mpf exponent range
tg at gmplib.org
Tue Aug 23 07:26:20 CEST 2011
Zimmermann Paul <Paul.Zimmermann at loria.fr> writes:
> Do people on this list have any opinions about
> the exponent range, of mpf, in particular, if we should make input and
> output work for the entire allowed number range?
my opinion is yes. If input/output functions do not work for the entire
allowed number range, this should be documented, so that the user knows
what are the exact limits.
I agree that it should at least be documented.
By the way the documentation says:
The exponent of each float is a fixed precision, one machine word on
most systems. In the current implementation the exponent is a count of
limbs, so for example on a 32-bit system this means a range of roughly
2^-68719476768 to 2^68719476736, or on a 64-bit system this will be
It would be nice to make precise the bounds on a 64-bit system. I guess
the maximum is 2^(2^63*64), but what is the minimum?
I'd expect 2^-(63*64+64).
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