79136e895f
It achieves 2.0x speedup on intel E5 and 1.1x to 2.5x speedup on various arm64 microarchitectures. The algorithm cuts data into blocks of 1024 bytes and calculates crc for each block, which is furthur divided into three subblocks of 336 bytes(42 uint64) each, and 16 remaining bytes(2 uint64). For each iteration, three independent crc are caculated for one uint64 from each subgroup. It increases IPC(instructions per cycle) much. After subblocks are done, three crc and remaining two uint64 are combined using carry-less multiplication to reach the final result for one block of 1024 bytes. Signed-off-by: Yibo Cai <yibo.cai@arm.com> Message-Id: <1541042759-24767-1-git-send-email-yibo.cai@arm.com>
96 lines
2.5 KiB
C++
96 lines
2.5 KiB
C++
/*
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* Copyright (C) 2015 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Scylla is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#define BOOST_TEST_MODULE core
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#include <boost/test/unit_test.hpp>
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#include "utils/crc.hh"
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#include <seastar/core/print.hh>
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inline
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uint32_t
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do_compute_crc(utils::crc32& c) {
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return c.get();
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}
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template <typename T, typename... Rest>
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inline
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uint32_t
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do_compute_crc(utils::crc32& c, const T& val, const Rest&... rest) {
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c.process_le(val);
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return do_compute_crc(c, rest...);
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}
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template <typename... T>
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inline
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uint32_t
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compute_crc(const T&... vals) {
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utils::crc32 c;
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return do_compute_crc(c, vals...);
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}
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BOOST_AUTO_TEST_CASE(crc_1_vs_4) {
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using b = uint8_t;
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BOOST_REQUIRE_EQUAL(compute_crc(0x01020304), compute_crc(b(4), b(3), b(2), b(1)));
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}
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BOOST_AUTO_TEST_CASE(crc_121_vs_4) {
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using b = uint8_t;
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using w = uint16_t;
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BOOST_REQUIRE_EQUAL(compute_crc(0x01020304), compute_crc(b(4), w(0x0203), b(1)));
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}
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BOOST_AUTO_TEST_CASE(crc_44_vs_8) {
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using q = uint64_t;
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BOOST_REQUIRE_EQUAL(compute_crc(q(0x0102030405060708)), compute_crc(0x05060708, 0x01020304));
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}
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// Test crc32::process()
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BOOST_AUTO_TEST_CASE(crc_process) {
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const size_t max_size = 7 + 4096 + 31; // cover all code path
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const size_t test_sizes[] = {
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0, 1, 8, 9, 1023, 1024, 1025, 1032, 1033, 4095, 4096, 4097, max_size
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};
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// Create data buffer offset 8 bytes boundary by 1 byte
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uint64_t data64[max_size/8 + 2];
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uint8_t *data = (reinterpret_cast<uint8_t*>(data64)) + 1;
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// Fill data with test pattern
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for (size_t i = 0; i < max_size; ++i) {
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data[i] = i + 1;
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}
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for (size_t size : test_sizes) {
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utils::crc32 c1, c2;
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// Get correct answer with simplest method
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for (size_t i = 0; i < size; ++i) {
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c1.process_le(data[i]);
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}
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// Calculate crc by optimized routine
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c2.process(data, size);
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BOOST_REQUIRE_EQUAL(c1.get(), c2.get());
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}
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}
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