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Commented out old odd-parity lfs_crc table

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We've been linking in this now-unused CRC table when we don't
need to be:

           code          stack
  before: 33976           2824
  after:  33856 (-0.4%)   2824 (+0.0%)

The only catch was it's use in lfs_emubd to provide optional checksums
when debugging. But the actual checksum doesn't matter, so this can be
migrated to crc32c.
This commit is contained in:
Christopher Haster
2024-05-02 12:19:48 -05:00
parent 6ad4cd5168
commit add985a3f4
4 changed files with 48 additions and 48 deletions
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lfs_util.c
+18 -18
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@@ -55,24 +55,24 @@ ssize_t lfs_fromleb128(uint32_t *word, const void *buffer, size_t size) {
}
// Software CRC implementation with small lookup table
uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
static const uint32_t rtable[16] = {
0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
};
const uint8_t *data = buffer;
for (size_t i = 0; i < size; i++) {
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
}
return crc;
}
//// Software CRC implementation with small lookup table
//uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size) {
// static const uint32_t rtable[16] = {
// 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
// 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
// 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
// 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
// };
//
// const uint8_t *data = buffer;
//
// for (size_t i = 0; i < size; i++) {
// crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
// crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
// }
//
// return crc;
//}
// Calculate crc32c incrementally
uint32_t lfs_crc32c(uint32_t crc, const void *buffer, size_t size) {