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>

Readme.txt

@@ -1,91 +1,90 @@
-1. Introduction
----------------
-
-Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is
-not a complete chess program, but requires some UCI compatible GUI
-(like XBoard with PolyGlot, eboard, Jos�, Arena, Sigma Chess, Shredder,
-Chess 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 your GUI.
-
-This version of Stockfish supports up to 8 CPUs, but has not been
-tested thoroughly with more than 2.  The program tries to detect the
-number of CPUs on your computer and set the number of search threads
-accordingly, but please be aware that the detection is not always
-correct.  It is therefore recommended to inspect the value of the
-"Threads" UCI parameter, and to make sure it equals the number of CPU
+1. Introduction
+---------------
+
+Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is
+not a complete chess program, but requires some UCI compatible GUI
+(like XBoard with PolyGlot, eboard, Jos�, Arena, Sigma Chess, Shredder,
+Chess 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 your GUI.
+
+This version of Stockfish supports up to 8 CPUs, but has not been
+tested thoroughly with more than 2.  The program tries to detect the
+number of CPUs on your computer and set the number of search threads
+accordingly, but please be aware that the detection is not always
+correct.  It is therefore recommended to inspect the value of the
+"Threads" UCI parameter, and to make sure it equals the number of CPU
 cores on your computer. If you are using more than four threads, it
 is recommended to raise the value of "Minimum Split Depth" UCI parameter
 to 6.
-
-
-2. Files
---------
-
-This distribution of Stockfish consists of the following files:
-
-  * Readme.txt, the file you are currently reading.
-
-  * Copying.txt, a text file containing the GNU General Public
-    License.
-
-  * src/, a subdirectory containing the full source code, including a
-    Makefile that can be used to compile Stockfish on Unix-like
-    systems.  For further information about how to compile Stockfish
-    yourself, read section 4 below.
-
-  * polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
-    adapter.
-
-
-3. Opening books
-----------------
-
-This version of Stockfish has experimental 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
-UCI parameter "Book File".
-
-
-4. Compiling it yourself
-------------------------
-
-On Unix-like systems, it should usually be possible to compile
-Stockfish directly from the source code with the included Makefile.
-The exception is computer with big-endian CPUs, like PowerPC
-Macintoshes. Some of the bitboard routines in the current version of
-Stockfish are endianness-sensitive, and won't work on a big-endian CPU.
-
-Stockfish has POPCNT instruction runtime detection and support. This can
-give an extra speed on Core i7 or similar systems. To enable this feature
-(disabled by default) simply uncomment #define USE_POPCNT in bitcount.h
-before to compile.
-
-On 64 bit Unix-like systems the 'bsfq' assembly instruction will be used
-for bit counting. Detection is automatic at compile time, but in case you
-experience compile problems you can comment out #define USE_BSFQ line in types.h
-
-
-5. Terms of use
----------------
-
-Stockfish is free, and distributed under the GNU General Public License
-(GPL).  Essentially, this means that you are free to do almost exactly
-what you want with the program, including distributing it among your
-friends, making it available for download from your web site, selling
-it (either by itself or as part of some bigger software package), or
-using it as the starting point for a software project of your own.
-
-The only real limitation is that whenever you distribute Stockfish in
-some way, you must always include the full source code, or a pointer
-to where the source code can be found.  If you make any changes to the
-source code, these changes must also be made available under the GPL.
-
-For full details, read the copy of the GPL found in the file named
-Copying.txt.
-
-
-6. Feedback
------------
-
-The author's e-mail address is mcostalba@gmail.com
+
+
+2. Files
+--------
+
+This distribution of Stockfish consists of the following files:
+
+  * Readme.txt, the file you are currently reading.
+
+  * Copying.txt, a text file containing the GNU General Public
+    License.
+
+  * src/, a subdirectory containing the full source code, including a
+    Makefile that can be used to compile Stockfish on Unix-like
+    systems.  For further information about how to compile Stockfish
+    yourself, read section 4 below.
+
+  * polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot
+    adapter.
+
+
+3. Opening books
+----------------
+
+This version of Stockfish has experimental 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
+UCI parameter "Book File".
+
+
+4. Compiling it yourself
+------------------------
+
+On Unix-like systems, it should usually be possible to compile
+Stockfish directly from the source code with the included Makefile.
+
+For big-endian machines like Power PC you need to enable the proper
+flag changing from -DNBIGENDIAN to -DBIGENDIAN in the Makefile.
+
+Stockfish has POPCNT instruction runtime detection and support. This can
+give an extra speed on Core i7 or similar systems. To enable this feature
+compile with 'make icc-profile-popcnt'
+
+On 64 bit Unix-like systems the 'bsfq' assembly instruction will be used
+for bit counting. Detection is automatic at compile time, but in case you
+experience compile problems you can comment out #define USE_BSFQ line in types.h
+
+
+5. Terms of use
+---------------
+
+Stockfish is free, and distributed under the GNU General Public License
+(GPL).  Essentially, this means that you are free to do almost exactly
+what you want with the program, including distributing it among your
+friends, making it available for download from your web site, selling
+it (either by itself or as part of some bigger software package), or
+using it as the starting point for a software project of your own.
+
+The only real limitation is that whenever you distribute Stockfish in
+some way, you must always include the full source code, or a pointer
+to where the source code can be found.  If you make any changes to the
+source code, these changes must also be made available under the GPL.
+
+For full details, read the copy of the GPL found in the file named
+Copying.txt.
+
+
+6. Feedback
+-----------
+
+The author's e-mail address is mcostalba@gmail.com

src/Makefile

@@ -21,6 +21,10 @@
 ### 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
@@ -39,6 +43,14 @@ ICCFLAGS += -DNDEBUG
 ICCFLAGS-OSX += -DNDEBUG
 
 
+### ==========================================================================
+### Remove below comments to compile for a big-endian machine
+### ==========================================================================
+#GCCFLAGS += -DBIGENDIAN
+#ICCFLAGS += -DBIGENDIAN
+#ICCFLAGS-OSX += -DBIGENDIAN
+
+
 ### ==========================================================================
 ### Run built-in benchmark for pgo-builds with:  32MB hash  1 thread  10 depth
 ### These settings are generally fast, but may be changed experimentally
@@ -47,9 +59,9 @@ PGOBENCH = ./$(EXE) bench 32 1 10 default depth
 
 
 ### General compiler settings. Do not change
-GCCFLAGS += -g -Wall -fno-exceptions -fno-rtti -fno-strict-aliasing
-ICCFLAGS += -g -Wall -fno-exceptions -fno-rtti -fno-strict-aliasing -wd383,869,981,10187,10188,11505,11503
-ICCFLAGS-OSX += -g -Wall -fno-exceptions -fno-rtti -fno-strict-aliasing -wd383,869,981,10187,10188,11505,11503
+GCCFLAGS += -g -Wall -fno-exceptions -fno-rtti
+ICCFLAGS += -g -Wall -fno-exceptions -fno-rtti -wd383,869,981,10187,10188,11505,11503
+ICCFLAGS-OSX += -g -Wall -fno-exceptions -fno-rtti -wd383,869,981,10187,10188,11505,11503
 
 
 ### General linker settings. Do not change
@@ -72,8 +84,10 @@ 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"
 	@echo "make osx-ppc32      >  PPC-Mac OS X 32 bit. Compiler = g++"
 	@echo "make osx-ppc64      >  PPC-Mac OS X 64 bit. Compiler = g++"
 	@echo "make osx-x86        >  x86-Mac OS X 32 bit. Compiler = g++"
@@ -82,14 +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
@@ -99,6 +117,13 @@ gcc:
 	CXXFLAGS="$(GCCFLAGS)" \
 	all
 
+gcc-popcnt:
+	$(MAKE) \
+	CXX='g++' \
+	CXXFLAGS="$(GCCFLAGS) -DUSE_POPCNT" \
+	all
+
+
 icc:
 	$(MAKE) \
 	CXX='icpc' \
@@ -133,11 +158,46 @@ icc-profile:
 	$(MAKE) icc-profile-use
 	@rm -rf profdir bench.txt
 
+icc-profile-make-with-popcnt:
+	$(MAKE) \
+	CXX='icpc' \
+	CXXFLAGS="$(ICCFLAGS) -DUSE_POPCNT" \
+	CXXFLAGS+='-prof-gen=srcpos -prof_dir ./profdir' \
+	all
+
+icc-profile-use-with-popcnt:
+	$(MAKE) \
+	CXX='icpc' \
+	CXXFLAGS="$(ICCFLAGS) -DUSE_POPCNT" \
+	CXXFLAGS+='-prof_use -prof_dir ./profdir' \
+	all
+
+icc-profile-popcnt:
+	@rm -rf profdir
+	@mkdir profdir
+	@touch *.cpp *.h
+	$(MAKE) icc-profile-make
+	@echo ""
+	@echo "Running benchmark for pgo-build (popcnt disabled)..."
+	@$(PGOBENCH) > /dev/null
+	@touch *.cpp *.h
+	$(MAKE) icc-profile-make-with-popcnt
+	@echo ""
+	@echo "Running benchmark for pgo-build (popcnt enabled)..."
+	@$(PGOBENCH) > /dev/null
+	@echo "Benchmarks finished. Build final executable now ..."
+	@echo ""
+	@touch *.cpp *.h
+	$(MAKE) icc-profile-use-with-popcnt
+	@rm -rf profdir bench.txt
+
+
 osx-ppc32:
 	$(MAKE) \
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
 	CXXFLAGS+='-arch ppc' \
+	CXXFLAGS+='-DBIGENDIAN' \
 	LDFLAGS+='-arch ppc' \
 	all
 
@@ -146,6 +206,7 @@ osx-ppc64:
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
 	CXXFLAGS+='-arch ppc64' \
+	CXXFLAGS+='-DBIGENDIAN' \
 	LDFLAGS+='-arch ppc64' \
 	all
 
@@ -153,16 +214,16 @@ osx-x86:
 	$(MAKE) \
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch i386' \
-	LDFLAGS+='-arch i386' \
+	CXXFLAGS+='-arch i386 -mdynamic-no-pic' \
+	LDFLAGS+='-arch i386 -mdynamic-no-pic' \
 	all
 
 osx-x86_64:
 	$(MAKE) \
 	CXX='g++' \
 	CXXFLAGS="$(GCCFLAGS)" \
-	CXXFLAGS+='-arch x86_64' \
-	LDFLAGS+='-arch x86_64' \
+	CXXFLAGS+='-arch x86_64 -mdynamic-no-pic' \
+	LDFLAGS+='-arch x86_64 -mdynamic-no-pic' \
 	all
 	
 osx-icc32:
@@ -245,6 +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:
@@ -255,9 +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);
@@ -104,7 +104,7 @@ void benchmark(const string& commandLine) {
 
   if (limitType == "time")
       secsPerPos = val * 1000;
-  else if (limitType == "depth")
+  else if (limitType == "depth" || limitType == "perft")
       maxDepth = val;
   else
       maxNodes = val;
@@ -153,7 +153,9 @@ void benchmark(const string& commandLine) {
       int dummy[2] = {0, 0};
       Position pos(*it);
       cerr << "\nBench position: " << cnt << '/' << positions.size() << endl << endl;
-      if (!think(pos, true, false, 0, dummy, dummy, 0, maxDepth, maxNodes, secsPerPos, moves))
+      if (limitType == "perft")
+          totalNodes += perft(pos, maxDepth * OnePly);
+      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 const int BitTable[64] = {
+static CACHE_LINE_ALIGNMENT
+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,
@@ -317,8 +317,8 @@ Square pop_1st_bit(Bitboard* b) {
 
 #elif !defined(USE_BSFQ)
 
-CACHE_LINE_ALIGNMENT
-static const int BitTable[64] = {
+static CACHE_LINE_ALIGNMENT
+const int BitTable[64] = {
   63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
   51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
   26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
@@ -336,30 +336,72 @@ union b_union {
 
     Bitboard b;
     struct {
+#if defined (BIGENDIAN)
+        uint32_t h;
+        uint32_t l;
+#else
         uint32_t l;
         uint32_t h;
+#endif
     } dw;
 };
 
-// WARNING: Needs -fno-strict-aliasing compiler option
 Square pop_1st_bit(Bitboard* bb) {
 
-  b_union u;
+   b_union u;
+   Square ret;
 
-  u.b = *bb;
+   u.b = *bb;
 
