-mno-sse -mno-sse2 -mno-mmx -mno-3dnow when compiling kernel

Thomas Krause -CI- freebsd-amd64 at chef-ingenieur.de
Sun Feb 13 10:56:41 PST 2005


Steve Kargl schrieb:
> On Sun, Feb 13, 2005 at 07:29:53PM +0100, Thomas Krause -CI- wrote:
> 
>>Hello,
>>why are the Switches "-mno-sse -mno-sse2 -mno-mmx -mno-3dnow" are set
>>when compiling an amd64 kernel? I think, the CPU supports all thease
>>features.
>>
> 
> 
> AFAIK, floating point is not permitted in the kernel.  Why would
> you need to use sse, sse2, mmx, or 3dnow?
> 
I don't know, if thease features are useful in the kernel. But when
compiling a x86 kernel, they are not disabled.

As I remember, you can compile libpng using mmx features. (I'm unsure,
if you need a mmx-optimized kernel for that.)

Regards,
Thomas.



More information about the freebsd-amd64 mailing list