Added "equiv_struct -maxiter <N>"

diff --git a/passes/equiv/equiv_struct.cc b/passes/equiv/equiv_struct.cc
index 9f962d7ecdb238096d1111b104c08dad1025836b..283ccb0946bd1c200b64f297507acdf38efd65bf 100644 (file)
--- a/passes/equiv/equiv_struct.cc
+++ b/passes/equiv/equiv_struct.cc
@@ -114,11 +114,11 @@ struct EquivStructWorker
                module->remove(cell_b);
        }
 
-       EquivStructWorker(Module *module, bool mode_fwd, bool mode_icells) :
+       EquivStructWorker(Module *module, bool mode_fwd, bool mode_icells, int iter_num) :
                        module(module), sigmap(module), equiv_bits(module),
                        mode_fwd(mode_fwd), mode_icells(mode_icells), merge_count(0)
        {
-               log("  Starting new iteration.\n");
+               log("  Starting iteration %d.\n", iter_num);
 
                pool<SigBit> equiv_inputs;
                pool<IdString> cells;
@@ -296,11 +296,15 @@ struct EquivStructPass : public Pass {
                log("        by default, the internal RTL and gate cell types are ignored. add\n");
                log("        this option to also process those cell types with this command.\n");
                log("\n");
+               log("    -maxiter <N>\n");
+               log("        maximum number of iterations to run before aborting\n");
+               log("\n");
        }
        virtual void execute(std::vector<std::string> args, Design *design)
        {
                bool mode_icells = false;
                bool mode_fwd = false;
+               int max_iter = -1;
 
                log_header("Executing EQUIV_STRUCT pass.\n");
 
@@ -314,6 +318,10 @@ struct EquivStructPass : public Pass {
                                mode_icells = true;
                                continue;
                        }
+                       if (args[argidx] == "-maxiter" && argidx+1 < args.size()) {
+                               max_iter = atoi(args[++argidx].c_str());
+                               continue;
+                       }
                        break;
                }
                extra_args(args, argidx, design);
@@ -321,8 +329,12 @@ struct EquivStructPass : public Pass {
                for (auto module : design->selected_modules()) {
                        int module_merge_count = 0;
                        log("Running equiv_struct on module %s:\n", log_id(module));
-                       while (1) {
-                               EquivStructWorker worker(module, mode_fwd, mode_icells);
+                       for (int iter = 0;; iter++) {
+                               if (iter == max_iter) {
+                                       log("  Reached iteration limit of %d.\n", iter);
+                                       break;
+                               }
+                               EquivStructWorker worker(module, mode_fwd, mode_icells, iter+1);
                                if (worker.merge_count == 0)
                                        break;
                                module_merge_count += worker.merge_count;