Added some FIXME to track needed tests

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 6bc77d3ba61224197a72a5ada11e509ef08103c6..097243a0c73b45daa354f14985cc8e1ad12828f4 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -32,7 +32,6 @@
 #include "book.h"
 #include "evaluate.h"
 #include "history.h"
-#include "maxgain.h"
 #include "misc.h"
 #include "movegen.h"
 #include "movepick.h"
@@ -264,9 +263,6 @@ namespace {
   // History table
   History H;
 
-  // MaxGain table
-  MaxGain MG;
-
   /// Functions
 
   Value id_loop(const Position& pos, Move searchMoves[]);
@@ -289,6 +285,7 @@ namespace {
   Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
   void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
   void update_killers(Move m, SearchStack& ss);
+  void update_gains(const Position& pos, Move move, Value before, Value after);
 
   bool fail_high_ply_1();
   int current_search_time();
@@ -703,7 +700,6 @@ namespace {
     // Initialize
     TT.new_search();
     H.clear();
-    MG.clear();
     init_ss_array(ss);
     IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0));
     Iteration = 1;
@@ -1165,21 +1161,14 @@ namespace {
         tte = TT.retrieve(pos.get_key());
     }
 
-    // Evaluate the position statically
     isCheck = pos.is_check();
-    EvalInfo ei;
     if (!isCheck)
     {
+        // Update gain statistics of the previous move that lead
+        // us in this position.
+        EvalInfo ei;
         ss[ply].eval = evaluate(pos, ei, threadID);
-
-        // Store gain statistics
-        Move m = ss[ply - 1].currentMove;
-        if (   m != MOVE_NULL
-            && pos.captured_piece() == NO_PIECE_TYPE
-            && !move_is_castle(m)
-            && !move_is_promotion(m))
-            MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
-
+        update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
     }
 
     // Initialize a MovePicker object for the current position, and prepare
@@ -1419,19 +1408,17 @@ namespace {
         ss[ply].eval = staticValue;
         futilityValue = staticValue + PostFutilityValueMargin; //FIXME: Remove me, only for split
         staticValue = refine_eval(tte, staticValue, ply); // Enhance accuracy with TT value if possible
-
-        // Store gain statistics
-        Move m = ss[ply - 1].currentMove;
-        if (   m != MOVE_NULL
-            && pos.captured_piece() == NO_PIECE_TYPE
-            && !move_is_castle(m)
-            && !move_is_promotion(m))
-            MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
+        update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
     }
 
-    // Post futility pruning
-    if (depth < SelectiveDepth && staticValue - PostFutilityValueMargin >= beta)
-        return (staticValue - PostFutilityValueMargin);
+    // Do a "stand pat". If we are above beta by a good margin then
+    // return immediately.
+    // FIXME: test with added condition 'allowNullmove || depth <= OnePly' and !value_is_mate(beta)
+    // FIXME: test with modified condition 'depth < RazorDepth'
+    if (  !isCheck
+        && depth < SelectiveDepth
+        && staticValue - PostFutilityValueMargin >= beta)
+        return staticValue - PostFutilityValueMargin;
 
     // Null move search
     if (    allowNullmove
@@ -1556,6 +1543,8 @@ namespace {
       movesSearched[moveCount++] = ss[ply].currentMove = move;
 
       // Futility pruning for captures
+      // FIXME: test disabling 'Futility pruning for captures'
+      // FIXME: test with 'newDepth < RazorDepth'
       Color them = opposite_color(pos.side_to_move());
 
       if (   !isCheck
@@ -1577,7 +1566,6 @@ namespace {
               continue;
       }
 
-
       // Futility pruning
       if (   !isCheck
           && !dangerous
@@ -1605,7 +1593,7 @@ namespace {
               if (predictedDepth >= OnePly)
                   preFutilityValueMargin = 112 * bitScanReverse32(int(predictedDepth) * int(predictedDepth) / 2);
 
-              preFutilityValueMargin += MG.retrieve(pos.piece_on(move_from(move)), move_from(move), move_to(move)) + 45;
+              preFutilityValueMargin += H.gain(pos.piece_on(move_from(move)), move_from(move), move_to(move)) + 45;
 
               futilityValueScaled = ss[ply].eval + preFutilityValueMargin - moveCount * IncrementalFutilityMargin;
 
@@ -1764,16 +1752,9 @@ namespace {
     if (!isCheck)
     {
         ss[ply].eval = staticValue;
-        // Store gain statistics
-        Move m = ss[ply - 1].currentMove;
-        if (   m != MOVE_NULL
-            && pos.captured_piece() == NO_PIECE_TYPE
-            && !move_is_castle(m)
-            && !move_is_promotion(m))
-            MG.store(pos.piece_on(move_to(m)), move_from(m), move_to(m), ss[ply - 1].eval, -ss[ply].eval);
+        update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
     }
 
-
     // Initialize "stand pat score", and return it immediately if it is
     // at least beta.
     bestValue = staticValue;
@@ -2655,6 +2636,21 @@ namespace {
   }
 
 
+  // update_gains() updates the gains table of a non-capture move given
+  // the static position evaluation before and after the move.
+
+  void update_gains(const Position& pos, Move m, Value before, Value after) {
+
+    if (   m != MOVE_NULL
+        && before != VALUE_NONE
+        && after != VALUE_NONE
+        && pos.captured_piece() == NO_PIECE_TYPE
+        && !move_is_castle(m)
+        && !move_is_promotion(m))
+        H.set_gain(pos.piece_on(move_to(m)), move_from(m), move_to(m), -(before + after));
+  }
+
+
   // fail_high_ply_1() checks if some thread is currently resolving a fail
   // high at ply 1 at the node below the first root node.  This information
   // is used for time management.