Better value clipping in game_phase()

No functional change.

diff --git a/src/position.cpp b/src/position.cpp
index e2a59e5df3b44eee261e530261a1134bd3ea738f..bdbfea8017583fe3b8ca432738bc54a6dec886af 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -465,15 +465,16 @@ const string Position::pretty(Move m) const {
 }
 
 
 }
 
 

-/// Position::game_phase() calculates the game phase of the position
+/// Position::game_phase() calculates the game phase interpolating total non-pawn
+/// material between endgame and midgame limits.

 
 Phase Position::game_phase() const {
 
   Value npm = st->npMaterial[WHITE] + st->npMaterial[BLACK];
 
 
 Phase Position::game_phase() const {
 
   Value npm = st->npMaterial[WHITE] + st->npMaterial[BLACK];
 

-  return  npm >= MidgameLimit ? PHASE_MIDGAME
-        : npm <= EndgameLimit ? PHASE_ENDGAME
-        : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
+  npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
+
+  return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));

 }
 
 
 }