https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105035
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:8698ff67cdff4364c8adad2921ed532359a155ec commit r12-7797-g8698ff67cdff4364c8adad2921ed532359a155ec Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Mar 24 12:23:51 2022 +0100 fold-const: Handle C++ dependent COMPONENT_REFs in operand_equal_p [PR105035] As mentioned in the PR, operand_equal_p already contains some hacks so that it can be called already on pre-instantiation C++ trees from templates, but the recent change to compare DECL_FIELD_OFFSET in the COMPONENT_REF case broke this. Many such COMPONENT_REFs are already punted on earlier because they have NULL TREE_TYPE, but in this case the code knows what type they have but still uses an IDENTIFIER_NODE as second operand of COMPONENT_REF (I think SCOPE_REF is something that could be used too). The following patch looks at those DECL_FIELD_*OFFSET fields only if both field[01] args are FIELD_DECLs and otherwise keeps it to the earlier OP_SAME (1) check that guards this whole block. 2022-03-24 Jakub Jelinek <ja...@redhat.com> PR c++/105035 * fold-const.cc (operand_equal_p) <case COMPONENT_REF>: If either field0 or field1 is not a FIELD_DECL, return false. * g++.dg/warn/Wduplicated-cond2.C: New test.