[Bug middle-end/66325] New: ICE in gcc.c-torture/execute/930408-1.c, verify_type fails with --enable-checking=yes

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66325

            Bug ID: 66325
           Summary: ICE in gcc.c-torture/execute/930408-1.c, verify_type
                    fails with --enable-checking=yes
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
                CC: hubicka at gcc dot gnu.org
  Target Milestone: ---
            Target: arm-none-eabi

I'm getting this ICEs in the arm testsuite:
FAIL: gcc.c-torture/execute/930408-1.c   -O3 -g  (internal compiler error)
FAIL: gcc.c-torture/execute/930408-1.c   -O3 -g  (test for excess errors)
FAIL: gcc.c-torture/execute/930408-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error)
FAIL: gcc.c-torture/execute/930408-1.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
FAIL: gcc.c-torture/execute/930408-1.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (internal compiler error)
FAIL: gcc.c-torture/execute/930408-1.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)

The ICE backtrace is:

930408-1.c:6:1: error: type variant differs by TYPE_PACKED.
 } s;
 ^
 <enumeral_type 0x7f7dbda115e8 foo asm_written unsigned packed type_0 QI
    size <integer_cst 0x7f7dbdba4000 type <integer_type 0x7f7dbdb95150
bitsizetype> constant 8>
    unit size <integer_cst 0x7f7dbdba4018 type <integer_type 0x7f7dbdb950a8
sizetype> constant 1>
    align 8 symtab -1113450304 alias set -1 canonical type 0x7f7dbda115e8
precision 8 min <integer_cst 0x7f7dbdba4030 0> max <integer_cst 0x7f7dbdb91fc0
255>
    values <tree_list 0x7f7dbdc7ee60
        value <integer_cst 0x7f7dbdba42d0 constant 0>
        chain <tree_list 0x7f7dbdc7ee88
            purpose <identifier_node 0x7f7dbda21960 e1 symbol <const_decl
0x7f7dbda2f070 e1>>
            value <integer_cst 0x7f7dbdba42e8 constant 1>>>
    chain <type_decl 0x7f7dbdbb2980 D.4163>>
 <enumeral_type 0x7f7dbda11690 E unsigned QI
    size <integer_cst 0x7f7dbdba4000 type <integer_type 0x7f7dbdb95150
bitsizetype> constant 8>
    unit size <integer_cst 0x7f7dbdba4018 type <integer_type 0x7f7dbdb950a8
sizetype> constant 1>
    align 8 symtab -1113450384 alias set -1 canonical type 0x7f7dbda115e8
precision 8 min <integer_cst 0x7f7dbdba4030 0> max <integer_cst 0x7f7dbdb91fc0
255>
    values <tree_list 0x7f7dbdc7ee60
        purpose <identifier_node 0x7f7dbda21910 e0 symbol <const_decl
0x7f7dbda2f000 e0>>
        value <integer_cst 0x7f7dbdba42d0 constant 0>
        chain <tree_list 0x7f7dbdc7ee88
            purpose <identifier_node 0x7f7dbda21960 e1 symbol <const_decl
0x7f7dbda2f070 e1>>
            value <integer_cst 0x7f7dbdba42e8 constant 1>>>
    chain <type_decl 0x7f7dbdbb2980 D.4163>>
930408-1.c:6:1: internal compiler error: verify_type failed
0xd47e13 verify_type(tree_node const*)
        $TOP/gcc/tree.c:13276
0x723fbc gen_type_die_with_usage
        $TOP/gcc/dwarf2out.c:20250
0x725079 gen_type_die
        $TOP/gcc/dwarf2out.c:20434
0x7383cc gen_decl_die
        $TOP/gcc/dwarf2out.c:21041
0x736545 gen_member_die
        $TOP/gcc/dwarf2out.c:19945
0x736545 gen_struct_or_union_type_die
        $TOP/gcc/dwarf2out.c:20038
0x736545 gen_tagged_type_die
        $TOP/gcc/dwarf2out.c:20227
0x724c88 gen_type_die_with_usage
        $TOP/gcc/dwarf2out.c:20381
0x725079 gen_type_die
        $TOP/gcc/dwarf2out.c:20434
0x737c80 gen_decl_die
        $TOP/gcc/dwarf2out.c:20987
0x738f4b dwarf2out_decl
        $TOP/gcc/dwarf2out.c:21397
0x73a161 dwarf2out_type_decl
        $TOP/gcc/dwarf2out.c:21096
0x9ce063 rest_of_type_compilation(tree_node*, int)
        $TOP/gcc/passes.c:309
0x55312f finish_struct(unsigned int, tree_node*, tree_node*, tree_node*,
c_struct_parse_info*)
        $TOP/gcc/c/c-decl.c:7850
0x59b443 c_parser_struct_or_union_specifier
        $TOP/gcc/c/c-parser.c:2829
0x59b443 c_parser_declspecs
        $TOP/gcc/c/c-parser.c:2403
0x5a39e0 c_parser_declaration_or_fndef
        $TOP/gcc/c/c-parser.c:1571
0x5ab4fe c_parser_external_declaration
        $TOP/gcc/c/c-parser.c:1452
0x5ab797 c_parser_translation_unit
        $TOP/gcc/c/c-parser.c:1339
0x5ab797 c_parse_file()
        $TOP/gcc/c/c-parser.c:15457
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.

I see this at least as far back as r223695 and it appears on trunk at r223800.
Honza, is this related to your type work recently?

My arm-none-eabi compiler is configured with:
--enable-checking=yes --with-newlib --with-fpu=neon-fp-armv8
--with-arch=armv8-a --without-isl