Upgrade V8 to version 4.9.385.28

https://chromium.googlesource.com/v8/v8/+/4.9.385.28

FPIIM-449

Change-Id: I4b2e74289d4bf3667f2f3dc8aa2e541f63e26eb4
diff --git a/src/regexp/x87/regexp-macro-assembler-x87.cc b/src/regexp/x87/regexp-macro-assembler-x87.cc
new file mode 100644
index 0000000..01d0b24
--- /dev/null
+++ b/src/regexp/x87/regexp-macro-assembler-x87.cc
@@ -0,0 +1,1263 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#if V8_TARGET_ARCH_X87
+
+#include "src/regexp/x87/regexp-macro-assembler-x87.h"
+
+#include "src/log.h"
+#include "src/macro-assembler.h"
+#include "src/profiler/cpu-profiler.h"
+#include "src/regexp/regexp-macro-assembler.h"
+#include "src/regexp/regexp-stack.h"
+#include "src/unicode.h"
+
+namespace v8 {
+namespace internal {
+
+#ifndef V8_INTERPRETED_REGEXP
+/*
+ * This assembler uses the following register assignment convention
+ * - edx : Current character.  Must be loaded using LoadCurrentCharacter
+ *         before using any of the dispatch methods.  Temporarily stores the
+ *         index of capture start after a matching pass for a global regexp.
+ * - 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 and ebx are free to use for computations.
+ *
+ * Each call to a public method should retain this convention.
+ * The stack will have the following structure:
+ *       - Isolate* isolate     (address of the current isolate)
+ *       - direct_call          (if 1, direct call from JavaScript code, if 0
+ *                               call through the runtime system)
+ *       - stack_area_base      (high end of the memory area to use as
+ *                               backtracking stack)
+ *       - capture array size   (may fit multiple sets of matches)
+ *       - 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)
+ *       - start index          (character index of start)
+ *       - String* 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
+ *       - success counter      (only for global regexps to count matches).
+ *       - Offset of location before start of input (effectively character
+ *         string start - 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, by calling the code entry as cast to a function with the signature:
+ * int (*match)(String* input_string,
+ *              int start_index,
+ *              Address start,
+ *              Address end,
+ *              int* capture_output_array,
+ *              bool at_start,
+ *              byte* stack_area_base,
+ *              bool direct_call)
+ */
+
+#define __ ACCESS_MASM(masm_)
+
+RegExpMacroAssemblerX87::RegExpMacroAssemblerX87(Isolate* isolate, Zone* zone,
+                                                 Mode mode,
+                                                 int registers_to_save)
+    : NativeRegExpMacroAssembler(isolate, zone),
+      masm_(new MacroAssembler(isolate, NULL, kRegExpCodeSize,
+                               CodeObjectRequired::kYes)),
+      mode_(mode),
+      num_registers_(registers_to_save),
+      num_saved_registers_(registers_to_save),
+      entry_label_(),
+      start_label_(),
+      success_label_(),
+      backtrack_label_(),
+      exit_label_() {
+  DCHECK_EQ(0, registers_to_save % 2);
+  __ jmp(&entry_label_);   // We'll write the entry code later.
+  __ bind(&start_label_);  // And then continue from here.
+}
+
+
+RegExpMacroAssemblerX87::~RegExpMacroAssemblerX87() {
+  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 RegExpMacroAssemblerX87::stack_limit_slack()  {
+  return RegExpStack::kStackLimitSlack;
+}
+
+
+void RegExpMacroAssemblerX87::AdvanceCurrentPosition(int by) {
+  if (by != 0) {
+    __ add(edi, Immediate(by * char_size()));
+  }
+}
+
+
+void RegExpMacroAssemblerX87::AdvanceRegister(int reg, int by) {
+  DCHECK(reg >= 0);
+  DCHECK(reg < num_registers_);
+  if (by != 0) {
+    __ add(register_location(reg), Immediate(by));
+  }
+}
+
+
+void RegExpMacroAssemblerX87::Backtrack() {
+  CheckPreemption();
+  // Pop Code* offset from backtrack stack, add Code* and jump to location.
