[LAD] vectorization

[Christian Schoenebeck]

Am Mittwoch, 16. April 2008 12:17:23 schrieb Jens M Andreasen:
> Then you will probably like this run of ./mixdown:
>
> Benchmarking mixdown (WITH coeff):
> pure C++                : 150 ms <-- pretty good, eh? ;-)
> ASM SSE                 : 140 ms
> GCC vector extensions   : 150 ms
>
> This is with -ftree-vectorize added to your compile options.

Hey, nice! :-)

But that works only well for the inlined version. If the mixer C(++) function 
is located in another object file and the compiler is forced to use real 
function calls, then the C(++) result is still worse than the gcc vector 
version, even with "-ftree-vectorize":

Benchmarking mixdown (no coeff):
pure C++                : 690 ms
ASM SSE                 : 210 ms
GCC vector extensions   : 190 ms

Benchmarking mixdown (WITH coeff):
pure C++                : 1120 ms
ASM SSE                 : 320 ms
GCC vector extensions   : 300 ms

CU
Christian