[Bug c/86122] New: [8/9 Regression] ICE in useless_type_conversion_p, at gimple-expr.c:87

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86122

            Bug ID: 86122
           Summary: [8/9 Regression] ICE in useless_type_conversion_p, at
                    gimple-expr.c:87
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Changed between 20170618 and 20170716, at -O[gs123] :

$ cat z1.c
_Complex int f (_Complex int x)
{
  x += __INT_MAX__;
  x += 1;
  return x;
}

$ cat z2.c
_Complex int f (_Complex int x)
{
  x += 1;
  x += __INT_MAX__;
  return x;
}

$ gcc-7 -c z1.c -O2
$
$ gcc-9-20180610 -c z1.c -O2
during GIMPLE pass: ccp
z1.c: In function 'f':
z1.c:6:1: internal compiler error: Segmentation fault
 }
 ^
0xa9cbbf crash_signal
        ../../gcc/toplev.c:324
0x8538d4 useless_type_conversion_p(tree_node*, tree_node*)
        ../../gcc/gimple-expr.c:87
0xda7f98 gimple_simplify_VIEW_CONVERT_EXPR
        <...>/gcc/gimple-match.c:15232
0xd9d1b0 gimple_simplify
        <...>/gcc/gimple-match.c:29642
0xd9f6de gimple_resimplify1(gimple**, gimple_match_op*, tree_node*
(*)(tree_node*))
        ../../gcc/gimple-match-head.c:101
0x5a6bd8 gimple_simplify_154
        <...>/gcc/gimple-match.c:6971
0xe18869 gimple_simplify_PLUS_EXPR
        <...>/gcc/gimple-match.c:31369
0xd90c3f gimple_simplify
        <...>/gcc/gimple-match.c:80000
0xd92dd8 gimple_resimplify2(gimple**, gimple_match_op*, tree_node*
(*)(tree_node*))
        ../../gcc/gimple-match-head.c:155
0xe50041 gimple_simplify(gimple*, gimple_match_op*, gimple**, tree_node*
(*)(tree_node*), tree_node* (*)(tree_node*))
        ../../gcc/gimple-match-head.c:628
0x85a7e2 gimple_fold_stmt_to_constant_1(gimple*, tree_node* (*)(tree_node*),
tree_node* (*)(tree_node*))
        ../../gcc/gimple-fold.c:6097
0xb6eac5 ccp_fold
        ../../gcc/tree-ssa-ccp.c:1258
0xb6eac5 evaluate_stmt
        ../../gcc/tree-ssa-ccp.c:1785
0xb6faf5 visit_assignment
        ../../gcc/tree-ssa-ccp.c:2352
0xbe56e3 ssa_propagation_engine::simulate_stmt(gimple*)
        ../../gcc/tree-ssa-propagate.c:237
0xbe5a0a ssa_propagation_engine::simulate_block(basic_block_def*)
        ../../gcc/tree-ssa-propagate.c:371
0xbe66a9 ssa_propagation_engine::ssa_propagate()
        ../../gcc/tree-ssa-propagate.c:800
0xb66df7 do_ssa_ccp
        ../../gcc/tree-ssa-ccp.c:2471
0xb66df7 execute
        ../../gcc/tree-ssa-ccp.c:2515