Apparently there's some poor branch prediction behavior with various gcc versions. Apply tweak from v3 in assert_glerror().

indra/llrender/llgl.cpp

@@ -1465,19 +1465,29 @@ void do_assert_glerror()
 
 void assert_glerror()
 {
-	if (gNoRender)
+	if(!gNoRender)
+	{}
+	else
+	{
 		return;
+	}
 	if (!gGLActive)
 	{
 		//LL_WARNS() << "GL used while not active!" << LL_ENDL;
-
-		if (gDebugSession)
+		
+		if (!gDebugSession)
+		{}
+		else
 		{
 			//ll_fail("GL used while not active");
 		}
 	}
 
-	if (gDebugGL) 
+	if (!gDebugGL) 
+	{
+		//funny looking if for branch prediction -- gDebugGL is almost always false and assert_glerror is called often
+	}
+	else
 	{
 		do_assert_glerror();
 	}