[Bug c++/84424] New: ICE on C++ code: tree check: expected record_type or union_type or qual_union_type, have vector_type in reduced_constant_expression_p, at cp/constexpr.c:1766

["su at cs dot ucdavis.edu" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84424

            Bug ID: 84424
           Summary: ICE on C++ code: tree check: expected record_type or
                    union_type or qual_union_type, have vector_type in
                    reduced_constant_expression_p, at cp/constexpr.c:1766
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu
  Target Milestone: ---

This seems to be a recent regression as the code is accepted by 7.2.0. 

$ g++tk -v
Using built-in specs.
COLLECT_GCC=g++tk
COLLECT_LTO_WRAPPER=/home/su/software/tmp/gcc/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/8.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto
--prefix=/home/su/software/tmp/gcc/gcc-trunk --disable-bootstrap
Thread model: posix
gcc version 8.0.1 20180216 (experimental) [trunk revision 257739] (GCC)
$
$ g++-7.2.0 -c tmp.cpp
$
$ g++tk -c tmp.cpp
tmp.cpp:4:42: internal compiler error: tree check: expected record_type or
union_type or qual_union_type, have vector_type in
reduced_constant_expression_p, at cp/constexpr.c:1766
 constexpr vec v = __builtin_shuffle (v, u);
                                          ^
0x63cd06 tree_check_failed(tree_node const*, char const*, int, char const*,
...)
        ../../gcc-source-trunk/gcc/tree.c:9337
0x70aefc tree_check3(tree_node*, char const*, int, char const*, tree_code,
tree_code, tree_code)
        ../../gcc-source-trunk/gcc/tree.h:3172
0x70aefc reduced_constant_expression_p(tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:1766
0x70af64 verify_constant
        ../../gcc-source-trunk/gcc/cp/constexpr.c:1809
0x71267b cxx_eval_trinary_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3378
0x71267b cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4526
0x71954d cxx_eval_outermost_constant_expr
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4801
0x92a5a2 store_init_value(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, int)
        ../../gcc-source-trunk/gcc/cp/typeck2.c:833
0x750492 check_initializer
        ../../gcc-source-trunk/gcc/cp/decl.c:6378
0x778871 cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int)
        ../../gcc-source-trunk/gcc/cp/decl.c:7032
0x83428d cp_parser_init_declarator
        ../../gcc-source-trunk/gcc/cp/parser.c:19705
0x835f1f cp_parser_simple_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:13046
0x836e68 cp_parser_block_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12864
0x842c84 cp_parser_declaration
        ../../gcc-source-trunk/gcc/cp/parser.c:12761
0x841606 cp_parser_declaration_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:12637
0x841923 cp_parser_translation_unit
        ../../gcc-source-trunk/gcc/cp/parser.c:4559
0x841923 c_parse_file()
        ../../gcc-source-trunk/gcc/cp/parser.c:38860
0x98a825 c_common_parse_file()
        ../../gcc-source-trunk/gcc/c-family/c-opts.c:1132
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
$


------------------------------------------------------------------


typedef int vec __attribute__ ((vector_size (2 * sizeof (int))));

constexpr vec u = { 1, 2 };
constexpr vec v = __builtin_shuffle (v, u);