From owner-freebsd-current  Thu Oct 31  0:51:15 2002
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Date: Thu, 31 Oct 2002 20:02:19 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: Terry Lambert <tlambert2@mindspring.com>
Cc: "M. Warner Losh" <imp@bsdimp.com>, <rittle@labs.mot.com>,
	<rittle@latour.rsch.comm.mot.com>, <current@FreeBSD.ORG>,
	<dschultz@uclink.Berkeley.EDU>
Subject: Re: Lack of real long double support
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On Wed, 30 Oct 2002, Terry Lambert wrote:

> This is the basis of Bruce's complaint:
>
> http://docs.freebsd.org/cgi/getmsg.cgi?fetch=1099099+0+archive/2002/freebsd-current/20021027.freebsd-current
>
> | gcc can't actually support the full range, since it doesn't control
> | the runtime environement (it could issue a fninit before main() to
> | change the default, but it shouldn't and doesn't).  The exponent
> | range is lost long before printf() is reached.  E.g.,
> |
> |         long double x= DBL_MAX;
> |         long double y = 2 * x;
> |
> | gives +Inf for y since the result is doesn't fit in 53-bit precision.
> | The system header correctly reports this default precision.  Any header
> | genrated by the gcc build should be no different, since the build should
> | run in the target environment.

Please forget this wrong example :-).  The precision doesn't affect the
exponent range.

Bruce


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