[turbofan] Call frequencies for JSCallFunction and JSCallConstruct.

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/compilation-info.h"
 #include "src/compiler/bytecode-branch-analysis.h"
@@ skipping 1159 matching lines @@
       environment()->LookupRegister(bytecode_iterator().GetRegisterOperand(0));
   interpreter::Register receiver = bytecode_iterator().GetRegisterOperand(1);
   size_t arg_count = bytecode_iterator().GetRegisterCountOperand(2);
 
   // Slot index of 0 is used indicate no feedback slot is available. Assert
   // the assumption that slot index 0 is never a valid feedback slot.
   STATIC_ASSERT(TypeFeedbackVector::kReservedIndexCount > 0);
   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);
 }
 
 void BytecodeGraphBuilder::VisitCall() { BuildCall(TailCallMode::kDisallow); }
 
 void BytecodeGraphBuilder::VisitTailCall() {
   TailCallMode tail_call_mode =
       bytecode_array_->GetIsolate()->is_tail_call_elimination_enabled()
           ? TailCallMode::kAllow
@@ skipping 88 matching lines @@
   size_t arg_count = bytecode_iterator().GetRegisterCountOperand(2);
   // Slot index of 0 is used indicate no feedback slot is available. Assert
   // the assumption that slot index 0 is never a valid feedback slot.
   STATIC_ASSERT(TypeFeedbackVector::kReservedIndexCount > 0);
   VectorSlotPair feedback =
       CreateVectorSlotPair(bytecode_iterator().GetIndexOperand(3));
 
   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);
 }
 
 void BytecodeGraphBuilder::BuildThrow() {
   FrameStateBeforeAndAfter states(this);
   Node* value = environment()->LookupAccumulator();
   Node* call = NewNode(javascript()->CallRuntime(Runtime::kThrow), value);
   environment()->BindAccumulator(call, &states);
@@ skipping 50 matching lines @@
       feedback_vector()->ToSlot(bytecode_iterator().GetIndexOperand(1));
   DCHECK_EQ(FeedbackVectorSlotKind::GENERAL, feedback_vector()->GetKind(slot));
   Object* feedback = feedback_vector()->Get(slot);
   CompareOperationHint hint = CompareOperationHint::kAny;
   if (feedback->IsSmi()) {
     hint = CompareOperationHintFromFeedback((Smi::cast(feedback))->value());
   }
   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)));
 }
 
 void BytecodeGraphBuilder::VisitSub() {
   BuildBinaryOp(javascript()->Subtract(
       GetBinaryOperationHint(kBinaryOperationHintIndex)));
 }
 
@@ skipping 704 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8