Revert of [builtins] Migrate String.prototype.charCodeAt and String.prototype.charAt to TurboFan.

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index bda1c0d2355ac8675ddeea325293674e0a72ae21..90e11e3d6cccbc10323287f2250452ea74889cf0 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -4165,199 +4165,6 @@
   return *result;
 }
 
-// -----------------------------------------------------------------------------
-// ES6 section 21.1 String Objects
-
-// ES6 section 21.1.3.1 String.prototype.charAt ( pos )
-void Builtins::Generate_StringPrototypeCharAt(
-    compiler::CodeStubAssembler* assembler) {
-  typedef compiler::CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef compiler::CodeStubAssembler::Variable Variable;
-
-  Node* receiver = assembler->Parameter(0);
-  Node* position = assembler->Parameter(1);
-  Node* context = assembler->Parameter(4);
-
-  // Check that {receiver} is coercible to Object and convert it to a String.
-  receiver =
-      assembler->ToThisString(context, receiver, "String.prototype.charAt");
-
-  // Convert the {position} to a Smi and check that it's in bounds of the
-  // {receiver}.
-  // TODO(bmeurer): Find an abstraction for this!
-  {
-    // Check if the {position} is already a Smi.
-    Variable var_position(assembler, MachineRepresentation::kTagged);
-    var_position.Bind(position);
-    Label if_positionissmi(assembler),
-        if_positionisnotsmi(assembler, Label::kDeferred);
-    assembler->Branch(assembler->WordIsSmi(position), &if_positionissmi,
-                      &if_positionisnotsmi);
-    assembler->Bind(&if_positionisnotsmi);
-    {
-      // Convert the {position} to an Integer via the ToIntegerStub.
-      Callable callable = CodeFactory::ToInteger(assembler->isolate());
-      Node* index = assembler->CallStub(callable, context, position);
-
-      // Check if the resulting {index} is now a Smi.
-      Label if_indexissmi(assembler, Label::kDeferred),
-          if_indexisnotsmi(assembler, Label::kDeferred);
-      assembler->Branch(assembler->WordIsSmi(index), &if_indexissmi,
-                        &if_indexisnotsmi);
-
-      assembler->Bind(&if_indexissmi);
-      {
-        var_position.Bind(index);
-        assembler->Goto(&if_positionissmi);
-      }
-
-      assembler->Bind(&if_indexisnotsmi);
-      {
-        // The ToIntegerStub canonicalizes everything in Smi range to Smi
-        // representation, so any HeapNumber returned is not in Smi range.
-        // The only exception here is -0.0, which we treat as 0.
-        Node* index_value = assembler->LoadHeapNumberValue(index);
-        Label if_indexiszero(assembler, Label::kDeferred),
-            if_indexisnotzero(assembler, Label::kDeferred);
-        assembler->Branch(assembler->Float64Equal(
-                              index_value, assembler->Float64Constant(0.0)),
-                          &if_indexiszero, &if_indexisnotzero);
-
-        assembler->Bind(&if_indexiszero);
-        {
-          var_position.Bind(assembler->SmiConstant(Smi::FromInt(0)));
-          assembler->Goto(&if_positionissmi);
-        }
-
-        assembler->Bind(&if_indexisnotzero);
-        {
-          // The {index} is some other integral Number, that is definitely
-          // neither -0.0 nor in Smi range.
-          assembler->Return(assembler->EmptyStringConstant());
-        }
-      }
-    }
-    assembler->Bind(&if_positionissmi);
-    position = var_position.value();
-
-    // Determine the actual length of the {receiver} String.
-    Node* receiver_length =
-        assembler->LoadObjectField(receiver, String::kLengthOffset);
-
-    // Return "" if the Smi {position} is outside the bounds of the {receiver}.
-    Label if_positioninbounds(assembler),
-        if_positionnotinbounds(assembler, Label::kDeferred);
-    assembler->Branch(assembler->SmiAboveOrEqual(position, receiver_length),
-                      &if_positionnotinbounds, &if_positioninbounds);
-    assembler->Bind(&if_positionnotinbounds);
-    assembler->Return(assembler->EmptyStringConstant());
-    assembler->Bind(&if_positioninbounds);
-  }
-
-  // Load the character code at the {position} from the {receiver}.
-  Node* code = assembler->StringCharCodeAt(receiver, position);
-
