From 3d73760146461a4d4b80289ef6e8ce06102d5464 Mon Sep 17 00:00:00 2001 From: Eryn Wells Date: Fri, 15 Aug 2025 16:14:34 -0700 Subject: [PATCH 1/2] [bitboard, board] Remove BitBoard::empty() and BitBoard::full() These have been deprecated for a while. Clean up the remaining uses and remove the methods from BitBoard. --- bitboard/src/bitboard.rs | 18 ++++-------------- bitboard/src/library.rs | 18 +++++++++--------- board/src/movement.rs | 20 ++++++++++---------- board/src/sight.rs | 2 +- 4 files changed, 24 insertions(+), 34 deletions(-) diff --git a/bitboard/src/bitboard.rs b/bitboard/src/bitboard.rs index ccee9bd..35ce927 100644 --- a/bitboard/src/bitboard.rs +++ b/bitboard/src/bitboard.rs @@ -46,16 +46,6 @@ impl BitBoard { pub const EMPTY: BitBoard = BitBoard(u64::MIN); pub const FULL: BitBoard = BitBoard(u64::MAX); - #[deprecated(note = "Use BitBoard::EMPTY instead")] - pub const fn empty() -> BitBoard { - Self::EMPTY - } - - #[deprecated(note = "Use BitBoard::FULL instead")] - pub const fn full() -> BitBoard { - Self::FULL - } - pub const fn new(bits: u64) -> BitBoard { BitBoard(bits) } @@ -109,7 +99,7 @@ impl BitBoard { /// /// ``` /// use chessfriend_bitboard::BitBoard; - /// assert!(BitBoard::empty().is_empty()); + /// assert!(BitBoard::EMPTY.is_empty()); /// assert!(!BitBoard::full().is_empty()); /// assert!(!BitBoard::new(0b1000).is_empty()); /// ``` @@ -125,7 +115,7 @@ impl BitBoard { /// /// ``` /// use chessfriend_bitboard::BitBoard; - /// assert!(!BitBoard::empty().is_populated()); + /// assert!(!BitBoard::EMPTY.is_populated()); /// assert!(BitBoard::full().is_populated()); /// assert!(BitBoard::new(0b1).is_populated()); /// ``` @@ -564,8 +554,8 @@ mod tests { let b = bitboard![B5 G7 H3]; assert_eq!(a ^ b, bitboard![B5 C5 H3]); - assert_eq!(a ^ BitBoard::empty(), a); - assert_eq!(BitBoard::empty() ^ BitBoard::empty(), BitBoard::empty()); + assert_eq!(a ^ BitBoard::EMPTY, a); + assert_eq!(BitBoard::EMPTY ^ BitBoard::EMPTY, BitBoard::EMPTY); } #[test] diff --git a/bitboard/src/library.rs b/bitboard/src/library.rs index 6a60392..3ea670c 100644 --- a/bitboard/src/library.rs +++ b/bitboard/src/library.rs @@ -110,14 +110,14 @@ pub(super) struct MoveLibrary { impl MoveLibrary { const fn new() -> MoveLibrary { MoveLibrary { - rays: [[BitBoard::empty(); Direction::NUM]; Square::NUM], - pawn_attacks: [[BitBoard::empty(); Square::NUM]; Color::NUM], - pawn_pushes: [[BitBoard::empty(); Square::NUM]; Color::NUM], - knight_moves: [BitBoard::empty(); Square::NUM], - bishop_moves: [BitBoard::empty(); Square::NUM], - rook_moves: [BitBoard::empty(); Square::NUM], - queen_moves: [BitBoard::empty(); Square::NUM], - king_moves: [BitBoard::empty(); Square::NUM], + rays: [[BitBoard::EMPTY; Direction::NUM]; Square::NUM], + pawn_attacks: [[BitBoard::EMPTY; Square::NUM]; Color::NUM], + pawn_pushes: [[BitBoard::EMPTY; Square::NUM]; Color::NUM], + knight_moves: [BitBoard::EMPTY; Square::NUM], + bishop_moves: [BitBoard::EMPTY; Square::NUM], + rook_moves: [BitBoard::EMPTY; Square::NUM], + queen_moves: [BitBoard::EMPTY; Square::NUM], + king_moves: [BitBoard::EMPTY; Square::NUM], } } @@ -238,7 +238,7 @@ impl MoveLibrary { } fn _generate_ray(sq: BitBoard, shift: fn(&BitBoard) -> BitBoard) -> BitBoard { - let mut ray = BitBoard::empty(); + let mut ray = BitBoard::EMPTY; let mut iter = shift(&sq); while !iter.is_empty() { diff --git a/board/src/movement.rs b/board/src/movement.rs index 2935eee..3ebf44c 100644 --- a/board/src/movement.rs +++ b/board/src/movement.rs @@ -41,7 +41,7 @@ impl Movement for Piece { let parameters = Board::castling_parameters(Wing::KingSide, color); parameters.target.king.into() } else { - BitBoard::empty() + BitBoard::EMPTY }; let queenside_target_square = if board @@ -51,7 +51,7 @@ impl Movement for Piece { let parameters = Board::castling_parameters(Wing::QueenSide, color); parameters.target.king.into() } else { - BitBoard::empty() + BitBoard::EMPTY }; self.sight(square, board) | kingside_target_square | queenside_target_square @@ -99,11 +99,11 @@ mod tests { #[test] fn white_pushes_empty_board() { assert_eq!( - pawn_pushes(Square::E4.into(), Color::White, BitBoard::empty()), + pawn_pushes(Square::E4.into(), Color::White, BitBoard::EMPTY), bitboard![E5] ); assert_eq!