-  if (u.dw.l)
-  {
-      *((uint32_t*)bb) = u.dw.l & (u.dw.l - 1);
-      return Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
-  }
-
-  *((uint32_t*)bb+1) = u.dw.h & (u.dw.h - 1); // Little endian only?
-  return Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
+   if (u.dw.l)
+   {
+       ret = Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
+       u.dw.l &= (u.dw.l - 1);
+       *bb = u.b;
+       return ret;
+   }
+   ret = Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
+   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)
+   {
+      b >>= 16;
+      result += 16;
+   }
+   if (b > 0xFF)
+   {
+      b >>= 8;
+      result += 8;
+   }
+   return result + MsbTable[b];
+}
+
 namespace {
 
   // All functions below are used to precompute various bitboards during

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
@@ -349,6 +349,7 @@ extern Square pop_1st_bit(Bitboard* b);
 
 extern void print_bitboard(Bitboard b);
 extern void init_bitboards();
+extern int bitScanReverse32(uint32_t b);
 
 
 #endif // !defined(BITBOARD_H_INCLUDED)

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
@@ -22,62 +22,22 @@
 #if !defined(BITCOUNT_H_INCLUDED)
 #define BITCOUNT_H_INCLUDED
 
-// To enable POPCNT support uncomment USE_POPCNT define. For PGO compile on a Core i7
-// you may want to collect profile data first with USE_POPCNT disabled and then, in a
-// second profiling session, with USE_POPCNT enabled so to exercise both paths. Don't
-// forget to leave USE_POPCNT enabled for the final optimized compile though ;-)
-
-//#define USE_POPCNT
-
-
 #include "types.h"
 
-// Select type of intrinsic bit count instruction to use
-
-#if defined(__INTEL_COMPILER) && defined(IS_64BIT) && 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 a dummy template to workaround a compile error if _mm_popcnt_u64() is not defined.
-//
-// If _mm_popcnt_u64() is defined in <nmmintrin.h> it will be choosen first due to
-// C++ overload rules that always prefer a function to a template with the same name.
-// If not, we avoid a compile error and because cpu_has_popcnt() should return false,
-// our templetized _mm_popcnt_u64() is never called anyway.
-template<typename T> inline unsigned _mm_popcnt_u64(T) { return 0; } // Is never called
-
-#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
-
-#elif defined(_MSC_VER) && defined(IS_64BIT) && 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;
-}
-
-// See comment of _mm_popcnt_u64<>() few lines above for an explanation.
-template<typename T> inline unsigned __popcnt64(T) { return 0; } // Is never called
-
-#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; }
-
+// Select type of intrinsic bit count instruction to use, see
+// README.txt on how to pgo compile with POPCNT support.
+#if !defined(USE_POPCNT)
 #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
@@ -144,10 +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
@@ -48,7 +48,8 @@ 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- (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 &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.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
@@ -25,6 +25,8 @@
 //// Includes
 ////
 
+#include <iostream>
+
 #include "material.h"
 #include "pawns.h"
 
@@ -45,8 +47,10 @@ class Position;
 
 struct EvalInfo {
 
+  EvalInfo() { futilityMargin[0] = futilityMargin[1] = Value(0); }
+
   // Middle game and endgame evaluations
-  Value mgValue, egValue;
+  Score value;
 
   // Pointers to material and pawn hash table entries
   MaterialInfo* mi;
@@ -89,11 +93,11 @@ struct EvalInfo {
   Move mateThreat[2];
 
   // Middle game and endgame mobility scores.
-  Value mgMobility, egMobility;
+  Score mobility;
 
   // Extra futility margin. This is added to the standard futility margin
-  // in the quiescence search.
-  Value futilityMargin;
+  // in the quiescence search. One for each color.
+  Value futilityMargin[2];
 };
 
 
@@ -102,7 +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
@@ -42,8 +42,7 @@ History::History() { clear(); }
 
 void History::clear() {
   memset(history, 0, 2 * 8 * 64 * sizeof(int));
-  memset(successCount, 0, 2 * 8 * 64 * sizeof(int));
-  memset(failureCount, 0, 2 * 8 * 64 * sizeof(int));
+  memset(maxStaticValueDelta, 0, 2 * 8 * 64 * sizeof(int));
 }
 
 
@@ -58,13 +57,12 @@ void History::success(Piece p, Square to, Depth d) {
   assert(square_is_ok(to));
 
   history[p][to] += int(d) * int(d);
-  successCount[p][to]++;
 
   // Prevent history overflow
   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;
 }
 
 
@@ -72,12 +70,18 @@ void History::success(Piece p, Square to, Depth d) {
 /// called for each non-capturing move which failed to produce a beta cutoff
 /// at a node where a beta cutoff was finally found.
 
-void History::failure(Piece p, Square to) {
+void History::failure(Piece p, Square to, Depth d) {
 
   assert(piece_is_ok(p));
   assert(square_is_ok(to));
 
-  failureCount[p][to]++;
+  history[p][to] -= int(d) * int(d);
+
+  // 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;
 }
 
 
@@ -93,13 +97,19 @@ int History::move_ordering_score(Piece p, Square to) const {
 }
 
 
-/// History::ok_to_prune() decides whether a move has been sufficiently
-/// unsuccessful that it makes sense to prune it entirely.
+/// 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.
 
-bool History::ok_to_prune(Piece p, Square to, Depth d) const {
-
-  assert(piece_is_ok(p));
-  assert(square_is_ok(to));
-
-  return (int(d) * successCount[p][to] < failureCount[p][to]);
+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"
 
 
 ////
@@ -47,14 +48,14 @@ public:
   History();
   void clear();
   void success(Piece p, Square to, Depth d);
-  void failure(Piece p, Square to);
+  void failure(Piece p, Square to, Depth d);
   int move_ordering_score(Piece p, Square to) const;
-  bool ok_to_prune(Piece p, Square to, Depth d) 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 successCount[16][64];
-  int failureCount[16][64];
+  int maxStaticValueDelta[16][64];  // [piece][from_square][to_square]
 };
 
 
@@ -70,7 +71,7 @@ private:
 /// 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
@@ -63,7 +63,7 @@ int main(int argc, char *argv[]) {
       if (string(argv[1]) != "bench" || argc < 4 || argc > 8)
           cout << "Usage: stockfish bench <hash size> <threads> "
                << "[time = 60s] [fen positions file = default] "
-               << "[time, depth or node limited = time] "
+               << "[time, depth, perft or node limited = time] "
                << "[timing file name = none]" << endl;
       else
       {

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
@@ -37,10 +37,15 @@ using namespace std;
 
 namespace {
 
+  // Values modified by Joona Kiiski
+  const Value MidgameLimit = Value(15581);
+  const Value EndgameLimit = Value(3998);
+
   // Polynomial material balance parameters
   const Value RedundantQueenPenalty = Value(320);
   const Value RedundantRookPenalty  = Value(554);
-  const int LinearCoefficients[6]   = { 1617, -162, -1172, -190, 105, 26 };
+
+  const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
 
   const int QuadraticCoefficientsSameColor[][6] = {
   { 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
@@ -129,6 +134,22 @@ MaterialInfoTable::~MaterialInfoTable() {
 }
 
 
+/// MaterialInfoTable::game_phase() calculates the phase given the current
+/// position. Because the phase is strictly a function of the material, it
+/// is stored in MaterialInfo.
+
+Phase MaterialInfoTable::game_phase(const Position& pos) {
+
+  Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
+
+  if (npm >= MidgameLimit)
+      return PHASE_MIDGAME;
+  else if (npm <= EndgameLimit)
+      return PHASE_ENDGAME;
+
+  return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
+}
+
 /// MaterialInfoTable::get_material_info() takes a position object as input,
 /// computes or looks up a MaterialInfo object, and returns a pointer to it.
 /// If the material configuration is not already present in the table, it
@@ -151,6 +172,9 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
   mi->clear();
   mi->key = key;
 
+  // Store game phase
+  mi->gamePhase = MaterialInfoTable::game_phase(pos);
+
   // Let's look if we have a specialized evaluation function for this
   // particular material configuration. First we look for a fixed
   // configuration one, then a generic one if previous search failed.
@@ -269,8 +293,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
                                  { pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
                                    pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
   Color c, them;
-  int sign;
-  int matValue = 0;
+  int sign, pt1, pt2, pc;
+  int v, vv, matValue = 0;
 
   for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
   {
@@ -304,25 +328,27 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
         matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
 
     them = opposite_color(c);
+    v = 0;
 
     // Second-degree polynomial material imbalance by Tord Romstad
     //
     // We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece",
     // this allow us to be more flexible in defining bishop pair bonuses.
-    for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
+    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
     {
-        int c1 = sign * pieceCount[c][pt1];
-        if (!c1)
+        pc = pieceCount[c][pt1];
+        if (!pc)
             continue;
 
-        matValue += c1 * LinearCoefficients[pt1];
+        vv = LinearCoefficients[pt1];
 
-        for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
-        {
-            matValue += c1 * pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2];
-            matValue += c1 * pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
-        }
+        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; pt2++)
+            vv +=  pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2]
+                 + pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
+
+        v += pc * vv;
     }
+    matValue += sign * v;
   }
   mi->value = int16_t(matValue / 16);
   return mi;
@@ -348,7 +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
@@ -51,9 +51,10 @@ class MaterialInfo {
 public:
   MaterialInfo() : key(0) { clear(); }
 
-  Value material_value() const;
+  Score material_value() const;
   ScaleFactor scale_factor(const Position& pos, Color c) const;
   int space_weight() const;
+  Phase game_phase() const;
   bool specialized_eval_exists() const;
   Value evaluate(const Position& pos) const;
 
@@ -66,6 +67,7 @@ private:
   EndgameEvaluationFunctionBase* evaluationFunction;
   EndgameScalingFunctionBase* scalingFunction[2];
   int spaceWeight;
+  Phase gamePhase;
 };
 
 /// The MaterialInfoTable class represents a pawn hash table. It is basically
@@ -81,6 +83,8 @@ public:
   ~MaterialInfoTable();
   MaterialInfo* get_material_info(const Position& pos);
 
+  static Phase game_phase(const Position& pos);
+
 private:
   unsigned size;
   MaterialInfo* entries;
@@ -92,12 +96,13 @@ private:
 //// Inline functions
 ////
 
+
 /// MaterialInfo::material_value simply returns the material balance
 /// evaluation that is independent from game phase.
 
-inline Value MaterialInfo::material_value() const {
+inline Score MaterialInfo::material_value() const {
 
-  return Value(value);
+  return make_score(value, value);
 }
 
 
@@ -141,6 +146,14 @@ inline int MaterialInfo::space_weight() const {
   return spaceWeight;
 }
 
+/// MaterialInfo::game_phase() returns the game phase according
+/// to this material configuration.
+
+inline Phase MaterialInfo::game_phase() const {
+
+  return gamePhase;
+}
+
 
 /// MaterialInfo::specialized_eval_exists decides whether there is a
 /// specialized evaluation function for the current material configuration,

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 = "1.5";
+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
@@ -62,9 +62,83 @@ struct MoveStack {
   int score;
 };
 
-// Note that operator< is set up such that std::sort() will sort in descending order
+// Note that operator< is set up such that sorting will be in descending order
 inline bool operator<(const MoveStack& f, const MoveStack& s) { return s.score < f.score; }
 
+// An helper insertion sort implementation
+template<typename T>
+inline void insertion_sort(T* firstMove, T* lastMove)
+{
+    T value;
+    T *cur, *p, *d;
+
+    if (firstMove != lastMove)
+        for (cur = firstMove + 1; cur != lastMove; cur++)
+        {
+            p = d = cur;
+            value = *p--;
+            if (value < *p)
+            {
+                do *d = *p;
+                while (--d != firstMove && value < *--p);
+                *d = value;
+            }
+        }
+}
+
+// Our dedicated sort in range [firstMove, lastMove), first splits
+// positive scores from ramining then order seaprately the two sets.
+template<typename T>
+inline void sort_moves(T* firstMove, T* lastMove, T** lastPositive)
+{
+    T tmp;
+    T *p, *d;
+
+    d = lastMove;
+    p = firstMove - 1;
+
+    d->score = -1; // right guard
+
+    // Split positives vs non-positives
+    do {
+        while ((++p)->score > 0);
+
+        if (p != d)
+        {
+            while (--d != p && d->score <= 0);
+
+            tmp = *p;
+            *p = *d;
+            *d = tmp;
+        }
+
+    } while (p != d);
+
+    // Sort just positive scored moves, remaining only when we get there
+    insertion_sort<T>(firstMove, p);
+    *lastPositive = p;
+}
+
+// Picks up the best move in range [curMove, lastMove), one per cycle.
+// It is faster then sorting all the moves in advance when moves are few,
+// as normally are the possible captures. Note that is not a stable alghoritm.
+template<typename T>
+inline T pick_best(T* curMove, T* lastMove)
+{
+    T bestMove, tmp;
+
+    bestMove = *curMove;
+    while (++curMove != lastMove)
+    {
+        if (*curMove < bestMove)
+        {
+            tmp = *curMove;
+            *curMove = bestMove;
+            bestMove = tmp;
+        }
+    }
+    return bestMove;
+}
 