+  Pop(ebx);
+  __ add(ebx, Immediate(masm_->CodeObject()));
+  __ jmp(ebx);
+}
+
+
+void RegExpMacroAssemblerX87::Bind(Label* label) {
+  __ bind(label);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacter(uint32_t c, Label* on_equal) {
+  __ cmp(current_character(), c);
+  BranchOrBacktrack(equal, on_equal);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacterGT(uc16 limit, Label* on_greater) {
+  __ cmp(current_character(), limit);
+  BranchOrBacktrack(greater, on_greater);
+}
+
+
+void RegExpMacroAssemblerX87::CheckAtStart(Label* on_at_start) {
+  __ lea(eax, Operand(edi, -char_size()));
+  __ cmp(eax, Operand(ebp, kStringStartMinusOne));
+  BranchOrBacktrack(equal, on_at_start);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotAtStart(int cp_offset,
+                                              Label* on_not_at_start) {
+  __ lea(eax, Operand(edi, -char_size() + cp_offset * char_size()));
+  __ cmp(eax, Operand(ebp, kStringStartMinusOne));
+  BranchOrBacktrack(not_equal, on_not_at_start);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacterLT(uc16 limit, Label* on_less) {
+  __ cmp(current_character(), limit);
+  BranchOrBacktrack(less, on_less);
+}
+
+
+void RegExpMacroAssemblerX87::CheckGreedyLoop(Label* on_equal) {
+  Label fallthrough;
+  __ cmp(edi, Operand(backtrack_stackpointer(), 0));
+  __ j(not_equal, &fallthrough);
+  __ add(backtrack_stackpointer(), Immediate(kPointerSize));  // Pop.
+  BranchOrBacktrack(no_condition, on_equal);
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotBackReferenceIgnoreCase(
+    int start_reg, bool read_backward, 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, edx);  // Length of capture.
+
+  // At this point, the capture registers are either both set or both cleared.
+  // If the capture length is zero, then the capture is either empty or cleared.
+  // Fall through in both cases.
+  __ j(equal, &fallthrough);
+
+  // Check that there are sufficient characters left in the input.
+  if (read_backward) {
+    __ mov(eax, Operand(ebp, kStringStartMinusOne));
+    __ add(eax, ebx);
+    __ cmp(edi, eax);
+    BranchOrBacktrack(less_equal, on_no_match);
+  } else {
+    __ mov(eax, edi);
+    __ add(eax, ebx);
+    BranchOrBacktrack(greater, on_no_match);
+  }
+
+  if (mode_ == LATIN1) {
+    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, esi);  // Start of capture
+    __ add(edi, esi);  // Start of text to match against capture.
+    if (read_backward) {
+      __ sub(edi, ebx);  // Offset by length when matching backwards.
+    }
+    __ add(ebx, 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?
+    Label convert_capture;
+    __ j(below_equal, &convert_capture);  // In range 'a'-'z'.
+    // Latin-1: Check for values in range [224,254] but not 247.
+    __ sub(ecx, Immediate(224 - 'a'));
+    __ cmp(ecx, Immediate(254 - 224));
+    __ j(above, &fail);  // Weren't Latin-1 letters.
+    __ cmp(ecx, Immediate(247 - 224));  // Check for 247.
+    __ j(equal, &fail);
+    __ bind(&convert_capture);
+    // Also convert capture character.
+    __ movzx_b(ecx, Operand(edx, 0));
+    __ or_(ecx, 0x20);
+
+    __ cmp(eax, ecx);
+    __ j(not_equal, &fail);
+
+    __ bind(&loop_increment);
+    // Increment pointers into match and capture strings.
+    __ add(edx, Immediate(1));
+    __ add(edi, Immediate(1));
+    // Compare to end of match, and loop if not done.
+    __ cmp(edi, ebx);
+    __ j(below, &loop);
+    __ 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(esp, Immediate(kPointerSize));
+    // Compute new value of character position after the matched part.
+    __ sub(edi, esi);
+    if (read_backward) {
+      // Subtract match length if we matched backward.
+      __ add(edi, register_location(start_reg));
+      __ sub(edi, register_location(start_reg + 1));
+    }
+  } else {
+    DCHECK(mode_ == UC16);
+    // Save registers before calling C function.
+    __ push(esi);
+    __ push(edi);
+    __ push(backtrack_stackpointer());
+    __ push(ebx);
+
+    static const int argument_count = 4;
+    __ PrepareCallCFunction(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(!)
+    //   Isolate* isolate
+
+    // Set isolate.
