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b941549573
Perhaps the generated files aren't even copyrightable but using the same license for them as for the rest of the liblzma keeps things more consistent for tools that look for license info.
90 lines
1.8 KiB
C
90 lines
1.8 KiB
C
// SPDX-License-Identifier: 0BSD
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///////////////////////////////////////////////////////////////////////////////
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//
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/// \file crc64_tablegen.c
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/// \brief Generate crc64_table_le.h and crc64_table_be.h
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///
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/// Compiling: gcc -std=c99 -o crc64_tablegen crc64_tablegen.c
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/// Add -DWORDS_BIGENDIAN to generate big endian table.
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//
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// Author: Lasse Collin
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//
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///////////////////////////////////////////////////////////////////////////////
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#include <stdio.h>
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#include "../../common/tuklib_integer.h"
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static uint64_t crc64_table[4][256];
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extern void
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init_crc64_table(void)
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{
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static const uint64_t poly64 = UINT64_C(0xC96C5795D7870F42);
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for (size_t s = 0; s < 4; ++s) {
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for (size_t b = 0; b < 256; ++b) {
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uint64_t r = s == 0 ? b : crc64_table[s - 1][b];
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for (size_t i = 0; i < 8; ++i) {
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if (r & 1)
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r = (r >> 1) ^ poly64;
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else
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r >>= 1;
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}
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crc64_table[s][b] = r;
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}
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}
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#ifdef WORDS_BIGENDIAN
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for (size_t s = 0; s < 4; ++s)
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for (size_t b = 0; b < 256; ++b)
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crc64_table[s][b] = bswap64(crc64_table[s][b]);
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#endif
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return;
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}
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static void
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print_crc64_table(void)
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{
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// Split the SPDX string so that it won't accidentally match
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// when tools search for the string.
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printf("// SPDX" "-License-Identifier" ": 0BSD\n\n"
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"// This file has been generated by crc64_tablegen.c.\n\n"
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"const uint64_t lzma_crc64_table[4][256] = {\n\t{");
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for (size_t s = 0; s < 4; ++s) {
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for (size_t b = 0; b < 256; ++b) {
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if ((b % 2) == 0)
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printf("\n\t\t");
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printf("UINT64_C(0x%016" PRIX64 ")",
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crc64_table[s][b]);
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if (b != 255)
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printf(",%s", (b+1) % 2 == 0 ? "" : " ");
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}
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if (s == 3)
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printf("\n\t}\n};\n");
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else
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printf("\n\t}, {");
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}
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return;
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}
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int
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main(void)
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{
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init_crc64_table();
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print_crc64_table();
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return 0;
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}
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