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

Jan Viktorin viktorin at rehivetech.com
Mon Nov 2 16:36:27 CET 2015


On Mon, 2 Nov 2015 15:26:19 +0000
"Hunt, David" <david.hunt at intel.com> wrote:

> 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. :)
> 

It was looking like we can share a lot of common code for both
architectures. I didn't know how much different are the cpuflags.

IMHO, it'd be better to have two directories arm and arm64. I thought
to refer from arm64 to arm where possible. But I don't know whether is
this possible with the DPDK build system.

Jan

> Dave.
> 
> 
> 
> 



-- 
   Jan Viktorin                  E-mail: Viktorin at RehiveTech.com
   System Architect              Web:    www.RehiveTech.com
   RehiveTech
   Brno, Czech Republic


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