DPDK patches and discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Stephen Hemminger <stephen@networkplumber.org>
Subject: [dpdk-dev] [RFC 4/4] net/ether: use bitops to speedup comparison
Date: Wed, 15 May 2019 15:19:52 -0700	[thread overview]
Message-ID: <20190515221952.21959-5-stephen@networkplumber.org> (raw)
Message-ID: <20190515221952.KRFF7LTFXFWU-I4ptKUnbf3c0JzGkYcWOYaKdEAYFHc@z> (raw)
In-Reply-To: <20190515221952.21959-1-stephen@networkplumber.org>

Using bit operations like or and xor is faster than a loop
on all architectures. Really just explicit unrolling.

Similar cast to uint16 unaligned is already done in
other functions here.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/librte_net/rte_ether.h | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
index b94e64b2195e..5d9242cda230 100644
--- a/lib/librte_net/rte_ether.h
+++ b/lib/librte_net/rte_ether.h
@@ -78,11 +78,10 @@ struct ether_addr {
 static inline int is_same_ether_addr(const struct ether_addr *ea1,
 				     const struct ether_addr *ea2)
 {
-	int i;
-	for (i = 0; i < ETHER_ADDR_LEN; i++)
-		if (ea1->addr_bytes[i] != ea2->addr_bytes[i])
-			return 0;
-	return 1;
+	const unaligned_uint16_t *w1 = (const uint16_t *)ea1;
+	const unaligned_uint16_t *w2 = (const uint16_t *)ea2;
+
+	return ((w1[0] ^ w2[0]) | (w1[1] ^ w2[1]) | (w1[2] ^ w2[2])) == 0;
 }
 
 /**
@@ -97,11 +96,9 @@ static inline int is_same_ether_addr(const struct ether_addr *ea1,
  */
 static inline int is_zero_ether_addr(const struct ether_addr *ea)
 {
-	int i;
-	for (i = 0; i < ETHER_ADDR_LEN; i++)
-		if (ea->addr_bytes[i] != 0x00)
-			return 0;
-	return 1;
+	const unaligned_uint16_t *w = (const uint16_t *)ea;
+
+	return (w[0] | w[1] | w[2]) == 0;
 }
 
 /**
-- 
2.20.1


  parent reply	other threads:[~2019-05-15 22:20 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-15 22:19 [dpdk-dev] [RFC 0/4] net/ether: improvements Stephen Hemminger
2019-05-15 22:19 ` Stephen Hemminger
2019-05-15 22:19 ` [dpdk-dev] [RFC 1/4] net/ether: deinline non-critical functions Stephen Hemminger
2019-05-15 22:19   ` Stephen Hemminger
2019-05-16  7:10   ` David Marchand
2019-05-16  7:10     ` David Marchand
2019-05-15 22:19 ` [dpdk-dev] [RFC 2/4] net/ether: add eth_unformat_addr Stephen Hemminger
2019-05-15 22:19   ` Stephen Hemminger
2019-05-16  7:28   ` David Marchand
2019-05-16  7:28     ` David Marchand
2019-05-15 22:19 ` [dpdk-dev] [RFC 3/4] ethdev: use eth_unformat_addr Stephen Hemminger
2019-05-15 22:19   ` Stephen Hemminger
2019-05-16  7:32   ` David Marchand
2019-05-16  7:32     ` David Marchand
2019-05-16 10:19   ` Bruce Richardson
2019-05-16 10:19     ` Bruce Richardson
2019-05-15 22:19 ` Stephen Hemminger [this message]
2019-05-15 22:19   ` [dpdk-dev] [RFC 4/4] net/ether: use bitops to speedup comparison Stephen Hemminger
2019-05-16  9:03   ` Mattias Rönnblom
2019-05-16  9:03     ` Mattias Rönnblom
2019-05-16 15:32     ` Stephen Hemminger
2019-05-16 16:03   ` Bruce Richardson
2019-05-16 16:06     ` Stephen Hemminger
2019-05-16 16:07       ` Bruce Richardson
2019-05-16 16:36         ` Bruce Richardson
2019-05-16 17:04           ` Stephen Hemminger
2019-05-16 20:37             ` Bruce Richardson
2019-05-16 20:41               ` Bruce Richardson

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=20190515221952.21959-5-stephen@networkplumber.org \
    --to=stephen@networkplumber.org \
    --cc=dev@dpdk.org \
    /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).