mpl: remove flip perturbations

Signed-off-by: João Mai <[email protected]>

Author: joaomai

src/mpl/src/SACoreHardMacro.cpp

@@ -29,7 +29,6 @@ SACoreHardMacro::SACoreHardMacro(PhysicalHierarchy* tree,
                                  float neg_swap_prob,
                                  float double_swap_prob,
                                  float exchange_prob,
-                                 float flip_prob,
                                  // Fast SA hyperparameter
                                  float init_prob,
                                  int max_num_step,
@@ -54,7 +53,6 @@ SACoreHardMacro::SACoreHardMacro(PhysicalHierarchy* tree,
                                         logger,
                                         block)
 {
-  flip_prob_ = flip_prob;
 }
 
 void SACoreHardMacro::run()
@@ -104,13 +102,6 @@ void SACoreHardMacro::calPenalty()
   }
 }
 
-void SACoreHardMacro::flipAllMacros()
-{
-  for (auto& macro_id : pos_seq_) {
-    macros_[macro_id].flip(false);
-  }
-}
-
 void SACoreHardMacro::perturb()
 {
   if (macros_.empty()) {
@@ -133,12 +124,9 @@ void SACoreHardMacro::perturb()
     action_id_ = 3;
     doubleSeqSwap();  // Swap two macros in pos_seq_ and
                       // other two macros in neg_seq_
-  } else if (op <= action_prob_4) {
+  } else {
     action_id_ = 4;
     exchangeMacros();  // exchange two macros in the sequence pair
-  } else {
-    action_id_ = 5;
-    flipAllMacros();
   }
 
   // update the macro locations based on Sequence Pair

src/mpl/src/SACoreHardMacro.h

@@ -30,7 +30,6 @@ class SACoreHardMacro : public SimulatedAnnealingCore<HardMacro>
                   float neg_swap_prob,
                   float double_swap_prob,
                   float exchange_prob,
-                  float flip_prob,
                   // Fast SA hyperparameter
                   float init_prob,
                   int max_num_step,
@@ -57,10 +56,6 @@ class SACoreHardMacro : public SimulatedAnnealingCore<HardMacro>
   void perturb() override;
   void saveState() override;
   void restoreState() override;
-  // actions used
-  void flipAllMacros();
-
-  float flip_prob_ = 0.0;
 };
 
 }  // namespace mpl

src/mpl/src/hier_rtlmp.cpp

@@ -299,7 +299,6 @@ void HierRTLMP::resetSAParameters()
   neg_swap_prob_ = 0.2;
   double_swap_prob_ = 0.2;
   exchange_swap_prob_ = 0.2;
-  flip_prob_ = 0.2;
   resize_prob_ = 0.0;
 
   placement_core_weights_.fence = 0.0;
@@ -727,7 +726,6 @@ void HierRTLMP::calculateMacroTilings(Cluster* cluster)
                                               neg_swap_prob_ / action_sum,
                                               double_swap_prob_ / action_sum,
                                               exchange_swap_prob_ / action_sum,
-                                              0.0,  // no flip
                                               init_prob_,
                                               max_num_step_,
                                               num_perturb_per_step,
@@ -782,7 +780,6 @@ void HierRTLMP::calculateMacroTilings(Cluster* cluster)
                                               neg_swap_prob_ / action_sum,
                                               double_swap_prob_ / action_sum,
                                               exchange_swap_prob_ / action_sum,
-                                              0.0,
                                               init_prob_,
                                               max_num_step_,
                                               num_perturb_per_step,
@@ -2459,14 +2456,12 @@ void HierRTLMP::placeMacros(Cluster* cluster)
 
   // set the action probabilities (summation to 1.0)
   const float action_sum = pos_swap_prob_ * 10 + neg_swap_prob_ * 10
-                           + double_swap_prob_ + exchange_swap_prob
-                           + flip_prob_;
+                           + double_swap_prob_ + exchange_swap_prob;
 
   float pos_swap_prob = pos_swap_prob_ * 10 / action_sum;
   float neg_swap_prob = neg_swap_prob_ * 10 / action_sum;
   float double_swap_prob = double_swap_prob_ / action_sum;
   exchange_swap_prob = exchange_swap_prob / action_sum;
-  float flip_prob = flip_prob_ / action_sum;
 
   const int macros_to_place = static_cast<int>(hard_macros.size());
 
@@ -2481,8 +2476,7 @@ void HierRTLMP::placeMacros(Cluster* cluster)
     pos_swap_prob = 0.0f;
     neg_swap_prob = 0.0f;
     double_swap_prob = 0.0f;
-    exchange_swap_prob = 0.95;
-    flip_prob = 0.05;
+    exchange_swap_prob = 1.0f;
 
     // Large arrays need more steps to properly converge.
     if (num_perturb_per_step > macros_to_place) {
@@ -2520,7 +2514,6 @@ void HierRTLMP::placeMacros(Cluster* cluster)
                                               neg_swap_prob,
                                               double_swap_prob,
                                               exchange_swap_prob,
-                                              flip_prob,
                                               init_prob_,
                                               max_num_step_,
                                               num_perturb_per_step,

src/mpl/src/hier_rtlmp.h

@@ -301,7 +301,6 @@ class HierRTLMP
   float neg_swap_prob_ = 0.2;
   float double_swap_prob_ = 0.2;
   float exchange_swap_prob_ = 0.2;
-  float flip_prob_ = 0.4;
   float resize_prob_ = 0.4;
 
   // since we convert from the database unit to the micrometer