rmp: Genetic algorithm for slack tuning

src/odb/test/replace_hier_mod1.tcl

@@ -36,7 +36,9 @@ report_checks -through r2/D -digits 3
 # - it looks like "-through" creates a cache internally.
 #report_checks -through u1z -through r2/D -digits 3
 puts "Equivalence check - pre"
-run_equivalence_test replace_hier_mod1 ./Nangate45/work_around_yosys/ "None"
+run_equivalence_test replace_hier_mod1 \
+  -lib_dir ./Nangate45/work_around_yosys/ \
+  -remove_cells "None"
 
 puts "### swap bc1 to inv_chain ###"
 #set_debug_level ODB replace_design 1
@@ -50,7 +52,9 @@ estimate_parasitics -placement
 report_checks -through r2/D -digits 3
 #report_checks -through u1z -through r2/D -digits 3
 puts "Equivalence check - swap (buffer_chain -> inv_chain)"
-run_equivalence_test replace_hier_mod1 ./Nangate45/work_around_yosys/ "None"
+run_equivalence_test replace_hier_mod1 \
+  -lib_dir ./Nangate45/work_around_yosys/ \
+  -remove_cells "None"
 
 puts "### swap bc1 back to buffer_chain ###"
 replace_hier_module bc1 buffer_chain
@@ -63,7 +67,9 @@ estimate_parasitics -placement
 report_checks -through r2/D -digits 3
 #report_checks -through u1z -through r2/D -digits 3
 puts "Equivalence check - swap for rollback (inv_chain -> buffer_chain)"
-run_equivalence_test replace_hier_mod1 ./Nangate45/work_around_yosys/ "None"
+run_equivalence_test replace_hier_mod1 \
+  -lib_dir ./Nangate45/work_around_yosys/ \
+  -remove_cells "None"
 
 puts "### swap bc1 back to inv_chain ###"
 replace_hier_module bc1 inv_chain
@@ -76,4 +82,6 @@ estimate_parasitics -placement
 report_checks -through r2/D -digits 3
 #report_checks -through u1z -through r2/D -digits 3
 puts "Equivalence check - redo swap (buffer_chain -> inv_chain)"
-run_equivalence_test replace_hier_mod1 ./Nangate45/work_around_yosys/ "None"
+run_equivalence_test replace_hier_mod1 \
+  -lib_dir ./Nangate45/work_around_yosys/ \
+  -remove_cells "None"

src/odb/test/replace_hier_mod2.tcl

@@ -43,7 +43,9 @@ estimate_parasitics -placement
 report_checks -through _carry_out_and_/C -field input
 report_cell_usage _551_
 puts "Checking equivalence after swap #2 (Rollback)..."
-run_equivalence_test replace_hier_mod2 sky130hd/work_around_yosys "None"
+run_equivalence_test replace_hier_mod2 \
+  -lib_dir ./sky130hd/work_around_yosys/ \
+  -remove_cells "None"
 
 # Swap #3. BRENT_KUNG -> KOGGE_STONE (Redo)
 replace_hier_module _551_ LCU_16_KOGGE_STONE
@@ -59,4 +61,6 @@ estimate_parasitics -placement
 report_checks -through _carry_out_and_/C -field input
 report_cell_usage _551_
 puts "Checking equivalence after swap #4 (Rollback again)..."
-run_equivalence_test replace_hier_mod2 sky130hd/work_around_yosys "None"
+run_equivalence_test replace_hier_mod2 \
+  -lib_dir ./sky130hd/work_around_yosys/ \
+  -remove_cells "None"

src/odb/test/replace_hier_mod6.tcl

@@ -43,7 +43,9 @@ proc do_swap { from_alu to_alu } {
     estimate_parasitics -placement
     report_checks -fields input_pins -through _001_
     report_cell_usage _120_
-    run_equivalence_test $test_name ./sky130hd/work_around_yosys/ "None"
+    run_equivalence_test $test_name \
+      -lib_dir ./sky130hd/work_around_yosys/ \
+      -remove_cells "None"
   } else {
     puts "Failed to replace hier module"
   }

src/odb/test/replace_hier_mod_undo2.tcl

@@ -64,4 +64,6 @@ odb::dbDatabase_undoEco $block
 report_cell_usage gcd_1/_552_
 report_checks -through gcd_1/_carry_out_and_/B -fields input_pins
 
