Merge branch 'cooking' of github.com:graphitemaster/gmqcc into cooking

This commit is contained in:
Dale Weiler 2013-11-23 06:41:24 -05:00
commit b1fd85b711

34
util.c
View file

@ -449,6 +449,40 @@ uint16_t util_crc16(uint16_t current, const char *k, size_t len) {
return h;
}
#if 0
/* for reference: table generated with this: */
/* compile with cc -std=c99 */
int main(void) {
for (unsigned i = 0; i < 0x100; ++i) {
uint16_t x = i << 8;
for (int j = 0; j < 8; ++j)
x = (x << 1) ^ ((x & 0x8000) ? 0x1021 : 0);
tab[0][i] = x;
}
for (unsigned i = 0; i < 0x100; ++i) {
uint16_t c = tab[0][i];
for (unsigned j = 1; j < 8; ++j) {
c = tab[0][c >> 8] ^ (c << 8);
tab[j][i] = c;
}
}
printf("static const uint16_t util_crc16_table[8][256] = {");
for (int i = 0; i < 8; ++i) {
printf("{\n");
for (int j = 0; j < 0x100; ++j) {
printf((j & 7) ? " " : " ");
printf((j != 0x100-1) ? "0x%04X," : "0x%04X", tab[i][j]);
if ((j & 7) == 7)
printf("\n");
}
printf((i != 7) ? "}," : "}");
}
printf("};\n");
return 0;
}
#endif
/*
* modifier is the match to make and the transposition from it, while add is the upper-value that determines the
* transposition from uppercase to lower case.