Path: utzoo!attcan!uunet!drivax!marking
From: marking@drivax.UUCP (M.Marking)
Newsgroups: comp.lang.c
Subject: Re: What C compilers have non-zero null pointers?
Message-ID: <GMKM5FY@drivax.UUCP>
Date: 13 Jul 90 04:50:49 GMT
References: <422@minya.UUCP>
Sender: marking@drivax.UUCP
Reply-To: marking@drivax.UUCP
Organization: Digital Research (Japan) Inc.
Lines: 12

jc@minya.UUCP (John Chambers) writes:

) After following a bit of debate in another newsgroup concerning 
) dereferencing null pointers, I've become curious as to how various
) C compilers actually represent null pointers.  I've never actually
) seen a C compiler that uses anything other than all 0 bits for
) a null pointer, but some people insist that this is quite common

My recollection is that there are "funny" NULLs on those machines
that use 1s-complement arithmetic (Univac 1100, some CDC stuff)
because sometimes you can conveniently generate exceptions on
"minus zero". But it's been a few years...