Re: [gentoo-user] Re: Cannot compile texinfo: Illegal instruction -> Wrong -march and -mtune flags?

[Florian Philipp]

Am Donnerstag 02 August 2007 22:07 schrieb Alexander Skwar:
> · Me, myself & I:
> > Indeed, I think that I just have mixed up -march and -mtune (aka. -mcpu).
>
> Seems like. I now have:
>
> CFLAGS="-O2 -mtune=pentium-m -march=athlon-xp -pipe -fomit-frame-pointer"
>
> and with this CFLAGS, I am able to compile texinfo.
>
> Alexander Skwar
> --

-march=pentium-m activates MMX, SSE and SSE2
-march=athlon-xp activates MMX, 3dNOW!, enhanced 3dNOW! and SSE

You see, they are not compatible and even if some code works I wouldn't bet 
multimedia apps will perform well.

With -mtune the instruction set stays the same. It is just "rearranged".