System: add common.floatExceptions.test to test floating point exceptions

Author: illwieckz

src/engine/framework/System.cpp

@@ -71,6 +71,9 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 	static Cvar::Cvar<bool> common_floatExceptions_overflow("common.floatExceptions.overflow",
 		"enable floating point exception for operation producing an overflow",
 		Cvar::INIT, false);
+	static Cvar::Cvar<bool> common_floatExceptions_test("common.floatExceptions.test",
+		"test floating point exceptions",
+		Cvar::INIT, false);
 #endif
 
 namespace Sys {
@@ -436,6 +439,28 @@ static void SetFloatingPointExceptions()
 		unsigned int current;
 		_controlfp_s(&current, exceptions, _MCW_EM);
 	#endif
+
+	if (common_floatExceptions_test.Get())
+	{
+		{
+			volatile float f = -1.0f;
+			Log::Warn("Testing of INVALID floating point exception.");
+			Log::Warn("Computing √%.0f…", static_cast<float>(f));
+			Log::Warn("Result of √%.0f: %.0f", static_cast<float>(f), sqrt(f));
+		}
+		{
+			volatile float f = 0.0f;
+			Log::Warn("Testing of DIVBYZERO floating point exception.");
+			Log::Warn("Computing 1÷%.0f…", static_cast<float>(f));
+			Log::Warn("Result of 1÷%.0f: %.0f", static_cast<float>(f), 1/f);
+		}
+		{
+			volatile float f = std::numeric_limits<float>::max();
+			Log::Warn("Testing of OVERFLOW floating point exception.");
+			Log::Warn("Computing 2×%.0f…", static_cast<float>(f));
+			Log::Warn("Result of 2×%.0f: %.0f", static_cast<float>(f), 2*f);
+		}
+	}
 #endif
 }