All assember in this directory are just version of the file crypto/bn/bn_asm.c. Quite a few of these files are just the assember output from gcc since on quite a few machines they are 2 times faster than the system compiler. For the x86, I have hand written assember because of the bad job all compilers seem to do on it. This normally gives a 2 time speed up in the RSA routines. For the DEC alpha, I also hand wrote the assember (except the division which is just the output from the C compiler pasted on the end of the file). On the 2 alpha C compilers I had access to, it was not possible to do 64b x 64b -> 128b calculations (both long and the long long data types were 64 bits). So the hand assember gives access to the 128 bit result and a 2 times speedup :-). There are 3 versions of assember for the HP PA-RISC. pa-risc.s is the origional one which works fine and generated using gcc :-) pa-risc2W.s and pa-risc2.s are 64 and 32-bit PA-RISC 2.0 implementations by Chris Ruemmler from HP (with some help from the HP C compiler).