Stockfish 3

Stockfish bench signature is: 4176431

Readme.md

@@ -1,5 +1,4 @@
-1. Introduction
----------------
+### Overview
 
 Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is
 not a complete chess program and requires some UCI-compatible GUI
@@ -8,46 +7,41 @@ Partner or Fritz) in order to be used comfortably. Read the
 documentation for your GUI of choice for information about how to use
 Stockfish with it.
 
-This version of Stockfish supports up to 32 CPUs, but has not been
+This version of Stockfish supports up to 64 CPUs, but has not been
 tested thoroughly with more than 4.  The program tries to detect the
 number of CPUs on your computer and sets the number of search threads
 accordingly, but please be aware that the detection is not always
 correct. It is therefore recommended to inspect the value of the
-"Threads" UCI parameter, and to make sure it equals the number of CPU
+*Threads* UCI parameter, and to make sure it equals the number of CPU
 cores on your computer. If you are using more than eight threads, it is
-recommended to raise the value of the "Min Split Depth" UCI parameter to
-7.
+recommended to raise the value of the *Min Split Depth* UCI parameter to 7.
 
 
-2. Files
---------
+### Files
 
 This distribution of Stockfish consists of the following files:
 
-  * Readme.txt, the file you are currently reading.
+  * Readme.md, the file you are currently reading.
 
   * Copying.txt, a text file containing the GNU General Public License.
 
-  * src/, a subdirectory containing the full source code, including a
-    Makefile that can be used to compile Stockfish on Unix-like systems.
-    For further information about how to compile Stockfish yourself read
-    section 4 below.
+  * src/, a subdirectory containing the full source code, including a Makefile
+    that can be used to compile Stockfish on Unix-like systems. For further
+    information about how to compile Stockfish yourself read section below.
 
   * polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
     adapter.
 
 
-3. Opening books
-----------------
+### Opening books
 
 This version of Stockfish has support for PolyGlot opening books. For
 information about how to create such books, consult the PolyGlot
-documentation. The book file can be selected by setting the "Book File"
+documentation. The book file can be selected by setting the *Book File*
 UCI parameter.
 
 
-4. Compiling it yourself
-------------------------
+### Compiling it yourself
 
 On Unix-like systems, it should be possible to compile Stockfish
 directly from the source code with the included Makefile.
@@ -55,17 +49,16 @@ directly from the source code with the included Makefile.
 Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT
 instruction, big-endian machines such as Power PC, and other platforms.
 
-In general it is recommended to run 'make help' to see a list of make
+In general it is recommended to run `make help` to see a list of make
 targets with corresponding descriptions. When not using Makefile to
 compile (for instance with Microsoft MSVC) you need to manually
-set/unset some switches in the compiler command line; see file "types.h"
+set/unset some switches in the compiler command line; see file *types.h*
 for a quick reference.
 
 
-5. Terms of use
----------------
+### Terms of use
 
-Stockfish is free, and distributed under the GNU General Public License
+Stockfish is free, and distributed under the **GNU General Public License**
 (GPL). Essentially, this means that you are free to do almost exactly
 what you want with the program, including distributing it among your
 friends, making it available for download from your web site, selling
@@ -78,4 +71,4 @@ to where the source code can be found. If you make any changes to the
 source code, these changes must also be made available under the GPL.
 
 For full details, read the copy of the GPL found in the file named
-Copying.txt.
+*Copying.txt*

polyglot.ini

@@ -1,4 +1,3 @@
-
 [PolyGlot]
 
 EngineDir = .
@@ -19,6 +18,7 @@ Use Search Log = false
 Search Log Filename = SearchLog.txt
 Book File = book.bin
 Best Book Move = false
+Contempt Factor = 0
 Mobility (Middle Game) = 100
 Mobility (Endgame) = 100
 Passed Pawns (Middle Game) = 100
@@ -29,7 +29,7 @@ Cowardice = 100
 Min Split Depth = 4
 Max Threads per Split Point = 5
 Threads = 1
-Use Sleeping Threads = true
+Use Sleeping Threads = false
 Hash = 128
 Ponder = true
 OwnBook = false

src/Makefile

@@ -1,6 +1,6 @@
 # Stockfish, a UCI chess playing engine derived from Glaurung 2.1
 # Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-# Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+# Copyright (C) 2008-2013 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
@@ -58,6 +58,7 @@ OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
 # bsfq = yes/no       --- -DUSE_BSFQ       --- Use bsfq x86_64 asm-instruction (only
 #                                              with GCC and ICC 64-bit)
 # popcnt = yes/no     --- -DUSE_POPCNT     --- Use popcnt x86_64 asm-instruction
+# sse = yes/no        --- -msse            --- Use Intel Streaming SIMD Extensions
 #
 # Note that Makefile is space sensitive, so when adding new architectures
 # or modifying existing flags, you have to make sure there are no extra spaces
@@ -77,6 +78,7 @@ ifeq ($(ARCH),general-64)
 	prefetch = no
 	bsfq = no
 	popcnt = no
+	sse = no
 endif
 
 ifeq ($(ARCH),general-32)
@@ -86,6 +88,7 @@ ifeq ($(ARCH),general-32)
 	prefetch = no
 	bsfq = no
 	popcnt = no
+	sse = no
 endif
 
 # x86-section
@@ -96,6 +99,7 @@ ifeq ($(ARCH),x86-64)
 	prefetch = yes
 	bsfq = yes
 	popcnt = no
+	sse = yes
 endif
 
 ifeq ($(ARCH),x86-64-modern)
@@ -105,6 +109,7 @@ ifeq ($(ARCH),x86-64-modern)
 	prefetch = yes
 	bsfq = yes
 	popcnt = yes
+	sse = yes
 endif
 
 ifeq ($(ARCH),x86-32)
@@ -114,6 +119,7 @@ ifeq ($(ARCH),x86-32)
 	prefetch = yes
 	bsfq = no
 	popcnt = no
+	sse = yes
 endif
 
 ifeq ($(ARCH),x86-32-old)
@@ -123,6 +129,18 @@ ifeq ($(ARCH),x86-32-old)
 	prefetch = no
 	bsfq = no
 	popcnt = no
+	sse = no
+endif
+
+#arm section
+ifeq ($(ARCH),armv7)
+	arch = armv7
+	os = any
+	bits = 32
+	prefetch = yes
+	bsfq = yes
+	popcnt = no
+	sse = no
 endif
 
 # osx-section
@@ -133,6 +151,7 @@ ifeq ($(ARCH),osx-ppc-64)
 	prefetch = no
 	bsfq = no
 	popcnt = no
+	sse = no
 endif
 
 ifeq ($(ARCH),osx-ppc-32)
@@ -142,6 +161,7 @@ ifeq ($(ARCH),osx-ppc-32)
 	prefetch = no
 	bsfq = no
 	popcnt = no
+	sse = no
 endif
 
 ifeq ($(ARCH),osx-x86-64)
@@ -151,6 +171,7 @@ ifeq ($(ARCH),osx-x86-64)
 	prefetch = yes
 	bsfq = yes
 	popcnt = no
+	sse = yes
 endif
 
 ifeq ($(ARCH),osx-x86-32)
@@ -160,6 +181,7 @@ ifeq ($(ARCH),osx-x86-32)
 	prefetch = yes
 	bsfq = no
 	popcnt = no
+	sse = yes
 endif
 
 
@@ -220,7 +242,7 @@ ifeq ($(comp),mingw)
 endif
 
 ifeq ($(comp),icc)
-	CXXFLAGS += -wd383,981,1418,1419,10187,10188,11505,11503 -Wcheck -Wabi -Wdeprecated -strict-ansi
+	CXXFLAGS += -wd383,981,1418,1419,1476,10187,10188,11505,11503 -Wcheck -Wabi -Wdeprecated -strict-ansi
 endif
 
 ifeq ($(comp),clang)
@@ -228,12 +250,16 @@ ifeq ($(comp),clang)
 endif
 
 ifeq ($(os),osx)
-	CXXFLAGS += -arch $(arch)
+	CXXFLAGS += -arch $(arch) -mmacosx-version-min=10.0
 endif
 
 ### 3.3 General linker settings
 LDFLAGS = $(EXTRALDFLAGS)
 
+ifeq ($(comp),mingw)
+	LDFLAGS += -static-libstdc++ -static-libgcc
+endif
+
 ### On mingw use Windows threads, otherwise POSIX
 ifneq ($(comp),mingw)
 	# Haiku has pthreads in its libroot, so only link it in on other platforms
@@ -243,7 +269,7 @@ ifneq ($(comp),mingw)
 endif
 
 ifeq ($(os),osx)
-	LDFLAGS += -arch $(arch)
+	LDFLAGS += -arch $(arch) -mmacosx-version-min=10.0
 endif
 
 ### 3.4 Debugging
@@ -265,6 +291,10 @@ ifeq ($(optimize),yes)
 				CXXFLAGS += -mdynamic-no-pic
 			endif
 		endif
+
+		ifeq ($(arch),armv7)
+			CXXFLAGS += -fno-gcse
+		endif
 	endif
 
 	ifeq ($(comp),mingw)
@@ -301,8 +331,10 @@ endif
 
 ### 3.7 prefetch
 ifeq ($(prefetch),yes)
-	CXXFLAGS += -msse
-	DEPENDFLAGS += -msse
+	ifeq ($(sse),yes)
+		CXXFLAGS += -msse
+		DEPENDFLAGS += -msse
+	endif
 else
 	CXXFLAGS += -DNO_PREFETCH
 endif
@@ -360,6 +392,7 @@ help:
 	@echo "osx-ppc-32           > PPC-Mac OS X 32 bit"
 	@echo "osx-x86-64           > x86-Mac OS X 64 bit"
 	@echo "osx-x86-32           > x86-Mac OS X 32 bit"
+	@echo "armv7                > ARMv7 32 bit"
 	@echo "general-64           > unspecified 64-bit"
 	@echo "general-32           > unspecified 32-bit"
 	@echo ""
@@ -438,6 +471,7 @@ config-sanity:
 	@echo "prefetch: '$(prefetch)'"
 	@echo "bsfq: '$(bsfq)'"
 	@echo "popcnt: '$(popcnt)'"
+	@echo "sse: '$(sse)'"
 	@echo ""
 	@echo "Flags:"
 	@echo "CXX: $(CXX)"
@@ -449,12 +483,13 @@ config-sanity:
 	@test "$(debug)" = "yes" || test "$(debug)" = "no"
 	@test "$(optimize)" = "yes" || test "$(optimize)" = "no"
 	@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
-	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc"
+	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || test "$(arch)" = "armv7"
 	@test "$(os)" = "any" || test "$(os)" = "osx"
 	@test "$(bits)" = "32" || test "$(bits)" = "64"
 	@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
 	@test "$(bsfq)" = "yes" || test "$(bsfq)" = "no"
 	@test "$(popcnt)" = "yes" || test "$(popcnt)" = "no"
+	@test "$(sse)" = "yes" || test "$(sse)" = "no"
 	@test "$(comp)" = "gcc" || test "$(comp)" = "icc" || test "$(comp)" = "mingw" || test "$(comp)" = "clang"
 
 $(EXE): $(OBJS)

src/benchmark.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -66,7 +66,7 @@ void benchmark(const Position& current, istream& is) {
   vector<string> fens;
 
   // Assign default values to missing arguments
-  string ttSize    = (is >> token) ? token : "128";
+  string ttSize    = (is >> token) ? token : "32";
   string threads   = (is >> token) ? token : "1";
   string limit     = (is >> token) ? token : "12";
   string fenFile   = (is >> token) ? token : "default";
@@ -82,6 +82,9 @@ void benchmark(const Position& current, istream& is) {
   else if (limitType == "nodes")
       limits.nodes = atoi(limit.c_str());
 
+  else if (limitType == "mate")
+      limits.mate = atoi(limit.c_str());
+
   else
       limits.depth = atoi(limit.c_str());
 
@@ -89,7 +92,7 @@ void benchmark(const Position& current, istream& is) {
       fens.assign(Defaults, Defaults + 16);
 
   else if (fenFile == "current")
-      fens.push_back(current.to_fen());
+      fens.push_back(current.fen());
 
   else
   {
@@ -99,7 +102,7 @@ void benchmark(const Position& current, istream& is) {
       if (!file.is_open())
       {
           cerr << "Unable to open file " << fenFile << endl;
-          exit(EXIT_FAILURE);
+          return;
       }
 
       while (getline(file, fen))
@@ -127,9 +130,9 @@ void benchmark(const Position& current, istream& is) {
       }
       else
       {
-          Threads.start_searching(pos, limits, vector<Move>(), st);
-          Threads.wait_for_search_finished();
-          nodes += Search::RootPosition.nodes_searched();
+          Threads.start_thinking(pos, limits, vector<Move>(), st);
+          Threads.wait_for_think_finished();
+          nodes += Search::RootPos.nodes_searched();
       }
   }
 

src/bitbase.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -18,12 +18,32 @@
 */
 
 #include <cassert>
+#include <vector>
 
 #include "bitboard.h"
 #include "types.h"
 
 namespace {
 
+  // The possible pawns squares are 24, the first 4 files and ranks from 2 to 7
+  const unsigned IndexMax = 2*24*64*64; // stm * psq * wksq * bksq = 196608
+
+  // Each uint32_t stores results of 32 positions, one per bit
+  uint32_t KPKBitbase[IndexMax / 32];
+
+  // A KPK bitbase index is an integer in [0, IndexMax] range
+  //
+  // Information is mapped in a way that minimizes number of iterations:
+  //
+  // bit  0- 5: white king square (from SQ_A1 to SQ_H8)
+  // bit  6-11: black king square (from SQ_A1 to SQ_H8)
+  // bit    12: side to move (WHITE or BLACK)
+  // bit 13-14: white pawn file (from FILE_A to FILE_D)
+  // bit 15-17: white pawn 6 - rank (from 6 - RANK_7 to 6 - RANK_2)
+  unsigned index(Color us, Square bksq, Square wksq, Square psq) {
+    return wksq + (bksq << 6) + (us << 12) + (file_of(psq) << 13) + ((6 - rank_of(psq)) << 15);
+  }
+
   enum Result {
     INVALID = 0,
     UNKNOWN = 1,
@@ -35,196 +55,119 @@ namespace {
 
   struct KPKPosition {
 
-    Result classify_leaf(int idx);
-    Result classify(int idx, Result db[]);
+    operator Result() const { return res; }
+    Result classify_leaf(unsigned idx);
+    Result classify(const std::vector<KPKPosition>& db)
+    { return us == WHITE ? classify<WHITE>(db) : classify<BLACK>(db); }
 
   private:
-    template<Color Us> Result classify(const Result db[]) const;
+    template<Color Us> Result classify(const std::vector<KPKPosition>& db);
 
-    template<Color Us> Bitboard k_attacks() const {
-      return Us == WHITE ? StepAttacksBB[W_KING][wksq] : StepAttacksBB[B_KING][bksq];
-    }
-
-    Bitboard p_attacks() const { return StepAttacksBB[W_PAWN][psq]; }
-    void decode_index(int idx);
-
-    Square wksq, bksq, psq;
-    Color stm;
+    Color us;
+    Square bksq, wksq, psq;
+    Result res;
   };
 
-  // The possible pawns squares are 24, the first 4 files and ranks from 2 to 7
-  const int IndexMax = 2 * 24 * 64 * 64; // stm * wp_sq * wk_sq * bk_sq = 196608
-
-  // Each uint32_t stores results of 32 positions, one per bit
-  uint32_t KPKBitbase[IndexMax / 32];
-
-  int index(Square wksq, Square bksq, Square psq, Color stm);
-}
+} // namespace
 
 
-uint32_t Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
+bool Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color us) {
 
-  int idx = index(wksq, bksq, wpsq, stm);
-  return KPKBitbase[idx / 32] & (1 << (idx & 31));
+  assert(file_of(wpsq) <= FILE_D);
+
+  unsigned idx = index(us, bksq, wksq, wpsq);
+  return KPKBitbase[idx / 32] & (1 << (idx & 0x1F));
 }
 
 
 void Bitbases::init_kpk() {
 
-  Result db[IndexMax];
-  KPKPosition pos;
-  int idx, bit, repeat = 1;
+  unsigned idx, repeat = 1;
+  std::vector<KPKPosition> db(IndexMax);
 
-  // Initialize table with known win / draw positions
+  // Initialize db with known win / draw positions
   for (idx = 0; idx < IndexMax; idx++)
-      db[idx] = pos.classify_leaf(idx);
+      db[idx].classify_leaf(idx);
 
-  // Iterate until all positions are classified (30 cycles needed)
+  // Iterate through the positions until no more of the unknown positions can be
+  // changed to either wins or draws (15 cycles needed).
   while (repeat)
       for (repeat = idx = 0; idx < IndexMax; idx++)
-          if (db[idx] == UNKNOWN && (db[idx] = pos.classify(idx, db)) != UNKNOWN)
+          if (db[idx] == UNKNOWN && db[idx].classify(db) != UNKNOWN)
               repeat = 1;
 
-  // Map 32 position results into one KPKBitbase[] entry
-  for (idx = 0; idx < IndexMax / 32; idx++)
-      for (bit = 0; bit < 32; bit++)
-          if (db[32 * idx + bit] == WIN)
-              KPKBitbase[idx] |= 1 << bit;
+  // Map 32 results into one KPKBitbase[] entry
+  for (idx = 0; idx < IndexMax; idx++)
+      if (db[idx] == WIN)
+          KPKBitbase[idx / 32] |= 1 << (idx & 0x1F);
 }
 
 
 namespace {
 
-  // A KPK bitbase index is an integer in [0, IndexMax] range
-  //
-  // Information is mapped in this way
-  //
-  // bit     0: side to move (WHITE or BLACK)
-  // bit  1- 6: black king square (from SQ_A1 to SQ_H8)
-  // bit  7-12: white king square (from SQ_A1 to SQ_H8)
-  // bit 13-14: white pawn file (from FILE_A to FILE_D)
-  // bit 15-17: white pawn rank - 1 (from RANK_2 - 1 to RANK_7 - 1)
+  Result KPKPosition::classify_leaf(unsigned idx) {
 
-  int index(Square w, Square b, Square p, Color c) {
-
-    assert(file_of(p) <= FILE_D);
-
-    return c + (b << 1) + (w << 7) + (file_of(p) << 13) + ((rank_of(p) - 1) << 15);
-  }
-
-  void KPKPosition::decode_index(int idx) {
-
-    stm  = Color(idx & 1);
-    bksq = Square((idx >> 1) & 63);
-    wksq = Square((idx >> 7) & 63);
-    psq  = File((idx >> 13) & 3) | Rank((idx >> 15) + 1);
-  }
-
-  Result KPKPosition::classify_leaf(int idx) {
-
-    decode_index(idx);
+    wksq = Square((idx >> 0) & 0x3F);
+    bksq = Square((idx >> 6) & 0x3F);
+    us   = Color((idx >> 12) & 0x01);
+    psq  = File((idx >> 13) & 3) | Rank(6 - (idx >> 15));
 
     // Check if two pieces are on the same square or if a king can be captured
     if (   wksq == psq || wksq == bksq || bksq == psq
-        || (k_attacks<WHITE>() & bksq)
-        || (stm == WHITE && (p_attacks() & bksq)))
-        return INVALID;
+        || (StepAttacksBB[KING][wksq] & bksq)
+        || (us == WHITE && (StepAttacksBB[PAWN][psq] & bksq)))
+        return res = INVALID;
 
-    // The position is an immediate win if it is white to move and the white
-    // pawn can be promoted without getting captured.
-    if (   rank_of(psq) == RANK_7
-        && stm == WHITE
-        && wksq != psq + DELTA_N
-        && (   square_distance(bksq, psq + DELTA_N) > 1
-            ||(k_attacks<WHITE>() & (psq + DELTA_N))))
-        return WIN;
+    if (us == WHITE)
+    {
+        // Immediate win if pawn can be promoted without getting captured
+        if (   rank_of(psq) == RANK_7
+            && wksq != psq + DELTA_N
+            && (   square_distance(bksq, psq + DELTA_N) > 1
+                ||(StepAttacksBB[KING][wksq] & (psq + DELTA_N))))
+            return res = WIN;
+    }
+    // Immediate draw if is stalemate or king captures undefended pawn
+    else if (  !(StepAttacksBB[KING][bksq] & ~(StepAttacksBB[KING][wksq] | StepAttacksBB[PAWN][psq]))
+             || (StepAttacksBB[KING][bksq] & psq & ~StepAttacksBB[KING][wksq]))
+        return res = DRAW;
 
-    // Check for known draw positions
-    //
-    // Case 1: Stalemate
-    if (   stm == BLACK
-        && !(k_attacks<BLACK>() & ~(k_attacks<WHITE>() | p_attacks())))
-        return DRAW;
-
-    // Case 2: King can capture undefended pawn
-    if (   stm == BLACK
-        && (k_attacks<BLACK>() & psq & ~k_attacks<WHITE>()))
-        return DRAW;
-
-    // Case 3: Black king in front of white pawn
-    if (   bksq == psq + DELTA_N
-        && rank_of(psq) < RANK_7)
-        return DRAW;
-
-    // Case 4: White king in front of pawn and black has opposition
-    if (   stm == WHITE
-        && wksq == psq + DELTA_N
-        && bksq == wksq + DELTA_N + DELTA_N
-        && rank_of(psq) < RANK_5)
-        return DRAW;
-
-    // Case 5: Stalemate with rook pawn
-    if (   bksq == SQ_A8
-        && file_of(psq) == FILE_A)
-        return DRAW;
-
-    // Case 6: White king trapped on the rook file
-    if (   file_of(wksq) == FILE_A
-        && file_of(psq) == FILE_A
-        && rank_of(wksq) > rank_of(psq)
-        && bksq == wksq + 2)
-        return DRAW;
-
-    return UNKNOWN;
+    return res = UNKNOWN;
   }
 
   template<Color Us>
-  Result KPKPosition::classify(const Result db[]) const {
+  Result KPKPosition::classify(const std::vector<KPKPosition>& db) {
 
-    // White to Move: If one move leads to a position classified as RESULT_WIN,
-    // the result of the current position is RESULT_WIN. If all moves lead to
-    // positions classified as RESULT_DRAW, the current position is classified
-    // RESULT_DRAW otherwise the current position is classified as RESULT_UNKNOWN.
+    // White to Move: If one move leads to a position classified as WIN, the result
+    // of the current position is WIN. If all moves lead to positions classified
+    // as DRAW, the current position is classified DRAW otherwise the current
+    // position is classified as UNKNOWN.
     //
-    // Black to Move: If one move leads to a position classified as RESULT_DRAW,
-    // the result of the current position is RESULT_DRAW. If all moves lead to
-    // positions classified as RESULT_WIN, the position is classified RESULT_WIN.
-    // Otherwise, the current position is classified as RESULT_UNKNOWN.
+    // Black to Move: If one move leads to a position classified as DRAW, the result
+    // of the current position is DRAW. If all moves lead to positions classified
+    // as WIN, the position is classified WIN otherwise the current position is
+    // classified UNKNOWN.
 
