8306+-0.6567     ^      6.7301+-0.4895        ^ definitely 2.5008x faster
untyped-string-from-char-code       17.6565+-0.5887     ^     10.9026+-2.4457        ^ definitely 1.6195x faster

<geometric>                         17.2385+-0.6145     ^      8.5458+-0.8659        ^ definitely 2.0172x faster

It's pretty cool that even in the untyped case, the FTL provides a significant win.
Comment 9 Filip Pizlo 2016-02-16 11:36:23 PST 
Landed in http://trac.webkit.org/changeset/196642