Stockfish 6

Stockfish bench signature is: 8918745

AUTHORS

@@ -0,0 +1,64 @@
+# Generated with git shortlog -sn | cut -c8-', which sorts by commits (manually moved Tord to top)
+
+Tord Romstad
+Marco Costalba
+Joona Kiiski
+Gary Linscott
+Lucas Braesch
+Reuven Peleg
+Chris Caino
+homoSapiensSapiens
+Jean-Francois Romang
+jundery
+Arjun Temurnikar
+Uri Blass
+Ralph Stößer
+Stefan Geschwentner
+Tom Vijlbrief
+Daylen Yang
+Henri Wiechers
+Leonid Pechenik
+mstembera
+Eelco de Groot
+Jerry Donald
+Jörg Oster
+Ryan Schmitt
+mcostalba
+Alexander Kure
+Dan Schmidt
+H. Felix Wittmann
+Justin Blanchard
+Linus Arver
+RyanTaker
+ceebo
+Joseph H Ellis
+Stephane Nicolet
+Ajith
+Andy Duplain
+Auguste Pop
+Balint Pfliegel
+Chris Cain
+Dariusz Orzechowski
+Gregor Cramer
+Hiraoka Takuya
+Hongzhi Cheng
+Jonathan Calovski
+Joseph R. Prostko
+Kelly Wilson
+Kojirion
+Matt Sullivan
+Matthew Sullivan
+Michel Van den Bergh
+Mysseno
+Pablo Vazquez
+Raminder Singh
+Richard Lloyd
+Ron Britvich
+Ronald de Man
+Ryan Takker
+Thanar2
+kinderchocolate
+pellanda
+renouve
+shane31
+thaspel

Readme.md

@@ -7,11 +7,13 @@ 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 128 CPUs. The engine defaults
+This version of Stockfish supports up to 128 cores. The engine defaults
 to one search thread, so it is therefore recommended to inspect the value of
 the *Threads* UCI parameter, and to make sure it equals the number of CPU
 cores on your computer.
 
+This version of Stockfish has support for Syzygybases.
+
 
 ### Files
 
@@ -22,19 +24,59 @@ This distribution of Stockfish consists of the following files:
   * 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 below.
-
-  * polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
-    adapter.
+    that can be used to compile Stockfish on Unix-like systems.
 
 
-### Opening books
+### Syzygybases
 
-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*
-UCI parameter.
+**Configuration**
+
+Syzygybases are configured using the UCI options "SyzygyPath",
+"SyzygyProbeDepth", "Syzygy50MoveRule" and "SyzygyProbeLimit".
+
+The option "SyzygyPath" should be set to the directory or directories that
+contain the .rtbw and .rtbz files. Multiple directories should be
+separated by ";" on Windows and by ":" on Unix-based operating systems.
+**Do not use spaces around the ";" or ":".**
+
+Example: `C:\tablebases\wdl345;C:\tablebases\wdl6;D:\tablebases\dtz345;D:\tablebases\dtz6`
+
+It is recommended to store .rtbw files on an SSD. There is no loss in
+storing the .rtbz files on a regular HD.
+
+Increasing the "SyzygyProbeDepth" option lets the engine probe less
+aggressively. Set this option to a higher value if you experience too much
+slowdown (in terms of nps) due to TB probing.
+
+Set the "Syzygy50MoveRule" option to false if you want tablebase positions
+that are drawn by the 50-move rule to count as win or loss. This may be useful
+for correspondence games (because of tablebase adjudication).
+
+The "SyzygyProbeLimit" option should normally be left at its default value.
+
+**What to expect**  
+If the engine is searching a position that is not in the tablebases (e.g.
+a position with 7 pieces), it will access the tablebases during the search.
+If the engine reports a very large score (typically 123.xx), this means
+that it has found a winning line into a tablebase position.
+
+If the engine is given a position to search that is in the tablebases, it
+will use the tablebases at the beginning of the search to preselect all
+good moves, i.e. all moves that preserve the win or preserve the draw while
+taking into account the 50-move rule.
+It will then perform a search only on those moves. **The engine will not move
+immediately**, unless there is only a single good move. **The engine likely
+will not report a mate score even if the position is known to be won.**
+
+It is therefore clear that behaviour is not identical to what one might
+be used to with Nalimov tablebases. There are technical reasons for this
+difference, the main technical reason being that Nalimov tablebases use the
+DTM metric (distance-to-mate), while Syzygybases use a variation of the
+DTZ metric (distance-to-zero, zero meaning any move that resets the 50-move
+counter). This special metric is one of the reasons that Syzygybases are
+more compact than Nalimov tablebases, while still storing all information
+needed for optimal play and in addition being able to take into account
+the 50-move rule.
 
 
 ### Compiling it yourself

polyglot.ini

@@ -1,43 +0,0 @@
-[PolyGlot]
-
-EngineDir = .
-EngineCommand = ./stockfish
-
-Book = false
-BookFile = book.bin
-
-Log = false
-LogFile = stockfish.log
-
-Resign = true
-ResignScore = 600
-
-[Engine]
-
-Write Debug Log = false
-Write Search Log = false
-Search Log Filename = SearchLog.txt
-Book File = book.bin
-Best Book Move = false
-Contempt Factor = 0
-Mobility (Midgame) = 100
-Mobility (Endgame) = 100
-Pawn Structure (Midgame) = 100
-Pawn Structure (Endgame) = 100
-Passed Pawns (Midgame) = 100
-Passed Pawns (Endgame) = 100
-Space = 100
-King Safety = 100
-Min Split Depth = 0
-Threads = 1
-Hash = 128
-Ponder = true
-OwnBook = false
-MultiPV = 1
-Skill Level = 20
-Emergency Move Horizon = 40
-Emergency Base Time = 200
-Emergency Move Time = 70
-Minimum Thinking Time = 20
-Slow Mover = 100
-UCI_Chess960 = 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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+# Copyright (C) 2008-2015 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
@@ -28,19 +28,15 @@ EXE = stockfish
 
 ### Installation dir definitions
 PREFIX = /usr/local
-# Haiku has a non-standard filesystem layout
-ifeq ($(UNAME),Haiku)
-	PREFIX=/boot/common
-endif
 BINDIR = $(PREFIX)/bin
 
 ### Built-in benchmark for pgo-builds
-PGOBENCH = ./$(EXE) bench 32 1 1 default time
+PGOBENCH = ./$(EXE) bench 16 1 1000 default time
 
 ### Object files
-OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
-	material.o misc.o movegen.o movepick.o notation.o pawns.o position.o \
-	search.o thread.o timeman.o tt.o uci.o ucioption.o
+OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
+	material.o misc.o movegen.o movepick.o pawns.o position.o \
+	search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o
 
 ### ==========================================================================
 ### Section 2. High-level Configuration
@@ -52,7 +48,6 @@ OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
 # debug = yes/no      --- -DNDEBUG         --- Enable/Disable debug mode
 # optimize = yes/no   --- (-O3/-fast etc.) --- Enable/Disable optimizations
 # arch = (name)       --- (-arch)          --- Target architecture
-# os = (name)         ---                  --- Target operating system
 # bits = 64/32        --- -DIS_64BIT       --- 64-/32-bit operating system
 # prefetch = yes/no   --- -DUSE_PREFETCH   --- Use prefetch x86 asm-instruction
 # bsfq = yes/no       --- -DUSE_BSFQ       --- Use bsfq x86_64 asm-instruction (only
@@ -68,7 +63,6 @@ OBJS = benchmark.o bitbase.o bitboard.o book.o endgame.o evaluate.o main.o \
 ### 2.1. General and architecture defaults
 optimize = yes
 debug = no
-os = any
 bits = 32
 prefetch = no
 bsfq = no
@@ -175,7 +169,7 @@ endif
 ifeq ($(COMP),clang)
 	comp=clang
 	CXX=clang++
-	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
+	CXXFLAGS += -pedantic -Wno-long-long -Wextra -Wshadow
 endif
 
 ifeq ($(comp),icc)
@@ -285,7 +279,11 @@ endif
 
 ### 3.9 popcnt
 ifeq ($(popcnt),yes)
-	CXXFLAGS += -msse3 -DUSE_POPCNT
+	ifeq ($(comp),icc)
+		CXXFLAGS += -msse3 -DUSE_POPCNT
+	else
+		CXXFLAGS += -msse3 -mpopcnt -DUSE_POPCNT
+	endif
 endif
 
 ### 3.10 pext
@@ -312,6 +310,14 @@ ifeq ($(comp),gcc)
 	endif
 endif
 
+### 3.12 Android 5 can only run position independent executables. Note that this
+### breaks Android 4.0 and earlier.
+ifeq ($(arch),armv7)
+	CXXFLAGS += -fPIE
+	LDFLAGS += -fPIE -pie
+endif
+
+
 ### ==========================================================================
 ### Section 4. Public targets
 ### ==========================================================================
@@ -350,10 +356,6 @@ help:
 	@echo "clang                   > LLVM Clang compiler"
 	@echo "icc                     > Intel compiler"
 	@echo ""
-	@echo "Non-standard targets:"
-	@echo ""
-	@echo "make hpux               >  Compile for HP-UX. Compiler = aCC"
-	@echo ""
 	@echo "Examples. If you don't know what to do, you likely want to run: "
 	@echo ""
 	@echo "make build ARCH=x86-64    (This is for 64-bit systems)"
@@ -372,14 +374,14 @@ profile-build:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_prepare)
 	@echo ""
 	@echo "Step 1/4. Building executable for benchmark ..."
-	@touch *.cpp *.h
+	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_make)
 	@echo ""
 	@echo "Step 2/4. Running benchmark for pgo-build ..."
 	@$(PGOBENCH) > /dev/null
 	@echo ""
 	@echo "Step 3/4. Building final executable ..."
-	@touch *.cpp
+	@touch *.cpp *.h syzygy/*.cpp syzygy/*.h
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) $(profile_use)
 	@echo ""
 	@echo "Step 4/4. Deleting profile data ..."
@@ -394,7 +396,7 @@ install:
 	-strip $(BINDIR)/$(EXE)
 
 clean:
-	$(RM) $(EXE) $(EXE).exe *.o .depend *~ core bench.txt *.gcda
+	$(RM) $(EXE) $(EXE).exe *.o .depend *~ core bench.txt *.gcda ./syzygy/*.o ./syzygy/*.gcda
 
 default:
 	help
@@ -411,7 +413,6 @@ config-sanity:
 	@echo "debug: '$(debug)'"
 	@echo "optimize: '$(optimize)'"
 	@echo "arch: '$(arch)'"
-	@echo "os: '$(os)'"
 	@echo "bits: '$(bits)'"
 	@echo "prefetch: '$(prefetch)'"
 	@echo "bsfq: '$(bsfq)'"
@@ -430,7 +431,6 @@ config-sanity:
 	@test "$(optimize)" = "yes" || test "$(optimize)" = "no"
 	@test "$(arch)" = "any" || test "$(arch)" = "x86_64" || test "$(arch)" = "i386" || \
 	 test "$(arch)" = "ppc64" || test "$(arch)" = "ppc" || test "$(arch)" = "armv7"
-	@test "$(os)" = "any"
 	@test "$(bits)" = "32" || test "$(bits)" = "64"
 	@test "$(prefetch)" = "yes" || test "$(prefetch)" = "no"
 	@test "$(bsfq)" = "yes" || test "$(bsfq)" = "no"
@@ -447,18 +447,21 @@ gcc-profile-prepare:
 
 gcc-profile-make:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
-	EXTRACXXFLAGS='-fprofile-generate' \
+	EXTRACXXFLAGS='-fprofile-arcs' \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
 gcc-profile-use:
+# Deleting corrupt ucioption.gc* profile files is necessary to avoid an 
+# "internal compiler error" for gcc versions 4.7.x
+	@rm -f ucioption.gc*
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) \
-	EXTRACXXFLAGS='-fprofile-use' \
+	EXTRACXXFLAGS='-fbranch-probabilities' \
 	EXTRALDFLAGS='-lgcov' \
 	all
 
 gcc-profile-clean:
-	@rm -rf *.gcda *.gcno bench.txt
+	@rm -rf *.gcda *.gcno syzygy/*.gcda syzygy/*.gcno bench.txt
 
 icc-profile-prepare:
 	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) icc-profile-clean
@@ -482,15 +485,3 @@ icc-profile-clean:
 
 -include .depend
 
-
-### ==========================================================================
-### Section 6. Non-standard targets
-### ==========================================================================
-
-hpux:
-	$(MAKE) \
-	CXX='/opt/aCC/bin/aCC -AA +hpxstd98 -mt +O3 -DNDEBUG -DNO_PREFETCH' \
-	CXXFLAGS="" \
-	LDFLAGS="" \
-	all
-

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -17,22 +17,24 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <algorithm>
 #include <fstream>
 #include <iostream>
 #include <istream>
 #include <vector>
 
 #include "misc.h"
-#include "notation.h"
 #include "position.h"
 #include "search.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
 
 using namespace std;
 
-static const char* Defaults[] = {
+namespace {
+
+const char* Defaults[] = {
   "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
   "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 10",
   "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 11",
@@ -62,9 +64,23 @@ static const char* Defaults[] = {
   "6k1/6p1/P6p/r1N5/5p2/7P/1b3PP1/4R1K1 w - - 0 1",
   "1r3k2/4q3/2Pp3b/3Bp3/2Q2p2/1p1P2P1/1P2KP2/3N4 w - - 0 1",
   "6k1/4pp1p/3p2p1/P1pPb3/R7/1r2P1PP/3B1P2/6K1 w - - 0 1",
-  "8/3p3B/5p2/5P2/p7/PP5b/k7/6K1 w - - 0 1"
+  "8/3p3B/5p2/5P2/p7/PP5b/k7/6K1 w - - 0 1",
+
+  // 5-man positions
+  "8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1",     // Kc2 - mate
+  "8/8/8/5N2/8/p7/8/2NK3k w - - 0 1",      // Na2 - mate
+  "8/3k4/8/8/8/4B3/4KB2/2B5 w - - 0 1",    // draw
+
+  // 6-man positions
+  "8/8/1P6/5pr1/8/4R3/7k/2K5 w - - 0 1",   // Re5 - mate
+  "8/2p4P/8/kr6/6R1/8/8/1K6 w - - 0 1",    // Ka2 - mate
+  "8/8/3P3k/8/1p6/8/1P6/1K3n2 b - - 0 1",  // Nd2 - draw
+
+  // 7-man positions
+  "8/R7/2q5/8/6k1/8/1P5p/K6R w - - 0 124", // Draw
 };
 
+} // namespace
 
 /// benchmark() runs a simple benchmark by letting Stockfish analyze a set
 /// of positions for a given limit each. There are five parameters: the
@@ -72,7 +88,7 @@ static const char* Defaults[] = {
 /// be used, the limit value spent for each position (optional, default is
 /// depth 13), an optional file name where to look for positions in FEN
 /// format (defaults are the positions defined above) and the type of the
-/// limit value: depth (default), time in secs or number of nodes.
+/// limit value: depth (default), time in millisecs or number of nodes.
 
 void benchmark(const Position& current, istream& is) {
 
@@ -81,7 +97,7 @@ void benchmark(const Position& current, istream& is) {
   vector<string> fens;
 
   // Assign default values to missing arguments
-  string ttSize    = (is >> token) ? token : "32";
+  string ttSize    = (is >> token) ? token : "16";
   string threads   = (is >> token) ? token : "1";
   string limit     = (is >> token) ? token : "13";
   string fenFile   = (is >> token) ? token : "default";
@@ -92,7 +108,7 @@ void benchmark(const Position& current, istream& is) {
   TT.clear();
 
   if (limitType == "time")
-      limits.movetime = 1000 * atoi(limit.c_str()); // movetime is in ms
+      limits.movetime = atoi(limit.c_str()); // movetime is in ms
 
   else if (limitType == "nodes")
       limits.nodes = atoi(limit.c_str());
@@ -104,7 +120,7 @@ void benchmark(const Position& current, istream& is) {
       limits.depth = atoi(limit.c_str());
 
   if (fenFile == "default")
-      fens.assign(Defaults, Defaults + 30);
+      fens.assign(Defaults, Defaults + 37);
 
   else if (fenFile == "current")
       fens.push_back(current.fen());
@@ -137,22 +153,9 @@ void benchmark(const Position& current, istream& is) {
 
       cerr << "\nPosition: " << i + 1 << '/' << fens.size() << endl;
 
-      if (limitType == "divide")
-          for (MoveList<LEGAL> it(pos); *it; ++it)
-          {
-              StateInfo si;
-              pos.do_move(*it, si);
-              uint64_t cnt = limits.depth > 1 ? Search::perft(pos, (limits.depth - 1) * ONE_PLY) : 1;
-              pos.undo_move(*it);
-              cerr << move_to_uci(*it, pos.is_chess960()) << ": " << cnt << endl;
-              nodes += cnt;
-          }
-      else if (limitType == "perft")
-      {
-          uint64_t cnt = Search::perft(pos, limits.depth * ONE_PLY);
-          cerr << "\nPerft " << limits.depth  << " leaf nodes: " << cnt << endl;
-          nodes += cnt;
-      }
+      if (limitType == "perft")
+          nodes += Search::perft<true>(pos, limits.depth * ONE_PLY);
+
       else
       {
           Threads.start_thinking(pos, limits, st);
@@ -161,7 +164,7 @@ void benchmark(const Position& current, istream& is) {
       }
   }
 
-  elapsed = Time::now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'
+  elapsed = std::max(Time::now() - elapsed, Time::point(1)); // Avoid a 'divide by zero'
 
   dbg_print(); // Just before to exit
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -41,7 +41,7 @@ namespace {
   // bit 13-14: white pawn file (from FILE_A to FILE_D)
   // bit 15-17: white pawn RANK_7 - rank (from RANK_7 - RANK_7 to RANK_7 - RANK_2)
   unsigned index(Color us, Square bksq, Square wksq, Square psq) {
-    return wksq + (bksq << 6) + (us << 12) + (file_of(psq) << 13) + ((RANK_7 - rank_of(psq)) << 15);
+    return wksq | (bksq << 6) | (us << 12) | (file_of(psq) << 13) | ((RANK_7 - rank_of(psq)) << 15);
   }
 
   enum Result {
@@ -71,7 +71,7 @@ namespace {
 } // namespace
 
 
-bool Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color us) {
+bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color us) {
 
   assert(file_of(wpsq) <= FILE_D);
 
@@ -80,7 +80,7 @@ bool Bitbases::probe_kpk(Square wksq, Square wpsq, Square bksq, Color us) {
 }
 
 
-void Bitbases::init_kpk() {
+void Bitbases::init() {
 
   unsigned idx, repeat = 1;
   std::vector<KPKPosition> db;
@@ -107,14 +107,14 @@ namespace {
 
   KPKPosition::KPKPosition(unsigned idx) {
 
-    wksq = Square((idx >>  0) & 0x3F);
-    bksq = Square((idx >>  6) & 0x3F);
-    us   = Color ((idx >> 12) & 0x01);
-    psq  = make_square(File((idx >> 13) & 0x03), Rank(RANK_7 - (idx >> 15)));
-    result  = UNKNOWN;
+    wksq   = Square((idx >>  0) & 0x3F);
+    bksq   = Square((idx >>  6) & 0x3F);
+    us     = Color ((idx >> 12) & 0x01);
+    psq    = make_square(File((idx >> 13) & 0x3), RANK_7 - Rank((idx >> 15) & 0x7));
+    result = UNKNOWN;
 
     // Check if two pieces are on the same square or if a king can be captured
-    if (   square_distance(wksq, bksq) <= 1
+    if (   distance(wksq, bksq) <= 1
         || wksq == psq
         || bksq == psq
         || (us == WHITE && (StepAttacksBB[PAWN][psq] & bksq)))
@@ -125,7 +125,7 @@ namespace {
         // Immediate win if a pawn can be promoted without getting captured
         if (   rank_of(psq) == RANK_7
             && wksq != psq + DELTA_N
-            && (   square_distance(bksq, psq + DELTA_N) > 1
+            && (   distance(bksq, psq + DELTA_N) > 1
                 ||(StepAttacksBB[KING][wksq] & (psq + DELTA_N))))
             result = WIN;
     }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -18,23 +18,23 @@
 */
 
 #include <algorithm>
-#include <cstring> // For memset
+#include <cstring>   // For std::memset
 
 #include "bitboard.h"
 #include "bitcount.h"
-#include "rkiss.h"
+#include "misc.h"
 
-CACHE_LINE_ALIGNMENT
+int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-Bitboard RMasks[SQUARE_NB];
-Bitboard RMagics[SQUARE_NB];
-Bitboard* RAttacks[SQUARE_NB];
-unsigned RShifts[SQUARE_NB];
+Bitboard  RookMasks  [SQUARE_NB];
+Bitboard  RookMagics [SQUARE_NB];
+Bitboard* RookAttacks[SQUARE_NB];
+unsigned  RookShifts [SQUARE_NB];
 
-Bitboard BMasks[SQUARE_NB];
-Bitboard BMagics[SQUARE_NB];
-Bitboard* BAttacks[SQUARE_NB];
-unsigned BShifts[SQUARE_NB];
+Bitboard  BishopMasks  [SQUARE_NB];
+Bitboard  BishopMagics [SQUARE_NB];
+Bitboard* BishopAttacks[SQUARE_NB];
+unsigned  BishopShifts [SQUARE_NB];
 
 Bitboard SquareBB[SQUARE_NB];
 Bitboard FileBB[FILE_NB];
@@ -44,53 +44,44 @@ Bitboard InFrontBB[COLOR_NB][RANK_NB];
 Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
 Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 Bitboard LineBB[SQUARE_NB][SQUARE_NB];
-Bitboard DistanceRingsBB[SQUARE_NB][8];
+Bitboard DistanceRingBB[SQUARE_NB][8];
 Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
 Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
 Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
 Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
-int SquareDistance[SQUARE_NB][SQUARE_NB];
-
 namespace {
 
   // De Bruijn sequences. See chessprogramming.wikispaces.com/BitScan
-  const uint64_t DeBruijn_64 = 0x3F79D71B4CB0A89ULL;
-  const uint32_t DeBruijn_32 = 0x783A9B23;
+  const uint64_t DeBruijn64 = 0x3F79D71B4CB0A89ULL;
+  const uint32_t DeBruijn32 = 0x783A9B23;
 
-  CACHE_LINE_ALIGNMENT
-
-  int MS1BTable[256];
-  Square BSFTable[SQUARE_NB];
-  Bitboard RTable[0x19000]; // Storage space for rook attacks
-  Bitboard BTable[0x1480];  // Storage space for bishop attacks
+  int MS1BTable[256];           // To implement software msb()
+  Square BSFTable[SQUARE_NB];   // To implement software bitscan
+  Bitboard RookTable[0x19000];  // To store rook attacks
+  Bitboard BishopTable[0x1480]; // To store bishop attacks
 
   typedef unsigned (Fn)(Square, Bitboard);
 
   void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
                    Bitboard masks[], unsigned shifts[], Square deltas[], Fn index);
 
-  FORCE_INLINE unsigned bsf_index(Bitboard b) {
+  // bsf_index() returns the index into BSFTable[] to look up the bitscan. Uses
+  // Matt Taylor's folding for 32 bit case, extended to 64 bit by Kim Walisch.
 
-    // Matt Taylor's folding for 32 bit systems, extended to 64 bits by Kim Walisch
-    b ^= (b - 1);
-    return Is64Bit ? (b * DeBruijn_64) >> 58
-                   : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn_32) >> 26;
+  FORCE_INLINE unsigned bsf_index(Bitboard b) {
+    b ^= b - 1;
+    return Is64Bit ? (b * DeBruijn64) >> 58
+                   : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn32) >> 26;
   }
 }
 
-/// lsb()/msb() finds the least/most significant bit in a non-zero bitboard.
-/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard.
-
 #ifndef USE_BSFQ
 
-Square lsb(Bitboard b) { return BSFTable[bsf_index(b)]; }
+/// Software fall-back of lsb() and msb() for CPU lacking hardware support
 
-Square pop_lsb(Bitboard* b) {
-
-  Bitboard bb = *b;
-  *b = bb & (bb - 1);
-  return BSFTable[bsf_index(bb)];
+Square lsb(Bitboard b) {
+  return BSFTable[bsf_index(b)];
 }
 
 Square msb(Bitboard b) {
@@ -124,8 +115,8 @@ Square msb(Bitboard b) {
 #endif // ifndef USE_BSFQ
 
 
-/// Bitboards::pretty() returns an ASCII representation of a bitboard to be
-/// printed to standard output. This is sometimes useful for debugging.
+/// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
+/// to be printed to standard output. Useful for debugging.
 
 const std::string Bitboards::pretty(Bitboard b) {
 
@@ -149,7 +140,10 @@ const std::string Bitboards::pretty(Bitboard b) {
 void Bitboards::init() {
 
   for (Square s = SQ_A1; s <= SQ_H8; ++s)
-      BSFTable[bsf_index(SquareBB[s] = 1ULL << s)] = s;
+  {
+      SquareBB[s] = 1ULL << s;
+      BSFTable[bsf_index(SquareBB[s])] = s;
+  }
 
   for (Bitboard b = 1; b < 256; ++b)
       MS1BTable[b] = more_than_one(b) ? MS1BTable[b - 1] : lsb(b);
@@ -178,8 +172,8 @@ void Bitboards::init() {
       for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
           if (s1 != s2)
           {
-              SquareDistance[s1][s2] = std::max(file_distance(s1, s2), rank_distance(s1, s2));
-              DistanceRingsBB[s1][SquareDistance[s1][s2] - 1] |= s2;
+              SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
+              DistanceRingBB[s1][SquareDistance[s1][s2] - 1] |= s2;
           }
 
   int steps[][9] = { {}, { 7, 9 }, { 17, 15, 10, 6, -6, -10, -15, -17 },
@@ -192,15 +186,15 @@ void Bitboards::init() {
               {
                   Square to = s + Square(c == WHITE ? steps[pt][i] : -steps[pt][i]);
 
-                  if (is_ok(to) && square_distance(s, to) < 3)
+                  if (is_ok(to) && distance(s, to) < 3)
                       StepAttacksBB[make_piece(c, pt)][s] |= to;
               }
 
-  Square RDeltas[] = { DELTA_N,  DELTA_E,  DELTA_S,  DELTA_W  };
-  Square BDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
+  Square RookDeltas[] = { DELTA_N,  DELTA_E,  DELTA_S,  DELTA_W  };
+  Square BishopDeltas[] = { DELTA_NE, DELTA_SE, DELTA_SW, DELTA_NW };
 
-  init_magics(RTable, RAttacks, RMagics, RMasks, RShifts, RDeltas, magic_index<ROOK>);
-  init_magics(BTable, BAttacks, BMagics, BMasks, BShifts, BDeltas, magic_index<BISHOP>);
+  init_magics(RookTable, RookAttacks, RookMagics, RookMasks, RookShifts, RookDeltas, magic_index<ROOK>);
+  init_magics(BishopTable, BishopAttacks, BishopMagics, BishopMasks, BishopShifts, BishopDeltas, magic_index<BISHOP>);
 
   for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
   {
@@ -230,7 +224,7 @@ namespace {
 
     for (int i = 0; i < 4; ++i)
         for (Square s = sq + deltas[i];
-             is_ok(s) && square_distance(s, s - deltas[i]) == 1;
+             is_ok(s) && distance(s, s - deltas[i]) == 1;
              s += deltas[i])
         {
             attack |= s;
@@ -251,12 +245,11 @@ namespace {
   void init_magics(Bitboard table[], Bitboard* attacks[], Bitboard magics[],
                    Bitboard masks[], unsigned shifts[], Square deltas[], Fn index) {
 
-    int MagicBoosters[][8] = { {  969, 1976, 2850,  542, 2069, 2852, 1708,  164 },
-                               { 3101,  552, 3555,  926,  834,   26, 2131, 1117 } };
+    int seeds[][RANK_NB] = { { 8977, 44560, 54343, 38998,  5731, 95205, 104912, 17020 },
+                             {  728, 10316, 55013, 32803, 12281, 15100,  16645,   255 } };
 
-    RKISS rk;
     Bitboard occupancy[4096], reference[4096], edges, b;
-    int i, size, booster;
+    int i, size;
 
     // attacks[s] is a pointer to the beginning of the attacks table for square 's'
     attacks[SQ_A1] = table;
@@ -282,7 +275,7 @@ namespace {
             reference[size] = sliding_attack(deltas, s, b);
 
             if (HasPext)
-                attacks[s][_pext_u64(b, masks[s])] = reference[size];
+                attacks[s][pext(b, masks[s])] = reference[size];
 
             size++;
             b = (b - masks[s]) & masks[s];
@@ -296,12 +289,13 @@ namespace {
         if (HasPext)
             continue;
 
-        booster = MagicBoosters[Is64Bit][rank_of(s)];
+        PRNG rng(seeds[Is64Bit][rank_of(s)]);
 
         // Find a magic for square 's' picking up an (almost) random number
         // until we find the one that passes the verification test.
         do {
-            do magics[s] = rk.magic_rand<Bitboard>(booster);
+            do
+                magics[s] = rng.sparse_rand<Bitboard>();
             while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
 
             std::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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -21,8 +21,17 @@
 #ifndef BITBOARD_H_INCLUDED
 #define BITBOARD_H_INCLUDED
 
+#include <string>
+
 #include "types.h"
 
+namespace Bitbases {
+
+void init();
+bool probe(Square wksq, Square wpsq, Square bksq, Color us);
+
+}
+
 namespace Bitboards {
 
 void init();
@@ -30,12 +39,7 @@ const std::string pretty(Bitboard b);
 
 }
 
-namespace Bitbases {
-
-void init_kpk();
-bool probe_kpk(Square wksq, Square wpsq, Square bksq, Color us);
-
-}
+const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
 
 const Bitboard FileABB = 0x0101010101010101ULL;
 const Bitboard FileBBB = FileABB << 1;
@@ -55,17 +59,17 @@ const Bitboard Rank6BB = Rank1BB << (8 * 5);
 const Bitboard Rank7BB = Rank1BB << (8 * 6);
 const Bitboard Rank8BB = Rank1BB << (8 * 7);
 
-CACHE_LINE_ALIGNMENT
+extern int SquareDistance[SQUARE_NB][SQUARE_NB];
 
-extern Bitboard RMasks[SQUARE_NB];
-extern Bitboard RMagics[SQUARE_NB];
-extern Bitboard* RAttacks[SQUARE_NB];
-extern unsigned RShifts[SQUARE_NB];
+extern Bitboard  RookMasks  [SQUARE_NB];
+extern Bitboard  RookMagics [SQUARE_NB];
+extern Bitboard* RookAttacks[SQUARE_NB];
+extern unsigned  RookShifts [SQUARE_NB];
 
-extern Bitboard BMasks[SQUARE_NB];
-extern Bitboard BMagics[SQUARE_NB];
-extern Bitboard* BAttacks[SQUARE_NB];
-extern unsigned BShifts[SQUARE_NB];
+extern Bitboard  BishopMasks  [SQUARE_NB];
+extern Bitboard  BishopMagics [SQUARE_NB];
+extern Bitboard* BishopAttacks[SQUARE_NB];
+extern unsigned  BishopShifts [SQUARE_NB];
 
 extern Bitboard SquareBB[SQUARE_NB];
 extern Bitboard FileBB[FILE_NB];
@@ -75,15 +79,12 @@ extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
 extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
 extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
-extern Bitboard DistanceRingsBB[SQUARE_NB][8];
+extern Bitboard DistanceRingBB[SQUARE_NB][8];
 extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
 extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
 extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
 extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
 
-extern int SquareDistance[SQUARE_NB][SQUARE_NB];
-
-const Bitboard DarkSquares = 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.
@@ -92,14 +93,6 @@ inline Bitboard operator&(Bitboard b, Square s) {
   return b & SquareBB[s];
 }
 
-inline Bitboard& operator|=(Bitboard& b, Square s) {
-  return b |= SquareBB[s];
-}
-
-inline Bitboard& operator^=(Bitboard& b, Square s) {
-  return b ^= SquareBB[s];
-}
-
 inline Bitboard operator|(Bitboard b, Square s) {
   return b | SquareBB[s];
 }
@@ -108,37 +101,21 @@ inline Bitboard operator^(Bitboard b, Square s) {
   return b ^ SquareBB[s];
 }
 
+inline Bitboard& operator|=(Bitboard& b, Square s) {
+  return b |= SquareBB[s];
+}
+
+inline Bitboard& operator^=(Bitboard& b, Square s) {
+  return b ^= SquareBB[s];
+}
+
 inline bool more_than_one(Bitboard b) {
   return b & (b - 1);
 }
 
-inline int square_distance(Square s1, Square s2) {
-  return SquareDistance[s1][s2];
-}
 
-inline int file_distance(Square s1, Square s2) {
-  return abs(file_of(s1) - file_of(s2));
-}
-
-inline int rank_distance(Square s1, Square s2) {
-  return abs(rank_of(s1) - rank_of(s2));
-}
-
-
-/// shift_bb() moves bitboard one step along direction Delta. Mainly for pawns.
-
-template<Square Delta>
-inline Bitboard shift_bb(Bitboard b) {
-
-  return  Delta == DELTA_N  ?  b             << 8 : Delta == DELTA_S  ?  b             >> 8
-        : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
-        : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
-        : 0;
-}
-
-
-/// rank_bb() and file_bb() take a file or a square as input and return
-/// a bitboard representing all squares on the given file or rank.
+/// rank_bb() and file_bb() return a bitboard representing all the squares on
+/// the given file or rank.
 
 inline Bitboard rank_bb(Rank r) {
   return RankBB[r];
@@ -157,119 +134,138 @@ inline Bitboard file_bb(Square s) {
 }
 
 
-/// adjacent_files_bb() takes a file as input and returns a bitboard representing
-/// all squares on the adjacent files.
+/// shift_bb() moves a bitboard one step along direction Delta. Mainly for pawns
+
+template<Square Delta>
+inline Bitboard shift_bb(Bitboard b) {
+  return  Delta == DELTA_N  ?  b             << 8 : Delta == DELTA_S  ?  b             >> 8
+        : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
+        : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
+        : 0;
+}
+
+
+/// adjacent_files_bb() returns a bitboard representing all the squares on the
+/// adjacent files of the given one.
 
 inline Bitboard adjacent_files_bb(File f) {
   return AdjacentFilesBB[f];
 }
 
 
-/// in_front_bb() takes a color and a rank as input, and returns a bitboard
-/// representing all the squares on all ranks in front of the rank, from the
-/// given color's point of view. For instance, in_front_bb(BLACK, RANK_3) will
-/// give all squares on ranks 1 and 2.
-
-inline Bitboard in_front_bb(Color c, Rank r) {
-  return InFrontBB[c][r];
-}
-
-
-/// between_bb() returns a bitboard representing all squares between two squares.
-/// For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with the bits for
-/// square d5 and e6 set.  If s1 and s2 are not on the same rank, file or diagonal,
-/// 0 is returned.
+/// between_bb() returns a bitboard representing all the squares between the two
+/// given ones. For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with
+/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank, file
+/// or diagonal, 0 is returned.
 
 inline Bitboard between_bb(Square s1, Square s2) {
   return BetweenBB[s1][s2];
 }
 
 
-/// forward_bb() takes a color and a square as input, and returns a bitboard
-/// representing all squares along the line in front of the square, from the
-/// point of view of the given color. Definition of the table is:
-/// ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s)
+/// in_front_bb() returns a bitboard representing all the squares on all the ranks
+/// in front of the given one, from the point of view of the given color. For
+/// instance, in_front_bb(BLACK, RANK_3) will return the squares on ranks 1 and 2.
+
+inline Bitboard in_front_bb(Color c, Rank r) {
+  return InFrontBB[c][r];
+}
+
+
+/// forward_bb() returns a bitboard representing all the squares along the line
+/// in front of the given one, from the point of view of the given color:
+///        ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s)
 
 inline Bitboard forward_bb(Color c, Square s) {
   return ForwardBB[c][s];
 }
 
 
-/// pawn_attack_span() takes a color and a square as input, and returns a bitboard
-/// representing all squares that can be attacked by a pawn of the given color
-/// when it moves along its file starting from the given square. Definition is:
-/// PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
+/// pawn_attack_span() returns a bitboard representing all the squares that can be
+/// attacked by a pawn of the given color when it moves along its file, starting
+/// from the given square:
+///       PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
 
 inline Bitboard pawn_attack_span(Color c, Square s) {
   return PawnAttackSpan[c][s];
 }
 
 
-/// passed_pawn_mask() takes a color and a square as input, and returns a
-/// bitboard mask which can be used to test if a pawn of the given color on
-/// the given square is a passed pawn. Definition of the table is:
-/// PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s)
+/// passed_pawn_mask() returns a bitboard mask which can be used to test if a
+/// pawn of the given color and on the given square is a passed pawn:
+///       PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s)
 
 inline Bitboard passed_pawn_mask(Color c, Square s) {
   return PassedPawnMask[c][s];
 }
 
 
-/// squares_of_color() returns a bitboard representing all squares with the same
-/// color of the given square.
+/// squares_of_color() returns a bitboard representing all the squares of the
+/// same color of the given one.
 
 inline Bitboard squares_of_color(Square s) {
   return DarkSquares & s ? DarkSquares : ~DarkSquares;
 }
 
 
-/// aligned() returns true if the squares s1, s2 and s3 are aligned
-/// either on a straight or on a diagonal line.
+/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
+/// straight or on a diagonal line.
 
 inline bool aligned(Square s1, Square s2, Square s3) {
   return LineBB[s1][s2] & s3;
 }
 
 
-/// Functions for computing sliding attack bitboards. Function attacks_bb() takes
-/// a square and a bitboard of occupied squares as input, and returns a bitboard
-/// representing all squares attacked by Pt (bishop or rook) on the given square.
-template<PieceType Pt>
-FORCE_INLINE unsigned magic_index(Square s, Bitboard occ) {
+/// distance() functions return the distance between x and y, defined as the
+/// number of steps for a king in x to reach y. Works with squares, ranks, files.
 
