vector: add a fixed point math implementation.

name                      old time/op  new time/op  delta

GlyphAlpha16Over-8        4.48µs ± 1%  3.56µs ± 0%  -20.70%   (p=0.000 n=9+10)
GlyphAlpha16Src-8         4.17µs ± 0%  3.38µs ± 1%  -19.09%  (p=0.000 n=10+10)
GlyphAlpha32Over-8        9.03µs ± 0%  6.74µs ± 0%  -25.33%   (p=0.000 n=9+10)
GlyphAlpha32Src-8         7.46µs ± 1%  5.98µs ± 0%  -19.80%   (p=0.000 n=10+9)
GlyphAlpha64Over-8        21.3µs ± 0%  16.4µs ± 0%  -22.84%  (p=0.000 n=10+10)
GlyphAlpha64Src-8         16.2µs ± 1%  13.1µs ± 0%  -19.33%  (p=0.000 n=10+10)
GlyphAlpha128Over-8       59.8µs ± 0%  47.2µs ± 0%  -21.11%    (p=0.000 n=9+9)
GlyphAlpha128Src-8        41.3µs ± 1%  33.0µs ± 0%  -20.26%   (p=0.000 n=9+10)
GlyphAlpha256Over-8        197µs ± 0%   158µs ± 0%  -19.44%   (p=0.000 n=9+10)
GlyphAlpha256Src-8         124µs ± 0%    98µs ± 0%  -21.17%    (p=0.000 n=9+9)

GlyphAlphaLoose16Over-8   4.73µs ± 0%  3.97µs ± 1%  -16.06%  (p=0.000 n=10+10)
GlyphAlphaLoose16Src-8    4.41µs ± 0%  3.64µs ± 1%  -17.50%  (p=0.000 n=10+10)
GlyphAlphaLoose32Over-8   9.62µs ± 0%  8.47µs ± 0%  -11.95%  (p=0.000 n=10+10)
GlyphAlphaLoose32Src-8    8.25µs ± 0%  7.19µs ± 0%  -12.88%    (p=0.000 n=9+9)
GlyphAlphaLoose64Over-8   25.6µs ± 0%  22.2µs ± 0%  -13.01%    (p=0.000 n=9+9)
GlyphAlphaLoose64Src-8    20.2µs ± 0%  17.2µs ± 1%  -14.98%  (p=0.000 n=10+10)
GlyphAlphaLoose128Over-8  83.4µs ± 1%  68.2µs ± 0%  -18.27%  (p=0.000 n=10+10)
GlyphAlphaLoose128Src-8   59.8µs ± 0%  47.4µs ± 0%  -20.77%   (p=0.000 n=10+9)
GlyphAlphaLoose256Over-8   273µs ± 1%   239µs ± 0%  -12.52%   (p=0.000 n=10+9)
GlyphAlphaLoose256Src-8    187µs ± 0%   155µs ± 1%  -16.91%   (p=0.000 n=9+10)

GlyphRGBA16Over-8         5.99µs ± 0%  5.24µs ± 1%  -12.60%   (p=0.000 n=9+10)
GlyphRGBA16Src-8          5.48µs ± 0%  4.68µs ± 0%  -14.68%   (p=0.000 n=9+10)
GlyphRGBA32Over-8         14.6µs ± 0%  13.5µs ± 0%   -7.60%    (p=0.000 n=9+9)
GlyphRGBA32Src-8          12.6µs ± 0%  11.4µs ± 0%   -9.62%    (p=0.000 n=9+9)
GlyphRGBA64Over-8         44.8µs ± 0%  42.2µs ± 0%   -5.69%    (p=0.000 n=9+9)
GlyphRGBA64Src-8          36.6µs ± 1%  33.5µs ± 1%   -8.55%    (p=0.000 n=9+9)
GlyphRGBA128Over-8         162µs ± 0%   148µs ± 1%   -8.85%   (p=0.000 n=10+9)
GlyphRGBA128Src-8          129µs ± 1%   114µs ± 0%  -11.61%   (p=0.000 n=9+10)
GlyphRGBA256Over-8         588µs ± 0%   573µs ± 0%   -2.53%   (p=0.000 n=9+10)
GlyphRGBA256Src-8          455µs ± 0%   426µs ± 1%   -6.51%   (p=0.000 n=9+10)

GlyphNRGBA16Over-8        27.0µs ± 4%  26.3µs ± 2%   -2.65%   (p=0.001 n=9+10)
GlyphNRGBA16Src-8         19.4µs ± 3%  18.6µs ± 1%   -4.35%   (p=0.000 n=9+10)
GlyphNRGBA32Over-8        97.4µs ± 3%  96.8µs ± 2%     ~      (p=0.447 n=9+10)
GlyphNRGBA32Src-8         66.6µs ± 3%  64.5µs ± 1%   -3.21%   (p=0.000 n=10+9)
GlyphNRGBA64Over-8         372µs ± 3%   368µs ± 1%     ~     (p=0.105 n=10+10)
GlyphNRGBA64Src-8          235µs ± 1%   234µs ± 1%     ~       (p=0.130 n=8+8)
GlyphNRGBA128Over-8       1.45ms ± 2%  1.48ms ± 3%   +2.06%    (p=0.014 n=9+9)
GlyphNRGBA128Src-8         926µs ± 3%   937µs ± 1%     ~      (p=0.113 n=10+9)
GlyphNRGBA256Over-8       5.76ms ± 2%  5.90ms ± 3%   +2.29%   (p=0.001 n=9+10)
GlyphNRGBA256Src-8        3.59ms ± 1%  3.86ms ± 1%   +7.46%   (p=0.000 n=9+10)

Change-Id: I72f25193b5be4e57af09e9eea4eee50545a34cbf
Reviewed-on: https://go-review.googlesource.com/29972
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2 files changed