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From: mcdaniel@uicsrd.csrd.uiuc.edu (Tim McDaniel)
Newsgroups: comp.lang.c
Subject: Re: How to multiply two ints and check overflow
Keywords: overflow
Message-ID: <1056@garcon.cso.uiuc.edu>
Date: 19 May 89 00:19:27 GMT
References: <434@skye.ed.ac.uk> <1034@garcon.cso.uiuc.edu>
Sender: news@garcon.cso.uiuc.edu
Reply-To: mcdaniel@uicsrd.csrd.uiuc.edu (Tim McDaniel)
Organization: Center for Supercomputing R&D (Cedar), U. of Ill.
Lines: 22

The INT_MIN and INT_MAX #defines are there for non-pANS C sites;
they're inherently unportable.  If INT_MIN is #defined as
	(-2147483648)
it may not work (it may get the wrong type, according to Chris Torek).
INT_MIN may have to be #defined as
	(-2147483647 - 1)
or
        (0x80000000)
or even just
        (-2147483647)
if your compiler won't let you input -(2**32) and you're willing to
sacrifice the smallest int.  (INT_MIN and INT_MAX don't have to be
exact, or even close, for my safemul code to work.)

--
"6:20 O Timothy, keep that which is committed to thy trust, avoiding
profane and vain babblings, and oppositions of science falsely so
called: 6:21 Which some professing have erred concerning the faith."

Tim, the Bizarre and Oddly-Dressed Enchanter  |  mcdaniel@uicsrd.csrd.uiuc.edu
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