[Ffmpeg-devel] [PATCH] SSE counterpart of ff_imdct_calc_3dn2

Rich Felker dalias
Thu Aug 24 18:15:54 CEST 2006


On Thu, Aug 24, 2006 at 09:59:37AM +0200, Guillaume POIRIER wrote:
> >Intrinsics are also gcc4-specific
> 
> False, They existed in 3.4 and I think in 3.3 also (I don't know about
> earlier releases, but for sure 2.95 do not support them).

Only gcc4 and later have the 3dnow intrinsics.

> Also, ICC is able to process these intrinsics, whereas it has a hard
> time with inline asm.

Supporting ICC would be nice, but you can always compile with asm
disabled.. Any viable compiler for high-performance needs to have full
inline asm available, not just a limited set of intrinsics for vector
ops.

> Rich, you should really consider that some ppl aren't willing to spend
> their youth on writting killer hand tuned asm code.

It takes maybe 5-10 minutes more to write the obvious handwritten asm
than to write the code with intrinsics, and performance should be same
or better. If you want to make it even faster you may spend somewhat
longer but your claims of "spending their youth" are exaggerated and
misleading.

> PS: yes, I totally made up the above figures

Obviously.

Rich





More information about the ffmpeg-devel mailing list