standards/130067: Wrong numeric limits in system headers?

[David Schultz]

The following reply was made to PR standards/130067; it has been noted by GNATS.

From: David Schultz <das at FreeBSD.ORG>
To: Bruce Evans <brde at optusnet.com.au>
Cc: Vaclav Haisman <v.haisman at sh.cvut.cz>, imp at FreeBSD.ORG,
        freebsd-gnats-submit at FreeBSD.ORG, freebsd-standards at FreeBSD.ORG
Subject: Re: standards/130067: Wrong numeric limits in system headers?
Date: Tue, 6 Jan 2009 14:03:13 -0500

 On FreeBSD/i386, long doubles are represented with 64 bits of
 precision, but computations are performed with 53 bits of
 precision. In a sane world, this discrepancy wouldn't exist, but
 for reasons I won't get into, they do, and probably always will.
 
 C99 defines the LDBL constants based on what can be represented,
 not what can be computed as the result of arithmetic operations,
 so my interpretation is that the values in float.h are correct,
 though confusing.