early stop to avoid linear solver divergence

asyncvlsi · Jul 10, 2023 · aaa744f · aaa744f
1 parent 223ac19
commit aaa744f
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Showing 2 changed files with 14 additions and 0 deletions.
diff --git a/dali/placer/global_placer/hpwl_optimizer.cc b/dali/placer/global_placer/hpwl_optimizer.cc
@@ -410,6 +410,9 @@ double B2BHpwlOptimizer::OptimizeQuadraticMetricX(double cg_stop_criterion) {
     }
     double evaluate_result = ckt_ptr_->WeightedHPWLX();
     eval_history.push_back(evaluate_result);
+    if (evaluate_result < hpwl_early_stop_threshold_){
+      break;
+    }
     //BOOST_LOG_TRIVIAL(info)  <<"  %d WeightedHPWLX: %e\n", i, evaluate_result);
     if (eval_history.size() >= 3) {
       bool is_converge = IsSeriesConverge(eval_history, 3, cg_stop_criterion);
@@ -465,6 +468,9 @@ double B2BHpwlOptimizer::OptimizeQuadraticMetricY(double cg_stop_criterion) {
     }
     double evaluate_result = ckt_ptr_->WeightedHPWLY();
     eval_history.push_back(evaluate_result);
+    if (evaluate_result < hpwl_early_stop_threshold_){
+      break;
+    }
     //BOOST_LOG_TRIVIAL(info)  <<"  %d WeightedHPWLY: %e\n", i, evaluate_result);
     if (eval_history.size() >= 3) {
       bool is_converge = IsSeriesConverge(eval_history, 3, cg_stop_criterion);
@@ -669,6 +675,9 @@ void B2BHpwlOptimizer::OptimizeHpwlXWithAnchor(int num_threads) {
     BuildProblemWithAnchorX();
     double evaluate_result = OptimizeQuadraticMetricX(cg_stop_criterion_);
     eval_history_x.push_back(evaluate_result);
+    if (evaluate_result < hpwl_early_stop_threshold_){
+      break;
+    }
     if (eval_history_x.size() >= 3) {
       bool is_converge = IsSeriesConverge(
           eval_history_x,
@@ -722,6 +731,9 @@ void B2BHpwlOptimizer::OptimizeHpwlYWithAnchor(int num_threads) {
     double evaluate_result =
         OptimizeQuadraticMetricY(cg_stop_criterion_);
     eval_history_y.push_back(evaluate_result);
+    if (evaluate_result < hpwl_early_stop_threshold_){
+      break;
+    }
     if (eval_history_y.size() >= 3) {
       bool is_converge = IsSeriesConverge(
           eval_history_y,

diff --git a/dali/placer/global_placer/hpwl_optimizer.h b/dali/placer/global_placer/hpwl_optimizer.h
@@ -121,6 +121,8 @@ class B2BHpwlOptimizer : public HpwlOptimizer {
   double width_epsilon_ = 1e-5;
   // this value will be set to 1/epsilon_factor_ times the average movable cell height
   double height_epsilon_ = 1e-5;
+  // early stop threshold
+  double hpwl_early_stop_threshold_ = 1.0;
 
   std::vector<int> Ax_row_size;
   std::vector<int> Ay_row_size;