Support for MIPS in architecture independent files....

src/mips/regexp-macro-assembler-mips.cc

Index: src/mips/regexp-macro-assembler-mips.cc
===================================================================
--- src/mips/regexp-macro-assembler-mips.cc	(revision 0)
+++ src/mips/regexp-macro-assembler-mips.cc	(revision 0)
@@ -0,0 +1,1268 @@
+
+// FROM ARM Code
+
+#include "v8.h"
+#include "unicode.h"
+#include "log.h"
+#include "ast.h"
+#include "regexp-stack.h"
+#include "macro-assembler.h"
+#include "regexp-macro-assembler.h"
+#include "mips/macro-assembler-mips.h"
+#include "mips/regexp-macro-assembler-mips.h"
+
+namespace v8 {
+namespace internal {
+
+#ifdef V8_NATIVE_REGEXP
+/*
+ * This assembler uses the following register assignment convention
+ * - r5 : Pointer to current code object (Code*) including heap object tag.
+ * - r6 : Current position in input, as negative offset from end of string.
+ *        Please notice that this is the byte offset, not the character offset!
+ * - r7 : Currently loaded character. Must be loaded using
+ *        LoadCurrentCharacter before using any of the dispatch methods.
+ * - r8 : points to tip of backtrack stack
+ * - r9 : Unused, might be used by C code and expected unchanged.
+ * - r10 : End of input (points to byte after last character in input).
+ * - r11 : Frame pointer. Used to access arguments, local variables and
+ *         RegExp registers.
+ * - r12 : IP register, used by assembler. Very volatile.
+ * - r13/sp : points to tip of C stack.
+ *
+ * The remaining registers are free for computations.
+ *
+ * Each call to a public method should retain this convention.
+ * The stack will have the following structure:
+ *       - stack_area_base    (High end of the memory area to use as
+ *                             backtracking stack)
+ *       - at_start           (if 1, start at start of string, if 0, don't)
+ *       --- sp when called ---
+ *       - link address
+ *       - backup of registers r4..r11
+ *       - int* capture_array (int[num_saved_registers_], for output).
+ *       - end of input       (Address of end of string)
+ *       - start of input     (Address of first character in string)
+ *       --- frame pointer ----
+ *       - void* input_string (location of a handle containing the string)
+ *       - Offset of location before start of input (effectively character
+ *         position -1). Used to initialize capture registers to a non-position.
+ *       - register 0         (Only positions must be stored in the first
+ *       - register 1          num_saved_registers_ registers)
+ *       - ...
+ *       - register num_registers-1
+ *       --- sp ---
+ *
+ * The first num_saved_registers_ registers are initialized to point to
+ * "character -1" in the string (i.e., char_size() bytes before the first
+ * character of the string). The remaining registers start out as garbage.
+ *
+ * The data up to the return address must be placed there by the calling
+ * code, by calling the code entry as cast to a function with the signature:
+ * int (*match)(String* input_string,
+ *              Address start,
+ *              Address end,
+ *              int* capture_output_array,
+ *              bool at_start,
+ *              byte* stack_area_base)
+ * The call is performed by NativeRegExpMacroAssembler::Execute()
+ * (in regexp-macro-assembler.cc).
+ */
+
+#define __ ACCESS_MASM(masm_)
+
+RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(
+    Mode mode,
+    int registers_to_save)
+    : masm_(new MacroAssembler(NULL, kRegExpCodeSize)),
+      mode_(mode),
+      num_registers_(registers_to_save),
+      num_saved_registers_(registers_to_save),
+      entry_label_(),
+      start_label_(),
+      success_label_(),
+      backtrack_label_(),
+      exit_label_() {
+//  ASSERT_EQ(0, registers_to_save % 2);
+//  __ jmp(&entry_label_);   // We'll write the entry code later.
+//  EmitBacktrackConstantPool();
+//  __ bind(&start_label_);  // And then continue from here.
+}
+//
+//
+RegExpMacroAssemblerMIPS::~RegExpMacroAssemblerMIPS() {
+  UNIMPLEMENTED();
+  delete masm_;
+  // Unuse labels in case we throw away the assembler without calling GetCode.
+//  entry_label_.Unuse();
+//  start_label_.Unuse();
+//  success_label_.Unuse();
+//  backtrack_label_.Unuse();
+//  exit_label_.Unuse();
+//  check_preempt_label_.Unuse();
+//  stack_overflow_label_.Unuse();
+}
+
+
+int RegExpMacroAssemblerMIPS::stack_limit_slack()  {
+  UNIMPLEMENTED();
+//  return RegExpStack::kStackLimitSlack;
+  return 0;
+}
+
+
+void RegExpMacroAssemblerMIPS::AdvanceCurrentPosition(int by) {
+  UNIMPLEMENTED();
+//  if (by != 0) {
+//    Label inside_string;
+//    __ add(current_input_offset(),
+//           current_input_offset(), Operand(by * char_size()));
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::AdvanceRegister(int reg, int by) {
+  UNIMPLEMENTED();
+//  ASSERT(reg >= 0);
+//  ASSERT(reg < num_registers_);
+//  if (by != 0) {
+//    __ ldr(r0, register_location(reg));
+//    __ add(r0, r0, Operand(by));
+//    __ str(r0, register_location(reg));
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::Backtrack() {
+  UNIMPLEMENTED();
+//  CheckPreemption();
+//  // Pop Code* offset from backtrack stack, add Code* and jump to location.
+//  Pop(r0);
+//  __ add(pc, r0, Operand(r5));
+}
+
+
+void RegExpMacroAssemblerMIPS::Bind(Label* label) {
+  UNIMPLEMENTED();
+//  __ bind(label);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckCharacter(uint32_t c, Label* on_equal) {
+  UNIMPLEMENTED();
+//  __ cmp(current_character(), Operand(c));
+//  BranchOrBacktrack(eq, on_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckCharacterGT(uc16 limit, Label* on_greater) {
+  UNIMPLEMENTED();
+//  __ cmp(current_character(), Operand(limit));
+//  BranchOrBacktrack(gt, on_greater);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckAtStart(Label* on_at_start) {
+  UNIMPLEMENTED();
+//  Label not_at_start;
+//  // Did we start the match at the start of the string at all?
