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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1988 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 /* 33 * drand48, etc. pseudo-random number generator 34 * This implementation assumes unsigned short integers of at least 35 * 16 bits, long integers of at least 32 bits, and ignores 36 * overflows on adding or multiplying two unsigned integers. 37 * Two's-complement representation is assumed in a few places. 38 * Some extra masking is done if unsigneds are exactly 16 bits 39 * or longs are exactly 32 bits, but so what? 40 * An assembly-language implementation would run significantly faster. 41 */ 42 /* 43 * New assumptions (supercede those stated above) for 64-bit work. 44 * Longs are now 64 bits, and we are bound by standards to return 45 * type long, hovever all internal calculations where long was 46 * previously used (32 bit precision) are now using the int32_t 47 * type (32 bit precision in both ILP32 and LP64 worlds). 48 */ 49 50 #include "lint.h" 51 #include <mtlib.h> 52 #include <synch.h> 53 #include <thread.h> 54 55 static mutex_t seed_lock = DEFAULTMUTEX; 56 57 #define EXPORT0(TYPE, fn, fnu) TYPE fn() { \ 58 TYPE res; \ 59 lmutex_lock(&seed_lock); \ 60 res = fnu(); \ 61 lmutex_unlock(&seed_lock); \ 62 return (res); } 63 #define EXPORT1(TYPE, fn, fnu) TYPE fn(unsigned short xsubi[3]) { \ 64 TYPE res; \ 65 lmutex_lock(&seed_lock); \ 66 res = fnu(xsubi); \ 67 lmutex_unlock(&seed_lock); \ 68 return (res); } 69 70 #define N 16 71 #define MASK ((unsigned)(1 << (N - 1)) + (1 << (N - 1)) - 1) 72 #define LOW(x) ((unsigned)(x) & MASK) 73 #define HIGH(x) LOW((x) >> N) 74 #define MUL(x, y, z) { int32_t l = (int32_t)(x) * (int32_t)(y); \ 75 (z)[0] = LOW(l); (z)[1] = HIGH(l); } 76 #define CARRY(x, y) ((int32_t)(x) + (int32_t)(y) > MASK) 77 #define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y))) 78 #define X0 0x330E 79 #define X1 0xABCD 80 #define X2 0x1234 81 #define A0 0xE66D 82 #define A1 0xDEEC 83 #define A2 0x5 84 #define C 0xB 85 #define SET3(x, x0, x1, x2) ((x)[0] = (x0), (x)[1] = (x1), (x)[2] = (x2)) 86 #define SETLOW(x, y, n) SET3(x, LOW((y)[n]), LOW((y)[(n)+1]), LOW((y)[(n)+2])) 87 #define SEED(x0, x1, x2) (SET3(x, x0, x1, x2), SET3(a, A0, A1, A2), c = C) 88 #define REST(v) for (i = 0; i < 3; i++) { xsubi[i] = x[i]; x[i] = temp[i]; } \ 89 return (v) 90 #define NEST(TYPE, f, F) static TYPE f(unsigned short *xsubi) { \ 91 int i; TYPE v; unsigned temp[3]; \ 92 for (i = 0; i < 3; i++) { temp[i] = x[i]; x[i] = LOW(xsubi[i]); } \ 93 v = F(); REST(v); } 94 95 /* Way ugly solution to problem names, but it works */ 96 #define x _drand48_x 97 #define a _drand48_a 98 #define c _drand48_c 99 /* End way ugly */ 100 static unsigned x[3] = { X0, X1, X2 }, a[3] = { A0, A1, A2 }, c = C; 101 static unsigned short lastx[3]; 102 static void next(void); 103 104 static double 105 _drand48_u(void) 106 { 107 static double two16m = 1.0 / ((int32_t)1 << N); 108 109 next(); 110 return (two16m * (two16m * (two16m * x[0] + x[1]) + x[2])); 111 } 112 113 NEST(double, _erand48_u, _drand48_u) 114 115 static long 116 _lrand48_u(void) 117 { 118 next(); 119 return ((long)((int32_t)x[2] << (N - 1)) + (x[1] >> 1)); 120 } 121 122 static long 123 _mrand48_u(void) 124 { 125 next(); 126 return ((long)((int32_t)x[2] << N) + x[1]); 127 } 128 129 static void 130 next(void) 131 { 132 unsigned p[2], q[2], r[2], carry0, carry1; 133 134 MUL(a[0], x[0], p); 135 ADDEQU(p[0], c, carry0); 136 ADDEQU(p[1], carry0, carry1); 137 MUL(a[0], x[1], q); 138 ADDEQU(p[1], q[0], carry0); 139 MUL(a[1], x[0], r); 140 x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] + 141 a[0] * x[2] + a[1] * x[1] + a[2] * x[0]); 142 x[1] = LOW(p[1] + r[0]); 143 x[0] = LOW(p[0]); 144 } 145 146 void 147 srand48(long seedval) 148 { 149 int32_t fixseed = (int32_t)seedval; /* limit to 32 bits */ 150 151 lmutex_lock(&seed_lock); 152 SEED(X0, LOW(fixseed), HIGH(fixseed)); 153 lmutex_unlock(&seed_lock); 154 } 155 156 unsigned short * 157 seed48(unsigned short seed16v[3]) 158 { 159 lmutex_lock(&seed_lock); 160 SETLOW(lastx, x, 0); 161 SEED(LOW(seed16v[0]), LOW(seed16v[1]), LOW(seed16v[2])); 162 lmutex_unlock(&seed_lock); 163 return (lastx); 164 } 165 166 void 167 lcong48(unsigned short param[7]) 168 { 169 lmutex_lock(&seed_lock); 170 SETLOW(x, param, 0); 171 SETLOW(a, param, 3); 172 c = LOW(param[6]); 173 lmutex_unlock(&seed_lock); 174 } 175 176 NEST(long, _nrand48_u, _lrand48_u) 177 178 NEST(long, _jrand48_u, _mrand48_u) 179 180 EXPORT0(double, drand48, _drand48_u) 181 EXPORT1(double, erand48, _erand48_u) 182 183 EXPORT0(long, lrand48, _lrand48_u) 184 EXPORT1(long, nrand48, _nrand48_u) 185 186 EXPORT0(long, mrand48, _mrand48_u) 187 EXPORT1(long, jrand48, _jrand48_u) 188 189 #ifdef DRIVER 190 /* 191 * This should print the sequences of integers in Tables 2 192 * and 1 of the TM: 193 * 1623, 3442, 1447, 1829, 1305, ... 194 * 657EB7255101, D72A0C966378, 5A743C062A23, ... 195 */ 196 #include <stdio.h> 197 198 main() 199 { 200 int i; 201 202 for (i = 0; i < 80; i++) { 203 printf("%4d ", (int)(4096 * drand48())); 204 printf("%.4X%.4X%.4X\n", x[2], x[1], x[0]); 205 } 206 } 207 #endif 208