+    __ mov(Operand(esp, 3 * kPointerSize),
+           Immediate(ExternalReference::isolate_address(isolate())));
+    // 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, esi);
+    if (read_backward) {
+      __ sub(edi, ebx);  // Offset by length when matching backwards.
+    }
+    __ mov(Operand(esp, 1 * kPointerSize), edi);
+    // Set byte_offset1.
+    // Start of capture, where edx already holds string-end negative offset.
+    __ add(edx, esi);
+    __ mov(Operand(esp, 0 * kPointerSize), edx);
+
+    {
+      AllowExternalCallThatCantCauseGC scope(masm_);
+      ExternalReference compare =
+          ExternalReference::re_case_insensitive_compare_uc16(isolate());
+      __ CallCFunction(compare, 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, eax);
+    BranchOrBacktrack(zero, on_no_match);
+    // On success, advance position by length of capture.
+    if (read_backward) {
+      __ sub(edi, ebx);
+    } else {
+      __ add(edi, ebx);
+    }
+  }
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotBackReference(int start_reg,
+                                                    bool read_backward,
+                                                    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, edx);  // Length to check.
+
+  // At this point, the capture registers are either both set or both cleared.
+  // If the capture length is zero, then the capture is either empty or cleared.
+  // Fall through in both cases.
+  __ j(equal, &fallthrough);
+
+  // Check that there are sufficient characters left in the input.
+  if (read_backward) {
+    __ mov(ebx, Operand(ebp, kStringStartMinusOne));
+    __ add(ebx, eax);
+    __ cmp(edi, ebx);
+    BranchOrBacktrack(less_equal, on_no_match);
+  } else {
+    __ mov(ebx, edi);
+    __ add(ebx, eax);
+    BranchOrBacktrack(greater, on_no_match);
+  }
+
+  // Save register to make it available below.
+  __ push(backtrack_stackpointer());
+
+  // Compute pointers to match string and capture string
+  __ add(edx, esi);  // Start of capture.
+  __ lea(ebx, Operand(esi, edi, times_1, 0));  // Start of match.
+  if (read_backward) {
+    __ sub(ebx, eax);  // Offset by length when matching backwards.
+  }
+  __ lea(ecx, Operand(eax, ebx, times_1, 0));  // End of match
+
+  Label loop;
+  __ bind(&loop);
+  if (mode_ == LATIN1) {
+    __ movzx_b(eax, Operand(edx, 0));
+    __ cmpb_al(Operand(ebx, 0));
+  } else {
+    DCHECK(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(edx, Immediate(char_size()));
+  __ add(ebx, Immediate(char_size()));
+  // Check if we have reached end of match area.
+  __ cmp(ebx, 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(edi, esi);
+  if (read_backward) {
+    // Subtract match length if we matched backward.
+    __ add(edi, register_location(start_reg));
+    __ sub(edi, register_location(start_reg + 1));
+  }
+  // Restore backtrack stackpointer.
+  __ pop(backtrack_stackpointer());
+
+  __ bind(&fallthrough);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotCharacter(uint32_t c,
+                                                 Label* on_not_equal) {
+  __ cmp(current_character(), c);
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacterAfterAnd(uint32_t c,
+                                                      uint32_t mask,
+                                                      Label* on_equal) {
+  if (c == 0) {
+    __ test(current_character(), Immediate(mask));
+  } else {
+    __ mov(eax, mask);
+    __ and_(eax, current_character());
+    __ cmp(eax, c);
+  }
+  BranchOrBacktrack(equal, on_equal);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotCharacterAfterAnd(uint32_t c,
+                                                         uint32_t mask,
+                                                         Label* on_not_equal) {
+  if (c == 0) {
+    __ test(current_character(), Immediate(mask));
+  } else {
+    __ mov(eax, mask);
+    __ and_(eax, current_character());
