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-7-bit Path: g2news2.google.com!news4.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!nx01.iad01.newshosting.com!newshosting.com!204.127.204.223.MISMATCH!wns13feed!worldnet.att.net!attbi_s71.POSTED!53ab2750!not-for-mail From: "Jeffrey R. Carter" Organization: jrcarter at acm dot org User-Agent: Thunderbird 1.5.0.7 (Windows/20060909) 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> <4jit04-0gq.ln1@newserver.thecreems.com> <453d1d36$0$25551$bf4948fe@news.tele2.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: NNTP-Posting-Host: 12.201.97.213 X-Complaints-To: abuse@mchsi.com X-Trace: attbi_s71 1161707065 12.201.97.213 (Tue, 24 Oct 2006 16:24:25 GMT) NNTP-Posting-Date: Tue, 24 Oct 2006 16:24:25 GMT Date: Tue, 24 Oct 2006 16:24:25 GMT Xref: g2news2.google.com comp.lang.ada:7182 Date: 2006-10-24T16:24:25+00:00 List-Id: Jeffrey Creem wrote: > > 2) Small changes to the original code that still meet the original > structure and intent of the original code can move the run time up and > down by at least 50% > 3) The two task based version of the code is running more than 2x faster > than the single task version on a 2 processor machine. Some of this is > from the two tasks but looking at the assembly, another portion of it is > related to #2 above in that the re-arrangement of the math allows the > compiler to get less brain dead. These seem quite odd to me. Perhaps whatever is causing this is also the cause of the speedup I saw in the sequential case when the multiplication is put in a procedure. -- Jeff Carter "You've got the brain of a four-year-old boy, and I bet he was glad to get rid of it." Horse Feathers 47