no SSE in kernel build?

[Littlefield, Tyler]

Hello all:
I had a quick question I was hoping someone could explain for me. I was 
looking at some of the kernel source, just trying to familiarize myself 
with it. I notice that SSE, MMX and other such instruction sets are 
explicitly disabled during kernel compilation--is there any particular 
reason why? I'm sure it's pretty obvious, but my knowledge of kernel 
workings is pretty limited. I've seen functions like memset/memcpy that 
make use of SSE and are incredibly fast; perhaps this could be useful on 
architectures that support it?

Finally, I'm interested in doing some performance work on the 
kernel--perhaps to help out somewhere. Is there anything at the kernel 
level a beginner could help out with? Where else might my help be 
useful? I know -some-, as I've worked a bit on a barebones OS, but I'm 
no means a kernel hacker.
Thanks,

-- 
Take care,
Ty
http://tds-solutions.net
He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave.