9b777967b1
Adds and uses fastMulDiv255Round() where possible,
which approximates x*y/255 as (x*y+x)/256. Seems like a sizeable
speedup, as seen below on Exclusion, Screen, and Modulate. The
existing NEON code uses this approximation for
{Src,Dst}x{In,Out,Over}, and without it we'd regress speed there.
This will require rebaselines whether or not we use this
approximation: the x86 bots change if we do, the ARM bots change
if we don't. None of the diffs are significant.
Desktop:
Xfermode_Screen_aa 5.82ms -> 5.54ms 0.95x
Xfermode_Modulate_aa 5.67ms -> 5.36ms 0.95x
Xfermode_Exclusion_aa 6.18ms -> 5.81ms 0.94x
Xfermode_Exclusion 5.03ms -> 4.24ms 0.84x
Xfermode_Screen 4.51ms -> 3.59ms 0.8x
Xfermode_Modulate 4.2ms -> 3.19ms 0.76x
Xfermode_DstOver 6.73ms -> 3.88ms 0.58x
Xfermode_SrcOut 6.47ms -> 3.48ms 0.54x
Xfermode_SrcIn 6.46ms -> 3.46ms 0.54x
Xfermode_DstOut 6.49ms -> 3.41ms 0.52x
Xfermode_DstIn 6.5ms -> 3.32ms 0.51x
Xfermode_Src_aa 9.53ms -> 4.75ms 0.5x
Xfermode_Clear_aa 9.65ms -> 4.8ms 0.5x
Xfermode_DstIn_aa 11.5ms -> 5.57ms 0.49x
Xfermode_DstOver_aa 11.6ms -> 5.63ms 0.49x
Xfermode_SrcOut_aa 11.6ms -> 5.5ms 0.47x
Xfermode_SrcIn_aa 11.7ms -> 5.51ms 0.47x
Xfermode_DstOut_aa 11.7ms -> 5.4ms 0.46x
N7 performance is close enough to 1x that I'm not sure whether
this is a net win, net loss, or truly neutral. I figure the bots will
show that.
I experimented with another approximation,
(x*(255-y))/255 ≈ (x*(256-y))/256. This was inconclusive, so I'm
leaving it out for now.
The remaining modes are the complicated conditional ones.
BUG=skia:
Review URL: https://codereview.chromium.org/1141953004
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| animations | ||
| bench | ||
| bin | ||
| debugger | ||
| dm | ||
| example | ||
| experimental | ||
| forth | ||
| gm | ||
| gyp | ||
| include | ||
| platform_tools | ||
| resources | ||
| samplecode | ||
| site | ||
| src | ||
| tests | ||
| third_party | ||
| tools | ||
| .gitignore | ||
| AUTHORS | ||
| codereview.settings | ||
| CONTRIBUTING | ||
| CQ_COMMITTERS | ||
| DEPS | ||
| Doxyfile | ||
| gyp_skia | ||
| gyp_skia.py | ||
| HASHTAGS | ||
| LICENSE | ||
| make.bat | ||
| make.py | ||
| Makefile | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README | ||
| README.chromium | ||
| skia.gyp | ||
| SKP_VERSION | ||
| whitespace.txt | ||
Skia is a complete 2D graphic library for drawing Text, Geometries, and Images. See full details, and build instructions, at https://skia.org.