X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmisc.h;h=246a56a016594bff70e628c360011480c14a5cdf;hp=34ef03259f9de5e6f1d75664aa0c16bef88f7e36;hb=9369f4963d9376820cb5ca4bad66b86e67b0a010;hpb=bc83515c9e821016d2113298ef988e99ceced1af

diff --git a/src/misc.h b/src/misc.h
index 34ef0325..246a56a0 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -20,6 +20,7 @@
 #ifndef MISC_H_INCLUDED
 #define MISC_H_INCLUDED
 
+#include <cassert>
 #include <ostream>
 #include <string>
 #include <vector>
@@ -32,7 +33,7 @@ void prefetch(char* addr);
 void start_logger(bool b);
 
 void dbg_hit_on(bool b);
-void dbg_hit_on_c(bool c, bool b);
+void dbg_hit_on(bool c, bool b);
 void dbg_mean_of(int v);
 void dbg_print();
 
@@ -46,7 +47,7 @@ namespace Time {
 template<class Entry, int Size>
 struct HashTable {
   HashTable() : table(Size, Entry()) {}
-  Entry* operator[](Key k) { return &table[(uint32_t)k & (Size - 1)]; }
+  Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
 
 private:
   std::vector<Entry> table;
@@ -59,4 +60,41 @@ std::ostream& operator<<(std::ostream&, SyncCout);
 #define sync_cout std::cout << IO_LOCK
 #define sync_endl std::endl << IO_UNLOCK
 
+
+/// xorshift64star Pseudo-Random Number Generator
+/// This class is based on original code written and dedicated
+/// to the public domain by Sebastiano Vigna (2014).
+/// It has the following characteristics:
+///
+///  -  Outputs 64-bit numbers
+///  -  Passes Dieharder and SmallCrush test batteries
+///  -  Does not require warm-up, no zeroland to escape
+///  -  Internal state is a single 64-bit integer
+///  -  Period is 2^64 - 1
+///  -  Speed: 1.60 ns/call (Core i7 @3.40GHz)
+///
+/// For further analysis see
+///   <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
+
+class PRNG {
+
+  uint64_t s;
+
+  uint64_t rand64() {
+
+    s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
+    return s * 2685821657736338717LL;
+  }
+
+public:
+  PRNG(uint64_t seed) : s(seed) { assert(seed); }
+
+  template<typename T> T rand() { return T(rand64()); }
+
+  /// Special generator used to fast init magic numbers.
+  /// Output values only have 1/8th of their bits set on average.
+  template<typename T> T sparse_rand()
+  { return T(rand64() & rand64() & rand64()); }
+};
+
 #endif // #ifndef MISC_H_INCLUDED