Revert r12258, r12300 and r12302 (global regexp).

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2556 matching lines @@
   FixedArrayBuilder array_builder_;
   Handle<String> subject_;
   int character_count_;
   bool is_ascii_;
 };
 
 
 class CompiledReplacement {
  public:
   explicit CompiledReplacement(Zone* zone)
-      : parts_(1, zone), replacement_substrings_(0, zone), zone_(zone) {}
+      : parts_(1, zone), replacement_substrings_(0, zone),
+        simple_hint_(false),
+        zone_(zone) {}
 
-  // Return whether the replacement is simple.
-  bool Compile(Handle<String> replacement,
+  void 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);
+             Handle<JSArray> last_match_info);
 
   // Number of distinct parts of the replacement pattern.
   int parts() {
     return parts_.length();
   }
 
+  bool simple_hint() {
+    return simple_hint_;
+  }
+
   Zone* zone() const { return zone_; }
 
  private:
   enum PartType {
     SUBJECT_PREFIX = 1,
     SUBJECT_SUFFIX,
     SUBJECT_CAPTURE,
     REPLACEMENT_SUBSTRING,
     REPLACEMENT_STRING,
 
@@ skipping 40 matching lines @@
     // 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) {
+  static 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];
@@ skipping 73 matching lines @@
           break;
         }
         default:
           i = next_index;
           break;
         }
       }
     }
     if (length > last) {
       if (last == 0) {
-        // Replacement is simple.  Do not use Apply to do the replacement.
+        parts->Add(ReplacementPart::ReplacementString(), zone);
         return true;
       } else {
         parts->Add(ReplacementPart::ReplacementSubString(last, length), zone);
       }
     }
     return false;
   }
 
   ZoneList<ReplacementPart> parts_;
   ZoneList<Handle<String> > replacement_substrings_;
+  bool simple_hint_;
   Zone* zone_;
 };
 
 
-bool CompiledReplacement::Compile(Handle<String> replacement,
+void CompiledReplacement::Compile(Handle<String> replacement,
                                   int capture_count,
                                   int subject_length) {
   {
     AssertNoAllocation no_alloc;
     String::FlatContent content = replacement->GetFlatContent();
     ASSERT(content.IsFlat());
-    bool simple = false;
     if (content.IsAscii()) {
-      simple = ParseReplacementPattern(&parts_,
-                                       content.ToAsciiVector(),
-                                       capture_count,
-                                       subject_length,
-                                       zone());
+      simple_hint_ = ParseReplacementPattern(&parts_,
+                                             content.ToAsciiVector(),
+                                             capture_count,
+                                             subject_length,
+                                             zone());
     } else {
       ASSERT(content.IsTwoByte());
-      simple = ParseReplacementPattern(&parts_,
-                                       content.ToUC16Vector(),
-                                       capture_count,
-                                       subject_length,
-                                       zone());
+      simple_hint_ = 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) {
-  ASSERT_LT(0, parts_.length());
+                                Handle<JSArray> last_match_info) {
   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];
+        FixedArray* match_info = FixedArray::cast(last_match_info->elements());
+        int from = RegExpImpl::GetCapture(match_info, capture * 2);
+        int to = RegExpImpl::GetCapture(match_info, 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:
@@ skipping 101 matching lines @@
                           pattern_content.ToUC16Vector(),
                           indices,
                           limit,
                           zone);
       }
     }
   }
 }
 
