https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65400
--- Comment #5 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- Created attachment 35033 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35033&action=edit stripped down second test case For completeness, here is the stripped down test case for the tail call flag. It reproduces with current trunk and: [-O2|-Os] -fsanitize=treand[,undefined] not with -O1 and not with -O3, and not in january either :)