Move backend specific files to separate directories.

src/ia32/regexp-macro-assembler-ia32.cc

+// Copyright 2008-2009 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 "unicode.h"
+#include "log.h"
+#include "ast.h"
+#include "regexp-stack.h"
+#include "macro-assembler.h"
+#include "regexp-macro-assembler.h"
+#include "ia32/macro-assembler-ia32.h"
+#include "ia32/regexp-macro-assembler-ia32.h"
+
+namespace v8 { namespace internal {
+
+/*
+ * This assembler uses the following register assignment convention
+ * - edx : current character. Must be loaded using LoadCurrentCharacter
+ *         before using any of the dispatch methods.
+ * - edi : current position in input, as negative offset from end of string.
+ *         Please notice that this is the byte offset, not the character offset!
+ * - esi : end of input (points to byte after last character in input).
+ * - ebp : frame pointer. Used to access arguments, local variables and
+ *         RegExp registers.
+ * - esp : points to tip of C stack.
+ * - ecx : points to tip of backtrack stack
+ *
+ * The registers eax, ebx and ecx are free to use for computations.
+ *
+ * Each call to a public method should retain this convention.
+ * The stack will have the following structure:
+ *       - stack_area_top     (High end of the memory area to use as
+ *                             backtracking stack)
+ *       - at_start           (if 1, start at start of string, if 0, don't)
+ *       - 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)
+ *       - void* input_string (location of a handle containing the string)
+ *       --- frame alignment (if applicable) ---
+ *       - return address
+ * ebp-> - old ebp
+ *       - backup of caller esi
+ *       - backup of caller edi
+ *       - backup of caller ebx
+ *       - Offset of location before start of input (effectively character
+ *         position -1). Used to initialize capture registers to a non-position.
+ *       - register 0  ebp[-4]  (Only positions must be stored in the first
+ *       - register 1  ebp[-8]   num_saved_registers_ registers)
+ *       - ...
+ *
+ * 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 starts out as garbage.
+ *
+ * The data up to the return address must be placed there by the calling
+ * code, e.g., by calling the code entry as cast to:
+ * int (*match)(String* input_string,
+ *              Address start,
+ *              Address end,
+ *              int* capture_output_array,
+ *              bool at_start,
+ *              byte* stack_area_top)
+ */
+
+#define __ ACCESS_MASM(masm_)
+
+RegExpMacroAssemblerIA32::RegExpMacroAssemblerIA32(
+    Mode mode,
+    int registers_to_save)
+    : masm_(new MacroAssembler(NULL, kRegExpCodeSize)),
+      constants_(kRegExpConstantsSize),
+      mode_(mode),
+      num_registers_(registers_to_save),
+      num_saved_registers_(registers_to_save),
+      entry_label_(),
+      start_label_(),
+      success_label_(),
+      backtrack_label_(),
+      exit_label_() {
+  __ jmp(&entry_label_);   // We'll write the entry code later.
+  __ bind(&start_label_);  // And then continue from here.
+}
+
+
+RegExpMacroAssemblerIA32::~RegExpMacroAssemblerIA32() {
+  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 RegExpMacroAssemblerIA32::stack_limit_slack()  {
+  return RegExpStack::kStackLimitSlack;
+}
+
+
+void RegExpMacroAssemblerIA32::AdvanceCurrentPosition(int by) {
+  if (by != 0) {
+    Label inside_string;
+    __ add(Operand(edi), Immediate(by * char_size()));
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::AdvanceRegister(int reg, int by) {
+  ASSERT(reg >= 0);
+  ASSERT(reg < num_registers_);
+  if (by != 0) {
+    __ add(register_location(reg), Immediate(by));
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::Backtrack() {
+  CheckPreemption();
+  // Pop Code* offset from backtrack stack, add Code* and jump to location.
+  Pop(ebx);
+  __ add(Operand(ebx), Immediate(masm_->CodeObject()));
+  __ jmp(Operand(ebx));
+}
+
+
+void RegExpMacroAssemblerIA32::Bind(Label* label) {
+  __ bind(label);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckBitmap(uc16 start,
+                                           Label* bitmap,
+                                           Label* on_zero) {
+  UNIMPLEMENTED();
+}
+
+
+void RegExpMacroAssemblerIA32::CheckCharacter(uint32_t c, Label* on_equal) {
+  __ cmp(current_character(), c);
+  BranchOrBacktrack(equal, on_equal);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckCharacterGT(uc16 limit, Label* on_greater) {
+  __ cmp(current_character(), limit);
+  BranchOrBacktrack(greater, on_greater);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckAtStart(Label* on_at_start) {
+  Label not_at_start;
+  // Did we start the match at the start of the string at all?
