More conservastive $eq/$ne/$eqx/$nex opt_const code

diff --git a/passes/opt/opt_const.cc b/passes/opt/opt_const.cc
index a3f3ee418479fa206d882d3cbc403e5234406131..84285567e229b75fc8a5c04c8ffcd173f5acff21 100644 (file)
--- a/passes/opt/opt_const.cc
+++ b/passes/opt/opt_const.cc
@@ -160,19 +160,13 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
 
                        assert(a.chunks.size() == b.chunks.size());
                        for (size_t i = 0; i < a.chunks.size(); i++) {
-                               if (a.chunks[i].wire == NULL && b.chunks[i].wire == NULL &&
-                                               a.chunks[i].data.bits[0] != b.chunks[i].data.bits[0]) {
+                               if (a.chunks[i].wire == NULL && b.chunks[i].wire == NULL && a.chunks[i].data.bits[0] != b.chunks[i].data.bits[0] &&
+                                               a.chunks[i].data.bits[0] <= RTLIL::State::S1 && b.chunks[i].data.bits[0] <= RTLIL::State::S1) {
                                        RTLIL::SigSpec new_y = RTLIL::SigSpec((cell->type == "$eq" || cell->type == "$eqx") ?  RTLIL::State::S0 : RTLIL::State::S1);
                                        new_y.extend(cell->parameters["\\Y_WIDTH"].as_int(), false);
                                        replace_cell(module, cell, "empty", "\\Y", new_y);
                                        goto next_cell;
                                }
-                               if (cell->type == "$eq" || cell->type == "$ne") {
-                                       if (a.chunks[i].wire == NULL && a.chunks[i].data.bits[0] > RTLIL::State::S1)
-                                               continue;
-                                       if (b.chunks[i].wire == NULL && b.chunks[i].data.bits[0] > RTLIL::State::S1)
-                                               continue;
-                               }
                                if (a.chunks[i] == b.chunks[i])
                                        continue;
                                new_a.append(a.chunks[i]);