Reducing the number of passes has the usual change in the antialiasing
side-effects, as well as the boon of being faster (and theorectically more
accurate through reduced loss of dynamic range.)
On an i5-2520m:
swfdec-giant-steps-full 3240.43 -> 2651.36: 1.22x speedup
grads-heat-map 166.84 -> 136.79: 1.22x speedup
swfdec-giant-steps 940.19 -> 796.24: 1.18x speedup
ocitysmap 953.51 -> 831.96: 1.15x speedup
webkit-canvas-alpha 13924.01 -> 13115.70: 1.06x speedup
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Having discovered that I had recreated the references images with a
buggy rasteriser, we now need to recreate them with the correct reference
settings.
