Bug 69490 - Make zoom multiplier float instead of double to match RenderStyle::effectiveZoom etc. and thus avoid unnecessary precision conversions.
Summary: Make zoom multiplier float instead of double to match RenderStyle::effectiveZ...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Luke Macpherson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-10-05 17:34 PDT by Luke Macpherson
Modified: 2012-01-23 18:36 PST (History)
7 users (show)

See Also:

Attachments
Patch (5.68 KB, patch)
2011-10-05 17:36 PDT, Luke Macpherson 		no flags Details | Formatted Diff | Diff
Patch for landing (6.10 KB, patch)
2012-01-22 17:05 PST, Luke Macpherson 		no flags Details | Formatted Diff | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Luke Macpherson 2011-10-05 17:34:45 PDT 
Make zoom multiplier float instead of double to match RenderStyle::effectiveZoom etc. and thus avoid unnecessary precision conversions.
Comment 1 Luke Macpherson 2011-10-05 17:36:39 PDT 
Created attachment 109891 [details]
Patch
Comment 2 Luke Macpherson 2011-10-05 17:49:27 PDT 
The motivation for this was seeing cycles wasted in the profiler output doing precision conversion from float to double. This is especially wasteful because the value is later discarded when zoom is 1.0.
Comment 3 Luke Macpherson 2011-10-06 20:28:31 PDT 
FYI, the performance difference isn't noticeable on PerformanceTests/Parser/html5-full-render.html

ToT:
Testing 6092696 byte document in 13 500000 byte chunks.
Running 20 times
Ignoring warm-up run (43051)
42380 42317 42440 42383 42279 42400 42350 42404 42390 42406
42224 42464 42225 42859 42056 42281 42751 42235 42230 42451

avg 42376.25
median 42381.5
stdev 174.0677669759683
min 42056
max 42859

With float patch:
Testing 6092696 byte document in 13 500000 byte chunks.
Running 20 times
Ignoring warm-up run (42785)
42227 42249 42308 42343 42462 42386 42531 42521 42463 42367
42502 42122 42512 42245 42244 42572 42313 42514 42091 42463

avg 42371.75
median 42376.5
stdev 139.20735433158694
min 42091
max 42572
Comment 4 Andreas Kling 2012-01-20 10:24:17 PST 
Comment on attachment 109891 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=109891&action=review

r=me assuming this still applies.

> Source/WebCore/ChangeLog:16
> +        Change type signatures of computeLenght template prototype.

Typo, computeLength.
Comment 5 Luke Macpherson 2012-01-22 17:05:26 PST 
Created attachment 123503 [details]
Patch for landing
Comment 6 WebKit Review Bot 2012-01-23 18:36:38 PST 
Comment on attachment 123503 [details]
Patch for landing

Clearing flags on attachment: 123503

Committed r105678: <http://trac.webkit.org/changeset/105678>
Comment 7 WebKit Review Bot 2012-01-23 18:36:45 PST 
All reviewed patches have been landed.  Closing bug.