[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Linus' sha1 is much faster!
From: |
Giuseppe Scrivano |
Subject: |
Re: Linus' sha1 is much faster! |
Date: |
Mon, 17 Aug 2009 12:51:17 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.1.50 (gnu/linux) |
Pádraig Brady <address@hidden> writes:
> -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
> -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i586
> -mtune=generic -fasynchronous-unwind-tables -D_GNU_SOURCE=1
thanks. I did again all tests on my machine using these same options.
I repeated each test 6 times and I took the median without consider the
first result. Except the first run that it is not considered, I didn't
report a big variance on results of the same test.
gcc 4.3.3
gnulib sha1: real 0m2.543s
gnulib sha1 lookup: real 0m1.906s (-25%)
linus's sha1: real 0m2.468s (-3%)
linus's sha1 no asm: real 0m2.289s (-9%)
gcc 4.4.1
gnulib sha1: real 0m3.386s
gnulib sha1 lookup: real 0m3.110s (-8%)
linus's sha1: real 0m1.701s (-49%)
linus's sha1 no asm: real 0m1.284s (-62%)
I don't see such big differences in asm generated by gcc 4.4.1 and gcc
4.3.3 to explain this performance difference, what I noticed immediately
is that in the gcc-4.4 generated asm there are more "lea" instructions
(+30%), but I doubt this is the reason of these poor results. Anyway, I
haven't yet looked much in details.
Cheers,
Giuseppe
Re: Linus' sha1 is much faster!, Giuseppe Scrivano, 2009/08/16
Re: Linus' sha1 is much faster!, Pádraig Brady, 2009/08/16
Re: Linus' sha1 is much faster!, Giuseppe Scrivano, 2009/08/17