https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97777
--- Comment #5 from qinzhao at gcc dot gnu.org --- the following patch in reg-stack.c fixed the failure: qinzhao@gcc10:~/Work/write_gcc/gcc$ git diff reg-stack.c diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c index 8f98bd85750..3dab843f803 100644 --- a/gcc/reg-stack.c +++ b/gcc/reg-stack.c @@ -3426,7 +3426,8 @@ static unsigned int rest_of_handle_stack_regs (void) { #ifdef STACK_REGS - reg_to_stack (); + if (reg_to_stack ()) + df_insn_rescan_all (); regstack_completed = 1; #endif return 0;