--- nono/exp/optestm88k/optestm88k_gen.cpp	2026/04/29 17:05:09	1.1.1.4
+++ nono/exp/optestm88k/optestm88k_gen.cpp	2026/04/29 17:05:16	1.1.1.5
@@ -347,7 +347,7 @@ setround(uint32 rm)
 		mode = FE_UPWARD;
 		break;
 	 default:
-		__unreachable();
+		PANIC("corrupted rm=%d", rm);
 	}
 	std::fesetround(mode);
 }