38a54df863
People keep tripping over the old copyrights and copy-pasting them to new files. Search and replace "Cloudius Systems" with "ScyllaDB". Message-Id: <1460013664-25966-1-git-send-email-penberg@scylladb.com>
98 lines
2.6 KiB
C++
98 lines
2.6 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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#pragma once
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#include <cstdint>
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#include <smmintrin.h>
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class crc32 {
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uint32_t _r = 0;
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public:
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// All process() functions assume input is in
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// host byte order (i.e. equivalent to storing
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// the value in a buffer and crcing the buffer).
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void process(int8_t in) {
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_r = _mm_crc32_u8(_r, in);
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}
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void process(uint8_t in) {
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_r = _mm_crc32_u8(_r, in);
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}
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void process(int16_t in) {
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_r = _mm_crc32_u16(_r, in);
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}
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void process(uint16_t in) {
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_r = _mm_crc32_u16(_r, in);
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}
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void process(int32_t in) {
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_r = _mm_crc32_u32(_r, in);
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}
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void process(uint32_t in) {
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_r = _mm_crc32_u32(_r, in);
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}
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void process(int64_t in) {
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_r = _mm_crc32_u64(_r, in);
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}
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void process(uint64_t in) {
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_r = _mm_crc32_u64(_r, in);
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}
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void process(const uint8_t* in, size_t size) {
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if ((reinterpret_cast<uintptr_t>(in) & 1) && size >= 1) {
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process(*in);
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++in;
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--size;
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}
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if ((reinterpret_cast<uintptr_t>(in) & 3) && size >= 2) {
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process(*reinterpret_cast<const uint16_t*>(in));
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in += 2;
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size -= 2;
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}
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if ((reinterpret_cast<uintptr_t>(in) & 7) && size >= 4) {
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process(*reinterpret_cast<const uint32_t*>(in));
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in += 4;
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size -= 4;
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}
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// FIXME: do in three parallel loops
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while (size >= 8) {
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process(*reinterpret_cast<const uint64_t*>(in));
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in += 8;
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size -= 8;
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}
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if (size >= 4) {
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process(*reinterpret_cast<const uint32_t*>(in));
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in += 4;
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size -= 4;
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}
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if (size >= 2) {
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process(*reinterpret_cast<const uint16_t*>(in));
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in += 2;
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size -= 2;
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}
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if (size >= 1) {
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process(*in);
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}
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}
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uint32_t get() const {
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return _r;
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}
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};
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