+//  __ ldr(r0, MemOperand(frame_pointer(), kAtStart));
+//  __ cmp(r0, Operand(0));
+//  BranchOrBacktrack(eq, &not_at_start);
+//
+//  // If we did, are we still at the start of the input?
+//  __ ldr(r1, MemOperand(frame_pointer(), kInputStart));
+//  __ add(r0, end_of_input_address(), Operand(current_input_offset()));
+//  __ cmp(r0, r1);
+//  BranchOrBacktrack(eq, on_at_start);
+//  __ bind(&not_at_start);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotAtStart(Label* on_not_at_start) {
+  UNIMPLEMENTED();
+//  // Did we start the match at the start of the string at all?
+//  __ ldr(r0, MemOperand(frame_pointer(), kAtStart));
+//  __ cmp(r0, Operand(0));
+//  BranchOrBacktrack(eq, on_not_at_start);
+//  // If we did, are we still at the start of the input?
+//  __ ldr(r1, MemOperand(frame_pointer(), kInputStart));
+//  __ add(r0, end_of_input_address(), Operand(current_input_offset()));
+//  __ cmp(r0, r1);
+//  BranchOrBacktrack(ne, on_not_at_start);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckCharacterLT(uc16 limit, Label* on_less) {
+  UNIMPLEMENTED();
+//  __ cmp(current_character(), Operand(limit));
+//  BranchOrBacktrack(lt, on_less);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckCharacters(Vector<const uc16> str,
+                                              int cp_offset,
+                                              Label* on_failure,
+                                              bool check_end_of_string) {
+  UNIMPLEMENTED();
+//  if (on_failure == NULL) {
+//    // Instead of inlining a backtrack for each test, (re)use the global
+//    // backtrack target.
+//    on_failure = &backtrack_label_;
+//  }
+//
+//  if (check_end_of_string) {
+//    // Is last character of required match inside string.
+//    CheckPosition(cp_offset + str.length() - 1, on_failure);
+//  }
+//
+//  __ add(r0, end_of_input_address(), Operand(current_input_offset()));
+//  if (cp_offset != 0) {
+//    int byte_offset = cp_offset * char_size();
+//    __ add(r0, r0, Operand(byte_offset));
+//  }
+//
+//  // r0 : Address of characters to match against str.
+//  int stored_high_byte = 0;
+//  for (int i = 0; i < str.length(); i++) {
+//    if (mode_ == ASCII) {
+//      __ ldrb(r1, MemOperand(r0, char_size(), PostIndex));
+//      ASSERT(str[i] <= String::kMaxAsciiCharCode);
+//      __ cmp(r1, Operand(str[i]));
+//    } else {
+//      __ ldrh(r1, MemOperand(r0, char_size(), PostIndex));
+//      uc16 match_char = str[i];
+//      int match_high_byte = (match_char >> 8);
+//      if (match_high_byte == 0) {
+//        __ cmp(r1, Operand(str[i]));
+//      } else {
+//        if (match_high_byte != stored_high_byte) {
+//          __ mov(r2, Operand(match_high_byte));
+//          stored_high_byte = match_high_byte;
+//        }
+//        __ add(r3, r2, Operand(match_char & 0xff));
+//        __ cmp(r1, r3);
+//      }
+//    }
+//    BranchOrBacktrack(ne, on_failure);
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckGreedyLoop(Label* on_equal) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, MemOperand(backtrack_stackpointer(), 0));
+//  __ cmp(current_input_offset(), r0);
+//  __ add(backtrack_stackpointer(),
+//         backtrack_stackpointer(), Operand(kPointerSize), LeaveCC, eq);
+//  BranchOrBacktrack(eq, on_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
+    int start_reg,
+    Label* on_no_match) {
+  UNIMPLEMENTED();
+//  Label fallthrough;
+//  __ ldr(r0, register_location(start_reg));  // Index of start of capture
+//  __ ldr(r1, register_location(start_reg + 1));  // Index of end of capture
+//  __ sub(r1, r1, r0, SetCC);  // Length of capture.
+//
+//  // If length is zero, either the capture is empty or it is not participating.
+//  // In either case succeed immediately.
+//  __ b(eq, &fallthrough);
+//
+//  // Check that there are enough characters left in the input.
+//  __ cmn(r1, Operand(current_input_offset()));
+//  BranchOrBacktrack(gt, on_no_match);
+//
+//  if (mode_ == ASCII) {
+//    Label success;
+//    Label fail;
+//    Label loop_check;
+//
+//    // r0 - offset of start of capture
+//    // r1 - length of capture
+//    __ add(r0, r0, Operand(end_of_input_address()));
+//    __ add(r2, end_of_input_address(), Operand(current_input_offset()));
+//    __ add(r1, r0, Operand(r1));
+//
+//    // r0 - Address of start of capture.
+//    // r1 - Address of end of capture
+//    // r2 - Address of current input position.
+//
+//    Label loop;
+//    __ bind(&loop);
+//    __ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
+//    __ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
+//    __ cmp(r4, r3);
+//    __ b(eq, &loop_check);
+//
+//    // Mismatch, try case-insensitive match (converting letters to lower-case).
+//    __ orr(r3, r3, Operand(0x20));  // Convert capture character to lower-case.
+//    __ orr(r4, r4, Operand(0x20));  // Also convert input character.
+//    __ cmp(r4, r3);
+//    __ b(ne, &fail);
+//    __ sub(r3, r3, Operand('a'));
+//    __ cmp(r3, Operand('z' - 'a'));  // Is r3 a lowercase letter?
+//    __ b(hi, &fail);
+//
+//
+//    __ bind(&loop_check);
+//    __ cmp(r0, r1);
+//    __ b(lt, &loop);
+//    __ jmp(&success);
+//
+//    __ bind(&fail);
+//    BranchOrBacktrack(al, on_no_match);
+//
+//    __ bind(&success);
+//    // Compute new value of character position after the matched part.
