Subject: Re: [boost] [Review Request] Multiprecision Arithmetic Library
From: Andrii Sydorchuk (sydorchuk.andriy_at_[hidden])
Date: 2012-04-03 05:05:39
> Just a crazy idea ... what about if the exponent is a big integer as
> well? And the mantissa ... guess you can go all crazy, hope this is
> supported by the library!
My main point against this idea would be that this might drop performance a
As far as I know GMP library also uses 64 bit exponent for floating-point
Is there any reason not to make the exponent type a template parameter so
> the user can chose arbittrarily instead of trying to anticipate future
> uses of
> the library?
I would suggest this to be a good solution. At least support of int32 and
int64 via template parameter would be vital.
Yeah -- the diameter of the observable universe (not the observed universe
> -- the physically observable universe) in Plank units (the smallest
> physically meaningful length according to QM) is about 1.5*2^204, so 9 bits
> (positive and negative exponents) is all that is required to express the
> exponent for any physical distance in any physically meaningful units.
I have some experience with implementing multiprecision geometric
At some point I needed to cast 2048 bit big integer to 64 bit double and
the problem is
that double is not capable to handle it. This is so far the only issue I
limitation of 11 bits exponent. Also we might consider the fact that
IEEE754 architecture for
128 bit double has 15 bit exponent the same as for the 80 bit double.
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