( - pawn_pushes(Square::E2.into(), Color::White, BitBoard::empty()), + pawn_pushes(Square::E2.into(), Color::White, BitBoard::EMPTY), bitboard![E3 E4] ); } @@ -111,11 +111,11 @@ mod tests { #[test] fn black_pawn_empty_board() { assert_eq!( - pawn_pushes(Square::A4.into(), Color::Black, BitBoard::empty()), + pawn_pushes(Square::A4.into(), Color::Black, BitBoard::EMPTY), bitboard![A3] ); assert_eq!( - pawn_pushes(Square::B7.into(), Color::Black, BitBoard::empty()), + pawn_pushes(Square::B7.into(), Color::Black, BitBoard::EMPTY), bitboard![B6 B5] ); } @@ -124,7 +124,7 @@ mod tests { fn white_pushes_blocker() { assert_eq!( pawn_pushes(Square::C5.into(), Color::White, bitboard![C6]), - BitBoard::empty() + BitBoard::EMPTY ); assert_eq!( pawn_pushes(Square::D2.into(), Color::White, bitboard![D4]), @@ -132,7 +132,7 @@ mod tests { ); assert_eq!( pawn_pushes(Square::D2.into(), Color::White, bitboard![D3]), - BitBoard::empty() + BitBoard::EMPTY ); } @@ -140,7 +140,7 @@ mod tests { fn black_pushes_blocker() { assert_eq!( pawn_pushes(Square::C5.into(), Color::Black, bitboard![C4]), - BitBoard::empty() + BitBoard::EMPTY ); assert_eq!( pawn_pushes(Square::D7.into(), Color::Black, bitboard![D5]), @@ -148,7 +148,7 @@ mod tests { ); assert_eq!( pawn_pushes(Square::D7.into(), Color::Black, bitboard![D6]), - BitBoard::empty() + BitBoard::EMPTY ); } } diff --git a/board/src/sight.rs b/board/src/sight.rs index b8e366e..e682cb0 100644 --- a/board/src/sight.rs +++ b/board/src/sight.rs @@ -305,7 +305,7 @@ mod tests { let piece = piece!(White Pawn); let sight = piece.sight(Square::E4, &pos); - assert_eq!(sight, BitBoard::empty()); + assert_eq!(sight, BitBoard::EMPTY); } #[test] From 182bf8112669b156faa27f63e87384e1cfff9df5 Mon Sep 17 00:00:00 2001 From: Eryn Wells Date: Fri, 15 Aug 2025 16:15:09 -0700 Subject: [PATCH 2/2] [board] Fix a counter underflow in the piece set During perft runs, the PieceSet counter would occasionally underflow, causing the whole program to crash. This is because, when building a Board from a list of bitboards, Counts::increment() was only being called once, even when the bitboard had more than one piece in it. Fix the bug by incrementing during the loop that sets up the mailbox. Additionally, refactor the increment() and decrement() methods to be a little more succinct. --- board/src/piece_sets.rs | 3 +-- board/src/piece_sets/counts.rs | 19 ++++++++++--------- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/board/src/piece_sets.rs b/board/src/piece_sets.rs index de43caa..52af054 100644 --- a/board/src/piece_sets.rs +++ b/board/src/piece_sets.rs @@ -51,11 +51,10 @@ impl PieceSet { color_occupancy[color_index] |= bitboard; shape_occupancy[shape_index] |= bitboard; - counts.increment(color, shape); - for square in bitboard.occupied_squares(&IterationDirection::default()) { let piece = Piece::new(color, shape); mailbox.set(piece, square); + counts.increment(color, shape); } } } diff --git a/board/src/piece_sets/counts.rs b/board/src/piece_sets/counts.rs index effbbe0..7d3cade 100644 --- a/board/src/piece_sets/counts.rs +++ b/board/src/piece_sets/counts.rs @@ -17,20 +17,21 @@ impl Counts { const SQUARE_NUM: u8 = Square::NUM as u8; let updated_value = self.0[color as usize][shape as usize] + 1; - if updated_value <= SQUARE_NUM { - self.0[color as usize][shape as usize] = updated_value; - } else { - unreachable!("piece count for {color} {shape} overflowed"); + if updated_value > SQUARE_NUM { + let shape_name = shape.name(); + panic!("piece count for {color} {shape_name} overflowed"); } + + self.0[color as usize][shape as usize] = updated_value; } pub fn decrement(&mut self, color: Color, shape: Shape) { let count = self.0[color as usize][shape as usize]; - if let Some(updated_count) = count.checked_sub(1) { - self.0[color as usize][shape as usize] = updated_count; - } else { - unreachable!("piece count for {color} {shape} underflowed"); - } + let updated_count = count.checked_sub(1).unwrap_or_else(|| { + let shape_name = shape.name(); + panic!("piece count for {color} {shape_name} should not underflow"); + }); + self.0[color as usize][shape as usize] = updated_count; } #[cfg(test)]