Commit 7f96ca101a

@@ -1455,6 +1455,10 @@ fn airOverflow(self: *Self, inst: Air.Inst.Index) !void {
                         }
                     };
 
+                    if (tag == .sub_with_overflow) {
+                        break :result MCValue{ .register_v_flag = dest.register };
+                    }
+
                     switch (int_info.signedness) {
                         .unsigned => break :result MCValue{ .register_c_flag = dest.register },
                         .signed => break :result MCValue{ .register_v_flag = dest.register },