+    __ cmp(eax, c);
+  }
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerX87::CheckNotCharacterAfterMinusAnd(
+    uc16 c,
+    uc16 minus,
+    uc16 mask,
+    Label* on_not_equal) {
+  DCHECK(minus < String::kMaxUtf16CodeUnit);
+  __ lea(eax, Operand(current_character(), -minus));
+  if (c == 0) {
+    __ test(eax, Immediate(mask));
+  } else {
+    __ and_(eax, mask);
+    __ cmp(eax, c);
+  }
+  BranchOrBacktrack(not_equal, on_not_equal);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacterInRange(
+    uc16 from,
+    uc16 to,
+    Label* on_in_range) {
+  __ lea(eax, Operand(current_character(), -from));
+  __ cmp(eax, to - from);
+  BranchOrBacktrack(below_equal, on_in_range);
+}
+
+
+void RegExpMacroAssemblerX87::CheckCharacterNotInRange(
+    uc16 from,
+    uc16 to,
+    Label* on_not_in_range) {
+  __ lea(eax, Operand(current_character(), -from));
+  __ cmp(eax, to - from);
+  BranchOrBacktrack(above, on_not_in_range);
+}
+
+
+void RegExpMacroAssemblerX87::CheckBitInTable(
+    Handle<ByteArray> table,
+    Label* on_bit_set) {
+  __ mov(eax, Immediate(table));
+  Register index = current_character();
+  if (mode_ != LATIN1 || kTableMask != String::kMaxOneByteCharCode) {
+    __ mov(ebx, kTableSize - 1);
+    __ and_(ebx, current_character());
+    index = ebx;
+  }
+  __ cmpb(FieldOperand(eax, index, times_1, ByteArray::kHeaderSize), 0);
+  BranchOrBacktrack(not_equal, on_bit_set);
+}
+
+
+bool RegExpMacroAssemblerX87::CheckSpecialCharacterClass(uc16 type,
+                                                          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_ == LATIN1) {
+      // One byte space characters are '\t'..'\r', ' ' and \u00a0.
+      Label success;
+      __ cmp(current_character(), ' ');
+      __ j(equal, &success, Label::kNear);
+      // Check range 0x09..0x0d
+      __ lea(eax, Operand(current_character(), -'\t'));
+      __ cmp(eax, '\r' - '\t');
+      __ j(below_equal, &success, Label::kNear);
+      // \u00a0 (NBSP).
+      __ cmp(eax, 0x00a0 - '\t');
+      BranchOrBacktrack(not_equal, on_no_match);
+      __ bind(&success);
+      return true;
+    }
+    return false;
+  case 'S':
+    // The emitted code for generic character classes is good enough.
+    return false;
+  case 'd':
+    // Match ASCII digits ('0'..'9')
+    __ lea(eax, Operand(current_character(), -'0'));
+    __ cmp(eax, '9' - '0');
+    BranchOrBacktrack(above, on_no_match);
+    return true;
+  case 'D':
+    // Match non ASCII-digits
+    __ lea(eax, Operand(current_character(), -'0'));
+    __ cmp(eax, '9' - '0');
+    BranchOrBacktrack(below_equal, on_no_match);
+    return true;
+  case '.': {
+    // Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
+    __ mov(eax, current_character());
+    __ xor_(eax, Immediate(0x01));
+    // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+    __ sub(eax, Immediate(0x0b));
+    __ cmp(eax, 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(eax, Immediate(0x2028 - 0x0b));
+      __ cmp(eax, 0x2029 - 0x2028);
+      BranchOrBacktrack(below_equal, on_no_match);
+    }
+    return true;
+  }
+  case 'w': {
+    if (mode_ != LATIN1) {
+      // Table is 256 entries, so all Latin1 characters can be tested.
+      __ cmp(current_character(), Immediate('z'));
+      BranchOrBacktrack(above, on_no_match);
+    }
+    DCHECK_EQ(0, word_character_map[0]);  // Character '\0' is not a word char.
+    ExternalReference word_map = ExternalReference::re_word_character_map();
+    __ test_b(current_character(),
+              Operand::StaticArray(current_character(), times_1, word_map));
+    BranchOrBacktrack(zero, on_no_match);
+    return true;
+  }
+  case 'W': {
+    Label done;
+    if (mode_ != LATIN1) {
+      // Table is 256 entries, so all Latin1 characters can be tested.
+      __ cmp(current_character(), Immediate('z'));
+      __ j(above, &done);
+    }
+    DCHECK_EQ(0, word_character_map[0]);  // Character '\0' is not a word char.