     Result r = INVALID;
-    Bitboard b = k_attacks<Us>();
+    Bitboard b = StepAttacksBB[KING][Us == WHITE ? wksq : bksq];
 
     while (b)
-    {
-        r |= Us == WHITE ? db[index(pop_lsb(&b), bksq, psq, BLACK)]
-                         : db[index(wksq, pop_lsb(&b), psq, WHITE)];
-
-        if (Us == WHITE && (r & WIN))
-            return WIN;
-
-        if (Us == BLACK && (r & DRAW))
-            return DRAW;
-    }
+        r |= Us == WHITE ? db[index(~Us, bksq, pop_lsb(&b), psq)]
+                         : db[index(~Us, pop_lsb(&b), wksq, psq)];
 
     if (Us == WHITE && rank_of(psq) < RANK_7)
     {
         Square s = psq + DELTA_N;
-        r |= db[index(wksq, bksq, s, BLACK)]; // Single push
+        r |= db[index(BLACK, bksq, wksq, s)]; // Single push
 
         if (rank_of(s) == RANK_3 && s != wksq && s != bksq)
-            r |= db[index(wksq, bksq, s + DELTA_N, BLACK)]; // Double push
-
-        if (r & WIN)
-            return WIN;
+            r |= db[index(BLACK, bksq, wksq, s + DELTA_N)]; // Double push
     }
 
-    return r & UNKNOWN ? UNKNOWN : Us == WHITE ? DRAW : WIN;
+    if (Us == WHITE)
+        return res = r & WIN  ? WIN  : r & UNKNOWN ? UNKNOWN : DRAW;
+    else
+        return res = r & DRAW ? DRAW : r & UNKNOWN ? UNKNOWN : WIN;
   }
 
-  Result KPKPosition::classify(int idx, Result db[]) {
-
-    decode_index(idx);
-    return stm == WHITE ? classify<WHITE>(db) : classify<BLACK>(db);
-  }
-
-}
+} // namespace

src/bitboard.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -28,45 +28,44 @@
 
 CACHE_LINE_ALIGNMENT
 
-Bitboard RMasks[64];
-Bitboard RMagics[64];
-Bitboard* RAttacks[64];
-unsigned RShifts[64];
+Bitboard RMasks[SQUARE_NB];
+Bitboard RMagics[SQUARE_NB];
+Bitboard* RAttacks[SQUARE_NB];
+unsigned RShifts[SQUARE_NB];
 
-Bitboard BMasks[64];
-Bitboard BMagics[64];
-Bitboard* BAttacks[64];
-unsigned BShifts[64];
+Bitboard BMasks[SQUARE_NB];
+Bitboard BMagics[SQUARE_NB];
+Bitboard* BAttacks[SQUARE_NB];
+unsigned BShifts[SQUARE_NB];
 
-Bitboard SquareBB[64];
-Bitboard FileBB[8];
-Bitboard RankBB[8];
-Bitboard AdjacentFilesBB[8];
-Bitboard ThisAndAdjacentFilesBB[8];
-Bitboard InFrontBB[2][8];
-Bitboard StepAttacksBB[16][64];
-Bitboard BetweenBB[64][64];
-Bitboard DistanceRingsBB[64][8];
-Bitboard ForwardBB[2][64];
-Bitboard PassedPawnMask[2][64];
-Bitboard AttackSpanMask[2][64];
-Bitboard PseudoAttacks[6][64];
+Bitboard SquareBB[SQUARE_NB];
+Bitboard FileBB[FILE_NB];
+Bitboard RankBB[RANK_NB];
+Bitboard AdjacentFilesBB[FILE_NB];
+Bitboard ThisAndAdjacentFilesBB[FILE_NB];
+Bitboard InFrontBB[COLOR_NB][RANK_NB];
+Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+Bitboard DistanceRingsBB[SQUARE_NB][8];
+Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
+Bitboard AttackSpanMask[COLOR_NB][SQUARE_NB];
+Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
-int SquareDistance[64][64];
+int SquareDistance[SQUARE_NB][SQUARE_NB];
 
 namespace {
 
   // De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan
-  const uint64_t DeBruijn_64 = 0x218A392CD3D5DBFULL;
+  const uint64_t DeBruijn_64 = 0x3F79D71B4CB0A89ULL;
   const uint32_t DeBruijn_32 = 0x783A9B23;
 
   CACHE_LINE_ALIGNMENT
 
   int MS1BTable[256];
-  Square BSFTable[64];
+  Square BSFTable[SQUARE_NB];
   Bitboard RTable[0x19000]; // Storage space for rook attacks
   Bitboard BTable[0x1480];  // Storage space for bishop attacks
-  uint8_t BitCount8Bit[256];
 
   typedef unsigned (Fn)(Square, Bitboard);
 
@@ -75,12 +74,10 @@ namespace {
 
   FORCE_INLINE unsigned bsf_index(Bitboard b) {
 
-    if (Is64Bit)
-        return ((b & -b) * DeBruijn_64) >> 58;
-
-    // Use Matt Taylor's folding trick for 32 bit systems
+    // Matt Taylor's folding for 32 bit systems, extended to 64 bits by Kim Walisch
     b ^= (b - 1);
-    return ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26;
+    return Is64Bit ? (b * DeBruijn_64) >> 58
+                   : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26;
   }
 }
 
@@ -161,9 +158,6 @@ void Bitboards::init() {
   for (int i = 0; i < 64; i++)
       BSFTable[bsf_index(1ULL << i)] = Square(i);
 
-  for (Bitboard b = 0; b < 256; b++)
-      BitCount8Bit[b] = (uint8_t)popcount<Max15>(b);
-
   for (Square s = SQ_A1; s <= SQ_H8; s++)
       SquareBB[s] = 1ULL << s;
 
@@ -326,7 +320,7 @@ namespace {
         // until we find the one that passes the verification test.
         do {
             do magics[s] = pick_random(rk, booster);
-            while (BitCount8Bit[(magics[s] * masks[s]) >> 56] < 6);
+            while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
 
             memset(attacks[s], 0, size * sizeof(Bitboard));
 

src/bitboard.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -33,36 +33,37 @@ void print(Bitboard b);
 namespace Bitbases {
 
 void init_kpk();
-uint32_t probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
+bool probe_kpk(Square wksq, Square wpsq, Square bksq, Color us);
 
 }
 
 CACHE_LINE_ALIGNMENT
 
-extern Bitboard RMasks[64];
-extern Bitboard RMagics[64];
-extern Bitboard* RAttacks[64];
-extern unsigned RShifts[64];
+extern Bitboard RMasks[SQUARE_NB];
+extern Bitboard RMagics[SQUARE_NB];
+extern Bitboard* RAttacks[SQUARE_NB];
+extern unsigned RShifts[SQUARE_NB];
 
-extern Bitboard BMasks[64];
-extern Bitboard BMagics[64];
-extern Bitboard* BAttacks[64];
-extern unsigned BShifts[64];
+extern Bitboard BMasks[SQUARE_NB];
+extern Bitboard BMagics[SQUARE_NB];
+extern Bitboard* BAttacks[SQUARE_NB];
+extern unsigned BShifts[SQUARE_NB];
 
-extern Bitboard SquareBB[64];
-extern Bitboard FileBB[8];
-extern Bitboard RankBB[8];
-extern Bitboard AdjacentFilesBB[8];
-extern Bitboard ThisAndAdjacentFilesBB[8];
-extern Bitboard InFrontBB[2][8];
-extern Bitboard StepAttacksBB[16][64];
-extern Bitboard BetweenBB[64][64];
-extern Bitboard DistanceRingsBB[64][8];
-extern Bitboard ForwardBB[2][64];
-extern Bitboard PassedPawnMask[2][64];
-extern Bitboard AttackSpanMask[2][64];
-extern Bitboard PseudoAttacks[6][64];
+extern Bitboard SquareBB[SQUARE_NB];
+extern Bitboard FileBB[FILE_NB];
+extern Bitboard RankBB[RANK_NB];
+extern Bitboard AdjacentFilesBB[FILE_NB];
+extern Bitboard ThisAndAdjacentFilesBB[FILE_NB];
+extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
+extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard DistanceRingsBB[SQUARE_NB][8];
+extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
+extern Bitboard AttackSpanMask[COLOR_NB][SQUARE_NB];
+extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
+const Bitboard BlackSquares = 0xAA55AA55AA55AA55ULL;
 
 /// Overloads of bitwise operators between a Bitboard and a Square for testing
 /// whether a given bit is set in a bitboard, and for setting and clearing bits.
@@ -199,8 +200,7 @@ inline bool squares_aligned(Square s1, Square s2, Square s3) {
 /// the same color of the given square.
 
 inline Bitboard same_color_squares(Square s) {
-  return Bitboard(0xAA55AA55AA55AA55ULL) & s ?  0xAA55AA55AA55AA55ULL
-                                             : ~0xAA55AA55AA55AA55ULL;
+  return BlackSquares & s ? BlackSquares : ~BlackSquares;
 }
 
 
@@ -247,6 +247,21 @@ FORCE_INLINE Square msb(Bitboard b) {
   return (Square) index;
 }
 
+#  elif defined(__arm__)
+
+FORCE_INLINE int lsb32(uint32_t v) {
+  __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
+  return __builtin_clz(v);
+}
+
+FORCE_INLINE Square msb(Bitboard b) {
+  return (Square) (63 - __builtin_clzll(b));
+}
+
+FORCE_INLINE Square lsb(Bitboard b) {
+  return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
+}
+
 #  else
 
 FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
@@ -265,7 +280,7 @@ FORCE_INLINE Square msb(Bitboard b) {
 
 FORCE_INLINE Square pop_lsb(Bitboard* b) {
   const Square s = lsb(*b);
-  *b &= ~(1ULL << s);
+  *b &= *b - 1;
   return s;
 }
 

src/bitcount.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -33,8 +33,8 @@ enum BitCountType {
 };
 
 /// Determine at compile time the best popcount<> specialization according if
-/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count or
-/// use hardware popcnt instruction when available.
+/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count
+/// and if hardware popcnt instruction is available.
 const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32;
 const BitCountType Max15 = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64_MAX15 : CNT_32_MAX15;
 
@@ -44,44 +44,38 @@ template<BitCountType> inline int popcount(Bitboard);
 
 template<>
 inline int popcount<CNT_64>(Bitboard b) {
-  b -= ((b>>1) & 0x5555555555555555ULL);
-  b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
-  b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
-  b *= 0x0101010101010101ULL;
-  return int(b >> 56);
+  b -=  (b >> 1) & 0x5555555555555555ULL;
+  b  = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+  b  = ((b >> 4) + b) & 0x0F0F0F0F0F0F0F0FULL;
+  return (b * 0x0101010101010101ULL) >> 56;
 }
 
 template<>
 inline int popcount<CNT_64_MAX15>(Bitboard b) {
-  b -= (b>>1) & 0x5555555555555555ULL;
-  b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
-  b *= 0x1111111111111111ULL;
-  return int(b >> 60);
+  b -=  (b >> 1) & 0x5555555555555555ULL;
+  b  = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
+  return (b * 0x1111111111111111ULL) >> 60;
 }
 
 template<>
 inline int popcount<CNT_32>(Bitboard b) {
   unsigned w = unsigned(b >> 32), v = unsigned(b);
-  v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
-  w -= (w >> 1) & 0x55555555;
-  v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
-  w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
-  v = ((v >> 4) + v) & 0x0F0F0F0F; // 0-8 in 8 bits
-  v += (((w >> 4) + w) & 0x0F0F0F0F);  // 0-16 in 8 bits
-  v *= 0x01010101; // mul is fast on amd procs
-  return int(v >> 24);
+  v -=  (v >> 1) & 0x55555555; // 0-2 in 2 bits
+  w -=  (w >> 1) & 0x55555555;
+  v  = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
+  w  = ((w >> 2) & 0x33333333) + (w & 0x33333333);
+  v  = ((v >> 4) + v + (w >> 4) + w) & 0x0F0F0F0F;
+  return (v * 0x01010101) >> 24;
 }
 
 template<>
 inline int popcount<CNT_32_MAX15>(Bitboard b) {
   unsigned w = unsigned(b >> 32), v = unsigned(b);
-  v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
-  w -= (w >> 1) & 0x55555555;
-  v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
-  w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
-  v += w; // 0-8 in 4 bits
-  v *= 0x11111111;
-  return int(v >> 28);
+  v -=  (v >> 1) & 0x55555555; // 0-2 in 2 bits
+  w -=  (w >> 1) & 0x55555555;
+  v  = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
+  w  = ((w >> 2) & 0x33333333) + (w & 0x33333333);
+  return ((v + w) * 0x11111111) >> 28;
 }
 
 template<>
@@ -102,9 +96,8 @@ inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
 
 #else
 
-  unsigned long ret;
-  __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
-  return ret;
+  __asm__("popcnt %1, %0" : "=r" (b) : "r" (b));
+  return b;
 
 #endif
 }

src/book.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -38,7 +38,7 @@ namespace {
   // A Polyglot book is a series of "entries" of 16 bytes. All integers are
   // stored in big-endian format, with highest byte first (regardless of size).
   // The entries are ordered according to the key in ascending order.
-  struct BookEntry {
+  struct Entry {
     uint64_t key;
     uint16_t move;
     uint16_t count;
@@ -46,7 +46,15 @@ namespace {
   };
 
   // Random numbers from PolyGlot, used to compute book hash keys
-  const Key PolyGlotRandoms[781] = {
+  const union {
+    Key PolyGlotRandoms[781];
+    struct {
+      Key psq[12][64];  // [piece][square]
+      Key castle[4];    // [castle right]
+      Key enpassant[8]; // [file]
+      Key turn;
+    } Zobrist;
+  } PG = {{
     0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL,
     0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL,
     0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL,
@@ -308,51 +316,40 @@ namespace {
     0x003A93D8B2806962ULL, 0x1C99DED33CB890A1ULL, 0xCF3145DE0ADD4289ULL,
     0xD0E4427A5514FB72ULL, 0x77C621CC9FB3A483ULL, 0x67A34DAC4356550BULL,
     0xF8D626AAAF278509ULL
-  };
+  }};
 
-  // Offsets to the PolyGlotRandoms[] array of zobrist keys
-  const Key* ZobPiece     = PolyGlotRandoms;
-  const Key* ZobCastle    = ZobPiece     + 12 * 64; // Pieces * squares
-  const Key* ZobEnPassant = ZobCastle    + 4;       // Castle flags
-  const Key* ZobTurn      = ZobEnPassant + 8;       // Number of files
+  // polyglot_key() returns the PolyGlot hash key of the given position
+  Key polyglot_key(const Position& pos) {
 
-  // book_key() returns the PolyGlot hash key of the given position
-  uint64_t book_key(const Position& pos) {
-
-    uint64_t key = 0;
+    Key key = 0;
     Bitboard b = pos.pieces();
 
     while (b)
     {
-        // In PolyGlotRandoms[] pieces are stored in the following sequence:
-        // BP = 0, WP = 1, BN = 2, WN = 3, ... BK = 10, WK = 11
         Square s = pop_lsb(&b);
         Piece p = pos.piece_on(s);
-        int pieceOfs = 2 * (type_of(p) - 1) + (color_of(p) == WHITE);
-        key ^= ZobPiece[64 * pieceOfs + s];
+
+        // PolyGlot pieces are: BP = 0, WP = 1, BN = 2, ... BK = 10, WK = 11
+        key ^= PG.Zobrist.psq[2 * (type_of(p) - 1) + (color_of(p) == WHITE)][s];
     }
 
     b = pos.can_castle(ALL_CASTLES);
 
     while (b)
-        key ^= ZobCastle[pop_lsb(&b)];
+        key ^= PG.Zobrist.castle[pop_lsb(&b)];
 
     if (pos.ep_square() != SQ_NONE)
-        key ^= ZobEnPassant[file_of(pos.ep_square())];
+        key ^= PG.Zobrist.enpassant[file_of(pos.ep_square())];
 
     if (pos.side_to_move() == WHITE)
-        key ^= ZobTurn[0];
+        key ^= PG.Zobrist.turn;
 
     return key;
   }
 
 } // namespace
 
-PolyglotBook::PolyglotBook() {
-
-  for (int i = Time::now() % 10000; i > 0; i--)
-      RKiss.rand<unsigned>(); // Make random number generation less deterministic
-}
+PolyglotBook::PolyglotBook() : rkiss(Time::now() % 10000) {}
 
 PolyglotBook::~PolyglotBook() { if (is_open()) close(); }
 
@@ -370,7 +367,7 @@ template<typename T> PolyglotBook& PolyglotBook::operator>>(T& n) {
   return *this;
 }
 
-template<> PolyglotBook& PolyglotBook::operator>>(BookEntry& e) {
+template<> PolyglotBook& PolyglotBook::operator>>(Entry& e) {
   return *this >> e.key >> e.move >> e.count >> e.learn;
 }
 
@@ -400,13 +397,13 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest
   if (fileName != fName && !open(fName.c_str()))
       return MOVE_NONE;
 
-  BookEntry e;
+  Entry e;
   uint16_t best = 0;
   unsigned sum = 0;
   Move move = MOVE_NONE;
-  uint64_t key = book_key(pos);
+  Key key = polyglot_key(pos);
 
-  seekg(find_first(key) * sizeof(BookEntry), ios_base::beg);
+  seekg(find_first(key) * sizeof(Entry), ios_base::beg);
 
   while (*this >> e, e.key == key && good())
   {
@@ -416,7 +413,7 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest
       // Choose book move according to its score. If a move has a very
       // high score it has higher probability to be choosen than a move
       // with lower score. Note that first entry is always chosen.
-      if (   (sum && RKiss.rand<unsigned>() % sum < e.count)
+      if (   (sum && rkiss.rand<unsigned>() % sum < e.count)
           || (pickBest && e.count == best))
           move = Move(e.move);
   }
@@ -440,7 +437,7 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest
 
   // Add 'special move' flags and verify it is legal
   for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
-      if (move == (ml.move() & 0x3FFF))
+      if (move == (ml.move() ^ type_of(ml.move())))
           return ml.move();
 
   return MOVE_NONE;
@@ -451,12 +448,12 @@ Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest
 /// the book file for the given key. Returns the index of the leftmost book
 /// entry with the same key as the input.
 
-size_t PolyglotBook::find_first(uint64_t key) {
+size_t PolyglotBook::find_first(Key key) {
 
   seekg(0, ios::end); // Move pointer to end, so tellg() gets file's size
 
-  size_t low = 0, mid, high = (size_t)tellg() / sizeof(BookEntry) - 1;
-  BookEntry e;
+  size_t low = 0, mid, high = (size_t)tellg() / sizeof(Entry) - 1;
+  Entry e;
 
   assert(low <= high);
 
@@ -466,7 +463,7 @@ size_t PolyglotBook::find_first(uint64_t key) {
 
       assert(mid >= low && mid < high);
 
-      seekg(mid * sizeof(BookEntry), ios_base::beg);
+      seekg(mid * sizeof(Entry), ios_base::beg);
       *this >> e;
 
       if (key <= e.key)

src/book.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -36,9 +36,9 @@ private:
   template<typename T> PolyglotBook& operator>>(T& n);
 
   bool open(const char* fName);
-  size_t find_first(uint64_t key);
+  size_t find_first(Key key);
 
-  RKISS RKiss;
+  RKISS rkiss;
   std::string fileName;
 };
 

src/endgame.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -31,7 +31,7 @@ namespace {
 
   // Table used to drive the defending king towards the edge of the board
   // in KX vs K and KQ vs KR endgames.
-  const int MateTable[64] = {
+  const int MateTable[SQUARE_NB] = {
     100, 90, 80, 70, 70, 80, 90, 100,
      90, 70, 60, 50, 50, 60, 70,  90,
      80, 60, 40, 30, 30, 40, 60,  80,
@@ -44,7 +44,7 @@ namespace {
 
   // Table used to drive the defending king towards a corner square of the
   // right color in KBN vs K endgames.
-  const int KBNKMateTable[64] = {
+  const int KBNKMateTable[SQUARE_NB] = {
     200, 190, 180, 170, 160, 150, 140, 130,
     190, 180, 170, 160, 150, 140, 130, 140,
     180, 170, 155, 140, 140, 125, 140, 150,
@@ -95,10 +95,12 @@ Endgames::Endgames() {
   add<KRKP>("KRKP");
   add<KRKB>("KRKB");
   add<KRKN>("KRKN");
+  add<KQKP>("KQKP");
   add<KQKR>("KQKR");
   add<KBBKN>("KBBKN");
 
   add<KNPK>("KNPK");
+  add<KNPKB>("KNPKB");
   add<KRPKR>("KRPKR");
   add<KBPKB>("KBPKB");
   add<KBPKN>("KBPKN");
@@ -132,7 +134,7 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
 
   // Stalemate detection with lone king
   if (    pos.side_to_move() == weakerSide
-      && !pos.in_check()
+      && !pos.checkers()
       && !MoveList<LEGAL>(pos).size()) {
     return VALUE_DRAW;
   }
@@ -169,12 +171,12 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
 
   Square winnerKSq = pos.king_square(strongerSide);
   Square loserKSq = pos.king_square(weakerSide);
-  Square bishopSquare = pos.piece_list(strongerSide, BISHOP)[0];
+  Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
 
   // kbnk_mate_table() tries to drive toward corners A1 or H8,
   // if we have a bishop that cannot reach the above squares we
   // mirror the kings so to drive enemy toward corners A8 or H1.
-  if (opposite_colors(bishopSquare, SQ_A1))
+  if (opposite_colors(bishopSq, SQ_A1))
   {
       winnerKSq = mirror(winnerKSq);
       loserKSq = mirror(loserKSq);
@@ -198,21 +200,21 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
   assert(pos.piece_count(weakerSide, PAWN) == 0);
 
   Square wksq, bksq, wpsq;
-  Color stm;
+  Color us;
 
   if (strongerSide == WHITE)
   {
       wksq = pos.king_square(WHITE);
       bksq = pos.king_square(BLACK);
       wpsq = pos.piece_list(WHITE, PAWN)[0];
-      stm = pos.side_to_move();
+      us   = pos.side_to_move();
   }
   else
   {
       wksq = ~pos.king_square(BLACK);
       bksq = ~pos.king_square(WHITE);
       wpsq = ~pos.piece_list(BLACK, PAWN)[0];
-      stm  = ~pos.side_to_move();
+      us   = ~pos.side_to_move();
   }
 
   if (file_of(wpsq) >= FILE_E)
@@ -222,7 +224,7 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
       wpsq = mirror(wpsq);
   }
 
-  if (!Bitbases::probe_kpk(wksq, wpsq, bksq, stm))
+  if (!Bitbases::probe_kpk(wksq, wpsq, bksq, us))
       return VALUE_DRAW;
 
   Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(wpsq));
@@ -326,6 +328,37 @@ Value Endgame<KRKN>::operator()(const Position& pos) const {
 }
 
 
+/// KQ vs KP.  In general, a win for the stronger side, however, there are a few
+/// important exceptions.  Pawn on 7th rank, A,C,F or H file, with king next can
+/// be a draw, so we scale down to distance between kings only.
+template<>
+Value Endgame<KQKP>::operator()(const Position& pos) const {
+
+  assert(pos.non_pawn_material(strongerSide) == QueenValueMg);
+  assert(pos.piece_count(strongerSide, PAWN) == 0);
+  assert(pos.non_pawn_material(weakerSide) == 0);
+  assert(pos.piece_count(weakerSide, PAWN) == 1);
+
+  Square winnerKSq = pos.king_square(strongerSide);
+  Square loserKSq = pos.king_square(weakerSide);
+  Square pawnSq = pos.piece_list(weakerSide, PAWN)[0];
+
+  Value result =  QueenValueEg
+                - PawnValueEg
+                + DistanceBonus[square_distance(winnerKSq, loserKSq)];
+
+  if (   square_distance(loserKSq, pawnSq) == 1
+      && relative_rank(weakerSide, pawnSq) == RANK_7)
+  {
+      File f = file_of(pawnSq);
+
+      if (f == FILE_A || f == FILE_C || f == FILE_F || f == FILE_H)
+          result = Value(DistanceBonus[square_distance(winnerKSq, loserKSq)]);
+  }
+  return strongerSide == pos.side_to_move() ? result : -result;
+}
+
+
 /// KQ vs KR.  This is almost identical to KX vs K:  We give the attacking
 /// king a bonus for having the kings close together, and for forcing the
 /// defending king towards the edge.  If we also take care to avoid null move
@@ -439,6 +472,29 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
               return SCALE_FACTOR_DRAW;
       }
   }
+
+  // All pawns on same B or G file? Then potential draw
+  if (    (pawnFile == FILE_B || pawnFile == FILE_G)
+      && !(pos.pieces(PAWN) & ~file_bb(pawnFile))
+      && pos.non_pawn_material(weakerSide) == 0
+      && pos.piece_count(weakerSide, PAWN) >= 1)
+  {
+      // Get weaker pawn closest to opponent's queening square
+      Bitboard wkPawns = pos.pieces(weakerSide, PAWN);
+      Square weakerPawnSq = strongerSide == WHITE ? msb(wkPawns) : lsb(wkPawns);
+
+      Square strongerKingSq = pos.king_square(strongerSide);
+      Square weakerKingSq = pos.king_square(weakerSide);
+      Square bishopSq = pos.piece_list(strongerSide, BISHOP)[0];
+
+      // Draw if weaker pawn is on rank 7, bishop can't attack the pawn, and
+      // weaker king can stop opposing opponent's king from penetrating.
+      if (   relative_rank(strongerSide, weakerPawnSq) == RANK_7
+          && opposite_colors(bishopSq, weakerPawnSq)
+          && square_distance(weakerPawnSq, weakerKingSq) <= square_distance(weakerPawnSq, strongerKingSq))
+          return SCALE_FACTOR_DRAW;
+  }
+
   return SCALE_FACTOR_NONE;
 }
 
@@ -849,6 +905,24 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
 }
 
 
+/// K, knight and a pawn vs K and bishop. If knight can block bishop from taking
+/// pawn, it's a win. Otherwise, drawn.
+template<>
+ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
+
+  Square pawnSq = pos.piece_list(strongerSide, PAWN)[0];
+  Square bishopSq = pos.piece_list(weakerSide, BISHOP)[0];
+  Square weakerKingSq = pos.king_square(weakerSide);
+
+  // King needs to get close to promoting pawn to prevent knight from blocking.
+  // Rules for this are very tricky, so just approximate.
+  if (forward_bb(strongerSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
+      return ScaleFactor(square_distance(weakerKingSq, pawnSq));
+
+  return SCALE_FACTOR_NONE;
+}
+
+
 /// K and a pawn vs K and a pawn. This is done by removing the weakest side's
 /// pawn and probing the KP vs K bitbase: If the weakest side has a draw without
 /// the pawn, she probably has at least a draw with the pawn as well. The exception
@@ -865,14 +939,14 @@ ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
   Square wksq = pos.king_square(strongerSide);
   Square bksq = pos.king_square(weakerSide);
   Square wpsq = pos.piece_list(strongerSide, PAWN)[0];
-  Color stm = pos.side_to_move();
+  Color us = pos.side_to_move();
 
   if (strongerSide == BLACK)
   {
       wksq = ~wksq;
       bksq = ~bksq;
       wpsq = ~wpsq;
-      stm  = ~stm;
+      us   = ~us;
   }
 
   if (file_of(wpsq) >= FILE_E)
@@ -890,5 +964,5 @@ ScaleFactor Endgame<KPKP>::operator()(const Position& pos) const {
 
   // Probe the KPK bitbase with the weakest side's pawn removed. If it's a draw,
   // it's probably at least a draw even with the pawn.
-  return Bitbases::probe_kpk(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
+  return Bitbases::probe_kpk(wksq, wpsq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
 }

src/endgame.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -39,6 +39,7 @@ enum EndgameType {
   KRKP,  // KR vs KP
   KRKB,  // KR vs KB
   KRKN,  // KR vs KN
+  KQKP,  // KQ vs KP
   KQKR,  // KQ vs KR
   KBBKN, // KBB vs KN
   KNNK,  // KNN vs K
@@ -57,6 +58,7 @@ enum EndgameType {
   KBPPKB,  // KBPP vs KB
   KBPKN,   // KBP vs KN
   KNPK,    // KNP vs K
+  KNPKB,   // KNP vs KB
   KPKP     // KP vs KP
 };
 
@@ -111,7 +113,7 @@ class Endgames {
 
 public:
   Endgames();
-  ~Endgames();
+ ~Endgames();
 
   template<typename T> T probe(Key key, T& eg)
   { return eg = map(eg).count(key) ? map(eg)[key] : NULL; }

src/evaluate.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -36,13 +36,13 @@ namespace {
   struct EvalInfo {
 
     // Pointers to material and pawn hash table entries
-    MaterialEntry* mi;
-    PawnEntry* pi;
+    Material::Entry* mi;
+    Pawns::Entry* pi;
 
     // attackedBy[color][piece type] is a bitboard representing all squares
-    // attacked by a given color and piece type, attackedBy[color][0] contains
-    // all squares attacked by the given color.
-    Bitboard attackedBy[2][8];
+    // attacked by a given color and piece type, attackedBy[color][ALL_PIECES]
+    // contains all squares attacked by the given color.
+    Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
 
     // kingRing[color] is the zone around the king which is considered
     // by the king safety evaluation. This consists of the squares directly
@@ -50,25 +50,25 @@ namespace {
     // squares two ranks in front of the king. For instance, if black's king
     // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8,
     // f7, g7, h7, f6, g6 and h6.
-    Bitboard kingRing[2];
+    Bitboard kingRing[COLOR_NB];
 
