diff options
| -rw-r--r-- | passes/opt/opt_expr.cc | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc index 45331aa0b..a54a5c6b8 100644 --- a/passes/opt/opt_expr.cc +++ b/passes/opt/opt_expr.cc @@ -718,6 +718,23 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons } } + if (cell->type == "$_TBUF_" || cell->type == "$tribuf") { + RTLIL::SigSpec input = cell->getPort(cell->type == "$_TBUF_" ? "\\E" : "\\EN"); + RTLIL::SigSpec a = cell->getPort("\\A"); + assign_map.apply(input); + assign_map.apply(a); + if (input == State::S1) + ACTION_DO("\\Y", cell->getPort("\\A")); + if (input == State::S0 && !a.is_fully_undef()) { + cover("opt.opt_expr.action_" S__LINE__); + log("Replacing data input of %s cell `%s' in module `%s' with constant undef.\n", + cell->type.c_str(), cell->name.c_str(), module->name.c_str()); + cell->setPort("\\A", SigSpec(State::Sx, GetSize(a))); + did_something = true; + goto next_cell; + } + } + if (cell->type == "$eq" || cell->type == "$ne" || cell->type == "$eqx" || cell->type == "$nex") { RTLIL::SigSpec a = cell->getPort("\\A"); |