https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100367
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jason Merrill <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:cd67343703ef4fa61de837f4690eba70d2760825 commit r12-928-gcd67343703ef4fa61de837f4690eba70d2760825 Author: Jason Merrill <ja...@redhat.com> Date: Tue May 18 12:29:33 2021 -0400 c++: ICE with <=> fallback [PR100367] Here, when genericizing lexicographical_compare_three_way, we haven't yet walked the operands, so (a == a) still sees ADDR_EXPR <a>, but this is after we've changed the type of a to REFERENCE_TYPE. When we try to fold (a == a) by constexpr evaluation, the constexpr code doesn't understand trying to take the address of a reference, and we end up crashing. Fixed by avoiding constexpr evaluation in genericize_spaceship, by using fold_build2 instead of build_new_op on scalar operands. Class operands should have been expanded during parsing. PR c++/100367 PR c++/96299 gcc/cp/ChangeLog: * method.c (genericize_spaceship): Use fold_build2 for scalar operands. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/spaceship-fallback1.C: New test.
