drivers/filesystems/btrfs/crc32c.c

   1 /* Copyright (c) Mark Harmstone 2016-17
   2  *
   3  * This file is part of WinBtrfs.
   4  *
   5  * WinBtrfs is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public Licence as published by
   7  * the Free Software Foundation, either version 3 of the Licence, or
   8  * (at your option) any later version.
   9  *
  10  * WinBtrfs is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU Lesser General Public Licence for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public Licence
  16  * along with WinBtrfs.  If not, see <http://www.gnu.org/licenses/>. */
  17
  18 #include <windef.h>
  19 #ifndef __REACTOS__
  20 #include <smmintrin.h>
  21
  22 extern BOOL have_sse42;
  23 #endif /* __REACTOS__ */
  24
  25 static const UINT32 crctable[] = {
  26     0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4, 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
  27     0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b, 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
  28     0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b, 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
  29     0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54, 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
  30     0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a, 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
  31     0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5, 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
  32     0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45, 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
  33     0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a, 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
  34     0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48, 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
  35     0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687, 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
  36     0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927, 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
  37     0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8, 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
  38     0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096, 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
  39     0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859, 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
  40     0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9, 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
  41     0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36, 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
  42     0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c, 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
  43     0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043, 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
  44     0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3, 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
  45     0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c, 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
  46     0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652, 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
  47     0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d, 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
  48     0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d, 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
  49     0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2, 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
  50     0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530, 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
  51     0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff, 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
  52     0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f, 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
  53     0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90, 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
  54     0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee, 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
  55     0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321, 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
  56     0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81, 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
  57     0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e, 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351,
  58 };
  59
  60 #ifndef __REACTOS__
  61 // HW code taken from https://github.com/rurban/smhasher/blob/master/crc32_hw.c
  62 #define ALIGN_SIZE      0x08UL
  63 #define ALIGN_MASK      (ALIGN_SIZE - 1)
  64 #define CALC_CRC(op, crc, type, buf, len)                               \
  65   do {                                                                  \
  66     for (; (len) >= sizeof (type); (len) -= sizeof(type), buf += sizeof (type)) { \
  67       (crc) = op((crc), *(type *) (buf));                               \
  68     }                                                                   \
  69   } while(0)
  70
  71 static UINT32 crc32c_hw(const void *input, ULONG len, UINT32 crc) {
  72     const char* buf = (const char*)input;
  73
  74     // Annoyingly, the CRC32 intrinsics don't work properly in modern versions of MSVC -
  75     // it compiles _mm_crc32_u8 as if it was _mm_crc32_u32. And because we're apparently
  76     // not allowed to use inline asm on amd64, there's no easy way to fix this!
  77
  78     for (; (len > 0) && ((size_t)buf & ALIGN_MASK); len--, buf++) {
  79 #ifdef _MSC_VER
  80         crc = crctable[(crc ^ *buf) & 0xff] ^ (crc >> 8);
  81 #else
  82         crc = _mm_crc32_u8(crc, *buf);
  83 #endif
  84     }
  85
  86 #ifdef _AMD64_
  87 #ifdef _MSC_VER
  88 #pragma warning(push)
  89 #pragma warning(disable:4244) // _mm_crc32_u64 wants to return UINT64(!)
  90 #pragma warning(disable:4242)
  91 #endif
  92     CALC_CRC(_mm_crc32_u64, crc, UINT64, buf, len);
  93 #ifdef _MSC_VER
  94 #pragma warning(pop)
  95 #endif
  96 #endif
  97     CALC_CRC(_mm_crc32_u32, crc, UINT32, buf, len);
  98
  99 #ifdef _MSC_VER
 100     for (; len > 0; len--, buf++) {
 101         crc = crctable[(crc ^ *buf) & 0xff] ^ (crc >> 8);
 102     }
 103 #else
 104     CALC_CRC(_mm_crc32_u16, crc, UINT16, buf, len);
 105     CALC_CRC(_mm_crc32_u8, crc, UINT8, buf, len);
 106 #endif
 107
 108     return crc;
 109 }
 110 #endif
 111
 112 UINT32 calc_crc32c(_In_ UINT32 seed, _In_reads_bytes_(msglen) UINT8* msg, _In_ ULONG msglen) {
 113     UINT32 rem;
 114     ULONG i;
 115
 116 #ifndef __REACTOS__
 117     if (have_sse42) {
 118         return crc32c_hw(msg, msglen, seed);
 119     } else {
 120 #endif
 121         rem = seed;
 122
 123         for (i = 0; i < msglen; i++) {
 124             rem = crctable[(rem ^ msg[i]) & 0xff] ^ (rem >> 8);
 125         }
 126 #ifndef __REACTOS__
 127     }
 128 #endif
 129
 130     return rem;
 131 }