From owner-cvs-all Thu Oct 25 15:25:45 2001 Delivered-To: cvs-all@freebsd.org Received: from iguana.aciri.org (iguana.aciri.org [192.150.187.36]) by hub.freebsd.org (Postfix) with ESMTP id 4038137B401; Thu, 25 Oct 2001 15:25:39 -0700 (PDT) Received: (from rizzo@localhost) by iguana.aciri.org (8.11.3/8.11.1) id f9PMJZe58898; Thu, 25 Oct 2001 15:19:35 -0700 (PDT) (envelope-from rizzo) Date: Thu, 25 Oct 2001 15:19:35 -0700 From: Luigi Rizzo To: Doug Rabson Cc: John Baldwin , Jonathan Lemon , cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/dev/fxp if_fxp.c Message-ID: <20011025151935.G57392@iguana.aciri.org> References: <20011025143748.C57392@iguana.aciri.org> <20011025231245.K549-100000@salmon.nlsystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20011025231245.K549-100000@salmon.nlsystems.com> User-Agent: Mutt/1.3.23i Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > does it mean that integer multiply in the kernel is bad on the ia64 :) > > Not really - its reasonably quick. They just didn't bother to add any > integer multipliers when there were two perfectly good floating point > units going idle. Moving integers in and out of float registers is quick > and easy so it actually makes sense. Divides are done with floating point > too. the point for not having FP in the kernel is not speed, but rather the fact that you do not have to save those registers in a context switch. This could just be an artifact of ancient times where FPU's were separate units... So, i guess the FP registers are saved in the IA64 context switch routines ? luigi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message