diff options
Diffstat (limited to 'passes/opt/opt_rmdff.cc')
| -rw-r--r-- | passes/opt/opt_rmdff.cc | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc index 384a4d85f..4870f76b6 100644 --- a/passes/opt/opt_rmdff.cc +++ b/passes/opt/opt_rmdff.cc @@ -93,7 +93,17 @@ delete_dff: } struct OptRmdffPass : public Pass { - OptRmdffPass() : Pass("opt_rmdff") { } + OptRmdffPass() : Pass("opt_rmdff", "remove DFFs with constant inputs") { } + virtual void help() + { + // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| + log("\n"); + log(" opt_rmdff [selection]\n"); + log("\n"); + log("This pass identifies flip-flops with constant inputs and replaces them with\n"); + log("a constant driver.\n"); + log("\n"); + } virtual void execute(std::vector<std::string> args, RTLIL::Design *design) { int total_count = 0; @@ -103,10 +113,15 @@ struct OptRmdffPass : public Pass { for (auto &mod_it : design->modules) { + if (!design->selected(mod_it.second)) + continue; + assign_map.set(mod_it.second); std::vector<std::string> dff_list; for (auto &it : mod_it.second->cells) { + if (!design->selected(mod_it.second, it.second)) + continue; if (it.second->type == "$_DFF_N_") dff_list.push_back(it.first); if (it.second->type == "$_DFF_P_") dff_list.push_back(it.first); if (it.second->type == "$_DFF_NN0_") dff_list.push_back(it.first); |