+  __ cmp(Operand(ebp, kAtStart), Immediate(0));
+  BranchOrBacktrack(equal, &not_at_start);
+  // If we did, are we still at the start of the input?
+  __ lea(eax, Operand(esi, edi, times_1, 0));
+  __ cmp(eax, Operand(ebp, kInputStart));
+  BranchOrBacktrack(equal, on_at_start);
+  __ bind(&not_at_start);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotAtStart(Label* on_not_at_start) {
+  // Did we start the match at the start of the string at all?
+  __ cmp(Operand(ebp, kAtStart), Immediate(0));
+  BranchOrBacktrack(equal, on_not_at_start);
+  // If we did, are we still at the start of the input?
+  __ lea(eax, Operand(esi, edi, times_1, 0));
+  __ cmp(eax, Operand(ebp, kInputStart));
+  BranchOrBacktrack(not_equal, on_not_at_start);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckCharacterLT(uc16 limit, Label* on_less) {
+  __ cmp(current_character(), limit);
+  BranchOrBacktrack(less, on_less);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckCharacters(Vector<const uc16> str,
+                                               int cp_offset,
+                                               Label* on_failure,
+                                               bool check_end_of_string) {
+  int byte_length = str.length() * char_size();
+  int byte_offset = cp_offset * char_size();
+  if (check_end_of_string) {
+    // Check that there are at least str.length() characters left in the input.
+    __ cmp(Operand(edi), Immediate(-(byte_offset + byte_length)));
+    BranchOrBacktrack(greater, on_failure);
+  }
+
+  Label backtrack;
+  if (on_failure == NULL) {
+    // Avoid inlining the Backtrack macro for each test.
+    Label skip_backtrack;
+    __ jmp(&skip_backtrack);
+    __ bind(&backtrack);
+    Backtrack();
+    __ bind(&skip_backtrack);
+    on_failure = &backtrack;
+  }
+
+  for (int i = 0; i < str.length(); i++) {
+    if (mode_ == ASCII) {
+      __ cmpb(Operand(esi, edi, times_1, byte_offset + i),
+              static_cast<int8_t>(str[i]));
+    } else {
+      ASSERT(mode_ == UC16);
+      __ cmpw(Operand(esi, edi, times_1, byte_offset + i * sizeof(uc16)),
+              Immediate(str[i]));
+    }
+    BranchOrBacktrack(not_equal, on_failure);
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::CheckGreedyLoop(Label* on_equal) {
+  Label fallthrough;
+  __ cmp(edi, Operand(backtrack_stackpointer(), 0));
+  __ j(not_equal, &fallthrough);
+  __ add(Operand(backtrack_stackpointer()), Immediate(kPointerSize));  // Pop.
+  BranchOrBacktrack(no_condition, on_equal);
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
+    int start_reg,
+    Label* on_no_match) {
+  Label fallthrough;
+  __ mov(edx, register_location(start_reg));  // Index of start of capture
+  __ mov(ebx, register_location(start_reg + 1));  // Index of end of capture
+  __ sub(ebx, Operand(edx));  // Length of capture.
+
+  // The length of a capture should not be negative. This can only happen
+  // if the end of the capture is unrecorded, or at a point earlier than
+  // the start of the capture.
+  BranchOrBacktrack(less, on_no_match, not_taken);
+
+  // If length is zero, either the capture is empty or it is completely
+  // uncaptured. In either case succeed immediately.
+  __ j(equal, &fallthrough);
+
+  if (mode_ == ASCII) {
+    Label success;
+    Label fail;
+    Label loop_increment;
+    // Save register contents to make the registers available below.
+    __ push(edi);
+    __ push(backtrack_stackpointer());
+    // After this, the eax, ecx, and edi registers are available.
+
+    __ add(edx, Operand(esi));  // Start of capture
+    __ add(edi, Operand(esi));  // Start of text to match against capture.
+    __ add(ebx, Operand(edi));  // End of text to match against capture.
+
+    Label loop;
+    __ bind(&loop);
+    __ movzx_b(eax, Operand(edi, 0));
+    __ cmpb_al(Operand(edx, 0));
+    __ j(equal, &loop_increment);
+
+    // Mismatch, try case-insensitive match (converting letters to lower-case).
+    __ or_(eax, 0x20);  // Convert match character to lower-case.
+    __ lea(ecx, Operand(eax, -'a'));
+    __ cmp(ecx, static_cast<int32_t>('z' - 'a'));  // Is eax a lowercase letter?
+    __ j(above, &fail);
+    // Also convert capture character.
+    __ movzx_b(ecx, Operand(edx, 0));
+    __ or_(ecx, 0x20);
+
+    __ cmp(eax, Operand(ecx));
+    __ j(not_equal, &fail);
+
+    __ bind(&loop_increment);
+    // Increment pointers into match and capture strings.
