[thirdparty/openssl.git] / 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 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).
Commit	Line	Data
d02b48c6	1	All assember in this directory are just version of the file
775c63fc	2	crypto/bn/bn_asm.c.
d02b48c6 RE	3
	4	Quite a few of these files are just the assember output from gcc since on
	5	quite a few machines they are 2 times faster than the system compiler.
	6
	7	For the x86, I have hand written assember because of the bad job all
	8	compilers seem to do on it. This normally gives a 2 time speed up in the RSA
	9	routines.
	10
	11	For the DEC alpha, I also hand wrote the assember (except the division which
	12	is just the output from the C compiler pasted on the end of the file).
	13	On the 2 alpha C compilers I had access to, it was not possible to do
	14	64b x 64b -> 128b calculations (both long and the long long data types
	15	were 64 bits). So the hand assember gives access to the 128 bit result and
	16	a 2 times speedup :-).
	17
d0c2ebf4 RL	18	There are 3 versions of assember for the HP PA-RISC.
	19
	20	pa-risc.s is the origional one which works fine and generated using gcc :-)
	21
	22	pa-risc2W.s and pa-risc2.s are 64 and 32-bit PA-RISC 2.0 implementations
	23	by Chris Ruemmler from HP (with some help from the HP C compiler).