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

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Aug 8, 2009, 17:10 UTC
Message-ID: <alpine.LFD.2.01.0908081004560.3288@localhost.localdomain>
In-Reply-To: <4A7D0E7B.3030601@gmail.com>

On Sat, 8 Aug 2009, Artur Skawina wrote:

Show 5 quoted lines

> 
> I've inlined the byteswapping in 'opensslb', maybe that one will
> do a bit better.
> 
> http://www.src.multimo.pl/YDpqIo7Li27O0L0h/sha1bench.tar.gz

Hmm. Testing on my atom, the inlined bswap is worse, but the asm versions are generally superior to any C one:

	#             TIME[s] SPEED[MB/s]
	rfc3174         2.194       27.82
	rfc3174          2.19       27.87
	linus           0.947       64.45
	linusph        0.9381       65.06
	linusv         0.8943       68.25
	linusvph       0.8803       69.34
	linusasm       0.9349       65.29
	linusp4         1.006       60.66
	linusas         1.062       57.48
	linusas2        1.009        60.5
	mozilla         2.264       26.96
	mozillaas       2.197       27.78
	openssl         0.648       94.19
	opensslb       0.7419       82.27
	spelvin         0.636       95.96
	spelvina       0.6671       91.49
	nettle          0.717       85.12
	nettle-ror     0.7137       85.52
	nettle-p4sch   0.7158       85.27

Interestingly, -mtune=prescott does well for that 'linusv' version on atom too, and gets it up to

	linusv         0.8365       72.96

and it's the only one that improves. Odd interactions.

			Linus