From a7f4ee75406fc93bc0db6711204511a52d35166a Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 16 Oct 2010 11:24:03 +0100 Subject: [PATCH] Unify sp_search() and search() step 3 Remove old sp_search() code. No functional change. Signed-off-by: Marco Costalba --- src/search.cpp | 163 +------------------------------------------------ 1 file changed, 2 insertions(+), 161 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 723d1ba9..64b8dd0e 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -292,9 +292,6 @@ namespace { return search(pos, ss, alpha, beta, depth, ply); } - template - void sp_search(Position& pos, SearchStack* ss, Value dumy, Value beta, Depth depth, int ply); - template Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); @@ -1185,6 +1182,7 @@ namespace { split_start: // Initialize a MovePicker object for the current position + // FIXME currently MovePicker() c'tor is needless called also in SplitPoint MovePicker mpBase = MovePicker(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); MovePicker& mp = SplitPoint ? *ss->sp->mp : mpBase; CheckInfo ci(pos); @@ -1288,7 +1286,7 @@ split_start: { lock_grab(&(ss->sp->lock)); if (futilityValueScaled > ss->sp->bestValue) - ss->sp->bestValue = futilityValueScaled; + ss->sp->bestValue = bestValue = futilityValueScaled; } else if (futilityValueScaled > bestValue) bestValue = futilityValueScaled; @@ -1638,163 +1636,6 @@ split_start: search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->ply); } - template - void sp_search(Position& pos, SearchStack* ss, Value, Value beta, Depth depth, int ply) { - - StateInfo st; - Move move; - Depth ext, newDepth; - Value value; - Value futilityValueScaled; // NonPV specific - bool isCheck, moveIsCheck, captureOrPromotion, dangerous; - int moveCount; - value = -VALUE_INFINITE; - SplitPoint* sp = ss->sp; - Move threatMove = sp->threatMove; - MovePicker& mp = *sp->mp; - int threadID = pos.thread(); - - CheckInfo ci(pos); - isCheck = pos.is_check(); - - // Step 10. Loop through moves - // Loop through all legal moves until no moves remain or a beta cutoff occurs - lock_grab(&(sp->lock)); - - while ( sp->bestValue < beta - && (move = mp.get_next_move()) != MOVE_NONE - && !ThreadsMgr.thread_should_stop(threadID)) - { - moveCount = ++sp->moveCount; - lock_release(&(sp->lock)); - - assert(move_is_ok(move)); - - moveIsCheck = pos.move_is_check(move, ci); - captureOrPromotion = pos.move_is_capture_or_promotion(move); - - // Step 11. Decide the new search depth - ext = extension(pos, move, captureOrPromotion, moveIsCheck, false, sp->mateThreat, &dangerous); - newDepth = depth - ONE_PLY + ext; - - // Update current move - ss->currentMove = move; - - // Step 12. Futility pruning (is omitted in PV nodes) - if ( !PvNode - && !captureOrPromotion - && !isCheck - && !dangerous - && !move_is_castle(move)) - { - // Move count based pruning - if ( moveCount >= futility_move_count(depth) - && !(threatMove && connected_threat(pos, move, threatMove)) - && sp->bestValue > value_mated_in(PLY_MAX)) - { - lock_grab(&(sp->lock)); - continue; - } - - // Value based pruning - Depth predictedDepth = newDepth - reduction(depth, moveCount); - futilityValueScaled = ss->eval + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_on(move_from(move)), move_to(move)); - - if (futilityValueScaled < beta) - { - lock_grab(&(sp->lock)); - - if (futilityValueScaled > sp->bestValue) - sp->bestValue = futilityValueScaled; - continue; - } - } - - // Step 13. Make the move - pos.do_move(move, st, ci, moveIsCheck); - - // Step 14. Reduced search - // If the move fails high will be re-searched at full depth. - bool doFullDepthSearch = true; - - if ( !captureOrPromotion - && !dangerous - && !move_is_castle(move) - && !move_is_killer(move, ss)) - { - ss->reduction = reduction(depth, moveCount); - if (ss->reduction) - { - Value localAlpha = sp->alpha; - Depth d = newDepth - ss->reduction; - value = d < ONE_PLY ? -qsearch(pos, ss+1, -(localAlpha+1), -localAlpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -(localAlpha+1), -localAlpha, d, ply+1); - - doFullDepthSearch = (value > localAlpha); - } - - // The move failed high, but if reduction is very big we could - // face a false positive, retry with a less aggressive reduction, - // if the move fails high again then go with full depth search. - if (doFullDepthSearch && ss->reduction > 2 * ONE_PLY) - { - assert(newDepth - ONE_PLY >= ONE_PLY); - - ss->reduction = ONE_PLY; - Value localAlpha = sp->alpha; - value = -search(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth-ss->reduction, ply+1); - doFullDepthSearch = (value > localAlpha); - } - ss->reduction = DEPTH_ZERO; // Restore original reduction - } - - // Step 15. Full depth search - if (doFullDepthSearch) - { - Value localAlpha = sp->alpha; - value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(localAlpha+1), -localAlpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth, ply+1); - - // Step extra. pv search (only in PV nodes) - // Search only for possible new PV nodes, if instead value >= beta then - // parent node fails low with value <= alpha and tries another move. - if (PvNode && value > localAlpha && value < beta) - value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -sp->alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -beta, -sp->alpha, newDepth, ply+1); - } - - // Step 16. Undo move - pos.undo_move(move); - - assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); - - // Step 17. Check for new best move - lock_grab(&(sp->lock)); - - if (value > sp->bestValue && !ThreadsMgr.thread_should_stop(threadID)) - { - sp->bestValue = value; - if (value > sp->alpha) - { - if (!PvNode || value >= beta) - sp->stopRequest = true; - - if (PvNode && value < beta) // We want always sp->alpha < beta - sp->alpha = value; - - sp->parentSstack->bestMove = ss->bestMove = move; - } - } - } - - /* Here we have the lock still grabbed */ - - sp->slaves[threadID] = 0; - - lock_release(&(sp->lock)); - } - // connected_moves() tests whether two moves are 'connected' in the sense // that the first move somehow made the second move possible (for instance -- 2.39.2