-  Bitboard* const Masks  = Pt == ROOK ? RMasks  : BMasks;
-  Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics;
-  unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts;
+template<typename T> inline int distance(T x, T y) { return x < y ? y - x : x - y; }
+template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
+
+template<typename T1, typename T2> inline int distance(T2 x, T2 y);
+template<> inline int distance<File>(Square x, Square y) { return distance(file_of(x), file_of(y)); }
+template<> inline int distance<Rank>(Square x, Square y) { return distance(rank_of(x), rank_of(y)); }
+
+
+/// attacks_bb() returns a bitboard representing all the squares attacked by a
+/// piece of type Pt (bishop or rook) placed on 's'. The helper magic_index()
+/// looks up the index using the 'magic bitboards' approach.
+template<PieceType Pt>
+FORCE_INLINE unsigned magic_index(Square s, Bitboard occupied) {
+
+  Bitboard* const Masks  = Pt == ROOK ? RookMasks  : BishopMasks;
+  Bitboard* const Magics = Pt == ROOK ? RookMagics : BishopMagics;
+  unsigned* const Shifts = Pt == ROOK ? RookShifts : BishopShifts;
 
   if (HasPext)
-      return unsigned(_pext_u64(occ, Masks[s]));
+      return unsigned(pext(occupied, Masks[s]));
 
   if (Is64Bit)
-      return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
+      return unsigned(((occupied & Masks[s]) * Magics[s]) >> Shifts[s]);
 
-  unsigned lo = unsigned(occ) & unsigned(Masks[s]);
-  unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32);
+  unsigned lo = unsigned(occupied) & unsigned(Masks[s]);
+  unsigned hi = unsigned(occupied >> 32) & unsigned(Masks[s] >> 32);
   return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s];
 }
 
 template<PieceType Pt>
-inline Bitboard attacks_bb(Square s, Bitboard occ) {
-  return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index<Pt>(s, occ)];
+inline Bitboard attacks_bb(Square s, Bitboard occupied) {
+  return (Pt == ROOK ? RookAttacks : BishopAttacks)[s][magic_index<Pt>(s, occupied)];
 }
 
-inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occ) {
+inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occupied) {
 
   switch (type_of(pc))
   {
-  case BISHOP: return attacks_bb<BISHOP>(s, occ);
-  case ROOK  : return attacks_bb<ROOK>(s, occ);
-  case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
+  case BISHOP: return attacks_bb<BISHOP>(s, occupied);
+  case ROOK  : return attacks_bb<ROOK>(s, occupied);
+  case QUEEN : return attacks_bb<BISHOP>(s, occupied) | attacks_bb<ROOK>(s, occupied);
   default    : return StepAttacksBB[pc][s];
   }
 }
 
-/// lsb()/msb() finds the least/most significant bit in a non-zero bitboard.
-/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard.
+
+/// lsb() and msb() return the least/most significant bit in a non-zero bitboard
 
 #ifdef USE_BSFQ
 
@@ -302,7 +298,7 @@ FORCE_INLINE Square lsb(Bitboard b) {
   return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
 }
 
-#  else
+#  else // Assumed gcc or compatible compiler
 
 FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
   Bitboard idx;
@@ -318,21 +314,24 @@ FORCE_INLINE Square msb(Bitboard b) {
 
 #  endif
 
+#else // ifdef(USE_BSFQ)
+
+Square lsb(Bitboard b);
+Square msb(Bitboard b);
+
+#endif
+
+
+/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard
+
 FORCE_INLINE Square pop_lsb(Bitboard* b) {
   const Square s = lsb(*b);
   *b &= *b - 1;
   return s;
 }
 
-#else // if defined(USE_BSFQ)
 
-extern Square msb(Bitboard b);
-extern Square lsb(Bitboard b);
-extern Square pop_lsb(Bitboard* b);
-
-#endif
-
-/// frontmost_sq() and backmost_sq() find the square corresponding to the
+/// frontmost_sq() and backmost_sq() return the square corresponding to the
 /// most/least advanced bit relative to the given color.
 
 inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -22,6 +22,7 @@
 #define BITCOUNT_H_INCLUDED
 
 #include <cassert>
+
 #include "types.h"
 
 enum BitCountType {
@@ -35,7 +36,7 @@ enum BitCountType {
 /// Determine at compile time the best popcount<> specialization according to
 /// whether the platform is 32 or 64 bit, the maximum number of non-zero
 /// bits to count and if the hardware popcnt instruction is available.
-const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32;
+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;
 
 
@@ -94,10 +95,9 @@ inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
 
   return (int)__popcnt64(b);
 
-#else
+#else // Assumed gcc or compatible compiler
 
-  __asm__("popcnt %1, %0" : "=r" (b) : "r" (b));
-  return b;
+  return __builtin_popcountll(b);
 
 #endif
 }

src/book.cpp

@@ -1,478 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 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/>.
-*/
-
-/*
-  The code in this file is based on the opening book code in PolyGlot
-  by Fabien Letouzey. PolyGlot is available under the GNU General
-  Public License, and can be downloaded from http://wbec-ridderkerk.nl
-*/
-
-#include <algorithm>
-#include <cassert>
-
-#include "book.h"
-#include "misc.h"
-#include "movegen.h"
-
-using namespace std;
-
-namespace {
-
-  // A Polyglot book is a series of "entries" of 16 bytes. All integers are
-  // stored in big-endian format, with the highest byte first (regardless of
-  // size). The entries are ordered according to the key in ascending order.
-  struct Entry {
-    uint64_t key;
-    uint16_t move;
-    uint16_t count;
-    uint32_t learn;
-  };
-
-  // Random numbers from PolyGlot, used to compute book hash keys
-  const union {
-    Key PolyGlotRandoms[781];
-    struct {
-      Key psq[12][64];  // [piece][square]
-      Key castling[4];  // [castling flag]
-      Key enpassant[8]; // [file]
-      Key turn;
-    } Zobrist;
-  } PG = {{
-    0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL,
-    0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL,
-    0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL,
-    0x1A083822CEAFE02DULL, 0x9605D5F0E25EC3B0ULL, 0xD021FF5CD13A2ED5ULL,
-    0x40BDF15D4A672E32ULL, 0x011355146FD56395ULL, 0x5DB4832046F3D9E5ULL,
-    0x239F8B2D7FF719CCULL, 0x05D1A1AE85B49AA1ULL, 0x679F848F6E8FC971ULL,
-    0x7449BBFF801FED0BULL, 0x7D11CDB1C3B7ADF0ULL, 0x82C7709E781EB7CCULL,
-    0xF3218F1C9510786CULL, 0x331478F3AF51BBE6ULL, 0x4BB38DE5E7219443ULL,
-    0xAA649C6EBCFD50FCULL, 0x8DBD98A352AFD40BULL, 0x87D2074B81D79217ULL,
-    0x19F3C751D3E92AE1ULL, 0xB4AB30F062B19ABFULL, 0x7B0500AC42047AC4ULL,
-    0xC9452CA81A09D85DULL, 0x24AA6C514DA27500ULL, 0x4C9F34427501B447ULL,
-    0x14A68FD73C910841ULL, 0xA71B9B83461CBD93ULL, 0x03488B95B0F1850FULL,
-    0x637B2B34FF93C040ULL, 0x09D1BC9A3DD90A94ULL, 0x3575668334A1DD3BULL,
-    0x735E2B97A4C45A23ULL, 0x18727070F1BD400BULL, 0x1FCBACD259BF02E7ULL,
-    0xD310A7C2CE9B6555ULL, 0xBF983FE0FE5D8244ULL, 0x9F74D14F7454A824ULL,
-    0x51EBDC4AB9BA3035ULL, 0x5C82C505DB9AB0FAULL, 0xFCF7FE8A3430B241ULL,
-    0x3253A729B9BA3DDEULL, 0x8C74C368081B3075ULL, 0xB9BC6C87167C33E7ULL,
-    0x7EF48F2B83024E20ULL, 0x11D505D4C351BD7FULL, 0x6568FCA92C76A243ULL,
-    0x4DE0B0F40F32A7B8ULL, 0x96D693460CC37E5DULL, 0x42E240CB63689F2FULL,
-    0x6D2BDCDAE2919661ULL, 0x42880B0236E4D951ULL, 0x5F0F4A5898171BB6ULL,
-    0x39F890F579F92F88ULL, 0x93C5B5F47356388BULL, 0x63DC359D8D231B78ULL,
-    0xEC16CA8AEA98AD76ULL, 0x5355F900C2A82DC7ULL, 0x07FB9F855A997142ULL,
-    0x5093417AA8A7ED5EULL, 0x7BCBC38DA25A7F3CULL, 0x19FC8A768CF4B6D4ULL,
-    0x637A7780DECFC0D9ULL, 0x8249A47AEE0E41F7ULL, 0x79AD695501E7D1E8ULL,
-    0x14ACBAF4777D5776ULL, 0xF145B6BECCDEA195ULL, 0xDABF2AC8201752FCULL,
-    0x24C3C94DF9C8D3F6ULL, 0xBB6E2924F03912EAULL, 0x0CE26C0B95C980D9ULL,
-    0xA49CD132BFBF7CC4ULL, 0xE99D662AF4243939ULL, 0x27E6AD7891165C3FULL,
-    0x8535F040B9744FF1ULL, 0x54B3F4FA5F40D873ULL, 0x72B12C32127FED2BULL,
-    0xEE954D3C7B411F47ULL, 0x9A85AC909A24EAA1ULL, 0x70AC4CD9F04F21F5ULL,
-    0xF9B89D3E99A075C2ULL, 0x87B3E2B2B5C907B1ULL, 0xA366E5B8C54F48B8ULL,
-    0xAE4A9346CC3F7CF2ULL, 0x1920C04D47267BBDULL, 0x87BF02C6B49E2AE9ULL,
-    0x092237AC237F3859ULL, 0xFF07F64EF8ED14D0ULL, 0x8DE8DCA9F03CC54EULL,
-    0x9C1633264DB49C89ULL, 0xB3F22C3D0B0B38EDULL, 0x390E5FB44D01144BULL,
-    0x5BFEA5B4712768E9ULL, 0x1E1032911FA78984ULL, 0x9A74ACB964E78CB3ULL,
-    0x4F80F7A035DAFB04ULL, 0x6304D09A0B3738C4ULL, 0x2171E64683023A08ULL,
-    0x5B9B63EB9CEFF80CULL, 0x506AACF489889342ULL, 0x1881AFC9A3A701D6ULL,
-    0x6503080440750644ULL, 0xDFD395339CDBF4A7ULL, 0xEF927DBCF00C20F2ULL,
-    0x7B32F7D1E03680ECULL, 0xB9FD7620E7316243ULL, 0x05A7E8A57DB91B77ULL,
-    0xB5889C6E15630A75ULL, 0x4A750A09CE9573F7ULL, 0xCF464CEC899A2F8AULL,
-    0xF538639CE705B824ULL, 0x3C79A0FF5580EF7FULL, 0xEDE6C87F8477609DULL,
-    0x799E81F05BC93F31ULL, 0x86536B8CF3428A8CULL, 0x97D7374C60087B73ULL,
-    0xA246637CFF328532ULL, 0x043FCAE60CC0EBA0ULL, 0x920E449535DD359EULL,
-    0x70EB093B15B290CCULL, 0x73A1921916591CBDULL, 0x56436C9FE1A1AA8DULL,
-    0xEFAC4B70633B8F81ULL, 0xBB215798D45DF7AFULL, 0x45F20042F24F1768ULL,
-    0x930F80F4E8EB7462ULL, 0xFF6712FFCFD75EA1ULL, 0xAE623FD67468AA70ULL,
-    0xDD2C5BC84BC8D8FCULL, 0x7EED120D54CF2DD9ULL, 0x22FE545401165F1CULL,
-    0xC91800E98FB99929ULL, 0x808BD68E6AC10365ULL, 0xDEC468145B7605F6ULL,
-    0x1BEDE3A3AEF53302ULL, 0x43539603D6C55602ULL, 0xAA969B5C691CCB7AULL,
-    0xA87832D392EFEE56ULL, 0x65942C7B3C7E11AEULL, 0xDED2D633CAD004F6ULL,
-    0x21F08570F420E565ULL, 0xB415938D7DA94E3CULL, 0x91B859E59ECB6350ULL,
-    0x10CFF333E0ED804AULL, 0x28AED140BE0BB7DDULL, 0xC5CC1D89724FA456ULL,
-    0x5648F680F11A2741ULL, 0x2D255069F0B7DAB3ULL, 0x9BC5A38EF729ABD4ULL,
-    0xEF2F054308F6A2BCULL, 0xAF2042F5CC5C2858ULL, 0x480412BAB7F5BE2AULL,
-    0xAEF3AF4A563DFE43ULL, 0x19AFE59AE451497FULL, 0x52593803DFF1E840ULL,
-    0xF4F076E65F2CE6F0ULL, 0x11379625747D5AF3ULL, 0xBCE5D2248682C115ULL,
-    0x9DA4243DE836994FULL, 0x066F70B33FE09017ULL, 0x4DC4DE189B671A1CULL,
-    0x51039AB7712457C3ULL, 0xC07A3F80C31FB4B4ULL, 0xB46EE9C5E64A6E7CULL,
-    0xB3819A42ABE61C87ULL, 0x21A007933A522A20ULL, 0x2DF16F761598AA4FULL,
-    0x763C4A1371B368FDULL, 0xF793C46702E086A0ULL, 0xD7288E012AEB8D31ULL,
-    0xDE336A2A4BC1C44BULL, 0x0BF692B38D079F23ULL, 0x2C604A7A177326B3ULL,
-    0x4850E73E03EB6064ULL, 0xCFC447F1E53C8E1BULL, 0xB05CA3F564268D99ULL,
-    0x9AE182C8BC9474E8ULL, 0xA4FC4BD4FC5558CAULL, 0xE755178D58FC4E76ULL,
-    0x69B97DB1A4C03DFEULL, 0xF9B5B7C4ACC67C96ULL, 0xFC6A82D64B8655FBULL,
-    0x9C684CB6C4D24417ULL, 0x8EC97D2917456ED0ULL, 0x6703DF9D2924E97EULL,
-    0xC547F57E42A7444EULL, 0x78E37644E7CAD29EULL, 0xFE9A44E9362F05FAULL,
-    0x08BD35CC38336615ULL, 0x9315E5EB3A129ACEULL, 0x94061B871E04DF75ULL,
-    0xDF1D9F9D784BA010ULL, 0x3BBA57B68871B59DULL, 0xD2B7ADEEDED1F73FULL,
-    0xF7A255D83BC373F8ULL, 0xD7F4F2448C0CEB81ULL, 0xD95BE88CD210FFA7ULL,
-    0x336F52F8FF4728E7ULL, 0xA74049DAC312AC71ULL, 0xA2F61BB6E437FDB5ULL,
-    0x4F2A5CB07F6A35B3ULL, 0x87D380BDA5BF7859ULL, 0x16B9F7E06C453A21ULL,
-    0x7BA2484C8A0FD54EULL, 0xF3A678CAD9A2E38CULL, 0x39B0BF7DDE437BA2ULL,
-    0xFCAF55C1BF8A4424ULL, 0x18FCF680573FA594ULL, 0x4C0563B89F495AC3ULL,
-    0x40E087931A00930DULL, 0x8CFFA9412EB642C1ULL, 0x68CA39053261169FULL,
-    0x7A1EE967D27579E2ULL, 0x9D1D60E5076F5B6FULL, 0x3810E399B6F65BA2ULL,
-    0x32095B6D4AB5F9B1ULL, 0x35CAB62109DD038AULL, 0xA90B24499FCFAFB1ULL,
-    0x77A225A07CC2C6BDULL, 0x513E5E634C70E331ULL, 0x4361C0CA3F692F12ULL,
-    0xD941ACA44B20A45BULL, 0x528F7C8602C5807BULL, 0x52AB92BEB9613989ULL,
-    0x9D1DFA2EFC557F73ULL, 0x722FF175F572C348ULL, 0x1D1260A51107FE97ULL,
-    0x7A249A57EC0C9BA2ULL, 0x04208FE9E8F7F2D6ULL, 0x5A110C6058B920A0ULL,
-    0x0CD9A497658A5698ULL, 0x56FD23C8F9715A4CULL, 0x284C847B9D887AAEULL,
-    0x04FEABFBBDB619CBULL, 0x742E1E651C60BA83ULL, 0x9A9632E65904AD3CULL,
-    0x881B82A13B51B9E2ULL, 0x506E6744CD974924ULL, 0xB0183DB56FFC6A79ULL,
-    0x0ED9B915C66ED37EULL, 0x5E11E86D5873D484ULL, 0xF678647E3519AC6EULL,
-    0x1B85D488D0F20CC5ULL, 0xDAB9FE6525D89021ULL, 0x0D151D86ADB73615ULL,
-    0xA865A54EDCC0F019ULL, 0x93C42566AEF98FFBULL, 0x99E7AFEABE000731ULL,
-    0x48CBFF086DDF285AULL, 0x7F9B6AF1EBF78BAFULL, 0x58627E1A149BBA21ULL,
-    0x2CD16E2ABD791E33ULL, 0xD363EFF5F0977996ULL, 0x0CE2A38C344A6EEDULL,
-    0x1A804AADB9CFA741ULL, 0x907F30421D78C5DEULL, 0x501F65EDB3034D07ULL,
-    0x37624AE5A48FA6E9ULL, 0x957BAF61700CFF4EULL, 0x3A6C27934E31188AULL,
-    0xD49503536ABCA345ULL, 0x088E049589C432E0ULL, 0xF943AEE7FEBF21B8ULL,
-    0x6C3B8E3E336139D3ULL, 0x364F6FFA464EE52EULL, 0xD60F6DCEDC314222ULL,
-    0x56963B0DCA418FC0ULL, 0x16F50EDF91E513AFULL, 0xEF1955914B609F93ULL,
-    0x565601C0364E3228ULL, 0xECB53939887E8175ULL, 0xBAC7A9A18531294BULL,
-    0xB344C470397BBA52ULL, 0x65D34954DAF3CEBDULL, 0xB4B81B3FA97511E2ULL,
-    0xB422061193D6F6A7ULL, 0x071582401C38434DULL, 0x7A13F18BBEDC4FF5ULL,
-    0xBC4097B116C524D2ULL, 0x59B97885E2F2EA28ULL, 0x99170A5DC3115544ULL,
-    0x6F423357E7C6A9F9ULL, 0x325928EE6E6F8794ULL, 0xD0E4366228B03343ULL,
-    0x565C31F7DE89EA27ULL, 0x30F5611484119414ULL, 0xD873DB391292ED4FULL,
-    0x7BD94E1D8E17DEBCULL, 0xC7D9F16864A76E94ULL, 0x947AE053EE56E63CULL,
-    0xC8C93882F9475F5FULL, 0x3A9BF55BA91F81CAULL, 0xD9A11FBB3D9808E4ULL,
-    0x0FD22063EDC29FCAULL, 0xB3F256D8ACA0B0B9ULL, 0xB03031A8B4516E84ULL,
-    0x35DD37D5871448AFULL, 0xE9F6082B05542E4EULL, 0xEBFAFA33D7254B59ULL,
-    0x9255ABB50D532280ULL, 0xB9AB4CE57F2D34F3ULL, 0x693501D628297551ULL,
-    0xC62C58F97DD949BFULL, 0xCD454F8F19C5126AULL, 0xBBE83F4ECC2BDECBULL,
-    0xDC842B7E2819E230ULL, 0xBA89142E007503B8ULL, 0xA3BC941D0A5061CBULL,
-    0xE9F6760E32CD8021ULL, 0x09C7E552BC76492FULL, 0x852F54934DA55CC9ULL,
-    0x8107FCCF064FCF56ULL, 0x098954D51FFF6580ULL, 0x23B70EDB1955C4BFULL,
-    0xC330DE426430F69DULL, 0x4715ED43E8A45C0AULL, 0xA8D7E4DAB780A08DULL,
-    0x0572B974F03CE0BBULL, 0xB57D2E985E1419C7ULL, 0xE8D9ECBE2CF3D73FULL,
-    0x2FE4B17170E59750ULL, 0x11317BA87905E790ULL, 0x7FBF21EC8A1F45ECULL,
-    0x1725CABFCB045B00ULL, 0x964E915CD5E2B207ULL, 0x3E2B8BCBF016D66DULL,
-    0xBE7444E39328A0ACULL, 0xF85B2B4FBCDE44B7ULL, 0x49353FEA39BA63B1ULL,
-    0x1DD01AAFCD53486AULL, 0x1FCA8A92FD719F85ULL, 0xFC7C95D827357AFAULL,
-    0x18A6A990C8B35EBDULL, 0xCCCB7005C6B9C28DULL, 0x3BDBB92C43B17F26ULL,
-    0xAA70B5B4F89695A2ULL, 0xE94C39A54A98307FULL, 0xB7A0B174CFF6F36EULL,
-    0xD4DBA84729AF48ADULL, 0x2E18BC1AD9704A68ULL, 0x2DE0966DAF2F8B1CULL,
-    0xB9C11D5B1E43A07EULL, 0x64972D68DEE33360ULL, 0x94628D38D0C20584ULL,
-    0xDBC0D2B6AB90A559ULL, 0xD2733C4335C6A72FULL, 0x7E75D99D94A70F4DULL,
-    0x6CED1983376FA72BULL, 0x97FCAACBF030BC24ULL, 0x7B77497B32503B12ULL,
-    0x8547EDDFB81CCB94ULL, 0x79999CDFF70902CBULL, 0xCFFE1939438E9B24ULL,
-    0x829626E3892D95D7ULL, 0x92FAE24291F2B3F1ULL, 0x63E22C147B9C3403ULL,
-    0xC678B6D860284A1CULL, 0x5873888850659AE7ULL, 0x0981DCD296A8736DULL,
-    0x9F65789A6509A440ULL, 0x9FF38FED72E9052FULL, 0xE479EE5B9930578CULL,
-    0xE7F28ECD2D49EECDULL, 0x56C074A581EA17FEULL, 0x5544F7D774B14AEFULL,
-    0x7B3F0195FC6F290FULL, 0x12153635B2C0CF57ULL, 0x7F5126DBBA5E0CA7ULL,
-    0x7A76956C3EAFB413ULL, 0x3D5774A11D31AB39ULL, 0x8A1B083821F40CB4ULL,
-    0x7B4A38E32537DF62ULL, 0x950113646D1D6E03ULL, 0x4DA8979A0041E8A9ULL,
-    0x3BC36E078F7515D7ULL, 0x5D0A12F27AD310D1ULL, 0x7F9D1A2E1EBE1327ULL,
-    0xDA3A361B1C5157B1ULL, 0xDCDD7D20903D0C25ULL, 0x36833336D068F707ULL,
-    0xCE68341F79893389ULL, 0xAB9090168DD05F34ULL, 0x43954B3252DC25E5ULL,
-    0xB438C2B67F98E5E9ULL, 0x10DCD78E3851A492ULL, 0xDBC27AB5447822BFULL,
-    0x9B3CDB65F82CA382ULL, 0xB67B7896167B4C84ULL, 0xBFCED1B0048EAC50ULL,
-    0xA9119B60369FFEBDULL, 0x1FFF7AC80904BF45ULL, 0xAC12FB171817EEE7ULL,
-    0xAF08DA9177DDA93DULL, 0x1B0CAB936E65C744ULL, 0xB559EB1D04E5E932ULL,
-    0xC37B45B3F8D6F2BAULL, 0xC3A9DC228CAAC9E9ULL, 0xF3B8B6675A6507FFULL,
-    0x9FC477DE4ED681DAULL, 0x67378D8ECCEF96CBULL, 0x6DD856D94D259236ULL,
-    0xA319CE15B0B4DB31ULL, 0x073973751F12DD5EULL, 0x8A8E849EB32781A5ULL,
-    0xE1925C71285279F5ULL, 0x74C04BF1790C0EFEULL, 0x4DDA48153C94938AULL,
-    0x9D266D6A1CC0542CULL, 0x7440FB816508C4FEULL, 0x13328503DF48229FULL,
-    0xD6BF7BAEE43CAC40ULL, 0x4838D65F6EF6748FULL, 0x1E152328F3318DEAULL,
-    0x8F8419A348F296BFULL, 0x72C8834A5957B511ULL, 0xD7A023A73260B45CULL,
-    0x94EBC8ABCFB56DAEULL, 0x9FC10D0F989993E0ULL, 0xDE68A2355B93CAE6ULL,
-    0xA44CFE79AE538BBEULL, 0x9D1D84FCCE371425ULL, 0x51D2B1AB2DDFB636ULL,
-    0x2FD7E4B9E72CD38CULL, 0x65CA5B96B7552210ULL, 0xDD69A0D8AB3B546DULL,
-    0x604D51B25FBF70E2ULL, 0x73AA8A564FB7AC9EULL, 0x1A8C1E992B941148ULL,
-    0xAAC40A2703D9BEA0ULL, 0x764DBEAE7FA4F3A6ULL, 0x1E99B96E70A9BE8BULL,
-    0x2C5E9DEB57EF4743ULL, 0x3A938FEE32D29981ULL, 0x26E6DB8FFDF5ADFEULL,
-    0x469356C504EC9F9DULL, 0xC8763C5B08D1908CULL, 0x3F6C6AF859D80055ULL,
-    0x7F7CC39420A3A545ULL, 0x9BFB227EBDF4C5CEULL, 0x89039D79D6FC5C5CULL,
-    0x8FE88B57305E2AB6ULL, 0xA09E8C8C35AB96DEULL, 0xFA7E393983325753ULL,
-    0xD6B6D0ECC617C699ULL, 0xDFEA21EA9E7557E3ULL, 0xB67C1FA481680AF8ULL,
-    0xCA1E3785A9E724E5ULL, 0x1CFC8BED0D681639ULL, 0xD18D8549D140CAEAULL,
-    0x4ED0FE7E9DC91335ULL, 0xE4DBF0634473F5D2ULL, 0x1761F93A44D5AEFEULL,
-    0x53898E4C3910DA55ULL, 0x734DE8181F6EC39AULL, 0x2680B122BAA28D97ULL,
-    0x298AF231C85BAFABULL, 0x7983EED3740847D5ULL, 0x66C1A2A1A60CD889ULL,
-    0x9E17E49642A3E4C1ULL, 0xEDB454E7BADC0805ULL, 0x50B704CAB602C329ULL,
-    0x4CC317FB9CDDD023ULL, 0x66B4835D9EAFEA22ULL, 0x219B97E26FFC81BDULL,
-    0x261E4E4C0A333A9DULL, 0x1FE2CCA76517DB90ULL, 0xD7504DFA8816EDBBULL,
-    0xB9571FA04DC089C8ULL, 0x1DDC0325259B27DEULL, 0xCF3F4688801EB9AAULL,
-    0xF4F5D05C10CAB243ULL, 0x38B6525C21A42B0EULL, 0x36F60E2BA4FA6800ULL,
-    0xEB3593803173E0CEULL, 0x9C4CD6257C5A3603ULL, 0xAF0C317D32ADAA8AULL,
-    0x258E5A80C7204C4BULL, 0x8B889D624D44885DULL, 0xF4D14597E660F855ULL,
-    0xD4347F66EC8941C3ULL, 0xE699ED85B0DFB40DULL, 0x2472F6207C2D0484ULL,
-    0xC2A1E7B5B459AEB5ULL, 0xAB4F6451CC1D45ECULL, 0x63767572AE3D6174ULL,
-    0xA59E0BD101731A28ULL, 0x116D0016CB948F09ULL, 0x2CF9C8CA052F6E9FULL,
-    0x0B090A7560A968E3ULL, 0xABEEDDB2DDE06FF1ULL, 0x58EFC10B06A2068DULL,
-    0xC6E57A78FBD986E0ULL, 0x2EAB8CA63CE802D7ULL, 0x14A195640116F336ULL,
-    0x7C0828DD624EC390ULL, 0xD74BBE77E6116AC7ULL, 0x804456AF10F5FB53ULL,
-    0xEBE9EA2ADF4321C7ULL, 0x03219A39EE587A30ULL, 0x49787FEF17AF9924ULL,
-    0xA1E9300CD8520548ULL, 0x5B45E522E4B1B4EFULL, 0xB49C3B3995091A36ULL,
-    0xD4490AD526F14431ULL, 0x12A8F216AF9418C2ULL, 0x001F837CC7350524ULL,
-    0x1877B51E57A764D5ULL, 0xA2853B80F17F58EEULL, 0x993E1DE72D36D310ULL,
-    0xB3598080CE64A656ULL, 0x252F59CF0D9F04BBULL, 0xD23C8E176D113600ULL,
-    0x1BDA0492E7E4586EULL, 0x21E0BD5026C619BFULL, 0x3B097ADAF088F94EULL,
-    0x8D14DEDB30BE846EULL, 0xF95CFFA23AF5F6F4ULL, 0x3871700761B3F743ULL,
-    0xCA672B91E9E4FA16ULL, 0x64C8E531BFF53B55ULL, 0x241260ED4AD1E87DULL,
-    0x106C09B972D2E822ULL, 0x7FBA195410E5CA30ULL, 0x7884D9BC6CB569D8ULL,
-    0x0647DFEDCD894A29ULL, 0x63573FF03E224774ULL, 0x4FC8E9560F91B123ULL,
-    0x1DB956E450275779ULL, 0xB8D91274B9E9D4FBULL, 0xA2EBEE47E2FBFCE1ULL,
-    0xD9F1F30CCD97FB09ULL, 0xEFED53D75FD64E6BULL, 0x2E6D02C36017F67FULL,
-    0xA9AA4D20DB084E9BULL, 0xB64BE8D8B25396C1ULL, 0x70CB6AF7C2D5BCF0ULL,
-    0x98F076A4F7A2322EULL, 0xBF84470805E69B5FULL, 0x94C3251F06F90CF3ULL,
-    0x3E003E616A6591E9ULL, 0xB925A6CD0421AFF3ULL, 0x61BDD1307C66E300ULL,
-    0xBF8D5108E27E0D48ULL, 0x240AB57A8B888B20ULL, 0xFC87614BAF287E07ULL,
-    0xEF02CDD06FFDB432ULL, 0xA1082C0466DF6C0AULL, 0x8215E577001332C8ULL,
-    0xD39BB9C3A48DB6CFULL, 0x2738259634305C14ULL, 0x61CF4F94C97DF93DULL,
-    0x1B6BACA2AE4E125BULL, 0x758F450C88572E0BULL, 0x959F587D507A8359ULL,
-    0xB063E962E045F54DULL, 0x60E8ED72C0DFF5D1ULL, 0x7B64978555326F9FULL,
-    0xFD080D236DA814BAULL, 0x8C90FD9B083F4558ULL, 0x106F72FE81E2C590ULL,
-    0x7976033A39F7D952ULL, 0xA4EC0132764CA04BULL, 0x733EA705FAE4FA77ULL,
-    0xB4D8F77BC3E56167ULL, 0x9E21F4F903B33FD9ULL, 0x9D765E419FB69F6DULL,
-    0xD30C088BA61EA5EFULL, 0x5D94337FBFAF7F5BULL, 0x1A4E4822EB4D7A59ULL,
-    0x6FFE73E81B637FB3ULL, 0xDDF957BC36D8B9CAULL, 0x64D0E29EEA8838B3ULL,
-    0x08DD9BDFD96B9F63ULL, 0x087E79E5A57D1D13ULL, 0xE328E230E3E2B3FBULL,
-    0x1C2559E30F0946BEULL, 0x720BF5F26F4D2EAAULL, 0xB0774D261CC609DBULL,
-    0x443F64EC5A371195ULL, 0x4112CF68649A260EULL, 0xD813F2FAB7F5C5CAULL,
-    0x660D3257380841EEULL, 0x59AC2C7873F910A3ULL, 0xE846963877671A17ULL,
-    0x93B633ABFA3469F8ULL, 0xC0C0F5A60EF4CDCFULL, 0xCAF21ECD4377B28CULL,
-    0x57277707199B8175ULL, 0x506C11B9D90E8B1DULL, 0xD83CC2687A19255FULL,
-    0x4A29C6465A314CD1ULL, 0xED2DF21216235097ULL, 0xB5635C95FF7296E2ULL,
-    0x22AF003AB672E811ULL, 0x52E762596BF68235ULL, 0x9AEBA33AC6ECC6B0ULL,
-    0x944F6DE09134DFB6ULL, 0x6C47BEC883A7DE39ULL, 0x6AD047C430A12104ULL,
-    0xA5B1CFDBA0AB4067ULL, 0x7C45D833AFF07862ULL, 0x5092EF950A16DA0BULL,
-    0x9338E69C052B8E7BULL, 0x455A4B4CFE30E3F5ULL, 0x6B02E63195AD0CF8ULL,
-    0x6B17B224BAD6BF27ULL, 0xD1E0CCD25BB9C169ULL, 0xDE0C89A556B9AE70ULL,
-    0x50065E535A213CF6ULL, 0x9C1169FA2777B874ULL, 0x78EDEFD694AF1EEDULL,
-    0x6DC93D9526A50E68ULL, 0xEE97F453F06791EDULL, 0x32AB0EDB696703D3ULL,
-    0x3A6853C7E70757A7ULL, 0x31865CED6120F37DULL, 0x67FEF95D92607890ULL,
-    0x1F2B1D1F15F6DC9CULL, 0xB69E38A8965C6B65ULL, 0xAA9119FF184CCCF4ULL,
-    0xF43C732873F24C13ULL, 0xFB4A3D794A9A80D2ULL, 0x3550C2321FD6109CULL,
-    0x371F77E76BB8417EULL, 0x6BFA9AAE5EC05779ULL, 0xCD04F3FF001A4778ULL,
-    0xE3273522064480CAULL, 0x9F91508BFFCFC14AULL, 0x049A7F41061A9E60ULL,
-    0xFCB6BE43A9F2FE9BULL, 0x08DE8A1C7797DA9BULL, 0x8F9887E6078735A1ULL,
-    0xB5B4071DBFC73A66ULL, 0x230E343DFBA08D33ULL, 0x43ED7F5A0FAE657DULL,
-    0x3A88A0FBBCB05C63ULL, 0x21874B8B4D2DBC4FULL, 0x1BDEA12E35F6A8C9ULL,
-    0x53C065C6C8E63528ULL, 0xE34A1D250E7A8D6BULL, 0xD6B04D3B7651DD7EULL,
-    0x5E90277E7CB39E2DULL, 0x2C046F22062DC67DULL, 0xB10BB459132D0A26ULL,
-    0x3FA9DDFB67E2F199ULL, 0x0E09B88E1914F7AFULL, 0x10E8B35AF3EEAB37ULL,
-    0x9EEDECA8E272B933ULL, 0xD4C718BC4AE8AE5FULL, 0x81536D601170FC20ULL,
-    0x91B534F885818A06ULL, 0xEC8177F83F900978ULL, 0x190E714FADA5156EULL,
-    0xB592BF39B0364963ULL, 0x89C350C893AE7DC1ULL, 0xAC042E70F8B383F2ULL,
-    0xB49B52E587A1EE60ULL, 0xFB152FE3FF26DA89ULL, 0x3E666E6F69AE2C15ULL,
-    0x3B544EBE544C19F9ULL, 0xE805A1E290CF2456ULL, 0x24B33C9D7ED25117ULL,
-    0xE74733427B72F0C1ULL, 0x0A804D18B7097475ULL, 0x57E3306D881EDB4FULL,
-    0x4AE7D6A36EB5DBCBULL, 0x2D8D5432157064C8ULL, 0xD1E649DE1E7F268BULL,
-    0x8A328A1CEDFE552CULL, 0x07A3AEC79624C7DAULL, 0x84547DDC3E203C94ULL,
-    0x990A98FD5071D263ULL, 0x1A4FF12616EEFC89ULL, 0xF6F7FD1431714200ULL,
-    0x30C05B1BA332F41CULL, 0x8D2636B81555A786ULL, 0x46C9FEB55D120902ULL,
-    0xCCEC0A73B49C9921ULL, 0x4E9D2827355FC492ULL, 0x19EBB029435DCB0FULL,
-    0x4659D2B743848A2CULL, 0x963EF2C96B33BE31ULL, 0x74F85198B05A2E7DULL,
-    0x5A0F544DD2B1FB18ULL, 0x03727073C2E134B1ULL, 0xC7F6AA2DE59AEA61ULL,
-    0x352787BAA0D7C22FULL, 0x9853EAB63B5E0B35ULL, 0xABBDCDD7ED5C0860ULL,
-    0xCF05DAF5AC8D77B0ULL, 0x49CAD48CEBF4A71EULL, 0x7A4C10EC2158C4A6ULL,
-    0xD9E92AA246BF719EULL, 0x13AE978D09FE5557ULL, 0x730499AF921549FFULL,
-    0x4E4B705B92903BA4ULL, 0xFF577222C14F0A3AULL, 0x55B6344CF97AAFAEULL,
-    0xB862225B055B6960ULL, 0xCAC09AFBDDD2CDB4ULL, 0xDAF8E9829FE96B5FULL,
-    0xB5FDFC5D3132C498ULL, 0x310CB380DB6F7503ULL, 0xE87FBB46217A360EULL,
-    0x2102AE466EBB1148ULL, 0xF8549E1A3AA5E00DULL, 0x07A69AFDCC42261AULL,
-    0xC4C118BFE78FEAAEULL, 0xF9F4892ED96BD438ULL, 0x1AF3DBE25D8F45DAULL,
-    0xF5B4B0B0D2DEEEB4ULL, 0x962ACEEFA82E1C84ULL, 0x046E3ECAAF453CE9ULL,
-    0xF05D129681949A4CULL, 0x964781CE734B3C84ULL, 0x9C2ED44081CE5FBDULL,
-    0x522E23F3925E319EULL, 0x177E00F9FC32F791ULL, 0x2BC60A63A6F3B3F2ULL,
-    0x222BBFAE61725606ULL, 0x486289DDCC3D6780ULL, 0x7DC7785B8EFDFC80ULL,
-    0x8AF38731C02BA980ULL, 0x1FAB64EA29A2DDF7ULL, 0xE4D9429322CD065AULL,
-    0x9DA058C67844F20CULL, 0x24C0E332B70019B0ULL, 0x233003B5A6CFE6ADULL,
-    0xD586BD01C5C217F6ULL, 0x5E5637885F29BC2BULL, 0x7EBA726D8C94094BULL,
-    0x0A56A5F0BFE39272ULL, 0xD79476A84EE20D06ULL, 0x9E4C1269BAA4BF37ULL,
-    0x17EFEE45B0DEE640ULL, 0x1D95B0A5FCF90BC6ULL, 0x93CBE0B699C2585DULL,
-    0x65FA4F227A2B6D79ULL, 0xD5F9E858292504D5ULL, 0xC2B5A03F71471A6FULL,
-    0x59300222B4561E00ULL, 0xCE2F8642CA0712DCULL, 0x7CA9723FBB2E8988ULL,
-    0x2785338347F2BA08ULL, 0xC61BB3A141E50E8CULL, 0x150F361DAB9DEC26ULL,
-    0x9F6A419D382595F4ULL, 0x64A53DC924FE7AC9ULL, 0x142DE49FFF7A7C3DULL,
-    0x0C335248857FA9E7ULL, 0x0A9C32D5EAE45305ULL, 0xE6C42178C4BBB92EULL,
-    0x71F1CE2490D20B07ULL, 0xF1BCC3D275AFE51AULL, 0xE728E8C83C334074ULL,
-    0x96FBF83A12884624ULL, 0x81A1549FD6573DA5ULL, 0x5FA7867CAF35E149ULL,
-    0x56986E2EF3ED091BULL, 0x917F1DD5F8886C61ULL, 0xD20D8C88C8FFE65FULL,
-    0x31D71DCE64B2C310ULL, 0xF165B587DF898190ULL, 0xA57E6339DD2CF3A0ULL,
-    0x1EF6E6DBB1961EC9ULL, 0x70CC73D90BC26E24ULL, 0xE21A6B35DF0C3AD7ULL,
-    0x003A93D8B2806962ULL, 0x1C99DED33CB890A1ULL, 0xCF3145DE0ADD4289ULL,
-    0xD0E4427A5514FB72ULL, 0x77C621CC9FB3A483ULL, 0x67A34DAC4356550BULL,
-    0xF8D626AAAF278509ULL
-  }};
-
-  // polyglot_key() returns the PolyGlot hash key of the given position
-  Key polyglot_key(const Position& pos) {
-
-    Key key = 0;
-    Bitboard b = pos.pieces();
-
-    while (b)
-    {
-        Square s = pop_lsb(&b);
-        Piece pc = pos.piece_on(s);
-
-        // PolyGlot pieces are: BP = 0, WP = 1, BN = 2, ... BK = 10, WK = 11
-        key ^= PG.Zobrist.psq[2 * (type_of(pc) - 1) + (color_of(pc) == WHITE)][s];
-    }
-
-    b = pos.can_castle(ANY_CASTLING);
-
-    while (b)
-        key ^= PG.Zobrist.castling[pop_lsb(&b)];
-
-    if (pos.ep_square() != SQ_NONE)
-        key ^= PG.Zobrist.enpassant[file_of(pos.ep_square())];
-
-    if (pos.side_to_move() == WHITE)
-        key ^= PG.Zobrist.turn;
-
-    return key;
-  }
-
-} // namespace
-
-PolyglotBook::PolyglotBook() : rkiss(Time::now() % 10000) {}
-
-PolyglotBook::~PolyglotBook() { if (is_open()) close(); }
-
-
-/// operator>>() reads sizeof(T) chars from the file's binary byte stream and
-/// converts them into a number of type T. A Polyglot book stores numbers in
-/// big-endian format.
-
-template<typename T> PolyglotBook& PolyglotBook::operator>>(T& n) {
-
-  n = 0;
-  for (size_t i = 0; i < sizeof(T); ++i)
-      n = T((n << 8) + ifstream::get());
-
-  return *this;
-}
-
-template<> PolyglotBook& PolyglotBook::operator>>(Entry& e) {
-  return *this >> e.key >> e.move >> e.count >> e.learn;
-}
-
-
-/// open() tries to open a book file with the given name after closing any
-/// existing one.
-
-bool PolyglotBook::open(const char* fName) {
-
-  if (is_open()) // Cannot close an already closed file
-      close();
-
-  ifstream::open(fName, ifstream::in | ifstream::binary);
-
-  fileName = is_open() ? fName : "";
-  ifstream::clear(); // Reset any error flag to allow a retry ifstream::open()
-  return !fileName.empty();
-}
-
-
-/// probe() tries to find a book move for the given position. If no move is
-/// found, it returns MOVE_NONE. If pickBest is true, then it always returns
-/// the highest-rated move, otherwise it randomly chooses one based on the
-/// move score.
-
-Move PolyglotBook::probe(const Position& pos, const string& fName, bool pickBest) {
-
-  if (fileName != fName && !open(fName.c_str()))
-      return MOVE_NONE;
-
-  Entry e;
-  uint16_t best = 0;
-  unsigned sum = 0;
-  Move move = MOVE_NONE;
-  Key key = polyglot_key(pos);
-
-  seekg(find_first(key) * sizeof(Entry), ios_base::beg);
-
-  while (*this >> e, e.key == key && good())
-  {
-      best = max(best, e.count);
-      sum += e.count;
-
-      // Choose book move according to its score. If a move has a very high
-      // score it has a higher probability of being choosen than a move with
-      // a lower score. Note that first entry is always chosen.
-      if (   (!pickBest && sum && rkiss.rand<unsigned>() % sum < e.count)
-          || (pickBest && e.count == best))
-          move = Move(e.move);
-  }
-
-  if (!move)
-      return MOVE_NONE;
-
-  // A PolyGlot book move is encoded as follows:
-  //
-  // bit  0- 5: destination square (from 0 to 63)
-  // bit  6-11: origin square (from 0 to 63)
-  // bit 12-14: promotion piece (from KNIGHT == 1 to QUEEN == 4)
-  //
-  // Castling moves follow the "king captures rook" representation. If a book
-  // move is a promotion, we have to convert it to our representation and in
-  // all other cases, we can directly compare with a Move after having masked
-  // out the special Move flags (bit 14-15) that are not supported by PolyGlot.
-  int pt = (move >> 12) & 7;
-  if (pt)
-      move = make<PROMOTION>(from_sq(move), to_sq(move), PieceType(pt + 1));
-
-  // Add 'special move' flags and verify it is legal
-  for (MoveList<LEGAL> it(pos); *it; ++it)
-      if (move == (*it ^ type_of(*it)))
-          return *it;
-
-  return MOVE_NONE;
-}
-
-
-/// find_first() takes a book key as input, and does a binary search through
-/// 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(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(Entry) - 1;
-  Entry e;
-
-  assert(low <= high);
-
-  while (low < high && good())
-  {
-      mid = (low + high) / 2;
-
-      assert(mid >= low && mid < high);
-
-      seekg(mid * sizeof(Entry), ios_base::beg);
-      *this >> e;
-
-      if (key <= e.key)
-          high = mid;
-      else
-          low = mid + 1;
-  }
-
-  assert(low == high);
-
-  return low;
-}

