[U-Boot] [PATCH] arm: Add armv6 and armv7 optimized swab functions

[Rob Herring]

Wolfgang,

On 12/17/2010 02:21 PM, Wolfgang Denk wrote:
> Dear Rob Herring,
>
> In message<1292425994-24331-1-git-send-email-robherring2 at gmail.com>  you wrote:
>> From: Rob Herring<rob.herring at 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 at 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