xref: /freebsd-10.1-release/crypto/openssl/crypto/bn/asm/README

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 2 versions of assember for the HP PA-RISC.
pa-risc.s is the origional one which works fine.
pa-risc2.s is a new version that often generates warnings but if the
tests pass, it gives performance that is over 2 times faster than
pa-risc.s.
Both were generated using gcc :-)