+    __ add(Operand(edx), Immediate(1));
+    __ add(Operand(edi), Immediate(1));
+    // Compare to end of match, and loop if not done.
+    __ cmp(edi, Operand(ebx));
+    __ j(below, &loop, taken);
+    __ jmp(&success);
+
+    __ bind(&fail);
+    // Restore original values before failing.
+    __ pop(backtrack_stackpointer());
+    __ pop(edi);
+    BranchOrBacktrack(no_condition, on_no_match);
+
+    __ bind(&success);
+    // Restore original value before continuing.
+    __ pop(backtrack_stackpointer());
+    // Drop original value of character position.
+    __ add(Operand(esp), Immediate(kPointerSize));
+    // Compute new value of character position after the matched part.
+    __ sub(edi, Operand(esi));
+  } else {
+    ASSERT(mode_ == UC16);
+    // Save registers before calling C function.
+    __ push(esi);
+    __ push(edi);
+    __ push(backtrack_stackpointer());
+    __ push(ebx);
+
+    const int argument_count = 3;
+    FrameAlign(argument_count, ecx);
+    // Put arguments into allocated stack area, last argument highest on stack.
+    // Parameters are
+    //   Address byte_offset1 - Address captured substring's start.
+    //   Address byte_offset2 - Address of current character position.
+    //   size_t byte_length - length of capture in bytes(!)
+
+    // Set byte_length.
+    __ mov(Operand(esp, 2 * kPointerSize), ebx);
+    // Set byte_offset2.
+    // Found by adding negative string-end offset of current position (edi)
+    // to end of string.
+    __ add(edi, Operand(esi));
+    __ mov(Operand(esp, 1 * kPointerSize), edi);
+    // Set byte_offset1.
+    // Start of capture, where edx already holds string-end negative offset.
+    __ add(edx, Operand(esi));
+    __ mov(Operand(esp, 0 * kPointerSize), edx);
+
+    Address function_address = FUNCTION_ADDR(&CaseInsensitiveCompareUC16);
+    CallCFunction(function_address, argument_count);
+    // Pop original values before reacting on result value.
+    __ pop(ebx);
+    __ pop(backtrack_stackpointer());
+    __ pop(edi);
+    __ pop(esi);
+
+    // Check if function returned non-zero for success or zero for failure.
+    __ or_(eax, Operand(eax));
+    BranchOrBacktrack(zero, on_no_match);
+    // On success, increment position by length of capture.
+    __ add(edi, Operand(ebx));
+  }
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotBackReference(
+    int start_reg,
+    Label* on_no_match) {
+  Label fallthrough;
+  Label success;
+  Label fail;
+
+  // Find length of back-referenced capture.
+  __ mov(edx, register_location(start_reg));
+  __ mov(eax, register_location(start_reg + 1));
+  __ sub(eax, Operand(edx));  // Length to check.
+  // Fail on partial or illegal capture (start of capture after end of capture).
+  BranchOrBacktrack(less, on_no_match);
+  // Succeed on empty capture (including no capture)
+  __ j(equal, &fallthrough);
+
+  // Check that there are sufficient characters left in the input.
+  __ mov(ebx, edi);
+  __ add(ebx, Operand(eax));
+  BranchOrBacktrack(greater, on_no_match);
+
+  // Save register to make it available below.
+  __ push(backtrack_stackpointer());
+
+  // Compute pointers to match string and capture string
+  __ lea(ebx, Operand(esi, edi, times_1, 0));  // Start of match.
+  __ add(edx, Operand(esi));  // Start of capture.
+  __ lea(ecx, Operand(eax, ebx, times_1, 0));  // End of match
+
+  Label loop;
+  __ bind(&loop);
+  if (mode_ == ASCII) {
+    __ movzx_b(eax, Operand(edx, 0));
+    __ cmpb_al(Operand(ebx, 0));
+  } else {
+    ASSERT(mode_ == UC16);
+    __ movzx_w(eax, Operand(edx, 0));
+    __ cmpw_ax(Operand(ebx, 0));
+  }
+  __ j(not_equal, &fail);
+  // Increment pointers into capture and match string.
+  __ add(Operand(edx), Immediate(char_size()));
+  __ add(Operand(ebx), Immediate(char_size()));
+  // Check if we have reached end of match area.
+  __ cmp(ebx, Operand(ecx));
+  __ j(below, &loop);
+  __ jmp(&success);
+
+  __ bind(&fail);
+  // Restore backtrack stackpointer.
+  __ pop(backtrack_stackpointer());
+  BranchOrBacktrack(no_condition, on_no_match);
+
+  __ bind(&success);
+  // Move current character position to position after match.
+  __ mov(edi, ecx);
+  __ sub(Operand(edi), esi);
+  // Restore backtrack stackpointer.
