[dpdk-dev] [PATCH v3 1/6] eal/arm: add 64-bit armv8 version of rte_memcpy.h

[Hunt, David]

On 02/11/2015 12:57, Jerin Jacob wrote:
> On Mon, Nov 02, 2015 at 12:22:47PM +0000, Hunt, David wrote:
>> Jerin,
>>     I've just benchmarked the libc version against the hand-coded version of
>> the memcpy routines, and the libc wins in most cases. This code was just an
>> initial attempt at optimising the memccpy's, so I feel that with the current
>> benchmark results, it would better just to remove the assembly versions, and
>> use the libc version for the initial release on ARMv8.
>> Then, in the future, the ARMv8 experts are free to submit an optimised
>> version as a patch in the future. Does that sound reasonable to you?
>
> Make sense. Based on my understanding, other blocks are also not optimized
> for arm64.
> So better to revert back to CONFIG_RTE_FORCE_INTRINSICS and
> libc for initial version.
>
> BTW: I just tested ./arm64-armv8a-linuxapp-gcc/app/test and
> "byteorder_autotest" is broken. I think existing arm64 code is not optimized
> beyond CONFIG_RTE_FORCE_INTRINSICS. So better to use verified
> CONFIG_RTE_FORCE_INTRINSICS scheme.

Agreed.

> if you guys are OK with arm and arm64 as two different platform then
> I can summit the complete working patch for arm64.(as in my current source
> code "arm64" is a different platform(lib/librte_eal/common/include/arch/arm64/)

Sure. That would be great. We initially started with two ARMv7 
patch-sets, and Jan merged into one. Something similar could happen for 
the ARMv8 patch set. We just want to end up with the best implementation 
possible. :)

Dave.