Move KPKBitbase[] where it belongs

No functional change.

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

src/bitbase.cpp

@@ -47,13 +47,23 @@ namespace {
 
   const int IndexMax = 2 * 24 * 64 * 64;
 
+  uint8_t KPKBitbase[IndexMax / 8];
+
   Result classify_wtm(const KPKPosition& pos, const Result bb[]);
   Result classify_btm(const KPKPosition& pos, const Result bb[]);
-  int compute_index(Square wksq, Square bksq, Square psq, Color stm);
+  int compute_index(Square wksq, Square bksq, Square wpsq, Color stm);
 }
 
 
-void generate_kpk_bitbase(uint8_t bitbase[]) {
+int probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm) {
+
+  int index = compute_index(wksq, bksq, wpsq, stm);
+
+  return KPKBitbase[index / 8] & (1 << (index & 7));
+}
+
+
+void init_kpk_bitbase() {
 
   bool repeat;
   int i, j, b;
@@ -86,7 +96,7 @@ void generate_kpk_bitbase(uint8_t bitbase[]) {
 
   } while (repeat);
 
-  // Compress result and map into supplied bitbase parameter
+  // Compress result and map into KPKBitbase[]
   for (i = 0; i < 24576; i++)
   {
       b = 0;
@@ -94,16 +104,16 @@ void generate_kpk_bitbase(uint8_t bitbase[]) {
           if (bb[8*i+j] == RESULT_WIN || bb[8*i+j] == RESULT_LOSS)
               b |= (1 << j);
 
-      bitbase[i] = (uint8_t)b;
+      KPKBitbase[i] = (uint8_t)b;
   }
 }
 
 
 namespace {
 
-  int compute_index(Square wksq, Square bksq, Square psq, Color stm) {
+  int compute_index(Square wksq, Square bksq, Square wpsq, Color stm) {
 
-      int p = int(square_file(psq)) + (int(square_rank(psq)) - 1) * 4;
+      int p = int(square_file(wpsq)) + (int(square_rank(wpsq)) - 1) * 4;
       int r = int(stm) + 2 * int(bksq) + 128 * int(wksq) + 8192 * p;
 
       assert(r >= 0 && r < IndexMax);

src/endgame.cpp

@@ -17,21 +17,13 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
-////
-//// Includes
-////
-
 #include <cassert>
 
 #include "bitcount.h"
 #include "endgame.h"
 #include "pawns.h"
 
-
-////
-//// Local definitions
-////
+extern int probe_kpk_bitbase(Square wksq, Square wpsq, Square bksq, Color stm);
 
 namespace {
 
@@ -69,9 +61,6 @@ namespace {
   // and knight in KR vs KN endgames.
   const int KRKNKingKnightDistancePenalty[8] = { 0, 0, 4, 10, 20, 32, 48, 70 };
 
-  // Bitbase for KP vs K
-  uint8_t KPKBitbase[24576];
-
   // Various inline functions for accessing the above arrays
   inline Value mate_table(Square s) {
     return Value(MateTable[s]);
@@ -89,23 +78,6 @@ namespace {
     return Value(KRKNKingKnightDistancePenalty[d]);
   }
 
-  // Function for probing the KP vs K bitbase
-  int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
-
-}
-
-
-////
-//// Functions
-////
-
-/// init_bitbases() is called during program initialization, and simply loads
-/// bitbases from disk into memory.  At the moment, there is only the bitbase
-/// for KP vs K, but we may decide to add other bitbases later.
-extern void generate_kpk_bitbase(uint8_t bitbase[]);
-
-void init_bitbases() {
-  generate_kpk_bitbase(KPKBitbase);
 }
 
 
@@ -204,7 +176,7 @@ Value EvaluationFunction<KPK>::apply(const Position& pos) const {
       wpsq = flop_square(wpsq);
   }
 
-  if (!probe_kpk(wksq, wpsq, bksq, stm))
+  if (!probe_kpk_bitbase(wksq, wpsq, bksq, stm))
       return VALUE_DRAW;
 
   Value result =  VALUE_KNOWN_WIN
@@ -890,21 +862,5 @@ ScaleFactor ScalingFunction<KPKP>::apply(const Position& pos) const {
 
   // Probe the KPK bitbase with the weakest side's pawn removed. If it's a
   // draw, it's probably at least a draw even with the pawn.
-  return probe_kpk(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
-}
-
-
-namespace {
-
-  // Probe the KP vs K bitbase
-
-  int probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm) {
-
-    int wp = square_file(wpsq) + 4 * (square_rank(wpsq) - 1);
-    int index = int(stm) + 2 * bksq + 128 * wksq + 8192 * wp;
-
-    assert(index >= 0 && index < 24576 * 8);
-
-    return KPKBitbase[index / 8] & (1 << (index & 7));
-  }
+  return probe_kpk_bitbase(wksq, wpsq, bksq, stm) ? SCALE_FACTOR_NONE : SCALE_FACTOR_ZERO;
 }

src/main.cpp

@@ -38,7 +38,7 @@ using namespace std;
 
 extern bool execute_uci_command(const string& cmd);
 extern void benchmark(int argc, char* argv[]);
-extern void init_bitbases();
+extern void init_kpk_bitbase();
 
 int main(int argc, char* argv[]) {
 
@@ -54,7 +54,7 @@ int main(int argc, char* argv[]) {
   Position::init_zobrist();
   Position::init_piece_square_tables();
   init_eval(1);
-  init_bitbases();
+  init_kpk_bitbase();
   init_search();
   init_threads();