     // kingAttackersCount[color] is the number of pieces of the given color
     // which attack a square in the kingRing of the enemy king.
-    int kingAttackersCount[2];
+    int kingAttackersCount[COLOR_NB];
 
     // kingAttackersWeight[color] is the sum of the "weight" of the pieces of the
     // given color which attack a square in the kingRing of the enemy king. The
     // weights of the individual piece types are given by the variables
     // QueenAttackWeight, RookAttackWeight, BishopAttackWeight and
     // KnightAttackWeight in evaluate.cpp
-    int kingAttackersWeight[2];
+    int kingAttackersWeight[COLOR_NB];
 
     // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
     // directly adjacent to the king of the given color. Pieces which attack
     // more than one square are counted multiple times. For instance, if black's
     // king is on g8 and there's a white knight on g5, this knight adds
     // 2 to kingAdjacentZoneAttacksCount[BLACK].
-    int kingAdjacentZoneAttacksCount[2];
+    int kingAdjacentZoneAttacksCount[COLOR_NB];
   };
 
   // Evaluation grain size, must be a power of 2
@@ -88,7 +88,7 @@ namespace {
   //
   // Values modified by Joona Kiiski
   const Score WeightsInternal[] = {
-      S(252, 344), S(216, 266), S(46, 0), S(247, 0), S(259, 0)
+      S(289, 344), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
   };
 
   // MobilityBonus[PieceType][attacked] contains mobility bonuses for middle and
@@ -114,7 +114,7 @@ namespace {
 
   // OutpostBonus[PieceType][Square] contains outpost bonuses of knights and
   // bishops, indexed by piece type and square (from white's point of view).
-  const Value OutpostBonus[][64] = {
+  const Value OutpostBonus[][SQUARE_NB] = {
   {
   //  A     B     C     D     E     F     G     H
     V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights
@@ -134,7 +134,7 @@ namespace {
 
   // ThreatBonus[attacking][attacked] contains threat bonuses according to
   // which piece type attacks which one.
-  const Score ThreatBonus[][8] = {
+  const Score ThreatBonus[][PIECE_TYPE_NB] = {
     {}, {},
     { S(0, 0), S( 7, 39), S( 0,  0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
     { S(0, 0), S( 7, 39), S(24, 49), S( 0,  0), S(41,100), S(41,100) }, // BISHOP
@@ -150,16 +150,18 @@ namespace {
 
   #undef S
 
+  const Score BishopPinBonus = make_score(66, 11);
+
   // Bonus for having the side to move (modified by Joona Kiiski)
   const Score Tempo = make_score(24, 11);
 
   // Rooks and queens on the 7th rank
-  const Score RookOn7thBonus  = make_score(3, 20);
-  const Score QueenOn7thBonus = make_score(1,  8);
+  const Score RookOn7thBonus  = make_score(11, 20);
+  const Score QueenOn7thBonus = make_score( 3,  8);
 
   // Rooks and queens attacking pawns on the same rank
-  const Score RookOnPawnBonus  = make_score(3, 48);
-  const Score QueenOnPawnBonus = make_score(1, 40);
+  const Score RookOnPawnBonus  = make_score(10, 28);
+  const Score QueenOnPawnBonus = make_score( 4, 20);
 
   // Rooks on open files (modified by Joona Kiiski)
   const Score RookOpenFileBonus     = make_score(43, 21);
@@ -169,6 +171,9 @@ namespace {
   // right to castle.
   const Value TrappedRookPenalty = Value(180);
 
+  // Penalty for bishop with pawns on the same coloured squares
+  const Score BishopPawnsPenalty = make_score(8, 12);
+
   // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
   // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
   // happen in Chess960 games.
@@ -221,11 +226,11 @@ namespace {
 
   // KingDangerTable[Color][attackUnits] contains the actual king danger
   // weighted scores, indexed by color and by a calculated integer number.
-  Score KingDangerTable[2][128];
+  Score KingDangerTable[COLOR_NB][128];
 
   // TracedTerms[Color][PieceType || TracedType] contains a breakdown of the
   // evaluation terms, used when tracing.
-  Score TracedScores[2][16];
+  Score TracedScores[COLOR_NB][16];
   std::stringstream TraceStream;
 
   enum TracedType {
@@ -267,8 +272,6 @@ namespace {
 
 namespace Eval {
 
-  Color RootColor;
-
   /// evaluate() is the main evaluation function. It always computes two
   /// values, an endgame score and a middle game score, and interpolates
   /// between them based on the remaining material.
@@ -289,14 +292,6 @@ namespace Eval {
     Weights[KingDangerUs]   = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
     Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
 
-    // King safety is asymmetrical. Our king danger level is weighted by
-    // "Cowardice" UCI parameter, instead the opponent one by "Aggressiveness".
-    // If running in analysis mode, make sure we use symmetrical king safety. We
-    // do this by replacing both Weights[kingDangerUs] and Weights[kingDangerThem]
-    // by their average.
-    if (Options["UCI_AnalyseMode"])
-        Weights[KingDangerUs] = Weights[KingDangerThem] = (Weights[KingDangerUs] + Weights[KingDangerThem]) / 2;
-
     const int MaxSlope = 30;
     const int Peak = 1280;
 
@@ -319,7 +314,7 @@ namespace Eval {
     Value margin;
     std::string totals;
 
-    RootColor = pos.side_to_move();
+    Search::RootColor = pos.side_to_move();
 
     TraceStream.str("");
     TraceStream << std::showpoint << std::showpos << std::fixed << std::setprecision(2);
@@ -363,11 +358,12 @@ namespace {
 template<bool Trace>
 Value do_evaluate(const Position& pos, Value& margin) {
 
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
   EvalInfo ei;
-  Value margins[2];
+  Value margins[COLOR_NB];
   Score score, mobilityWhite, mobilityBlack;
+  Thread* th = pos.this_thread();
 
   // margins[] store the uncertainty estimation of position's evaluation
   // that typically is used by the search for pruning decisions.
@@ -379,7 +375,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
 
   // Probe the material hash table
-  ei.mi = pos.this_thread()->materialTable.probe(pos);
+  ei.mi = Material::probe(pos, th->materialTable, th->endgames);
   score += ei.mi->material_value();
 
   // If we have a specialized evaluation function for the current material
@@ -391,7 +387,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   }
 
   // Probe the pawn hash table
-  ei.pi = pos.this_thread()->pawnTable.probe(pos);
+  ei.pi = Pawns::probe(pos, th->pawnsTable);
   score += ei.pi->pawns_value();
 
   // Initialize attack and king safety bitboards
@@ -496,7 +492,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
     // Init king safety tables only if we are going to use them
     if (   pos.piece_count(Us, QUEEN)
-        && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
+        && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
     {
         ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
         b &= ei.attackedBy[Us][PAWN];
@@ -577,23 +573,22 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
         mobility += MobilityBonus[Piece][mob];
 
-        // Add a bonus if a slider is pinning an enemy piece
-        if (   (Piece == BISHOP || Piece == ROOK || Piece == QUEEN)
-            && (PseudoAttacks[Piece][pos.king_square(Them)] & s))
-        {
-            b = BetweenBB[s][pos.king_square(Them)] & pos.pieces();
-
-            assert(b);
-
-            if (!more_than_one(b) && (b & pos.pieces(Them)))
-                score += ThreatBonus[Piece][type_of(pos.piece_on(lsb(b)))];
-        }
-
         // Decrease score if we are attacked by an enemy pawn. Remaining part
         // of threat evaluation must be done later when we have full attack info.
         if (ei.attackedBy[Them][PAWN] & s)
             score -= ThreatenedByPawnPenalty[Piece];
 
+        // Otherwise give a bonus if we are a bishop and can pin a piece or
+        // can give a discovered check through an x-ray attack.
+        else if (    Piece == BISHOP
+                 && (PseudoAttacks[Piece][pos.king_square(Them)] & s)
+                 && !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
+                 score += BishopPinBonus;
+
+        // Penalty for bishop with same coloured pawns
+        if (Piece == BISHOP)
+            score -= BishopPawnsPenalty * ei.pi->pawns_on_same_color_squares(Us, s);
+
         // Bishop and knight outposts squares
         if (    (Piece == BISHOP || Piece == KNIGHT)
             && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
@@ -696,16 +691,15 @@ Value do_evaluate(const Position& pos, Value& margin) {
     // Undefended minors get penalized even if not under attack
     undefendedMinors =  pos.pieces(Them)
                       & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
-                      & ~ei.attackedBy[Them][0];
+                      & ~ei.attackedBy[Them][ALL_PIECES];
 
     if (undefendedMinors)
-        score += more_than_one(undefendedMinors) ? UndefendedMinorPenalty * 2
-                                                 : UndefendedMinorPenalty;
+        score += UndefendedMinorPenalty;
 
     // Enemy pieces not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
                  & ~ei.attackedBy[Them][PAWN]
-                 & ei.attackedBy[Us][0];
+                 & ei.attackedBy[Us][ALL_PIECES];
 
     if (!weakEnemies)
         return score;
@@ -744,9 +738,9 @@ Value do_evaluate(const Position& pos, Value& margin) {
     score += evaluate_pieces<QUEEN,  Us, Trace>(pos, ei, mobility, mobilityArea);
 
     // Sum up all attacked squares
-    ei.attackedBy[Us][0] =   ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
-                           | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
-                           | ei.attackedBy[Us][QUEEN]  | ei.attackedBy[Us][KING];
+    ei.attackedBy[Us][ALL_PIECES] =   ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
+                                    | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
+                                    | ei.attackedBy[Us][QUEEN]  | ei.attackedBy[Us][KING];
     return score;
   }
 
@@ -772,7 +766,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
     {
         // Find the attacked squares around the king which has no defenders
         // apart from the king itself
-        undefended = ei.attackedBy[Them][0] & ei.attackedBy[Us][KING];
+        undefended = ei.attackedBy[Them][ALL_PIECES] & ei.attackedBy[Us][KING];
         undefended &= ~(  ei.attackedBy[Us][PAWN]   | ei.attackedBy[Us][KNIGHT]
                         | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK]
                         | ei.attackedBy[Us][QUEEN]);
@@ -820,7 +814,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
         }
 
         // Analyse enemy's safe distance checks for sliders and knights
-        safe = ~(pos.pieces(Them) | ei.attackedBy[Us][0]);
+        safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
 
         b1 = pos.attacks_from<ROOK>(ksq) & safe;
         b2 = pos.attacks_from<BISHOP>(ksq) & safe;
@@ -853,8 +847,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
         // value that will be used for pruning because this value can sometimes
         // be very big, and so capturing a single attacking piece can therefore
         // result in a score change far bigger than the value of the captured piece.
-        score -= KingDangerTable[Us == Eval::RootColor][attackUnits];
-        margins[Us] += mg_value(KingDangerTable[Us == Eval::RootColor][attackUnits]);
+        score -= KingDangerTable[Us == Search::RootColor][attackUnits];
+        margins[Us] += mg_value(KingDangerTable[Us == Search::RootColor][attackUnits]);
     }
 
     if (Trace)
@@ -907,7 +901,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
             if (pos.is_empty(blockSq))
             {
                 squaresToQueen = forward_bb(Us, s);
-                defendedSquares = squaresToQueen & ei.attackedBy[Us][0];
+                defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
 
                 // If there is an enemy rook or queen attacking the pawn from behind,
                 // add all X-ray attacks by the rook or queen. Otherwise consider only
@@ -916,7 +910,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
                     && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
                     unsafeSquares = squaresToQueen;
                 else
-                    unsafeSquares = squaresToQueen & (ei.attackedBy[Them][0] | pos.pieces(Them));
+                    unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
 
                 // If there aren't enemy attacks or pieces along the path to queen give
                 // huge bonus. Even bigger if we protect the pawn's path.
@@ -993,14 +987,14 @@ Value do_evaluate(const Position& pos, Value& margin) {
             // Compute plies to queening and check direct advancement
             movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
             oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
-            pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
+            pathDefended = ((ei.attackedBy[c][ALL_PIECES] & queeningPath) == queeningPath);
 
             if (movesToGo >= oppMovesToGo && !pathDefended)
                 continue;
 
             // Opponent king cannot block because path is defended and position
             // is not in check. So only friendly pieces can be blockers.
-            assert(!pos.in_check());
+            assert(!pos.checkers());
             assert((queeningPath & pos.pieces()) == (queeningPath & pos.pieces(c)));
 
             // Add moves needed to free the path from friendly pieces and retest condition
@@ -1140,14 +1134,18 @@ Value do_evaluate(const Position& pos, Value& margin) {
     Bitboard safe =   SpaceMask[Us]
                    & ~pos.pieces(Us, PAWN)
                    & ~ei.attackedBy[Them][PAWN]
-                   & (ei.attackedBy[Us][0] | ~ei.attackedBy[Them][0]);
+                   & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]);
 
     // Find all squares which are at most three squares behind some friendly pawn
     Bitboard behind = pos.pieces(Us, PAWN);
     behind |= (Us == WHITE ? behind >>  8 : behind <<  8);
     behind |= (Us == WHITE ? behind >> 16 : behind << 16);
 
-    return popcount<Max15>(safe) + popcount<Max15>(behind & safe);
+    // Since SpaceMask[Us] is fully on our half of the board
+    assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0);
+
+    // Count safe + (behind & safe) with a single popcount
+    return popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
   }
 
 

src/evaluate.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -26,8 +26,6 @@ class Position;
 
 namespace Eval {
 
-extern Color RootColor;
-
 extern void init();
 extern Value evaluate(const Position& pos, Value& margin);
 extern std::string trace(const Position& pos);

src/history.h

@@ -1,72 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 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
-  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 <http://www.gnu.org/licenses/>.
-*/
-
-#if !defined(HISTORY_H_INCLUDED)
-#define HISTORY_H_INCLUDED
-
-#include <algorithm>
-#include <cstring>
-
-#include "types.h"
-
-/// The History class stores statistics about how often different moves
-/// have been successful or unsuccessful during the current search. These
-/// statistics are used for reduction and move ordering decisions. History
-/// entries are stored according only to moving piece and destination square,
-/// in particular two moves with different origin but same destination and
-/// same piece will be considered identical.
-
-class History {
-
-public:
-  void clear();
-  Value value(Piece p, Square to) const;
-  void add(Piece p, Square to, Value bonus);
-  Value gain(Piece p, Square to) const;
-  void update_gain(Piece p, Square to, Value g);
-
-  static const Value MaxValue = Value(2000);
-
-private:
-  Value history[16][64];  // [piece][to_square]
-  Value maxGains[16][64]; // [piece][to_square]
-};
-
-inline void History::clear() {
-  memset(history,  0, 16 * 64 * sizeof(Value));
-  memset(maxGains, 0, 16 * 64 * sizeof(Value));
-}
-
-inline Value History::value(Piece p, Square to) const {
-  return history[p][to];
-}
-
-inline void History::add(Piece p, Square to, Value bonus) {
-  if (abs(history[p][to] + bonus) < MaxValue) history[p][to] += bonus;
-}
-
-inline Value History::gain(Piece p, Square to) const {
-  return maxGains[p][to];
-}
-
-inline void History::update_gain(Piece p, Square to, Value g) {
-  maxGains[p][to] = std::max(g, maxGains[p][to] - 1);
-}
-
-#endif // !defined(HISTORY_H_INCLUDED)

src/main.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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

src/material.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -17,7 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
+#include <algorithm>  // For std::min
 #include <cassert>
 #include <cstring>
 
@@ -38,15 +38,29 @@ namespace {
   const Value RedundantQueenPenalty = Value(320);
   const Value RedundantRookPenalty  = Value(554);
 
-  const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
+  //                                  pair  pawn knight bishop rook queen
+  const int LinearCoefficients[6] = { 1617, -162, -1172, -190,  105,  26 };
 
-  const int QuadraticCoefficientsSameColor[][8] = {
-  { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
-  { 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } };
+  const int QuadraticCoefficientsSameColor[][PIECE_TYPE_NB] = {
+    // pair pawn knight bishop rook queen
+    {   7                               }, // Bishop pair
+    {  39,    2                         }, // Pawn
+    {  35,  271,  -4                    }, // Knight
+    {   7,  105,   4,    7              }, // Bishop
+    { -27,   -2,  46,   100,   56       }, // Rook
+    {  58,   29,  83,   148,   -3,  -25 }  // Queen
+  };
 
-  const int QuadraticCoefficientsOppositeColor[][8] = {
-  { 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 },
-  { 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } };
+  const int QuadraticCoefficientsOppositeColor[][PIECE_TYPE_NB] = {
+    //           THEIR PIECES
+    // pair pawn knight bishop rook queen
+    {  41                               }, // Bishop pair
+    {  37,   41                         }, // Pawn
+    {  10,   62,  41                    }, // Knight      OUR PIECES
+    {  57,   64,  39,    41             }, // Bishop
+    {  50,   40,  23,   -22,   41       }, // Rook
+    { 106,  101,   3,   151,  171,   41 }  // Queen
+  };
 
   // Endgame evaluation and scaling functions accessed direcly and not through
   // the function maps because correspond to more then one material hash key.
@@ -81,18 +95,54 @@ namespace {
           && pos.piece_count(Them, PAWN)  >= 1;
   }
 
+  /// imbalance() calculates imbalance comparing piece count of each
+  /// piece type for both colors.
+
+  template<Color Us>
+  int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
+
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+    int pt1, pt2, pc, v;
+    int value = 0;
+
+    // Redundancy of major pieces, formula based on Kaufman's paper
+    // "The Evaluation of Material Imbalances in Chess"
+    if (pieceCount[Us][ROOK] > 0)
+        value -=  RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
+                + RedundantQueenPenalty * pieceCount[Us][QUEEN];
+
+    // Second-degree polynomial material imbalance by Tord Romstad
+    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+    {
+        pc = pieceCount[Us][pt1];
+        if (!pc)
+            continue;
+
+        v = LinearCoefficients[pt1];
+
+        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+            v +=  QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
+                + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
+
+        value += pc * v;
+    }
+    return value;
+  }
+
 } // namespace
 
+namespace Material {
 
-/// MaterialTable::probe() takes a position object as input, looks up a MaterialEntry
+/// Material::probe() takes a position object as input, looks up a MaterialEntry
 /// object, and returns a pointer to it. If the material configuration is not
 /// already present in the table, it is computed and stored there, so we don't
 /// have to recompute everything when the same material configuration occurs again.
 
-MaterialEntry* MaterialTable::probe(const Position& pos) {
+Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
 
   Key key = pos.material_key();
-  MaterialEntry* e = entries[key];
+  Entry* e = entries[key];
 
   // If e->key matches the position's material hash key, it means that we
   // have analysed this material configuration before, and we can simply
@@ -100,10 +150,10 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
   if (e->key == key)
       return e;
 
-  memset(e, 0, sizeof(MaterialEntry));
+  memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = MaterialTable::game_phase(pos);
+  e->gamePhase = game_phase(pos);
 
   // Let's look if we have a specialized evaluation function for this
   // particular material configuration. First we look for a fixed
@@ -215,7 +265,7 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
   // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
   // for the bishop pair "extended piece", this allow us to be more flexible
   // in defining bishop pair bonuses.
-  const int pieceCount[2][8] = {
+  const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
   { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
     pos.piece_count(WHITE, BISHOP)    , pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
   { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
@@ -226,47 +276,11 @@ MaterialEntry* MaterialTable::probe(const Position& pos) {
 }
 
 
-/// MaterialTable::imbalance() calculates imbalance comparing piece count of each
-/// piece type for both colors.
-
-template<Color Us>
-int MaterialTable::imbalance(const int pieceCount[][8]) {
-
-  const Color Them = (Us == WHITE ? BLACK : WHITE);
-
-  int pt1, pt2, pc, v;
-  int value = 0;
-
-  // Redundancy of major pieces, formula based on Kaufman's paper
-  // "The Evaluation of Material Imbalances in Chess"
-  if (pieceCount[Us][ROOK] > 0)
-      value -=  RedundantRookPenalty * (pieceCount[Us][ROOK] - 1)
-              + RedundantQueenPenalty * pieceCount[Us][QUEEN];
-
-  // Second-degree polynomial material imbalance by Tord Romstad
-  for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
-  {
-      pc = pieceCount[Us][pt1];
-      if (!pc)
-          continue;
-
-      v = LinearCoefficients[pt1];
-
-      for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
-          v +=  QuadraticCoefficientsSameColor[pt1][pt2] * pieceCount[Us][pt2]
-              + QuadraticCoefficientsOppositeColor[pt1][pt2] * pieceCount[Them][pt2];
-
-      value += pc * v;
-  }
-  return value;
-}
-
-
-/// MaterialTable::game_phase() calculates the phase given the current
+/// Material::game_phase() calculates the phase given the current
 /// position. Because the phase is strictly a function of the material, it
 /// is stored in MaterialEntry.
 
-Phase MaterialTable::game_phase(const Position& pos) {
+Phase game_phase(const Position& pos) {
 
   Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
 
@@ -274,3 +288,5 @@ Phase MaterialTable::game_phase(const Position& pos) {
         : npm <= EndgameLimit ? PHASE_ENDGAME
         : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
 }
+
+} // namespace Material

src/material.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -25,96 +25,53 @@
 #include "position.h"
 #include "types.h"
 
-const int MaterialTableSize = 8192;
+namespace Material {
 
-/// Game phase
-enum Phase {
-  PHASE_ENDGAME = 0,
-  PHASE_MIDGAME = 128
-};
-
-
-/// MaterialEntry is a class which contains various information about a
-/// material configuration. It contains a material balance evaluation,
-/// a function pointer to a special endgame evaluation function (which in
-/// most cases is NULL, meaning that the standard evaluation function will
-/// be used), and "scale factors" for black and white.
+/// Material::Entry contains various information about a material configuration.
+/// It contains a material balance evaluation, a function pointer to a special
+/// endgame evaluation function (which in most cases is NULL, meaning that the
+/// standard evaluation function will be used), and "scale factors".
 ///
 /// The scale factors are used to scale the evaluation score up or down.
 /// For instance, in KRB vs KR endgames, the score is scaled down by a factor
 /// of 4, which will result in scores of absolute value less than one pawn.
 
-class MaterialEntry {
+struct Entry {
 
-  friend struct MaterialTable;
-
-public:
-  Score material_value() const;
+  Score material_value() const { return make_score(value, value); }
+  int space_weight() const { return spaceWeight; }
+  Phase game_phase() const { return gamePhase; }
+  bool specialized_eval_exists() const { return evaluationFunction != NULL; }
+  Value evaluate(const Position& p) const { return (*evaluationFunction)(p); }
   ScaleFactor scale_factor(const Position& pos, Color c) const;
-  int space_weight() const;
-  Phase game_phase() const;
-  bool specialized_eval_exists() const;
-  Value evaluate(const Position& pos) const;
 
-private:
   Key key;
   int16_t value;
-  uint8_t factor[2];
+  uint8_t factor[COLOR_NB];
   EndgameBase<Value>* evaluationFunction;
-  EndgameBase<ScaleFactor>* scalingFunction[2];
+  EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB];
   int spaceWeight;
   Phase gamePhase;
 };
 
+typedef HashTable<Entry, 8192> Table;
 
-/// The MaterialTable class represents a material hash table. The most important
-/// method is probe(), which returns a pointer to a MaterialEntry object.
+Entry* probe(const Position& pos, Table& entries, Endgames& endgames);
+Phase game_phase(const Position& pos);
 
-struct MaterialTable {
-
-  MaterialEntry* probe(const Position& pos);
-  static Phase game_phase(const Position& pos);
-  template<Color Us> static int imbalance(const int pieceCount[][8]);
-
-  HashTable<MaterialEntry, MaterialTableSize> entries;
-  Endgames endgames;
-};
-
-
-/// MaterialEntry::scale_factor takes a position and a color as input, and
+/// Material::scale_factor takes a position and a color as input, and
 /// returns a scale factor for the given color. We have to provide the
 /// position in addition to the color, because the scale factor need not
 /// to be a constant: It can also be a function which should be applied to
 /// the position. For instance, in KBP vs K endgames, a scaling function
 /// which checks for draws with rook pawns and wrong-colored bishops.
 
-inline ScaleFactor MaterialEntry::scale_factor(const Position& pos, Color c) const {
+inline ScaleFactor Entry::scale_factor(const Position& pos, Color c) const {
 
-  if (!scalingFunction[c])
-      return ScaleFactor(factor[c]);
-
-  ScaleFactor sf = (*scalingFunction[c])(pos);
-  return sf == SCALE_FACTOR_NONE ? ScaleFactor(factor[c]) : sf;
+  return !scalingFunction[c] || (*scalingFunction[c])(pos) == SCALE_FACTOR_NONE
+        ? ScaleFactor(factor[c]) : (*scalingFunction[c])(pos);
 }
 
-inline Value MaterialEntry::evaluate(const Position& pos) const {
-  return (*evaluationFunction)(pos);
-}
-
-inline Score MaterialEntry::material_value() const {
-  return make_score(value, value);
-}
-
-inline int MaterialEntry::space_weight() const {
-  return spaceWeight;
-}
-
-inline Phase MaterialEntry::game_phase() const {
-  return gamePhase;
-}
-
-inline bool MaterialEntry::specialized_eval_exists() const {
-  return evaluationFunction != NULL;
 }
 
 #endif // !defined(MATERIAL_H_INCLUDED)

src/misc.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -31,16 +31,16 @@
 using namespace std;
 
 /// Version number. If Version is left empty, then Tag plus current
-/// date (in the format YYMMDD) is used as a version number.
+/// date, in the format DD-MM-YY, are used as a version number.
 