+    ExternalReference word_map = ExternalReference::re_word_character_map();
+    __ test_b(current_character(),
+              Operand::StaticArray(current_character(), times_1, word_map));
+    BranchOrBacktrack(not_zero, on_no_match);
+    if (mode_ != LATIN1) {
+      __ bind(&done);
+    }
+    return true;
+  }
+  // Non-standard classes (with no syntactic shorthand) used internally.
+  case '*':
+    // Match any character.
+    return true;
+  case 'n': {
+    // Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 or 0x2029).
+    // The opposite of '.'.
+    __ mov(eax, current_character());
+    __ xor_(eax, Immediate(0x01));
+    // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+    __ sub(eax, Immediate(0x0b));
+    __ cmp(eax, 0x0c - 0x0b);
+    if (mode_ == LATIN1) {
+      BranchOrBacktrack(above, on_no_match);
+    } else {
+      Label done;
+      BranchOrBacktrack(below_equal, &done);
+      DCHECK_EQ(UC16, mode_);
+      // 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(eax, Immediate(0x2028 - 0x0b));
+      __ cmp(eax, 1);
+      BranchOrBacktrack(above, on_no_match);
+      __ bind(&done);
+    }
+    return true;
+  }
+  // No custom implementation (yet): s(UC16), S(UC16).
+  default:
+    return false;
+  }
+}
+
+
+void RegExpMacroAssemblerX87::Fail() {
+  STATIC_ASSERT(FAILURE == 0);  // Return value for failure is zero.
+  if (!global()) {
+    __ Move(eax, Immediate(FAILURE));
+  }
+  __ jmp(&exit_label_);
+}
+
+
+Handle<HeapObject> RegExpMacroAssemblerX87::GetCode(Handle<String> source) {
+  Label return_eax;
+  // Finalize code - write the entry point code now we know how many
+  // registers we need.
+
+  // Entry code:
+  __ bind(&entry_label_);
+
+  // Tell the system that we have a stack frame.  Because the type is MANUAL, no
+  // code is generated.
+  FrameScope scope(masm_, StackFrame::MANUAL);
+
+  // Actually emit code to start a 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));  // Number of successful matches in a global regexp.
+  __ push(Immediate(0));  // Make room for "string start - 1" constant.
+
+  // Check if we have space on the stack for registers.
+  Label stack_limit_hit;
+  Label stack_ok;
+
+  ExternalReference stack_limit =
+      ExternalReference::address_of_stack_limit(isolate());
+  __ mov(ecx, esp);
+  __ sub(ecx, Operand::StaticVariable(stack_limit));
+  // Handle it if the stack pointer is already below the stack limit.
+  __ j(below_equal, &stack_limit_hit);
+  // 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);
+  // Exit with OutOfMemory exception. There is not enough space on the stack
+  // for our working registers.
+  __ mov(eax, EXCEPTION);
+  __ jmp(&return_eax);
+
+  __ bind(&stack_limit_hit);
+  CallCheckStackGuardState(ebx);
+  __ or_(eax, eax);
+  // If returned value is non-zero, we exit with the returned value as result.
+  __ j(not_zero, &return_eax);
+
+  __ bind(&stack_ok);
+  // Load start index for later use.
+  __ mov(ebx, Operand(ebp, kStartIndex));
+
+  // Allocate space on stack for registers.
+  __ sub(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, esi);
+
+  // Set eax to address of char before start of the string.
+  // (effectively string position -1).
+  __ neg(ebx);
+  if (mode_ == UC16) {
+    __ lea(eax, Operand(edi, ebx, times_2, -char_size()));
+  } else {
+    __ lea(eax, Operand(edi, ebx, times_1, -char_size()));
+  }
+  // Store this value in a local variable, for use when clearing
+  // position registers.
+  __ mov(Operand(ebp, kStringStartMinusOne), eax);
+
+#if V8_OS_WIN
+  // Ensure that we write 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.
+  }
+#endif  // V8_OS_WIN
+
+  Label load_char_start_regexp, start_regexp;
+  // Load newline if index is at start, previous character otherwise.
+  __ cmp(Operand(ebp, kStartIndex), Immediate(0));
+  __ j(not_equal, &load_char_start_regexp, Label::kNear);
+  __ mov(current_character(), '\n');
+  __ jmp(&start_regexp, Label::kNear);
+
+  // Global regexp restarts matching here.
+  __ bind(&load_char_start_regexp);
+  // Load previous char as initial value of current character register.
