From: James Cloos <cloos@jhcloos.com>
To: jay.p.belanger@gmail.com
Cc: emacs-devel@gnu.org
Subject: Re: Code for converting between Elisp and Calc floats
Date: Thu, 22 Oct 2009 16:04:54 -0400 [thread overview]
Message-ID: <m3fx9bdwjl.fsf@lugabout.jhcloos.org> (raw)
In-Reply-To: <87aazj2r7d.fsf_-_@vh213601.truman.edu> (Jay Belanger's message of "Thu, 22 Oct 2009 13:56:06 -0500")
>>>>> "Jay" == Jay Belanger <jay.p.belanger@gmail.com> writes:
Jay> +--------------------+----------------------------------------+
Jay> |10 |79bit binary IEEE is used by Lisp floats|
Jay> +--------------------+----------------------------------------+
Jay> # elif (DBL_MANT_DIG == 1+64 \
Jay> && DBL_MIN_EXP == 1+-16382 \
Jay> && DBL_MAX_EXP == 1+16383)
Jay> # define HAVE_DOUBLE_SIZEOF 10
Jay> # elif (DBL_MANT_DIG == 1+112 \
Jay> && DBL_MIN_EXP == 1+-16382 \
Jay> && DBL_MAX_EXP == 1+16383)
Jay> # define HAVE_DOUBLE_SIZEOF 16
Jay> # else
Jay> # define HAVE_DOUBLE_SIZEOF 0
Jay> # endif
As there is no implied bit in the i387's 80-bit float; I suspect
that the DBL_MANT_DIG == 1+64 will never match.
Also -- and I've no idea whether this is relevant -- the 128 bit long
doubles used on IBM's mainframes (and perhaps elsewhere) are the sum
of two 64 bit doubles; they have more significant bits, but their
exponents are no larger than a double.
-JimC
--
James Cloos <cloos@jhcloos.com> OpenPGP: 1024D/ED7DAEA6
next prev parent reply other threads:[~2009-10-22 20:04 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-08 20:47 allow C-x v i / C-x v v to create a repository if none is available Dan Nicolaescu
2009-10-08 21:10 ` Chong Yidong
2009-10-09 19:18 ` Stefan Monnier
2009-10-09 19:32 ` Dan Nicolaescu
2009-10-13 18:40 ` Stefan Monnier
2009-10-13 15:59 ` Dan Nicolaescu
2009-10-21 19:06 ` Dan Nicolaescu
2009-10-23 7:45 ` Dan Nicolaescu
2009-10-23 13:12 ` Stefan Monnier
2009-10-24 2:34 ` Miles Bader
2009-10-24 6:35 ` Dan Nicolaescu
2009-10-22 18:56 ` Code for converting between Elisp and Calc floats Jay Belanger
2009-10-22 20:04 ` James Cloos [this message]
2009-10-23 0:50 ` Stefan Monnier
2009-10-24 20:03 ` Jay Belanger
2009-10-25 0:56 ` Stefan Monnier
2009-10-25 5:36 ` David Kastrup
2009-10-25 11:36 ` Vincent Belaïche
2009-10-25 14:11 ` Chong Yidong
2009-10-25 19:29 ` Vincent Belaïche
2009-10-26 2:30 ` Stefan Monnier
2009-10-26 12:48 ` Vincent Belaïche
2009-10-27 3:22 ` Stefan Monnier
2009-10-25 13:57 ` Stefan Monnier
2009-10-25 18:35 ` Eli Zaretskii
2009-10-26 2:02 ` Large files (was: Code for converting between Elisp and Calc floats) Stefan Monnier
2009-10-23 13:11 ` Code for converting between Elisp and Calc floats Richard Stallman
2009-10-23 13:26 ` David Kastrup
2009-10-24 17:34 ` Richard Stallman
-- strict thread matches above, loose matches on Subject: below --
2009-10-27 4:56 Vincent Belaïche
2009-10-27 6:16 ` Stefan Monnier
2009-10-27 19:38 ` Vincent Belaïche
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