 ////
 //// Inline functions
@@ -82,6 +156,10 @@ inline PieceType move_promotion_piece(Move m) {
   return PieceType((int(m) >> 12) & 7);
 }
 
+inline int move_is_special(Move m) {
+  return m & (0x1F << 12);
+}
+
 inline int move_is_promotion(Move m) {
   return m & (7 << 12);
 }

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
@@ -52,16 +52,12 @@ namespace {
     EVASION
   };
 
-  // Functions
-  bool castling_is_check(const Position&, CastlingSide);
-
   // Helper templates
   template<CastlingSide Side>
   MoveStack* generate_castle_moves(const Position&, MoveStack*);
 
   template<Color Us, MoveType Type>
-  MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard = EmptyBoardBB,
-                                 Square = SQ_NONE, Bitboard = EmptyBoardBB);
+  MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square);
 
   // Template generate_piece_moves (captures and non-captures) with specializations and overloads
   template<PieceType>
@@ -71,37 +67,29 @@ namespace {
   MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
 
   template<PieceType Piece, MoveType Type>
-  inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
+  inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) {
 
     assert(Piece == PAWN);
-    assert(Type == CAPTURE || Type == NON_CAPTURE);
+    assert(Type == CAPTURE || Type == NON_CAPTURE || Type == EVASION);
 
-    return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m)
-                        : generate_pawn_moves<BLACK, Type>(p, m));
+    return (us == WHITE ? generate_pawn_moves<WHITE, Type>(p, m, t, SQ_NONE)
+                        : generate_pawn_moves<BLACK, Type>(p, m, t, SQ_NONE));
   }
 
-  // Template generate_piece_checks with specializations
+  // Templates for non-capture checks generation
+
+  template<PieceType Piece>
+  MoveStack* generate_discovered_checks(const Position&, MoveStack*, Square);
+
   template<PieceType>
-  MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square);
+  MoveStack* generate_direct_checks(const Position&, MoveStack*, Color, Bitboard, Square);
 
   template<>
-  inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+  inline MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
 
     return (us == WHITE ? generate_pawn_moves<WHITE, CHECK>(p, m, dc, ksq)
                         : generate_pawn_moves<BLACK, CHECK>(p, m, dc, ksq));
   }
-
-  // Template generate_piece_evasions with specializations
-  template<PieceType>
-  MoveStack* generate_piece_evasions(const Position&, MoveStack*, Color, Bitboard, Bitboard);
-
-  template<>
-  inline MoveStack* generate_piece_evasions<PAWN>(const Position& p, MoveStack* m,
-                                                  Color us, Bitboard t, Bitboard pnd) {
-
-    return (us == WHITE ? generate_pawn_moves<WHITE, EVASION>(p, m, pnd, SQ_NONE, t)
-                        : generate_pawn_moves<BLACK, EVASION>(p, m, pnd, SQ_NONE, t));
-  }
 }
 
 
@@ -125,7 +113,7 @@ MoveStack* generate_captures(const Position& pos, MoveStack* mlist) {
   mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
   mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
   mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
-  mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us);
+  mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us, target);
   return  generate_piece_moves<KING>(pos, mlist, us, target);
 }
 
@@ -141,7 +129,7 @@ MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
   Color us = pos.side_to_move();
   Bitboard target = pos.empty_squares();
 
-  mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us);
+  mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us, target);
   mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
   mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
   mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
@@ -152,175 +140,111 @@ MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) {
 }
 
 
-/// generate_non_capture_checks() generates all pseudo-legal non-captures and
+/// generate_non_capture_checks() generates all pseudo-legal non-captures and knight
 /// underpromotions that give check. Returns a pointer to the end of the move list.
 
-MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
+MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) {
 
   assert(pos.is_ok());
   assert(!pos.is_check());
 
+  Bitboard b, dc;
+  Square from;
   Color us = pos.side_to_move();
   Square ksq = pos.king_square(opposite_color(us));
 
   assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
 
-  // Pieces moves
-  mlist = generate_piece_checks<PAWN>(pos, mlist, us, dc, ksq);
-  mlist = generate_piece_checks<KNIGHT>(pos, mlist, us, dc, ksq);
-  mlist = generate_piece_checks<BISHOP>(pos, mlist, us, dc, ksq);
-  mlist = generate_piece_checks<ROOK>(pos, mlist, us, dc, ksq);
-  mlist = generate_piece_checks<QUEEN>(pos, mlist, us, dc, ksq);
-  mlist = generate_piece_checks<KING>(pos, mlist, us, dc, ksq);
+  // Discovered non-capture checks
+  b = dc = pos.discovered_check_candidates(us);
 
-  // Castling moves that give check. Very rare but nice to have!
-  if (   pos.can_castle_queenside(us)
-      && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D)
-      && castling_is_check(pos, QUEEN_SIDE))
-      mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+  while (b)
+  {
+     from = pop_1st_bit(&b);
+     switch (pos.type_of_piece_on(from))
+     {
+      case PAWN:   /* Will be generated togheter with pawns direct checks */     break;
+      case KNIGHT: mlist = generate_discovered_checks<KNIGHT>(pos, mlist, from); break;
+      case BISHOP: mlist = generate_discovered_checks<BISHOP>(pos, mlist, from); break;
+      case ROOK:   mlist = generate_discovered_checks<ROOK>(pos, mlist, from);   break;
+      case KING:   mlist = generate_discovered_checks<KING>(pos, mlist, from);   break;
+      default: assert(false); break;
+     }
+  }
 
-  if (   pos.can_castle_kingside(us)
-      && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F)
-      && castling_is_check(pos, KING_SIDE))
-      mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
-
-  return mlist;
+  // Direct non-capture checks
+  mlist = generate_direct_checks<PAWN>(pos, mlist, us, dc, ksq);
+  mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, dc, ksq);
+  mlist = generate_direct_checks<BISHOP>(pos, mlist, us, dc, ksq);
+  mlist = generate_direct_checks<ROOK>(pos, mlist, us, dc, ksq);
+  return  generate_direct_checks<QUEEN>(pos, mlist, us, dc, ksq);
 }
 
 
-/// generate_evasions() generates all check evasions when the side to move is
-/// in check. Unlike the other move generation functions, this one generates
-/// only legal moves. Returns a pointer to the end of the move list.
+/// 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.
 
-MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
+MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) {
 
   assert(pos.is_ok());
   assert(pos.is_check());
 
-  Square from, to;
+  Bitboard b, target;
+  Square from, checksq;
+  int checkersCnt = 0;
   Color us = pos.side_to_move();
-  Color them = opposite_color(us);
   Square ksq = pos.king_square(us);
-  Bitboard sliderAttacks = EmptyBoardBB;
   Bitboard checkers = pos.checkers();
+  Bitboard sliderAttacks = EmptyBoardBB;
 
   assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
-
-  // The bitboard of occupied pieces without our king
-  Bitboard b_noKing = pos.occupied_squares();
-  clear_bit(&b_noKing, ksq);
+  assert(checkers);
 
   // Find squares attacked by slider checkers, we will remove
-  // them from the king evasions set so to avoid a couple
-  // of cycles in the slow king evasions legality check loop
-  // and to be able to use attackers_to().
-  Bitboard b = checkers & pos.pieces(BISHOP, QUEEN);
-  while (b)
+  // them from the king evasions set so to early skip known
+  // illegal moves and avoid an useless legality check later.
+  b = checkers;
+  do
   {
-      from = pop_1st_bit(&b);
-      sliderAttacks |= bishop_attacks_bb(from, b_noKing);
-  }
+      checkersCnt++;
+      checksq = pop_1st_bit(&b);
 
-  b = checkers & pos.pieces(ROOK, QUEEN);
-  while (b)
-  {
-      from = pop_1st_bit(&b);
-      sliderAttacks |= rook_attacks_bb(from, b_noKing);
-  }
+      assert(pos.color_of_piece_on(checksq) == opposite_color(us));
+
+      switch (pos.type_of_piece_on(checksq))
+      {
+      case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break;
+      case ROOK:   sliderAttacks |= RookPseudoAttacks[checksq];   break;
+      case QUEEN:
+          // In case of a queen remove also squares attacked in the other direction to
+          // avoid possible illegal moves when queen and king are on adjacent squares.
+          if (direction_is_straight(checksq, ksq))
+              sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from<BISHOP>(checksq);
+          else
+              sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from<ROOK>(checksq);
+      default:
+          break;
+      }
+  } while (b);
 
   // Generate evasions for king, capture and non capture moves
-  Bitboard enemy = pos.pieces_of_color(them);
-  Bitboard b1 = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
-  while (b1)
-  {
-      // Note that we can use attackers_to() only because we have already
-      // removed from b1 the squares attacked by slider checkers.
-      to = pop_1st_bit(&b1);
-      if (!(pos.attackers_to(to) & enemy))
-          (*mlist++).move = make_move(ksq, to);
-  }
+  b = pos.attacks_from<KING>(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks;
+  from = ksq;
+  SERIALIZE_MOVES(b);
 
-  // Generate evasions for other pieces only if not double check. We use a
-  // simple bit twiddling hack here rather than calling count_1s in order to
-  // save some time (we know that pos.checkers() has at most two nonzero bits).
-  if (!(checkers & (checkers - 1))) // Only one bit set?
-  {
-      Square checksq = first_1(checkers);
+  // Generate evasions for other pieces only if not double check
+  if (checkersCnt > 1)
+      return mlist;
 
-      assert(pos.color_of_piece_on(checksq) == them);
+  // Find squares where a blocking evasion or a capture of the
+  // checker piece is possible.
+  target = squares_between(checksq, ksq) | checkers;
 
-      // Generate captures of the checking piece
-
-      // Pawn captures
-      b1 = pos.attacks_from<PAWN>(checksq, them) & pos.pieces(PAWN, us) & ~pinned;
-      while (b1)
-      {
-          from = pop_1st_bit(&b1);
-          if (relative_rank(us, checksq) == RANK_8)
-          {
-              (*mlist++).move = make_promotion_move(from, checksq, QUEEN);
-              (*mlist++).move = make_promotion_move(from, checksq, ROOK);
-              (*mlist++).move = make_promotion_move(from, checksq, BISHOP);
-              (*mlist++).move = make_promotion_move(from, checksq, KNIGHT);
-          } else
-              (*mlist++).move = make_move(from, checksq);
-      }
-
-      // Pieces captures
-      b1 = (  (pos.attacks_from<KNIGHT>(checksq) & pos.pieces(KNIGHT, us))
-            | (pos.attacks_from<BISHOP>(checksq) & pos.pieces(BISHOP, QUEEN, us))
-            | (pos.attacks_from<ROOK>(checksq)   & pos.pieces(ROOK, QUEEN, us)) ) & ~pinned;
-
-      while (b1)
-      {
-          from = pop_1st_bit(&b1);
-          (*mlist++).move = make_move(from, checksq);
-      }
-
-      // Blocking check evasions are possible only if the checking piece is a slider
-      if (sliderAttacks)
-      {
-          Bitboard blockSquares = squares_between(checksq, ksq);
-
-          assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB);
-
-          if (blockSquares)
-          {
-              mlist = generate_piece_evasions<PAWN>(pos, mlist, us, blockSquares, pinned);
-              mlist = generate_piece_evasions<KNIGHT>(pos, mlist, us, blockSquares, pinned);
-              mlist = generate_piece_evasions<BISHOP>(pos, mlist, us, blockSquares, pinned);
-              mlist = generate_piece_evasions<ROOK>(pos, mlist, us, blockSquares, pinned);
-              mlist = generate_piece_evasions<QUEEN>(pos, mlist, us, blockSquares, pinned);
-          }
-      }
-
-      // Finally, the special case of en passant captures. An en passant
-      // capture can only be a check evasion if the check is not a discovered
-      // check. If pos.ep_square() is set, the last move made must have been
-      // a double pawn push. If, furthermore, the checking piece is a pawn,
-      // an en passant check evasion may be possible.
-      if (pos.ep_square() != SQ_NONE && (checkers & pos.pieces(PAWN, them)))
-      {
-          to = pos.ep_square();
-          b1 = pos.attacks_from<PAWN>(to, them) & pos.pieces(PAWN, us);
-
-          // The checking pawn cannot be a discovered (bishop) check candidate
-          // otherwise we were in check also before last double push move.
-          assert(!bit_is_set(pos.discovered_check_candidates(them), checksq));
-          assert(count_1s(b1) == 1 || count_1s(b1) == 2);
-
-          b1 &= ~pinned;
-          while (b1)
-          {
-              from = pop_1st_bit(&b1);
-              // Move is always legal because checking pawn is not a discovered
-              // check candidate and our capturing pawn has been already tested
-              // against pinned pieces.
-              (*mlist++).move = make_ep_move(from, to);
-          }
-      }
-  }
-  return mlist;
+  mlist = generate_piece_moves<PAWN, EVASION>(pos, mlist, us, target);
+  mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
+  mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
+  mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
+  return  generate_piece_moves<QUEEN>(pos, mlist, us, target);
 }
 
