Date:	Sat, 12 May 2001 08:42:44 +0300
From:	"Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Sender:	halo1 AT zahav DOT net DOT il
To:	Dennis Yelle <dennis51 AT jps DOT net>
Message-Id:	<2110-Sat12May2001084244+0300-eliz@is.elta.co.il>
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CC:	djgpp AT delorie DOT com
In-reply-to:	<3AFC71C1.D3CDF864@jps.net> (message from Dennis Yelle on Fri, 11
	May 2001 16:12:01 -0700)
Subject:	Re: cout ignores the last 11 bits of long double
References:	<3AFC71C1 DOT D3CDF864 AT jps DOT net>
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> From: Dennis Yelle <dennis51 AT jps DOT net>
> Newsgroups: comp.os.msdos.djgpp
> Date: Fri, 11 May 2001 16:12:01 -0700
> 
> i: 51:
> hex:    3fffb89ba24891f7b800
> cout:   1.4422495703074085238171164746745489537716
> printf: 1.4422495703074085238171164746745489537720
> 
> i: 52:
> hex:    3fffb89ba24891f7b400
> cout:   1.4422495703074083017725115496432408690453
> printf: 1.4422495703074084127948140121588949114080
> -------------------------^^^^^^^^^^^^^^^^^^^^^^^^^
> i: 53:
> hex:    3fffb89ba24891f7b600
> cout:   1.4422495703074085238171164746745489537716
> printf: 1.4422495703074084683059652434167219325900
> -------------------------^^^^^^^^^^^^^^^^^^^^^^^^^
> i: 54:
> hex:    3fffb89ba24891f7b500
> cout:   1.4422495703074085238171164746745489537716
> printf: 1.4422495703074084405503896277878084219990
> -------------------------^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> Notice that the cout result for i: 53 is the same
> as for i: 51, but the printf result is different.
> 
> It looks like cout operator<< ignores the last 11 bits of a 
> long double.

I'm guessing that cout somehow converts the argument to double
internally, which gives only about 16.5 digits of precision.

Anyway, bugs in libtsdc++ should be posted elsewhere.  DJGPP doesn't
maintain that library, only ports it.

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