Article View: comp.std.c
Article #4592Re: sizeof(1L) in preprocesor;How to tell sizeof(double)>sizeof(long) ?
From: Nick Maclaren
Date: Tue, 09 Jan 1996 11:39
Date: Tue, 09 Jan 1996 11:39
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1679 bytes
1679 bytes
In article <tuent98zl4.fsf@nemo.bedford.waii.com>, gsez020@nemo.bedford.waii.com (Pete Forman) writes: |> >>>>> "Andreas" == Andreas Schwab <schwab@lamothe.informatik.uni-dortmund.de> writes: |> >>>>> "Mark" == Mark Brader <msb@sq.com> writes: |> |> Mark> #if LONG_MAX * DBL_EPSILON > 1 |> |> Andreas> This doesn't work as floating point numbers aren't |> Andreas> allowed in #if expressions. |> |> Try changing to something like |> |> #if LONG_MAX >> DBL_MANT_DIG > 1 Don't bother - the 'constants' in <float.h> aren't! This is a specific exclusion to make life easier for systems with separate floating-point processors, and makes <float.h> almost useless for numerical analysts. I tried to get this imbecility (and it IS an imbecility) fixed, but I failed. So any portable library of mathematical functions has to define its own system-dependent constants, and can use <float.h> only for comparison :-( Nick Maclaren, University of Cambridge Computer Laboratory, New Museums Site, Pembroke Street, Cambridge CB2 3QG, England. Email: nmm1@cam.ac.uk Tel.: +44 1223 334761 Fax: +44 1223 334679
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Path: arc1-ca.pugleaf.net!lyra.csx.cam.ac.uk!nmm1 From: nmm1@cus.cam.ac.uk (Nick Maclaren) Newsgroups: comp.std.c Subject: Re: sizeof(1L) in preprocesor;How to tell sizeof(double)>sizeof(long) ? Date: 9 Jan 1996 11:39:50 GMT Organization: University of Cambridge, England Message-ID: <4ctk66$57j@lyra.csx.cam.ac.uk> References: <sc3f9vb6gk.fsf@lns101.lns.cornell.edu> <1996Jan5.094122.16151@sq.com> <vyzd98ug7w4.fsf@lamothe.informatik.uni-dortmund.de> <tuent98zl4.fsf@nemo.bedford.waii.com> NNTP-Posting-Host: ursa.cus.cam.ac.uk