diff --git a/src/Makefile b/src/Makefile
index dafea2dd..aa7d97f8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -68,7 +68,7 @@ LDFLAGS = -lpthread
OBJS = application.o bitboard.o pawns.o material.o endgame.o evaluate.o main.o \
misc.o move.o movegen.o history.o movepick.o search.o piece.o \
position.o direction.o tt.o value.o uci.o ucioption.o \
- mersenne.o book.o bitbase.o san.o benchmark.o
+ maxgain.o mersenne.o book.o bitbase.o san.o benchmark.o
### General rules. Do not change
diff --git a/src/maxgain.cpp b/src/maxgain.cpp
new file mode 100644
index 00000000..8c1ff48a
--- /dev/null
+++ b/src/maxgain.cpp
@@ -0,0 +1,67 @@
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2009 Marco Costalba
+
+ 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 .
+*/
+
+
+////
+//// Includes
+////
+
+#include
+#include
+
+#include "maxgain.h"
+#include "value.h"
+
+////
+//// Functions
+////
+
+
+/// Constructor
+
+MaxGain::MaxGain() { clear(); }
+
+
+/// MaxGain::clear() clears the table
+
+void MaxGain::clear() {
+ memset(maxStaticValueDelta, 0, 16 * 64 * 64 * sizeof(int));
+}
+
+
+/// MaxGain::store
+
+void MaxGain::store(Piece p, Square from, Square to, Value prev, Value curr)
+{
+ if (prev == VALUE_NONE || curr == VALUE_NONE)
+ return;
+
+ Value delta = curr - prev;
+ if (delta >= maxStaticValueDelta[p][from][to])
+ maxStaticValueDelta[p][from][to] = delta;
+ else
+ maxStaticValueDelta[p][from][to]--;
+}
+
+// MaxGain::retrieve
+
+Value MaxGain::retrieve(Piece p, Square from, Square to)
+{
+ return (Value) maxStaticValueDelta[p][from][to];
+}
diff --git a/src/maxgain.h b/src/maxgain.h
new file mode 100644
index 00000000..6bdc5b87
--- /dev/null
+++ b/src/maxgain.h
@@ -0,0 +1,51 @@
+/*
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2009 Marco Costalba
+
+ 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 .
+*/
+
+
+#if !defined(MAXGAIN_H_INCLUDED)
+#define MAXGAIN_H_INCLUDED
+
+////
+//// Includes
+////
+
+#include "move.h"
+#include "piece.h"
+#include "value.h"
+
+
+////
+//// Types
+////
+
+class MaxGain {
+
+public:
+ MaxGain();
+ void clear();
+ void store(Piece p, Square from, Square to, Value prev, Value curr);
+ Value retrieve(Piece p, Square from, Square to);
+
+private:
+ int maxStaticValueDelta[16][64][64]; // [piece][from_square][to_square]
+};
+
+
+#endif // !defined(MAXGAIN_H_INCLUDED)
+
diff --git a/src/position.cpp b/src/position.cpp
index a389e9c0..2508db66 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1301,6 +1301,11 @@ void Position::undo_null_move() {
}
+///
+PieceType Position::captured_piece() const {
+ return st->capture;
+}
+
/// Position::see() is a static exchange evaluator: It tries to estimate the
/// material gain or loss resulting from a move. There are three versions of
/// this function: One which takes a destination square as input, one takes a
diff --git a/src/position.h b/src/position.h
index c4dbfcf6..591107e4 100644
--- a/src/position.h
+++ b/src/position.h
@@ -241,6 +241,9 @@ public:
void do_null_move(StateInfo& st);
void undo_null_move();
+ // Past
+ PieceType captured_piece() const;
+
// Static exchange evaluation
int see(Square from, Square to) const;
int see(Move m) const;
diff --git a/src/search.cpp b/src/search.cpp
index e44dd854..6232f0cb 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -32,6 +32,7 @@
#include "book.h"
#include "evaluate.h"
#include "history.h"
+#include "maxgain.h"
#include "misc.h"
#include "movegen.h"
#include "movepick.h"
@@ -263,6 +264,8 @@ namespace {
// History table
History H;
+ // MaxGain table
+ MaxGain MG;
/// Functions