https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94770
--- Comment #4 from Bence Szabó <sbence92 at gmail dot com> --- As a remark for 'same code with -std=c++14 and -std=c++17 here', I can confirm, the example you provided also produces same assembly for me in c++14 and c++17. Also compiling t032 with only c++14 or only c++17 still results in a failing test case (30.71) and then a crash. Maybe this is not the same abi problem?