opt_lut: collect and display statistics.

diff --git a/passes/opt/opt_lut.cpp b/passes/opt/opt_lut.cpp
index f33b23cf4ad93e15dad726058353ab8627e28abe..b043f6c10139166536ddd513e7a1d2b078f95904 100644 (file)
--- a/passes/opt/opt_lut.cpp
+++ b/passes/opt/opt_lut.cpp
@@ -30,6 +30,11 @@ struct OptLutWorker
        ModIndex index;
        SigMap sigmap;
 
+       pool<RTLIL::Cell*> luts;
+       dict<RTLIL::Cell*, int> luts_arity;
+
+       int combined_count = 0;
+
        bool evaluate_lut(RTLIL::Cell *lut, dict<SigBit, bool> inputs)
        {
                SigSpec lut_input = sigmap(lut->getPort("\\A"));
@@ -53,12 +58,27 @@ struct OptLutWorker
                return lut_table.extract(lut_index).as_int();
        }
 
+       void show_stats_by_arity()
+       {
+               dict<int, int> arity_counts;
+               int max_arity = 0;
+               for (auto lut_arity : luts_arity)
+               {
+                       max_arity = max(max_arity, lut_arity.second);
+                       arity_counts[lut_arity.second]++;
+               }
+
+               log("Number of LUTs: %6zu\n", luts.size());
+               for (int arity = 1; arity <= max_arity; arity++)
+               {
+                       if (arity_counts[arity])
+                               log("  %d-LUT: %13d\n", arity, arity_counts[arity]);
+               }
+       }
+
        OptLutWorker(RTLIL::Module *module) :
                module(module), index(module), sigmap(module)
        {
-               pool<RTLIL::Cell*> luts;
-               dict<RTLIL::Cell*, int> luts_arity;
-
                log("Discovering LUTs.\n");
                for (auto cell : module->selected_cells())
                {
@@ -79,10 +99,10 @@ struct OptLutWorker
                                luts_arity[cell] = lut_arity;
                        }
                }
+               show_stats_by_arity();
 
                log("\n");
                log("Combining LUTs.\n");
-
                pool<RTLIL::Cell*> worklist = luts;
                while (worklist.size())
                {
@@ -241,9 +261,12 @@ struct OptLutWorker
 
                                        worklist.insert(lutM);
                                        worklist.erase(lutR);
+
+                                       combined_count++;
                                }
                        }
                }
+               show_stats_by_arity();
        }
 };
 
@@ -271,10 +294,16 @@ struct OptLutPass : public Pass {
                }
                extra_args(args, argidx, design);
 
+               int total_count = 0;
                for (auto module : design->selected_modules())
                {
                        OptLutWorker worker(module);
+                       total_count += worker.combined_count;
                }
+               if (total_count)
+                       design->scratchpad_set_bool("opt.did_something", true);
+               log("\n");
+               log("Combined %d LUTs.\n", total_count);
        }
 } OptLutPass;