[Bug tree-optimization/84090] New: [8 Regression] ICE in gimple_redirect_edge_and_branch, at tree-cfg.c:6151

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84090

            Bug ID: 84090
           Summary: [8 Regression] ICE in gimple_redirect_edge_and_branch,
                    at tree-cfg.c:6151
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: powerpc-*-linux-gnu, powerpcspe-*-linux-gnu

gcc-8.0.0-alpha20180121 snapshot (r256935) ICEs when compiling the following
snippet w/ -mcpu=power9 (7400, 7450, 970, G4, G5, cell, e6500, power7, power8,
powerpc64le) -O1 -ftrapv -ftree-loop-vectorize:

void
dn (int uk, int gz)
{
  while (uk < 1)
    if (gz != 0)
      {
        short int pp;

        for (pp = 0; pp < 1; ++pp)
          {
 e6:
            gz += pp;
          }
      }

  goto e6;
}

% powerpc-e300c3-linux-gnu-gcc-8.0.0-alpha20180121 -mcpu=power9 -O1 -ftrapv
-ftree-loop-vectorize -c de5zx0pd.c
during GIMPLE pass: vect            
de5zx0pd.c: In function 'dn':
de5zx0pd.c:2:1: internal compiler error: in gimple_redirect_edge_and_branch, at
tree-cfg.c:6151
 dn (int uk, int gz)
 ^~
0xc9ee71 gimple_redirect_edge_and_branch
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-cfg.c:6151
0x727708 redirect_edge_and_branch(edge_def*, basic_block_def*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/cfghooks.c:369
0xc92d70 gimple_split_edge
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-cfg.c:2964
0x728043 split_edge(edge_def*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/cfghooks.c:648
0x90555e gimple_find_edge_insert_loc
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/gimple-iterator.c:811
0x9068bb gsi_insert_seq_on_edge_immediate(edge_def*, gimple*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/gimple-iterator.c:855
0xf1a261 vectorizable_live_operation(gimple*, gimple_stmt_iterator*,
_slp_tree*, int, gimple**)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-vect-loop.c:8311
0xf11f27 vect_transform_stmt(gimple*, gimple_stmt_iterator*, bool*, _slp_tree*,
_slp_instance*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-vect-stmts.c:9561
0xf220ef vect_transform_loop(_loop_vec_info*)
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-vect-loop.c:8870
0xf442da vectorize_loops()
       
/var/tmp/portage/cross-powerpc-e300c3-linux-gnu/gcc-8.0.0_alpha20180121/work/gcc-8-20180121/gcc/tree-vectorizer.c:740