> Ah!  I misunderstood.  Yes, that sounds sensible and clever.  Do we
> have any ports that return a pointer differently from an integer (eg, I
> think some compilers for the 68k return pointer in a0 and int in d0)?

It seems the return value of cpu_switch isn't well defined!
Most of the 68k ports exit:
	moveq   #1,%d0                  | return 1 (for alternate returns)
	rts

Although the sun3 one adds:
	movl    %d0,%a0

and the mac68k doesn't seem to set d0 or a0.

So maybe cheating isn't on, and all the cpu_switch routines
will need to be changed (to return 0).

I think the sparc port returns an undefined value.

	David

-- 
David Laight: david@l8s.co.uk