From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,325a055bed62c230 X-Google-Attributes: gid103376,public From: rracine@myremarq.com (Roger Racine) Subject: Re: Apex vs GNAT on solaris Date: 1999/12/09 Message-ID: <384fa0a4.864668076@newsnew.draper.com>#1/1 X-Deja-AN: 558552710 References: <82hiuj$74o$1@nnrp1.deja.com> <82hnll$ahu$1@nnrp1.deja.com> <384cfdb3.691883075@newsnew.draper.com> <82ku6s$jhi$1@nnrp1.deja.com> <384e52db.779218947@newsnew.draper.com> <82nhpr$g0l$1@nnrp1.deja.com> X-Complaints-To: abuse@draper.com X-Trace: newsnew.draper.com 944745380 13711 140.102.40.31 (9 Dec 1999 13:16:20 GMT) NNTP-Posting-Date: 9 Dec 1999 13:16:20 GMT Newsgroups: comp.lang.ada Date: 1999-12-09T13:16:20+00:00 List-Id: On Thu, 09 Dec 1999 06:21:49 GMT, Robert Dewar wrote: >In article <384e52db.779218947@newsnew.draper.com>, > rracine@myremarq.com (Roger Racine) wrote: >If we really felt the default were wrong, we would consider >changing it, but in fact we agree with gcc's choice of defaults >anyway. There is certainly no disadvantage in practice (we don't >see any problem of users shying away from optimization merely >because it is not the default -- why, even you, who are SO >inclined to use the default, end up following normal practice >and using -O2 :-) > I am only trying to tell you that there are many people with my experience. I am trying to help ACT. You do not need to convince -me- to use a higher level of optimization. I happen to have built the GNU tools, and have enough sense to use the same options as are used building those tools. That, however, is not going to be the case for many other people (they have not built the GNU tools). I truly believe you that all optimization levels are tested. There are, unfortunately, many people who are not subscribed to this newslist, and there are many who would not believe the CEO of a compiler company making this claim. :-) >The one disadvantage of the no optimization default seems to >be the problem of naive benchmarking, which in fact is the >scenario that started this thread. > Exactly. Which also could lead to selection of a compiler vendor for the wrong reason (See. I am really only concerned with ACT's interests). Or it could lead to programs losing time fixing performance problems that would be unnecessary if they simply used a higher optimization level (OK, so it is not -just- ACT's interests). And the disadvantage of having -O1 or -O2 the default is what? I have not seen any difficulty debugging -O2 code yet. Compilation speed is probably at least one order of magnitude faster than what I was used to 6 or 7 years ago. >But I don't think it is right to change the default just because >of this concern. Indeed, anyone doing benchmarks who does not >understand the need for carefully studying what options should >be used is going to get meaningless results in any case. Again, I only am trying to make you understand that there are many people who have experiences similar to mine. I spoke to some colleagues yesterday about this thread, and they were truly surprised and shocked to learn that the default was picked -not- based on "best optimization that is well-tested". I think we can end this thread. The decision is certainly the compiler vendors' to make. I think I have made my point that I believe there are people (like my colleagues I talked to), large in number, who will use the default, or less, with confidence, but will not use higher without a good reason. There are compiler vendors who pick their defaults based on the criterion I mentioned. Roger Racine