change limb size

Torbjorn Granlund tg at
Mon Jun 7 17:45:14 CEST 2004

Olivier Ruatta <Olivier.Ruatta at> writes:

  I want to change the size of the limb of natural numbers representation. I
  use the code above and nothing change. Does someone can explain me what I
  misunderstoud ?

A whole lot, I am afraid.

The limb size is compiled into the library, and is determined from
the available types of tghe processor and the host environment.
Trying to change it by overriding our mp_bits_per_limb variable
name, does not somehow cause the library to be recompiled.  C
doesn't work like that.

You cannot arbitrarily change the limb size even by recompiling
the library.  For a few machines, you can choose between a 32-bit
and a 64-bit ABI, and for a few of these, that means changing the
limb size as well.  There is more about that in the manual, but I
doubt it is relevant to what you want to do.

Hope this helps.


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