Small code tidy up and test results

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 4d7195b3e2290905b6d325da28507adcd80ea718..4e5103f035fceb52253d00a739c701114999323a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -129,18 +129,17 @@ namespace {
   };
 
 
-  /// Constants and variables
+  /// Constants and variables initialized from UCI options
 
   // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV
-  // nodes:
-  int LMRPVMoves = 15;
-  int LMRNonPVMoves = 4;
+  // nodes
+  int LMRPVMoves, LMRNonPVMoves;
 
-  // Depth limit for use of dynamic threat detection:
-  Depth ThreatDepth = 5*OnePly;
+  // Depth limit for use of dynamic threat detection
+  Depth ThreatDepth;
 
-  // Depth limit for selective search:
-  Depth SelectiveDepth = 7*OnePly;
+  // Depth limit for selective search
+  Depth SelectiveDepth;
 
   // Use internal iterative deepening?
   const bool UseIIDAtPVNodes = true;
@@ -177,33 +176,34 @@ namespace {
   const bool PruneBlockingMoves = false;
 
   // Use futility pruning?
-  bool UseQSearchFutilityPruning = true;
-  bool UseFutilityPruning = true;
+  bool UseQSearchFutilityPruning, UseFutilityPruning;
 
   // Margins for futility pruning in the quiescence search, and at frontier
   // and near frontier nodes
-  Value FutilityMarginQS = Value(0x80);
-  Value FutilityMargins[6] = { Value(0x100), Value(0x200), Value(0x250),
-                               Value(0x2A0), Value(0x340), Value(0x3A0) };
+  const Value FutilityMarginQS = Value(0x80);
 
-  // Razoring
-  const bool RazorAtDepthOne = false;
-  Depth RazorDepth = 4*OnePly;
-  Value RazorMargin = Value(0x300);
+   // Remaining depth:                  1 ply         1.5 ply       2 ply         2.5 ply       3 ply         3.5 ply
+   const Value FutilityMargins[12] = { Value(0x100), Value(0x120), Value(0x200), Value(0x220), Value(0x250), Value(0x270),
+  //                                   4 ply         4.5 ply       5 ply         5.5 ply       6 ply         6.5 ply
+                                      Value(0x2A0), Value(0x2C0), Value(0x340), Value(0x360), Value(0x3A0), Value(0x3C0) };
+   // Razoring
+   const Depth RazorDepth = 4*OnePly;
+
+  // Remaining depth:                 1 ply         1.5 ply       2 ply         2.5 ply       3 ply         3.5 ply
+  const Value RazorMargins[6]     = { Value(0x180), Value(0x300), Value(0x300), Value(0x3C0), Value(0x3C0), Value(0x3C0) };
+
+  // Remaining depth:                 1 ply         1.5 ply       2 ply         2.5 ply       3 ply         3.5 ply
+   const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
 
   // Last seconds noise filtering (LSN)
-  bool UseLSNFiltering = false;
+  bool UseLSNFiltering;
   bool looseOnTime = false;
-  int LSNTime = 4 * 1000; // In milliseconds
-  Value LSNValue = Value(0x200);
+  int LSNTime; // In milliseconds
+  Value LSNValue;
 
-  // Extensions.  Array index 0 is used at non-PV nodes, index 1 at PV nodes.
-  Depth CheckExtension[2] = {OnePly, OnePly};
-  Depth SingleReplyExtension[2] = {OnePly / 2, OnePly / 2};
-  Depth PawnPushTo7thExtension[2] = {OnePly / 2, OnePly / 2};
-  Depth PassedPawnExtension[2] = {Depth(0), Depth(0)};
-  Depth PawnEndgameExtension[2] = {OnePly, OnePly};
-  Depth MateThreatExtension[2] = {Depth(0), Depth(0)};
+  // Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes.
+  Depth CheckExtension[2], SingleReplyExtension[2], PawnPushTo7thExtension[2];
+  Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2];
 
   // Search depth at iteration 1
   const Depth InitialDepth = OnePly /*+ OnePly/2*/;
@@ -221,7 +221,7 @@ namespace {
   int BestMoveChangesByIteration[PLY_MAX_PLUS_2];
 
   // MultiPV mode
-  int MultiPV = 1;
+  int MultiPV;
 
   // Time managment variables
   int SearchStartTime;
@@ -241,15 +241,15 @@ namespace {
   int ExactMaxTime;
 
   // Show current line?
-  bool ShowCurrentLine = false;
+  bool ShowCurrentLine;
 
   // Log file
-  bool UseLogFile = false;
+  bool UseLogFile;
   std::ofstream LogFile;
 
   // MP related variables
-  Depth MinimumSplitDepth = 4*OnePly;
-  int MaxThreadsPerSplitPoint = 4;
+  Depth MinimumSplitDepth;
+  int MaxThreadsPerSplitPoint;
   Thread Threads[THREAD_MAX];
   Lock MPLock;
   bool AllThreadsShouldExit = false;
@@ -443,14 +443,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move,
   UseQSearchFutilityPruning = get_option_value_bool("Futility Pruning (Quiescence Search)");
   UseFutilityPruning = get_option_value_bool("Futility Pruning (Main Search)");
 
-  FutilityMarginQS = value_from_centipawns(get_option_value_int("Futility Margin (Quiescence Search)"));
-  int fmScale = get_option_value_int("Futility Margin Scale Factor (Main Search)");
-  for (int i = 0; i < 6; i++)
-      FutilityMargins[i] = (FutilityMargins[i] * fmScale) / 100;
-
-  RazorDepth = (get_option_value_int("Maximum Razoring Depth") + 1) * OnePly;
-  RazorMargin = value_from_centipawns(get_option_value_int("Razoring Margin"));
-
   UseLSNFiltering = get_option_value_bool("LSN filtering");
   LSNTime = get_option_value_int("LSN Time Margin (sec)") * 1000;
   LSNValue = value_from_centipawns(get_option_value_int("LSN Value Margin"));
@@ -1316,17 +1308,14 @@ namespace {
     }
     // Null move search not allowed, try razoring
     else if (   !value_is_mate(beta)
-             && approximateEval < beta - RazorMargin
              && depth < RazorDepth
-             && (RazorAtDepthOne || depth > OnePly)
+             && approximateEval < beta - RazorApprMargins[int(depth) - 2]
              && ttMove == MOVE_NONE
              && !pos.has_pawn_on_7th(pos.side_to_move()))
     {
         Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID);
-        if (   (v < beta - RazorMargin - RazorMargin / 4)
-            || (depth <= 2*OnePly && v < beta - RazorMargin)
-            || (depth <=   OnePly && v < beta - RazorMargin / 2))
-            return v;
+        if (v < beta - RazorMargins[int(depth) - 2])
+          return v;
     }
 
     // Go with internal iterative deepening if we don't have a TT move
@@ -1385,8 +1374,7 @@ namespace {
           {
               if (futilityValue == VALUE_NONE)
                   futilityValue =  evaluate(pos, ei, threadID)
-                                 + FutilityMargins[int(depth)/2 - 1]
-                                 + 32 * (depth & 1);
+                                 + FutilityMargins[int(depth) - 2];
 
               if (futilityValue < beta)
               {