Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!ll-xn!mit-eddie!uw-beaver!cornell!rochester!PT.CS.CMU.EDU!andrew.cmu.edu!bader+
From: bader+@andrew.cmu.edu (Miles Bader)
Newsgroups: comp.arch
Subject: Re: RISC data alignment
Message-ID: <IW6lccy00UkaBO00hb@andrew.cmu.edu>
Date: 18 Feb 88 16:51:52 GMT
References: <2635@calmasd.GE.COM> <28200092@ccvaxa> <496@ecrcvax.UUCP>,
	<3001@bloom-beacon.MIT.EDU>
Organization: Carnegie Mellon University
Lines: 17
In-Reply-To: <3001@bloom-beacon.MIT.EDU>


jfc@athena.mit.edu (John F Carr) writes:
> Isn't code which depends on allignment and spacing risky anyway?  
> If a program assumes that for
> 
> struct { int a;
>          int b;
>        } s;
> 
>  (&(s.a) - &(s.b)) == 1 it is making an unsupported assumption.  Can 
> someone post an example of a program which is portable and depends on
> the K&R rule quoted above?

The common case is that of extending the last element of a
structure...  Does anyone have code that will break if the elements
are ordered arbitrarily, BUT the last element is kept last?

-Miles