second modify PI

fx_s2308_double.h

@@ -10,7 +10,7 @@ typedef double fx_s2308;
 #define FX_MUL(a,b) DOUBLE_TO_FX(FX_TO_DOUBLE(a)*FX_TO_DOUBLE(b))
 #define FX_DIV(a,b) DOUBLE_TO_FX(FX_TO_DOUBLE(a)/FX_TO_DOUBLE(b))
 
-#define FX_PI DOUBLE_TO_FX(M_PI)
+#define FX_PI (DOUBLE_TO_FX(M_PI))
 
 fx_s2308 fx_sine(fx_s2308 a);
 fx_s2308 fx_sqrt(fx_s2308 a);