abc9_ops: suppress -prep_box warning for abc9_flop

diff --git a/passes/techmap/abc9_ops.cc b/passes/techmap/abc9_ops.cc
index e46ad0a026a8faefe807d458279eb74a53432b32..cffcc189e4609c6f11ebb0c75d98991cb79b410d 100644 (file)
--- a/passes/techmap/abc9_ops.cc
+++ b/passes/techmap/abc9_ops.cc
@@ -670,7 +670,7 @@ void prep_box(RTLIL::Design *design, bool dff_mode)
                ss << std::endl;
 
                auto &t = timing.setup_module(module).comb;
-               if (t.empty())
+               if (!abc9_flop && t.empty())
                        log_warning("(* abc9_box *) module '%s' has no timing (and thus no connectivity) information.\n", log_id(module));
 
                for (const auto &o : outputs) {