+//    __ sub(current_input_offset(), r2, end_of_input_address());
+//  } else {
+//    ASSERT(mode_ == UC16);
+//    int argument_count = 3;
+//    FrameAlign(argument_count, r2);
+//
+//    // r0 - offset of start of capture
+//    // r1 - length of capture
+//
+//    // Put arguments into arguments registers.
+//    // Parameters are
+//    //   r0: Address byte_offset1 - Address captured substring's start.
+//    //   r1: Address byte_offset2 - Address of current character position.
+//    //   r2: size_t byte_length - length of capture in bytes(!)
+//
+//    // Address of start of capture.
+//    __ add(r0, r0, Operand(end_of_input_address()));
+//    // Length of capture.
+//    __ mov(r2, Operand(r1));
+//    // Save length in callee-save register for use on return.
+//    __ mov(r4, Operand(r1));
+//    // Address of current input position.
+//    __ add(r1, current_input_offset(), Operand(end_of_input_address()));
+//
+//    ExternalReference function =
+//        ExternalReference::re_case_insensitive_compare_uc16();
+//    CallCFunction(function, argument_count);
+//
+//    // Check if function returned non-zero for success or zero for failure.
+//    __ cmp(r0, Operand(0));
+//    BranchOrBacktrack(eq, on_no_match);
+//    // On success, increment position by length of capture.
+//    __ add(current_input_offset(), current_input_offset(), Operand(r4));
+//  }
+//
+//  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotBackReference(
+    int start_reg,
+    Label* on_no_match) {
+  UNIMPLEMENTED();
+//  Label fallthrough;
+//  Label success;
+//
+//  // Find length of back-referenced capture.
+//  __ ldr(r0, register_location(start_reg));
+//  __ ldr(r1, register_location(start_reg + 1));
+//  __ sub(r1, r1, r0, SetCC);  // Length to check.
+//  // Succeed on empty capture (including no capture).
+//  __ b(eq, &fallthrough);
+//
+//  // Check that there are enough characters left in the input.
+//  __ cmn(r1, Operand(current_input_offset()));
+//  BranchOrBacktrack(gt, on_no_match);
+//
+//  // Compute pointers to match string and capture string
+//  __ add(r0, r0, Operand(end_of_input_address()));
+//  __ add(r2, end_of_input_address(), Operand(current_input_offset()));
+//  __ add(r1, r1, Operand(r0));
+//
+//  Label loop;
+//  __ bind(&loop);
+//  if (mode_ == ASCII) {
+//    __ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
+//    __ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
+//  } else {
+//    ASSERT(mode_ == UC16);
+//    __ ldrh(r3, MemOperand(r0, char_size(), PostIndex));
+//    __ ldrh(r4, MemOperand(r2, char_size(), PostIndex));
+//  }
+//  __ cmp(r3, r4);
+//  BranchOrBacktrack(ne, on_no_match);
+//  __ cmp(r0, r1);
+//  __ b(lt, &loop);
+//
+//  // Move current character position to position after match.
+//  __ sub(current_input_offset(), r2, end_of_input_address());
+//  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotRegistersEqual(int reg1,
+                                                      int reg2,
+                                                      Label* on_not_equal) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, register_location(reg1));
+//  __ ldr(r1, register_location(reg2));
+//  __ cmp(r0, r1);
+//  BranchOrBacktrack(ne, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotCharacter(uint32_t c,
+                                                Label* on_not_equal) {
+  UNIMPLEMENTED();
+//  __ cmp(current_character(), Operand(c));
+//  BranchOrBacktrack(ne, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckCharacterAfterAnd(uint32_t c,
+                                                     uint32_t mask,
+                                                     Label* on_equal) {
+  UNIMPLEMENTED();
+//  __ and_(r0, current_character(), Operand(mask));
+//  __ cmp(r0, Operand(c));
+//  BranchOrBacktrack(eq, on_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterAnd(uint32_t c,
+                                                        uint32_t mask,
+                                                        Label* on_not_equal) {
+  UNIMPLEMENTED();
+//  __ and_(r0, current_character(), Operand(mask));
+//  __ cmp(r0, Operand(c));
+//  BranchOrBacktrack(ne, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterMinusAnd(
+    uc16 c,
+    uc16 minus,
+    uc16 mask,
+    Label* on_not_equal) {
+  UNIMPLEMENTED();
+//  ASSERT(minus < String::kMaxUC16CharCode);
+//  __ sub(r0, current_character(), Operand(minus));
+//  __ and_(r0, r0, Operand(mask));
+//  __ cmp(r0, Operand(c));
+//  BranchOrBacktrack(ne, on_not_equal);
+}
+
+
+bool RegExpMacroAssemblerMIPS::CheckSpecialCharacterClass(uc16 type,
+                                                         int cp_offset,
+                                                         bool check_offset,
+                                                         Label* on_no_match) {
+  UNIMPLEMENTED();
+//  // Range checks (c in min..max) are generally implemented by an unsigned
+//  // (c - min) <= (max - min) check
+//  switch (type) {
+//  case 's':
+//    // Match space-characters
+//    if (mode_ == ASCII) {
+//      // ASCII space characters are '\t'..'\r' and ' '.
+//      if (check_offset) {
+//        LoadCurrentCharacter(cp_offset, on_no_match);
+//      } else {
+//        LoadCurrentCharacterUnchecked(cp_offset, 1);
+//      }
+//      Label success;
+//      __ cmp(current_character(), Operand(' '));
+//      __ b(eq, &success);
+//      // Check range 0x09..0x0d
+//      __ sub(r0, current_character(), Operand('\t'));
+//      __ cmp(r0, Operand('\r' - '\t'));
+//      BranchOrBacktrack(hi, on_no_match);
+//      __ bind(&success);
+//      return true;
+//    }
+//    return false;
+//  case 'S':
+//    // Match non-space characters.
+//    if (check_offset) {
+//      LoadCurrentCharacter(cp_offset, on_no_match, 1);
+//    } else {
+//      LoadCurrentCharacterUnchecked(cp_offset, 1);
+//    }
+//    if (mode_ == ASCII) {
+//      // ASCII space characters are '\t'..'\r' and ' '.
