Move magic random to RKISS

[stockfish] / src / bitboard.cpp

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 6784effd3d6b546c64e4192f10984b651ec0b8d2..b7eed922d10b0badeb0c4580ea34b76e31adaabf 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -246,20 +246,6 @@ namespace {
   }
 
 
-  Bitboard pick_random(RKISS& rk, int booster) {
-
-    // Values s1 and s2 are used to rotate the candidate magic of a
-    // quantity known to be optimal to quickly find the magics.
-    int s1 = booster & 63, s2 = (booster >> 6) & 63;
-
-    Bitboard m = rk.rand<Bitboard>();
-    m = (m >> s1) | (m << (64 - s1));
-    m &= rk.rand<Bitboard>();
-    m = (m >> s2) | (m << (64 - s2));
-    return m & rk.rand<Bitboard>();
-  }
-
-
   // init_magics() computes all rook and bishop attacks at startup. Magic
   // bitboards are used to look up attacks of sliding pieces. As a reference see
   // chessprogramming.wikispaces.com/Magic+Bitboards. In particular, here we
@@ -268,8 +254,9 @@ namespace {
   void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
                    Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
 
-    int MagicBoosters[][8] = { { 3191, 2184, 1310, 3618, 2091, 1308, 2452, 3996 },
-                               { 1059, 3608,  605, 3234, 3326,   38, 2029, 3043 } };
+    int MagicBoosters[][8] = { {  969, 1976, 2850,  542, 2069, 2852, 1708,  164 },
+                               { 3101,  552, 3555,  926,  834, 4122, 2131, 1117 } };
+
     RKISS rk;
     Bitboard occupancy[4096], reference[4096], edges, b;
     int i, size, booster;
@@ -309,7 +296,7 @@ namespace {
         // Find a magic for square 's' picking up an (almost) random number
         // until we find the one that passes the verification test.
         do {
-            do magics[s] = pick_random(rk, booster);
+            do magics[s] = rk.magic_rand<Bitboard>(booster);
             while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
 
             std::memset(attacks[s], 0, size * sizeof(Bitboard));