[webkit-reviews] review requested: [Bug 96590] Added 8 bit path to WidthIterator::advance() : [Attachment 163893] Patch with updates

[bugzilla-daemon at webkit.org]

Michael Saboff <msaboff at apple.com> has asked  for review:
Bug 96590: Added 8 bit path to WidthIterator::advance()
https://bugs.webkit.org/show_bug.cgi?id=96590

Attachment 163893: Patch with updates 
https://bugs.webkit.org/attachment.cgi?id=163893&action=review

------- Additional Comments from Michael Saboff <msaboff at apple.com>
Updated the original patch with two changes.

Changed Source/WebCore/platform/graphics/Latin1TextIterator.h to be an svn copy
of Source/WebCore/platform/graphics/SurrogatePairAwareTextIterator.h to retain
history.

Ran performance tests of original patch and it showed a regression in the
Layout test.  Changed SurrogatePairAwareTextIterator to have inline versions of
advance and consume with a new consumeSlowCase for the possible surrogate pair
cases.	Performance result of this patch are:

			Baseline	With patch	Diff
flexbox-column-nowrap	103708.6	109858.0
flexbox-column-nowrap	109955.7	106864.1
flexbox-column-nowrap	108447.6	106678.0	
flexbox-column-nowrap	106098.8	107921.9	
		Mean	107052.7	107830.5       -0.81%
flexbox-column-wrap	109909.5	106872.5       
flexbox-column-wrap	108883.3	105228.3	
flexbox-column-wrap	106647.2	106476.6	
flexbox-column-wrap	105324.4	107460.5	
		Mean	107691.1	106509.5	1.10%
flexbox-row-nowrap	146211.5	142378.8	
flexbox-row-nowrap	147438.1	143749.6	
flexbox-row-nowrap	143789.2	144680.3	
flexbox-row-nowrap	148418.2	145950.7	
		Mean	146464.3	144189.8       -1.55%
flexbox-row-wrap	104452.9	109111.9       
flexbox-row-wrap	109038.1	109778.9	
flexbox-row-wrap	107117.2	109969.8	
flexbox-row-wrap	107728.8	107058.3	
		Mean	107084.3	108979.7	1.77%
floats_100_100_nested	   222.5	   217.5	
floats_100_100_nested	   224.0	   215.5
floats_100_100_nested	   224.5	   214.5
floats_100_100_nested	   224.0	   216.5
		Mean	   223.8	   216.0	3.46%
floats_100_100		   205.0	   198.5	
floats_100_100		   207.0	   201.0
floats_100_100		   205.5	   199.5
floats_100_100		   206.0	   200.5
		Mean	   205.9	   199.9	2.91%
floats_2_100_nested	   463.3	   463.2	
floats_2_100_nested	   462.7	   464.3
floats_2_100_nested	   464.7	   463.7
floats_2_100_nested	   467.0	   462.3
		Mean	   464.4	   463.4	0.23%
floats_2_100		   203.0	   203.2	
floats_2_100		   203.8	   207.6
floats_2_100		   205.9	   207.5
floats_2_100		   203.3	   203.7
		Mean	   204.0	   205.5       -0.74%
floats_20_100_nested	   623.5	   613.7       
floats_20_100_nested	   621.5	   617.2
floats_20_100_nested	   629.8	   615.8
floats_20_100_nested	   627.3	   615.2
		Mean	   625.5	   615.5	1.61%
floats_20_100		   426.3	   424.0	
floats_20_100		   422.6	   420.3
floats_20_100		   423.6	   420.3
floats_20_100		   426.9	   420.1
		Mean	   424.8	   421.2	0.86%
floats_50_100_nested	   380.0	   372.8	
floats_50_100_nested	   378.0	   368.0
floats_50_100_nested	   378.0	   370.6
floats_50_100_nested	   377.4	   371.4
		Mean	   378.4	   370.7	2.02%
floats_50_100		   307.2	   300.4	
floats_50_100		   304.4	   300.0
floats_50_100		   307.2	   299.0
floats_50_100		   304.4	   299.8
		Mean	   305.8	   299.8	1.96%
line-layout		    75.5	    78.2	
line-layout		    75.7	    78.5
line-layout		    75.4	    78.2
line-layout		    75.4	    78.2
		Mean	    75.5	    78.3	3.68%