Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site watdaisy.UUCP
Path: utzoo!watmath!watdaisy!djsalomon
From: djsalomon@watdaisy.UUCP (Daniel J. Salomon)
Newsgroups: net.lang.c
Subject: Re: String copy idiom.
Message-ID: <7047@watdaisy.UUCP>
Date: Fri, 8-Mar-85 13:36:17 EST
Article-I.D.: watdaisy.7047
Posted: Fri Mar  8 13:36:17 1985
Date-Received: Sat, 9-Mar-85 08:04:29 EST
References: <7042@watdaisy.UUCP> <7044@watdaisy.UUCP>
Distribution: net
Organization: U of Waterloo, Ontario
Lines: 12

> The VAX 4.2 BSD UNIX library routine 'strcpy' uses code equivalent
> to the less efficient sequence:  while (*s++ = *t++);
> Perhaps it should be changed.
> 

SORRY for this error.
The idiom "while (*s++ = *t++);" generates the fastest possible code
if s and t are declared to be registers, which they are in the
system version of strcpy.  But note that if s and t are not in
registers then the sequence:
    while (*s = *t) {s++; t++;}
is more efficient.