https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81278
--- Comment #6 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #5) > The bisection looks weird, that is the point before which the unreduced > testcase obviously will fail to compile, but that doesn't mean it is the > point where the -fcompare-debug bug has been introduced. Yes. Maybe just try to configure LLVM with -O3 and then run "GCC_COMPARE_DEBUG=1 ninja" (this is how I came accross the testcase). And then use the full failing gcc command for bisection. I will give it a try later.