From owner-freebsd-hackers Thu Nov 9 12:59:41 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id MAA06549 for hackers-outgoing; Thu, 9 Nov 1995 12:59:41 -0800 Received: from bacchus.eng.umd.edu (bacchus.eng.umd.edu [129.2.94.5]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id MAA06544 for ; Thu, 9 Nov 1995 12:59:38 -0800 Received: from latte.eng.umd.edu (latte.eng.umd.edu [129.2.98.15]) by bacchus.eng.umd.edu (8.7/8.7) with ESMTP id PAA25828; Thu, 9 Nov 1995 15:59:36 -0500 (EST) Received: (chuckr@localhost) by latte.eng.umd.edu (8.7/8.6.4) id PAA11031; Thu, 9 Nov 1995 15:59:35 -0500 (EST) Date: Thu, 9 Nov 1995 15:59:35 -0500 (EST) From: Chuck Robey X-Sender: chuckr@latte.eng.umd.edu To: Michael Smith cc: hackers@FreeBSD.org Subject: Re: Load/Store using FPU regs ... In-Reply-To: <199511090901.JAA09519@genesis.atrad.adelaide.edu.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@FreeBSD.org Precedence: bulk On Thu, 9 Nov 1995, Michael Smith wrote: > koshy@blr.novell.com stands accused of saying: > > >>> L20: fldl (%ebx) fstpl (%ecx) ... > > >>> > > >>> The resulting program copies data at about 60 Megabytes per > > >>> second. > > > > > > Using the FPU registers for memmove/bitblt operations was a technique > > I first saw on an i860. We used to do a series of reads into FPU regs > > Wheras those of us with 68K backgrounds are rolling in the aisles about > this one 8) > > (For the uninitiated; the 68K can read/write arbitrary groups of registers > and increment/decrement the source/destination pointers at the same time. > Depending on coding technique, you can read or write as much as 56 > bytes at a time; the big win (microcoded processor, remember) being no > instruction fetches between reads. It's a pity that Motorola have axed > it as a mainstram family 8( ) Axed the family? They have the newest child out now, 68060, I don't think they've axed the family. > > Anyway, enough from the nostalgia corner - I'm too young for this! > > -- > ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ > ]] Genesis Software genesis@atrad.adelaide.edu.au [[ > ]] High-speed data acquisition and (GSM mobile) 041-122-496 [[ > ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ > ]] My car has "demand start" -Terry Lambert UNIX: live FreeBSD or die! [[ > ========================================================================== Chuck Robey chuckr@eng.umd.edu, I run FreeBSD-current on n3lxx + Journey2 Here's OJ's internet address in hex code: 00 2F 2F 2F 2F 5C 7F 2D 0D 15 1B 19 24 24 24 18 If you can't recall the translation, here it is: null character, slash, slash, slash, slash, backslash, rubout, dash, carriage return, negative acknowledgement, escape, end of media, dollar sign, dollar sign, dollar sign, cancel