From f9d3b48ad0ed62732bb07d4811f4fd17cf088cfe Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 10 Apr 2010 16:40:03 +0100 Subject: [PATCH] Introduce "Zugzwang detection" temporary hack for 1.7.1 Add an UCI option "Zugzwang detection" OFF by default that enables correct detection of zugzwang. This is just to let 1.7.1 be 100% compatible with 1.7 and should be removed after release. Verified 100% functional equivalent to 1.7 Signed-off-by: Marco Costalba --- src/search.cpp | 5 +++-- src/ucioption.cpp | 3 +++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 3f843641..0fa78248 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -257,7 +257,7 @@ namespace { int SearchStartTime, MaxNodes, MaxDepth, MaxSearchTime; int AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime; bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit; - bool FirstRootMove, AbortSearch, Quit, AspirationFailLow; + bool FirstRootMove, AbortSearch, Quit, AspirationFailLow, ZugDetection; // Log file bool UseLogFile; @@ -425,6 +425,7 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, MultiPV = get_option_value_int("MultiPV"); Chess960 = get_option_value_bool("UCI_Chess960"); UseLogFile = get_option_value_bool("Use Search Log"); + ZugDetection = get_option_value_bool("Zugzwang detection"); // To be removed after 1.7.1 if (UseLogFile) LogFile.open(get_option_value_string("Search Log Filename").c_str(), std::ios::out | std::ios::app); @@ -2315,7 +2316,7 @@ namespace { Value v = value_from_tt(tte->value(), ply); - return (allowNullmove || !(tte->type() & VALUE_TYPE_NULL)) + return (allowNullmove || !(tte->type() & VALUE_TYPE_NULL) || !ZugDetection) && ( tte->depth() >= depth || v >= Max(value_mate_in(PLY_MAX), beta) diff --git a/src/ucioption.cpp b/src/ucioption.cpp index af568a37..154e1410 100644 --- a/src/ucioption.cpp +++ b/src/ucioption.cpp @@ -113,6 +113,9 @@ namespace { o["UCI_Chess960"] = Option(false); o["UCI_AnalyseMode"] = Option(false); + // Temporary hack for 1.7.1 to be removed in next release + o["Zugzwang detection"] = Option(false); + // Any option should know its name so to be easily printed for (Options::iterator it = o.begin(); it != o.end(); ++it) it->second.name = it->first; -- 2.39.2