 
@@ -332,24 +256,25 @@ MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLega
 
   assert(pos.is_ok());
 
+  MoveStack *last, *cur = mlist;
   Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
 
-  if (pos.is_check())
-      return generate_evasions(pos, mlist, pinned);
-
   // Generate pseudo-legal moves
-  MoveStack* last = generate_captures(pos, mlist);
-  last = generate_noncaptures(pos, last);
+  if (pos.is_check())
+      last = generate_evasions(pos, mlist);
+  else
+      last = generate_noncaptures(pos, generate_captures(pos, mlist));
+
   if (pseudoLegal)
       return last;
 
   // Remove illegal moves from the list
-  for (MoveStack* cur = mlist; cur != last; cur++)
-      if (!pos.pl_move_is_legal(cur->move, pinned))
-      {
+  while (cur != last)
+      if (pos.pl_move_is_legal(cur->move, pinned))
+          cur++;
+      else
           cur->move = (--last)->move;
-          cur--;
-      }
+
   return last;
 }
 
@@ -361,10 +286,11 @@ MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLega
 bool move_is_legal(const Position& pos, const Move m) {
 
   MoveStack mlist[256];
-  MoveStack* last = generate_moves(pos, mlist, true);
-  for (MoveStack* cur = mlist; cur != last; cur++)
+  MoveStack *cur, *last = generate_moves(pos, mlist, true);
+
+   for (cur = mlist; cur != last; cur++)
       if (cur->move == m)
-          return pos.pl_move_is_legal(m);
+          return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move()));
 
   return false;
 }
@@ -372,25 +298,23 @@ bool move_is_legal(const Position& pos, const Move m) {
 
 /// Fast version of move_is_legal() that takes a position a move and a
 /// bitboard of pinned pieces as input, and tests whether the move is legal.
-/// This version must only be used when the side to move is not in check.
 
 bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
 
   assert(pos.is_ok());
-  assert(!pos.is_check());
   assert(move_is_ok(m));
   assert(pinned == pos.pinned_pieces(pos.side_to_move()));
 
-  // Use a slower but simpler function for uncommon cases
-  if (move_is_ep(m) || move_is_castle(m))
-      return move_is_legal(pos, m);
-
   Color us = pos.side_to_move();
   Color them = opposite_color(us);
   Square from = move_from(m);
   Square to = move_to(m);
   Piece pc = pos.piece_on(from);
 
+  // Use a slower but simpler function for uncommon cases
+  if (move_is_ep(m) || move_is_castle(m))
+      return move_is_legal(pos, m);
+
   // If the from square is not occupied by a piece belonging to the side to
   // move, the move is obviously not legal.
   if (color_of_piece(pc) != us)
@@ -459,13 +383,13 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
           return false;
       }
       // The move is pseudo-legal, check if it is also legal
-      return pos.pl_move_is_legal(m, pinned);
+      return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned);
   }
 
   // Luckly we can handle all the other pieces in one go
-  return (   bit_is_set(pos.attacks_from(pc, from), to)
-          && pos.pl_move_is_legal(m, pinned)
-          && !move_is_promotion(m));
+  return    bit_is_set(pos.attacks_from(pc, from), to)
+        && (pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned))
+        && !move_is_promotion(m);
 }
 
 
@@ -474,8 +398,8 @@ namespace {
   template<PieceType Piece>
   MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
 
-    Square from;
     Bitboard b;
+    Square from;
     const Square* ptr = pos.piece_list_begin(us, Piece);
 
     while ((from = *ptr++) != SQ_NONE)
@@ -497,24 +421,6 @@ namespace {
     return mlist;
   }
 
-  template<PieceType Piece>
-  MoveStack* generate_piece_evasions(const Position& pos, MoveStack* mlist,
-                                     Color us, Bitboard target, Bitboard pinned) {
-    Square from;
-    Bitboard b;
-    const Square* ptr = pos.piece_list_begin(us, Piece);
-
-    while ((from = *ptr++) != SQ_NONE)
-    {
-        if (pinned && bit_is_set(pinned, from))
-            continue;
-
-        b = pos.attacks_from<Piece>(from) & target;
-        SERIALIZE_MOVES(b);
-    }
-    return mlist;
-  }
-
   template<Color Us, SquareDelta Direction>
   inline Bitboard move_pawns(Bitboard p) {
 
@@ -528,8 +434,8 @@ namespace {
         return p;
   }
 
-  template<Color Us, SquareDelta Diagonal>
-  MoveStack* generate_pawn_diagonal_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) {
+  template<Color Us, MoveType Type, SquareDelta Diagonal>
+  inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces) {
 
     // Calculate our parametrized parameters at compile time
     const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
@@ -538,136 +444,152 @@ namespace {
     const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
     const SquareDelta TTDELTA_NE = (Diagonal == DELTA_NE ? TDELTA_NE : TDELTA_NW);
 
+    Bitboard b1, b2;
     Square to;
 
     // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
-    Bitboard b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
+    b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
 
-    // Capturing promotions
-    if (promotion)
+    // Capturing promotions and under-promotions
+    if (b1 & TRank8BB)
     {
-        Bitboard b2 = b1 & TRank8BB;
+        b2 = b1 & TRank8BB;
         b1 &= ~TRank8BB;
         while (b2)
         {
             to = pop_1st_bit(&b2);
-            (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+
+            if (Type == CAPTURE || Type == EVASION)
+                (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
+
+            if (Type == NON_CAPTURE || Type == EVASION)
+            {
+                (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, ROOK);
+                (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, BISHOP);
+                (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, KNIGHT);
+            }
+
+            // This is the only possible under promotion that can give a check
+            // not already included in the queen-promotion. It is not sure that
+            // the promoted knight will give check, but it doesn't worth to verify.
+            if (Type == CHECK)
+                (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, KNIGHT);
         }
     }
 
-    // Capturing non-promotions
-    SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+    // Serialize standard captures
+    if (Type == CAPTURE || Type == EVASION)
+        SERIALIZE_MOVES_D(b1, -TTDELTA_NE);
+
     return mlist;
   }
 
   template<Color Us, MoveType Type>
-  MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard dcp,
-                                 Square ksq, Bitboard blockSquares) {
+  MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
 
     // Calculate our parametrized parameters at compile time
     const Color Them = (Us == WHITE ? BLACK : WHITE);
     const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
     const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
     const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
-    const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
-    const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
     const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
 
-    Bitboard b1, b2, dcPawns1, dcPawns2;
     Square to;
-    Bitboard pawns = (Type == EVASION ? pos.pieces(PAWN, Us) & ~dcp : pos.pieces(PAWN, Us));
-    bool possiblePromotion = pawns & TRank7BB;
+    Bitboard b1, b2, enemyPieces, emptySquares;
+    Bitboard pawns = pos.pieces(PAWN, Us);
 
-    if (Type == CAPTURE)
+    // Standard captures and capturing promotions and underpromotions
+    if (Type == CAPTURE || Type == EVASION || (pawns & TRank7BB))
     {
-        // Standard captures and capturing promotions in both directions
-        Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
-        mlist = generate_pawn_diagonal_captures<Us, DELTA_NE>(mlist, pawns, enemyPieces, possiblePromotion);
-        mlist = generate_pawn_diagonal_captures<Us, DELTA_NW>(mlist, pawns, enemyPieces, possiblePromotion);
+        enemyPieces = (Type == CAPTURE ? target : pos.pieces_of_color(opposite_color(Us)));
+
+        if (Type == EVASION)
+            enemyPieces &= target; // Capture only the checker piece
+
+        mlist = generate_pawn_captures<Us, Type, DELTA_NE>(mlist, pawns, enemyPieces);
+        mlist = generate_pawn_captures<Us, Type, DELTA_NW>(mlist, pawns, enemyPieces);
     }
 
-    if (possiblePromotion)
+    // Non-capturing promotions and underpromotions
+    if (pawns & TRank7BB)
     {
-        // When generating checks consider under-promotion moves (both captures
-        // and non captures) only if can give a discovery check. Note that dcp
-        // is dc bitboard or pinned bitboard when Type == EVASION.
-        Bitboard pp = (Type == CHECK ? pawns & dcp : pawns);
+        b1 = move_pawns<Us, DELTA_N>(pawns) & TRank8BB & pos.empty_squares();
 
-        if (Type != EVASION && Type != CAPTURE)
-        {
-            Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
-
-            // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
-            b1 = move_pawns<Us, DELTA_NE>(pp) & ~FileABB & enemyPieces & TRank8BB;
-            while (b1)
-            {
-                to = pop_1st_bit(&b1);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
-            }
-
-            // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
-            b1 = move_pawns<Us, DELTA_NW>(pp) & ~FileHBB & enemyPieces & TRank8BB;
-            while (b1)
-            {
-                to = pop_1st_bit(&b1);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
-                (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
-            }
-        }
-
-        // Underpromotion pawn pushes. Also queen promotions for evasions and captures.
-        b1 = move_pawns<Us, DELTA_N>(pp) & TRank8BB;
-        b1 &= (Type == EVASION ? blockSquares : pos.empty_squares());
+        if (Type == EVASION)
+            b1 &= target; // Only blocking promotion pushes
 
         while (b1)
         {
             to = pop_1st_bit(&b1);
-            if (Type == EVASION || Type == CAPTURE)
+
+            if (Type == CAPTURE || Type == EVASION)
                 (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
 
-            if (Type != CAPTURE)
+            if (Type == NON_CAPTURE || Type == EVASION)
             {
                 (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
                 (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
                 (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
             }
+
+            // This is the only possible under promotion that can give a check
+            // not already included in the queen-promotion.
+            if (Type == CHECK && bit_is_set(pos.attacks_from<KNIGHT>(to), pos.king_square(Them)))
+                (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
         }
     }
 
+    // Standard pawn pushes and double pushes
     if (Type != CAPTURE)
     {
-        Bitboard emptySquares = pos.empty_squares();
-        dcPawns1 = dcPawns2 = EmptyBoardBB;
-        if (Type == CHECK && (pawns & dcp))
-        {
-            // Pawn moves which gives discovered check. This is possible only if the
-            // pawn is not on the same file as the enemy king, because we don't
-            // generate captures.
-            dcPawns1 = move_pawns<Us, DELTA_N>(pawns & dcp & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
-            dcPawns2 = move_pawns<Us, DELTA_N>(dcPawns1 & TRank3BB) & emptySquares;
-        }
+        emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares());
 
-        // Single pawn pushes
+        // Single and double pawn pushes
         b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares & ~TRank8BB;
-        b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns1 :
-              (Type == EVASION ? b1 & blockSquares : b1));
-        SERIALIZE_MOVES_D(b2, -TDELTA_N);
+        b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
 
-        // Double pawn pushes
-        b1 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
-        b2 = (Type == CHECK ? (b1 & pos.attacks_from<PAWN>(ksq, Them)) | dcPawns2 :
-              (Type == EVASION ? b1 & blockSquares : b1));
+        // Filter out unwanted pushes according to the move type
+        if (Type == EVASION)
+        {
+            b1 &= target;
+            b2 &= target;
+        }
+        else if (Type == CHECK)
+        {
+            // Pawn moves which give direct cheks
+            b1 &= pos.attacks_from<PAWN>(ksq, Them);
+            b2 &= pos.attacks_from<PAWN>(ksq, Them);
+
+            // Pawn moves which gives discovered check. This is possible only if
+            // the pawn is not on the same file as the enemy king, because we
+            //  don't generate captures.
+            if (pawns & target) // For CHECK type target is dc bitboard
+            {
+                Bitboard dc1 = move_pawns<Us, DELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares & ~TRank8BB;
+                Bitboard dc2 = move_pawns<Us, DELTA_N>(dc1 & TRank3BB) & emptySquares;
+
+                b1 |= dc1;
+                b2 |= dc2;
+            }
+        }
+        SERIALIZE_MOVES_D(b1, -TDELTA_N);
         SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
     }
-    else if (pos.ep_square() != SQ_NONE) // En passant captures
+
+    // En passant captures
+    if ((Type == CAPTURE || Type == EVASION) && pos.ep_square() != SQ_NONE)
     {
         assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
         assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
 
