deepcrayon
/
stockfish
1
0
Fork 0
Code Releases Activity

Remove AdjacentFiles 

This is a non-functional simplification that removes the AdjacentFiles array.
This array is simple enough to calculate that the pre-calculated array provides
no benefit. Reduces the memory footprint.

STC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 74839 W: 16390 L: 16373 D: 42076
http://tests.stockfishchess.org/tests/view/5c3d75920ebc596a450cfb67

No functionnal change
pull/1899/head
protonspring 2019-01-14 22:53:43 -07:00 committed by Stéphane Nicolet
parent 3732c55c18
commit 3300517ecb
2 changed files with 2 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/bitboard.cpp
View File

@ -29,7 +29,6 @@ int SquareDistance[SQUARE_NB][SQUARE_NB];
Bitboard SquareBB[SQUARE_NB];
Bitboard FileBB[FILE_NB];
Bitboard RankBB[RANK_NB];
Bitboard AdjacentFilesBB[FILE_NB];
Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
Bitboard LineBB[SQUARE_NB][SQUARE_NB];
@ -97,9 +96,6 @@ void Bitboards::init() {
for (Rank r = RANK_1; r <= RANK_8; ++r)
RankBB[r] = r > RANK_1 ? RankBB[r - 1] << 8 : Rank1BB;
for (File f = FILE_A; f <= FILE_H; ++f)
AdjacentFilesBB[f] = (f > FILE_A ? FileBB[f - 1] : 0) | (f < FILE_H ? FileBB[f + 1] : 0);
for (Rank r = RANK_1; r < RANK_8; ++r)
ForwardRanksBB[WHITE][r] = ~(ForwardRanksBB[BLACK][r + 1] = ForwardRanksBB[BLACK][r] | RankBB[r]);
@ -107,7 +103,7 @@ void Bitboards::init() {
for (Square s = SQ_A1; s <= SQ_H8; ++s)
{
ForwardFileBB [c][s] = ForwardRanksBB[c][rank_of(s)] & FileBB[file_of(s)];
PawnAttackSpan[c][s] = ForwardRanksBB[c][rank_of(s)] & AdjacentFilesBB[file_of(s)];
PawnAttackSpan[c][s] = ForwardRanksBB[c][rank_of(s)] & adjacent_files_bb(file_of(s));
PassedPawnMask[c][s] = ForwardFileBB [c][s] | PawnAttackSpan[c][s];
}

3
src/bitboard.h
View File

@ -65,7 +65,6 @@ extern int SquareDistance[SQUARE_NB][SQUARE_NB];
extern Bitboard SquareBB[SQUARE_NB];
extern Bitboard FileBB[FILE_NB];
extern Bitboard RankBB[RANK_NB];
extern Bitboard AdjacentFilesBB[FILE_NB];
extern Bitboard ForwardRanksBB[COLOR_NB][RANK_NB];
extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
@ -195,7 +194,7 @@ constexpr Bitboard double_pawn_attacks_bb(Bitboard b) {
/// adjacent files of the given one.
inline Bitboard adjacent_files_bb(File f) {
return AdjacentFilesBB[f];
return shift<EAST>(FileBB[f]) | shift<WEST>(FileBB[f]);
}