 
+// Two smis before and after the match, for very long strings.
+const int kMaxBuilderEntriesPerRegExpMatch = 5;
+
+
+static void SetLastMatchInfoNoCaptures(Handle<String> subject,
+                                       Handle<JSArray> last_match_info,
+                                       int match_start,
+                                       int match_end) {
+  // Fill last_match_info with a single capture.
+  last_match_info->EnsureSize(2 + RegExpImpl::kLastMatchOverhead);
+  AssertNoAllocation no_gc;
+  FixedArray* elements = FixedArray::cast(last_match_info->elements());
+  RegExpImpl::SetLastCaptureCount(elements, 2);
+  RegExpImpl::SetLastInput(elements, *subject);
+  RegExpImpl::SetLastSubject(elements, *subject);
+  RegExpImpl::SetCapture(elements, 0, match_start);
+  RegExpImpl::SetCapture(elements, 1, match_end);
+}
+
+
+template <typename SubjectChar, typename PatternChar>
+static bool SearchStringMultiple(Isolate* isolate,
+                                 Vector<const SubjectChar> subject,
+                                 Vector<const PatternChar> pattern,
+                                 String* pattern_string,
+                                 FixedArrayBuilder* builder,
+                                 int* match_pos) {
+  int pos = *match_pos;
+  int subject_length = subject.length();
+  int pattern_length = pattern.length();
+  int max_search_start = subject_length - pattern_length;
+  StringSearch<PatternChar, SubjectChar> search(isolate, pattern);
+  while (pos <= max_search_start) {
+    if (!builder->HasCapacity(kMaxBuilderEntriesPerRegExpMatch)) {
+      *match_pos = pos;
+      return false;
+    }
+    // Position of end of previous match.
+    int match_end = pos + pattern_length;
+    int new_pos = search.Search(subject, match_end);
+    if (new_pos >= 0) {
+      // A match.
+      if (new_pos > match_end) {
+        ReplacementStringBuilder::AddSubjectSlice(builder,
+            match_end,
+            new_pos);
+      }
+      pos = new_pos;
+      builder->Add(pattern_string);
+    } else {
+      break;
+    }
+  }
+
+  if (pos < max_search_start) {
+    ReplacementStringBuilder::AddSubjectSlice(builder,
+                                              pos + pattern_length,
+                                              subject_length);
+  }
+  *match_pos = pos;
+  return true;
+}
+
+
+
+
 template<typename ResultSeqString>
 MUST_USE_RESULT static MaybeObject* StringReplaceAtomRegExpWithString(
     Isolate* isolate,
     Handle<String> subject,
     Handle<JSRegExp> pattern_regexp,
     Handle<String> replacement,
-    Handle<JSArray> last_match_info) {
+    Handle<JSArray> last_match_info,
+    Zone* zone) {
   ASSERT(subject->IsFlat());
   ASSERT(replacement->IsFlat());
 
-  Zone* zone = isolate->runtime_zone();
-  ZoneScope zone_space(zone, DELETE_ON_EXIT);
-  ZoneList<int> indices(8, zone);
+  ZoneScope zone_space(isolate->runtime_zone(), DELETE_ON_EXIT);
+  ZoneList<int> indices(8, isolate->runtime_zone());
   ASSERT_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);
+  FindStringIndicesDispatch(isolate, *subject, pattern, &indices, 0xffffffff,
+                            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);
@@ skipping 34 matching lines @@
     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);
+  SetLastMatchInfoNoCaptures(subject,
+                             last_match_info,
+                             indices.at(matches - 1),
+                             indices.at(matches - 1) + pattern_len);
 
   return *result;
 }
 
 
 MUST_USE_RESULT static MaybeObject* StringReplaceRegExpWithString(
     Isolate* isolate,
-    Handle<String> subject,
-    Handle<JSRegExp> regexp,
-    Handle<String> replacement,
-    Handle<JSArray> last_match_info) {
+    String* subject,
+    JSRegExp* regexp,
+    String* replacement,
+    JSArray* last_match_info,
+    Zone* zone) {
   ASSERT(subject->IsFlat());
   ASSERT(replacement->IsFlat());
 
-  bool is_global = regexp->GetFlags().is_global();
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
+  HandleScope handles(isolate);

[ulan, 2012/08/21 09:43:40]

Empty line is missing here.

[Yang, 2012/08/21 09:46:10]

Done.

+  int length = subject->length();
+  Handle<String> subject_handle(subject);
+  Handle<JSRegExp> regexp_handle(regexp);
+  Handle<String> replacement_handle(replacement);
+  Handle<JSArray> last_match_info_handle(last_match_info);
+  Handle<Object> match = RegExpImpl::Exec(regexp_handle,
+                                          subject_handle,
+                                          0,
+                                          last_match_info_handle);
+  if (match.is_null()) {
+    return Failure::Exception();
+  }
+  if (match->IsNull()) {
+    return *subject_handle;
+  }
+
+  int capture_count = regexp_handle->CaptureCount();
 
   // CompiledReplacement uses zone allocation.
-  Zone* zone = isolate->runtime_zone();
   ZoneScope zonescope(zone, DELETE_ON_EXIT);
   CompiledReplacement compiled_replacement(zone);
-  bool simple_replace = compiled_replacement.Compile(replacement,
-                                                     capture_count,
-                                                     subject_length);
+
+  compiled_replacement.Compile(replacement_handle,
+                               capture_count,
+                               length);
+
+  bool is_global = regexp_handle->GetFlags().is_global();
 
