From: Arnd Bergmann <arnd@arndb.de>
To: "Jörn Engel" <joern@logfs.org>
Cc: Chris Simmonds <chris@2net.co.uk>,
Marco <marco.stornelli@gmail.com>,
Sam Ravnborg <sam@ravnborg.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Linux Embedded <linux-embedded@vger.kernel.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/14] Pramfs: Include files
Date: Tue, 23 Jun 2009 01:07:42 +0200 [thread overview]
Message-ID: <200906230107.43667.arnd@arndb.de> (raw)
In-Reply-To: <20090622214155.GA19332@logfs.org>
On Monday 22 June 2009, Jörn Engel wrote:
> Four loops doing the same increment with different data types: long,
> u64, we32 (wrong-endian) and we64. Compile with no optimizations.
>
> Results on my i386 notebook:
> long: 453953 us
> we32: 880273 us
> u64: 504214 us
> we64: 2259953 us
> loops: 100000000
(couldn't resist)
The we64 number is artificially high because the glibc bswap_64
implementation forces the conversion to be done on the stack.
Using __builtin_bswap64 make this look more logical, and
makes your point even stronger (on core 2, using -m32):
long: 236792 us
we32: 500827 us
u64: 265990 us
we64: 757380 us
loops: 100000000
Arnd <><
next prev parent reply other threads:[~2009-06-22 23:08 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-13 13:21 [PATCH 06/14] Pramfs: Include files Marco
2009-06-13 14:04 ` Sam Ravnborg
2009-06-13 22:59 ` Arnd Bergmann
2009-06-14 7:15 ` Marco
2009-06-21 17:07 ` Marco
2009-06-21 20:22 ` Arnd Bergmann
2009-06-22 6:23 ` Marco Stornelli
2009-06-22 11:17 ` Arnd Bergmann
2009-06-22 18:05 ` Marco
2009-06-22 18:33 ` Arnd Bergmann
2009-06-22 19:31 ` Chris Simmonds
2009-06-22 20:30 ` Sam Ravnborg
2009-06-22 22:00 ` Tim Bird
2009-06-23 4:21 ` Sam Ravnborg
2009-06-23 17:38 ` Marco
2009-06-23 19:26 ` Jörn Engel
2009-06-23 21:15 ` David Woodhouse
2009-06-23 21:55 ` Arnd Bergmann
2009-06-24 6:32 ` Marco Stornelli
2009-06-24 15:30 ` Arnd Bergmann
2009-06-24 16:49 ` Marco
2009-06-22 21:41 ` Jörn Engel
2009-06-22 22:20 ` David Woodhouse
2009-06-23 5:57 ` Jörn Engel
2009-06-23 8:31 ` David Woodhouse
2009-06-22 23:07 ` Arnd Bergmann [this message]
2009-06-23 6:40 ` Marco Stornelli
2009-06-14 7:15 ` Marco
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