src/book.h

@@ -1,45 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 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/>.
-*/
-
-#ifndef BOOK_H_INCLUDED
-#define BOOK_H_INCLUDED
-
-#include <fstream>
-#include <string>
-
-#include "position.h"
-#include "rkiss.h"
-
-class PolyglotBook : private std::ifstream {
-public:
-  PolyglotBook();
- ~PolyglotBook();
-  Move probe(const Position& pos, const std::string& fName, bool pickBest);
-
-private:
-  template<typename T> PolyglotBook& operator>>(T& n);
-
-  bool open(const char* fName);
-  size_t find_first(Key key);
-
-  RKISS rkiss;
-  std::string fileName;
-};
-
-#endif // #ifndef BOOK_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -60,8 +60,8 @@ namespace {
   const int PushAway [8] = { 0, 5, 20, 40, 60, 80, 90, 100 };
 
 #ifndef NDEBUG
-  bool verify_material(const Position& pos, Color c, Value npm, int num_pawns) {
-    return pos.non_pawn_material(c) == npm && pos.count<PAWN>(c) == num_pawns;
+  bool verify_material(const Position& pos, Color c, Value npm, int pawnsCnt) {
+    return pos.non_pawn_material(c) == npm && pos.count<PAWN>(c) == pawnsCnt;
   }
 #endif
 
@@ -162,12 +162,13 @@ Value Endgame<KXK>::operator()(const Position& pos) const {
   Value result =  pos.non_pawn_material(strongSide)
                 + pos.count<PAWN>(strongSide) * PawnValueEg
                 + PushToEdges[loserKSq]
-                + PushClose[square_distance(winnerKSq, loserKSq)];
+                + PushClose[distance(winnerKSq, loserKSq)];
 
   if (   pos.count<QUEEN>(strongSide)
       || pos.count<ROOK>(strongSide)
       ||(pos.count<BISHOP>(strongSide) && pos.count<KNIGHT>(strongSide))
-      || pos.bishop_pair(strongSide))
+      ||(pos.count<BISHOP>(strongSide) > 1 && opposite_colors(pos.list<BISHOP>(strongSide)[0],
+                                                              pos.list<BISHOP>(strongSide)[1])))
       result += VALUE_KNOWN_WIN;
 
   return strongSide == pos.side_to_move() ? result : -result;
@@ -196,7 +197,7 @@ Value Endgame<KBNK>::operator()(const Position& pos) const {
   }
 
   Value result =  VALUE_KNOWN_WIN
-                + PushClose[square_distance(winnerKSq, loserKSq)]
+                + PushClose[distance(winnerKSq, loserKSq)]
                 + PushToCorners[loserKSq];
 
   return strongSide == pos.side_to_move() ? result : -result;
@@ -217,7 +218,7 @@ Value Endgame<KPK>::operator()(const Position& pos) const {
 
   Color us = strongSide == pos.side_to_move() ? WHITE : BLACK;
 
-  if (!Bitbases::probe_kpk(wksq, psq, bksq, us))
+  if (!Bitbases::probe(wksq, psq, bksq, us))
       return VALUE_DRAW;
 
   Value result = VALUE_KNOWN_WIN + PawnValueEg + Value(rank_of(psq));
@@ -246,26 +247,26 @@ Value Endgame<KRKP>::operator()(const Position& pos) const {
 
   // If the stronger side's king is in front of the pawn, it's a win
   if (wksq < psq && file_of(wksq) == file_of(psq))
-      result = RookValueEg - square_distance(wksq, psq);
+      result = RookValueEg - distance(wksq, psq);
 
   // If the weaker side's king is too far from the pawn and the rook,
   // it's a win.
-  else if (   square_distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide)
-           && square_distance(bksq, rsq) >= 3)
-      result = RookValueEg - square_distance(wksq, psq);
+  else if (   distance(bksq, psq) >= 3 + (pos.side_to_move() == weakSide)
+           && distance(bksq, rsq) >= 3)
+      result = RookValueEg - distance(wksq, psq);
 
   // If the pawn is far advanced and supported by the defending king,
   // the position is drawish
   else if (   rank_of(bksq) <= RANK_3
-           && square_distance(bksq, psq) == 1
+           && distance(bksq, psq) == 1
            && rank_of(wksq) >= RANK_4
-           && square_distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide))
-      result = Value(80) - 8 * square_distance(wksq, psq);
+           && distance(wksq, psq) > 2 + (pos.side_to_move() == strongSide))
+      result = Value(80) - 8 * distance(wksq, psq);
 
   else
-      result =  Value(200) - 8 * (  square_distance(wksq, psq + DELTA_S)
-                                  - square_distance(bksq, psq + DELTA_S)
-                                  - square_distance(psq, queeningSq));
+      result =  Value(200) - 8 * (  distance(wksq, psq + DELTA_S)
+                                  - distance(bksq, psq + DELTA_S)
+                                  - distance(psq, queeningSq));
 
   return strongSide == pos.side_to_move() ? result : -result;
 }
@@ -294,7 +295,7 @@ Value Endgame<KRKN>::operator()(const Position& pos) const {
 
   Square bksq = pos.king_square(weakSide);
   Square bnsq = pos.list<KNIGHT>(weakSide)[0];
-  Value result = Value(PushToEdges[bksq] + PushAway[square_distance(bksq, bnsq)]);
+  Value result = Value(PushToEdges[bksq] + PushAway[distance(bksq, bnsq)]);
   return strongSide == pos.side_to_move() ? result : -result;
 }
 
@@ -313,10 +314,10 @@ Value Endgame<KQKP>::operator()(const Position& pos) const {
   Square loserKSq = pos.king_square(weakSide);
   Square pawnSq = pos.list<PAWN>(weakSide)[0];
 
-  Value result = Value(PushClose[square_distance(winnerKSq, loserKSq)]);
+  Value result = Value(PushClose[distance(winnerKSq, loserKSq)]);
 
   if (   relative_rank(weakSide, pawnSq) != RANK_7
-      || square_distance(loserKSq, pawnSq) != 1
+      || distance(loserKSq, pawnSq) != 1
       || !((FileABB | FileCBB | FileFBB | FileHBB) & pawnSq))
       result += QueenValueEg - PawnValueEg;
 
@@ -340,7 +341,7 @@ Value Endgame<KQKR>::operator()(const Position& pos) const {
   Value result =  QueenValueEg
                 - RookValueEg
                 + PushToEdges[loserKSq]
-                + PushClose[square_distance(winnerKSq, loserKSq)];
+                + PushClose[distance(winnerKSq, loserKSq)];
 
   return strongSide == pos.side_to_move() ? result : -result;
 }
@@ -375,7 +376,7 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
       Square kingSq = pos.king_square(weakSide);
 
       if (   opposite_colors(queeningSq, bishopSq)
-          && square_distance(queeningSq, kingSq) <= 1)
+          && distance(queeningSq, kingSq) <= 1)
           return SCALE_FACTOR_DRAW;
   }
 
@@ -398,8 +399,8 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
           && (pos.pieces(strongSide, PAWN) & (weakPawnSq + pawn_push(weakSide)))
           && (opposite_colors(bishopSq, weakPawnSq) || pos.count<PAWN>(strongSide) == 1))
       {
-          int strongKingDist = square_distance(weakPawnSq, strongKingSq);
-          int weakKingDist = square_distance(weakPawnSq, weakKingSq);
+          int strongKingDist = distance(weakPawnSq, strongKingSq);
+          int weakKingDist = distance(weakPawnSq, weakKingSq);
 
           // It's a draw if the weak king is on its back two ranks, within 2
           // squares of the blocking pawn and the strong king is not
@@ -469,7 +470,7 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   // If the pawn is not too far advanced and the defending king defends the
   // queening square, use the third-rank defence.
   if (   r <= RANK_5
-      && square_distance(bksq, queeningSq) <= 1
+      && distance(bksq, queeningSq) <= 1
       && wksq <= SQ_H5
       && (rank_of(brsq) == RANK_6 || (r <= RANK_3 && rank_of(wrsq) != RANK_6)))
       return SCALE_FACTOR_DRAW;
@@ -477,15 +478,15 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   // The defending side saves a draw by checking from behind in case the pawn
   // has advanced to the 6th rank with the king behind.
   if (   r == RANK_6
-      && square_distance(bksq, queeningSq) <= 1
+      && distance(bksq, queeningSq) <= 1
       && rank_of(wksq) + tempo <= RANK_6
-      && (rank_of(brsq) == RANK_1 || (!tempo && abs(file_of(brsq) - f) >= 3)))
+      && (rank_of(brsq) == RANK_1 || (!tempo && distance(file_of(brsq), f) >= 3)))
       return SCALE_FACTOR_DRAW;
 
   if (   r >= RANK_6
       && bksq == queeningSq
       && rank_of(brsq) == RANK_1
-      && (!tempo || square_distance(wksq, wpsq) >= 2))
+      && (!tempo || distance(wksq, wpsq) >= 2))
       return SCALE_FACTOR_DRAW;
 
   // White pawn on a7 and rook on a8 is a draw if black's king is on g7 or h7
@@ -501,8 +502,8 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   // away, it's a draw.
   if (   r <= RANK_5
       && bksq == wpsq + DELTA_N
-      && square_distance(wksq, wpsq) - tempo >= 2
-      && square_distance(wksq, brsq) - tempo >= 2)
+      && distance(wksq, wpsq) - tempo >= 2
+      && distance(wksq, brsq) - tempo >= 2)
       return SCALE_FACTOR_DRAW;
 
   // Pawn on the 7th rank supported by the rook from behind usually wins if the
@@ -512,22 +513,22 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
       && f != FILE_A
       && file_of(wrsq) == f
       && wrsq != queeningSq
-      && (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo)
-      && (square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo))
-      return ScaleFactor(SCALE_FACTOR_MAX - 2 * square_distance(wksq, queeningSq));
+      && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo)
+      && (distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo))
+      return ScaleFactor(SCALE_FACTOR_MAX - 2 * distance(wksq, queeningSq));
 
   // Similar to the above, but with the pawn further back
   if (   f != FILE_A
       && file_of(wrsq) == f
       && wrsq < wpsq
-      && (square_distance(wksq, queeningSq) < square_distance(bksq, queeningSq) - 2 + tempo)
-      && (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wpsq + DELTA_N) - 2 + tempo)
-      && (  square_distance(bksq, wrsq) + tempo >= 3
-          || (    square_distance(wksq, queeningSq) < square_distance(bksq, wrsq) + tempo
-              && (square_distance(wksq, wpsq + DELTA_N) < square_distance(bksq, wrsq) + tempo))))
+      && (distance(wksq, queeningSq) < distance(bksq, queeningSq) - 2 + tempo)
+      && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wpsq + DELTA_N) - 2 + tempo)
+      && (  distance(bksq, wrsq) + tempo >= 3
+          || (    distance(wksq, queeningSq) < distance(bksq, wrsq) + tempo
+              && (distance(wksq, wpsq + DELTA_N) < distance(bksq, wrsq) + tempo))))
       return ScaleFactor(  SCALE_FACTOR_MAX
-                         - 8 * square_distance(wpsq, queeningSq)
-                         - 2 * square_distance(wksq, queeningSq));
+                         - 8 * distance(wpsq, queeningSq)
+                         - 2 * distance(wksq, queeningSq));
 
   // If the pawn is not far advanced and the defending king is somewhere in
   // the pawn's path, it's probably a draw.
@@ -535,9 +536,9 @@ ScaleFactor Endgame<KRPKR>::operator()(const Position& pos) const {
   {
       if (file_of(bksq) == file_of(wpsq))
           return ScaleFactor(10);
-      if (   abs(file_of(bksq) - file_of(wpsq)) == 1
-          && square_distance(wksq, bksq) > 2)
-          return ScaleFactor(24 - 2 * square_distance(wksq, bksq));
+      if (   distance<File>(bksq, wpsq) == 1
+          && distance(wksq, bksq) > 2)
+          return ScaleFactor(24 - 2 * distance(wksq, bksq));
   }
   return SCALE_FACTOR_NONE;
 }
@@ -564,7 +565,7 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
       // corner but not trapped there.
       if (rk == RANK_5 && !opposite_colors(bsq, psq))
       {
-          int d = square_distance(psq + 3 * push, ksq);
+          int d = distance(psq + 3 * push, ksq);
 
           if (d <= 2 && !(d == 0 && ksq == pos.king_square(strongSide) + 2 * push))
               return ScaleFactor(24);
@@ -577,9 +578,9 @@ ScaleFactor Endgame<KRPKB>::operator()(const Position& pos) const {
       // pawn from a reasonable distance and the defending king is near
       // the corner
       if (   rk == RANK_6
-          && square_distance(psq + 2 * push, ksq) <= 1
+          && distance(psq + 2 * push, ksq) <= 1
           && (PseudoAttacks[BISHOP][bsq] & (psq + push))
-          && file_distance(bsq, psq) >= 2)
+          && distance<File>(bsq, psq) >= 2)
           return ScaleFactor(8);
   }
 
@@ -604,8 +605,8 @@ ScaleFactor Endgame<KRPPKRP>::operator()(const Position& pos) const {
 
   Rank r = std::max(relative_rank(strongSide, wpsq1), relative_rank(strongSide, wpsq2));
 
-  if (   file_distance(bksq, wpsq1) <= 1
-      && file_distance(bksq, wpsq2) <= 1
+  if (   distance<File>(bksq, wpsq1) <= 1
+      && distance<File>(bksq, wpsq2) <= 1
       && relative_rank(strongSide, bksq) > r)
   {
       switch (r) {
@@ -638,7 +639,7 @@ ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
   // the king is within one file of the pawns, it's a draw.
   if (   !(pawns & ~in_front_bb(weakSide, rank_of(ksq)))
       && !((pawns & ~FileABB) && (pawns & ~FileHBB))
-      && file_distance(ksq, psq) <= 1)
+      &&  distance<File>(ksq, psq) <= 1)
       return SCALE_FACTOR_DRAW;
 
   return SCALE_FACTOR_NONE;
@@ -690,7 +691,7 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
               return SCALE_FACTOR_DRAW;
 
           if (  (pos.attacks_from<BISHOP>(weakBishopSq) & path)
-              && square_distance(weakBishopSq, pawnSq) >= 3)
+              && distance(weakBishopSq, pawnSq) >= 3)
               return SCALE_FACTOR_DRAW;
       }
   }
@@ -729,7 +730,7 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
       blockSq2 = make_square(file_of(psq1), rank_of(psq2));
   }
 
-  switch (file_distance(psq1, psq2))
+  switch (distance<File>(psq1, psq2))
   {
   case 0:
     // Both pawns are on the same file. It's an easy draw if the defender firmly
@@ -749,7 +750,7 @@ ScaleFactor Endgame<KBPPKB>::operator()(const Position& pos) const {
         && opposite_colors(ksq, wbsq)
         && (   bbsq == blockSq2
             || (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(weakSide, BISHOP))
-            || abs(r1 - r2) >= 2))
+            || distance(r1, r2) >= 2))
         return SCALE_FACTOR_DRAW;
 
     else if (   ksq == blockSq2
@@ -802,7 +803,7 @@ ScaleFactor Endgame<KNPK>::operator()(const Position& pos) const {
   Square pawnSq     = normalize(pos, strongSide, pos.list<PAWN>(strongSide)[0]);
   Square weakKingSq = normalize(pos, strongSide, pos.king_square(weakSide));
 
-  if (pawnSq == SQ_A7 && square_distance(SQ_A8, weakKingSq) <= 1)
+  if (pawnSq == SQ_A7 && distance(SQ_A8, weakKingSq) <= 1)
       return SCALE_FACTOR_DRAW;
 
   return SCALE_FACTOR_NONE;
@@ -821,7 +822,7 @@ ScaleFactor Endgame<KNPKB>::operator()(const Position& pos) const {
   // 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(strongSide, pawnSq) & pos.attacks_from<BISHOP>(bishopSq))
-      return ScaleFactor(square_distance(weakKingSq, pawnSq));
+      return ScaleFactor(distance(weakKingSq, pawnSq));
 
   return SCALE_FACTOR_NONE;
 }
@@ -852,5 +853,5 @@ 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, psq, bksq, us) ? SCALE_FACTOR_NONE : SCALE_FACTOR_DRAW;
+  return Bitbases::probe(wksq, psq, 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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -45,7 +45,7 @@ enum EndgameType {
 
 
   // Scaling functions
-  SCALE_FUNS,
+  SCALING_FUNCTIONS,
 
   KBPsK,   // KB and pawns vs K
   KQKRPs,  // KQ vs KR and pawns
@@ -76,26 +76,26 @@ template<typename T>
 struct EndgameBase {
 
   virtual ~EndgameBase() {}
-  virtual Color color() const = 0;
+  virtual Color strong_side() const = 0;
   virtual T operator()(const Position&) const = 0;
 };
 
 
-template<EndgameType E, typename T = typename eg_fun<(E > SCALE_FUNS)>::type>
+template<EndgameType E, typename T = typename eg_fun<(E > SCALING_FUNCTIONS)>::type>
 struct Endgame : public EndgameBase<T> {
 
   explicit Endgame(Color c) : strongSide(c), weakSide(~c) {}
-  Color color() const { return strongSide; }
+  Color strong_side() const { return strongSide; }
   T operator()(const Position&) const;
 
 private:
-  const Color strongSide, weakSide;
+  Color strongSide, weakSide;
 };
 
 
 /// The Endgames class stores the pointers to endgame evaluation and scaling
-/// base objects in two std::map typedefs. We then use polymorphism to invoke
-/// the actual endgame function by calling its virtual operator().
+/// base objects in two std::map. We use polymorphism to invoke the actual
+/// endgame function by calling its virtual operator().
 
 class Endgames {
 
@@ -114,8 +114,9 @@ public:
   Endgames();
  ~Endgames();
 
-  template<typename T> T probe(Key key, T& eg)
-  { return eg = map(eg).count(key) ? map(eg)[key] : NULL; }
+  template<typename T> T probe(Key key, T& eg) {
+    return eg = map(eg).count(key) ? map(eg)[key] : NULL;
+  }
 };
 
 #endif // #ifndef ENDGAME_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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 <algorithm>
 #include <cassert>
+#include <cstring>   // For std::memset
 #include <iomanip>
 #include <sstream>
 
@@ -26,8 +27,6 @@
 #include "evaluate.h"
 #include "material.h"
 #include "pawns.h"
-#include "thread.h"
-#include "ucioption.h"
 
 namespace {
 
@@ -58,9 +57,8 @@ namespace {
 
     // 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
+    // weights of the individual piece types are given by the elements in the
+    // KingAttackWeights array.
     int kingAttackersWeight[COLOR_NB];
 
     // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares
@@ -76,36 +74,29 @@ namespace {
   namespace Tracing {
 
     enum Terms { // First 8 entries are for PieceType
-      PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
+      MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
     };
 
-    Score terms[COLOR_NB][TERMS_NB];
+    Score scores[COLOR_NB][TERMS_NB];
     EvalInfo ei;
     ScaleFactor sf;
 
     double to_cp(Value v);
-    void add_term(int idx, Score term_w, Score term_b = SCORE_ZERO);
-    void format_row(std::stringstream& ss, const char* name, int idx);
+    void write(int idx, Color c, Score s);
+    void write(int idx, Score w, Score b = SCORE_ZERO);
+    void print(std::stringstream& ss, const char* name, int idx);
     std::string do_trace(const Position& pos);
   }
 
-  // Evaluation weights, initialized from UCI options
-  enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
-  struct Weight { int mg, eg; } Weights[6];
-
-  typedef Value V;
-  #define S(mg, eg) make_score(mg, eg)
-
-  // Internal evaluation weights. These are applied on top of the evaluation
-  // weights read from UCI parameters. The purpose is to be able to change
-  // the evaluation weights while keeping the default values of the UCI
-  // parameters at 100, which looks prettier.
-  //
-  // Values modified by Joona Kiiski
-  const Score WeightsInternal[] = {
-    S(289, 344), S(233, 201), S(221, 273), S(46, 0), S(271, 0), S(307, 0)
+  // Evaluation weights, indexed by evaluation term
+  enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety };
+  const struct Weight { int mg, eg; } Weights[] = {
+    {289, 344}, {233, 201}, {221, 273}, {46, 0}, {321, 0}
   };
 
+  #define V(v) Value(v)
+  #define S(mg, eg) make_score(mg, eg)
+
   // MobilityBonus[PieceType][attacked] contains bonuses for middle and end
   // game, indexed by piece type and number of attacked squares not occupied by
   // friendly pieces.
@@ -145,37 +136,40 @@ namespace {
     V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) }
   };
 
-  // Threat[attacking][attacked] contains bonuses according to which piece
-  // type attacks which one.
-  const Score Threat[][PIECE_TYPE_NB] = {
-    { S(0, 0), S( 7, 39), S(24, 49), S(24, 49), S(41,100), S(41,100) }, // Minor
-    { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) }  // Major
+  // Threat[defended/weak][minor/major attacking][attacked PieceType] contains
+  // bonuses according to which piece type attacks which one.
+  const Score Threat[][2][PIECE_TYPE_NB] = {
+  { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) },   // Defended Minor
+    { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major
+  { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) },   // Weak Minor
+    { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } }  // Weak Major
   };
 
   // ThreatenedByPawn[PieceType] contains a penalty according to which piece
   // type is attacked by an enemy pawn.
   const Score ThreatenedByPawn[] = {
-    S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
+    S(0, 0), S(0, 0), S(87, 118), S(84, 122), S(114, 203), S(121, 217)
   };
 
-  // Hanging[side to move] contains a bonus for each enemy hanging piece
-  const Score Hanging[2] = { S(23, 20) , S(35, 45) };
-
-  #undef S
-
-  const Score Tempo            = make_score(24, 11);
-  const Score RookOnPawn       = make_score(10, 28);
-  const Score RookOpenFile     = make_score(43, 21);
-  const Score RookSemiopenFile = make_score(19, 10);
-  const Score BishopPawns      = make_score( 8, 12);
-  const Score MinorBehindPawn  = make_score(16,  0);
-  const Score TrappedRook      = make_score(90,  0);
-  const Score Unstoppable      = make_score( 0, 20);
+  // Assorted bonuses and penalties used by evaluation
+  const Score KingOnOne          = S( 2, 58);
+  const Score KingOnMany         = S( 6,125);
+  const Score RookOnPawn         = S( 7, 27);
+  const Score RookOnOpenFile     = S(43, 21);
+  const Score RookOnSemiOpenFile = S(19, 10);
+  const Score BishopPawns        = S( 8, 12);
+  const Score MinorBehindPawn    = S(16,  0);
+  const Score TrappedRook        = S(92,  0);
+  const Score Unstoppable        = S( 0, 20);
+  const Score Hanging            = S(31, 26);
 
   // 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.
-  const Score TrappedBishopA1H1 = make_score(50, 50);
+  const Score TrappedBishopA1H1 = S(50, 50);
+
+  #undef S
+  #undef V
 
   // SpaceMask[Color] contains the area of the board which is considered
   // by the space evaluation. In the middlegame, each side is given a bonus
@@ -186,41 +180,29 @@ namespace {
     (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB)
   };
 
-  // King danger constants and variables. The king danger scores are taken
-  // from KingDanger[]. Various little "meta-bonuses" measuring the strength
+  // King danger constants and variables. The king danger scores are looked-up
+  // in KingDanger[]. Various little "meta-bonuses" measuring the strength
   // of the enemy attack are added up into an integer, which is used as an
   // index to KingDanger[].
   //
   // KingAttackWeights[PieceType] contains king attack weights by piece type
-  const int KingAttackWeights[] = { 0, 0, 2, 2, 3, 5 };
+  const int KingAttackWeights[] = { 0, 0, 6, 2, 5, 5 };
 
   // Bonuses for enemy's safe checks
-  const int QueenContactCheck = 24;
-  const int RookContactCheck  = 16;
-  const int QueenCheck        = 12;
-  const int RookCheck         = 8;
-  const int BishopCheck       = 2;
-  const int KnightCheck       = 3;
+  const int QueenContactCheck = 92;
+  const int RookContactCheck  = 68;
+  const int QueenCheck        = 50;
+  const int RookCheck         = 36;
+  const int BishopCheck       = 7;
+  const int KnightCheck       = 14;
 
-  // KingDanger[Color][attackUnits] contains the actual king danger weighted
-  // scores, indexed by color and by a calculated integer number.
-  Score KingDanger[COLOR_NB][128];
+  // KingDanger[attackUnits] contains the actual king danger weighted
+  // scores, indexed by a calculated integer number.
+  Score KingDanger[512];
 
-
-  // apply_weight() weighs score 'v' by weight 'w' trying to prevent overflow
-  Score apply_weight(Score v, const Weight& w) {
-    return make_score(mg_value(v) * w.mg / 256, eg_value(v) * w.eg / 256);
-  }
-
-
-  // weight_option() computes the value of an evaluation weight, by combining
-  // two UCI-configurable weights (midgame and endgame) with an internal weight.
-
-  Weight weight_option(const std::string& mgOpt, const std::string& egOpt, Score internalWeight) {
-
-    Weight w = { Options[mgOpt] * mg_value(internalWeight) / 100,
-                 Options[egOpt] * eg_value(internalWeight) / 100 };
-    return w;
+  // apply_weight() weighs score 's' by weight 'w' trying to prevent overflow
+  Score apply_weight(Score s, const Weight& w) {
+    return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256);
   }
 
 
@@ -239,7 +221,7 @@ namespace {
     ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
 
     // Init king safety tables only if we are going to use them
-    if (pos.count<QUEEN>(Us) && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
+    if (pos.non_pawn_material(Us) >= QueenValueMg)
     {
         ei.kingRing[Them] = b | shift_bb<Down>(b);
         b &= ei.attackedBy[Us][PAWN];
@@ -251,10 +233,10 @@ namespace {
   }
 
 
-  // evaluate_outposts() evaluates bishop and knight outpost squares
+  // evaluate_outpost() evaluates bishop and knight outpost squares
 
   template<PieceType Pt, Color Us>
-  Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+  Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
@@ -274,7 +256,7 @@ namespace {
             bonus += bonus / 2;
     }
 
-    return make_score(bonus, bonus);
+    return make_score(bonus * 2, bonus / 2);
   }
 
 
@@ -331,65 +313,65 @@ namespace {
 
         if (Pt == BISHOP || Pt == KNIGHT)
         {
-            // Penalty for bishop with same colored pawns
-            if (Pt == BISHOP)
-                score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
-
-            // Bishop and knight outposts squares
+            // Bonus for outpost square
             if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
-                score += evaluate_outposts<Pt, Us>(pos, ei, s);
+                score += evaluate_outpost<Pt, Us>(pos, ei, s);
 
-            // Bishop or knight behind a pawn
+            // Bonus when behind a pawn
             if (    relative_rank(Us, s) < RANK_5
                 && (pos.pieces(PAWN) & (s + pawn_push(Us))))
                 score += MinorBehindPawn;
+
+            // Penalty for pawns on same color square of bishop
+            if (Pt == BISHOP)
+                score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
+
+            // An important Chess960 pattern: A cornered bishop blocked by a friendly
+            // pawn diagonally in front of it is a very serious problem, especially
+            // when that pawn is also blocked.
+            if (   Pt == BISHOP
+                && pos.is_chess960()
+                && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+            {
+                Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
+                if (pos.piece_on(s + d) == make_piece(Us, PAWN))
+                    score -= !pos.empty(s + d + pawn_push(Us))                ? TrappedBishopA1H1 * 4
+                            : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
+                                                                              : TrappedBishopA1H1;
+            }
         }
 
         if (Pt == ROOK)
         {
-            // Rook piece attacking enemy pawns on the same rank/file
+            // Bonus for aligning with enemy pawns on the same rank/file
             if (relative_rank(Us, s) >= RANK_5)
             {
-                Bitboard pawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
-                if (pawns)
-                    score += popcount<Max15>(pawns) * RookOnPawn;
+                Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s];
+                if (alignedPawns)
+                    score += popcount<Max15>(alignedPawns) * RookOnPawn;
             }
 
-            // Give a bonus for a rook on a open or semi-open file
+            // Bonus when on an open or semi-open file
             if (ei.pi->semiopen_file(Us, file_of(s)))
-                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOpenFile : RookSemiopenFile;
+                score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile;
 
-            if (mob > 3 || ei.pi->semiopen_file(Us, file_of(s)))
-                continue;
+            // Penalize when trapped by the king, even more if king cannot castle
+            if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s)))
+            {
+                Square ksq = pos.king_square(Us);
 
-            Square ksq = pos.king_square(Us);
-
-            // Penalize rooks which are trapped by a king. Penalize more if the
-            // king has lost its castling capability.
-            if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
-                && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
-                && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
-                score -= (TrappedRook - make_score(mob * 8, 0)) * (1 + !pos.can_castle(Us));
-        }
-
-        // An important Chess960 pattern: A cornered bishop blocked by a friendly
-        // pawn diagonally in front of it is a very serious problem, especially
-        // when that pawn is also blocked.
-        if (   Pt == BISHOP
-            && pos.is_chess960()
-            && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
-        {
-            Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W);
-            if (pos.piece_on(s + d) == make_piece(Us, PAWN))
-                score -= !pos.empty(s + d + pawn_push(Us))                ? TrappedBishopA1H1 * 4
-                        : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
-                                                                          : TrappedBishopA1H1;
+                if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+                    && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
+                    && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
+                    score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
+            }
         }
     }
 
     if (Trace)
-        Tracing::terms[Us][Pt] = score;
+        Tracing::write(Pt, Us, score);
 
+    // Recursively call evaluate_pieces() of next piece type until KING excluded
     return score - evaluate_pieces<NextPt, Them, Trace>(pos, ei, mobility, mobilityArea);
   }
 
@@ -425,34 +407,32 @@ namespace {
                         | ei.attackedBy[Us][QUEEN]);
 
         // Initialize the 'attackUnits' variable, which is used later on as an
-        // index to the KingDanger[] array. The initial value is based on the
+        // index into the KingDanger[] array. The initial value is based on the
         // number and types of the enemy's attacking pieces, the number of
         // attacked and undefended squares around our king and the quality of
         // the pawn shelter (current 'score' value).
-        attackUnits =  std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
-                     + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
-                     + 2 * (ei.pinnedPieces[Us] != 0)
-                     - mg_value(score) / 32;
+        attackUnits =  std::min(77, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them])
+                     + 10 * ei.kingAdjacentZoneAttacksCount[Them]
+                     + 19 * popcount<Max15>(undefended)
+                     +  9 * (ei.pinnedPieces[Us] != 0)
+                     - mg_value(score) * 63 / 512
+                     - !pos.count<QUEEN>(Them) * 60;
 
