Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!rpi!zaphod.mps.ohio-state.edu!mips!winchester!mash From: mash@mips.COM (John Mashey) Newsgroups: comp.sys.m88k Subject: Re: DG's use of m88k Message-ID: <36485@mips.mips.COM> Date: 27 Feb 90 12:47:04 GMT References: <7521@imag.imag.fr> <36461@mips.mips.COM> <25EA4069.17611@paris.ics.uci.edu> Sender: news@mips.COM Reply-To: mash@mips.COM (John Mashey) Organization: MIPS Computer Systems, Inc. Lines: 36 In article <25EA4069.17611@paris.ics.uci.edu> rfg@ics.uci.edu (Ronald Guilmette) writes: >In article <36461@mips.mips.COM> mash@mips.COM (John Mashey) writes: >If individual program are measuring for "scientific" performance, they >should probably be labeled as such. In the SPEC newsletter, each of the benchmarks is described in at least moderate detail, and the scientific ones are certainly identifiable. >Now that I got thah off my chest, I'd like to ask a question about the >GCC member of the SPEC suite. > >It is my understanding that GCC spends a great deal of its time doing >code generation and/or optimization. Obviously, the actual amount of >time spent doing these things can (potentially) vary a great deal depending >upon the target machine that you are having GCC generate code for. Therefore, >it would seem that in order to obtain a really "fair" apples-to-apples >comparison of performance using GCC as a test case, you would have to run >GCC on host machine X and have it compile some code for target machine Z >and then run GCC hosted on machine Y and again have it produce code targeted >for the same target machine (Z) as in previous tests. That's what it does: the target is always the same. >Of course, some people might say that the cost of compiling for a particular >machine *should* be factored in as a part of the overall "performance" >of the machine itself. Perhaps that's true, but again it may be a question >of properly "labeling" the results so that people who read the SPEC numbers >fully understand that compilation speed FOR THAT MACHINE was factored in. >(People who do no software development will not care about this factor >at all, but conversly, professional software developers might care about >that particular performance factor above all else). There may sometime be such a benchmark, but the gcc one isn't it. -- -john mashey DISCLAIMER: UUCP: {ames,decwrl,prls,pyramid}!mips!mash OR mash@mips.com DDD: 408-991-0253 or 408-720-1700, x253 USPS: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086