+//      __ cmp(current_character(), Operand(' '));
+//      BranchOrBacktrack(eq, on_no_match);
+//      __ sub(r0, current_character(), Operand('\t'));
+//      __ cmp(r0, Operand('\r' - '\t'));
+//      BranchOrBacktrack(ls, on_no_match);
+//      return true;
+//    }
+//    return false;
+//  case 'd':
+//    // Match ASCII digits ('0'..'9')
+//    if (check_offset) {
+//      LoadCurrentCharacter(cp_offset, on_no_match, 1);
+//    } else {
+//      LoadCurrentCharacterUnchecked(cp_offset, 1);
+//    }
+//    __ sub(r0, current_character(), Operand('0'));
+//    __ cmp(current_character(), Operand('9' - '0'));
+//    BranchOrBacktrack(hi, on_no_match);
+//    return true;
+//  case 'D':
+//    // Match non ASCII-digits
+//    if (check_offset) {
+//      LoadCurrentCharacter(cp_offset, on_no_match, 1);
+//    } else {
+//      LoadCurrentCharacterUnchecked(cp_offset, 1);
+//    }
+//    __ sub(r0, current_character(), Operand('0'));
+//    __ cmp(r0, Operand('9' - '0'));
+//    BranchOrBacktrack(ls, on_no_match);
+//    return true;
+//  case '.': {
+//    // Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
+//    if (check_offset) {
+//      LoadCurrentCharacter(cp_offset, on_no_match, 1);
+//    } else {
+//      LoadCurrentCharacterUnchecked(cp_offset, 1);
+//    }
+//    __ eor(r0, current_character(), Operand(0x01));
+//    // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+//    __ sub(r0, r0, Operand(0x0b));
+//    __ cmp(r0, Operand(0x0c - 0x0b));
+//    BranchOrBacktrack(ls, on_no_match);
+//    if (mode_ == UC16) {
+//      // Compare original value to 0x2028 and 0x2029, using the already
+//      // computed (current_char ^ 0x01 - 0x0b). I.e., check for
+//      // 0x201d (0x2028 - 0x0b) or 0x201e.
+//      __ sub(r0, r0, Operand(0x2028 - 0x0b));
+//      __ cmp(r0, Operand(1));
+//      BranchOrBacktrack(ls, on_no_match);
+//    }
+//    return true;
+//  }
+//  case '*':
+//    // Match any character.
+//    if (check_offset) {
+//      CheckPosition(cp_offset, on_no_match);
+//    }
+//    return true;
+//  // No custom implementation (yet): w, W, s(UC16), S(UC16).
+//  default:
+//    return false;
+//  }
+  return false;
+}
+
+
+void RegExpMacroAssemblerMIPS::Fail() {
+  UNIMPLEMENTED();
+//  __ mov(r0, Operand(FAILURE));
+//  __ jmp(&exit_label_);
+}
+
+
+Handle<Object> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
+  UNIMPLEMENTED();
+//  // Finalize code - write the entry point code now we know how many
+//  // registers we need.
+//
+//  // Entry code:
+//  __ bind(&entry_label_);
+//  // Push Link register.
+//  // Push arguments
+//  // Save callee-save registers.
+//  // Start new stack frame.
+//  // Order here should correspond to order of offset constants in header file.
+//  RegList registers_to_retain = r4.bit() | r5.bit() | r6.bit() |
+//      r7.bit() | r8.bit() | r9.bit() | r10.bit() | fp.bit();
+//  RegList argument_registers = r0.bit() | r1.bit() | r2.bit() | r3.bit();
+//  __ stm(db_w, sp, argument_registers | registers_to_retain | lr.bit());
+//  // Set frame pointer just above the arguments.
+//  __ add(frame_pointer(), sp, Operand(4 * kPointerSize));
+//  __ push(r0);  // Make room for "position - 1" constant (value is irrelevant).
+//
+//  // Check if we have space on the stack for registers.
+//  Label stack_limit_hit;
+//  Label stack_ok;
+//
+//  ExternalReference stack_guard_limit =
+//      ExternalReference::address_of_stack_guard_limit();
+//  __ mov(r0, Operand(stack_guard_limit));
+//  __ ldr(r0, MemOperand(r0));
+//  __ sub(r0, sp, r0, SetCC);
+//  // Handle it if the stack pointer is already below the stack limit.
+//  __ b(ls, &stack_limit_hit);
+//  // Check if there is room for the variable number of registers above
+//  // the stack limit.
+//  __ cmp(r0, Operand(num_registers_ * kPointerSize));
+//  __ b(hs, &stack_ok);
+//  // Exit with OutOfMemory exception. There is not enough space on the stack
+//  // for our working registers.
+//  __ mov(r0, Operand(EXCEPTION));
+//  __ jmp(&exit_label_);
+//
+//  __ bind(&stack_limit_hit);
+//  CallCheckStackGuardState(r0);
+//  __ cmp(r0, Operand(0));
+//  // If returned value is non-zero, we exit with the returned value as result.
+//  __ b(ne, &exit_label_);
+//
+//  __ bind(&stack_ok);
+//
+//  // Allocate space on stack for registers.
+//  __ sub(sp, sp, Operand(num_registers_ * kPointerSize));
+//  // Load string end.
+//  __ ldr(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
+//  // Load input start.
+//  __ ldr(r0, MemOperand(frame_pointer(), kInputStart));
+//  // Find negative length (offset of start relative to end).
+//  __ sub(current_input_offset(), r0, end_of_input_address());
+//  // Set r0 to address of char before start of input
+//  // (effectively string position -1).
+//  __ sub(r0, current_input_offset(), Operand(char_size()));
+//  // Store this value in a local variable, for use when clearing
+//  // position registers.
+//  __ str(r0, MemOperand(frame_pointer(), kInputStartMinusOne));
+//  if (num_saved_registers_ > 0) {  // Always is, if generated from a regexp.
+//    // Fill saved registers with initial value = start offset - 1
+//
+//    // Address of register 0.
