From 2adbb80b8b9eae1378f6c00075446ac7459bb924 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sun, 11 Jul 2010 10:47:04 +0100 Subject: [PATCH] Space inflate bitbase.cpp Also heavy cleanup while there. No functional change. Signed-off-by: Marco Costalba --- src/bitbase.cpp | 384 ++++++++++++++++++++++-------------------------- 1 file changed, 177 insertions(+), 207 deletions(-) diff --git a/src/bitbase.cpp b/src/bitbase.cpp index 801815e7..4a0518fd 100644 --- a/src/bitbase.cpp +++ b/src/bitbase.cpp @@ -26,7 +26,6 @@ #include "bitbase.h" #include "bitboard.h" -#include "move.h" #include "square.h" @@ -46,30 +45,22 @@ namespace { struct KPKPosition { void from_index(int index); - int to_index() const; bool is_legal() const; bool is_immediate_draw() const; bool is_immediate_win() const; - Bitboard wk_attacks() const; - Bitboard bk_attacks() const; - Bitboard pawn_attacks() const; + Bitboard wk_attacks() const { return StepAttackBB[WK][whiteKingSquare]; } + Bitboard bk_attacks() const { return StepAttackBB[BK][blackKingSquare]; } + Bitboard pawn_attacks() const { return StepAttackBB[WP][pawnSquare]; } Square whiteKingSquare, blackKingSquare, pawnSquare; Color sideToMove; }; + const int IndexMax = 2 * 24 * 64 * 64; - Result *Bitbase; - const int IndexMax = 2*24*64*64; - int UnknownCount = 0; - - void initialize(); - bool next_iteration(); - Result classify_wtm(const KPKPosition &p); - Result classify_btm(const KPKPosition &p); + Result classify_wtm(const KPKPosition& pos, const Result bb[]); + Result classify_btm(const KPKPosition& pos, const Result bb[]); int compute_index(Square wksq, Square bksq, Square psq, Color stm); - int compress_result(Result r); - } @@ -78,273 +69,252 @@ namespace { //// void generate_kpk_bitbase(uint8_t bitbase[]) { - // Allocate array and initialize: - Bitbase = new Result[IndexMax]; - initialize(); - - // Iterate until all positions are classified: - while(next_iteration()); - // Compress bitbase into the supplied parameter: + bool repeat; int i, j, b; - for(i = 0; i < 24576; i++) { - for(b = 0, j = 0; j < 8; b |= (compress_result(Bitbase[8*i+j]) << j), j++); - assert(b == int(uint8_t(b))); - bitbase[i] = (uint8_t)b; + KPKPosition pos; + Result bb[IndexMax]; + + // Initialize table + for (i = 0; i < IndexMax; i++) + { + pos.from_index(i); + bb[i] = !pos.is_legal() ? RESULT_INVALID + : pos.is_immediate_draw() ? RESULT_DRAW + : pos.is_immediate_win() ? RESULT_WIN : RESULT_UNKNOWN; } - // Release allocated memory: - delete [] Bitbase; + // Iterate until all positions are classified (30 cycles needed) + do { + repeat = false; + + for (i = 0; i < IndexMax; i++) + if (bb[i] == RESULT_UNKNOWN) + { + pos.from_index(i); + + bb[i] = (pos.sideToMove == WHITE) ? classify_wtm(pos, bb) + : classify_btm(pos, bb); + if (bb[i] != RESULT_UNKNOWN) + repeat = true; + } + + } while (repeat); + + // Compress result and map into supplied bitbase parameter + for (i = 0; i < 24576; i++) + { + b = 0; + for (j = 0; j < 8; j++) + if (bb[8*i+j] == RESULT_WIN || bb[8*i+j] == RESULT_LOSS) + b |= (1 << j); + + bitbase[i] = (uint8_t)b; + } } namespace { + int compute_index(Square wksq, Square bksq, Square psq, Color stm) { + + int p = int(square_file(psq)) + (int(square_rank(psq)) - 1) * 4; + int r = int(stm) + 2 * int(bksq) + 128 * int(wksq) + 8192 * p; + + assert(r >= 0 && r < IndexMax); + + return r; + } + void KPKPosition::from_index(int index) { - int s; + + int s = (index / 8192) % 24; + sideToMove = Color(index % 2); blackKingSquare = Square((index / 2) % 64); whiteKingSquare = Square((index / 128) % 64); - s = (index / 8192) % 24; pawnSquare = make_square(File(s % 4), Rank(s / 4 + 1)); } - - int KPKPosition::to_index() const { - return compute_index(whiteKingSquare, blackKingSquare, pawnSquare, - sideToMove); - } - - bool KPKPosition::is_legal() const { - if(whiteKingSquare == pawnSquare || whiteKingSquare == blackKingSquare || - pawnSquare == blackKingSquare) - return false; - if(sideToMove == WHITE) { - if(bit_is_set(this->wk_attacks(), blackKingSquare)) - return