Number of significand bits in long double?

Steve Kargl sgk at troutmask.apl.washington.edu
Thu Aug 4 17:10:33 GMT 2005


On Thu, Aug 04, 2005 at 10:08:14AM -0700, Bakul Shah wrote:
> > PROPERTIES OF LONG DOUBLE
> > Base = 2
> > Significant base digits = 53 (= at least 15 decimal digits)
> 
> $ cat x.c
> #include <machine/float.h>
> static double x = DBL_MAX;
> static long double min = LDBL_MIN;
> static long double max = LDBL_MAX;

> So this indicates long double is 15 bits of exponent, 64 bits of mantissa.

No. It has 15 bits for the exponent and uses only 53 bits
for the significand on i386.

-- 
Steve


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