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///////////////////////////////////////////////////////////////////////////////
//
/// \file crc32_init.c
/// \brief CRC32 table initialization
//
// This code is based on various public domain sources.
// This code has been put into the public domain.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
//
///////////////////////////////////////////////////////////////////////////////
#ifdef HAVE_CONFIG_H
# include "check.h"
#endif
#ifdef WORDS_BIGENDIAN
# include "../../common/bswap.h"
#endif
uint32_t lzma_crc32_table[8][256];
extern void
lzma_crc32_init(void)
{
static const uint32_t poly32 = UINT32_C(0xEDB88320);
for (size_t s = 0; s < 8; ++s) {
for (size_t b = 0; b < 256; ++b) {
uint32_t r = s == 0 ? b : lzma_crc32_table[s - 1][b];
for (size_t i = 0; i < 8; ++i) {
if (r & 1)
r = (r >> 1) ^ poly32;
else
r >>= 1;
}
lzma_crc32_table[s][b] = r;
}
}
#ifdef WORDS_BIGENDIAN
for (size_t s = 0; s < 8; ++s)
for (size_t b = 0; b < 256; ++b)
lzma_crc32_table[s][b]
= bswap_32(lzma_crc32_table[s][b]);
#endif
return;
}
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