+//    __ add(r1, frame_pointer(), Operand(kRegisterZero));
+//    __ mov(r2, Operand(num_saved_registers_));
+//    Label init_loop;
+//    __ bind(&init_loop);
+//    __ str(r0, MemOperand(r1, kPointerSize, NegPostIndex));
+//    __ sub(r2, r2, Operand(1), SetCC);
+//    __ b(ne, &init_loop);
+//  }
+//
+//  // Initialize backtrack stack pointer.
+//  __ ldr(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
+//  // Initialize code pointer register
+//  __ mov(code_pointer(), Operand(masm_->CodeObject()));
+//  // Load previous char as initial value of current character register.
+//  Label at_start;
+//  __ ldr(r0, MemOperand(frame_pointer(), kAtStart));
+//  __ cmp(r0, Operand(0));
+//  __ b(ne, &at_start);
+//  LoadCurrentCharacterUnchecked(-1, 1);  // Load previous char.
+//  __ jmp(&start_label_);
+//  __ bind(&at_start);
+//  __ mov(current_character(), Operand('\n'));
+//  __ jmp(&start_label_);
+//
+//
+//  // Exit code:
+//  if (success_label_.is_linked()) {
+//    // Save captures when successful.
+//    __ bind(&success_label_);
+//    if (num_saved_registers_ > 0) {
+//      // copy captures to output
+//      __ ldr(r1, MemOperand(frame_pointer(), kInputStart));
+//      __ ldr(r0, MemOperand(frame_pointer(), kRegisterOutput));
+//      __ sub(r1, end_of_input_address(), r1);
+//      // r1 is length of input in bytes.
+//      if (mode_ == UC16) {
+//        __ mov(r1, Operand(r1, LSR, 1));
+//      }
+//      // r1 is length of input in characters.
+//
+//      ASSERT_EQ(0, num_saved_registers_ % 2);
+//      // Always an even number of capture registers. This allows us to
+//      // unroll the loop once to add an operation between a load of a register
+//      // and the following use of that register.
+//      for (int i = 0; i < num_saved_registers_; i += 2) {
+//        __ ldr(r2, register_location(i));
+//        __ ldr(r3, register_location(i + 1));
+//        if (mode_ == UC16) {
+//          __ add(r2, r1, Operand(r2, ASR, 1));
+//          __ add(r3, r1, Operand(r3, ASR, 1));
+//        } else {
+//          __ add(r2, r1, Operand(r2));
+//          __ add(r3, r1, Operand(r3));
+//        }
+//        __ str(r2, MemOperand(r0, kPointerSize, PostIndex));
+//        __ str(r3, MemOperand(r0, kPointerSize, PostIndex));
+//      }
+//    }
+//    __ mov(r0, Operand(SUCCESS));
+//  }
+//  // Exit and return r0
+//  __ bind(&exit_label_);
+//  // Skip sp past regexp registers and local variables..
+//  __ mov(sp, frame_pointer());
+//  // Restore registers r4..r11 and return (restoring lr to pc).
+//  __ ldm(ia_w, sp, registers_to_retain | pc.bit());
+//
+//  // Backtrack code (branch target for conditional backtracks).
+//  if (backtrack_label_.is_linked()) {
+//    __ bind(&backtrack_label_);
+//    Backtrack();
+//  }
+//
+//  Label exit_with_exception;
+//
+//  // Preempt-code
+//  if (check_preempt_label_.is_linked()) {
+//    SafeCallTarget(&check_preempt_label_);
+//
+//    CallCheckStackGuardState(r0);
+//    __ cmp(r0, Operand(0));
+//    // If returning non-zero, we should end execution with the given
+//    // result as return value.
+//    __ b(ne, &exit_label_);
+//
+//    // String might have moved: Reload end of string from frame.
+//    __ ldr(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
+//    SafeReturn();
+//  }
+//
+//  // Backtrack stack overflow code.
+//  if (stack_overflow_label_.is_linked()) {
+//    SafeCallTarget(&stack_overflow_label_);
+//    // Reached if the backtrack-stack limit has been hit.
+//
+//    Label grow_failed;
+//
+//    // Call GrowStack(backtrack_stackpointer())
+//    int num_arguments = 2;
+//    FrameAlign(num_arguments, r0);
+//    __ mov(r0, backtrack_stackpointer());
+//    __ add(r1, frame_pointer(), Operand(kStackHighEnd));
+//    ExternalReference grow_stack =
+//      ExternalReference::re_grow_stack();
+//    CallCFunction(grow_stack, num_arguments);
+//    // If return NULL, we have failed to grow the stack, and
+//    // must exit with a stack-overflow exception.
+//    __ cmp(r0, Operand(0));
+//    __ b(eq, &exit_with_exception);
+//    // Otherwise use return value as new stack pointer.
+//    __ mov(backtrack_stackpointer(), r0);
+//    // Restore saved registers and continue.
+//    SafeReturn();
+//  }
+//
+//  if (exit_with_exception.is_linked()) {
+//    // If any of the code above needed to exit with an exception.
+//    __ bind(&exit_with_exception);
+//    // Exit with Result EXCEPTION(-1) to signal thrown exception.
+//    __ mov(r0, Operand(EXCEPTION));
+//    __ jmp(&exit_label_);
+//  }
+//
+  CodeDesc code_desc;
+  masm_->GetCode(&code_desc);
+  Handle<Code> code = Factory::NewCode(code_desc,
+                                       NULL,
+                                       Code::ComputeFlags(Code::REGEXP),
+                                       masm_->CodeObject());
+  LOG(RegExpCodeCreateEvent(*code, *source));
+  return Handle<Object>::cast(code);
+}
+
+
+void RegExpMacroAssemblerMIPS::GoTo(Label* to) {
+  UNIMPLEMENTED();
+//  BranchOrBacktrack(al, to);
+}
+
+
+void RegExpMacroAssemblerMIPS::IfRegisterGE(int reg,
+                                           int comparand,
+                                           Label* if_ge) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, register_location(reg));
+//  __ cmp(r0, Operand(comparand));
+//  BranchOrBacktrack(ge, if_ge);
+}
+
+
+void RegExpMacroAssemblerMIPS::IfRegisterLT(int reg,
+                                           int comparand,
+                                           Label* if_lt) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, register_location(reg));
+//  __ cmp(r0, Operand(comparand));
+//  BranchOrBacktrack(lt, if_lt);
+}
+
+
+void RegExpMacroAssemblerMIPS::IfRegisterEqPos(int reg,
+                                              Label* if_eq) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, register_location(reg));
+//  __ cmp(r0, Operand(current_input_offset()));
+//  BranchOrBacktrack(eq, if_eq);
+}
+
+
+RegExpMacroAssembler::IrregexpImplementation
+    RegExpMacroAssemblerMIPS::Implementation() {
+  UNIMPLEMENTED();
+  return kARMImplementation;
+}
+
+
+void RegExpMacroAssemblerMIPS::LoadCurrentCharacter(int cp_offset,
+                                                   Label* on_end_of_input,
+                                                   bool check_bounds,
+                                                   int characters) {
+  UNIMPLEMENTED();
+//  ASSERT(cp_offset >= -1);      // ^ and \b can look behind one character.
