From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail19d.g19.rapidsite.net (mail19d.dulles19-verio.com [204.202.242.120]) by ozlabs.org (Postfix) with SMTP id DD39D679F4 for ; Wed, 8 Mar 2006 02:54:33 +1100 (EST) From: "Russell McGuire" To: "'Dan Malek'" Subject: RE: GNU and Freescale MPC83xx / e300 core support? Date: Tue, 7 Mar 2006 07:54:19 -0800 Message-ID: <002b01c641ff$666ccc70$6405a8c0@absolut> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <50206c46cf7e37ede345eebf82ad6fbc@embeddedalley.com> Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Thanks all... The author of that comment humbly apologizes for his ineptitude on the FPU. It would appear both cores have the same number of execution units, i.e. 5 So David, I guess in all this the only real difference seems to be the bus architecture, raw clock speed, and perhaps a few new instructions. I checked both manuals this morning and they do differ in some small ways. * 603e, up to 4 instructions in the pipeline, only 3 being complete per clock * e300, up to 5 instructions in the pipeline, still only 3 being completed or start per clock. * Add/compare instructions are now executed in the IU unit instead of the load/store unit. May be the same, but wasn't specific in earlier 603e manuals. * One more HID0 bit than G2, ability to interrupt based on cache parity error * new icbt instruction, instruction cache initialization So there is a section inside the 8360E manual that outlines the specific enhancements. "Features specific to the e300 core not present on the G2 processors follow:" Page 1-5. So I guess my question is back up, does anyone know if an optimized compiler would offer any noticeable performance enhancements in regards to these changes? Other than the obvious instruction being added? Thanks -Russ -----Original Message----- From: Dan Malek [mailto:dan@embeddedalley.com] Sent: Tuesday, March 07, 2006 4:33 AM To: Russell McGuire Cc: 'David Hawkins'; linuxppc-embedded@ozlabs.org Subject: Re: GNU and Freescale MPC83xx / e300 core support? On Mar 7, 2006, at 12:52 AM, Russell McGuire wrote: > ..... The most obvious core difference is > the Floating Point unit; the MPC8280, 603e or G2LE core had no floating > point ability at all. I just want to state for archive purposes this simply isn't true. All of those processors had hardware FPUs. If you would take a few seconds and read the product overviews for these parts, you can make your own informed decision. The person you are talking to doesn't seem to have all of the facts in order. -- Dan