[Mesa-dev] [PATCH 0/3] Pixman for Mesa

Juha-Pekka Heikkilä juhapekka.heikkila at gmail.com
Wed Sep 3 12:20:15 PDT 2014

On Wed, Sep 3, 2014 at 7:31 PM, Brian Paul <brianp at vmware.com> wrote:
> On 08/28/2014 06:51 AM, Juha-Pekka Heikkila wrote:
>> Here is new version of my patch set for using Pixman in Mesa
>> for texture format conversions, mostly complete rewrite after recent
>> changes in src/mesa/main/texstore.c. This set does not cause
>> regressions in Piglit quick set on SNB.
>> Here are some timings I came up from with this set when running
>> glTexImage2d in a loop (on SNB, IVB was comparable):
>>                                        No Pixman       Pixman     %
>> GL_UNSIGNED_INT_8_8_8_8,GL_BGRA     2816.648926  2148.145020  0.76
>> GL_UNSIGNED_SHORT_5_6_5,GL_RGB     19560.732422 2062.745117  0.11
>> GL_UNSIGNED_SHORT_5_6_5_REV,GL_RGB 19525.605469 4035.947998  0.21
> What are the units for those numbers?  What does the percentage mean?

These numbers are timings, the numbers themselves are in milliseconds.
The unit here is not really of the essence but the comparison of time
spent. The percentage mean amount of time Pixmanized version of Mesa
spent in glTexImage2D() vs. current Mesa master compiled with "-O2
-march=native" on my Sandybridge.

The test itself I have written is to run 256x256 texture into
glTexImage2D 1000 times with above mentioned formats so in human terms
these numbers mean in my test Pixman does conversion for ten 256x256
GL_UNSIGNED_SHORT_5_6_5,GL_RGB type textures in the time where current
upstream Mesa does one.


> -Brian
>> For these tests Mesa was compiled with "-march=native -O2". There were
>> some
>> formats which were clearly faster on current Mesa implementation than what
>> Pixman gave me, for example RGB888 to RGBA8888 conversion took about twice
>> the time of what current Mesa implementation does and r10g10b10a2 was even
>> much slower. Generally 16 bit formats are much faster on Pixman but there
>> are differences in formats and types which prevented from enabling some
>> formats for now, most notable missing GL_UNSIGNED_SHORT_4_4_4_4
>> /Juha-Pekka
>> Juha-Pekka Heikkila (3):
>>    mesa: Add Pixman library to configure.ac
>>    mesa: Add Pixman usage to texstore.c
>>    mesa: Pixman texture conversion for argb path
>>   configure.ac             |  30 ++++++++++
>>   src/mesa/main/texstore.c | 149
>> +++++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 179 insertions(+)

More information about the mesa-dev mailing list