X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=7a8d3253048d2db2d7595493cb242692970f6d57;hp=176006fcc1073ea837b04b27dcdcc8d3ace22e0e;hb=62937d1007e0f97e629f376adca4f4ad738e95d1;hpb=759b3c79cf94d101163f646b1eb2a9f9c64293ab diff --git a/src/search.cpp b/src/search.cpp index 176006fc..7a8d3253 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -31,8 +31,8 @@ #include "movepick.h" #include "position.h" #include "search.h" -#include "timeman.h" #include "thread.h" +#include "timeman.h" #include "tt.h" #include "uci.h" #include "syzygy/tbprobe.h" @@ -67,8 +67,7 @@ namespace { constexpr int SkipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 }; // Razor and futility margins - constexpr int RazorMargin1 = 590; - constexpr int RazorMargin2 = 604; + constexpr int RazorMargin[] = {0, 590, 604}; Value futility_margin(Depth d, bool improving) { return Value((175 - 50 * improving) * d / ONE_PLY); } @@ -690,21 +689,13 @@ namespace { // Step 7. Razoring (skipped when in check) if ( !PvNode - && depth <= 2 * ONE_PLY) + && depth < 3 * ONE_PLY + && eval <= alpha - RazorMargin[depth / ONE_PLY]) { - if ( depth == ONE_PLY - && eval + RazorMargin1 <= alpha) - return qsearch(pos, ss, alpha, alpha+1); - - else if (eval + RazorMargin2 <= alpha) - { - Value ralpha = alpha - RazorMargin2; - - Value v = qsearch(pos, ss, ralpha, ralpha+1); - - if (v <= ralpha) - return v; - } + Value ralpha = alpha - (depth >= 2 * ONE_PLY) * RazorMargin[depth / ONE_PLY]; + Value v = qsearch(pos, ss, ralpha, ralpha+1); + if (depth < 2 * ONE_PLY || v <= ralpha) + return v; } // Step 8. Futility pruning: child node (skipped when in check) @@ -800,7 +791,7 @@ namespace { // Step 11. Internal iterative deepening (skipped when in check) if ( depth >= 6 * ONE_PLY && !ttMove - && (PvNode || ss->staticEval + 256 >= beta)) + && (PvNode || ss->staticEval + 128 >= beta)) { Depth d = 3 * depth / 4 - 2 * ONE_PLY; search(pos, ss, alpha, beta, d, cutNode, true); @@ -1157,7 +1148,6 @@ moves_loop: // When in check, search starts from here Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) { constexpr bool PvNode = NT == PV; - const bool inCheck = bool(pos.checkers()); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); @@ -1171,7 +1161,7 @@ moves_loop: // When in check, search starts from here Move ttMove, move, bestMove; Depth ttDepth; Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha; - bool ttHit, givesCheck, evasionPrunable; + bool ttHit, inCheck, givesCheck, evasionPrunable; int moveCount; if (PvNode) @@ -1183,6 +1173,7 @@ moves_loop: // When in check, search starts from here (ss+1)->ply = ss->ply + 1; ss->currentMove = bestMove = MOVE_NONE; + inCheck = pos.checkers(); moveCount = 0; // Check for an immediate draw or maximum ply reached