Move string-related runtime functions into separate files.

src/runtime/runtime.cc

 // Copyright 2012 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 <stdlib.h>
 #include <limits>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 10 matching lines @@
 #include "src/conversions.h"
 #include "src/cpu-profiler.h"
 #include "src/date.h"
 #include "src/dateparser-inl.h"
 #include "src/debug.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
 #include "src/full-codegen.h"
 #include "src/global-handles.h"
 #include "src/isolate-inl.h"
-#include "src/json-parser.h"
-#include "src/json-stringifier.h"
-#include "src/jsregexp-inl.h"
-#include "src/jsregexp.h"
 #include "src/liveedit.h"
 #include "src/misc-intrinsics.h"
 #include "src/parser.h"
 #include "src/prototype.h"
 #include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/runtime-profiler.h"
 #include "src/scopeinfo.h"
 #include "src/smart-pointers.h"
-#include "src/string-search.h"
-#include "src/uri.h"
 #include "src/utils.h"
 #include "src/v8threads.h"
 #include "src/vm-state-inl.h"
 #include "third_party/fdlibm/fdlibm.h"
 
 
 #ifndef _STLP_VENDOR_CSTD
 // STLPort doesn't import fpclassify and isless into the std namespace.
 using std::fpclassify;
 using std::isless;
@@ skipping 1926 matching lines @@
   if (obj->IsJSGlobalProxy()) {
     PrototypeIterator iter(isolate, obj);
     if (iter.IsAtEnd()) return isolate->heap()->false_value();
     DCHECK(iter.GetCurrent()->IsJSGlobalObject());
     obj = JSObject::cast(iter.GetCurrent());
   }
   return isolate->heap()->ToBoolean(obj->map()->is_extensible());
 }
 
 
-RUNTIME_FUNCTION(Runtime_RegExpCompile) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, re, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, pattern, 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, flags, 2);
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     RegExpImpl::Compile(re, pattern, flags));
-  return *result;
-}
-
-
 RUNTIME_FUNCTION(Runtime_CreateApiFunction) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(FunctionTemplateInfo, data, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, prototype, 1);
   return *isolate->factory()->CreateApiFunction(data, prototype);
 }
 
 
 RUNTIME_FUNCTION(Runtime_IsTemplate) {
@@ skipping 378 matching lines @@
   CONVERT_SMI_ARG_CHECKED(properties, 1);
   // Conservative upper limit to prevent fuzz tests from going OOM.
   RUNTIME_ASSERT(properties <= 100000);
   if (object->HasFastProperties() && !object->IsJSGlobalProxy()) {
     JSObject::NormalizeProperties(object, KEEP_INOBJECT_PROPERTIES, properties);
   }
   return *object;
 }
 
 
-RUNTIME_FUNCTION(Runtime_RegExpExecRT) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 4);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 1);
-  CONVERT_INT32_ARG_CHECKED(index, 2);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, last_match_info, 3);
-  // Due to the way the JS calls are constructed this must be less than the
-  // length of a string, i.e. it is always a Smi.  We check anyway for security.
-  RUNTIME_ASSERT(index >= 0);
-  RUNTIME_ASSERT(index <= subject->length());
-  isolate->counters()->regexp_entry_runtime()->Increment();
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      RegExpImpl::Exec(regexp, subject, index, last_match_info));
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_RegExpConstructResult) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_SMI_ARG_CHECKED(size, 0);
-  RUNTIME_ASSERT(size >= 0 && size <= FixedArray::kMaxLength);
-  CONVERT_ARG_HANDLE_CHECKED(Object, index, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, input, 2);
-  Handle<FixedArray> elements = isolate->factory()->NewFixedArray(size);
-  Handle<Map> regexp_map(isolate->native_context()->regexp_result_map());
-  Handle<JSObject> object =
-      isolate->factory()->NewJSObjectFromMap(regexp_map, NOT_TENURED, false);
-  Handle<JSArray> array = Handle<JSArray>::cast(object);
-  array->set_elements(*elements);
-  array->set_length(Smi::FromInt(size));
-  // Write in-object properties after the length of the array.
-  array->InObjectPropertyAtPut(JSRegExpResult::kIndexIndex, *index);
-  array->InObjectPropertyAtPut(JSRegExpResult::kInputIndex, *input);
-  return *array;
-}
-
-
-RUNTIME_FUNCTION(Runtime_RegExpInitializeObject) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 6);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, source, 1);
-  // If source is the empty string we set it to "(?:)" instead as
-  // suggested by ECMA-262, 5th, section 15.10.4.1.
-  if (source->length() == 0) source = isolate->factory()->query_colon_string();
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, global, 2);
-  if (!global->IsTrue()) global = isolate->factory()->false_value();
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, ignoreCase, 3);
-  if (!ignoreCase->IsTrue()) ignoreCase = isolate->factory()->false_value();
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, multiline, 4);
-  if (!multiline->IsTrue()) multiline = isolate->factory()->false_value();
-
-  CONVERT_ARG_HANDLE_CHECKED(Object, sticky, 5);
-  if (!sticky->IsTrue()) sticky = isolate->factory()->false_value();
-
-  Map* map = regexp->map();
-  Object* constructor = map->constructor();
-  if (!FLAG_harmony_regexps && constructor->IsJSFunction() &&
-      JSFunction::cast(constructor)->initial_map() == map) {
-    // If we still have the original map, set in-object properties directly.
-    regexp->InObjectPropertyAtPut(JSRegExp::kSourceFieldIndex, *source);
-    // Both true and false are immovable immortal objects so no need for write
-    // barrier.
-    regexp->InObjectPropertyAtPut(JSRegExp::kGlobalFieldIndex, *global,
-                                  SKIP_WRITE_BARRIER);
-    regexp->InObjectPropertyAtPut(JSRegExp::kIgnoreCaseFieldIndex, *ignoreCase,
-                                  SKIP_WRITE_BARRIER);
-    regexp->InObjectPropertyAtPut(JSRegExp::kMultilineFieldIndex, *multiline,
-                                  SKIP_WRITE_BARRIER);
-    regexp->InObjectPropertyAtPut(JSRegExp::kLastIndexFieldIndex,
-                                  Smi::FromInt(0), SKIP_WRITE_BARRIER);
-    return *regexp;
-  }
-
-  // Map has changed, so use generic, but slower, method.  We also end here if
-  // the --harmony-regexp flag is set, because the initial map does not have
-  // space for the 'sticky' flag, since it is from the snapshot, but must work
-  // both with and without --harmony-regexp.  When sticky comes out from under
-  // the flag, we will be able to use the fast initial map.
-  PropertyAttributes final =
-      static_cast<PropertyAttributes>(READ_ONLY | DONT_ENUM | DONT_DELETE);
-  PropertyAttributes writable =
-      static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE);
-  Handle<Object> zero(Smi::FromInt(0), isolate);
-  Factory* factory = isolate->factory();
-  JSObject::SetOwnPropertyIgnoreAttributes(regexp, factory->source_string(),
-                                           source, final).Check();
-  JSObject::SetOwnPropertyIgnoreAttributes(regexp, factory->global_string(),
-                                           global, final).Check();
-  JSObject::SetOwnPropertyIgnoreAttributes(
-      regexp, factory->ignore_case_string(), ignoreCase, final).Check();
-  JSObject::SetOwnPropertyIgnoreAttributes(regexp, factory->multiline_string(),
-                                           multiline, final).Check();
-  if (FLAG_harmony_regexps) {
-    JSObject::SetOwnPropertyIgnoreAttributes(regexp, factory->sticky_string(),
-                                             sticky, final).Check();
-  }
-  JSObject::SetOwnPropertyIgnoreAttributes(regexp, factory->last_index_string(),
-                                           zero, writable).Check();
-  return *regexp;
-}
-
-
 RUNTIME_FUNCTION(Runtime_FinishArrayPrototypeSetup) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, prototype, 0);
   Object* length = prototype->length();
   RUNTIME_ASSERT(length->IsSmi() && Smi::cast(length)->value() == 0);
   RUNTIME_ASSERT(prototype->HasFastSmiOrObjectElements());
   // This is necessary to enable fast checks for absence of elements
   // on Array.prototype and below.
   prototype->set_elements(isolate->heap()->empty_fixed_array());
@@ skipping 67 matching lines @@
   if (shared->native() || shared->strict_mode() == STRICT) {
     return isolate->heap()->undefined_value();
   }
   // Returns undefined for strict or native functions, or
   // the associated global receiver for "normal" functions.
 
   return function->global_proxy();
 }
 
 
-RUNTIME_FUNCTION(Runtime_MaterializeRegExpLiteral) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 4);
-  CONVERT_ARG_HANDLE_CHECKED(FixedArray, literals, 0);
-  CONVERT_SMI_ARG_CHECKED(index, 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, pattern, 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, flags, 3);
-
-  // Get the RegExp function from the context in the literals array.
-  // This is the RegExp function from the context in which the
-  // function was created.  We do not use the RegExp function from the
-  // current native context because this might be the RegExp function
-  // from another context which we should not have access to.
-  Handle<JSFunction> constructor = Handle<JSFunction>(
-      JSFunction::NativeContextFromLiterals(*literals)->regexp_function());
-  // Compute the regular expression literal.
-  Handle<Object> regexp;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, regexp,
-      RegExpImpl::CreateRegExpLiteral(constructor, pattern, flags));
-  literals->set(index, *regexp);
-  return *regexp;
-}
-
-
 RUNTIME_FUNCTION(Runtime_FunctionGetName) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
 
   CONVERT_ARG_CHECKED(JSFunction, f, 0);
   return f->shared()->name();
 }
 
 
 RUNTIME_FUNCTION(Runtime_FunctionSetName) {
@@ skipping 371 matching lines @@
   // %ObjectFreeze is a fast path and these cases are handled elsewhere.
   RUNTIME_ASSERT(!object->HasSloppyArgumentsElements() &&
                  !object->map()->is_observed() && !object->IsJSProxy());
 