+  __ pop(backtrack_stackpointer());
+
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotRegistersEqual(int reg1,
+                                                      int reg2,
+                                                      Label* on_not_equal) {
+  __ mov(eax, register_location(reg1));
+  __ cmp(eax, register_location(reg2));
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotCharacter(uint32_t c,
+                                                 Label* on_not_equal) {
+  __ cmp(current_character(), c);
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckCharacterAfterAnd(uint32_t c,
+                                                      uint32_t mask,
+                                                      Label* on_equal) {
+  __ mov(eax, current_character());
+  __ and_(eax, mask);
+  __ cmp(eax, c);
+  BranchOrBacktrack(equal, on_equal);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotCharacterAfterAnd(uint32_t c,
+                                                         uint32_t mask,
+                                                         Label* on_not_equal) {
+  __ mov(eax, current_character());
+  __ and_(eax, mask);
+  __ cmp(eax, c);
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckNotCharacterAfterMinusAnd(
+    uc16 c,
+    uc16 minus,
+    uc16 mask,
+    Label* on_not_equal) {
+  ASSERT(minus < String::kMaxUC16CharCode);
+  __ lea(eax, Operand(current_character(), -minus));
+  __ and_(eax, mask);
+  __ cmp(eax, c);
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+bool RegExpMacroAssemblerIA32::CheckSpecialCharacterClass(uc16 type,
+                                                          int cp_offset,
+                                                          bool check_offset,
+                                                          Label* on_no_match) {
+  // 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(), ' ');
+      __ j(equal, &success);
+      // Check range 0x09..0x0d
+      __ sub(Operand(current_character()), Immediate('\t'));
+      __ cmp(current_character(), '\r' - '\t');
+      BranchOrBacktrack(above, 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(), ' ');
+      BranchOrBacktrack(equal, on_no_match);
+      __ sub(Operand(current_character()), Immediate('\t'));
+      __ cmp(current_character(), '\r' - '\t');
+      BranchOrBacktrack(below_equal, 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(Operand(current_character()), Immediate('0'));
+    __ cmp(current_character(), '9' - '0');
+    BranchOrBacktrack(above, 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(Operand(current_character()), Immediate('0'));
+    __ cmp(current_character(), '9' - '0');
+    BranchOrBacktrack(below_equal, 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);
+    }
+    __ xor_(Operand(current_character()), Immediate(0x01));
+    // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+    __ sub(Operand(current_character()), Immediate(0x0b));
+    __ cmp(current_character(), 0x0c - 0x0b);
+    BranchOrBacktrack(below_equal, 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(Operand(current_character()), Immediate(0x2028 - 0x0b));
+      __ cmp(current_character(), 1);
+      BranchOrBacktrack(below_equal, 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;
+  }
+}
+
+void RegExpMacroAssemblerIA32::DispatchHalfNibbleMap(
+    uc16 start,
+    Label* half_nibble_map,
+    const Vector<Label*>& destinations) {
+  UNIMPLEMENTED();
+}
+
+
+void RegExpMacroAssemblerIA32::DispatchByteMap(
+    uc16 start,
+    Label* byte_map,
+    const Vector<Label*>& destinations) {
+  UNIMPLEMENTED();
+}
+
+
+void RegExpMacroAssemblerIA32::DispatchHighByteMap(
+    byte start,
+    Label* byte_map,
+    const Vector<Label*>& destinations) {
+  UNIMPLEMENTED();
+}
+
+
+void RegExpMacroAssemblerIA32::EmitOrLink(Label* label) {
+  UNIMPLEMENTED();  // Has no use.
+}
+
+
+void RegExpMacroAssemblerIA32::Fail() {
+  ASSERT(FAILURE == 0);  // Return value for failure is zero.
+  __ xor_(eax, Operand(eax));  // zero eax.
+  __ jmp(&exit_label_);
+}
+
+
+Handle<Object> RegExpMacroAssemblerIA32::GetCode(Handle<String> source) {
+  // Finalize code - write the entry point code now we know how many
+  // registers we need.
+
+  // Entry code:
+  __ bind(&entry_label_);
+  // Start new stack frame.
+  __ push(ebp);
+  __ mov(ebp, esp);
+  // Save callee-save registers. Order here should correspond to order of
+  // kBackup_ebx etc.
+  __ push(esi);
+  __ push(edi);
+  __ push(ebx);  // Callee-save on MacOS.
+  __ push(Immediate(0));  // Make room for "input start - 1" constant.
+
+  // Check if we have space on the stack for registers.
+  Label retry_stack_check;
+  Label stack_limit_hit;
+  Label stack_ok;
+
+  __ bind(&retry_stack_check);
+  ExternalReference stack_guard_limit =
+      ExternalReference::address_of_stack_guard_limit();
+  __ mov(ecx, esp);
+  __ sub(ecx, Operand::StaticVariable(stack_guard_limit));
+  // Handle it if the stack pointer is already below the stack limit.
