freebsd at jdc.parodius.com
Fri Nov 10 22:24:48 UTC 2006
On Fri, Nov 10, 2006 at 11:34:22AM -0800, Jason C. Wells wrote:
> I have set CPUTYPE=p3 in make.conf. When I compile my kernel I see
> -march=pentium3 as I expect. I also see -mno-mmx and -mno-sse are set
> which I do not expect given that -march=pentium3 is used. I presume
> that I want MMX and SSE since my processor supports it. What options do
> I set and where do I set them to get a kernel properly tuned for pentium3?
The kernel will "support" MMX and SSE -- that is, any programs (root
or userland) which use MMX/SSE will work just fine. That is: any
programs built with gcc can indeed support MMX and SSE operations.
The kernel itself _will not_ use any SSE or MMX operations when built.
This is because these optimisations are known to break the FreeBSD
kernel. This applies to all i386 architectures, and probably 64-bit
architectures too (not sure).
CPUTYPE=p3 (or pentium4, or any other type) will not change this
| Jeremy Chadwick jdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |
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