-static const string Version = "";
+static const string Version = "3";
 static const string Tag = "";
 
 
-/// engine_info() returns the full name of the current Stockfish version.
-/// This will be either "Stockfish YYMMDD" (where YYMMDD is the date when
-/// the program was compiled) or "Stockfish <version number>", depending
-/// on whether Version is empty.
+/// engine_info() returns the full name of the current Stockfish version. This
+/// will be either "Stockfish <Tag> DD-MM-YY" (where DD-MM-YY is the date when
+/// the program was compiled) or "Stockfish <Version>", depending on whether
+/// Version is empty.
 
 const string engine_info(bool to_uci) {
 
@@ -57,8 +57,8 @@ const string engine_info(bool to_uci) {
   {
       date >> month >> day >> year;
 
-      s << Tag << setfill('0') << " " << year.substr(2)
-        << setw(2) << (1 + months.find(month) / 4) << setw(2) << day;
+      s << Tag << string(Tag.empty() ? "" : " ") << setfill('0') << setw(2) << day
+        << "-" << setw(2) << (1 + months.find(month) / 4) << "-" << year.substr(2);
   }
 
   s << cpu64 << popcnt << (to_uci ? "\nid author ": " by ")
@@ -227,18 +227,21 @@ void prefetch(char*) {}
 
 #else
 
-#   include <xmmintrin.h>
-
 void prefetch(char* addr) {
 
-#  if defined(__INTEL_COMPILER) || defined(__ICL)
+#  if defined(__INTEL_COMPILER)
    // This hack prevents prefetches to be optimized away by
    // Intel compiler. Both MSVC and gcc seems not affected.
    __asm__ ("");
 #  endif
 
-  _mm_prefetch(addr, _MM_HINT_T2);
-  _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
+#  if defined(__INTEL_COMPILER) || defined(_MSC_VER)
+  _mm_prefetch(addr, _MM_HINT_T0);
+  _mm_prefetch(addr+64, _MM_HINT_T0); // 64 bytes ahead
+#  else
+  __builtin_prefetch(addr);
+  __builtin_prefetch(addr+64);
+#  endif
 }
 
 #endif

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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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

src/movegen.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -44,7 +44,7 @@ namespace {
     Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
     Bitboard enemies = pos.pieces(~us);
 
-    assert(!pos.in_check());
+    assert(!pos.checkers());
 
     const int K = Chess960 ? kto > kfrom ? -1 : 1
                            : Side == KING_SIDE ? -1 : 1;
@@ -249,41 +249,38 @@ namespace {
   }
 
 
-  FORCE_INLINE MoveStack* generate_king_moves(const Position& pos, MoveStack* mlist,
-                                              Color us, Bitboard target) {
-    Square from = pos.king_square(us);
-    Bitboard b = pos.attacks_from<KING>(from) & target;
-    SERIALIZE(b);
-    return mlist;
-  }
-
-
   template<GenType Type> FORCE_INLINE
-  MoveStack* generate_all_moves(const Position& pos, MoveStack* mlist, Color us,
-                                Bitboard target, const CheckInfo* ci = NULL) {
+  MoveStack* generate_all(const Position& pos, MoveStack* mlist, Color us,
+                          Bitboard target, const CheckInfo* ci = NULL) {
+
+    const bool Checks = Type == QUIET_CHECKS;
 
     mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target, ci)
                          : generate_pawn_moves<BLACK, Type>(pos, mlist, target, ci));
 
-    mlist = generate_moves<KNIGHT, Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<BISHOP, Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<ROOK,   Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
-    mlist = generate_moves<QUEEN,  Type == QUIET_CHECKS>(pos, mlist, us, target, ci);
+    mlist = generate_moves<KNIGHT, Checks>(pos, mlist, us, target, ci);
+    mlist = generate_moves<BISHOP, Checks>(pos, mlist, us, target, ci);
+    mlist = generate_moves<ROOK,   Checks>(pos, mlist, us, target, ci);
+    mlist = generate_moves<QUEEN,  Checks>(pos, mlist, us, target, ci);
 
     if (Type != QUIET_CHECKS && Type != EVASIONS)
-        mlist = generate_king_moves(pos, mlist, us, target);
+    {
+        Square from = pos.king_square(us);
+        Bitboard b = pos.attacks_from<KING>(from) & target;
+        SERIALIZE(b);
+    }
 
     if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
     {
         if (pos.is_chess960())
         {
-            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, true>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, true>(pos, mlist, us);
+            mlist = generate_castle<KING_SIDE,  Checks, true>(pos, mlist, us);
+            mlist = generate_castle<QUEEN_SIDE, Checks, true>(pos, mlist, us);
         }
         else
         {
-            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, false>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, false>(pos, mlist, us);
+            mlist = generate_castle<KING_SIDE,  Checks, false>(pos, mlist, us);
+            mlist = generate_castle<QUEEN_SIDE, Checks, false>(pos, mlist, us);
         }
     }
 
@@ -307,21 +304,15 @@ template<GenType Type>
 MoveStack* generate(const Position& pos, MoveStack* mlist) {
 
   assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
   Color us = pos.side_to_move();
-  Bitboard target;
 
-  if (Type == CAPTURES)
-      target = pos.pieces(~us);
+  Bitboard target = Type == CAPTURES     ?  pos.pieces(~us)
+                  : Type == QUIETS       ? ~pos.pieces()
+                  : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
 
-  else if (Type == QUIETS)
-      target = ~pos.pieces();
-
-  else if (Type == NON_EVASIONS)
-      target = ~pos.pieces(us);
-
-  return generate_all_moves<Type>(pos, mlist, us, target);
+  return generate_all<Type>(pos, mlist, us, target);
 }
 
 // Explicit template instantiations
@@ -335,9 +326,8 @@ template MoveStack* generate<NON_EVASIONS>(const Position&, MoveStack*);
 template<>
 MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
 
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
-  Color us = pos.side_to_move();
   CheckInfo ci(pos);
   Bitboard dc = ci.dcCandidates;
 
@@ -357,7 +347,7 @@ MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
      SERIALIZE(b);
   }
 
-  return generate_all_moves<QUIET_CHECKS>(pos, mlist, us, ~pos.pieces(), &ci);
+  return generate_all<QUIET_CHECKS>(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
 }
 
 
@@ -366,7 +356,7 @@ MoveStack* generate<QUIET_CHECKS>(const Position& pos, MoveStack* mlist) {
 template<>
 MoveStack* generate<EVASIONS>(const Position& pos, MoveStack* mlist) {
 
-  assert(pos.in_check());
+  assert(pos.checkers());
 
   Square from, checksq;
   int checkersCnt = 0;
@@ -419,7 +409,7 @@ MoveStack* generate<EVASIONS>(const Position& pos, MoveStack* mlist) {
   // Generate blocking evasions or captures of the checking piece
   Bitboard target = between_bb(checksq, ksq) | pos.checkers();
 
-  return generate_all_moves<EVASIONS>(pos, mlist, us, target);
+  return generate_all<EVASIONS>(pos, mlist, us, target);
 }
 
 
@@ -432,7 +422,7 @@ MoveStack* generate<LEGAL>(const Position& pos, MoveStack* mlist) {
   Bitboard pinned = pos.pinned_pieces();
   Square ksq = pos.king_square(pos.side_to_move());
 
-  end = pos.in_check() ? generate<EVASIONS>(pos, mlist)
+  end = pos.checkers() ? generate<EVASIONS>(pos, mlist)
                        : generate<NON_EVASIONS>(pos, mlist);
   while (cur != end)
       if (   (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)

src/movegen.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -46,6 +46,10 @@ struct MoveList {
   bool end() const { return cur == last; }
   Move move() const { return cur->move; }
   size_t size() const { return last - mlist; }
+  bool contains(Move m) const {
+    for (const MoveStack* it(mlist); it != last; ++it) if (it->move == m) return true;
+    return false;
+  }
 
 private:
   MoveStack mlist[MAX_MOVES];

src/movepick.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -18,10 +18,8 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>
 #include <cassert>
 
-#include "movegen.h"
 #include "movepick.h"
 #include "thread.h"
 
@@ -37,6 +35,20 @@ namespace {
     STOP
   };
 
+  // Our insertion sort, guaranteed to be stable, as is needed
+  void insertion_sort(MoveStack* begin, MoveStack* end)
+  {
+    MoveStack tmp, *p, *q;
+
+    for (p = begin + 1; p < end; ++p)
+    {
+        tmp = *p;
+        for (q = p; q != begin && *(q-1) < tmp; --q)
+            *q = *(q-1);
+        *q = tmp;
+    }
+  }
+
   // Unary predicate used by std::partition to split positive scores from remaining
   // ones so to sort separately the two sets, and with the second sort delayed.
   inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; }
@@ -59,7 +71,7 @@ namespace {
 /// move ordering is at the current node.
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
-                       Search::Stack* s, Value beta) : pos(p), H(h), depth(d) {
+                       Search::Stack* s, Value beta) : pos(p), Hist(h), depth(d) {
 
   assert(d > DEPTH_ZERO);
 
@@ -68,7 +80,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
   endBadCaptures = moves + MAX_MOVES - 1;
   ss = s;
 
-  if (p.in_check())
+  if (p.checkers())
       phase = EVASION;
 
   else
@@ -79,12 +91,12 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
       killers[1].move = ss->killers[1];
 
       // Consider sligtly negative captures as good if at low depth and far from beta
-      if (ss && ss->eval < beta - PawnValueMg && d < 3 * ONE_PLY)
+      if (ss && ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY)
           captureThreshold = -PawnValueMg;
 
       // Consider negative captures as good if still enough to reach beta
-      else if (ss && ss->eval > beta)
-          captureThreshold = beta - ss->eval;
+      else if (ss && ss->staticEval > beta)
+          captureThreshold = beta - ss->staticEval;
   }
 
   ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
@@ -92,11 +104,11 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
 }
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
-                       Square sq) : pos(p), H(h), cur(moves), end(moves) {
+                       Square sq) : pos(p), Hist(h), cur(moves), end(moves) {
 
   assert(d <= DEPTH_ZERO);
 
-  if (p.in_check())
+  if (p.checkers())
       phase = EVASION;
 
   else if (d > DEPTH_QS_NO_CHECKS)
@@ -124,14 +136,14 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
 }
 
 MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
-                       : pos(p), H(h), cur(moves), end(moves) {
+                       : pos(p), Hist(h), cur(moves), end(moves) {
 
-  assert(!pos.in_check());
+  assert(!pos.checkers());
 
   phase = PROBCUT;
 
   // In ProbCut we generate only captures better than parent's captured piece
-  captureThreshold = PieceValue[Mg][pt];
+  captureThreshold = PieceValue[MG][pt];
   ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
 
   if (ttMove && (!pos.is_capture(ttMove) ||  pos.see(ttMove) <= captureThreshold))
@@ -141,12 +153,10 @@ MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType
 }
 
 
-/// MovePicker::score_captures(), MovePicker::score_noncaptures() and
-/// MovePicker::score_evasions() assign a numerical move ordering score
-/// to each move in a move list.  The moves with highest scores will be
-/// picked first by next_move().
-
-void MovePicker::score_captures() {
+/// score() assign a numerical move ordering score to each move in a move list.
+/// The moves with highest scores will be picked first.
+template<>
+void MovePicker::score<CAPTURES>() {
   // Winning and equal captures in the main search are ordered by MVV/LVA.
   // Suprisingly, this appears to perform slightly better than SEE based
   // move ordering. The reason is probably that in a position with a winning
@@ -165,51 +175,54 @@ void MovePicker::score_captures() {
   for (MoveStack* it = moves; it != end; ++it)
   {
       m = it->move;
-      it->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
+      it->score =  PieceValue[MG][pos.piece_on(to_sq(m))]
                  - type_of(pos.piece_moved(m));
 
       if (type_of(m) == PROMOTION)
-          it->score += PieceValue[Mg][promotion_type(m)];
+          it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN];
+
+      else if (type_of(m) == ENPASSANT)
+          it->score += PieceValue[MG][PAWN];
   }
 }
 
-void MovePicker::score_noncaptures() {
+template<>
+void MovePicker::score<QUIETS>() {
 
   Move m;
 
   for (MoveStack* it = moves; it != end; ++it)
   {
       m = it->move;
-      it->score = H.value(pos.piece_moved(m), to_sq(m));
+      it->score = Hist[pos.piece_moved(m)][to_sq(m)];
   }
 }
 
-void MovePicker::score_evasions() {
+template<>
+void MovePicker::score<EVASIONS>() {
   // Try good captures ordered by MVV/LVA, then non-captures if destination square
   // is not under attack, ordered by history value, then bad-captures and quiet
   // moves with a negative SEE. This last group is ordered by the SEE score.
   Move m;
   int seeScore;
 
-  if (end < moves + 2)
-      return;
-
   for (MoveStack* it = moves; it != end; ++it)
   {
       m = it->move;
       if ((seeScore = pos.see_sign(m)) < 0)
-          it->score = seeScore - History::MaxValue; // Be sure we are at the bottom
+          it->score = seeScore - History::Max; // At the bottom
+
       else if (pos.is_capture(m))
-          it->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
-                     - type_of(pos.piece_moved(m)) + History::MaxValue;
+          it->score =  PieceValue[MG][pos.piece_on(to_sq(m))]
+                     - type_of(pos.piece_moved(m)) + History::Max;
       else
-          it->score = H.value(pos.piece_moved(m), to_sq(m));
+          it->score = Hist[pos.piece_moved(m)][to_sq(m)];
   }
 }
 
 
-/// MovePicker::generate_next() generates, scores and sorts the next bunch of moves,
-/// when there are no more moves to try for the current phase.
+/// generate_next() generates, scores and sorts the next bunch of moves, when
+/// there are no more moves to try for the current phase.
 
 void MovePicker::generate_next() {
 
@@ -219,7 +232,7 @@ void MovePicker::generate_next() {
 
   case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
       end = generate<CAPTURES>(pos, moves);
-      score_captures();
+      score<CAPTURES>();
       return;
 
   case KILLERS_S1:
@@ -229,16 +242,16 @@ void MovePicker::generate_next() {
 
   case QUIETS_1_S1:
       endQuiets = end = generate<QUIETS>(pos, moves);
-      score_noncaptures();
+      score<QUIETS>();
       end = std::partition(cur, end, has_positive_score);
-      sort<MoveStack>(cur, end);
+      insertion_sort(cur, end);
       return;
 
   case QUIETS_2_S1:
       cur = end;
       end = endQuiets;
       if (depth >= 3 * ONE_PLY)
-          sort<MoveStack>(cur, end);
+          insertion_sort(cur, end);
       return;
 
   case BAD_CAPTURES_S1:
@@ -249,7 +262,8 @@ void MovePicker::generate_next() {
 
   case EVASIONS_S2:
       end = generate<EVASIONS>(pos, moves);
-      score_evasions();
+      if (end > moves + 1)
+          score<EVASIONS>();
       return;
 
   case QUIET_CHECKS_S3:
@@ -268,11 +282,10 @@ void MovePicker::generate_next() {
 }
 
 
-/// MovePicker::next_move() is the most important method of the MovePicker class.
-/// It returns a new pseudo legal move every time it is called, until there
-/// are no more moves left. It picks the move with the biggest score from a list
-/// of generated moves taking care not to return the tt move if has already been
-/// searched previously.
+/// next_move() is the most important method of the MovePicker class. It returns
+/// a new pseudo legal move every time is called, until there are no more moves
+/// left. It picks the move with the biggest score from a list of generated moves
+/// taking care not returning the ttMove if has already been searched previously.
 template<>
 Move MovePicker::next_move<false>() {
 
@@ -359,6 +372,6 @@ Move MovePicker::next_move<false>() {
 
 /// Version of next_move() to use at split point nodes where the move is grabbed
 /// from the split point's shared MovePicker object. This function is not thread
-/// safe so should be lock protected by the caller.
+/// safe so must be lock protected by the caller.
 template<>
-Move MovePicker::next_move<true>() { return ss->sp->mp->next_move<false>(); }
+Move MovePicker::next_move<true>() { return ss->splitPoint->movePicker->next_move<false>(); }

src/movepick.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -20,12 +20,48 @@
 #if !defined MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-#include "history.h"
+#include <algorithm> // For std::max
+#include <cstring>   // For memset
+
+#include "movegen.h"
 #include "position.h"
 #include "search.h"
 #include "types.h"
 
 
+/// The Stats struct stores moves statistics. According to the template parameter
+/// the class can store both History and Gains type statistics. History records
+/// how often different moves have been successful or unsuccessful during the
+/// current search and is used for reduction and move ordering decisions. Gains
+/// records the move's best evaluation gain from one ply to the next and is used
+/// for pruning decisions. Entries are stored according only to moving piece and
+/// destination square, in particular two moves with different origin but same
+/// destination and same piece will be considered identical.
+template<bool Gain>
+struct Stats {
+
+  static const Value Max = Value(2000);
+
+  const Value* operator[](Piece p) const { return &table[p][0]; }
+  void clear() { memset(table, 0, sizeof(table)); }
+
+  void update(Piece p, Square to, Value v) {
+
+    if (Gain)
+        table[p][to] = std::max(v, table[p][to] - 1);
+
+    else if (abs(table[p][to] + v) < Max)
+        table[p][to] +=  v;
+  }
+
+private:
+  Value table[PIECE_NB][SQUARE_NB];
+};
+
+typedef Stats<false> History;
+typedef Stats<true> Gains;
+
+
 /// MovePicker class is used to pick one pseudo legal move at a time from the
 /// current position. The most important method is next_move(), which returns a
 /// new pseudo legal move each time it is called, until there are no moves left,
@@ -44,13 +80,11 @@ public:
   template<bool SpNode> Move next_move();
 
 private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
+  template<GenType> void score();
   void generate_next();
 
   const Position& pos;
-  const History& H;
+  const History& Hist;
   Search::Stack* ss;
   Depth depth;
   Move ttMove;

src/notation.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -20,7 +20,7 @@
 #include <cassert>
 #include <iomanip>
 #include <sstream>
-#include <string>
+#include <stack>
 
 #include "movegen.h"
 #include "notation.h"
@@ -28,7 +28,7 @@
 
 using namespace std;
 
-static const char* PieceToChar = " PNBRQK  pnbrqk";
+static const char* PieceToChar[COLOR_NB] = { " PNBRQK", " pnbrqk" };
 
 
 /// score_to_uci() converts a value to a string suitable for use with the UCI
@@ -75,7 +75,7 @@ const string move_to_uci(Move m, bool chess960) {
   string move = square_to_string(from) + square_to_string(to);
 
   if (type_of(m) == PROMOTION)
-      move += PieceToChar[make_piece(BLACK, promotion_type(m))]; // Lower case
+      move += PieceToChar[BLACK][promotion_type(m)]; // Lower case
 
   return move;
 }
@@ -108,10 +108,9 @@ const string move_to_san(Position& pos, Move m) {
   if (m == MOVE_NULL)
       return "(null)";
 
-  assert(pos.move_is_legal(m));
+  assert(MoveList<LEGAL>(pos).contains(m));
 
-  Bitboard attackers;
-  bool ambiguousMove, ambiguousFile, ambiguousRank;
+  Bitboard others, b;
   string san;
   Color us = pos.side_to_move();
   Square from = from_sq(m);
@@ -125,33 +124,25 @@ const string move_to_san(Position& pos, Move m) {
   {
       if (pt != PAWN)
       {
-          san = PieceToChar[pt]; // Upper case
+          san = PieceToChar[WHITE][pt]; // Upper case
 
-          // Disambiguation if we have more then one piece with destination 'to'
-          // note that for pawns is not needed because starting file is explicit.
-          ambiguousMove = ambiguousFile = ambiguousRank = false;
+          // Disambiguation if we have more then one piece of type 'pt' that can
+          // reach 'to' with a legal move.
+          others = b = (pos.attacks_from(pc, to) & pos.pieces(us, pt)) ^ from;
 
-          attackers = (pos.attacks_from(pc, to) & pos.pieces(us, pt)) ^ from;
-
-          while (attackers)
+          while (b)
           {
-              Square sq = pop_lsb(&attackers);
-
-              // Pinned pieces are not included in the possible sub-set
-              if (!pos.pl_move_is_legal(make_move(sq, to), pos.pinned_pieces()))
-                  continue;
-
-              ambiguousFile |= file_of(sq) == file_of(from);
-              ambiguousRank |= rank_of(sq) == rank_of(from);
-              ambiguousMove = true;
+              Move move = make_move(pop_lsb(&b), to);
+              if (!pos.pl_move_is_legal(move, pos.pinned_pieces()))
+                  others ^= from_sq(move);
           }
 
-          if (ambiguousMove)
+          if (others)
           {
-              if (!ambiguousFile)
+              if (!(others & file_bb(from)))
                   san += file_to_char(file_of(from));
 
-              else if (!ambiguousRank)
+              else if (!(others & rank_bb(from)))
                   san += rank_to_char(rank_of(from));
 
               else
@@ -167,7 +158,7 @@ const string move_to_san(Position& pos, Move m) {
       san += square_to_string(to);
 
       if (type_of(m) == PROMOTION)
-          san += string("=") + PieceToChar[promotion_type(m)];
+          san += string("=") + PieceToChar[WHITE][promotion_type(m)];
   }
 
   if (pos.move_gives_check(m, CheckInfo(pos)))
@@ -226,7 +217,7 @@ string pretty_pv(Position& pos, int depth, Value value, int64_t msecs, Move pv[]
   const int64_t K = 1000;
   const int64_t M = 1000000;
 
-  StateInfo state[MAX_PLY_PLUS_2], *st = state;
+  std::stack<StateInfo> st;
   Move* m = pv;
   string san, padding;
   size_t length;
@@ -261,7 +252,8 @@ string pretty_pv(Position& pos, int depth, Value value, int64_t msecs, Move pv[]
       s << san << ' ';
       length += san.length() + 1;
 
-      pos.do_move(*m++, *st++);
+      st.push(StateInfo());
+      pos.do_move(*m++, st.top());
   }
 
   while (m != pv)

src/notation.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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

src/pawns.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -30,34 +30,34 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Doubled pawn penalty by opposed flag and file
-  const Score DoubledPawnPenalty[2][8] = {
+  const Score DoubledPawnPenalty[2][FILE_NB] = {
   { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
     S(23, 48), S(23, 48), S(20, 48), S(13, 43) },
   { S(13, 43), S(20, 48), S(23, 48), S(23, 48),
     S(23, 48), S(23, 48), S(20, 48), S(13, 43) }};
 
   // Isolated pawn penalty by opposed flag and file
-  const Score IsolatedPawnPenalty[2][8] = {
+  const Score IsolatedPawnPenalty[2][FILE_NB] = {
   { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
     S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
   { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
     S(40, 35), S(40, 35), S(36, 35), S(25, 30) }};
 
   // Backward pawn penalty by opposed flag and file
-  const Score BackwardPawnPenalty[2][8] = {
+  const Score BackwardPawnPenalty[2][FILE_NB] = {
   { S(30, 42), S(43, 46), S(49, 46), S(49, 46),
     S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
   { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
     S(33, 31), S(33, 31), S(29, 31), S(20, 28) }};
 
   // Pawn chain membership bonus by file
-  const Score ChainBonus[8] = {
+  const Score ChainBonus[FILE_NB] = {
     S(11,-1), S(13,-1), S(13,-1), S(14,-1),
     S(14,-1), S(13,-1), S(13,-1), S(11,-1)
   };
 
   // Candidate passed pawn bonus by rank
-  const Score CandidateBonus[8] = {
+  const Score CandidateBonus[RANK_NB] = {
     S( 0, 0), S( 6, 13), S(6,13), S(14,29),
     S(34,68), S(83,166), S(0, 0), S( 0, 0)
   };
@@ -65,12 +65,12 @@ namespace {
   const Score PawnStructureWeight = S(233, 201);
 
   // Weakness of our pawn shelter in front of the king indexed by [king pawn][rank]
-  const Value ShelterWeakness[2][8] =
+  const Value ShelterWeakness[2][RANK_NB] =
   { { V(141), V(0), V(38), V(102), V(128), V(141), V(141) },
     { V( 61), V(0), V(16), V( 44), V( 56), V( 61), V( 61) } };
 
   // Danger of enemy pawns moving toward our king indexed by [pawn blocked][rank]
-  const Value StormDanger[2][8] =
+  const Value StormDanger[2][RANK_NB] =
   { { V(26), V(0), V(128), V(51), V(26) },
     { V(13), V(0), V( 64), V(25), V(13) } };
 
@@ -80,18 +80,122 @@ namespace {
 
   #undef S
   #undef V
+
+  template<Color Us>
+  Score evaluate_pawns(const Position& pos, Bitboard ourPawns,
+                       Bitboard theirPawns, Pawns::Entry* e) {
+
+    const Color Them = (Us == WHITE ? BLACK : WHITE);
+
+    Bitboard b;
+    Square s;
+    File f;
+    Rank r;
+    bool passed, isolated, doubled, opposed, chain, backward, candidate;
+    Score value = SCORE_ZERO;
+    const Square* pl = pos.piece_list(Us, PAWN);
+
+    // Loop through all pawns of the current color and score each pawn
+    while ((s = *pl++) != SQ_NONE)
+    {
+        assert(pos.piece_on(s) == make_piece(Us, PAWN));
+
+        f = file_of(s);
+        r = rank_of(s);
+
+        // This file cannot be half open
+        e->halfOpenFiles[Us] &= ~(1 << f);
+
+        // Our rank plus previous one. Used for chain detection
+        b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
+
+        // Flag the pawn as passed, isolated, doubled or member of a pawn
+        // chain (but not the backward one).
+        chain    =   ourPawns   & adjacent_files_bb(f) & b;
+        isolated = !(ourPawns   & adjacent_files_bb(f));
+        doubled  =   ourPawns   & forward_bb(Us, s);
+        opposed  =   theirPawns & forward_bb(Us, s);
+        passed   = !(theirPawns & passed_pawn_mask(Us, s));
+
+        // Test for backward pawn
+        backward = false;
+
+        // If the pawn is passed, isolated, or member of a pawn chain it cannot
+        // be backward. If there are friendly pawns behind on adjacent files
+        // or if can capture an enemy pawn it cannot be backward either.
+        if (   !(passed | isolated | chain)
+            && !(ourPawns & attack_span_mask(Them, s))
+            && !(pos.attacks_from<PAWN>(s, Us) & theirPawns))
+        {
+            // We now know that there are no friendly pawns beside or behind this
+            // pawn on adjacent files. We now check whether the pawn is
+            // backward by looking in the forward direction on the adjacent
+            // files, and seeing whether we meet a friendly or an enemy pawn first.
+            b = pos.attacks_from<PAWN>(s, Us);
+
+            // Note that we are sure to find something because pawn is not passed
+            // nor isolated, so loop is potentially infinite, but it isn't.
+            while (!(b & (ourPawns | theirPawns)))
+                Us == WHITE ? b <<= 8 : b >>= 8;
+
+            // The friendly pawn needs to be at least two ranks closer than the
+            // enemy pawn in order to help the potentially backward pawn advance.
+            backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
+        }
+
+        assert(opposed | passed | (attack_span_mask(Us, s) & theirPawns));
+
+        // A not passed pawn is a candidate to become passed if it is free to
+        // advance and if the number of friendly pawns beside or behind this
+        // pawn on adjacent files is higher or equal than the number of
+        // enemy pawns in the forward direction on the adjacent files.
+        candidate =   !(opposed | passed | backward | isolated)
+                   && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != 0
+                   &&  popcount<Max15>(b) >= popcount<Max15>(attack_span_mask(Us, s) & theirPawns);
+
+        // Passed pawns will be properly scored in evaluation because we need
+        // full attack info to evaluate passed pawns. Only the frontmost passed
+        // pawn on each file is considered a true passed pawn.
+        if (passed && !doubled)
+            e->passedPawns[Us] |= s;
+
+        // Score this pawn
+        if (isolated)
+            value -= IsolatedPawnPenalty[opposed][f];
+
+        if (doubled)
+            value -= DoubledPawnPenalty[opposed][f];
+
+        if (backward)
+            value -= BackwardPawnPenalty[opposed][f];
+
+        if (chain)
+            value += ChainBonus[f];
+
+        if (candidate)
+            value += CandidateBonus[relative_rank(Us, s)];
+    }
+
+    e->pawnsOnSquares[Us][BLACK] = popcount<Max15>(ourPawns & BlackSquares);
+    e->pawnsOnSquares[Us][WHITE] = pos.piece_count(Us, PAWN) - e->pawnsOnSquares[Us][BLACK];
+
+    e->pawnsOnSquares[Them][BLACK] = popcount<Max15>(theirPawns & BlackSquares);
+    e->pawnsOnSquares[Them][WHITE] = pos.piece_count(Them, PAWN) - e->pawnsOnSquares[Them][BLACK];
+
+    return value;
+  }
 }
 
+namespace Pawns {
 
-/// PawnTable::probe() takes a position object as input, computes a PawnEntry
-/// object, and returns a pointer to it. The result is also stored in a hash
-/// table, so we don't have to recompute everything when the same pawn structure
-/// occurs again.
+/// probe() takes a position object as input, computes a Entry object, and returns
+/// a pointer to it. The result is also stored in a hash table, so we don't have
+/// to recompute everything when the same pawn structure occurs again.
 
