1/* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Landon Curt Noll. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34static const char copyright[] = 35"@(#) Copyright (c) 1989, 1993\n\ 36 The Regents of the University of California. All rights reserved.\n"; 37#endif /* not lint */ 38 39#ifndef lint 40#if 0 41static char sccsid[] = "@(#)primes.c 8.5 (Berkeley) 5/10/95"; 42#endif 43static const char rcsid[] = 44 "$FreeBSD: releng/10.3/games/primes/primes.c 203932 2010-02-15 18:46:02Z imp $"; 45#endif /* not lint */ 46 47/* 48 * primes - generate a table of primes between two values 49 * 50 * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo 51 * 52 * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\ 53 * 54 * usage: 55 * primes [-h] [start [stop]] 56 * 57 * Print primes >= start and < stop. If stop is omitted, 58 * the value 4294967295 (2^32-1) is assumed. If start is 59 * omitted, start is read from standard input. 60 * 61 * validation check: there are 664579 primes between 0 and 10^7 62 */ 63 64#include <ctype.h> 65#include <err.h> 66#include <errno.h> 67#include <limits.h> 68#include <math.h> 69#include <stdio.h> 70#include <stdlib.h> 71#include <string.h> 72#include <unistd.h> 73 74#include "primes.h" 75 76/* 77 * Eratosthenes sieve table 78 * 79 * We only sieve the odd numbers. The base of our sieve windows are always 80 * odd. If the base of table is 1, table[i] represents 2*i-1. After the 81 * sieve, table[i] == 1 if and only if 2*i-1 is prime. 82 * 83 * We make TABSIZE large to reduce the overhead of inner loop setup. 84 */ 85static char table[TABSIZE]; /* Eratosthenes sieve of odd numbers */ 86 87static int hflag; 88 89static void primes(ubig, ubig); 90static ubig read_num_buf(void); 91static void usage(void); 92 93int 94main(int argc, char *argv[]) 95{ 96 ubig start; /* where to start generating */ 97 ubig stop; /* don't generate at or above this value */ 98 int ch; 99 char *p; 100 101 while ((ch = getopt(argc, argv, "h")) != -1) 102 switch (ch) { 103 case 'h': 104 hflag++; 105 break; 106 case '?': 107 default: 108 usage(); 109 } 110 argc -= optind; 111 argv += optind; 112 113 start = 0; 114 stop = BIG; 115 116 /* 117 * Convert low and high args. Strtoul(3) sets errno to 118 * ERANGE if the number is too large, but, if there's 119 * a leading minus sign it returns the negation of the 120 * result of the conversion, which we'd rather disallow. 121 */ 122 switch (argc) { 123 case 2: 124 /* Start and stop supplied on the command line. */ 125 if (argv[0][0] == '-' || argv[1][0] == '-') 126 errx(1, "negative numbers aren't permitted."); 127 128 errno = 0; 129 start = strtoul(argv[0], &p, 0); 130 if (errno) 131 err(1, "%s", argv[0]); 132 if (*p != '\0') 133 errx(1, "%s: illegal numeric format.", argv[0]); 134 135 errno = 0; 136 stop = strtoul(argv[1], &p, 0); 137 if (errno) 138 err(1, "%s", argv[1]); 139 if (*p != '\0') 140 errx(1, "%s: illegal numeric format.", argv[1]); 141 break; 142 case 1: 143 /* Start on the command line. */ 144 if (argv[0][0] == '-') 145 errx(1, "negative numbers aren't permitted."); 146 147 errno = 0; 148 start = strtoul(argv[0], &p, 0); 149 if (errno) 150 err(1, "%s", argv[0]); 151 if (*p != '\0') 152 errx(1, "%s: illegal numeric format.", argv[0]); 153 break; 154 case 0: 155 start = read_num_buf(); 156 break; 157 default: 158 usage(); 159 } 160 161 if (start > stop) 162 errx(1, "start value must be less than stop value."); 163 primes(start, stop); 164 return (0); 165} 166 167/* 168 * read_num_buf -- 169 * This routine returns a number n, where 0 <= n && n <= BIG. 170 */ 171static ubig 172read_num_buf(void) 173{ 174 ubig val; 175 char *p, buf[LINE_MAX]; /* > max number of digits. */ 176 177 for (;;) { 178 if (fgets(buf, sizeof(buf), stdin) == NULL) { 179 if (ferror(stdin)) 180 err(1, "stdin"); 181 exit(0); 182 } 183 for (p = buf; isblank(*p); ++p); 184 if (*p == '\n' || *p == '\0') 185 continue; 186 if (*p == '-') 187 errx(1, "negative numbers aren't permitted."); 188 errno = 0; 189 val = strtoul(buf, &p, 0); 190 if (errno) 191 err(1, "%s", buf); 192 if (*p != '\n') 193 errx(1, "%s: illegal numeric format.", buf); 194 return (val); 195 } 196} 197 198/* 199 * primes - sieve and print primes from start up to and but not including stop 200 */ 201static void 202primes(ubig start, ubig stop) 203{ 204 char *q; /* sieve spot */ 205 ubig factor; /* index and factor */ 206 char *tab_lim; /* the limit to sieve on the table */ 207 const ubig *p; /* prime table pointer */ 208 ubig fact_lim; /* highest prime for current block */ 209 ubig mod; /* temp storage for mod */ 210 211 /* 212 * A number of systems can not convert double values into unsigned 213 * longs when the values are larger than the largest signed value. 214 * We don't have this problem, so we can go all the way to BIG. 215 */ 216 if (start < 3) { 217 start = (ubig)2; 218 } 219 if (stop < 3) { 220 stop = (ubig)2; 221 } 222 if (stop <= start) { 223 return; 224 } 225 226 /* 227 * be sure that the values are odd, or 2 228 */ 229 if (start != 2 && (start&0x1) == 0) { 230 ++start; 231 } 232 if (stop != 2 && (stop&0x1) == 0) { 233 ++stop; 234 } 235 236 /* 237 * quick list of primes <= pr_limit 238 */ 239 if (start <= *pr_limit) { 240 /* skip primes up to the start value */ 241 for (p = &prime[0], factor = prime[0]; 242 factor < stop && p <= pr_limit; factor = *(++p)) { 243 if (factor >= start) { 244 printf(hflag ? "0x%lx\n" : "%lu\n", factor); 245 } 246 } 247 /* return early if we are done */ 248 if (p <= pr_limit) { 249 return; 250 } 251 start = *pr_limit+2; 252 } 253 254 /* 255 * we shall sieve a bytemap window, note primes and move the window 256 * upward until we pass the stop point 257 */ 258 while (start < stop) { 259 /* 260 * factor out 3, 5, 7, 11 and 13 261 */ 262 /* initial pattern copy */ 263 factor = (start%(2*3*5*7*11*13))/2; /* starting copy spot */ 264 memcpy(table, &pattern[factor], pattern_size-factor); 265 /* main block pattern copies */ 266 for (fact_lim=pattern_size-factor; 267 fact_lim+pattern_size<=TABSIZE; fact_lim+=pattern_size) { 268 memcpy(&table[fact_lim], pattern, pattern_size); 269 } 270 /* final block pattern copy */ 271 memcpy(&table[fact_lim], pattern, TABSIZE-fact_lim); 272 273 /* 274 * sieve for primes 17 and higher 275 */ 276 /* note highest useful factor and sieve spot */ 277 if (stop-start > TABSIZE+TABSIZE) { 278 tab_lim = &table[TABSIZE]; /* sieve it all */ 279 fact_lim = sqrt(start+1.0+TABSIZE+TABSIZE); 280 } else { 281 tab_lim = &table[(stop-start)/2]; /* partial sieve */ 282 fact_lim = sqrt(stop+1.0); 283 } 284 /* sieve for factors >= 17 */ 285 factor = 17; /* 17 is first prime to use */ 286 p = &prime[7]; /* 19 is next prime, pi(19)=7 */ 287 do { 288 /* determine the factor's initial sieve point */ 289 mod = start%factor; 290 if (mod & 0x1) { 291 q = &table[(factor-mod)/2]; 292 } else { 293 q = &table[mod ? factor-(mod/2) : 0]; 294 } 295 /* sive for our current factor */ 296 for ( ; q < tab_lim; q += factor) { 297 *q = '\0'; /* sieve out a spot */ 298 } 299 factor = *p++; 300 } while (factor <= fact_lim); 301 302 /* 303 * print generated primes 304 */ 305 for (q = table; q < tab_lim; ++q, start+=2) { 306 if (*q) { 307 printf(hflag ? "0x%lx\n" : "%lu\n", start); 308 } 309 } 310 } 311} 312 313static void 314usage(void) 315{ 316 fprintf(stderr, "usage: primes [-h] [start [stop]]\n"); 317 exit(1); 318} 319