+        // An en passant capture can be an evasion only if the checking piece
+        // 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 == EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N))
+            return mlist;
+
         b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+
         assert(b1 != EmptyBoardBB);
 
         while (b1)
@@ -680,43 +602,49 @@ namespace {
   }
 
   template<PieceType Piece>
-  MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us,
+  MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) {
+
+    assert(Piece != QUEEN);
+
+    Bitboard b = pos.attacks_from<Piece>(from) & pos.empty_squares();
+    if (Piece == KING)
+    {
+        Square ksq = pos.king_square(opposite_color(pos.side_to_move()));
+        b &= ~QueenPseudoAttacks[ksq];
+    }
+    SERIALIZE_MOVES(b);
+    return mlist;
+  }
+
+  template<PieceType Piece>
+  MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
                                    Bitboard dc, Square ksq) {
+    assert(Piece != KING);
 
-    Bitboard target = pos.pieces(Piece, us);
+    Bitboard checkSqs, b;
+    Square from;
+    const Square* ptr = pos.piece_list_begin(us, Piece);
 
-    // Discovered non-capture checks
-    Bitboard b = target & dc;
+    if ((from = *ptr++) == SQ_NONE)
+        return mlist;
 
-    assert(Piece != QUEEN || !b);
+    checkSqs = pos.attacks_from<Piece>(ksq) & pos.empty_squares();
 
-    while (b)
+    do
     {
-        Square from = pop_1st_bit(&b);
-        Bitboard bb = pos.attacks_from<Piece>(from) & pos.empty_squares();
-        if (Piece == KING)
-            bb &= ~QueenPseudoAttacks[ksq];
+        if (   (Piece == QUEEN  && !(QueenPseudoAttacks[from]  & checkSqs))
+            || (Piece == ROOK   && !(RookPseudoAttacks[from]   & checkSqs))
+            || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+            continue;
 
-        SERIALIZE_MOVES(bb);
-    }
+        if (dc && bit_is_set(dc, from))
+            continue;
 
-    // Direct non-capture checks
-    b = target & ~dc;
-    Bitboard checkSqs = pos.attacks_from<Piece>(ksq) & pos.empty_squares();
-    if (Piece != KING && checkSqs)
-    {
-        while (b)
-        {
-            Square from = pop_1st_bit(&b);
-            if (   (Piece == QUEEN  && !(QueenPseudoAttacks[from]  & checkSqs))
-                || (Piece == ROOK   && !(RookPseudoAttacks[from]   & checkSqs))
-                || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
-                continue;
+        b = pos.attacks_from<Piece>(from) & checkSqs;
+        SERIALIZE_MOVES(b);
+
+    } while ((from = *ptr++) != SQ_NONE);
 
-            Bitboard bb = pos.attacks_from<Piece>(from) & checkSqs;
-            SERIALIZE_MOVES(bb);
-        }
-    }
     return mlist;
   }
 
@@ -762,17 +690,4 @@ namespace {
     }
     return mlist;
   }
-
-  bool castling_is_check(const Position& pos, CastlingSide side) {
-
-    // After castling opponent king is attacked by the castled rook?
-    File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F);
-    Color us = pos.side_to_move();
-    Square ksq = pos.king_square(us);
-    Bitboard occ = pos.occupied_squares();
-
-    clear_bit(&occ, ksq); // Remove our king from the board
-    Square rsq = make_square(rookFile, square_rank(ksq));
-    return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us)));
-  }
 }

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
@@ -34,8 +34,8 @@
 
 extern MoveStack* generate_captures(const Position& pos, MoveStack* mlist);
 extern MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist);
-extern MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc);
-extern MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned);
+extern MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist);
+extern MoveStack* generate_evasions(const Position& pos, MoveStack* mlist);
 extern MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal = false);
 extern bool move_is_legal(const Position& pos, const Move m, Bitboard pinned);
 extern bool move_is_legal(const Position& pos, const Move m);

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
@@ -23,7 +23,6 @@
 //// Includes
 ////
 
-#include <algorithm>
 #include <cassert>
 
 #include "history.h"
@@ -53,7 +52,7 @@ namespace {
 
   CACHE_LINE_ALIGNMENT
   const uint8_t MainSearchPhaseTable[] = { PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP};
-  const uint8_t EvasionsPhaseTable[] = { PH_EVASIONS, PH_STOP};
+  const uint8_t EvasionsPhaseTable[] = { PH_TT_MOVES, PH_EVASIONS, PH_STOP};
   const uint8_t QsearchWithChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP};
   const uint8_t QsearchWithoutChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_STOP};
 }
@@ -72,13 +71,15 @@ 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;
 
-  if (ss)
+  pinned = p.pinned_pieces(pos.side_to_move());
+
+  if (ss && !p.is_check())
   {
       ttMoves[1].move = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller;
       searchTT |= ttMoves[1].move;
@@ -87,21 +88,30 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
   } else
       ttMoves[1].move = killers[0].move = killers[1].move = MOVE_NONE;
 
-  Color us = pos.side_to_move();
-
-  dc = p.discovered_check_candidates(us);
-  pinned = p.pinned_pieces(us);
-
   if (p.is_check())
       phasePtr = EvasionsPhaseTable;
   else if (d > Depth(0))
-      phasePtr = MainSearchPhaseTable + !searchTT;
-  else if (d == Depth(0))
-      phasePtr = QsearchWithChecksPhaseTable + !searchTT;
-  else
-      phasePtr = QsearchWithoutChecksPhaseTable + !searchTT;
+  {
+      // 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--;
+      phasePtr = MainSearchPhaseTable;
+  } 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();
 }
 
@@ -123,7 +133,6 @@ void MovePicker::go_next_phase() {
   case PH_GOOD_CAPTURES:
       lastMove = generate_captures(pos, moves);
       score_captures();
-      std::sort(moves, lastMove);
       return;
 
   case PH_KILLERS:
@@ -134,7 +143,7 @@ void MovePicker::go_next_phase() {
   case PH_NONCAPTURES:
       lastMove = generate_noncaptures(pos, moves);
       score_noncaptures();
-      std::sort(moves, lastMove);
+      sort_moves(moves, lastMove, &lastGoodNonCapture);
       return;
 
   case PH_BAD_CAPTURES:
@@ -142,29 +151,26 @@ void MovePicker::go_next_phase() {
       // to get SEE move ordering.
       curMove = badCaptures;
       lastMove = lastBadCapture;
-      std::sort(badCaptures, lastMove);
       return;
 
   case PH_EVASIONS:
       assert(pos.is_check());
-      lastMove = generate_evasions(pos, moves, pinned);
-      score_evasions();
-      std::sort(moves, lastMove);
+      lastMove = generate_evasions(pos, moves);
+      score_evasions_or_checks();
       return;
 
   case PH_QCAPTURES:
       lastMove = generate_captures(pos, moves);
       score_captures();
-      std::sort(moves, lastMove);
       return;
 
   case PH_QCHECKS:
-      // Perhaps we should order moves move here?  FIXME
-      lastMove = generate_non_capture_checks(pos, moves, dc);
+      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:
@@ -202,8 +208,8 @@ void MovePicker::score_captures() {
       if (move_is_promotion(m))
           cur->score = QueenValueMidgame;
       else
-          cur->score = int(pos.midgame_value_of_piece_on(move_to(m)))
-                      -int(pos.type_of_piece_on(move_from(m)));
+          cur->score =  pos.midgame_value_of_piece_on(move_to(m))
+                      - pos.type_of_piece_on(move_from(m));
   }
 }
 
@@ -224,29 +230,36 @@ 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
-      cur->score = hs + pos.pst_delta<Position::MidGame>(piece, from, to);
+      // Gain table based scoring
+      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
+  // negative SEE. This last group is ordered by the SEE score.
   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 (m == ttMoves[0].move)
-          cur->score = 2 * HistoryMax;
-      else if (!pos.square_is_empty(move_to(m)))
-      {
-          int seeScore = pos.see(m);
-          cur->score = seeScore + (seeScore >= 0 ? HistoryMax : 0);
-      } else
+      if ((seeScore = pos.see_sign(m)) < 0)
+          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;
+      else
           cur->score = H.move_ordering_score(pos.piece_on(move_from(m)), move_to(m));
   }
 }
@@ -256,36 +269,35 @@ 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() {
 
-  assert(!pos.is_check() || *phasePtr == PH_EVASIONS || *phasePtr == PH_STOP);
-  assert( pos.is_check() || *phasePtr != PH_EVASIONS);
-
   Move move;
 
   while (true)
   {
       while (curMove != lastMove)
       {
-          move = (curMove++)->move;
-
           switch (phase) {
 
           case PH_TT_MOVES:
+              move = (curMove++)->move;
               if (   move != MOVE_NONE
                   && move_is_legal(pos, move, pinned))
                   return move;
               break;
 
           case PH_GOOD_CAPTURES:
+              move = pick_best(curMove++, lastMove).move;
               if (   move != ttMoves[0].move
                   && move != ttMoves[1].move
                   && pos.pl_move_is_legal(move, pinned))
               {
                   // 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
@@ -298,6 +310,7 @@ Move MovePicker::get_next_move() {
               break;
 
           case PH_KILLERS:
+              move = (curMove++)->move;
               if (   move != MOVE_NONE
                   && move != ttMoves[0].move
                   && move != ttMoves[1].move
@@ -307,6 +320,12 @@ 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
                   && move != killers[0].move
@@ -315,13 +334,20 @@ Move MovePicker::get_next_move() {
                   return move;
               break;
 
-          case PH_EVASIONS:
           case PH_BAD_CAPTURES:
+              move = pick_best(curMove++, lastMove).move;
               return move;
 
+          case PH_EVASIONS:
           case PH_QCAPTURES:
+              move = pick_best(curMove++, lastMove).move;
+              if (   move != ttMoves[0].move
+                  && pos.pl_move_is_legal(move, pinned))
+                  return move;
+              break;
+
           case PH_QCHECKS:
-              // Maybe postpone the legality check until after futility pruning?
+              move = (curMove++)->move;
               if (   move != ttMoves[0].move
                   && pos.pl_move_is_legal(move, pinned))
                   return move;
@@ -339,21 +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"
 
 
@@ -50,26 +49,23 @@ 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;
-  Bitboard discovered_check_candidates() 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 phase;
+  int badCaptureThreshold, phase;
   const uint8_t* phasePtr;
-  MoveStack *curMove, *lastMove, *lastBadCapture;
-  Bitboard dc, pinned;
+  MoveStack *curMove, *lastMove, *lastGoodNonCapture, *lastBadCapture;
+  Bitboard pinned;
   MoveStack moves[256], badCaptures[64];
 };
 
@@ -88,12 +84,4 @@ inline int MovePicker::number_of_evasions() const {
   return int(lastMove - moves);
 }
 
-/// MovePicker::discovered_check_candidates() returns a bitboard containing
-/// all pieces which can possibly give discovered check. This bitboard is
-/// computed by the constructor function.
-
-inline Bitboard MovePicker::discovered_check_candidates() const {
-  return dc;
-}
-
 #endif // !defined(MOVEPICK_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) 2008-2009 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
@@ -38,64 +38,36 @@ namespace {
 
   /// Constants and variables
 
-  // Doubled pawn penalty by file, middle game
-  const Value DoubledPawnMidgamePenalty[8] = {
-    Value(13), Value(20), Value(23), Value(23),
-    Value(23), Value(23), Value(20), Value(13)
+  #define S(mg, eg) make_score(mg, eg)
+
+  // Doubled pawn penalty by file
+  const Score DoubledPawnPenalty[8] = {
+    S(13, 43), S(20, 48), S(23, 48), S(23, 48),
+    S(23, 48), S(23, 48), S(20, 48), S(13, 43)
   };
 
-  // Doubled pawn penalty by file, endgame
-  const Value DoubledPawnEndgamePenalty[8] = {
-    Value(43), Value(48), Value(48), Value(48),
-    Value(48), Value(48), Value(48), Value(43)
+  // Isolated pawn penalty by file
+  const Score IsolatedPawnPenalty[8] = {
+    S(25, 30), S(36, 35), S(40, 35), S(40, 35),
+    S(40, 35), S(40, 35), S(36, 35), S(25, 30)
   };
 
