Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uakari.primate.wisc.edu!uflorida!haven!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: May too many register variables hurt? (was Re: Novice question.)
Message-ID: <14538@smoke.brl.mil>
Date: 20 Nov 90 17:42:01 GMT
References: <965@demott.COM> <11476@j.cc.purdue.edu> <967@mwtech.UUCP>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 13

In article <967@mwtech.UUCP> martin@mwtech.UUCP (Martin Weitzel) writes:
>In general, my advice is to use no more than two register variables, and
>only in the *outmost* blocklevel in the body of any function.

Mine is the opposite.

>The order in which the variables are declared is a-b-c, so c will not
>profit from its storage class.

Sure it will.  Since b and c are declared in separate parallel blocks,
older-technology compilers such as PCC will share the explicit register
that is assigned for these two variables.  This is in fact a good way
to exploit "register" in such compilers.