aaru-dps/Aaru.Checksums.Native
1
0
Fork 0
mirror of https://github.com/aaru-dps/Aaru.Checksums.Native.git synced 2025-12-16 19:24:29 +00:00
Code Issues Packages Projects Releases Wiki Activity

Add unit tests for CRC32.

Browse Source
This commit is contained in:
Natalia Portillo
2021-10-05 02:41:28 +01:00
parent 26769548f5
commit 8e2f7e2b55
3 changed files with 76 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
crc32.c
View File

@@ -61,21 +61,27 @@ AARU_EXPORT int AARU_CALL crc32_update(crc32_ctx* ctx, const uint8_t* data, uint
}
#endif
crc32_slicing(&ctx->crc, data, len);
return 0;
}
void crc32_slicing(uint32_t* crc, const unsigned char* data, long len)
{
// Unroll according to Intel slicing by uint8_t
// http://www.intel.com/technology/comms/perfnet/download/CRC_generators.pdf
// http://sourceforge.net/projects/slicing-by-8/
uint32_t crc;
uint32_t c;
const uint32_t* current;
const uint8_t* current_char = (const uint8_t*)data;
const size_t unroll = 4;
const size_t bytes_at_once = 8 * unroll;
uintptr_t unaligned_length = (4 - (((uintptr_t)current_char) & 3)) & 3;
crc = ctx->crc;
c = *crc;
while((len != 0) && (unaligned_length != 0))
{
crc = (crc >> 8) ^ crc32_table[0][(crc & 0xFF) ^ *current_char++];
c = (c >> 8) ^ crc32_table[0][(c & 0xFF) ^ *current_char++];
len--;
unaligned_length--;
}
@@ -87,12 +93,12 @@ AARU_EXPORT int AARU_CALL crc32_update(crc32_ctx* ctx, const uint8_t* data, uint
size_t unrolling;
for(unrolling = 0; unrolling < unroll; unrolling++)
{
uint32_t one = *current++ ^ crc;
uint32_t one = *current++ ^ c;
uint32_t two = *current++;
// TODO: Big endian!
crc = crc32_table[0][(two >> 24) & 0xFF] ^ crc32_table[1][(two >> 16) & 0xFF] ^
crc32_table[2][(two >> 8) & 0xFF] ^ crc32_table[3][two & 0xFF] ^ crc32_table[4][(one >> 24) & 0xFF] ^
crc32_table[5][(one >> 16) & 0xFF] ^ crc32_table[6][(one >> 8) & 0xFF] ^ crc32_table[7][one & 0xFF];
c = crc32_table[0][(two >> 24) & 0xFF] ^ crc32_table[1][(two >> 16) & 0xFF] ^
crc32_table[2][(two >> 8) & 0xFF] ^ crc32_table[3][two & 0xFF] ^ crc32_table[4][(one >> 24) & 0xFF] ^
crc32_table[5][(one >> 16) & 0xFF] ^ crc32_table[6][(one >> 8) & 0xFF] ^ crc32_table[7][one & 0xFF];
}
len -= bytes_at_once;
@@ -100,10 +106,9 @@ AARU_EXPORT int AARU_CALL crc32_update(crc32_ctx* ctx, const uint8_t* data, uint
current_char = (const uint8_t*)current;
while(len-- != 0) crc = (crc >> 8) ^ crc32_table[0][(crc & 0xFF) ^ *current_char++];
while(len-- != 0) c = (c >> 8) ^ crc32_table[0][(c & 0xFF) ^ *current_char++];
ctx->crc = crc;
return 0;
*crc = c;
}
AARU_EXPORT int AARU_CALL crc32_final(crc32_ctx* ctx, uint32_t* crc)