Fixes in aqfp_view and fanout_limit_view

include/mockturtle/views/aqfp_view.hpp

@@ -226,6 +226,11 @@ class aqfp_view : public Ntk
         count += num_buffers( n );
       });
     }
+    else
+    {
+      assert( !_ps.balance_pis && "Does not make sense to balance but not branch PIs" );
+    }
+
     this->foreach_gate( [&]( auto const& n ){
       count += num_buffers( n );
     });
@@ -420,6 +425,13 @@ class aqfp_view : public Ntk
     this->foreach_gate( [&]( auto const& n ){
         on_update( n );
       });
+
+    if ( _ps.branch_pis )
+    {
+      this->foreach_pi( [&]( auto const& n ){
+        on_update( n );
+      });
+    }
   }
 
   void on_update( node const& n )

test/views/fanout_limit_view.cpp

@@ -0,0 +1,120 @@
+#include <catch.hpp>
+
+#include <mockturtle/traits.hpp>
+#include <mockturtle/networks/mig.hpp>
+#include <mockturtle/views/fanout_limit_view.hpp>
+
+using namespace mockturtle;
+
+TEST_CASE( "test node replication", "[fanout_limit_view]" )
+{
+  using node = mig_network::node;
+  using signal = mig_network::signal;
+
+  fanout_limit_view_params ps{4u};
+  fanout_limit_view<mig_network> lim_mig{ps};
+
+  signal const a = lim_mig.create_pi();
+  signal const b = lim_mig.create_pi();
+  signal const c = lim_mig.create_pi();
+
+  /* create a node */
+  signal const f1 = lim_mig.create_maj( a, b, c );
+
+  /* make f1 very popular */
+  lim_mig.create_and( f1, a );
+  lim_mig.create_and( f1, b );
+  lim_mig.create_and( f1, c );
+  lim_mig.create_or( f1, a );
+
+  CHECK( lim_mig.num_gates() == 5u );
+
+  lim_mig.create_or( f1, b );
+  lim_mig.create_or( f1, c );
+
+  CHECK( lim_mig.num_gates() == 8u );
+  lim_mig.foreach_gate( [&]( node const& n ){
+      CHECK( lim_mig.fanout_size( n ) <= 4u );
+    });
+}
+
+TEST_CASE( "test rippled replication", "[fanout_limit_view]" )
+{
+  using node = mig_network::node;
+  using signal = mig_network::signal;
+
+  fanout_limit_view_params ps{4u};
+  fanout_limit_view<mig_network> lim_mig{ps};
+
+  signal const a = lim_mig.create_pi();
+  signal const b = lim_mig.create_pi();
+  signal const c = lim_mig.create_pi();
+  signal const d = lim_mig.create_pi();
+  signal const e = lim_mig.create_pi();
+
+  /* create two nodes */
+  signal const f1 = lim_mig.create_maj( a, b, c );
+  signal const f2 = lim_mig.create_maj( d, f1, e );
+
+  /* make f1 and f2 popular */
+  lim_mig.create_and( f1, a );
+  lim_mig.create_and( f1, b );
+  lim_mig.create_and( f1, c );
+
+  lim_mig.create_and( f2, a );
+  lim_mig.create_and( f2, b );
+  lim_mig.create_and( f2, c );
+  lim_mig.create_or( f2, a );
+
+  CHECK( lim_mig.num_gates() == 9u );
+  lim_mig.foreach_gate( [&]( node const& n ){
+      CHECK( lim_mig.fanout_size( n ) <= 4u );
+    });
+
+  /* +3 majority gates, because first f2 has to be replicated, and then also f1 */
+  lim_mig.create_or( f2, b );
+
+  CHECK( lim_mig.num_gates() == 12u );
+  lim_mig.foreach_gate( [&]( node const& n ){
+      CHECK( lim_mig.fanout_size( n ) <= 4u );
+    });
+
+  CHECK( lim_mig.fanout_size( lim_mig.get_node( f1 ) ) == 4u );
+  CHECK( lim_mig.fanout_size( lim_mig.get_node( f2 ) ) == 4u );
+}
+
+TEST_CASE( "test duplicate fanout node", "[fanout_limit_view]" )
+{
+  using node = mig_network::node;
+  using signal = mig_network::signal;
+
+  fanout_limit_view_params ps{4u};
+  fanout_limit_view<mig_network> lim_mig{ps};
+
+  signal const a = lim_mig.create_pi();
+  signal const b = lim_mig.create_pi();
+  signal const c = lim_mig.create_pi();
+
+  signal const f = lim_mig.create_maj( a, b, c );
+
+  /* only one node is needed for fanout up to 4 */
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+
+  CHECK( lim_mig.num_gates() == 1u );
+  CHECK( lim_mig.fanout_size( lim_mig.get_node( f ) ) == 4u );
+
+  /* afterward the node need to be replicated */
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+  lim_mig.create_po( f );
+
+  CHECK( lim_mig.num_gates() == 2u );
+
+  lim_mig.foreach_gate( [&]( node const& n ){
+      CHECK( lim_mig.fanout_size( n ) <= 4u );
+    });
+}