-PawnEntry* PawnTable::probe(const Position& pos) {
+Entry* probe(const Position& pos, Table& entries) {
 
   Key key = pos.pawn_key();
-  PawnEntry* e = entries[key];
+  Entry* e = entries[key];
 
   // If e->key matches the position's pawn hash key, it means that we
   // have analysed this pawn structure before, and we can simply return
@@ -118,112 +222,11 @@ PawnEntry* PawnTable::probe(const Position& pos) {
 }
 
 
-/// PawnTable::evaluate_pawns() evaluates each pawn of the given color
-
-template<Color Us>
-Score PawnTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                                Bitboard theirPawns, PawnEntry* e) {
-
-  const Color Them = (Us == WHITE ? BLACK : WHITE);
-
-  Bitboard b;
-  Square s;
-  File f;
-  Rank r;
-  bool passed, isolated, doubled, opposed, chain, backward, candidate;
-  Score value = SCORE_ZERO;
-  const Square* pl = pos.piece_list(Us, PAWN);
-
-  // Loop through all pawns of the current color and score each pawn
-  while ((s = *pl++) != SQ_NONE)
-  {
-      assert(pos.piece_on(s) == make_piece(Us, PAWN));
-
-      f = file_of(s);
-      r = rank_of(s);
-
-      // This file cannot be half open
-      e->halfOpenFiles[Us] &= ~(1 << f);
-
-      // Our rank plus previous one. Used for chain detection
-      b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
-
-      // Flag the pawn as passed, isolated, doubled or member of a pawn
-      // chain (but not the backward one).
-      chain    =   ourPawns   & adjacent_files_bb(f) & b;
-      isolated = !(ourPawns   & adjacent_files_bb(f));
-      doubled  =   ourPawns   & forward_bb(Us, s);
-      opposed  =   theirPawns & forward_bb(Us, s);
-      passed   = !(theirPawns & passed_pawn_mask(Us, s));
-
-      // Test for backward pawn
-      backward = false;
-
-      // If the pawn is passed, isolated, or member of a pawn chain it cannot
-      // be backward. If there are friendly pawns behind on adjacent files
-      // or if can capture an enemy pawn it cannot be backward either.
-      if (   !(passed | isolated | chain)
-          && !(ourPawns & attack_span_mask(Them, s))
-          && !(pos.attacks_from<PAWN>(s, Us) & theirPawns))
-      {
-          // We now know that there are no friendly pawns beside or behind this
-          // pawn on adjacent files. We now check whether the pawn is
-          // backward by looking in the forward direction on the adjacent
-          // files, and seeing whether we meet a friendly or an enemy pawn first.
-          b = pos.attacks_from<PAWN>(s, Us);
-
-          // Note that we are sure to find something because pawn is not passed
-          // nor isolated, so loop is potentially infinite, but it isn't.
-          while (!(b & (ourPawns | theirPawns)))
-              Us == WHITE ? b <<= 8 : b >>= 8;
-
-          // The friendly pawn needs to be at least two ranks closer than the
-          // enemy pawn in order to help the potentially backward pawn advance.
-          backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
-      }
-
-      assert(opposed | passed | (attack_span_mask(Us, s) & theirPawns));
-
-      // A not passed pawn is a candidate to become passed if it is free to
-      // advance and if the number of friendly pawns beside or behind this
-      // pawn on adjacent files is higher or equal than the number of
-      // enemy pawns in the forward direction on the adjacent files.
-      candidate =   !(opposed | passed | backward | isolated)
-                 && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != 0
-                 &&  popcount<Max15>(b) >= popcount<Max15>(attack_span_mask(Us, s) & theirPawns);
-
-      // Passed pawns will be properly scored in evaluation because we need
-      // full attack info to evaluate passed pawns. Only the frontmost passed
-      // pawn on each file is considered a true passed pawn.
-      if (passed && !doubled)
-          e->passedPawns[Us] |= s;
-
-      // Score this pawn
-      if (isolated)
-          value -= IsolatedPawnPenalty[opposed][f];
-
-      if (doubled)
-          value -= DoubledPawnPenalty[opposed][f];
-
-      if (backward)
-          value -= BackwardPawnPenalty[opposed][f];
-
-      if (chain)
-          value += ChainBonus[f];
-
-      if (candidate)
-          value += CandidateBonus[relative_rank(Us, s)];
-  }
-
-  return value;
-}
-
-
-/// PawnEntry::shelter_storm() calculates shelter and storm penalties for the file
+/// Entry::shelter_storm() calculates shelter and storm penalties for the file
 /// the king is on, as well as the two adjacent files.
 
 template<Color Us>
-Value PawnEntry::shelter_storm(const Position& pos, Square ksq) {
+Value Entry::shelter_storm(const Position& pos, Square ksq) {
 
   const Color Them = (Us == WHITE ? BLACK : WHITE);
 
@@ -234,7 +237,7 @@ Value PawnEntry::shelter_storm(const Position& pos, Square ksq) {
   Rank rkUs, rkThem;
   File kf = file_of(ksq);
 
-  kf = (kf == FILE_A) ? kf++ : (kf == FILE_H) ? kf-- : kf;
+  kf = (kf == FILE_A) ? FILE_B : (kf == FILE_H) ? FILE_G : kf;
 
   for (int f = kf - 1; f <= kf + 1; f++)
   {
@@ -253,11 +256,11 @@ Value PawnEntry::shelter_storm(const Position& pos, Square ksq) {
 }
 
 
-/// PawnEntry::update_safety() calculates and caches a bonus for king safety. It is
+/// Entry::update_safety() calculates and caches a bonus for king safety. It is
 /// called only when king square changes, about 20% of total king_safety() calls.
 
 template<Color Us>
-Score PawnEntry::update_safety(const Position& pos, Square ksq) {
+Score Entry::update_safety(const Position& pos, Square ksq) {
 
   kingSquares[Us] = ksq;
   castleRights[Us] = pos.can_castle(Us);
@@ -283,5 +286,7 @@ Score PawnEntry::update_safety(const Position& pos, Square ksq) {
 }
 
 // Explicit template instantiation
-template Score PawnEntry::update_safety<WHITE>(const Position& pos, Square ksq);
-template Score PawnEntry::update_safety<BLACK>(const Position& pos, Square ksq);
+template Score Entry::update_safety<WHITE>(const Position& pos, Square ksq);
+template Score Entry::update_safety<BLACK>(const Position& pos, Square ksq);
+
+} // namespace Pawns

src/pawns.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -24,31 +24,31 @@
 #include "position.h"
 #include "types.h"
 
-const int PawnTableSize = 16384;
+namespace Pawns {
 
-/// PawnEntry is a class which contains various information about a pawn
-/// structure. Currently, it only includes a middle game and an end game
-/// pawn structure evaluation, and a bitboard of passed pawns. We may want
-/// to add further information in the future. A lookup to the pawn hash
-/// table (performed by calling the probe method in a PawnTable object)
-/// returns a pointer to a PawnEntry object.
+/// Pawns::Entry contains various information about a pawn structure. Currently,
+/// it only includes a middle game and end game pawn structure evaluation, and a
+/// bitboard of passed pawns. We may want to add further information in the future.
+/// A lookup to the pawn hash table (performed by calling the probe function)
+/// returns a pointer to an Entry object.
 
-class PawnEntry {
+struct Entry {
 
-  friend struct PawnTable;
-
-public:
-  Score pawns_value() const;
-  Bitboard pawn_attacks(Color c) const;
-  Bitboard passed_pawns(Color c) const;
-  int file_is_half_open(Color c, File f) const;
-  int has_open_file_to_left(Color c, File f) const;
-  int has_open_file_to_right(Color c, File f) const;
+  Score pawns_value() const { return value; }
+  Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
+  Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
+  int file_is_half_open(Color c, File f) const { return halfOpenFiles[c] & (1 << int(f)); }
+  int has_open_file_to_left(Color c, File f) const { return halfOpenFiles[c] & ((1 << int(f)) - 1); }
+  int has_open_file_to_right(Color c, File f) const { return halfOpenFiles[c] & ~((1 << int(f+1)) - 1); }
+  int pawns_on_same_color_squares(Color c, Square s) const { return pawnsOnSquares[c][!!(BlackSquares & s)]; }
 
   template<Color Us>
-  Score king_safety(const Position& pos, Square ksq);
+  Score king_safety(const Position& pos, Square ksq)  {
+
+    return kingSquares[Us] == ksq && castleRights[Us] == pos.can_castle(Us)
+         ? kingSafety[Us] : update_safety<Us>(pos, ksq);
+  }
 
-private:
   template<Color Us>
   Score update_safety(const Position& pos, Square ksq);
 
@@ -56,60 +56,21 @@ private:
   Value shelter_storm(const Position& pos, Square ksq);
 
   Key key;
-  Bitboard passedPawns[2];
-  Bitboard pawnAttacks[2];
-  Square kingSquares[2];
-  int minKPdistance[2];
-  int castleRights[2];
+  Bitboard passedPawns[COLOR_NB];
+  Bitboard pawnAttacks[COLOR_NB];
+  Square kingSquares[COLOR_NB];
+  int minKPdistance[COLOR_NB];
+  int castleRights[COLOR_NB];
   Score value;
-  int halfOpenFiles[2];
-  Score kingSafety[2];
+  int halfOpenFiles[COLOR_NB];
+  Score kingSafety[COLOR_NB];
+  int pawnsOnSquares[COLOR_NB][COLOR_NB];
 };
 
+typedef HashTable<Entry, 16384> Table;
 
-/// The PawnTable class represents a pawn hash table. The most important
-/// method is probe, which returns a pointer to a PawnEntry object.
+Entry* probe(const Position& pos, Table& entries);
 
-struct PawnTable {
-
-  PawnEntry* probe(const Position& pos);
-
-  template<Color Us>
-  static Score evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                              Bitboard theirPawns, PawnEntry* e);
-
-  HashTable<PawnEntry, PawnTableSize> entries;
-};
-
-
-inline Score PawnEntry::pawns_value() const {
-  return value;
-}
-
-inline Bitboard PawnEntry::pawn_attacks(Color c) const {
-  return pawnAttacks[c];
-}
-
-inline Bitboard PawnEntry::passed_pawns(Color c) const {
-  return passedPawns[c];
-}
-
-inline int PawnEntry::file_is_half_open(Color c, File f) const {
-  return halfOpenFiles[c] & (1 << int(f));
-}
-
-inline int PawnEntry::has_open_file_to_left(Color c, File f) const {
-  return halfOpenFiles[c] & ((1 << int(f)) - 1);
-}
-
-inline int PawnEntry::has_open_file_to_right(Color c, File f) const {
-  return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
-}
-
-template<Color Us>
-inline Score PawnEntry::king_safety(const Position& pos, Square ksq) {
-  return kingSquares[Us] == ksq && castleRights[Us] == pos.can_castle(Us)
-       ? kingSafety[Us] : update_safety<Us>(pos, ksq);
 }
 
 #endif // !defined(PAWNS_H_INCLUDED)

src/platform.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -40,6 +40,7 @@ typedef unsigned __int64 uint64_t;
 
 #else
 #  include <inttypes.h>
+#  include <unistd.h>  // Used by sysconf(_SC_NPROCESSORS_ONLN)
 #endif
 
 #if !defined(_WIN32) && !defined(_WIN64) // Linux - Unix
@@ -92,6 +93,9 @@ typedef CRITICAL_SECTION Lock;
 typedef HANDLE WaitCondition;
 typedef HANDLE NativeHandle;
 
+// On Windows 95 and 98 parameter lpThreadId my not be null
+inline DWORD* dwWin9xKludge() { static DWORD dw; return &dw; }
+
 #  define lock_init(x) InitializeCriticalSection(&(x))
 #  define lock_grab(x) EnterCriticalSection(&(x))
 #  define lock_release(x) LeaveCriticalSection(&(x))
@@ -101,7 +105,7 @@ typedef HANDLE NativeHandle;
 #  define cond_signal(x) SetEvent(x)
 #  define cond_wait(x,y) { lock_release(y); WaitForSingleObject(x, INFINITE); lock_grab(y); }
 #  define cond_timedwait(x,y,z) { lock_release(y); WaitForSingleObject(x,z); lock_grab(y); }
-#  define thread_create(x,f,t) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,t,0,NULL), x != NULL)
+#  define thread_create(x,f,t) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,t,0,dwWin9xKludge()), x != NULL)
 #  define thread_join(x) { WaitForSingleObject(x, INFINITE); CloseHandle(x); }
 
 #endif

src/position.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -19,6 +19,7 @@
 
 #include <cassert>
 #include <cstring>
+#include <iomanip>
 #include <iostream>
 #include <sstream>
 #include <algorithm>
@@ -40,16 +41,16 @@ static const string PieceToChar(" PNBRQK  pnbrqk");
 
 CACHE_LINE_ALIGNMENT
 
-Score pieceSquareTable[16][64]; // [piece][square]
-Value PieceValue[2][18] = {     // [Mg / Eg][piece / pieceType]
+Score pieceSquareTable[PIECE_NB][SQUARE_NB];
+Value PieceValue[PHASE_NB][PIECE_NB] = {
 { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
 { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } };
 
 namespace Zobrist {
 
-Key psq[2][8][64]; // [color][pieceType][square / piece count]
-Key enpassant[8];  // [file]
-Key castle[16];    // [castleRight]
+Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+Key enpassant[FILE_NB];
+Key castle[CASTLE_RIGHT_NB];
 Key side;
 Key exclusion;
 
@@ -86,10 +87,10 @@ void init() {
 
   for (PieceType pt = PAWN; pt <= KING; pt++)
   {
-      PieceValue[Mg][make_piece(BLACK, pt)] = PieceValue[Mg][pt];
-      PieceValue[Eg][make_piece(BLACK, pt)] = PieceValue[Eg][pt];
+      PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
+      PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
 
-      Score v = make_score(PieceValue[Mg][pt], PieceValue[Eg][pt]);
+      Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
 
       for (Square s = SQ_A1; s <= SQ_H8; s++)
       {
@@ -172,11 +173,11 @@ Position& Position::operator=(const Position& pos) {
 }
 
 
-/// Position::from_fen() initializes the position object with the given FEN
-/// string. This function is not very robust - make sure that input FENs are
-/// correct (this is assumed to be the responsibility of the GUI).
+/// Position::set() initializes the position object with the given FEN string.
+/// This function is not very robust - make sure that input FENs are correct,
+/// this is assumed to be the responsibility of the GUI.
 
-void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
+void Position::set(const string& fenStr, bool isChess960, Thread* th) {
 /*
    A FEN string defines a particular position using only the ASCII character set.
 
@@ -214,13 +215,13 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
   char col, row, token;
   size_t p;
   Square sq = SQ_A8;
-  std::istringstream fen(fenStr);
+  std::istringstream ss(fenStr);
 
   clear();
-  fen >> std::noskipws;
+  ss >> std::noskipws;
 
   // 1. Piece placement
-  while ((fen >> token) && !isspace(token))
+  while ((ss >> token) && !isspace(token))
   {
       if (isdigit(token))
           sq += Square(token - '0'); // Advance the given number of files
@@ -236,16 +237,16 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
   }
 
   // 2. Active color
-  fen >> token;
+  ss >> token;
   sideToMove = (token == 'w' ? WHITE : BLACK);
-  fen >> token;
+  ss >> token;
 
   // 3. Castling availability. Compatible with 3 standards: Normal FEN standard,
   // Shredder-FEN that uses the letters of the columns on which the rooks began
   // the game instead of KQkq and also X-FEN standard that, in case of Chess960,
   // if an inner rook is associated with the castling right, the castling tag is
   // replaced by the file letter of the involved rook, as for the Shredder-FEN.
-  while ((fen >> token) && !isspace(token))
+  while ((ss >> token) && !isspace(token))
   {
       Square rsq;
       Color c = islower(token) ? BLACK : WHITE;
@@ -268,8 +269,8 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
   }
 
   // 4. En passant square. Ignore if no pawn capture is possible
-  if (   ((fen >> col) && (col >= 'a' && col <= 'h'))
-      && ((fen >> row) && (row == '3' || row == '6')))
+  if (   ((ss >> col) && (col >= 'a' && col <= 'h'))
+      && ((ss >> row) && (row == '3' || row == '6')))
   {
       st->epSquare = File(col - 'a') | Rank(row - '1');
 
@@ -278,11 +279,11 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) {
   }
 
   // 5-6. Halfmove clock and fullmove number
-  fen >> std::skipws >> st->rule50 >> startPosPly;
+  ss >> std::skipws >> st->rule50 >> gamePly;
 
   // Convert from fullmove starting from 1 to ply starting from 0,
   // handle also common incorrect FEN with fullmove = 0.
-  startPosPly = std::max(2 * (startPosPly - 1), 0) + int(sideToMove == BLACK);
+  gamePly = std::max(2 * (gamePly - 1), 0) + int(sideToMove == BLACK);
 
   st->key = compute_key();
   st->pawnKey = compute_pawn_key();
@@ -325,71 +326,64 @@ void Position::set_castle_right(Color c, Square rfrom) {
 }
 
 
-/// Position::to_fen() returns a FEN representation of the position. In case
+/// Position::fen() returns a FEN representation of the position. In case
 /// of Chess960 the Shredder-FEN notation is used. Mainly a debugging function.
 
-const string Position::to_fen() const {
+const string Position::fen() const {
 
-  std::ostringstream fen;
-  Square sq;
-  int emptyCnt;
+  std::ostringstream ss;
 
   for (Rank rank = RANK_8; rank >= RANK_1; rank--)
   {
-      emptyCnt = 0;
-
       for (File file = FILE_A; file <= FILE_H; file++)
       {
-          sq = file | rank;
+          Square sq = file | rank;
 
           if (is_empty(sq))
-              emptyCnt++;
-          else
           {
-              if (emptyCnt > 0)
-              {
-                  fen << emptyCnt;
-                  emptyCnt = 0;
-              }
-              fen << PieceToChar[piece_on(sq)];
+              int emptyCnt = 1;
+
+              for ( ; file < FILE_H && is_empty(sq++); file++)
+                  emptyCnt++;
+
+              ss << emptyCnt;
           }
+          else
+              ss << PieceToChar[piece_on(sq)];
       }
 
-      if (emptyCnt > 0)
-          fen << emptyCnt;
-
       if (rank > RANK_1)
-          fen << '/';
+          ss << '/';
   }
 
-  fen << (sideToMove == WHITE ? " w " : " b ");
+  ss << (sideToMove == WHITE ? " w " : " b ");
 
   if (can_castle(WHITE_OO))
-      fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, KING_SIDE))))) : 'K');
+      ss << (chess960 ? file_to_char(file_of(castle_rook_square(WHITE,  KING_SIDE)), false) : 'K');
 
   if (can_castle(WHITE_OOO))
-      fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE))))) : 'Q');
+      ss << (chess960 ? file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE)), false) : 'Q');
 
   if (can_castle(BLACK_OO))
-      fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, KING_SIDE))) : 'k');
+      ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK,  KING_SIDE)),  true) : 'k');
 
   if (can_castle(BLACK_OOO))
-      fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE))) : 'q');
+      ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE)),  true) : 'q');
 
   if (st->castleRights == CASTLES_NONE)
-      fen << '-';
+      ss << '-';
 
-  fen << (ep_square() == SQ_NONE ? " - " : " " + square_to_string(ep_square()) + " ")
-      << st->rule50 << " " << 1 + (startPosPly - int(sideToMove == BLACK)) / 2;
+  ss << (ep_square() == SQ_NONE ? " - " : " " + square_to_string(ep_square()) + " ")
+      << st->rule50 << " " << 1 + (gamePly - int(sideToMove == BLACK)) / 2;
 
-  return fen.str();
+  return ss.str();
 }
 
 
-/// Position::print() prints an ASCII representation of the position to
-/// the standard output. If a move is given then also the san is printed.
+/// Position::pretty() returns an ASCII representation of the position to be
+/// printed to the standard output together with the move's san notation.
 
-void Position::print(Move move) const {
+const string Position::pretty(Move move) const {
 
   const string dottedLine =            "\n+---+---+---+---+---+---+---+---+";
   const string twoRows =  dottedLine + "\n|   | . |   | . |   | . |   | . |"
@@ -397,19 +391,27 @@ void Position::print(Move move) const {
 
   string brd = twoRows + twoRows + twoRows + twoRows + dottedLine;
 
-  sync_cout;
+  std::ostringstream ss;
 
   if (move)
-  {
-      Position p(*this);
-      cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move);
-  }
+      ss << "\nMove: " << (sideToMove == BLACK ? ".." : "")
+         << move_to_san(*const_cast<Position*>(this), move);
 
   for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
       if (piece_on(sq) != NO_PIECE)
           brd[513 - 68*rank_of(sq) + 4*file_of(sq)] = PieceToChar[piece_on(sq)];
 
-  cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << sync_endl;
+  ss << brd << "\nFen: " << fen() << "\nKey: " << std::hex << std::uppercase
+     << std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
+
+  for (Bitboard b = checkers(); b; )
+      ss << square_to_string(pop_lsb(&b)) << " ";
+
+  ss << "\nLegal moves: ";
+  for (MoveList<LEGAL> ml(*this); !ml.end(); ++ml)
+      ss << move_to_san(*const_cast<Position*>(this), ml.move()) << " ";
+
+  return ss.str();
 }
 
 
@@ -475,37 +477,6 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
 }
 
 
-/// Position::move_attacks_square() tests whether a move from the current
-/// position attacks a given square.
-
-bool Position::move_attacks_square(Move m, Square s) const {
-
-  assert(is_ok(m));
-  assert(is_ok(s));
-
-  Bitboard occ, xray;
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-  Piece piece = piece_moved(m);
-
-  assert(!is_empty(from));
-
-  // Update occupancy as if the piece is moving
-  occ = pieces() ^ from ^ to;
-
-  // The piece moved in 'to' attacks the square 's' ?
-  if (attacks_from(piece, to, occ) & s)
-      return true;
-
-  // Scan for possible X-ray attackers behind the moved piece
-  xray =  (attacks_bb<  ROOK>(s, occ) & pieces(color_of(piece), QUEEN, ROOK))
-        | (attacks_bb<BISHOP>(s, occ) & pieces(color_of(piece), QUEEN, BISHOP));
-
-  // Verify attackers are triggered by our move and not already existing
-  return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
-}
-
-
 /// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
 
 bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
@@ -553,20 +524,6 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
 }
 
 
-/// Position::move_is_legal() takes a random move and tests whether the move
-/// is legal. This version is not very fast and should be used only in non
-/// time-critical paths.
-
-bool Position::move_is_legal(const Move m) const {
-
-  for (MoveList<LEGAL> ml(*this); !ml.end(); ++ml)
-      if (ml.move() == m)
-          return true;
-
-  return false;
-}
-
-
 /// Position::is_pseudo_legal() takes a random move and tests whether the move
 /// is pseudo legal. It is used to validate moves from TT that can be corrupted
 /// due to SMP concurrent access or hash position key aliasing.
@@ -574,14 +531,13 @@ bool Position::move_is_legal(const Move m) const {
 bool Position::is_pseudo_legal(const Move m) const {
 
   Color us = sideToMove;
-  Color them = ~sideToMove;
   Square from = from_sq(m);
   Square to = to_sq(m);
   Piece pc = piece_moved(m);
 
   // Use a slower but simpler function for uncommon cases
   if (type_of(m) != NORMAL)
-      return move_is_legal(m);
+      return MoveList<LEGAL>(*this).contains(m);
 
   // Is not a promotion, so promotion piece must be empty
   if (promotion_type(m) - 2 != NO_PIECE_TYPE)
@@ -593,7 +549,7 @@ bool Position::is_pseudo_legal(const Move m) const {
       return false;
 
   // The destination square cannot be occupied by a friendly piece
-  if (color_of(piece_on(to)) == us)
+  if (piece_on(to) != NO_PIECE && color_of(piece_on(to)) == us)
       return false;
 
   // Handle the special case of a pawn move
@@ -619,7 +575,7 @@ bool Position::is_pseudo_legal(const Move m) const {
       case DELTA_SE:
       // Capture. The destination square must be occupied by an enemy
       // piece (en passant captures was handled earlier).
-      if (color_of(piece_on(to)) != them)
+      if (piece_on(to) == NO_PIECE || color_of(piece_on(to)) != ~us)
           return false;
 