   // Shortcut for simple non-regexp global replacements
   if (is_global &&
-      regexp->TypeTag() == JSRegExp::ATOM &&
-      simple_replace) {
-    if (subject->HasOnlyAsciiChars()) {
+          regexp_handle->TypeTag() == JSRegExp::ATOM &&
+           compiled_replacement.simple_hint()) {
+         if (subject_handle->HasOnlyAsciiChars() &&
+             replacement_handle->HasOnlyAsciiChars()) {
       return StringReplaceAtomRegExpWithString<SeqAsciiString>(
-          isolate, subject, regexp, replacement, last_match_info);
-    } else {
+                 isolate,
+                 subject_handle,
+                 regexp_handle,
+                 replacement_handle,
+                 last_match_info_handle,
+                 zone);
+         } else {
       return StringReplaceAtomRegExpWithString<SeqTwoByteString>(
-          isolate, subject, regexp, replacement, last_match_info);
+                 isolate,
+                 subject_handle,
+                 regexp_handle,
+                 replacement_handle,
+                 last_match_info_handle,
+                 zone);
     }
   }
 
-  RegExpImpl::GlobalCache global_cache(regexp, subject, is_global, isolate);
-  if (global_cache.HasException()) return Failure::Exception();
-
-  int32_t* current_match = global_cache.FetchNext();
-  if (current_match == NULL) {
-    if (global_cache.HasException()) return Failure::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) * (is_global ? 4 : 1) + 1;
   ReplacementStringBuilder builder(isolate->heap(),
-                                   subject,
+                                   subject_handle,
                                    expected_parts);
 
+  // Index of end of last match.
+  int prev = 0;
+
+
   // 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;
-
+  bool matched = true;
   do {
+    ASSERT(last_match_info_handle->HasFastObjectElements());
+    // Increase the capacity of the builder before entering local handle-scope,
+    // so its internal buffer can safely allocate a new handle if it grows.
     builder.EnsureCapacity(parts_added_per_loop);
 
-    int start = current_match[0];
-    int end = current_match[1];
+    HandleScope loop_scope(isolate);
+    int start, end;
+    {
+      AssertNoAllocation match_info_array_is_not_in_a_handle;
+      FixedArray* match_info_array =
+          FixedArray::cast(last_match_info_handle->elements());
+
+      ASSERT_EQ(capture_count * 2 + 2,
+                RegExpImpl::GetLastCaptureCount(match_info_array));
+      start = RegExpImpl::GetCapture(match_info_array, 0);
+      end = RegExpImpl::GetCapture(match_info_array, 1);
+    }
 
     if (prev < start) {
       builder.AddSubjectSlice(prev, start);
     }
+    compiled_replacement.Apply(&builder,
+                               start,
+                               end,
+                               last_match_info_handle);
 
-    if (simple_replace) {
-      builder.AddString(replacement);
-    } else {
-      compiled_replacement.Apply(&builder,
-                                 start,
-                                 end,
-                                 current_match);
-    }
     prev = end;
 
     // Only continue checking for global regexps.
     if (!is_global) break;
 
-    current_match = global_cache.FetchNext();
-  } while (current_match != NULL);
+    // Continue from where the match ended, unless it was an empty match.
+    int next = end;
+    if (start == end) {
+      next = end + 1;
+      if (next > length) break;
+    }
 
-  if (global_cache.HasException()) return Failure::Exception();
+    match = RegExpImpl::Exec(regexp_handle,
+                             subject_handle,
+                             next,
+                             last_match_info_handle);
+    if (match.is_null()) {
+      return Failure::Exception();
+    }
+    matched = !match->IsNull();
+  } while (matched);
 
-  if (prev < subject_length) {
-    builder.EnsureCapacity(2);
-    builder.AddSubjectSlice(prev, subject_length);
+  if (prev < length) {
+    builder.AddSubjectSlice(prev, length);
   }
 
-  RegExpImpl::SetLastMatchInfo(last_match_info,
-                               subject,
-                               capture_count,
-                               global_cache.LastSuccessfulMatch());
-
   return *(builder.ToString());
 }
 
 
 template <typename ResultSeqString>
 MUST_USE_RESULT static MaybeObject* StringReplaceRegExpWithEmptyString(
     Isolate* isolate,
-    Handle<String> subject,
-    Handle<JSRegExp> regexp,
-    Handle<JSArray> last_match_info) {
+    String* subject,
+    JSRegExp* regexp,
+    JSArray* last_match_info,
+    Zone* zone) {
   ASSERT(subject->IsFlat());
 