+  __ j(below_equal, &stack_limit_hit, not_taken);
+  // Check if there is room for the variable number of registers above
+  // the stack limit.
+  __ cmp(ecx, num_registers_ * kPointerSize);
+  __ j(above_equal, &stack_ok, taken);
+  // Exit with OutOfMemory exception. There is not enough space on the stack
+  // for our working registers.
+  __ mov(eax, EXCEPTION);
+  __ jmp(&exit_label_);
+
+  __ bind(&stack_limit_hit);
+  CallCheckStackGuardState(ebx);
+  __ or_(eax, Operand(eax));
+  // If returned value is non-zero, we exit with the returned value as result.
+  // Otherwise it was a preemption and we just check the limit again.
+  __ j(equal, &retry_stack_check);
+  // Return value was non-zero. Exit with exception or retry.
+  __ jmp(&exit_label_);
+
+  __ bind(&stack_ok);
+
+  // Allocate space on stack for registers.
+  __ sub(Operand(esp), Immediate(num_registers_ * kPointerSize));
+  // Load string length.
+  __ mov(esi, Operand(ebp, kInputEnd));
+  // Load input position.
+  __ mov(edi, Operand(ebp, kInputStart));
+  // Set up edi to be negative offset from string end.
+  __ sub(edi, Operand(esi));
+  if (num_saved_registers_ > 0) {
+    // Fill saved registers with initial value = start offset - 1
+    // Fill in stack push order, to avoid accessing across an unwritten
+    // page (a problem on Windows).
+    __ mov(ecx, kRegisterZero);
+    // Set eax to address of char before start of input
+    // (effectively string position -1).
+    __ lea(eax, Operand(edi, -char_size()));
+    // Store this value in a local variable, for use when clearing
+    // position registers.
+    __ mov(Operand(ebp, kInputStartMinusOne), eax);
+    Label init_loop;
+    __ bind(&init_loop);
+    __ mov(Operand(ebp, ecx, times_1, +0), eax);
+    __ sub(Operand(ecx), Immediate(kPointerSize));
+    __ cmp(ecx, kRegisterZero - num_saved_registers_ * kPointerSize);
+    __ j(greater, &init_loop);
+  }
+  // Ensure that we have written to each stack page, in order. Skipping a page
+  // on Windows can cause segmentation faults. Assuming page size is 4k.
+  const int kPageSize = 4096;
+  const int kRegistersPerPage = kPageSize / kPointerSize;
+  for (int i = num_saved_registers_ + kRegistersPerPage - 1;
+      i < num_registers_;
+      i += kRegistersPerPage) {
+    __ mov(register_location(i), eax);  // One write every page.
+  }
+
+
+  // Initialize backtrack stack pointer.
+  __ mov(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
+  // Load previous char as initial value of current-character.
+  Label at_start;
+  __ cmp(Operand(ebp, kAtStart), Immediate(0));
+  __ j(not_equal, &at_start);
+  LoadCurrentCharacterUnchecked(-1, 1);  // Load previous char.
+  __ jmp(&start_label_);
+  __ bind(&at_start);
+  __ mov(current_character(), '\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
+      __ mov(ebx, Operand(ebp, kRegisterOutput));
+      __ mov(ecx, Operand(ebp, kInputEnd));
+      __ sub(ecx, Operand(ebp, kInputStart));
+      for (int i = 0; i < num_saved_registers_; i++) {
+        __ mov(eax, register_location(i));
+        __ add(eax, Operand(ecx));  // Convert to index from start, not end.
+        if (mode_ == UC16) {
+          __ sar(eax, 1);  // Convert byte index to character index.
+        }
+        __ mov(Operand(ebx, i * kPointerSize), eax);
+      }
+    }
+    __ mov(eax, Immediate(SUCCESS));
+  }
+  // Exit and return eax
+  __ bind(&exit_label_);
+  // Skip esp past regexp registers.
+  __ lea(esp, Operand(ebp, kBackup_ebx));
+  // Restore callee-save registers.
+  __ pop(ebx);
+  __ pop(edi);
+  __ pop(esi);
+  // Exit function frame, restore previous one.
+  __ pop(ebp);
+  __ ret(0);
+
+  // 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()) {
+    __ bind(&check_preempt_label_);
+
+    __ push(backtrack_stackpointer());
+    __ push(edi);
+
+    Label retry;
+
+    __ bind(&retry);
+    CallCheckStackGuardState(ebx);
+    __ or_(eax, Operand(eax));
+    // If returning non-zero, we should end execution with the given
+    // result as return value.
+    __ j(not_zero, &exit_label_);
+    // Check if we are still preempted.
