mpf_t precision problem?

Torbjorn Granlund tg at
Mon Mar 22 19:55:02 CET 2010

Randall <randallrathbun at> writes:

  The problem with the gmp++ class mpf_class appears to be down inside
  the mpf_t itself.  I wrote a pure C program, but it is exhibiting the
  exact same problems, perhaps worse.
You ask for 220 bits of precision, corresponding to about 66 decimal
digits.  GMP rounds the requested precision to a full word (aka limb),
meaning that you get 256 bits of precision, about 77 decimal digits.

The print statement for reciprocal is incorrect.

No GMP bug.


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