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

[Uoti Urpala]

On Thu, 2006-08-24 at 12:15 -0400, Rich Felker wrote:
> > 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.

Not necessarily, and certainly not gcc-compatible inline asm. How many
asm routines are there in FFmpeg or MPlayer that could not achieve
comparable speed with intrinsics only?

> > 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.

It takes much more at least if you don't already have a lot of
experience writing general asm. If you don't do much asm programming
otherwise practicing it just for FFmpeg/MPlayer usage doesn't pay off.