Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Contiguous Arrays
Message-ID: <1989Feb26.044828.16296@utzoo.uucp>
Organization: U of Toronto Zoology
References: <2508@ssc-vax.UUCP> <8943@alice.UUCP> <1828@valhalla.ee.rochester.edu> <7799@sneaky.TANDY.COM> <7309@killer.DALLAS.TX.US> <9718@smoke.BRL.MIL>
Date: Sun, 26 Feb 89 04:48:28 GMT

In article <9718@smoke.BRL.MIL> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>>To make it even more serious, I do not know of any twos-
>>complement computer that even has a signed vs. unsigned add instruction.
>
>They are one and the same.

Only if the instructions don't do anything drastic about overflow.  If they
do, then the two are different, as on (for example) the MIPS machines, which
have (if memory serves) a signed add that traps overflows and an unsigned
add that just wraps around.
-- 
The Earth is our mother;       |     Henry Spencer at U of Toronto Zoology
our nine months are up.        | uunet!attcan!utzoo!henry henry@zoo.toronto.edu