Path: utzoo!mnetor!uunet!mcvax!enea!tut!santra!clinet!msa
From: msa@clinet.FI (Markku Savela)
Newsgroups: comp.lang.c
Subject: Indexing vs pointers
Message-ID: <629@clinet.FI>
Date: 27 Apr 88 16:48:30 GMT
References: <1988Apr8.183815.3187@utzoo.uucp> <449@goofy.megatest.UUCP> <2200@louie.udel.EDU> <587@vsi.UUCP>
Reply-To: msa@clinet.UUCP (Markku Savela)
Organization: City Lines Oy, Helsinki, Finland
Lines: 31
Summary: It's not always clear which is better (performancewise...)

In article <587@vsi.UUCP> friedl@vsi.UUCP (Stephen J. Friedl) writes:
>
>Let's put this goto business in perspective:
>
>	/*
> 	 * strcpy() - written by John Doe
>	 */
>	strcpy(dst, src)
>	char	dst[], src[];
>	{
>	int	i;
>
>		for (i = 0; dst[i] = src[i]; i++)
>			;
>	}
>
>     Who objects to this?

	I don't!  I'm actually using similar loops in my C-programs
that are written for MS-DOS machines.  Just try compiling the above
code and a variation using pointers with LARGE MEMORY MODEL!

	Compare the results (in ASM). Believe or not, the variant
using indexes is much more compact than the one using pointers (and
saying "register i" improves it even more...)

	The question is of course: is there really any penalty in
using indexed versions with other architectures (like motorola)?

--
markku savela,   msa@clinet.fi