https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91683
--- Comment #7 from Jim Wilson <wilson at gcc dot gnu.org> --- > Would --param=ggc-min-expand=0 and/or --param=ggc-min-heapsize=0 help to > reproduce the issue? I don't think so. The problem occurs in ensure_regno_capacity, which isn't affected by frequency of garbage collection. It is only affected by the number of gen_reg_rtx calls. It is already the case that ggc_free overwrites freed memory with 0xa5 when ENABLE_GC_CHECKING is on, that is what exposed the problem.