[MPlayer-dev-eng] [PATCH] make --disable-mmx also disable sse{, 2}

[Trent Piepho]

On Sun, 17 Dec 2006, Zuxy Meng wrote:
> 2006/12/17, Luca Barbato <lu_zero at gentoo.org>:
> > since seems that sse requires mmx as the rest could make sense to be
> > consistent...
>
> I don't think so. Most SSE/SSE2 routines don't (and shouldn't IMHO)
> involve any MMX instructions.

With SSE1, there is no way to load integers != 32 bits into an SSE
register, and 32 bit integers can only be loaded from memory or an mmx
register.  To get two 32-bit integers out of an SSE register, you have to
go to an mmx register, there is no "cvtps2pi xmm, mem64" instruction.

If you want to load 8 bit integers into an SSE register, the only
reasonable way to do it is to unpack them into zero extended 32-bit values
with mmx.