Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!charon!dik
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: comp.arch
Subject: Re: MIPS, Compaq and Microsoft in bed - NYT story
Message-ID: <2935@charon.cwi.nl>
Date: 14 Feb 91 02:27:20 GMT
References: <45758@mips.mips.COM> <3188@crdos1.crd.ge.COM> <5974@labtam.labtam.oz>
Sender: news@cwi.nl
Organization: CWI, Amsterdam
Lines: 17

In article <5974@labtam.labtam.oz> graeme@labtam.labtam.oz (Graeme Gill) writes:
 > In article <3188@crdos1.crd.ge.COM>, davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) writes:
 > > 
 > >   Since all you can portable do in C is add or subtract ints and
etc.
 > 	Just a small point, but a lot of these machines have memory alignment
 > restrictions. How do you ensure address alignment if you can't do an
 > AND on an address ?
The talk was about portable.  To get address alignment for an int on a Cray for
instance you do:
	a = (int *)((int)a & 0x1fffffffffffffff);
is that portable?  To see some real hacks about attempts to get address
alignment, look at the code for the Bourne Shell, and be amazed that it
works on so very many machines.
--
dik t. winter, cwi, amsterdam, nederland
dik@cwi.nl