Experimental support for RegExp lookbehind.

src/regexp/arm64/regexp-macro-assembler-arm64.h

 // Copyright 2013 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_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_
 #define V8_REGEXP_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_
 
 #include "src/arm64/assembler-arm64.h"
 #include "src/macro-assembler.h"
 #include "src/regexp/regexp-macro-assembler.h"
@@ skipping 21 matching lines @@
                                       Label* on_equal);
   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
   virtual void CheckCharacters(Vector<const uc16> str,
                                int cp_offset,
                                Label* on_failure,
                                bool check_end_of_string);
   // 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(unsigned c, Label* on_not_equal);
   virtual void CheckNotCharacterAfterAnd(unsigned c,
                                          unsigned mask,
                                          Label* on_not_equal);
   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
                                               uc16 minus,
                                               uc16 mask,
                                               Label* on_not_equal);
   virtual void CheckCharacterInRange(uc16 from,
@@ skipping 128 matching lines @@
   Register frame_pointer() { return fp; }
 
   // The register containing the backtrack stack top. Provides a meaningful
   // name to the register.
   Register backtrack_stackpointer() { return x23; }
 
   // Register holding pointer to the current code object.
   Register code_pointer() { return x20; }
 
   // Register holding the value used for clearing capture registers.
-  Register non_position_value() { return w24; }
+  Register string_start_minus_one() { return w24; }
   // The top 32 bit of this register is used to store this value
   // twice. This is used for clearing more than one register at a time.
   Register twice_non_position_value() { return x24; }
 
   // Byte size of chars in the string to match (decided by the Mode argument)
   int char_size() { return static_cast<int>(mode_); }
 
   // Equivalent to a conditional branch to the label, unless the label
   // is NULL, in which case it is a conditional Backtrack.
   void BranchOrBacktrack(Condition condition, Label* to);
@@ skipping 82 matching lines @@
   Label stack_overflow_label_;
 };
 
 #endif  // V8_INTERPRETED_REGEXP
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_