+    ExternalReference stack_guard_limit =
+        ExternalReference::address_of_stack_guard_limit();
+    __ cmp(esp, Operand::StaticVariable(stack_guard_limit));
+    __ j(below_equal, &retry);
+
+    __ pop(edi);
+    __ pop(backtrack_stackpointer());
+    // String might have moved: Reload esi from frame.
+    __ mov(esi, Operand(ebp, kInputEnd));
+    SafeReturn();
+  }
+
+  // Backtrack stack overflow code.
+  if (stack_overflow_label_.is_linked()) {
+    __ bind(&stack_overflow_label_);
+    // Reached if the backtrack-stack limit has been hit.
+
+    Label grow_failed;
+    // Save registers before calling C function
+    __ push(esi);
+    __ push(edi);
+
+    // Call GrowStack(backtrack_stackpointer())
+    int num_arguments = 2;
+    FrameAlign(num_arguments, ebx);
+    __ lea(eax, Operand(ebp, kStackHighEnd));
+    __ mov(Operand(esp, 1 * kPointerSize), eax);
+    __ mov(Operand(esp, 0 * kPointerSize), backtrack_stackpointer());
+    CallCFunction(FUNCTION_ADDR(&GrowStack), num_arguments);
+    // If return NULL, we have failed to grow the stack, and
+    // must exit with a stack-overflow exception.
+    __ or_(eax, Operand(eax));
+    __ j(equal, &exit_with_exception);
+    // Otherwise use return value as new stack pointer.
+    __ mov(backtrack_stackpointer(), eax);
+    // Restore saved registers and continue.
+    __ pop(edi);
+    __ pop(esi);
+    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(eax, 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 RegExpMacroAssemblerIA32::GoTo(Label* to) {
+  BranchOrBacktrack(no_condition, to);
+}
+
+
+void RegExpMacroAssemblerIA32::IfRegisterGE(int reg,
+                                            int comparand,
+                                            Label* if_ge) {
+  __ cmp(register_location(reg), Immediate(comparand));
+  BranchOrBacktrack(greater_equal, if_ge);
+}
+
+
+void RegExpMacroAssemblerIA32::IfRegisterLT(int reg,
+                                            int comparand,
+                                            Label* if_lt) {
+  __ cmp(register_location(reg), Immediate(comparand));
+  BranchOrBacktrack(less, if_lt);
+}
+
+
+void RegExpMacroAssemblerIA32::IfRegisterEqPos(int reg,
+                                               Label* if_eq) {
+  __ cmp(edi, register_location(reg));
+  BranchOrBacktrack(equal, if_eq);
+}
+
+
+RegExpMacroAssembler::IrregexpImplementation
+    RegExpMacroAssemblerIA32::Implementation() {
+  return kIA32Implementation;
+}
+
+
+void RegExpMacroAssemblerIA32::LoadCurrentCharacter(int cp_offset,
+                                                    Label* on_end_of_input,
+                                                    bool check_bounds,
+                                                    int characters) {
+  ASSERT(cp_offset >= -1);      // ^ and \b can look behind one character.
+  ASSERT(cp_offset < (1<<30));  // Be sane! (And ensure negation works)
+  CheckPosition(cp_offset + characters - 1, on_end_of_input);
+  LoadCurrentCharacterUnchecked(cp_offset, characters);
+}
+
+
+void RegExpMacroAssemblerIA32::PopCurrentPosition() {
+  Pop(edi);
+}
+
+
+void RegExpMacroAssemblerIA32::PopRegister(int register_index) {
+  Pop(eax);
+  __ mov(register_location(register_index), eax);
+}
+
+
+void RegExpMacroAssemblerIA32::PushBacktrack(Label* label) {
+  Push(Immediate::CodeRelativeOffset(label));
+  CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerIA32::PushCurrentPosition() {
+  Push(edi);
+}
+
+
+void RegExpMacroAssemblerIA32::PushRegister(int register_index,
+                                            StackCheckFlag check_stack_limit) {
+  __ mov(eax, register_location(register_index));
+  Push(eax);
+  if (check_stack_limit) CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerIA32::ReadCurrentPositionFromRegister(int reg) {
+  __ mov(edi, register_location(reg));
+}
+
+
+void RegExpMacroAssemblerIA32::ReadStackPointerFromRegister(int reg) {
+  __ mov(backtrack_stackpointer(), register_location(reg));
+  __ add(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
+}
+
+
+void RegExpMacroAssemblerIA32::SetRegister(int register_index, int to) {
+  ASSERT(register_index >= num_saved_registers_);  // Reserved for positions!
