Make rkiss seed deterministic

Search at fixed depth with one thread must be
reproducible so remove randomess from time().

Also better license description.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2010-11-07 12:33:17 +01:00
parent 8fb16df70e
commit 4cd53b68d0

View File

@@ -1,4 +1,26 @@
/** *********************************************************************** **
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
This file is based on original code by Heinz van Saanen and is
available under the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
** A small "keep it simple and stupid" RNG with some fancy merits:
**
** Quite platform independent
@@ -8,24 +30,11 @@
** Average cycle length: ~2^126
** 64 bit seed
** Return doubles with a full 53 bit mantissa
** Thread save
** Thread safe
**
** (c) Heinz van Saanen
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
** *********************************************************************** **/
*/
#if !defined(RKISS_H_INCLUDED)
#define RKISS_H_INCLUDED
@@ -35,9 +44,6 @@
//// Includes
////
#include <cstdlib>
#include <ctime>
#include "types.h"
@@ -62,21 +68,17 @@ class RKISS {
}
// Init seed and scramble a few rounds
void raninit(uint64_t seed) {
void raninit() {
s.a = 0xf1ea5eed;
s.b = s.c = s.d = seed;
for (uint64_t i = 0; i < 8; i++)
s.b = s.c = s.d = 0xd4e12c77;
for (uint64_t i = 0; i < 73; i++)
rand64();
}
public:
// Instance seed random or implicite
RKISS() { ::srand(uint32_t(time(NULL))); raninit(uint64_t(::rand())); }
// Return random number of type T (must be castable from uint64_t)
template<typename T>
T rand() { return T(rand64()); }
RKISS() { raninit(); }
template<typename T> T rand() { return T(rand64()); }
};
#endif // !defined(RKISS_H_INCLUDED)