[Bug tree-optimization/106522] New: [13 Regression] ICE in gimple_phi_arg, at gimple.h:4594 since r13-1950-g9bb19e143cfe8863

[marxin at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106522

            Bug ID: 106522
           Summary: [13 Regression] ICE in gimple_phi_arg, at
                    gimple.h:4594 since r13-1950-g9bb19e143cfe8863
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: tamar.christina at arm dot com
  Target Milestone: ---

The following crashes:

$ cat ice.c
int bytestart, bytemem_0_0, modlookup_l_p;

void
modlookup_l() {
  long j;
  while (modlookup_l_p)
    while (bytestart && j && bytemem_0_0)
      j = j + 1;
}

$ gcc ice.c -O1 -fno-tree-forwprop -c
during GIMPLE pass: phiopt
ice.c: In function ‘modlookup_l’:
ice.c:4:1: internal compiler error: in gimple_phi_arg, at gimple.h:4594
    4 | modlookup_l() {
      | ^~~~~~~~~~~
0x7d2a04 gimple_phi_arg
        /home/marxin/Programming/gcc/gcc/gimple.h:4594
0x7d2a04 gimple_phi_arg_def
        /home/marxin/Programming/gcc/gcc/gimple.h:4639
0x7d3d1f gimple_phi_arg_def
        /home/marxin/Programming/gcc/gcc/tree-ssa-phiopt.cc:337
0x7d3d1f tree_ssa_phiopt_worker
        /home/marxin/Programming/gcc/gcc/tree-ssa-phiopt.cc:314
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.