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From: Rob Herring <robherring2@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arm: Add armv6 and armv7 optimized swab functions
Date: Fri, 17 Dec 2010 14:52:49 -0600	[thread overview]
Message-ID: <4D0BCDA1.2000907@gmail.com> (raw)
In-Reply-To: <20101217202103.8351115192A@gemini.denx.de>

Wolfgang,

On 12/17/2010 02:21 PM, Wolfgang Denk wrote:
> Dear Rob Herring,
>
> In message<1292425994-24331-1-git-send-email-robherring2@gmail.com>  you wrote:
>> From: Rob Herring<rob.herring@calxeda.com>
>>
>> swab functions are heavily used by FDT code, so enable
>> optimized assembly code for ARMv6 and later.
>>
>> Signed-off-by: Rob Herring<rob.herring@calxeda.com>
>> ---
>>   arch/arm/include/asm/byteorder.h |   16 ++++++++++++++++
>>   1 files changed, 16 insertions(+), 0 deletions(-)
>
> Do you have any numbers if this changes gives any measurable
> improvement?

I have an instruction trace capture and see repeated calls to swab32 by 
the fdt code. It's an obvious low hanging fruit. The boot time for 
device tree vs. non-device tree is noticeably longer, but I don't have 
any formal measurements.

Rob

  reply	other threads:[~2010-12-17 20:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-15 15:13 [U-Boot] [PATCH] arm: Add armv6 and armv7 optimized swab functions Rob Herring
2010-12-17 20:21 ` Wolfgang Denk
2010-12-17 20:52   ` Rob Herring [this message]
2010-12-17 21:27 ` Måns Rullgård
2010-12-18 17:12   ` Rob Herring
2010-12-18 18:17     ` Måns Rullgård
2010-12-18 21:59     ` Wolfgang Denk

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