   Handle<Object> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, JSObject::Freeze(object));
   return *result;
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringCharCodeAtRT) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 2);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
-  CONVERT_NUMBER_CHECKED(uint32_t, i, Uint32, args[1]);
-
-  // Flatten the string.  If someone wants to get a char at an index
-  // in a cons string, it is likely that more indices will be
-  // accessed.
-  subject = String::Flatten(subject);
-
-  if (i >= static_cast<uint32_t>(subject->length())) {
-    return isolate->heap()->nan_value();
-  }
-
-  return Smi::FromInt(subject->Get(i));
-}
-
-
-RUNTIME_FUNCTION(Runtime_CharFromCode) {
-  HandleScope handlescope(isolate);
-  DCHECK(args.length() == 1);
-  if (args[0]->IsNumber()) {
-    CONVERT_NUMBER_CHECKED(uint32_t, code, Uint32, args[0]);
-    code &= 0xffff;
-    return *isolate->factory()->LookupSingleCharacterStringFromCode(code);
-  }
-  return isolate->heap()->empty_string();
-}
-
-
-class FixedArrayBuilder {
- public:
-  explicit FixedArrayBuilder(Isolate* isolate, int initial_capacity)
-      : array_(isolate->factory()->NewFixedArrayWithHoles(initial_capacity)),
-        length_(0),
-        has_non_smi_elements_(false) {
-    // Require a non-zero initial size. Ensures that doubling the size to
-    // extend the array will work.
-    DCHECK(initial_capacity > 0);
-  }
-
-  explicit FixedArrayBuilder(Handle<FixedArray> backing_store)
-      : array_(backing_store), length_(0), has_non_smi_elements_(false) {
-    // Require a non-zero initial size. Ensures that doubling the size to
-    // extend the array will work.
-    DCHECK(backing_store->length() > 0);
-  }
-
-  bool HasCapacity(int elements) {
-    int length = array_->length();
-    int required_length = length_ + elements;
-    return (length >= required_length);
-  }
-
-  void EnsureCapacity(int elements) {
-    int length = array_->length();
-    int required_length = length_ + elements;
-    if (length < required_length) {
-      int new_length = length;
-      do {
-        new_length *= 2;
-      } while (new_length < required_length);
-      Handle<FixedArray> extended_array =
-          array_->GetIsolate()->factory()->NewFixedArrayWithHoles(new_length);
-      array_->CopyTo(0, *extended_array, 0, length_);
-      array_ = extended_array;
-    }
-  }
-
-  void Add(Object* value) {
-    DCHECK(!value->IsSmi());
-    DCHECK(length_ < capacity());
-    array_->set(length_, value);
-    length_++;
-    has_non_smi_elements_ = true;
-  }
-
-  void Add(Smi* value) {
-    DCHECK(value->IsSmi());
-    DCHECK(length_ < capacity());
-    array_->set(length_, value);
-    length_++;
-  }
-
-  Handle<FixedArray> array() { return array_; }
-
-  int length() { return length_; }
-
-  int capacity() { return array_->length(); }
-
-  Handle<JSArray> ToJSArray(Handle<JSArray> target_array) {
-    JSArray::SetContent(target_array, array_);
-    target_array->set_length(Smi::FromInt(length_));
-    return target_array;
-  }
-
-
- private:
-  Handle<FixedArray> array_;
-  int length_;
-  bool has_non_smi_elements_;
-};
-
-
-// Forward declarations.
-const int kStringBuilderConcatHelperLengthBits = 11;
-const int kStringBuilderConcatHelperPositionBits = 19;
-
-template <typename schar>
-static inline void StringBuilderConcatHelper(String*, schar*, FixedArray*, int);
-
-typedef BitField<int, 0, kStringBuilderConcatHelperLengthBits>
-    StringBuilderSubstringLength;
-typedef BitField<int, kStringBuilderConcatHelperLengthBits,
-                 kStringBuilderConcatHelperPositionBits>
-    StringBuilderSubstringPosition;
-
-
-class ReplacementStringBuilder {
- public:
-  ReplacementStringBuilder(Heap* heap, Handle<String> subject,
-                           int estimated_part_count)
-      : heap_(heap),
-        array_builder_(heap->isolate(), estimated_part_count),
-        subject_(subject),
-        character_count_(0),
-        is_one_byte_(subject->IsOneByteRepresentation()) {
-    // Require a non-zero initial size. Ensures that doubling the size to
-    // extend the array will work.
-    DCHECK(estimated_part_count > 0);
-  }
-
-  static inline void AddSubjectSlice(FixedArrayBuilder* builder, int from,
-                                     int to) {
-    DCHECK(from >= 0);
-    int length = to - from;
-    DCHECK(length > 0);
-    if (StringBuilderSubstringLength::is_valid(length) &&
-        StringBuilderSubstringPosition::is_valid(from)) {
-      int encoded_slice = StringBuilderSubstringLength::encode(length) |
-                          StringBuilderSubstringPosition::encode(from);
-      builder->Add(Smi::FromInt(encoded_slice));
-    } else {
-      // Otherwise encode as two smis.
-      builder->Add(Smi::FromInt(-length));
-      builder->Add(Smi::FromInt(from));
-    }
-  }
-
-
-  void EnsureCapacity(int elements) { array_builder_.EnsureCapacity(elements); }
-
-
-  void AddSubjectSlice(int from, int to) {
-    AddSubjectSlice(&array_builder_, from, to);
-    IncrementCharacterCount(to - from);
-  }
-
-
-  void AddString(Handle<String> string) {
-    int length = string->length();
-    DCHECK(length > 0);
-    AddElement(*string);
-    if (!string->IsOneByteRepresentation()) {
-      is_one_byte_ = false;
-    }
-    IncrementCharacterCount(length);
-  }
-
-
-  MaybeHandle<String> ToString() {
-    Isolate* isolate = heap_->isolate();
-    if (array_builder_.length() == 0) {
-      return isolate->factory()->empty_string();
-    }
-
-    Handle<String> joined_string;
-    if (is_one_byte_) {
-      Handle<SeqOneByteString> seq;
-      ASSIGN_RETURN_ON_EXCEPTION(
-          isolate, seq,
-          isolate->factory()->NewRawOneByteString(character_count_), String);
-
-      DisallowHeapAllocation no_gc;
-      uint8_t* char_buffer = seq->GetChars();
-      StringBuilderConcatHelper(*subject_, char_buffer, *array_builder_.array(),
-                                array_builder_.length());
-      joined_string = Handle<String>::cast(seq);
-    } else {
-      // Two-byte.
-      Handle<SeqTwoByteString> seq;
-      ASSIGN_RETURN_ON_EXCEPTION(
-          isolate, seq,
-          isolate->factory()->NewRawTwoByteString(character_count_), String);
-
-      DisallowHeapAllocation no_gc;
-      uc16* char_buffer = seq->GetChars();
-      StringBuilderConcatHelper(*subject_, char_buffer, *array_builder_.array(),
-                                array_builder_.length());
-      joined_string = Handle<String>::cast(seq);
-    }
-    return joined_string;
-  }
-
-
-  void IncrementCharacterCount(int by) {
-    if (character_count_ > String::kMaxLength - by) {
-      STATIC_ASSERT(String::kMaxLength < kMaxInt);
-      character_count_ = kMaxInt;
-    } else {
-      character_count_ += by;
-    }
-  }
-
- private:
-  void AddElement(Object* element) {
-    DCHECK(element->IsSmi() || element->IsString());
-    DCHECK(array_builder_.capacity() > array_builder_.length());
-    array_builder_.Add(element);
-  }
-
-  Heap* heap_;
-  FixedArrayBuilder array_builder_;
-  Handle<String> subject_;
-  int character_count_;
-  bool is_one_byte_;
-};
-
-
-class CompiledReplacement {
- public:
-  explicit CompiledReplacement(Zone* zone)
-      : parts_(1, zone), replacement_substrings_(0, zone), zone_(zone) {}
-
-  // Return whether the replacement is simple.
-  bool Compile(Handle<String> replacement, int capture_count,
-               int subject_length);
-
-  // Use Apply only if Compile returned false.
-  void Apply(ReplacementStringBuilder* builder, int match_from, int match_to,
-             int32_t* match);
-
-  // Number of distinct parts of the replacement pattern.
-  int parts() { return parts_.length(); }
-
-  Zone* zone() const { return zone_; }
-
- private:
-  enum PartType {
-    SUBJECT_PREFIX = 1,
-    SUBJECT_SUFFIX,
-    SUBJECT_CAPTURE,
-    REPLACEMENT_SUBSTRING,
-    REPLACEMENT_STRING,
-    NUMBER_OF_PART_TYPES
-  };
-
-  struct ReplacementPart {
-    static inline ReplacementPart SubjectMatch() {
-      return ReplacementPart(SUBJECT_CAPTURE, 0);
-    }
-    static inline ReplacementPart SubjectCapture(int capture_index) {
-      return ReplacementPart(SUBJECT_CAPTURE, capture_index);
-    }
-    static inline ReplacementPart SubjectPrefix() {
-      return ReplacementPart(SUBJECT_PREFIX, 0);
-    }
-    static inline ReplacementPart SubjectSuffix(int subject_length) {
-      return ReplacementPart(SUBJECT_SUFFIX, subject_length);
-    }
-    static inline ReplacementPart ReplacementString() {
-      return ReplacementPart(REPLACEMENT_STRING, 0);
-    }
-    static inline ReplacementPart ReplacementSubString(int from, int to) {
-      DCHECK(from >= 0);
-      DCHECK(to > from);
-      return ReplacementPart(-from, to);
-    }
-
-    // If tag <= 0 then it is the negation of a start index of a substring of
-    // the replacement pattern, otherwise it's a value from PartType.
-    ReplacementPart(int tag, int data) : tag(tag), data(data) {
-      // Must be non-positive or a PartType value.
-      DCHECK(tag < NUMBER_OF_PART_TYPES);
-    }
-    // Either a value of PartType or a non-positive number that is
-    // the negation of an index into the replacement string.
-    int tag;
-    // The data value's interpretation depends on the value of tag:
-    // tag == SUBJECT_PREFIX ||
-    // tag == SUBJECT_SUFFIX:  data is unused.
-    // tag == SUBJECT_CAPTURE: data is the number of the capture.
-    // tag == REPLACEMENT_SUBSTRING ||
-    // tag == REPLACEMENT_STRING:    data is index into array of substrings
-    //                               of the replacement string.
-    // tag <= 0: Temporary representation of the substring of the replacement
-    //           string ranging over -tag .. data.
-    //           Is replaced by REPLACEMENT_{SUB,}STRING when we create the
-    //           substring objects.
-    int data;
-  };
-
-  template <typename Char>
-  bool ParseReplacementPattern(ZoneList<ReplacementPart>* parts,
-                               Vector<Char> characters, int capture_count,
-                               int subject_length, Zone* zone) {
-    int length = characters.length();
-    int last = 0;
-    for (int i = 0; i < length; i++) {
-      Char c = characters[i];
-      if (c == '$') {
-        int next_index = i + 1;
-        if (next_index == length) {  // No next character!
-          break;
-        }
-        Char c2 = characters[next_index];
-        switch (c2) {
-          case '$':
-            if (i > last) {
-              // There is a substring before. Include the first "$".
-              parts->Add(
-                  ReplacementPart::ReplacementSubString(last, next_index),
-                  zone);
-              last = next_index + 1;  // Continue after the second "$".
-            } else {
-              // Let the next substring start with the second "$".
-              last = next_index;
-            }
-            i = next_index;
-            break;
-          case '`':
-            if (i > last) {
-              parts->Add(ReplacementPart::ReplacementSubString(last, i), zone);
-            }
-            parts->Add(ReplacementPart::SubjectPrefix(), zone);
-            i = next_index;
-            last = i + 1;
-            break;
-          case '\'':
-            if (i > last) {
-              parts->Add(ReplacementPart::ReplacementSubString(last, i), zone);
-            }
-            parts->Add(ReplacementPart::SubjectSuffix(subject_length), zone);
-            i = next_index;
-            last = i + 1;
-            break;
-          case '&':
-            if (i > last) {
-              parts->Add(ReplacementPart::ReplacementSubString(last, i), zone);
-            }
-            parts->Add(ReplacementPart::SubjectMatch(), zone);
-            i = next_index;
-            last = i + 1;
-            break;
-          case '0':
-          case '1':
-          case '2':
-          case '3':
-          case '4':
-          case '5':
-          case '6':
-          case '7':
-          case '8':
-          case '9': {
-            int capture_ref = c2 - '0';
-            if (capture_ref > capture_count) {
-              i = next_index;
-              continue;
-            }
-            int second_digit_index = next_index + 1;
-            if (second_digit_index < length) {
-              // Peek ahead to see if we have two digits.
-              Char c3 = characters[second_digit_index];
-              if ('0' <= c3 && c3 <= '9') {  // Double digits.
-                int double_digit_ref = capture_ref * 10 + c3 - '0';
-                if (double_digit_ref <= capture_count) {
-                  next_index = second_digit_index;
-                  capture_ref = double_digit_ref;
-                }
-              }
-            }
-            if (capture_ref > 0) {
-              if (i > last) {
-                parts->Add(ReplacementPart::ReplacementSubString(last, i),
-                           zone);
-              }
-              DCHECK(capture_ref <= capture_count);
-              parts->Add(ReplacementPart::SubjectCapture(capture_ref), zone);
-              last = next_index + 1;
-            }
-            i = next_index;
-            break;
-          }
-          default:
-            i = next_index;
-            break;
-        }
-      }
-    }
-    if (length > last) {
-      if (last == 0) {
-        // Replacement is simple.  Do not use Apply to do the replacement.
-        return true;
-      } else {
-        parts->Add(ReplacementPart::ReplacementSubString(last, length), zone);
-      }
-    }
-    return false;
-  }
-
-  ZoneList<ReplacementPart> parts_;
-  ZoneList<Handle<String> > replacement_substrings_;
-  Zone* zone_;
-};
-
-
-bool CompiledReplacement::Compile(Handle<String> replacement, int capture_count,
-                                  int subject_length) {
-  {
-    DisallowHeapAllocation no_gc;
-    String::FlatContent content = replacement->GetFlatContent();
-    DCHECK(content.IsFlat());
-    bool simple = false;
-    if (content.IsOneByte()) {
-      simple = ParseReplacementPattern(&parts_, content.ToOneByteVector(),
-                                       capture_count, subject_length, zone());
-    } else {
-      DCHECK(content.IsTwoByte());
-      simple = ParseReplacementPattern(&parts_, content.ToUC16Vector(),
-                                       capture_count, subject_length, zone());
-    }
-    if (simple) return true;
-  }
-
-  Isolate* isolate = replacement->GetIsolate();
-  // Find substrings of replacement string and create them as String objects.
-  int substring_index = 0;
-  for (int i = 0, n = parts_.length(); i < n; i++) {
-    int tag = parts_[i].tag;
-    if (tag <= 0) {  // A replacement string slice.
-      int from = -tag;
-      int to = parts_[i].data;
-      replacement_substrings_.Add(
-          isolate->factory()->NewSubString(replacement, from, to), zone());
-      parts_[i].tag = REPLACEMENT_SUBSTRING;
-      parts_[i].data = substring_index;
-      substring_index++;
-    } else if (tag == REPLACEMENT_STRING) {
-      replacement_substrings_.Add(replacement, zone());
-      parts_[i].data = substring_index;
-      substring_index++;
-    }
-  }
-  return false;
-}
-
-
-void CompiledReplacement::Apply(ReplacementStringBuilder* builder,
-                                int match_from, int match_to, int32_t* match) {
-  DCHECK_LT(0, parts_.length());
-  for (int i = 0, n = parts_.length(); i < n; i++) {
-    ReplacementPart part = parts_[i];
-    switch (part.tag) {
-      case SUBJECT_PREFIX:
-        if (match_from > 0) builder->AddSubjectSlice(0, match_from);
-        break;
-      case SUBJECT_SUFFIX: {
-        int subject_length = part.data;
-        if (match_to < subject_length) {
-          builder->AddSubjectSlice(match_to, subject_length);
-        }
-        break;
-      }
-      case SUBJECT_CAPTURE: {
-        int capture = part.data;
-        int from = match[capture * 2];
-        int to = match[capture * 2 + 1];
-        if (from >= 0 && to > from) {
-          builder->AddSubjectSlice(from, to);
-        }
-        break;
-      }
-      case REPLACEMENT_SUBSTRING:
-      case REPLACEMENT_STRING:
-        builder->AddString(replacement_substrings_[part.data]);
-        break;
-      default:
-        UNREACHABLE();
-    }
-  }
-}
-
-
-void FindOneByteStringIndices(Vector<const uint8_t> subject, char pattern,
