From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 8887DC346 for ; Wed, 10 Jun 2015 17:26:02 +0200 (CEST) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP; 10 Jun 2015 08:25:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,588,1427785200"; d="scan'208";a="585439582" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga003.jf.intel.com with ESMTP; 10 Jun 2015 08:25:35 -0700 Received: from sivswdev02.ir.intel.com (sivswdev02.ir.intel.com [10.237.217.46]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id t5AFPS8Y024234; Wed, 10 Jun 2015 16:25:28 +0100 Received: from sivswdev02.ir.intel.com (localhost [127.0.0.1]) by sivswdev02.ir.intel.com with ESMTP id t5AFPScw014846; Wed, 10 Jun 2015 16:25:28 +0100 Received: (from pdelarax@localhost) by sivswdev02.ir.intel.com with id t5AFPSQb014841; Wed, 10 Jun 2015 16:25:28 +0100 From: Pablo de Lara To: dev@dpdk.org Date: Wed, 10 Jun 2015 16:25:23 +0100 Message-Id: <1433949927-14767-7-git-send-email-pablo.de.lara.guarch@intel.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1433949927-14767-1-git-send-email-pablo.de.lara.guarch@intel.com> References: <1432289771-12799-1-git-send-email-pablo.de.lara.guarch@intel.com> <1433949927-14767-1-git-send-email-pablo.de.lara.guarch@intel.com> Subject: [dpdk-dev] [PATCH v6 06/10] hash: update jhash function with the latest available X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Jun 2015 15:26:03 -0000 Jenkins hash function was developed originally in 1996, and was integrated in first versions of DPDK. The function has been improved in 2006, achieving up to 35% better performance, compared to the original one. This patch integrates that code into the rte_jhash library. It also updates the precalculated hash values in the unit test, as the code now returns different values (expected). A final note has been added in release notes for stating the changes made. Signed-off-by: Pablo de Lara --- app/test/test_hash_functions.c | 12 +- doc/guides/rel_notes/new_features.rst | 5 + lib/librte_hash/rte_jhash.h | 269 +++++++++++++++++++++++++--------- 3 files changed, 207 insertions(+), 79 deletions(-) diff --git a/app/test/test_hash_functions.c b/app/test/test_hash_functions.c index fcc9d05..c6cdccf 100644 --- a/app/test/test_hash_functions.c +++ b/app/test/test_hash_functions.c @@ -55,14 +55,14 @@ * key size = 8, key = 0x0706050403020100 */ static uint32_t hash_values_jhash[2][10] = {{ - 0x821cc2db, 0xa491f494, 0xace4cd87, 0x9e867842, - 0xd32442d6, 0x5fbafeab, 0x9cac434c, 0xecad9b0d, - 0x2dcf235e, 0xaab655d0 + 0xe4cf1d42, 0xd4ccb93c, 0x5e84eafc, 0x21362cfe, + 0x2f4775ab, 0x9ff036cc, 0xeca51474, 0xbc9d6816, + 0x12926a31, 0x1c9fa888 }, { - 0xc1111b14, 0x9a95039e, 0x84f208a0, 0xfa28f3fb, - 0xfa13f7d3, 0xc7aed470, 0x74caa938, 0xa9288066, - 0xd0140735, 0xbf00519d + 0x8270ac65, 0x05fa6668, 0x762df861, 0xda088f2f, + 0x59614cd4, 0x7a94f690, 0xdc1e4993, 0x30825494, + 0x91d0e462, 0x768087fc } }; static uint32_t hash_values_crc[2][10] = {{ diff --git a/doc/guides/rel_notes/new_features.rst b/doc/guides/rel_notes/new_features.rst index 4b4974d..5b724ab 100644 --- a/doc/guides/rel_notes/new_features.rst +++ b/doc/guides/rel_notes/new_features.rst @@ -121,4 +121,9 @@ New Features * Job Stats library and Sample Application. +* Enhanced Jenkins hash (jhash) library + +.. note:: The hash values returned by the new jhash library are different + from the ones returned by the previous library. + For further features supported in this release, see Chapter 3 Supported Features. diff --git a/lib/librte_hash/rte_jhash.h b/lib/librte_hash/rte_jhash.h index a4bf5a1..1cb5c44 100644 --- a/lib/librte_hash/rte_jhash.h +++ b/lib/librte_hash/rte_jhash.h @@ -1,7 +1,7 @@ /*- * BSD LICENSE * - * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + * Copyright(c) 2010-2015 Intel Corporation. All rights reserved. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -45,38 +45,62 @@ extern "C" { #endif #include +#include +#include /* jhash.h: Jenkins hash support. * - * Copyright (C) 1996 Bob Jenkins (bob_jenkins@burtleburtle.net) + * Copyright (C) 2006 Bob Jenkins (bob_jenkins@burtleburtle.net) * * http://burtleburtle.net/bob/hash/ * * These are the credits from Bob's sources: * - * lookup2.c, by Bob Jenkins, December 1996, Public Domain. - * hash(), hash2(), hash3, and mix() are externally useful functions. - * Routines to test the hash are included if SELF_TEST is defined. - * You can use this free for any purpose. It has no warranty. + * lookup3.c, by Bob Jenkins, May 2006, Public Domain. + * + * These are functions for producing 32-bit hashes for hash table lookup. + * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() + * are externally useful functions. Routines to test the hash are included + * if SELF_TEST is defined. You can use this free for any purpose. It's in + * the public domain. It has no warranty. * * $FreeBSD$ */ +#define rot(x, k) (((x) << (k)) | ((x) >> (32-(k)))) + /** @internal Internal function. NOTE: Arguments are modified. */ #define __rte_jhash_mix(a, b, c) do { \ - a -= b; a -= c; a ^= (c>>13); \ - b -= c; b -= a; b ^= (a<<8); \ - c -= a; c -= b; c ^= (b>>13); \ - a -= b; a -= c; a ^= (c>>12); \ - b -= c; b -= a; b ^= (a<<16); \ - c -= a; c -= b; c ^= (b>>5); \ - a -= b; a -= c; a ^= (c>>3); \ - b -= c; b -= a; b ^= (a<<10); \ - c -= a; c -= b; c ^= (b>>15); \ + a -= c; a ^= rot(c, 4); c += b; \ + b -= a; b ^= rot(a, 6); a += c; \ + c -= b; c ^= rot(b, 8); b += a; \ + a -= c; a ^= rot(c, 16); c += b; \ + b -= a; b ^= rot(a, 19); a += c; \ + c -= b; c ^= rot(b, 4); b += a; \ +} while (0) + +#define __rte_jhash_final(a, b, c) do { \ + c ^= b; c -= rot(b, 14); \ + a ^= c; a -= rot(c, 11); \ + b ^= a; b -= rot(a, 25); \ + c ^= b; c -= rot(b, 16); \ + a ^= c; a -= rot(c, 4); \ + b ^= a; b -= rot(a, 14); \ + c ^= b; c -= rot(b, 24); \ } while (0) /** The golden ratio: an arbitrary value. */ -#define RTE_JHASH_GOLDEN_RATIO 0x9e3779b9 +#define RTE_JHASH_GOLDEN_RATIO 0xdeadbeef + +#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN +#define BIT_SHIFT(x, y, k) (((x) >> (k)) | ((uint64_t)(y) << (32-(k)))) +#else +#define BIT_SHIFT(x, y, k) (((uint64_t)(x) << (k)) | ((y) >> (32-(k)))) +#endif + +#define LOWER8b_MASK rte_le_to_cpu_32(0xff) +#define LOWER16b_MASK rte_le_to_cpu_32(0xffff) +#define