From 4a71dc3e4c7cd8ac65c2ee11d9553fa45d9ada5f Mon Sep 17 00:00:00 2001
From: Thomas Debesse <dev@illwieckz.net>
Date: Thu, 5 Dec 2024 08:56:31 +0100
Subject: [PATCH] System: add common.floatExceptions.test to test floating
 point exceptions

---
 src/engine/framework/System.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/engine/framework/System.cpp b/src/engine/framework/System.cpp
index a863dcbce4..cb98778339 100644
--- a/src/engine/framework/System.cpp
+++ b/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 exception",
+		Cvar::INIT, false);
 #endif
 
 namespace Sys {
@@ -436,6 +439,27 @@ static void SetFloatingPointExceptions()
 			unsigned int current;
 			_controlfp_s(&current, exceptions, _MCW_EM);
 		#endif
+
+		if (common_floatExceptions_test.Get())
+		{
+			Log::Warn("Testing of floating point exceptions:");
+
+			{
+				volatile float f = -1.0f;
+				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("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("Computing 2×%.0f…", static_cast<float>(f));
+				Log::Warn("Result of 2×%.0f: %.0f", static_cast<float>(f), 2*f);
+			}
+		}
 	#endif
 }