-  bool is_global = regexp->GetFlags().is_global();
+  HandleScope handles(isolate);
+
+  Handle<String> subject_handle(subject);
+  Handle<JSRegExp> regexp_handle(regexp);
+  Handle<JSArray> last_match_info_handle(last_match_info);
 
   // Shortcut for simple non-regexp global replacements
-  if (is_global &&
-      regexp->TypeTag() == JSRegExp::ATOM) {
-    Handle<String> empty_string(HEAP->empty_string());
-    if (subject->HasOnlyAsciiChars()) {
+  if (regexp_handle->GetFlags().is_global() &&
+      regexp_handle->TypeTag() == JSRegExp::ATOM) {
+    Handle<String> empty_string_handle(HEAP->empty_string());
+    if (subject_handle->HasOnlyAsciiChars()) {
       return StringReplaceAtomRegExpWithString<SeqAsciiString>(
           isolate,
-          subject,
-          regexp,
-          empty_string,
-          last_match_info);
+          subject_handle,
+          regexp_handle,
+          empty_string_handle,
+          last_match_info_handle,
+          zone);
     } else {
       return StringReplaceAtomRegExpWithString<SeqTwoByteString>(
           isolate,
-          subject,
-          regexp,
-          empty_string,
-          last_match_info);
+          subject_handle,
+          regexp_handle,
+          empty_string_handle,
+          last_match_info_handle,
+          zone);
     }
   }
 
-  RegExpImpl::GlobalCache global_cache(regexp, subject, is_global, isolate);
-  if (global_cache.HasException()) return Failure::Exception();
+  Handle<Object> match = RegExpImpl::Exec(regexp_handle,
+                                          subject_handle,
+                                          0,
+                                          last_match_info_handle);
+  if (match.is_null()) return Failure::Exception();
+  if (match->IsNull()) return *subject_handle;
 
-  int32_t* current_match = global_cache.FetchNext();
-  if (current_match == NULL) {
-    if (global_cache.HasException()) return Failure::Exception();
-    return *subject;
+  ASSERT(last_match_info_handle->HasFastObjectElements());
+
+  int start, end;
+  {
+    AssertNoAllocation match_info_array_is_not_in_a_handle;
+    FixedArray* match_info_array =
+        FixedArray::cast(last_match_info_handle->elements());
+
+    start = RegExpImpl::GetCapture(match_info_array, 0);
+    end = RegExpImpl::GetCapture(match_info_array, 1);
   }
 
-  int start = current_match[0];
-  int end = current_match[1];
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
+  bool global = regexp_handle->GetFlags().is_global();
 
-  int new_length = subject_length - (end - start);
-  if (new_length == 0) return isolate->heap()->empty_string();
+  if (start == end && !global) return *subject_handle;
 
+  int length = subject_handle->length();
+  int new_length = length - (end - start);
+  if (new_length == 0) {
+    return isolate->heap()->empty_string();
+  }
   Handle<ResultSeqString> answer;
   if (ResultSeqString::kHasAsciiEncoding) {
     answer = Handle<ResultSeqString>::cast(
         isolate->factory()->NewRawAsciiString(new_length));
   } else {
     answer = Handle<ResultSeqString>::cast(
         isolate->factory()->NewRawTwoByteString(new_length));
   }
 
-  if (!is_global) {
-    RegExpImpl::SetLastMatchInfo(
-        last_match_info, subject, capture_count, current_match);
-    if (start == end) {
-      return *subject;
-    } else {
-      if (start > 0) {
-        String::WriteToFlat(*subject, answer->GetChars(), 0, start);
-      }
-      if (end < subject_length) {
-        String::WriteToFlat(
-            *subject, answer->GetChars() + start, end, subject_length);
-      }
-      return *answer;
+  // If the regexp isn't global, only match once.
+  if (!global) {
+    if (start > 0) {
+      String::WriteToFlat(*subject_handle,
+                          answer->GetChars(),
+                          0,
+                          start);
     }
+    if (end < length) {
+      String::WriteToFlat(*subject_handle,
+                          answer->GetChars() + start,
+                          end,
+                          length);
+    }
+    return *answer;
   }
 
-  int prev = 0;
+  int prev = 0;  // Index of end of last match.
+  int next = 0;  // Start of next search (prev unless last match was empty).
   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);
+      String::WriteToFlat(*subject_handle,
+                          answer->GetChars() + position,
+                          prev,
+                          start);
       position += start - prev;
     }
     prev = end;
+    next = end;
+    // Continue from where the match ended, unless it was an empty match.
+    if (start == end) {
+      next++;
+      if (next > length) break;
+    }
+    match = RegExpImpl::Exec(regexp_handle,
+                             subject_handle,
+                             next,
+                             last_match_info_handle);
+    if (match.is_null()) return Failure::Exception();
+    if (match->IsNull()) break;
 
