HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-23 10:36:26 +08:00
Code Issues Packages Projects Releases Wiki Activity

Small cleanups

Browse Source 
closes https://github.com/official-stockfish/Stockfish/pull/2567

No functional change.
This commit is contained in:
Joost VandeVondele
2020-03-14 17:04:50 +01:00
parent ec2002c594
commit ddcbacd04d
8 changed files with 30 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
src/endgame.cpp
View File

@@ -24,8 +24,6 @@
#include "endgame.h"
#include "movegen.h"
using std::string;
namespace {
// Used to drive the king towards the edge of the board
@@ -326,23 +324,23 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
// No assertions about the material of weakSide, because we want draws to
// be detected even when the weaker side has some pawns.
Bitboard strongpawns = pos.pieces(strongSide, PAWN);
Bitboard allpawns = pos.pieces(PAWN);
Bitboard strongPawns = pos.pieces(strongSide, PAWN);
Bitboard allPawns = pos.pieces(PAWN);
// All strongSide pawns are on a single rook file?
if (!(strongpawns & ~FileABB) || !(strongpawns & ~FileHBB))
if (!(strongPawns & ~FileABB) || !(strongPawns & ~FileHBB))
{
Square bishopSq = pos.square<BISHOP>(strongSide);
Square queeningSq = relative_square(strongSide, make_square(file_of(lsb(strongpawns)), RANK_8));
Square weakkingSq = pos.square<KING>(weakSide);
Square queeningSq = relative_square(strongSide, make_square(file_of(lsb(strongPawns)), RANK_8));
Square weakKingSq = pos.square<KING>(weakSide);
if ( opposite_colors(queeningSq, bishopSq)
&& distance(queeningSq, weakkingSq) <= 1)
&& distance(queeningSq, weakKingSq) <= 1)
return SCALE_FACTOR_DRAW;
}
// If all the pawns are on the same B or G file, then it's potentially a draw
if ((!(allpawns & ~FileBBB) || !(allpawns & ~FileGBB))
if ((!(allPawns & ~FileBBB) || !(allPawns & ~FileGBB))
&& pos.non_pawn_material(weakSide) == 0
&& pos.count<PAWN>(weakSide) >= 1)
{
@@ -356,8 +354,8 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
// There's potential for a draw if our pawn is blocked on the 7th rank,
// the bishop cannot attack it or they only have one pawn left
if ( relative_rank(strongSide, weakPawnSq) == RANK_7
&& (strongpawns & (weakPawnSq + pawn_push(weakSide)))
&& (opposite_colors(bishopSq, weakPawnSq) || !more_than_one(strongpawns)))
&& (strongPawns & (weakPawnSq + pawn_push(weakSide)))
&& (opposite_colors(bishopSq, weakPawnSq) || !more_than_one(strongPawns)))
{
int strongKingDist = distance(weakPawnSq, strongKingSq);
int weakKingDist = distance(weakPawnSq, weakKingSq);
@@ -588,11 +586,9 @@ ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
Square ksq = pos.square<KING>(weakSide);
Bitboard pawns = pos.pieces(strongSide, PAWN);
// If all pawns are ahead of the king, on a single rook file and
// the king is within one file of the pawns, it's a draw.
if ( !(pawns & ~forward_ranks_bb(weakSide, ksq))
&& !((pawns & ~FileABB) && (pawns & ~FileHBB))
&& distance<File>(ksq, lsb(pawns)) <= 1)
// If all pawns are ahead of the king on a single rook file, it's a draw.
if (!((pawns & ~FileABB) || (pawns & ~FileHBB)) &&
!(pawns & ~passed_pawn_span(weakSide, ksq)))
return SCALE_FACTOR_DRAW;
return SCALE_FACTOR_NONE;
@@ -615,8 +611,7 @@ ScaleFactor Endgame<KBPKB>::operator()(const Position& pos) const {
Square weakKingSq = pos.square<KING>(weakSide);
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( file_of(weakKingSq) == file_of(pawnSq)
&& relative_rank(strongSide, pawnSq) < relative_rank(strongSide, weakKingSq)
if ( (forward_file_bb(strongSide, pawnSq) & weakKingSq)
&& ( opposite_colors(weakKingSq, strongBishopSq)
|| relative_rank(strongSide, weakKingSq) <= RANK_6))
return SCALE_FACTOR_DRAW;