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| author |   ast <ast@NetBSD.org> | 2014-10-02 21:36:37 +0000 |
|---|---|---|
| committer | ast <ast@NetBSD.org> | 2014-10-02 21:36:37 +0000 |
| commit | 2eb43769534644ef8af78e6a1fa70c755d41200b (patch) | |
| tree | f39dbbb28c3e53e18a61d031583f9cccc1c89416 /primes/primes.h | |
| parent | d43706be7b336fd46d5a93d300182a17193f5544 (diff) | |
| download | bsdgames-darwin-2eb43769534644ef8af78e6a1fa70c755d41200b.tar.gz bsdgames-darwin-2eb43769534644ef8af78e6a1fa70c755d41200b.tar.zst bsdgames-darwin-2eb43769534644ef8af78e6a1fa70c755d41200b.zip | |
Imported and adapted from FreeBSD svn r272166 and r272207; this fixes
false positives for products of primes larger than 2^16. For example,
before this commit:
$ /usr/games/primes 4295360521 4295360522
4295360521
but
$ /usr/games/factor 4295360521
4295360521: 65539 65539
or
$ /usr/games/primes 3825123056546413049 3825123056546413050
3825123056546413049
yet
$ /usr/games/factor 3825123056546413049
3825123056546413049: 165479 23115459100831
or
$ /usr/games/primes 18446744073709551577
18446744073709551577
although
$ /usr/games/factor 18446744073709551577
18446744073709551577: 139646831 132095686967
Incidentally, the above examples show the smallest and largest cases that
were erroneously stated as prime in the range 2^32 .. 3825123056546413049
.. 2^64; the primes(6) program now stops at 3825123056546413050 as
primality tests on larger integers would be by brute force factorization.
In addition, special to the NetBSD version:
. for -d option, skip first difference when start is >65537 as it is incorrect
. corrected usage to mention both the existing -d as well as the new -h option
For original FreeBSD commit message by Colin Percival, see:
http://svnweb.freebsd.org/base?view=revision&revision=272166
Diffstat (limited to 'primes/primes.h')
| -rw-r--r-- | primes/primes.h | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/primes/primes.h b/primes/primes.h index a032c9b4..20da4ef6 100644 --- a/primes/primes.h +++ b/primes/primes.h @@ -1,4 +1,4 @@ -/* $NetBSD: primes.h,v 1.5 2003/08/07 09:37:34 agc Exp $ */ +/* $NetBSD: primes.h,v 1.6 2014/10/02 21:36:37 ast Exp $ */ /* * Copyright (c) 1989, 1993 @@ -37,14 +37,38 @@ /* * primes - generate a table of primes between two values * - * By: Landon Curt Noll chongo@toad.com, ...!{sun,tolsoft}!hoptoad!chongo + * By Landon Curt Noll, http://www.isthe.com/chongo/index.html /\oo/\ * - * chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\ */ -/* ubig is the type that holds a large unsigned value */ -typedef unsigned long ubig; /* must be >=32 bit unsigned value */ -#define BIG ULONG_MAX /* largest value will sieve */ +#include <stdint.h> /* bytes in sieve table (must be > 3*5*7*11) */ #define TABSIZE 256*1024 + +/* + * 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 const uint64_t prime[]; /* must be >=32 bit unsigned values */ +extern const uint64_t *const pr_limit; /* largest prime in the prime array */ + +/* Maximum size sieving alone can handle. */ +#define SIEVEMAX 4295098368ULL + +/* + * To avoid excessive sieves for small factors, we use the table below to + * setup our sieve blocks. Each element represents an odd number starting + * with 1. All non-zero elements are factors of 3, 5, 7, 11 and 13. + */ +extern const char pattern[]; +extern const size_t pattern_size; /* length of pattern array */ + +/* Test for primality using strong pseudoprime tests. */ +int isprime(uint64_t); + +/* Maximum value which the SPSP code can handle. */ +#define SPSPMAX 3825123056546413050ULL |