MIG resynthesis engines (lsils#414)

- Implements three MIG resynthesis algorithms in mig_resyn_engines.hpp and adds simple tests for them: 
  1. A simple bottom-up approach that will always create a chain of MAJ gates.
  2. A complicated top-down decomposition heuristic which is still work-in-progress.
  3. A re-implementation of Akers synthesis.
- Adds the interface to use these engines in mig_resub.
- Ports changes from kitty.

include/mockturtle/algorithms/mig_resub.hpp

@@ -34,6 +34,8 @@
 
 #include <mockturtle/algorithms/resubstitution.hpp>
 #include <mockturtle/networks/mig.hpp>
+#include <mockturtle/algorithms/mig_resyn_engines.hpp>
+#include <mockturtle/utils/index_list.hpp>
 
 namespace kitty
 {
@@ -643,6 +645,62 @@ struct mig_resub_functor
  binate_divisors bdivs;
 }; /* mig_resub_functor */
 
+template<typename Ntk, typename Simulator, typename TTcare, typename Engine = mig_resyn_engine<kitty::partial_truth_table>>
+struct mig_resub_functor_new
+{
+public:
+ using node = mig_network::node;
+ using signal = mig_network::signal;
+ using stats = mig_resub_stats;
+
+public:
+ explicit mig_resub_functor_new( Ntk& ntk, Simulator const& sim, std::vector<node> const& divs, uint32_t num_divs, stats& st )
+ : ntk( ntk )
+ , sim( sim )
+ , tts( ntk )
+ , divs( divs )
+ , st( st )
+ {
+ assert( divs.size() == num_divs ); (void)num_divs;
+ div_signals.reserve( divs.size() );
+ }
+
+ std::optional<signal> operator()( node const& root, TTcare care, uint32_t required, uint32_t max_inserts, uint32_t potential_gain, uint32_t& real_gain )
+ {
+ (void)care; (void)required;
+ kitty::partial_truth_table root_tt;
+ root_tt = sim.get_tt( sim.get_phase( root ) ? !ntk.make_signal( root ) : ntk.make_signal( root ) );
+ Engine engine( root_tt );
+ for ( auto const& d : divs )
+ {
+ div_signals.emplace_back( sim.get_phase( d ) ? !ntk.make_signal( d ) : ntk.make_signal( d ) );
+ tts[d] = sim.get_tt( div_signals.back() );
+ }
+ engine.add_divisors( divs.begin(), divs.end(), tts );
+
+ auto const res = engine.compute_function( std::min( potential_gain - 1, max_inserts ) );
+ if ( res )
+ {
+ signal ret;
+ real_gain = potential_gain - (*res).num_gates();
+ insert( ntk, div_signals.begin(), div_signals.end(), *res, [&]( signal const& s ){ ret = s; } );
+ return ret;
+ }
+ else
+ {
+ return std::nullopt;
+ }
+ }
+
+private:
+ Ntk& ntk;
+ Simulator const& sim;
+ unordered_node_map<kitty::partial_truth_table, Ntk> tts;
+ std::vector<node> const& divs;
+ std::vector<signal> div_signals;
+ stats& st;
+};
+
 /*! \brief MIG-specific resubstitution algorithm.
  *
  * This algorithms iterates over each node, creates a
@@ -707,7 +765,7 @@ void mig_resubstitution( Ntk& ntk, resubstitution_params const& ps = {}, resubst
  {
  using truthtable_t = kitty::static_truth_table<8u>;
  using truthtable_dc_t = kitty::dynamic_truth_table;
- using resub_impl_t = detail::resubstitution_impl<Ntk, typename detail::window_based_resub_engine<Ntk, truthtable_t, truthtable_dc_t, mig_resub_functor<Ntk, typename detail::window_simulator<Ntk, truthtable_t>, truthtable_dc_t>>>;
+ using resub_impl_t = detail::resubstitution_impl<Ntk, typename detail::window_based_resub_engine<Ntk, truthtable_t, truthtable_dc_t, mig_resub_functor_new<Ntk, typename detail::window_simulator<Ntk, truthtable_t>, truthtable_dc_t>>>;
 
  resubstitution_stats st;
  typename resub_impl_t::engine_st_t engine_st;
@@ -732,7 +790,7 @@ void mig_resubstitution( Ntk& ntk, resubstitution_params const& ps = {}, resubst
  {
  using truthtable_t = kitty::dynamic_truth_table;
  using truthtable_dc_t = kitty::dynamic_truth_table;
- using resub_impl_t = detail::resubstitution_impl<Ntk, typename detail::window_based_resub_engine<Ntk, truthtable_t, truthtable_dc_t, mig_resub_functor<Ntk, typename detail::window_simulator<Ntk, truthtable_t>, truthtable_dc_t>>>;
+ using resub_impl_t = detail::resubstitution_impl<Ntk, typename detail::window_based_resub_engine<Ntk, truthtable_t, truthtable_dc_t, mig_resub_functor_new<Ntk, typename detail::window_simulator<Ntk, truthtable_t>, truthtable_dc_t>>>;
 
  resubstitution_stats st;
  typename resub_impl_t::engine_st_t engine_st;