[Pixman] [PATCH 0/2] Change conditions for setting FAST_PATH_SAMPLES_COVER_CLIP flags v2

Pekka Paalanen ppaalanen at gmail.com
Fri Sep 11 04:30:22 PDT 2015

From: Pekka Paalanen <pekka.paalanen at collabora.co.uk>


these two patches supersede the one patch "Change conditions for setting

I mainly bikeshedded the comments. I also split it in two, because I realized
that affine-bench would still work even if it was not patched at the same time.

I was going to also add a patch to remove the 8e margins from the overflow
checks in analyze_content(), but then I thought of projective transformations.
This piece of code is not conditional to the COVER_CLIP flags, so I think it
applies also to projective transformations. Since I cannot say whether the 8e
margin is needed, not needed, or misleading (i.e. some margin is needed but not
8e), I chose to not include that patch. There are no performance benefits to be
had, because failing the overflow tests just aborts the whole operation, so
it's unlikely anyone would be hitting it in the first place.

I intend to do some Cairo benchmarking with these, too, before I would be ready
to push these. Will be interesting to see the effects of these and the
follow-up patches that take the COVER flags even further.


Ben Avison (2):
  Remove the 8e extra safety margin in COVER_CLIP analysis
  affine-bench: remove 8e margin from COVER area

 pixman/pixman.c     | 17 ++++-------------
 test/affine-bench.c | 24 ++++++++++++++++++------
 2 files changed, 22 insertions(+), 19 deletions(-)


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