From 66cdd36d20afea221ac9af47866569a9bf038f30 Mon Sep 17 00:00:00 2001
From: aletempiac <alessandro.tempia@gmail.com>
Date: Wed, 15 Nov 2023 19:03:29 +0100
Subject: [PATCH] Runtime improvements in decomposition

---
 src/acd/ac_decomposition.hpp |  4 ++--
 src/acd/ac_wrapper.cpp       |  4 ++--
 src/acd/ac_wrapper.h         |  1 +
 src/acd/kitty_operators.hpp  | 38 +++++++++++++++++++++++++++++++++++-
 src/map/if/if.h              |  2 +-
 5 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/src/acd/ac_decomposition.hpp b/src/acd/ac_decomposition.hpp
index 4f94bcba4..59fd00ada 100644
--- a/src/acd/ac_decomposition.hpp
+++ b/src/acd/ac_decomposition.hpp
@@ -134,8 +134,8 @@ public:
 
       /* add cost if not support reducing */
       uint32_t additional_cost = ( num_vars - i > ps.lut_size ) ? 128 : 0;
-      /* check for feasible solution that improves the cost */
-      if ( cost <= ( 1 << ( ps.lut_size - i ) ) && cost + additional_cost < best_cost )
+      /* check for feasible solution that improves the cost */ /* TODO: remove limit on cost */
+      if ( cost <= ( 1 << ( ps.lut_size - i ) ) && cost + additional_cost < best_cost && cost < 12 )
       {
         best_tt = tt_p;
         permutations = perm;
diff --git a/src/acd/ac_wrapper.cpp b/src/acd/ac_wrapper.cpp
index b7cee0dd7..aabe8e86f 100644
--- a/src/acd/ac_wrapper.cpp
+++ b/src/acd/ac_wrapper.cpp
@@ -20,8 +20,8 @@ int acd_evaluate( word * pTruth, unsigned nVars, int lutSize, unsigned *pdelay,
   ac_decomposition_stats st;
 
   ac_decomposition_impl acd( tt, nVars, ps, &st );
-  acd.run( *pdelay );
-  int val = acd.compute_decomposition();
+  int val = acd.run( *pdelay );
+  // int val = acd.compute_decomposition();
 
   if ( val < 0 )
   {
diff --git a/src/acd/ac_wrapper.h b/src/acd/ac_wrapper.h
index 522a60b86..cb22acf80 100644
--- a/src/acd/ac_wrapper.h
+++ b/src/acd/ac_wrapper.h
@@ -4,6 +4,7 @@
 
 // #include "base/main/main.h"
 #include "misc/util/abc_global.h"
+#include "map/if/if.h"
 
 // ABC_NAMESPACE_HEADER_START
 
diff --git a/src/acd/kitty_operators.hpp b/src/acd/kitty_operators.hpp
index cf973ebe0..68a24cf2e 100644
--- a/src/acd/kitty_operators.hpp
+++ b/src/acd/kitty_operators.hpp
@@ -78,7 +78,43 @@ inline void operator|=( dynamic_truth_table& first, const dynamic_truth_table& s
 template<uint32_t NumVars>
 inline void operator|=( static_truth_table<NumVars>& first, const static_truth_table<NumVars>& second )
 {
-  first = binary_or( first, second );
+  // first = binary_or( first, second );
+  /* runtime improved version */
+  if constexpr ( NumVars <= 6 )
+  {
+    first._bits |= second._bits;
+    first.mask_bits();
+  }
+  else if constexpr ( NumVars == 7 )
+  {
+    first._bits[0] |= second._bits[0];
+    first._bits[1] |= second._bits[1];
+  }
+  else if constexpr ( NumVars == 8 )
+  {
+    first._bits[0] |= second._bits[0];
+    first._bits[1] |= second._bits[1];
+    first._bits[2] |= second._bits[2];
+    first._bits[3] |= second._bits[3];
+  }
+  else if constexpr ( NumVars == 9 )
+  {
+    first._bits[0] |= second._bits[0];
+    first._bits[1] |= second._bits[1];
+    first._bits[2] |= second._bits[2];
+    first._bits[3] |= second._bits[3];
+    first._bits[4] |= second._bits[4];
+    first._bits[5] |= second._bits[5];
+    first._bits[6] |= second._bits[6];
+    first._bits[7] |= second._bits[7];
+  }
+  else
+  {
+    for ( uint32_t i = 0; i < first.num_blocks(); ++i )
+    {
+      first._bits[i] |= second._bits[i];
+    }
+  }
 }
 
 } // namespace kitty
diff --git a/src/map/if/if.h b/src/map/if/if.h
index 156e8679f..56f0bb7ed 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -40,7 +40,7 @@
 #include "opt/dau/dau.h"
 #include "misc/vec/vecHash.h"
 #include "misc/vec/vecWec.h"
-#include "ACD/ac_wrapper.h"
+#include "acd/ac_wrapper.h"
 
 ABC_NAMESPACE_HEADER_START