       // From and to files must be one file apart, avoids a7h5
@@ -664,18 +620,16 @@ bool Position::is_pseudo_legal(const Move m) const {
   // Evasions generator already takes care to avoid some kind of illegal moves
   // and pl_move_is_legal() relies on this. So we have to take care that the
   // same kind of moves are filtered out here.
-  if (in_check())
+  if (checkers())
   {
       if (type_of(pc) != KING)
       {
-          Bitboard b = checkers();
-          Square checksq = pop_lsb(&b);
-
-          if (b) // double check ? In this case a king move is required
+          // Double check? In this case a king move is required
+          if (more_than_one(checkers()))
               return false;
 
           // Our move must be a blocking evasion or a capture of the checking piece
-          if (!((between_bb(checksq, king_square(us)) | checkers()) & to))
+          if (!((between_bb(lsb(checkers()), king_square(us)) | checkers()) & to))
               return false;
       }
       // In case of king moves under check we have to remove king so to catch
@@ -720,15 +674,16 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
   Color us = sideToMove;
   Square ksq = king_square(~us);
 
-  // Promotion with check ?
-  if (type_of(m) == PROMOTION)
+  switch (type_of(m))
+  {
+  case PROMOTION:
       return attacks_from(Piece(promotion_type(m)), to, pieces() ^ from) & ksq;
 
   // En passant capture with check ? We have already handled the case
   // of direct checks and ordinary discovered check, the only case we
   // need to handle is the unusual case of a discovered check through
   // the captured pawn.
-  if (type_of(m) == ENPASSANT)
+  case ENPASSANT:
   {
       Square capsq = file_of(to) | rank_of(from);
       Bitboard b = (pieces() ^ from ^ capsq) | to;
@@ -736,9 +691,7 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
       return  (attacks_bb<  ROOK>(ksq, b) & pieces(us, QUEEN, ROOK))
             | (attacks_bb<BISHOP>(ksq, b) & pieces(us, QUEEN, BISHOP));
   }
-
-  // Castling with check ?
-  if (type_of(m) == CASTLE)
+  case CASTLE:
   {
       Square kfrom = from;
       Square rfrom = to; // 'King captures the rook' notation
@@ -748,8 +701,10 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
 
       return attacks_bb<ROOK>(rto, b) & ksq;
   }
-
-  return false;
+  default:
+      assert(false);
+      return false;
+  }
 }
 
 
@@ -772,9 +727,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   Key k = st->key;
 
   // Copy some fields of old state to our new StateInfo object except the ones
-  // which are recalculated from scratch anyway, then switch our state pointer
-  // to point to the new, ready to be updated, state.
-  memcpy(&newSt, st, sizeof(ReducedStateInfo));
+  // which are going to be recalculated from scratch anyway, then switch our state
+  // pointer to point to the new, ready to be updated, state.
+  memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t));
 
   newSt.previous = st;
   st = &newSt;
@@ -782,18 +737,12 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   // Update side to move
   k ^= Zobrist::side;
 
-  // Increment the 50 moves rule draw counter. Resetting it to zero in the
-  // case of a capture or a pawn move is taken care of later.
+  // Increment ply counters.In particular rule50 will be later reset it to zero
+  // in case of a capture or a pawn move.
+  gamePly++;
   st->rule50++;
   st->pliesFromNull++;
 
-  if (type_of(m) == CASTLE)
-  {
-      st->key = k;
-      do_castle_move<true>(m);
-      return;
-  }
-
   Color us = sideToMove;
   Color them = ~us;
   Square from = from_sq(m);
@@ -803,9 +752,25 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
   PieceType capture = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to));
 
   assert(color_of(piece) == us);
-  assert(color_of(piece_on(to)) != us);
+  assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == them || type_of(m) == CASTLE);
   assert(capture != KING);
 
+  if (type_of(m) == CASTLE)
+  {
+      assert(piece == make_piece(us, KING));
+
+      bool kingSide = to > from;
+      Square rfrom = to; // Castle is encoded as "king captures friendly rook"
+      Square rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
+      to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
+      capture = NO_PIECE_TYPE;
+
+      do_castle(from, to, rfrom, rto);
+
+      st->psqScore += psq_delta(make_piece(us, ROOK), rfrom, rto);
+      k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
+  }
+
   if (capture)
   {
       Square capsq = to;
@@ -830,7 +795,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
           st->pawnKey ^= Zobrist::psq[them][PAWN][capsq];
       }
       else
-          st->npMaterial[them] -= PieceValue[Mg][capture];
+          st->npMaterial[them] -= PieceValue[MG][capture];
 
       // Remove the captured piece
       byTypeBB[ALL_PIECES] ^= capsq;
@@ -840,7 +805,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
       // Update piece list, move the last piece at index[capsq] position and
       // shrink the list.
       //
-      // WARNING: This is a not revresible operation. When we will reinsert the
+      // WARNING: This is a not reversible operation. When we will reinsert the
       // captured piece in undo_move() we will put it at the end of the list and
       // not in its original place, it means index[] and pieceList[] are not
       // guaranteed to be invariant to a do_move() + undo_move() sequence.
@@ -849,9 +814,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
       pieceList[them][capture][index[lastSquare]] = lastSquare;
       pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
 
-      // Update hash keys
+      // Update material hash key and prefetch access to materialTable
       k ^= Zobrist::psq[them][capture][capsq];
       st->materialKey ^= Zobrist::psq[them][capture][pieceCount[them][capture]];
+      prefetch((char*)thisThread->materialTable[st->materialKey]);
 
       // Update incremental scores
       st->psqScore -= pieceSquareTable[make_piece(them, capture)][capsq];
@@ -878,22 +844,25 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
       st->castleRights &= ~cr;
   }
 
-  // Prefetch TT access as soon as we know key is updated
+  // Prefetch TT access as soon as we know the new hash key
   prefetch((char*)TT.first_entry(k));
 
-  // Move the piece
-  Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
-  byTypeBB[ALL_PIECES] ^= from_to_bb;
-  byTypeBB[pt] ^= from_to_bb;
-  byColorBB[us] ^= from_to_bb;
+  // Move the piece. The tricky Chess960 castle is handled earlier
+  if (type_of(m) != CASTLE)
+  {
+      Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
+      byTypeBB[ALL_PIECES] ^= from_to_bb;
+      byTypeBB[pt] ^= from_to_bb;
+      byColorBB[us] ^= from_to_bb;
 
-  board[to] = board[from];
-  board[from] = NO_PIECE;
+      board[from] = NO_PIECE;
+      board[to] = piece;
 
-  // Update piece lists, index[from] is not updated and becomes stale. This
-  // works as long as index[] is accessed just by known occupied squares.
-  index[to] = index[from];
-  pieceList[us][pt][index[to]] = to;
+      // Update piece lists, index[from] is not updated and becomes stale. This
+      // works as long as index[] is accessed just by known occupied squares.
+      index[to] = index[from];
+      pieceList[us][pt][index[to]] = to;
+  }
 
   // If the moving piece is a pawn do some special extra work
   if (pt == PAWN)
@@ -938,20 +907,17 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
                          - pieceSquareTable[make_piece(us, PAWN)][to];
 
           // Update material
-          st->npMaterial[us] += PieceValue[Mg][promotion];
+          st->npMaterial[us] += PieceValue[MG][promotion];
       }
 
-      // Update pawn hash key
+      // Update pawn hash key and prefetch access to pawnsTable
       st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to];
+      prefetch((char*)thisThread->pawnsTable[st->pawnKey]);
 
       // Reset rule 50 draw counter
       st->rule50 = 0;
   }
 
-  // Prefetch pawn and material hash tables
-  prefetch((char*)thisThread->pawnTable.entries[st->pawnKey]);
-  prefetch((char*)thisThread->materialTable.entries[st->materialKey]);
-
   // Update incremental scores
   st->psqScore += psq_delta(piece, from, to);
 
@@ -1001,22 +967,14 @@ void Position::undo_move(Move m) {
 
   sideToMove = ~sideToMove;
 
-  if (type_of(m) == CASTLE)
-  {
-      do_castle_move<false>(m);
-      return;
-  }
-
   Color us = sideToMove;
   Color them = ~us;
   Square from = from_sq(m);
   Square to = to_sq(m);
-  Piece piece = piece_on(to);
-  PieceType pt = type_of(piece);
+  PieceType pt = type_of(piece_on(to));
   PieceType capture = st->capturedType;
 
-  assert(is_empty(from));
-  assert(color_of(piece) == us);
+  assert(is_empty(from) || type_of(m) == CASTLE);
   assert(capture != KING);
 
   if (type_of(m) == PROMOTION)
@@ -1044,19 +1002,32 @@ void Position::undo_move(Move m) {
       pt = PAWN;
   }
 
-  // Put the piece back at the source square
-  Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
-  byTypeBB[ALL_PIECES] ^= from_to_bb;
-  byTypeBB[pt] ^= from_to_bb;
-  byColorBB[us] ^= from_to_bb;
+  if (type_of(m) == CASTLE)
+  {
+      bool kingSide = to > from;
+      Square rfrom = to; // Castle is encoded as "king captures friendly rook"
+      Square rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
+      to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
+      capture = NO_PIECE_TYPE;
+      pt = KING;
+      do_castle(to, from, rto, rfrom);
+  }
+  else
+  {
+      // Put the piece back at the source square
+      Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
+      byTypeBB[ALL_PIECES] ^= from_to_bb;
+      byTypeBB[pt] ^= from_to_bb;
+      byColorBB[us] ^= from_to_bb;
 
-  board[from] = board[to];
-  board[to] = NO_PIECE;
+      board[to] = NO_PIECE;
+      board[from] = make_piece(us, pt);
 
-  // Update piece lists, index[to] is not updated and becomes stale. This
-  // works as long as index[] is accessed just by known occupied squares.
-  index[from] = index[to];
-  pieceList[us][pt][index[from]] = from;
+      // Update piece lists, index[to] is not updated and becomes stale. This
+      // works as long as index[] is accessed just by known occupied squares.
+      index[from] = index[to];
+      pieceList[us][pt][index[from]] = from;
+  }
 
   if (capture)
   {
@@ -1086,49 +1057,18 @@ void Position::undo_move(Move m) {
 
   // Finally point our state pointer back to the previous state
   st = st->previous;
+  gamePly--;
 
   assert(pos_is_ok());
 }
 
 
-/// Position::do_castle_move() is a private method used to do/undo a castling
-/// move. Note that castling moves are encoded as "king captures friendly rook"
-/// moves, for instance white short castling in a non-Chess960 game is encoded
-/// as e1h1.
-template<bool Do>
-void Position::do_castle_move(Move m) {
+/// Position::do_castle() is a helper used to do/undo a castling move. This
+/// is a bit tricky, especially in Chess960.
 
-  assert(is_ok(m));
-  assert(type_of(m) == CASTLE);
-
-  Square kto, kfrom, rfrom, rto, kAfter, rAfter;
+void Position::do_castle(Square kfrom, Square kto, Square rfrom, Square rto) {
 
   Color us = sideToMove;
-  Square kBefore = from_sq(m);
-  Square rBefore = to_sq(m);
-
-  // Find after-castle squares for king and rook
-  if (rBefore > kBefore) // O-O
-  {
-      kAfter = relative_square(us, SQ_G1);
-      rAfter = relative_square(us, SQ_F1);
-  }
-  else // O-O-O
-  {
-      kAfter = relative_square(us, SQ_C1);
-      rAfter = relative_square(us, SQ_D1);
-  }
-
-  kfrom = Do ? kBefore : kAfter;
-  rfrom = Do ? rBefore : rAfter;
-
-  kto = Do ? kAfter : kBefore;
-  rto = Do ? rAfter : rBefore;
-
-  assert(piece_on(kfrom) == make_piece(us, KING));
-  assert(piece_on(rfrom) == make_piece(us, ROOK));
-
-  // Move the pieces, with some care; in chess960 could be kto == rfrom
   Bitboard k_from_to_bb = SquareBB[kfrom] ^ SquareBB[kto];
   Bitboard r_from_to_bb = SquareBB[rfrom] ^ SquareBB[rto];
   byTypeBB[KING] ^= k_from_to_bb;
@@ -1136,105 +1076,63 @@ void Position::do_castle_move(Move m) {
   byTypeBB[ALL_PIECES] ^= k_from_to_bb ^ r_from_to_bb;
   byColorBB[us] ^= k_from_to_bb ^ r_from_to_bb;
 
-  // Update board
-  Piece king = make_piece(us, KING);
-  Piece rook = make_piece(us, ROOK);
+  // Could be from == to, so first set NO_PIECE then KING and ROOK
   board[kfrom] = board[rfrom] = NO_PIECE;
-  board[kto] = king;
-  board[rto] = rook;
+  board[kto] = make_piece(us, KING);
+  board[rto] = make_piece(us, ROOK);
 
-  // Update piece lists
-  pieceList[us][KING][index[kfrom]] = kto;
-  pieceList[us][ROOK][index[rfrom]] = rto;
-  int tmp = index[rfrom]; // In Chess960 could be kto == rfrom
-  index[kto] = index[kfrom];
-  index[rto] = tmp;
-
-  if (Do)
-  {
-      // Reset capture field
-      st->capturedType = NO_PIECE_TYPE;
-
-      // Update incremental scores
-      st->psqScore += psq_delta(king, kfrom, kto);
-      st->psqScore += psq_delta(rook, rfrom, rto);
-
-      // Update hash key
-      st->key ^= Zobrist::psq[us][KING][kfrom] ^ Zobrist::psq[us][KING][kto];
-      st->key ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
-
-      // Clear en passant square
-      if (st->epSquare != SQ_NONE)
-      {
-          st->key ^= Zobrist::enpassant[file_of(st->epSquare)];
-          st->epSquare = SQ_NONE;
-      }
-
-      // Update castling rights
-      st->key ^= Zobrist::castle[st->castleRights & castleRightsMask[kfrom]];
-      st->castleRights &= ~castleRightsMask[kfrom];
-
-      // Update checkers BB
-      st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
-
-      sideToMove = ~sideToMove;
-  }
-  else
-      // Undo: point our state pointer back to the previous state
-      st = st->previous;
-
-  assert(pos_is_ok());
+  // Could be kfrom == rto, so use a 'tmp' variable
+  int tmp = index[kfrom];
+  index[rto] = index[rfrom];
+  index[kto] = tmp;
+  pieceList[us][KING][index[kto]] = kto;
+  pieceList[us][ROOK][index[rto]] = rto;
 }
 
 
-/// Position::do_null_move() is used to do/undo a "null move": It flips the side
-/// to move and updates the hash key without executing any move on the board.
-template<bool Do>
-void Position::do_null_move(StateInfo& backupSt) {
+/// Position::do(undo)_null_move() is used to do(undo) a "null move": It flips
+/// the side to move without executing any move on the board.
 
-  assert(!in_check());
+void Position::do_null_move(StateInfo& newSt) {
 
-  // Back up the information necessary to undo the null move to the supplied
-  // StateInfo object. Note that differently from normal case here backupSt
-  // is actually used as a backup storage not as the new state. This reduces
-  // the number of fields to be copied.
-  StateInfo* src = Do ? st : &backupSt;
-  StateInfo* dst = Do ? &backupSt : st;
+  assert(!checkers());
 
-  dst->key      = src->key;
-  dst->epSquare = src->epSquare;
-  dst->psqScore = src->psqScore;
-  dst->rule50   = src->rule50;
-  dst->pliesFromNull = src->pliesFromNull;
+  memcpy(&newSt, st, sizeof(StateInfo)); // Fully copy here
+
+  newSt.previous = st;
+  st = &newSt;
+
+  if (st->epSquare != SQ_NONE)
+  {
+      st->key ^= Zobrist::enpassant[file_of(st->epSquare)];
+      st->epSquare = SQ_NONE;
+  }
+
+  st->key ^= Zobrist::side;
+  prefetch((char*)TT.first_entry(st->key));
+
+  st->rule50++;
+  st->pliesFromNull = 0;
 
   sideToMove = ~sideToMove;
 
-  if (Do)
-  {
-      if (st->epSquare != SQ_NONE)
-          st->key ^= Zobrist::enpassant[file_of(st->epSquare)];
-
-      st->key ^= Zobrist::side;
-      prefetch((char*)TT.first_entry(st->key));
-
-      st->epSquare = SQ_NONE;
-      st->rule50++;
-      st->pliesFromNull = 0;
-  }
-
   assert(pos_is_ok());
 }
 
-// Explicit template instantiations
-template void Position::do_null_move<false>(StateInfo& backupSt);
-template void Position::do_null_move<true>(StateInfo& backupSt);
+void Position::undo_null_move() {
+
+  assert(!checkers());
+
+  st = st->previous;
+  sideToMove = ~sideToMove;
+}
 
 
 /// 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
-/// move, and one which takes a 'from' and a 'to' square. The function does
-/// not yet understand promotions captures.
+/// material gain or loss resulting from a move. Parameter 'asymmThreshold' takes
+/// tempi into account. If the side who initiated the capturing sequence does the
+/// last capture, he loses a tempo and if the result is below 'asymmThreshold'
+/// the capturing sequence is considered bad.
 
 int Position::see_sign(Move m) const {
 
@@ -1243,13 +1141,13 @@ int Position::see_sign(Move m) const {
   // Early return if SEE cannot be negative because captured piece value
   // is not less then capturing one. Note that king moves always return
   // here because king midgame value is set to 0.
-  if (PieceValue[Mg][piece_on(to_sq(m))] >= PieceValue[Mg][piece_moved(m)])
+  if (PieceValue[MG][piece_on(to_sq(m))] >= PieceValue[MG][piece_moved(m)])
       return 1;
 
   return see(m);
 }
 
-int Position::see(Move m) const {
+int Position::see(Move m, int asymmThreshold) const {
 
   Square from, to;
   Bitboard occupied, attackers, stmAttackers;
@@ -1290,7 +1188,7 @@ int Position::see(Move m) const {
   stm = ~color_of(piece_on(from));
   stmAttackers = attackers & pieces(stm);
   if (!stmAttackers)
-      return PieceValue[Mg][captured];
+      return PieceValue[MG][captured];
 
   // The destination square is defended, which makes things rather more
   // difficult to compute. We proceed by building up a "swap list" containing
@@ -1298,14 +1196,14 @@ int Position::see(Move m) const {
   // destination square, where the sides alternately capture, and always
   // capture with the least valuable piece. After each capture, we look for
   // new X-ray attacks from behind the capturing piece.
-  swapList[0] = PieceValue[Mg][captured];
+  swapList[0] = PieceValue[MG][captured];
   captured = type_of(piece_on(from));
 
   do {
       assert(slIndex < 32);
 
       // Add the new entry to the swap list
-      swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[Mg][captured];
+      swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];
       slIndex++;
 
       // Locate and remove from 'occupied' the next least valuable attacker
@@ -1326,6 +1224,15 @@ int Position::see(Move m) const {
 
   } while (stmAttackers);
 
+  // If we are doing asymmetric SEE evaluation and the same side does the first
+  // and the last capture, he loses a tempo and gain must be at least worth
+  // 'asymmThreshold', otherwise we replace the score with a very low value,
+  // before negamaxing.
+  if (asymmThreshold)
+      for (int i = 0; i < slIndex; i += 2)
+          if (swapList[i] < asymmThreshold)
+              swapList[i] = - QueenValueMg * 16;
+
   // Having built the swap list, we negamax through it to find the best
   // achievable score from the point of view of the side to move.
   while (--slIndex)
@@ -1347,9 +1254,6 @@ void Position::clear() {
   for (int i = 0; i < 8; i++)
       for (int j = 0; j < 16; j++)
           pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
-
-  for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
-      board[sq] = NO_PIECE;
 }
 
 
@@ -1463,7 +1367,7 @@ Value Position::compute_non_pawn_material(Color c) const {
   Value value = VALUE_ZERO;
 
   for (PieceType pt = KNIGHT; pt <= QUEEN; pt++)
-      value += piece_count(c, pt) * PieceValue[Mg][pt];
+      value += piece_count(c, pt) * PieceValue[MG][pt];
 
   return value;
 }
@@ -1472,7 +1376,6 @@ Value Position::compute_non_pawn_material(Color c) const {
 /// Position::is_draw() tests whether the position is drawn by material,
 /// repetition, or the 50 moves rule. It does not detect stalemates, this
 /// must be done by the search.
-template<bool SkipRepetition>
 bool Position::is_draw() const {
 
   // Draw by material?
@@ -1481,37 +1384,30 @@ bool Position::is_draw() const {
       return true;
 
   // Draw by the 50 moves rule?
-  if (st->rule50 > 99 && (!in_check() || MoveList<LEGAL>(*this).size()))
+  if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
       return true;
 
   // Draw by repetition?
-  if (!SkipRepetition)
+  int i = 4, e = std::min(st->rule50, st->pliesFromNull);
+
+  if (i <= e)
   {
-      int i = 4, e = std::min(st->rule50, st->pliesFromNull);
+      StateInfo* stp = st->previous->previous;
 
-      if (i <= e)
-      {
-          StateInfo* stp = st->previous->previous;
+      do {
+          stp = stp->previous->previous;
 
-          do {
-              stp = stp->previous->previous;
+          if (stp->key == st->key)
+              return true;
 
-              if (stp->key == st->key)
-                  return true;
+          i += 2;
 
-              i +=2;
-
-          } while (i <= e);
-      }
+      } while (i <= e);
   }
 
   return false;
 }
 
-// Explicit template instantiations
-template bool Position::is_draw<false>() const;
-template bool Position::is_draw<true>() const;
-
 
 /// Position::flip() flips position with the white and black sides reversed. This
 /// is only useful for debugging especially for finding evaluation symmetry bugs.
@@ -1526,7 +1422,7 @@ void Position::flip() {
   thisThread = pos.this_thread();
   nodes = pos.nodes_searched();
   chess960 = pos.is_chess960();
-  startPosPly = pos.startpos_ply_counter();
+  gamePly = pos.game_ply();
 
   for (Square s = SQ_A1; s <= SQ_H8; s++)
       if (!pos.is_empty(s))
@@ -1593,7 +1489,7 @@ bool Position::pos_is_ok(int* failedStep) const {
 
   if ((*step)++, debugKingCount)
   {
-      int kingCount[2] = {};
+      int kingCount[COLOR_NB] = {};
 
       for (Square s = SQ_A1; s <= SQ_H8; s++)
           if (type_of(piece_on(s)) == KING)

src/position.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -21,6 +21,7 @@
 #define POSITION_H_INCLUDED
 
 #include <cassert>
+#include <cstddef>
 
 #include "bitboard.h"
 #include "types.h"
@@ -29,7 +30,7 @@
 /// The checkInfo struct is initialized at c'tor time and keeps info used
 /// to detect if a move gives check.
 class Position;
-class Thread;
+struct Thread;
 
 struct CheckInfo {
 
@@ -37,19 +38,19 @@ struct CheckInfo {
 
   Bitboard dcCandidates;
   Bitboard pinned;
-  Bitboard checkSq[8];
+  Bitboard checkSq[PIECE_TYPE_NB];
   Square ksq;
 };
 
 
 /// The StateInfo struct stores information we need to restore a Position
 /// object to its previous state when we retract a move. Whenever a move
-/// is made on the board (by calling Position::do_move), an StateInfo object
+/// is made on the board (by calling Position::do_move), a StateInfo object
 /// must be passed as a parameter.
 
 struct StateInfo {
   Key pawnKey, materialKey;
-  Value npMaterial[2];
+  Value npMaterial[COLOR_NB];
   int castleRights, rule50, pliesFromNull;
   Score psqScore;
   Square epSquare;
@@ -60,13 +61,10 @@ struct StateInfo {
   StateInfo* previous;
 };
 
-struct ReducedStateInfo {
-  Key pawnKey, materialKey;
-  Value npMaterial[2];
-  int castleRights, rule50, pliesFromNull;
-  Score psqScore;
-  Square epSquare;
-};
+
+/// When making a move the current StateInfo up to 'key' excluded is copied to
+/// the new one. Here we calculate the quad words (64bits) needed to be copied.
+const size_t StateCopySize64 = offsetof(StateInfo, key) / sizeof(uint64_t) + 1;
 
 
 /// The position data structure. A position consists of the following data:
@@ -95,13 +93,13 @@ class Position {
 public:
   Position() {}
   Position(const Position& p, Thread* t) { *this = p; thisThread = t; }
-  Position(const std::string& f, bool c960, Thread* t) { from_fen(f, c960, t); }
+  Position(const std::string& f, bool c960, Thread* t) { set(f, c960, t); }
   Position& operator=(const Position&);
 
   // Text input/output
-  void from_fen(const std::string& fen, bool isChess960, Thread* th);
-  const std::string to_fen() const;
-  void print(Move m = MOVE_NONE) const;
+  void set(const std::string& fen, bool isChess960, Thread* th);
+  const std::string fen() const;
+  const std::string pretty(Move m = MOVE_NONE) const;
 
   // Position representation
   Bitboard pieces() const;
@@ -124,7 +122,6 @@ public:
   Square castle_rook_square(Color c, CastlingSide s) const;
 
   // Checking
-  bool in_check() const;
   Bitboard checkers() const;
   Bitboard discovered_check_candidates() const;
   Bitboard pinned_pieces() const;
@@ -139,8 +136,6 @@ public:
 
   // Properties of moves
   bool move_gives_check(Move m, const CheckInfo& ci) const;
-  bool move_attacks_square(Move m, Square s) const;
-  bool move_is_legal(const Move m) const;
   bool pl_move_is_legal(Move m, Bitboard pinned) const;
   bool is_pseudo_legal(const Move m) const;
   bool is_capture(Move m) const;
@@ -159,10 +154,11 @@ public:
   void do_move(Move m, StateInfo& st);
   void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
-  template<bool Do> void do_null_move(StateInfo& st);
+  void do_null_move(StateInfo& st);
+  void undo_null_move();
 
   // Static exchange evaluation
-  int see(Move m) const;
+  int see(Move m, int asymmThreshold = 0) const;
   int see_sign(Move m) const;
 
   // Accessing hash keys
@@ -178,12 +174,12 @@ public:
 
   // Other properties of the position
   Color side_to_move() const;
-  int startpos_ply_counter() const;
+  int game_ply() const;
   bool is_chess960() const;
   Thread* this_thread() const;
   int64_t nodes_searched() const;
   void set_nodes_searched(int64_t n);
-  template<bool SkipRepetition> bool is_draw() const;
+  bool is_draw() const;
 
   // Position consistency check, for debugging
   bool pos_is_ok(int* failedStep = NULL) const;
@@ -195,8 +191,8 @@ private:
   void put_piece(Piece p, Square s);
   void set_castle_right(Color c, Square rfrom);
 
-  // Helper template functions
-  template<bool Do> void do_castle_move(Move m);
+  // Helper functions
+  void do_castle(Square kfrom, Square kto, Square rfrom, Square rto);
   template<bool FindPinned> Bitboard hidden_checkers() const;
 
   // Computing hash keys from scratch (for initialization and debugging)
@@ -209,20 +205,20 @@ private:
   Value compute_non_pawn_material(Color c) const;
 
   // Board and pieces
-  Piece board[64];             // [square]
-  Bitboard byTypeBB[8];        // [pieceType]
-  Bitboard byColorBB[2];       // [color]
-  int pieceCount[2][8];        // [color][pieceType]
-  Square pieceList[2][8][16];  // [color][pieceType][index]
-  int index[64];               // [square]
+  Piece board[SQUARE_NB];
+  Bitboard byTypeBB[PIECE_TYPE_NB];
+  Bitboard byColorBB[COLOR_NB];
+  int pieceCount[COLOR_NB][PIECE_TYPE_NB];
+  Square pieceList[COLOR_NB][PIECE_TYPE_NB][16];
+  int index[SQUARE_NB];
 
   // Other info
-  int castleRightsMask[64];      // [square]
-  Square castleRookSquare[2][2]; // [color][side]
-  Bitboard castlePath[2][2];     // [color][side]
+  int castleRightsMask[SQUARE_NB];
+  Square castleRookSquare[COLOR_NB][CASTLING_SIDE_NB];
+  Bitboard castlePath[COLOR_NB][CASTLING_SIDE_NB];
   StateInfo startState;
   int64_t nodes;
-  int startPosPly;
+  int gamePly;
   Color sideToMove;
   Thread* thisThread;
   StateInfo* st;
@@ -334,10 +330,6 @@ inline Bitboard Position::checkers() const {
   return st->checkersBB;
 }
 
-inline bool Position::in_check() const {
-  return st->checkersBB != 0;
-}
-
 inline Bitboard Position::discovered_check_candidates() const {
   return hidden_checkers<false>();
 }
@@ -384,8 +376,8 @@ inline bool Position::is_passed_pawn_push(Move m) const {
         && pawn_is_passed(sideToMove, to_sq(m));
 }
 
-inline int Position::startpos_ply_counter() const {
-  return startPosPly + st->pliesFromNull; // HACK
+inline int Position::game_ply() const {
+  return gamePly;
 }
 
 inline bool Position::opposite_bishops() const {

src/psqtab.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -29,7 +29,7 @@
 /// a given square a (midgame, endgame) score pair is assigned. PSQT is defined
 /// for white side, for black side the tables are symmetric.
 