-                              ZoneList<int>* indices, unsigned int limit,
-                              Zone* zone) {
-  DCHECK(limit > 0);
-  // Collect indices of pattern in subject using memchr.
-  // Stop after finding at most limit values.
-  const uint8_t* subject_start = subject.start();
-  const uint8_t* subject_end = subject_start + subject.length();
-  const uint8_t* pos = subject_start;
-  while (limit > 0) {
-    pos = reinterpret_cast<const uint8_t*>(
-        memchr(pos, pattern, subject_end - pos));
-    if (pos == NULL) return;
-    indices->Add(static_cast<int>(pos - subject_start), zone);
-    pos++;
-    limit--;
-  }
-}
-
-
-void FindTwoByteStringIndices(const Vector<const uc16> subject, uc16 pattern,
-                              ZoneList<int>* indices, unsigned int limit,
-                              Zone* zone) {
-  DCHECK(limit > 0);
-  const uc16* subject_start = subject.start();
-  const uc16* subject_end = subject_start + subject.length();
-  for (const uc16* pos = subject_start; pos < subject_end && limit > 0; pos++) {
-    if (*pos == pattern) {
-      indices->Add(static_cast<int>(pos - subject_start), zone);
-      limit--;
-    }
-  }
-}
-
-
-template <typename SubjectChar, typename PatternChar>
-void FindStringIndices(Isolate* isolate, Vector<const SubjectChar> subject,
-                       Vector<const PatternChar> pattern,
-                       ZoneList<int>* indices, unsigned int limit, Zone* zone) {
-  DCHECK(limit > 0);
-  // Collect indices of pattern in subject.
-  // Stop after finding at most limit values.
-  int pattern_length = pattern.length();
-  int index = 0;
-  StringSearch<PatternChar, SubjectChar> search(isolate, pattern);
-  while (limit > 0) {
-    index = search.Search(subject, index);
-    if (index < 0) return;
-    indices->Add(index, zone);
-    index += pattern_length;
-    limit--;
-  }
-}
-
-
-void FindStringIndicesDispatch(Isolate* isolate, String* subject,
-                               String* pattern, ZoneList<int>* indices,
-                               unsigned int limit, Zone* zone) {
-  {
-    DisallowHeapAllocation no_gc;
-    String::FlatContent subject_content = subject->GetFlatContent();
-    String::FlatContent pattern_content = pattern->GetFlatContent();
-    DCHECK(subject_content.IsFlat());
-    DCHECK(pattern_content.IsFlat());
-    if (subject_content.IsOneByte()) {
-      Vector<const uint8_t> subject_vector = subject_content.ToOneByteVector();
-      if (pattern_content.IsOneByte()) {
-        Vector<const uint8_t> pattern_vector =
-            pattern_content.ToOneByteVector();
-        if (pattern_vector.length() == 1) {
-          FindOneByteStringIndices(subject_vector, pattern_vector[0], indices,
-                                   limit, zone);
-        } else {
-          FindStringIndices(isolate, subject_vector, pattern_vector, indices,
-                            limit, zone);
-        }
-      } else {
-        FindStringIndices(isolate, subject_vector,
-                          pattern_content.ToUC16Vector(), indices, limit, zone);
-      }
-    } else {
-      Vector<const uc16> subject_vector = subject_content.ToUC16Vector();
-      if (pattern_content.IsOneByte()) {
-        Vector<const uint8_t> pattern_vector =
-            pattern_content.ToOneByteVector();
-        if (pattern_vector.length() == 1) {
-          FindTwoByteStringIndices(subject_vector, pattern_vector[0], indices,
-                                   limit, zone);
-        } else {
-          FindStringIndices(isolate, subject_vector, pattern_vector, indices,
-                            limit, zone);
-        }
-      } else {
-        Vector<const uc16> pattern_vector = pattern_content.ToUC16Vector();
-        if (pattern_vector.length() == 1) {
-          FindTwoByteStringIndices(subject_vector, pattern_vector[0], indices,
-                                   limit, zone);
-        } else {
-          FindStringIndices(isolate, subject_vector, pattern_vector, indices,
-                            limit, zone);
-        }
-      }
-    }
-  }
-}
-
-
-template <typename ResultSeqString>
-MUST_USE_RESULT static Object* StringReplaceGlobalAtomRegExpWithString(
-    Isolate* isolate, Handle<String> subject, Handle<JSRegExp> pattern_regexp,
-    Handle<String> replacement, Handle<JSArray> last_match_info) {
-  DCHECK(subject->IsFlat());
-  DCHECK(replacement->IsFlat());
-
-  ZoneScope zone_scope(isolate->runtime_zone());
-  ZoneList<int> indices(8, zone_scope.zone());
-  DCHECK_EQ(JSRegExp::ATOM, pattern_regexp->TypeTag());
-  String* pattern =
-      String::cast(pattern_regexp->DataAt(JSRegExp::kAtomPatternIndex));
-  int subject_len = subject->length();
-  int pattern_len = pattern->length();
-  int replacement_len = replacement->length();
-
-  FindStringIndicesDispatch(isolate, *subject, pattern, &indices, 0xffffffff,
-                            zone_scope.zone());
-
-  int matches = indices.length();
-  if (matches == 0) return *subject;
-
-  // Detect integer overflow.
-  int64_t result_len_64 = (static_cast<int64_t>(replacement_len) -
-                           static_cast<int64_t>(pattern_len)) *
-                              static_cast<int64_t>(matches) +
-                          static_cast<int64_t>(subject_len);
-  int result_len;
-  if (result_len_64 > static_cast<int64_t>(String::kMaxLength)) {
-    STATIC_ASSERT(String::kMaxLength < kMaxInt);
-    result_len = kMaxInt;  // Provoke exception.
-  } else {
-    result_len = static_cast<int>(result_len_64);
-  }
-
-  int subject_pos = 0;
-  int result_pos = 0;
-
-  MaybeHandle<SeqString> maybe_res;
-  if (ResultSeqString::kHasOneByteEncoding) {
-    maybe_res = isolate->factory()->NewRawOneByteString(result_len);
-  } else {
-    maybe_res = isolate->factory()->NewRawTwoByteString(result_len);
-  }
-  Handle<SeqString> untyped_res;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, untyped_res, maybe_res);
-  Handle<ResultSeqString> result = Handle<ResultSeqString>::cast(untyped_res);
-
-  for (int i = 0; i < matches; i++) {
-    // Copy non-matched subject content.
-    if (subject_pos < indices.at(i)) {
-      String::WriteToFlat(*subject, result->GetChars() + result_pos,
-                          subject_pos, indices.at(i));
-      result_pos += indices.at(i) - subject_pos;
-    }
-
-    // Replace match.
-    if (replacement_len > 0) {
-      String::WriteToFlat(*replacement, result->GetChars() + result_pos, 0,
-                          replacement_len);
-      result_pos += replacement_len;
-    }
-
-    subject_pos = indices.at(i) + pattern_len;
-  }
-  // Add remaining subject content at the end.
-  if (subject_pos < subject_len) {
-    String::WriteToFlat(*subject, result->GetChars() + result_pos, subject_pos,
-                        subject_len);
-  }
-
-  int32_t match_indices[] = {indices.at(matches - 1),
-                             indices.at(matches - 1) + pattern_len};
-  RegExpImpl::SetLastMatchInfo(last_match_info, subject, 0, match_indices);
-
-  return *result;
-}
-
-
-MUST_USE_RESULT static Object* StringReplaceGlobalRegExpWithString(
-    Isolate* isolate, Handle<String> subject, Handle<JSRegExp> regexp,
-    Handle<String> replacement, Handle<JSArray> last_match_info) {
-  DCHECK(subject->IsFlat());
-  DCHECK(replacement->IsFlat());
-
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
-
-  // CompiledReplacement uses zone allocation.
-  ZoneScope zone_scope(isolate->runtime_zone());
-  CompiledReplacement compiled_replacement(zone_scope.zone());
-  bool simple_replace =
-      compiled_replacement.Compile(replacement, capture_count, subject_length);
-
-  // Shortcut for simple non-regexp global replacements
-  if (regexp->TypeTag() == JSRegExp::ATOM && simple_replace) {
-    if (subject->HasOnlyOneByteChars() && replacement->HasOnlyOneByteChars()) {
-      return StringReplaceGlobalAtomRegExpWithString<SeqOneByteString>(
-          isolate, subject, regexp, replacement, last_match_info);
-    } else {
-      return StringReplaceGlobalAtomRegExpWithString<SeqTwoByteString>(
-          isolate, subject, regexp, replacement, last_match_info);
-    }
-  }
-
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  int32_t* current_match = global_cache.FetchNext();
-  if (current_match == NULL) {
-    if (global_cache.HasException()) return isolate->heap()->exception();
-    return *subject;
-  }
-
-  // Guessing the number of parts that the final result string is built
-  // from. Global regexps can match any number of times, so we guess
-  // conservatively.
-  int expected_parts = (compiled_replacement.parts() + 1) * 4 + 1;
-  ReplacementStringBuilder builder(isolate->heap(), subject, expected_parts);
-
-  // Number of parts added by compiled replacement plus preceeding
-  // string and possibly suffix after last match.  It is possible for
-  // all components to use two elements when encoded as two smis.
-  const int parts_added_per_loop = 2 * (compiled_replacement.parts() + 2);
-
-  int prev = 0;
-
-  do {
-    builder.EnsureCapacity(parts_added_per_loop);
-
-    int start = current_match[0];
-    int end = current_match[1];
-
-    if (prev < start) {
-      builder.AddSubjectSlice(prev, start);
-    }
-
-    if (simple_replace) {
-      builder.AddString(replacement);
-    } else {
-      compiled_replacement.Apply(&builder, start, end, current_match);
-    }
-    prev = end;
-
-    current_match = global_cache.FetchNext();
-  } while (current_match != NULL);
-
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  if (prev < subject_length) {
-    builder.EnsureCapacity(2);
-    builder.AddSubjectSlice(prev, subject_length);
-  }
-
-  RegExpImpl::SetLastMatchInfo(last_match_info, subject, capture_count,
-                               global_cache.LastSuccessfulMatch());
-
-  Handle<String> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, builder.ToString());
-  return *result;
-}
-
-
-template <typename ResultSeqString>
-MUST_USE_RESULT static Object* StringReplaceGlobalRegExpWithEmptyString(
-    Isolate* isolate, Handle<String> subject, Handle<JSRegExp> regexp,
-    Handle<JSArray> last_match_info) {
-  DCHECK(subject->IsFlat());
-
-  // Shortcut for simple non-regexp global replacements
-  if (regexp->TypeTag() == JSRegExp::ATOM) {
-    Handle<String> empty_string = isolate->factory()->empty_string();
-    if (subject->IsOneByteRepresentation()) {
-      return StringReplaceGlobalAtomRegExpWithString<SeqOneByteString>(
-          isolate, subject, regexp, empty_string, last_match_info);
-    } else {
-      return StringReplaceGlobalAtomRegExpWithString<SeqTwoByteString>(
-          isolate, subject, regexp, empty_string, last_match_info);
-    }
-  }
-
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  int32_t* current_match = global_cache.FetchNext();
-  if (current_match == NULL) {
-    if (global_cache.HasException()) return isolate->heap()->exception();
-    return *subject;
-  }
-
-  int start = current_match[0];
-  int end = current_match[1];
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
-
-  int new_length = subject_length - (end - start);
-  if (new_length == 0) return isolate->heap()->empty_string();
-
-  Handle<ResultSeqString> answer;
-  if (ResultSeqString::kHasOneByteEncoding) {
-    answer = Handle<ResultSeqString>::cast(
-        isolate->factory()->NewRawOneByteString(new_length).ToHandleChecked());
-  } else {
-    answer = Handle<ResultSeqString>::cast(
-        isolate->factory()->NewRawTwoByteString(new_length).ToHandleChecked());
-  }
-
-  int prev = 0;
-  int position = 0;
-
-  do {
-    start = current_match[0];
-    end = current_match[1];
-    if (prev < start) {
-      // Add substring subject[prev;start] to answer string.
-      String::WriteToFlat(*subject, answer->GetChars() + position, prev, start);
-      position += start - prev;
-    }
-    prev = end;
-
-    current_match = global_cache.FetchNext();
-  } while (current_match != NULL);
-
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  RegExpImpl::SetLastMatchInfo(last_match_info, subject, capture_count,
-                               global_cache.LastSuccessfulMatch());
-
-  if (prev < subject_length) {
-    // Add substring subject[prev;length] to answer string.
-    String::WriteToFlat(*subject, answer->GetChars() + position, prev,
-                        subject_length);
-    position += subject_length - prev;
-  }
-
-  if (position == 0) return isolate->heap()->empty_string();
-
-  // Shorten string and fill
-  int string_size = ResultSeqString::SizeFor(position);
-  int allocated_string_size = ResultSeqString::SizeFor(new_length);
-  int delta = allocated_string_size - string_size;
-
-  answer->set_length(position);
-  if (delta == 0) return *answer;
-
-  Address end_of_string = answer->address() + string_size;
-  Heap* heap = isolate->heap();
-
-  // The trimming is performed on a newly allocated object, which is on a
-  // fresly allocated page or on an already swept page. Hence, the sweeper
-  // thread can not get confused with the filler creation. No synchronization
-  // needed.
-  heap->CreateFillerObjectAt(end_of_string, delta);
-  heap->AdjustLiveBytes(answer->address(), -delta, Heap::FROM_MUTATOR);
-  return *answer;
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringReplaceGlobalRegExpWithString) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 4);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, replacement, 2);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, last_match_info, 3);
-
-  RUNTIME_ASSERT(regexp->GetFlags().is_global());
-  RUNTIME_ASSERT(last_match_info->HasFastObjectElements());
-
-  subject = String::Flatten(subject);
-
-  if (replacement->length() == 0) {
-    if (subject->HasOnlyOneByteChars()) {
-      return StringReplaceGlobalRegExpWithEmptyString<SeqOneByteString>(
-          isolate, subject, regexp, last_match_info);
-    } else {
-      return StringReplaceGlobalRegExpWithEmptyString<SeqTwoByteString>(
-          isolate, subject, regexp, last_match_info);
-    }
-  }
-
-  replacement = String::Flatten(replacement);
-
-  return StringReplaceGlobalRegExpWithString(isolate, subject, regexp,
-                                             replacement, last_match_info);
-}
-
-
-// This may return an empty MaybeHandle if an exception is thrown or
-// we abort due to reaching the recursion limit.
-MaybeHandle<String> StringReplaceOneCharWithString(
-    Isolate* isolate, Handle<String> subject, Handle<String> search,
-    Handle<String> replace, bool* found, int recursion_limit) {
-  StackLimitCheck stackLimitCheck(isolate);
-  if (stackLimitCheck.HasOverflowed() || (recursion_limit == 0)) {
-    return MaybeHandle<String>();
-  }
-  recursion_limit--;
-  if (subject->IsConsString()) {
-    ConsString* cons = ConsString::cast(*subject);
-    Handle<String> first = Handle<String>(cons->first());
-    Handle<String> second = Handle<String>(cons->second());
-    Handle<String> new_first;
-    if (!StringReplaceOneCharWithString(isolate, first, search, replace, found,
-                                        recursion_limit).ToHandle(&new_first)) {
-      return MaybeHandle<String>();
-    }
-    if (*found) return isolate->factory()->NewConsString(new_first, second);
-
-    Handle<String> new_second;
-    if (!StringReplaceOneCharWithString(isolate, second, search, replace, found,
-                                        recursion_limit)
-             .ToHandle(&new_second)) {
-      return MaybeHandle<String>();
-    }
-    if (*found) return isolate->factory()->NewConsString(first, new_second);
-
-    return subject;
-  } else {
-    int index = Runtime::StringMatch(isolate, subject, search, 0);
-    if (index == -1) return subject;
-    *found = true;
-    Handle<String> first = isolate->factory()->NewSubString(subject, 0, index);
-    Handle<String> cons1;
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, cons1, isolate->factory()->NewConsString(first, replace),
-        String);
-    Handle<String> second =
-        isolate->factory()->NewSubString(subject, index + 1, subject->length());
-    return isolate->factory()->NewConsString(cons1, second);
-  }
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringReplaceOneCharWithString) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, search, 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, replace, 2);
-
-  // If the cons string tree is too deep, we simply abort the recursion and
-  // retry with a flattened subject string.
-  const int kRecursionLimit = 0x1000;
-  bool found = false;
-  Handle<String> result;
-  if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found,
-                                     kRecursionLimit).ToHandle(&result)) {
-    return *result;
-  }
-  if (isolate->has_pending_exception()) return isolate->heap()->exception();
-
-  subject = String::Flatten(subject);
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result,
-      StringReplaceOneCharWithString(isolate, subject, search, replace, &found,
-                                     kRecursionLimit));
-  return *result;
-}
-
-
-// Perform string match of pattern on subject, starting at start index.
-// Caller must ensure that 0 <= start_index <= sub->length(),
-// and should check that pat->length() + start_index <= sub->length().
-int Runtime::StringMatch(Isolate* isolate, Handle<String> sub,
-                         Handle<String> pat, int start_index) {
-  DCHECK(0 <= start_index);
-  DCHECK(start_index <= sub->length());
-
-  int pattern_length = pat->length();
-  if (pattern_length == 0) return start_index;
-
-  int subject_length = sub->length();
-  if (start_index + pattern_length > subject_length) return -1;
-
-  sub = String::Flatten(sub);
-  pat = String::Flatten(pat);
-
-  DisallowHeapAllocation no_gc;  // ensure vectors stay valid
-  // Extract flattened substrings of cons strings before getting encoding.
-  String::FlatContent seq_sub = sub->GetFlatContent();
-  String::FlatContent seq_pat = pat->GetFlatContent();
-
-  // dispatch on type of strings
-  if (seq_pat.IsOneByte()) {
-    Vector<const uint8_t> pat_vector = seq_pat.ToOneByteVector();
-    if (seq_sub.IsOneByte()) {
-      return SearchString(isolate, seq_sub.ToOneByteVector(), pat_vector,
-                          start_index);
-    }
-    return SearchString(isolate, seq_sub.ToUC16Vector(), pat_vector,
-                        start_index);
-  }
-  Vector<const uc16> pat_vector = seq_pat.ToUC16Vector();
-  if (seq_sub.IsOneByte()) {
-    return SearchString(isolate, seq_sub.ToOneByteVector(), pat_vector,
-                        start_index);
-  }
-  return SearchString(isolate, seq_sub.ToUC16Vector(), pat_vector, start_index);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringIndexOf) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, sub, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, pat, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, index, 2);
-
-  uint32_t start_index;
-  if (!index->ToArrayIndex(&start_index)) return Smi::FromInt(-1);
-
-  RUNTIME_ASSERT(start_index <= static_cast<uint32_t>(sub->length()));
-  int position = Runtime::StringMatch(isolate, sub, pat, start_index);
-  return Smi::FromInt(position);
-}
-
-
-template <typename schar, typename pchar>
-static int StringMatchBackwards(Vector<const schar> subject,
-                                Vector<const pchar> pattern, int idx) {
-  int pattern_length = pattern.length();
-  DCHECK(pattern_length >= 1);
-  DCHECK(idx + pattern_length <= subject.length());
-
-  if (sizeof(schar) == 1 && sizeof(pchar) > 1) {
-    for (int i = 0; i < pattern_length; i++) {
-      uc16 c = pattern[i];
-      if (c > String::kMaxOneByteCharCode) {
-        return -1;
-      }
-    }
-  }
-
-  pchar pattern_first_char = pattern[0];
-  for (int i = idx; i >= 0; i--) {
-    if (subject[i] != pattern_first_char) continue;
-    int j = 1;
-    while (j < pattern_length) {
-      if (pattern[j] != subject[i + j]) {
-        break;
-      }
-      j++;
-    }
-    if (j == pattern_length) {
-      return i;
-    }
-  }
-  return -1;
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringLastIndexOf) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, sub, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, pat, 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, index, 2);
-
-  uint32_t start_index;
-  if (!index->ToArrayIndex(&start_index)) return Smi::FromInt(-1);
-
-  uint32_t pat_length = pat->length();
-  uint32_t sub_length = sub->length();
-
-  if (start_index + pat_length > sub_length) {
-    start_index = sub_length - pat_length;
-  }
-
-  if (pat_length == 0) {
-    return Smi::FromInt(start_index);
-  }
-
-  sub = String::Flatten(sub);
-  pat = String::Flatten(pat);
-
-  int position = -1;
-  DisallowHeapAllocation no_gc;  // ensure vectors stay valid
-
-  String::FlatContent sub_content = sub->GetFlatContent();
-  String::FlatContent pat_content = pat->GetFlatContent();
-
-  if (pat_content.IsOneByte()) {
-    Vector<const uint8_t> pat_vector = pat_content.ToOneByteVector();
-    if (sub_content.IsOneByte()) {
-      position = StringMatchBackwards(sub_content.ToOneByteVector(), pat_vector,
-                                      start_index);
-    } else {
-      position = StringMatchBackwards(sub_content.ToUC16Vector(), pat_vector,
-                                      start_index);
-    }
-  } else {
-    Vector<const uc16> pat_vector = pat_content.ToUC16Vector();
-    if (sub_content.IsOneByte()) {
-      position = StringMatchBackwards(sub_content.ToOneByteVector(), pat_vector,
-                                      start_index);
-    } else {
-      position = StringMatchBackwards(sub_content.ToUC16Vector(), pat_vector,
-                                      start_index);
-    }
-  }
-
-  return Smi::FromInt(position);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringLocaleCompare) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 2);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, str1, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, str2, 1);
-
-  if (str1.is_identical_to(str2)) return Smi::FromInt(0);  // Equal.
-  int str1_length = str1->length();
-  int str2_length = str2->length();
-
-  // Decide trivial cases without flattening.
-  if (str1_length == 0) {
-    if (str2_length == 0) return Smi::FromInt(0);  // Equal.
-    return Smi::FromInt(-str2_length);
-  } else {
-    if (str2_length == 0) return Smi::FromInt(str1_length);
-  }
-
-  int end = str1_length < str2_length ? str1_length : str2_length;
-
-  // No need to flatten if we are going to find the answer on the first
-  // character.  At this point we know there is at least one character
-  // in each string, due to the trivial case handling above.
-  int d = str1->Get(0) - str2->Get(0);
-  if (d != 0) return Smi::FromInt(d);
-
-  str1 = String::Flatten(str1);
-  str2 = String::Flatten(str2);
-
-  DisallowHeapAllocation no_gc;
-  String::FlatContent flat1 = str1->GetFlatContent();
-  String::FlatContent flat2 = str2->GetFlatContent();
-
-  for (int i = 0; i < end; i++) {
-    if (flat1.Get(i) != flat2.Get(i)) {
-      return Smi::FromInt(flat1.Get(i) - flat2.Get(i));
-    }
-  }
-
-  return Smi::FromInt(str1_length - str2_length);
-}
-
-
-RUNTIME_FUNCTION(Runtime_SubString) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
-  int start, end;
-  // We have a fast integer-only case here to avoid a conversion to double in
-  // the common case where from and to are Smis.
-  if (args[1]->IsSmi() && args[2]->IsSmi()) {
-    CONVERT_SMI_ARG_CHECKED(from_number, 1);
-    CONVERT_SMI_ARG_CHECKED(to_number, 2);
-    start = from_number;
-    end = to_number;
-  } else {
-    CONVERT_DOUBLE_ARG_CHECKED(from_number, 1);
-    CONVERT_DOUBLE_ARG_CHECKED(to_number, 2);
-    start = FastD2IChecked(from_number);
-    end = FastD2IChecked(to_number);
-  }
-  RUNTIME_ASSERT(end >= start);
-  RUNTIME_ASSERT(start >= 0);
-  RUNTIME_ASSERT(end <= string->length());
-  isolate->counters()->sub_string_runtime()->Increment();
-
-  return *isolate->factory()->NewSubString(string, start, end);
-}
-
-
-RUNTIME_FUNCTION(Runtime_InternalizeString) {
-  HandleScope handles(isolate);
-  RUNTIME_ASSERT(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
-  return *isolate->factory()->InternalizeString(string);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringMatch) {
-  HandleScope handles(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, regexp_info, 2);
-
-  RUNTIME_ASSERT(regexp_info->HasFastObjectElements());
-
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  int capture_count = regexp->CaptureCount();
-
-  ZoneScope zone_scope(isolate->runtime_zone());
-  ZoneList<int> offsets(8, zone_scope.zone());
-
-  while (true) {
-    int32_t* match = global_cache.FetchNext();
-    if (match == NULL) break;
-    offsets.Add(match[0], zone_scope.zone());  // start
-    offsets.Add(match[1], zone_scope.zone());  // end
-  }
-
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  if (offsets.length() == 0) {
-    // Not a single match.
-    return isolate->heap()->null_value();
-  }
-
-  RegExpImpl::SetLastMatchInfo(regexp_info, subject, capture_count,
-                               global_cache.LastSuccessfulMatch());
-
-  int matches = offsets.length() / 2;
-  Handle<FixedArray> elements = isolate->factory()->NewFixedArray(matches);
-  Handle<String> substring =
-      isolate->factory()->NewSubString(subject, offsets.at(0), offsets.at(1));
-  elements->set(0, *substring);
-  for (int i = 1; i < matches; i++) {
-    HandleScope temp_scope(isolate);
-    int from = offsets.at(i * 2);
-    int to = offsets.at(i * 2 + 1);
-    Handle<String> substring =
-        isolate->factory()->NewProperSubString(subject, from, to);
-    elements->set(i, *substring);
-  }
-  Handle<JSArray> result = isolate->factory()->NewJSArrayWithElements(elements);
-  result->set_length(Smi::FromInt(matches));
-  return *result;
-}
-
-
-// Only called from Runtime_RegExpExecMultiple so it doesn't need to maintain
-// separate last match info.  See comment on that function.
-template <bool has_capture>
-static Object* SearchRegExpMultiple(Isolate* isolate, Handle<String> subject,
-                                    Handle<JSRegExp> regexp,
-                                    Handle<JSArray> last_match_array,
-                                    Handle<JSArray> result_array) {
-  DCHECK(subject->IsFlat());
-  DCHECK_NE(has_capture, regexp->CaptureCount() == 0);
-
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
-
-  static const int kMinLengthToCache = 0x1000;
-
-  if (subject_length > kMinLengthToCache) {
-    Handle<Object> cached_answer(
-        RegExpResultsCache::Lookup(isolate->heap(), *subject, regexp->data(),
-                                   RegExpResultsCache::REGEXP_MULTIPLE_INDICES),
-        isolate);
-    if (*cached_answer != Smi::FromInt(0)) {
-      Handle<FixedArray> cached_fixed_array =
-          Handle<FixedArray>(FixedArray::cast(*cached_answer));
-      // The cache FixedArray is a COW-array and can therefore be reused.
-      JSArray::SetContent(result_array, cached_fixed_array);
-      // The actual length of the result array is stored in the last element of
-      // the backing store (the backing FixedArray may have a larger capacity).
-      Object* cached_fixed_array_last_element =
-          cached_fixed_array->get(cached_fixed_array->length() - 1);
-      Smi* js_array_length = Smi::cast(cached_fixed_array_last_element);
-      result_array->set_length(js_array_length);
-      RegExpImpl::SetLastMatchInfo(last_match_array, subject, capture_count,
-                                   NULL);
-      return *result_array;
-    }
-  }
-
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  // Ensured in Runtime_RegExpExecMultiple.
-  DCHECK(result_array->HasFastObjectElements());
-  Handle<FixedArray> result_elements(
-      FixedArray::cast(result_array->elements()));
-  if (result_elements->length() < 16) {
-    result_elements = isolate->factory()->NewFixedArrayWithHoles(16);
-  }
-
-  FixedArrayBuilder builder(result_elements);
-
-  // Position to search from.
-  int match_start = -1;
-  int match_end = 0;
-  bool first = true;
-
-  // Two smis before and after the match, for very long strings.
-  static const int kMaxBuilderEntriesPerRegExpMatch = 5;
-
-  while (true) {
-    int32_t* current_match = global_cache.FetchNext();
-    if (current_match == NULL) break;
-    match_start = current_match[0];
-    builder.EnsureCapacity(kMaxBuilderEntriesPerRegExpMatch);
-    if (match_end < match_start) {
-      ReplacementStringBuilder::AddSubjectSlice(&builder, match_end,
-                                                match_start);
-    }
-    match_end = current_match[1];
-    {
-      // Avoid accumulating new handles inside loop.
-      HandleScope temp_scope(isolate);
-      Handle<String> match;
-      if (!first) {
-        match = isolate->factory()->NewProperSubString(subject, match_start,
-                                                       match_end);
-      } else {
-        match =
-            isolate->factory()->NewSubString(subject, match_start, match_end);
-        first = false;
-      }
-
-      if (has_capture) {
-        // Arguments array to replace function is match, captures, index and
-        // subject, i.e., 3 + capture count in total.
-        Handle<FixedArray> elements =
-            isolate->factory()->NewFixedArray(3 + capture_count);
-
-        elements->set(0, *match);
-        for (int i = 1; i <= capture_count; i++) {
-          int start = current_match[i * 2];
-          if (start >= 0) {
-            int end = current_match[i * 2 + 1];
-            DCHECK(start <= end);
-            Handle<String> substring =
-                isolate->factory()->NewSubString(subject, start, end);
-            elements->set(i, *substring);
-          } else {
-            DCHECK(current_match[i * 2 + 1] < 0);
-            elements->set(i, isolate->heap()->undefined_value());
-          }
-        }
-        elements->set(capture_count + 1, Smi::FromInt(match_start));
-        elements->set(capture_count + 2, *subject);
-        builder.Add(*isolate->factory()->NewJSArrayWithElements(elements));
-      } else {
-        builder.Add(*match);
-      }
-    }
-  }
-
-  if (global_cache.HasException()) return isolate->heap()->exception();
-
-  if (match_start >= 0) {
-    // Finished matching, with at least one match.
-    if (match_end < subject_length) {
-      ReplacementStringBuilder::AddSubjectSlice(&builder, match_end,
-                                                subject_length);
-    }
-
-    RegExpImpl::SetLastMatchInfo(last_match_array, subject, capture_count,
-                                 NULL);
-
-    if (subject_length > kMinLengthToCache) {
-      // Store the length of the result array into the last element of the
-      // backing FixedArray.
-      builder.EnsureCapacity(1);
-      Handle<FixedArray> fixed_array = builder.array();
-      fixed_array->set(fixed_array->length() - 1,
-                       Smi::FromInt(builder.length()));
-      // Cache the result and turn the FixedArray into a COW array.
-      RegExpResultsCache::Enter(isolate, subject,
-                                handle(regexp->data(), isolate), fixed_array,
-                                RegExpResultsCache::REGEXP_MULTIPLE_INDICES);
-    }
-    return *builder.ToJSArray(result_array);
-  } else {
-    return isolate->heap()->null_value();  // No matches at all.
-  }
-}
-
-
-// This is only called for StringReplaceGlobalRegExpWithFunction.  This sets
-// lastMatchInfoOverride to maintain the last match info, so we don't need to
-// set any other last match array info.
-RUNTIME_FUNCTION(Runtime_RegExpExecMultiple) {
-  HandleScope handles(isolate);
-  DCHECK(args.length() == 4);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 1);
-  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, last_match_info, 2);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, result_array, 3);
-  RUNTIME_ASSERT(last_match_info->HasFastObjectElements());
-  RUNTIME_ASSERT(result_array->HasFastObjectElements());
-
-  subject = String::Flatten(subject);
-  RUNTIME_ASSERT(regexp->GetFlags().is_global());
-
-  if (regexp->CaptureCount() == 0) {
-    return SearchRegExpMultiple<false>(isolate, subject, regexp,
-                                       last_match_info, result_array);
-  } else {
-    return SearchRegExpMultiple<true>(isolate, subject, regexp, last_match_info,
-                                      result_array);
-  }
-}
-
-
 RUNTIME_FUNCTION(Runtime_NumberToRadixString) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_SMI_ARG_CHECKED(radix, 1);
   RUNTIME_ASSERT(2 <= radix && radix <= 36);
 
