edif: Just ignore connections to 'z

Connecting a const 'z to a net should be equivalent to not connecting it
at all, so let's just ignore such connections on output.

diff --git a/backends/edif/edif.cc b/backends/edif/edif.cc
index 6d9469538eba648522d775a5eb38ac91b02f829d..e9beace838c507a2b03ce31867ead1822a1efd25 100644 (file)
--- a/backends/edif/edif.cc
+++ b/backends/edif/edif.cc
@@ -404,6 +404,8 @@ struct EdifBackend : public Backend {
                                                for (auto &ref : it.second)
                                                        log_warning("Exporting x-bit on %s as zero bit.\n", ref.c_str());
                                                sig = RTLIL::State::S0;
+                                       } else if (sig == RTLIL::State::Sz) {
+                                               continue;
                                        } else {
                                                for (auto &ref : it.second)
                                                        log_error("Don't know how to handle %s on %s.\n", log_signal(sig), ref.c_str());