Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!asuvax!noao!arizona!mike
From: mike@cs.arizona.edu (Mike Coffin)
Newsgroups: comp.lang.misc
Subject: Re: Arrays in languages (was: Anyone want to design a language?)
Message-ID: <18419@megaron.cs.arizona.edu>
Date: 28 Feb 90 05:10:45 GMT
References: <8849@boring.cwi.nl>
Organization: U of Arizona CS Dept, Tucson
Lines: 19

From article <8849@boring.cwi.nl>, by dik@cwi.nl (Dik T. Winter):
> ...
> Many C users think that aliassing can be detected by the run time, so that
> multiple parts of code can be generated depending on the presence of an
> alias or not.  This is not true.  If two pointers point to different
> arrays one may not compare them. ...

The *programmer* is not allowed to compare pointers from different
arrays, but it's legal for the *compiler* to generate code to compare
them.  The compiler is certainly not constrained to generate legal C
code.

-mike


-- 
Mike Coffin				mike@arizona.edu
Univ. of Ariz. Dept. of Comp. Sci.	{allegra,cmcl2}!arizona!mike
Tucson, AZ  85721			(602)621-2858