-run_equivalence_test replace_hier_mod5 ./Nangate45/work_around_yosys/ "None"
+run_equivalence_test replace_hier_mod5 \
+  -lib_dir ./Nangate45/work_around_yosys/ \
+  -remove_cells "None"

src/rmp/BUILD

@@ -18,8 +18,14 @@ cc_library(
         "src/annealing_strategy.h",
         "src/delay_optimization_strategy.cpp",
         "src/delay_optimization_strategy.h",
+        "src/genetic_strategy.cpp",
+        "src/genetic_strategy.h",
+        "src/gia.cpp",
+        "src/gia.h",
         "src/logic_optimization_strategy.h",
         "src/resynthesis_strategy.h",
+        "src/slack_tuning_strategy.cpp",
+        "src/slack_tuning_strategy.h",
         "src/utils.cpp",
         "src/utils.h",
         "src/zero_slack_strategy.cpp",
@@ -52,6 +58,9 @@ cc_library(
         "@boost.optional",
         "@boost.phoenix",
         "@boost.spirit",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/hash",
+        "@com_google_absl//absl/random",
     ],
 )
 

src/rmp/README.md

@@ -96,6 +96,45 @@ resynth_annealing
 | `-revert_after` | After the given number of iterations that worsen slack, revert to best found solution. |
 | `-initial_ops` | Size of the initial random solution (number of commands in the script for ABC). |
 
+### Resynth with genetic slack tuning
+
+Resynthesize parts of the design with an ABC script found via genetic algorithm.
+An individual in a population is a series of operations on ABC's internal AIG data structure.
+Each such operation is considered a gene. Genotype can be changed by a mutation with operations such
+as adding, removing or swapping genes with a `mut_prob` probability. Individual can also be changed
+by crossing two genes together with a `cross_prob` probability.
+The optimization function is defined as the worst slack.
+
+```tcl
+resynth_genetic
+    [-corner corner]
+    [-slack_threshold slack_threshold]
+    [-seed seed]
+    [-pop_size pop_size]
+    [-mut_prob mut_prob]
+    [-cross_prob cross_prob]
+    [-tourn_prob tourn_prob]
+    [-tourn_size tourn_size]
+    [-iters iters]
+    [-initial_ops initial_ops]
+```
+
+#### Options
+
+| Switch Name | Description |
+| ----- | ----- |
+| `-corner` | Process corner to use. |
+| `-slack_threshold` | Specifies a (setup) timing slack value below which timing paths need to be analyzed for restructuring. The default value is `0`. |
+| `-seed` | Seed to use for randomness. |
+| `-pop_size` | Population size. |
+| `-mut_prob` | Probability of applying mutation operator. |
+| `-cross_prob` | Probability of applying crossover operator. |
+| `-tourn_prob` | Tournament probability. |
+| `-tourn_size` | Tournament size. |
+| `-iters` | Number of iterations to run genetic algorithm. |
+| `-initial_ops` | Size of the initial random solution (number of commands in the script for ABC). |
+
+
 ## Example scripts
 