-    current_match = global_cache.FetchNext();
-  } while (current_match != NULL);
+    ASSERT(last_match_info_handle->HasFastObjectElements());
+    HandleScope loop_scope(isolate);
+    {
+      AssertNoAllocation match_info_array_is_not_in_a_handle;
+      FixedArray* match_info_array =
+          FixedArray::cast(last_match_info_handle->elements());
+      start = RegExpImpl::GetCapture(match_info_array, 0);
+      end = RegExpImpl::GetCapture(match_info_array, 1);
+    }
+  } while (true);
 
-  if (global_cache.HasException()) return Failure::Exception();
-
-  RegExpImpl::SetLastMatchInfo(last_match_info,
-                               subject,
-                               capture_count,
-                               global_cache.LastSuccessfulMatch());
-
-  if (prev < subject_length) {
+  if (prev < length) {
     // Add substring subject[prev;length] to answer string.
-    String::WriteToFlat(
-        *subject, answer->GetChars() + position, prev, subject_length);
-    position += subject_length - prev;
+    String::WriteToFlat(*subject_handle,
+                        answer->GetChars() + position,
+                        prev,
+                        length);
+    position += length - prev;
   }
 
-  if (position == 0) return isolate->heap()->empty_string();
+  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;
   isolate->heap()->CreateFillerObjectAt(end_of_string, delta);
   if (Marking::IsBlack(Marking::MarkBitFrom(*answer))) {
     MemoryChunk::IncrementLiveBytesFromMutator(answer->address(), -delta);
   }
 
   return *answer;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringReplaceRegExpWithString) {
   ASSERT(args.length() == 4);
 
-  HandleScope scope(isolate);
+  CONVERT_ARG_CHECKED(String, subject, 0);
+  if (!subject->IsFlat()) {
+    Object* flat_subject;
+    { MaybeObject* maybe_flat_subject = subject->TryFlatten();
+      if (!maybe_flat_subject->ToObject(&flat_subject)) {
+        return maybe_flat_subject;
+      }
+    }
+    subject = String::cast(flat_subject);
+  }
 
-  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);
+  CONVERT_ARG_CHECKED(String, replacement, 2);
+  if (!replacement->IsFlat()) {
+    Object* flat_replacement;
+    { MaybeObject* maybe_flat_replacement = replacement->TryFlatten();
+      if (!maybe_flat_replacement->ToObject(&flat_replacement)) {
+        return maybe_flat_replacement;
+      }
+    }
+    replacement = String::cast(flat_replacement);
+  }
 
-  if (!subject->IsFlat()) subject = FlattenGetString(subject);
-
-  if (!replacement->IsFlat()) replacement = FlattenGetString(replacement);
+  CONVERT_ARG_CHECKED(JSRegExp, regexp, 1);
+  CONVERT_ARG_CHECKED(JSArray, last_match_info, 3);
 
   ASSERT(last_match_info->HasFastObjectElements());
 
+  Zone* zone = isolate->runtime_zone();
   if (replacement->length() == 0) {
     if (subject->HasOnlyAsciiChars()) {
       return StringReplaceRegExpWithEmptyString<SeqAsciiString>(
-          isolate, subject, regexp, last_match_info);
+          isolate, subject, regexp, last_match_info, zone);
     } else {
       return StringReplaceRegExpWithEmptyString<SeqTwoByteString>(
-          isolate, subject, regexp, last_match_info);
+          isolate, subject, regexp, last_match_info, zone);
     }
   }
 
-  return StringReplaceRegExpWithString(
-      isolate, subject, regexp, replacement, last_match_info);
+  return StringReplaceRegExpWithString(isolate,
+                                       subject,
+                                       regexp,
+                                       replacement,
+                                       last_match_info,
+                                       zone);
 }
 
 
 Handle<String> Runtime::StringReplaceOneCharWithString(Isolate* isolate,
                                                        Handle<String> subject,
                                                        Handle<String> search,
                                                        Handle<String> replace,
                                                        bool* found,
                                                        int recursion_limit) {
   if (recursion_limit == 0) return Handle<String>::null();
@@ skipping 302 matching lines @@
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringMatch) {
   ASSERT_EQ(3, args.length());
 
