[Interpreter] Collect type feedback for subtract operation and pass it to turbofan.

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/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 1123 matching lines @@
   Node* node = NewNode(js_op, left, right);
   environment()->BindAccumulator(node, &states);
 }
 
 void BytecodeGraphBuilder::VisitAdd() {
   BinaryOperationHints hints = BinaryOperationHints::Any();
   BuildBinaryOp(javascript()->Add(hints));
 }
 
 void BytecodeGraphBuilder::VisitSub() {
-  BinaryOperationHints hints = BinaryOperationHints::Any();
+  // TODO(mythria): Move this to a helper function, once more binary operations
+  // record type feedback.

[rmcilroy, 2016/08/08 08:27:31]

Could you just do this now so that it's reused when we add more?

[mythria, 2016/08/09 00:51:59]

Done.

+  FeedbackVectorSlot slot =
+      feedback_vector()->ToSlot(bytecode_iterator().GetIndexOperand(1));
+  DCHECK_EQ(FeedbackVectorSlotKind::GENERAL, feedback_vector()->GetKind(slot));
+  Object* feedback = feedback_vector()->Get(slot);
+  BinaryOperationHints::Hint hint = BinaryOperationHints::Hint::kAny;
+  if (feedback->IsSmi()) {
+    hint = BinaryOperationHintFromFeedback((Smi::cast(feedback))->value());
+  }
+  BinaryOperationHints hints(hint, hint, hint);
   BuildBinaryOp(javascript()->Subtract(hints));
 }
 
 void BytecodeGraphBuilder::VisitMul() {
   BinaryOperationHints hints = BinaryOperationHints::Any();
   BuildBinaryOp(javascript()->Multiply(hints));
 }
 
 void BytecodeGraphBuilder::VisitDiv() {
   BinaryOperationHints hints = BinaryOperationHints::Any();
@@ skipping 668 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