[dpdk-dev] [PATCH] hash: replace libc memcmp with optimized memory compare functions for arm64

Jerin Jacob jerin.jacob at caviumnetworks.com
Thu Nov 19 14:51:15 CET 2015


The following measurements shows improvement over the default
libc memcmp function

Length(B) by X% over libc memcmp
  16	  149.57%
  32	  122.7%
  48	  104.96%
  64	  98.21%
  80	  93.75%
  96	  90.55%
 112	  110.48%
 128	  137.24%

Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
---
 lib/librte_hash/rte_cmp_arm64.h   | 114 ++++++++++++++++++++++++++++++++++++++
 lib/librte_hash/rte_cuckoo_hash.c |   7 ++-
 2 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 lib/librte_hash/rte_cmp_arm64.h

diff --git a/lib/librte_hash/rte_cmp_arm64.h b/lib/librte_hash/rte_cmp_arm64.h
new file mode 100644
index 0000000..6fd937b
--- /dev/null
+++ b/lib/librte_hash/rte_cmp_arm64.h
@@ -0,0 +1,114 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Cavium networks. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Cavium networks nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* Functions to compare multiple of 16 byte keys (up to 128 bytes) */
+static int
+rte_hash_k16_cmp_eq(const void *key1, const void *key2,
+		    size_t key_len __rte_unused)
+{
+	uint64_t x0, x1, y0, y1;
+
+	asm volatile(
+		"ldp %x[x1], %x[x0], [%x[p1]]"
+		: [x1]"=r"(x1), [x0]"=r"(x0)
+		: [p1]"r"(key1)
+		);
+	asm volatile(
+		"ldp %x[y1], %x[y0], [%x[p2]]"
+		: [y1]"=r"(y1), [y0]"=r"(y0)
+		: [p2]"r"(key2)
+		);
+	x0 ^= y0;
+	x1 ^= y1;
+	return !(x0 == 0 && x1 == 0);
+}
+
+static int
+rte_hash_k32_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k16_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k16_cmp_eq((const char *) key1 + 16,
+				(const char *) key2 + 16, key_len);
+}
+
+static int
+rte_hash_k48_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k16_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k16_cmp_eq((const char *) key1 + 16,
+				(const char *) key2 + 16, key_len) ||
+		rte_hash_k16_cmp_eq((const char *) key1 + 32,
+				(const char *) key2 + 32, key_len);
+}
+
+static int
+rte_hash_k64_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k32_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k32_cmp_eq((const char *) key1 + 32,
+				(const char *) key2 + 32, key_len);
+}
+
+static int
+rte_hash_k80_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k64_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k16_cmp_eq((const char *) key1 + 64,
+				(const char *) key2 + 64, key_len);
+}
+
+static int
+rte_hash_k96_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k64_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k32_cmp_eq((const char *) key1 + 64,
+				(const char *) key2 + 64, key_len);
+}
+
+static int
+rte_hash_k112_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k64_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k32_cmp_eq((const char *) key1 + 64,
+				(const char *) key2 + 64, key_len) ||
+		rte_hash_k16_cmp_eq((const char *) key1 + 96,
+				(const char *) key2 + 96, key_len);
+}
+
+static int
+rte_hash_k128_cmp_eq(const void *key1, const void *key2, size_t key_len)
+{
+	return rte_hash_k64_cmp_eq(key1, key2, key_len) ||
+		rte_hash_k64_cmp_eq((const char *) key1 + 64,
+				(const char *) key2 + 64, key_len);
+}
diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 1e970de..e6520dd 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -63,6 +63,10 @@
 #include "rte_cmp_x86.h"
 #endif
 
+#if defined(RTE_ARCH_ARM64)
+#include "rte_cmp_arm64.h"
+#endif
+
 TAILQ_HEAD(rte_hash_list, rte_tailq_entry);
 
 static struct rte_tailq_elem rte_hash_tailq = {
@@ -280,7 +284,8 @@ rte_hash_create(const struct rte_hash_parameters *params)
  * If x86 architecture is used, select appropriate compare function,
  * which may use x86 instrinsics, otherwise use memcmp
  */
-#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) || defined(RTE_ARCH_X86_X32)
+#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) ||\
+	 defined(RTE_ARCH_X86_X32) || defined(RTE_ARCH_ARM64)
 	/* Select function to compare keys */
 	switch (params->key_len) {
 	case 16:
-- 
2.1.0



More information about the dev mailing list