         // Analyse the enemy's safe queen contact checks. Firstly, find the
-        // undefended squares around the king that are attacked by the enemy's
-        // queen...
+        // undefended squares around the king reachable by the enemy queen...
         b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them);
         if (b)
         {
             // ...and then remove squares not supported by another enemy piece
-            b &= (  ei.attackedBy[Them][PAWN]   | ei.attackedBy[Them][KNIGHT]
-                  | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]);
+            b &=  ei.attackedBy[Them][PAWN]   | ei.attackedBy[Them][KNIGHT]
+                | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK];
 
             if (b)
-                attackUnits +=  QueenContactCheck
-                              * popcount<Max15>(b)
-                              * (Them == pos.side_to_move() ? 2 : 1);
+                attackUnits += QueenContactCheck * popcount<Max15>(b);
         }
 
         // Analyse the enemy's safe rook contact checks. Firstly, find the
-        // undefended squares around the king that are attacked by the enemy's
-        // rooks...
+        // undefended squares around the king reachable by the enemy rooks...
         b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
 
         // Consider only squares where the enemy's rook gives check
@@ -465,15 +445,13 @@ namespace {
                   | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]);
 
             if (b)
-                attackUnits +=  RookContactCheck
-                              * popcount<Max15>(b)
-                              * (Them == pos.side_to_move() ? 2 : 1);
+                attackUnits += RookContactCheck * popcount<Max15>(b);
         }
 
         // Analyse the enemy's safe distance checks for sliders and knights
-        safe = ~(pos.pieces(Them) | ei.attackedBy[Us][ALL_PIECES]);
+        safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them));
 
-        b1 = pos.attacks_from<ROOK>(ksq) & safe;
+        b1 = pos.attacks_from<ROOK  >(ksq) & safe;
         b2 = pos.attacks_from<BISHOP>(ksq) & safe;
 
         // Enemy queen safe checks
@@ -496,16 +474,13 @@ namespace {
         if (b)
             attackUnits += KnightCheck * popcount<Max15>(b);
 
-        // To index KingDanger[] attackUnits must be in [0, 99] range
-        attackUnits = std::min(99, std::max(0, attackUnits));
-
         // Finally, extract the king danger score from the KingDanger[]
         // array and subtract the score from evaluation.
-        score -= KingDanger[Us == Search::RootColor][attackUnits];
+        score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
     }
 
     if (Trace)
-        Tracing::terms[Us][KING] = score;
+        Tracing::write(KING, Us, score);
 
     return score;
   }
@@ -519,33 +494,55 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b, weakEnemies;
+    enum { Defended, Weak };
+    enum { Minor, Major };
+
+    Bitboard b, weak, defended;
     Score score = SCORE_ZERO;
 
-    // Enemies not defended by a pawn and under our attack
-    weakEnemies =  pos.pieces(Them)
-                 & ~ei.attackedBy[Them][PAWN]
-                 & ei.attackedBy[Us][ALL_PIECES];
+    // Non-pawn enemies defended by a pawn
+    defended =  (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+              &  ei.attackedBy[Them][PAWN];
 
-    // Add a bonus according if the attacking pieces are minor or major
-    if (weakEnemies)
+    // Add a bonus according to the kind of attacking pieces
+    if (defended)
     {
-        b = weakEnemies & (ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
-        if (b)
-            score += Threat[0][type_of(pos.piece_on(lsb(b)))];
+        b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+        while (b)
+            score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&b)))];
 
-        b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
-        if (b)
-            score += Threat[1][type_of(pos.piece_on(lsb(b)))];
+        b = defended & (ei.attackedBy[Us][ROOK]);
+        while (b)
+            score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))];
+    }
 
-        b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
+    // Enemies not defended by a pawn and under our attack
+    weak =   pos.pieces(Them)
+          & ~ei.attackedBy[Them][PAWN]
+          &  ei.attackedBy[Us][ALL_PIECES];
+
+    // Add a bonus according to the kind of attacking pieces
+    if (weak)
+    {
+        b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+        while (b)
+            score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))];
+
+        b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
+        while (b)
+            score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))];
+
+        b = weak & ~ei.attackedBy[Them][ALL_PIECES];
         if (b)
-            score += more_than_one(b) ? Hanging[Us != pos.side_to_move()] * popcount<Max15>(b)
-                                      : Hanging[Us == pos.side_to_move()];
+            score += Hanging * popcount<Max15>(b);
+
+        b = weak & ei.attackedBy[Us][KING];
+        if (b)
+            score += more_than_one(b) ? KingOnMany : KingOnOne;
     }
 
     if (Trace)
-        Tracing::terms[Us][Tracing::THREAT] = score;
+        Tracing::write(Tracing::THREAT, Us, score);
 
     return score;
   }
@@ -580,32 +577,28 @@ namespace {
             Square blockSq = s + pawn_push(Us);
 
             // Adjust bonus based on the king's proximity
-            ebonus +=  square_distance(pos.king_square(Them), blockSq) * 5 * rr
-                     - square_distance(pos.king_square(Us  ), blockSq) * 2 * rr;
+            ebonus +=  distance(pos.king_square(Them), blockSq) * 5 * rr
+                     - distance(pos.king_square(Us  ), blockSq) * 2 * rr;
 
             // If blockSq is not the queening square then consider also a second push
             if (relative_rank(Us, blockSq) != RANK_8)
-                ebonus -= square_distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;
+                ebonus -= distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr;
 
             // If the pawn is free to advance, then increase the bonus
             if (pos.empty(blockSq))
             {
-                squaresToQueen = forward_bb(Us, s);
+                // If there is a rook or queen attacking/defending the pawn from behind,
+                // consider all the squaresToQueen. Otherwise consider only the squares
+                // in the pawn's path attacked or occupied by the enemy.
+                defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s);
 
-                // 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
-                // the squares in the pawn's path attacked or occupied by the enemy.
-                if (    unlikely(forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN))
-                    && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
-                    unsafeSquares = squaresToQueen;
-                else
-                    unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
+                Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
 
-                if (    unlikely(forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN))
-                    && (forward_bb(Them, s) & pos.pieces(Us, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
-                    defendedSquares = squaresToQueen;
-                else
-                    defendedSquares = squaresToQueen & ei.attackedBy[Us][ALL_PIECES];
+                if (!(pos.pieces(Us) & bb))
+                    defendedSquares &= ei.attackedBy[Us][ALL_PIECES];
+
+                if (!(pos.pieces(Them) & bb))
+                    unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
 
                 // If there aren't any enemy attacks, assign a big bonus. Otherwise
                 // assign a smaller bonus if the block square isn't attacked.
@@ -621,6 +614,8 @@ namespace {
 
                 mbonus += k * rr, ebonus += k * rr;
             }
+            else if (pos.pieces(Us) & blockSq)
+                mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2;
         } // rr != 0
 
         if (pos.count<PAWN>(Us) < pos.count<PAWN>(Them))
@@ -630,36 +625,21 @@ namespace {
     }
 
     if (Trace)
-        Tracing::terms[Us][Tracing::PASSED] = apply_weight(score, Weights[PassedPawns]);
+        Tracing::write(Tracing::PASSED, Us, apply_weight(score, Weights[PassedPawns]));
 
     // Add the scores to the middlegame and endgame eval
     return apply_weight(score, Weights[PassedPawns]);
   }
 
 
-  // evaluate_unstoppable_pawns() scores the most advanced among the passed and
-  // candidate pawns. In case opponent has no pieces but pawns, this is somewhat
-  // related to the possibility that pawns are unstoppable.
-
-  Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei) {
-
-    Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
-
-    if (!b || pos.non_pawn_material(~us))
-        return SCORE_ZERO;
-
-    return Unstoppable * int(relative_rank(us, frontmost_sq(us, b)));
-  }
-
-
   // evaluate_space() computes the space evaluation for a given side. The
   // space evaluation is a simple bonus based on the number of safe squares
   // available for minor pieces on the central four files on ranks 2--4. Safe
   // squares one, two or three squares behind a friendly pawn are counted
-  // twice. Finally, the space bonus is scaled by a weight taken from the
-  // material hash table. The aim is to improve play on game opening.
+  // twice. Finally, the space bonus is multiplied by a weight. The aim is to
+  // improve play on game opening.
   template<Color Us>
-  int evaluate_space(const Position& pos, const EvalInfo& ei) {
+  Score evaluate_space(const Position& pos, const EvalInfo& ei) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
@@ -680,7 +660,11 @@ namespace {
     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));
+    int bonus = popcount<Full>((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe));
+    int weight =  pos.count<KNIGHT>(Us) + pos.count<BISHOP>(Us)
+                + pos.count<KNIGHT>(Them) + pos.count<BISHOP>(Them);
+
+    return make_score(bonus * weight * weight, 0);
   }
 
 
@@ -693,16 +677,15 @@ namespace {
 
     EvalInfo ei;
     Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO };
-    Thread* thisThread = pos.this_thread();
 
     // Initialize score by reading the incrementally updated scores included
-    // in the position object (material + piece square tables) and adding a
-    // Tempo bonus. Score is computed from the point of view of white.
-    score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
+    // in the position object (material + piece square tables).
+    // Score is computed from the point of view of white.
+    score = pos.psq_score();
 
     // Probe the material hash table
-    ei.mi = Material::probe(pos, thisThread->materialTable, thisThread->endgames);
-    score += ei.mi->material_value();
+    ei.mi = Material::probe(pos);
+    score += ei.mi->imbalance();
 
     // If we have a specialized evaluation function for the current material
     // configuration, call it and return.
@@ -710,8 +693,8 @@ namespace {
         return ei.mi->evaluate(pos);
 
     // Probe the pawn hash table
-    ei.pi = Pawns::probe(pos, thisThread->pawnsTable);
-    score += apply_weight(ei.pi->pawns_value(), Weights[PawnStructure]);
+    ei.pi = Pawns::probe(pos);
+    score += apply_weight(ei.pi->pawns_score(), Weights[PawnStructure]);
 
     // Initialize attack and king safety bitboards
     init_eval_info<WHITE>(pos, ei);
@@ -741,42 +724,52 @@ namespace {
     score +=  evaluate_passed_pawns<WHITE, Trace>(pos, ei)
             - evaluate_passed_pawns<BLACK, Trace>(pos, ei);
 
-    // If one side has only a king, score for potential unstoppable pawns
-    if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
-        score +=  evaluate_unstoppable_pawns(pos, WHITE, ei)
-                - evaluate_unstoppable_pawns(pos, BLACK, ei);
-
-    // Evaluate space for both sides, only in middlegame
-    if (ei.mi->space_weight())
+    // If both sides have only pawns, score for potential unstoppable pawns
+    if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK))
     {
-        int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
-        score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
+        Bitboard b;
+        if ((b = ei.pi->passed_pawns(WHITE)) != 0)
+            score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable;
+
+        if ((b = ei.pi->passed_pawns(BLACK)) != 0)
+            score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable;
+    }
+
+    // Evaluate space for both sides, only during opening
+    if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
+    {
+        Score s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+        score += apply_weight(s, Weights[Space]);
     }
 
     // Scale winning side if position is more drawish than it appears
-    ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
-                                                  : ei.mi->scale_factor(pos, BLACK);
+    Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK;
+    ScaleFactor sf = ei.mi->scale_factor(pos, strongSide);
 
-    // If we don't already have an unusual scale factor, check for opposite
-    // colored bishop endgames, and use a lower scale for those.
+    // If we don't already have an unusual scale factor, check for certain
+    // types of endgames, and use a lower scale for those.
     if (    ei.mi->game_phase() < PHASE_MIDGAME
-        &&  pos.opposite_bishops()
         && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
     {
-        // Ignoring any pawns, do both sides only have a single bishop and no
-        // other pieces?
-        if (   pos.non_pawn_material(WHITE) == BishopValueMg
-            && pos.non_pawn_material(BLACK) == BishopValueMg)
+        if (pos.opposite_bishops())
         {
-            // Check for KBP vs KB with only a single pawn that is almost
-            // certainly a draw or at least two pawns.
-            bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
-            sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
-        }
-        else
+            // Endgame with opposite-colored bishops and no other pieces (ignoring pawns)
+            // is almost a draw, in case of KBP vs KB is even more a draw.
+            if (   pos.non_pawn_material(WHITE) == BishopValueMg
+                && pos.non_pawn_material(BLACK) == BishopValueMg)
+                sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8);
+
             // Endgame with opposite-colored bishops, but also other pieces. Still
             // a bit drawish, but not as drawish as with only the two bishops.
-             sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
+            else
+                 sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
+        }
+        // Endings where weaker side can place his king in front of the opponent's
+        // pawns are drawish.
+        else if (    abs(eg_value(score)) <= BishopValueEg
+                 &&  ei.pi->pawn_span(strongSide) <= 1
+                 && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide)))
+                 sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38);
     }
 
     // Interpolate between a middlegame and a (scaled by 'sf') endgame score
@@ -788,20 +781,19 @@ namespace {
     // In case of tracing add all single evaluation contributions for both white and black
     if (Trace)
     {
-        Tracing::add_term(Tracing::PST, pos.psq_score());
-        Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value());
-        Tracing::add_term(PAWN, ei.pi->pawns_value());
-        Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
-                                           , apply_weight(mobility[BLACK], Weights[Mobility]));
-        Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
-        Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
-        Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
-        Tracing::add_term(Tracing::TOTAL, score);
+        Tracing::write(Tracing::MATERIAL, pos.psq_score());
+        Tracing::write(Tracing::IMBALANCE, ei.mi->imbalance());
+        Tracing::write(PAWN, ei.pi->pawns_score());
+        Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
+                                        , apply_weight(mobility[BLACK], Weights[Mobility]));
+        Tracing::write(Tracing::SPACE, apply_weight(evaluate_space<WHITE>(pos, ei), Weights[Space])
+                                     , apply_weight(evaluate_space<BLACK>(pos, ei), Weights[Space]));
+        Tracing::write(Tracing::TOTAL, score);
         Tracing::ei = ei;
         Tracing::sf = sf;
     }
 
-    return pos.side_to_move() == WHITE ? v : -v;
+    return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo;
   }
 
 
@@ -809,25 +801,27 @@ namespace {
 
   double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; }
 
-  void Tracing::add_term(int idx, Score wScore, Score bScore) {
+  void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; }
 
-    terms[WHITE][idx] = wScore;
-    terms[BLACK][idx] = bScore;
+  void Tracing::write(int idx, Score w, Score b) {
+
+    write(idx, WHITE, w);
+    write(idx, BLACK, b);
   }
 
-  void Tracing::format_row(std::stringstream& ss, const char* name, int idx) {
+  void Tracing::print(std::stringstream& ss, const char* name, int idx) {
 
-    Score wScore = terms[WHITE][idx];
-    Score bScore = terms[BLACK][idx];
+    Score wScore = scores[WHITE][idx];
+    Score bScore = scores[BLACK][idx];
 
     switch (idx) {
-    case PST: case IMBALANCE: case PAWN: case TOTAL:
-        ss << std::setw(20) << name << " |   ---   --- |   ---   --- | "
+    case MATERIAL: case IMBALANCE: case PAWN: case TOTAL:
+        ss << std::setw(15) << name << " |   ---   --- |   ---   --- | "
            << std::setw(5)  << to_cp(mg_value(wScore - bScore)) << " "
            << std::setw(5)  << to_cp(eg_value(wScore - bScore)) << " \n";
         break;
     default:
-        ss << std::setw(20) << name << " | " << std::noshowpos
+        ss << std::setw(15) << name << " | " << std::noshowpos
            << std::setw(5)  << to_cp(mg_value(wScore)) << " "
            << std::setw(5)  << to_cp(eg_value(wScore)) << " | "
            << std::setw(5)  << to_cp(mg_value(bScore)) << " "
@@ -839,32 +833,32 @@ namespace {
 
   std::string Tracing::do_trace(const Position& pos) {
 
-    std::memset(terms, 0, sizeof(terms));
+    std::memset(scores, 0, sizeof(scores));
 
     Value v = do_evaluate<true>(pos);
     v = pos.side_to_move() == WHITE ? v : -v; // White's point of view
 
     std::stringstream ss;
     ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
-       << "           Eval term |    White    |    Black    |    Total    \n"
-       << "                     |   MG    EG  |   MG    EG  |   MG    EG  \n"
-       << "---------------------+-------------+-------------+-------------\n";
+       << "      Eval term |    White    |    Black    |    Total    \n"
+       << "                |   MG    EG  |   MG    EG  |   MG    EG  \n"
+       << "----------------+-------------+-------------+-------------\n";
 
-    format_row(ss, "Material, PST, Tempo", PST);
-    format_row(ss, "Material imbalance", IMBALANCE);
-    format_row(ss, "Pawns", PAWN);
-    format_row(ss, "Knights", KNIGHT);
-    format_row(ss, "Bishops", BISHOP);
-    format_row(ss, "Rooks", ROOK);
-    format_row(ss, "Queens", QUEEN);
-    format_row(ss, "Mobility", MOBILITY);
-    format_row(ss, "King safety", KING);
-    format_row(ss, "Threats", THREAT);
-    format_row(ss, "Passed pawns", PASSED);
-    format_row(ss, "Space", SPACE);
+    print(ss, "Material", MATERIAL);
+    print(ss, "Imbalance", IMBALANCE);
+    print(ss, "Pawns", PAWN);
+    print(ss, "Knights", KNIGHT);
+    print(ss, "Bishops", BISHOP);
+    print(ss, "Rooks", ROOK);
+    print(ss, "Queens", QUEEN);
+    print(ss, "Mobility", MOBILITY);
+    print(ss, "King safety", KING);
+    print(ss, "Threats", THREAT);
+    print(ss, "Passed pawns", PASSED);
+    print(ss, "Space", SPACE);
 
-    ss << "---------------------+-------------+-------------+-------------\n";
-    format_row(ss, "Total", TOTAL);
+    ss << "----------------+-------------+-------------+-------------\n";
+    print(ss, "Total", TOTAL);
 
     ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n";
 
@@ -893,27 +887,18 @@ namespace Eval {
   }
 
 
-  /// init() computes evaluation weights from the corresponding UCI parameters
-  /// and setup king tables.
+  /// init() computes evaluation weights, usually at startup
 
   void init() {
 
-    Weights[Mobility]       = weight_option("Mobility (Midgame)", "Mobility (Endgame)", WeightsInternal[Mobility]);
-    Weights[PawnStructure]  = weight_option("Pawn Structure (Midgame)", "Pawn Structure (Endgame)", WeightsInternal[PawnStructure]);
-    Weights[PassedPawns]    = weight_option("Passed Pawns (Midgame)", "Passed Pawns (Endgame)", WeightsInternal[PassedPawns]);
-    Weights[Space]          = weight_option("Space", "Space", WeightsInternal[Space]);
-    Weights[KingDangerUs]   = weight_option("Cowardice", "Cowardice", WeightsInternal[KingDangerUs]);
-    Weights[KingDangerThem] = weight_option("Aggressiveness", "Aggressiveness", WeightsInternal[KingDangerThem]);
-
-    const double MaxSlope = 30;
+    const double MaxSlope = 7.5;
     const double Peak = 1280;
+    double t = 0.0;
 
-    for (int t = 0, i = 1; i < 100; ++i)
+    for (int i = 1; i < 400; ++i)
     {
-        t = int(std::min(Peak, std::min(0.4 * i * i, t + MaxSlope)));
-
-        KingDanger[1][i] = apply_weight(make_score(t, 0), Weights[KingDangerUs]);
-        KingDanger[0][i] = apply_weight(make_score(t, 0), Weights[KingDangerThem]);
+        t = std::min(Peak, std::min(0.025 * i * i, t + MaxSlope));
+        KingDanger[i] = apply_weight(make_score(int(t), 0), Weights[KingSafety]);
     }
   }
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -20,15 +20,19 @@
 #ifndef EVALUATE_H_INCLUDED
 #define EVALUATE_H_INCLUDED
 
+#include <string>
+
 #include "types.h"
 
 class Position;
 
 namespace Eval {
 
-extern void init();
-extern Value evaluate(const Position& pos);
-extern std::string trace(const Position& pos);
+const Value Tempo = Value(17); // Must be visible to search
+
+void init();
+Value evaluate(const Position& pos);
+std::string trace(const Position& pos);
 
 }
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -25,7 +25,8 @@
 #include "search.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
+#include "syzygy/tbprobe.h"
 
 int main(int argc, char* argv[]) {
 
@@ -34,11 +35,12 @@ int main(int argc, char* argv[]) {
   UCI::init(Options);
   Bitboards::init();
   Position::init();
-  Bitbases::init_kpk();
+  Bitbases::init();
   Search::init();
-  Pawns::init();
   Eval::init();
+  Pawns::init();
   Threads.init();
+  Tablebases::init(Options["SyzygyPath"]);
   TT.resize(Options["Hash"]);
 
   UCI::loop(argc, argv);

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -17,33 +17,34 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <algorithm>  // For std::min
+#include <algorithm> // For std::min
 #include <cassert>
-#include <cstring>
+#include <cstring>   // For std::memset
 
 #include "material.h"
+#include "thread.h"
 
 using namespace std;
 
 namespace {
 
-  // Polynomial material balance parameters
+  // Polynomial material imbalance parameters
 
-  //                                  pair  pawn knight bishop rook queen
-  const int LinearCoefficients[6] = { 1852, -162, -1122, -183,  249, -154 };
+  //                      pair  pawn knight bishop rook queen
+  const int Linear[6] = { 1852, -162, -1122, -183,  249, -154 };
 
-  const int QuadraticCoefficientsSameSide[][PIECE_TYPE_NB] = {
+  const int QuadraticOurs[][PIECE_TYPE_NB] = {
     //            OUR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
     {  39,    2                         }, // Pawn
-    {  35,  271,  -4                    }, // knight      OUR PIECES
+    {  35,  271,  -4                    }, // Knight      OUR PIECES
     {   0,  105,   4,    0              }, // Bishop
     { -27,   -2,  46,   100,  -141      }, // Rook
     {-177,   25, 129,   142,  -137,   0 }  // Queen
   };
 
-  const int QuadraticCoefficientsOppositeSide[][PIECE_TYPE_NB] = {
+  const int QuadraticTheirs[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
@@ -56,7 +57,7 @@ namespace {
 
   // Endgame evaluation and scaling functions are accessed directly and not through
   // the function maps because they correspond to more than one material hash key.
-  Endgame<KXK>   EvaluateKXK[]   = { Endgame<KXK>(WHITE),   Endgame<KXK>(BLACK) };
+  Endgame<KXK>    EvaluateKXK[] = { Endgame<KXK>(WHITE),    Endgame<KXK>(BLACK) };
 
   Endgame<KBPsK>  ScaleKBPsK[]  = { Endgame<KBPsK>(WHITE),  Endgame<KBPsK>(BLACK) };
   Endgame<KQKRPs> ScaleKQKRPs[] = { Endgame<KQKRPs>(WHITE), Endgame<KQKRPs>(BLACK) };
@@ -66,8 +67,7 @@ namespace {
   // Helper templates used to detect a given material distribution
   template<Color Us> bool is_KXK(const Position& pos) {
     const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return  !pos.count<PAWN>(Them)
-          && pos.non_pawn_material(Them) == VALUE_ZERO
+    return  !more_than_one(pos.pieces(Them))
           && pos.non_pawn_material(Us) >= RookValueMg;
   }
 
@@ -94,57 +94,52 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    int pt1, pt2, pc, v;
-    int value = 0;
+    int bonus = 0;
 
     // Second-degree polynomial material imbalance by Tord Romstad
-    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
+    for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
     {
-        pc = pieceCount[Us][pt1];
-        if (!pc)
+        if (!pieceCount[Us][pt1])
             continue;
 
-        v = LinearCoefficients[pt1];
+        int v = Linear[pt1];
 
-        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
-            v +=  QuadraticCoefficientsSameSide[pt1][pt2] * pieceCount[Us][pt2]
-                + QuadraticCoefficientsOppositeSide[pt1][pt2] * pieceCount[Them][pt2];
+        for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
+            v +=  QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
+                + QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
 
-        value += pc * v;
+        bonus += pieceCount[Us][pt1] * v;
     }
 
-    return value;
+    return bonus;
   }
 
 } // namespace
 
 namespace Material {
 
-/// 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.
+/// Material::probe() looks up the current position's material configuration in
+/// the material hash table. It returns a pointer to the Entry if the position
+/// is found. Otherwise a new Entry is computed and stored there, so we don't
+/// have to recompute all when the same material configuration occurs again.
 
-Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
+Entry* probe(const Position& pos) {
 
   Key key = pos.material_key();
-  Entry* e = entries[key];
+  Entry* e = pos.this_thread()->materialTable[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
-  // return the information we found the last time instead of recomputing it.
   if (e->key == key)
       return e;
 
   std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = game_phase(pos);
+  e->gamePhase = pos.game_phase();
 
   // Let's look if we have a specialized evaluation function for this particular
   // material configuration. Firstly we look for a fixed configuration one, then
   // for a generic one if the previous search failed.
-  if (endgames.probe(key, e->evaluationFunction))
+  if (pos.this_thread()->endgames.probe(key, e->evaluationFunction))
       return e;
 
   if (is_KXK<WHITE>(pos))
@@ -159,22 +154,19 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
       return e;
   }
 
-  // OK, we didn't find any special evaluation function for the current
-  // material configuration. Is there a suitable scaling function?
-  //
-  // We face problems when there are several conflicting applicable
-  // scaling functions and we need to decide which one to use.
+  // OK, we didn't find any special evaluation function for the current material
+  // configuration. Is there a suitable specialized scaling function?
   EndgameBase<ScaleFactor>* sf;
 
-  if (endgames.probe(key, sf))
+  if (pos.this_thread()->endgames.probe(key, sf))
   {
-      e->scalingFunction[sf->color()] = sf;
+      e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned
       return e;
   }
 
-  // Generic scaling functions that refer to more than one material
-  // distribution. They should be probed after the specialized ones.
-  // Note that these ones don't return after setting the function.
+  // We didn't find any specialized scaling function, so fall back on generic
+  // ones that refer to more than one material distribution. Note that in this
+  // case we don't return after setting the function.
   if (is_KBPsKs<WHITE>(pos))
       e->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
 
@@ -190,16 +182,18 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
   Value npm_w = pos.non_pawn_material(WHITE);
   Value npm_b = pos.non_pawn_material(BLACK);
 
-  if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN))
+  if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
   {
       if (!pos.count<PAWN>(BLACK))
       {
           assert(pos.count<PAWN>(WHITE) >= 2);
+
           e->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
       }
       else if (!pos.count<PAWN>(WHITE))
       {
           assert(pos.count<PAWN>(BLACK) >= 2);
+
           e->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
       }
       else if (pos.count<PAWN>(WHITE) == 1 && pos.count<PAWN>(BLACK) == 1)
@@ -211,14 +205,16 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
       }
   }
 
-  // No pawns makes it difficult to win, even with a material advantage. This
-  // catches some trivial draws like KK, KBK and KNK and gives a very drawish
-  // scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
+  // Zero or just one pawn makes it difficult to win, even with a small material
+  // advantage. This catches some trivial draws like KK, KBK and KNK and gives a
+  // drawish scale factor for cases such as KRKBP and KmmKm (except for KBBKN).
   if (!pos.count<PAWN>(WHITE) && npm_w - npm_b <= BishopValueMg)
-      e->factor[WHITE] = uint8_t(npm_w < RookValueMg ? SCALE_FACTOR_DRAW : npm_b <= BishopValueMg ? 4 : 12);
+      e->factor[WHITE] = uint8_t(npm_w <  RookValueMg   ? SCALE_FACTOR_DRAW :
+                                 npm_b <= BishopValueMg ? 4 : 12);
 
   if (!pos.count<PAWN>(BLACK) && npm_b - npm_w <= BishopValueMg)
-      e->factor[BLACK] = uint8_t(npm_b < RookValueMg ? SCALE_FACTOR_DRAW : npm_w <= BishopValueMg ? 4 : 12);
+      e->factor[BLACK] = uint8_t(npm_b <  RookValueMg   ? SCALE_FACTOR_DRAW :
+                                 npm_w <= BishopValueMg ? 4 : 12);
 
   if (pos.count<PAWN>(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
       e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;
@@ -226,40 +222,17 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
   if (pos.count<PAWN>(BLACK) == 1 && npm_b - npm_w <= BishopValueMg)
       e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN;
 
-  // Compute the space weight
-  if (npm_w + npm_b >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg)
-  {
-      int minorPieceCount =  pos.count<KNIGHT>(WHITE) + pos.count<BISHOP>(WHITE)
-                           + pos.count<KNIGHT>(BLACK) + pos.count<BISHOP>(BLACK);
-
-      e->spaceWeight = make_score(minorPieceCount * minorPieceCount, 0);
-  }
-
   // Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
   // for the bishop pair "extended piece", which allows us to be more flexible
   // in defining bishop pair bonuses.
-  const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
+  const int PieceCount[COLOR_NB][PIECE_TYPE_NB] = {
   { pos.count<BISHOP>(WHITE) > 1, pos.count<PAWN>(WHITE), pos.count<KNIGHT>(WHITE),
     pos.count<BISHOP>(WHITE)    , pos.count<ROOK>(WHITE), pos.count<QUEEN >(WHITE) },
   { pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
     pos.count<BISHOP>(BLACK)    , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
 
-  e->value = (int16_t)((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
+  e->value = int16_t((imbalance<WHITE>(PieceCount) - imbalance<BLACK>(PieceCount)) / 16);
   return e;
 }
 
-
-/// 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 game_phase(const Position& pos) {
-
-  Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
-
-  return  npm >= MidgameLimit ? PHASE_MIDGAME
-        : 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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -28,47 +28,44 @@
 namespace Material {
 
 /// Material::Entry contains various information about a material configuration.
-/// It contains a material balance evaluation, a function pointer to a special
+/// It contains a material imbalance 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".
+/// 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.
+/// 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.
 
 struct Entry {
 
-  Score material_value() const { return make_score(value, value); }
-  Score space_weight() const { return spaceWeight; }
+  Score imbalance() const { return make_score(value, value); }
   Phase game_phase() const { return gamePhase; }
   bool specialized_eval_exists() const { return evaluationFunction != NULL; }
   Value evaluate(const Position& pos) const { return (*evaluationFunction)(pos); }
 
-  // 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 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 for draws with rook pawns and wrong-colored bishops.
-
+  // 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 may also be a function which should be applied to
+  // the position. For instance, in KBP vs K endgames, the scaling function looks
+  // for rook pawns and wrong-colored bishops.
   ScaleFactor scale_factor(const Position& pos, Color c) const {
-
-    return !scalingFunction[c] || (*scalingFunction[c])(pos) == SCALE_FACTOR_NONE
-          ? ScaleFactor(factor[c]) : (*scalingFunction[c])(pos);
+    return   !scalingFunction[c]
+          || (*scalingFunction[c])(pos) == SCALE_FACTOR_NONE ? ScaleFactor(factor[c])
+                                                             : (*scalingFunction[c])(pos);
   }
 
   Key key;
   int16_t value;
   uint8_t factor[COLOR_NB];
   EndgameBase<Value>* evaluationFunction;
-  EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB];
-  Score spaceWeight;
+  EndgameBase<ScaleFactor>* scalingFunction[COLOR_NB]; // Could be one for each
+                                                       // side (e.g. KPKP, KBPsKs)
   Phase gamePhase;
 };
 
 typedef HashTable<Entry, 8192> Table;
 
-Entry* probe(const Position& pos, Table& entries, Endgames& endgames);
-Phase game_phase(const Position& pos);
+Entry* probe(const Position& pos);
 
 } // namespace Material
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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 <fstream>
 #include <iomanip>
 #include <iostream>
 #include <sstream>
@@ -26,58 +27,14 @@
 
 using namespace std;
 
+namespace {
+
 /// Version number. If Version is left empty, then compile date in the format
 /// DD-MM-YY and show in engine_info.
-static const string Version = "5";
-
-
-/// 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) {
-
-  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
-  string month, day, year;
-  stringstream ss, date(__DATE__); // From compiler, format is "Sep 21 2008"
-
-  ss << "Stockfish " << Version << setfill('0');
-
-  if (Version.empty())
-  {
-      date >> month >> day >> year;
-      ss << setw(2) << day << setw(2) << (1 + months.find(month) / 4) << year.substr(2);
-  }
-
-  ss << (Is64Bit ? " 64" : "")
-     << (HasPext ? " BMI2" : (HasPopCnt ? " SSE4.2" : ""))
-     << (to_uci  ? "\nid author ": " by ")
-     << "Tord Romstad, Marco Costalba and Joona Kiiski";
-
-  return ss.str();
-}
-
-
-/// Debug functions used mainly to collect run-time statistics
-
-static int64_t hits[2], means[2];
-
-void dbg_hit_on(bool b) { ++hits[0]; if (b) ++hits[1]; }
-void dbg_hit_on_c(bool c, bool b) { if (c) dbg_hit_on(b); }
-void dbg_mean_of(int v) { ++means[0]; means[1] += v; }
-
-void dbg_print() {
-
-  if (hits[0])
-      cerr << "Total " << hits[0] << " Hits " << hits[1]
-           << " hit rate (%) " << 100 * hits[1] / hits[0] << endl;
-
-  if (means[0])
-      cerr << "Total " << means[0] << " Mean "
-           << (double)means[1] / means[0] << endl;
-}
+const string Version = "6";
 
+/// Debug counters
+int64_t hits[2], means[2];
 
 /// Our fancy logging facility. The trick here is to replace cin.rdbuf() and
 /// cout.rdbuf() with two Tie objects that tie cin and cout to a file stream. We
@@ -136,6 +93,53 @@ public:
   }
 };
 
+} // namespace
+
+/// 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) {
+
+  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
+  string month, day, year;
+  stringstream ss, date(__DATE__); // From compiler, format is "Sep 21 2008"
+
+  ss << "Stockfish " << Version << setfill('0');
+
+  if (Version.empty())
+  {
+      date >> month >> day >> year;
+      ss << setw(2) << day << setw(2) << (1 + months.find(month) / 4) << year.substr(2);
+  }
+
+  ss << (Is64Bit ? " 64" : "")
+     << (HasPext ? " BMI2" : (HasPopCnt ? " POPCNT" : ""))
+     << (to_uci  ? "\nid author ": " by ")
+     << "Tord Romstad, Marco Costalba and Joona Kiiski";
+
+  return ss.str();
+}
+
+
+/// Debug functions used mainly to collect run-time statistics
+
+void dbg_hit_on(bool b) { ++hits[0]; if (b) ++hits[1]; }
+void dbg_hit_on_c(bool c, bool b) { if (c) dbg_hit_on(b); }
+void dbg_mean_of(int v) { ++means[0]; means[1] += v; }
+
+void dbg_print() {
+
+  if (hits[0])
+      cerr << "Total " << hits[0] << " Hits " << hits[1]
+           << " hit rate (%) " << 100 * hits[1] / hits[0] << endl;
+
+  if (means[0])
+      cerr << "Total " << means[0] << " Mean "
+           << (double)means[1] / means[0] << endl;
+}
+
 
 /// Used to serialize access to std::cout to avoid multiple threads writing at
 /// the same time.

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -20,27 +20,22 @@
 #ifndef MISC_H_INCLUDED
 #define MISC_H_INCLUDED
 
-#include <fstream>
+#include <cassert>
+#include <ostream>
 #include <string>
 #include <vector>
 
 #include "types.h"
 
-extern const std::string engine_info(bool to_uci = false);
-extern void timed_wait(WaitCondition&, Lock&, int);
-extern void prefetch(char* addr);
-extern void start_logger(bool b);
+const std::string engine_info(bool to_uci = false);
+void timed_wait(WaitCondition&, Lock&, int);
+void prefetch(char* addr);
+void start_logger(bool b);
 
-extern void dbg_hit_on(bool b);
-extern void dbg_hit_on_c(bool c, bool b);
-extern void dbg_mean_of(int v);
-extern void dbg_print();
-
-
-struct Log : public std::ofstream {
-  Log(const std::string& f = "log.txt") : std::ofstream(f.c_str(), std::ios::out | std::ios::app) {}
- ~Log() { if (is_open()) close(); }
-};
+void dbg_hit_on(bool b);
+void dbg_hit_on_c(bool c, bool b);
+void dbg_mean_of(int v);
+void dbg_print();
 
 
 namespace Time {
@@ -52,7 +47,7 @@ namespace Time {
 template<class Entry, int Size>
 struct HashTable {
   HashTable() : table(Size, Entry()) {}
-  Entry* operator[](Key k) { return &table[(uint32_t)k & (Size - 1)]; }
+  Entry* operator[](Key key) { return &table[(uint32_t)key & (Size - 1)]; }
 
 private:
   std::vector<Entry> table;
@@ -65,4 +60,41 @@ std::ostream& operator<<(std::ostream&, SyncCout);
 #define sync_cout std::cout << IO_LOCK
 #define sync_endl std::endl << IO_UNLOCK
 
+
+/// xorshift64star Pseudo-Random Number Generator
+/// This class is based on original code written and dedicated
+/// to the public domain by Sebastiano Vigna (2014).
+/// It has the following characteristics:
+///
+///  -  Outputs 64-bit numbers
+///  -  Passes Dieharder and SmallCrush test batteries
+///  -  Does not require warm-up, no zeroland to escape
+///  -  Internal state is a single 64-bit integer
+///  -  Period is 2^64 - 1
+///  -  Speed: 1.60 ns/call (Core i7 @3.40GHz)
+///
+/// For further analysis see
+///   <http://vigna.di.unimi.it/ftp/papers/xorshift.pdf>
+
+class PRNG {
+
+  uint64_t s;
+
+  uint64_t rand64() {
+
+    s ^= s >> 12, s ^= s << 25, s ^= s >> 27;
+    return s * 2685821657736338717LL;
+  }
+
+public:
+  PRNG(uint64_t seed) : s(seed) { assert(seed); }
+
+  template<typename T> T rand() { return T(rand64()); }
+
+  /// Special generator used to fast init magic numbers.
+  /// Output values only have 1/8th of their bits set on average.
+  template<typename T> T sparse_rand()
+  { return T(rand64() & rand64() & rand64()); }
+};
+
 #endif // #ifndef MISC_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -25,12 +25,12 @@
 namespace {
 
   template<CastlingRight Cr, bool Checks, bool Chess960>
-  ExtMove* generate_castling(const Position& pos, ExtMove* mlist, Color us, const CheckInfo* ci) {
+  ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us, const CheckInfo* ci) {
 
     static const bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO);
 
     if (pos.castling_impeded(Cr) || !pos.can_castle(Cr))
-        return mlist;
+        return moveList;
 
     // After castling, the rook and king final positions are the same in Chess960
     // as they would be in standard chess.
@@ -46,59 +46,51 @@ namespace {
 
     for (Square s = kto; s != kfrom; s += K)
         if (pos.attackers_to(s) & enemies)
-            return mlist;
+            return moveList;
 
     // Because we generate only legal castling moves we need to verify that
     // when moving the castling rook we do not discover some hidden checker.
     // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
     if (Chess960 && (attacks_bb<ROOK>(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN)))
-        return mlist;
+        return moveList;
 
     Move m = make<CASTLING>(kfrom, rfrom);
 
     if (Checks && !pos.gives_check(m, *ci))
-        return mlist;
+        return moveList;
 
-    (mlist++)->move = m;
+    (moveList++)->move = m;
 
-    return mlist;
+    return moveList;
   }
 
 
   template<GenType Type, Square Delta>
-  inline ExtMove* generate_promotions(ExtMove* mlist, Bitboard pawnsOn7,
-                                      Bitboard target, const CheckInfo* ci) {
+  inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) {
 
-    Bitboard b = shift_bb<Delta>(pawnsOn7) & target;
+    if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
 
-    while (b)
+    if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        Square to = pop_lsb(&b);
-
-        if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
-            (mlist++)->move = make<PROMOTION>(to - Delta, to, QUEEN);
-
-        if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS)
-        {
-            (mlist++)->move = make<PROMOTION>(to - Delta, to, ROOK);
-            (mlist++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
-            (mlist++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
-        }
-
-        // Knight promotion is the only promotion that can give a direct check
-        // that's not already included in the queen promotion.
-        if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
-            (mlist++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
-        else
-            (void)ci; // Silence a warning under MSVC
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, ROOK);
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, BISHOP);
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
     }
 
-    return mlist;
+    // Knight promotion is the only promotion that can give a direct check
+    // that's not already included in the queen promotion.
+    if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq))
+        (moveList++)->move = make<PROMOTION>(to - Delta, to, KNIGHT);
+    else
+        (void)ci; // Silence a warning under MSVC
+
+    return moveList;
   }
 
 
   template<Color Us, GenType Type>
-  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* mlist,
+  ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList,
                                Bitboard target, const CheckInfo* ci) {
 
     // Compute our parametrized parameters at compile time, named according to
@@ -111,7 +103,7 @@ namespace {
     const Square   Right    = (Us == WHITE ? DELTA_NE : DELTA_SW);
     const Square   Left     = (Us == WHITE ? DELTA_NW : DELTA_SE);
 
-    Bitboard b1, b2, dc1, dc2, emptySquares;
+    Bitboard emptySquares;
 
     Bitboard pawnsOn7    = pos.pieces(Us, PAWN) &  TRank7BB;
     Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB;
@@ -124,8 +116,8 @@ namespace {
     {
         emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces());
 
-        b1 = shift_bb<Up>(pawnsNotOn7)   & emptySquares;
-        b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
+        Bitboard b1 = shift_bb<Up>(pawnsNotOn7)   & emptySquares;
+        Bitboard b2 = shift_bb<Up>(b1 & TRank3BB) & emptySquares;
 
         if (Type == EVASIONS) // Consider only blocking squares
         {
@@ -144,8 +136,8 @@ namespace {
             // promotion has been already generated amongst the captures.
             if (pawnsNotOn7 & ci->dcCandidates)
             {
-                dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
-                dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
+                Bitboard dc1 = shift_bb<Up>(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq);
+                Bitboard dc2 = shift_bb<Up>(dc1 & TRank3BB) & emptySquares;
 
                 b1 |= dc1;
                 b2 |= dc2;
@@ -155,13 +147,13 @@ namespace {
         while (b1)
         {
             Square to = pop_lsb(&b1);
-            (mlist++)->move = make_move(to - Up, to);
+            (moveList++)->move = make_move(to - Up, to);
         }
 
         while (b2)
         {
             Square to = pop_lsb(&b2);
-            (mlist++)->move = make_move(to - Up - Up, to);
+            (moveList++)->move = make_move(to - Up - Up, to);
         }
     }
 
@@ -174,27 +166,36 @@ namespace {
         if (Type == EVASIONS)
             emptySquares &= target;
 
-        mlist = generate_promotions<Type, Right>(mlist, pawnsOn7, enemies, ci);
-        mlist = generate_promotions<Type, Left >(mlist, pawnsOn7, enemies, ci);
-        mlist = generate_promotions<Type, Up>(mlist, pawnsOn7, emptySquares, ci);
+        Bitboard b1 = shift_bb<Right>(pawnsOn7) & enemies;
+        Bitboard b2 = shift_bb<Left >(pawnsOn7) & enemies;
+        Bitboard b3 = shift_bb<Up   >(pawnsOn7) & emptySquares;
+
+        while (b1)
+            moveList = make_promotions<Type, Right>(moveList, pop_lsb(&b1), ci);
+
+        while (b2)
+            moveList = make_promotions<Type, Left >(moveList, pop_lsb(&b2), ci);
+
+        while (b3)
+            moveList = make_promotions<Type, Up   >(moveList, pop_lsb(&b3), ci);
     }
 
     // Standard and en-passant captures
     if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS)
     {
-        b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
-        b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
+        Bitboard b1 = shift_bb<Right>(pawnsNotOn7) & enemies;
+        Bitboard b2 = shift_bb<Left >(pawnsNotOn7) & enemies;
 
         while (b1)
         {
             Square to = pop_lsb(&b1);
-            (mlist++)->move = make_move(to - Right, to);
+            (moveList++)->move = make_move(to - Right, to);
         }
 
         while (b2)
         {
             Square to = pop_lsb(&b2);
-            (mlist++)->move = make_move(to - Left, to);
+            (moveList++)->move = make_move(to - Left, to);
         }
 
         if (pos.ep_square() != SQ_NONE)
@@ -205,23 +206,23 @@ namespace {
             // is the double pushed pawn and so is in the target. Otherwise this
             // is a discovery check and we are forced to do otherwise.
             if (Type == EVASIONS && !(target & (pos.ep_square() - Up)))
-                return mlist;
+                return moveList;
 
             b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
 
             assert(b1);
 
             while (b1)
-                (mlist++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
+                (moveList++)->move = make<ENPASSANT>(pop_lsb(&b1), pos.ep_square());
         }
     }
 
-    return mlist;
+    return moveList;
   }
 
 
   template<PieceType Pt, bool Checks> FORCE_INLINE
-  ExtMove* generate_moves(const Position& pos, ExtMove* mlist, Color us,
+  ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us,
                           Bitboard target, const CheckInfo* ci) {
 
     assert(Pt != KING && Pt != PAWN);
@@ -236,7 +237,7 @@ namespace {
                 && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
                 continue;
 
-            if (unlikely(ci->dcCandidates) && (ci->dcCandidates & from))
+            if (ci->dcCandidates && (ci->dcCandidates & from))
                 continue;
         }
 
@@ -246,51 +247,50 @@ namespace {
             b &= ci->checkSq[Pt];
 
         while (b)
-            (mlist++)->move = make_move(from, pop_lsb(&b));
+            (moveList++)->move = make_move(from, pop_lsb(&b));
     }
 
-    return mlist;
+    return moveList;
   }
 
 
   template<Color Us, GenType Type> FORCE_INLINE
-  ExtMove* generate_all(const Position& pos, ExtMove* mlist, Bitboard target,
+  ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target,
                         const CheckInfo* ci = NULL) {
 
     const bool Checks = Type == QUIET_CHECKS;
 
-    mlist = generate_pawn_moves<Us, Type>(pos, mlist, 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);
+    moveList = generate_pawn_moves<Us, Type>(pos, moveList, target, ci);
+    moveList = generate_moves<KNIGHT, Checks>(pos, moveList, Us, target, ci);
+    moveList = generate_moves<BISHOP, Checks>(pos, moveList, Us, target, ci);
+    moveList = generate_moves<  ROOK, Checks>(pos, moveList, Us, target, ci);
+    moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target, ci);
 
     if (Type != QUIET_CHECKS && Type != EVASIONS)
     {
         Square ksq = pos.king_square(Us);
         Bitboard b = pos.attacks_from<KING>(ksq) & target;
         while (b)
-            (mlist++)->move = make_move(ksq, pop_lsb(&b));
+            (moveList++)->move = make_move(ksq, pop_lsb(&b));
     }
 
     if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
     {
         if (pos.is_chess960())
         {
-            mlist = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, true>(pos, mlist, Us, ci);
-            mlist = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, true>(pos, mlist, Us, ci);
+            moveList = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
+            moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, true>(pos, moveList, Us, ci);
         }
         else
         {
-            mlist = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, false>(pos, mlist, Us, ci);
-            mlist = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, false>(pos, mlist, Us, ci);
+            moveList = generate_castling<MakeCastling<Us,  KING_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
+            moveList = generate_castling<MakeCastling<Us, QUEEN_SIDE>::right, Checks, false>(pos, moveList, Us, ci);
         }
     }
 
-    return mlist;
+    return moveList;
   }
 
-
 } // namespace
 
 
@@ -304,19 +304,19 @@ namespace {
 /// non-captures. Returns a pointer to the end of the move list.
 
 template<GenType Type>
-ExtMove* generate(const Position& pos, ExtMove* mlist) {
+ExtMove* generate(const Position& pos, ExtMove* moveList) {
 
   assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS);
   assert(!pos.checkers());
 
   Color us = pos.side_to_move();
 
-  Bitboard target = Type == CAPTURES     ?  pos.pieces(~us)
-                  : Type == QUIETS       ? ~pos.pieces()
-                  : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
+  Bitboard target =  Type == CAPTURES     ?  pos.pieces(~us)
+                   : Type == QUIETS       ? ~pos.pieces()
+                   : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
 
-  return us == WHITE ? generate_all<WHITE, Type>(pos, mlist, target)
-                     : generate_all<BLACK, Type>(pos, mlist, target);
+  return us == WHITE ? generate_all<WHITE, Type>(pos, moveList, target)
+                     : generate_all<BLACK, Type>(pos, moveList, target);
 }
 
 // Explicit template instantiations
@@ -328,7 +328,7 @@ template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
 /// generate<QUIET_CHECKS> generates all pseudo-legal non-captures and knight
 /// underpromotions that give check. Returns a pointer to the end of the move list.
 template<>
-ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* mlist) {
+ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
 
   assert(!pos.checkers());
 
@@ -350,18 +350,18 @@ ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* mlist) {
          b &= ~PseudoAttacks[QUEEN][ci.ksq];
 
      while (b)
-         (mlist++)->move = make_move(from, pop_lsb(&b));
+         (moveList++)->move = make_move(from, pop_lsb(&b));
   }
 
-  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci)
-                     : generate_all<BLACK, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci);
+  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci)
+                     : generate_all<BLACK, QUIET_CHECKS>(pos, moveList, ~pos.pieces(), &ci);
 }
 
 
 /// generate<EVASIONS> generates all pseudo-legal check evasions when the side
 /// to move is in check. Returns a pointer to the end of the move list.
 template<>
-ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* mlist) {
+ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
 
   assert(pos.checkers());
 
@@ -382,37 +382,37 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* mlist) {
   // Generate evasions for king, capture and non capture moves
   Bitboard b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
   while (b)
-      (mlist++)->move = make_move(ksq, pop_lsb(&b));
+      (moveList++)->move = make_move(ksq, pop_lsb(&b));
 
   if (more_than_one(pos.checkers()))
-      return mlist; // Double check, only a king move can save the day
+      return moveList; // Double check, only a king move can save the day
 
   // Generate blocking evasions or captures of the checking piece
   Square checksq = lsb(pos.checkers());
   Bitboard target = between_bb(checksq, ksq) | checksq;
 
-  return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, mlist, target)
-                     : generate_all<BLACK, EVASIONS>(pos, mlist, target);
+  return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList, target)
+                     : generate_all<BLACK, EVASIONS>(pos, moveList, target);
 }
 
 
 /// generate<LEGAL> generates all the legal moves in the given position
 
 template<>
-ExtMove* generate<LEGAL>(const Position& pos, ExtMove* mlist) {
+ExtMove* generate<LEGAL>(const Position& pos, ExtMove* moveList) {
 
-  ExtMove *end, *cur = mlist;
   Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
   Square ksq = pos.king_square(pos.side_to_move());
+  ExtMove* cur = moveList;
 
-  end = pos.checkers() ? generate<EVASIONS>(pos, mlist)
-                       : generate<NON_EVASIONS>(pos, mlist);
-  while (cur != end)
+  moveList = pos.checkers() ? generate<EVASIONS    >(pos, moveList)
+                            : generate<NON_EVASIONS>(pos, moveList);
+  while (cur != moveList)
       if (   (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
           && !pos.legal(cur->move, pinned))
-          cur->move = (--end)->move;
+          cur->move = (--moveList)->move;
       else
           ++cur;
 
-  return end;
+  return moveList;
 }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -22,6 +22,8 @@
 
 #include "types.h"
 
+class Position;
+
 enum GenType {
   CAPTURES,
   QUIETS,
@@ -31,27 +33,34 @@ enum GenType {
   LEGAL
 };
 
-class Position;
+struct ExtMove {
+  Move move;
+  Value value;
+};
+
+inline bool operator<(const ExtMove& f, const ExtMove& s) {
+  return f.value < s.value;
+}
 
 template<GenType>
-ExtMove* generate(const Position& pos, ExtMove* mlist);
+ExtMove* generate(const Position& pos, ExtMove* moveList);
 
 /// The MoveList struct is a simple wrapper around generate(). It sometimes comes
 /// in handy to use this class instead of the low level generate() function.
 template<GenType T>
 struct MoveList {
 
-  explicit MoveList(const Position& pos) : cur(mlist), last(generate<T>(pos, mlist)) { last->move = MOVE_NONE; }
+  explicit MoveList(const Position& pos) : cur(moveList), last(generate<T>(pos, moveList)) { last->move = MOVE_NONE; }
   void operator++() { ++cur; }
   Move operator*() const { return cur->move; }
-  size_t size() const { return last - mlist; }
+  size_t size() const { return last - moveList; }
   bool contains(Move m) const {
-    for (const ExtMove* it(mlist); it != last; ++it) if (it->move == m) return true;
+    for (const ExtMove* it(moveList); it != last; ++it) if (it->move == m) return true;
     return false;
   }
 
 private:
-  ExtMove mlist[MAX_MOVES];
+  ExtMove moveList[MAX_MOVES];
   ExtMove *cur, *last;
 };
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -51,7 +51,7 @@ namespace {
 
   // Unary predicate used by std::partition to split positive values from remaining
   // ones so as to sort the two sets separately, with the second sort delayed.
-  inline bool has_positive_value(const ExtMove& ms) { return ms.value > 0; }
+  inline bool has_positive_value(const ExtMove& move) { return move.value > VALUE_ZERO; }
 
   // Picks the best move in the range (begin, end) and moves it to the front.
   // It's faster than sorting all the moves in advance when there are few
@@ -61,7 +61,7 @@ namespace {
       std::swap(*begin, *std::max_element(begin, end));
       return begin;
   }
-}
+} // namespace
 
 
 /// Constructors of the MovePicker class. As arguments we pass information
@@ -103,15 +103,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats&
       stage = QSEARCH_0;
 
   else if (d > DEPTH_QS_RECAPTURES)
-  {
       stage = QSEARCH_1;
 
-      // Skip TT move if is not a capture or a promotion. This avoids qsearch
-      // tree explosion due to a possible perpetual check or similar rare cases
-      // when TT table is full.
-      if (ttm && !pos.capture_or_promotion(ttm))
-          ttm = MOVE_NONE;
-  }
   else
   {
       stage = RECAPTURE;

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -40,7 +40,7 @@
 template<bool Gain, typename T>
 struct Stats {
 
-  static const Value Max = Value(2000);
+  static const Value Max = Value(250);
 
   const T* operator[](Piece pc) const { return table[pc]; }
   void clear() { std::memset(table, 0, sizeof(table)); }

src/notation.cpp

@@ -1,256 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 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/>.
-*/
-
-#include <cassert>
-#include <iomanip>
-#include <sstream>
-#include <stack>
-
-#include "movegen.h"
-#include "notation.h"
-#include "position.h"
-
-using namespace std;
-
-static const char* PieceToChar[COLOR_NB] = { " PNBRQK", " pnbrqk" };
-
-
-/// score_to_uci() converts a value to a string suitable for use with the UCI
-/// protocol specifications:
-///
-/// cp <x>     The score from the engine's point of view in centipawns.
-/// mate <y>   Mate in y moves, not plies. If the engine is getting mated
-///            use negative values for y.
-
-string score_to_uci(Value v, Value alpha, Value beta) {
-
-  stringstream ss;
-
-  if (abs(v) < VALUE_MATE_IN_MAX_PLY)
-      ss << "cp " << v * 100 / PawnValueEg;
-  else
-      ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
-
-  ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
-
-  return ss.str();
-}
-
-
-/// move_to_uci() converts a move to a string in coordinate notation
-/// (g1f3, a7a8q, etc.). The only special case is castling moves, where we print
-/// in the e1g1 notation in normal chess mode, and in e1h1 notation in chess960
-/// mode. Internally castling moves are always encoded as "king captures rook".
-
-const string move_to_uci(Move m, bool chess960) {
-
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-
-  if (m == MOVE_NONE)
-      return "(none)";
-
-  if (m == MOVE_NULL)
-      return "0000";
-
-  if (type_of(m) == CASTLING && !chess960)
-      to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
-
-  string move = to_string(from) + to_string(to);
-
-  if (type_of(m) == PROMOTION)
-      move += PieceToChar[BLACK][promotion_type(m)]; // Lower case
-
-  return move;
-}
-
-
-/// move_from_uci() takes a position and a string representing a move in
-/// simple coordinate notation and returns an equivalent legal Move if any.
-
-Move move_from_uci(const Position& pos, string& str) {
-
-  if (str.length() == 5) // Junior could send promotion piece in uppercase
-      str[4] = char(tolower(str[4]));
-
-  for (MoveList<LEGAL> it(pos); *it; ++it)
-      if (str == move_to_uci(*it, pos.is_chess960()))
-          return *it;
-
-  return MOVE_NONE;
-}
-
-
-/// move_to_san() takes a position and a legal Move as input and returns its
-/// short algebraic notation representation.
-
-const string move_to_san(Position& pos, Move m) {
-
-  if (m == MOVE_NONE)
-      return "(none)";
-
-  if (m == MOVE_NULL)
-      return "(null)";
-
-  assert(MoveList<LEGAL>(pos).contains(m));
-
-  Bitboard others, b;
-  string san;
-  Color us = pos.side_to_move();
-  Square from = from_sq(m);
-  Square to = to_sq(m);
-  Piece pc = pos.piece_on(from);
-  PieceType pt = type_of(pc);
-
-  if (type_of(m) == CASTLING)
-      san = to > from ? "O-O" : "O-O-O";
-  else
-  {
-      if (pt != PAWN)
-      {
-          san = PieceToChar[WHITE][pt]; // Upper case
-
-          // A disambiguation occurs 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;
-
-          while (b)
-          {
-              Square s = pop_lsb(&b);
-              if (!pos.legal(make_move(s, to), pos.pinned_pieces(us)))
-                  others ^= s;
-          }
-
-          if (!others)
-          { /* Disambiguation is not needed */ }
-
-          else if (!(others & file_bb(from)))
-              san += to_char(file_of(from));
-
-          else if (!(others & rank_bb(from)))
-              san += to_char(rank_of(from));
-
-          else
-              san += to_string(from);
-      }
-      else if (pos.capture(m))
-          san = to_char(file_of(from));
-
-      if (pos.capture(m))
-          san += 'x';
-
-      san += to_string(to);
-
-      if (type_of(m) == PROMOTION)
-          san += string("=") + PieceToChar[WHITE][promotion_type(m)];
-  }
-
-  if (pos.gives_check(m, CheckInfo(pos)))
-  {
-      StateInfo st;
-      pos.do_move(m, st);
-      san += MoveList<LEGAL>(pos).size() ? "+" : "#";
-      pos.undo_move(m);
-  }
-
-  return san;
-}
-
-
-/// pretty_pv() formats human-readable search information, typically to be
-/// appended to the search log file. It uses the two helpers below to pretty
-/// format the time and score respectively.
-
-static string format(int64_t msecs) {
-
-  const int MSecMinute = 1000 * 60;
-  const int MSecHour   = 1000 * 60 * 60;
-
-  int64_t hours   =   msecs / MSecHour;
-  int64_t minutes =  (msecs % MSecHour) / MSecMinute;
-  int64_t seconds = ((msecs % MSecHour) % MSecMinute) / 1000;
-
-  stringstream ss;
-
-  if (hours)
-      ss << hours << ':';
-
-  ss << setfill('0') << setw(2) << minutes << ':' << setw(2) << seconds;
-
-  return ss.str();
-}
-
-static string format(Value v) {
-
-  stringstream ss;
-
-  if (v >= VALUE_MATE_IN_MAX_PLY)
-      ss << "#" << (VALUE_MATE - v + 1) / 2;
-
-  else if (v <= VALUE_MATED_IN_MAX_PLY)
-      ss << "-#" << (VALUE_MATE + v) / 2;
-
-  else
-      ss << setprecision(2) << fixed << showpos << double(v) / PawnValueEg;
-
-  return ss.str();
-}
-
-string pretty_pv(Position& pos, int depth, Value value, int64_t msecs, Move pv[]) {
-
-  const uint64_t K = 1000;
-  const uint64_t M = 1000000;
-
-  std::stack<StateInfo> st;
-  Move* m = pv;
-  string san, str, padding;
-  stringstream ss;
-
-  ss << setw(2) << depth << setw(8) << format(value) << setw(8) << format(msecs);
-
-  if (pos.nodes_searched() < M)
-      ss << setw(8) << pos.nodes_searched() / 1 << "  ";
-
-  else if (pos.nodes_searched() < K * M)
-      ss << setw(7) << pos.nodes_searched() / K << "K  ";
-
-  else
-      ss << setw(7) << pos.nodes_searched() / M << "M  ";
-
-  str = ss.str();
-  padding = string(str.length(), ' ');
-
-  while (*m != MOVE_NONE)
-  {
-      san = move_to_san(pos, *m) + ' ';
-
-      if ((str.length() + san.length()) % 80 <= san.length()) // Exceed 80 cols
-          str += "\n" + padding;
-
-      str += san;
-
-      st.push(StateInfo());
-      pos.do_move(*m++, st.top());
-  }
-
-  while (m != pv)
-      pos.undo_move(*--m);
-
-  return str;
-}

src/notation.h

@@ -1,35 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 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/>.
-*/
-
-#ifndef NOTATION_H_INCLUDED
-#define NOTATION_H_INCLUDED
-
-#include <string>
-
-#include "types.h"
-
-class Position;
-
-std::string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE);
-Move move_from_uci(const Position& pos, std::string& str);
-const std::string move_to_uci(Move m, bool chess960);
-const std::string move_to_san(Position& pos, Move m);
-std::string pretty_pv(Position& pos, int depth, Value score, int64_t msecs, Move pv[]);
-
-#endif // #ifndef NOTATION_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -24,6 +24,7 @@
 #include "bitcount.h"
 #include "pawns.h"
 #include "position.h"
+#include "thread.h"
 
 namespace {
 
@@ -49,34 +50,46 @@ namespace {
   { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
     S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
 
-  // Connected pawn bonus by file and rank (initialized by formula)
-  Score Connected[FILE_NB][RANK_NB];
+  // Connected pawn bonus by opposed, phalanx flags and rank
+  Score Connected[2][2][RANK_NB];
 
-  // Candidate passed pawn bonus by rank
-  const Score CandidatePassed[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) };
-
-  // Bonus for file distance of the two outermost pawns
-  const Score PawnsFileSpan = S(0, 15);
+  // Levers bonus by rank
+  const Score Lever[RANK_NB] = {
+    S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
+    S(20,20), S(40,40), S(0, 0), S(0, 0) };
 
   // Unsupported pawn penalty
   const Score UnsupportedPawnPenalty = S(20, 10);
 
-  // Weakness of our pawn shelter in front of the king indexed by [rank]
-  const Value ShelterWeakness[RANK_NB] =
-  { V(100), V(0), V(27), V(73), V(92), V(101), V(101) };
+  // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
+  const Value ShelterWeakness[][RANK_NB] = {
+  { V(100), V(13), V(24), V(64), V(89), V( 93), V(104) },
+  { V(110), V( 1), V(29), V(75), V(96), V(102), V(107) },
+  { V(102), V( 0), V(39), V(74), V(88), V(101), V( 98) },
+  { V( 88), V( 4), V(33), V(67), V(92), V( 94), V(107) } };
 
-  // Danger of enemy pawns moving toward our king indexed by
-  // [no friendly pawn | pawn unblocked | pawn blocked][rank of enemy pawn]
-  const Value StormDanger[3][RANK_NB] = {
-  { V( 0),  V(64), V(128), V(51), V(26) },
-  { V(26),  V(32), V( 96), V(38), V(20) },
-  { V( 0),  V( 0), V(160), V(25), V(13) } };
+  // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
+  const Value StormDanger[][4][RANK_NB] = {
+  { { V( 0),  V(  63), V( 128), V(43), V(27) },
+    { V( 0),  V(  62), V( 131), V(44), V(26) },
+    { V( 0),  V(  59), V( 121), V(50), V(28) },
+    { V( 0),  V(  62), V( 127), V(54), V(28) } },
+  { { V(24),  V(  40), V(  93), V(42), V(22) },
+    { V(24),  V(  28), V( 101), V(38), V(20) },
+    { V(24),  V(  32), V(  95), V(36), V(23) },
+    { V(27),  V(  24), V(  99), V(36), V(24) } },
+  { { V( 0),  V(   0), V(  81), V(16), V( 6) },
+    { V( 0),  V(   0), V( 165), V(29), V( 9) },
+    { V( 0),  V(   0), V( 163), V(23), V(12) },
+    { V( 0),  V(   0), V( 161), V(28), V(13) } },
+  { { V( 0),  V(-296), V(-299), V(55), V(25) },
+    { V( 0),  V(  67), V( 131), V(46), V(21) },
+    { V( 0),  V(  65), V( 135), V(50), V(31) },
+    { V( 0),  V(  62), V( 128), V(51), V(24) } } };
 
   // Max bonus for king safety. Corresponds to start position with all the pawns
   // in front of the king and no enemy pawn on the horizon.
-  const Value MaxSafetyBonus = V(263);
+  const Value MaxSafetyBonus = V(257);
 
   #undef S
   #undef V
@@ -89,17 +102,17 @@ namespace {
     const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
     const Square Left  = (Us == WHITE ? DELTA_NW : DELTA_SE);
 
-    Bitboard b, p, doubled;
+    Bitboard b, p, doubled, connected;
     Square s;
-    File f;
-    bool passed, isolated, opposed, connected, backward, candidate, unsupported;
-    Score value = SCORE_ZERO;
+    bool passed, isolated, opposed, phalanx, backward, unsupported, lever;
+    Score score = SCORE_ZERO;
     const Square* pl = pos.list<PAWN>(Us);
+    const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
 
-    Bitboard ourPawns = pos.pieces(Us, PAWN);
+    Bitboard ourPawns   = pos.pieces(Us  , PAWN);
     Bitboard theirPawns = pos.pieces(Them, PAWN);
 
-    e->passedPawns[Us] = e->candidatePawns[Us] = 0;
+    e->passedPawns[Us] = 0;
     e->kingSquares[Us] = SQ_NONE;
     e->semiopenFiles[Us] = 0xFF;
     e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
@@ -111,7 +124,7 @@ namespace {
     {
         assert(pos.piece_on(s) == make_piece(Us, PAWN));
 
-        f = file_of(s);
+        File f = file_of(s);
 
         // This file cannot be semi-open
         e->semiopenFiles[Us] &= ~(1 << f);
@@ -119,17 +132,16 @@ namespace {
         // Previous rank
         p = rank_bb(s - pawn_push(Us));
 
-        // Our rank plus previous one
-        b = rank_bb(s) | p;
-
         // Flag the pawn as passed, isolated, doubled,
         // unsupported or connected (but not the backward one).
-        connected   =   ourPawns   & adjacent_files_bb(f) & b;
+        connected   =   ourPawns   & adjacent_files_bb(f) & (rank_bb(s) | p);
+        phalanx     =   connected  & rank_bb(s);
         unsupported = !(ourPawns   & adjacent_files_bb(f) & p);
         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));
+        lever       =   theirPawns & pawnAttacksBB[s];
 
         // Test for backward pawn.
         // If the pawn is passed, isolated, or connected it cannot be
@@ -155,14 +167,6 @@ namespace {
 
         assert(opposed | passed | (pawn_attack_span(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 than or equal to the number of
-        // enemy pawns in the forward direction on the adjacent files.
-        candidate =   !(opposed | passed | backward | isolated)
-                   && (b = pawn_attack_span(Them, s + pawn_push(Us)) & ourPawns) != 0
-                   &&  popcount<Max15>(b) >= popcount<Max15>(pawn_attack_span(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.
@@ -171,74 +175,67 @@ namespace {
 
         // Score this pawn
         if (isolated)
-            value -= Isolated[opposed][f];
+            score -= Isolated[opposed][f];
 
         if (unsupported && !isolated)
-            value -= UnsupportedPawnPenalty;
+            score -= UnsupportedPawnPenalty;
 
         if (doubled)
-            value -= Doubled[f] / rank_distance(s, lsb(doubled));
+            score -= Doubled[f] / distance<Rank>(s, frontmost_sq(Us, doubled));
 
         if (backward)
-            value -= Backward[opposed][f];
+            score -= Backward[opposed][f];
 
         if (connected)
-            value += Connected[f][relative_rank(Us, s)];
+            score += Connected[opposed][phalanx][relative_rank(Us, s)];
 
-        if (candidate)
-        {
-            value += CandidatePassed[relative_rank(Us, s)];
-
-            if (!doubled)
-                e->candidatePawns[Us] |= s;
-        }
+        if (lever)
+            score += Lever[relative_rank(Us, s)];
     }
 
-    // In endgame it's better to have pawns on both wings. So give a bonus according
-    // to file distance between left and right outermost pawns.
-    if (pos.count<PAWN>(Us) > 1)
-    {
-        b = e->semiopenFiles[Us] ^ 0xFF;
-        value += PawnsFileSpan * int(msb(b) - lsb(b));
-    }
+    b = e->semiopenFiles[Us] ^ 0xFF;
+    e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
 
-    return value;
+    return score;
   }
 
 } // namespace
 
 namespace Pawns {
 
-/// init() initializes some tables by formula instead of hard-coding their values
+/// Pawns::init() initializes some tables needed by evaluation. Instead of using
+/// hard-coded tables, when makes sense, we prefer to calculate them with a formula
+/// to reduce independent parameters and to allow easier tuning and better insight.
 
-void init() {
+void init()
+{
+  static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 };
 
-  const int bonusesByFile[8] = { 1, 3, 3, 4, 4, 3, 3, 1 };
-  int bonus;
-
-  for (Rank r = RANK_1; r < RANK_8; ++r)
-      for (File f = FILE_A; f <= FILE_H; ++f)
-      {
-          bonus = r * (r-1) * (r-2) + bonusesByFile[f] * (r/2 + 1);
-          Connected[f][r] = make_score(bonus, bonus);
-      }
+  for (int opposed = 0; opposed <= 1; ++opposed)
+      for (int phalanx = 0; phalanx <= 1; ++phalanx)
+          for (Rank r = RANK_2; r < RANK_8; ++r)
+          {
+              int bonus = Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0);
+              Connected[opposed][phalanx][r] = make_score(bonus / 2, bonus >> opposed);
+          }
 }
 
 
-/// 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.
+/// Pawns::probe() looks up the current position's pawns configuration in
+/// the pawns hash table. It returns a pointer to the Entry if the position
+/// is found. Otherwise a new Entry is computed and stored there, so we don't
+/// have to recompute all when the same pawns configuration occurs again.
 
-Entry* probe(const Position& pos, Table& entries) {
+Entry* probe(const Position& pos) {
 
   Key key = pos.pawn_key();
-  Entry* e = entries[key];
+  Entry* e = pos.this_thread()->pawnsTable[key];
 
   if (e->key == key)
       return e;
 
   e->key = key;
-  e->value = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
+  e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
   return e;
 }
 
@@ -250,30 +247,29 @@ template<Color Us>
 Value Entry::shelter_storm(const Position& pos, Square ksq) {
 
   const Color Them = (Us == WHITE ? BLACK : WHITE);
-  static const Bitboard MiddleEdges = (FileABB | FileHBB) & (Rank2BB | Rank3BB);
 
-  Value safety = MaxSafetyBonus;
+  enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing };
+
   Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
-  Rank rkUs, rkThem;
-  File kf = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
+  Value safety = MaxSafetyBonus;
+  File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
 
-  for (File f = kf - File(1); f <= kf + File(1); ++f)
+  for (File f = center - File(1); f <= center + File(1); ++f)
   {
       b = ourPawns & file_bb(f);
-      rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
+      Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
 
       b  = theirPawns & file_bb(f);
-      rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
+      Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
 
-      if (   (MiddleEdges & make_square(f, rkThem))
-          && file_of(ksq) == f
-          && relative_rank(Us, ksq) == rkThem - 1)
-          safety += 200;
-      else
-          safety -= ShelterWeakness[rkUs]
-                  + StormDanger[rkUs == RANK_1 ? 0 : rkThem == rkUs + 1 ? 2 : 1][rkThem];
+      safety -=  ShelterWeakness[std::min(f, FILE_H - f)][rkUs]
+               + StormDanger
+                 [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing  :
+                  rkUs   == RANK_1                                          ? NoFriendlyPawn :
+                  rkThem == rkUs + 1                                        ? BlockedByPawn  : Unblocked]
+                 [std::min(f, FILE_H - f)][rkThem];
   }
 
   return safety;
@@ -288,14 +284,14 @@ Score Entry::do_king_safety(const Position& pos, Square ksq) {
 
   kingSquares[Us] = ksq;
   castlingRights[Us] = pos.can_castle(Us);
-  minKPdistance[Us] = 0;
+  minKingPawnDistance[Us] = 0;
 
   Bitboard pawns = pos.pieces(Us, PAWN);
   if (pawns)
-      while (!(DistanceRingsBB[ksq][minKPdistance[Us]++] & pawns)) {}
+      while (!(DistanceRingBB[ksq][minKingPawnDistance[Us]++] & pawns)) {}
 
   if (relative_rank(Us, ksq) > RANK_4)
-      return make_score(0, -16 * minKPdistance[Us]);
+      return make_score(0, -16 * minKingPawnDistance[Us]);
 
   Value bonus = shelter_storm<Us>(pos, ksq);
 
@@ -306,7 +302,7 @@ Score Entry::do_king_safety(const Position& pos, Square ksq) {
   if (pos.can_castle(MakeCastling<Us, QUEEN_SIDE>::right))
       bonus = std::max(bonus, shelter_storm<Us>(pos, relative_square(Us, SQ_C1)));
 
-  return make_score(bonus, -16 * minKPdistance[Us]);
+  return make_score(bonus, -16 * minKingPawnDistance[Us]);
 }
 
 // Explicit template instantiation

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -32,10 +32,10 @@ namespace Pawns {
 
 struct Entry {
 
-  Score pawns_value() const { return value; }
+  Score pawns_score() const { return score; }
   Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
   Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
-  Bitboard candidate_pawns(Color c) const { return candidatePawns[c]; }
+  int pawn_span(Color c) const { return pawnSpan[c]; }
 
   int semiopen_file(Color c, File f) const {
     return semiopenFiles[c] & (1 << f);
@@ -62,22 +62,22 @@ struct Entry {
   Value shelter_storm(const Position& pos, Square ksq);
 
   Key key;
-  Score value;
+  Score score;
   Bitboard passedPawns[COLOR_NB];
-  Bitboard candidatePawns[COLOR_NB];
   Bitboard pawnAttacks[COLOR_NB];
   Square kingSquares[COLOR_NB];
   Score kingSafety[COLOR_NB];
-  int minKPdistance[COLOR_NB];
+  int minKingPawnDistance[COLOR_NB];
   int castlingRights[COLOR_NB];
   int semiopenFiles[COLOR_NB];
+  int pawnSpan[COLOR_NB];
   int pawnsOnSquares[COLOR_NB][COLOR_NB]; // [color][light/dark squares]
 };
 
 typedef HashTable<Entry, 16384> Table;
 
 void init();
-Entry* probe(const Position& pos, Table& entries);
+Entry* probe(const Position& pos);
 
 } // namespace Pawns
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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/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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -19,31 +19,25 @@
 
 #include <algorithm>
 #include <cassert>
-#include <cstring>
+#include <cstring>   // For std::memset
 #include <iomanip>
 #include <sstream>
 
 #include "bitcount.h"
+#include "misc.h"
 #include "movegen.h"
-#include "notation.h"
 #include "position.h"
 #include "psqtab.h"
-#include "rkiss.h"
 #include "thread.h"
 #include "tt.h"
+#include "uci.h"
 
 using std::string;
 
-static const string PieceToChar(" PNBRQK  pnbrqk");
-
-CACHE_LINE_ALIGNMENT
-
 Value PieceValue[PHASE_NB][PIECE_NB] = {
 { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg },
 { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } };
 
-static Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
-
 namespace Zobrist {
 
   Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
@@ -57,6 +51,9 @@ Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion;}
 
 namespace {
 
+const string PieceToChar(" PNBRQK  pnbrqk");
+Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+
 // min_attacker() is a helper function used by see() to locate the least
 // valuable attacker for the side to move, remove the attacker we just found
 // from the bitboards and scan for new X-ray attacks behind it.
@@ -108,6 +105,30 @@ CheckInfo::CheckInfo(const Position& pos) {
 }
 
 
+/// operator<<(Position) returns an ASCII representation of the position
+
+std::ostream& operator<<(std::ostream& os, const Position& pos) {
+
+  os << "\n +---+---+---+---+---+---+---+---+\n";
+
+  for (Rank r = RANK_8; r >= RANK_1; --r)
+  {
+      for (File f = FILE_A; f <= FILE_H; ++f)
+          os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
+
+      os << " |\n +---+---+---+---+---+---+---+---+\n";
+  }
+
+  os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
+     << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: ";
+
+  for (Bitboard b = pos.checkers(); b; )
+      os << UCI::square(pop_lsb(&b)) << " ";
+
+  return os;
+}
+
+
 /// Position::init() initializes at startup the various arrays used to compute
 /// hash keys and the piece square tables. The latter is a two-step operation:
 /// Firstly, the white halves of the tables are copied from PSQT[] tables.
@@ -116,28 +137,28 @@ CheckInfo::CheckInfo(const Position& pos) {
 
 void Position::init() {
 
-  RKISS rk;
+  PRNG rng(1070372);
 
   for (Color c = WHITE; c <= BLACK; ++c)
       for (PieceType pt = PAWN; pt <= KING; ++pt)
           for (Square s = SQ_A1; s <= SQ_H8; ++s)
-              Zobrist::psq[c][pt][s] = rk.rand<Key>();
+              Zobrist::psq[c][pt][s] = rng.rand<Key>();
 
   for (File f = FILE_A; f <= FILE_H; ++f)
-      Zobrist::enpassant[f] = rk.rand<Key>();
+      Zobrist::enpassant[f] = rng.rand<Key>();
 
-  for (int cf = NO_CASTLING; cf <= ANY_CASTLING; ++cf)
+  for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
   {
-      Bitboard b = cf;
+      Bitboard b = cr;
       while (b)
       {
           Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
-          Zobrist::castling[cf] ^= k ? k : rk.rand<Key>();
+          Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
       }
   }
 
-  Zobrist::side = rk.rand<Key>();
-  Zobrist::exclusion  = rk.rand<Key>();
+  Zobrist::side = rng.rand<Key>();
+  Zobrist::exclusion  = rng.rand<Key>();
 
   for (PieceType pt = PAWN; pt <= KING; ++pt)
   {
@@ -155,9 +176,8 @@ void Position::init() {
 }
 
 
-/// Position::operator=() creates a copy of 'pos'. We want the new born Position
-/// object to not depend on any external data so we detach state pointer from
-/// the source one.
+/// Position::operator=() creates a copy of 'pos' but detaching the state pointer
+/// from the source to be self-consistent and not depending on any external data.
 
