[stubs] Port ToName stub to TurboFan.

src/code-stub-assembler.cc

 // Copyright 2016 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/code-stub-assembler.h"
 #include "src/code-factory.h"
 #include "src/frames-inl.h"
 #include "src/frames.h"
 #include "src/ic/handler-configuration.h"
 #include "src/ic/stub-cache.h"
@@ skipping 2198 matching lines @@
         MachineRepresentation::kWord16, result,
         IntPtrConstant(SeqTwoByteString::kHeaderSize - kHeapObjectTag), code);
     var_result.Bind(result);
     Goto(&if_done);
   }
 
   Bind(&if_done);
   return var_result.value();
 }
 
+Node* CodeStubAssembler::ToName(Node* context, Node* value) {
+  typedef CodeStubAssembler::Label Label;
+  typedef CodeStubAssembler::Variable Variable;
+
+  Label end(this);
+  Variable var_result(this, MachineRepresentation::kTagged);
+
+  Label is_number(this, Label::kDeferred);

[Igor Sheludko, 2016/09/06 08:23:04]

I would suggest not to use deferred labels when rewriting hand written assembly
to TurboFan since the deferred blocks are in most cases penalized by gap moves.
Please check what kind of assembly does TF generate.

+  GotoIf(WordIsSmi(value), &is_number);
+
+  Label not_name(this, Label::kDeferred);

[Igor Sheludko, 2016/09/06 08:23:04]

Same here.

+  Node* value_instance_type = LoadInstanceType(value);

[Igor Sheludko, 2016/09/06 08:23:04]

Please add
  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);

+  GotoIf(Int32GreaterThan(value_instance_type, Int32Constant(LAST_NAME_TYPE)),
+         &not_name);
+
+  var_result.Bind(value);
+  Goto(&end);
+
+  Bind(&is_number);
+  {
+    Callable callable = CodeFactory::NumberToString(isolate());
+    var_result.Bind(CallStub(callable, context, value));
+    Goto(&end);
+  }
+
+  Bind(&not_name);
+  {
+    GotoIf(Word32Equal(value_instance_type, Int32Constant(HEAP_NUMBER_TYPE)),
+           &is_number);
+
+    Label not_oddball(this, Label::kDeferred);

[Igor Sheludko, 2016/09/06 08:23:04]

Same here.

+    GotoIf(Word32NotEqual(value_instance_type, Int32Constant(ODDBALL_TYPE)),
+           &not_oddball);
+
+    var_result.Bind(LoadObjectField(value, Oddball::kToStringOffset));
+    Goto(&end);
+
+    Bind(&not_oddball);
+    {
+      var_result.Bind(CallRuntime(Runtime::kToName, context, value));
+      Goto(&end);
+    }
+  }
+
+  Bind(&end);
+  return var_result.value();
+}
+
 Node* CodeStubAssembler::BitFieldDecode(Node* word32, uint32_t shift,
                                         uint32_t mask) {
   return Word32Shr(Word32And(word32, Int32Constant(mask)),
                    static_cast<int>(shift));
 }
 
 void CodeStubAssembler::SetCounter(StatsCounter* counter, int value) {
   if (FLAG_native_code_counters && counter->Enabled()) {
     Node* counter_address = ExternalConstant(ExternalReference(counter));
     StoreNoWriteBarrier(MachineRepresentation::kWord32, counter_address,
@@ skipping 1983 matching lines @@
                        Heap::kTheHoleValueRootIndex);
 
   // Store the WeakCell in the feedback vector.
   StoreFixedArrayElement(feedback_vector, slot, cell, UPDATE_WRITE_BARRIER,
                          CodeStubAssembler::SMI_PARAMETERS);
   return cell;
 }
 
 }  // namespace internal
 }  // namespace v8