https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91267
--- Comment #2 from David Binderman <dcb314 at hotmail dot com> --- Reduced C source code is a, b; c(f) { char *d, *e; while (d) { if (f) if (e) g(); h(e - (d + a)); b = e - d; d = i(); } } Problem seems to occur between revisions 273750 and 273800.