Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!ames!claris!drc
From: drc@claris.UUCP (Dennis Cohen)
Newsgroups: comp.lang.c
Subject: Re: Absolute size of 'short'
Keywords: unsigned wrap-around
Message-ID: <4456@claris.UUCP>
Date: 2 Aug 88 14:24:44 GMT
References: <214@ISIDAPS5.UUCP>
Reply-To: drc@claris.UUCP (Dennis Cohen)
Organization: Claris Corporation, Mountain View CA
Lines: 23

In article <214@ISIDAPS5.UUCP> mike@ISIDAPS5.UUCP (Mike Maloney) writes:
>Is the size of a (signed or unsigned) short integer guarenteed to
>be two bytes?  I need to manipulate and compare some unsigned ints
>modulo 65536.  It would be clean and convenient to just let the
>machine handle my wrap-around from 0 to 0xffff and verse-vica.
>

Sorry, but the answer is "No".  As a matter of fact, it can't even be
guaranteed between compilers for the same piece of iron.  An example is the
Megamax C compiler for the Mac (and I think the Amiga as well) defines a
short to be 8 bits, an int to be 16, and a long is 32; the other four
compilers that I've used on the Mac define a short to be 16 bits.  The only
thing that is supposed to be guaranteed is:

	sizeof(short) <= sizeof(int) <= sizeof(long)

You might even find some where they're all the same size (I seem to recall a
compiler for CP/M which did that).

Dennis Cohen
Claris Corp.
------------
Disclaimer:  Any opinions expressed above are _MINE_!