FreeBSD 6.2, rebuild the system with CPUTYPE=prescott?

[Daniel Tourde]

Hello,

Let me present myself:
- I am an advanced user of Gentoo Linux. I know quiet a lot about that system 
and about how to optimize it to fit the hardware the best possible way.
- I am a casual FreeBSD user. I like it a lot though, it is lean and very well 
structured.

I am the happy own of a Dell Inspiron 9400 with a Dual Core processor in it 
(note, not a Dual Core 2).

http://gentoo-wiki.com/Safe_Cflags gives some information about this processor 
and about the parameter to give to gcc to obtain the best out of it:

Intel Core Solo/Duo (Yonah)
vendor_id  : GenuineIntel
 cpu family  : 6
 model  : 14
 model name  : Genuine Intel(R) CPU       [Model] @ XXXGHz
 (the above info is from a T2400, other models may have different cpu families 
and model numbers) 
CHOST="i686-pc-linux-gnu"
CFLAGS="-march=prescott -O2 -pipe -fomit-frame-pointer"

This is a 32bit chip 
Note: It has been confirmed by hongjiu.lu at intel.com that prescott is the 
correct microarchitecture to use with this CPU. 

So now, I am trying to rebuild my FreeBSD 6.2 system playing a bit with the 
parameters in the make.conf file (see /usr/share/examples/etc/make.conf) to 
get the best out of my machine (double processor, MMX, SSE[1-3] and co...)
#CPUTYPE?=pentium3
#NO_CPU_CFLAGS=         # Don't add -march=<cpu> to CFLAGS automatically
#NO_CPU_COPTFLAGS=      # Don't add -march=<cpu> to COPTFLAGS automatically


So far, the only thing I did was to set CPUTYPE to pentium4 but I am pretty 
sure, it can be done in a better way. The question being 'how?'

So, can anyone guide me?

Daniel