[turbofan] Call frequencies for JSCallFunction and JSCallConstruct.

src/compiler/bytecode-graph-builder.cc

Index: src/compiler/bytecode-graph-builder.cc
diff --git a/src/compiler/bytecode-graph-builder.cc b/src/compiler/bytecode-graph-builder.cc
index a7a1cb58f40c883488876446f3ddba8fe70121cc..683bd1e9a930c2c4cc601eff53f0266958b8eee7 100644
--- a/src/compiler/bytecode-graph-builder.cc
+++ b/src/compiler/bytecode-graph-builder.cc
@@ -1177,8 +1177,9 @@ void BytecodeGraphBuilder::BuildCall(TailCallMode tail_call_mode) {
   VectorSlotPair feedback =
       CreateVectorSlotPair(bytecode_iterator().GetIndexOperand(3));
 
+  float const frequency = ComputeCallFrequency();
   const Operator* call = javascript()->CallFunction(
-      arg_count + 1, feedback, receiver_hint, tail_call_mode);
+      arg_count + 1, frequency, feedback, receiver_hint, tail_call_mode);
   Node* value = ProcessCallArguments(call, callee, receiver, arg_count + 1);
   environment()->BindAccumulator(value, &states);
 }
@@ -1287,8 +1288,9 @@ void BytecodeGraphBuilder::VisitNew() {
   Node* new_target = environment()->LookupAccumulator();
   Node* callee = environment()->LookupRegister(callee_reg);
 
-  const Operator* call =
-      javascript()->CallConstruct(static_cast<int>(arg_count) + 2, feedback);
+  float const frequency = ComputeCallFrequency();
+  const Operator* call = javascript()->CallConstruct(
+      static_cast<int>(arg_count) + 2, frequency, feedback);
   Node* value = ProcessCallNewArguments(call, callee, new_target, first_arg,
                                         arg_count + 2);
   environment()->BindAccumulator(value, &states);
@@ -1359,6 +1361,15 @@ CompareOperationHint BytecodeGraphBuilder::GetCompareOperationHint() {
   return hint;
 }
 
+float BytecodeGraphBuilder::ComputeCallFrequency() const {
+  if (int const slot_index = bytecode_iterator().GetIndexOperand(3)) {

[rmcilroy, 2016/09/12 09:05:41]

Drive-by-nit. Not super keen on this getting the bytecode operand in the helper
function (particularly since we already pull out the feedback VectorSlotPair in
the caller). Could you pass through the feedback_extra slot to the helper
instead?

[Benedikt Meurer, 2016/09/13 17:45:07]

Done.

+    FeedbackVectorSlot const slot = feedback_vector()->ToSlot(slot_index + 1);
+    Object* const feedback_extra = feedback_vector()->Get(slot);
+    if (feedback_extra->IsSmi()) return Smi::cast(feedback_extra)->value();
+  }
+  return 0.0f;
+}
+
 void BytecodeGraphBuilder::VisitAdd() {
   BuildBinaryOp(
       javascript()->Add(GetBinaryOperationHint(kBinaryOperationHintIndex)));