-  // Isolated pawn penalty by file, middle game
-  const Value IsolatedPawnMidgamePenalty[8] = {
-    Value(25), Value(36), Value(40), Value(40),
-    Value(40), Value(40), Value(36), Value(25)
+  // Backward pawn penalty by file
+  const Score BackwardPawnPenalty[8] = {
+    S(20, 28), S(29, 31), S(33, 31), S(33, 31),
+    S(33, 31), S(33, 31), S(29, 31), S(20, 28)
   };
 
-  // Isolated pawn penalty by file, endgame
-  const Value IsolatedPawnEndgamePenalty[8] = {
-    Value(30), Value(35), Value(35), Value(35),
-    Value(35), Value(35), Value(35), Value(30)
+  // Pawn chain membership bonus by file
+  const Score ChainBonus[8] = {
+    S(11,-1), S(13,-1), S(13,-1), S(14,-1),
+    S(14,-1), S(13,-1), S(13,-1), S(11,-1)
   };
 
-  // Backward pawn penalty by file, middle game
-  const Value BackwardPawnMidgamePenalty[8] = {
-    Value(20), Value(29), Value(33), Value(33),
-    Value(33), Value(33), Value(29), Value(20)
-  };
-
-  // Backward pawn penalty by file, endgame
-  const Value BackwardPawnEndgamePenalty[8] = {
-    Value(28), Value(31), Value(31), Value(31),
-    Value(31), Value(31), Value(31), Value(28)
-  };
-
-  // Pawn chain membership bonus by file, middle game
-  const Value ChainMidgameBonus[8] = {
-    Value(11), Value(13), Value(13), Value(14),
-    Value(14), Value(13), Value(13), Value(11)
-  };
-
-  // Pawn chain membership bonus by file, endgame
-  const Value ChainEndgameBonus[8] = {
-    Value(-1), Value(-1), Value(-1), Value(-1),
-    Value(-1), Value(-1), Value(-1), Value(-1)
-  };
-
-  // Candidate passed pawn bonus by rank, middle game
-  const Value CandidateMidgameBonus[8] = {
-    Value( 0), Value( 6), Value(6), Value(14),
-    Value(34), Value(83), Value(0), Value( 0)
-  };
-
-  // Candidate passed pawn bonus by rank, endgame
-  const Value CandidateEndgameBonus[8] = {
-    Value( 0), Value( 13), Value(13), Value(29),
-    Value(68), Value(166), Value( 0), Value( 0)
+  // Candidate passed pawn bonus by rank
+  const Score CandidateBonus[8] = {
+    S( 0, 0), S( 6, 13), S(6,13), S(14,29),
+    S(34,68), S(83,166), S(0, 0), S( 0, 0)
   };
 
   // Pawn storm tables for positions with opposite castling
@@ -190,207 +162,184 @@ PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
   pi->clear();
   pi->key = key;
 
-  Value mgValue[2] = {Value(0), Value(0)};
-  Value egValue[2] = {Value(0), Value(0)};
-
   // Calculate pawn attacks
-  pi->pawnAttacks[WHITE] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB);
-  pi->pawnAttacks[BLACK] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB);
+  Bitboard whitePawns = pos.pieces(PAWN, WHITE);
+  Bitboard blackPawns = pos.pieces(PAWN, BLACK);
+  pi->pawnAttacks[WHITE] = ((whitePawns << 9) & ~FileABB) | ((whitePawns << 7) & ~FileHBB);
+  pi->pawnAttacks[BLACK] = ((blackPawns >> 7) & ~FileABB) | ((blackPawns >> 9) & ~FileHBB);
 
-  // Loop through the pawns for both colors
-  for (Color us = WHITE; us <= BLACK; us++)
-  {
-    Color them = opposite_color(us);
-    Bitboard ourPawns = pos.pieces(PAWN, us);
-    Bitboard theirPawns = pos.pieces(PAWN, them);
-    Bitboard pawns = ourPawns;
-
-    // Initialize pawn storm scores by giving bonuses for open files
-    for (File f = FILE_A; f <= FILE_H; f++)
-        if (!(pawns & file_bb(f)))
-        {
-            pi->ksStormValue[us] += KStormOpenFileBonus[f];
-            pi->qsStormValue[us] += QStormOpenFileBonus[f];
-            pi->halfOpenFiles[us] |= (1 << f);
-        }
-
-    // Loop through all pawns of the current color and score each pawn
-    while (pawns)
-    {
-        Square s = pop_1st_bit(&pawns);
-        File f = square_file(s);
-        Rank r = square_rank(s);
-
-        assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN));
-
-        // Passed, isolated or doubled pawn?
-        bool passed   = Position::pawn_is_passed(theirPawns, us, s);
-        bool isolated = Position::pawn_is_isolated(ourPawns, s);
-        bool doubled  = Position::pawn_is_doubled(ourPawns, us, s);
-
-        // We calculate kingside and queenside pawn storm
-        // scores for both colors. These are used when evaluating
-        // middle game positions with opposite side castling.
-        //
-        // Each pawn is given a base score given by a piece square table
-        // (KStormTable[] or QStormTable[]). Pawns which seem to have good
-        // chances of creating an open file by exchanging itself against an
-        // enemy pawn on an adjacent file gets an additional bonus.
-
-        // Kingside pawn storms
-        int bonus = KStormTable[relative_square(us, s)];
-        if (f >= FILE_F)
-        {
-            Bitboard b = outpost_mask(us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
-            while (b)
-            {
-                Square s2 = pop_1st_bit(&b);
-                if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-                {
-                    // The enemy pawn has no pawn beside itself, which makes it
-                    // particularly vulnerable. Big bonus, especially against a
-                    // 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;
-
-        // Queenside pawn storms
-        bonus = QStormTable[relative_square(us, s)];
-        if (f <= FILE_C)
-        {
-            Bitboard b = outpost_mask(us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
-            while (b)
-            {
-                Square s2 = pop_1st_bit(&b);
-                if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
-                {
-                    // The enemy pawn has no pawn beside itself, which makes it
-                    // particularly vulnerable. Big bonus, especially against a
-                    // 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;
-
-        // Member of a pawn chain (but not the backward one)? We could speed up
-        // the test a little by introducing an array of masks indexed by color
-        // and square for doing the test, but because everything is hashed,
-        // it probably won't make any noticable difference.
-        bool chain =  ourPawns
-                    & neighboring_files_bb(f)
-                    & (rank_bb(r) | rank_bb(r - (us == WHITE ? 1 : -1)));
-
-        // Test for backward pawn
-        //
-        // If the pawn is passed, isolated, or member of a pawn chain
-        // it cannot be backward. If can capture an enemy pawn or if
-        // there are friendly pawns behind on neighboring files it cannot
-        // be backward either.
-        bool backward;
-        if (   passed
-            || isolated
-            || chain
-            || (pos.attacks_from<PAWN>(s, us) & theirPawns)
-            || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)))
-            backward = false;
-        else
-        {
-            // We now know that there are no friendly pawns beside or behind this
-            // pawn on neighboring files. We now check whether the pawn is
-            // backward by looking in the forward direction on the neighboring
-            // files, and seeing whether we meet a friendly or an enemy pawn first.
-            Bitboard b = pos.attacks_from<PAWN>(s, us);
-            if (us == WHITE)
-            {
-                for ( ; !(b & (ourPawns | theirPawns)); b <<= 8);
-                backward = (b | (b << 8)) & theirPawns;
-            }
-            else
-            {
-                for ( ; !(b & (ourPawns | theirPawns)); b >>= 8);
-                backward = (b | (b >> 8)) & theirPawns;
-            }
-        }
-
-        // Test for candidate passed pawn
-        bool candidate;
-        candidate =    !passed
-                    && !(theirPawns & file_bb(f))
-                    && (  count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns)
-                        - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r)              & theirPawns)
-                        >= 0);
-
-        // In order to prevent doubled passed pawns from receiving a too big
-        // bonus, only the frontmost passed pawn on each file is considered as
-        // a true passed pawn.
-        if (passed && (ourPawns & squares_in_front_of(us, s)))
-            passed = false;
-
-        // Score this pawn
-        if (passed)
-            set_bit(&(pi->passedPawns), s);
-
-        if (isolated)
-        {
-            mgValue[us] -= IsolatedPawnMidgamePenalty[f];
-            egValue[us] -= IsolatedPawnEndgamePenalty[f];
-            if (!(theirPawns & file_bb(f)))
-            {
-                mgValue[us] -= IsolatedPawnMidgamePenalty[f] / 2;
-                egValue[us] -= IsolatedPawnEndgamePenalty[f] / 2;
-            }
-        }
-        if (doubled)
-        {
-            mgValue[us] -= DoubledPawnMidgamePenalty[f];
-            egValue[us] -= DoubledPawnEndgamePenalty[f];
-        }
-        if (backward)
-        {
-            mgValue[us] -= BackwardPawnMidgamePenalty[f];
-            egValue[us] -= BackwardPawnEndgamePenalty[f];
-            if (!(theirPawns & file_bb(f)))
-            {
-                mgValue[us] -= BackwardPawnMidgamePenalty[f] / 2;
-                egValue[us] -= BackwardPawnEndgamePenalty[f] / 2;
-            }
-        }
-        if (chain)
-        {
-            mgValue[us] += ChainMidgameBonus[f];
-            egValue[us] += ChainEndgameBonus[f];
-        }
-        if (candidate)
-        {
-            mgValue[us] += CandidateMidgameBonus[relative_rank(us, s)];
-            egValue[us] += CandidateEndgameBonus[relative_rank(us, s)];
-        }
-    } // while(pawns)
-  } // for(colors)
-
-  pi->mgValue = int16_t(mgValue[WHITE] - mgValue[BLACK]);
-  pi->egValue = int16_t(egValue[WHITE] - egValue[BLACK]);
+  // Evaluate pawns for both colors
+  pi->value =  evaluate_pawns<WHITE>(pos, whitePawns, blackPawns, pi)
+             - evaluate_pawns<BLACK>(pos, blackPawns, whitePawns, pi);
   return pi;
 }
 
