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=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,b49d3a703a4b4db5 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII Path: g2news1.google.com!postnews.google.com!f33g2000yqe.googlegroups.com!not-for-mail From: jonathan Newsgroups: comp.lang.ada Subject: Re: compiler settings in AdaGIDE Date: Sun, 25 Jul 2010 15:57:29 -0700 (PDT) Organization: http://groups.google.com Message-ID: References: <02d1f899-ad8f-493b-8f64-3791868a1bdb@q35g2000yqn.googlegroups.com> NNTP-Posting-Host: 143.117.23.233 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1280098649 10625 127.0.0.1 (25 Jul 2010 22:57:29 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 25 Jul 2010 22:57:29 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: f33g2000yqe.googlegroups.com; posting-host=143.117.23.233; posting-account=Jzt5lQoAAAB4PhTgRLOPGuTLd_K1LY-C User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.19) Gecko/2010062510 Iceweasel/3.0.6 (Debian-3.0.6-3),gzip(gfe) Xref: g2news1.google.com comp.lang.ada:12566 Date: 2010-07-25T15:57:29-07:00 List-Id: On Jul 25, 2:29=A0pm, Ada novice wrote: > Many thanks for all these precious information. The settings > > -gnatnp -O2 -march=3Dnative -ffast-math -funroll-loops > > was only 1 s faster (1537 s) as compared to using > > -gnatVa -O3 -gnatn -funroll-loops -gnatf -gnato Interesting result. I repeated the 100 calls to COMPLEX_EIGENVALUES.Eigen ( P, W, V, FAIL) test on a 121 x 121 sized matrix. I still get the same big decrease in running time from the -ffast-math switch. Generic_Complex_Eigenvalues seems sensitive to -ffast-math, but I've never seen any other program care much about it. > 1. I see that you use -gnatnp. Is this safe to do so i.e. to suppress > all checks? If I remove the -gnatp then running time goes from 3.61 to 6.1 sec. If I remove the -gnatnp then running time goes from 3.61 to 6.7 sec. (I suspect that you know that -gnatnp is really -gnatn -gnatp). On a high percentage of ordinary problems (usually data analysis) I would not care at all about the increased running time, and I would not remove the checks. There is another class of program I write and these run for days or weeks. These I never stop optimizing and testing, and all checks are removed! > 2. In the specification -march=3D"machine architecture here", you use > native for the machine architecture. Does this apply to Intel > processors as well? I just checked the gcc man pages and found nothing at all about -march=3Dnative. It helps a little on all the machines I've used and occasionally in the past it has helped enormously. Just now I removed -march=3Dnative from the Generic_Complex_Eigenvalues test and running time went from 3.61 sec to 3.58 sec. When I remove it from the Jacobi benchmark, the program slows down slightly. So the switch seems to do something on my intel machine, but all I can say now is that the difference is very small and unpredictable. J.