-static const Score PSQT[][64] = {
+static const Score PSQT[][SQUARE_NB] = {
   { },
   { // Pawn
    S(  0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(0,  0), S( 0, 0), S( 0, 0), S(  0, 0),

src/rkiss.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -61,17 +61,15 @@ class RKISS {
     return s.d = e + s.a;
   }
 
-  // Init seed and scramble a few rounds
-  void raninit() {
+public:
+  RKISS(int seed = 73) {
 
     s.a = 0xf1ea5eed;
     s.b = s.c = s.d = 0xd4e12c77;
-    for (int i = 0; i < 73; i++)
+    for (int i = 0; i < seed; i++) // Scramble a few rounds
         rand64();
   }
 
-public:
-  RKISS() { raninit(); }
   template<typename T> T rand() { return T(rand64()); }
 };
 

src/search.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -38,15 +38,16 @@ namespace Search {
 /// has its own array of Stack objects, indexed by the current ply.
 
 struct Stack {
-  SplitPoint* sp;
+  SplitPoint* splitPoint;
   int ply;
   Move currentMove;
   Move excludedMove;
   Move killers[2];
   Depth reduction;
-  Value eval;
+  Value staticEval;
   Value evalMargin;
   int skipNullMove;
+  int futilityMoveCount;
 };
 
 
@@ -56,12 +57,11 @@ struct Stack {
 /// all non-pv moves.
 struct RootMove {
 
-  RootMove(){} // Needed by sort()
   RootMove(Move m) : score(-VALUE_INFINITE), prevScore(-VALUE_INFINITE) {
     pv.push_back(m); pv.push_back(MOVE_NONE);
   }
 
-  bool operator<(const RootMove& m) const { return score < m.score; }
+  bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
   bool operator==(const Move& m) const { return pv[0] == m; }
 
   void extract_pv_from_tt(Position& pos);
@@ -80,9 +80,9 @@ struct RootMove {
 struct LimitsType {
 
   LimitsType() { memset(this, 0, sizeof(LimitsType)); }
-  bool use_time_management() const { return !(movetime | depth | nodes | infinite); }
+  bool use_time_management() const { return !(mate | movetime | depth | nodes | infinite); }
 
-  int time[2], inc[2], movestogo, depth, nodes, movetime, infinite, ponder;
+  int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, nodes, movetime, mate, infinite, ponder;
 };
 
 
@@ -98,7 +98,8 @@ typedef std::auto_ptr<std::stack<StateInfo> > StateStackPtr;
 extern volatile SignalsType Signals;
 extern LimitsType Limits;
 extern std::vector<RootMove> RootMoves;
-extern Position RootPosition;
+extern Position RootPos;
+extern Color RootColor;
 extern Time::point SearchTime;
 extern StateStackPtr SetupStates;
 

src/thread.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -17,6 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm> // For std::count
 #include <cassert>
 #include <iostream>
 
@@ -32,26 +33,24 @@ ThreadPool Threads; // Global object
 namespace { extern "C" {
 
  // start_routine() is the C function which is called when a new thread
- // is launched. It is a wrapper to member function pointed by start_fn.
+ // is launched. It is a wrapper to the virtual function idle_loop().
 
- long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; }
+ long start_routine(Thread* th) { th->idle_loop(); return 0; }
 
 } }
 
 
 // Thread c'tor starts a newly-created thread of execution that will call
-// the idle loop function pointed by start_fn going immediately to sleep.
+// the the virtual function idle_loop(), going immediately to sleep.
 
-Thread::Thread(Fn fn) {
+Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC
 
-  is_searching = do_exit = false;
-  maxPly = splitPointsCnt = 0;
-  curSplitPoint = NULL;
-  start_fn = fn;
+  searching = exit = false;
+  maxPly = splitPointsSize = 0;
+  activeSplitPoint = NULL;
+  activePosition = NULL;
   idx = Threads.size();
 
-  do_sleep = (fn != &Thread::main_loop); // Avoid a race with start_searching()
-
   if (!thread_create(handle, start_routine, this))
   {
       std::cerr << "Failed to create thread number " << idx << std::endl;
@@ -60,47 +59,49 @@ Thread::Thread(Fn fn) {
 }
 
 
-// Thread d'tor waits for thread termination before to return.
+// Thread d'tor waits for thread termination before to return
 
 Thread::~Thread() {
 
-  assert(do_sleep);
-
-  do_exit = true; // Search must be already finished
-  wake_up();
+  exit = true; // Search must be already finished
+  notify_one();
   thread_join(handle); // Wait for thread termination
 }
 
 
-// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
-// then calls check_time(). If maxPly is 0 thread sleeps until is woken up.
+// TimerThread::idle_loop() is where the timer thread waits msec milliseconds
+// and then calls check_time(). If msec is 0 thread sleeps until is woken up.
 extern void check_time();
 
-void Thread::timer_loop() {
+void TimerThread::idle_loop() {
 
-  while (!do_exit)
+  while (!exit)
   {
       mutex.lock();
-      sleepCondition.wait_for(mutex, maxPly ? maxPly : INT_MAX);
+
+      if (!exit)
+          sleepCondition.wait_for(mutex, msec ? msec : INT_MAX);
+
       mutex.unlock();
-      check_time();
+
+      if (msec)
+          check_time();
   }
 }
 
 
-// Thread::main_loop() is where the main thread is parked waiting to be started
+// MainThread::idle_loop() is where the main thread is parked waiting to be started
 // when there is a new search. Main thread will launch all the slave threads.
 
-void Thread::main_loop() {
+void MainThread::idle_loop() {
 
   while (true)
   {
       mutex.lock();
 
-      do_sleep = true; // Always return to sleep after a search
-      is_searching = false;
+      thinking = false;
 
-      while (do_sleep && !do_exit)
+      while (!thinking && !exit)
       {
           Threads.sleepCondition.notify_one(); // Wake up UI thread if needed
           sleepCondition.wait(mutex);
@@ -108,22 +109,23 @@ void Thread::main_loop() {
 
       mutex.unlock();
 
-      if (do_exit)
+      if (exit)
           return;
 
-      is_searching = true;
+      searching = true;
 
       Search::think();
 
-      assert(is_searching);
+      assert(searching);
+
+      searching = false;
   }
 }
 
 
-// Thread::wake_up() wakes up the thread, normally at the beginning of the search
-// or, if "sleeping threads" is used at split time.
+// Thread::notify_one() wakes up the thread when there is some search to do
 
-void Thread::wake_up() {
+void Thread::notify_one() {
 
   mutex.lock();
   sleepCondition.notify_one();
@@ -131,19 +133,12 @@ void Thread::wake_up() {
 }
 
 
-// Thread::wait_for_stop_or_ponderhit() is called when the maximum depth is
-// reached while the program is pondering. The point is to work around a wrinkle
-// in the UCI protocol: When pondering, the engine is not allowed to give a
-// "bestmove" before the GUI sends it a "stop" or "ponderhit" command. We simply
-// wait here until one of these commands (that raise StopRequest) is sent and
-// then return, after which the bestmove and pondermove will be printed.
+// Thread::wait_for() set the thread to sleep until condition 'b' turns true
 
-void Thread::wait_for_stop_or_ponderhit() {
-
-  Signals.stopOnPonderhit = true;
+void Thread::wait_for(volatile const bool& b) {
 
   mutex.lock();
-  while (!Signals.stop) sleepCondition.wait(mutex);;
+  while (!b) sleepCondition.wait(mutex);
   mutex.unlock();
 }
 
@@ -153,7 +148,7 @@ void Thread::wait_for_stop_or_ponderhit() {
 
 bool Thread::cutoff_occurred() const {
 
-  for (SplitPoint* sp = curSplitPoint; sp; sp = sp->parent)
+  for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parentSplitPoint)
       if (sp->cutoff)
           return true;
 
@@ -164,46 +159,47 @@ bool Thread::cutoff_occurred() const {
 // Thread::is_available_to() checks whether the thread is available to help the
 // thread 'master' at a split point. An obvious requirement is that thread must
 // be idle. With more than two threads, this is not sufficient: If the thread is
-// the master of some active split point, it is only available as a slave to the
-// slaves which are busy searching the split point at the top of slaves split
-// point stack (the "helpful master concept" in YBWC terminology).
+// the master of some split point, it is only available as a slave to the slaves
+// which are busy searching the split point at the top of slaves split point
+// stack (the "helpful master concept" in YBWC terminology).
 
 bool Thread::is_available_to(Thread* master) const {
 
-  if (is_searching)
+  if (searching)
       return false;
 
   // Make a local copy to be sure doesn't become zero under our feet while
   // testing next condition and so leading to an out of bound access.
-  int spCnt = splitPointsCnt;
+  int size = splitPointsSize;
 
-  // No active split points means that the thread is available as a slave for any
+  // No split points means that the thread is available as a slave for any
   // other thread otherwise apply the "helpful master" concept if possible.
-  return !spCnt || (splitPoints[spCnt - 1].slavesMask & (1ULL << master->idx));
+  return !size || (splitPoints[size - 1].slavesMask & (1ULL << master->idx));
 }
 
 
-// init() is called at startup. Initializes lock and condition variable and
-// launches requested threads sending them immediately to sleep. We cannot use
+// init() is called at startup to create and launch requested threads, that will
+// go immediately to sleep due to 'sleepWhileIdle' set to true. We cannot use
 // a c'tor becuase Threads is a static object and we need a fully initialized
-// engine at this point due to allocation of endgames in Thread c'tor.
+// engine at this point due to allocation of Endgames in Thread c'tor.
 
 void ThreadPool::init() {
 
-  timer = new Thread(&Thread::timer_loop);
-  threads.push_back(new Thread(&Thread::main_loop));
+  sleepWhileIdle = true;
+  timer = new TimerThread();
+  push_back(new MainThread());
   read_uci_options();
 }
 
 
-// exit() cleanly terminates the threads before the program exits.
+// exit() cleanly terminates the threads before the program exits
 
 void ThreadPool::exit() {
 
-  for (size_t i = 0; i < threads.size(); i++)
-      delete threads[i];
+  delete timer; // As first because check_time() accesses threads data
 
-  delete timer;
+  for (iterator it = begin(); it != end(); ++it)
+      delete *it;
 }
 
 
@@ -216,221 +212,170 @@ void ThreadPool::read_uci_options() {
 
   maxThreadsPerSplitPoint = Options["Max Threads per Split Point"];
   minimumSplitDepth       = Options["Min Split Depth"] * ONE_PLY;
-  useSleepingThreads      = Options["Use Sleeping Threads"];
   size_t requested        = Options["Threads"];
 
   assert(requested > 0);
 
-  while (threads.size() < requested)
-      threads.push_back(new Thread(&Thread::idle_loop));
+  while (size() < requested)
+      push_back(new Thread());
 
-  while (threads.size() > requested)
+  while (size() > requested)
   {
-      delete threads.back();
-      threads.pop_back();
+      delete back();
+      pop_back();
   }
 }
 
 
-// wake_up() is called before a new search to start the threads that are waiting
-// on the sleep condition and to reset maxPly. When useSleepingThreads is set
-// threads will be woken up at split time.
+// slave_available() tries to find an idle thread which is available as a slave
+// for the thread 'master'.
 
-void ThreadPool::wake_up() const {
+Thread* ThreadPool::available_slave(Thread* master) const {
 
-  for (size_t i = 0; i < threads.size(); i++)
-  {
-      threads[i]->maxPly = 0;
-      threads[i]->do_sleep = false;
+  for (const_iterator it = begin(); it != end(); ++it)
+      if ((*it)->is_available_to(master))
+          return *it;
 
-      if (!useSleepingThreads)
-          threads[i]->wake_up();
-  }
-}
-
-
-// sleep() is called after the search finishes to ask all the threads but the
-// main one to go waiting on a sleep condition.
-
-void ThreadPool::sleep() const {
-
-  // Main thread will go to sleep by itself to avoid a race with start_searching()
-  for (size_t i = 1; i < threads.size(); i++)
-      threads[i]->do_sleep = true;
-}
-
-
-// available_slave_exists() tries to find an idle thread which is available as
-// a slave for the thread 'master'.
-
-bool ThreadPool::available_slave_exists(Thread* master) const {
-
-  for (size_t i = 0; i < threads.size(); i++)
-      if (threads[i]->is_available_to(master))
-          return true;
-
-  return false;
+  return NULL;
 }
 
 
 // split() does the actual work of distributing the work at a node between
 // several available threads. If it does not succeed in splitting the node
-// (because no idle threads are available, or because we have no unused split
-// point objects), the function immediately returns. If splitting is possible, a
-// SplitPoint object is initialized with all the data that must be copied to the
-// helper threads and then helper threads are told that they have been assigned
-// work. This will cause them to instantly leave their idle loops and call
-// search(). When all threads have returned from search() then split() returns.
+// (because no idle threads are available), the function immediately returns.
+// If splitting is possible, a SplitPoint object is initialized with all the
+// data that must be copied to the helper threads and then helper threads are
+// told that they have been assigned work. This will cause them to instantly
+// leave their idle loops and call search(). When all threads have returned from
+// search() then split() returns.
 
 template <bool Fake>
-Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
-                        Value bestValue, Move* bestMove, Depth depth,
-                        Move threatMove, int moveCount, MovePicker* mp, int nodeType) {
+void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue,
+                   Move* bestMove, Depth depth, Move threatMove, int moveCount,
+                   MovePicker* movePicker, int nodeType) {
 
   assert(pos.pos_is_ok());
-  assert(bestValue > -VALUE_INFINITE);
-  assert(bestValue <= alpha);
-  assert(alpha < beta);
-  assert(beta <= VALUE_INFINITE);
-  assert(depth > DEPTH_ZERO);
-
-  Thread* master = pos.this_thread();
-
-  if (master->splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
-      return bestValue;
+  assert(*bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE);
+  assert(*bestValue > -VALUE_INFINITE);
+  assert(depth >= Threads.minimumSplitDepth);
+  assert(searching);
+  assert(splitPointsSize < MAX_SPLITPOINTS_PER_THREAD);
 
   // Pick the next available split point from the split point stack
-  SplitPoint& sp = master->splitPoints[master->splitPointsCnt];
+  SplitPoint& sp = splitPoints[splitPointsSize];
 
-  sp.parent = master->curSplitPoint;
-  sp.master = master;
-  sp.cutoff = false;
-  sp.slavesMask = 1ULL << master->idx;
+  sp.masterThread = this;
+  sp.parentSplitPoint = activeSplitPoint;
+  sp.slavesMask = 1ULL << idx;
   sp.depth = depth;
+  sp.bestValue = *bestValue;
   sp.bestMove = *bestMove;
   sp.threatMove = threatMove;
   sp.alpha = alpha;
   sp.beta = beta;
   sp.nodeType = nodeType;
-  sp.bestValue = bestValue;
-  sp.mp = mp;
+  sp.movePicker = movePicker;
   sp.moveCount = moveCount;
   sp.pos = &pos;
   sp.nodes = 0;
+  sp.cutoff = false;
   sp.ss = ss;
 
-  assert(master->is_searching);
-
-  master->curSplitPoint = &sp;
-  int slavesCnt = 0;
-
   // Try to allocate available threads and ask them to start searching setting
-  // is_searching flag. This must be done under lock protection to avoid concurrent
+  // 'searching' flag. This must be done under lock protection to avoid concurrent
   // allocation of the same slave by another master.
+  Threads.mutex.lock();
   sp.mutex.lock();
-  mutex.lock();
 
-  for (size_t i = 0; i < threads.size() && !Fake; ++i)
-      if (threads[i]->is_available_to(master))
-      {
-          sp.slavesMask |= 1ULL << i;
-          threads[i]->curSplitPoint = &sp;
-          threads[i]->is_searching = true; // Slave leaves idle_loop()
+  splitPointsSize++;
+  activeSplitPoint = &sp;
+  activePosition = NULL;
 
-          if (useSleepingThreads)
-              threads[i]->wake_up();
+  size_t slavesCnt = 1; // This thread is always included
+  Thread* slave;
 
-          if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
-              break;
-      }
-
-  master->splitPointsCnt++;
-
-  mutex.unlock();
-  sp.mutex.unlock();
+  while (    (slave = Threads.available_slave(this)) != NULL
+         && ++slavesCnt <= Threads.maxThreadsPerSplitPoint && !Fake)
+  {
+      sp.slavesMask |= 1ULL << slave->idx;
+      slave->activeSplitPoint = &sp;
+      slave->searching = true; // Slave leaves idle_loop()
+      slave->notify_one(); // Could be sleeping
+  }
 
   // Everything is set up. The master thread enters the idle loop, from which
-  // it will instantly launch a search, because its is_searching flag is set.
+  // it will instantly launch a search, because its 'searching' flag is set.
   // The thread will return from the idle loop when all slaves have finished
   // their work at this split point.
-  if (slavesCnt || Fake)
+  if (slavesCnt > 1 || Fake)
   {
-      master->idle_loop();
+      sp.mutex.unlock();
+      Threads.mutex.unlock();
+
+      Thread::idle_loop(); // Force a call to base class idle_loop()
 
       // In helpful master concept a master can help only a sub-tree of its split
       // point, and because here is all finished is not possible master is booked.
-      assert(!master->is_searching);
+      assert(!searching);
+      assert(!activePosition);
+
+      // We have returned from the idle loop, which means that all threads are
+      // finished. Note that setting 'searching' and decreasing splitPointsSize is
+      // done under lock protection to avoid a race with Thread::is_available_to().
+      Threads.mutex.lock();
+      sp.mutex.lock();
   }
 
-  // We have returned from the idle loop, which means that all threads are
-  // finished. Note that setting is_searching and decreasing splitPointsCnt is
-  // done under lock protection to avoid a race with Thread::is_available_to().
-  sp.mutex.lock(); // To protect sp.nodes
-  mutex.lock();
-
-  master->is_searching = true;
-  master->splitPointsCnt--;
-  master->curSplitPoint = sp.parent;
+  searching = true;
+  splitPointsSize--;
+  activeSplitPoint = sp.parentSplitPoint;
+  activePosition = &pos;
   pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
   *bestMove = sp.bestMove;
+  *bestValue = sp.bestValue;
 
-  mutex.unlock();
   sp.mutex.unlock();
-
-  return sp.bestValue;
+  Threads.mutex.unlock();
 }
 
 // Explicit template instantiations
-template Value ThreadPool::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
-template Value ThreadPool::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
+template void Thread::split<false>(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int);
+template void Thread::split< true>(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int);
 
 
-// set_timer() is used to set the timer to trigger after msec milliseconds.
-// If msec is 0 then timer is stopped.
+// wait_for_think_finished() waits for main thread to go to sleep then returns
 
-void ThreadPool::set_timer(int msec) {
+void ThreadPool::wait_for_think_finished() {
 
-  timer->mutex.lock();
-  timer->maxPly = msec;
-  timer->sleepCondition.notify_one(); // Wake up and restart the timer
-  timer->mutex.unlock();
-}
-
-
-// wait_for_search_finished() waits for main thread to go to sleep, this means
-// search is finished. Then returns.
-
-void ThreadPool::wait_for_search_finished() {
-
-  Thread* t = main_thread();
+  MainThread* t = main_thread();
   t->mutex.lock();
-  t->sleepCondition.notify_one(); // In case is waiting for stop or ponderhit
-  while (!t->do_sleep) sleepCondition.wait(t->mutex);
+  while (t->thinking) sleepCondition.wait(t->mutex);
   t->mutex.unlock();
 }
 
 
-// start_searching() wakes up the main thread sleeping in  main_loop() so to start
-// a new search, then returns immediately.
+// start_thinking() wakes up the main thread sleeping in MainThread::idle_loop()
+// so to start a new search, then returns immediately.
 
-void ThreadPool::start_searching(const Position& pos, const LimitsType& limits,
-                                 const std::vector<Move>& searchMoves, StateStackPtr& states) {
-  wait_for_search_finished();
+void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
+                                const std::vector<Move>& searchMoves, StateStackPtr& states) {
+  wait_for_think_finished();
 
   SearchTime = Time::now(); // As early as possible
 
   Signals.stopOnPonderhit = Signals.firstRootMove = false;
   Signals.stop = Signals.failedLowAtRoot = false;
 
-  RootPosition = pos;
+  RootPos = pos;
   Limits = limits;
   SetupStates = states; // Ownership transfer here
   RootMoves.clear();
 
   for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
-      if (searchMoves.empty() || count(searchMoves.begin(), searchMoves.end(), ml.move()))
+      if (   searchMoves.empty()
+          || std::count(searchMoves.begin(), searchMoves.end(), ml.move()))
           RootMoves.push_back(RootMove(ml.move()));
 
-  main_thread()->do_sleep = false;
-  main_thread()->wake_up();
+  main_thread()->thinking = true;
+  main_thread()->notify_one(); // Starts main thread
 }

src/thread.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -28,7 +28,7 @@
 #include "position.h"
 #include "search.h"
 
-const int MAX_THREADS = 32;
+const int MAX_THREADS = 64; // Because SplitPoint::slavesMask is a uint64_t
 const int MAX_SPLITPOINTS_PER_THREAD = 8;
 
 struct Mutex {
@@ -56,22 +56,22 @@ private:
   WaitCondition c;
 };
 
-class Thread;
+struct Thread;
 
 struct SplitPoint {
 
   // Const data after split point has been setup
   const Position* pos;
   const Search::Stack* ss;
+  Thread* masterThread;
   Depth depth;
   Value beta;
   int nodeType;
-  Thread* master;
   Move threatMove;
 
   // Const pointers to shared data
-  MovePicker* mp;
-  SplitPoint* parent;
+  MovePicker* movePicker;
+  SplitPoint* parentSplitPoint;
 
   // Shared data
   Mutex mutex;
@@ -90,77 +90,76 @@ struct SplitPoint {
 /// tables so that once we get a pointer to an entry its life time is unlimited
 /// and we don't have to care about someone changing the entry under our feet.
 
-class Thread {
+struct Thread {
 
-  typedef void (Thread::* Fn) (); // Pointer to member function
+  Thread();
+  virtual ~Thread();
 
-public:
-  Thread(Fn fn);
- ~Thread();
-
-  void wake_up();
+  virtual void idle_loop();
+  void notify_one();
   bool cutoff_occurred() const;
   bool is_available_to(Thread* master) const;
-  void idle_loop();
-  void main_loop();
-  void timer_loop();
-  void wait_for_stop_or_ponderhit();
+  void wait_for(volatile const bool& b);
+
+  template <bool Fake>
+  void split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
+             Depth depth, Move threatMove, int moveCount, MovePicker* movePicker, int nodeType);
 
   SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
-  MaterialTable materialTable;
-  PawnTable pawnTable;
+  Material::Table materialTable;
+  Endgames endgames;
+  Pawns::Table pawnsTable;
+  Position* activePosition;
   size_t idx;
   int maxPly;
   Mutex mutex;
   ConditionVariable sleepCondition;
   NativeHandle handle;
-  Fn start_fn;
-  SplitPoint* volatile curSplitPoint;
-  volatile int splitPointsCnt;
-  volatile bool is_searching;
-  volatile bool do_sleep;
-  volatile bool do_exit;
+  SplitPoint* volatile activeSplitPoint;
+  volatile int splitPointsSize;
+  volatile bool searching;
+  volatile bool exit;
 };
 
 
-/// ThreadPool class handles all the threads related stuff like init, starting,
+/// MainThread and TimerThread are sublassed from Thread to characterize the two
+/// special threads: the main one and the recurring timer.
+
+struct MainThread : public Thread {
+  MainThread() : thinking(true) {} // Avoid a race with start_thinking()
+  virtual void idle_loop();
+  volatile bool thinking;
+};
+
+struct TimerThread : public Thread {
+  TimerThread() : msec(0) {}
+  virtual void idle_loop();
+  int msec;
+};
+
+
+/// ThreadPool struct handles all the threads related stuff like init, starting,
 /// parking and, the most important, launching a slave thread at a split point.
 /// All the access to shared thread data is done through this class.
 
