linux-kernel - Re: i686 quirk for AMD Geode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <40101cc30911061418w357b74d8i3bf9a9537de052d4@mail.gmail.com>
Date:	Fri, 6 Nov 2009 23:18:06 +0100
From:	Matteo Croce <technoboy85@...il.com>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Ingo Molnar <mingo@...e.hu>, linux-kernel@...r.kernel.org
Subject: Re: i686 quirk for AMD Geode

On Fri, Nov 6, 2009 at 5:44 PM, H. Peter Anvin <hpa@...or.com> wrote:
> On 11/06/2009 06:59 AM, Matteo Croce wrote:
>> indeed it has MMX, MMXEXT and CMOV, just lacks the long NOP instruction (NOPL).
>
> MMX and MMXEXT are hardly hallmarks of i686, which leaves only cmov.
> I'm somewhat wondering about the general value of this patch; is i686
> code really that much faster on Geode that it's worth it?
>
>        -hpa
>
> --
> H. Peter Anvin, Intel Open Source Technology Center
> I work for Intel.  I don't speak on their behalf.
>
>

yes, I did some test like gzip, bzip2, lame etc and they give more or less
the same results of dhrystone

root@...x:/usr/src# CFLAGS='-march=i586' ./dry.c
gcc -c -O3 -march=i586 ./dry.c -o dry1.o
gcc -DPASS2 -O3 -march=i586 ./dry.c dry1.o  -o dry2

Dhrystone Benchmark, Version C, Version 2.2
Program compiled without 'register' attribute
Using times(), HZ=100

Trying 5000000 runs through Dhrystone:
Microseconds for one run through Dhrystone:        1.4
Dhrystones per Second:                          740741

root@...x:/usr/src# CFLAGS='-march=i686' ./dry.c
gcc -c -O3 -march=i686 ./dry.c -o dry1.o
gcc -DPASS2 -O3 -march=i686 ./dry.c dry1.o  -o dry2

Dhrystone Benchmark, Version C, Version 2.2
Program compiled without 'register' attribute
Using times(), HZ=100

Trying 5000000 runs through Dhrystone:
Microseconds for one run through Dhrystone:        1.2
Dhrystones per Second:                          841751
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/