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Another micro-optmization in valuate_passed_pawns()

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very small gain, but still a gain at the cost of
an extra indentation level.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2009-01-07 14:17:50 +01:00
parent 9b87d151bc
commit 5cacefe7c6
1 changed files with 44 additions and 41 deletions
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81
src/evaluate.cpp
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@ -932,50 +932,53 @@ namespace {
Value ebonus = Value(10 + r * r * 10); Value ebonus = Value(10 + r * r * 10);
// Adjust bonus based on king proximity // Adjust bonus based on king proximity
ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr); if (tr != 0)
ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
// If the pawn is free to advance, increase bonus
if (tr != 0 && pos.square_is_empty(blockSq))
{ {
b2 = squares_in_front_of(us, s); ebonus -= Value(square_distance(ourKingSq, blockSq) * 3 * tr);
b3 = b2 & ei.attacked_by(them); ebonus -= Value(square_distance(ourKingSq, blockSq + pawn_push(us)) * 1 * tr);
b4 = b2 & ei.attacked_by(us); ebonus += Value(square_distance(theirKingSq, blockSq) * 6 * tr);
// If there is an enemy rook or queen attacking the pawn from behind, // If the pawn is free to advance, increase bonus
// add all X-ray attacks by the rook or queen. if (pos.square_is_empty(blockSq))
if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s)
&& (squares_behind(us, s) & pos.rooks_and_queens(them)))
b3 = b2;
if ((b2 & pos.pieces_of_color(them)) == EmptyBoardBB)
{ {
// There are no enemy pieces in the pawn's path! Are any of the b2 = squares_in_front_of(us, s);
// squares in the pawn's path attacked by the enemy? b3 = b2 & ei.attacked_by(them);
if (b3 == EmptyBoardBB) b4 = b2 & ei.attacked_by(us);
// No enemy attacks, huge bonus!
ebonus += Value(tr * (b2 == b4 ? 17 : 15)); // If there is an enemy rook or queen attacking the pawn from behind,
// add all X-ray attacks by the rook or queen.
if ( bit_is_set(ei.attacked_by(them,ROOK) | ei.attacked_by(them,QUEEN),s)
&& (squares_behind(us, s) & pos.rooks_and_queens(them)))
b3 = b2;
if ((b2 & pos.pieces_of_color(them)) == EmptyBoardBB)
{
// There are no enemy pieces in the pawn's path! Are any of the
// squares in the pawn's path attacked by the enemy?
if (b3 == EmptyBoardBB)
// No enemy attacks, huge bonus!
ebonus += Value(tr * (b2 == b4 ? 17 : 15));
else
// OK, there are enemy attacks. Are those squares which are
// attacked by the enemy also attacked by us? If yes, big bonus
// (but smaller than when there are no enemy attacks), if no,
// somewhat smaller bonus.
ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8));
}
else else
// OK, there are enemy attacks. Are those squares which are {
// attacked by the enemy also attacked by us? If yes, big bonus // There are some enemy pieces in the pawn's path. While this is
// (but smaller than when there are no enemy attacks), if no, // sad, we still assign a moderate bonus if all squares in the path
// somewhat smaller bonus. // which are either occupied by or attacked by enemy pieces are
ebonus += Value(tr * ((b3 & b4) == b3 ? 13 : 8)); // also attacked by us.
if (((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB)
ebonus += Value(tr * 6);
}
// At last, add a small bonus when there are no *friendly* pieces
// in the pawn's path.
if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
ebonus += Value(tr);
} }
else
{
// There are some enemy pieces in the pawn's path. While this is
// sad, we still assign a moderate bonus if all squares in the path
// which are either occupied by or attacked by enemy pieces are
// also attacked by us.
if (((b3 | (b2 & pos.pieces_of_color(them))) & ~b4) == EmptyBoardBB)
ebonus += Value(tr * 6);
}
// At last, add a small bonus when there are no *friendly* pieces
// in the pawn's path.
if ((b2 & pos.pieces_of_color(us)) == EmptyBoardBB)
ebonus += Value(tr);
} }
// If the pawn is supported by a friendly pawn, increase bonus // If the pawn is supported by a friendly pawn, increase bonus