Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 SMI; site sun.uucp Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!decvax!decwrl!sun!guy From: guy@sun.uucp (Guy Harris) Newsgroups: net.lang.c Subject: Re: more questions about efficient C code Message-ID: <2391@sun.uucp> Date: Mon, 8-Jul-85 05:32:42 EDT Article-I.D.: sun.2391 Posted: Mon Jul 8 05:32:42 1985 Date-Received: Thu, 11-Jul-85 00:20:25 EDT References: <474@crystal.UUCP> <420@enmasse.UUCP> <2367@sun.uucp> <422@gatech.CSNET> <463@sftri.UUCP> Distribution: net Organization: Sun Microsystems, Inc. Lines: 21 > AT&T compilers these days all come with a tool, call "dis", for > disassembler. that look at object files and tell you exactly what > instructions are in them. Well, some AT&T compilers, anyway - the S5R2 documentation describes DIS(1) as "3B20 only". > This is neccessary because it is sometimes not possible to look at a > .s and tell exactly what instructions the assembler will produce. For > example an assembler might replace some long forms of jumps by short > forms. The PDP-11, VAX, and 68000 assemblers I've seen don't replace long jumps with short jumps; they replace a "generic" jump with a short or long jump. Then again, for the purposes of inspecting generated code to see "how good it is", this shouldn't make much of a difference; looking at the ".s" files should suffice. The disassembler may be useful for 3Bs; I believe they have a "generic" assembler language which translates into 3B20 or WE32000-series binary code. Guy Harris