cut_rewriting.rst

Cut rewriting

Header: mockturtle/algorithms/cut_rewriting.hpp

The following example shows how to rewrite an MIG using precomputed optimum networks. In this case the maximum number of variables for a node function is 4.

/* derive some MIG */
mig_network mig = ...;

/* node resynthesis */
mig_npn_resynthesis resyn;
cut_rewriting_params ps;
ps.cut_enumeration_ps.cut_size = 4;
mig = cut_rewriting( mig, resyn, ps );
mig = cleanup_dangling( mig );

It is possible to change the cost function of nodes in cut rewriting. Here is an example, in which the cost function only accounts for AND gates in a network, which corresponds to the multiplicative complexity of a function.

template<class Ntk>
struct mc_cost
{
  uint32_t operator()( Ntk const& ntk, node<Ntk> const& n ) const
  {
    return ntk.is_and( n ) ? 1 : 0;
  }
};

SomeResynthesisClass resyn;
ntk = cut_rewriting<SomeResynthesisClass, mc_cost>( ntk, resyn );

Parameters and statistics

mockturtle::cut_rewriting_params

mockturtle::cut_rewriting_stats

Algorithm

mockturtle::cut_rewriting

mockturtle::cut_rewriting_with_compatibility_graph

Rewriting functions

One can use resynthesis functions that can be passed to node_resynthesis, see node_resynthesis_functions.