Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site umcp-cs.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!think!harvard!seismo!umcp-cs!chris From: chris@umcp-cs.UUCP (Chris Torek) Newsgroups: net.lang.c Subject: Re: register variables Message-ID: <409@umcp-cs.UUCP> Date: Mon, 24-Jun-85 12:39:52 EDT Article-I.D.: umcp-cs.409 Posted: Mon Jun 24 12:39:52 1985 Date-Received: Wed, 26-Jun-85 04:52:38 EDT References: <472@crystal.UUCP> <551@ucsfcgl.UUCP> Distribution: net Organization: U of Maryland, Computer Science Dept., College Park, MD Lines: 23 Ken Arnold makes a good point here: > You have an infinite number of registers. No, seriously, this is the > way to think about it. You should declare EVERYTHING which you don't > have to take the address of to be a register. [...] Just be somewhat > careful to declare things in the order you care about. I have to admit to getting into the sloppy habit of stopping after six register declarations. But that's not why I'm writing this. . . what I really want to do is make another point here, and that is that you should declare register variables before ordinary variables (in general), since some machines (Pyramids) ignore the word ``register'' and just put the first N (12) variables in registers. (Such a machine must, of course, be able to take the address of a register.) Also (last point---I promise!), to C compiler writers: please don't parse the list of declarations and then perform the declarations in reverse order! -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251) UUCP: seismo!umcp-cs!chris CSNet: chris@umcp-cs ARPA: chris@maryland