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 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,7767a311e01e1cd X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII Path: g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.comcast.com!news.comcast.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 22 Oct 2006 20:32:15 -0500 Date: Sun, 22 Oct 2006 21:31:09 -0400 From: Jeffrey Creem User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: GNAT compiler switches and optimization References: <1161341264.471057.252750@h48g2000cwc.googlegroups.com> <9Qb_g.111857$aJ.65708@attbi_s21> <434o04-7g7.ln1@newserver.thecreems.com> <4539ce34$1_2@news.bluewin.ch> <453A532F.2070709@obry.net> <9kfq04-sgm.ln1@newserver.thecreems.com> <5vgs04-64f.ln1@newserver.thecreems.com> <453bc74e$0$19614$426a74cc@news.free.fr> In-Reply-To: <453bc74e$0$19614$426a74cc@news.free.fr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Message-ID: <4jit04-0gq.ln1@newserver.thecreems.com> NNTP-Posting-Host: 24.147.74.171 X-Trace: sv3-iaM0oM2I6rVKm/yxtDpMOTpwp3l47tj87pwoiklLMRK0+1ONfsr9p4A4cJJpo9GUdig9lHPg9FP6ub2!vq512sWmG3h74npxeu/xDGl2yeFRDQs983M7tFfleLgUu9IaYIUM9OpnQqIE/2pOzSGU6Jgtfu8+!Frk= X-Complaints-To: abuse@comcast.net X-DMCA-Complaints-To: dmca@comcast.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: g2news2.google.com comp.lang.ada:7148 Date: 2006-10-22T21:31:09-04:00 List-Id: Damien Carbonne wrote: > Jeffrey Creem a �crit : > >> Followup on the bug report. >> >> One of the comments asserted that the two programs were not equivilent >> though I am not yet 100% convinced that I believe it yet. >> > > >> >> >> Can someone that understands FORTRAN better make an argument about the >> "closeness" of this approach v.s. the other? > > > I've been following this thread for some times and I'm not a Fortran > Guru,however, IIRC, Fortran arrays and Ada arrays don't have the same > memory layout (Something like row major order and column major order). > I've not compared programs of this thread with care, but I've the > feeling that this could change things. > Some years ago, I had to mix Ada and Fortran, and I remember that we had > to invert loops order to obtain the same result. > One would need to add 'pragma Convention (Fortran, Real_Matrix)' on Ada > side to obtain the same result, or to exchange loops. > My knowledge of Fortran was limited to Fortran 77, and I don't know if > this is still valid with Fortran 95 or later. > But if is still true, I would not consider the 2 programs as equivalent. > > Regards > > Damien Carbonne > Yes, there is always the chance of row major/column major issues creeping in and causing dramatically different cache results however the original poster seemed to have tried the swap to no effect, and the code assembly code appears to show that this is/was not the problem.