From owner-freebsd-alpha Sun Aug 20 13:51:18 2000 Delivered-To: freebsd-alpha@freebsd.org Received: from alcanet.com.au (mail.alcanet.com.au [203.62.196.10]) by hub.freebsd.org (Postfix) with SMTP id 6257237B42C for ; Sun, 20 Aug 2000 13:51:13 -0700 (PDT) Received: by border.alcanet.com.au id <115216>; Mon, 21 Aug 2000 06:51:04 +1000 Content-return: prohibited Date: Mon, 21 Aug 2000 06:50:54 +1000 From: Peter Jeremy Subject: Re: optimized mem* and str* functions In-reply-to: <20000819152032.A1483@freebie.demon.nl>; from wkb@freebie.demon.nl on Sat, Aug 19, 2000 at 03:20:32PM +0200 To: Wilko Bulte Cc: alpha@FreeBSD.org Mail-followup-to: Wilko Bulte , alpha@FreeBSD.ORG Message-Id: <00Aug21.065104est.115216@border.alcanet.com.au> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-disposition: inline User-Agent: Mutt/1.2.4i References: <39999750.C80F3B0B@imimic.com> <00Aug18.140950est.115233@border.alcanet.com.au> <20000819152032.A1483@freebie.demon.nl> Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On 2000-Aug-19 15:20:32 +0200, Wilko Bulte wrote: >The later alpha/AXP implementations have byte manipulation instructions >IIRC. Correct. > Are they used when available? DEC CC and (AFAIK) GCC don't generate them by default, but they can be enabled (with GCC) by specifying `-mbwx' or `-mcpu=ev56' (or later). Note that using the byte instructions isn't necessarily an optimisation. It's often (usually?) faster to load a full register and unroll the loop to process each byte in the register. Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message