have impact on performance, because amount of multiplications does not
increase with this switch, not on sparcv9 that is. On the contrary, it
actually improves performance, because it spares a load of instructions
used to chase carries. Not to mention that BN assembler modules can be
shared more freely between 32- and 64-bit builts.

Submitted by: Douglas Stebila

space, but gives total flexibility [back].

made...