Re: [PATCH v2] ARM: Add Cortex-A15 optimized NEON and VFP memcpy routines, with IFUNC.

[Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>]

On 18 April 2013 13:55, Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> wrote:
> On 18 April 2013 13:24, Will Newton <will.newton@linaro.org> wrote:
>> Thanks for the offer, I don't have any armv6 hardware to test with.
>> The easiest way to test is probably using the cortex-strings package
>> (as the patch I posted is for armv7).
>>
>> https://launchpad.net/cortex-strings
>>
>> "try-this -t memcpy" will benchmark the code I submitted, "try-glibc
>> -t memcpy" will benchmark the current glibc code.
>
> OK, I'll try to do this tonight (i.e. ~8 hours from now) since the
> board is at home and I'm not.  I assume you want 'current glibc code'
> to be master?  The distribution version is 2.17 IIRC or at worst 2.16.

`try-this` crashes with a SIGILL:

Program received signal SIGILL, Illegal instruction.
memset () at src/linaro-a9/memset.S:64
64              cbz     r2, 10f         @ Exit if 0 length
(gdb) bt

I don't know much arm assembly, but digging around a bit I found that
cbz is implemented on armv6T2 or later and hence not available on my
board.  If you're interested in making this work on armv6 then I can
give this a shot - I've been meaning to start playing with arm
assembly anyway.

Siddhesh
--
http://siddhesh.in