   // Fast case where the result is a one character string.
   if (args[0]->IsSmi()) {
     int value = args.smi_at(0);
     if (value >= 0 && value < radix) {
@@ skipping 1580 matching lines @@
     // The current spec draft has not updated "ToNumber Applied to the String
     // Type", https://bugs.ecmascript.org/show_bug.cgi?id=1584
     flags |= ALLOW_OCTAL | ALLOW_BINARY;
   }
 
   return *isolate->factory()->NewNumber(
       StringToDouble(isolate->unicode_cache(), *subject, flags));
 }
 
 
-RUNTIME_FUNCTION(Runtime_NewString) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_INT32_ARG_CHECKED(length, 0);
-  CONVERT_BOOLEAN_ARG_CHECKED(is_one_byte, 1);
-  if (length == 0) return isolate->heap()->empty_string();
-  Handle<String> result;
-  if (is_one_byte) {
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, result, isolate->factory()->NewRawOneByteString(length));
-  } else {
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, result, isolate->factory()->NewRawTwoByteString(length));
-  }
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_TruncateString) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(SeqString, string, 0);
-  CONVERT_INT32_ARG_CHECKED(new_length, 1);
-  RUNTIME_ASSERT(new_length >= 0);
-  return *SeqString::Truncate(string, new_length);
-}
-
-
-RUNTIME_FUNCTION(Runtime_URIEscape) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, source, 0);
-  Handle<String> string = String::Flatten(source);
-  DCHECK(string->IsFlat());
-  Handle<String> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result, string->IsOneByteRepresentationUnderneath()
-                           ? URIEscape::Escape<uint8_t>(isolate, source)
-                           : URIEscape::Escape<uc16>(isolate, source));
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_URIUnescape) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, source, 0);
-  Handle<String> string = String::Flatten(source);
-  DCHECK(string->IsFlat());
-  Handle<String> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result, string->IsOneByteRepresentationUnderneath()
-                           ? URIUnescape::Unescape<uint8_t>(isolate, source)
-                           : URIUnescape::Unescape<uc16>(isolate, source));
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_QuoteJSONString) {
-  HandleScope scope(isolate);
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
-  DCHECK(args.length() == 1);
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result, BasicJsonStringifier::StringifyString(isolate, string));
-  return *result;
-}
-
-
-RUNTIME_FUNCTION(Runtime_BasicJSONStringify) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
-  BasicJsonStringifier stringifier(isolate);
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     stringifier.Stringify(object));
-  return *result;
-}
-
-
 RUNTIME_FUNCTION(Runtime_StringParseInt) {
   HandleScope handle_scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
   CONVERT_NUMBER_CHECKED(int, radix, Int32, args[1]);
   RUNTIME_ASSERT(radix == 0 || (2 <= radix && radix <= 36));
 
   subject = String::Flatten(subject);
   double value;
 
@@ skipping 20 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
 
   subject = String::Flatten(subject);
   double value = StringToDouble(isolate->unicode_cache(), *subject,
                                 ALLOW_TRAILING_JUNK, base::OS::nan_value());
 
