diff --git a/src/Makefile b/src/Makefile
index b23d671f..7ddb643c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -231,7 +231,7 @@ ifeq ($(COMP),clang)
 endif
 
 ### 3.2 General compiler settings
-CXXFLAGS = -g -Wall -Wcast-qual -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
+CXXFLAGS = -Wall -Wcast-qual -fno-exceptions -fno-rtti $(EXTRACXXFLAGS)
 
 ifeq ($(comp),gcc)
 	CXXFLAGS += -ansi -pedantic -Wno-long-long -Wextra -Wshadow
@@ -275,6 +275,8 @@ endif
 ### 3.4 Debugging
 ifeq ($(debug),no)
 	CXXFLAGS += -DNDEBUG
+else
+	CXXFLAGS += -g 
 endif
 
 ### 3.5 Optimization
@@ -354,6 +356,7 @@ endif
 ### needs access to the optimization flags.
 ifeq ($(comp),gcc)
 	ifeq ($(optimize),yes)
+	ifeq ($(debug),no)
 		GCC_MAJOR := `$(CXX) -dumpversion | cut -f1 -d.`
 		GCC_MINOR := `$(CXX) -dumpversion | cut -f2 -d.`
 		ifeq (1,$(shell expr \( $(GCC_MAJOR) \> 4 \) \| \( $(GCC_MAJOR) \= 4 \& $(GCC_MINOR) \>= 5 \)))
@@ -361,6 +364,7 @@ ifeq ($(comp),gcc)
 			LDFLAGS += $(CXXFLAGS)
 		endif
 	endif
+	endif
 endif
 
 ### ==========================================================================
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 68984802..c5af2f89 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -821,7 +821,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
                 // If there is an enemy rook or queen attacking the pawn from behind,
                 // add all X-ray attacks by the rook or queen. Otherwise consider only
                 // the squares in the pawn's path attacked or occupied by the enemy.
-                if (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s))
+                if (   (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN)) // Unlikely
+                    && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
                     unsafeSquares = squaresToQueen;
                 else
                     unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));