Bug 153518

Summary:

B3's integer range analysis should know that Mul'ing two sufficiently small numbers will yield a number that still has a meaningful range

Product:

WebKit

Reporter:

Filip Pizlo <fpizlo>

Component:

JavaScriptCore

Assignee:

Filip Pizlo <fpizlo>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

barraclough, benjamin, commit-queue, ggaren, keith_miller, mark.lam, mhahnenb, msaboff, oliver, saam, sam

Priority:

Version:

WebKit Nightly Build

Hardware:

All

OS:

All

Bug Depends on:

Bug Blocks:

150507

Attachments:

Description	Flags
the patch	benjamin: review+

Description Filip Pizlo 2016-01-26 15:25:27 PST

I almost added these optimizations to the DFG integer range optimization phase.  That phase is very complicated.  B3's integer range analysis is trivial.  So I added it to B3.

Eventually we'll want this same machinery in DFG also.

Comment 1 Filip Pizlo 2016-01-26 15:27:47 PST

Created attachment 269936 [details]
the patch

Comment 2 WebKit Commit Bot 2016-01-26 15:30:42 PST

Attachment 269936 [details] did not pass style-queue:


ERROR: Source/JavaScriptCore/b3/B3ReduceStrength.cpp:1968:  Multi line control clauses should use braces.  [whitespace/braces] [4]
Total errors found: 1 in 3 files


If any of these errors are false positives, please file a bug against check-webkit-style.

Comment 3 Filip Pizlo 2016-01-26 16:49:27 PST

Landed in http://trac.webkit.org/changeset/195637