I486_CPU or I586_CPU in kernel config

[Chuck Swiger]

On May 30, 2011, at 4:53 PM, Warren Block wrote:
> On Mon, 30 May 2011, Adam Vande More wrote:
>> Perhaps this is the one you meant?
>> http://lists.freebsd.org/pipermail/freebsd-questions/2009-January/190568.html
> 
> That's the one!  Thanks!
> 
>> Actually the two threads touch on the same subject, and it seems removal of those options is still desirable on newer CPU's.
> 
> sys/i386/i386/support.s is mentioned, but doesn't seem to have anything explicitly specific for 586.  There are some i686 entries.

It depends on which version of FreeBSD we're talking about.  At the time of my post, FreeBSD 7.0 had just come out and FreeBSD 6.3/6.4 were widely used.  If you check CVSweb or SVN:

   http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/i386/i386/support.s
   svn://svn.freebsd.org/base/stable/7/sys/i386/i386/support.s

...you'll see a half-dozen entries which are conditionalized against I586_CPU:

% grep -A 1 I586_CPU support.s
#if defined(I586_CPU) && defined(DEV_NPX)
kernel_fpu_lock:
--
#if defined(I586_CPU) && defined(DEV_NPX)
ENTRY(i586_bzero)
--
#endif /* I586_CPU && defined(DEV_NPX) */

--
#if defined(I586_CPU) && defined(DEV_NPX)
ENTRY(i586_bcopy)
--
#endif /* I586_CPU && defined(DEV_NPX) */

--
#if defined(I586_CPU) && defined(DEV_NPX)
	ALIGN_TEXT
--
#if defined(I586_CPU) && defined(DEV_NPX)
ENTRY(i586_copyout)
--
#endif /* I586_CPU && defined(DEV_NPX) */

--
#if defined(I586_CPU) && defined(DEV_NPX)
	ALIGN_TEXT
--
#if defined(I586_CPU) && defined(DEV_NPX)
	ALIGN_TEXT
--
#if defined(I586_CPU) && defined(DEV_NPX)
ENTRY(i586_copyin)
--
#endif /* I586_CPU && defined(DEV_NPX) */

#if defined(I586_CPU) && defined(DEV_NPX)
/* fastmove(src, dst, len)
--
#endif /* I586_CPU && defined(DEV_NPX) */

It appears that this file was significantly re-written under FreeBSD-8.  Anyway, actually comparing and gathering some data is the most useful result, and I'm happy to see the numbers from Warren's test.

Regards,
-- 
-Chuck