X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fendgame.cpp;h=754e40317b96b07b27281dd203e7e6303433d0d3;hp=0d9d3c26c216b2fbeb394b5a887c21530ac90425;hb=c1c09844525c764f869b29360519808aab5a7069;hpb=4f3fe89fb6e957fd971a76080687ba358ec27603

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 0d9d3c26..754e4031 100644
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -17,20 +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 {
 
@@ -68,9 +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]);
@@ -88,23 +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);
 }
 
 
@@ -155,7 +128,7 @@ Value EvaluationFunction<KBNK>::apply(const Position& pos) const {
   // kbnk_mate_table() tries to drive toward corners A1 or H8,
   // if we have a bishop that cannot reach the above squares we
   // mirror the kings so to drive enemy toward corners A8 or H1.
-  if (!same_color_squares(bishopSquare, SQ_A1))
+  if (opposite_color_squares(bishopSquare, SQ_A1))
   {
       winnerKSq = flop_square(winnerKSq);
       loserKSq = flop_square(loserKSq);
@@ -203,7 +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
@@ -401,8 +374,8 @@ ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) const {
       Square queeningSq = relative_square(strongerSide, make_square(pawnFile, RANK_8));
       Square kingSq = pos.king_square(weakerSide);
 
-      if (  !same_color_squares(queeningSq, bishopSq)
-          && file_distance(square_file(kingSq), pawnFile) <= 1)
+      if (   opposite_color_squares(queeningSq, bishopSq)
+          && abs(square_file(kingSq) - pawnFile) <= 1)
       {
           // The bishop has the wrong color, and the defending king is on the
           // file of the pawn(s) or the neighboring file. Find the rank of the
@@ -678,12 +651,12 @@ ScaleFactor ScalingFunction<KBPKB>::apply(const Position& pos) const {
   // Case 1: Defending king blocks the pawn, and cannot be driven away
   if (   square_file(weakerKingSq) == square_file(pawnSq)
       && relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
-      && (  !same_color_squares(weakerKingSq, strongerBishopSq)
+      && (   opposite_color_squares(weakerKingSq, strongerBishopSq)
           || relative_rank(strongerSide, weakerKingSq) <= RANK_6))
       return SCALE_FACTOR_ZERO;
 
   // Case 2: Opposite colored bishops
-  if (!same_color_squares(strongerBishopSq, weakerBishopSq))
+  if (opposite_color_squares(strongerBishopSq, weakerBishopSq))
   {
       // We assume that the position is drawn in the following three situations:
       //
@@ -728,8 +701,7 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
   Square wbsq = pos.piece_list(strongerSide, BISHOP, 0);
   Square bbsq = pos.piece_list(weakerSide, BISHOP, 0);
 
-  if (same_color_squares(wbsq, bbsq))
-      // Not opposite-colored bishops, no scaling
+  if (!opposite_color_squares(wbsq, bbsq))
       return SCALE_FACTOR_NONE;
 
   Square ksq = pos.king_square(weakerSide);
@@ -757,7 +729,7 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
     // some square in the frontmost pawn's path.
     if (   square_file(ksq) == square_file(blockSq1)
         && relative_rank(strongerSide, ksq) >= relative_rank(strongerSide, blockSq1)
-        && !same_color_squares(ksq, wbsq))
+        && opposite_color_squares(ksq, wbsq))
         return SCALE_FACTOR_ZERO;
     else
         return SCALE_FACTOR_NONE;
@@ -767,14 +739,14 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
     // in front of the frontmost pawn's path, and the square diagonally behind
     // this square on the file of the other pawn.
     if (   ksq == blockSq1
-        && !same_color_squares(ksq, wbsq)
+        && opposite_color_squares(ksq, wbsq)
         && (   bbsq == blockSq2
             || (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(BISHOP, weakerSide))
-            || rank_distance(r1, r2) >= 2))
+            || abs(r1 - r2) >= 2))
         return SCALE_FACTOR_ZERO;
 
     else if (   ksq == blockSq2
-             && !same_color_squares(ksq, wbsq)
+             && opposite_color_squares(ksq, wbsq)
              && (   bbsq == blockSq1
                  || (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(BISHOP, weakerSide))))
         return SCALE_FACTOR_ZERO;
@@ -808,7 +780,7 @@ ScaleFactor ScalingFunction<KBPKN>::apply(const Position& pos) const {
 
   if (   square_file(weakerKingSq) == square_file(pawnSq)
       && relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
-      && (  !same_color_squares(weakerKingSq, strongerBishopSq)
+      && (   opposite_color_squares(weakerKingSq, strongerBishopSq)
           || relative_rank(strongerSide, weakerKingSq) <= RANK_6))
       return SCALE_FACTOR_ZERO;
 
@@ -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;
 }