LOWER24b_MASK rte_le_to_cpu_32(0xffffff) /** * The most generic version, hashes an arbitrary sequence @@ -95,42 +119,130 @@ extern "C" { static inline uint32_t rte_jhash(const void *key, uint32_t length, uint32_t initval) { - uint32_t a, b, c, len; - const uint8_t *k = (const uint8_t *)key; - const uint32_t *k32 = (const uint32_t *)key; + uint32_t a, b, c; - len = length; - a = b = RTE_JHASH_GOLDEN_RATIO; - c = initval; + /* Set up the internal state */ + a = b = c = RTE_JHASH_GOLDEN_RATIO + ((uint32_t)length) + initval; - while (len >= 12) { - a += k32[0]; - b += k32[1]; - c += k32[2]; + /* Check key alignment. For x86 architecture, first case is always optimal */ +#if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) || defined(RTE_ARCH_X86_X32) + const uint32_t *k = key; + const uint32_t s = 0; +#else + const uint32_t *k = (uint32_t *)(uintptr_t)key & (uintptr_t)~3); + const uint32_t s = ((uintptr_t)key & 3) * CHAR_BIT; +#endif - __rte_jhash_mix(a,b,c); + if (s == 0) { + while (length > 12) { + a += k[0]; + b += k[1]; + c += k[2]; - k += (3 * sizeof(uint32_t)), k32 += 3; - len -= (3 * sizeof(uint32_t)); - } + __rte_jhash_mix(a, b, c); - c += length; - switch (len) { - case 11: c += ((uint32_t)k[10] << 24); - case 10: c += ((uint32_t)k[9] << 16); - case 9 : c += ((uint32_t)k[8] << 8); - case 8 : b += ((uint32_t)k[7] << 24); - case 7 : b += ((uint32_t)k[6] << 16); - case 6 : b += ((uint32_t)k[5] << 8); - case 5 : b += k[4]; - case 4 : a += ((uint32_t)k[3] << 24); - case 3 : a += ((uint32_t)k[2] << 16); - case 2 : a += ((uint32_t)k[1] << 8); - case 1 : a += k[0]; - default: break; - }; + k += 3; + length -= 12; + } - __rte_jhash_mix(a,b,c); + switch (length) { + case 12: + c += k[2]; b += k[1]; a += k[0]; break; + case 11: + c += k[2] & LOWER24b_MASK; b += k[1]; a += k[0]; break; + case 10: + c += k[2] & LOWER16b_MASK; b += k[1]; a += k[0]; break; + case 9: + c += k[2] & LOWER8b_MASK; b += k[1]; a += k[0]; break; + case 8: + b += k[1]; a += k[0]; break; + case 7: + b += k[1] & LOWER24b_MASK; a += k[0]; break; + case 6: + b += k[1] & LOWER16b_MASK; a += k[0]; break; + case 5: + b += k[1] & LOWER8b_MASK; a += k[0]; break; + case 4: + a += k[0]; break; + case 3: + a += k[0] & LOWER24b_MASK; break; + case 2: + a += k[0] & LOWER16b_MASK; break; + case 1: + a += k[0] & LOWER8b_MASK; break; + /* zero length strings require no mixing */ + case 0: + return c; + }; + } else { + /* all but the last block: affect some 32 bits of (a, b, c) */ + while (length > 12) { + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + c += BIT_SHIFT(k[2], k[3], s); + __rte_jhash_mix(a, b, c); + + k += 3; + length -= 12; + } + + /* last block: affect all 32 bits of (c) */ + switch (length) { + case 12: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + c += BIT_SHIFT(k[2], k[3], s); + break; + case 11: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + c += BIT_SHIFT(k[2], k[3], s) & LOWER24b_MASK; + break; + case 10: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + c += BIT_SHIFT(k[2], k[3], s) & LOWER16b_MASK; + break; + case 9: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + c += BIT_SHIFT(k[2], k[3], s) & LOWER8b_MASK; + break; + case 8: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s); + break; + case 7: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s) & LOWER24b_MASK; + break; + case 6: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s) & LOWER16b_MASK; + break; + case 5: + a += BIT_SHIFT(k[0], k[1], s); + b += BIT_SHIFT(k[1], k[2], s) & LOWER8b_MASK; + break; + case 4: + a += BIT_SHIFT(k[0], k[1], s); + break; + case 3: + a += BIT_SHIFT(k[0], k[1], s) & LOWER24b_MASK; + break; + case 2: + a += BIT_SHIFT(k[0], k[1], s) & LOWER16b_MASK; + break; + case 1: + a += BIT_SHIFT(k[0], k[1], s) & LOWER8b_MASK; + break; + /* zero length strings require no mixing */ + case 0: + return c; + } + } + + __rte_jhash_final(a, b, c); return c; } @@ -151,33 +263,54 @@ rte_jhash(const void *key, uint32_t length, uint32_t initval) static inline uint32_t rte_jhash2(const uint32_t *k, uint32_t length, uint32_t initval) { - uint32_t a, b, c, len; + uint32_t a, b, c; - a = b = RTE_JHASH_GOLDEN_RATIO; - c = initval; - len = length; + /* Set up the internal state */ + a = b = c = RTE_JHASH_GOLDEN_RATIO + (((uint32_t)length) << 2) + initval; - while (len >= 3) { + /* Handle most of the key */ + while (length > 3) { a += k[0]; b += k[1]; c += k[2]; + __rte_jhash_mix(a, b, c); - k += 3; len -= 3; - } - c += length * 4; + k += 3; + length -= 3; + } - switch (len) { - case 2 : b += k[1]; - case 1 : a += k[0]; - default: break; + /* Handle the last 3 uint32_t's */ + switch (length) { + case 3: + c += k[2]; + /* Fallthrough */ + case 2: + b += k[1]; + /* Fallthrough */ + case 1: + a += k[0]; + __rte_jhash_final(a, b, c); + /* Fallthrough */ + /* case 0: nothing left to add */ + case 0: + break; }; - __rte_jhash_mix(a,b,c); - return c; } +static inline uint32_t +__rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval) +{ + a += RTE_JHASH_GOLDEN_RATIO + initval; + b += RTE_JHASH_GOLDEN_RATIO + initval; + c += RTE_JHASH_GOLDEN_RATIO + initval; + + __rte_jhash_final(a, b, c); + + return c; +} /** * A special ultra-optimized versions that knows it is hashing exactly @@ -197,17 +330,7 @@ rte_jhash2(const uint32_t *k, uint32_t length, uint32_t initval) static inline uint32_t rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval) { - a += RTE_JHASH_GOLDEN_RATIO; - b += RTE_JHASH_GOLDEN_RATIO; - c += initval; - - __rte_jhash_mix(a, b, c); - - /* - * NOTE: In particular the "c += length; __rte_jhash_mix(a,b,c);" - * normally done at the end is not done here. - */ - return c; + return __rte_jhash_3words(a + 12, b + 12, c + 12, initval); } /** @@ -226,7 +349,7 @@ rte_jhash_3words(uint32_t a, uint32_t b, uint32_t c, uint32_t initval) static inline uint32_t rte_jhash_2words(uint32_t a, uint32_t b, uint32_t initval) { - return rte_jhash_3words(a, b, 0, initval); + return __rte_jhash_3words(a + 8, b + 8, 8, initval); } /** @@ -243,7 +366,7 @@ rte_jhash_2words(uint32_t a, uint32_t b, uint32_t initval) static inline uint32_t rte_jhash_1word(uint32_t a, uint32_t initval) { - return rte_jhash_3words(a, 0, 0, initval); + return __rte_jhash_3words(a + 4, 4, 4, initval); } #ifdef __cplusplus -- 2.4.2