Re: [gentoo-user] USE="mmx mmxext sse sse2 ssse3 3dnow 3dnowext"

[Daniel Iliev]

On Wed, 27 May 2009 09:14:03 +0100
Stroller <stroller@××××××××××××××××××.uk> wrote:

>
> On 27 May 2009, at 01:47, Daniel Iliev wrote:
> >
> > There could be problems if you had enabled all the EIS flags
> > globally (in make.conf) instead only for mplayer, because other
> > programs don't have the "run-time cpu detection" feature and will
> > fail in their attempts to use for example 3dnow! on an Intel CPU.
> >
> > I hope I was clear enough, apologies for my Englush.
>
> Hi there,
>
> The thing is that run-time CPU detection is unnecessary, if you're
> always going to be using this mplayer binary you've just built on
> the same system. mplayer will be built correctly without this
> cpudetection flag (just put all the USE flags corresponding to EIS
> instructions in package.use as previously discussed, but without
> cpudetection).
>

I'm afraid the common sense says disabling the "cpudetection" USE
flag could lead to the problem I described in my previous message.
Please, don't get me wrong - I'm not arguing and I've never tried to
build mplayer with EIS that is unsupported by the CPU. It may work if
the build system detects and corrects such errors when cpudetection is
disabled.

I personally set the correct EIS USE flags for my CPU globally and
disable the cpudetection flag. This has the advantage that all programs
supporting one or another EIS would be built with the EIS code included.
I didn't suggest you this approach because I believe somewhere in this
thread you mentioned you wanted to use the same settings on several
different systems.

-- 
Best regards,
Daniel