https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105769
--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Richard Biener from comment #10) > I think that's the usual pattern for the two other stack-slot sharing PRs we > have. The liveness analysis makes wrong assumptions about CLOBBER and > CLOBBER > isn't a barrier for address-takens (and we don't have birth CLOBBERs). > > But why does -fstack-reuse=none not help? Because -fstack-reuse= controls behavior of the gimplifier/inliner (what kind of CLOBBERs are emitted), not whether we reuse stack slots during expansion or not. And the CLOBBERs that matter here aren't coming from the -fstack-reuse= controlled ones, but from C++ lifetime DSE. -flifetime-dse=1 option works as workaround in this case.
