[Bug c++/83659] New: ICE on compilable C++ code: in tree_to_shwi, at tree.c:6821

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83659

            Bug ID: 83659
           Summary: ICE on compilable C++ code: in tree_to_shwi, at
                    tree.c:6821
           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 affects 7.x and the current trunk, and is a regression from 6.4.x. 

$ 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/8.0.0/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 8.0.0 20180102 (experimental) [trunk revision 256110] (GCC)
$
$ g++-6.4.0 small.cpp
$ icc small.cpp
$ clang++ small.cpp
$
$ g++tk small.cpp
small.cpp: In function ‘int main()’:
small.cpp:7:42: internal compiler error: in tree_to_shwi, at tree.c:6821
   reinterpret_cast < int * > (&a)[-1] += 1;
                                          ^
0x11559a2 tree_to_shwi(tree_node const*)
        ../../gcc-source-trunk/gcc/tree.c:6821
0x703bd7 cxx_fold_indirect_ref
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3112
0x70bc4b cxx_eval_indirect_ref
        ../../gcc-source-trunk/gcc/cp/constexpr.c:3215
0x70bc4b cxx_eval_constant_expression
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4271
0x7126ed cxx_eval_outermost_constant_expr
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4769
0x715c06 maybe_constant_value(tree_node*, tree_node*)
        ../../gcc-source-trunk/gcc/cp/constexpr.c:4983
0x729de1 cp_fully_fold(tree_node*)
        ../../gcc-source-trunk/gcc/cp/cp-gimplify.c:2033
0x90b967 cp_build_binary_op(unsigned int, tree_code, tree_node*, tree_node*,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:5381
0x919111 cp_build_modify_expr(unsigned int, tree_node*, tree_code, tree_node*,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:8067
0x6d66ea build_new_op_1
        ../../gcc-source-trunk/gcc/cp/call.c:5963
0x6d6fce build_new_op(unsigned int, tree_code, int, tree_node*, tree_node*,
tree_node*, tree_node**, int)
        ../../gcc-source-trunk/gcc/cp/call.c:6047
0x91b133 build_x_modify_expr(unsigned int, tree_node*, tree_code, tree_node*,
int)
        ../../gcc-source-trunk/gcc/cp/typeck.c:8263
0x8042a6 cp_parser_assignment_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9458
0x80499a cp_parser_expression
        ../../gcc-source-trunk/gcc/cp/parser.c:9586
0x808179 cp_parser_expression_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:11042
0x81185c cp_parser_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:10858
0x812a1f cp_parser_statement_seq_opt
        ../../gcc-source-trunk/gcc/cp/parser.c:11185
0x812b2f cp_parser_compound_statement
        ../../gcc-source-trunk/gcc/cp/parser.c:11139
0x827f40 cp_parser_function_body
        ../../gcc-source-trunk/gcc/cp/parser.c:21681
0x827f40 cp_parser_ctor_initializer_opt_and_function_body
        ../../gcc-source-trunk/gcc/cp/parser.c:21716
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 V __attribute__ ((__vector_size__ (16)));

V a;

int main ()
{ 
  reinterpret_cast < int * > (&a)[-1] += 1;
  return 0;
}