 Example scripts on running `rmp` for a sample design of `gcd` as follows:

src/rmp/include/rmp/Restructure.h

@@ -71,6 +71,7 @@ class Restructure
   void reset();
   void resynth(sta::Corner* corner);
   void resynthAnnealing(sta::Corner* corner);
+  void resynthGenetic(sta::Corner* corner);
   void run(char* liberty_file_name,
            float slack_threshold,
            unsigned max_depth,
@@ -88,6 +89,23 @@ class Restructure
     annealing_revert_after_ = revert_after;
   }
   void setAnnealingInitialOps(unsigned ops) { annealing_init_ops_ = ops; }
+  void setGeneticSeed(std::mt19937::result_type seed) { genetic_seed_ = seed; }
+  void setGeneticPopSize(unsigned pop_size) { genetic_pop_size_ = pop_size; }
+  void setGeneticMutProb(float mut_prob) { genetic_mut_prob_ = mut_prob; }
+  void setGeneticCrossProb(float cross_prob)
+  {
+    genetic_cross_prob_ = cross_prob;
+  }
+  void setGeneticTournSize(unsigned tourn_size)
+  {
+    genetic_tourn_size_ = tourn_size;
+  }
+  void setGeneticTournProb(float tourn_prob)
+  {
+    genetic_tourn_prob_ = tourn_prob;
+  }
+  void setGeneticIters(unsigned iters) { genetic_iters_ = iters; }
+  void setGeneticInitialOps(unsigned ops) { genetic_init_ops_ = ops; }
   void setSlackThreshold(sta::Slack thresh) { slack_threshold_ = thresh; }
   void setMode(const char* mode_name);
   void setTieLoPort(sta::LibertyPort* loport);
@@ -129,6 +147,17 @@ class Restructure
   unsigned annealing_iters_ = 100;
   std::optional<unsigned> annealing_revert_after_;
   unsigned annealing_init_ops_ = 10;
+
+  // Genetic
+  std::optional<std::mt19937::result_type> genetic_seed_;
+  unsigned genetic_pop_size_ = 4;
+  float genetic_mut_prob_ = 0.5;
+  float genetic_cross_prob_ = 0.5;
+  unsigned genetic_tourn_size_ = 4;
+  float genetic_tourn_prob_ = 0.8;
+  unsigned genetic_iters_ = 10;
+  unsigned genetic_init_ops_ = 10;
+
   sta::Slack slack_threshold_ = 0;
 
   std::string input_blif_file_name_;

src/rmp/src/CMakeLists.txt

@@ -16,6 +16,9 @@ add_library(rmp_lib
     Restructure.cpp
     annealing_strategy.cpp
     delay_optimization_strategy.cpp
+    genetic_strategy.cpp
+    gia.cpp
+    slack_tuning_strategy.cpp
     utils.cpp
     zero_slack_strategy.cpp
 )
@@ -48,6 +51,8 @@ target_include_directories(rmp
 target_include_directories(rmp_lib
   PUBLIC
     ../include
+  PRIVATE
+    .
 )
 
 target_link_libraries(rmp_lib
@@ -59,6 +64,7 @@ target_link_libraries(rmp_lib
     utl_lib
     cut
     ${ABC_LIBRARY}
+    absl_hash
 )
 
 target_link_libraries(rmp

src/rmp/src/Restructure.cpp

@@ -28,6 +28,7 @@
 #include "cut/blif.h"
 #include "db_sta/dbNetwork.hh"
 #include "db_sta/dbSta.hh"
+#include "genetic_strategy.h"
 #include "odb/db.h"
 #include "rsz/Resizer.hh"
 #include "sta/Delay.hh"
@@ -102,6 +103,22 @@ void Restructure::resynthAnnealing(sta::Corner* corner)
       open_sta_, name_generator_, resizer_, logger_);
 }
 
+void Restructure::resynthGenetic(sta::Corner* corner)
+{
+  GeneticStrategy genetic_strategy(corner,
+                                   slack_threshold_,
+                                   genetic_seed_,
+                                   genetic_pop_size_,
+                                   genetic_mut_prob_,
+                                   genetic_cross_prob_,
+                                   genetic_tourn_size_,
+                                   genetic_tourn_prob_,
+                                   genetic_iters_,
+                                   genetic_init_ops_);
+  genetic_strategy.OptimizeDesign(
+      open_sta_, name_generator_, resizer_, logger_);
+}
+
 void Restructure::run(char* liberty_file_name,
                       float slack_threshold,
                       unsigned max_depth,