gcc6 @6.1.0_0 Internal compiler error: in fold_binary_loc

[macports@…]

Attempting to compile the attached file, using a C++14 constexpr function, with g++-mp-6 results in

consterr.cpp: In function 'int main()':
consterr.cpp:29:34:   in constexpr expansion of 'operator*<int, 3, 2>(x2p1, xm1)'
consterr.cpp:29:34: internal compiler error: in fold_binary_loc, at fold-const.c:9252
     constexpr auto prod = x2p1 * xm1;
                                  ^~~

consterr.cpp:29:34: internal compiler error: Abort trap: 6
g++-mp-6: internal compiler error: Abort trap: 6 (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://trac.macports.org/newticket> for instructions.

It compiles succesfully with clang++ (Apple LLVM version 7.3.0 (clang-703.0.31)). I am on OS X El Capitan, 10.11.4, with Xcode 7.3.1 installed.

[macports@…]

P.S. I'd be happy to report this to GCC instead, which seems indicated. I was just following the directions to report it here first ;-)

[macports@…]

I have verified that this occurs on other platforms, so I reported it at GCC (​https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71226). This can be closed.

[mf2k (Frank Schima)]

In the future, please Cc the port maintainers (port info --maintainers gcc6), if any.