Retire the misdesigned StepAttacks[] array.

[stockfish] / src / bitbase.cpp

diff --git a/src/bitbase.cpp b/src/bitbase.cpp
index 0e4521c1eb9ac20306de568c7832b11415791c6b..d206210414846e3c3392ac655318080397c8b4a4 100644 (file)
--- a/src/bitbase.cpp
+++ b/src/bitbase.cpp
@@ -117,7 +117,7 @@ namespace {
     if (   distance(ksq[WHITE], ksq[BLACK]) <= 1
         || ksq[WHITE] == psq
         || ksq[BLACK] == psq
     if (   distance(ksq[WHITE], ksq[BLACK]) <= 1
         || ksq[WHITE] == psq
         || ksq[BLACK] == psq

-        || (us == WHITE && (StepAttacksBB[W_PAWN][psq] & ksq[BLACK])))
+        || (us == WHITE && (PawnAttacks[WHITE][psq] & ksq[BLACK])))

         result = INVALID;
 
     // Immediate win if a pawn can be promoted without getting captured
         result = INVALID;
 
     // Immediate win if a pawn can be promoted without getting captured


@@ -125,13 +125,13 @@ namespace {
              && rank_of(psq) == RANK_7
              && ksq[us] != psq + NORTH
              && (    distance(ksq[~us], psq + NORTH) > 1
              && rank_of(psq) == RANK_7
              && ksq[us] != psq + NORTH
              && (    distance(ksq[~us], psq + NORTH) > 1

-                 || (StepAttacksBB[KING][ksq[us]] & (psq + NORTH))))
+                 || (PseudoAttacks[KING][ksq[us]] & (psq + NORTH))))

         result = WIN;
 
     // Immediate draw if it is a stalemate or a king captures undefended pawn
     else if (   us == BLACK
         result = WIN;
 
     // Immediate draw if it is a stalemate or a king captures undefended pawn
     else if (   us == BLACK

-             && (  !(StepAttacksBB[KING][ksq[us]] & ~(StepAttacksBB[KING][ksq[~us]] | StepAttacksBB[W_PAWN][psq]))
-                 || (StepAttacksBB[KING][ksq[us]] & psq & ~StepAttacksBB[KING][ksq[~us]])))
+             && (  !(PseudoAttacks[KING][ksq[us]] & ~(PseudoAttacks[KING][ksq[~us]] | PawnAttacks[~us][psq]))
+                 || (PseudoAttacks[KING][ksq[us]] & psq & ~PseudoAttacks[KING][ksq[~us]])))

         result = DRAW;
 
     // Position will be classified later
         result = DRAW;
 
     // Position will be classified later


@@ -157,7 +157,7 @@ namespace {
     const Result Bad  = (Us == WHITE ? DRAW  : WIN);
 
     Result r = INVALID;
     const Result Bad  = (Us == WHITE ? DRAW  : WIN);
 
     Result r = INVALID;

-    Bitboard b = StepAttacksBB[KING][ksq[Us]];
+    Bitboard b = PseudoAttacks[KING][ksq[Us]];

 
     while (b)
         r |= Us == WHITE ? db[index(Them, ksq[Them]  , pop_lsb(&b), psq)]
 
     while (b)
         r |= Us == WHITE ? db[index(Them, ksq[Them]  , pop_lsb(&b), psq)]