Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site harvard.ARPA Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!teddy!panda!talcott!harvard!sasaki From: sasaki@harvard.ARPA (Marty Sasaki) Newsgroups: net.lang.pascal,net.lang.c Subject: optimizing compilers vs. optimizing programmers Message-ID: <285@harvard.ARPA> Date: Sat, 12-Jan-85 19:59:17 EST Article-I.D.: harvard.285 Posted: Sat Jan 12 19:59:17 1985 Date-Received: Mon, 14-Jan-85 03:15:38 EST Distribution: net Organization: Aiken Computation Laboratory, Harvard Lines: 38 Xref: watmath net.lang.pascal:185 net.lang.c:3855 Warning! This posting contains a major digression from the discussion of Pascal as a system implementation language. I thought it would be interesting enough in general for a posting. All of this talk about optimization of C code vs. Pascal code, and Pascal as a system implementation language reminds me of the time I asked someone in the VMS development group why they didn't choose C for their system implementation language (they chose Bliss). He answered that C required an optimizing programmer in order to produce code that was good enough for an operating system kernel. The VMS folks also looked at Pascal, but felt that they didn't have enough control of the machine in Pascal without seriously changing the language. In the discussion that followed the VMS guy basically said (please note that these are my interpretations of the conversation): 1. They had to assume that the programmers that they used would be good, but not necessarily great. 2. The language/compiler had to be very good to sell management on using a high level language for system implementation. Point 2 is important all by itself, but point 1 implies that the programmer would probably not be able to consistantly produce code that was efficient and that worked in a timely fashion. An optimizing compiler was doubly important. To those that argue that Bliss is no better than assembly language let me say that tests done by DEC indicate that the Bliss-32 compiler produces code better than that written by experienced assembly language programmers. -- Marty Sasaki Havard University Science Center sasaki@harvard.{arpa,uucp} 617-495-1270