Bug 152925

Summary: B3 needs Neg()
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Filip Pizlo <fpizlo>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, keith_miller, mark.lam, msaboff, saam
Priority: P2    
Version: WebKit Nightly Build   
Hardware: All   
OS: All   
Bug Depends on:    
Bug Blocks: 150279    
Attachments:
Description Flags
work in progress
none
the patch mark.lam: review+

Description Filip Pizlo 2016-01-08 13:49:18 PST
Currently B3 expresses -x as 0-x.  That's wrong in case of floating point.

It's probably better if we just have a Neg opcode, and this opcode should work for both ints and floats.
Comment 1 Filip Pizlo 2016-01-08 14:12:29 PST
Created attachment 268584 [details]
work in progress
Comment 2 Filip Pizlo 2016-01-08 15:35:42 PST
Created attachment 268595 [details]
the patch
Comment 3 Mark Lam 2016-01-08 16:00:01 PST
Comment on attachment 268595 [details]
the patch

View in context: https://bugs.webkit.org/attachment.cgi?id=268595&action=review

r=me

> Source/JavaScriptCore/ChangeLog:18
> +        So, this introduces a proper Neg() opcode to B3. It's not the canonical way of saying

typo: "not" ==> "now".
Comment 4 Filip Pizlo 2016-01-08 16:03:59 PST
Landed in http://trac.webkit.org/changeset/194802