[Bug sanitizer/63520] New: ICE: in get_biv_step, at loop-iv.c:824 with -fsanitize=undefined on ppc64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63520

            Bug ID: 63520
           Summary: ICE: in get_biv_step, at loop-iv.c:824 with
                    -fsanitize=undefined on ppc64
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
            Target: powerpc64-unknown-linux-gnu

trippels@gcc1-power7 libdecnumber % cat decNumber.i
int a;
void
fn1 (void)
{
  for (;;)
    {
      if (a == 1)
        break;
      a -= 1;
    }
}

trippels@gcc1-power7 libdecnumber % gcc -c -fsanitize=undefined -O2 decNumber.i
decNumber.i: In function âfn1â:
decNumber.i:11:1: internal compiler error: in get_biv_step, at loop-iv.c:824
 }
 ^
0x105a9b13 get_biv_step
        ../../gcc/gcc/loop-iv.c:824
0x105a9b13 iv_analyze_biv
        ../../gcc/gcc/loop-iv.c:913
0x105a9f8b iv_analyze_op
        ../../gcc/gcc/loop-iv.c:1189
0x105a9e6f iv_analyze_op
        ../../gcc/gcc/loop-iv.c:1159
0x105aa2cb iv_analyze_expr(rtx_insn*, rtx_def*, machine_mode, rtx_iv*)
        ../../gcc/gcc/loop-iv.c:969
0x105aa3d3 iv_analyze_expr(rtx_insn*, rtx_def*, machine_mode, rtx_iv*)
        ../../gcc/gcc/loop-iv.c:1025
0x105aabeb iv_analyze_def
        ../../gcc/gcc/loop-iv.c:1120
0x105a9df3 iv_analyze_op
        ../../gcc/gcc/loop-iv.c:1191
0x105ab30b iv_number_of_iterations
        ../../gcc/gcc/loop-iv.c:2387
0x105ab30b check_simple_exit
        ../../gcc/gcc/loop-iv.c:2950
0x105ab30b find_simple_exit(loop*, niter_desc*)
        ../../gcc/gcc/loop-iv.c:2975
0x105ac97f get_simple_loop_desc(loop*)
        ../../gcc/gcc/loop-iv.c:3056
0x10d8e99f doloop_optimize
        ../../gcc/gcc/loop-doloop.c:617
0x10d8e99f doloop_optimize_loops()
        ../../gcc/gcc/loop-doloop.c:745
0x1059f253 execute
        ../../gcc/gcc/loop-init.c:643
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.