Xref: utzoo comp.lang.fortran:1599 comp.lang.misc:2305 Path: utzoo!utgpu!watmath!clyde!att!rutgers!tut.cis.ohio-state.edu!bloom-beacon!gatech!gitpyr!loligo!mccalpin From: mccalpin@loligo.fsu.edu (John McCalpin) Newsgroups: comp.lang.fortran,comp.lang.misc,comp.sys.super Subject: Re: Assembly or .... Keywords: Assembler, HLL Message-ID: <159@loligo.fsu.edu> Date: 1 Dec 88 23:12:51 GMT Reply-To: mccalpin@loligo.UUCP (John McCalpin) Organization: Supercomputer Computations Research Institute Lines: 18 References: I notice that no one has discussed supercomputers in this long discussion on the merits of learning assembly language. To achieve any sort of reasonable performance on a vector supercomputer, you must know a lot about the architecture. Some machines are worse than others --- the CDC/ETA machines and the Cray-2 come to mind as machines on which it is remarkably easy to get bad performance.... On the other hand, it is almost never necessary for users to _write_ is assembly language on these machines to get good performance - you just need to know what the vectorizer is able to convert into efficient code. Also on the CDC/ETA machines, the entire instruction set is available in FTN200 anyway via special calls. (This actually produces inline code, but they are written as subroutine calls). John D. McCalpin Supercomputer Computations Research Institute The Florida State University mccalpin@masig1.ocean.fsu.edu