https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97000
--- Comment #5 from Tom de Vries <vries at gcc dot gnu.org> --- Right, I just found this: ... /* IFN_UNIQUE should be the last insn, to make checking for it as cheap as possible. */ || (gimple_call_internal_p (stmt) && gimple_call_internal_unique_p (stmt))) gimple_call_set_ctrl_altering (stmt, true); ...