Re: i686 quirk for AMD Geode

Matteo Croce
2009-10-03T22:55:03Z

On Sun, Oct 4, 2009 at 12:32 AM, Gabor Gombas <gombasg@sztaki.hu> wrote:
> On Sun, Oct 04, 2009 at 12:04:03AM +0200, Matteo Croce wrote:
>
>> yes cmov and i686 are unrelated but some distros (Debian & co.)
>> compiles libraries for two archs:
>> i486 and i686-cmov so only i686 machines does benefit from cmov.
>> This is why I cared about having an i686 aware userspace but it seems
>> that for a missing instruction I can't do that
>
> You could emulate the missing instruction. As long as it is not really
> used, the performance cost of the emulation should not matter. Of course
> if userspace starts to use long NOPs extensively then it becomes a
> problem.

Emulate? I can replace it with two plain NOPs.
How can I do the "emulation"? trapping SIGILL?