Date: Tue, 16 Mar 1999 15:17:44 +1100 From: "Andrew Reilly" <andrew@lake.com.au> To: Matthew Dillon <dillon@apollo.backplane.com>, "Stephen J. Roznowski" <sjr@home.net> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: Use of "register" in code Message-ID: <19990316151744.A39973@reilly.home> In-Reply-To: <199903160349.TAA05543@apollo.backplane.com>; from Matthew Dillon on Mon, Mar 15, 1999 at 07:49:45PM -0800 References: <199903160333.WAA06493@istari.home.net> <199903160349.TAA05543@apollo.backplane.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Mar 15, 1999 at 07:49:45PM -0800, Matthew Dillon wrote: > :I've been looking at merging some NetBSD fixes for games, and I noticed > :that they have removed the "register" declaration from (at least) this > :section of the code tree. > : > :Are these register declarations useful, or are they just "historical > :artifacts"? If they are just historical artifacts, should they be > :removed? > : > :Thanks, > :-- > :Stephen J. Roznowski (sjr@home.net) > > The register declarations are useless historical artifacts. Why do you say that? "register" in a declaration has a specific semantic meaning that isn't (to my knowledge) duplicated by any other language mechanism, and that is "this variable does not exist in the memory space, and so _cannot_ be de-referenced with "&" or modified by an asignment through a pointer." Register pointer variables and temporaries are very important for preventing C compilers from producing pessimistic inner loop code. -- Andrew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19990316151744.A39973>