Re: hwcap supporting architectures?
At Sat, 25 Dec 2004 21:59:41 -0600,
Marcelo E. Magallon <firstname.lastname@example.org> wrote:
> Since the optimized i386 library does use MMX (it does perform runtime
> checking) and is compiled with -mcpu=i686  (gcc doesn't seem to be
> emitting CMOVs though) I think the proper place is
> /usr/lib/i686/mmx/cmov (I have no intention of babysitting the
> generation of cmovs with each difference compiler release, therefore
> mmx/cmov instead of just mmx)
If it uses i686 and mmx code, /usr/lib/i686/mmx/cmov is OK.
Note that MMX will be removed from the next glibc 2.3.4 upload. It
will provide only SSE2 (and CMOV, debian-specific for only VIA C3
processor). If you want to keep adding mmx, we may need discussion
about this issue in future. But nowadays many processors can use
SSE2, so I guess changing cmov to SSE2 can fix the problem.
> My understanding is that this is also significant on sparc (-mcpu=v9)
> and that this belongs in /usr/lib/v9. Is this right?
Sparc defines HWCAP_SPARC_V9 and HWCAP_SPARC_ULTRA3. So v9 is right.
See glibc sparc packages.
> Mesa upstream uses -mcpu=ev5 -mieee on alpha. Is that ok? Where does
> this belong into? /usr/lib/ev5?
IIRC, alpha does not define any hwcaps.
> It also uses -mcpu=603 on powerpc. From my understanding this is a lot
> hairier than other architectures since there's a whole load more
> subarchitectures which are potentially incompatible with each other.
Powerpc does not define any hwcaps, too.