From b4a04d80385d76bb701f6727b0150889ec437723 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Tue, 2 Jun 2009 10:20:41 +0100 Subject: [PATCH] Use one History table per thread This reduces contention and reduce history trashing effect especially at high search depths. No functional change for single CPU case. After 999 games at 1+0 on Dual Core Intel we have Mod vs Orig +233 =526 -240 -2 ELO We need to test at longer time controls and possibly with a QUAD where we could foreseen an improvment. Signed-off-by: Marco Costalba --- src/search.cpp | 29 ++++++++++++++--------------- src/thread.h | 2 ++ 2 files changed, 16 insertions(+), 15 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index cc2a0613..d8c0c7dd 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -207,9 +207,6 @@ namespace { // Search depth at iteration 1 const Depth InitialDepth = OnePly /*+ OnePly/2*/; - // History tables - History H; - // Node counters int NodesSincePoll; int NodesBetweenPolls = 30000; @@ -284,10 +281,10 @@ namespace { bool move_is_killer(Move m, const SearchStack& ss); Depth extension(const Position &pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous); bool ok_to_do_nullmove(const Position &pos); - bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d); + bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d, const History& H); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); bool ok_to_history(const Position &pos, Move m); - void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount); + void update_history(const Position& pos, Move m, Depth depth, History& H, Move movesSearched[], int moveCount); void update_killers(Move m, SearchStack& ss); bool fail_high_ply_1(); @@ -645,7 +642,9 @@ namespace { // Initialize TT.new_search(); - H.clear(); + for (int i = 0; i < THREAD_MAX; i++) + Threads[i].H.clear(); + for (int i = 0; i < 3; i++) { ss[i].init(i); @@ -1057,7 +1056,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search all moves - MovePicker mp = MovePicker(pos, true, ttMove, depth, H, &ss[ply]); + MovePicker mp = MovePicker(pos, true, ttMove, depth, Threads[threadID].H, &ss[ply]); Move move, movesSearched[256]; int moveCount = 0; @@ -1186,7 +1185,7 @@ namespace { Move m = ss[ply].pv[ply]; if (ok_to_history(pos, m)) // Only non capture moves are considered { - update_history(pos, m, depth, movesSearched, moveCount); + update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount); update_killers(m, ss[ply]); } TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m); @@ -1318,7 +1317,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search all moves: - MovePicker mp = MovePicker(pos, false, ttMove, depth, H, &ss[ply]); + MovePicker mp = MovePicker(pos, false, ttMove, depth, Threads[threadID].H, &ss[ply]); Move move, movesSearched[256]; int moveCount = 0; @@ -1356,7 +1355,7 @@ namespace { { // History pruning. See ok_to_prune() definition if ( moveCount >= 2 + int(depth) - && ok_to_prune(pos, move, ss[ply].threatMove, depth)) + && ok_to_prune(pos, move, ss[ply].threatMove, depth, Threads[threadID].H)) continue; // Value based pruning @@ -1446,7 +1445,7 @@ namespace { Move m = ss[ply].pv[ply]; if (ok_to_history(pos, m)) // Only non capture moves are considered { - update_history(pos, m, depth, movesSearched, moveCount); + update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount); update_killers(m, ss[ply]); } TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m); @@ -1539,7 +1538,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth == 0) will be generated. - MovePicker mp = MovePicker(pos, pvNode, ttMove, depth, H); + MovePicker mp = MovePicker(pos, pvNode, ttMove, depth, Threads[threadID].H); Move move; int moveCount = 0; Bitboard dcCandidates = mp.discovered_check_candidates(); @@ -1682,7 +1681,7 @@ namespace { && !moveIsCapture && !move_promotion(move) && moveCount >= 2 + int(sp->depth) - && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)) + && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth, Threads[threadID].H)) continue; // Make and search the move. @@ -2290,7 +2289,7 @@ namespace { // non-tactical moves late in the move list close to the leaves are // candidates for pruning. - bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d) { + bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d, const History& H) { Square mfrom, mto, tfrom, tto; assert(move_is_ok(m)); @@ -2369,7 +2368,7 @@ namespace { // update_history() registers a good move that produced a beta-cutoff // in history and marks as failures all the other moves of that ply. - void update_history(const Position& pos, Move m, Depth depth, + void update_history(const Position& pos, Move m, Depth depth, History& H, Move movesSearched[], int moveCount) { H.success(pos.piece_on(move_from(m)), move_to(m), depth); diff --git a/src/thread.h b/src/thread.h index dc839d44..558a6752 100644 --- a/src/thread.h +++ b/src/thread.h @@ -26,6 +26,7 @@ //// Includes //// +#include "history.h" #include "lock.h" #include "movepick.h" #include "position.h" @@ -73,6 +74,7 @@ struct Thread { volatile bool idle; volatile bool workIsWaiting; volatile bool printCurrentLine; + History H; unsigned char pad[64]; // set some distance among local data for each thread }; -- 2.39.2