false; - if(bit_is_set(this->pawn_attacks(), blackKingSquare)) + + if ( whiteKingSquare == pawnSquare + || whiteKingSquare == blackKingSquare + || pawnSquare == blackKingSquare) return false; + + if (sideToMove == WHITE) + { + if ( bit_is_set(wk_attacks(), blackKingSquare) + || bit_is_set(pawn_attacks(), blackKingSquare)) + return false; } - else { - if(bit_is_set(this->bk_attacks(), whiteKingSquare)) + else if (bit_is_set(bk_attacks(), whiteKingSquare)) return false; - } + return true; } - bool KPKPosition::is_immediate_draw() const { - if(sideToMove == BLACK) { - Bitboard wka = this->wk_attacks(); - Bitboard bka = this->bk_attacks(); - // Case 1: Stalemate - if((bka & ~(wka | this->pawn_attacks())) == EmptyBoardBB) - return true; + if (sideToMove == BLACK) + { + Bitboard wka = wk_attacks(); + Bitboard bka = bk_attacks(); - // Case 2: King can capture pawn - if(bit_is_set(bka, pawnSquare) && !bit_is_set(wka, pawnSquare)) - return true; + // Case 1: Stalemate + if ((bka & ~(wka | pawn_attacks())) == EmptyBoardBB) + return true; + + // Case 2: King can capture pawn + if (bit_is_set(bka, pawnSquare) && !bit_is_set(wka, pawnSquare)) + return true; } - else { - // Case 1: Stalemate - if(whiteKingSquare == SQ_A8 && pawnSquare == SQ_A7 && - (blackKingSquare == SQ_C7 || blackKingSquare == SQ_C8)) - return true; + else + { + // Case 1: Stalemate + if ( whiteKingSquare == SQ_A8 + && pawnSquare == SQ_A7 + && (blackKingSquare == SQ_C7 || blackKingSquare == SQ_C8)) + return true; } - return false; } - bool KPKPosition::is_immediate_win() const { - // The position is an immediate win if it is white to move and the white - // pawn can be promoted without getting captured: - return - sideToMove == WHITE && - square_rank(pawnSquare) == RANK_7 && - (square_distance(blackKingSquare, pawnSquare+DELTA_N) > 1 || - bit_is_set(this->wk_attacks(), pawnSquare+DELTA_N)); - } - - Bitboard KPKPosition::wk_attacks() const { - return StepAttackBB[WK][whiteKingSquare]; + // The position is an immediate win if it is white to move and the + // white pawn can be promoted without getting captured. + return sideToMove == WHITE + && square_rank(pawnSquare) == RANK_7 + && ( square_distance(blackKingSquare, pawnSquare + DELTA_N) > 1 + || bit_is_set(wk_attacks(), pawnSquare + DELTA_N)); } + Result classify_wtm(const KPKPosition& pos, const Result bb[]) { - Bitboard KPKPosition::bk_attacks() const { - return StepAttackBB[BK][blackKingSquare]; - } + // If one move leads to a position classified as RESULT_LOSS, the result + // of the current position is RESULT_WIN. If all moves lead to positions + // classified as RESULT_DRAW, the current position is classified RESULT_DRAW + // otherwise the current position is classified as RESULT_UNKNOWN. + bool unknownFound = false; + Bitboard b; + Square s; + int idx; - Bitboard KPKPosition::pawn_attacks() const { - return StepAttackBB[WP][pawnSquare]; - } + // King moves + b = pos.wk_attacks(); + while (b) + { + s = pop_1st_bit(&b); + idx = compute_index(s, pos.blackKingSquare, pos.pawnSquare, BLACK); + switch (bb[idx]) { - void initialize() { - KPKPosition p; - for(int i = 0; i < IndexMax; i++) { - p.from_index(i); - if(!p.is_legal()) - Bitbase[i] = RESULT_INVALID; - else if(p.is_immediate_draw()) - Bitbase[i] = RESULT_DRAW; - else if(p.is_immediate_win()) - Bitbase[i] = RESULT_WIN; - else { - Bitbase[i] = RESULT_UNKNOWN; - UnknownCount++; - } - } - } + case RESULT_LOSS: + return RESULT_WIN; + case RESULT_UNKNOWN: + unknownFound = true; - bool next_iteration() { - KPKPosition p; - int previousUnknownCount = UnknownCount; + case RESULT_DRAW: + case RESULT_INVALID: + break; - for(int i = 0; i < IndexMax; i++) - if(Bitbase[i] == RESULT_UNKNOWN) { - p.from_index(i); + default: + assert(false); + } + } - Bitbase[i] = (p.sideToMove == WHITE)? classify_wtm(p) : classify_btm(p); + // Pawn moves + if (square_rank(pos.pawnSquare) < RANK_7) + { + s = pos.pawnSquare + DELTA_N; + idx = compute_index(pos.whiteKingSquare, pos.blackKingSquare, s, BLACK); - if(Bitbase[i] == RESULT_WIN || Bitbase[i] == RESULT_LOSS || - Bitbase[i] == RESULT_DRAW) - UnknownCount--; - } + switch (bb[idx]) { - return UnknownCount != previousUnknownCount; - } + case RESULT_LOSS: + return RESULT_WIN; + case RESULT_UNKNOWN: + unknownFound = true; - Result classify_wtm(const KPKPosition &p) { + case RESULT_DRAW: + case RESULT_INVALID: + break; - // If one move leads to a position classified as RESULT_LOSS, the result - // of the current position is RESULT_WIN. If all moves lead to positions - // classified as RESULT_DRAW, the current position is classified as - // RESULT_DRAW. Otherwise, the current position is classified as - // RESULT_UNKNOWN. + default: + assert(false); + } - bool unknownFound = false; - Bitboard b; - Square s; + // Double pawn push + if ( square_rank(s) == RANK_3 + && s != pos.whiteKingSquare + && s != pos.blackKingSquare) + { + s += DELTA_N; + idx = compute_index(pos.whiteKingSquare, pos.blackKingSquare, s, BLACK); - // King moves - b = p.wk_attacks(); - while(b) { - s = pop_1st_bit(&b); - switch(Bitbase[compute_index(s, p.blackKingSquare, p.pawnSquare, - BLACK)]) { - case RESULT_LOSS: - return RESULT_WIN; - - case RESULT_UNKNOWN: - unknownFound = true; - break; - - case RESULT_DRAW: case RESULT_INVALID: - break; - - default: - assert(false); - } - } + switch (bb[idx]) { - // Pawn moves - if(square_rank(p.pawnSquare) < RANK_7) { - s = p.pawnSquare + DELTA_N; - switch(Bitbase[compute_index(p.whiteKingSquare, p.blackKingSquare, s, - BLACK)]) { - case RESULT_LOSS: - return RESULT_WIN; - - case RESULT_UNKNOWN: - unknownFound = true; - break; - - case RESULT_DRAW: case RESULT_INVALID: - break; - - default: - assert(false); - } - - if(square_rank(s) == RANK_3 && - s != p.whiteKingSquare && s != p.blackKingSquare) { - s += DELTA_N; - switch(Bitbase[compute_index(p.whiteKingSquare, p.blackKingSquare, s, - BLACK)]) { - case RESULT_LOSS: - return RESULT_WIN; + case RESULT_LOSS: + return RESULT_WIN; - case RESULT_UNKNOWN: - unknownFound = true; - break; + case RESULT_UNKNOWN: + unknownFound = true; - case RESULT_DRAW: case RESULT_INVALID: - break; + case RESULT_DRAW: + case RESULT_INVALID: + break; - default: - assert(false); + default: + assert(false); + } } - } } - - return unknownFound? RESULT_UNKNOWN : RESULT_DRAW; + return unknownFound ? RESULT_UNKNOWN : RESULT_DRAW; } - Result classify_btm(const KPKPosition &p) { + Result classify_btm(const KPKPosition& pos, const Result bb[]) { // If one move leads to a position classified as RESULT_DRAW, the result - // of the current position is RESULT_DRAW. If all moves lead to positions + // of the current position is RESULT_DRAW. If all moves lead to positions // classified as RESULT_WIN, the current position is classified as - // RESULT_LOSS. Otherwise, the current position is classified as + // RESULT_LOSS. Otherwise, the current position is classified as // RESULT_UNKNOWN. bool unknownFound = false; Bitboard b; Square s; + int idx; // King moves - b = p.bk_attacks(); - while(b) { - s = pop_1st_bit(&b); - switch(Bitbase[compute_index(p.whiteKingSquare, s, p.pawnSquare, - WHITE)]) { - case RESULT_DRAW: - return RESULT_DRAW; - - case RESULT_UNKNOWN: - unknownFound = true; - break; - - case RESULT_WIN: case RESULT_INVALID: - break; - - default: - assert(false); - } - } + b = pos.bk_attacks(); + while (b) + { + s = pop_1st_bit(&b); + idx = compute_index(pos.whiteKingSquare, s, pos.pawnSquare, WHITE); - return unknownFound? RESULT_UNKNOWN : RESULT_LOSS; - } + switch (bb[idx]) { + case RESULT_DRAW: + return RESULT_DRAW; - int compute_index(Square wksq, Square bksq, Square psq, Color stm) { - int p = int(square_file(psq)) + (int(square_rank(psq)) - 1) * 4; - int result = int(stm) + 2*int(bksq) + 128*int(wksq) + 8192*p; - assert(result >= 0 && result < IndexMax); - return result; - } + case RESULT_UNKNOWN: + unknownFound = true; + case RESULT_WIN: + case RESULT_INVALID: + break; - int compress_result(Result r) { - return (r == RESULT_WIN || r == RESULT_LOSS)? 1 : 0; + default: + assert(false); + } + } + return unknownFound ? RESULT_UNKNOWN : RESULT_LOSS; } } -- 2.39.2