 
+/// PawnInfoTable::evaluate_pawns() evaluates each pawn of the given color
+
+template<Color Us>
+Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
+                                    Bitboard theirPawns, PawnInfo* pi) {
+  Square s;
+  File f;
+  Rank r;
+  bool passed, isolated, doubled, chain, backward, candidate;
+  int bonus;
+  Score value = make_score(0, 0);
+  const Square* ptr = pos.piece_list_begin(Us, PAWN);
+
+  // Initialize pawn storm scores by giving bonuses for open files
+  for (f = FILE_A; f <= FILE_H; f++)
+      if (!(ourPawns & file_bb(f)))
+      {
+          pi->ksStormValue[Us] += KStormOpenFileBonus[f];
+          pi->qsStormValue[Us] += QStormOpenFileBonus[f];
+          pi->halfOpenFiles[Us] |= (1 << f);
+      }
+
+  // Loop through all pawns of the current color and score each pawn
+  while ((s = *ptr++) != SQ_NONE)
+  {
+      f = square_file(s);
+      r = square_rank(s);
+
+      assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
+
+      // Passed, isolated or doubled pawn?
+      passed   = Position::pawn_is_passed(theirPawns, Us, s);
+      isolated = Position::pawn_is_isolated(ourPawns, s);
+      doubled  = Position::pawn_is_doubled(ourPawns, Us, s);
+
+      // We calculate kingside and queenside pawn storm
+      // scores for both colors. These are used when evaluating
+      // middle game positions with opposite side castling.
+      //
+      // Each pawn is given a base score given by a piece square table
+      // (KStormTable[] or QStormTable[]). Pawns which seem to have good
+      // chances of creating an open file by exchanging itself against an
+      // enemy pawn on an adjacent file gets an additional bonus.
+
+      // Kingside pawn storms
+      bonus = KStormTable[relative_square(Us, s)];
+      if (f >= FILE_F)
+      {
+          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);
+
+              bonus += v;
+          }
+      }
+      pi->ksStormValue[Us] += bonus;
+
+      // Queenside pawn storms
+      bonus = QStormTable[relative_square(Us, s)];
+      if (f <= FILE_C)
+      {
+          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);
+
+              bonus += v;
+          }
+      }
+      pi->qsStormValue[Us] += bonus;
+
+      // Member of a pawn chain (but not the backward one)? We could speed up
+      // the test a little by introducing an array of masks indexed by color
+      // and square for doing the test, but because everything is hashed,
+      // it probably won't make any noticable difference.
+      chain =  ourPawns
+             & neighboring_files_bb(f)
+             & (rank_bb(r) | rank_bb(r - (Us == WHITE ? 1 : -1)));
+
+      // Test for backward pawn
+      //
+      // If the pawn is passed, isolated, or member of a pawn chain
+      // it cannot be backward. If can capture an enemy pawn or if
+      // there are friendly pawns behind on neighboring files it cannot
+      // be backward either.
+      if (   (passed | isolated | chain)
+          || (ourPawns & behind_bb(Us, r) & neighboring_files_bb(f))
+          || (pos.attacks_from<PAWN>(s, Us) & theirPawns))
+          backward = false;
+      else
+      {
+          // We now know that there are no friendly pawns beside or behind this
+          // pawn on neighboring files. We now check whether the pawn is
+          // backward by looking in the forward direction on the neighboring
+          // files, and seeing whether we meet a friendly or an enemy pawn first.
+          Bitboard b = pos.attacks_from<PAWN>(s, Us);
+
+          // Note that we are sure to find something because pawn is not passed
+          // nor isolated, so loop is potentially infinite, but it isn't.
+          while (!(b & (ourPawns | theirPawns)))
+              Us == WHITE ? b <<= 8 : b >>= 8;
+
+          // The friendly pawn needs to be at least two ranks closer than the enemy
+          // pawn in order to help the potentially backward pawn advance.
+          backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
+      }
+
+      // Test for candidate passed pawn
+      candidate =   !passed
+                 && !(theirPawns & file_bb(f))
+                 && (  count_1s_max_15(neighboring_files_bb(f) & (behind_bb(Us, r) | rank_bb(r)) & ourPawns)
+                     - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(Us, r)              & theirPawns)
+                     >= 0);
+
+      // In order to prevent doubled passed pawns from receiving a too big
+      // bonus, only the frontmost passed pawn on each file is considered as
+      // a true passed pawn.
+      if (passed && (ourPawns & squares_in_front_of(Us, s)))
+          passed = false;
+
+      // Score this pawn
+      if (passed)
+          set_bit(&(pi->passedPawns), s);
+
+      if (isolated)
+      {
+          value -= IsolatedPawnPenalty[f];
+          if (!(theirPawns & file_bb(f)))
+              value -= IsolatedPawnPenalty[f] / 2;
+      }
+      if (doubled)
+          value -= DoubledPawnPenalty[f];
+
+      if (backward)
+      {
+          value -= BackwardPawnPenalty[f];
+          if (!(theirPawns & file_bb(f)))
+              value -= BackwardPawnPenalty[f] / 2;
+      }
+      if (chain)
+          value += ChainBonus[f];
+
+      if (candidate)
+          value += CandidateBonus[relative_rank(Us, s)];
+  }
+
+  return value;
+}
+
+
 /// PawnInfo::updateShelter calculates and caches king shelter. It is called
 /// only when king square changes, about 20% of total get_king_shelter() calls.
 int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) {

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
@@ -45,10 +45,9 @@ class PawnInfo {
   friend class PawnInfoTable;
 
 public:
-  PawnInfo() : key(0) { clear(); }
+  PawnInfo() { clear(); }
 
-  Value mg_value() const;
-  Value eg_value() const;
+  Score pawns_value() const;
   Value kingside_storm_value(Color c) const;
   Value queenside_storm_value(Color c) const;
   Bitboard pawn_attacks(Color c) const;
@@ -65,7 +64,7 @@ private:
   Key key;
   Bitboard passedPawns;
   Bitboard pawnAttacks[2];
-  int16_t mgValue, egValue;
+  Score value;
   int16_t ksStormValue[2], qsStormValue[2];
   uint8_t halfOpenFiles[2];
   Square kingSquares[2];
@@ -85,6 +84,9 @@ public:
   PawnInfo* get_pawn_info(const Position& pos);
 
 private:
+  template<Color Us>
+  Score evaluate_pawns(const Position& pos, Bitboard ourPawns, Bitboard theirPawns, PawnInfo* pi);
+
   unsigned size;
   PawnInfo* entries;
 };
@@ -94,12 +96,8 @@ private:
 //// Inline functions
 ////
 
-inline Value PawnInfo::mg_value() const {
-  return Value(mgValue);
-}
-
-inline Value PawnInfo::eg_value() const {
-  return Value(egValue);
+inline Score PawnInfo::pawns_value() const {
+  return value;
 }
 
 inline Bitboard PawnInfo::passed_pawns() const {

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.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
@@ -63,6 +63,18 @@ const int MaxGameLength = 220;
 //// Types
 ////
 
+/// struct checkInfo is initialized at c'tor time and keeps
+/// info used to detect if a move gives check.
+
+struct CheckInfo {
+
+    CheckInfo(const Position&);
+
+    Square ksq;
+    Bitboard dcCandidates;
+    Bitboard checkSq[8];
+};
+
 /// Castle rights, encoded as bit fields
 
 enum CastleRights {
@@ -87,12 +99,13 @@ enum Phase {
 /// must be passed as a parameter.
 
 struct StateInfo {
-  Key key, pawnKey, materialKey;
-  int castleRights, rule50;
+  Key pawnKey, materialKey;
+  int castleRights, rule50, pliesFromNull;
   Square epSquare;
-  Value mgValue, egValue;
+  Score value;
   Value npMaterial[2];
 
+  Key key;
   PieceType capture;
   Bitboard checkersBB;
   StateInfo* previous;
@@ -133,9 +146,9 @@ public:
   };
 
   // Constructors
-  Position() {}
-  Position(const Position& pos);
-  Position(const std::string& fen);
+  Position();
+  explicit Position(const Position& pos);
+  explicit Position(const std::string& fen);
 
   // Text input/output
   void from_fen(const std::string& fen);
@@ -143,7 +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
@@ -202,14 +214,18 @@ public:
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
 
   // Properties of moves
-  bool pl_move_is_legal(Move m) const;
   bool pl_move_is_legal(Move m, Bitboard pinned) const;
+  bool pl_move_is_evasion(Move m, Bitboard pinned) const;
   bool move_is_check(Move m) const;
-  bool move_is_check(Move m, Bitboard dcCandidates) const;
+  bool move_is_check(Move m, const CheckInfo& ci) const;
   bool move_is_capture(Move m) const;
+  bool move_is_capture_or_promotion(Move m) const;
   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);
@@ -220,9 +236,9 @@ 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, Bitboard dcCandidates);
+  void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
   void do_null_move(StateInfo& st);
   void undo_null_move();
@@ -235,15 +251,14 @@ public:
 
   // Accessing hash keys
   Key get_key() const;
+  Key get_exclusion_key() const;
   Key get_pawn_key() const;
   Key get_material_key() const;
 
   // Incremental evaluation
-  Value mg_value() const;
-  Value eg_value() const;
+  Score value() const;
   Value non_pawn_material(Color c) const;
-  Phase game_phase() const;
-  template<GamePhase> Value pst_delta(Piece piece, Square from, Square to) const;
+  Score pst_delta(Piece piece, Square from, Square to) const;
 
   // Game termination checks
   bool is_mate() const;
@@ -283,9 +298,6 @@ private:
   void undo_castle_move(Move m);
   void find_checkers();
 
-  template<PieceType Piece>
-  void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
-
   template<bool FindPinned>
   Bitboard hidden_checkers(Color c) const;
 
@@ -295,8 +307,8 @@ private:
   Key compute_material_key() const;
 
   // Computing incremental evaluation scores and material counts
-  template<GamePhase> Value pst(Color c, PieceType pt, Square s) const;
-  template<GamePhase> Value compute_value() const;
+  Score pst(Color c, PieceType pt, Square s) const;
+  Score compute_value() const;
   Value compute_non_pawn_material(Color c) const;
 
   // Board
@@ -316,19 +328,19 @@ 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];
   static Key zobMaterial[2][8][16];
   static Key zobSideToMove;
-  static Value MgPieceSquareTable[16][64];
-  static Value EgPieceSquareTable[16][64];
+  static Score PieceSquareTable[16][64];
+  static Key zobExclusion;
 };
 
 
@@ -493,6 +505,10 @@ inline Key Position::get_key() const {
   return st->key;
 }
 
+inline Key Position::get_exclusion_key() const {
+  return st->key ^ zobExclusion;
+}
+
 inline Key Position::get_pawn_key() const {
   return st->pawnKey;
 }
@@ -501,46 +517,22 @@ inline Key Position::get_material_key() const {
   return st->materialKey;
 }
 
-template<Position::GamePhase Ph>
-inline Value Position::pst(Color c, PieceType pt, Square s) const {
-  return (Ph == MidGame ? MgPieceSquareTable[piece_of_color_and_type(c, pt)][s]
-                        : EgPieceSquareTable[piece_of_color_and_type(c, pt)][s]);
+inline Score Position::pst(Color c, PieceType pt, Square s) const {
+  return PieceSquareTable[piece_of_color_and_type(c, pt)][s];
 }
 
-template<Position::GamePhase Ph>
-inline Value Position::pst_delta(Piece piece, Square from, Square to) const {
-  return (Ph == MidGame ? MgPieceSquareTable[piece][to] - MgPieceSquareTable[piece][from]
-                        : EgPieceSquareTable[piece][to] - EgPieceSquareTable[piece][from]);
+inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
+  return PieceSquareTable[piece][to] - PieceSquareTable[piece][from];
 }
 
-inline Value Position::mg_value() const {
-  return st->mgValue;
-}
-
-inline Value Position::eg_value() const {
-  return st->egValue;
+inline Score Position::value() const {
+  return st->value;
 }
 
 inline Value Position::non_pawn_material(Color c) const {
   return st->npMaterial[c];
 }
 
-inline Phase Position::game_phase() const {
-
-  // Values modified by Joona Kiiski
-  static const Value MidgameLimit = Value(15581);
-  static const Value EndgameLimit = Value(3998);
-
-  Value npm = non_pawn_material(WHITE) + non_pawn_material(BLACK);
-
-  if (npm >= MidgameLimit)
-      return PHASE_MIDGAME;
-  else if(npm <= EndgameLimit)
-      return PHASE_ENDGAME;
-  else
-      return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
-
 inline bool Position::move_is_passed_pawn_push(Move m) const {
 
   Color c = side_to_move();
@@ -568,8 +560,17 @@ inline bool Position::has_pawn_on_7th(Color c) const {
 inline bool Position::move_is_capture(Move m) const {
 
   // Move must not be MOVE_NONE !
+  return (m & (3 << 15)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+}
 
-  return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+inline bool Position::move_is_capture_or_promotion(Move m) const {
+
+  // Move must not be MOVE_NONE !
+  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);
-  p.do_move(m, st);
-  if (p.is_check())
-      san += p.is_mate()? "#" : "+";
+  pos.do_move(m, st);
+  if (pos.is_check())
+      san += pos.is_mate() ? "#" : "+";
+  pos.undo_move(m);
 
   return san;
 }
@@ -142,13 +142,14 @@ Move move_from_san(const Position& pos, const string& movestr) {
   assert(pos.is_ok());
 
   MovePicker mp = MovePicker(pos, MOVE_NONE, OnePly, H);
+  Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
 
   // Castling moves
   if (movestr == "O-O-O" || movestr == "O-O-O+")
   {
       Move m;
       while ((m = mp.get_next_move()) != MOVE_NONE)
-          if (move_is_long_castle(m) && pos.pl_move_is_legal(m))
+          if (move_is_long_castle(m) && pos.pl_move_is_legal(m, pinned))
               return m;
 
       return MOVE_NONE;
@@ -157,7 +158,7 @@ Move move_from_san(const Position& pos, const string& movestr) {
   {
       Move m;
       while ((m = mp.get_next_move()) != MOVE_NONE)
-          if (move_is_short_castle(m) && pos.pl_move_is_legal(m))
+          if (move_is_short_castle(m) && pos.pl_move_is_legal(m, pinned))
               return m;
 
     return MOVE_NONE;
@@ -325,14 +326,15 @@ const string line_to_san(const Position& pos, Move line[], int startColumn, bool
 /// when the UCI parameter "Use Search Log" is "true").
 
 const string pretty_pv(const Position& pos, int time, int depth,
-                       uint64_t nodes, Value score, Move pv[]) {
+                       uint64_t nodes, Value score, ValueType type, Move pv[]) {
   std::stringstream s;
 
   // Depth
   s << std::setw(2) << depth << "  ";
 
