186d7f5d3SJohn Marino /* 286d7f5d3SJohn Marino * Copyright (c) 1993 Martin Birgmeier 386d7f5d3SJohn Marino * All rights reserved. 486d7f5d3SJohn Marino * 586d7f5d3SJohn Marino * You may redistribute unmodified or modified versions of this source 686d7f5d3SJohn Marino * code provided that the above copyright notice and this and the 786d7f5d3SJohn Marino * following conditions are retained. 886d7f5d3SJohn Marino * 986d7f5d3SJohn Marino * This software is provided ``as is'', and comes with no warranties 1086d7f5d3SJohn Marino * of any kind. I shall in no event be liable for anything that happens 1186d7f5d3SJohn Marino * to anyone/anything when using this software. 1286d7f5d3SJohn Marino */ 1386d7f5d3SJohn Marino 1486d7f5d3SJohn Marino #include "rand48.h" 1586d7f5d3SJohn Marino 1686d7f5d3SJohn Marino unsigned short _rand48_seed[3] = { 1786d7f5d3SJohn Marino RAND48_SEED_0, 1886d7f5d3SJohn Marino RAND48_SEED_1, 1986d7f5d3SJohn Marino RAND48_SEED_2 2086d7f5d3SJohn Marino }; 2186d7f5d3SJohn Marino unsigned short _rand48_mult[3] = { 2286d7f5d3SJohn Marino RAND48_MULT_0, 2386d7f5d3SJohn Marino RAND48_MULT_1, 2486d7f5d3SJohn Marino RAND48_MULT_2 2586d7f5d3SJohn Marino }; 2686d7f5d3SJohn Marino unsigned short _rand48_add = RAND48_ADD; 2786d7f5d3SJohn Marino 2886d7f5d3SJohn Marino void _dorand48(unsigned short xseed[3])2986d7f5d3SJohn Marino_dorand48(unsigned short xseed[3]) 3086d7f5d3SJohn Marino { 3186d7f5d3SJohn Marino unsigned long accu; 3286d7f5d3SJohn Marino unsigned short temp[2]; 3386d7f5d3SJohn Marino 3486d7f5d3SJohn Marino accu = (unsigned long) _rand48_mult[0] * (unsigned long) xseed[0] + 3586d7f5d3SJohn Marino (unsigned long) _rand48_add; 3686d7f5d3SJohn Marino temp[0] = (unsigned short) accu; /* lower 16 bits */ 3786d7f5d3SJohn Marino accu >>= sizeof(unsigned short) * 8; 3886d7f5d3SJohn Marino accu += (unsigned long) _rand48_mult[0] * (unsigned long) xseed[1] + 3986d7f5d3SJohn Marino (unsigned long) _rand48_mult[1] * (unsigned long) xseed[0]; 4086d7f5d3SJohn Marino temp[1] = (unsigned short) accu; /* middle 16 bits */ 4186d7f5d3SJohn Marino accu >>= sizeof(unsigned short) * 8; 4286d7f5d3SJohn Marino accu += _rand48_mult[0] * xseed[2] + _rand48_mult[1] * xseed[1] + _rand48_mult[2] * xseed[0]; 4386d7f5d3SJohn Marino xseed[0] = temp[0]; 4486d7f5d3SJohn Marino xseed[1] = temp[1]; 4586d7f5d3SJohn Marino xseed[2] = (unsigned short) accu; 4686d7f5d3SJohn Marino } 47