Split PSQT init from Position init

Easier for tuning psq tables:

TUNE(myParameters, PSQT::init);

Also move PSQT code in a new *.cpp file, and retire the
old and hacky psqtab.h that required to be included only
once to work correctly, this is not idiomatic for a header
file.

Give wide visibility to psq tables (previously visible only
in position.cpp), this will easy the use of psq tables outside
Position, for instance in move ordering.

Finally trivial code style fixes of the latest patches.

Original patch of Lucas Braesch.

No functional change.

src/Makefile

@@ -35,7 +35,7 @@ PGOBENCH = ./$(EXE) bench 16 1 1000 default time
 
 ### Object files
 OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
-	material.o misc.o movegen.o movepick.o pawns.o position.o \
+	material.o misc.o movegen.o movepick.o pawns.o position.o psqt.o \
 	search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o
 
 ### ==========================================================================

src/main.cpp

@@ -33,6 +33,7 @@ int main(int argc, char* argv[]) {
   std::cout << engine_info() << std::endl;
 
   UCI::init(Options);
+  PSQT::init();
   Bitboards::init();
   Position::init();
   Bitbases::init();

src/movepick.cpp

@@ -147,9 +147,9 @@ void MovePicker::score<CAPTURES>() {
   // badCaptures[] array, but instead of doing it now we delay until the move
   // has been picked up in pick_move_from_list(). This way we save some SEE
   // calls in case we get a cutoff.
-  for (auto& m : *this){
-      m.value = PieceValue[MG][pos.piece_on(to_sq(m))] - 200*relative_rank(pos.side_to_move(), to_sq(m));
-  }
+  for (auto& m : *this)
+      m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
+               - 200 * relative_rank(pos.side_to_move(), to_sq(m));
 }
 
 template<>

src/position.cpp

@@ -27,7 +27,6 @@
 #include "misc.h"
 #include "movegen.h"
 #include "position.h"
-#include "psqtab.h"
 #include "thread.h"
 #include "tt.h"
 #include "uci.h"
@@ -52,7 +51,6 @@ Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion; }
 namespace {
 
 const string PieceToChar(" PNBRQK  pnbrqk");
-Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
 
 // min_attacker() is a helper function used by see() to locate the least
 // valuable attacker for the side to move, remove the attacker we just found
@@ -130,10 +128,7 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) {
 
 
 /// Position::init() initializes at startup the various arrays used to compute
-/// hash keys and the piece square tables. The latter is a two-step operation:
-/// Firstly, the white halves of the tables are copied from PSQT[] tables.
-/// Secondly, the black halves of the tables are initialized by flipping and
-/// changing the sign of the white scores.
+/// hash keys.
 
 void Position::init() {
 
@@ -160,20 +155,6 @@ void Position::init() {
 
   Zobrist::side = rng.rand<Key>();
   Zobrist::exclusion  = rng.rand<Key>();
-
-  for (PieceType pt = PAWN; pt <= KING; ++pt)
-  {
-      PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
-      PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
-
-      Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
-
-      for (Square s = SQ_A1; s <= SQ_H8; ++s)
-      {
-         psq[WHITE][pt][ s] =  (v + PSQT[pt][s]);
-         psq[BLACK][pt][~s] = -(v + PSQT[pt][s]);
-      }
-  }
 }
 
 
@@ -373,7 +354,7 @@ void Position::set_state(StateInfo* si) const {
       Square s = pop_lsb(&b);
       Piece pc = piece_on(s);
       si->key ^= Zobrist::psq[color_of(pc)][type_of(pc)][s];
-      si->psq += psq[color_of(pc)][type_of(pc)][s];
+      si->psq += PSQT::psq[color_of(pc)][type_of(pc)][s];
   }
 
   if (si->epSquare != SQ_NONE)
@@ -725,7 +706,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
       do_castling<true>(us, from, to, rfrom, rto);
 
       captured = NO_PIECE_TYPE;
-      st->psq += psq[us][ROOK][rto] - psq[us][ROOK][rfrom];
+      st->psq += PSQT::psq[us][ROOK][rto] - PSQT::psq[us][ROOK][rfrom];
       k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto];
   }
 
@@ -764,7 +745,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
       prefetch(thisThread->materialTable[st->materialKey]);
 
       // Update incremental scores
-      st->psq -= psq[them][captured][capsq];
+      st->psq -= PSQT::psq[them][captured][capsq];
 
       // Reset rule 50 counter
       st->rule50 = 0;
@@ -820,7 +801,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
                             ^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]];
 
           // Update incremental score
-          st->psq += psq[us][promotion][to] - psq[us][PAWN][to];
+          st->psq += PSQT::psq[us][promotion][to] - PSQT::psq[us][PAWN][to];
 
           // Update material
           st->nonPawnMaterial[us] += PieceValue[MG][promotion];
@@ -835,7 +816,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
   }
 
   // Update incremental scores
-  st->psq += psq[us][pt][to] - psq[us][pt][from];
+  st->psq += PSQT::psq[us][pt][to] - PSQT::psq[us][pt][from];
 
   // Set capture piece
   st->capturedType = captured;

src/position.h

@@ -30,6 +30,13 @@
 class Position;
 struct Thread;
 
+namespace PSQT {
+
+  extern Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+
+  void init();
+}
+
 /// CheckInfo struct is initialized at c'tor time and keeps info used to detect
 /// if a move gives check.
 

src/psqt.cpp

@@ -17,19 +17,16 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef PSQTAB_H_INCLUDED
-#define PSQTAB_H_INCLUDED
-
 #include "types.h"
 
+namespace PSQT {
+
 #define S(mg, eg) make_score(mg, eg)
 
-
-/// PSQT[PieceType][Square] contains Piece-Square scores. For each piece type on
-/// a given square a (middlegame, endgame) score pair is assigned. PSQT is defined
-/// for the white side and the tables are symmetric for the black side.
-
-static const Score PSQT[][SQUARE_NB] = {
+/// BaseTable[PieceType][Square] contains Piece-Square scores. For each piece
+/// type on a given square a (middlegame, endgame) score pair is assigned. Table
+/// is defined just for the white side; it is symmetric for the black side.
+const Score BaseTable[][SQUARE_NB] = {
   { },
   { // Pawn
    S(  0, 0), S(  0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S( 0, 0), S(  0, 0), S(  0, 0),
@@ -95,4 +92,23 @@ static const Score PSQT[][SQUARE_NB] = {
 
 #undef S
 
-#endif // #ifndef PSQTAB_H_INCLUDED
+Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB];
+
+// init() initializes piece square tables: the white halves of the tables are
+// copied from BaseTable[] adding the piece value, then the black halves of the
+// tables are initialized by flipping and changing the sign of the white scores.
+void init() {
+
+  for (PieceType pt = PAWN; pt <= KING; ++pt)
+  {
+      PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt];
+      PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt];
+
+      Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]);
+
+      for (Square s = SQ_A1; s <= SQ_H8; ++s)
+          psq[BLACK][pt][~s] = -(psq[WHITE][pt][ s] = (v + BaseTable[pt][s]));
+  }
+}
+
+} // namespace PSQT

src/search.cpp

@@ -961,7 +961,8 @@ moves_loop: // When in check and at SpNode search starts from here
 
           if (   (!PvNode && cutNode)
               || (   History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO
-                  && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq][pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
+                  && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq]
+                                        [pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO))
               ss->reduction += ONE_PLY;
 
           if (move == countermove)