   // Score
-  s << std::setw(8) << score_string(score);
+  s << ((type == VALUE_TYPE_LOWER)? ">" : ((type == VALUE_TYPE_UPPER)? "<" : " "));
+  s << std::setw(7) << score_string(score);
 
   // Time
   s << std::setw(8) << time_string(time) << " ";
@@ -366,11 +368,12 @@ namespace {
         return AMBIGUITY_NONE;
 
     MovePicker mp = MovePicker(pos, MOVE_NONE, OnePly, H);
+    Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
     Move mv, moveList[8];
 
     int n = 0;
     while ((mv = mp.get_next_move()) != MOVE_NONE)
-        if (move_to(mv) == to && pos.piece_on(move_from(mv)) == pc && pos.pl_move_is_legal(mv))
+        if (move_to(mv) == to && pos.piece_on(move_from(mv)) == pc && pos.pl_move_is_legal(mv, pinned))
             moveList[n++] = mv;
 
     if (n == 1)

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
@@ -36,9 +36,9 @@
 //// 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, Move pv[]);
+extern const std::string pretty_pv(const Position& pos, int time, int depth, uint64_t nodes, Value score, ValueType type, Move pv[]);
 
 #endif // !defined(SAN_H_INCLUDED)

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"
 
 
 ////
@@ -46,14 +47,16 @@ 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];
+  Move pv[PLY_MAX_PLUS_2];
   Move currentMove;
   Move mateKiller;
   Move threatMove;
   Move killers[KILLER_MAX];
   Depth reduction;
+  Value eval;
 
   void init(int ply);
   void initKillers();
@@ -64,11 +67,13 @@ 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[]);
+extern int perft(Position &pos, Depth depth);
 extern int64_t nodes_searched();
 
 

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 {
-  SplitPoint *parent;
-  Position pos;
-  SearchStack sstack[THREAD_MAX][PLY_MAX];
-  SearchStack *parentSstack;
-  int ply;
-  Depth depth;
-  volatile Value alpha, beta, bestValue;
+
+  // Const data after splitPoint has been setup
+  SplitPoint* parent;
+  const Position* pos;
   bool pvNode;
-  Bitboard dcCandidates;
-  int master, slaves[THREAD_MAX];
+  Depth depth;
+  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;
-  MovePicker *mp;
+  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;
+  SplitPoint* splitPoint;
+  volatile int activeSplitPoints;
   uint64_t nodes;
   uint64_t betaCutOffs[2];
-  bool failHighPly1;
-  volatile bool stop;
-  volatile bool running;
-  volatile bool idle;
-  volatile bool workIsWaiting;
-  volatile bool printCurrentLine;
+  volatile ThreadState state;
   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>
-#include <xmmintrin.h>
+#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);
-
-  unsigned newSize = 1024;
+  size_t 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
@@ -208,7 +213,9 @@ void TranspositionTable::insert_pv(const Position& pos, Move pv[]) {
 
   for (int i = 0; pv[i] != MOVE_NONE; i++)
   {
-      store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]);
+      TTEntry *tte = retrieve(p.get_key());
+      if (!tte || tte->move() != pv[i])
+          store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, Depth(-127*OnePly), pv[i]);
       p.do_move(pv[i], st);
   }
 }
@@ -220,27 +227,26 @@ void TranspositionTable::insert_pv(const Position& pos, Move pv[]) {
 /// will often get single-move PVs when the search stops while failing high,
 /// and a single-move PV means that we don't have a ponder move.
 
-void TranspositionTable::extract_pv(const Position& pos, Move pv[]) {
+void TranspositionTable::extract_pv(const Position& pos, Move pv[], const int PLY_MAX) {
 
-  int ply;
-  Position p(pos);
-  StateInfo st[100];
-
-  for (ply = 0; pv[ply] != MOVE_NONE; ply++)
-      p.do_move(pv[ply], st[ply]);
-
-  bool stop;
   const TTEntry* tte;
-  for (stop = false, tte = retrieve(p.get_key());
-       tte && tte->move() != MOVE_NONE && !stop;
-       tte = retrieve(p.get_key()), ply++)
+  StateInfo st;
+  Position p(pos);
+  int ply = 0;
+
+  // Update position to the end of current PV
+  while (pv[ply] != MOVE_NONE)
+      p.do_move(pv[ply++], st);
+
+  // Try to add moves from TT while possible
+  while (   (tte = retrieve(p.get_key())) != NULL
+         && tte->move() != MOVE_NONE
+         && move_is_legal(p, tte->move())
+         && (!p.is_draw() || ply < 2)
+         && ply < PLY_MAX)
   {
-      if (!move_is_legal(p, tte->move()))
-          break;
       pv[ply] = tte->move();
-      p.do_move(pv[ply], st[ply]);
-      for (int j = 0; j < ply; j++)
-          if (st[j].key == p.get_key()) stop = true;
+      p.do_move(pv[ply++], st);
   }
   pv[ply] = MOVE_NONE;
 }

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
@@ -95,14 +95,14 @@ 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;
   void prefetch(const Key posKey) const;
   void new_search();
   void insert_pv(const Position& pos, Move pv[]);
-  void extract_pv(const Position& pos, Move pv[]);
+  void extract_pv(const Position& pos, Move pv[], const int PLY_MAX);
   int full() const;
 
 private:
@@ -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
@@ -33,7 +33,7 @@ typedef __int16 int16;
 typedef unsigned __int16 uint16_t;
 typedef __int32 int32_t;
 typedef unsigned __int32 uint32_t;
-typedef __int64 int64;
+typedef __int64 int64_t;
 typedef unsigned __int64 uint64_t;
 
 typedef __int16 int16_t;
@@ -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
@@ -61,6 +61,7 @@ namespace {
   void set_option(UCIInputParser& uip);
   void set_position(UCIInputParser& uip);
   bool go(UCIInputParser& uip);
+  void perft(UCIInputParser& uip);
 }
 
 
@@ -106,7 +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;
@@ -123,7 +125,7 @@ namespace {
     }
     else if (token == "ucinewgame")
     {
-        push_button("Clear Hash");
+        push_button("New Game");
         Position::init_piece_square_tables();
         RootPosition.from_fen(StartPosition);
     }
@@ -147,23 +149,19 @@ namespace {
     else if (token == "eval")
     {
         EvalInfo ei;
-        cout << "Incremental mg: " << RootPosition.mg_value()
-             << "\nIncremental eg: " << RootPosition.eg_value()
+        cout << "Incremental mg: " << mg_value(RootPosition.value())
+             << "\nIncremental eg: " << eg_value(RootPosition.value())
              << "\nFull eval: " << evaluate(RootPosition, ei, 0) << endl;
     }
     else if (token == "key")
         cout << "key: " << hex << RootPosition.get_key()
              << "\nmaterial key: " << RootPosition.get_material_key()
              << "\npawn key: " << RootPosition.get_pawn_key() << endl;
+    else if (token == "perft")
+        perft(uip);
     else
-    {
         cout << "Unknown command: " << command << endl;
-        while (!uip.eof())
-        {
-            uip >> token;
-            cout << token << endl;
-        }
-    }
+
     return true;
   }
 
@@ -178,33 +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)
@@ -212,7 +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();
         }
     }
   }
@@ -226,27 +224,22 @@ namespace {
 
   void set_option(UCIInputParser& uip) {
 
-    string token, name;
+    string token, name, value;
 
-    uip >> token;
-    if (token == "name")
+    if (!(uip >> token)) // operator>>() skips any whitespace
+        return;
+
+    if (token == "name" && uip >> name)
     {
-        uip >> name;
-        while (!uip.eof())
-        {
-            uip >> token;
-            if (token == "value")
-                break;
-
+        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);
     }
@@ -273,10 +266,8 @@ namespace {
 
     searchMoves[0] = MOVE_NONE;
 
-    while (!uip.eof())
+    while (uip >> token)
     {
-        uip >> token;
-
         if (token == "infinite")
             infinite = true;
         else if (token == "ponder")
@@ -300,22 +291,35 @@ namespace {
         else if (token == "searchmoves")
         {
             int numOfMoves = 0;
-            while (!uip.eof())
-            {
-                uip >> token;
+            while (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(),
                  time, inc, movesToGo, depth, nodes, moveTime, searchMoves);
   }
 
+  void perft(UCIInputParser& uip) {
+
+    string token;
+    int depth, tm, n;
+    Position pos(RootPosition);
+
+    if (!(uip >> depth))
+        return;
+
+    tm = get_system_time();
+
+    n = perft(pos, depth * OnePly);
+
+    tm = get_system_time() - tm;
+    std::cout << "\nNodes " << n
+              << "\nTime (ms) " << tm
+              << "\nNodes/second " << (int)(n/(tm/1000.0)) << std::endl;
+  }
 }

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 Reply Extension (non-PV nodes)"] = Option(2, 0, 2);
+    o["Single Evasion Extension (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);
@@ -116,19 +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["Hash"] = Option(32, 4, 4096);
+    o["Threads"] = Option(1, 1, MAX_THREADS);
+    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);
 
@@ -169,6 +150,18 @@ namespace {
       return ret;
   }
 
+  // Specialization for std::string where instruction 'ss >> ret;'
+  // would erroneusly tokenize a string with spaces.
+
+  template<>
+  string get_option_value<string>(const string& optionName) {
+
+      if (options.find(optionName) == options.end())
+          return string();
+
+      return options[optionName].currentValue;
+  }
+
 }
 
 ////
@@ -183,15 +176,18 @@ void init_uci_options() {
 
   load_defaults(options);
 
-  // Limit the default value of "Threads" to 7 even if we have 8 CPU cores.
-  // According to Ken Dail's tests, Glaurung plays much better with 7 than
-  // 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.
+  // Set optimal value for parameter "Minimum Split Depth"
+  // according to number of available cores.
   assert(options.find("Threads") != options.end());
   assert(options.find("Minimum Split Depth") != options.end());
 
-  options["Threads"].defaultValue = stringify(Min(cpu_count(), 7));
-  options["Threads"].currentValue = stringify(Min(cpu_count(), 7));
+  Option& thr = options["Threads"];
+  Option& msd = options["Minimum Split Depth"];
+
+  thr.defaultValue = thr.currentValue = stringify(cpu_count());
+
+  if (cpu_count() >= 8)
+      msd.defaultValue = msd.currentValue = stringify(7);
 }
 
 
@@ -279,10 +275,28 @@ void set_option_value(const string& name, const string& value) {
   else if (v == "false")
       v = "0";
 
-  if (options.find(name) != options.end())
-      options[name].currentValue = v;
-  else
+  if (options.find(name) == options.end())
+  {
       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;
 }
 
 
@@ -302,7 +316,7 @@ void push_button(const string& buttonName) {
 bool button_was_pressed(const string& buttonName) {
 
   if (!get_option_value<bool>(buttonName))
-	  return false;
+      return false;
 
   set_option_value(buttonName, "false");
   return true;

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
@@ -48,10 +48,49 @@ enum Value {
   VALUE_KNOWN_WIN = 15000,
   VALUE_MATE = 30000,
   VALUE_INFINITE = 30001,
-  VALUE_NONE = 30002
+  VALUE_NONE = 30002,
+  VALUE_ENSURE_SIGNED = -1
 };
 
 
+/// Score enum keeps a midgame and an endgame value in a single
+/// integer (enum), first LSB 16 bits are used to store endgame
+/// value, while upper bits are used for midgame value.
+
+// 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)); }
+#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); }
+
+inline Score operator-(Score s) { return Score(-int(s)); }
+inline Score operator+(Score s1, Score s2) { return Score(int(s1) + int(s2)); }
+inline Score operator-(Score s1, Score s2) { return Score(int(s1) - int(s2)); }
+inline void operator+=(Score& s1, Score s2) { s1 = Score(int(s1) + int(s2)); }
+inline void operator-=(Score& s1, Score s2) { s1 = Score(int(s1) - int(s2)); }
+inline Score operator*(int i, Score s) { return Score(i * int(s)); }
+
+// Division must be handled separately for each term
+inline Score operator/(Score s, int i) { return make_score(mg_value(s) / i, eg_value(s) / i); }
+
+// Only declared but not defined. We don't want to multiply two scores due to
+// a very high risk of overflow. So user should explicitly convert to integer.
+inline Score operator*(Score s1, Score s2);
+
+
 ////
 //// Constants and variables
 ////
@@ -97,8 +136,7 @@ const Value PieceValueEndgame[17] = {
 
 /// Bonus for having the side to move (modified by Joona Kiiski)
 
-const Value TempoValueMidgame = Value(48);
-const Value TempoValueEndgame = Value(22);
+const Score TempoValue = make_score(48, 22);
 
 
 ////