Experimental support for RegExp lookbehind.

src/regexp/x64/regexp-macro-assembler-x64.h

 // 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.
 
 #ifndef V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
 #define V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
 
 #include "src/macro-assembler.h"
 #include "src/regexp/regexp-macro-assembler.h"
 #include "src/x64/assembler-x64.h"
@@ skipping 16 matching lines @@
   virtual void CheckAtStart(Label* on_at_start);
   virtual void CheckCharacter(uint32_t c, Label* on_equal);
   virtual void CheckCharacterAfterAnd(uint32_t c,
                                       uint32_t mask,
                                       Label* on_equal);
   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
   // A "greedy loop" is a loop that is both greedy and with a simple
   // body. It has a particularly simple implementation.
   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
-  virtual void CheckNotAtStart(Label* on_not_at_start);
-  virtual void CheckNotBackReference(int start_reg, Label* on_no_match);
+  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
+  virtual void CheckNotBackReference(int start_reg, bool read_backward,
+                                     Label* on_no_match);
   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
+                                               bool read_backward,
                                                Label* on_no_match);
   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(uint32_t c,
                                          uint32_t mask,
                                          Label* on_not_equal);
   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
                                               uc16 minus,
                                               uc16 mask,
                                               Label* on_not_equal);
   virtual void CheckCharacterInRange(uc16 from,
@@ skipping 223 matching lines @@
   Label check_preempt_label_;
   Label stack_overflow_label_;
 };
 
 #endif  // V8_INTERPRETED_REGEXP
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_