Xref: utzoo comp.arch:4807 comp.lang.c:10109
Path: utzoo!attcan!uunet!husc6!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.arch,comp.lang.c
Subject: Re: negative addresses
Message-ID: <7881@brl-smoke.ARPA>
Date: 13 May 88 19:55:39 GMT
References: <2393@uvacs.CS.VIRGINIA.EDU> <21541@amdcad.AMD.COM> <1988May12.162906.16901@utzoo.uucp>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 17

In article <1988May12.162906.16901@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>Unfortunately, it is a real problem, because there are zillions of
>programs that implicitly assume that pointers are all-zeros.

I don't think this is true.  How about an example?

>... uninitialized static variables are
>*not* initialized to all-zeros, they are initialized to the zero value
>of their data type, which means the null pointer for pointers.  Now this
>would be a bit of a pain for compilers on machines with odd representations
>of the null pointer.

Not that much of a problem, really.  The compiler knows about static
data at compile time, and if not explicitly initialized it can output
something like
	ptrname: .word 0xF0F0F0F0 ; null pointer pattern
in the data section of the code it generates.