   return *isolate->factory()->NewNumber(value);
 }
 
 
-static inline bool ToUpperOverflows(uc32 character) {
-  // y with umlauts and the micro sign are the only characters that stop
-  // fitting into one-byte when converting to uppercase.
-  static const uc32 yuml_code = 0xff;
-  static const uc32 micro_code = 0xb5;
-  return (character == yuml_code || character == micro_code);
-}
-
-
-template <class Converter>
-MUST_USE_RESULT static Object* ConvertCaseHelper(
-    Isolate* isolate, String* string, SeqString* result, int result_length,
-    unibrow::Mapping<Converter, 128>* mapping) {
-  DisallowHeapAllocation no_gc;
-  // We try this twice, once with the assumption that the result is no longer
-  // than the input and, if that assumption breaks, again with the exact
-  // length.  This may not be pretty, but it is nicer than what was here before
-  // and I hereby claim my vaffel-is.
-  //
-  // NOTE: This assumes that the upper/lower case of an ASCII
-  // character is also ASCII.  This is currently the case, but it
-  // might break in the future if we implement more context and locale
-  // dependent upper/lower conversions.
-  bool has_changed_character = false;
-
-  // Convert all characters to upper case, assuming that they will fit
-  // in the buffer
-  Access<ConsStringIteratorOp> op(isolate->runtime_state()->string_iterator());
-  StringCharacterStream stream(string, op.value());
-  unibrow::uchar chars[Converter::kMaxWidth];
-  // We can assume that the string is not empty
-  uc32 current = stream.GetNext();
-  bool ignore_overflow = Converter::kIsToLower || result->IsSeqTwoByteString();
-  for (int i = 0; i < result_length;) {
-    bool has_next = stream.HasMore();
-    uc32 next = has_next ? stream.GetNext() : 0;
-    int char_length = mapping->get(current, next, chars);
-    if (char_length == 0) {
-      // The case conversion of this character is the character itself.
-      result->Set(i, current);
-      i++;
-    } else if (char_length == 1 &&
-               (ignore_overflow || !ToUpperOverflows(current))) {
-      // Common case: converting the letter resulted in one character.
-      DCHECK(static_cast<uc32>(chars[0]) != current);
-      result->Set(i, chars[0]);
-      has_changed_character = true;
-      i++;
-    } else if (result_length == string->length()) {
-      bool overflows = ToUpperOverflows(current);
-      // We've assumed that the result would be as long as the
-      // input but here is a character that converts to several
-      // characters.  No matter, we calculate the exact length
-      // of the result and try the whole thing again.
-      //
-      // Note that this leaves room for optimization.  We could just
-      // memcpy what we already have to the result string.  Also,
-      // the result string is the last object allocated we could
-      // "realloc" it and probably, in the vast majority of cases,
-      // extend the existing string to be able to hold the full
-      // result.
-      int next_length = 0;
-      if (has_next) {
-        next_length = mapping->get(next, 0, chars);
-        if (next_length == 0) next_length = 1;
-      }
-      int current_length = i + char_length + next_length;
-      while (stream.HasMore()) {
-        current = stream.GetNext();
-        overflows |= ToUpperOverflows(current);
-        // NOTE: we use 0 as the next character here because, while
-        // the next character may affect what a character converts to,
-        // it does not in any case affect the length of what it convert
-        // to.
-        int char_length = mapping->get(current, 0, chars);
-        if (char_length == 0) char_length = 1;
-        current_length += char_length;
-        if (current_length > String::kMaxLength) {
-          AllowHeapAllocation allocate_error_and_return;
-          THROW_NEW_ERROR_RETURN_FAILURE(isolate,
-                                         NewInvalidStringLengthError());
-        }
-      }
-      // Try again with the real length.  Return signed if we need
-      // to allocate a two-byte string for to uppercase.
-      return (overflows && !ignore_overflow) ? Smi::FromInt(-current_length)
-                                             : Smi::FromInt(current_length);
-    } else {
-      for (int j = 0; j < char_length; j++) {
-        result->Set(i, chars[j]);
-        i++;
-      }
-      has_changed_character = true;
-    }
-    current = next;
-  }
-  if (has_changed_character) {
-    return result;
-  } else {
-    // If we didn't actually change anything in doing the conversion
-    // we simple return the result and let the converted string
-    // become garbage; there is no reason to keep two identical strings
-    // alive.
-    return string;
-  }
-}
-
-
-namespace {
-
-static const uintptr_t kOneInEveryByte = kUintptrAllBitsSet / 0xFF;
-static const uintptr_t kAsciiMask = kOneInEveryByte << 7;
-
-// Given a word and two range boundaries returns a word with high bit
-// set in every byte iff the corresponding input byte was strictly in
-// the range (m, n). All the other bits in the result are cleared.
-// This function is only useful when it can be inlined and the
-// boundaries are statically known.
-// Requires: all bytes in the input word and the boundaries must be
-// ASCII (less than 0x7F).
-static inline uintptr_t AsciiRangeMask(uintptr_t w, char m, char n) {
-  // Use strict inequalities since in edge cases the function could be
-  // further simplified.
-  DCHECK(0 < m && m < n);
-  // Has high bit set in every w byte less than n.
-  uintptr_t tmp1 = kOneInEveryByte * (0x7F + n) - w;
-  // Has high bit set in every w byte greater than m.
-  uintptr_t tmp2 = w + kOneInEveryByte * (0x7F - m);
-  return (tmp1 & tmp2 & (kOneInEveryByte * 0x80));
-}
-
-
-#ifdef DEBUG
-static bool CheckFastAsciiConvert(char* dst, const char* src, int length,
-                                  bool changed, bool is_to_lower) {
-  bool expected_changed = false;
-  for (int i = 0; i < length; i++) {
-    if (dst[i] == src[i]) continue;
-    expected_changed = true;
-    if (is_to_lower) {
-      DCHECK('A' <= src[i] && src[i] <= 'Z');
-      DCHECK(dst[i] == src[i] + ('a' - 'A'));
-    } else {
-      DCHECK('a' <= src[i] && src[i] <= 'z');
-      DCHECK(dst[i] == src[i] - ('a' - 'A'));
-    }
-  }
-  return (expected_changed == changed);
-}
-#endif
-
-
-template <class Converter>
-static bool FastAsciiConvert(char* dst, const char* src, int length,
-                             bool* changed_out) {
-#ifdef DEBUG
-  char* saved_dst = dst;
-  const char* saved_src = src;
-#endif
-  DisallowHeapAllocation no_gc;
-  // We rely on the distance between upper and lower case letters
-  // being a known power of 2.
-  DCHECK('a' - 'A' == (1 << 5));
-  // Boundaries for the range of input characters than require conversion.
-  static const char lo = Converter::kIsToLower ? 'A' - 1 : 'a' - 1;
-  static const char hi = Converter::kIsToLower ? 'Z' + 1 : 'z' + 1;
-  bool changed = false;
-  uintptr_t or_acc = 0;
-  const char* const limit = src + length;
-
-  // dst is newly allocated and always aligned.
-  DCHECK(IsAligned(reinterpret_cast<intptr_t>(dst), sizeof(uintptr_t)));
-  // Only attempt processing one word at a time if src is also aligned.
-  if (IsAligned(reinterpret_cast<intptr_t>(src), sizeof(uintptr_t))) {
-    // Process the prefix of the input that requires no conversion one aligned
-    // (machine) word at a time.
-    while (src <= limit - sizeof(uintptr_t)) {
-      const uintptr_t w = *reinterpret_cast<const uintptr_t*>(src);
-      or_acc |= w;
-      if (AsciiRangeMask(w, lo, hi) != 0) {
-        changed = true;
-        break;
-      }
-      *reinterpret_cast<uintptr_t*>(dst) = w;
-      src += sizeof(uintptr_t);
-      dst += sizeof(uintptr_t);
-    }
-    // Process the remainder of the input performing conversion when
-    // required one word at a time.
-    while (src <= limit - sizeof(uintptr_t)) {
-      const uintptr_t w = *reinterpret_cast<const uintptr_t*>(src);
-      or_acc |= w;
-      uintptr_t m = AsciiRangeMask(w, lo, hi);
-      // The mask has high (7th) bit set in every byte that needs
-      // conversion and we know that the distance between cases is
-      // 1 << 5.
-      *reinterpret_cast<uintptr_t*>(dst) = w ^ (m >> 2);
-      src += sizeof(uintptr_t);
-      dst += sizeof(uintptr_t);
-    }
-  }
-  // Process the last few bytes of the input (or the whole input if
-  // unaligned access is not supported).
-  while (src < limit) {
-    char c = *src;
-    or_acc |= c;
-    if (lo < c && c < hi) {
-      c ^= (1 << 5);
-      changed = true;
-    }
-    *dst = c;
-    ++src;
-    ++dst;
-  }
-
-  if ((or_acc & kAsciiMask) != 0) return false;
-
-  DCHECK(CheckFastAsciiConvert(saved_dst, saved_src, length, changed,
-                               Converter::kIsToLower));
-
-  *changed_out = changed;
-  return true;
-}
-
-}  // namespace
-
-
-template <class Converter>
-MUST_USE_RESULT static Object* ConvertCase(
-    Handle<String> s, Isolate* isolate,
-    unibrow::Mapping<Converter, 128>* mapping) {
-  s = String::Flatten(s);
-  int length = s->length();
-  // Assume that the string is not empty; we need this assumption later
-  if (length == 0) return *s;
-
-  // Simpler handling of ASCII strings.
-  //
-  // NOTE: This assumes that the upper/lower case of an ASCII
-  // character is also ASCII.  This is currently the case, but it
-  // might break in the future if we implement more context and locale
-  // dependent upper/lower conversions.
-  if (s->IsOneByteRepresentationUnderneath()) {
-    // Same length as input.
-    Handle<SeqOneByteString> result =
-        isolate->factory()->NewRawOneByteString(length).ToHandleChecked();
-    DisallowHeapAllocation no_gc;
-    String::FlatContent flat_content = s->GetFlatContent();
-    DCHECK(flat_content.IsFlat());
-    bool has_changed_character = false;
-    bool is_ascii = FastAsciiConvert<Converter>(
-        reinterpret_cast<char*>(result->GetChars()),
-        reinterpret_cast<const char*>(flat_content.ToOneByteVector().start()),
-        length, &has_changed_character);
-    // If not ASCII, we discard the result and take the 2 byte path.
-    if (is_ascii) return has_changed_character ? *result : *s;
-  }
-
-  Handle<SeqString> result;  // Same length as input.
-  if (s->IsOneByteRepresentation()) {
-    result = isolate->factory()->NewRawOneByteString(length).ToHandleChecked();
-  } else {
-    result = isolate->factory()->NewRawTwoByteString(length).ToHandleChecked();
-  }
-
-  Object* answer = ConvertCaseHelper(isolate, *s, *result, length, mapping);
-  if (answer->IsException() || answer->IsString()) return answer;
-
-  DCHECK(answer->IsSmi());
-  length = Smi::cast(answer)->value();
-  if (s->IsOneByteRepresentation() && length > 0) {
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, result, isolate->factory()->NewRawOneByteString(length));
-  } else {
-    if (length < 0) length = -length;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, result, isolate->factory()->NewRawTwoByteString(length));
-  }
-  return ConvertCaseHelper(isolate, *s, *result, length, mapping);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringToLowerCase) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, s, 0);
-  return ConvertCase(s, isolate, isolate->runtime_state()->to_lower_mapping());
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringToUpperCase) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, s, 0);
-  return ConvertCase(s, isolate, isolate->runtime_state()->to_upper_mapping());
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringTrim) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
-  CONVERT_BOOLEAN_ARG_CHECKED(trimLeft, 1);
-  CONVERT_BOOLEAN_ARG_CHECKED(trimRight, 2);
-
-  string = String::Flatten(string);
-  int length = string->length();
-
-  int left = 0;
-  UnicodeCache* unicode_cache = isolate->unicode_cache();
-  if (trimLeft) {
-    while (left < length &&
-           unicode_cache->IsWhiteSpaceOrLineTerminator(string->Get(left))) {
-      left++;
-    }
-  }
-
-  int right = length;
-  if (trimRight) {
-    while (
-        right > left &&
-        unicode_cache->IsWhiteSpaceOrLineTerminator(string->Get(right - 1))) {
-      right--;
-    }
-  }
-
-  return *isolate->factory()->NewSubString(string, left, right);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringSplit) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, pattern, 1);
-  CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[2]);
-  RUNTIME_ASSERT(limit > 0);
-
-  int subject_length = subject->length();
-  int pattern_length = pattern->length();
-  RUNTIME_ASSERT(pattern_length > 0);
-
-  if (limit == 0xffffffffu) {
-    Handle<Object> cached_answer(
-        RegExpResultsCache::Lookup(isolate->heap(), *subject, *pattern,
-                                   RegExpResultsCache::STRING_SPLIT_SUBSTRINGS),
-        isolate);
-    if (*cached_answer != Smi::FromInt(0)) {
-      // The cache FixedArray is a COW-array and can therefore be reused.
-      Handle<JSArray> result = isolate->factory()->NewJSArrayWithElements(
-          Handle<FixedArray>::cast(cached_answer));
-      return *result;
-    }
-  }
-
-  // The limit can be very large (0xffffffffu), but since the pattern
-  // isn't empty, we can never create more parts than ~half the length
-  // of the subject.
-
-  subject = String::Flatten(subject);
-  pattern = String::Flatten(pattern);
-
-  static const int kMaxInitialListCapacity = 16;
-
-  ZoneScope zone_scope(isolate->runtime_zone());
-
-  // Find (up to limit) indices of separator and end-of-string in subject
-  int initial_capacity = Min<uint32_t>(kMaxInitialListCapacity, limit);
-  ZoneList<int> indices(initial_capacity, zone_scope.zone());
-
-  FindStringIndicesDispatch(isolate, *subject, *pattern, &indices, limit,
-                            zone_scope.zone());
-
-  if (static_cast<uint32_t>(indices.length()) < limit) {
-    indices.Add(subject_length, zone_scope.zone());
-  }
-
-  // The list indices now contains the end of each part to create.
-
-  // Create JSArray of substrings separated by separator.
-  int part_count = indices.length();
-
-  Handle<JSArray> result = isolate->factory()->NewJSArray(part_count);
-  JSObject::EnsureCanContainHeapObjectElements(result);
-  result->set_length(Smi::FromInt(part_count));
-
-  DCHECK(result->HasFastObjectElements());
-
-  if (part_count == 1 && indices.at(0) == subject_length) {
-    FixedArray::cast(result->elements())->set(0, *subject);
-    return *result;
-  }
-
-  Handle<FixedArray> elements(FixedArray::cast(result->elements()));
-  int part_start = 0;
-  for (int i = 0; i < part_count; i++) {
-    HandleScope local_loop_handle(isolate);
-    int part_end = indices.at(i);
-    Handle<String> substring =
-        isolate->factory()->NewProperSubString(subject, part_start, part_end);
-    elements->set(i, *substring);
-    part_start = part_end + pattern_length;
-  }
-
-  if (limit == 0xffffffffu) {
-    if (result->HasFastObjectElements()) {
-      RegExpResultsCache::Enter(isolate, subject, pattern, elements,
-                                RegExpResultsCache::STRING_SPLIT_SUBSTRINGS);
-    }
-  }
-
-  return *result;
-}
-
-
-// Copies Latin1 characters to the given fixed array looking up
-// one-char strings in the cache. Gives up on the first char that is
-// not in the cache and fills the remainder with smi zeros. Returns
-// the length of the successfully copied prefix.
-static int CopyCachedOneByteCharsToArray(Heap* heap, const uint8_t* chars,
-                                         FixedArray* elements, int length) {
-  DisallowHeapAllocation no_gc;
-  FixedArray* one_byte_cache = heap->single_character_string_cache();
-  Object* undefined = heap->undefined_value();
-  int i;
-  WriteBarrierMode mode = elements->GetWriteBarrierMode(no_gc);
-  for (i = 0; i < length; ++i) {
-    Object* value = one_byte_cache->get(chars[i]);
-    if (value == undefined) break;
-    elements->set(i, value, mode);
-  }
-  if (i < length) {
-    DCHECK(Smi::FromInt(0) == 0);
-    memset(elements->data_start() + i, 0, kPointerSize * (length - i));
-  }
-#ifdef DEBUG
-  for (int j = 0; j < length; ++j) {
-    Object* element = elements->get(j);
-    DCHECK(element == Smi::FromInt(0) ||
-           (element->IsString() && String::cast(element)->LooksValid()));
-  }
-#endif
-  return i;
-}
-
-
-// Converts a String to JSArray.
-// For example, "foo" => ["f", "o", "o"].
-RUNTIME_FUNCTION(Runtime_StringToArray) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, s, 0);
-  CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);
-
-  s = String::Flatten(s);
-  const int length = static_cast<int>(Min<uint32_t>(s->length(), limit));
-
-  Handle<FixedArray> elements;
-  int position = 0;
-  if (s->IsFlat() && s->IsOneByteRepresentation()) {
-    // Try using cached chars where possible.
-    elements = isolate->factory()->NewUninitializedFixedArray(length);
-
-    DisallowHeapAllocation no_gc;
-    String::FlatContent content = s->GetFlatContent();
-    if (content.IsOneByte()) {
-      Vector<const uint8_t> chars = content.ToOneByteVector();
-      // Note, this will initialize all elements (not only the prefix)
-      // to prevent GC from seeing partially initialized array.
-      position = CopyCachedOneByteCharsToArray(isolate->heap(), chars.start(),
-                                               *elements, length);
-    } else {
-      MemsetPointer(elements->data_start(), isolate->heap()->undefined_value(),
-                    length);
-    }
-  } else {
-    elements = isolate->factory()->NewFixedArray(length);
-  }
-  for (int i = position; i < length; ++i) {
-    Handle<Object> str =
-        isolate->factory()->LookupSingleCharacterStringFromCode(s->Get(i));
-    elements->set(i, *str);
-  }
-
-#ifdef DEBUG
-  for (int i = 0; i < length; ++i) {
-    DCHECK(String::cast(elements->get(i))->length() == 1);
-  }
-#endif
-
-  return *isolate->factory()->NewJSArrayWithElements(elements);
-}
-
-
 RUNTIME_FUNCTION(Runtime_NewStringWrapper) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(String, value, 0);
   return *Object::ToObject(isolate, value).ToHandleChecked();
 }
 
