https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57335
--- Comment #14 from Orgad Shaneh <orgads at gmail dot com> --- With 6.1, this doesn't only fail for static_assert. Even a simple function call fails: struct Bits { unsigned char a : 7; unsigned char b : 1; constexpr Bits() : a(0), b(0) {} }; struct Foo { constexpr Foo(int) { } constexpr bool b() const { return bits.b; } private: Bits bits; }; void func(bool) {} void foo() { constexpr Foo foo(42); func(foo.b()); } ../test/foo.cpp: In function ‘void foo()’: ../test/foo.cpp:21:14: in constexpr expansion of ‘foo.Foo::b()’ ../test/foo.cpp:21:16: internal compiler error: in cxx_eval_bit_field_ref, at cp/constexpr.c:2226 func(foo.b()); ^ 0x6fbb43 cxx_eval_bit_field_ref ../../src/gcc/cp/constexpr.c:2226 0x6fbb43 cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3849 0x6fed08 cxx_eval_binary_expression ../../src/gcc/cp/constexpr.c:1725 0x6f9c52 cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3806 0x6fed08 cxx_eval_binary_expression ../../src/gcc/cp/constexpr.c:1725 0x6f9c52 cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3806 0x6fc651 cxx_eval_store_expression ../../src/gcc/cp/constexpr.c:3123 0x6fa39c cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3633 0x6f9f88 cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3645 0x6f92d2 cxx_eval_call_expression ../../src/gcc/cp/constexpr.c:1494 0x6fab6f cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3556 0x6f9f08 cxx_eval_constant_expression ../../src/gcc/cp/constexpr.c:3901 0x6fd1f6 cxx_eval_outermost_constant_expr ../../src/gcc/cp/constexpr.c:4121 0x6feabc maybe_constant_value_1 ../../src/gcc/cp/constexpr.c:4316 0x6feabc maybe_constant_value(tree_node*, tree_node*) ../../src/gcc/cp/constexpr.c:4340 0x5d6b11 build_over_call ../../src/gcc/cp/call.c:7561 0x5d879f build_new_function_call(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool, int) ../../src/gcc/cp/call.c:4152 0x6acaca finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool, bool, int) ../../src/gcc/cp/semantics.c:2461 0x65eaf2 cp_parser_postfix_expression ../../src/gcc/cp/parser.c:6904 0x65cee2 cp_parser_unary_expression ../../src/gcc/cp/parser.c:7988