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, regexp_info, 2);
   HandleScope handles;
 
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return Failure::Exception();
+  Handle<Object> match = RegExpImpl::Exec(regexp, subject, 0, regexp_info);
 
-  int capture_count = regexp->CaptureCount();
+  if (match.is_null()) {
+    return Failure::Exception();
+  }
+  if (match->IsNull()) {
+    return isolate->heap()->null_value();
+  }
+  int length = subject->length();
 
   Zone* zone = isolate->runtime_zone();
   ZoneScope zone_space(zone, DELETE_ON_EXIT);
   ZoneList<int> offsets(8, zone);
-
-  while (true) {
-    int32_t* match = global_cache.FetchNext();
-    if (match == NULL) break;
-    offsets.Add(match[0], zone);  // start
-    offsets.Add(match[1], zone);  // end
-  }
-
-  if (global_cache.HasException()) return Failure::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 start;
+  int end;
+  do {
+    {
+      AssertNoAllocation no_alloc;
+      FixedArray* elements = FixedArray::cast(regexp_info->elements());
+      start = Smi::cast(elements->get(RegExpImpl::kFirstCapture))->value();
+      end = Smi::cast(elements->get(RegExpImpl::kFirstCapture + 1))->value();
+    }
+    offsets.Add(start, zone);
+    offsets.Add(end, zone);
+    if (start == end) if (++end > length) break;
+    match = RegExpImpl::Exec(regexp, subject, end, regexp_info);
+    if (match.is_null()) {
+      return Failure::Exception();
+    }
+  } while (!match->IsNull());
   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));
+  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);
+  for (int i = 1; i < matches ; i++) {
     int from = offsets.at(i * 2);
     int to = offsets.at(i * 2 + 1);
-    Handle<String> substring =
-        isolate->factory()->NewProperSubString(subject, from, to);
+    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 int SearchRegExpMultiple(
+static bool SearchStringMultiple(Isolate* isolate,
+                                 Handle<String> subject,
+                                 Handle<String> pattern,
+                                 Handle<JSArray> last_match_info,
+                                 FixedArrayBuilder* builder) {
+  ASSERT(subject->IsFlat());
+  ASSERT(pattern->IsFlat());
+
+  // Treating as if a previous match was before first character.
+  int match_pos = -pattern->length();
+
+  for (;;) {  // Break when search complete.
+    builder->EnsureCapacity(kMaxBuilderEntriesPerRegExpMatch);
+    AssertNoAllocation no_gc;
+    String::FlatContent subject_content = subject->GetFlatContent();
+    String::FlatContent pattern_content = pattern->GetFlatContent();
+    if (subject_content.IsAscii()) {
+      Vector<const char> subject_vector = subject_content.ToAsciiVector();
+      if (pattern_content.IsAscii()) {
+        if (SearchStringMultiple(isolate,
+                                 subject_vector,
+                                 pattern_content.ToAsciiVector(),
+                                 *pattern,
+                                 builder,
+                                 &match_pos)) break;
+      } else {
+        if (SearchStringMultiple(isolate,
+                                 subject_vector,
+                                 pattern_content.ToUC16Vector(),
+                                 *pattern,
+                                 builder,
+                                 &match_pos)) break;
+      }
+    } else {
+      Vector<const uc16> subject_vector = subject_content.ToUC16Vector();
+      if (pattern_content.IsAscii()) {
+        if (SearchStringMultiple(isolate,
+                                 subject_vector,
+                                 pattern_content.ToAsciiVector(),
+                                 *pattern,
+                                 builder,
+                                 &match_pos)) break;
+      } else {
+        if (SearchStringMultiple(isolate,
+                                 subject_vector,
+                                 pattern_content.ToUC16Vector(),
+                                 *pattern,
+                                 builder,
+                                 &match_pos)) break;
+      }
+    }
+  }
+
+  if (match_pos >= 0) {
+    SetLastMatchInfoNoCaptures(subject,
+                               last_match_info,
+                               match_pos,
+                               match_pos + pattern->length());
+    return true;
+  }
+  return false;  // No matches at all.
+}
+
+
+static int SearchRegExpNoCaptureMultiple(
     Isolate* isolate,
     Handle<String> subject,
     Handle<JSRegExp> regexp,
     Handle<JSArray> last_match_array,
     FixedArrayBuilder* builder) {
   ASSERT(subject->IsFlat());
-  ASSERT_NE(has_capture, regexp->CaptureCount() == 0);
-
-  RegExpImpl::GlobalCache global_cache(regexp, subject, true, isolate);
-  if (global_cache.HasException()) return RegExpImpl::RE_EXCEPTION;
-
-  int capture_count = regexp->CaptureCount();
-  int subject_length = subject->length();
-
-  // Position to search from.
+  ASSERT(regexp->CaptureCount() == 0);
   int match_start = -1;
   int match_end = 0;
+  int pos = 0;
+  int registers_per_match = RegExpImpl::IrregexpPrepare(regexp, subject);
+  if (registers_per_match < 0) return RegExpImpl::RE_EXCEPTION;
+
+  int max_matches;
+  int num_registers = RegExpImpl::GlobalOffsetsVectorSize(regexp,
+                                                          registers_per_match,
+                                                          &max_matches);
+  OffsetsVector registers(num_registers, isolate);
+  Vector<int32_t> register_vector(registers.vector(), registers.length());
+  int subject_length = subject->length();
   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;
+  for (;;) {  // Break on failure, return on exception.
+    int num_matches = RegExpImpl::IrregexpExecRaw(regexp,
+                                                  subject,
+                                                  pos,
+                                                  register_vector);
+    if (num_matches > 0) {
+      for (int match_index = 0; match_index < num_matches; match_index++) {
+        int32_t* current_match = &register_vector[match_index * 2];
+        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];
+        HandleScope loop_scope(isolate);
+        if (!first) {
+          builder->Add(*isolate->factory()->NewProperSubString(subject,
+                                                               match_start,
+                                                               match_end));
+        } else {
+          builder->Add(*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);
+      // If we did not get the maximum number of matches, we can stop here
+      // since there are no matches left.
+      if (num_matches < max_matches) break;
 
