From owner-freebsd-standards Fri Apr 12 9:39:36 2002 Delivered-To: freebsd-standards@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 8B61D37B404 for ; Fri, 12 Apr 2002 09:39:33 -0700 (PDT) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.11.4/8.11.6) id g3CGdOZ90234; Fri, 12 Apr 2002 12:39:24 -0400 (EDT) (envelope-from wollman) Date: Fri, 12 Apr 2002 12:39:24 -0400 (EDT) From: Garrett Wollman Message-Id: <200204121639.g3CGdOZ90234@khavrinen.lcs.mit.edu> To: "Tim J. Robbins" Cc: freebsd-standards@FreeBSD.ORG Subject: Re: standards/36783 In-Reply-To: <200204121240.g3CCe3a52899@freefall.freebsd.org> References: <200204121240.g3CCe3a52899@freefall.freebsd.org> Sender: owner-freebsd-standards@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG < said: > This format string for long double is the same as that used for double. > says #define LDBL_DIG DBL_DIG , but it seems > odd to be printing out long doubles with no more precision than doubles. The exact type of a `long double' differs from machine to machine. On IA-32 machines, it's usually 80-bit ``extended double precision''. On SPARCv9, it's always ``quad precision'' (which is not an IEEE-sanctioned type, but is the obvious analogue of IEEE double with twice as many bits in the representation). Some other processors have other representations. Because of the way the IA-32 FPU is configured by default, using extended precision generally doesn't do any good, and I think in the current compilers a double and a long double are both implemented as FPU doubles. (This certainly was true at one time.) -GAWollman To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-standards" in the body of the message