+  LoadCurrentCharacterUnchecked(-1, 1);
+  __ bind(&start_regexp);
+
+  // Initialize on-stack registers.
+  if (num_saved_registers_ > 0) {  // Always is, if generated from a regexp.
+    // 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).
+    if (num_saved_registers_ > 8) {
+      __ mov(ecx, kRegisterZero);
+      Label init_loop;
+      __ bind(&init_loop);
+      __ mov(Operand(ebp, ecx, times_1, 0), eax);
+      __ sub(ecx, Immediate(kPointerSize));
+      __ cmp(ecx, kRegisterZero - num_saved_registers_ * kPointerSize);
+      __ j(greater, &init_loop);
+    } else {  // Unroll the loop.
+      for (int i = 0; i < num_saved_registers_; i++) {
+        __ mov(register_location(i), eax);
+      }
+    }
+  }
+
+  // Initialize backtrack stack pointer.
+  __ mov(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
+
+  __ 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));
+      __ mov(edx, Operand(ebp, kStartIndex));
+      __ sub(ecx, Operand(ebp, kInputStart));
+      if (mode_ == UC16) {
+        __ lea(ecx, Operand(ecx, edx, times_2, 0));
+      } else {
+        __ add(ecx, edx);
+      }
+      for (int i = 0; i < num_saved_registers_; i++) {
+        __ mov(eax, register_location(i));
+        if (i == 0 && global_with_zero_length_check()) {
+          // Keep capture start in edx for the zero-length check later.
+          __ mov(edx, eax);
+        }
+        // Convert to index from start of string, not end.
+        __ add(eax, ecx);
+        if (mode_ == UC16) {
+          __ sar(eax, 1);  // Convert byte index to character index.
+        }
+        __ mov(Operand(ebx, i * kPointerSize), eax);
+      }
+    }
+
+    if (global()) {
+      // Restart matching if the regular expression is flagged as global.
+      // Increment success counter.
+      __ inc(Operand(ebp, kSuccessfulCaptures));
+      // Capture results have been stored, so the number of remaining global
+      // output registers is reduced by the number of stored captures.
+      __ mov(ecx, Operand(ebp, kNumOutputRegisters));
+      __ sub(ecx, Immediate(num_saved_registers_));
+      // Check whether we have enough room for another set of capture results.
+      __ cmp(ecx, Immediate(num_saved_registers_));
+      __ j(less, &exit_label_);
+
+      __ mov(Operand(ebp, kNumOutputRegisters), ecx);
+      // Advance the location for output.
+      __ add(Operand(ebp, kRegisterOutput),
+             Immediate(num_saved_registers_ * kPointerSize));
+
+      // Prepare eax to initialize registers with its value in the next run.
+      __ mov(eax, Operand(ebp, kStringStartMinusOne));
+
+      if (global_with_zero_length_check()) {
+        // Special case for zero-length matches.
+        // edx: capture start index
+        __ cmp(edi, edx);
+        // Not a zero-length match, restart.
+        __ j(not_equal, &load_char_start_regexp);
+        // edi (offset from the end) is zero if we already reached the end.
+        __ test(edi, edi);
+        __ j(zero, &exit_label_, Label::kNear);
+        // Advance current position after a zero-length match.
+        if (mode_ == UC16) {
+          __ add(edi, Immediate(2));
+        } else {
+          __ inc(edi);
+        }
+      }
+
+      __ jmp(&load_char_start_regexp);
+    } else {
+      __ mov(eax, Immediate(SUCCESS));
+    }
+  }
+
+  __ bind(&exit_label_);
+  if (global()) {
+    // Return the number of successful captures.
+    __ mov(eax, Operand(ebp, kSuccessfulCaptures));
+  }
+
+  __ bind(&return_eax);
+  // 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()) {
+    SafeCallTarget(&check_preempt_label_);
+
+    __ push(backtrack_stackpointer());
+    __ push(edi);
+
+    CallCheckStackGuardState(ebx);
+    __ or_(eax, eax);
+    // If returning non-zero, we should end execution with the given
+    // result as return value.
