From: "Hunt, David" <david.hunt@intel.com>
To: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 1/6] eal/arm: add 64-bit armv8 version of rte_memcpy.h
Date: Mon, 2 Nov 2015 12:22:47 +0000 [thread overview]
Message-ID: <56375597.8070805@intel.com> (raw)
In-Reply-To: <20151102045728.GB16413@localhost.localdomain>
On 02/11/2015 04:57, Jerin Jacob wrote:
> On Fri, Oct 30, 2015 at 01:49:14PM +0000, David Hunt wrote:
>> Signed-off-by: David Hunt <david.hunt@intel.com>
--snip--
>> +#ifndef _RTE_MEMCPY_ARM_64_H_
>> +#define _RTE_MEMCPY_ARM_64_H_
>> +
>> +#include <stdint.h>
>> +#include <string.h>
>> +
>> +#ifdef __cplusplus
>> +extern "C" {
>> +#endif
>> +
>> +#include "generic/rte_memcpy.h"
>> +
>> +#ifdef __ARM_NEON_FP
>
> SIMD is not optional in armv8 spec.So every armv8 machine will have
> SIMD instruction unlike armv7.More over LDP/STP instruction is
> not part of SIMD.So this check is not required or it can
> be replaced with a check that select memcpy from either libc or this specific
> implementation
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?
Rgds,
Dave.
--snip--
next prev parent reply other threads:[~2015-11-02 12:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-30 13:49 [dpdk-dev] [PATCH v3 0/6] ARMv8 additions to ARMv7 support David Hunt
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 1/6] eal/arm: add 64-bit armv8 version of rte_memcpy.h David Hunt
2015-11-02 4:57 ` Jerin Jacob
2015-11-02 12:22 ` Hunt, David [this message]
2015-11-02 12:45 ` Jan Viktorin
2015-11-02 12:57 ` Jerin Jacob
2015-11-02 15:26 ` Hunt, David
2015-11-02 15:36 ` Jan Viktorin
2015-11-02 15:49 ` Hunt, David
2015-11-02 16:29 ` Jerin Jacob
2015-11-02 17:29 ` Jan Viktorin
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 2/6] eal/arm: add 64-bit armv8 version of rte_prefetch.h David Hunt
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 3/6] eal/arm: add 64-bit armv8 version of rte_cycles.h David Hunt
2015-11-02 5:15 ` Jerin Jacob
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 4/6] eal/arm: fix 64-bit armv8 compilation of rte_cpuflags.h David Hunt
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 5/6] mk: add support for armv8 on top of armv7 David Hunt
2015-11-02 4:43 ` Jerin Jacob
2015-10-30 13:49 ` [dpdk-dev] [PATCH v3 6/6] test: add checks for cpu flags on armv8 David Hunt
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