Xref: utzoo comp.lang.c++:2178 comp.lang.c:14498 comp.lang.forth:714 comp.lang.fortran:1583 comp.lang.misc:2270 Path: utzoo!utgpu!watmath!clyde!att!rutgers!mit-eddie!bu-cs!purdue!decwrl!labrea!csli!gandalf From: gandalf@csli.STANFORD.EDU (Juergen Wagner) Newsgroups: comp.lang.c++,comp.lang.c,comp.lang.forth,comp.lang.fortran,comp.lang.misc Subject: Re: Assembly or .... Message-ID: <6660@csli.STANFORD.EDU> Date: 2 Dec 88 21:01:22 GMT References: <1388@aucs.UUCP> <729@convex.UUCP> <1961@crete.cs.glasgow.ac.uk> <1988Nov29.181235.23628@utzoo.uucp> <960@vsi.COM> Reply-To: wagner@arisia.xerox.com (Juergen Wagner) Organization: Center for the Study of Language and Information, Stanford U. Lines: 17 In article <960@vsi.COM> friedl@vsi.COM (Stephen J. Friedl) writes: >In article <1988Nov29.181235.23628@utzoo.uucp>, henry@utzoo.uucp (Henry >Spencer) writes: >> Alas, if you buy your newer faster CPUs from Motorola or Intel, they can't >> tell you how many cycles each instruction takes! > >Why is this? >... Because of instruction prefetching, overlapping of instruction executions, ... The time an instruction takes to execute depends on its context. Strictly speaking, e.g. a 68020 is not a von-Neumann machine! -- Juergen Wagner gandalf@csli.stanford.edu wagner@arisia.xerox.com