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Annotation of coherent/b/bin/as/hash.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Read a string return the hash value computed using CRC-16 methods.
                      3:  */
                      4: unsigned short
                      5: hash(p)
                      6: register char *p;
                      7: {
                      8:        register unsigned char tmp, c; /* warning types are carefully chosen */
                      9:        register unsigned short h;
                     10: 
                     11:        /*
                     12:         * Tables for the table-driven CRC16 algorithm.
                     13:         * This should be relatively uniform statistically.
                     14:         */
                     15:        static  unsigned short crctab1[] = {
                     16:                0000000,        0140301,        0140601,        0000500,
                     17:                0141401,        0001700,        0001200,        0141101,
                     18:                0143001,        0003300,        0003600,        0143501,
                     19:                0002400,        0142701,        0142201,        0002100
                     20:        };
                     21: 
                     22:        static  unsigned short crctab2[] = {
                     23:                0000000,        0146001,        0154001,        0012000,
                     24:                0170001,        0036000,        0024000,        0162001,
                     25:                0120001,        0066000,        0074000,        0132001,
                     26:                0050000,        0116001,        0104001,        0043000
                     27:        };
                     28: 
                     29:        for(h = 0; c = *p; p++) {
                     30:                tmp = c ^ h;
                     31:                h = (h >> 8) ^ crctab1[tmp & 15] ^ crctab2[tmp >> 4];
                     32:        }
                     33:        return(h);
                     34: }

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