[Mesa-dev] [RFC]Improves st_finalize_texture cycles consumption

[Vincent Lejeune]

Hi,

I did some profiling with perf under nexuiz and found that st_finalize_texture
function was one of the most cycle consumming. (~1,50% whereas darkplaces took ~30%)

I rewrite some part of this function to make it a bit faster ; with these 2 patches,
st_finalize_texture consumption went down to ~1%, so a 40-50% boost.
This does however not translate to more fps to Nexuiz : if there is any improvement,
it is not noticeable (too much noise in measurements). On the other hand, the function
has become less readable. I had to manually unroll loops and use intermediate values
(gcc does not do it automaticaly, using default parameters).
Of course I think that we should make less call to this function to see a true gain,
but this would require more work.

Regards,
Vincent