+//  ASSERT(cp_offset < (1<<30));  // Be sane! (And ensure negation works)
+//  if (check_bounds) {
+//    CheckPosition(cp_offset + characters - 1, on_end_of_input);
+//  }
+//  LoadCurrentCharacterUnchecked(cp_offset, characters);
+}
+
+
+void RegExpMacroAssemblerMIPS::PopCurrentPosition() {
+  UNIMPLEMENTED();
+//  Pop(current_input_offset());
+}
+
+
+void RegExpMacroAssemblerMIPS::PopRegister(int register_index) {
+  UNIMPLEMENTED();
+//  Pop(r0);
+//  __ str(r0, register_location(register_index));
+}
+
+
+//static bool is_valid_memory_offset(int value) {
+//  if (value < 0) value = -value;
+//  return value < (1<<12);
+//}
+
+
+void RegExpMacroAssemblerMIPS::PushBacktrack(Label* label) {
+  UNIMPLEMENTED();
+//  if (label->is_bound()) {
+//    int target = label->pos();
+//    __ mov(r0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
+//  } else {
+//    int constant_offset = GetBacktrackConstantPoolEntry();
+//    masm_->label_at_put(label, constant_offset);
+//    // Reading pc-relative is based on the address 8 bytes ahead of
+//    // the current opcode.
+//    unsigned int offset_of_pc_register_read =
+//      masm_->pc_offset() + Assembler::kPcLoadDelta;
+//    int pc_offset_of_constant =
+//      constant_offset - offset_of_pc_register_read;
+//    ASSERT(pc_offset_of_constant < 0);
+//    if (is_valid_memory_offset(pc_offset_of_constant)) {
+//      masm_->BlockConstPoolBefore(masm_->pc_offset() + Assembler::kInstrSize);
+//      __ ldr(r0, MemOperand(pc, pc_offset_of_constant));
+//    } else {
+//      // Not a 12-bit offset, so it needs to be loaded from the constant
+//      // pool.
+//      masm_->BlockConstPoolBefore(
+//          masm_->pc_offset() + 2 * Assembler::kInstrSize);
+//      __ mov(r0, Operand(pc_offset_of_constant + Assembler::kInstrSize));
+//      __ ldr(r0, MemOperand(pc, r0));
+//    }
+//  }
+//  Push(r0);
+//  CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerMIPS::PushCurrentPosition() {
+  UNIMPLEMENTED();
+//  Push(current_input_offset());
+}
+
+
+void RegExpMacroAssemblerMIPS::PushRegister(int register_index,
+                                           StackCheckFlag check_stack_limit) {
+  UNIMPLEMENTED();
+//  __ ldr(r0, register_location(register_index));
+//  Push(r0);
+//  if (check_stack_limit) CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerMIPS::ReadCurrentPositionFromRegister(int reg) {
+  UNIMPLEMENTED();
+//  __ ldr(current_input_offset(), register_location(reg));
+}
+
+
+void RegExpMacroAssemblerMIPS::ReadStackPointerFromRegister(int reg) {
+  UNIMPLEMENTED();
+//  __ ldr(backtrack_stackpointer(), register_location(reg));
+//  __ ldr(r0, MemOperand(frame_pointer(), kStackHighEnd));
+//  __ add(backtrack_stackpointer(), backtrack_stackpointer(), Operand(r0));
+}
+
+
+void RegExpMacroAssemblerMIPS::SetRegister(int register_index, int to) {
+  UNIMPLEMENTED();
+//  ASSERT(register_index >= num_saved_registers_);  // Reserved for positions!
+//  __ mov(r0, Operand(to));
+//  __ str(r0, register_location(register_index));
+}
+
+
+void RegExpMacroAssemblerMIPS::Succeed() {
+  UNIMPLEMENTED();
+//  __ jmp(&success_label_);
+}
+
+
+void RegExpMacroAssemblerMIPS::WriteCurrentPositionToRegister(int reg,
+                                                             int cp_offset) {
+  UNIMPLEMENTED();
+//  if (cp_offset == 0) {
+//    __ str(current_input_offset(), register_location(reg));
+//  } else {
+//    __ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
+//    __ str(r0, register_location(reg));
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::ClearRegisters(int reg_from, int reg_to) {
+  UNIMPLEMENTED();
+//  ASSERT(reg_from <= reg_to);
+//  __ ldr(r0, MemOperand(frame_pointer(), kInputStartMinusOne));
+//  for (int reg = reg_from; reg <= reg_to; reg++) {
+//    __ str(r0, register_location(reg));
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
+  UNIMPLEMENTED();
+//  __ ldr(r1, MemOperand(frame_pointer(), kStackHighEnd));
+//  __ sub(r0, backtrack_stackpointer(), r1);
+//  __ str(r0, register_location(reg));
+}
+
+
+// Private methods:
+//
+void RegExpMacroAssemblerMIPS::CallCheckStackGuardState(Register scratch) {
+  UNIMPLEMENTED();
+//  int num_arguments = 3;
+//  FrameAlign(num_arguments, scratch);
+//  // RegExp code frame pointer.
