Add Null move support to MovePicker.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 32d1a8bdb32512b1355d5f47b24b9376a7494a70..704cf720008d76e300b512ad378c99a14c0900ca 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -190,9 +190,6 @@ namespace {
   // Remaining depth:                 1 ply         1.5 ply       2 ply         2.5 ply       3 ply         3.5 ply
   const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
 
-  // The main transposition table
-  TranspositionTable TT;
-
 
   /// Variables initialized by UCI options
 
@@ -663,7 +660,6 @@ namespace {
 
     // Initialize
     TT.new_search();
-    p.setTranspositionTable(&TT);
     H.clear();
     for (int i = 0; i < 3; i++)
     {
@@ -1285,13 +1281,15 @@ namespace {
     bool mateThreat = false;
     bool isCheck = pos.is_check();
 
+    bool useNullMove = (    allowNullmove
+                        &&  depth > OnePly
+                        && !isCheck
+                        && !value_is_mate(beta)
+                        &&  ok_to_do_nullmove(pos)
+                        &&  approximateEval >= beta - NullMoveMargin);
+
     // Null move search
-    if (    allowNullmove
-        &&  depth > OnePly
-        && !isCheck
-        && !value_is_mate(beta)
-        &&  ok_to_do_nullmove(pos)
-        &&  approximateEval >= beta - NullMoveMargin)
+    if (useNullMove)
     {
         ss[ply].currentMove = MOVE_NULL;
 
@@ -1330,12 +1328,13 @@ namespace {
         }
     }
     // Null move search not allowed, try razoring
-    else if (   !value_is_mate(beta)
-             && depth < RazorDepth
-             && approximateEval < beta - RazorApprMargins[int(depth) - 2]
-             && ss[ply - 1].currentMove != MOVE_NULL
-             && ttMove == MOVE_NONE
-             && !pos.has_pawn_on_7th(pos.side_to_move()))
+    if (    !useNullMove
+         && !value_is_mate(beta)
+         && depth < RazorDepth
+         && approximateEval < beta - RazorApprMargins[int(depth) - 2]
+         && ss[ply - 1].currentMove != MOVE_NULL
+         && ttMove == MOVE_NONE
+         && !pos.has_pawn_on_7th(pos.side_to_move()))
     {
         Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
         if (v < beta - RazorMargins[int(depth) - 2])
@@ -2271,12 +2270,13 @@ namespace {
 
     if (pos.type_of_piece_on(move_from(m)) == PAWN)
     {
-        if (pos.move_is_pawn_push_to_7th(m))
+        Color c = pos.side_to_move();
+        if (relative_rank(c, move_to(m)) == RANK_7)
         {
             result += PawnPushTo7thExtension[pvNode];
             *dangerous = true;
         }
-        if (pos.move_is_passed_pawn_push(m))
+        if (pos.pawn_is_passed(c, move_to(m)))
         {
             result += PassedPawnExtension[pvNode];
             *dangerous = true;