Scale invocation count by the number of BBs in the flow-graph of a method.

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
diff --git a/runtime/vm/flow_graph_compiler.cc b/runtime/vm/flow_graph_compiler.cc
index 90a8f7d13ef8e5ab4e417d714fd0fb9fa340232d..8b1ea0663005760c7832af5711c73f8e08c0ddc2 100644
--- a/runtime/vm/flow_graph_compiler.cc
+++ b/runtime/vm/flow_graph_compiler.cc
@@ -33,6 +33,11 @@ DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, intrinsify);
 DECLARE_FLAG(bool, propagate_ic_data);
 DECLARE_FLAG(int, optimization_counter_threshold);
+DEFINE_FLAG(int, optimization_counter_scale, 2000,
+    "The scale of invocation count, by size of the function.");
+DEFINE_FLAG(int, min_optimization_counter_threshold, 5000,
+    "The minimum invocation count for a function.");
+DECLARE_FLAG(int, reoptimization_counter_threshold);
 DECLARE_FLAG(bool, use_cha);
 DECLARE_FLAG(bool, use_osr);
 DECLARE_FLAG(int, stacktrace_every);
@@ -1429,4 +1434,21 @@ const ICData* FlowGraphCompiler::GetOrAddStaticCallICData(
   return &ic_data;
 }
 
+
+intptr_t FlowGraphCompiler::GetOptimizationThreshold() const {
+  intptr_t threshold;
+  if (is_optimizing()) {
+    threshold = FLAG_reoptimization_counter_threshold;
+  } else {
+    const intptr_t basic_blocks = flow_graph().preorder().length();
+    ASSERT(basic_blocks > 0);
+    threshold = FLAG_optimization_counter_scale * basic_blocks +
+        FLAG_min_optimization_counter_threshold;
+    if (threshold > FLAG_optimization_counter_threshold) {
+      threshold = FLAG_optimization_counter_threshold;
+    }
+  }
+  return threshold;
+}
+
 }  // namespace dart