It's early in testing yet, but I just converted an ultra60
to HAVE_GCC3=yes kernel and userland (pkgsrc building now).

So far, it looks good except for a mysterious problem at boot.

Sometimes on booting the new kernel, it will panic very early in
the boot process (just after copyright), typically in pool_init,
with an alignment fault.  These happen fairly often (5 out of 8
boots, so far).

The panic is an alignment fault.

There's not much of interest in the traceback at this point (main),
but just ask for other info that might be useful.  I didn't have
it on serial console at the time, but that can be arranged easily
enough.

If the boot survives past this point, it seems to be stable, though
I haven't really put it under load yet. It's built a dozen or so
of the usual suspects from pkgsrc so far, and I'll leave it rebuilding
src again overnight.

--
Dan.