Path: csiph.com!weretis.net!feeder6.news.weretis.net!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: "Steven G. Kargl" Newsgroups: comp.compilers Subject: Re: Undefined Behavior Optimizations in Fortran Date: Thu, 26 Jan 2023 21:12:12 -0000 (UTC) Organization: A noiseless patient Spider Sender: johnl@iecc.com Approved: comp.compilers@iecc.com Message-ID: <23-01-074@comp.compilers> References: <23-01-027@comp.compilers> <23-01-031@comp.compilers> <23-01-041@comp.compilers> <23-01-062@comp.compilers> <23-01-063@comp.compilers> <23-01-073@comp.compilers> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="90413"; mail-complaints-to="abuse@iecc.com" Keywords: Fortran, comment Posted-Date: 26 Jan 2023 21:05:52 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:3342 On Mon, 23 Jan 2023 18:50:31 -0800, gah4 wrote: > > As far as I can tell, Fortran makes no claims regarding > fixed point overflow, being undefined or system dependent. > It makes claims. F2018 (18-007r1.pdf), p. 148. The execution of any numeric operation whose result is not defined by the arithmetic used by the processor is prohibited. If you want to go back to F66, one finds in Sec. 6.4, "Evaluation of Experssions." No element may be evaluated whose values is not mathematically defined. -- steve [Like I said, IBM didn't promise that SSP would work anywhere else. -John]