+  __ mov(register_location(register_index), Immediate(to));
+}
+
+
+void RegExpMacroAssemblerIA32::Succeed() {
+  __ jmp(&success_label_);
+}
+
+
+void RegExpMacroAssemblerIA32::WriteCurrentPositionToRegister(int reg,
+                                                              int cp_offset) {
+  if (cp_offset == 0) {
+    __ mov(register_location(reg), edi);
+  } else {
+    __ lea(eax, Operand(edi, cp_offset * char_size()));
+    __ mov(register_location(reg), eax);
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::ClearRegisters(int reg_from, int reg_to) {
+  ASSERT(reg_from <= reg_to);
+  __ mov(eax, Operand(ebp, kInputStartMinusOne));
+  for (int reg = reg_from; reg <= reg_to; reg++) {
+    __ mov(register_location(reg), eax);
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::WriteStackPointerToRegister(int reg) {
+  __ mov(eax, backtrack_stackpointer());
+  __ sub(eax, Operand(ebp, kStackHighEnd));
+  __ mov(register_location(reg), eax);
+}
+
+
+RegExpMacroAssemblerIA32::Result RegExpMacroAssemblerIA32::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 = StringShape(*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(StringShape(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;
+  RegExpMacroAssemblerIA32::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;
+}
+
+// Private methods:
+
+static unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
+
+RegExpMacroAssemblerIA32::Result RegExpMacroAssemblerIA32::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_top = RegExpStack::stack_top();
+
+  int result = matcher_func(input,
+                            start_offset,
+                            input_start,
+                            input_end,
+                            output,
+                            at_start_val,
+                            stack_top);
+  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);
+}
+
+
+int RegExpMacroAssemblerIA32::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) {
+      canonicalize.get(c1, '\0', &c1);
+      if (c1 != c2) {
+        canonicalize.get(c2, '\0', &c2);
+        if (c1 != c2) {
+          return 0;
+        }
+      }
+    }
+  }
+  return 1;
+}
+
+
+void RegExpMacroAssemblerIA32::CallCheckStackGuardState(Register scratch) {
+  int num_arguments = 3;
+  FrameAlign(num_arguments, scratch);
+  // RegExp code frame pointer.
+  __ mov(Operand(esp, 2 * kPointerSize), ebp);
+  // Code* of self.
+  __ mov(Operand(esp, 1 * kPointerSize), Immediate(masm_->CodeObject()));
+  // Next address on the stack (will be address of return address).
+  __ lea(eax, Operand(esp, -kPointerSize));
+  __ mov(Operand(esp, 0 * kPointerSize), eax);
+  CallCFunction(FUNCTION_ADDR(&CheckStackGuardState), 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));
+}
+
+
+const byte* RegExpMacroAssemblerIA32::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 (StringShape(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);
+}
+
+
+int RegExpMacroAssemblerIA32::CheckStackGuardState(Address* return_address,
+                                                   Code* re_code,
+                                                   Address re_frame) {
+  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 = StringShape(*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 (StringShape(*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 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 byte*>(re_frame, kInputStart) = new_address;
+    frame_entry<const byte*>(re_frame, kInputEnd) = new_address + byte_length;
+  }
+
+  return 0;
+}
+
+
+Address RegExpMacroAssemblerIA32::GrowStack(Address stack_pointer,
+                                            Address* stack_top) {
+  size_t size = RegExpStack::stack_capacity();
+  Address old_stack_top = RegExpStack::stack_top();
+  ASSERT(old_stack_top == *stack_top);
+  ASSERT(stack_pointer <= old_stack_top);
+  ASSERT(static_cast<size_t>(old_stack_top - stack_pointer) <= size);
+  Address new_stack_top = RegExpStack::EnsureCapacity(size * 2);
+  if (new_stack_top == NULL) {
+    return NULL;
+  }
+  *stack_top = new_stack_top;
+  return new_stack_top - (old_stack_top - stack_pointer);
+}
+
+
+Operand RegExpMacroAssemblerIA32::register_location(int register_index) {
+  ASSERT(register_index < (1<<30));
+  if (num_registers_ <= register_index) {
+    num_registers_ = register_index + 1;
+  }
+  return Operand(ebp, kRegisterZero - register_index * kPointerSize);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckPosition(int cp_offset,
+                                             Label* on_outside_input) {
+  __ cmp(edi, -cp_offset * char_size());
+  BranchOrBacktrack(greater_equal, on_outside_input);
+}
+
+
+void RegExpMacroAssemblerIA32::BranchOrBacktrack(Condition condition,
+                                                 Label* to,
+                                                 Hint hint) {
+  if (condition < 0) {  // No condition
+    if (to == NULL) {
+      Backtrack();
+      return;
+    }
+    __ jmp(to);
+    return;
+  }
+  if (to == NULL) {
+    __ j(condition, &backtrack_label_, hint);
+    return;
+  }
+  __ j(condition, to, hint);
+}
+
+
+void RegExpMacroAssemblerIA32::SafeCall(Label* to) {
+  Label return_to;
+  __ push(Immediate::CodeRelativeOffset(&return_to));
+  __ jmp(to);
+  __ bind(&return_to);
+}
+
+
+void RegExpMacroAssemblerIA32::SafeReturn() {
+  __ pop(ebx);
+  __ add(Operand(ebx), Immediate(masm_->CodeObject()));
+  __ jmp(Operand(ebx));
+}
+
+
+void RegExpMacroAssemblerIA32::Push(Register source) {
+  ASSERT(!source.is(backtrack_stackpointer()));
+  // Notice: This updates flags, unlike normal Push.
