[Mesa-dev] [PATCH] softpipe: Take all lods into account when texture sampling.

[Olivier Galibert]

On Wed, Jun 20, 2012 at 01:44:14PM +0100, Roland Scheidegger wrote:
> A lot of code I just glossed over it, but seems to look ok other than 
> the (performance) implications this might have.

Actually whether there's a performance implication is not obvious.  In
practice the code just kicks the 4-pixel loop one or two function
calls higher.  This unshares some tests, some function calls, and the
mip-size computation shifts.  For normal texturing and on x86 the
tests are correctly predicted after the first one, and so are the
function calls, giving all of them a near zero cost.  So I'm not sure
the costs is that measurable.

With the actual vectorization the llvmpipe situation may be different
(not so sure with the aos texturing though).

Best,

  OG.