Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!spool.mu.edu!cs.umn.edu!uc!shamash!timbuk!jot From: jot@fig12.cray.com (Otto Tennant) Newsgroups: comp.lang.fortran Subject: Re: NAG Fortran 90 announcement Message-ID: Date: 26 Jun 91 05:15:49 GMT Article-I.D.: fig12.JOT.91Jun25224852 References: <26334@lanl.gov> <26453@beta.gov> <1991Jun25.214710.21152@murdoch.acc.Virginia.EDU> <26487@beta.gov> Organization: Cray Research, Inc. Lines: 25 In-reply-to: jlg@cochiti.lanl.gov's message of 26 Jun 91 00:52:55 GMT I'm missing something here. In an earlier post, Mr. Giles noted that one must be able to sweep through an array with equal ease by either rows or columns. This is a simple fact. The C language seems to require that arrays be implemented as pointers to things. This means that one direction is preferred. C is not alone in this. (Thousands will correct me on this, but when I looked at Ada some years ago, it shared this problem.) A translator which produces C, however, is not required to produce readable C. Multi-dimensional Fortran arrays become C vectors with hairy subscripts. In the absence of "#pragma" directives, this does not address the efficiency issue: the aliasing problem is merely directed to a different part of the compiler. But what boots it? The F90 compiler produces a correct description of the described computation in a different language. If the different language is feeble in some respects, well, compilers get smarter every day. -- =============================================================================== J.Otto Tennant Forsan et haec olim meminisse juvabit. jot@cray.com Cray Research, Inc. Virgil (612) 683-5872 665 Lone Oak Drive Eagan, MN 55121