+  __ sub(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
+  __ mov(Operand(backtrack_stackpointer(), 0), source);
+}
+
+
+void RegExpMacroAssemblerIA32::Push(Immediate value) {
+  // Notice: This updates flags, unlike normal Push.
+  __ sub(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
+  __ mov(Operand(backtrack_stackpointer(), 0), value);
+}
+
+
+void RegExpMacroAssemblerIA32::Pop(Register target) {
+  ASSERT(!target.is(backtrack_stackpointer()));
+  __ mov(target, Operand(backtrack_stackpointer(), 0));
+  // Notice: This updates flags, unlike normal Pop.
+  __ add(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
+}
+
+
+void RegExpMacroAssemblerIA32::CheckPreemption() {
+  // Check for preemption.
+  Label no_preempt;
+  ExternalReference stack_guard_limit =
+      ExternalReference::address_of_stack_guard_limit();
+  __ cmp(esp, Operand::StaticVariable(stack_guard_limit));
+  __ j(above, &no_preempt, taken);
+
+  SafeCall(&check_preempt_label_);
+
+  __ bind(&no_preempt);
+}
+
+
+void RegExpMacroAssemblerIA32::CheckStackLimit() {
+  if (FLAG_check_stack) {
+    Label no_stack_overflow;
+    ExternalReference stack_limit =
+        ExternalReference::address_of_regexp_stack_limit();
+    __ cmp(backtrack_stackpointer(), Operand::StaticVariable(stack_limit));
+    __ j(above, &no_stack_overflow);
+
+    SafeCall(&stack_overflow_label_);
+
+    __ bind(&no_stack_overflow);
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::FrameAlign(int num_arguments, Register scratch) {
+  // TODO(lrn): Since we no longer use the system stack arbitrarily (but we do
+  // use it, e.g., for SafeCall), we know the number of elements on the stack
+  // since the last frame alignment. We might be able to do this simpler then.
+  int frameAlignment = OS::ActivationFrameAlignment();
+  if (frameAlignment != 0) {
+    // Make stack end at alignment and make room for num_arguments words
+    // and the original value of esp.
+    __ mov(scratch, esp);
+    __ sub(Operand(esp), Immediate((num_arguments + 1) * kPointerSize));
+    ASSERT(IsPowerOf2(frameAlignment));
+    __ and_(esp, -frameAlignment);
+    __ mov(Operand(esp, num_arguments * kPointerSize), scratch);
+  } else {
+    __ sub(Operand(esp), Immediate(num_arguments * kPointerSize));
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::CallCFunction(Address function_address,
+                                             int num_arguments) {
+  __ mov(Operand(eax), Immediate(reinterpret_cast<int32_t>(function_address)));
+  __ call(Operand(eax));
+  if (OS::ActivationFrameAlignment() != 0) {
+    __ mov(esp, Operand(esp, num_arguments * kPointerSize));
+  } else {
+    __ add(Operand(esp), Immediate(num_arguments * sizeof(int32_t)));
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::LoadCurrentCharacterUnchecked(int cp_offset,
+                                                             int characters) {
+  if (mode_ == ASCII) {
+    if (characters == 4) {
+      __ mov(current_character(), Operand(esi, edi, times_1, cp_offset));
+    } else if (characters == 2) {
+      __ movzx_w(current_character(), Operand(esi, edi, times_1, cp_offset));
+    } else {
+      ASSERT(characters == 1);
+      __ movzx_b(current_character(), Operand(esi, edi, times_1, cp_offset));
+    }
+  } else {
+    ASSERT(mode_ == UC16);
+    if (characters == 2) {
+      __ mov(current_character(),
+             Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
+    } else {
+      ASSERT(characters == 1);
+      __ movzx_w(current_character(),
+                 Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
+    }
+  }
+}
+
+
+void RegExpMacroAssemblerIA32::LoadConstantBufferAddress(Register reg,
+                                                         ArraySlice* buffer) {
+  __ mov(reg, buffer->array());
+  __ add(Operand(reg), Immediate(buffer->base_offset()));
+}
+
+#undef __
+}}  // namespace v8::internal