+//  __ mov(r2, frame_pointer());
+//  // Code* of self.
+//  __ mov(r1, Operand(masm_->CodeObject()));
+//  // r0 becomes return address pointer.
+//  ExternalReference stack_guard_check =
+//      ExternalReference::re_check_stack_guard_state();
+//  CallCFunctionUsingStub(stack_guard_check, num_arguments);
+}
+//
+//
+//// Helper function for reading a value out of a stack frame.
+//template <typename T>
+//static T& frame_entry(Address re_frame, int frame_offset) {
+//  return reinterpret_cast<T&>(Memory::int32_at(re_frame + frame_offset));
+//}
+//
+//
+int RegExpMacroAssemblerMIPS::CheckStackGuardState(Address* return_address,
+                                                  Code* re_code,
+                                                  Address re_frame) {
+  UNIMPLEMENTED();
+//  if (StackGuard::IsStackOverflow()) {
+//    Top::StackOverflow();
+//    return EXCEPTION;
+//  }
+//
+//  // If not real stack overflow the stack guard was used to interrupt
+//  // execution for another purpose.
+//
+//  // Prepare for possible GC.
+//  HandleScope handles;
+//  Handle<Code> code_handle(re_code);
+//
+//  Handle<String> subject(frame_entry<String*>(re_frame, kInputString));
+//  // Current string.
+//  bool is_ascii = subject->IsAsciiRepresentation();
+//
+//  ASSERT(re_code->instruction_start() <= *return_address);
+//  ASSERT(*return_address <=
+//      re_code->instruction_start() + re_code->instruction_size());
+//
+//  Object* result = Execution::HandleStackGuardInterrupt();
+//
+//  if (*code_handle != re_code) {  // Return address no longer valid
+//    int delta = *code_handle - re_code;
+//    // Overwrite the return address on the stack.
+//    *return_address += delta;
+//  }
+//
+//  if (result->IsException()) {
+//    return EXCEPTION;
+//  }
+//
+//  // String might have changed.
+//  if (subject->IsAsciiRepresentation() != is_ascii) {
+//    // If we changed between an ASCII and an UC16 string, the specialized
+//    // code cannot be used, and we need to restart regexp matching from
+//    // scratch (including, potentially, compiling a new version of the code).
+//    return RETRY;
+//  }
+//
+//  // Otherwise, the content of the string might have moved. It must still
+//  // be a sequential or external string with the same content.
+//  // Update the start and end pointers in the stack frame to the current
+//  // location (whether it has actually moved or not).
+//  ASSERT(StringShape(*subject).IsSequential() ||
+//      StringShape(*subject).IsExternal());
+//
+//  // The original start address of the characters to match.
+//  const byte* start_address = frame_entry<const byte*>(re_frame, kInputStart);
+//
+//  // Find the current start address of the same character at the current string
+//  // position.
+//  int start_index = frame_entry<int>(re_frame, kStartIndex);
+//  const byte* new_address = StringCharacterPosition(*subject, start_index);
+//
+//  if (start_address != new_address) {
+//    // If there is a difference, update the object pointer and start and end
+//    // addresses in the RegExp stack frame to match the new value.
+//    const byte* end_address = frame_entry<const byte* >(re_frame, kInputEnd);
+//    int byte_length = end_address - start_address;
+//    frame_entry<const String*>(re_frame, kInputString) = *subject;
+//    frame_entry<const byte*>(re_frame, kInputStart) = new_address;
+//    frame_entry<const byte*>(re_frame, kInputEnd) = new_address + byte_length;
+//  }
+//
+  return 0;
+}
+
+
+MemOperand RegExpMacroAssemblerMIPS::register_location(int register_index) {
+  ASSERT(register_index < (1<<30));
+  if (num_registers_ <= register_index) {
+    num_registers_ = register_index + 1;
+  }
+  return MemOperand(frame_pointer(),
+                    kRegisterZero - register_index * kPointerSize);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckPosition(int cp_offset,
+                                            Label* on_outside_input) {
+  UNIMPLEMENTED();
+//  __ cmp(current_input_offset(), Operand(-cp_offset * char_size()));
+//  BranchOrBacktrack(ge, on_outside_input);
+}
+
+
+void RegExpMacroAssemblerMIPS::BranchOrBacktrack(Condition condition,
+                                                Label* to) {
+  UNIMPLEMENTED();
+//  if (condition == al) {  // Unconditional.
+//    if (to == NULL) {
+//      Backtrack();
+//      return;
+//    }
+//    __ jmp(to);
+//    return;
+//  }
+//  if (to == NULL) {
+//    __ b(condition, &backtrack_label_);
+//    return;
+//  }
+//  __ b(condition, to);
+}
+
+
+void RegExpMacroAssemblerMIPS::SafeCall(Label* to, Condition cond) {
+  UNIMPLEMENTED();
+//  __ bl(to, cond);
+}
+
+
+void RegExpMacroAssemblerMIPS::SafeReturn() {
+  UNIMPLEMENTED();
+//  __ pop(lr);
+//  __ add(pc, lr, Operand(masm_->CodeObject()));
+}
+
+
+void RegExpMacroAssemblerMIPS::SafeCallTarget(Label* name) {
+  UNIMPLEMENTED();
+//  __ bind(name);
+//  __ sub(lr, lr, Operand(masm_->CodeObject()));
+//  __ push(lr);
+}
+
+
+void RegExpMacroAssemblerMIPS::Push(Register source) {
+  UNIMPLEMENTED();
+//  ASSERT(!source.is(backtrack_stackpointer()));
+//  __ str(source,
+//         MemOperand(backtrack_stackpointer(), kPointerSize, NegPreIndex));
+}
+
+
+void RegExpMacroAssemblerMIPS::Pop(Register target) {
+  UNIMPLEMENTED();
+//  ASSERT(!target.is(backtrack_stackpointer()));
+//  __ ldr(target,
+//         MemOperand(backtrack_stackpointer(), kPointerSize, PostIndex));
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckPreemption() {
+  UNIMPLEMENTED();
+//  // Check for preemption.
