Bug 156871 - [JSC] Commute FDiv-by-constant into FMul-by-reciprocal when it is safe
Summary: [JSC] Commute FDiv-by-constant into FMul-by-reciprocal when it is safe
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Benjamin Poulain
URL:
Keywords:
Depends on: 156892
Blocks:
  Show dependency tree / graph
 
Reported: 2016-04-21 14:34 PDT by Benjamin Poulain
Modified: 2016-04-22 01:56 PDT (History)
7 users (show)

See Also:

Attachments
Patch (17.42 KB, patch)
2016-04-21 14:47 PDT, Benjamin Poulain 		no flags Details | Formatted Diff | Diff
Patch for landing (17.42 KB, patch)
2016-04-21 20:43 PDT, Benjamin Poulain 		no flags Details | Formatted Diff | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Benjamin Poulain 2016-04-21 14:34:28 PDT 
[JSC] Commute FDiv-by-constant into FMul-by-reciprocal when it is safe
Comment 1 Benjamin Poulain 2016-04-21 14:47:50 PDT 
Created attachment 276964 [details]
Patch
Comment 2 Filip Pizlo 2016-04-21 15:02:07 PDT 
Comment on attachment 276964 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=276964&action=review

> Source/JavaScriptCore/ChangeLog:16
> +        LLVM does something similar in InstCombine.

Is this bit-equivalent for sure?  LLVM doesn't have to obey IEEE as well as we do.
Comment 3 Benjamin Poulain 2016-04-21 20:43:54 PDT 
Created attachment 277002 [details]
Patch for landing
Comment 4 WebKit Commit Bot 2016-04-21 21:46:34 PDT 
Comment on attachment 277002 [details]
Patch for landing

Clearing flags on attachment: 277002

Committed r199866: <http://trac.webkit.org/changeset/199866>
Comment 5 WebKit Commit Bot 2016-04-21 21:46:37 PDT 
All reviewed patches have been landed.  Closing bug.
Comment 6 Csaba Osztrogonác 2016-04-22 01:56:59 PDT 
(In reply to comment #4)
> Comment on attachment 277002 [details]
> Patch for landing
> 
> Clearing flags on attachment: 277002
> 
> Committed r199866: <http://trac.webkit.org/changeset/199866>

and the buildfix landed in https://trac.webkit.org/changeset/199868
Please don't ignore red EWS bubbles, it's not WebKit2.