133 lines
3.9 KiB
C++
133 lines
3.9 KiB
C++
/*
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Copyright (c) 2014, Arvid Norberg
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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* Neither the name of the author nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "libtorrent/crc32c.hpp"
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#include "libtorrent/cpuid.hpp"
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#include <boost/crc.hpp>
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namespace libtorrent
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{
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bool supports_sse42()
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{
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#if TORRENT_HAS_SSE
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unsigned int cpui[4];
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cpuid(cpui, 1);
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return cpui[2] & (1 << 20);
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#else
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return false;
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#endif
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}
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static bool sse42_support = supports_sse42();
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boost::uint32_t crc32c_32(boost::uint32_t v)
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{
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#if TORRENT_HAS_SSE
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if (sse42_support)
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{
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boost::uint32_t ret = 0xffffffff;
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#ifdef __GNUC__
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// we can't use these because then we'd have to tell
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// -msse4.2 to gcc on the command line
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// return __builtin_ia32_crc32si(ret, v) ^ 0xffffffff;
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asm ("crc32l\t" "(%1), %0"
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: "=r"(ret)
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: "r"(&v), "0"(ret));
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return ret ^ 0xffffffff;
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#else
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return _mm_crc32_u32(ret, v) ^ 0xffffffff;
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#endif
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}
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#endif
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boost::crc_optimal<32, 0x1EDC6F41, 0xFFFFFFFF, 0xFFFFFFFF, true, true> crc;
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crc.process_bytes(&v, 4);
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return crc.checksum();
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}
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boost::uint32_t crc32c(boost::uint64_t const* buf, int num_words)
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{
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#if TORRENT_HAS_SSE
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if (sse42_support)
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{
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#if defined _M_AMD64 || defined __x86_64__ \
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|| defined __x86_64 || defined _M_X64 || defined __amd64__
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boost::uint64_t ret = 0xffffffff;
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for (int i = 0; i < num_words; ++i)
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{
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#ifdef __GNUC__
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// we can't use these because then we'd have to tell
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// -msse4.2 to gcc on the command line
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// ret = __builtin_ia32_crc32di(ret, buf[i]);
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__asm__("crc32q\t" "(%1), %0"
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: "=r"(ret)
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: "r"(buf+i), "0"(ret));
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#else
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ret = _mm_crc32_u64(ret, buf[i]);
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#endif
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}
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return boost::uint32_t(ret) ^ 0xffffffff;
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#else
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boost::uint32_t ret = 0xffffffff;
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boost::uint32_t const* buf0 = reinterpret_cast<boost::uint32_t const*>(buf);
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for (int i = 0; i < num_words; ++i)
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{
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#ifdef __GNUC__
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// we can't use these because then we'd have to tell
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// -msse4.2 to gcc on the command line
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// ret = __builtin_ia32_crc32si(ret, buf0[i*2]);
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// ret = __builtin_ia32_crc32si(ret, buf0[i*2+1]);
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asm ("crc32l\t" "(%1), %0"
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: "=r"(ret)
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: "r"(buf0+i*2), "0"(ret));
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asm ("crc32l\t" "(%1), %0"
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: "=r"(ret)
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: "r"(buf0+i*2+1), "0"(ret));
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#else
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ret = _mm_crc32_u32(ret, buf0[i*2]);
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ret = _mm_crc32_u32(ret, buf0[i*2+1]);
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#endif
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}
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return ret ^ 0xffffffff;
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#endif // amd64 or x86
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}
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#endif // x86 or amd64 and gcc or msvc
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boost::crc_optimal<32, 0x1EDC6F41, 0xFFFFFFFF, 0xFFFFFFFF, true, true> crc;
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crc.process_bytes(buf, num_words * 8);
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return crc.checksum();
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}
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}
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