+//  ExternalReference stack_guard_limit =
+//      ExternalReference::address_of_stack_guard_limit();
+//  __ mov(r0, Operand(stack_guard_limit));
+//  __ ldr(r0, MemOperand(r0));
+//  __ cmp(sp, r0);
+//  SafeCall(&check_preempt_label_, ls);
+}
+
+
+void RegExpMacroAssemblerMIPS::CheckStackLimit() {
+  UNIMPLEMENTED();
+//  if (FLAG_check_stack) {
+//    ExternalReference stack_limit =
+//        ExternalReference::address_of_regexp_stack_limit();
+//    __ mov(r0, Operand(stack_limit));
+//    __ ldr(r0, MemOperand(r0));
+//    __ cmp(backtrack_stackpointer(), Operand(r0));
+//    SafeCall(&stack_overflow_label_, ls);
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::EmitBacktrackConstantPool() {
+  UNIMPLEMENTED();
+//  __ CheckConstPool(false, false);
+//  __ BlockConstPoolBefore(
+//      masm_->pc_offset() + kBacktrackConstantPoolSize * Assembler::kInstrSize);
+//  backtrack_constant_pool_offset_ = masm_->pc_offset();
+//  for (int i = 0; i < kBacktrackConstantPoolSize; i++) {
+//    __ emit(0);
+//  }
+//
+//  backtrack_constant_pool_capacity_ = kBacktrackConstantPoolSize;
+}
+
+
+int RegExpMacroAssemblerMIPS::GetBacktrackConstantPoolEntry() {
+  UNIMPLEMENTED();
+//  while (backtrack_constant_pool_capacity_ > 0) {
+//    int offset = backtrack_constant_pool_offset_;
+//    backtrack_constant_pool_offset_ += kPointerSize;
+//    backtrack_constant_pool_capacity_--;
+//    if (masm_->pc_offset() - offset < 2 * KB) {
+//      return offset;
+//    }
+//  }
+//  Label new_pool_skip;
+//  __ jmp(&new_pool_skip);
+//  EmitBacktrackConstantPool();
+//  __ bind(&new_pool_skip);
+//  int offset = backtrack_constant_pool_offset_;
+//  backtrack_constant_pool_offset_ += kPointerSize;
+//  backtrack_constant_pool_capacity_--;
+//  return offset;
+  return 0;
+}
+
+
+void RegExpMacroAssemblerMIPS::FrameAlign(int num_arguments, Register scratch) {
+  UNIMPLEMENTED();
+//  int frameAlignment = OS::ActivationFrameAlignment();
+//  // Up to four simple arguments are passed in registers r0..r3.
+//  int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
+//  if (frameAlignment != 0) {
+//    // Make stack end at alignment and make room for num_arguments - 4 words
+//    // and the original value of sp.
+//    __ mov(scratch, sp);
+//    __ sub(sp, sp, Operand((stack_passed_arguments + 1) * kPointerSize));
+//    ASSERT(IsPowerOf2(frameAlignment));
+//    __ and_(sp, sp, Operand(-frameAlignment));
+//    __ str(scratch, MemOperand(sp, stack_passed_arguments * kPointerSize));
+//  } else {
+//    __ sub(sp, sp, Operand(stack_passed_arguments * kPointerSize));
+//  }
+}
+
+
+void RegExpMacroAssemblerMIPS::CallCFunction(ExternalReference function,
+                                            int num_arguments) {
+  UNIMPLEMENTED();
+//  __ mov(r5, Operand(function));
+//  // Just call directly. The function called cannot cause a GC, or
+//  // allow preemption, so the return address in the link register
+//  // stays correct.
+//  __ Call(r5);
+//  int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
+//  if (OS::ActivationFrameAlignment() > kIntSize) {
+//    __ ldr(sp, MemOperand(sp, stack_passed_arguments * kPointerSize));
+//  } else {
+//    __ add(sp, sp, Operand(stack_passed_arguments * sizeof(kPointerSize)));
+//  }
+//  __ mov(code_pointer(), Operand(masm_->CodeObject()));
+}
+
+
+void RegExpMacroAssemblerMIPS::CallCFunctionUsingStub(
+    ExternalReference function,
+    int num_arguments) {
+  UNIMPLEMENTED();
+//  // Must pass all arguments in registers. The stub pushes on the stack.
+//  ASSERT(num_arguments <= 4);
+//  __ mov(r5, Operand(function));
+//  RegExpCEntryStub stub;
+//  __ CallStub(&stub);
+//  if (OS::ActivationFrameAlignment() != 0) {
+//    __ ldr(sp, MemOperand(sp, 0));
+//  }
+//  __ mov(code_pointer(), Operand(masm_->CodeObject()));
+}
+
+
+void RegExpMacroAssemblerMIPS::LoadCurrentCharacterUnchecked(int cp_offset,
+                                                            int characters) {
+  UNIMPLEMENTED();
+//  Register offset = current_input_offset();
+//  if (cp_offset != 0) {
+//    __ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
+//    offset = r0;
+//  }
+//  // We assume that we cannot do unaligned loads on ARM, so this function
+//  // must only be used to load a single character at a time.
+//  ASSERT(characters == 1);
+//  if (mode_ == ASCII) {
+//    __ ldrb(current_character(), MemOperand(end_of_input_address(), offset));
+//  } else {
+//    ASSERT(mode_ == UC16);
+//    __ ldrh(current_character(), MemOperand(end_of_input_address(), offset));
+//  }
+}
+
+
+//void RegExpCEntryStub::Generate(MacroAssembler* masm_) {
+//  UNIMPLEMENTED();
+//  int stack_alignment = OS::ActivationFrameAlignment();
+//  if (stack_alignment < kPointerSize) stack_alignment = kPointerSize;
+//  // Stack is already aligned for call, so decrement by alignment
+//  // to make room for storing the link register.
+//  __ str(lr, MemOperand(sp, stack_alignment, NegPreIndex));
+//  __ mov(r0, sp);
+//  __ Call(r5);
+//  __ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
+//}
+
+#undef __
+
+#endif  // V8_NATIVE_REGEXP
+
+}}  // namespace v8::internal