Stockfish 1.7

Signatures are:

./stockfish bench 128 1 12 default depth
8299338

./stockfish bench 128 1 13 default depth
15694903

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/Makefile

@@ -21,15 +21,16 @@
 ### Executable name. Do not change
 EXE = stockfish
 
+### Installation dir definitions
+PREFIX = /usr/local
+BINDIR = $(PREFIX)/bin
+
 
 ### ==========================================================================
 ### Compiler speed switches for both GCC and ICC. These settings are generally
 ### fast on a broad range of systems, but may be changed experimentally
-###
-### NOTE: Some versions of gcc miscompile value.h with -O2 or -O3, this is the
-### safe setup, try changing to -O3 or -O2 and verify it works for you.
 ### ==========================================================================
-GCCFLAGS = -O1 -msse
+GCCFLAGS = -O3 -msse
 ICCFLAGS = -fast -msse
 ICCFLAGS-OSX = -fast -mdynamic-no-pic
 
@@ -83,6 +84,7 @@ help:
 	@echo "Makefile options:"
 	@echo ""
 	@echo "make                >  Default: Compiler = g++"
+	@echo "make gcc-popcnt     >  Compiler = g++ + popcnt-support"
 	@echo "make icc            >  Compiler = icpc"
 	@echo "make icc-profile    >  Compiler = icpc + automatic pgo-build"
 	@echo "make icc-profile-popcnt >  Compiler = icpc + automatic pgo-build + popcnt-support"
@@ -94,14 +96,18 @@ help:
 	@echo "make osx-icc64      >  x86-Mac OS X 64 bit. Compiler = icpc"
 	@echo "make osx-icc32-profile > OSX 32 bit. Compiler = icpc + automatic pgo-build"
 	@echo "make osx-icc64-profile > OSX 64 bit. Compiler = icpc + automatic pgo-build"
+	@echo "make hpux           >  HP-UX. Compiler = aCC"
 	@echo "make strip          >  Strip executable"
 	@echo "make clean          >  Clean up"
 	@echo ""
 
 all: $(EXE) .depend
 
+test check: default
+	@$(PGOBENCH)
+
 clean:
-	$(RM) *.o .depend *~ $(EXE)
+	$(RM) *.o .depend *~ $(EXE) core bench.txt
 
 
 ### Possible targets. You may add your own ones here
@@ -111,6 +117,13 @@ gcc:
 	CXXFLAGS="$(GCCFLAGS)" \
 	all
 
+gcc-popcnt:
+	$(MAKE) \
+	CXX='g++' \
+	CXXFLAGS="$(GCCFLAGS) -DUSE_POPCNT" \
+	all
+
+
 icc:
 	$(MAKE) \
 	CXX='icpc' \
@@ -184,6 +197,7 @@ osx-ppc32:
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
 	CXXFLAGS+='-arch ppc' \
+	CXXFLAGS+='-DBIGENDIAN' \
 	LDFLAGS+='-arch ppc' \
 	all
 
@@ -192,6 +206,7 @@ osx-ppc64:
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
 	CXXFLAGS+='-arch ppc64' \
+	CXXFLAGS+='-DBIGENDIAN' \
 	LDFLAGS+='-arch ppc64' \
 	all
 
@@ -199,16 +214,16 @@ osx-x86:
 	$(MAKE) \
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch i386' \
+	CXXFLAGS+='-arch i386 -mdynamic-no-pic' \
-	LDFLAGS+='-arch i386' \
+	LDFLAGS+='-arch i386 -mdynamic-no-pic' \
 	all
 
 osx-x86_64:
 	$(MAKE) \
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch x86_64' \
+	CXXFLAGS+='-arch x86_64 -mdynamic-no-pic' \
-	LDFLAGS+='-arch x86_64' \
+	LDFLAGS+='-arch x86_64 -mdynamic-no-pic' \
 	all
 	
 osx-icc32:
@@ -291,6 +306,12 @@ osx-icc64-profile:
 	$(MAKE) osx-icc64-profile-use
 	@rm -rf profdir bench.txt
 
+hpux:
+	$(MAKE) \
+	CXX='/opt/aCC/bin/aCC -AA +hpxstd98 -DBIGENDIAN -mt +O3 -DNDEBUG' \
+	CXXFLAGS="" \
+	LDFLAGS="" \
+	all
 
 
 strip:
@@ -301,9 +322,14 @@ strip:
 $(EXE): $(OBJS)
 	$(CXX) $(LDFLAGS) -o $@ $(OBJS)
 
+### Installation
+install: default
+	-mkdir -p -m 755 $(BINDIR)
+	-cp $(EXE) $(BINDIR)
+	-strip $(BINDIR)/$(EXE)
 
 ### Dependencies. Do not change
 .depend:
-	$(CXX) -msse -MM $(OBJS:.o=.cpp) > $@
+	-@$(CXX) -msse -MM $(OBJS:.o=.cpp) > $@ 2> /dev/null
 
-include .depend
+-include .depend

src/application.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -49,6 +49,7 @@ Application::Application() {
     Position::init_piece_square_tables();
     init_eval(1);
     init_bitbases();
+    init_search();
     init_threads();
 
     // Make random number generation less deterministic, for book moves
@@ -58,7 +59,7 @@ Application::Application() {
 
 Application::~Application() {
 
-  stop_threads();
+  exit_threads();
   quit_eval();
 }
 

src/application.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -84,9 +84,9 @@ void benchmark(const string& commandLine) {
   }
   csStr >> threads;
   csVal >> val;
-  if (val < 1 || val > THREAD_MAX)
+  if (val < 1 || val > MAX_THREADS)
   {
-      cerr << "The number of threads must be between 1 and " << THREAD_MAX << endl;
+      cerr << "The number of threads must be between 1 and " << MAX_THREADS << endl;
       Application::exit_with_failure();
   }
   set_option_value("Hash", ttSize);
@@ -155,7 +155,7 @@ void benchmark(const string& commandLine) {
       cerr << "\nBench position: " << cnt << '/' << positions.size() << endl << endl;
       if (limitType == "perft")
           totalNodes += perft(pos, maxDepth * OnePly);
-      else if (!think(pos, true, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
+      else if (!think(pos, false, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
           break;
       totalNodes += nodes_searched();
   }

src/benchmark.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/bitbase.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -297,8 +297,8 @@ void init_bitboards() {
 
 #if defined(IS_64BIT) && !defined(USE_BSFQ)
 
-CACHE_LINE_ALIGNMENT
+static CACHE_LINE_ALIGNMENT
-static const int BitTable[64] = {
+const int BitTable[64] = {
   0, 1, 2, 7, 3, 13, 8, 19, 4, 25, 14, 28, 9, 34, 20, 40, 5, 17, 26, 38, 15,
   46, 29, 48, 10, 31, 35, 54, 21, 50, 41, 57, 63, 6, 12, 18, 24, 27, 33, 39,
   16, 37, 45, 47, 30, 53, 49, 56, 62, 11, 23, 32, 36, 44, 52, 55, 61, 22, 43,
@@ -348,45 +348,58 @@ union b_union {
 
 Square pop_1st_bit(Bitboard* bb) {
 
-   b_union* u;
+   b_union u;
    Square ret;
 
-   u = (b_union*)bb;
+   u.b = *bb;
 
-   if (u->dw.l)
+   if (u.dw.l)
    {
-       ret = Square(BitTable[((u->dw.l ^ (u->dw.l - 1)) * 0x783a9b23) >> 26]);
+       ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
-       u->dw.l &= (u->dw.l - 1);
+       u.dw.l &= (u.dw.l - 1);
+       *bb = u.b;
        return ret;
    }
-   ret = Square(BitTable[((~(u->dw.h ^ (u->dw.h - 1))) * 0x783a9b23) >> 26]);
+   ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
-   u->dw.h &= (u->dw.h - 1);
+   u.dw.h &= (u.dw.h - 1);
+   *bb = u.b;
    return ret;
 }
 
 #endif
 
+// Optimized bitScanReverse32() implementation by Pascal Georges. Note
+// that first bit is 1, this allow to differentiate between 0 and 1.
+static CACHE_LINE_ALIGNMENT
+const char MsbTable[256] = {
+  0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
+  5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+  6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7,
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+  7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+  8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+  8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+  8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+  8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+  8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
+};
+
 int bitScanReverse32(uint32_t b)
 {
    int result = 0;
 
