*) Implement binary inversion algorithm for BN_mod_inverse in addition
to the algorithm using long divison. The binary algorithm can be
- used only if the modulus is odd. It is faster only for relatively
- small moduli (roughly 20% for 128-bit moduli, roughly 5% for 256-bit
- moduli), so we use it only for moduli up to 400 bits.
+ used only if the modulus is odd. On 32-bit systems, it is faster
+ only for relatively small moduli (roughly 20-30% for 128-bit moduli,
+ roughly 5-15% for 256-bit moduli), so we use it only for moduli
+ up to 450 bits. In 64-bit environments, the binary algorithm
+ appears to be advantageous for much longer moduli; here we use it
+ for moduli up to 2048 bits.
[Bodo Moeller]
*) Change bctest again: '-x' expressions are not available in all