Merge regexp2000 back into bleeding_edge

src/assembler-irregexp.h

Index: src/assembler-irregexp.h
===================================================================
--- src/assembler-irregexp.h	(revision 0)
+++ src/assembler-irregexp.h	(revision 830)
@@ -0,0 +1,137 @@
+// Copyright 2006-2008 the V8 project authors. All rights reserved.

[Erik Corry, 2008/11/25 11:03:52]

Missing license boilerplate.

+
+// A light-weight assembler for the Irregexp byte code.
+
+#ifndef V8_ASSEMBLER_IRREGEXP_H_
+#define V8_ASSEMBLER_IRREGEXP_H_
+
+namespace v8 { namespace internal {
+
+
+class IrregexpAssembler {
+ public:
+  // Create an assembler. Instructions and relocation information are emitted
+  // into a buffer, with the instructions starting from the beginning and the
+  // relocation information starting from the end of the buffer. See CodeDesc
+  // for a detailed comment on the layout (globals.h).
+  //
+  // If the provided buffer is NULL, the assembler allocates and grows its own
+  // buffer, and buffer_size determines the initial buffer size. The buffer is
+  // owned by the assembler and deallocated upon destruction of the assembler.
+  //
+  // If the provided buffer is not NULL, the assembler uses the provided buffer
+  // for code generation and assumes its size to be buffer_size. If the buffer
+  // is too small, a fatal error occurs. No deallocation of the buffer is done
+  // upon destruction of the assembler.
+  explicit IrregexpAssembler(Vector<byte>);
+  ~IrregexpAssembler();
+
+  // CP = current position in source.
+  // BT = backtrack label.
+
+  // Stack.
+  void PushCurrentPosition(int cp_offset = 0);
+  void PushBacktrack(Label* l);
+  void PushRegister(int index);
+  void WriteCurrentPositionToRegister(int index, int cp_offset = 0);
+  void ReadCurrentPositionFromRegister(int index);
+  void WriteStackPointerToRegister(int index);
+  void ReadStackPointerFromRegister(int index);
+  void SetRegister(int index, int value);
+  void AdvanceRegister(int index, int by);
+
+  void PopCurrentPosition();
+  void PopBacktrack();
+  void PopRegister(int index);
+
+  void Fail();
+  void Succeed();
+
+  void Break();  // This instruction will cause a fatal VM error if hit.

[Mads Ager (chromium), 2008/11/25 21:09:41]

I would prefer to have this comment on the line before.

[Erik Corry, 2008/11/26 12:18:36]

Fixed.

+
+  void Bind(Label* l);  // Binds an unbound label L to the current code posn.

[Mads Ager (chromium), 2008/11/25 21:09:41]

Ditto.

[Erik Corry, 2008/11/26 12:18:36]

Fixed.

+
+  void AdvanceCP(int by);
+
+  void GoTo(Label* l);
+
+  // Loads current char into a machine register.  Jumps to the label if we
+  // reached the end of the subject string.  Fall through otherwise.
+  void LoadCurrentChar(int cp_offset, Label* on_end);
+
+  // Checks current char register against a singleton.
+  void CheckCharacter(uc16 c, Label* on_match);
+  void CheckNotCharacter(uc16 c, Label* on_mismatch);
+  void OrThenCheckNotCharacter(uc16 c, uc16 mask, Label* on_mismatch);
+  void MinusOrThenCheckNotCharacter(uc16 c, uc16 mask, Label* on_mismatch);
+
+  // Used to check current char register against a range.
+  void CheckCharacterLT(uc16 limit, Label* on_less);
+  void CheckCharacterGT(uc16 limit, Label* on_greater);
+
+  // Checks current position for a match against a
+  // previous capture.  Advances current position by the length of the capture
+  // iff it matches.  The capture is stored in a given register and the
+  // the register after.  If a register contains -1 then the other register

[Mads Ager (chromium), 2008/11/25 21:09:41]

Two occurrences of 'the' after each other.  Also, reformatting the comment would
be nice.

[Erik Corry, 2008/11/26 12:18:36]

Fixed

+  // must always contain -1 and the on_mismatch label will never be called.
+  void CheckNotBackReference(int capture_index, Label* on_mismatch);
+
+  // Checks a register for strictly-less-than or greater-than-or-equal.
+  void CheckRegisterLT(int reg_index, uint16_t vs, Label* on_less_than);
+  void CheckRegisterGE(int reg_index, uint16_t vs, Label* on_greater_equal);
+
+  // Subtracts a 16 bit value from the current character, uses the result to
+  // look up in a bit array, uses the result of that decide whether to fall

[Mads Ager (chromium), 2008/11/25 21:09:41]

decide -> to decide

[Erik Corry, 2008/11/26 12:18:36]

Fixed

+  // though (on 1) or jump to the on_zero label (on 0).
+  void LookupMap1(uc16 start, Label* bit_map, Label* on_zero);
+
+  // Subtracts a 16 bit value from the current character, uses the result to
+  // look up in a 2-bit array, uses the result of that to look up in a label
+  // table and jumps to the label.
+  void LookupMap2(uc16 start,
+                  Label* half_nibble_map,
+                  const Vector<Label*>& table);
+
+  // Subtracts a 16 bit value from the current character, uses the result to
+  // look up in a byte array, uses the result of that to look up in a label
+  // array and jumps to the label.
+  void LookupMap8(uc16 start, Label* byte_map, const Vector<Label*>& table);
+
+  // Takes the high byte of the current character, uses the result to
+  // look up in a byte array, uses the result of that to look up in a label
+  // array and jumps to the label.
+  void LookupHighMap8(byte start, Label* byte_map, const Vector<Label*>& table);
+
+  // Code and bitmap emission.
+  inline void Emit32(uint32_t x);
+  inline void Emit16(uint32_t x);
+  inline void Emit(uint32_t x);
+
+  // Bytecode buffer.
+  int length();
+  void Copy(Address a);
+
+  inline void EmitOrLink(Label* l);
+ private:
+  // Don't use this.
+  IrregexpAssembler() { UNREACHABLE(); }

[Mads Ager (chromium), 2008/11/25 21:09:41]

Can you use DISALLOW_IMPLICIT_CONSTRUCTORS(IrregexpAssembler) here (in other
words, should we hide default copy and assign as well)?  If you cannot, you
should leave out the implementation and just have IrregexpAssembler();  That way
you get link errors if you extend this with a friend class that accidentally
calls the default constructor.

[Erik Corry, 2008/11/26 12:18:36]

Fixed.

+  // The buffer into which code and relocation info are generated.
+  Vector<byte> buffer_;
+
+  inline void CheckRegister(int byte_code,
+                            int reg_index,
+                            uint16_t vs,
+                            Label* on_true);
+  // Code generation.
+  int pc_;  // The program counter; moves forward.

[Mads Ager (chromium), 2008/11/25 21:09:41]

Move this comment to the line before the declaration?

[Erik Corry, 2008/11/26 12:18:36]

I blame the Strongtalk team.

Fixed.  Also removed the 'moves forward'.  What else is it going to do?

+
+  // True if the assembler owns the buffer, false if buffer is external.
+  bool own_buffer_;
+
+  void Expand();

[iposva, 2008/11/26 06:56:22]

Please move the method definition before the fields to be consistent with the
C++ style guide:
  Typedefs and Enums
  Constants
  Constructors
  Destructor
  Methods, including static methods
  Data Members, including static data members

[Erik Corry, 2008/11/26 12:18:36]

I moved this method but haven't reordered the entire file, since doing so would
be inconsistent with the rest of V8.

+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_ASSEMBLER_IRREGEXP_H_