I could be missing something here, but is the sun3x kernel
	compiled with -m68030? I see the .s files are assembled with
	-m68030, but I do not see it in the CFLAGS?

	The 680{2,3,4,6}0 issue is pretty much independant of which 68k
	based arch is being used - assuming the userland is completely
	sharable. (a sun3x and 68030 based mac would be able to run the
	same -m68030 compiled userland).

	If we want to provide better performance for 68030 and above
	then we should ensure there is an easy way to turn on 
	-m680{3,4,5,6}0 in /etc/mk.conf, and then document it.

	It might also be an idea to tweak the Xserver config to compile
	different -m680X0 X servers, thos I can see that being a
	nightmare.

		David/absolute

	  -=-  Maybe your misinterpretation of my actions is 
	      in conflict with your misconception of who I am  -=-

On Tue, 5 May 1998, Jeremy Cooper wrote:

> On Tue, 5 May 1998, Erik E. Fair wrote:
> 
> > [ argument for compiling certain m68k platforms to take advantage of  ]
> > [ 68030 and higher instructions                                       ]
> 
> It is a stated and accomplished design goal that all m68k ports share the
> same user-level architecture.  The argument you have presented for
> utilizing the '030 and higher instructions on certain machines goes
> against this goal. 
> 
> This might seem wasteful on some machines, but the advantages are not so
> great.
> 
> 1) It is currently assumed that all m68k platforms are at least 68020, not
>    68000 as you had stated.  So we are at least utilizing the 68020
>    instructions on all platforms.
> 
> 2) Most of the improvements in the 68030 over the 68020 are an integrated
>    MMU and some additional instructions which are only useful in
>    supervisor (kernel) mode.  There is no appreciable benefit to user
>    mode applications.
>  
> 3) The 68040's improvements are likewise mostly beneficial to supervisor
>    mode code.  There are some special instructions line move16 which can
>    improve user mode speed, but it is better that the use of these
>    instructions be kept to shared library routines - routines that could
>    theoretically be relinked with their '040 or higher counterparts at
>    runtime.  (Anyone have any comments on doing something like this?)
> 
> -J
> 
>   
>