341 lines
8.7 KiB
C
341 lines
8.7 KiB
C
/* $NetBSD: primes.c,v 1.22 2018/02/03 15:40:29 christos Exp $ */
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
|
|
The Regents of the University of California. All rights reserved.");
|
|
#endif /* not lint */
|
|
|
|
#ifndef lint
|
|
#if 0
|
|
static char sccsid[] = "@(#)primes.c 8.5 (Berkeley) 5/10/95";
|
|
#else
|
|
__RCSID("$NetBSD: primes.c,v 1.22 2018/02/03 15:40:29 christos Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
|
|
/*
|
|
* primes - generate a table of primes between two values
|
|
*
|
|
* By Landon Curt Noll, http://www.isthe.com/chongo/index.html /\oo/\
|
|
*
|
|
* usage:
|
|
* primes [-dh] [start [stop]]
|
|
*
|
|
* Print primes >= start and < stop. If stop is omitted,
|
|
* the value SPSPMAX is assumed. If start is
|
|
* omitted, start is read from standard input.
|
|
* -d: print difference to previous prime, e.g. 3 (1)
|
|
* -h: print primes in hexadecimal
|
|
*
|
|
* 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 dflag, hflag;
|
|
|
|
static void primes(uint64_t, uint64_t);
|
|
static uint64_t read_num_buf(void);
|
|
static void usage(void) __dead;
|
|
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
uint64_t start; /* where to start generating */
|
|
uint64_t stop; /* don't generate at or above this value */
|
|
int ch;
|
|
char *p;
|
|
|
|
while ((ch = getopt(argc, argv, "dh")) != -1)
|
|
switch (ch) {
|
|
case 'd':
|
|
dflag++;
|
|
break;
|
|
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 <= ULONG_MAX.
|
|
*/
|
|
static uint64_t
|
|
read_num_buf(void)
|
|
{
|
|
uint64_t 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((unsigned char)*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(uint64_t start, uint64_t stop)
|
|
{
|
|
char *q; /* sieve spot */
|
|
uint64_t factor; /* index and factor */
|
|
char *tab_lim; /* the limit to sieve on the table */
|
|
const uint64_t *p; /* prime table pointer */
|
|
uint64_t fact_lim; /* highest prime for current block */
|
|
uint64_t mod; /* temp storage for mod */
|
|
uint64_t prev = 0;
|
|
|
|
/*
|
|
* 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 ULONG_MAX.
|
|
*/
|
|
if (start < 3) {
|
|
start = 2;
|
|
}
|
|
if (stop < 3) {
|
|
stop = 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 : "%" PRIu64, factor);
|
|
if (dflag) {
|
|
printf(" (%" PRIu64 ")", factor - prev);
|
|
}
|
|
putchar('\n');
|
|
}
|
|
prev = 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];
|
|
}
|
|
/* sieve 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 : "%" PRIu64, start);
|
|
if (dflag && (prev || (start <= *pr_limit))) {
|
|
printf(" (%" PRIu64 ")", start - prev);
|
|
}
|
|
putchar('\n');
|
|
prev = start;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
usage(void)
|
|
{
|
|
(void)fprintf(stderr, "usage: primes [-dh] [start [stop]]\n");
|
|
exit(1);
|
|
}
|