Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!zaphod.mps.ohio-state.edu!wuarchive!texbell!texsun!newstop!sun!khb From: khb@chiba.Eng.Sun.COM (Keith Bierman - SPD Advanced Languages) Newsgroups: comp.lang.fortran Subject: Re: How do compilers handle dimensions? Message-ID: Date: 17 Jul 90 20:31:26 GMT References: <90198.114258FC138001@ysub.ysu.edu> Sender: news@sun.Eng.Sun.COM Organization: Sun MegaSystems Lines: 43 In-reply-to: FC138001@ysub.ysu.edu's message of 17 Jul 90 15:42:58 GMT In article <90198.114258FC138001@ysub.ysu.edu> FC138001@ysub.ysu.edu (Phil Munro) writes: 1. The normal dimension byte size on the mainframe machine (which I presume is a 64-bit machine) is *4. Does this size, and the byte = 8 bits *4 means 4 bytes = 32 bits. In days gone by, words were king, not bytes. X3.9-1978 talks about storage units which are more like words than bytes. By convention (but not any formal standard) real*4 means "single precision" aka real and generally 32-bit real*8 means "double precision" aka double precision and generally 64-bit Since some machines (viz. cdc 6600 and its ilk) have 60-bit words, real*4 means real (i.e. 60-bit) ... but for all byte oriented machines, that I am aware of, real*4 gets you 32-bit quanties. 2. Are the dimension statements REAL*8, etc., part of Fortran 77, 90 or whatever, or are they just a VS extension? I don't recall who introduced *n syntax first. It is commonly found on: vms Sun Convex PC (misc. compilers, lahey, ms, etc.) LPI (all platforms) DG and many, many others. cheers -- Keith H. Bierman |*My thoughts are my own. !! kbierman@Eng.Sun.COM It's Not My Fault | MTS --Only my work belongs to Sun* khb@chiba.Eng.Sun.COM I Voted for Bill & | Advanced Languages/Floating Point Group (415 336 2648) Opus "When the going gets Weird .. the Weird turn PRO"