[Pixman] [PATCH] fill: Special-case single pixel wide lines

Søren Sandmann sandmann at cs.au.dk
Fri Sep 23 01:37:02 PDT 2011

Chris Wilson <chris at chris-wilson.co.uk> writes:

> A common condition (in benchmarks at least) are single pixel wide
> vertical lines. This is the worst-cast behaviour for the fast-paths like
> SSE2 which require long runs in order to offset the ramp up cost of
> aligning and using the SIMD registers.
> For example, box-outline consists of drawing a single aligned box with a
> hairline outline:
> before: 2327 (stroke), 2509 (fill)
> after: 674 (stroke), 843 (fill)
> [measured in *ns* on an i7-640]
> (Double-pixel wide lines, such as a stroke-width 1 outline of a
> misaligned box are also very common, but cannot hit pixman_fill(), so
> rapidly diminishing returns for optimising other widths.)

Looks good to me.

Generally, if nobody has said anything for some reasonable length of
time, feel free to push.


More information about the Pixman mailing list