1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* Copyright (c) 1988 AT&T */ 30 /* All Rights Reserved */ 31 32 33 /* 34 * drand48, etc. pseudo-random number generator 35 * This implementation assumes unsigned short integers of at least 36 * 16 bits, long integers of at least 32 bits, and ignores 37 * overflows on adding or multiplying two unsigned integers. 38 * Two's-complement representation is assumed in a few places. 39 * Some extra masking is done if unsigneds are exactly 16 bits 40 * or longs are exactly 32 bits, but so what? 41 * An assembly-language implementation would run significantly faster. 42 */ 43 /* 44 * New assumptions (supercede those stated above) for 64-bit work. 45 * Longs are now 64 bits, and we are bound by standards to return 46 * type long, hovever all internal calculations where long was 47 * previously used (32 bit precision) are now using the int32_t 48 * type (32 bit precision in both ILP32 and LP64 worlds). 49 */ 50 #pragma weak drand48 = _drand48 51 #pragma weak erand48 = _erand48 52 #pragma weak lrand48 = _lrand48 53 #pragma weak mrand48 = _mrand48 54 #pragma weak srand48 = _srand48 55 #pragma weak seed48 = _seed48 56 #pragma weak lcong48 = _lcong48 57 #pragma weak nrand48 = _nrand48 58 #pragma weak jrand48 = _jrand48 59 60 #include "synonyms.h" 61 #include <mtlib.h> 62 #include <synch.h> 63 #include <thread.h> 64 65 static mutex_t seed_lock = DEFAULTMUTEX; 66 67 #define EXPORT0(TYPE, fn, fnu) TYPE fn() { \ 68 TYPE res; \ 69 lmutex_lock(&seed_lock); \ 70 res = fnu(); \ 71 lmutex_unlock(&seed_lock); \ 72 return (res); } 73 #define EXPORT1(TYPE, fn, fnu) TYPE fn(unsigned short xsubi[3]) { \ 74 TYPE res; \ 75 lmutex_lock(&seed_lock); \ 76 res = fnu(xsubi); \ 77 lmutex_unlock(&seed_lock); \ 78 return (res); } 79 80 #define N 16 81 #define MASK ((unsigned)(1 << (N - 1)) + (1 << (N - 1)) - 1) 82 #define LOW(x) ((unsigned)(x) & MASK) 83 #define HIGH(x) LOW((x) >> N) 84 #define MUL(x, y, z) { int32_t l = (int32_t)(x) * (int32_t)(y); \ 85 (z)[0] = LOW(l); (z)[1] = HIGH(l); } 86 #define CARRY(x, y) ((int32_t)(x) + (int32_t)(y) > MASK) 87 #define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y))) 88 #define X0 0x330E 89 #define X1 0xABCD 90 #define X2 0x1234 91 #define A0 0xE66D 92 #define A1 0xDEEC 93 #define A2 0x5 94 #define C 0xB 95 #define SET3(x, x0, x1, x2) ((x)[0] = (x0), (x)[1] = (x1), (x)[2] = (x2)) 96 #define SETLOW(x, y, n) SET3(x, LOW((y)[n]), LOW((y)[(n)+1]), LOW((y)[(n)+2])) 97 #define SEED(x0, x1, x2) (SET3(x, x0, x1, x2), SET3(a, A0, A1, A2), c = C) 98 #define REST(v) for (i = 0; i < 3; i++) { xsubi[i] = x[i]; x[i] = temp[i]; } \ 99 return (v) 100 #define NEST(TYPE, f, F) static TYPE f(unsigned short *xsubi) { \ 101 int i; TYPE v; unsigned temp[3]; \ 102 for (i = 0; i < 3; i++) { temp[i] = x[i]; x[i] = LOW(xsubi[i]); } \ 103 v = F(); REST(v); } 104 105 /* Way ugly solution to problem names, but it works */ 106 #define x _drand48_x 107 #define a _drand48_a 108 #define c _drand48_c 109 /* End way ugly */ 110 static unsigned x[3] = { X0, X1, X2 }, a[3] = { A0, A1, A2 }, c = C; 111 static unsigned short lastx[3]; 112 static void next(void); 113 114 static double 115 _drand48_u(void) 116 { 117 static double two16m = 1.0 / ((int32_t)1 << N); 118 119 next(); 120 return (two16m * (two16m * (two16m * x[0] + x[1]) + x[2])); 121 } 122 123 NEST(double, _erand48_u, _drand48_u) 124 125 static long 126 _lrand48_u(void) 127 { 128 next(); 129 return ((long)((int32_t)x[2] << (N - 1)) + (x[1] >> 1)); 130 } 131 132 static long 133 _mrand48_u(void) 134 { 135 next(); 136 return ((long)((int32_t)x[2] << N) + x[1]); 137 } 138 139 static void 140 next(void) 141 { 142 unsigned p[2], q[2], r[2], carry0, carry1; 143 144 MUL(a[0], x[0], p); 145 ADDEQU(p[0], c, carry0); 146 ADDEQU(p[1], carry0, carry1); 147 MUL(a[0], x[1], q); 148 ADDEQU(p[1], q[0], carry0); 149 MUL(a[1], x[0], r); 150 x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] + 151 a[0] * x[2] + a[1] * x[1] + a[2] * x[0]); 152 x[1] = LOW(p[1] + r[0]); 153 x[0] = LOW(p[0]); 154 } 155 156 void 157 _srand48(long seedval) 158 { 159 int32_t fixseed = (int32_t)seedval; /* limit to 32 bits */ 160 161 lmutex_lock(&seed_lock); 162 SEED(X0, LOW(fixseed), HIGH(fixseed)); 163 lmutex_unlock(&seed_lock); 164 } 165 166 unsigned short * 167 seed48(unsigned short seed16v[3]) 168 { 169 lmutex_lock(&seed_lock); 170 SETLOW(lastx, x, 0); 171 SEED(LOW(seed16v[0]), LOW(seed16v[1]), LOW(seed16v[2])); 172 lmutex_unlock(&seed_lock); 173 return (lastx); 174 } 175 176 void 177 lcong48(unsigned short param[7]) 178 { 179 lmutex_lock(&seed_lock); 180 SETLOW(x, param, 0); 181 SETLOW(a, param, 3); 182 c = LOW(param[6]); 183 lmutex_unlock(&seed_lock); 184 } 185 186 NEST(long, _nrand48_u, _lrand48_u) 187 188 NEST(long, _jrand48_u, _mrand48_u) 189 190 EXPORT0(double, _drand48, _drand48_u) 191 EXPORT1(double, _erand48, _erand48_u) 192 193 EXPORT0(long, _lrand48, _lrand48_u) 194 EXPORT1(long, _nrand48, _nrand48_u) 195 196 EXPORT0(long, _mrand48, _mrand48_u) 197 EXPORT1(long, _jrand48, _jrand48_u) 198 199 #ifdef DRIVER 200 /* 201 * This should print the sequences of integers in Tables 2 202 * and 1 of the TM: 203 * 1623, 3442, 1447, 1829, 1305, ... 204 * 657EB7255101, D72A0C966378, 5A743C062A23, ... 205 */ 206 #include <stdio.h> 207 208 main() 209 { 210 int i; 211 212 for (i = 0; i < 80; i++) { 213 printf("%4d ", (int)(4096 * drand48())); 214 printf("%.4X%.4X%.4X\n", x[2], x[1], x[0]); 215 } 216 } 217 #endif 218