https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80147
--- Comment #5 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- (In reply to Andrew Pinski from comment #4) > For that example you need -ftrapping-math (which may or may not be enabled > by default soon). The man page says: "The default is -ftrapping-math." But even when given explicitly, no warnings are generated. Anyway, for the integer case, 0 / 0 is undefined behavior, so that warnings are expected to make sure that one doesn't get undefined behavior.