amd64 default CFLAGS

[Kris Kennaway]

On Wed, Mar 09, 2005 at 10:27:49AM +0100, Divacky Roman wrote:
> hi,
> 
> why is it necessary (if its at all) to have this: 
> -mfpmath=387 -mno-sse -mno-sse2 -mno-mmx -mno-3dnow in default CFLAGS for amd64
> architecture?

This is the default COPTFLAGS, not CFLAGS, right?  You can't use
special instructions like sse in the kernel because they require extra
register state operations that would cost performance.

Kris