Path: g2news2.google.com!news3.google.com!feeder.news-service.com!news2.euro.net!multikabel.net!newsfeed20.multikabel.net!dedekind.zen.co.uk!zen.net.uk!hamilton.zen.co.uk!feed4.jnfs.ja.net!jnfs.ja.net!gemini.csx.cam.ac.uk!news.cam.ac.uk!not-for-mail From: n...@cam.ac.uk Newsgroups: comp.lang.fortran Subject: Re: how to declare doubles in f95 Date: Thu, 29 Jan 2009 20:51:37 +0000 (GMT) Organization: University of Cambridge Lines: 34 Message-ID: References: <0b898c8f-5866-4942-bf2b-171655d6658a@r15g2000prh.googlegroups.com> <1iuawnt.17aehjr1dmhi26N%nospam@see.signature> NNTP-Posting-Host: soup.linux.pwf.cam.ac.uk In article , glen herrmannsfeldt wrote: >Richard Maine wrote: > >> It became common practice for compilers for other machines to have at >> least an option to make single precision be 64 bits in order to >> facilitate porting of such code. It is such a common option that people >> today continue using those options and writing code that assumes single >> precision is 64 bits, even if they have never seen anything like a CDC. >> To my knowledge, a majority, or at least a large fraction, of today's >> compilers have such options. Questions relating to this come up quite >> regularly on this newsgroup. > >I don't remember that option on the IBM compilers, other than adding > > IMPLICIT REAL*8 (A-H,O-$) > >which I did see many times. ($ was the 27th letter of the alphabet.) >(As far as I know, IBM started the use of IMPLICIT, maybe for this.) > >Also, there were many routines with sets of declarations and >DATA statements at the beginning where you uncomment the ones >appropriate for your machine. It was called AUTODBL. If I recall (and I may well not), it was not present in IBM's original development compilers for the System/360 (Code-and-go and G), and may not have been even in the Program Product, G1. I think I have enough old manuals to check .... Anyway, it was a crock. Regards, Nick Maclaren.