More opt_clean cleanups

Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/passes/opt/opt_clean.cc b/passes/opt/opt_clean.cc
index 249939876c834b72dfd06096f1b420618521c31d..6ca6ac820f0c89faa0d3603eaf5ce89d4ea8dc73 100644 (file)
--- a/passes/opt/opt_clean.cc
+++ b/passes/opt/opt_clean.cc
@@ -320,22 +320,32 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
                if (initval.is_fully_undef())
                        wire->attributes.erase("\\init");
 
-               bool delete_this_wire = false;
+               if (GetSize(wire) == 0) {
+                       // delete zero-width wires
+                       goto delete_this_wire;
+               } else
                if (wire->port_id != 0 || wire->get_bool_attribute("\\keep") || !initval.is_fully_undef()) {
-                       /* do not delete anything with "keep" or module ports or initialized wires */
+                       // do not delete anything with "keep" or module ports or initialized wires
                } else
                if (!purge_mode && check_public_name(wire->name)) {
-                       /* do not get rid of public names unless in purge mode */
-               } else {
-                       if (!raw_used_signals_noaliases.check_any(s1))
-                               delete_this_wire = true;
-                       if (!used_signals_nodrivers.check_any(s2))
-                               delete_this_wire = true;
+                       // do not get rid of public names unless in purge mode
+               } else
+               if (!raw_used_signals_noaliases.check_any(s1)) {
+                       // delete wires that aren't used by anything directly
+                       goto delete_this_wire;
+               } else
+               if (!used_signals_nodrivers.check_any(s2)) {
+                       // delete wires that aren't used by anything indirectly, even though other wires may alias it
+                       goto delete_this_wire;
                }
 
-               if (delete_this_wire) {
+               if (0)
+               {
+       delete_this_wire:
                        del_wires_queue.insert(wire);
-               } else {
+               }
+               else
+               {
                        RTLIL::SigSig new_conn;
                        for (int i = 0; i < GetSize(s1); i++)
                                if (s1[i] != s2[i]) {
@@ -355,25 +365,25 @@ void rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
                                used_signals.add(new_conn.second);
                                module->connect(new_conn);
                        }
-               }
 
-               if (!used_signals_nodrivers.check_all(s2)) {
-                       std::string unused_bits;
-                       for (int i = 0; i < GetSize(s2); i++) {
-                               if (s2[i].wire == NULL)
-                                       continue;
-                               if (!used_signals_nodrivers.check(s2[i])) {
-                                       if (!unused_bits.empty())
-                                               unused_bits += " ";
-                                       unused_bits += stringf("%d", i);
+                       if (!used_signals_nodrivers.check_all(s2)) {
+                               std::string unused_bits;
+                               for (int i = 0; i < GetSize(s2); i++) {
+                                       if (s2[i].wire == NULL)
+                                               continue;
+                                       if (!used_signals_nodrivers.check(s2[i])) {
+                                               if (!unused_bits.empty())
+                                                       unused_bits += " ";
+                                               unused_bits += stringf("%d", i);
+                                       }
                                }
-                       }
-                       if (unused_bits.empty() || wire->port_id != 0)
+                               if (unused_bits.empty() || wire->port_id != 0)
+                                       wire->attributes.erase("\\unused_bits");
+                               else
+                                       wire->attributes["\\unused_bits"] = RTLIL::Const(unused_bits);
+                       } else {
                                wire->attributes.erase("\\unused_bits");
-                       else
-                               wire->attributes["\\unused_bits"] = RTLIL::Const(unused_bits);
-               } else {
-                       wire->attributes.erase("\\unused_bits");
+                       }
                }
        }