-  // And return the single character string with only that {code}.
-  Node* result = assembler->StringFromCharCode(code);
-  assembler->Return(result);
-}
-
-// ES6 section 21.1.3.2 String.prototype.charCodeAt ( pos )
-void Builtins::Generate_StringPrototypeCharCodeAt(
-    compiler::CodeStubAssembler* assembler) {
-  typedef compiler::CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef compiler::CodeStubAssembler::Variable Variable;
-
-  Node* receiver = assembler->Parameter(0);
-  Node* position = assembler->Parameter(1);
-  Node* context = assembler->Parameter(4);
-
-  // Check that {receiver} is coercible to Object and convert it to a String.
-  receiver =
-      assembler->ToThisString(context, receiver, "String.prototype.charCodeAt");
-
-  // Convert the {position} to a Smi and check that it's in bounds of the
-  // {receiver}.
-  // TODO(bmeurer): Find an abstraction for this!
-  {
-    // Check if the {position} is already a Smi.
-    Variable var_position(assembler, MachineRepresentation::kTagged);
-    var_position.Bind(position);
-    Label if_positionissmi(assembler),
-        if_positionisnotsmi(assembler, Label::kDeferred);
-    assembler->Branch(assembler->WordIsSmi(position), &if_positionissmi,
-                      &if_positionisnotsmi);
-    assembler->Bind(&if_positionisnotsmi);
-    {
-      // Convert the {position} to an Integer via the ToIntegerStub.
-      Callable callable = CodeFactory::ToInteger(assembler->isolate());
-      Node* index = assembler->CallStub(callable, context, position);
-
-      // Check if the resulting {index} is now a Smi.
-      Label if_indexissmi(assembler, Label::kDeferred),
-          if_indexisnotsmi(assembler, Label::kDeferred);
-      assembler->Branch(assembler->WordIsSmi(index), &if_indexissmi,
-                        &if_indexisnotsmi);
-
-      assembler->Bind(&if_indexissmi);
-      {
-        var_position.Bind(index);
-        assembler->Goto(&if_positionissmi);
-      }
-
-      assembler->Bind(&if_indexisnotsmi);
-      {
-        // The ToIntegerStub canonicalizes everything in Smi range to Smi
-        // representation, so any HeapNumber returned is not in Smi range.
-        // The only exception here is -0.0, which we treat as 0.
-        Node* index_value = assembler->LoadHeapNumberValue(index);
-        Label if_indexiszero(assembler, Label::kDeferred),
-            if_indexisnotzero(assembler, Label::kDeferred);
-        assembler->Branch(assembler->Float64Equal(
-                              index_value, assembler->Float64Constant(0.0)),
-                          &if_indexiszero, &if_indexisnotzero);
-
-        assembler->Bind(&if_indexiszero);
-        {
-          var_position.Bind(assembler->SmiConstant(Smi::FromInt(0)));
-          assembler->Goto(&if_positionissmi);
-        }
-
-        assembler->Bind(&if_indexisnotzero);
-        {
-          // The {index} is some other integral Number, that is definitely
-          // neither -0.0 nor in Smi range.
-          assembler->Return(assembler->NaNConstant());
-        }
-      }
-    }
-    assembler->Bind(&if_positionissmi);
-    position = var_position.value();
-
-    // Determine the actual length of the {receiver} String.
-    Node* receiver_length =
-        assembler->LoadObjectField(receiver, String::kLengthOffset);
-
-    // Return NaN if the Smi {position} is outside the bounds of the {receiver}.
-    Label if_positioninbounds(assembler),
-        if_positionnotinbounds(assembler, Label::kDeferred);
-    assembler->Branch(assembler->SmiAboveOrEqual(position, receiver_length),
-                      &if_positionnotinbounds, &if_positioninbounds);
-    assembler->Bind(&if_positionnotinbounds);
-    assembler->Return(assembler->NaNConstant());
-    assembler->Bind(&if_positioninbounds);
-  }
-
-  // Load the character at the {position} from the {receiver}.
-  Node* value = assembler->StringCharCodeAt(receiver, position);
-  Node* result = assembler->SmiFromWord32(value);
-  assembler->Return(result);
-}
-
-// -----------------------------------------------------------------------------
-// ES6 section 21.1 ArrayBuffer Objects
 
 // ES6 section 24.1.2.1 ArrayBuffer ( length ) for the [[Call]] case.
 BUILTIN(ArrayBufferConstructor) {