From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266295AbUHGHtx (ORCPT ); Sat, 7 Aug 2004 03:49:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267776AbUHGHtw (ORCPT ); Sat, 7 Aug 2004 03:49:52 -0400 Received: from pfepb.post.tele.dk ([195.41.46.236]:49727 "EHLO pfepb.post.tele.dk") by vger.kernel.org with ESMTP id S266295AbUHGHtv (ORCPT ); Sat, 7 Aug 2004 03:49:51 -0400 Subject: Re: [PATCH] Re-implemented i586 asm AES (updated) From: Kasper Sandberg To: Linus Torvalds Cc: Andi Kleen , James Morris , LKML Mailinglist In-Reply-To: References: <2qbyt-1Op-45@gated-at.bofh.it> <2qemF-3Pj-49@gated-at.bofh.it> Content-Type: text/plain Date: Sat, 07 Aug 2004 09:49:45 +0200 Message-Id: <1091864985.9992.0.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 1.5.91 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org i dont know anything at all about this, but wouldnt it be possible to optimize it even more, if there were a version for each cpu, like one for athlon-xp and one for p4? On Fri, 2004-08-06 at 09:43 -0700, Linus Torvalds wrote: > > On Fri, 6 Aug 2004, Andi Kleen wrote: > > > > You could use .altinstructions to patch a jump in at runtime > > based on CPU capabilities. Assuming MMX is really faster of course. > > I seriously doubt that the MMX code could be faster. > > The only MMX code in the original was saving some integer contents to a > scratch MMX register rather than saving to memory. There's _no_ way that > is faster, especially since in the kernel it would require us much extra > work to first check that the FP context is safed. Even _without_ the extra > work I simply cannot imagine that a "movd reg,mmx" is faster than a plain > "movl reg,stackslot". > > Linus > - > 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/ >