 Position& Position::operator=(const Position& pos) {
 
@@ -226,7 +246,7 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) {
       incremented after Black's move.
 */
 
-  char col, row, token;
+  unsigned char col, row, token;
   size_t idx;
   Square sq = SQ_A8;
   std::istringstream ss(fenStr);
@@ -342,7 +362,7 @@ void Position::set_castling_right(Color c, Square rfrom) {
 void Position::set_state(StateInfo* si) const {
 
   si->key = si->pawnKey = si->materialKey = 0;
-  si->npMaterial[WHITE] = si->npMaterial[BLACK] = VALUE_ZERO;
+  si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
   si->psq = SCORE_ZERO;
 
   si->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove);
@@ -376,7 +396,7 @@ void Position::set_state(StateInfo* si) const {
 
   for (Color c = WHITE; c <= BLACK; ++c)
       for (PieceType pt = KNIGHT; pt <= QUEEN; ++pt)
-          si->npMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt];
+          si->nonPawnMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt];
 }
 
 
@@ -409,59 +429,37 @@ const string Position::fen() const {
   ss << (sideToMove == WHITE ? " w " : " b ");
 
   if (can_castle(WHITE_OO))
-      ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE |  KING_SIDE)), false) : 'K');
+      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE |  KING_SIDE))) : 'K');
 
   if (can_castle(WHITE_OOO))
-      ss << (chess960 ? to_char(file_of(castling_rook_square(WHITE | QUEEN_SIDE)), false) : 'Q');
+      ss << (chess960 ? char('A' + file_of(castling_rook_square(WHITE | QUEEN_SIDE))) : 'Q');
 
   if (can_castle(BLACK_OO))
-      ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK |  KING_SIDE)),  true) : 'k');
+      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK |  KING_SIDE))) : 'k');
 
   if (can_castle(BLACK_OOO))
-      ss << (chess960 ? to_char(file_of(castling_rook_square(BLACK | QUEEN_SIDE)),  true) : 'q');
+      ss << (chess960 ? char('a' + file_of(castling_rook_square(BLACK | QUEEN_SIDE))) : 'q');
 
   if (!can_castle(WHITE) && !can_castle(BLACK))
       ss << '-';
 
-  ss << (ep_square() == SQ_NONE ? " - " : " " + to_string(ep_square()) + " ")
+  ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::square(ep_square()) + " ")
      << st->rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2;
 
   return ss.str();
 }
 
 
-/// Position::pretty() returns an ASCII representation of the position to be
-/// printed to the standard output together with the move's san notation.
+/// Position::game_phase() calculates the game phase interpolating total non-pawn
+/// material between endgame and midgame limits.
 
-const string Position::pretty(Move m) const {
+Phase Position::game_phase() const {
 
-  std::ostringstream ss;
+  Value npm = st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
 
-  if (m)
-      ss << "\nMove: " << (sideToMove == BLACK ? ".." : "")
-         << move_to_san(*const_cast<Position*>(this), m);
+  npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
 
-  ss << "\n +---+---+---+---+---+---+---+---+\n";
-
-  for (Rank r = RANK_8; r >= RANK_1; --r)
-  {
-      for (File f = FILE_A; f <= FILE_H; ++f)
-          ss << " | " << PieceToChar[piece_on(make_square(f, r))];
-
-      ss << " |\n +---+---+---+---+---+---+---+---+\n";
-  }
-
-  ss << "\nFen: " << fen() << "\nKey: " << std::hex << std::uppercase
-     << std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
-
-  for (Bitboard b = checkers(); b; )
-      ss << to_string(pop_lsb(&b)) << " ";
-
-  ss << "\nLegal moves: ";
-  for (MoveList<LEGAL> it(*this); *it; ++it)
-      ss << move_to_san(*const_cast<Position*>(this), *it) << " ";
-
-  return ss.str();
+  return Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
 }
 
 
@@ -493,16 +491,16 @@ Bitboard Position::check_blockers(Color c, Color kingColor) const {
 
 
 /// Position::attackers_to() computes a bitboard of all pieces which attack a
-/// given square. Slider attacks use the occ bitboard to indicate occupancy.
+/// given square. Slider attacks use the occupied bitboard to indicate occupancy.
 
-Bitboard Position::attackers_to(Square s, Bitboard occ) const {
+Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
 
-  return  (attacks_from<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
-        | (attacks_from<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
-        | (attacks_from<KNIGHT>(s)      & pieces(KNIGHT))
-        | (attacks_bb<ROOK>(s, occ)     & pieces(ROOK, QUEEN))
-        | (attacks_bb<BISHOP>(s, occ)   & pieces(BISHOP, QUEEN))
-        | (attacks_from<KING>(s)        & pieces(KING));
+  return  (attacks_from<PAWN>(s, BLACK)    & pieces(WHITE, PAWN))
+        | (attacks_from<PAWN>(s, WHITE)    & pieces(BLACK, PAWN))
+        | (attacks_from<KNIGHT>(s)         & pieces(KNIGHT))
+        | (attacks_bb<ROOK>(s, occupied)   & pieces(ROOK, QUEEN))
+        | (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
+        | (attacks_from<KING>(s)           & pieces(KING));
 }
 
 
@@ -527,15 +525,15 @@ bool Position::legal(Move m, Bitboard pinned) const {
       Square ksq = king_square(us);
       Square to = to_sq(m);
       Square capsq = to - pawn_push(us);
-      Bitboard occ = (pieces() ^ from ^ capsq) | to;
+      Bitboard occupied = (pieces() ^ from ^ capsq) | to;
 
       assert(to == ep_square());
       assert(moved_piece(m) == make_piece(us, PAWN));
       assert(piece_on(capsq) == make_piece(~us, PAWN));
       assert(piece_on(to) == NO_PIECE);
 
-      return   !(attacks_bb<  ROOK>(ksq, occ) & pieces(~us, QUEEN, ROOK))
-            && !(attacks_bb<BISHOP>(ksq, occ) & pieces(~us, QUEEN, BISHOP));
+      return   !(attacks_bb<  ROOK>(ksq, occupied) & pieces(~us, QUEEN, ROOK))
+            && !(attacks_bb<BISHOP>(ksq, occupied) & pieces(~us, QUEEN, BISHOP));
   }
 
   // If the moving piece is a king, check whether the destination
@@ -643,7 +641,7 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const {
       return true;
 
   // Is there a discovered check?
-  if (   unlikely(ci.dcCandidates)
+  if (    ci.dcCandidates
       && (ci.dcCandidates & from)
       && !aligned(from, to, ci.ksq))
       return true;
@@ -768,7 +766,7 @@ 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][captured];
+          st->nonPawnMaterial[them] -= PieceValue[MG][captured];
 
       // Update board and piece lists
       remove_piece(capsq, them, captured);
@@ -803,9 +801,6 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
       st->castlingRights &= ~cr;
   }
 
-  // Prefetch TT access as soon as we know the new hash key
-  prefetch((char*)TT.first_entry(k));
-
   // Move the piece. The tricky Chess960 castling is handled earlier
   if (type_of(m) != CASTLING)
       move_piece(from, to, us, pt);
@@ -841,7 +836,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
           st->psq += psq[us][promotion][to] - psq[us][PAWN][to];
 
           // Update material
-          st->npMaterial[us] += PieceValue[MG][promotion];
+          st->nonPawnMaterial[us] += PieceValue[MG][promotion];
       }
 
       // Update pawn hash key and prefetch access to pawnsTable
@@ -875,7 +870,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
               st->checkersBB |= to;
 
           // Discovered checks
-          if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
+          if (ci.dcCandidates && (ci.dcCandidates & from))
           {
               if (pt != ROOK)
                   st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
@@ -1012,6 +1007,26 @@ void Position::undo_null_move() {
 }
 
 
+/// Position::key_after() computes the new hash key after the given move. Needed
+/// for speculative prefetch. It doesn't recognize special moves like castling,
+/// en-passant and promotions.
+
+Key Position::key_after(Move m) const {
+
+  Color us = sideToMove;
+  Square from = from_sq(m);
+  Square to = to_sq(m);
+  PieceType pt = type_of(piece_on(from));
+  PieceType captured = type_of(piece_on(to));
+  Key k = st->key ^ Zobrist::side;
+
+  if (captured)
+      k ^= Zobrist::psq[~us][captured][to];
+
+  return k ^ Zobrist::psq[us][pt][to] ^ Zobrist::psq[us][pt][from];
+}
+
+
 /// Position::see() is a static exchange evaluator: It tries to estimate the
 /// material gain or loss resulting from a move.
 
@@ -1113,10 +1128,6 @@ Value Position::see(Move m) const {
 
 bool Position::is_draw() const {
 
-  if (   !pieces(PAWN)
-      && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg))
-      return true;
-
   if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
       return true;
 
@@ -1222,8 +1233,8 @@ bool Position::pos_is_ok(int* step) const {
       if (   st->key != si.key
           || st->pawnKey != si.pawnKey
           || st->materialKey != si.materialKey
-          || st->npMaterial[WHITE] != si.npMaterial[WHITE]
-          || st->npMaterial[BLACK] != si.npMaterial[BLACK]
+          || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
+          || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
           || st->psq != si.psq
           || st->checkersBB != si.checkersBB)
           return false;

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -21,17 +21,18 @@
 #define POSITION_H_INCLUDED
 
 #include <cassert>
-#include <cstddef>
+#include <cstddef>  // For offsetof()
+#include <string>
 
 #include "bitboard.h"
 #include "types.h"
 
-
-/// The checkInfo struct is initialized at c'tor time and keeps info used
-/// to detect if a move gives check.
 class Position;
 struct Thread;
 
+/// CheckInfo struct is initialized at c'tor time and keeps info used to detect
+/// if a move gives check.
+
 struct CheckInfo {
 
   explicit CheckInfo(const Position&);
@@ -39,51 +40,61 @@ struct CheckInfo {
   Bitboard dcCandidates;
   Bitboard pinned;
   Bitboard checkSq[PIECE_TYPE_NB];
-  Square ksq;
+  Square   ksq;
 };
 
 
-/// The StateInfo struct stores information needed 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), a StateInfo
-/// object must be passed as a parameter.
+/// StateInfo struct stores information needed 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), a StateInfo object must be passed.
 
 struct StateInfo {
-  Key pawnKey, materialKey;
-  Value npMaterial[COLOR_NB];
-  int castlingRights, rule50, pliesFromNull;
-  Score psq;
+
+  // Copied when making a move
+  Key    pawnKey;
+  Key    materialKey;
+  Value  nonPawnMaterial[COLOR_NB];
+  int    castlingRights;
+  int    rule50;
+  int    pliesFromNull;
+  Score  psq;
   Square epSquare;
 
-  Key key;
-  Bitboard checkersBB;
-  PieceType capturedType;
+  // Not copied when making a move
+  Key        key;
+  Bitboard   checkersBB;
+  PieceType  capturedType;
   StateInfo* previous;
 };
 
 
 /// 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.
+/// the new one. Here we calculate the quad words (64 bit) needed to be copied.
 const size_t StateCopySize64 = offsetof(StateInfo, key) / sizeof(uint64_t) + 1;
 
 
-/// The Position class stores the information regarding the board representation
-/// like pieces, side to move, hash keys, castling info, etc. The most important
-/// methods are do_move() and undo_move(), used by the search to update node info
-/// when traversing the search tree.
+/// Position class stores information regarding the board representation as
+/// pieces, side to move, hash keys, castling info, etc. Important methods are
+/// do_move() and undo_move(), used by the search to update node info when
+/// traversing the search tree.
 
 class Position {
+
+  friend std::ostream& operator<<(std::ostream&, const Position&);
+
+  Position(const Position&); // Disable the default copy constructor
+
 public:
-  Position() {}
-  Position(const Position& pos, Thread* t) { *this = pos; thisThread = t; }
-  Position(const std::string& f, bool c960, Thread* t) { set(f, c960, t); }
-  Position& operator=(const Position&);
   static void init();
 
-  // Text input/output
+  Position() {} // To define the global object RootPos
+  Position(const Position& pos, Thread* th) { *this = pos; thisThread = th; }
+  Position(const std::string& f, bool c960, Thread* th) { set(f, c960, th); }
+  Position& operator=(const Position&); // To assign RootPos from UCI
+
+  // FEN string input/output
   void set(const std::string& fenStr, bool isChess960, Thread* th);
   const std::string fen() const;
-  const std::string pretty(Move m = MOVE_NONE) const;
 
   // Position representation
   Bitboard pieces() const;
@@ -112,7 +123,7 @@ public:
 
   // Attacks to/from a given square
   Bitboard attackers_to(Square s) const;
-  Bitboard attackers_to(Square s, Bitboard occ) const;
+  Bitboard attackers_to(Square s, Bitboard occupied) const;
   Bitboard attacks_from(Piece pc, Square s) const;
   template<PieceType> Bitboard attacks_from(Square s) const;
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
@@ -130,7 +141,6 @@ public:
   // Piece specific
   bool pawn_passed(Color c, Square s) const;
   bool pawn_on_7th(Color c) const;
-  bool bishop_pair(Color c) const;
   bool opposite_bishops() const;
 
   // Doing and undoing moves
@@ -146,22 +156,23 @@ public:
 
   // Accessing hash keys
   Key key() const;
+  Key key_after(Move m) const;
   Key exclusion_key() const;
-  Key pawn_key() const;
   Key material_key() const;
-
-  // Incremental piece-square evaluation
-  Score psq_score() const;
-  Value non_pawn_material(Color c) const;
+  Key pawn_key() const;
 
   // Other properties of the position
   Color side_to_move() const;
+  Phase game_phase() const;
   int game_ply() const;
   bool is_chess960() const;
   Thread* this_thread() const;
   uint64_t nodes_searched() const;
   void set_nodes_searched(uint64_t n);
   bool is_draw() const;
+  int rule50_count() const;
+  Score psq_score() const;
+  Value non_pawn_material(Color c) const;
 
   // Position consistency check, for debugging
   bool pos_is_ok(int* step = NULL) const;
@@ -173,7 +184,7 @@ private:
   void set_castling_right(Color c, Square rfrom);
   void set_state(StateInfo* si) const;
 
-  // Helper functions
+  // Other helpers
   Bitboard check_blockers(Color c, Color kingColor) const;
   void put_piece(Square s, Color c, PieceType pt);
   void remove_piece(Square s, Color c, PieceType pt);
@@ -181,15 +192,13 @@ private:
   template<bool Do>
   void do_castling(Square from, Square& to, Square& rfrom, Square& rto);
 
-  // Board and pieces
+  // Data members
   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 castlingRightsMask[SQUARE_NB];
   Square castlingRookSquare[CASTLING_RIGHT_NB];
   Bitboard castlingPath[CASTLING_RIGHT_NB];
@@ -202,12 +211,12 @@ private:
   bool chess960;
 };
 
-inline uint64_t Position::nodes_searched() const {
-  return nodes;
+inline Color Position::side_to_move() const {
+  return sideToMove;
 }
 
-inline void Position::set_nodes_searched(uint64_t n) {
-  nodes = n;
+inline bool Position::empty(Square s) const {
+  return board[s] == NO_PIECE;
 }
 
 inline Piece Position::piece_on(Square s) const {
@@ -218,14 +227,6 @@ inline Piece Position::moved_piece(Move m) const {
   return board[from_sq(m)];
 }
 
-inline bool Position::empty(Square s) const {
-  return board[s] == NO_PIECE;
-}
-
-inline Color Position::side_to_move() const {
-  return sideToMove;
-}
-
 inline Bitboard Position::pieces() const {
   return byTypeBB[ALL_PIECES];
 }
@@ -258,14 +259,14 @@ template<PieceType Pt> inline const Square* Position::list(Color c) const {
   return pieceList[c][Pt];
 }
 
-inline Square Position::ep_square() const {
-  return st->epSquare;
-}
-
 inline Square Position::king_square(Color c) const {
   return pieceList[c][KING][0];
 }
 
+inline Square Position::ep_square() const {
+  return st->epSquare;
+}
+
 inline int Position::can_castle(CastlingRight cr) const {
   return st->castlingRights & cr;
 }
@@ -284,7 +285,6 @@ inline Square Position::castling_rook_square(CastlingRight cr) const {
 
 template<PieceType Pt>
 inline Bitboard Position::attacks_from(Square s) const {
-
   return  Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, byTypeBB[ALL_PIECES])
         : Pt == QUEEN  ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
         : StepAttacksBB[Pt][s];
@@ -341,26 +341,31 @@ inline Score Position::psq_score() const {
 }
 
 inline Value Position::non_pawn_material(Color c) const {
-  return st->npMaterial[c];
+  return st->nonPawnMaterial[c];
 }
 
 inline int Position::game_ply() const {
   return gamePly;
 }
 
-inline bool Position::opposite_bishops() const {
+inline int Position::rule50_count() const {
+  return st->rule50;
+}
 
+inline uint64_t Position::nodes_searched() const {
+  return nodes;
+}
+
+inline void Position::set_nodes_searched(uint64_t n) {
+  nodes = n;
+}
+
+inline bool Position::opposite_bishops() const {
   return   pieceCount[WHITE][BISHOP] == 1
         && pieceCount[BLACK][BISHOP] == 1
         && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
 }
 
-inline bool Position::bishop_pair(Color c) const {
-
-  return   pieceCount[c][BISHOP] >= 2
-        && opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
-}
-
 inline bool Position::pawn_on_7th(Color c) const {
   return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
 }
@@ -377,7 +382,7 @@ inline bool Position::capture_or_promotion(Move m) const {
 
 inline bool Position::capture(Move m) const {
 
-  // Note that castling is encoded as "king captures the rook"
+  // Castling is encoded as "king captures the rook"
   assert(is_ok(m));
   return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == ENPASSANT;
 }
@@ -398,12 +403,13 @@ inline void Position::put_piece(Square s, Color c, PieceType pt) {
   byColorBB[c] |= s;
   index[s] = pieceCount[c][pt]++;
   pieceList[c][pt][index[s]] = s;
+  pieceCount[c][ALL_PIECES]++;
 }
 
 inline void Position::move_piece(Square from, Square to, Color c, PieceType pt) {
 
-  // index[from] is not updated and becomes stale. This works as long
-  // as index[] is accessed just by known occupied squares.
+  // index[from] is not updated and becomes stale. This works as long as index[]
+  // is accessed just by known occupied squares.
   Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
   byTypeBB[ALL_PIECES] ^= from_to_bb;
   byTypeBB[pt] ^= from_to_bb;
@@ -423,11 +429,12 @@ inline void Position::remove_piece(Square s, Color c, PieceType pt) {
   byTypeBB[ALL_PIECES] ^= s;
   byTypeBB[pt] ^= s;
   byColorBB[c] ^= s;
-  /* board[s] = NO_PIECE; */ // Not needed, will be overwritten by capturing
+  /* board[s] = NO_PIECE;  Not needed, overwritten by the capturing one */
   Square lastSquare = pieceList[c][pt][--pieceCount[c][pt]];
   index[lastSquare] = index[s];
   pieceList[c][pt][index[lastSquare]] = lastSquare;
   pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE;
+  pieceCount[c][ALL_PIECES]--;
 }
 
 #endif // #ifndef POSITION_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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/rkiss.h

@@ -1,81 +0,0 @@
-/*
-  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 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/>.
-
-  This file is based on original code by Heinz van Saanen and is
-  available under 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.
-*/
-
-#ifndef RKISS_H_INCLUDED
-#define RKISS_H_INCLUDED
-
-#include "types.h"
-
-/// RKISS is our pseudo random number generator (PRNG) used to compute hash keys.
-/// George Marsaglia invented the RNG-Kiss-family in the early 90's. This is a
-/// specific version that Heinz van Saanen derived from some public domain code
-/// by Bob Jenkins. Following the feature list, as tested by Heinz.
-///
-/// - Quite platform independent
-/// - Passes ALL dieharder tests! Here *nix sys-rand() e.g. fails miserably:-)
-/// - ~12 times faster than my *nix sys-rand()
-/// - ~4 times faster than SSE2-version of Mersenne twister
-/// - Average cycle length: ~2^126
-/// - 64 bit seed
-/// - Return doubles with a full 53 bit mantissa
-/// - Thread safe
-
-class RKISS {
-
-  uint64_t a, b, c, d;
-
-  uint64_t rotate_L(uint64_t x, unsigned k) const {
-    return (x << k) | (x >> (64 - k));
-  }
-
-  uint64_t rand64() {
-
-    const uint64_t e = a - rotate_L(b,  7);
-    a = b ^ rotate_L(c, 13);
-    b = c + rotate_L(d, 37);
-    c = d + e;
-    return d = e + a;
-  }
-
-public:
-  RKISS(int seed = 73) {
-
-    a = 0xF1EA5EED, b = c = d = 0xD4E12C77;
-
-    for (int i = 0; i < seed; ++i) // Scramble a few rounds
-        rand64();
-  }
-
-  template<typename T> T rand() { return T(rand64()); }
-
-  /// Special generator used to fast init magic numbers. Here the
-  /// trick is to rotate the randoms of a given quantity 's' known
-  /// to be optimal to quickly find a good magic candidate.
-  template<typename T> T magic_rand(int s) {
-    return rotate_L(rotate_L(rand<T>(), (s >> 0) & 0x3F) & rand<T>()
-                                      , (s >> 6) & 0x3F) & rand<T>();
-  }
-};
-
-#endif // #ifndef RKISS_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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 @@
 #ifndef SEARCH_H_INCLUDED
 #define SEARCH_H_INCLUDED
 
-#include <memory>
+#include <memory>  // For std::auto_ptr
 #include <stack>
 #include <vector>
 
@@ -32,12 +32,13 @@ struct SplitPoint;
 
 namespace Search {
 
-/// The Stack struct keeps track of the information we need to remember from
-/// nodes shallower and deeper in the tree during the search. Each search thread
-/// has its own array of Stack objects, indexed by the current ply.
+/// Stack struct keeps track of the information we need to remember from nodes
+/// shallower and deeper in the tree during the search. Each search thread has
+/// its own array of Stack objects, indexed by the current ply.
 
 struct Stack {
   SplitPoint* splitPoint;
+  Move* pv;
   int ply;
   Move currentMove;
   Move ttMove;
@@ -45,49 +46,49 @@ struct Stack {
   Move killers[2];
   Depth reduction;
   Value staticEval;
-  int skipNullMove;
+  bool skipEarlyPruning;
 };
 
+/// RootMove struct is used for moves at the root of the tree. For each root move
+/// we store a score and a PV (really a refutation in the case of moves which
+/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
 
-/// RootMove struct is used for moves at the root of the tree. For each root
-/// move we store a score, a node count, and a PV (really a refutation in the
-/// case of moves which fail low). Score is normally set at -VALUE_INFINITE for
-/// all non-pv moves.
 struct RootMove {
 
-  RootMove(Move m) : score(-VALUE_INFINITE), prevScore(-VALUE_INFINITE) {
-    pv.push_back(m); pv.push_back(MOVE_NONE);
-  }
+  RootMove(Move m) : score(-VALUE_INFINITE), previousScore(-VALUE_INFINITE), pv(1, m) {}
 
   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);
   void insert_pv_in_tt(Position& pos);
+  Move extract_ponder_from_tt(Position& pos);
 
   Value score;
-  Value prevScore;
+  Value previousScore;
   std::vector<Move> pv;
 };
 
+typedef std::vector<RootMove> RootMoveVector;
 
-/// The LimitsType struct stores information sent by GUI about available time
-/// to search the current move, maximum depth/time, if we are in analysis mode
-/// or if we have to ponder while it's our opponent's turn to move.
+/// LimitsType struct stores information sent by GUI about available time to
+/// search the current move, maximum depth/time, if we are in analysis mode or
+/// if we have to ponder while it's our opponent's turn to move.
 
 struct LimitsType {
 
-  LimitsType() { // Using memset on a std::vector is undefined behavior
-    time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = movestogo =
-    depth = nodes = movetime = mate = infinite = ponder = 0;
+  LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
+    nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = movestogo =
+    depth = movetime = mate = infinite = ponder = 0;
+  }
+
+  bool use_time_management() const {
+    return !(mate | movetime | depth | nodes | infinite);
   }
-  bool use_time_management() const { return !(mate | movetime | depth | nodes | infinite); }
 
   std::vector<Move> searchmoves;
-  int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, nodes, movetime, mate, infinite, ponder;
+  int time[COLOR_NB], inc[COLOR_NB], movestogo, depth, movetime, mate, infinite, ponder;
+  int64_t nodes;
 };
 
-
 /// The SignalsType struct stores volatile flags updated during the search
 /// typically in an async fashion e.g. to stop the search by the GUI.
 
@@ -99,15 +100,14 @@ typedef std::auto_ptr<std::stack<StateInfo> > StateStackPtr;
 
 extern volatile SignalsType Signals;
 extern LimitsType Limits;
-extern std::vector<RootMove> RootMoves;
+extern RootMoveVector RootMoves;
 extern Position RootPos;
-extern Color RootColor;
 extern Time::point SearchTime;
 extern StateStackPtr SetupStates;
 
-extern void init();
-extern uint64_t perft(Position& pos, Depth depth);
-extern void think();
+void init();
+void think();
+template<bool Root> uint64_t perft(Position& pos, Depth depth);
 
 } // namespace Search
 

src/syzygy/tbcore.h

@@ -0,0 +1,169 @@
+/*
+  Copyright (c) 2011-2013 Ronald de Man
+*/
+
+#ifndef TBCORE_H
+#define TBCORE_H
+
+#ifndef _WIN32
+#include <pthread.h>
+#define SEP_CHAR ':'
+#define FD int
+#define FD_ERR -1
+#else
+#include <windows.h>
+#define SEP_CHAR ';'
+#define FD HANDLE
+#define FD_ERR INVALID_HANDLE_VALUE
+#endif
+
+#ifndef _WIN32
+#define LOCK_T pthread_mutex_t
+#define LOCK_INIT(x) pthread_mutex_init(&(x), NULL)
+#define LOCK(x) pthread_mutex_lock(&(x))
+#define UNLOCK(x) pthread_mutex_unlock(&(x))
+#else
+#define LOCK_T HANDLE
+#define LOCK_INIT(x) do { x = CreateMutex(NULL, FALSE, NULL); } while (0)
+#define LOCK(x) WaitForSingleObject(x, INFINITE)
+#define UNLOCK(x) ReleaseMutex(x)
+#endif
+
+#ifndef _MSC_VER
+#define BSWAP32(v) __builtin_bswap32(v)
+#define BSWAP64(v) __builtin_bswap64(v)
+#else
+#define BSWAP32(v) _byteswap_ulong(v)
+#define BSWAP64(v) _byteswap_uint64(v)
+#endif
+
+#define WDLSUFFIX ".rtbw"
+#define DTZSUFFIX ".rtbz"
+#define WDLDIR "RTBWDIR"
+#define DTZDIR "RTBZDIR"
+#define TBPIECES 6
+
+typedef unsigned long long uint64;
+typedef unsigned int uint32;
+typedef unsigned char ubyte;
+typedef unsigned short ushort;
+
+const ubyte WDL_MAGIC[4] = { 0x71, 0xe8, 0x23, 0x5d };
+const ubyte DTZ_MAGIC[4] = { 0xd7, 0x66, 0x0c, 0xa5 };
+
+#define TBHASHBITS 10
+
+struct TBHashEntry;
+
+typedef uint64 base_t;
+
+struct PairsData {
+  char *indextable;
+  ushort *sizetable;
+  ubyte *data;
+  ushort *offset;
+  ubyte *symlen;
+  ubyte *sympat;
+  int blocksize;
+  int idxbits;
+  int min_len;
+  base_t base[1]; // C++ complains about base[]...
+};
+
+struct TBEntry {
+  char *data;
+  uint64 key;
+  uint64 mapping;
+  ubyte ready;
+  ubyte num;
+  ubyte symmetric;
+  ubyte has_pawns;
+}
+#ifndef _WIN32
+__attribute__((__may_alias__))
+#endif
+;
+
+struct TBEntry_piece {
+  char *data;
+  uint64 key;
+  uint64 mapping;
+  ubyte ready;
+  ubyte num;
+  ubyte symmetric;
+  ubyte has_pawns;
+  ubyte enc_type;
+  struct PairsData *precomp[2];
+  int factor[2][TBPIECES];
+  ubyte pieces[2][TBPIECES];
+  ubyte norm[2][TBPIECES];
+};
+
+struct TBEntry_pawn {
+  char *data;
+  uint64 key;
+  uint64 mapping;
+  ubyte ready;
+  ubyte num;
+  ubyte symmetric;
+  ubyte has_pawns;
+  ubyte pawns[2];
+  struct {
+    struct PairsData *precomp[2];
+    int factor[2][TBPIECES];
+    ubyte pieces[2][TBPIECES];
+    ubyte norm[2][TBPIECES];
+  } file[4];
+};
+
+struct DTZEntry_piece {
+  char *data;
+  uint64 key;
+  uint64 mapping;
+  ubyte ready;
+  ubyte num;
+  ubyte symmetric;
+  ubyte has_pawns;
+  ubyte enc_type;
+  struct PairsData *precomp;
+  int factor[TBPIECES];
+  ubyte pieces[TBPIECES];
+  ubyte norm[TBPIECES];
+  ubyte flags; // accurate, mapped, side
+  ushort map_idx[4];
+  ubyte *map;
+};
+
+struct DTZEntry_pawn {
+  char *data;
+  uint64 key;
+  uint64 mapping;
+  ubyte ready;
+  ubyte num;
+  ubyte symmetric;
+  ubyte has_pawns;
+  ubyte pawns[2];
+  struct {
+    struct PairsData *precomp;
+    int factor[TBPIECES];
+    ubyte pieces[TBPIECES];
+    ubyte norm[TBPIECES];
+  } file[4];
+  ubyte flags[4];
+  ushort map_idx[4][4];
+  ubyte *map;
+};
+
+struct TBHashEntry {
+  uint64 key;
+  struct TBEntry *ptr;
+};
+
+struct DTZTableEntry {
+  uint64 key1;
+  uint64 key2;
+  struct TBEntry *entry;
+};
+
+#endif
+

src/syzygy/tbprobe.cpp

@@ -0,0 +1,831 @@
+/*
+  Copyright (c) 2013 Ronald de Man
+  This file may be redistributed and/or modified without restrictions.
+
+  tbprobe.cpp contains the Stockfish-specific routines of the
+  tablebase probing code. It should be relatively easy to adapt
+  this code to other chess engines.
+*/
+
+#include <algorithm>
+
+#include "../position.h"
+#include "../movegen.h"
+#include "../bitboard.h"
+#include "../search.h"
+#include "../bitcount.h"
+
+#include "tbprobe.h"
+#include "tbcore.h"
+
+#include "tbcore.cpp"
+
+namespace Zobrist {
+  extern Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+}
+
+int Tablebases::MaxCardinality = 0;
+
+// Given a position with 6 or fewer pieces, produce a text string
+// of the form KQPvKRP, where "KQP" represents the white pieces if
+// mirror == 0 and the black pieces if mirror == 1.
+static void prt_str(Position& pos, char *str, int mirror)
+{
+  Color color;
+  PieceType pt;
+  int i;
+
+  color = !mirror ? WHITE : BLACK;
+  for (pt = KING; pt >= PAWN; --pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      *str++ = pchr[6 - pt];
+  *str++ = 'v';
+  color = ~color;
+  for (pt = KING; pt >= PAWN; --pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      *str++ = pchr[6 - pt];
+  *str++ = 0;
+}
+
+// Given a position, produce a 64-bit material signature key.
+// If the engine supports such a key, it should equal the engine's key.
+static uint64 calc_key(Position& pos, int mirror)
+{
+  Color color;
+  PieceType pt;
+  int i;
+  uint64 key = 0;
+
+  color = !mirror ? WHITE : BLACK;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      key ^= Zobrist::psq[WHITE][pt][i - 1];
+  color = ~color;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = popcount<Max15>(pos.pieces(color, pt)); i > 0; i--)
+      key ^= Zobrist::psq[BLACK][pt][i - 1];
+
+  return key;
+}
+
+// Produce a 64-bit material key corresponding to the material combination
+// defined by pcs[16], where pcs[1], ..., pcs[6] is the number of white
+// pawns, ..., kings and pcs[9], ..., pcs[14] is the number of black
+// pawns, ..., kings.
+static uint64 calc_key_from_pcs(int *pcs, int mirror)
+{
+  int color;
+  PieceType pt;
+  int i;
+  uint64 key = 0;
+
+  color = !mirror ? 0 : 8;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = 0; i < pcs[color + pt]; i++)
+      key ^= Zobrist::psq[WHITE][pt][i];
+  color ^= 8;
+  for (pt = PAWN; pt <= KING; ++pt)
+    for (i = 0; i < pcs[color + pt]; i++)
+      key ^= Zobrist::psq[BLACK][pt][i];
+
+  return key;
+}
+
+bool is_little_endian() {
+  union {
+    int i;
+    char c[sizeof(int)];
+  } x;
+  x.i = 1;
+  return x.c[0] == 1;
+}
+
+static ubyte decompress_pairs(struct PairsData *d, uint64 idx)
+{
+  static const bool isLittleEndian = is_little_endian();
+  return isLittleEndian ? decompress_pairs<true >(d, idx)
+                        : decompress_pairs<false>(d, idx);
+}
+
+// probe_wdl_table and probe_dtz_table require similar adaptations.
+static int probe_wdl_table(Position& pos, int *success)
+{
+  struct TBEntry *ptr;
+  struct TBHashEntry *ptr2;
+  uint64 idx;
+  uint64 key;
+  int i;
+  ubyte res;
+  int p[TBPIECES];
+
+  // Obtain the position's material signature key.
+  key = pos.material_key();
+
+  // Test for KvK.
+  if (key == (Zobrist::psq[WHITE][KING][0] ^ Zobrist::psq[BLACK][KING][0]))
+    return 0;
+
+  ptr2 = TB_hash[key >> (64 - TBHASHBITS)];
+  for (i = 0; i < HSHMAX; i++)
+    if (ptr2[i].key == key) break;
+  if (i == HSHMAX) {
+    *success = 0;
+    return 0;
+  }
+
+  ptr = ptr2[i].ptr;
+  if (!ptr->ready) {
+    LOCK(TB_mutex);
+    if (!ptr->ready) {
+      char str[16];
+      prt_str(pos, str, ptr->key != key);
+      if (!init_table_wdl(ptr, str)) {
+        ptr2[i].key = 0ULL;
+        *success = 0;
+        UNLOCK(TB_mutex);
+        return 0;
+      }
+      // Memory barrier to ensure ptr->ready = 1 is not reordered.
+#ifdef _MSC_VER
+      _ReadWriteBarrier();
+#else
+      __asm__ __volatile__ ("" ::: "memory");
+#endif
+      ptr->ready = 1;
+    }
+    UNLOCK(TB_mutex);
+  }
+
+  int bside, mirror, cmirror;
+  if (!ptr->symmetric) {
+    if (key != ptr->key) {
+      cmirror = 8;
+      mirror = 0x38;
+      bside = (pos.side_to_move() == WHITE);
+    } else {
+      cmirror = mirror = 0;
+      bside = !(pos.side_to_move() == WHITE);
+    }
+  } else {
+    cmirror = pos.side_to_move() == WHITE ? 0 : 8;
+    mirror = pos.side_to_move() == WHITE ? 0 : 0x38;
+    bside = 0;
+  }
+
+  // p[i] is to contain the square 0-63 (A1-H8) for a piece of type
+  // pc[i] ^ cmirror, where 1 = white pawn, ..., 14 = black king.
+  // Pieces of the same type are guaranteed to be consecutive.
+  if (!ptr->has_pawns) {
+    struct TBEntry_piece *entry = (struct TBEntry_piece *)ptr;
+    ubyte *pc = entry->pieces[bside];
+    for (i = 0; i < entry->num;) {
+      Bitboard bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                      (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb);
+      } while (bb);
+    }
+    idx = encode_piece(entry, entry->norm[bside], p, entry->factor[bside]);
+    res = decompress_pairs(entry->precomp[bside], idx);
+  } else {
+    struct TBEntry_pawn *entry = (struct TBEntry_pawn *)ptr;
+    int k = entry->file[0].pieces[0][0] ^ cmirror;
+    Bitboard bb = pos.pieces((Color)(k >> 3), (PieceType)(k & 0x07));
+    i = 0;
+    do {
+      p[i++] = pop_lsb(&bb) ^ mirror;
+    } while (bb);
+    int f = pawn_file(entry, p);
+    ubyte *pc = entry->file[f].pieces[bside];
+    for (; i < entry->num;) {
+      bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                    (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb) ^ mirror;
+      } while (bb);
+    }
+    idx = encode_pawn(entry, entry->file[f].norm[bside], p, entry->file[f].factor[bside]);
+    res = decompress_pairs(entry->file[f].precomp[bside], idx);
+  }
+
+  return ((int)res) - 2;
+}
+
+static int probe_dtz_table(Position& pos, int wdl, int *success)
+{
+  struct TBEntry *ptr;
+  uint64 idx;
+  int i, res;
+  int p[TBPIECES];
+
+  // Obtain the position's material signature key.
+  uint64 key = pos.material_key();
+
+  if (DTZ_table[0].key1 != key && DTZ_table[0].key2 != key) {
+    for (i = 1; i < DTZ_ENTRIES; i++)
+      if (DTZ_table[i].key1 == key) break;
+    if (i < DTZ_ENTRIES) {
+      struct DTZTableEntry table_entry = DTZ_table[i];
+      for (; i > 0; i--)
+        DTZ_table[i] = DTZ_table[i - 1];
+      DTZ_table[0] = table_entry;
+    } else {
+      struct TBHashEntry *ptr2 = TB_hash[key >> (64 - TBHASHBITS)];
+      for (i = 0; i < HSHMAX; i++)
+        if (ptr2[i].key == key) break;
+      if (i == HSHMAX) {
+        *success = 0;
+        return 0;
+      }
+      ptr = ptr2[i].ptr;
+      char str[16];
+      int mirror = (ptr->key != key);
+      prt_str(pos, str, mirror);
+      if (DTZ_table[DTZ_ENTRIES - 1].entry)
+        free_dtz_entry(DTZ_table[DTZ_ENTRIES-1].entry);
+      for (i = DTZ_ENTRIES - 1; i > 0; i--)
+        DTZ_table[i] = DTZ_table[i - 1];
+      load_dtz_table(str, calc_key(pos, mirror), calc_key(pos, !mirror));
+    }
+  }
+
+  ptr = DTZ_table[0].entry;
+  if (!ptr) {
+    *success = 0;
+    return 0;
+  }
+
+  int bside, mirror, cmirror;
+  if (!ptr->symmetric) {
+    if (key != ptr->key) {
+      cmirror = 8;
+      mirror = 0x38;
+      bside = (pos.side_to_move() == WHITE);
+    } else {
+      cmirror = mirror = 0;
+      bside = !(pos.side_to_move() == WHITE);
+    }
+  } else {
+    cmirror = pos.side_to_move() == WHITE ? 0 : 8;
+    mirror = pos.side_to_move() == WHITE ? 0 : 0x38;
+    bside = 0;
+  }
+
+  if (!ptr->has_pawns) {
+    struct DTZEntry_piece *entry = (struct DTZEntry_piece *)ptr;
+    if ((entry->flags & 1) != bside && !entry->symmetric) {
+      *success = -1;
+      return 0;
+    }
+    ubyte *pc = entry->pieces;
+    for (i = 0; i < entry->num;) {
+      Bitboard bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                                    (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb);
+      } while (bb);
+    }
+    idx = encode_piece((struct TBEntry_piece *)entry, entry->norm, p, entry->factor);
+    res = decompress_pairs(entry->precomp, idx);
+
+    if (entry->flags & 2)
+      res = entry->map[entry->map_idx[wdl_to_map[wdl + 2]] + res];
+
+    if (!(entry->flags & pa_flags[wdl + 2]) || (wdl & 1))
+      res *= 2;
+  } else {
+    struct DTZEntry_pawn *entry = (struct DTZEntry_pawn *)ptr;
+    int k = entry->file[0].pieces[0] ^ cmirror;
+    Bitboard bb = pos.pieces((Color)(k >> 3), (PieceType)(k & 0x07));
+    i = 0;
+    do {
+      p[i++] = pop_lsb(&bb) ^ mirror;
+    } while (bb);
+    int f = pawn_file((struct TBEntry_pawn *)entry, p);
+    if ((entry->flags[f] & 1) != bside) {
+      *success = -1;
+      return 0;
+    }
+    ubyte *pc = entry->file[f].pieces;
+    for (; i < entry->num;) {
+      bb = pos.pieces((Color)((pc[i] ^ cmirror) >> 3),
+                            (PieceType)(pc[i] & 0x07));
+      do {
+        p[i++] = pop_lsb(&bb) ^ mirror;
+      } while (bb);
+    }
+    idx = encode_pawn((struct TBEntry_pawn *)entry, entry->file[f].norm, p, entry->file[f].factor);
+    res = decompress_pairs(entry->file[f].precomp, idx);
+
+    if (entry->flags[f] & 2)
+      res = entry->map[entry->map_idx[f][wdl_to_map[wdl + 2]] + res];
+
+    if (!(entry->flags[f] & pa_flags[wdl + 2]) || (wdl & 1))
+      res *= 2;
+  }
+
+  return res;
+}
+
+// Add underpromotion captures to list of captures.
+static ExtMove *add_underprom_caps(Position& pos, ExtMove *stack, ExtMove *end)
+{
+  ExtMove *moves, *extra = end;
+
+  for (moves = stack; moves < end; moves++) {
+    Move move = moves->move;
+    if (type_of(move) == PROMOTION && !pos.empty(to_sq(move))) {
+      (*extra++).move = (Move)(move - (1 << 12));
+      (*extra++).move = (Move)(move - (2 << 12));
+      (*extra++).move = (Move)(move - (3 << 12));
+    }
+  }
+
+  return extra;
+}
+
+static int probe_ab(Position& pos, int alpha, int beta, int *success)
+{
+  int v;
+  ExtMove stack[64];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  // Generate (at least) all legal non-ep captures including (under)promotions.
+  // It is OK to generate more, as long as they are filtered out below.
+  if (!pos.checkers()) {
+    end = generate<CAPTURES>(pos, stack);
+    // Since underpromotion captures are not included, we need to add them.
+    end = add_underprom_caps(pos, stack, end);
+  } else
+    end = generate<EVASIONS>(pos, stack);
+
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (!pos.capture(capture) || type_of(capture) == ENPASSANT
+                        || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    v = -probe_ab(pos, -beta, -alpha, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v > alpha) {
+      if (v >= beta) {
+        *success = 2;
+        return v;
+      }
+      alpha = v;
+    }
+  }
+
+  v = probe_wdl_table(pos, success);
+  if (*success == 0) return 0;
+  if (alpha >= v) {
+    *success = 1 + (alpha > 0);
+    return alpha;
+  } else {
+    *success = 1;
+    return v;
+  }
+}
+
+// Probe the WDL table for a particular position.
+// If *success != 0, the probe was successful.
+// The return value is from the point of view of the side to move:
+// -2 : loss
+// -1 : loss, but draw under 50-move rule
+//  0 : draw
+//  1 : win, but draw under 50-move rule
+//  2 : win
+int Tablebases::probe_wdl(Position& pos, int *success)
+{
+  int v;
+
+  *success = 1;
+  v = probe_ab(pos, -2, 2, success);
+
+  // If en passant is not possible, we are done.
+  if (pos.ep_square() == SQ_NONE)
+    return v;
+  if (!(*success)) return 0;
+
+  // Now handle en passant.
+  int v1 = -3;
+  // Generate (at least) all legal en passant captures.
+  ExtMove stack[192];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  if (!pos.checkers())
+    end = generate<CAPTURES>(pos, stack);
+  else
+    end = generate<EVASIONS>(pos, stack);
+
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (type_of(capture) != ENPASSANT
+          || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    int v0 = -probe_ab(pos, -2, 2, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v0 > v1) v1 = v0;
+  }
+  if (v1 > -3) {
+    if (v1 >= v) v = v1;
+    else if (v == 0) {
+      // Check whether there is at least one legal non-ep move.
+      for (moves = stack; moves < end; moves++) {
+        Move capture = moves->move;
+        if (type_of(capture) == ENPASSANT) continue;
+        if (pos.legal(capture, ci.pinned)) break;
+      }
+      if (moves == end && !pos.checkers()) {
+        end = generate<QUIETS>(pos, end);
+        for (; moves < end; moves++) {
+          Move move = moves->move;
+          if (pos.legal(move, ci.pinned))
+            break;
+        }
+      }
+      // If not, then we are forced to play the losing ep capture.
+      if (moves == end)
+        v = v1;
+    }
+  }
+
+  return v;
+}
+
+// This routine treats a position with en passant captures as one without.
+static int probe_dtz_no_ep(Position& pos, int *success)
+{
+  int wdl, dtz;
+
+  wdl = probe_ab(pos, -2, 2, success);
+  if (*success == 0) return 0;
+
+  if (wdl == 0) return 0;
+
+  if (*success == 2)
+    return wdl == 2 ? 1 : 101;
+
+  ExtMove stack[192];
+  ExtMove *moves, *end = NULL;
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  if (wdl > 0) {
+    // Generate at least all legal non-capturing pawn moves
+    // including non-capturing promotions.
+    if (!pos.checkers())
+      end = generate<NON_EVASIONS>(pos, stack);
+    else
+      end = generate<EVASIONS>(pos, stack);
+
+    for (moves = stack; moves < end; moves++) {
+      Move move = moves->move;
+      if (type_of(pos.moved_piece(move)) != PAWN || pos.capture(move)
+                || !pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      int v = -probe_ab(pos, -2, -wdl + 1, success);
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v == wdl)
+        return v == 2 ? 1 : 101;
+    }
+  }
+
+  dtz = 1 + probe_dtz_table(pos, wdl, success);
+  if (*success >= 0) {
+    if (wdl & 1) dtz += 100;
+    return wdl >= 0 ? dtz : -dtz;
+  }
+
+  if (wdl > 0) {
+    int best = 0xffff;
+    for (moves = stack; moves < end; moves++) {
+      Move move = moves->move;
+      if (pos.capture(move) || type_of(pos.moved_piece(move)) == PAWN
+                || !pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      int v = -Tablebases::probe_dtz(pos, success);
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v > 0 && v + 1 < best)
+        best = v + 1;
+    }
+    return best;
+  } else {
+    int best = -1;
+    if (!pos.checkers())
+      end = generate<NON_EVASIONS>(pos, stack);
+    else
+      end = generate<EVASIONS>(pos, stack);
+    for (moves = stack; moves < end; moves++) {
+      int v;
+      Move move = moves->move;
+      if (!pos.legal(move, ci.pinned))
+        continue;
+      pos.do_move(move, st, ci, pos.gives_check(move, ci));
+      if (st.rule50 == 0) {
+        if (wdl == -2) v = -1;
+        else {
+          v = probe_ab(pos, 1, 2, success);
+          v = (v == 2) ? 0 : -101;
+        }
+      } else {
+        v = -Tablebases::probe_dtz(pos, success) - 1;
+      }
+      pos.undo_move(move);
+      if (*success == 0) return 0;
+      if (v < best)
+        best = v;
+    }
+    return best;
+  }
+}
+
+static int wdl_to_dtz[] = {
+  -1, -101, 0, 101, 1
+};
+
+// Probe the DTZ table for a particular position.
+// If *success != 0, the probe was successful.
+// The return value is from the point of view of the side to move:
+//         n < -100 : loss, but draw under 50-move rule
+// -100 <= n < -1   : loss in n ply (assuming 50-move counter == 0)
+//         0        : draw
+//     1 < n <= 100 : win in n ply (assuming 50-move counter == 0)
+//   100 < n        : win, but draw under 50-move rule
+//
+// The return value n can be off by 1: a return value -n can mean a loss
+// in n+1 ply and a return value +n can mean a win in n+1 ply. This
+// cannot happen for tables with positions exactly on the "edge" of
+// the 50-move rule.
+//
+// This implies that if dtz > 0 is returned, the position is certainly
+// a win if dtz + 50-move-counter <= 99. Care must be taken that the engine
+// picks moves that preserve dtz + 50-move-counter <= 99.
+//
+// If n = 100 immediately after a capture or pawn move, then the position
+// is also certainly a win, and during the whole phase until the next
+// capture or pawn move, the inequality to be preserved is
+// dtz + 50-movecounter <= 100.
+//
+// In short, if a move is available resulting in dtz + 50-move-counter <= 99,
+// then do not accept moves leading to dtz + 50-move-counter == 100.
+//
+int Tablebases::probe_dtz(Position& pos, int *success)
+{
+  *success = 1;
+  int v = probe_dtz_no_ep(pos, success);
+
+  if (pos.ep_square() == SQ_NONE)
+    return v;
+  if (*success == 0) return 0;
+
+  // Now handle en passant.
+  int v1 = -3;
+
+  ExtMove stack[192];
+  ExtMove *moves, *end;
+  StateInfo st;
+
+  if (!pos.checkers())
+    end = generate<CAPTURES>(pos, stack);
+  else
+    end = generate<EVASIONS>(pos, stack);
+  CheckInfo ci(pos);
+
+  for (moves = stack; moves < end; moves++) {
+    Move capture = moves->move;
+    if (type_of(capture) != ENPASSANT
+                || !pos.legal(capture, ci.pinned))
+      continue;
+    pos.do_move(capture, st, ci, pos.gives_check(capture, ci));
+    int v0 = -probe_ab(pos, -2, 2, success);
+    pos.undo_move(capture);
+    if (*success == 0) return 0;
+    if (v0 > v1) v1 = v0;
+  }
+  if (v1 > -3) {
+    v1 = wdl_to_dtz[v1 + 2];
+    if (v < -100) {
+      if (v1 >= 0)
+        v = v1;
+    } else if (v < 0) {
+      if (v1 >= 0 || v1 < 100)
+        v = v1;
+    } else if (v > 100) {
+      if (v1 > 0)
+        v = v1;
+    } else if (v > 0) {
+      if (v1 == 1)
+        v = v1;
+    } else if (v1 >= 0) {
+      v = v1;
+    } else {
+      for (moves = stack; moves < end; moves++) {
+        Move move = moves->move;
+        if (type_of(move) == ENPASSANT) continue;
+        if (pos.legal(move, ci.pinned)) break;
+      }
+      if (moves == end && !pos.checkers()) {
+        end = generate<QUIETS>(pos, end);
+        for (; moves < end; moves++) {
+          Move move = moves->move;
+          if (pos.legal(move, ci.pinned))
+            break;
+        }
+      }
+      if (moves == end)
+        v = v1;
+    }
+  }
+
+  return v;
+}
+
+// Check whether there has been at least one repetition of positions
+// since the last capture or pawn move.
+static int has_repeated(StateInfo *st)
+{
+  while (1) {
+    int i = 4, e = std::min(st->rule50, st->pliesFromNull);
+    if (e < i)
+      return 0;
+    StateInfo *stp = st->previous->previous;
+    do {
+      stp = stp->previous->previous;
+      if (stp->key == st->key)
+        return 1;
+      i += 2;
+    } while (i <= e);
+    st = st->previous;
+  }
+}
+
+static Value wdl_to_Value[5] = {
+  -VALUE_MATE + MAX_PLY + 1,
+  VALUE_DRAW - 2,
+  VALUE_DRAW,
+  VALUE_DRAW + 2,
+  VALUE_MATE - MAX_PLY - 1
+};
+
+// Use the DTZ tables to filter out moves that don't preserve the win or draw.
+// If the position is lost, but DTZ is fairly high, only keep moves that
+// maximise DTZ.
+//
+// A return value false indicates that not all probes were successful and that
+// no moves were filtered out.
+bool Tablebases::root_probe(Position& pos, Search::RootMoveVector& rootMoves, Value& score)
+{
+  int success;
+
+  int dtz = probe_dtz(pos, &success);
+  if (!success) return false;
+
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  // Probe each move.
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    Move move = rootMoves[i].pv[0];
+    pos.do_move(move, st, ci, pos.gives_check(move, ci));
+    int v = 0;
+    if (pos.checkers() && dtz > 0) {
+      ExtMove s[192];
+      if (generate<LEGAL>(pos, s) == s)
+        v = 1;
+    }
+    if (!v) {
+      if (st.rule50 != 0) {
+        v = -Tablebases::probe_dtz(pos, &success);
+        if (v > 0) v++;
+        else if (v < 0) v--;
+      } else {
+        v = -Tablebases::probe_wdl(pos, &success);
+        v = wdl_to_dtz[v + 2];
+      }
+    }
+    pos.undo_move(move);
+    if (!success) return false;
+    rootMoves[i].score = (Value)v;
+  }
+
+  // Obtain 50-move counter for the root position.
+  // In Stockfish there seems to be no clean way, so we do it like this:
+  int cnt50 = st.previous->rule50;
+
+  // Use 50-move counter to determine whether the root position is
+  // won, lost or drawn.
+  int wdl = 0;
+  if (dtz > 0)
+    wdl = (dtz + cnt50 <= 100) ? 2 : 1;
+  else if (dtz < 0)
+    wdl = (-dtz + cnt50 <= 100) ? -2 : -1;
+
+  // Determine the score to report to the user.
+  score = wdl_to_Value[wdl + 2];
+  // If the position is winning or losing, but too few moves left, adjust the
+  // score to show how close it is to winning or losing.
+  // NOTE: int(PawnValueEg) is used as scaling factor in score_to_uci().
+  if (wdl == 1 && dtz <= 100)
+    score = (Value)(((200 - dtz - cnt50) * int(PawnValueEg)) / 200);
+  else if (wdl == -1 && dtz >= -100)
+    score = -(Value)(((200 + dtz - cnt50) * int(PawnValueEg)) / 200);
+
+  // Now be a bit smart about filtering out moves.
+  size_t j = 0;
+  if (dtz > 0) { // winning (or 50-move rule draw)
+    int best = 0xffff;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v > 0 && v < best)
+        best = v;
+    }
+    int max = best;
+    // If the current phase has not seen repetitions, then try all moves
+    // that stay safely within the 50-move budget, if there are any.
+    if (!has_repeated(st.previous) && best + cnt50 <= 99)
+      max = 99 - cnt50;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v > 0 && v <= max)
+        rootMoves[j++] = rootMoves[i];
+    }
+  } else if (dtz < 0) { // losing (or 50-move rule draw)
+    int best = 0;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      int v = rootMoves[i].score;
+      if (v < best)
+        best = v;
+    }
+    // Try all moves, unless we approach or have a 50-move rule draw.
+    if (-best * 2 + cnt50 < 100)
+      return true;
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      if (rootMoves[i].score == best)
+        rootMoves[j++] = rootMoves[i];
+    }
+  } else { // drawing
+    // Try all moves that preserve the draw.
+    for (size_t i = 0; i < rootMoves.size(); i++) {
+      if (rootMoves[i].score == 0)
+        rootMoves[j++] = rootMoves[i];
+    }
+  }
+  rootMoves.resize(j, Search::RootMove(MOVE_NONE));
+
+  return true;
+}
+
+// Use the WDL tables to filter out moves that don't preserve the win or draw.
+// This is a fallback for the case that some or all DTZ tables are missing.
+//
+// A return value false indicates that not all probes were successful and that
+// no moves were filtered out.
+bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoveVector& rootMoves, Value& score)
+{
+  int success;
+
+  int wdl = Tablebases::probe_wdl(pos, &success);
+  if (!success) return false;
+  score = wdl_to_Value[wdl + 2];
+
+  StateInfo st;
+  CheckInfo ci(pos);
+
+  int best = -2;
+
+  // Probe each move.
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    Move move = rootMoves[i].pv[0];
+    pos.do_move(move, st, ci, pos.gives_check(move, ci));
+    int v = -Tablebases::probe_wdl(pos, &success);
+    pos.undo_move(move);
+    if (!success) return false;
+    rootMoves[i].score = (Value)v;
+    if (v > best)
+      best = v;
+  }
+
+  size_t j = 0;
+  for (size_t i = 0; i < rootMoves.size(); i++) {
+    if (rootMoves[i].score == best)
+      rootMoves[j++] = rootMoves[i];
+  }
+  rootMoves.resize(j, Search::RootMove(MOVE_NONE));
+
+  return true;
+}
+

src/syzygy/tbprobe.h

@@ -0,0 +1,18 @@
+#ifndef TBPROBE_H
+#define TBPROBE_H
+
+#include "../search.h"
+
+namespace Tablebases {
+
+extern int MaxCardinality;
+
+void init(const std::string& path);
+int probe_wdl(Position& pos, int *success);
+int probe_dtz(Position& pos, int *success);
+bool root_probe(Position& pos, Search::RootMoveVector& rootMoves, Value& score);
+bool root_probe_wdl(Position& pos, Search::RootMoveVector& rootMoves, Value& score);
+
+}
+
+#endif

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -23,7 +23,7 @@
 #include "movegen.h"
 #include "search.h"
 #include "thread.h"
-#include "ucioption.h"
+#include "uci.h"
 
 using namespace Search;
 
@@ -40,7 +40,7 @@ namespace {
 
 
  // Helpers to launch a thread after creation and joining before delete. Must be
- // outside Thread c'tor and d'tor because the object will be fully initialized
+ // outside Thread c'tor and d'tor because the object must be fully initialized
  // when start_routine (and hence virtual idle_loop) is called and when joining.
 
  template<typename T> T* new_thread() {
@@ -50,7 +50,11 @@ namespace {
  }
 
  void delete_thread(ThreadBase* th) {
+
+   th->mutex.lock();
    th->exit = true; // Search must be already finished
+   th->mutex.unlock();
+
    th->notify_one();
    thread_join(th->handle); // Wait for thread termination
    delete th;
@@ -59,7 +63,7 @@ namespace {
 }
 
 
-// notify_one() wakes up the thread when there is some work to do
+// ThreadBase::notify_one() wakes up the thread when there is some work to do
 
 void ThreadBase::notify_one() {
 
@@ -69,20 +73,20 @@ void ThreadBase::notify_one() {
 }
 
 
-// wait_for() set the thread to sleep until condition 'b' turns true
+// ThreadBase::wait_for() set the thread to sleep until 'condition' turns true
 
-void ThreadBase::wait_for(volatile const bool& b) {
+void ThreadBase::wait_for(volatile const bool& condition) {
 
   mutex.lock();
-  while (!b) sleepCondition.wait(mutex);
+  while (!condition) sleepCondition.wait(mutex);
   mutex.unlock();
 }
 
 
-// Thread c'tor just inits data and does not launch any execution thread.
-// Such a thread will only be started when c'tor returns.
+// Thread c'tor makes some init but does not launch any execution thread that
+// will be started only when c'tor returns.
 
-Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC
+Thread::Thread() /* : splitPoints() */ { // Initialization of non POD broken in MSVC
 
   searching = false;
   maxPly = splitPointsSize = 0;
@@ -92,7 +96,7 @@ Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC
 }
 
 
-// cutoff_occurred() checks whether a beta cutoff has occurred in the
+// Thread::cutoff_occurred() checks whether a beta cutoff has occurred in the
 // current active split point, or in some ancestor of the split point.
 
 bool Thread::cutoff_occurred() const {
@@ -119,7 +123,7 @@ bool Thread::available_to(const Thread* master) const {
 
   // Make a local copy to be sure it doesn't become zero under our feet while
   // testing next condition and so leading to an out of bounds access.
-  int size = splitPointsSize;
+  const int size = splitPointsSize;
 
   // No split points means that the thread is available as a slave for any
   // other thread otherwise apply the "helpful master" concept if possible.
@@ -127,146 +131,25 @@ bool Thread::available_to(const Thread* master) const {
 }
 
 
-// TimerThread::idle_loop() is where the timer thread waits msec milliseconds
-// and then calls check_time(). If msec is 0 thread sleeps until it's woken up.
-
-void TimerThread::idle_loop() {
-
-  while (!exit)
-  {
-      mutex.lock();
-
-      if (!exit)
-          sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX);
-
-      mutex.unlock();
-
-      if (run)
-          check_time();
-  }
-}
-
-
-// MainThread::idle_loop() is where the main thread is parked waiting to be started
-// when there is a new search. The main thread will launch all the slave threads.
-
-void MainThread::idle_loop() {
-
-  while (true)
-  {
-      mutex.lock();
-
-      thinking = false;
-
-      while (!thinking && !exit)
-      {
-          Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed
-          sleepCondition.wait(mutex);
-      }
-
-      mutex.unlock();
-
-      if (exit)
-          return;
-
-      searching = true;
-
-      Search::think();
-
-      assert(searching);
-
-      searching = false;
-  }
-}
-
-
-// init() is called at startup to create and launch requested threads, that will
-// go immediately to sleep. We cannot use a c'tor because Threads is a static
-// object and we need a fully initialized engine at this point due to allocation
-// of Endgames in Thread c'tor.
-
-void ThreadPool::init() {
-
-  timer = new_thread<TimerThread>();
-  push_back(new_thread<MainThread>());
-  read_uci_options();
-}
-
-
-// exit() cleanly terminates the threads before the program exits. Cannot be done in
-// d'tor because we have to terminate the threads before to free ThreadPool object.
-
-void ThreadPool::exit() {
-
-  delete_thread(timer); // As first because check_time() accesses threads data
-
-  for (iterator it = begin(); it != end(); ++it)
-      delete_thread(*it);
-}
-
-
-// read_uci_options() updates internal threads parameters from the corresponding
-// UCI options and creates/destroys threads to match the requested number. Thread
-// objects are dynamically allocated to avoid creating all possible threads
-// in advance (which include pawns and material tables), even if only a few
-// are to be used.
-
-void ThreadPool::read_uci_options() {
-
-  minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
-  size_t requested  = Options["Threads"];
-
-  assert(requested > 0);
-
-  // If zero (default) then set best minimum split depth automatically
-  if (!minimumSplitDepth)
-      minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
-
-  while (size() < requested)
-      push_back(new_thread<Thread>());
-
-  while (size() > requested)
-  {
-      delete_thread(back());
-      pop_back();
-  }
-}
-
-
-// available_slave() tries to find an idle thread which is available as a slave
-// for the thread 'master'.
-
-Thread* ThreadPool::available_slave(const Thread* master) const {
-
-  for (const_iterator it = begin(); it != end(); ++it)
-      if ((*it)->available_to(master))
-          return *it;
-
-  return NULL;
-}
-
-
-// split() does the actual work of distributing the work at a node between
+// Thread::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), 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
+// informed 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>
-void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Value* bestValue,
+void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue,
                    Move* bestMove, Depth depth, int moveCount,
                    MovePicker* movePicker, int nodeType, bool cutNode) {
 
-  assert(pos.pos_is_ok());
+  assert(searching);
   assert(-VALUE_INFINITE < *bestValue && *bestValue <= alpha && alpha < beta && beta <= 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
+  // Pick and init the next available split point
   SplitPoint& sp = splitPoints[splitPointsSize];
 
   sp.masterThread = this;
@@ -297,14 +180,15 @@ void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Valu
   activeSplitPoint = &sp;
   activePosition = NULL;
 
-  if (!Fake)
-      for (Thread* slave; (slave = Threads.available_slave(this)) != NULL; )
-      {
-          sp.slavesMask.set(slave->idx);
-          slave->activeSplitPoint = &sp;
-          slave->searching = true; // Slave leaves idle_loop()
-          slave->notify_one(); // Could be sleeping
-      }
+  Thread* slave;
+
+  while ((slave = Threads.available_slave(this)) != NULL)
+  {
+      sp.slavesMask.set(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 'searching' flag is set.
@@ -322,8 +206,8 @@ void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Valu
   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::available_to().
+  // finished. Note that setting 'searching' and decreasing splitPointsSize must
+  // be done under lock protection to avoid a race with Thread::available_to().
   Threads.mutex.lock();
   sp.mutex.lock();
 
@@ -339,27 +223,142 @@ void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Valu
   Threads.mutex.unlock();
 }
 
-// Explicit template instantiations
-template void Thread::split<false>(Position&, const Stack*, Value, Value, Value*, Move*, Depth, int, MovePicker*, int, bool);
-template void Thread::split< true>(Position&, const Stack*, Value, Value, Value*, Move*, Depth, int, MovePicker*, int, bool);
 
+// TimerThread::idle_loop() is where the timer thread waits Resolution milliseconds
+// and then calls check_time(). When not searching, thread sleeps until it's woken up.
 
-// wait_for_think_finished() waits for main thread to go to sleep then returns
+void TimerThread::idle_loop() {
 
-void ThreadPool::wait_for_think_finished() {
+  while (!exit)
+  {
+      mutex.lock();
 
-  MainThread* t = main();
-  t->mutex.lock();
-  while (t->thinking) sleepCondition.wait(t->mutex);
-  t->mutex.unlock();
+      if (!exit)
+          sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX);
+
+      mutex.unlock();
+
+      if (run)
+          check_time();
+  }
 }
 
 
-// start_thinking() wakes up the main thread sleeping in MainThread::idle_loop()
-// so to start a new search, then returns immediately.
+// MainThread::idle_loop() is where the main thread is parked waiting to be started
+// when there is a new search. The main thread will launch all the slave threads.
 
-void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits, StateStackPtr& states) {
+void MainThread::idle_loop() {
 
+  while (!exit)
+  {
+      mutex.lock();
+
+      thinking = false;
+
+      while (!thinking && !exit)
+      {
+          Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed
+          sleepCondition.wait(mutex);
+      }
+
+      mutex.unlock();
+
+      if (!exit)
+      {
+          searching = true;
+
+          Search::think();
+
+          assert(searching);
+
+          searching = false;
+      }
+  }
+}
+
+
+// ThreadPool::init() is called at startup to create and launch requested threads,
+// that will go immediately to sleep. We cannot use a c'tor because Threads is a
+// static object and we need a fully initialized engine at this point due to
+// allocation of Endgames in Thread c'tor.
+
+void ThreadPool::init() {
+
+  timer = new_thread<TimerThread>();
+  push_back(new_thread<MainThread>());
+  read_uci_options();
+}
+
+
+// ThreadPool::exit() terminates the threads before the program exits. Cannot be
+// done in d'tor because threads must be terminated before freeing us.
+
+void ThreadPool::exit() {
+
+  delete_thread(timer); // As first because check_time() accesses threads data
+
+  for (iterator it = begin(); it != end(); ++it)
+      delete_thread(*it);
+}
+
+
+// ThreadPool::read_uci_options() updates internal threads parameters from the
+// corresponding UCI options and creates/destroys threads to match the requested
+// number. Thread objects are dynamically allocated to avoid creating all possible
+// threads in advance (which include pawns and material tables), even if only a
+// few are to be used.
+
+void ThreadPool::read_uci_options() {
+
+  minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
+  size_t requested  = Options["Threads"];
+
+  assert(requested > 0);
+
+  // If zero (default) then set best minimum split depth automatically
+  if (!minimumSplitDepth)
+      minimumSplitDepth = requested < 8 ? 4 * ONE_PLY : 7 * ONE_PLY;
+
+  while (size() < requested)
+      push_back(new_thread<Thread>());
+
+  while (size() > requested)
+  {
+      delete_thread(back());
+      pop_back();
+  }
+}
+
+
+// ThreadPool::available_slave() tries to find an idle thread which is available
+// as a slave for the thread 'master'.
+
+Thread* ThreadPool::available_slave(const Thread* master) const {
+
+  for (const_iterator it = begin(); it != end(); ++it)
+      if ((*it)->available_to(master))
+          return *it;
+
+  return NULL;
+}
+
+
+// ThreadPool::wait_for_think_finished() waits for main thread to finish the search
+
+void ThreadPool::wait_for_think_finished() {
+
+  MainThread* th = main();
+  th->mutex.lock();
+  while (th->thinking) sleepCondition.wait(th->mutex);
+  th->mutex.unlock();
+}
+
+
+// ThreadPool::start_thinking() wakes up the main thread sleeping in
+// MainThread::idle_loop() and starts a new search, then returns immediately.
+
+void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
+                                StateStackPtr& states) {
   wait_for_think_finished();
 
   SearchTime = Time::now(); // As early as possible

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -29,9 +29,14 @@
 #include "position.h"
 #include "search.h"
 
+struct Thread;
+
 const int MAX_THREADS = 128;
 const int MAX_SPLITPOINTS_PER_THREAD = 8;
 
+/// Mutex and ConditionVariable struct are wrappers of the low level locking
+/// machinery and are modeled after the corresponding C++11 classes.
+
 struct Mutex {
   Mutex() { lock_init(l); }
  ~Mutex() { lock_destroy(l); }
@@ -57,13 +62,15 @@ private:
   WaitCondition c;
 };
 
-struct Thread;
+
+/// SplitPoint struct stores information shared by the threads searching in
+/// parallel below the same split point. It is populated at splitting time.
 
 struct SplitPoint {
 
   // Const data after split point has been setup
   const Position* pos;
-  const Search::Stack* ss;
+  Search::Stack* ss;
   Thread* masterThread;
   Depth depth;
   Value beta;
@@ -74,7 +81,7 @@ struct SplitPoint {
   MovePicker* movePicker;
   SplitPoint* parentSplitPoint;
 
-  // Shared data
+  // Shared variable data
   Mutex mutex;
   std::bitset<MAX_THREADS> slavesMask;
   volatile bool allSlavesSearching;
@@ -117,14 +124,13 @@ struct Thread : public ThreadBase {
   bool cutoff_occurred() const;
   bool available_to(const Thread* master) const;
 
-  template <bool Fake>
-  void split(Position& pos, const Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
+  void split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove,
              Depth depth, int moveCount, MovePicker* movePicker, int nodeType, bool cutNode);
 
   SplitPoint splitPoints[MAX_SPLITPOINTS_PER_THREAD];
+  Pawns::Table pawnsTable;
   Material::Table materialTable;
   Endgames endgames;
-  Pawns::Table pawnsTable;
   Position* activePosition;
   size_t idx;
   int maxPly;
@@ -144,10 +150,13 @@ struct MainThread : public Thread {
 };
 
 struct TimerThread : public ThreadBase {
+
+  static const int Resolution = 5; // Millisec between two check_time() calls
+
   TimerThread() : run(false) {}
   virtual void idle_loop();
+
   bool run;
-  static const int Resolution = 5; // msec between two check_time() calls
 };
 
 
@@ -157,10 +166,10 @@ struct TimerThread : public ThreadBase {
 
 struct ThreadPool : public std::vector<Thread*> {
 
-  void init(); // No c'tor and d'tor, threads rely on globals that should
-  void exit(); // be initialized and are valid during the whole thread lifetime.
+  void init(); // No c'tor and d'tor, threads rely on globals that should be
+  void exit(); // initialized and are valid during the whole thread lifetime.
 
-  MainThread* main() { return static_cast<MainThread*>((*this)[0]); }
+  MainThread* main() { return static_cast<MainThread*>(at(0)); }
   void read_uci_options();
   Thread* available_slave(const Thread* master) const;
   void wait_for_think_finished();

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -23,7 +23,7 @@
 
 #include "search.h"
 #include "timeman.h"
-#include "ucioption.h"
+#include "uci.h"
 
 namespace {
 
@@ -33,10 +33,6 @@ namespace {
   const double MaxRatio   = 7.0;  // When in trouble, we can step over reserved time with this ratio
   const double StealRatio = 0.33; // However we must not steal time from remaining moves over this ratio
 
-  const double xscale     = 9.3;
-  const double xshift     = 59.8;
-  const double skewfactor = 0.172;
-
 
   // move_importance() is a skew-logistic function based on naive statistical
   // analysis of "how many games are still undecided after n half-moves". Game
@@ -45,82 +41,76 @@ namespace {
 
   double move_importance(int ply) {
 
-    return pow((1 + exp((ply - xshift) / xscale)), -skewfactor) + DBL_MIN; // Ensure non-zero
+    const double XScale = 9.3;
+    const double XShift = 59.8;
+    const double Skew   = 0.172;
+
+    return pow((1 + exp((ply - XShift) / XScale)), -Skew) + DBL_MIN; // Ensure non-zero
   }
 
   template<TimeType T>
-  int remaining(int myTime, int movesToGo, int currentPly, int slowMover)
+  int remaining(int myTime, int movesToGo, int ply, int slowMover)
   {
     const double TMaxRatio   = (T == OptimumTime ? 1 : MaxRatio);
     const double TStealRatio = (T == OptimumTime ? 0 : StealRatio);
 
-    double thisMoveImportance = (move_importance(currentPly) * slowMover) / 100;
+    double moveImportance = (move_importance(ply) * slowMover) / 100;
     double otherMovesImportance = 0;
 
     for (int i = 1; i < movesToGo; ++i)
-        otherMovesImportance += move_importance(currentPly + 2 * i);
+        otherMovesImportance += move_importance(ply + 2 * i);
 
-    double ratio1 = (TMaxRatio * thisMoveImportance) / (TMaxRatio * thisMoveImportance + otherMovesImportance);
-    double ratio2 = (thisMoveImportance + TStealRatio * otherMovesImportance) / (thisMoveImportance + otherMovesImportance);
+    double ratio1 = (TMaxRatio * moveImportance) / (TMaxRatio * moveImportance + otherMovesImportance);
+    double ratio2 = (moveImportance + TStealRatio * otherMovesImportance) / (moveImportance + otherMovesImportance);
 
-    return int(myTime * std::min(ratio1, ratio2));
+    return int(myTime * std::min(ratio1, ratio2)); // Intel C++ asks an explicit cast
   }
 
 } // namespace
 
 
-void TimeManager::init(const Search::LimitsType& limits, int currentPly, Color us)
+/// init() is called at the beginning of the search and calculates the allowed
+/// thinking time out of the time control and current game ply. We support four
+/// different kinds of time controls, passed in 'limits':
+///
+///  inc == 0 && movestogo == 0 means: x basetime  [sudden death!]
+///  inc == 0 && movestogo != 0 means: x moves in y minutes
+///  inc >  0 && movestogo == 0 means: x basetime + z increment
+///  inc >  0 && movestogo != 0 means: x moves in y minutes + z increment
+
+void TimeManager::init(const Search::LimitsType& limits, Color us, int ply)
 {
-  /* We support four different kinds of time controls:
-
-      increment == 0 && movesToGo == 0 means: x basetime  [sudden death!]
-      increment == 0 && movesToGo != 0 means: x moves in y minutes
-      increment >  0 && movesToGo == 0 means: x basetime + z increment
-      increment >  0 && movesToGo != 0 means: x moves in y minutes + z increment
-
-    Time management is adjusted by following UCI parameters:
-
-      emergencyMoveHorizon: Be prepared to always play at least this many moves
-      emergencyBaseTime   : Always attempt to keep at least this much time (in ms) at clock
-      emergencyMoveTime   : Plus attempt to keep at least this much time for each remaining emergency move
-      minThinkingTime     : No matter what, use at least this much thinking before doing the move
-  */
-
-  int hypMTG, hypMyTime, t1, t2;
-
-  // Read uci parameters
-  int emergencyMoveHorizon = Options["Emergency Move Horizon"];
-  int emergencyBaseTime    = Options["Emergency Base Time"];
-  int emergencyMoveTime    = Options["Emergency Move Time"];
-  int minThinkingTime      = Options["Minimum Thinking Time"];
-  int slowMover            = Options["Slow Mover"];
+  int minThinkingTime = Options["Minimum Thinking Time"];
+  int moveOverhead    = Options["Move Overhead"];
+  int slowMover       = Options["Slow Mover"];
 
   // Initialize unstablePvFactor to 1 and search times to maximum values
   unstablePvFactor = 1;
   optimumSearchTime = maximumSearchTime = std::max(limits.time[us], minThinkingTime);
 
-  // We calculate optimum time usage for different hypothetical "moves to go"-values and choose the
-  // minimum of calculated search time values. Usually the greatest hypMTG gives the minimum values.
-  for (hypMTG = 1; hypMTG <= (limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon); ++hypMTG)
+  const int MaxMTG = limits.movestogo ? std::min(limits.movestogo, MoveHorizon) : MoveHorizon;
+
+  // We calculate optimum time usage for different hypothetical "moves to go"-values
+  // and choose the minimum of calculated search time values. Usually the greatest
+  // hypMTG gives the minimum values.
+  for (int hypMTG = 1; hypMTG <= MaxMTG; ++hypMTG)
   {
       // Calculate thinking time for hypothetical "moves to go"-value
-      hypMyTime =  limits.time[us]
-                 + limits.inc[us] * (hypMTG - 1)
-                 - emergencyBaseTime
-                 - emergencyMoveTime * std::min(hypMTG, emergencyMoveHorizon);
+      int hypMyTime =  limits.time[us]
+                     + limits.inc[us] * (hypMTG - 1)
+                     - moveOverhead * (2 + std::min(hypMTG, 40));
 
       hypMyTime = std::max(hypMyTime, 0);
 
-      t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, currentPly, slowMover);
-      t2 = minThinkingTime + remaining<MaxTime>(hypMyTime, hypMTG, currentPly, slowMover);
+      int t1 = minThinkingTime + remaining<OptimumTime>(hypMyTime, hypMTG, ply, slowMover);
+      int t2 = minThinkingTime + remaining<MaxTime    >(hypMyTime, hypMTG, ply, slowMover);
 
-      optimumSearchTime = std::min(optimumSearchTime, t1);
-      maximumSearchTime = std::min(maximumSearchTime, t2);
+      optimumSearchTime = std::min(t1, optimumSearchTime);
+      maximumSearchTime = std::min(t2, maximumSearchTime);
   }
 
   if (Options["Ponder"])
       optimumSearchTime += optimumSearchTime / 4;
 
-  // Make sure that maxSearchTime is not over absoluteMaxSearchTime
   optimumSearchTime = std::min(optimumSearchTime, maximumSearchTime);
 }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -25,7 +25,7 @@
 
 class TimeManager {
 public:
-  void init(const Search::LimitsType& limits, int currentPly, Color us);
+  void init(const Search::LimitsType& limits, Color us, int ply);
   void pv_instability(double bestMoveChanges) { unstablePvFactor = 1 + bestMoveChanges; }
   int available_time() const { return int(optimumSearchTime * unstablePvFactor * 0.71); }
   int maximum_time() const { return maximumSearchTime; }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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 <cstring>
+#include <cstring>   // For std::memset
 #include <iostream>
 
 #include "bitboard.h"
@@ -30,18 +30,19 @@ TranspositionTable TT; // Our global transposition table
 /// 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::resize(uint64_t mbSize) {
+void TranspositionTable::resize(size_t mbSize) {
 
-  assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);
+  assert(sizeof(Cluster) == CacheLineSize / 2);
 
-  uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
+  size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(Cluster));
 
-  if (hashMask == size - ClusterSize)
+  if (newClusterCount == clusterCount)
       return;
 
-  hashMask = size - ClusterSize;
+  clusterCount = newClusterCount;
+
   free(mem);
-  mem = calloc(size * sizeof(TTEntry) + CACHE_LINE_SIZE - 1, 1);
+  mem = calloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1, 1);
 
   if (!mem)
   {
@@ -50,72 +51,48 @@ void TranspositionTable::resize(uint64_t mbSize) {
       exit(EXIT_FAILURE);
   }
 
-  table = (TTEntry*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
+  table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
 }
 
 
 /// TranspositionTable::clear() overwrites the entire transposition table
-/// with zeroes. It is called whenever the table is resized, or when the
+/// with zeros. It is called whenever the table is resized, or when the
 /// user asks the program to clear the table (from the UCI interface).
 
 void TranspositionTable::clear() {
 
-  std::memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry));
+  std::memset(table, 0, clusterCount * sizeof(Cluster));
 }
 
 
-/// TranspositionTable::probe() looks up the current position in the
-/// transposition table. Returns a pointer to the TTEntry or NULL if
-/// position is not found.
+/// TranspositionTable::probe() looks up the current position in the transposition
+/// table. It returns true and a pointer to the TTEntry if the position is found.
+/// Otherwise, it returns false and a pointer to an empty or least valuable TTEntry
+/// to be replaced later. A TTEntry t1 is considered to be 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.
 
-const TTEntry* TranspositionTable::probe(const Key key) const {
+TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
 
-  TTEntry* tte = first_entry(key);
-  uint32_t key32 = key >> 32;
+  TTEntry* const tte = first_entry(key);
+  const uint16_t key16 = key >> 48;  // Use the high 16 bits as key inside the cluster
 
-  for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
-      if (tte->key32 == key32)
+  for (int i = 0; i < ClusterSize; ++i)
+      if (!tte[i].key16 || tte[i].key16 == key16)
       {
-          tte->generation8 = generation; // Refresh
-          return tte;
+          if (tte[i].key16)
+              tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
+
+          return found = (bool)tte[i].key16, &tte[i];
       }
 
-  return NULL;
-}
-
-
-/// TranspositionTable::store() writes a new entry containing position key and
-/// valuable information of current position. The lowest order bits of position
-/// key are used to decide in which cluster the position will be placed.
-/// When a new entry is written and there are no empty entries available in the
-/// cluster, it replaces the least valuable of the entries. A TTEntry t1 is considered
-/// to be 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 key, Value v, Bound b, Depth d, Move m, Value statV) {
-
-  TTEntry *tte, *replace;
-  uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster
-
-  tte = replace = first_entry(key);
-
-  for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
-  {
-      if (!tte->key32 || tte->key32 == key32) // Empty or overwrite old
-      {
-          if (!m)
-              m = tte->move(); // Preserve any existing ttMove
-
-          replace = tte;
-          break;
-      }
-
-      // Implement replace strategy
-      if (  (    tte->generation8 == generation || tte->bound() == BOUND_EXACT)
-          - (replace->generation8 == generation)
-          - (tte->depth16 < replace->depth16) < 0)
-          replace = tte;
-  }
-
-  replace->save(key32, v, b, d, m, generation, statV);
+  // Find an entry to be replaced according to the replacement strategy
+  TTEntry* replace = tte;
+  for (int i = 1; i < ClusterSize; ++i)
+      if (  ((  tte[i].genBound8 & 0xFC) == generation8 || tte[i].bound() == BOUND_EXACT)
+          - ((replace->genBound8 & 0xFC) == generation8)
+          - (tte[i].depth8 < replace->depth8) < 0)
+          replace = &tte[i];
+
+  return found = false, replace;
 }

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -23,42 +23,45 @@
 #include "misc.h"
 #include "types.h"
 
-/// The TTEntry is the 14 bytes transposition table entry, defined as below:
+/// TTEntry struct is the 10 bytes transposition table entry, defined as below:
 ///
-/// key        32 bit
+/// key        16 bit
 /// move       16 bit
-/// bound type  8 bit
-/// generation  8 bit
 /// value      16 bit
-/// depth      16 bit
 /// eval value 16 bit
+/// generation  6 bit
+/// bound type  2 bit
+/// depth       8 bit
 
 struct TTEntry {
 
-  Move  move()  const      { return (Move )move16; }
-  Bound bound() const      { return (Bound)bound8; }
-  Value value() const      { return (Value)value16; }
-  Depth depth() const      { return (Depth)depth16; }
-  Value eval_value() const { return (Value)evalValue; }
+  Move  move()  const { return (Move )move16; }
+  Value value() const { return (Value)value16; }
+  Value eval()  const { return (Value)eval16; }
+  Depth depth() const { return (Depth)depth8; }
+  Bound bound() const { return (Bound)(genBound8 & 0x3); }
+
+  void save(Key k, Value v, Bound b, Depth d, Move m, Value ev, uint8_t g) {
+
+    if (m || (k >> 48) != key16) // Preserve any existing move for the same position
+        move16 = (uint16_t)m;
+
+    key16     = (uint16_t)(k >> 48);
+    value16   = (int16_t)v;
+    eval16    = (int16_t)ev;
+    genBound8 = (uint8_t)(g | b);
+    depth8    = (int8_t)d;
+  }
 
 private:
   friend class TranspositionTable;
 
-  void save(uint32_t k, Value v, Bound b, Depth d, Move m, uint8_t g, Value ev) {
-
-    key32       = (uint32_t)k;
-    move16      = (uint16_t)m;
-    bound8      = (uint8_t)b;
-    generation8 = (uint8_t)g;
-    value16     = (int16_t)v;
-    depth16     = (int16_t)d;
-    evalValue   = (int16_t)ev;
-  }
-
-  uint32_t key32;
+  uint16_t key16;
   uint16_t move16;
-  uint8_t bound8, generation8;
-  int16_t value16, depth16, evalValue;
+  int16_t  value16;
+  int16_t  eval16;
+  uint8_t  genBound8;
+  int8_t   depth8;
 };
 
 
@@ -70,35 +73,34 @@ private:
 
 class TranspositionTable {
 
-  static const unsigned ClusterSize = 4;
+  static const int CacheLineSize = 64;
+  static const int ClusterSize = 3;
+
+  struct Cluster {
+    TTEntry entry[ClusterSize];
+    char padding[2]; // Align to the cache line size
+  };
 
 public:
  ~TranspositionTable() { free(mem); }
-  void new_search() { ++generation; }
-
-  const TTEntry* probe(const Key key) const;
-  TTEntry* first_entry(const Key key) const;
-  void resize(uint64_t mbSize);
+  void new_search() { generation8 += 4; } // Lower 2 bits are used by Bound
+  uint8_t generation() const { return generation8; }
+  TTEntry* probe(const Key key, bool& found) const;
+  void resize(size_t mbSize);
   void clear();
-  void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV);
+
+  // The lowest order bits of the key are used to get the index of the cluster
+  TTEntry* first_entry(const Key key) const {
+    return &table[(size_t)key & (clusterCount - 1)].entry[0];
+  }
 
 private:
-  uint32_t hashMask;
-  TTEntry* table;
+  size_t clusterCount;
+  Cluster* table;
   void* mem;
-  uint8_t generation; // Size must be not bigger than TTEntry::generation8
+  uint8_t generation8; // Size must be not bigger than TTEntry::genBound8
 };
 
 extern TranspositionTable TT;
 
-
-/// TranspositionTable::first_entry() returns a pointer to the first entry of
-/// 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 key) const {
-
-  return table + ((uint32_t)key & hashMask);
-}
-
 #endif // #ifndef TT_H_INCLUDED

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -20,20 +20,19 @@
 #ifndef TYPES_H_INCLUDED
 #define TYPES_H_INCLUDED
 
-/// For Linux and OSX configuration is done automatically using Makefile. To get
-/// started type 'make help'.
+/// When compiling with provided Makefile (e.g. for Linux and OSX), configuration
+/// is done automatically. To get started type 'make help'.
 ///
-/// For Windows, part of the configuration is detected automatically, but some
-/// switches need to be set manually:
+/// When Makefile is not used (e.g. with Microsoft Visual Studio) some switches
+/// need to be set manually:
 ///
-/// -DNDEBUG      | Disable debugging mode. Always use this.
+/// -DNDEBUG      | Disable debugging mode. Always use this for release.
 ///
-/// -DNO_PREFETCH | Disable use of prefetch asm-instruction. A must if you want
-///               | the executable to run on some very old machines.
+/// -DNO_PREFETCH | Disable use of prefetch asm-instruction. You may need this to
+///               | run on some very old machines.
 ///
 /// -DUSE_POPCNT  | Add runtime support for use of popcnt asm-instruction. Works
-///               | only in 64-bit mode. For compiling requires hardware with
-///               | popcnt support.
+///               | only in 64-bit mode and requires hardware with popcnt support.
 
 #include <cassert>
 #include <cctype>
@@ -42,33 +41,33 @@
 
 #include "platform.h"
 
-#define unlikely(x) (x) // For code annotation purposes
+/// Predefined macros hell:
+///
+/// __GNUC__           Compiler is gcc, Clang or Intel on Linux
+/// __INTEL_COMPILER   Compiler is Intel
+/// _MSC_VER           Compiler is MSVC or Intel on Windows
+/// _WIN32             Building on Windows (any)
+/// _WIN64             Building on Windows 64 bit
 
-#if defined(_WIN64) && !defined(IS_64BIT)
+#if defined(_WIN64) && !defined(IS_64BIT) // Last condition means Makefile is not used
 #  include <intrin.h> // MSVC popcnt and bsfq instrinsics
 #  define IS_64BIT
 #  define USE_BSFQ
 #endif
 
-#if defined(USE_POPCNT) && defined(_MSC_VER) && defined(__INTEL_COMPILER)
+#if defined(USE_POPCNT) && defined(__INTEL_COMPILER) && defined(_MSC_VER)
 #  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(USE_PEXT)
 #  include <immintrin.h> // Header for _pext_u64() intrinsic
+#  define pext(b, m) _pext_u64(b, m)
 #else
-#  define _pext_u64(b, m) (0)
-#endif
-
-#  if !defined(NO_PREFETCH) && (defined(__INTEL_COMPILER) || defined(_MSC_VER))
-#   include <xmmintrin.h> // Intel and Microsoft header for _mm_prefetch()
-#  endif
-
-#define CACHE_LINE_SIZE 64
-#if defined(_MSC_VER) || defined(__INTEL_COMPILER)
-#  define CACHE_LINE_ALIGNMENT __declspec(align(CACHE_LINE_SIZE))
-#else
-#  define CACHE_LINE_ALIGNMENT  __attribute__ ((aligned(CACHE_LINE_SIZE)))
+#  define pext(b, m) (0)
 #endif
 
 #ifdef _MSC_VER
@@ -100,9 +99,8 @@ const bool Is64Bit = false;
 typedef uint64_t Key;
 typedef uint64_t Bitboard;
 
-const int MAX_MOVES      = 256;
-const int MAX_PLY        = 120;
-const int MAX_PLY_PLUS_6 = MAX_PLY + 6;
+const int MAX_MOVES = 256;
+const int MAX_PLY   = 128;
 
 /// A move needs 16 bits to be stored
 ///
@@ -136,12 +134,12 @@ enum CastlingSide {
   KING_SIDE, QUEEN_SIDE, CASTLING_SIDE_NB = 2
 };
 
-enum CastlingRight {  // Defined as in PolyGlot book hash key
+enum CastlingRight {
   NO_CASTLING,
   WHITE_OO,
-  WHITE_OOO   = WHITE_OO << 1,
-  BLACK_OO    = WHITE_OO << 2,
-  BLACK_OOO   = WHITE_OO << 3,
+  WHITE_OOO = WHITE_OO << 1,
+  BLACK_OO  = WHITE_OO << 2,
+  BLACK_OOO = WHITE_OO << 3,
   ANY_CASTLING = WHITE_OO | WHITE_OOO | BLACK_OO | BLACK_OOO,
   CASTLING_RIGHT_NB = 16
 };
@@ -181,8 +179,8 @@ enum Value {
   VALUE_INFINITE  = 32001,
   VALUE_NONE      = 32002,
 
-  VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - MAX_PLY,
-  VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + MAX_PLY,
+  VALUE_MATE_IN_MAX_PLY  =  VALUE_MATE - 2 * MAX_PLY,
+  VALUE_MATED_IN_MAX_PLY = -VALUE_MATE + 2 * MAX_PLY,
 
   VALUE_ENSURE_INTEGER_SIZE_P = INT_MAX,
   VALUE_ENSURE_INTEGER_SIZE_N = INT_MIN,
@@ -211,14 +209,15 @@ enum Piece {
 
 enum Depth {
 
-  ONE_PLY = 2,
+  ONE_PLY = 1,
 
-  DEPTH_ZERO          =  0 * ONE_PLY,
-  DEPTH_QS_CHECKS     =  0 * ONE_PLY,
-  DEPTH_QS_NO_CHECKS  = -1 * ONE_PLY,
-  DEPTH_QS_RECAPTURES = -5 * ONE_PLY,
+  DEPTH_ZERO          =  0,
+  DEPTH_QS_CHECKS     =  0,
+  DEPTH_QS_NO_CHECKS  = -1,
+  DEPTH_QS_RECAPTURES = -5,
 
-  DEPTH_NONE = -127 * ONE_PLY
+  DEPTH_NONE = -6,
+  DEPTH_MAX  = MAX_PLY
 };
 
 enum Square {
@@ -256,9 +255,9 @@ enum Rank {
 };
 
 
-/// The Score enum stores a middlegame and an endgame value in a single integer
-/// (enum). The least significant 16 bits are used to store the endgame value
-/// and the upper 16 bits are used to store the middlegame value. The compiler
+/// Score enum stores a middlegame and an endgame value in a single integer.
+/// The least significant 16 bits are used to store the endgame value and
+/// the upper 16 bits are used to store the middlegame value. The compiler
 /// is free to choose the enum type as long as it can store the data, so we
 /// ensure that Score is an integer type by assigning some big int values.
 enum Score {
@@ -267,47 +266,41 @@ enum Score {
   SCORE_ENSURE_INTEGER_SIZE_N = INT_MIN
 };
 
-typedef union {
-  uint32_t full;
-  struct { int16_t eg, mg; } half;
-} ScoreView;
-
 inline Score make_score(int mg, int eg) {
-  ScoreView v;
-  v.half.mg = (int16_t)(mg - (uint16_t(eg) >> 15));
-  v.half.eg = (int16_t)eg;
-  return Score(v.full);
+  return Score((mg << 16) + eg);
 }
 
+/// Extracting the signed lower and upper 16 bits is not so trivial because
+/// according to the standard a simple cast to short is implementation defined
+/// and so is a right shift of a signed integer.
 inline Value mg_value(Score s) {
-  ScoreView v;
-  v.full = s;
-  return Value(v.half.mg + (uint16_t(v.half.eg) >> 15));
+
+  union { uint16_t u; int16_t s; } mg = { uint16_t(unsigned(s + 0x8000) >> 16) };
+  return Value(mg.s);
 }
 
 inline Value eg_value(Score s) {
-  ScoreView v;
-  v.full = s;
-  return Value(v.half.eg);
+
+  union { uint16_t u; int16_t s; } eg = { uint16_t(unsigned(s)) };
+  return Value(eg.s);
 }
 
-#define ENABLE_BASE_OPERATORS_ON(T)                                         \
-inline T operator+(const T d1, const T d2) { return T(int(d1) + int(d2)); } \
-inline T operator-(const T d1, const T d2) { return T(int(d1) - int(d2)); } \
-inline T operator*(int i, const T d) { return T(i * int(d)); }              \
-inline T operator*(const T d, int i) { return T(int(d) * i); }              \
-inline T operator-(const T d) { return T(-int(d)); }                        \
-inline T& operator+=(T& d1, const T d2) { return d1 = d1 + d2; }            \
-inline T& operator-=(T& d1, const T d2) { return d1 = d1 - d2; }            \
+#define ENABLE_BASE_OPERATORS_ON(T)                             \
+inline T operator+(T d1, T d2) { return T(int(d1) + int(d2)); } \
+inline T operator-(T d1, T d2) { return T(int(d1) - int(d2)); } \
+inline T operator*(int i, T d) { return T(i * int(d)); }        \
+inline T operator*(T d, int i) { return T(int(d) * i); }        \
+inline T operator-(T d) { return T(-int(d)); }                  \
+inline T& operator+=(T& d1, T d2) { return d1 = d1 + d2; }      \
+inline T& operator-=(T& d1, T d2) { return d1 = d1 - d2; }      \
 inline T& operator*=(T& d, int i) { return d = T(int(d) * i); }
 
-ENABLE_BASE_OPERATORS_ON(Score)
-
-#define ENABLE_FULL_OPERATORS_ON(T)                                         \
-ENABLE_BASE_OPERATORS_ON(T)                                                 \
-inline T& operator++(T& d) { return d = T(int(d) + 1); }                    \
-inline T& operator--(T& d) { return d = T(int(d) - 1); }                    \
-inline T operator/(const T d, int i) { return T(int(d) / i); }              \
+#define ENABLE_FULL_OPERATORS_ON(T)                             \
+ENABLE_BASE_OPERATORS_ON(T)                                     \
+inline T& operator++(T& d) { return d = T(int(d) + 1); }        \
+inline T& operator--(T& d) { return d = T(int(d) - 1); }        \
+inline T operator/(T d, int i) { return T(int(d) / i); }        \
+inline int operator/(T d1, T d2) { return int(d1) / int(d2); }  \
 inline T& operator/=(T& d, int i) { return d = T(int(d) / i); }
 
 ENABLE_FULL_OPERATORS_ON(Value)
@@ -319,6 +312,8 @@ ENABLE_FULL_OPERATORS_ON(Square)
 ENABLE_FULL_OPERATORS_ON(File)
 ENABLE_FULL_OPERATORS_ON(Rank)
 
+ENABLE_BASE_OPERATORS_ON(Score)
+
 #undef ENABLE_FULL_OPERATORS_ON
 #undef ENABLE_BASE_OPERATORS_ON
 
@@ -339,15 +334,6 @@ inline Score operator/(Score s, int i) {
 
 extern Value PieceValue[PHASE_NB][PIECE_NB];
 
-struct ExtMove {
-  Move move;
-  Value value;
-};
-
-inline bool operator<(const ExtMove& f, const ExtMove& s) {
-  return f.value < s.value;
-}
-
 inline Color operator~(Color c) {
   return Color(c ^ BLACK);
 }
@@ -414,14 +400,6 @@ inline bool opposite_colors(Square s1, Square s2) {
   return ((s >> 3) ^ s) & 1;
 }
 
-inline char to_char(File f, bool tolower = true) {
-  return char(f - FILE_A + (tolower ? 'a' : 'A'));
-}
-
-inline char to_char(Rank r) {
-  return char(r - RANK_1 + '1');
-}
-
 inline Square pawn_push(Color c) {
   return c == WHITE ? DELTA_N : DELTA_S;
 }
@@ -452,14 +430,7 @@ inline Move make(Square from, Square to, PieceType pt = KNIGHT) {
 }
 
 inline bool is_ok(Move m) {
-  return from_sq(m) != to_sq(m); // Catches also MOVE_NULL and MOVE_NONE
-}
-
-#include <string>
-
-inline const std::string to_string(Square s) {
-  char ch[] = { to_char(file_of(s)), to_char(rank_of(s)), 0 };
-  return ch;
+  return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
 }
 
 #endif // #ifndef 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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -17,18 +17,17 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <iomanip>
 #include <iostream>
 #include <sstream>
 #include <string>
 
 #include "evaluate.h"
-#include "notation.h"
+#include "movegen.h"
 #include "position.h"
 #include "search.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
 
 using namespace std;
 
@@ -39,9 +38,9 @@ namespace {
   // FEN string of the initial position, normal chess
   const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
-  // Keep a track of the position keys along the setup moves (from the start position
-  // to the position just before the search starts). This is needed by the repetition
-  // draw detection code.
+  // Stack to keep track of the position states along the setup moves (from the
+  // start position to the position just before the search starts). Needed by
+  // 'draw by repetition' detection.
   Search::StateStackPtr SetupStates;
 
 
@@ -72,7 +71,7 @@ namespace {
     SetupStates = Search::StateStackPtr(new std::stack<StateInfo>());
 
     // Parse move list (if any)
-    while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
+    while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
     {
         SetupStates->push(StateInfo());
         pos.do_move(m, SetupStates->top());
@@ -105,7 +104,7 @@ 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 starts
+  // the thinking time and other parameters from the input string, then starts
   // the search.
 
   void go(const Position& pos, istringstream& is) {
@@ -114,10 +113,9 @@ namespace {
     string token;
 
     while (is >> token)
-    {
         if (token == "searchmoves")
             while (is >> token)
-                limits.searchmoves.push_back(move_from_uci(pos, token));
+                limits.searchmoves.push_back(UCI::to_move(pos, token));
 
         else if (token == "wtime")     is >> limits.time[WHITE];
         else if (token == "btime")     is >> limits.time[BLACK];
@@ -130,7 +128,6 @@ namespace {
         else if (token == "mate")      is >> limits.mate;
         else if (token == "infinite")  limits.infinite = true;
         else if (token == "ponder")    limits.ponder = true;
-    }
 
     Threads.start_thinking(pos, limits, SetupStates);
   }
@@ -138,10 +135,11 @@ namespace {
 } // namespace
 
 
-/// Wait for a command from the user, parse this text string as an UCI command,
-/// and call the appropriate functions. Also intercepts EOF from stdin to ensure
-/// that we exit gracefully if the GUI dies unexpectedly. In addition to the UCI
-/// commands, the function also supports a few debug commands.
+/// UCI::loop() waits for a command from stdin, parses it and calls the appropriate
+/// function. Also intercepts EOF from stdin to ensure gracefully exiting if the
+/// GUI dies unexpectedly. When called with some command line arguments, e.g. to
+/// run 'bench', once the command is executed the function returns immediately.
+/// In addition to the UCI ones, also some additional debug commands are supported.
 
 void UCI::loop(int argc, char* argv[]) {
 
@@ -152,64 +150,56 @@ void UCI::loop(int argc, char* argv[]) {
       cmd += std::string(argv[i]) + " ";
 
   do {
-      if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input
+      if (argc == 1 && !getline(cin, cmd)) // Block here waiting for input or EOF
           cmd = "quit";
 
       istringstream is(cmd);
 
+      token.clear(); // getline() could return empty or blank line
       is >> skipws >> token;
 
-      if (token == "quit" || token == "stop" || token == "ponderhit")
+      // The 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 == "quit"
+          ||  token == "stop"
+          || (token == "ponderhit" && Search::Signals.stopOnPonderhit))
       {
-          // The 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
-          // switch from pondering to normal search.
-          if (token != "ponderhit" || Search::Signals.stopOnPonderhit)
-          {
-              Search::Signals.stop = true;
-              Threads.main()->notify_one(); // Could be sleeping
-          }
-          else
-              Search::Limits.ponder = false;
+          Search::Signals.stop = true;
+          Threads.main()->notify_one(); // Could be sleeping
       }
-      else if (token == "perft" || token == "divide")
-      {
-          int depth;
-          stringstream ss;
-
-          is >> depth;
-          ss << Options["Hash"]    << " "
-             << Options["Threads"] << " " << depth << " current " << token;
-
-          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 << nouppercase << setfill(' ') << sync_endl;
+      else if (token == "ponderhit")
+          Search::Limits.ponder = false; // Switch to normal search
 
       else if (token == "uci")
           sync_cout << "id name " << engine_info(true)
                     << "\n"       << Options
                     << "\nuciok"  << sync_endl;
 
-      else if (token == "eval")
-      {
-          Search::RootColor = pos.side_to_move(); // Ensure it is set
-          sync_cout << Eval::trace(pos) << sync_endl;
-      }
-      else if (token == "ucinewgame") { /* Avoid returning "Unknown command" */ }
+      else if (token == "isready")    sync_cout << "readyok" << sync_endl;
+      else if (token == "ucinewgame") TT.clear();
       else if (token == "go")         go(pos, is);
       else if (token == "position")   position(pos, is);
       else if (token == "setoption")  setoption(is);
+
+      // Additional custom non-UCI commands, useful for debugging
       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 == "d")          sync_cout << pos << sync_endl;
+      else if (token == "eval")       sync_cout << Eval::trace(pos) << sync_endl;
+      else if (token == "perft")
+      {
+          int depth;
+          stringstream ss;
+
+          is >> depth;
+          ss << Options["Hash"]    << " "
+             << Options["Threads"] << " " << depth << " current perft";
+
+          benchmark(pos, ss);
+      }
       else
           sync_cout << "Unknown command: " << cmd << sync_endl;
 
@@ -217,3 +207,76 @@ void UCI::loop(int argc, char* argv[]) {
 
   Threads.wait_for_think_finished(); // Cannot quit whilst the search is running
 }
+
+
+/// UCI::value() converts a Value to a string suitable for use with the UCI
+/// protocol specification:
+///
+/// cp <x>    The score from the engine's point of view in centipawns.
+/// mate <y>  Mate in y moves, not plies. If the engine is getting mated
+///           use negative values for y.
+
+string UCI::value(Value v) {
+
+  stringstream ss;
+
+  if (abs(v) < VALUE_MATE - MAX_PLY)
+      ss << "cp " << v * 100 / PawnValueEg;
+  else
+      ss << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+
+  return ss.str();
+}
+
+
+/// UCI::square() converts a Square to a string in algebraic notation (g1, a7, etc.)
+
+std::string UCI::square(Square s) {
+
+  char sq[] = { char('a' + file_of(s)), char('1' + rank_of(s)), 0 }; // NULL terminated
+  return sq;
+}
+
+
+/// UCI::move() converts a Move to a string in coordinate notation (g1f3, a7a8q).
+/// The only special case is castling, where we print in the e1g1 notation in
+/// normal chess mode, and in e1h1 notation in chess960 mode. Internally all
+/// castling moves are always encoded as 'king captures rook'.
+
+string UCI::move(Move m, bool chess960) {
+
+  Square from = from_sq(m);
+  Square to = to_sq(m);
+
+  if (m == MOVE_NONE)
+      return "(none)";
+
+  if (m == MOVE_NULL)
+      return "0000";
+
+  if (type_of(m) == CASTLING && !chess960)
+      to = make_square(to > from ? FILE_G : FILE_C, rank_of(from));
+
+  string move = UCI::square(from) + UCI::square(to);
+
+  if (type_of(m) == PROMOTION)
+      move += " pnbrqk"[promotion_type(m)];
+
+  return move;
+}
+
+
+/// UCI::to_move() converts a string representing a move in coordinate notation
+/// (g1f3, a7a8q) to the corresponding legal Move, if any.
+
+Move UCI::to_move(const Position& pos, string& str) {
+
+  if (str.length() == 5) // Junior could send promotion piece in uppercase
+      str[4] = char(tolower(str[4]));
+
+  for (MoveList<LEGAL> it(pos); *it; ++it)
+      if (str == UCI::move(*it, pos.is_chess960()))
+          return *it;
+
+  return MOVE_NONE;
+}

src/uci.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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -23,6 +23,10 @@
 #include <map>
 #include <string>
 
+#include "types.h"
+
+class Position;
+
 namespace UCI {
 
 class Option;
@@ -46,8 +50,8 @@ public:
   Option(const char* v, OnChange = NULL);
   Option(int v, int min, int max, OnChange = NULL);
 
-  Option& operator=(const std::string& v);
-  void operator<<(const Option& o);
+  Option& operator=(const std::string&);
+  void operator<<(const Option&);
   operator int() const;
   operator std::string() const;
 
@@ -62,6 +66,10 @@ private:
 
 void init(OptionsMap&);
 void loop(int argc, char* argv[]);
+std::string value(Value v);
+std::string square(Square s);
+std::string move(Move m, bool chess960);
+Move to_move(const Position& pos, std::string& str);
 
 } // namespace UCI
 

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) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 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
@@ -22,11 +22,11 @@
 #include <cstdlib>
 #include <sstream>
 
-#include "evaluate.h"
 #include "misc.h"
 #include "thread.h"
 #include "tt.h"
-#include "ucioption.h"
+#include "uci.h"
+#include "syzygy/tbprobe.h"
 
 using std::string;
 
@@ -35,11 +35,11 @@ UCI::OptionsMap Options; // Global object
 namespace UCI {
 
 /// 'On change' actions, triggered by an option's value change
-void on_logger(const Option& o) { start_logger(o); }
-void on_eval(const Option&) { Eval::init(); }
-void on_threads(const Option&) { Threads.read_uci_options(); }
-void on_hash_size(const Option& o) { TT.resize(o); }
 void on_clear_hash(const Option&) { TT.clear(); }
+void on_hash_size(const Option& o) { TT.resize(o); }
+void on_logger(const Option& o) { start_logger(o); }
+void on_threads(const Option&) { Threads.read_uci_options(); }
+void on_tb_path(const Option& o) { Tablebases::init(o); }
 
 
 /// Our case insensitive less() function as required by UCI protocol
@@ -54,35 +54,25 @@ bool CaseInsensitiveLess::operator() (const string& s1, const string& s2) const
 
 void init(OptionsMap& o) {
 
-  o["Write Debug Log"]          << Option(false, on_logger);
-  o["Write Search Log"]         << Option(false);
-  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 (Midgame)"]       << Option(100, 0, 200, on_eval);
-  o["Mobility (Endgame)"]       << Option(100, 0, 200, on_eval);
-  o["Pawn Structure (Midgame)"] << Option(100, 0, 200, on_eval);
-  o["Pawn Structure (Endgame)"] << Option(100, 0, 200, on_eval);
-  o["Passed Pawns (Midgame)"]   << Option(100, 0, 200, on_eval);
-  o["Passed Pawns (Endgame)"]   << Option(100, 0, 200, on_eval);
-  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(0, 0, 12, on_threads);
-  o["Threads"]                  << Option(1, 1, MAX_THREADS, on_threads);
-  o["Hash"]                     << Option(32, 1, 16384, on_hash_size);
-  o["Clear Hash"]               << Option(on_clear_hash);
-  o["Ponder"]                   << Option(true);
-  o["OwnBook"]                  << Option(false);
-  o["MultiPV"]                  << Option(1, 1, 500);
-  o["Skill Level"]              << Option(20, 0, 20);
-  o["Emergency Move Horizon"]   << Option(40, 0, 50);
-  o["Emergency Base Time"]      << Option(60, 0, 30000);
-  o["Emergency Move Time"]      << Option(30, 0, 5000);
-  o["Minimum Thinking Time"]    << Option(20, 0, 5000);
-  o["Slow Mover"]               << Option(80, 10, 1000);
-  o["UCI_Chess960"]             << Option(false);
+  const int MaxHashMB = Is64Bit ? 1024 * 1024 : 2048;
+
+  o["Write Debug Log"]       << Option(false, on_logger);
+  o["Contempt"]              << Option(0, -100, 100);
+  o["Min Split Depth"]       << Option(0, 0, 12, on_threads);
+  o["Threads"]               << Option(1, 1, MAX_THREADS, on_threads);
+  o["Hash"]                  << Option(16, 1, MaxHashMB, on_hash_size);
+  o["Clear Hash"]            << Option(on_clear_hash);
+  o["Ponder"]                << Option(true);
+  o["MultiPV"]               << Option(1, 1, 500);
+  o["Skill Level"]           << Option(20, 0, 20);
+  o["Move Overhead"]         << Option(30, 0, 5000);
+  o["Minimum Thinking Time"] << Option(20, 0, 5000);
+  o["Slow Mover"]            << Option(80, 10, 1000);
+  o["UCI_Chess960"]          << Option(false);
+  o["SyzygyPath"]            << Option("<empty>", on_tb_path);
+  o["SyzygyProbeDepth"]      << Option(1, 1, 100);
+  o["Syzygy50MoveRule"]      << Option(true);
+  o["SyzygyProbeLimit"]      << Option(6, 0, 6);
 }