1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
82 lines
1.8 KiB
C
82 lines
1.8 KiB
C
#include <stdio.h>
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#include "crc32defs.h"
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#include <inttypes.h>
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#define ENTRIES_PER_LINE 4
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#define LE_TABLE_SIZE (1 << CRC_LE_BITS)
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#define BE_TABLE_SIZE (1 << CRC_BE_BITS)
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static uint32_t crc32table_le[LE_TABLE_SIZE];
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static uint32_t crc32table_be[BE_TABLE_SIZE];
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/**
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* crc32init_le() - allocate and initialize LE table data
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*
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* crc is the crc of the byte i; other entries are filled in based on the
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* fact that crctable[i^j] = crctable[i] ^ crctable[j].
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*
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*/
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static void crc32init_le(void)
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{
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unsigned i, j;
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uint32_t crc = 1;
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crc32table_le[0] = 0;
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for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) {
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crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
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for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
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crc32table_le[i + j] = crc ^ crc32table_le[j];
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}
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}
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/**
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* crc32init_be() - allocate and initialize BE table data
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*/
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static void crc32init_be(void)
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{
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unsigned i, j;
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uint32_t crc = 0x80000000;
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crc32table_be[0] = 0;
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for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
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crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
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for (j = 0; j < i; j++)
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crc32table_be[i + j] = crc ^ crc32table_be[j];
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}
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}
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static void output_table(uint32_t table[], int len, char *trans)
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{
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int i;
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for (i = 0; i < len - 1; i++) {
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if (i % ENTRIES_PER_LINE == 0)
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printf("\n");
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printf("%s(0x%8.8xL), ", trans, table[i]);
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}
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printf("%s(0x%8.8xL)\n", trans, table[len - 1]);
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}
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int main(int argc, char** argv)
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{
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printf("/* this file is generated - do not edit */\n\n");
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if (CRC_LE_BITS > 1) {
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crc32init_le();
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printf("static const u32 crc32table_le[] = {");
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output_table(crc32table_le, LE_TABLE_SIZE, "tole");
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printf("};\n");
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}
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if (CRC_BE_BITS > 1) {
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crc32init_be();
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printf("static const u32 crc32table_be[] = {");
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output_table(crc32table_be, BE_TABLE_SIZE, "tobe");
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printf("};\n");
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}
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return 0;
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}
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