-class ThreadPool {
+struct ThreadPool : public std::vector<Thread*> {
 
-public:
   void init(); // No c'tor and d'tor, threads rely on globals that should
   void exit(); // be initialized and valid during the whole thread lifetime.
 
-  Thread& operator[](size_t id) { return *threads[id]; }
-  bool use_sleeping_threads() const { return useSleepingThreads; }
-  int min_split_depth() const { return minimumSplitDepth; }
-  size_t size() const { return threads.size(); }
-  Thread* main_thread() { return threads[0]; }
-
-  void wake_up() const;
-  void sleep() const;
+  MainThread* main_thread() { return static_cast<MainThread*>((*this)[0]); }
   void read_uci_options();
-  bool available_slave_exists(Thread* master) const;
-  void set_timer(int msec);
-  void wait_for_search_finished();
-  void start_searching(const Position&, const Search::LimitsType&,
-                       const std::vector<Move>&, Search::StateStackPtr&);
+  Thread* available_slave(Thread* master) const;
+  void wait_for_think_finished();
+  void start_thinking(const Position&, const Search::LimitsType&,
+                      const std::vector<Move>&, Search::StateStackPtr&);
 
-  template <bool Fake>
-  Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
-              Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType);
-private:
-  friend class Thread;
-
-  std::vector<Thread*> threads;
-  Thread* timer;
+  bool sleepWhileIdle;
+  Depth minimumSplitDepth;
+  size_t maxThreadsPerSplitPoint;
   Mutex mutex;
   ConditionVariable sleepCondition;
-  Depth minimumSplitDepth;
-  int maxThreadsPerSplitPoint;
-  bool useSleepingThreads;
+  TimerThread* timer;
 };
 
 extern ThreadPool Threads;

src/timeman.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -29,7 +29,7 @@ namespace {
   /// Constants
 
   const int MoveHorizon  = 50;    // Plan time management at most this many moves ahead
-  const float MaxRatio   = 3.0f;  // When in trouble, we can step over reserved time with this ratio
+  const float MaxRatio   = 7.0f;  // When in trouble, we can step over reserved time with this ratio
   const float StealRatio = 0.33f; // However we must not steal time from remaining moves over this ratio
 
 

src/timeman.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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

src/tt.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -25,35 +25,25 @@
 
 TranspositionTable TT; // Our global transposition table
 
-TranspositionTable::TranspositionTable() {
-
-  size = generation = 0;
-  entries = NULL;
-}
-
-TranspositionTable::~TranspositionTable() {
-
-  delete [] entries;
-}
-
 
 /// TranspositionTable::set_size() sets the size of the transposition table,
-/// measured in megabytes. Transposition table consists of a power of 2 number of
-/// TTCluster and each cluster consists of ClusterSize number of TTEntries. Each
-/// non-empty entry contains information of exactly one position.
+/// measured in megabytes. Transposition table consists of a power of 2 number
+/// of clusters and each cluster consists of ClusterSize number of TTEntry.
 
 void TranspositionTable::set_size(size_t mbSize) {
 
-  size_t newSize = 1ULL << msb((mbSize << 20) / sizeof(TTCluster));
+  assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);
 
-  if (newSize == size)
+  uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
+
+  if (hashMask == size - ClusterSize)
       return;
 
-  size = newSize;
-  delete [] entries;
-  entries = new (std::nothrow) TTCluster[size];
+  hashMask = size - ClusterSize;
+  delete [] table;
+  table = new (std::nothrow) TTEntry[size];
 
-  if (!entries)
+  if (!table)
   {
       std::cerr << "Failed to allocate " << mbSize
                 << "MB for transposition table." << std::endl;
@@ -70,7 +60,7 @@ void TranspositionTable::set_size(size_t mbSize) {
 
 void TranspositionTable::clear() {
 
-  memset(entries, 0, size * sizeof(TTCluster));
+  memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry));
 }
 
 
@@ -82,23 +72,23 @@ void TranspositionTable::clear() {
 /// more valuable than a TTEntry t2 if t1 is from the current search and t2 is from
 /// a previous search, or if the depth of t1 is bigger than the depth of t2.
 
-void TranspositionTable::store(const Key posKey, Value v, Bound t, Depth d, Move m, Value statV, Value kingD) {
+void TranspositionTable::store(const Key key, Value v, Bound t, Depth d, Move m, Value statV, Value kingD) {
 
   int c1, c2, c3;
   TTEntry *tte, *replace;
-  uint32_t posKey32 = posKey >> 32; // Use the high 32 bits as key inside the cluster
+  uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster
 
-  tte = replace = first_entry(posKey);
+  tte = replace = first_entry(key);
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
+  for (unsigned i = 0; i < ClusterSize; i++, tte++)
   {
-      if (!tte->key() || tte->key() == posKey32) // Empty or overwrite old
+      if (!tte->key() || tte->key() == key32) // Empty or overwrite old
       {
           // Preserve any existing ttMove
           if (m == MOVE_NONE)
               m = tte->move();
 
-          tte->save(posKey32, v, t, d, m, generation, statV, kingD);
+          tte->save(key32, v, t, d, m, generation, statV, kingD);
           return;
       }
 
@@ -110,7 +100,7 @@ void TranspositionTable::store(const Key posKey, Value v, Bound t, Depth d, Move
       if (c1 + c2 + c3 > 0)
           replace = tte;
   }
-  replace->save(posKey32, v, t, d, m, generation, statV, kingD);
+  replace->save(key32, v, t, d, m, generation, statV, kingD);
 }
 
 
@@ -118,24 +108,14 @@ void TranspositionTable::store(const Key posKey, Value v, Bound t, Depth d, Move
 /// transposition table. Returns a pointer to the TTEntry or NULL if
 /// position is not found.
 
-TTEntry* TranspositionTable::probe(const Key posKey) const {
+TTEntry* TranspositionTable::probe(const Key key) const {
 
-  uint32_t posKey32 = posKey >> 32;
-  TTEntry* tte = first_entry(posKey);
+  TTEntry* tte = first_entry(key);
+  uint32_t key32 = key >> 32;
 
-  for (int i = 0; i < ClusterSize; i++, tte++)
-      if (tte->key() == posKey32)
+  for (unsigned i = 0; i < ClusterSize; i++, tte++)
+      if (tte->key() == key32)
           return tte;
 
   return NULL;
 }
-
-
-/// TranspositionTable::new_search() is called at the beginning of every new
-/// search. It increments the "generation" variable, which is used to
-/// distinguish transposition table entries from previous searches from
-/// entries from the current search.
-
-void TranspositionTable::new_search() {
-  generation++;
-}

src/tt.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -44,7 +44,7 @@
 class TTEntry {
 
 public:
-  void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value statV, Value statM) {
+  void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g, Value ev, Value em) {
 
     key32        = (uint32_t)k;
     move16       = (uint16_t)m;
@@ -52,63 +52,52 @@ public:
     generation8  = (uint8_t)g;
     value16      = (int16_t)v;
     depth16      = (int16_t)d;
-    staticValue  = (int16_t)statV;
-    staticMargin = (int16_t)statM;
+    evalValue    = (int16_t)ev;
+    evalMargin   = (int16_t)em;
   }
   void set_generation(int g) { generation8 = (uint8_t)g; }
 
-  uint32_t key() const              { return key32; }
-  Depth depth() const               { return (Depth)depth16; }
-  Move move() const                 { return (Move)move16; }
-  Value value() const               { return (Value)value16; }
-  Bound type() const                { return (Bound)bound; }
-  int generation() const            { return (int)generation8; }
-  Value static_value() const        { return (Value)staticValue; }
-  Value static_value_margin() const { return (Value)staticMargin; }
+  uint32_t key() const      { return key32; }
+  Depth depth() const       { return (Depth)depth16; }
+  Move move() const         { return (Move)move16; }
+  Value value() const       { return (Value)value16; }
+  Bound type() const        { return (Bound)bound; }
+  int generation() const    { return (int)generation8; }
+  Value eval_value() const  { return (Value)evalValue; }
+  Value eval_margin() const { return (Value)evalMargin; }
 
 private:
   uint32_t key32;
   uint16_t move16;
   uint8_t bound, generation8;
-  int16_t value16, depth16, staticValue, staticMargin;
+  int16_t value16, depth16, evalValue, evalMargin;
 };
 
 
-/// This is the number of TTEntry slots for each cluster
-const int ClusterSize = 4;
-
-
-/// TTCluster consists of ClusterSize number of TTEntries. Size of TTCluster
-/// must not be bigger than a cache line size. In case it is less, it should
-/// be padded to guarantee always aligned accesses.
-
-struct TTCluster {
-  TTEntry data[ClusterSize];
-};
-
-
-/// The transposition table class. This is basically just a huge array containing
-/// TTCluster objects, and a few methods for writing and reading entries.
+/// A TranspositionTable consists of a power of 2 number of clusters and each
+/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
+/// contains information of exactly one position. Size of a cluster shall not be
+/// bigger than a cache line size. In case it is less, it should be padded to
+/// guarantee always aligned accesses.
 
 class TranspositionTable {
 
-  TranspositionTable(const TranspositionTable&);
-  TranspositionTable& operator=(const TranspositionTable&);
+  static const unsigned ClusterSize = 4; // A cluster is 64 Bytes
 
 public:
-  TranspositionTable();
-  ~TranspositionTable();
+ ~TranspositionTable() { delete [] table; }
+  void new_search() { generation++; }
+
+  TTEntry* probe(const Key key) const;
+  TTEntry* first_entry(const Key key) const;
+  void refresh(const TTEntry* tte) const;
   void set_size(size_t mbSize);
   void clear();
-  void store(const Key posKey, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);
-  TTEntry* probe(const Key posKey) const;
-  void new_search();
-  TTEntry* first_entry(const Key posKey) const;
-  void refresh(const TTEntry* tte) const;
+  void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV, Value kingD);
 
 private:
-  size_t size;
-  TTCluster* entries;
+  uint32_t hashMask;
+  TTEntry* table;
   uint8_t generation; // Size must be not bigger then TTEntry::generation8
 };
 
@@ -119,9 +108,9 @@ extern TranspositionTable TT;
 /// a cluster given a position. The lowest order bits of the key are used to
 /// get the index of the cluster.
 
-inline TTEntry* TranspositionTable::first_entry(const Key posKey) const {
+inline TTEntry* TranspositionTable::first_entry(const Key key) const {
 
-  return entries[((uint32_t)posKey) & (size - 1)].data;
+  return table + ((uint32_t)key & hashMask);
 }
 
 

src/types.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -35,13 +35,14 @@
 ///               | only in 64-bit mode. For compiling requires hardware with
 ///               | popcnt support.
 
+#include <cassert>
 #include <cctype>
 #include <climits>
 #include <cstdlib>
 
 #include "platform.h"
 
-#if defined(_WIN64)
+#if defined(_WIN64) && !defined(IS_64BIT)
 #  include <intrin.h> // MSVC popcnt and bsfq instrinsics
 #  define IS_64BIT
 #  define USE_BSFQ
@@ -51,6 +52,10 @@
 #  include <nmmintrin.h> // Intel header for _mm_popcnt_u64() intrinsic
 #endif
 
+#  if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
+#   include <xmmintrin.h> // Intel and Microsoft header for _mm_prefetch()
+#  endif
+
 #if defined(_MSC_VER) || defined(__INTEL_COMPILER)
 #  define CACHE_LINE_ALIGNMENT __declspec(align(64))
 #else
@@ -132,12 +137,20 @@ enum CastleRight {  // Defined as in PolyGlot book hash key
   WHITE_OOO    = 2,
   BLACK_OO     = 4,
   BLACK_OOO    = 8,
-  ALL_CASTLES  = 15
+  ALL_CASTLES  = 15,
+  CASTLE_RIGHT_NB = 16
 };
 
 enum CastlingSide {
   KING_SIDE,
-  QUEEN_SIDE
+  QUEEN_SIDE,
+  CASTLING_SIDE_NB = 2
+};
+
+enum Phase {
+  PHASE_ENDGAME = 0,
+  PHASE_MIDGAME = 128,
+  MG = 0, EG = 1, PHASE_NB = 2
 };
 
 enum ScaleFactor {
@@ -168,8 +181,6 @@ enum Value {
   VALUE_ENSURE_INTEGER_SIZE_P = INT_MAX,
   VALUE_ENSURE_INTEGER_SIZE_N = INT_MIN,
 
-  Mg = 0, Eg = 1,
-
   PawnValueMg   = 198,   PawnValueEg   = 258,
   KnightValueMg = 817,   KnightValueEg = 846,
   BishopValueMg = 836,   BishopValueEg = 857,
@@ -179,17 +190,19 @@ enum Value {
 
 enum PieceType {
   NO_PIECE_TYPE = 0, ALL_PIECES = 0,
-  PAWN = 1, KNIGHT = 2, BISHOP = 3, ROOK = 4, QUEEN = 5, KING = 6
+  PAWN = 1, KNIGHT = 2, BISHOP = 3, ROOK = 4, QUEEN = 5, KING = 6,
+  PIECE_TYPE_NB = 8
 };
 
 enum Piece {
-  NO_PIECE = 16, // color_of(NO_PIECE) == NO_COLOR
+  NO_PIECE = 0,
   W_PAWN = 1, W_KNIGHT =  2, W_BISHOP =  3, W_ROOK =  4, W_QUEEN =  5, W_KING =  6,
-  B_PAWN = 9, B_KNIGHT = 10, B_BISHOP = 11, B_ROOK = 12, B_QUEEN = 13, B_KING = 14
+  B_PAWN = 9, B_KNIGHT = 10, B_BISHOP = 11, B_ROOK = 12, B_QUEEN = 13, B_KING = 14,
+  PIECE_NB = 16
 };
 
 enum Color {
-  WHITE, BLACK, NO_COLOR
+  WHITE, BLACK, NO_COLOR, COLOR_NB = 2
 };
 
 enum Depth {
@@ -215,6 +228,8 @@ enum Square {
   SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
   SQ_NONE,
 
+  SQUARE_NB = 64,
+
   DELTA_N =  8,
   DELTA_E =  1,
   DELTA_S = -8,
@@ -229,11 +244,11 @@ enum Square {
 };
 
 enum File {
-  FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H
+  FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NB = 8
 };
 
 enum Rank {
-  RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8
+  RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NB = 8
 };
 
 
@@ -320,9 +335,9 @@ inline Score apply_weight(Score v, Score w) {
 
 namespace Zobrist {
 
-  extern Key psq[2][8][64]; // [color][pieceType][square / piece count]
-  extern Key enpassant[8];  // [file]
-  extern Key castle[16];    // [castleRight]
+  extern Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+  extern Key enpassant[FILE_NB];
+  extern Key castle[CASTLE_RIGHT_NB];
   extern Key side;
   extern Key exclusion;
 
@@ -331,9 +346,9 @@ namespace Zobrist {
 
 CACHE_LINE_ALIGNMENT
 
-extern Score pieceSquareTable[16][64]; // [piece][square]
-extern Value PieceValue[2][18];        // [Mg / Eg][piece / pieceType]
-extern int SquareDistance[64][64];     // [square][square]
+extern Score pieceSquareTable[PIECE_NB][SQUARE_NB];
+extern Value PieceValue[PHASE_NB][PIECE_NB];
+extern int SquareDistance[SQUARE_NB][SQUARE_NB];
 
 struct MoveStack {
   Move move;
@@ -377,6 +392,7 @@ inline PieceType type_of(Piece p)  {
 }
 
 inline Color color_of(Piece p) {
+  assert(p != NO_PIECE);
   return Color(p >> 3);
 }
 
@@ -425,12 +441,12 @@ inline int square_distance(Square s1, Square s2) {
   return SquareDistance[s1][s2];
 }
 
-inline char file_to_char(File f) {
-  return char(f - FILE_A + int('a'));
+inline char file_to_char(File f, bool tolower = true) {
+  return char(f - FILE_A + (tolower ? 'a' : 'A'));
 }
 
 inline char rank_to_char(Rank r) {
-  return char(r - RANK_1 + int('1'));
+  return char(r - RANK_1 + '1');
 }
 
 inline Square pawn_push(Color c) {
@@ -459,7 +475,7 @@ inline Move make_move(Square from, Square to) {
 
 template<MoveType T>
 inline Move make(Square from, Square to, PieceType pt = KNIGHT) {
-  return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12)) ;
+  return Move(to | (from << 6) | T | ((pt - KNIGHT) << 12));
 }
 
 inline bool is_ok(Move m) {
@@ -473,21 +489,4 @@ inline const std::string square_to_string(Square s) {
   return ch;
 }
 
-/// Our insertion sort implementation, works with pointers and iterators and is
-/// guaranteed to be stable, as is needed.
-template<typename T, typename K>
-void sort(K first, K last)
-{
-  T tmp;
-  K p, q;
-
-  for (p = first + 1; p < last; p++)
-  {
-      tmp = *p;
-      for (q = p; q != first && *(q-1) < tmp; --q)
-          *q = *(q-1);
-      *q = tmp;
-  }
-}
-
 #endif // !defined(TYPES_H_INCLUDED)

src/uci.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -17,6 +17,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <iomanip>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -26,7 +27,6 @@
 #include "position.h"
 #include "search.h"
 #include "thread.h"
-#include "tt.h"
 #include "ucioption.h"
 
 using namespace std;
@@ -44,7 +44,7 @@ namespace {
 
   void set_option(istringstream& up);
   void set_position(Position& pos, istringstream& up);
-  void go(Position& pos, istringstream& up);
+  void go(const Position& pos, istringstream& up);
 }
 
 
@@ -56,78 +56,32 @@ namespace {
 void UCI::loop(const string& args) {
 
   Position pos(StartFEN, false, Threads.main_thread()); // The root position
-  string cmd, token;
+  string token, cmd = args;
 
-  while (token != "quit")
-  {
-      if (!args.empty())
-          cmd = args;
-
-      else if (!getline(cin, cmd)) // Block here waiting for input
+  do {
+      if (args.empty() && !getline(cin, cmd)) // Block here waiting for input
           cmd = "quit";
 
       istringstream is(cmd);
 
       is >> skipws >> token;
 
-      if (token == "quit" || token == "stop")
+      if (token == "quit" || token == "stop" || token == "ponderhit")
       {
-          Search::Signals.stop = true;
-          Threads.wait_for_search_finished(); // Cannot quit while threads are running
-      }
-
-      else if (token == "ponderhit")
-      {
-          // The opponent has played the expected move. GUI sends "ponderhit" if
-          // we were told to ponder on the same move the opponent has played. We
-          // should continue searching but switching from pondering to normal search.
-          Search::Limits.ponder = false;
-
-          if (Search::Signals.stopOnPonderhit)
+          // GUI sends 'ponderhit' to tell us to ponder on the same move the
+          // opponent has played. In case Signals.stopOnPonderhit is set we are
+          // waiting for 'ponderhit' to stop the search (for instance because we
+          // already ran out of time), otherwise we should continue searching but
+          // switching from pondering to normal search.
+          if (token != "ponderhit" || Search::Signals.stopOnPonderhit)
           {
               Search::Signals.stop = true;
-              Threads.main_thread()->wake_up(); // Could be sleeping
+              Threads.main_thread()->notify_one(); // Could be sleeping
           }
+          else
+              Search::Limits.ponder = false;
       }
-
-      else if (token == "go")
-          go(pos, is);
-
-      else if (token == "ucinewgame")
-          TT.clear();
-
-      else if (token == "isready")
-          sync_cout << "readyok" << sync_endl;
-
-      else if (token == "position")
-          set_position(pos, is);
-
-      else if (token == "setoption")
-          set_option(is);
-
-      else if (token == "d")
-          pos.print();
-
-      else if (token == "flip")
-          pos.flip();
-
-      else if (token == "eval")
-          sync_cout << Eval::trace(pos) << sync_endl;
-
-      else if (token == "bench")
-          benchmark(pos, is);
-
-      else if (token == "key")
-          sync_cout << "key: " << hex     << pos.key()
-                    << "\nmaterial key: " << pos.material_key()
-                    << "\npawn key: "     << pos.pawn_key() << sync_endl;
-
-      else if (token == "uci")
-          sync_cout << "id name " << engine_info(true)
-                    << "\n"       << Options
-                    << "\nuciok"  << sync_endl;
-
-      else if (token == "perft" && (is >> token)) // Read depth
+      else if (token == "perft" && (is >> token)) // Read perft depth
       {
           stringstream ss;
 
@@ -136,16 +90,33 @@ void UCI::loop(const string& args) {
 
           benchmark(pos, ss);
       }
+      else if (token == "key")
+          sync_cout << hex << uppercase << setfill('0')
+                    << "position key: "   << setw(16) << pos.key()
+                    << "\nmaterial key: " << setw(16) << pos.material_key()
+                    << "\npawn key:     " << setw(16) << pos.pawn_key()
+                    << dec << sync_endl;
 
+      else if (token == "uci")
+          sync_cout << "id name " << engine_info(true)
+                    << "\n"       << Options
+                    << "\nuciok"  << sync_endl;
+
+      else if (token == "ucinewgame") { /* Avoid returning "Unknown command" */ }
+      else if (token == "go")         go(pos, is);
+      else if (token == "position")   set_position(pos, is);
+      else if (token == "setoption")  set_option(is);
+      else if (token == "flip")       pos.flip();
+      else if (token == "bench")      benchmark(pos, is);
+      else if (token == "d")          sync_cout << pos.pretty() << sync_endl;
+      else if (token == "isready")    sync_cout << "readyok" << sync_endl;
+      else if (token == "eval")       sync_cout << Eval::trace(pos) << sync_endl;
       else
           sync_cout << "Unknown command: " << cmd << sync_endl;
 
-      if (!args.empty()) // Command line arguments have one-shot behaviour
-      {
-          Threads.wait_for_search_finished();
-          break;
-      }
-  }
+  } while (token != "quit" && args.empty()); // Args have one-shot behaviour
+
+  Threads.wait_for_think_finished(); // Cannot quit while search is running
 }
 
 
@@ -174,7 +145,7 @@ namespace {
     else
         return;
 
-    pos.from_fen(fen, Options["UCI_Chess960"], Threads.main_thread());
+    pos.set(fen, Options["UCI_Chess960"], Threads.main_thread());
     SetupStates = Search::StateStackPtr(new std::stack<StateInfo>());
 
     // Parse move list (if any)
@@ -211,10 +182,10 @@ namespace {
 
 
   // go() is called when engine receives the "go" UCI command. The function sets
-  // the thinking time and other parameters from the input string, and then starts
+  // the thinking time and other parameters from the input string, and starts
   // the search.
 
-  void go(Position& pos, istringstream& is) {
+  void go(const Position& pos, istringstream& is) {
 
     Search::LimitsType limits;
     vector<Move> searchMoves;
@@ -222,31 +193,23 @@ namespace {
 
     while (is >> token)
     {
-        if (token == "wtime")
-            is >> limits.time[WHITE];
-        else if (token == "btime")
-            is >> limits.time[BLACK];
-        else if (token == "winc")
-            is >> limits.inc[WHITE];
-        else if (token == "binc")
-            is >> limits.inc[BLACK];
-        else if (token == "movestogo")
-            is >> limits.movestogo;
-        else if (token == "depth")
-            is >> limits.depth;
-        else if (token == "nodes")
-            is >> limits.nodes;
-        else if (token == "movetime")
-            is >> limits.movetime;
-        else if (token == "infinite")
-            limits.infinite = true;
-        else if (token == "ponder")
-            limits.ponder = true;
-        else if (token == "searchmoves")
+        if (token == "searchmoves")
             while (is >> token)
                 searchMoves.push_back(move_from_uci(pos, token));
+
+        else if (token == "wtime")     is >> limits.time[WHITE];
+        else if (token == "btime")     is >> limits.time[BLACK];
+        else if (token == "winc")      is >> limits.inc[WHITE];
+        else if (token == "binc")      is >> limits.inc[BLACK];
+        else if (token == "movestogo") is >> limits.movestogo;
+        else if (token == "depth")     is >> limits.depth;
+        else if (token == "nodes")     is >> limits.nodes;
+        else if (token == "movetime")  is >> limits.movetime;
+        else if (token == "mate")      is >> limits.mate;
+        else if (token == "infinite")  limits.infinite = true;
+        else if (token == "ponder")    limits.ponder = true;
     }
 
-    Threads.start_searching(pos, limits, searchMoves, SetupStates);
+    Threads.start_thinking(pos, limits, searchMoves, SetupStates);
   }
 }

src/ucioption.cpp

@@ -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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -64,6 +64,7 @@ void init(OptionsMap& o) {
   o["Search Log Filename"]         = Option("SearchLog.txt");
   o["Book File"]                   = Option("book.bin");
   o["Best Book Move"]              = Option(false);
+  o["Contempt Factor"]             = Option(0, -50,  50);
   o["Mobility (Middle Game)"]      = Option(100, 0, 200, on_eval);
   o["Mobility (Endgame)"]          = Option(100, 0, 200, on_eval);
   o["Passed Pawns (Middle Game)"]  = Option(100, 0, 200, on_eval);
@@ -71,11 +72,11 @@ void init(OptionsMap& o) {
   o["Space"]                       = Option(100, 0, 200, on_eval);
   o["Aggressiveness"]              = Option(100, 0, 200, on_eval);
   o["Cowardice"]                   = Option(100, 0, 200, on_eval);
-  o["Min Split Depth"]             = Option(msd, 4, 7, on_threads);
+  o["Min Split Depth"]             = Option(msd, 4, 12, on_threads);
   o["Max Threads per Split Point"] = Option(5, 4, 8, on_threads);
   o["Threads"]                     = Option(cpus, 1, MAX_THREADS, on_threads);
-  o["Use Sleeping Threads"]        = Option(true, on_threads);
-  o["Hash"]                        = Option(32, 4, 8192, on_hash_size);
+  o["Use Sleeping Threads"]        = Option(false);
+  o["Hash"]                        = Option(32, 1, 8192, on_hash_size);
   o["Clear Hash"]                  = Option(on_clear_hash);
   o["Ponder"]                      = Option(true);
   o["OwnBook"]                     = Option(false);

src/ucioption.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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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