[cairo] perf: long dashed lines
Vladimir Vukicevic
vladimir at pobox.com
Sat Feb 2 15:54:46 PST 2008
Here's one patch that yields a decent speed win... _compute_face was
doing a lot of floating point math on values that are constant for any
given segment; this pulls those computations up out of the loops and
just passes the values down. Note that there are subtle changes in
the test output with this; this is, I believe, due to the change in
how some values are calculated in _cairo_stroker_line_to_dashed
(particularly dx2, dy2 in the loop).
I don't have cairo-perf runs to post, I need to get to a machine
without speedstep to do that. The instruction count reduction is
around 30%.
- Vlad
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