[PATCH] ARM: Add Cortex-A15 optimized NEON and VFP memcpy routines, with IFUNC.

Will Newton will.newton@linaro.org
Mon Apr 15 10:49:00 GMT 2013


On 15 April 2013 11:45, Måns Rullgård <mans@mansr.com> wrote:
> Will Newton <will.newton@linaro.org> writes:
>
>> On 15 April 2013 11:06, Måns Rullgård <mans@mansr.com> wrote:
>>
>> Hi Måns,
>>
>>>> Add a high performance memcpy routine optimized for Cortex-A15 with
>>>> variants for use in the presence of NEON and VFP hardware, selected
>>>> at runtime using indirect function support.
>>>
>>> How does this perform on Cortex-A9?
>>
>> The code is also faster on A9 although the gains are not quite as
>> pronounced.
>
> That should be expected.  As long as it's not slower, it's all well.
>
> Out of interest, did you compare this memcpy to any other NEON versions
> floating about, such as the one in bionic?

It's been tested against all the versions of memcpy in the
cortex-strings package on launchpad, which includes a version from
bionic, although I don't believe it uses NEON. AFAIK the latest code
in bionic for A15 is an ARM Ltd. copyright version similar to the one
in newlib, which this code is faster than in almost all cases.

--
Will Newton
Toolchain Working Group, Linaro



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