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56 lines
2.2 KiB
56 lines
2.2 KiB
/* crc32_braid_comb.c -- compute the CRC-32 of a data stream |
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* Copyright (C) 1995-2022 Mark Adler |
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* For conditions of distribution and use, see copyright notice in zlib.h |
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* |
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* This interleaved implementation of a CRC makes use of pipelined multiple |
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* arithmetic-logic units, commonly found in modern CPU cores. It is due to |
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* Kadatch and Jenkins (2010). See doc/crc-doc.1.0.pdf in this distribution. |
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*/ |
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#include "zutil.h" |
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#include "crc32_braid_p.h" |
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#include "crc32_braid_tbl.h" |
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#include "crc32_braid_comb_p.h" |
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/* ========================================================================= */ |
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static uint32_t crc32_combine_(uint32_t crc1, uint32_t crc2, z_off64_t len2) { |
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return multmodp(x2nmodp(len2, 3), crc1) ^ crc2; |
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} |
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static uint32_t crc32_combine_gen_(z_off64_t len2) { |
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return x2nmodp(len2, 3); |
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} |
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static uint32_t crc32_combine_op_(uint32_t crc1, uint32_t crc2, const uint32_t op) { |
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return multmodp(op, crc1) ^ crc2; |
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} |
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/* ========================================================================= */ |
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#ifdef ZLIB_COMPAT |
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unsigned long Z_EXPORT PREFIX(crc32_combine)(unsigned long crc1, unsigned long crc2, z_off_t len2) { |
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return (unsigned long)crc32_combine_((uint32_t)crc1, (uint32_t)crc2, len2); |
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} |
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unsigned long Z_EXPORT PREFIX4(crc32_combine)(unsigned long crc1, unsigned long crc2, z_off64_t len2) { |
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return (unsigned long)crc32_combine_((uint32_t)crc1, (uint32_t)crc2, len2); |
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} |
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unsigned long Z_EXPORT PREFIX(crc32_combine_gen)(z_off_t len2) { |
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return crc32_combine_gen_(len2); |
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} |
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unsigned long Z_EXPORT PREFIX4(crc32_combine_gen)(z_off64_t len2) { |
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return crc32_combine_gen_(len2); |
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} |
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unsigned long Z_EXPORT PREFIX(crc32_combine_op)(unsigned long crc1, unsigned long crc2, const unsigned long op) { |
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return (unsigned long)crc32_combine_op_((uint32_t)crc1, (uint32_t)crc2, (uint32_t)op); |
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} |
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#else |
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uint32_t Z_EXPORT PREFIX4(crc32_combine)(uint32_t crc1, uint32_t crc2, z_off64_t len2) { |
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return crc32_combine_(crc1, crc2, len2); |
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} |
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uint32_t Z_EXPORT PREFIX(crc32_combine_gen)(z_off64_t len2) { |
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return crc32_combine_gen_(len2); |
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} |
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uint32_t Z_EXPORT PREFIX(crc32_combine_op)(uint32_t crc1, uint32_t crc2, const uint32_t op) { |
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return crc32_combine_op_(crc1, crc2, op); |
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} |
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#endif |
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/* ========================================================================= */
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