-        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];
-            ASSERT(start <= end);
-            Handle<String> substring =
-                isolate->factory()->NewSubString(subject, start, end);
-            elements->set(i, *substring);
-          } else {
-            ASSERT(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));
+      if (match_start != match_end) {
+        pos = match_end;
       } else {
-        builder->Add(*match);
+        pos = match_end + 1;
+        if (pos > subject_length) break;
       }
+    } else if (num_matches == 0) {
+      break;
+    } else {
+      ASSERT_EQ(num_matches, RegExpImpl::RE_EXCEPTION);
+      return RegExpImpl::RE_EXCEPTION;
     }
   }
 
-  if (global_cache.HasException()) return RegExpImpl::RE_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);
-
+    SetLastMatchInfoNoCaptures(subject,
+                               last_match_array,
+                               match_start,
+                               match_end);
     return RegExpImpl::RE_SUCCESS;
   } else {
     return RegExpImpl::RE_FAILURE;  // No matches at all.
   }
 }
 
 
+// Only called from Runtime_RegExpExecMultiple so it doesn't need to maintain
+// separate last match info.  See comment on that function.
+static int SearchRegExpMultiple(
+    Isolate* isolate,
+    Handle<String> subject,
+    Handle<JSRegExp> regexp,
+    Handle<JSArray> last_match_array,
+    FixedArrayBuilder* builder,
+    Zone* zone) {
+
+  ASSERT(subject->IsFlat());
+  int registers_per_match = RegExpImpl::IrregexpPrepare(regexp, subject);
+  if (registers_per_match < 0) return RegExpImpl::RE_EXCEPTION;
+
+  int max_matches;
+  int num_registers = RegExpImpl::GlobalOffsetsVectorSize(regexp,
+                                                          registers_per_match,
+                                                          &max_matches);
+  OffsetsVector registers(num_registers, isolate);
+  Vector<int32_t> register_vector(registers.vector(), registers.length());
+
+  int num_matches = RegExpImpl::IrregexpExecRaw(regexp,
+                                                subject,
+                                                0,
+                                                register_vector);
+
+  int capture_count = regexp->CaptureCount();
+  int subject_length = subject->length();
+
+  // Position to search from.
+  int pos = 0;
+  // End of previous match. Differs from pos if match was empty.
+  int match_end = 0;
+  bool first = true;
+
+  if (num_matches > 0) {
+    do {
+      int match_start = 0;
+      for (int match_index = 0; match_index < num_matches; match_index++) {
+        int32_t* current_match =
+            &register_vector[match_index * registers_per_match];
+        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);
+          // 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);
+          Handle<String> match;
+          if (!first) {
+            match = isolate->factory()->NewProperSubString(subject,
+                                                           match_start,
+                                                           match_end);
+          } else {
+            match = isolate->factory()->NewSubString(subject,
+                                                     match_start,
+                                                     match_end);
+          }
+          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];
+              ASSERT(start <= end);
+              Handle<String> substring;
+              if (!first) {
+                substring =
+                    isolate->factory()->NewProperSubString(subject, start, end);
+              } else {
+                substring =
+                    isolate->factory()->NewSubString(subject, start, end);
+              }
+              elements->set(i, *substring);
+            } else {
+              ASSERT(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));
+        }
+        first = false;
+      }
+
+      // If we did not get the maximum number of matches, we can stop here
+      // since there are no matches left.
+      if (num_matches < max_matches) break;
+
+      if (match_end > match_start) {
+        pos = match_end;
