[patch] spantmp2.h optimization

[Felix <fx...@gm...>]

Hi,

the attached patch optimizes the spantmp2.h template by avoiding
redundant address computations for every pixel in linear spans. Since
the assembler read functions make the same assumptions that should not
affect existing users of the template.

Unfortunately there is hardly any measurable speedup on the Savage. But
I suspect that's a hardware limitation with CPU access to tiled surfaces
(linear mapping of tiled frame buffer). If the effect of my patch is
more significant on other hardware I'll commit this patch to CVS. A good
test should be the glxgears framerate with no_rast=3Dtrue.

(I only tested it with 16bpp so far, before committing anything I'd make
sure that 32bpp works as well.)

Regards,
  Felix

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| Felix K=FChling <fx...@gm...>                     http://fxk.de.vu |
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