[Bug rtl-optimization/109179] [13 Regression] addkf3-sw.c:51:1: internal compiler error: RTL check: expected elt 3 type 'e' or 'u', have '0'

["bergner at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109179

--- Comment #8 from Peter Bergner <bergner at gcc dot gnu.org> ---
Here's another creduced test case, this one with -O2 optimization:

bergner@ltcden2-lp1:PR109179$ cat bug2.i 
union u
{
  _Float128 flt;
  long sign;
};

_Float128
foo (long src)
{
  union u var;
  var.sign = src;
  return var.flt;
}
bergner@ltcden2-lp1:PR109179$ gcc -S -O2 -mcpu=power8 bug2.i 
during RTL pass: reload
bug2.i: In function ‘foo’:
bug2.i:13:1: internal compiler error: RTL check: expected elt 3 type 'e' or
'u', have '0' (rtx note) in PATTERN, at rtl.h:1509
   13 | }
      | ^
0x1148c663 rtl_check_failed_type2(rtx_def const*, int, int, int, char const*,
int, char const*)
        /home/bergner/gcc/gcc-fsf-mainline-chip-ice/gcc/rtl.cc:907
0x10a0a207 PATTERN(rtx_def*)
        /home/bergner/gcc/gcc-fsf-mainline-chip-ice/gcc/rtl.h:1509
0x1278c123 insn_extract(rtx_insn*)
       
/home/bergner/gcc/build/gcc-fsf-mainline-chip-ice-regtest/gcc/insn-extract.cc:23
0x1118c9e7 lra_set_insn_recog_data(rtx_insn*)
        /home/bergner/gcc/gcc-fsf-mainline-chip-ice/gcc/lra.cc:1059
0x11194f23 lra_get_insn_recog_data(rtx_insn*)
        /home/bergner/gcc/gcc-fsf-mainline-chip-ice/gcc/lra-int.h:493
0x111b8de7 combine_reload_insn
        /home/bergner/gcc/gcc-fsf-mainline-chip-ice/gcc/lra-constraints.cc:5017