Article View: comp.std.c
Article #8Re: What is the value of `(unsigned) -1' ??
From: Michael Meissner
Date: Tue, 27 Oct 1992 12:12
Date: Tue, 27 Oct 1992 12:12
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In article <1992Oct27.071744.4871@netcom.com> rfg@netcom.com (Ronald F. Guilmette) writes: | | The Subject line say it all. I've read section 3.2.1.2 and it appears that | the authors of the ANSI/ISO C standard went out of their way to define | the value of every conceivable arithmetic conversion *except* the conversion | of a negative signed integral value to an unsigned integral value of the | same size. | | If anyone has evidence to the contrary, please share it. (Please don't | provide opinions... provide citations instead. Thanks.) That's because it is implementation defined. In a two's complement 32-bit system, (unsigned)-1 returns 0xffffffff. In a one's complement 32-bit system, (unsigned)-1 returns 0xfffffffe. In a sign/magnitude 32-bit system, (unsigned)-1 returns 0x80000001. -- Michael Meissner email: meissner@osf.org phone: 617-621-8861 Open Software Foundation, 11 Cambridge Center, Cambridge, MA, 02142 You are in a twisty little passage of standards, all conflicting.
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Newsgroups: comp.std.c Path: arc1-ca.pugleaf.net!sparky!uunet!think.com!paperboy.osf.org!meissner From: meissner@osf.org (Michael Meissner) Subject: Re: What is the value of `(unsigned) -1' ?? In-Reply-To: rfg@netcom.com's message of Tue, 27 Oct 1992 07:17:44 GMT Message-ID: <MEISSNER.92Oct27121234@tiktok.osf.org> Sender: news@osf.org (USENET News System) Organization: Open Software Foundation References: <1992Oct27.071744.4871@netcom.com> Date: 27 Oct 92 12:12:34 Lines: 22