Added "share -limit"

diff --git a/passes/opt/share.cc b/passes/opt/share.cc
index cdda2934980828d74ccafe213a6ad65f5ca3ecfb..5ed9af00912234c29859b128cee80e1e998ed3ef 100644 (file)
--- a/passes/opt/share.cc
+++ b/passes/opt/share.cc
@@ -27,6 +27,7 @@ PRIVATE_NAMESPACE_BEGIN
 
 struct ShareWorkerConfig
 {
+       int limit;
        bool opt_force;
        bool opt_aggressive;
        bool opt_fast;
@@ -751,7 +752,7 @@ struct ShareWorker
                log("Found %d cells in module %s that may be considered for resource sharing.\n",
                                SIZE(shareable_cells), log_id(module));
 
-               while (!shareable_cells.empty())
+               while (!shareable_cells.empty() && config.limit != 0)
                {
                        RTLIL::Cell *cell = *shareable_cells.begin();
                        shareable_cells.erase(cell);
@@ -959,6 +960,9 @@ struct ShareWorker
                                        for (auto c : topo_bit_drivers[bit])
                                                topo_cell_drivers[cell].insert(c);
 
+                               if (config.limit > 0)
+                                       config.limit--;
+
                                topo_cell_drivers[cell].insert(topo_cell_drivers[other_cell].begin(), topo_cell_drivers[other_cell].end());
                                topo_cell_drivers[other_cell] = topo_cell_drivers[cell];
                                break;
@@ -1013,11 +1017,15 @@ struct SharePass : public Pass {
                log("    in much easier SAT problems at the cost of maybe missing some oportunities\n");
                log("    for resource sharing.\n");
                log("\n");
+               log("  -limit N\n");
+               log("    Only perform the first N merges, then stop. This is useful for debugging.\n");
+               log("\n");
        }
        virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
        {
                ShareWorkerConfig config;
 
+               config.limit = -1;
                config.opt_force = false;
                config.opt_aggressive = false;
                config.opt_fast = false;
@@ -1073,6 +1081,10 @@ struct SharePass : public Pass {
                                config.opt_fast = true;
                                continue;
                        }
+                       if (args[argidx] == "-limit" && argidx+1 < args.size()) {
+                               config.limit = atoi(args[++argidx].c_str());
+                               continue;
+                       }
                        break;
                }
                extra_args(args, argidx, design);