Re: [PATCH 0/7] block-sha1: improved SHA1 hashing

From: Artur Skawina <art.08.09@gmail.com>
Date: Aug 8, 2009, 05:34 UTC
Message-ID: <4A7D0E7B.3030601@gmail.com>
In-Reply-To: <alpine.LFD.2.01.0908072107170.3288@localhost.localdomain>

Linus Torvalds wrote:

Show 25 quoted lines

> 
> I think I have found a way to avoid the gcc crazyness.
> 
> Lookie here:
> 
> 	#             TIME[s] SPEED[MB/s]
> 	rfc3174         5.094       119.8
> 	rfc3174         5.098       119.7
> 	linus           1.462       417.5
> 	linusas         2.008         304
> 	linusas2        1.878         325
> 	mozilla         5.566       109.6
> 	mozillaas       5.866       104.1
> 	openssl         1.609       379.3
> 	spelvin         1.675       364.5
> 	spelvina        1.601       381.3
> 	nettle          1.591       383.6
> 
> notice? I outperform all the hand-tuned asm on 32-bit too. By quite a 
> margin, in fact.
> 
> Now, I didn't try a P4, and it's possible that it won't do that there, but 
> the 32-bit code generation sure looks impressive on my Nehalem box. The 
> magic? I force the stores to the 512-bit hash bucket to be done in order. 
> That seems to help a lot.

I named it 'linusv':

P4/i686: # TIME[s] SPEED[MB/s] rfc3174 1.456 41.92 rfc3174 1.445 42.22 linus 0.5865 104.1 linusph 0.5643 108.2 linusv 0.3697 165.1 linusvph 0.3618 168.7 linusp4 0.4312 141.5 linusas 0.4091 149.2 linusas2 0.4364 139.9 mozilla 1.102 55.37 mozillaas 1.297 47.07 openssl 0.261 233.9 opensslb 0.2395 254.9 spelvin 0.2653 230 nettle 0.438 139.4

and when tuning for prescott:

linus 0.6544 93.27 linusph 0.6523 93.57 linusv 0.3439 177.5 linusvph 0.3547 172.1 linusp4 0.3585 170.3

so it isn't as fast as the openssl asm ones, but it does win in the C category.

> I outperform all the hand-tuned asm on 32-bit too. By quite a 
> margin, in fact.

I've inlined the byteswapping in 'opensslb', maybe that one will do a bit better.

http://www.src.multimo.pl/YDpqIo7Li27O0L0h/sha1bench.tar.gz

artur