+      } else {
+        pos = match_end + 1;
+        if (pos > subject_length) {
+          break;
+        }
+      }
+
+      num_matches = RegExpImpl::IrregexpExecRaw(regexp,
+                                                subject,
+                                                pos,
+                                                register_vector);
+    } while (num_matches > 0);
+
+    if (num_matches != RegExpImpl::RE_EXCEPTION) {
+      // Finished matching, with at least one match.
+      if (match_end < subject_length) {
+        ReplacementStringBuilder::AddSubjectSlice(builder,
+                                                  match_end,
+                                                  subject_length);
+      }
+
+      int last_match_capture_count = (capture_count + 1) * 2;
+      int last_match_array_size =
+          last_match_capture_count + RegExpImpl::kLastMatchOverhead;
+      last_match_array->EnsureSize(last_match_array_size);
+      AssertNoAllocation no_gc;
+      FixedArray* elements = FixedArray::cast(last_match_array->elements());
+      // We have to set this even though the rest of the last match array is
+      // ignored.
+      RegExpImpl::SetLastCaptureCount(elements, last_match_capture_count);
+      // These are also read without consulting the override.
+      RegExpImpl::SetLastSubject(elements, *subject);
+      RegExpImpl::SetLastInput(elements, *subject);
+      return RegExpImpl::RE_SUCCESS;
+    }
+  }
+  // No matches at all, return failure or exception result directly.
+  return num_matches;
+}
+
+
 // 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(MaybeObject*, Runtime_RegExpExecMultiple) {
   ASSERT(args.length() == 4);
   HandleScope handles(isolate);
 
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 1);
   if (!subject->IsFlat()) FlattenString(subject);
   CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, last_match_info, 2);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, result_array, 3);
 
   ASSERT(last_match_info->HasFastObjectElements());
   ASSERT(regexp->GetFlags().is_global());
   Handle<FixedArray> result_elements;
   if (result_array->HasFastObjectElements()) {
     result_elements =
         Handle<FixedArray>(FixedArray::cast(result_array->elements()));
   }
   if (result_elements.is_null() || result_elements->length() < 16) {
     result_elements = isolate->factory()->NewFixedArrayWithHoles(16);
   }
   FixedArrayBuilder builder(result_elements);
 
+  if (regexp->TypeTag() == JSRegExp::ATOM) {
+    Handle<String> pattern(
+        String::cast(regexp->DataAt(JSRegExp::kAtomPatternIndex)));
+    ASSERT(pattern->IsFlat());
+    if (SearchStringMultiple(isolate, subject, pattern,
+                             last_match_info, &builder)) {
+      return *builder.ToJSArray(result_array);
+    }
+    return isolate->heap()->null_value();
+  }
+
+  ASSERT_EQ(regexp->TypeTag(), JSRegExp::IRREGEXP);
+
   int result;
   if (regexp->CaptureCount() == 0) {
-    result = SearchRegExpMultiple<false>(
-        isolate, subject, regexp, last_match_info, &builder);
+    result = SearchRegExpNoCaptureMultiple(isolate,
+                                           subject,
+                                           regexp,
+                                           last_match_info,
+                                           &builder);
   } else {
-    result = SearchRegExpMultiple<true>(
-        isolate, subject, regexp, last_match_info, &builder);
+    result = SearchRegExpMultiple(isolate,
+                                  subject,
+                                  regexp,
+                                  last_match_info,
+                                  &builder,
+                                  isolate->runtime_zone());
   }
-
   if (result == RegExpImpl::RE_SUCCESS) return *builder.ToJSArray(result_array);
   if (result == RegExpImpl::RE_FAILURE) return isolate->heap()->null_value();
   ASSERT_EQ(result, RegExpImpl::RE_EXCEPTION);
   return Failure::Exception();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_NumberToRadixString) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
@@ skipping 9536 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal