use cmake everywhere for desktop build, fix build warnings

src/decn/decn.c

@@ -467,6 +467,7 @@ static int8_t compare_magn(void){ //returns a<b: -1, a==b: 0, a>b: 1
 	return a_signif_b;
 }
 
+#ifdef USE_COMPARE_DECN
 static int8_t compare_decn(void){ //returns a<b: -1, a==b: 0, a>b: 1
 	int8_t is_neg;
 
@@ -497,6 +498,7 @@ static int8_t compare_decn(void){ //returns a<b: -1, a==b: 0, a>b: 1
 
 	return is_neg * compare_magn();
 }
+#endif //USE_COMPARE_DECN
 
 //WARNING: for add_decn() and sub_mag() functions only
 //acc and the number from which exponent was taken MUST be stripped of leading 0s first

src/decn/proto/CMakeLists.txt

@@ -0,0 +1,9 @@
+
+add_executable(div div_mfp.cpp)
+target_link_libraries(div gmp)
+
+add_executable(ln ln_mfp.cpp)
+target_link_libraries(ln mpfr)
+
+add_executable(exp exp.cpp)
+target_link_libraries(exp mpfr)

src/decn/proto/Makefile

@@ -1,10 +0,0 @@
-all: div ln exp
-
-div: div_mfp.cpp
-	g++ -Wall div_mfp.cpp -o div -lgmp
-
-ln: ln_mfp.cpp
-	g++ -Wall ln_mfp.cpp -o ln -lmpfr
-
-exp: exp.cpp
-	g++ -Wall exp.cpp -o exp -lmpfr