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