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+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Landon Curt Noll.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1989, 1993\n\
+ The Regents of the University of California. All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)primes.c 8.4 (Berkeley) 3/21/94";
+#endif /* not lint */
+
+/*
+ * primes - generate a table of primes between two values
+ *
+ * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo
+ *
+ * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
+ *
+ * usage:
+ * primes [start [stop]]
+ *
+ * Print primes >= start and < stop. If stop is omitted,
+ * the value 4294967295 (2^32-1) is assumed. If start is
+ * omitted, start is read from standard input.
+ *
+ * validation check: there are 664579 primes between 0 and 10^7
+ */
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <limits.h>
+#include <math.h>
+#include <memory.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "primes.h"
+
+/*
+ * Eratosthenes sieve table
+ *
+ * We only sieve the odd numbers. The base of our sieve windows are always
+ * odd. If the base of table is 1, table[i] represents 2*i-1. After the
+ * sieve, table[i] == 1 if and only iff 2*i-1 is prime.
+ *
+ * We make TABSIZE large to reduce the overhead of inner loop setup.
+ */
+char table[TABSIZE]; /* Eratosthenes sieve of odd numbers */
+
+/*
+ * prime[i] is the (i-1)th prime.
+ *
+ * We are able to sieve 2^32-1 because this byte table yields all primes
+ * up to 65537 and 65537^2 > 2^32-1.
+ */
+extern ubig prime[];
+extern ubig *pr_limit; /* largest prime in the prime array */
+
+/*
+ * To avoid excessive sieves for small factors, we use the table below to
+ * setup our sieve blocks. Each element represents a odd number starting
+ * with 1. All non-zero elements are factors of 3, 5, 7, 11 and 13.
+ */
+extern char pattern[];
+extern int pattern_size; /* length of pattern array */
+
+void primes __P((ubig, ubig));
+ubig read_num_buf __P((void));
+void usage __P((void));
+
+int
+main(argc, argv)
+ int argc;
+ char *argv[];
+{
+ ubig start; /* where to start generating */
+ ubig stop; /* don't generate at or above this value */
+ int ch;
+ char *p;
+
+ while ((ch = getopt(argc, argv, "")) != EOF)
+ switch (ch) {
+ case '?':
+ default:
+ usage();
+ }
+ argc -= optind;
+ argv += optind;
+
+ start = 0;
+ stop = BIG;
+
+ /*
+ * Convert low and high args. Strtoul(3) sets errno to
+ * ERANGE if the number is too large, but, if there's
+ * a leading minus sign it returns the negation of the
+ * result of the conversion, which we'd rather disallow.
+ */
+ switch (argc) {
+ case 2:
+ /* Start and stop supplied on the command line. */
+ if (argv[0][0] == '-' || argv[1][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+
+ errno = 0;
+ start = strtoul(argv[0], &p, 10);
+ if (errno)
+ err(1, "%s", argv[0]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[0]);
+
+ errno = 0;
+ stop = strtoul(argv[1], &p, 10);
+ if (errno)
+ err(1, "%s", argv[1]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[1]);
+ break;
+ case 1:
+ /* Start on the command line. */
+ if (argv[0][0] == '-')
+ errx(1, "negative numbers aren't permitted.");
+
+ errno = 0;
+ start = strtoul(argv[0], &p, 10);
+ if (errno)
+ err(1, "%s", argv[0]);
+ if (*p != '\0')
+ errx(1, "%s: illegal numeric format.", argv[0]);
+ break;
+ case 0:
+ start = read_num_buf();
+ break;
+ default:
+ usage();
+ }
+
+ if (start > stop)
+ errx(1, "start value must be less than stop value.");
+ primes(start, stop);
+ exit(0);
+}
+
+/*
+ * read_num_buf --
+ * This routine returns a number n, where 0 <= n && n <= BIG.
