diff options
Diffstat (limited to 'passes/opt/opt_reduce.cc')
| -rw-r--r-- | passes/opt/opt_reduce.cc | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/passes/opt/opt_reduce.cc b/passes/opt/opt_reduce.cc index deb4cc2c3..98351762e 100644 --- a/passes/opt/opt_reduce.cc +++ b/passes/opt/opt_reduce.cc @@ -216,7 +216,22 @@ struct OptReduceWorker }; struct OptReducePass : public Pass { - OptReducePass() : Pass("opt_reduce") { } + OptReducePass() : Pass("opt_reduce", "simplify large MUXes and AND/OR gates") { } + virtual void help() + { + // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| + log("\n"); + log(" opt_reduce [selection]\n"); + log("\n"); + log("This pass performs two interlinked optimizations:\n"); + log("\n"); + log("1. it consolidates trees of large AND gates or OR gates and eliminates\n"); + log("duplicated inputs.\n"); + log("\n"); + log("2. it identifies duplicated inputs to MUXes and replaces them with a single\n"); + log("input with the original control signals OR'ed together.\n"); + log("\n"); + } virtual void execute(std::vector<std::string> args, RTLIL::Design *design) { log_header("Executing OPT_REDUCE pass (consolidate $*mux and $reduce_* inputs).\n"); |