bodrato at mail.dm.unipi.it writes: No, according to a comment in gmp-impl.h about MPN_COPY_DECR /* Copy N limbs from SRC to DST decrementing, N==0 allowed. */ Silly me...and that explains the com_n.asm therein; it was made from copyi.asm. (Most of my copyi.asm patch is OK, though. I just need to move the L(1) label a bit.) -- Torbjörn Please encrypt, key id 0xC8601622