Re: [RFC] x86-64: Use SSE for copy_page and clear_page

[dean gaudet]

On Mon, 30 May 2005, dean gaudet wrote:

> On Mon, 30 May 2005, Benjamin LaHaise wrote:
> 
> > Below is a patch that uses 128 bit SSE instructions for copy_page and 
> > clear_page.  This is an improvement on P4 systems as can be seen by 
> > running the test program at http://www.kvack.org/~bcrl/xmm64.c to get 
> > results like:
> 
> it looks like the patch uses SSE2 instructions (pxor, movdqa, movntdq)... 
> if you use xorps, movaps, movntps then it works on SSE processors as well.

oh and btw... on x86-64 you might want to look at using movnti with 64-bit 
registers... the memory datapath on these processors is actually 64-bits 
wide, and the 128-bit stores are broken into two 64-bit pieces internally 
anyhow.  the advantage of using movnti over movntdq/movntps is that you 
don't have to save/restore the xmm register set.

-dean
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