On Thu, 6 Aug 2009, Artur Skawina wrote: > > For those curious just how close the C version is to the various > asm and C implementations, the q&d microbenchmark is at > http://www.src.multimo.pl/YDpqIo7Li27O0L0h/sha1bench.tar.gz Hmm. That thing doesn't work at all on x86-64. Even apart from the asm sources, your timing thing does soem really odd things (why do you do that odd "iret" in GETCYCLES and GETTIME?). You're better off using lfence/mfence/cpuid, and I think you could make it work on 64-bit that way too. I just hacked it away for testing. > In short: 88% of openssl speed on P3, 42% on P4, 66% on Atom. I'll use this to see if I can improve the 32-bit case. On Nehalem, with your benchmark, I get: # TIME[s] SPEED[MB/s] rfc3174 5.122 119.2 # New hash result: d829b9e028e64840094ab6702f9acdf11bec3937 rfc3174 5.153 118.5 linus 2.092 291.8 linusas 2.056 296.8 linusas2 1.909 319.8 mozilla 5.139 118.8 mozillaas 5.775 105.7 openssl 1.627 375.1 spelvin 1.678 363.7 spelvina 1.603 380.8 nettle 1.592 383.4 And with the hacked version to get some 64-bit numbers: # TIME[s] SPEED[MB/s] rfc3174 3.992 152.9 # New hash result: b78fd74c0033a4dfe0ededccb85ab00cb56880ab rfc3174 3.991 152.9 linus 1.54 396.3 linusas 1.533 398.1 linusas2 1.603 380.9 mozilla 4.352 140.3 mozillaas 4.227 144.4 so as you can see, your improvements in 32-bit mode are actually de-provements in 64-bit mode (ok, your first one seems to be a tiny improvement, but I think it's in the noise). But you're right, I need to try to improve the 32-bit case. Linus -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html