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| author | Jeff Johnston <jjohnstn@redhat.com> | 2000-06-09 18:50:05 +0000 |
|---|---|---|
| committer | Jeff Johnston <jjohnstn@redhat.com> | 2000-06-09 18:50:05 +0000 |
| commit | 46a43a99c6b835dd6f10e2fd4d24cd5c70a26691 (patch) | |
| tree | 8d4dab67e74cfebee22703642dc0f7ff961a9db4 /newlib/libc/stdlib/rand.c | |
| parent | b6c40e83e9f6513e7aee7583a75bff4ec3892bed (diff) | |
| download | cygnal-46a43a99c6b835dd6f10e2fd4d24cd5c70a26691.tar.gz cygnal-46a43a99c6b835dd6f10e2fd4d24cd5c70a26691.tar.bz2 cygnal-46a43a99c6b835dd6f10e2fd4d24cd5c70a26691.zip | |
Fri Jun 9 14:28:00 2000 Jeff Johnston <jjohnstn@cygnus.com>
* libc/include/sys/reent.h (_rand_next): Changed to
unsigned long long and moved to end of _reent struct in _new union.
(_REENT_INIT): Changed to move _rand_next initialization.
* libc/stdlib/rand.c (rand): Changed to use unsigned long long
linear congruential algorithm that is used by DJGPP.
Diffstat (limited to 'newlib/libc/stdlib/rand.c')
| -rw-r--r-- | newlib/libc/stdlib/rand.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/newlib/libc/stdlib/rand.c b/newlib/libc/stdlib/rand.c index 3d739efbc..4cf7f2932 100644 --- a/newlib/libc/stdlib/rand.c +++ b/newlib/libc/stdlib/rand.c @@ -78,9 +78,12 @@ _DEFUN (srand, (seed), unsigned int seed) int _DEFUN_VOID (rand) { - return ((_REENT->_new._reent._rand_next = - _REENT->_new._reent._rand_next * 1103515245 + 12345 ) - & RAND_MAX ); + /* This multiplier was obtained from Knuth, D.E., "The Art of + Computer Programming," Vol 2, Seminumerical Algorithms, Third + Edition, Addison-Wesley, 1998, p. 106 (line 26) & p. 108 */ + _REENT->_new._reent._rand_next = + _REENT->_new._reent._rand_next * 6364136223846793005LL + 1; + return (int)((_REENT->_new._reent._rand_next >> 32) & RAND_MAX); } #endif /* _REENT_ONLY */ |