Enhancements to balancing, LUT mapping, and rewriting (#616)

* Fix to AIG balancing

* Adding substitute_node_no_restrash to data structures and fanout_view

* Fixes in rewrite, sequential network support in depth_view

* Increase support for sequential circuits in cut_enumeration

* Enhanced LUT mapping

* Adding new SOP and ESOP balancing algorithms

* Adding tests for balancing

* Fixing bad balancing in ESOPs

* Updating changelog

docs/algorithms/balancing.rst

@@ -15,6 +15,10 @@ Parameters and Statistics
 Algorithm
 ~~~~~~~~~
 
+.. doxygenfunction:: mockturtle::sop_balancing
+
+.. doxygenfunction:: mockturtle::esop_balancing
+
 .. doxygenfunction:: mockturtle::balancing
 
 Rebalancing engines
@@ -23,3 +27,7 @@ Rebalancing engines
 **Header:** ``mockturtle/algorithms/balancing/sop_balancing.hpp``
 
 .. doxygenstruct:: mockturtle::sop_rebalancing
+
+**Header:** ``mockturtle/algorithms/balancing/esop_balancing.hpp``
+
+.. doxygenstruct:: mockturtle::esop_rebalancing

docs/algorithms/lut_mapping.rst

@@ -22,11 +22,19 @@ configured using many options.
 The following example shows how to perform a LUT mapping to an And-inverter
 graph using the default settings:
 
+.. code-block:: c++
+
+   aig_network aig = ...;
+   klut_network klut = lut_map( aig );
+
+Alternatively, the mapping information can be saved on the original network
+as follows:
+
 .. code-block:: c++
 
    aig_network aig = ...;
    mapping_view mapped_aig{aig};
-   lut_map( mapped_aig );
+   lut_map_inplace( mapped_aig );
 
 Note that the AIG is wrapped into a `mapping_view` in order to equip the
 network structure with the required mapping methods.
@@ -46,7 +54,7 @@ computes the functions for the cut of each mapped node:
    ps.remove_dominated_cuts = false;
    ps.recompute_cuts = false;
    ps.cut_enumeration_ps.cut_size = 8;
-   lut_map<mapped_view<mig_network, true>, true>( mapped_mig, ps );
+   lut_map_inplace<mapped_view<mig_network, true>, true>( mapped_mig, ps );
 
 **Parameters and statistics**
 
@@ -60,6 +68,7 @@ computes the functions for the cut of each mapped node:
 
 .. doxygenfunction:: mockturtle::lut_map
 
+.. doxygenfunction:: mockturtle::lut_map_inplace
 
 LUT mapping 2
 -------------

docs/changelog.rst

@@ -14,6 +14,8 @@ v0.4 (not yet released)
     - Add access methods to check if a node is present in the network given its immediate fanin (e.g., `has_and` in `aig_network`) `#580 <https://github.com/lsils/mockturtle/pull/580>`_
     - Crossed networks (`crossed_klut_network` and `buffered_crossed_klut_network`) `#589 <https://github.com/lsils/mockturtle/pull/589>`_
     - Generic network implementation with additional node types (`generic_network`) `#594 <https://github.com/lsils/mockturtle/pull/594>`_
+    - Adding `substitute_node_no_restrash` to `aig_network`, `xag_network`, `mig_network`, `xmg_network`, and `fanout_view` to substitute nodes without structural hashing and simplifications `#616 <https://github.com/lsils/mockturtle/pull/616>`_
+    - Adding `replace_in_node_no_restrash` to `aig_network`, `xag_network`, `mig_network`, and `xmg_network` to replace a fanin without structural hashing and simplifications `#616 <https://github.com/lsils/mockturtle/pull/616>`_
 * Algorithms:
     - AIG balancing (`aig_balance`) `#580 <https://github.com/lsils/mockturtle/pull/580>`_
     - Cost-generic resubstitution (`cost_generic_resub`) `#554 <https://github.com/lsils/mockturtle/pull/554>`_
@@ -29,6 +31,8 @@ v0.4 (not yet released)
     - DAG-aware in-place rewriting (`rewrite`) `#605 <https://github.com/lsils/mockturtle/pull/605>`_
     - Dynamic cut enumeration (`dynamic_cut_enumeration_impl`) `#605 <https://github.com/lsils/mockturtle/pull/605>`_
     - Extensions and fixes in refactoring (`refactoring`) `#607 <https://github.com/lsils/mockturtle/pull/607>`_
+    - Improving LUT mapping, changing its interface, and integrating SOP/ESOP balancing (`lut_map`) `#616 <https://github.com/lsils/mockturtle/pull/616>`_
+    - Adding LUT-based SOP and ESOP balancing (`sop_balancing`, `esop_balancing`) `#616 <https://github.com/lsils/mockturtle/pull/616>`_
 * I/O:
     - Write gates to GENLIB file (`write_genlib`) `#606 <https://github.com/lsils/mockturtle/pull/606>`_
 * Views:

docs/network.rst

@@ -125,7 +125,7 @@ Restructuring
 ~~~~~~~~~~~~~
 
