From: Jianbo Liu <Jianbo.Liu@arm.com>
To: Guduri Prathyusha <gprathyusha@caviumnetworks.com>
Cc: tomasz.kantecki@intel.com, jianbo.liu@linaro.org,
guduriprathyusha@gmail.com, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] examples/l3fwd: fix NEON instructions
Date: Mon, 30 Oct 2017 13:59:27 +0800 [thread overview]
Message-ID: <20171030055926.GA26823@arm.com> (raw)
In-Reply-To: <20171029074807.30785-1-gprathyusha@caviumnetworks.com>
The 10/29/2017 13:18, Guduri Prathyusha wrote:
> To group consecutive packets with same destination port in bursts of 4
> neon intrinsic data types dp1 and dp2 are calculated such that if
> dst_port[]={a,b,c,d,e,f,g,h,i...} dp1 should contain: <a,b,c,d> and
> dp2 should contain: <b,c,d,e> in the first iteration. dp1 should
> be <e,f,g,h> and dp2 should be <f,g,h,i> in the next iteration. dp2 in
> the last iteration should be <w,x,y,y>.
>
> Whereas the existing code incorrectly calculates dp1 as <d,e,f,g> from
> second iteration and thus incorrect calculation of dp2 as <d,e,f,f>
> in the last iteration.
>
> This patch fixes the incorrect ARM NEON instructions on dp1 and dp2.
>
> Fixes: 569b290cdb36 ("examples/l3fwd: add NEON implementation")
>
> Signed-off-by: Guduri Prathyusha <gprathyusha@caviumnetworks.com>
> ---
> examples/l3fwd/l3fwd_neon.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/examples/l3fwd/l3fwd_neon.h b/examples/l3fwd/l3fwd_neon.h
> index 42d50d3c2..1eace4e03 100644
> --- a/examples/l3fwd/l3fwd_neon.h
> +++ b/examples/l3fwd/l3fwd_neon.h
> @@ -192,13 +192,13 @@ send_packets_multi(struct lcore_conf *qconf, struct rte_mbuf **pkts_burst,
> * dp1:
> * <d[j], d[j+1], d[j+2], d[j+3], ... >
> */
> - dp1 = vextq_u16(dp1, dp1, FWDSTEP - 1);
> + dp1 = vextq_u16(dp2, vdupq_n_u16(0), FWDSTEP - 1);
Can you write it as "dp1 = vextq_u16(dp2, dp1, FWDSTEP - 1)"? It's my typo.
> }
>
> /*
> * dp2: <d[j-3], d[j-2], d[j-1], d[j-1], ... >
> */
> - dp2 = vextq_u16(dp1, dp1, 1);
> + dp2 = vextq_u16(dp1, vdupq_n_u16(0), 1);
Same as above.
> dp2 = vsetq_lane_u16(vgetq_lane_u16(dp2, 2), dp2, 3);
> lp = port_groupx4(&pnum[j - FWDSTEP], lp, dp1, dp2);
>
> --
> 2.14.1
>
--
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
next prev parent reply other threads:[~2017-10-30 6:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-29 7:48 Guduri Prathyusha
2017-10-29 8:24 ` Guduri Prathyusha
2017-10-30 5:59 ` Jianbo Liu [this message]
2017-10-30 6:27 ` Jianbo Liu
2017-10-30 7:14 ` Guduri Prathyusha
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171030055926.GA26823@arm.com \
--to=jianbo.liu@arm.com \
--cc=dev@dpdk.org \
--cc=gprathyusha@caviumnetworks.com \
--cc=guduriprathyusha@gmail.com \
--cc=jianbo.liu@linaro.org \
--cc=tomasz.kantecki@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).