https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68972
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> --- It can be made to work (for example) by increasing the value of x to 32 but I don't yet understand what the powerpc64le back end does differently from, say the x86_64 back end, that it doesn't work as is.
