From: <ams AT ludd DOT luth DOT se>
Message-Id: <200304171703.h3HH307q016727@speedy.ludd.luth.se>
Subject: Long double confusion
To: DJGPP-WORKERS <djgpp-workers AT delorie DOT com>
Date: Thu, 17 Apr 2003 19:03:00 +0200 (CEST)
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Reply-To: djgpp-workers AT delorie DOT com

Hello.

I've been hacking on _isnanf(), _isnand() and _isnanld() (to be able
to support the C99 isnan macro).

My readings on the net doesn't show what a long double with it
exponent set to 0x7fff and a _cleared_ most significant bit in the
mantissa is. The most significant bit for a long double is the
integer bit (which isn't present in floats or doubles).

As far as I understand a long double with exponent == 0 and with
the most significant bit in the mantissa cleared is a denormal (which
isn't a NaN but a value close to 0).

But I don't know what to make of it when exponent != 0.

Are they all NaNs? Only the ones with exponent == 0x7fff? Or none of
them?

Any help?


Right,

						MartinS