 .. doxygenclass:: mockturtle::network
-   :members: substitute_node, substitute_nodes, replace_in_node, replace_in_outputs, take_out_node, is_dead
+   :members: substitute_node, substitute_node_no_restrash, substitute_nodes, replace_in_node, replace_in_node_no_restrash, replace_in_outputs, take_out_node, is_dead
    :no-link:
 
 Structural properties

experiments/balancing.cpp

@@ -0,0 +1,76 @@
+/* mockturtle: C++ logic network library
+ * Copyright (C) 2018-2023  EPFL
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string>
+#include <vector>
+
+#include <fmt/format.h>
+#include <lorina/aiger.hpp>
+#include <mockturtle/algorithms/balancing.hpp>
+#include <mockturtle/algorithms/lut_mapper.hpp>
+#include <mockturtle/io/aiger_reader.hpp>
+#include <mockturtle/networks/xag.hpp>
+#include <mockturtle/networks/klut.hpp>
+#include <mockturtle/views/depth_view.hpp>
+
+#include <experiments.hpp>
+
+int main()
+{
+  using namespace experiments;
+  using namespace mockturtle;
+
+  experiment<std::string, uint32_t, uint32_t, uint32_t, uint32_t, double, bool> exp( "sop_balancing", "benchmark", "size_before", "depth_before", "size_after", "depth_after", "runtime", "equivalent" );
+
+  for ( auto const& benchmark : epfl_benchmarks() )
+  {
+    fmt::print( "[i] processing {}\n", benchmark );
+    xag_network xag;
+    if ( lorina::read_aiger( benchmark_path( benchmark ), aiger_reader( xag ) ) != lorina::return_code::success )
+    {
+      continue;
+    }
+
+    const uint32_t size_before = xag.num_gates();
+    const uint32_t depth_before = depth_view{ xag }.depth();
+
+    lut_map_params ps;
+    ps.cut_enumeration_ps.cut_size = 4u;
+    lut_map_stats st;
+    const xag_network balanced_xag = esop_balancing( xag, ps, &st );
+
+    const uint32_t size_after = balanced_xag.num_gates();
+    const uint32_t depth_after = depth_view{ balanced_xag }.depth();
+
+    auto const cec = benchmark == "hyp" ? true : abc_cec( balanced_xag, benchmark );
+
+    exp( benchmark, size_before, depth_before, size_after, depth_after, to_seconds( st.time_total ), cec );
+  }
+
+  exp.save();
+  exp.table();
+
+  return 0;
+}

experiments/lut_mapper.cpp

@@ -28,7 +28,6 @@
 
 #include <fmt/format.h>
 #include <lorina/aiger.hpp>
-#include <mockturtle/algorithms/collapse_mapped.hpp>
 #include <mockturtle/algorithms/lut_mapper.hpp>
 #include <mockturtle/io/aiger_reader.hpp>
 #include <mockturtle/networks/aig.hpp>
@@ -61,9 +60,7 @@ int main()
     ps.area_oriented_mapping = false;
     ps.cut_expansion = true;
     lut_map_stats st;
-    mapping_view<aig_network, false> mapped_aig{ aig };
-    lut_map<decltype( mapped_aig ), false>( mapped_aig, ps, &st );
-    const auto klut = *collapse_mapped_network<klut_network>( mapped_aig );
+    const auto klut = lut_map( aig, ps, &st );
 
     depth_view<klut_network> klut_d{ klut };
 

include/mockturtle/algorithms/aig_balancing.hpp

@@ -65,7 +65,7 @@ class aig_balance_impl
 
 public:
   aig_balance_impl( Ntk& ntk, aig_balancing_params const& ps )
-      : ntk( ntk ), ps( ps ),storage( storage_init_size )
+      : ntk( ntk ), ps( ps ), storage( storage_init_size )
   {
   }
 
@@ -155,7 +155,7 @@ class aig_balance_impl
     /* replace if new */
     if ( n != ntk.get_node( root ) )
     {
-      ntk.substitute_node( n, root );
+      ntk.substitute_node_no_restrash( n, root );
     }
 
     /* remember the substitution and the new node as already balanced */