 
-bool Runtime::IsUpperCaseChar(RuntimeState* runtime_state, uint16_t ch) {
-  unibrow::uchar chars[unibrow::ToUppercase::kMaxWidth];
-  int char_length = runtime_state->to_upper_mapping()->get(ch, 0, chars);
-  return char_length == 0;
-}
-
-
 RUNTIME_FUNCTION(Runtime_NumberToStringRT) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_NUMBER_ARG_HANDLE_CHECKED(number, 0);
 
   return *isolate->factory()->NumberToString(number);
 }
 
 
 RUNTIME_FUNCTION(Runtime_NumberToStringSkipCache) {
@@ skipping 137 matching lines @@
 
   // We rely on implementation-defined behavior below, but at least not on
   // undefined behavior.
   CONVERT_NUMBER_CHECKED(uint32_t, x, Int32, args[0]);
   CONVERT_NUMBER_CHECKED(uint32_t, y, Int32, args[1]);
   int32_t product = static_cast<int32_t>(x * y);
   return *isolate->factory()->NewNumberFromInt(product);
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringAdd) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, str1, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, str2, 1);
-  isolate->counters()->string_add_runtime()->Increment();
-  Handle<String> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, result, isolate->factory()->NewConsString(str1, str2));
-  return *result;
-}
-
-
-template <typename sinkchar>
-static inline void StringBuilderConcatHelper(String* special, sinkchar* sink,
-                                             FixedArray* fixed_array,
-                                             int array_length) {
-  DisallowHeapAllocation no_gc;
-  int position = 0;
-  for (int i = 0; i < array_length; i++) {
-    Object* element = fixed_array->get(i);
-    if (element->IsSmi()) {
-      // Smi encoding of position and length.
-      int encoded_slice = Smi::cast(element)->value();
-      int pos;
-      int len;
-      if (encoded_slice > 0) {
-        // Position and length encoded in one smi.
-        pos = StringBuilderSubstringPosition::decode(encoded_slice);
-        len = StringBuilderSubstringLength::decode(encoded_slice);
-      } else {
-        // Position and length encoded in two smis.
-        Object* obj = fixed_array->get(++i);
-        DCHECK(obj->IsSmi());
-        pos = Smi::cast(obj)->value();
-        len = -encoded_slice;
-      }
-      String::WriteToFlat(special, sink + position, pos, pos + len);
-      position += len;
-    } else {
-      String* string = String::cast(element);
-      int element_length = string->length();
-      String::WriteToFlat(string, sink + position, 0, element_length);
-      position += element_length;
-    }
-  }
-}
-
-
-// Returns the result length of the concatenation.
-// On illegal argument, -1 is returned.
-static inline int StringBuilderConcatLength(int special_length,
-                                            FixedArray* fixed_array,
-                                            int array_length, bool* one_byte) {
-  DisallowHeapAllocation no_gc;
-  int position = 0;
-  for (int i = 0; i < array_length; i++) {
-    int increment = 0;
-    Object* elt = fixed_array->get(i);
-    if (elt->IsSmi()) {
-      // Smi encoding of position and length.
-      int smi_value = Smi::cast(elt)->value();
-      int pos;
-      int len;
-      if (smi_value > 0) {
-        // Position and length encoded in one smi.
-        pos = StringBuilderSubstringPosition::decode(smi_value);
-        len = StringBuilderSubstringLength::decode(smi_value);
-      } else {
-        // Position and length encoded in two smis.
-        len = -smi_value;
-        // Get the position and check that it is a positive smi.
-        i++;
-        if (i >= array_length) return -1;
-        Object* next_smi = fixed_array->get(i);
-        if (!next_smi->IsSmi()) return -1;
-        pos = Smi::cast(next_smi)->value();
-        if (pos < 0) return -1;
-      }
-      DCHECK(pos >= 0);
-      DCHECK(len >= 0);
-      if (pos > special_length || len > special_length - pos) return -1;
-      increment = len;
-    } else if (elt->IsString()) {
-      String* element = String::cast(elt);
-      int element_length = element->length();
-      increment = element_length;
-      if (*one_byte && !element->HasOnlyOneByteChars()) {
-        *one_byte = false;
-      }
-    } else {
-      return -1;
-    }
-    if (increment > String::kMaxLength - position) {
-      return kMaxInt;  // Provoke throw on allocation.
-    }
-    position += increment;
-  }
-  return position;
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringBuilderConcat) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
-  int32_t array_length;
-  if (!args[1]->ToInt32(&array_length)) {
-    THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
-  }
-  CONVERT_ARG_HANDLE_CHECKED(String, special, 2);
-
-  size_t actual_array_length = 0;
-  RUNTIME_ASSERT(
-      TryNumberToSize(isolate, array->length(), &actual_array_length));
-  RUNTIME_ASSERT(array_length >= 0);
-  RUNTIME_ASSERT(static_cast<size_t>(array_length) <= actual_array_length);
-
-  // This assumption is used by the slice encoding in one or two smis.
-  DCHECK(Smi::kMaxValue >= String::kMaxLength);
-
-  RUNTIME_ASSERT(array->HasFastElements());
-  JSObject::EnsureCanContainHeapObjectElements(array);
-
-  int special_length = special->length();
-  if (!array->HasFastObjectElements()) {
-    return isolate->Throw(isolate->heap()->illegal_argument_string());
-  }
-
-  int length;
-  bool one_byte = special->HasOnlyOneByteChars();
-
-  {
-    DisallowHeapAllocation no_gc;
-    FixedArray* fixed_array = FixedArray::cast(array->elements());
-    if (fixed_array->length() < array_length) {
-      array_length = fixed_array->length();
-    }
-
-    if (array_length == 0) {
-      return isolate->heap()->empty_string();
-    } else if (array_length == 1) {
-      Object* first = fixed_array->get(0);
-      if (first->IsString()) return first;
-    }
-    length = StringBuilderConcatLength(special_length, fixed_array,
-                                       array_length, &one_byte);
-  }
-
-  if (length == -1) {
-    return isolate->Throw(isolate->heap()->illegal_argument_string());
-  }
-
-  if (one_byte) {
-    Handle<SeqOneByteString> answer;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, answer, isolate->factory()->NewRawOneByteString(length));
-    StringBuilderConcatHelper(*special, answer->GetChars(),
-                              FixedArray::cast(array->elements()),
-                              array_length);
-    return *answer;
-  } else {
-    Handle<SeqTwoByteString> answer;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, answer, isolate->factory()->NewRawTwoByteString(length));
-    StringBuilderConcatHelper(*special, answer->GetChars(),
-                              FixedArray::cast(array->elements()),
-                              array_length);
-    return *answer;
-  }
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringBuilderJoin) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
-  int32_t array_length;
-  if (!args[1]->ToInt32(&array_length)) {
-    THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
-  }
-  CONVERT_ARG_HANDLE_CHECKED(String, separator, 2);
-  RUNTIME_ASSERT(array->HasFastObjectElements());
-  RUNTIME_ASSERT(array_length >= 0);
-
-  Handle<FixedArray> fixed_array(FixedArray::cast(array->elements()));
-  if (fixed_array->length() < array_length) {
-    array_length = fixed_array->length();
-  }
-
-  if (array_length == 0) {
-    return isolate->heap()->empty_string();
-  } else if (array_length == 1) {
-    Object* first = fixed_array->get(0);
-    RUNTIME_ASSERT(first->IsString());
-    return first;
-  }
-
-  int separator_length = separator->length();
-  RUNTIME_ASSERT(separator_length > 0);
-  int max_nof_separators =
-      (String::kMaxLength + separator_length - 1) / separator_length;
-  if (max_nof_separators < (array_length - 1)) {
-    THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
-  }
-  int length = (array_length - 1) * separator_length;
-  for (int i = 0; i < array_length; i++) {
-    Object* element_obj = fixed_array->get(i);
-    RUNTIME_ASSERT(element_obj->IsString());
-    String* element = String::cast(element_obj);
-    int increment = element->length();
-    if (increment > String::kMaxLength - length) {
-      STATIC_ASSERT(String::kMaxLength < kMaxInt);
-      length = kMaxInt;  // Provoke exception;
-      break;
-    }
-    length += increment;
-  }
-
-  Handle<SeqTwoByteString> answer;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, answer, isolate->factory()->NewRawTwoByteString(length));
-
-  DisallowHeapAllocation no_gc;
-
-  uc16* sink = answer->GetChars();
-#ifdef DEBUG
-  uc16* end = sink + length;
-#endif
-
-  RUNTIME_ASSERT(fixed_array->get(0)->IsString());
-  String* first = String::cast(fixed_array->get(0));
-  String* separator_raw = *separator;
-  int first_length = first->length();
-  String::WriteToFlat(first, sink, 0, first_length);
-  sink += first_length;
-
-  for (int i = 1; i < array_length; i++) {
-    DCHECK(sink + separator_length <= end);
-    String::WriteToFlat(separator_raw, sink, 0, separator_length);
-    sink += separator_length;
-
-    RUNTIME_ASSERT(fixed_array->get(i)->IsString());
-    String* element = String::cast(fixed_array->get(i));
-    int element_length = element->length();
-    DCHECK(sink + element_length <= end);
-    String::WriteToFlat(element, sink, 0, element_length);
-    sink += element_length;
-  }
-  DCHECK(sink == end);
-
-  // Use %_FastOneByteArrayJoin instead.
-  DCHECK(!answer->IsOneByteRepresentation());
-  return *answer;
-}
-
-template <typename Char>
-static void JoinSparseArrayWithSeparator(FixedArray* elements,
-                                         int elements_length,
-                                         uint32_t array_length,
-                                         String* separator,
-                                         Vector<Char> buffer) {
-  DisallowHeapAllocation no_gc;
-  int previous_separator_position = 0;
-  int separator_length = separator->length();
-  int cursor = 0;
-  for (int i = 0; i < elements_length; i += 2) {
-    int position = NumberToInt32(elements->get(i));
-    String* string = String::cast(elements->get(i + 1));
-    int string_length = string->length();
-    if (string->length() > 0) {
-      while (previous_separator_position < position) {
-        String::WriteToFlat<Char>(separator, &buffer[cursor], 0,
-                                  separator_length);
-        cursor += separator_length;
-        previous_separator_position++;
-      }
-      String::WriteToFlat<Char>(string, &buffer[cursor], 0, string_length);
-      cursor += string->length();
-    }
-  }
-  if (separator_length > 0) {
-    // Array length must be representable as a signed 32-bit number,
-    // otherwise the total string length would have been too large.
-    DCHECK(array_length <= 0x7fffffff);  // Is int32_t.
-    int last_array_index = static_cast<int>(array_length - 1);
-    while (previous_separator_position < last_array_index) {
-      String::WriteToFlat<Char>(separator, &buffer[cursor], 0,
-                                separator_length);
-      cursor += separator_length;
-      previous_separator_position++;
-    }
-  }
-  DCHECK(cursor <= buffer.length());
-}
-
-
-RUNTIME_FUNCTION(Runtime_SparseJoinWithSeparator) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_ARG_HANDLE_CHECKED(JSArray, elements_array, 0);
-  CONVERT_NUMBER_CHECKED(uint32_t, array_length, Uint32, args[1]);
-  CONVERT_ARG_HANDLE_CHECKED(String, separator, 2);
-  // elements_array is fast-mode JSarray of alternating positions
-  // (increasing order) and strings.
-  RUNTIME_ASSERT(elements_array->HasFastSmiOrObjectElements());
-  // array_length is length of original array (used to add separators);
-  // separator is string to put between elements. Assumed to be non-empty.
-  RUNTIME_ASSERT(array_length > 0);
-
-  // Find total length of join result.
-  int string_length = 0;
-  bool is_one_byte = separator->IsOneByteRepresentation();
-  bool overflow = false;
-  CONVERT_NUMBER_CHECKED(int, elements_length, Int32, elements_array->length());
-  RUNTIME_ASSERT(elements_length <= elements_array->elements()->length());
-  RUNTIME_ASSERT((elements_length & 1) == 0);  // Even length.
-  FixedArray* elements = FixedArray::cast(elements_array->elements());
-  for (int i = 0; i < elements_length; i += 2) {
-    RUNTIME_ASSERT(elements->get(i)->IsNumber());
-    CONVERT_NUMBER_CHECKED(uint32_t, position, Uint32, elements->get(i));
-    RUNTIME_ASSERT(position < array_length);
-    RUNTIME_ASSERT(elements->get(i + 1)->IsString());
-  }
-
-  {
-    DisallowHeapAllocation no_gc;
-    for (int i = 0; i < elements_length; i += 2) {
-      String* string = String::cast(elements->get(i + 1));
-      int length = string->length();
-      if (is_one_byte && !string->IsOneByteRepresentation()) {
-        is_one_byte = false;
-      }
-      if (length > String::kMaxLength ||
-          String::kMaxLength - length < string_length) {
-        overflow = true;
-        break;
-      }
-      string_length += length;
-    }
-  }
-
-  int separator_length = separator->length();
-  if (!overflow && separator_length > 0) {
-    if (array_length <= 0x7fffffffu) {
-      int separator_count = static_cast<int>(array_length) - 1;
-      int remaining_length = String::kMaxLength - string_length;
-      if ((remaining_length / separator_length) >= separator_count) {
-        string_length += separator_length * (array_length - 1);
-      } else {
-        // Not room for the separators within the maximal string length.
-        overflow = true;
-      }
-    } else {
-      // Nonempty separator and at least 2^31-1 separators necessary
-      // means that the string is too large to create.
-      STATIC_ASSERT(String::kMaxLength < 0x7fffffff);
-      overflow = true;
-    }
-  }
-  if (overflow) {
-    // Throw an exception if the resulting string is too large. See
-    // https://code.google.com/p/chromium/issues/detail?id=336820
-    // for details.
-    THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());
-  }
-
-  if (is_one_byte) {
-    Handle<SeqOneByteString> result = isolate->factory()
-                                          ->NewRawOneByteString(string_length)
-                                          .ToHandleChecked();
-    JoinSparseArrayWithSeparator<uint8_t>(
-        FixedArray::cast(elements_array->elements()), elements_length,
-        array_length, *separator,
-        Vector<uint8_t>(result->GetChars(), string_length));
-    return *result;
-  } else {
-    Handle<SeqTwoByteString> result = isolate->factory()
-                                          ->NewRawTwoByteString(string_length)
-                                          .ToHandleChecked();
-    JoinSparseArrayWithSeparator<uc16>(
-        FixedArray::cast(elements_array->elements()), elements_length,
-        array_length, *separator,
-        Vector<uc16>(result->GetChars(), string_length));
-    return *result;
-  }
-}
-
-
 RUNTIME_FUNCTION(Runtime_NumberOr) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
 
