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Merge pull request #7735 from deepikabhavnani/crc_lfs 

Optimized CRC implementation - (32-bit ANSI polynomial)
pull/7793/head
Nir Sonnenschein 2018-08-14 19:45:03 +03:00 committed by GitHub
parent 1d9c66af82 f593555cbb
commit ec4c33ca80
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 29 additions and 47 deletions
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31
drivers/MbedCRC.h
View File

@ -95,7 +95,14 @@ namespace mbed {
template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32> template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32>
class MbedCRC { class MbedCRC {
public: public:
enum CrcMode { HARDWARE = 0, TABLE, BITWISE }; enum CrcMode
{
#ifdef DEVICE_CRC
HARDWARE = 0,
#endif
TABLE = 1,
BITWISE
};
public: public:
typedef uint64_t crc_data_size_t; typedef uint64_t crc_data_size_t;
@ -170,12 +177,12 @@ public:
int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc) int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc)
{ {
switch (_mode) { switch (_mode) {
case HARDWARE:
#ifdef DEVICE_CRC #ifdef DEVICE_CRC
case HARDWARE:
hal_crc_compute_partial((uint8_t *)buffer, size); hal_crc_compute_partial((uint8_t *)buffer, size);
#endif // DEVICE_CRC
*crc = 0; *crc = 0;
return 0; return 0;
#endif
case TABLE: case TABLE:
return table_compute_partial(buffer, size, crc); return table_compute_partial(buffer, size, crc);
case BITWISE: case BITWISE:
@ -229,20 +236,22 @@ public:
{ {
MBED_ASSERT(crc != NULL); MBED_ASSERT(crc != NULL);
if (_mode == HARDWARE) {
#ifdef DEVICE_CRC #ifdef DEVICE_CRC
if (_mode == HARDWARE) {
*crc = hal_crc_get_result(); *crc = hal_crc_get_result();
return 0; return 0;
#else
return -1;
#endif
} }
#endif
uint32_t p_crc = *crc; uint32_t p_crc = *crc;
if ((width < 8) && (NULL == _crc_table)) { if ((width < 8) && (NULL == _crc_table)) {
p_crc = (uint32_t)(p_crc << (8 - width)); p_crc = (uint32_t)(p_crc << (8 - width));
} }
// Optimized algorithm for 32BitANSI does not need additional reflect_remainder
if ((TABLE == _mode) && (POLY_32BIT_ANSI == polynomial)) {
*crc = (p_crc ^ _final_xor) & get_crc_mask();
} else {
*crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask(); *crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask();
}
return 0; return 0;
} }
@ -420,9 +429,9 @@ private:
} }
} else { } else {
uint32_t *crc_table = (uint32_t *)_crc_table; uint32_t *crc_table = (uint32_t *)_crc_table;
for (crc_data_size_t byte = 0; byte < size; byte++) { for (crc_data_size_t i = 0; i < size; i++) {
data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8)); p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 0)) & 0xf];
p_crc = crc_table[data_byte] ^ (p_crc << 8); p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 4)) & 0xf];
} }
} }
*crc = p_crc & get_crc_mask(); *crc = p_crc & get_crc_mask();

38
drivers/TableCRC.cpp
View File

@ -108,39 +108,11 @@ extern const uint16_t Table_CRC_16bit_IBM[MBED_CRC_TABLE_SIZE] = {
0x220, 0x8225, 0x822f, 0x22a, 0x823b, 0x23e, 0x234, 0x8231, 0x8213, 0x216, 0x21c, 0x8219 0x220, 0x8225, 0x822f, 0x22a, 0x823b, 0x23e, 0x234, 0x8231, 0x8213, 0x216, 0x21c, 0x8219
}; };
extern const uint32_t Table_CRC_32bit_ANSI[MBED_CRC_TABLE_SIZE] = { extern const uint32_t Table_CRC_32bit_ANSI[MBED_OPTIMIZED_CRC_TABLE_SIZE] = {
0x0, 0x4c11db7, 0x9823b6e, 0xd4326d9, 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x18aeb13, 0x54bf6a4, 0x808d07d, 0xcc9cdca,
0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
0x315d626, 0x7d4cb91, 0xa97ed48, 0xe56f0ff, 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 0x29f3d35, 0x65e2082, 0xb1d065b, 0xfdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
}; };
/** @}*/ /** @}*/

3
drivers/TableCRC.h
View File

@ -24,12 +24,13 @@ namespace mbed {
/** @{*/ /** @{*/
#define MBED_CRC_TABLE_SIZE 256 #define MBED_CRC_TABLE_SIZE 256
#define MBED_OPTIMIZED_CRC_TABLE_SIZE 16
extern const uint8_t Table_CRC_7Bit_SD[MBED_CRC_TABLE_SIZE]; extern const uint8_t Table_CRC_7Bit_SD[MBED_CRC_TABLE_SIZE];
extern const uint8_t Table_CRC_8bit_CCITT[MBED_CRC_TABLE_SIZE]; extern const uint8_t Table_CRC_8bit_CCITT[MBED_CRC_TABLE_SIZE];
extern const uint16_t Table_CRC_16bit_CCITT[MBED_CRC_TABLE_SIZE]; extern const uint16_t Table_CRC_16bit_CCITT[MBED_CRC_TABLE_SIZE];
extern const uint16_t Table_CRC_16bit_IBM[MBED_CRC_TABLE_SIZE]; extern const uint16_t Table_CRC_16bit_IBM[MBED_CRC_TABLE_SIZE];
extern const uint32_t Table_CRC_32bit_ANSI[MBED_CRC_TABLE_SIZE]; extern const uint32_t Table_CRC_32bit_ANSI[MBED_OPTIMIZED_CRC_TABLE_SIZE];
/** @}*/ /** @}*/
} // namespace mbed } // namespace mbed