Revert of [stubs] Port String.prototype.substring to TurboFan

src/builtins/builtins-string.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/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 
 #include "src/code-factory.h"
 
 namespace v8 {
@@ skipping 453 matching lines @@
     Handle<String> valid_forms =
         isolate->factory()->NewStringFromStaticChars("NFC, NFD, NFKC, NFKD");
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate,
         NewRangeError(MessageTemplate::kNormalizationForm, valid_forms));
   }
 
   return *string;
 }
 
-namespace {
-
-compiler::Node* ToSmiBetweenZeroAnd(CodeStubAssembler* a,
-                                    compiler::Node* context,
-                                    compiler::Node* value,
-                                    compiler::Node* limit) {
-  typedef CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef CodeStubAssembler::Variable Variable;
-
-  Label out(a);
-  Variable var_result(a, MachineRepresentation::kTagged);
-
-  Node* const value_int =
-      a->ToInteger(context, value, CodeStubAssembler::kTruncateMinusZero);
-
-  Label if_issmi(a), if_isnotsmi(a, Label::kDeferred);
-  a->Branch(a->WordIsSmi(value_int), &if_issmi, &if_isnotsmi);
-
-  a->Bind(&if_issmi);
-  {
-    Label if_isinbounds(a), if_isoutofbounds(a, Label::kDeferred);
-    a->Branch(a->SmiAbove(value_int, limit), &if_isoutofbounds, &if_isinbounds);
-
-    a->Bind(&if_isinbounds);
-    {
-      var_result.Bind(value_int);
-      a->Goto(&out);
-    }
-
-    a->Bind(&if_isoutofbounds);
-    {
-      Node* const zero = a->SmiConstant(Smi::FromInt(0));
-      var_result.Bind(a->Select(a->SmiLessThan(value_int, zero), zero, limit));
-      a->Goto(&out);
-    }
-  }
-
-  a->Bind(&if_isnotsmi);
-  {
-    // {value} is a heap number - in this case, it is definitely out of bounds.
-    a->Assert(a->WordEqual(a->LoadMap(value_int), a->HeapNumberMapConstant()));
-
-    Node* const float_zero = a->Float64Constant(0.);
-    Node* const smi_zero = a->SmiConstant(Smi::FromInt(0));
-    Node* const value_float = a->LoadHeapNumberValue(value_int);
-    var_result.Bind(a->Select(a->Float64LessThan(value_float, float_zero),
-                              smi_zero, limit));
-    a->Goto(&out);
-  }
-
-  a->Bind(&out);
-  return var_result.value();
-}
-
-}  // namespace
-
-// ES6 section 21.1.3.19 String.prototype.substring ( start, end )
-void Builtins::Generate_StringPrototypeSubstring(CodeStubAssembler* a) {
-  typedef CodeStubAssembler::Label Label;
-  typedef compiler::Node Node;
-  typedef CodeStubAssembler::Variable Variable;
-
-  Label out(a);
-
-  Variable var_start(a, MachineRepresentation::kTagged);
-  Variable var_end(a, MachineRepresentation::kTagged);
-
-  Node* const receiver = a->Parameter(0);
-  Node* const start = a->Parameter(1);
-  Node* const end = a->Parameter(2);
-  Node* const context = a->Parameter(5);
-
-  // Check that {receiver} is coercible to Object and convert it to a String.
-  Node* const string =
-      a->ToThisString(context, receiver, "String.prototype.substring");
-
-  Node* const length = a->LoadStringLength(string);
-
-  // Conversion and bounds-checks for {start}.
-  var_start.Bind(ToSmiBetweenZeroAnd(a, context, start, length));
-
-  // Conversion and bounds-checks for {end}.
-  {
-    var_end.Bind(length);
-    a->GotoIf(a->WordEqual(end, a->UndefinedConstant()), &out);
-
-    var_end.Bind(ToSmiBetweenZeroAnd(a, context, end, length));
-
-    Label if_endislessthanstart(a);
-    a->Branch(a->SmiLessThan(var_end.value(), var_start.value()),
-              &if_endislessthanstart, &out);
-
-    a->Bind(&if_endislessthanstart);
-    {
-      Node* const tmp = var_end.value();
-      var_end.Bind(var_start.value());
-      var_start.Bind(tmp);
-      a->Goto(&out);
-    }
-  }
-
-  a->Bind(&out);
-  {
-    Node* result =
-        a->SubString(context, string, var_start.value(), var_end.value());
-    a->Return(result);
-  }
-}
-
 // ES6 section 21.1.3.25 String.prototype.toString ()
 void Builtins::Generate_StringPrototypeToString(CodeStubAssembler* assembler) {
   typedef compiler::Node Node;
 
   Node* receiver = assembler->Parameter(0);
   Node* context = assembler->Parameter(3);
 
   Node* result = assembler->ToThisValue(
       context, receiver, PrimitiveType::kString, "String.prototype.toString");
   assembler->Return(result);
@@ skipping 81 matching lines @@
   }
 
   iterator->set_string(isolate->heap()->empty_string());
 
   return *isolate->factory()->NewJSIteratorResult(
       isolate->factory()->undefined_value(), true);
 }
 
 }  // namespace internal
 }  // namespace v8