Re: Making 'eq' == 'eql' in bignum branch

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Sat, 28 Jul 2018 20:34:32 -0700
> 
> How about if we do to floats what fixnum+bignum would do to integers?
> 
> That is, on a 64-bit host, if the low-order 4 bits of the significand are all 
> zero, we encode the floating-point number directly in the Lisp_Object (with a 
> tag) so that the Lisp_Object need not be dereferenced and uses zero bytes of 
> floating-point heap. Otherwise, we put the floating-point value into a 
> special 
> hash-consed table that should use about 16 bytes per entry (one for the 
> double, 
> one for the pointer to it).

How likely is it to see a floating-point number with 4 low-order bits
of mantissa zero?