using mpn_preinv_divrem_1

Torbjorn Granlund tege at
Thu Sep 1 11:44:01 CEST 2005

Ashod Nakashian <saghmos at> writes:

  I've been reading the mpf_div_ui() code and was surprised to find out 
  that even though tune was enabling preinv division, the code was NOT 
  using the mpn_preinv_divrem_1 function.
It doesn't, since a precomputed value is not available.

In mpn_get_str, the divisors are invariant, which allows us to
table preinverted divisors.  That is what mpn_preinv_divrem_1 is
designed for.

In other cases, mpn_divrem_1 computes the inverse on-the-fly (for
machines where that helps).


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