Mark all compile-time constants as constexpr.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index bf34b77e5d8bd7f8ccbe0177fe4d2ae3da6e5038..176006fcc1073ea837b04b27dcdcc8d3ace22e0e 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -63,12 +63,12 @@ namespace {
   enum NodeType { NonPV, PV };
 
   // Sizes and phases of the skip-blocks, used for distributing search depths across the threads
-  const int SkipSize[]  = { 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 };
-  const int SkipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 };
+  constexpr int SkipSize[]  = { 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4 };
+  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
-  const int RazorMargin1 = 590;
-  const int RazorMargin2 = 604;
+  constexpr int RazorMargin1 = 590;
+  constexpr int RazorMargin2 = 604;
   Value futility_margin(Depth d, bool improving) {
     return Value((175 - 50 * improving) * d / ONE_PLY);
   }
@@ -455,12 +455,12 @@ void Thread::search() {
                      timeReduction *= 1.25;
 
               // Use part of the gained time from a previous stable move for the current move
-              double unstablePvFactor = 1.0 + mainThread->bestMoveChanges;
-              unstablePvFactor *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
+              double bestMoveInstability = 1.0 + mainThread->bestMoveChanges;
+              bestMoveInstability *= std::pow(mainThread->previousTimeReduction, 0.528) / timeReduction;
 
               // Stop the search if we have only one legal move, or if available time elapsed
               if (   rootMoves.size() == 1
-                  || Time.elapsed() > Time.optimum() * unstablePvFactor * improvingFactor / 581)
+                  || Time.elapsed() > Time.optimum() * bestMoveInstability * improvingFactor / 581)
               {
                   // If we are allowed to ponder do not stop the search now but
                   // keep pondering until the GUI sends "ponderhit" or "stop".
@@ -495,7 +495,7 @@ namespace {
     if (depth < ONE_PLY)
         return qsearch<NT>(pos, ss, alpha, beta);
 
-    const bool PvNode = NT == PV;
+    constexpr bool PvNode = NT == PV;
     const bool rootNode = PvNode && ss->ply == 0;
 
     assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE);
@@ -1156,7 +1156,7 @@ moves_loop: // When in check, search starts from here
   template <NodeType NT>
   Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
 
-    const bool PvNode = NT == PV;
+    constexpr bool PvNode = NT == PV;
     const bool inCheck = bool(pos.checkers());
 
     assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);