On Wed, 19 Feb 2003, Hauke Fath wrote:

> At 8:56 Uhr -0600 19.2.2003, Frederick Bruckman wrote:
> >In any case, I think we should stop imposing --soft-float on everyone
> >(-m68020-40 should be good enough for all fpu'd machines), and have
> >the release mechanism build a 'NOFPU' kernel with --soft-float and
> >without M68040.
>
> Hmmm.
>
> Maybe I have misunderstood the issue, but ISTR that kernels are built with
> --soft-float so that fpu state does not have to preserved, since the kernel
> does not touch the fpu registers.

That doesn't make sense to me. What would happen after returning
control to a different process? From examing mac68k's
locore.s:savectx(), I gather that we do, in fact, save the FP state
with a context switch.

For what it's worth, I've been running kernels built with no
soft-float on my Q840AV and Q630 since November, with no unusual
problems, albeit they're not doing much real work (occasionally
compiling packages, and one's serving a printer which has no ink).

Frederick