Re: [AD] blender operations SRC and DST

[Peter Wang <novalazy@xxxxxxxxxx>]

On 2011-06-08, Elias Pschernig <elias.pschernig@xxxxxxxxxx> wrote:
> On Wed, Jun 8, 2011 at 5:29 PM, Peter Wang <novalazy@xxxxxxxxxx> wrote:
> >
> > It's much worse on my machine, 10-12%.  I'd want to see what we can do
> > to avoid that kind of regression.
> >
> > Peter
> >
> > before patch:
> > Plain blit: 659.283 FPS
> > Scaled blit: 663.27 FPS
> > Rotated blit: 678.819 FPS
> >
> > after patch:
> > Plain blit: 576.974 FPS
> > Scaled blit: 592.111 FPS
> > Rotated blit: 610.166 FPS
> >
> 
> Looking at _al_blend_inline, I guess we can shuffle the code around so
> only the two new blend modes do anything differently but the existing
> ones remain as is.

Yes.  In addition (or afterwards) we might want to generate specialised
copies of _al_blend_inline for common operations, rather than relying on
the compiler to prune the dead branches in each inlined copy.  Manually
commenting out some of the (untaken) switch cases affects the benchmark
results so perhaps the compiler isn't doing that as well as I hoped.

Peter