Followup to: <Pine.LNX.4.44.0304171654530.14595-100000@home.transmeta.com>
By author: Linus Torvalds <torvalds@transmeta.com>
In newsgroup: linux.dev.kernel
>
> > 2) why no sse2-optimized memcpy? just that noone has done one yet?
>
> Yes. If you want to, it's definitely the right thing to do. More so than
> the 3dnow stuff that is by now ancient. HOWEVER, I don't think there are
> any really valid large memcpy() calls inside the kernel. All the valid
> ones are either special-cased (ie "copy_page()") or to user space.
>
It's questionable, though, if SSE-2 buys you anything SSE-1 doesn't
already have. SSE-2 is basically integer and scalar ops for SSE, but
data moving and even XOR is perfectly well handled by SSE-1.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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