   CONVERT_NUMBER_CHECKED(int32_t, x, Int32, args[0]);
   CONVERT_NUMBER_CHECKED(int32_t, y, Int32, args[1]);
   return *isolate->factory()->NewNumberFromInt(x | y);
 }
 
 
@@ skipping 60 matching lines @@
   Object* result;
   if ((fpclassify(x) == FP_ZERO) && (fpclassify(y) == FP_ZERO)) {
     result = Smi::FromInt(EQUAL);
   } else {
     result = Smi::FromInt(NOT_EQUAL);
   }
   return result;
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringEquals) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 2);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
-
-  bool not_equal = !String::Equals(x, y);
-  // This is slightly convoluted because the value that signifies
-  // equality is 0 and inequality is 1 so we have to negate the result
-  // from String::Equals.
-  DCHECK(not_equal == 0 || not_equal == 1);
-  STATIC_ASSERT(EQUAL == 0);
-  STATIC_ASSERT(NOT_EQUAL == 1);
-  return Smi::FromInt(not_equal);
-}
-
-
 RUNTIME_FUNCTION(Runtime_NumberCompare) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 3);
 
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
   CONVERT_DOUBLE_ARG_CHECKED(y, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, uncomparable_result, 2)
   if (std::isnan(x) || std::isnan(y)) return *uncomparable_result;
   if (x == y) return Smi::FromInt(EQUAL);
   if (isless(x, y)) return Smi::FromInt(LESS);
@@ skipping 70 matching lines @@
     x_scaled /= 10;
     tie = GREATER;
   }
 
   if (x_scaled < y_scaled) return Smi::FromInt(LESS);
   if (x_scaled > y_scaled) return Smi::FromInt(GREATER);
   return Smi::FromInt(tie);
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringCompare) {
-  HandleScope handle_scope(isolate);
-  DCHECK(args.length() == 2);
 
-  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
-
-  isolate->counters()->string_compare_runtime()->Increment();
-
-  // A few fast case tests before we flatten.
-  if (x.is_identical_to(y)) return Smi::FromInt(EQUAL);
-  if (y->length() == 0) {
-    if (x->length() == 0) return Smi::FromInt(EQUAL);
-    return Smi::FromInt(GREATER);
-  } else if (x->length() == 0) {
-    return Smi::FromInt(LESS);
-  }
-
-  int d = x->Get(0) - y->Get(0);
-  if (d < 0)
-    return Smi::FromInt(LESS);
-  else if (d > 0)
-    return Smi::FromInt(GREATER);
-
-  // Slow case.
-  x = String::Flatten(x);
-  y = String::Flatten(y);
-
-  DisallowHeapAllocation no_gc;
-  Object* equal_prefix_result = Smi::FromInt(EQUAL);
-  int prefix_length = x->length();
-  if (y->length() < prefix_length) {
-    prefix_length = y->length();
-    equal_prefix_result = Smi::FromInt(GREATER);
-  } else if (y->length() > prefix_length) {
-    equal_prefix_result = Smi::FromInt(LESS);
-  }
-  int r;
-  String::FlatContent x_content = x->GetFlatContent();
-  String::FlatContent y_content = y->GetFlatContent();
-  if (x_content.IsOneByte()) {
-    Vector<const uint8_t> x_chars = x_content.ToOneByteVector();
-    if (y_content.IsOneByte()) {
-      Vector<const uint8_t> y_chars = y_content.ToOneByteVector();
-      r = CompareChars(x_chars.start(), y_chars.start(), prefix_length);
-    } else {
-      Vector<const uc16> y_chars = y_content.ToUC16Vector();
-      r = CompareChars(x_chars.start(), y_chars.start(), prefix_length);
-    }
-  } else {
-    Vector<const uc16> x_chars = x_content.ToUC16Vector();
-    if (y_content.IsOneByte()) {
-      Vector<const uint8_t> y_chars = y_content.ToOneByteVector();
-      r = CompareChars(x_chars.start(), y_chars.start(), prefix_length);
-    } else {
-      Vector<const uc16> y_chars = y_content.ToUC16Vector();
-      r = CompareChars(x_chars.start(), y_chars.start(), prefix_length);
-    }
-  }
-  Object* result;
-  if (r == 0) {
-    result = equal_prefix_result;
-  } else {
-    result = (r < 0) ? Smi::FromInt(LESS) : Smi::FromInt(GREATER);
-  }
-  return result;
-}
 
 
 #define RUNTIME_UNARY_MATH(Name, name)                       \
   RUNTIME_FUNCTION(Runtime_Math##Name) {                     \
     HandleScope scope(isolate);                              \
     DCHECK(args.length() == 1);                              \
     isolate->counters()->math_##name()->Increment();         \
     CONVERT_DOUBLE_ARG_CHECKED(x, 0);                        \
     return *isolate->factory()->NewHeapNumber(std::name(x)); \
   }
@@ skipping 1983 matching lines @@
 RUNTIME_FUNCTION(Runtime_IsAttachedGlobal) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, global, 0);
   if (!global->IsJSGlobalObject()) return isolate->heap()->false_value();
   return isolate->heap()->ToBoolean(
       !JSGlobalObject::cast(global)->IsDetached());
 }
 
 
-RUNTIME_FUNCTION(Runtime_ParseJson) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, source, 0);
-
-  source = String::Flatten(source);
-  // Optimized fast case where we only have Latin1 characters.
-  Handle<Object> result;
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
-                                     source->IsSeqOneByteString()
-                                         ? JsonParser<true>::Parse(source)
-                                         : JsonParser<false>::Parse(source));
-  return *result;
-}
-
-
 bool CodeGenerationFromStringsAllowed(Isolate* isolate,
                                       Handle<Context> context) {
   DCHECK(context->allow_code_gen_from_strings()->IsFalse());
   // Check with callback if set.
   AllowCodeGenerationFromStringsCallback callback =
       isolate->allow_code_gen_callback();
   if (callback == NULL) {
     // No callback set and code generation disallowed.
     return false;
   } else {
@@ skipping 4760 matching lines @@
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate,
         NewTypeError("not_date_object", HandleVector<Object>(NULL, 0)));
   }
   JSDate* date = JSDate::cast(obj);
   if (index == 0) return date->value();
   return JSDate::GetField(date, Smi::FromInt(index));
 }
 
 
-RUNTIME_FUNCTION(RuntimeReference_StringCharFromCode) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_CharFromCode(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_StringCharAt) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 2);
-  if (!args[0]->IsString()) return Smi::FromInt(0);
-  if (!args[1]->IsNumber()) return Smi::FromInt(0);
-  if (std::isinf(args.number_at(1))) return isolate->heap()->empty_string();
-  Object* code = __RT_impl_Runtime_StringCharCodeAtRT(args, isolate);
-  if (code->IsNaN()) return isolate->heap()->empty_string();
-  return __RT_impl_Runtime_CharFromCode(Arguments(1, &code), isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_OneByteSeqStringSetChar) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_INT32_ARG_CHECKED(index, 0);
-  CONVERT_INT32_ARG_CHECKED(value, 1);
-  CONVERT_ARG_CHECKED(SeqOneByteString, string, 2);
-  string->SeqOneByteStringSet(index, value);
-  return string;
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_TwoByteSeqStringSetChar) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 3);
-  CONVERT_INT32_ARG_CHECKED(index, 0);
-  CONVERT_INT32_ARG_CHECKED(value, 1);
-  CONVERT_ARG_CHECKED(SeqTwoByteString, string, 2);
-  string->SeqTwoByteStringSet(index, value);
-  return string;
-}
-
-
 RUNTIME_FUNCTION(RuntimeReference_ObjectEquals) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_CHECKED(Object, obj1, 0);
   CONVERT_ARG_CHECKED(Object, obj2, 1);
   return isolate->heap()->ToBoolean(obj1 == obj2);
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_IsObject) {
@@ skipping 86 matching lines @@
 
 RUNTIME_FUNCTION(RuntimeReference_ClassOf) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   if (!obj->IsJSReceiver()) return isolate->heap()->null_value();
   return JSReceiver::cast(obj)->class_name();
 }
 
 
-RUNTIME_FUNCTION(RuntimeReference_StringCharCodeAt) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 2);
-  if (!args[0]->IsString()) return isolate->heap()->undefined_value();
-  if (!args[1]->IsNumber()) return isolate->heap()->undefined_value();
-  if (std::isinf(args.number_at(1))) return isolate->heap()->nan_value();
-  return __RT_impl_Runtime_StringCharCodeAtRT(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_StringAdd) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_StringAdd(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_SubString) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_SubString(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_StringCompare) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_StringCompare(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_RegExpExec) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_RegExpExecRT(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(RuntimeReference_RegExpConstructResult) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_RegExpConstructResult(args, isolate);
-}
-
-
 RUNTIME_FUNCTION(RuntimeReference_GetFromCache) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_SMI_ARG_CHECKED(id, 0);
   args[0] = isolate->native_context()->jsfunction_result_caches()->get(id);
   return __RT_impl_Runtime_GetFromCache(args, isolate);
 }
 
 
 RUNTIME_FUNCTION(RuntimeReference_NumberToString) {
@@ skipping 81 matching lines @@
   }
   return NULL;
 }
 
 
 const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
   return &(kIntrinsicFunctions[static_cast<int>(id)]);
 }
 }
 }  // namespace v8::internal