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From: ark@alice.UUCP (Andrew Koenig)
Newsgroups: comp.lang.c
Subject: Re: IEEE floating point format
Message-ID: <9707@alice.UUCP>
Date: 29 Jul 89 22:51:27 GMT
References: <2170002@hpldsla.HP.COM> <9697@alice.UUCP> <1270@atanasoff.cs.iastate.edu>
Organization: AT&T Bell Laboratories, Liberty Corner NJ
Lines: 32

In article <1270@atanasoff.cs.iastate.edu>, hascall@atanasoff.cs.iastate.edu (John Hascall) writes:
> In article <9697@alice.UUCP> ark@alice.UUCP (Andrew Koenig) writes:
> >In article <2170002@hpldsla.HP.COM>, manoj@hpldsla.HP.COM (Manoj Joshi) writes:

> >> What is the format for the IEEE floating point storage

> >The format is:

> >	field		32-bit format		64-bit format

> >	sign			1			1
> >	exponent		8			12
> >	fraction		23			55
>                             ------                    -----
> 				32 (ok!)                68 (huh?)

>       Is it <1,8,55>, <1,12,51> or some other thing?
>       (or have they found a way for more hidden bits :-)

Oh well.  I meant 51 bits in double precision, plus a hidden bit.
Similarly, the 23 bits in single precision doesn't include the
hidden bit.  Therefore there are effectively 24 significant bits
in single precision and 52 in double precision.

The largest integer N such that N and N-1 can both be exactly
represented in single precision is (2^24)-1; the largest for
double precision is (2^52)-1.

I hope I got it right this time.
-- 
				--Andrew Koenig
				  ark@europa.att.com