diff --git a/src/regexp-macro-assembler.cc b/src/regexp-macro-assembler.cc
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+++ b/src/regexp-macro-assembler.cc
@@ -0,0 +1,260 @@
+// Copyright 2008 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+#include "ast.h"
+#include "assembler.h"
+#include "regexp-stack.h"
+#include "regexp-macro-assembler.h"
+#if V8_TARGET_ARCH_ARM
+#include "arm/simulator-arm.h"
+#elif V8_TARGET_ARCH_IA32
+#include "ia32/simulator-ia32.h"
+#elif V8_TARGET_ARCH_X64
+#include "x64/simulator-x64.h"
+#endif
+
+namespace v8 {
+namespace internal {
+
+RegExpMacroAssembler::RegExpMacroAssembler() {
+}
+
+
+RegExpMacroAssembler::~RegExpMacroAssembler() {
+}
+
+
+bool RegExpMacroAssembler::CanReadUnaligned() {
+#ifdef V8_HOST_CAN_READ_UNALIGNED
+  return true;
+#else
+  return false;
+#endif
+}
+
+
+#ifdef V8_NATIVE_REGEXP  // Avoid unused code, e.g., on ARM.
+
+NativeRegExpMacroAssembler::NativeRegExpMacroAssembler() {
+}
+
+
+NativeRegExpMacroAssembler::~NativeRegExpMacroAssembler() {
+}
+
+
+bool NativeRegExpMacroAssembler::CanReadUnaligned() {
+#ifdef V8_TARGET_CAN_READ_UNALIGNED
+  return true;
+#else
+  return false;
+#endif
+}
+
+const byte* NativeRegExpMacroAssembler::StringCharacterPosition(
+    String* subject,
+    int start_index) {
+  // Not just flat, but ultra flat.
+  ASSERT(subject->IsExternalString() || subject->IsSeqString());
+  ASSERT(start_index >= 0);
+  ASSERT(start_index <= subject->length());
+  if (subject->IsAsciiRepresentation()) {
+    const byte* address;
+    if (StringShape(subject).IsExternal()) {
+      const char* data = ExternalAsciiString::cast(subject)->resource()->data();
+      address = reinterpret_cast<const byte*>(data);
+    } else {
+      ASSERT(subject->IsSeqAsciiString());
+      char* data = SeqAsciiString::cast(subject)->GetChars();
+      address = reinterpret_cast<const byte*>(data);
+    }
+    return address + start_index;
+  }
+  const uc16* data;
+  if (StringShape(subject).IsExternal()) {
+    data = ExternalTwoByteString::cast(subject)->resource()->data();
+  } else {
+    ASSERT(subject->IsSeqTwoByteString());
+    data = SeqTwoByteString::cast(subject)->GetChars();
+  }
+  return reinterpret_cast<const byte*>(data + start_index);
+}
+
+
+NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Match(
+    Handle<Code> regexp_code,
+    Handle<String> subject,
+    int* offsets_vector,
+    int offsets_vector_length,
+    int previous_index) {
+
+  ASSERT(subject->IsFlat());
+  ASSERT(previous_index >= 0);
+  ASSERT(previous_index <= subject->length());
+
+  // No allocations before calling the regexp, but we can't use
+  // AssertNoAllocation, since regexps might be preempted, and another thread
+  // might do allocation anyway.
+
+  String* subject_ptr = *subject;
+  // Character offsets into string.
+  int start_offset = previous_index;
+  int end_offset = subject_ptr->length();
+
+  bool is_ascii = subject->IsAsciiRepresentation();
+
+  if (StringShape(subject_ptr).IsCons()) {
+    subject_ptr = ConsString::cast(subject_ptr)->first();
+  } else if (StringShape(subject_ptr).IsSliced()) {
+    SlicedString* slice = SlicedString::cast(subject_ptr);
+    start_offset += slice->start();
+    end_offset += slice->start();
+    subject_ptr = slice->buffer();
+  }
+  // Ensure that an underlying string has the same ascii-ness.
+  ASSERT(subject_ptr->IsAsciiRepresentation() == is_ascii);
+  ASSERT(subject_ptr->IsExternalString() || subject_ptr->IsSeqString());
+  // String is now either Sequential or External
+  int char_size_shift = is_ascii ? 0 : 1;
+  int char_length = end_offset - start_offset;
+
+  const byte* input_start =
+      StringCharacterPosition(subject_ptr, start_offset);
+  int byte_length = char_length << char_size_shift;
+  const byte* input_end = input_start + byte_length;
+  Result res = Execute(*regexp_code,
+                       subject_ptr,
+                       start_offset,
+                       input_start,
+                       input_end,
+                       offsets_vector,
+                       previous_index == 0);
+
+  if (res == SUCCESS) {
+    // Capture values are relative to start_offset only.
+    // Convert them to be relative to start of string.
+    for (int i = 0; i < offsets_vector_length; i++) {
+      if (offsets_vector[i] >= 0) {
+        offsets_vector[i] += previous_index;
+      }
+    }
+  }
+
+  return res;
+}
+
+
+NativeRegExpMacroAssembler::Result NativeRegExpMacroAssembler::Execute(
+    Code* code,
+    String* input,
+    int start_offset,
+    const byte* input_start,
+    const byte* input_end,
+    int* output,
+    bool at_start) {
+  typedef int (*matcher)(String*, int, const byte*,
+                         const byte*, int*, int, Address);
+  matcher matcher_func = FUNCTION_CAST<matcher>(code->entry());
+
+  int at_start_val = at_start ? 1 : 0;
+
+  // Ensure that the minimum stack has been allocated.
+  RegExpStack stack;
+  Address stack_base = RegExpStack::stack_base();
+
+  int result = CALL_GENERATED_REGEXP_CODE(matcher_func,
+                                          input,
+                                          start_offset,
+                                          input_start,
+                                          input_end,
+                                          output,
+                                          at_start_val,
+                                          stack_base);
+  ASSERT(result <= SUCCESS);
+  ASSERT(result >= RETRY);
+
+  if (result == EXCEPTION && !Top::has_pending_exception()) {
+    // We detected a stack overflow (on the backtrack stack) in RegExp code,
+    // but haven't created the exception yet.
+    Top::StackOverflow();
+  }
+  return static_cast<Result>(result);
+}
+
+
+static unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
+
+int NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16(
+    Address byte_offset1,
+    Address byte_offset2,
+    size_t byte_length) {
+  // This function is not allowed to cause a garbage collection.
+  // A GC might move the calling generated code and invalidate the
+  // return address on the stack.
+  ASSERT(byte_length % 2 == 0);
+  uc16* substring1 = reinterpret_cast<uc16*>(byte_offset1);
+  uc16* substring2 = reinterpret_cast<uc16*>(byte_offset2);
+  size_t length = byte_length >> 1;
+
+  for (size_t i = 0; i < length; i++) {
+    unibrow::uchar c1 = substring1[i];
+    unibrow::uchar c2 = substring2[i];
+    if (c1 != c2) {
+      unibrow::uchar s1[1] = { c1 };
+      canonicalize.get(c1, '\0', s1);
+      if (s1[0] != c2) {
+        unibrow::uchar s2[1] = { c2 };
+        canonicalize.get(c2, '\0', s2);
+        if (s1[0] != s2[0]) {
+          return 0;
+        }
+      }
+    }
+  }
+  return 1;
+}
+
+
+Address NativeRegExpMacroAssembler::GrowStack(Address stack_pointer,
+                                              Address* stack_base) {
+  size_t size = RegExpStack::stack_capacity();
+  Address old_stack_base = RegExpStack::stack_base();
+  ASSERT(old_stack_base == *stack_base);
+  ASSERT(stack_pointer <= old_stack_base);
+  ASSERT(static_cast<size_t>(old_stack_base - stack_pointer) <= size);
+  Address new_stack_base = RegExpStack::EnsureCapacity(size * 2);
+  if (new_stack_base == NULL) {
+    return NULL;
+  }
+  *stack_base = new_stack_base;
+  intptr_t stack_content_size = old_stack_base - stack_pointer;
+  return new_stack_base - stack_content_size;
+}
+
+#endif  // V8_NATIVE_REGEXP
+} }  // namespace v8::internal