-   if (b > 0xFFFF) {
+   if (b > 0xFFFF)
+   {
       b >>= 16;
       result += 16;
    }
-   if (b > 0xFF) {
+   if (b > 0xFF)
+   {
       b >>= 8;
       result += 8;
    }
-   if (b > 0xF) {
+   return result + MsbTable[b];
-      b >>= 4;
-      result += 4;
-   }
-   if (b > 0x3) {
-      b >>= 2;
-      result += 2;
-   }
-   return result + (b > 0) + (b > 1);
 }
 
 namespace {

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -26,40 +26,18 @@
 
 // Select type of intrinsic bit count instruction to use, see
 // README.txt on how to pgo compile with POPCNT support.
-
+#if !defined(USE_POPCNT)
-#if defined(__INTEL_COMPILER) && defined(USE_POPCNT) // Intel compiler
-
-#include <nmmintrin.h>
-
-inline bool cpu_has_popcnt() {
-
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
-}
-
-#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
-
-#elif defined(_MSC_VER) && defined(USE_POPCNT) // Microsoft compiler
-
-#include <intrin.h>
-
-inline bool cpu_has_popcnt() {
-
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
-}
-
-#define POPCNT_INTRINSIC(x) __popcnt64(x)
-
-#else // Safe fallback for unsupported compilers or when USE_POPCNT is disabled
-
-inline bool cpu_has_popcnt() { return false; }
-
 #define POPCNT_INTRINSIC(x) 0
+#elif defined(_MSC_VER)
+#define POPCNT_INTRINSIC(x) (int)__popcnt64(x)
+#elif defined(__GNUC__)
 
-#endif // cpu_has_popcnt() and POPCNT_INTRINSIC() definitions
+#define POPCNT_INTRINSIC(x) ({ \
+   unsigned long __ret; \
+   __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
+   __ret; })
+
+#endif
 
 
 /// Software implementation of bit count functions
@@ -126,10 +104,23 @@ inline int count_1s_max_15(Bitboard b) {
 }
 
 
+// Detect hardware POPCNT support
+inline bool cpu_has_popcnt() {
+
+  int CPUInfo[4] = {-1};
+  __cpuid(CPUInfo, 0x00000001);
+  return (CPUInfo[2] >> 23) & 1;
+}
+
+
 // Global constant initialized at startup that is set to true if
 // CPU on which application runs supports POPCNT intrinsic. Unless
 // USE_POPCNT is not defined.
+#if defined(USE_POPCNT)
 const bool CpuHasPOPCNT = cpu_has_popcnt();
+#else
+const bool CpuHasPOPCNT = false;
+#endif
 
 
 // Global constant used to print info about the use of 64 optimized

src/book.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -390,7 +390,7 @@ void Book::close() {
 /// Book::file_name() returns the file name of the currently active book,
 /// or the empty string if no book is open.
 
-const string Book::file_name() const {
+const string Book::file_name() { // Not const to compile on HP-UX 11.X
 
   return is_open() ? fileName : "";
 }

src/book.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -53,11 +53,14 @@ struct BookEntry {
 };
 
 class Book : private std::ifstream {
+  Book(const Book&); // just decleared..
+  Book& operator=(const Book&); // ..to avoid a warning
 public:
+  Book() {}
   ~Book();
   void open(const std::string& fName);
   void close();
-  const std::string file_name() const;
+  const std::string file_name();
   Move get_move(const Position& pos);
 
 private:

src/color.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/depth.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -49,6 +49,7 @@ inline void operator+= (Depth &d1, Depth d2) { d1 += int(d2); }
 inline Depth operator- (Depth d, int i) { return Depth(int(d) - i); }
 inline Depth operator- (Depth d1, Depth d2) { return Depth(int(d1) - int(d2)); }
 inline void operator-= (Depth &d, int i) { d = Depth(int(d) - i); }
+inline void operator-= (Depth &d1, Depth d2) { d1 -= int(d2); }
 inline Depth operator* (Depth d, int i) { return Depth(int(d) * i); }
 inline Depth operator* (int i, Depth d) { return Depth(int(d) * i); }
 inline void operator*= (Depth &d, int i) { d = Depth(int(d) * i); }

src/direction.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/direction.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -224,15 +224,19 @@ namespace {
 
   const int AttackWeight[] = { 0, 0, KnightAttackWeight, BishopAttackWeight, RookAttackWeight, QueenAttackWeight };
 
-  // Bonuses for safe checks, initialized from UCI options
+  // Bonuses for safe checks
-  int QueenContactCheckBonus, DiscoveredCheckBonus;
+  const int QueenContactCheckBonus = 3;
-  int QueenCheckBonus, RookCheckBonus, BishopCheckBonus, KnightCheckBonus;
+  const int DiscoveredCheckBonus   = 3;
+  const int QueenCheckBonus        = 2; 
+  const int RookCheckBonus         = 1;
+  const int BishopCheckBonus       = 1; 
+  const int KnightCheckBonus       = 1;
 
   // Scan for queen contact mates?
   const bool QueenContactMates = true;
 
-  // Bonus for having a mate threat, initialized from UCI options
+  // Bonus for having a mate threat
-  int MateThreatBonus;
+  const int MateThreatBonus = 3;
 
   // InitKingDanger[] contains bonuses based on the position of the defending
   // king.
@@ -251,9 +255,10 @@ namespace {
   // in init_safety().
   Value SafetyTable[100];
 
-  // Pawn and material hash tables, indexed by the current thread id
+  // Pawn and material hash tables, indexed by the current thread id.
-  MaterialInfoTable* MaterialTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+  // Note that they will be initialized at 0 being global variables.
-  PawnInfoTable* PawnTable[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+  MaterialInfoTable* MaterialTable[MAX_THREADS];
+  PawnInfoTable* PawnTable[MAX_THREADS];
 
   // Sizes of pawn and material hash tables
   const int PawnTableSize = 16384;
@@ -304,7 +309,7 @@ template<bool HasPopCnt>
 Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
 
   assert(pos.is_ok());
-  assert(threadID >= 0 && threadID < THREAD_MAX);
+  assert(threadID >= 0 && threadID < MAX_THREADS);
   assert(!pos.is_check());
 
   memset(&ei, 0, sizeof(EvalInfo));
@@ -435,28 +440,13 @@ Value do_evaluate(const Position& pos, EvalInfo& ei, int threadID) {
 
 } // namespace
 
-/// quick_evaluate() does a very approximate evaluation of the current position.
-/// It currently considers only material and piece square table scores. Perhaps
-/// we should add scores from the pawn and material hash tables?
-
-Value quick_evaluate(const Position &pos) {
-
-  assert(pos.is_ok());
-
-  static const ScaleFactor sf[2] = {SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL};
-
-  Value v = scale_by_game_phase(pos.value(), MaterialInfoTable::game_phase(pos), sf);
-  return (pos.side_to_move() == WHITE ? v : -v);
-}
-
-
 /// init_eval() initializes various tables used by the evaluation function
 
 void init_eval(int threads) {
 
-  assert(threads <= THREAD_MAX);
+  assert(threads <= MAX_THREADS);
 
-  for (int i = 0; i < THREAD_MAX; i++)
+  for (int i = 0; i < MAX_THREADS; i++)
   {
     if (i >= threads)
     {
@@ -478,7 +468,7 @@ void init_eval(int threads) {
 
 void quit_eval() {
 
-  for (int i = 0; i < THREAD_MAX; i++)
+  for (int i = 0; i < MAX_THREADS; i++)
   {
       delete PawnTable[i];
       delete MaterialTable[i];
@@ -874,16 +864,13 @@ namespace {
       // capturing a single attacking piece can therefore result in a score
       // change far bigger than the value of the captured piece.
       Score v = apply_weight(make_score(SafetyTable[attackUnits], 0), WeightKingSafety[Us]);
-
       ei.value -= Sign[Us] * v;
-
+      ei.futilityMargin[Us] += mg_value(v);
-      if (Us == pos.side_to_move())
-          ei.futilityMargin += mg_value(v);
     }
   }
 
 
-  // evaluate_passed_pawns() evaluates the passed pawns of the given color
+  // evaluate_passed_pawns_of_color() evaluates the passed pawns of the given color
 
   template<Color Us>
   void evaluate_passed_pawns_of_color(const Position& pos, int movesToGo[], Square pawnToGo[], EvalInfo& ei) {
@@ -1217,29 +1204,17 @@ namespace {
 
   void init_safety() {
 
-    QueenContactCheckBonus = get_option_value_int("Queen Contact Check Bonus");
+    int maxSlope = 30;
-    QueenCheckBonus        = get_option_value_int("Queen Check Bonus");
+    int peak     = 0x500;
-    RookCheckBonus         = get_option_value_int("Rook Check Bonus");
+    double a     = 0.4;
-    BishopCheckBonus       = get_option_value_int("Bishop Check Bonus");
+    double b     = 0.0;
-    KnightCheckBonus       = get_option_value_int("Knight Check Bonus");
-    DiscoveredCheckBonus   = get_option_value_int("Discovered Check Bonus");
-    MateThreatBonus        = get_option_value_int("Mate Threat Bonus");
-
-    int maxSlope = get_option_value_int("King Safety Max Slope");
-    int peak     = get_option_value_int("King Safety Max Value") * 256 / 100;
-    double a     = get_option_value_int("King Safety Coefficient") / 100.0;
-    double b     = get_option_value_int("King Safety X Intercept");
-    bool quad    = (get_option_value_string("King Safety Curve") == "Quadratic");
-    bool linear  = (get_option_value_string("King Safety Curve") == "Linear");
 
     for (int i = 0; i < 100; i++)
     {
         if (i < b)
             SafetyTable[i] = Value(0);
-        else if (quad)
+        else
             SafetyTable[i] = Value((int)(a * (i - b) * (i - b)));
-        else if (linear)
-            SafetyTable[i] = Value((int)(100 * a * (i - b)));
     }
 
     for (int i = 0; i < 100; i++)

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -47,6 +47,8 @@ class Position;
 
 struct EvalInfo {
 
+  EvalInfo() { futilityMargin[0] = futilityMargin[1] = Value(0); }
+
   // Middle game and endgame evaluations
   Score value;
 
@@ -94,8 +96,8 @@ struct EvalInfo {
   Score mobility;
 
   // Extra futility margin. This is added to the standard futility margin
-  // in the quiescence search.
+  // in the quiescence search. One for each color.
-  Value futilityMargin;
+  Value futilityMargin[2];
 };
 
 
@@ -104,7 +106,6 @@ struct EvalInfo {
 ////
 
 extern Value evaluate(const Position& pos, EvalInfo& ei, int threadID);
-extern Value quick_evaluate(const Position& pos);
 extern void init_eval(int threads);
 extern void quit_eval();
 extern void read_weights(Color sideToMove);

src/history.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -42,6 +42,7 @@ History::History() { clear(); }
 
 void History::clear() {
   memset(history, 0, 2 * 8 * 64 * sizeof(int));
+  memset(maxStaticValueDelta, 0, 2 * 8 * 64 * sizeof(int));
 }
 
 
@@ -61,7 +62,7 @@ void History::success(Piece p, Square to, Depth d) {
   if (history[p][to] >= HistoryMax)
       for (int i = 0; i < 16; i++)
           for (int j = 0; j < 64; j++)
-              history[i][j] /= 4;
+              history[i][j] /= 2;
 }
 
 
@@ -75,8 +76,12 @@ void History::failure(Piece p, Square to, Depth d) {
   assert(square_is_ok(to));
 
   history[p][to] -= int(d) * int(d);
-  if (history[p][to] < 0)
+
-      history[p][to] = 0;
+  // Prevent history underflow
+  if (history[p][to] <= -HistoryMax)
+      for (int i = 0; i < 16; i++)
+          for (int j = 0; j < 64; j++)
+              history[i][j] /= 2;
 }
 
 
@@ -90,3 +95,21 @@ int History::move_ordering_score(Piece p, Square to) const {
 
   return history[p][to];
 }
+
+
+/// History::set_gain() and History::gain() store and retrieve the
+/// gain of a move given the delta of the static position evaluations
+/// before and after the move.
+
+void History::set_gain(Piece p, Square to, Value delta)
+{
+  if (delta >= maxStaticValueDelta[p][to])
+      maxStaticValueDelta[p][to] = delta;
+  else
+      maxStaticValueDelta[p][to]--;
+}
+
+Value History::gain(Piece p, Square to) const
+{
+  return Value(maxStaticValueDelta[p][to]);
+}

src/history.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -28,6 +28,7 @@
 #include "depth.h"
 #include "move.h"
 #include "piece.h"
+#include "value.h"
 
 
 ////
@@ -49,9 +50,12 @@ public:
   void success(Piece p, Square to, Depth d);
   void failure(Piece p, Square to, Depth d);
   int move_ordering_score(Piece p, Square to) const;
+  void set_gain(Piece p, Square to, Value delta);
+  Value gain(Piece p, Square to) const;
 
 private:
   int history[16][64];  // [piece][square]
+  int maxStaticValueDelta[16][64];  // [piece][from_square][to_square]
 };
 
 
@@ -61,13 +65,13 @@ private:
 
 /// HistoryMax controls how often the history counters will be scaled down:
 /// When the history score for a move gets bigger than HistoryMax, all
-/// entries in the table are divided by 4. It is difficult to guess what
+/// entries in the table are divided by 2. It is difficult to guess what
 /// the ideal value of this constant is. Scaling down the scores often has
 /// the effect that parts of the search tree which have been searched
 /// recently have a bigger importance for move ordering than the moves which
 /// have been searched a long time ago.
 
-const int HistoryMax = 25000 * OnePly;
+const int HistoryMax = 50000 * OnePly;
 
 
 #endif // !defined(HISTORY_H_INCLUDED)

src/lock.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -99,5 +99,4 @@ typedef CRITICAL_SECTION Lock;
 
 #endif
 
-
 #endif // !defined(LOCK_H_INCLUDED)

src/main.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

src/material.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -374,7 +374,6 @@ EndgameFunctions::EndgameFunctions() {
   add<ScalingFunction<KBPPKB>  >("KBPPKB");
   add<ScalingFunction<KBPKN>   >("KBPKN");
   add<ScalingFunction<KRPPKRP> >("KRPPKRP");
-  add<ScalingFunction<KRPPKRP> >("KRPPKRP");
 }
 
 EndgameFunctions::~EndgameFunctions() {

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/mersenne.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -27,6 +27,9 @@
 #  include <sys/time.h>
 #  include <sys/types.h>
 #  include <unistd.h>
+#  if defined(__hpux)
+#     include <sys/pstat.h>
+#  endif
 
 #else
 
@@ -38,6 +41,7 @@
 
 #include <cassert>
 #include <cstdio>
+#include <cstring>
 #include <iomanip>
 #include <iostream>
 #include <sstream>
@@ -50,7 +54,7 @@ using namespace std;
 /// Version number. If this is left empty, the current date (in the format
 /// YYMMDD) is used as a version number.
 
-static const string EngineVersion = "1.6.1";
+static const string EngineVersion = "1.7";
 static const string AppName = "Stockfish";
 static const string AppTag  = "";
 
@@ -179,23 +183,32 @@ int get_system_time() {
 }
 
 
-/// cpu_count() tries to detect the number of CPU cores.
+/// builtin_cpu_count() tries to detect the number of CPU cores, if
+/// hyper-threading is enabled this is the number of logical processors.
 
 #if !defined(_MSC_VER)
 
 #  if defined(_SC_NPROCESSORS_ONLN)
-int cpu_count() {
+static int builtin_cpu_count() {
   return Min(sysconf(_SC_NPROCESSORS_ONLN), 8);
 }
+#  elif defined(__hpux)
+static int builtin_cpu_count() {
+  struct pst_dynamic psd;
+  if (pstat_getdynamic(&psd, sizeof(psd), (size_t)1, 0) == -1)
+      return 1;
+
+  return Min(psd.psd_proc_cnt, 8);
+}
 #  else
-int cpu_count() {
+static int builtin_cpu_count() {
   return 1;
 }
 #  endif
 
 #else
 
-int cpu_count() {
+static int builtin_cpu_count() {
   SYSTEM_INFO s;
   GetSystemInfo(&s);
   return Min(s.dwNumberOfProcessors, 8);
@@ -204,6 +217,51 @@ int cpu_count() {
 #endif
 
 
+/// HT_enabled() returns true if hyper-threading is enabled on current machine
+
+static bool HT_enabled() {
+
+  char CPUString[0x20];
+  int CPUInfo[4] = {-1};
+  int nIds, nLogicalCPU, nCores;
+
+  // Detect CPU producer
+  __cpuid(CPUInfo, 0);
+  nIds = CPUInfo[0];
+
+  memset(CPUString, 0, sizeof(CPUString));
+  memcpy(&CPUString[0], &CPUInfo[1], sizeof(int));
+  memcpy(&CPUString[4], &CPUInfo[3], sizeof(int));
+  memcpy(&CPUString[8], &CPUInfo[2], sizeof(int));
+
+  // Not an Intel CPU or CPUID.4 not supported
+  if (strcmp(CPUString, "GenuineIntel") || nIds < 4)
+      return false;
+
+  // Detect if HT Technology is supported
+  __cpuid(CPUInfo, 1);
+  if (!((CPUInfo[3] >> 28) & 1))
+      return false;
+
+  nLogicalCPU = (CPUInfo[1] >> 16) & 0xFF;
+
+  // Detect number of cores
+  __cpuid(CPUInfo, 4);
+  nCores = 1 + ((CPUInfo[0] >> 26) & 0x3F);
+
+  return nLogicalCPU > nCores;
+}
+
+
+/// cpu_count() tries to detect the number of physical CPU cores taking
+/// in account hyper-threading.
+
+int cpu_count() {
+
+  return HT_enabled() ? builtin_cpu_count() / 2 : builtin_cpu_count();
+}
+
+
 /*
   From Beowulf, from Olithink
 */

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/move.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/move.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -86,10 +86,10 @@ inline void insertion_sort(T* firstMove, T* lastMove)
         }
 }
 
-// Our dedicated sort in range [firstMove, lastMove), it is well
+// Our dedicated sort in range [firstMove, lastMove), first splits
-// tuned for non-captures where we have a lot of zero scored moves.
+// positive scores from ramining then order seaprately the two sets.
 template<typename T>
-inline void sort_moves(T* firstMove, T* lastMove)
+inline void sort_moves(T* firstMove, T* lastMove, T** lastPositive)
 {
     T tmp;
     T *p, *d;
@@ -114,29 +114,9 @@ inline void sort_moves(T* firstMove, T* lastMove)
 
     } while (p != d);
 
-    // Sort positives
+    // Sort just positive scored moves, remaining only when we get there
     insertion_sort<T>(firstMove, p);
-
+    *lastPositive = p;
-    d = lastMove;
-    p--;
-
-    // Split zero vs negatives
-    do {
-        while ((++p)->score == 0);
-
-        if (p != d)
-        {
-            while (--d != p && d->score < 0);
-
-            tmp = *p;
-            *p = *d;
-            *d = tmp;
-        }
-
-    } while (p != d);
-
-    // Sort negatives
-    insertion_sort<T>(p, lastMove);
 }
 
 // Picks up the best move in range [curMove, lastMove), one per cycle.

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by

src/movegen.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -71,11 +71,11 @@ namespace {
 /// move ordering is at the current node.
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
-                       const History& h, SearchStack* ss) : pos(p), H(h) {
+                       const History& h, SearchStack* ss, Value beta) : pos(p), H(h) {
   int searchTT = ttm;
   ttMoves[0].move = ttm;
-  finished = false;
   lastBadCapture = badCaptures;
+  badCaptureThreshold = 0;
 
   pinned = p.pinned_pieces(pos.side_to_move());
 
@@ -91,12 +91,26 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
   if (p.is_check())
       phasePtr = EvasionsPhaseTable;
   else if (d > Depth(0))
+  {
+      // Consider sligtly negative captures as good if at low
+      // depth and far from beta.
+      if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * OnePly)
+          badCaptureThreshold = -PawnValueMidgame;
+
       phasePtr = MainSearchPhaseTable;
-  else if (d == Depth(0))
+  } else if (d == Depth(0))
       phasePtr = QsearchWithChecksPhaseTable;
   else
+  {
       phasePtr = QsearchWithoutChecksPhaseTable;
 
+      // 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 != MOVE_NONE && !pos.move_is_capture_or_promotion(ttm))
+          searchTT = ttMoves[0].move = MOVE_NONE;
+  }
+
   phasePtr += !searchTT - 1;
   go_next_phase();
 }
@@ -129,7 +143,7 @@ void MovePicker::go_next_phase() {
   case PH_NONCAPTURES:
       lastMove = generate_noncaptures(pos, moves);
       score_noncaptures();
-      sort_moves(moves, lastMove);
+      sort_moves(moves, lastMove, &lastGoodNonCapture);
       return;
 
   case PH_BAD_CAPTURES:
@@ -142,7 +156,7 @@ void MovePicker::go_next_phase() {
   case PH_EVASIONS:
       assert(pos.is_check());
       lastMove = generate_evasions(pos, moves);
-      score_evasions();
+      score_evasions_or_checks();
       return;
 
   case PH_QCAPTURES:
@@ -151,12 +165,12 @@ void MovePicker::go_next_phase() {
       return;
 
   case PH_QCHECKS:
-      // Perhaps we should order moves move here?  FIXME
       lastMove = generate_non_capture_checks(pos, moves);
+      score_evasions_or_checks();
       return;
 
   case PH_STOP:
-      lastMove = curMove + 1; // hack to be friendly for get_next_move()
+      lastMove = curMove + 1; // Avoids another go_next_phase() call
       return;
 
   default:
@@ -216,16 +230,16 @@ void MovePicker::score_noncaptures() {
       piece = pos.piece_on(from);
       hs = H.move_ordering_score(piece, to);
 
-      // Ensure history is always preferred to pst
+      // Ensure history has always highest priority
       if (hs > 0)
-          hs += 1000;
+          hs += 10000;
 
-      // pst based scoring
+      // Gain table based scoring
-      cur->score = hs + mg_value(pos.pst_delta(piece, from, to));
+      cur->score = hs + 16 * H.gain(piece, to);
   }
 }
 
-void MovePicker::score_evasions() {
+void MovePicker::score_evasions_or_checks() {
   // Try good captures ordered by MVV/LVA, then non-captures if
   // destination square is not under attack, ordered by history
   // value, and at the end bad-captures and non-captures with a
@@ -233,11 +247,15 @@ void MovePicker::score_evasions() {
   Move m;
   int seeScore;
 
+  // Skip if we don't have at least two moves to order
+  if (lastMove < moves + 2)
+      return;
+
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
       m = cur->move;
       if ((seeScore = pos.see_sign(m)) < 0)
-          cur->score = seeScore;
+          cur->score = seeScore - HistoryMax; // Be sure are at the bottom
       else if (pos.move_is_capture(m))
           cur->score =  pos.midgame_value_of_piece_on(move_to(m))
                       - pos.type_of_piece_on(move_from(m)) + HistoryMax;
@@ -251,6 +269,8 @@ void MovePicker::score_evasions() {
 /// are no more moves left.
 /// It picks the move with the biggest score from a list of generated moves taking
 /// care not to return the tt move if has already been searched previously.
+/// Note that this function is not thread safe so should be lock protected by
+/// caller when accessed through a shared MovePicker object.
 
 Move MovePicker::get_next_move() {
 
@@ -277,7 +297,7 @@ Move MovePicker::get_next_move() {
               {
                   // Check for a non negative SEE now
                   int seeValue = pos.see_sign(move);
-                  if (seeValue >= 0)
+                  if (seeValue >= badCaptureThreshold)
                       return move;
 
                   // Losing capture, move it to the badCaptures[] array, note
@@ -300,6 +320,11 @@ Move MovePicker::get_next_move() {
               break;
 
           case PH_NONCAPTURES:
+
+              // Sort negative scored moves only when we get there
+              if (curMove == lastGoodNonCapture)
+                  insertion_sort(lastGoodNonCapture, lastMove);
+
               move = (curMove++)->move;
               if (   move != ttMoves[0].move
                   && move != ttMoves[1].move
@@ -340,21 +365,3 @@ Move MovePicker::get_next_move() {
   }
 }
 
-/// A variant of get_next_move() which takes a lock as a parameter, used to
-/// prevent multiple threads from picking the same move at a split point.
-
-Move MovePicker::get_next_move(Lock &lock) {
-
-   lock_grab(&lock);
-   if (finished)
-   {
-       lock_release(&lock);
-       return MOVE_NONE;
-   }
-   Move m = get_next_move();
-   if (m == MOVE_NONE)
-       finished = true;
-
-   lock_release(&lock);
-   return m;
-}

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -27,7 +27,6 @@
 
 #include "depth.h"
 #include "history.h"
-#include "lock.h"
 #include "position.h"
 
 
@@ -50,24 +49,22 @@ class MovePicker {
   MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
 
 public:
-  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL);
+  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, Value beta = -VALUE_INFINITE);
   Move get_next_move();
-  Move get_next_move(Lock& lock);
   int number_of_evasions() const;
 
 private:
   void score_captures();
   void score_noncaptures();
-  void score_evasions();
+  void score_evasions_or_checks();
   void go_next_phase();
 
   const Position& pos;
   const History& H;
   MoveStack ttMoves[2], killers[2];
-  bool finished;
+  int badCaptureThreshold, phase;
-  int phase;
   const uint8_t* phasePtr;
-  MoveStack *curMove, *lastMove, *lastBadCapture;
+  MoveStack *curMove, *lastMove, *lastGoodNonCapture, *lastBadCapture;
   Bitboard pinned;
   MoveStack moves[256], badCaptures[64];
 };

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -226,21 +226,16 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
           Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
           while (b)
           {
+              // Give a bonus according to the distance of the nearest enemy pawn
               Square s2 = pop_1st_bit(&b);
+              int v = StormLeverBonus[f] - 2 * square_distance(s, s2);
+
+              // If enemy pawn has no pawn beside itself is particularly vulnerable.
+              // Big bonus, especially against a weakness on the rook file
               if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-              {
+                  v *= (square_file(s2) == FILE_H ? 4 : 2);
-                  // The enemy pawn has no pawn beside itself, which makes it
+
-                  // particularly vulnerable. Big bonus, especially against a
+              bonus += v;
-                  // weakness on the rook file.
-                  if (square_file(s2) == FILE_H)
-                      bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2);
-                  else
-                      bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2);
-              } else
-                  // There is at least one enemy pawn beside the enemy pawn we look
-                  // at, which means that the pawn has somewhat better chances of
-                  // defending itself by advancing. Smaller bonus.
-                  bonus += StormLeverBonus[f] - 2*square_distance(s, s2);
           }
       }
       pi->ksStormValue[Us] += bonus;
@@ -252,21 +247,16 @@ Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
           Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
           while (b)
           {
+              // Give a bonus according to the distance of the nearest enemy pawn
               Square s2 = pop_1st_bit(&b);
+              int v = StormLeverBonus[f] - 4 * square_distance(s, s2);
+
+              // If enemy pawn has no pawn beside itself is particularly vulnerable.
+              // Big bonus, especially against a weakness on the rook file
               if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-              {
+                  v *= (square_file(s2) == FILE_A ? 4 : 2);
-                  // The enemy pawn has no pawn beside itself, which makes it
+
-                  // particularly vulnerable. Big bonus, especially against a
+              bonus += v;
-                  // weakness on the rook file.
-                  if (square_file(s2) == FILE_A)
-                      bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2);
-                  else
-                      bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2);
-              } else
-                  // There is at least one enemy pawn beside the enemy pawn we look
-                  // at, which means that the pawn has somewhat better chances of
-                  // defending itself by advancing. Smaller bonus.
-                  bonus += StormLeverBonus[f] - 4*square_distance(s, s2);
           }
       }
       pi->qsStormValue[Us] += bonus;

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/piece.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/piece.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -44,8 +44,6 @@ using std::string;
 //// Variables
 ////
 
-int Position::castleRightsMask[64];
-
 Key Position::zobrist[2][8][64];
 Key Position::zobEp[64];
 Key Position::zobCastle[16];
@@ -76,15 +74,39 @@ CheckInfo::CheckInfo(const Position& pos) {
   checkSq[KING] = EmptyBoardBB;
 }
 
+
+/// Position c'tors. Here we always create a slower but safer copy of
+/// the original position or the FEN string, we want the new born Position
+/// object do not depend on any external data. Instead if we know what we
+/// are doing and we need speed we can create a position with default
+/// c'tor Position() and then use just fast_copy().
+
+Position::Position() {}
+
 Position::Position(const Position& pos) {
-  copy(pos);
+
+  memcpy(this, &pos, sizeof(Position));
+  detach(); // Always detach() in copy c'tor to avoid surprises
 }
 
 Position::Position(const string& fen) {
+
   from_fen(fen);
 }
 
 
+/// Position::detach() copies the content of the current state and castling
+/// masks inside the position itself. This is needed when the st pointee could
+/// become stale, as example because the caller is about to going out of scope.
+
+void Position::detach() {
+
+  startState = *st;
+  st = &startState;
+  st->previous = NULL; // as a safe guard
+}
+
+
 /// Position::from_fen() initializes the position object with the given FEN
 /// string. This function is not very robust - make sure that input FENs are
 /// correct (this is assumed to be the responsibility of the GUI).
@@ -204,11 +226,16 @@ void Position::from_fen(const string& fen) {
   while (fen[i] == ' ')
       i++;
 
-  // En passant square
+  // En passant square -- ignore if no capture is possible
   if (    i <= fen.length() - 2
       && (fen[i] >= 'a' && fen[i] <= 'h')
       && (fen[i+1] == '3' || fen[i+1] == '6'))
+  {
+      Square fenEpSquare = square_from_string(fen.substr(i, 2));
+      Color them = opposite_color(sideToMove);
+      if (attacks_from<PAWN>(fenEpSquare, them) & this->pieces(PAWN, sideToMove))
           st->epSquare = square_from_string(fen.substr(i, 2));
+  }
 
   // Various initialisation
   for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
@@ -265,11 +292,25 @@ const string Position::to_fen() const {
   }
   fen += (sideToMove == WHITE ? "w " : "b ");
   if (st->castleRights != NO_CASTLES)
+  {
+     if (initialKFile == FILE_E && initialQRFile == FILE_A && initialKRFile == FILE_H)
      {
         if (can_castle_kingside(WHITE))  fen += 'K';
         if (can_castle_queenside(WHITE)) fen += 'Q';
         if (can_castle_kingside(BLACK))  fen += 'k';
         if (can_castle_queenside(BLACK)) fen += 'q';
+     }
+     else
+     {
+        if (can_castle_kingside(WHITE))
+           fen += char(toupper(file_to_char(initialKRFile)));
+        if (can_castle_queenside(WHITE))
+           fen += char(toupper(file_to_char(initialQRFile)));
+        if (can_castle_kingside(BLACK))
+           fen += file_to_char(initialKRFile);
+        if (can_castle_queenside(BLACK))
+           fen += file_to_char(initialQRFile);
+     }
   } else
       fen += '-';
 
@@ -300,8 +341,9 @@ void Position::print(Move m) const {
   std::cout << std::endl;
   if (m != MOVE_NONE)
   {
+      Position p(*this);
       string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
-      std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl;
+      std::cout << "Move is: " << col << move_to_san(p, m) << std::endl;
   }
   for (Rank rank = RANK_8; rank >= RANK_1; rank--)
   {
@@ -326,20 +368,11 @@ void Position::print(Move m) const {
 }
 
 
-/// Position::copy() creates a copy of the input position.
-
-void Position::copy(const Position& pos) {
-
-  memcpy(this, &pos, sizeof(Position));
-  saveState(); // detach and copy state info
-}
-
-
 /// Position:hidden_checkers<>() returns a bitboard of all pinned (against the
 /// king) pieces for the given color and for the given pinner type. Or, when
 /// template parameter FindPinned is false, the pieces of the given color
 /// candidate for a discovery check against the enemy king.
-/// Note that checkersBB bitboard must be already updated.
+/// Bitboard checkersBB must be already updated when looking for pinners.
 
 template<bool FindPinned>
 Bitboard Position::hidden_checkers(Color c) const {
@@ -373,7 +406,8 @@ Bitboard Position::hidden_checkers(Color c) const {
 
 
 /// Position:pinned_pieces() returns a bitboard of all pinned (against the
-/// king) pieces for the given color.
+/// king) pieces for the given color. Note that checkersBB bitboard must
+/// be already updated.
 
 Bitboard Position::pinned_pieces(Color c) const {
 
@@ -383,7 +417,8 @@ Bitboard Position::pinned_pieces(Color c) const {
 
 /// Position:discovered_check_candidates() returns a bitboard containing all
 /// pieces for the given side which are candidates for giving a discovered
-/// check.
+/// check. Contrary to pinned_pieces() here there is no need of checkersBB
+/// to be already updated.
 
 Bitboard Position::discovered_check_candidates(Color c) const {
 
@@ -1422,19 +1457,6 @@ int Position::see(Square from, Square to) const {
 }
 
 
-/// Position::saveState() copies the content of the current state
-/// inside startState and makes st point to it. This is needed
-/// when the st pointee could become stale, as example because
-/// the caller is about to going out of scope.
-
-void Position::saveState() {
-
-  startState = *st;
-  st = &startState;
-  st->previous = NULL; // as a safe guard
-}
-
-
 /// Position::clear() erases the position object to a pristine state, with an
 /// empty board, white to move, and no castling rights.
 
@@ -1636,6 +1658,7 @@ Value Position::compute_non_pawn_material(Color c) const {
 /// Position::is_draw() tests whether the position is drawn by material,
 /// repetition, or the 50 moves rule. It does not detect stalemates, this
 /// must be done by the search.
+// FIXME: Currently we are not handling 50 move rule correctly when in check
 
 bool Position::is_draw() const {
 
@@ -1649,7 +1672,7 @@ bool Position::is_draw() const {
       return true;
 
   // Draw by repetition?
-  for (int i = 2; i < Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
+  for (int i = 4; i <= Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
       if (history[gamePly - i] == st->key)
           return true;
 
@@ -1843,6 +1866,7 @@ bool Position::is_ok(int* failedStep) const {
   static const bool debugNonPawnMaterial = false;
   static const bool debugPieceCounts = false;
   static const bool debugPieceList = false;
+  static const bool debugCastleSquares = false;
 
   if (failedStep) *failedStep = 1;
 
@@ -1979,6 +2003,25 @@ bool Position::is_ok(int* failedStep) const {
                       return false;
               }
   }
+
+  if (failedStep) (*failedStep)++;
+  if (debugCastleSquares) {
+      for (Color c = WHITE; c <= BLACK; c++) {
+          if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != piece_of_color_and_type(c, ROOK))
+              return false;
+          if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != piece_of_color_and_type(c, ROOK))
+              return false;
+      }
+      if (castleRightsMask[initial_kr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OO))
+          return false;
+      if (castleRightsMask[initial_qr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OOO))
+          return false;
+      if (castleRightsMask[initial_kr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OO))
+          return false;
+      if (castleRightsMask[initial_qr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OOO))
+          return false;
+  }
+
   if (failedStep) *failedStep = 0;
   return true;
 }

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -146,9 +146,9 @@ public:
   };
 
   // Constructors
-  Position() {}
+  Position();
-  Position(const Position& pos);
+  explicit Position(const Position& pos);
-  Position(const std::string& fen);
+  explicit Position(const std::string& fen);
 
   // Text input/output
   void from_fen(const std::string& fen);
@@ -156,7 +156,6 @@ public:
   void print(Move m = MOVE_NONE) const;
 
   // Copying
-  void copy(const Position& pos);
   void flipped_copy(const Position& pos);
 
   // The piece on a given square
@@ -224,6 +223,9 @@ public:
   bool move_is_passed_pawn_push(Move m) const;
   bool move_attacks_square(Move m, Square s) const;
 
+  // Piece captured with previous moves
+  PieceType captured_piece() const;
+
   // Information about pawns
   bool pawn_is_passed(Color c, Square s) const;
   static bool pawn_is_passed(Bitboard theirPawns, Color c, Square s);
@@ -234,7 +236,7 @@ public:
   bool square_is_weak(Square s, Color c) const;
 
   // Doing and undoing moves
-  void saveState();
+  void detach();
   void do_move(Move m, StateInfo& st);
   void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
@@ -326,12 +328,12 @@ private:
   Color sideToMove;
   int gamePly;
   Key history[MaxGameLength];
+  int castleRightsMask[64];
   File initialKFile, initialKRFile, initialQRFile;
   StateInfo startState;
   StateInfo* st;
 
   // Static variables
-  static int castleRightsMask[64];
   static Key zobrist[2][8][64];
   static Key zobEp[64];
   static Key zobCastle[16];
@@ -567,4 +569,8 @@ inline bool Position::move_is_capture_or_promotion(Move m) const {
   return (m & (0x1F << 12)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
 }
 
+inline PieceType Position::captured_piece() const {
+  return st->capture;
+}
+
 #endif // !defined(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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/san.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -63,7 +63,7 @@ namespace {
 /// that the move is a legal move from the position. The return value is
 /// a string containing the move in short algebraic notation.
 
-const string move_to_san(const Position& pos, Move m) {
+const string move_to_san(Position& pos, Move m) {
 
   assert(pos.is_ok());
   assert(move_is_ok(m));
@@ -123,10 +123,10 @@ const string move_to_san(const Position& pos, Move m) {
   // Position::move_is_check doesn't detect all checks (not castling moves,
   // promotions and en passant captures).
   StateInfo st;
-  Position p(pos);
+  pos.do_move(m, st);
-  p.do_move(m, st);
+  if (pos.is_check())
-  if (p.is_check())
+      san += pos.is_mate() ? "#" : "+";
-      san += p.is_mate()? "#" : "+";
+  pos.undo_move(m);
 
   return san;
 }

src/san.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -36,7 +36,7 @@
 //// Prototypes
 ////
 
-extern const std::string move_to_san(const Position& pos, Move m);
+extern const std::string move_to_san(Position& pos, Move m);
 extern Move move_from_san(const Position& pos, const std::string& str);
 extern const std::string line_to_san(const Position& pos, Move line[], int startColumn, bool breakLines);
 extern const std::string pretty_pv(const Position& pos, int time, int depth, uint64_t nodes, Value score, ValueType type, Move pv[]);

src/scale.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -27,6 +27,7 @@
 
 #include "depth.h"
 #include "move.h"
+#include "value.h"
 
 
 ////
@@ -46,6 +47,7 @@ const int KILLER_MAX = 2;
 /// from nodes shallower and deeper in the tree during the search.  Each
 /// search thread has its own array of SearchStack objects, indexed by the
 /// current ply.
+struct EvalInfo;
 
 struct SearchStack {
   Move pv[PLY_MAX_PLUS_2];
@@ -54,6 +56,7 @@ struct SearchStack {
   Move threatMove;
   Move killers[KILLER_MAX];
   Depth reduction;
+  Value eval;
 
   void init(int ply);
   void initKillers();
@@ -64,8 +67,9 @@ struct SearchStack {
 //// Prototypes
 ////
 
+extern void init_search();
 extern void init_threads();
-extern void stop_threads();
+extern void exit_threads();
 extern bool think(const Position &pos, bool infinite, bool ponder, int side_to_move,
                   int time[], int increment[], int movesToGo, int maxDepth,
                   int maxNodes, int maxTime, Move searchMoves[]);

src/square.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -26,6 +26,8 @@
 //// Includes
 ////
 
+#include <cstring>
+
 #include "lock.h"
 #include "movepick.h"
 #include "position.h"
@@ -36,7 +38,8 @@
 //// Constants and variables
 ////
 
-const int THREAD_MAX = 8;
+const int MAX_THREADS = 8;
+const int ACTIVE_SPLIT_POINTS_MAX = 8;
 
 
 ////
@@ -44,35 +47,48 @@ const int THREAD_MAX = 8;
 ////
 
 struct SplitPoint {
+
+  // Const data after splitPoint has been setup
   SplitPoint* parent;
-  Position pos;
+  const Position* pos;
-  SearchStack sstack[THREAD_MAX][PLY_MAX_PLUS_2];
-  SearchStack *parentSstack;
-  int ply;
-  Depth depth;
-  volatile Value alpha, beta, bestValue, futilityValue;
-  Value approximateEval;
   bool pvNode;
-  int master, slaves[THREAD_MAX];
+  Depth depth;
-  Lock lock;
+  bool mateThreat;
+  Value beta;
+  int ply, master, slaves[MAX_THREADS];
+  SearchStack sstack[MAX_THREADS][PLY_MAX_PLUS_2];
+
+  // Const pointers to shared data
   MovePicker* mp;
+  SearchStack* parentSstack;
+
+  // Shared data
+  Lock lock;
+  volatile Value alpha;
+  volatile Value bestValue;
   volatile int moves;
   volatile int cpus;
-  bool finished;
+  volatile bool stopRequest;
 };
 
+// ThreadState type is used to represent thread's current state
+
+enum ThreadState
+{
+  THREAD_SEARCHING,     // thread is performing work
+  THREAD_AVAILABLE,     // thread is polling for work
+  THREAD_SLEEPING,      // we are not thinking, so thread is sleeping
+  THREAD_BOOKED,        // other thread (master) has booked us as a slave
+  THREAD_WORKISWAITING, // master has ordered us to start
+  THREAD_TERMINATED     // we are quitting and thread is terminated
+};
 
 struct Thread {
   SplitPoint* splitPoint;
-  int activeSplitPoints;
+  volatile int activeSplitPoints;
   uint64_t nodes;
   uint64_t betaCutOffs[2];
-  bool failHighPly1;
+  volatile ThreadState state;
-  volatile bool stop;
-  volatile bool running;
-  volatile bool idle;
-  volatile bool workIsWaiting;
-  volatile bool printCurrentLine;
   unsigned char pad[64]; // set some distance among local data for each thread
 };
 

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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 +25,9 @@
 #include <cassert>
 #include <cmath>
 #include <cstring>
+#if !(defined(__hpux) || defined(__ppc__) || defined(__ppc64__) || defined(__arm__))
 #  include <xmmintrin.h>
+#endif
 
 #include "movegen.h"
 #include "tt.h"
@@ -53,11 +55,9 @@ TranspositionTable::~TranspositionTable() {
 /// TranspositionTable::set_size sets the size of the transposition table,
 /// measured in megabytes.
 
-void TranspositionTable::set_size(unsigned mbSize) {
+void TranspositionTable::set_size(size_t mbSize) {
 
-  assert(mbSize >= 4 && mbSize <= 4096);
+  size_t newSize = 1024;
-
-  unsigned newSize = 1024;
 
   // We store a cluster of ClusterSize number of TTEntry for each position
   // and newSize is the maximum number of storable positions.
@@ -125,6 +125,7 @@ void TranspositionTable::store(const Key posKey, Value v, ValueType t, Depth d,
           if (tte->key() && t == VALUE_TYPE_EV_LO)
               return;
 
+          // Preserve any exsisting ttMove
           if (m == MOVE_NONE)
               m = tte->move();
 
@@ -169,11 +170,14 @@ TTEntry* TranspositionTable::retrieve(const Key posKey) const {
 /// to be loaded from RAM, that can be very slow. When we will
 /// subsequently call retrieve() the TT data will be already
 /// quickly accessible in L1/L2 CPU cache.
+#if defined(__hpux) || defined(__ppc__) || defined(__ppc64__) || defined(__arm__)
+void TranspositionTable::prefetch(const Key) const {} // Not supported on HP UX
+#else
 
 void TranspositionTable::prefetch(const Key posKey) const {
 
 #if defined(__INTEL_COMPILER) || defined(__ICL)
-   // This hack prevents prefetches to be optimized away by the
+   // This hack prevents prefetches to be optimized away by
    // Intel compiler. Both MSVC and gcc seems not affected.
    __asm__ ("");
 #endif
@@ -183,6 +187,7 @@ void TranspositionTable::prefetch(const Key posKey) const {
   _mm_prefetch(addr+64, _MM_HINT_T2); // 64 bytes ahead
 }
 
+#endif
 
 /// TranspositionTable::new_search() is called at the beginning of every new
 /// search. It increments the "generation" variable, which is used to

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -95,7 +95,7 @@ class TranspositionTable {
 public:
   TranspositionTable();
   ~TranspositionTable();
-  void set_size(unsigned mbSize);
+  void set_size(size_t mbSize);
   void clear();
   void store(const Key posKey, Value v, ValueType type, Depth d, Move m);
   TTEntry* retrieve(const Key posKey) const;
@@ -114,7 +114,7 @@ private:
   unsigned writes; // heavy SMP read/write access here
   unsigned char pad_after[64];
 
-  unsigned size;
+  size_t size;
   TTCluster* entries;
   uint8_t generation;
 };

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -73,4 +73,28 @@ typedef uint64_t Bitboard;
 #define CACHE_LINE_ALIGNMENT  __attribute__ ((aligned(64)))
 #endif
 
+// Define a __cpuid() function for gcc compilers, for Intel and MSVC
+// is already available as an intrinsic.
+#if defined(_MSC_VER)
+#include <intrin.h>
+#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+inline void __cpuid(int CPUInfo[4], int InfoType)
+{
+  int* eax = CPUInfo + 0;
+  int* ebx = CPUInfo + 1;
+  int* ecx = CPUInfo + 2;
+  int* edx = CPUInfo + 3;
+
+  *eax = InfoType;
+  *ecx = 0;
+  __asm__("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
+                  : "0" (*eax), "2" (*ecx));
+}
+#else
+inline void __cpuid(int CPUInfo[4], int)
+{
+   CPUInfo[0] = CPUInfo[1] = CPUInfo[2] = CPUInfo[3] = 0;
+}
+#endif
+
 #endif // !defined(TYPES_H_INCLUDED)

src/uci.cpp

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -107,7 +107,8 @@ namespace {
     UCIInputParser uip(command);
     string token;
 
-    uip >> token; // operator>>() skips any whitespace
+    if (!(uip >> token)) // operator>>() skips any whitespace
+        return true;
 
     if (token == "quit")
         return false;
@@ -159,14 +160,8 @@ namespace {
     else if (token == "perft")
         perft(uip);
     else
-    {
         cout << "Unknown command: " << command << endl;
-        while (!uip.eof())
+
-        {
-            uip >> token;
-            cout << token << endl;
-        }
-    }
     return true;
   }
 
@@ -181,33 +176,33 @@ namespace {
 
     string token;
 
-    uip >> token; // operator>>() skips any whitespace
+    if (!(uip >> token)) // operator>>() skips any whitespace
+        return;
 
     if (token == "startpos")
         RootPosition.from_fen(StartPosition);
     else if (token == "fen")
     {
         string fen;
-        while (token != "moves" && !uip.eof())
+        while (uip >> token && token != "moves")
         {
-            uip >> token;
             fen += token;
             fen += ' ';
         }
         RootPosition.from_fen(fen);
     }
 
-    if (!uip.eof())
+    if (uip.good())
     {
         if (token != "moves")
           uip >> token;
+
         if (token == "moves")
         {
             Move move;
             StateInfo st;
-            while (!uip.eof())
+            while (uip >> token)
             {
-                uip >> token;
                 move = move_from_string(RootPosition, token);
                 RootPosition.do_move(move, st);
                 if (RootPosition.rule_50_counter() == 0)
@@ -215,7 +210,7 @@ namespace {
             }
             // Our StateInfo st is about going out of scope so copy
             // its content inside RootPosition before they disappear.
-            RootPosition.saveState();
+            RootPosition.detach();
         }
     }
   }
@@ -229,27 +224,22 @@ namespace {
 
   void set_option(UCIInputParser& uip) {
 
-    string token, name;
+    string token, name, value;
 
-    uip >> token;
+    if (!(uip >> token)) // operator>>() skips any whitespace
-    if (token == "name")
+        return;
-    {
-        uip >> name;
-        while (!uip.eof())
-        {
-            uip >> token;
-            if (token == "value")
-                break;
 
+    if (token == "name" && uip >> name)
+    {
+        while (uip >> token && token != "value")
             name += (" " + token);
-        }
-        if (token == "value")
-        {
-            // Reads until end of line and left trim white space
-            getline(uip, token);
-            token.erase(0, token.find_first_not_of(" \n\r\t"));
 
