diff --git a/Makefile b/Makefile
index b15ce9d02..3460fe086 100644
--- a/Makefile
+++ b/Makefile
@@ -755,6 +755,7 @@ OBJS += passes/techmap/demuxmap.o
 OBJS += passes/techmap/muxcover.o
 OBJS += passes/techmap/aigmap.o
 OBJS += passes/techmap/attrmap.o
+OBJS += passes/techmap/clockgate.o
 
 include $(YOSYS_SRC)/passes/hierarchy/Makefile.inc
 include $(YOSYS_SRC)/passes/memory/Makefile.inc
diff --git a/passes/sat/sim.cc b/passes/sat/sim.cc
index 355a0051b..9d1af647d 100644
--- a/passes/sat/sim.cc
+++ b/passes/sat/sim.cc
@@ -2524,6 +2524,8 @@ struct AnnotateActivity : public OutputWriter {
 		std::vector<double_t> &clktoggleCounts = itr->second.toggleCounts;
 		double clk_period = real_timescale * (double)max_time / (clktoggleCounts[0] / 2.0);
 		double frequency = 1.0 / clk_period;
+                double density = clktoggleCounts[0] / (real_timescale * (double)max_time);
+                worker->top->module->set_string_attribute("$DENSITY", std::to_string(density));
 		worker->top->module->set_string_attribute("$FREQUENCY", std::to_string(frequency));
 		worker->top->module->set_string_attribute("$DURATION", std::to_string(max_time));
 		std::stringstream ss;