+ */
+ubig
+read_num_buf()
+{
+ ubig val;
+ char *p, buf[100]; /* > max number of digits. */
+
+ for (;;) {
+ if (fgets(buf, sizeof(buf), stdin) == NULL) {
+ if (ferror(stdin))
+ err(1, "stdin");
+ exit(0);
+ }
+ for (p = buf; isblank(*p); ++p);
+ if (*p == '\n' || *p == '\0')
+ continue;
+ if (*p == '-')
+ errx(1, "negative numbers aren't permitted.");
+ errno = 0;
+ val = strtoul(buf, &p, 10);
+ if (errno)
+ err(1, "%s", buf);
+ if (*p != '\n')
+ errx(1, "%s: illegal numeric format.", buf);
+ return (val);
+ }
+}
+
+/*
+ * primes - sieve and print primes from start up to and but not including stop
+ */
+void
+primes(start, stop)
+ ubig start; /* where to start generating */
+ ubig stop; /* don't generate at or above this value */
+{
+ register char *q; /* sieve spot */
+ register ubig factor; /* index and factor */
+ register char *tab_lim; /* the limit to sieve on the table */
+ register ubig *p; /* prime table pointer */
+ register ubig fact_lim; /* highest prime for current block */
+
+ /*
+ * A number of systems can not convert double values into unsigned
+ * longs when the values are larger than the largest signed value.
+ * We don't have this problem, so we can go all the way to BIG.
+ */
+ if (start < 3) {
+ start = (ubig)2;
+ }
+ if (stop < 3) {
+ stop = (ubig)2;
+ }
+ if (stop <= start) {
+ return;
+ }
+
+ /*
+ * be sure that the values are odd, or 2
+ */
+ if (start != 2 && (start&0x1) == 0) {
+ ++start;
+ }
+ if (stop != 2 && (stop&0x1) == 0) {
+ ++stop;
+ }
+
+ /*
+ * quick list of primes <= pr_limit
+ */
+ if (start <= *pr_limit) {
+ /* skip primes up to the start value */
+ for (p = &prime[0], factor = prime[0];
+ factor < stop && p <= pr_limit; factor = *(++p)) {
+ if (factor >= start) {
+ printf("%u\n", factor);
+ }
+ }
+ /* return early if we are done */
+ if (p <= pr_limit) {
+ return;
+ }
+ start = *pr_limit+2;
+ }
+
+ /*
+ * we shall sieve a bytemap window, note primes and move the window
+ * upward until we pass the stop point
+ */
+ while (start < stop) {
+ /*
+ * factor out 3, 5, 7, 11 and 13
+ */
+ /* initial pattern copy */
+ factor = (start%(2*3*5*7*11*13))/2; /* starting copy spot */
+ memcpy(table, &pattern[factor], pattern_size-factor);
+ /* main block pattern copies */
+ for (fact_lim=pattern_size-factor;
+ fact_lim+pattern_size<=TABSIZE; fact_lim+=pattern_size) {
+ memcpy(&table[fact_lim], pattern, pattern_size);
+ }
+ /* final block pattern copy */
+ memcpy(&table[fact_lim], pattern, TABSIZE-fact_lim);
+
+ /*
+ * sieve for primes 17 and higher
+ */
+ /* note highest useful factor and sieve spot */
+ if (stop-start > TABSIZE+TABSIZE) {
+ tab_lim = &table[TABSIZE]; /* sieve it all */
+ fact_lim = (int)sqrt(
+ (double)(start)+TABSIZE+TABSIZE+1.0);
+ } else {
+ tab_lim = &table[(stop-start)/2]; /* partial sieve */
+ fact_lim = (int)sqrt((double)(stop)+1.0);
+ }
+ /* sieve for factors >= 17 */
+ factor = 17; /* 17 is first prime to use */
+ p = &prime[7]; /* 19 is next prime, pi(19)=7 */
+ do {
+ /* determine the factor's initial sieve point */
+ q = (char *)(start%factor); /* temp storage for mod */
+ if ((int)q & 0x1) {
+ q = &table[(factor-(int)q)/2];
+ } else {
+ q = &table[q ? factor-((int)q/2) : 0];
+ }
+ /* sive for our current factor */
+ for ( ; q < tab_lim; q += factor) {
+ *q = '\0'; /* sieve out a spot */
+ }
+ } while ((factor=(ubig)(*(p++))) <= fact_lim);
+
+ /*
+ * print generated primes
+ */
+ for (q = table; q < tab_lim; ++q, start+=2) {
+ if (*q) {
+ printf("%u\n", start);
+ }
+ }
+ }
+}
+
+void
+usage()
+{
+ (void)fprintf(stderr, "usage: primes [start [stop]]\n");
+ exit(1);
+}
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