-            set_option_value(name, token);
+        if (token == "value" && uip >> value)
+        {
+            while (uip >> token)
+                value += (" " + token);
+
+            set_option_value(name, value);
         } else
             push_button(name);
     }
@@ -276,10 +266,8 @@ namespace {
 
     searchMoves[0] = MOVE_NONE;
 
-    while (!uip.eof())
+    while (uip >> token)
     {
-        uip >> token;
-
         if (token == "infinite")
             infinite = true;
         else if (token == "ponder")
@@ -303,18 +291,13 @@ namespace {
         else if (token == "searchmoves")
         {
             int numOfMoves = 0;
-            while (!uip.eof())
+            while (uip >> token)
-            {
-                uip >> token;
                 searchMoves[numOfMoves++] = move_from_string(RootPosition, token);
-            }
+
             searchMoves[numOfMoves] = MOVE_NONE;
         }
     }
 
-    if (moveTime)
-        infinite = true;  // HACK
-
     assert(RootPosition.is_ok());
 
     return think(RootPosition, infinite, ponder, RootPosition.side_to_move(),
@@ -325,12 +308,11 @@ namespace {
 
     string token;
     int depth, tm, n;
-    Position pos = RootPosition;
+    Position pos(RootPosition);
 
-    if (uip.eof())
+    if (!(uip >> depth))
         return;
 
-    uip >> depth;
     tm = get_system_time();
 
     n = perft(pos, depth * OnePly);

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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -88,26 +88,10 @@ namespace {
     o["Space"] = Option(100, 0, 200);
     o["Aggressiveness"] = Option(100, 0, 200);
     o["Cowardice"] = Option(100, 0, 200);
-    o["King Safety Curve"] = Option("Quadratic", COMBO);
-
-       o["King Safety Curve"].comboValues.push_back("Quadratic");
-       o["King Safety Curve"].comboValues.push_back("Linear");  /*, "From File"*/
-
-    o["King Safety Coefficient"] = Option(40, 1, 100);
-    o["King Safety X Intercept"] = Option(0, 0, 20);
-    o["King Safety Max Slope"] = Option(30, 10, 100);
-    o["King Safety Max Value"] = Option(500, 100, 1000);
-    o["Queen Contact Check Bonus"] = Option(3, 0, 8);
-    o["Queen Check Bonus"] = Option(2, 0, 4);
-    o["Rook Check Bonus"] = Option(1, 0, 4);
-    o["Bishop Check Bonus"] = Option(1, 0, 4);
-    o["Knight Check Bonus"] = Option(1, 0, 4);
-    o["Discovered Check Bonus"] = Option(3, 0, 8);
-    o["Mate Threat Bonus"] = Option(3, 0, 8);
     o["Check Extension (PV nodes)"] = Option(2, 0, 2);
     o["Check Extension (non-PV nodes)"] = Option(1, 0, 2);
-    o["Single Reply Extension (PV nodes)"] = Option(2, 0, 2);
+    o["Single Evasion Extension (PV nodes)"] = Option(2, 0, 2);
-    o["Single Reply Extension (non-PV nodes)"] = Option(2, 0, 2);
+    o["Single Evasion Extension (non-PV nodes)"] = Option(2, 0, 2);
     o["Mate Threat Extension (PV nodes)"] = Option(0, 0, 2);
     o["Mate Threat Extension (non-PV nodes)"] = Option(0, 0, 2);
     o["Pawn Push to 7th Extension (PV nodes)"] = Option(1, 0, 2);
@@ -116,20 +100,16 @@ namespace {
     o["Passed Pawn Extension (non-PV nodes)"] = Option(0, 0, 2);
     o["Pawn Endgame Extension (PV nodes)"] = Option(2, 0, 2);
     o["Pawn Endgame Extension (non-PV nodes)"] = Option(2, 0, 2);
-    o["Full Depth Moves (PV nodes)"] = Option(10, 1, 100);
-    o["Full Depth Moves (non-PV nodes)"] = Option(3, 1, 100);
-    o["Threat Depth"] = Option(5, 0, 100);
     o["Randomness"] = Option(0, 0, 10);
     o["Minimum Split Depth"] = Option(4, 4, 7);
     o["Maximum Number of Threads per Split Point"] = Option(5, 4, 8);
-    o["Threads"] = Option(1, 1, 8);
+    o["Threads"] = Option(1, 1, MAX_THREADS);
-    o["Hash"] = Option(32, 4, 4096);
+    o["Hash"] = Option(32, 4, 8192);
     o["Clear Hash"] = Option(false, BUTTON);
     o["New Game"] = Option(false, BUTTON);
     o["Ponder"] = Option(true);
     o["OwnBook"] = Option(true);
     o["MultiPV"] = Option(1, 1, 500);
-    o["UCI_ShowCurrLine"] = Option(false);
     o["UCI_Chess960"] = Option(false);
     o["UCI_AnalyseMode"] = Option(false);
 
@@ -196,15 +176,18 @@ void init_uci_options() {
 
   load_defaults(options);
 
-  // Limit the default value of "Threads" to 7 even if we have 8 CPU cores.
+  // Set optimal value for parameter "Minimum Split Depth"
-  // According to Ken Dail's tests, Glaurung plays much better with 7 than
+  // according to number of available cores.
-  // with 8 threads.  This is weird, but it is probably difficult to find out
-  // why before I have a 8-core computer to experiment with myself.
   assert(options.find("Threads") != options.end());
   assert(options.find("Minimum Split Depth") != options.end());
 
-  options["Threads"].defaultValue = stringify(Min(cpu_count(), 7));
+  Option& thr = options["Threads"];
-  options["Threads"].currentValue = stringify(Min(cpu_count(), 7));
+  Option& msd = options["Minimum Split Depth"];
+
+  thr.defaultValue = thr.currentValue = stringify(cpu_count());
+
+  if (cpu_count() >= 8)
+      msd.defaultValue = msd.currentValue = stringify(7);
 }
 
 
@@ -292,10 +275,28 @@ void set_option_value(const string& name, const string& value) {
   else if (v == "false")
       v = "0";
 
-  if (options.find(name) != options.end())
+  if (options.find(name) == options.end())
-      options[name].currentValue = v;
+  {
-  else
       std::cout << "No such option: " << name << std::endl;
+      return;
+  }
+
+  // Normally it's up to the GUI to check for option's limits,
+  // but we could receive the new value directly from the user
+  // by teminal window. So let's check the bounds anyway.
+  Option& opt = options[name];
+
+  if (opt.type == CHECK && v != "0" && v != "1")
+      return;
+
+  else if (opt.type == SPIN)
+  {
+      int val = atoi(v.c_str());
+      if (val < opt.minValue || val > opt.maxValue)
+          return;
+  }
+
+  opt.currentValue = v;
 }
 
 

src/ucioption.h

@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/value.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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/value.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -48,7 +48,8 @@ enum Value {
   VALUE_KNOWN_WIN = 15000,
   VALUE_MATE = 30000,
   VALUE_INFINITE = 30001,
-  VALUE_NONE = 30002
+  VALUE_NONE = 30002,
+  VALUE_ENSURE_SIGNED = -1
 };
 
 
@@ -56,10 +57,22 @@ enum Value {
 /// integer (enum), first LSB 16 bits are used to store endgame
 /// value, while upper bits are used for midgame value.
 
-enum Score {};
+// Compiler is free to choose the enum type as long as can keep
+// its data, so ensure Score to be an integer type.
+enum Score { ENSURE_32_BITS_SIZE_P = (1 << 16), ENSURE_32_BITS_SIZE_N = -(1 << 16)};
 
+// Extracting the _signed_ lower and upper 16 bits it 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) { return Value(((int(s) + 32768) & ~0xffff) / 0x10000); }
+
+// Unfortunatly on Intel 64 bit we have a small speed regression, so use a faster code in
+// this case, although not 100% standard compliant it seems to work for Intel and MSVC.
+#if defined(IS_64BIT) && (!defined(__GNUC__) || defined(__INTEL_COMPILER))
 inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
-inline Value mg_value(Score s) { return Value((int(s) + 32768) >> 16); }
+#else
+inline Value eg_value(Score s) { return Value((int)(unsigned(s) & 0x7fffu) - (int)(unsigned(s) & 0x8000u)); }
+#endif
 
 inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }