Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!ucla-cs!zen!ucbvax!hplabs!pyramid!prls!mips!mash From: mash@mips.UUCP Newsgroups: comp.arch Subject: Re: The 360 was a design landmark (long) Message-ID: <642@winchester.UUCP> Date: Sun, 30-Aug-87 14:18:31 EDT Article-I.D.: winchest.642 Posted: Sun Aug 30 14:18:31 1987 Date-Received: Mon, 31-Aug-87 01:37:07 EDT References: <855@tjalk.cs.vu.nl> <2683@hoptoad.uucp> <8519@utzoo.UUCP> Reply-To: mash@winchester.UUCP (John Mashey) Organization: MIPS Computer Systems, Sunnyvale, CA Lines: 26 In article <8519@utzoo.UUCP> henry@utzoo.UUCP (Henry Spencer) writes: >> I was under the impression that most 370s did mundane payroll/bookkeeping >> stuff. For those tasks, bcd string performance would seem to be paramount. > >My recollection is that when you actually measure them, even COBOL programs >spend most of their time doing ordinary (non-bcd) instructions for overhead, >i/o control, addressing, etc. More specifically: a) In some of the work that lead to the 801, IBM found that the decimal operations were not really used very much over large mixes. b) HP found the same thing: they did include a few simple operations to help decimal arithmetic, but that's it. In particular, they did extensive studies and found that their COBOL programs (very relevant for some of their markets) spent a lot of time in the OS, record managers, etc. c) On the other hand, DEC (Clark & Levy, "Measurement and Analysis of Instrucion Use in the VAX 11/780", ACM SIGARCH, April 1982), finds that specific COBOL programs use the decimal operations heavily. This may or may not contradict what HP found, in that a given COBOL program may well use the operations, but the overall use of a runnign system may not do so as heavily. -- -john mashey DISCLAIMER: UUCP: {decvax,ucbvax,ihnp4}!decwrl!mips!mash OR mash@mips.com DDD: 408-991-0253 or 408-720-1700, x253 USPS: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086