/*
* 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. 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 const char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)primes.c 8.5 (Berkeley) 5/10/95";
#endif
static const char rcsid[] =
"$FreeBSD$";
#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 [-h] [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 <inttypes.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.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 if 2*i-1 is prime.
*
* We make TABSIZE large to reduce the overhead of inner loop setup.
*/
static char table[TABSIZE]; /* Eratosthenes sieve of odd numbers */
static int hflag;
static void primes(ubig, ubig);
static ubig read_num_buf(void);
static void usage(void);
int
main(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, "h")) != -1)
switch (ch) {
case 'h':
hflag++;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
start = 0;
stop = (uint64_t)(-1);
/*
* Convert low and high args. Strtoumax(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 = strtoumax(argv[0], &p, 0);
if (errno)
err(1, "%s", argv[0]);
if (*p != '\0')
errx(1, "%s: illegal numeric format.", argv[0]);
errno = 0;
stop = strtoumax(argv[1], &p, 0);
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 = strtoumax(argv[0], &p, 0);
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);
return (0);
}
/*
* read_num_buf --
* This routine returns a number n, where 0 <= n && n <= BIG.
*/
static ubig
read_num_buf(void)
{
ubig val;
char *p, buf[LINE_MAX]; /* > 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 = strtoumax(buf, &p, 0);
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
*/
static void
primes(ubig start, ubig stop)
{
char *q; /* sieve spot */
ubig factor; /* index and factor */
char *tab_lim; /* the limit to sieve on the table */
const ubig *p; /* prime table pointer */
ubig fact_lim; /* highest prime for current block */
ubig mod; /* temp storage for mod */
/*
* 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(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\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 = sqrt(start+1.0+TABSIZE+TABSIZE);
} else {
tab_lim = &table[(stop-start)/2]; /* partial sieve */
fact_lim = sqrt(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 */
mod = start%factor;
if (mod & 0x1) {
q = &table[(factor-mod)/2];
} else {
q = &table[mod ? factor-(mod/2) : 0];
}
/* sive for our current factor */
for ( ; q < tab_lim; q += factor) {
*q = '\0'; /* sieve out a spot */
}
factor = *p++;
} while (factor <= fact_lim);
/*
* print generated primes
*/
for (q = table; q < tab_lim; ++q, start+=2) {
if (*q) {
if (start > SIEVEMAX) {
if (!isprime(start))
continue;
}
printf(hflag ? "%" PRIx64 "\n" : "%" PRIu64 "\n", start);
}
}
}
}
static void
usage(void)
{
fprintf(stderr, "usage: primes [-h] [start [stop]]\n");
exit(1);
}