+    __ j(not_zero, &return_eax);
+
+    __ 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()) {
+    SafeCallTarget(&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())
+    static const int num_arguments = 3;
+    __ PrepareCallCFunction(num_arguments, ebx);
+    __ mov(Operand(esp, 2 * kPointerSize),
+           Immediate(ExternalReference::isolate_address(isolate())));
+    __ lea(eax, Operand(ebp, kStackHighEnd));
+    __ mov(Operand(esp, 1 * kPointerSize), eax);
+    __ mov(Operand(esp, 0 * kPointerSize), backtrack_stackpointer());
+    ExternalReference grow_stack =
+        ExternalReference::re_grow_stack(isolate());
+    __ CallCFunction(grow_stack, num_arguments);
+    // If return NULL, we have failed to grow the stack, and
+    // must exit with a stack-overflow exception.
+    __ or_(eax, 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(&return_eax);
+  }
+
+  CodeDesc code_desc;
+  masm_->GetCode(&code_desc);
+  Handle<Code> code =
+      isolate()->factory()->NewCode(code_desc,
+                                    Code::ComputeFlags(Code::REGEXP),
+                                    masm_->CodeObject());
+  PROFILE(isolate(), RegExpCodeCreateEvent(*code, *source));
+  return Handle<HeapObject>::cast(code);
+}
+
+
+void RegExpMacroAssemblerX87::GoTo(Label* to) {
+  BranchOrBacktrack(no_condition, to);
+}
+
+
+void RegExpMacroAssemblerX87::IfRegisterGE(int reg,
+                                            int comparand,
+                                            Label* if_ge) {
+  __ cmp(register_location(reg), Immediate(comparand));
+  BranchOrBacktrack(greater_equal, if_ge);
+}
+
+
+void RegExpMacroAssemblerX87::IfRegisterLT(int reg,
+                                            int comparand,
+                                            Label* if_lt) {
+  __ cmp(register_location(reg), Immediate(comparand));
+  BranchOrBacktrack(less, if_lt);
+}
+
+
+void RegExpMacroAssemblerX87::IfRegisterEqPos(int reg,
+                                               Label* if_eq) {
+  __ cmp(edi, register_location(reg));
+  BranchOrBacktrack(equal, if_eq);
+}
+
+
+RegExpMacroAssembler::IrregexpImplementation
+    RegExpMacroAssemblerX87::Implementation() {
+  return kX87Implementation;
+}
+
+
+void RegExpMacroAssemblerX87::LoadCurrentCharacter(int cp_offset,
+                                                    Label* on_end_of_input,
+                                                    bool check_bounds,
+                                                    int characters) {
+  DCHECK(cp_offset < (1<<30));  // Be sane! (And ensure negation works)
+  if (check_bounds) {
+    if (cp_offset >= 0) {
+      CheckPosition(cp_offset + characters - 1, on_end_of_input);
+    } else {
+      CheckPosition(cp_offset, on_end_of_input);
+    }
+  }
+  LoadCurrentCharacterUnchecked(cp_offset, characters);
+}
+
+
+void RegExpMacroAssemblerX87::PopCurrentPosition() {
+  Pop(edi);
+}
+
+
+void RegExpMacroAssemblerX87::PopRegister(int register_index) {
+  Pop(eax);
+  __ mov(register_location(register_index), eax);
+}
+
+
+void RegExpMacroAssemblerX87::PushBacktrack(Label* label) {
+  Push(Immediate::CodeRelativeOffset(label));
+  CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerX87::PushCurrentPosition() {
+  Push(edi);
+}
+
+
+void RegExpMacroAssemblerX87::PushRegister(int register_index,
+                                            StackCheckFlag check_stack_limit) {
+  __ mov(eax, register_location(register_index));
+  Push(eax);
+  if (check_stack_limit) CheckStackLimit();
+}
+
+
+void RegExpMacroAssemblerX87::ReadCurrentPositionFromRegister(int reg) {
+  __ mov(edi, register_location(reg));
+}
+
+
+void RegExpMacroAssemblerX87::ReadStackPointerFromRegister(int reg) {
+  __ mov(backtrack_stackpointer(), register_location(reg));
+  __ add(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
+}
+
+void RegExpMacroAssemblerX87::SetCurrentPositionFromEnd(int by)  {
+  Label after_position;
+  __ cmp(edi, -by * char_size());
+  __ j(greater_equal, &after_position, Label::kNear);
+  __ mov(edi, -by * char_size());
+  // On RegExp code entry (where this operation is used), the character before
+  // the current position is expected to be already loaded.
+  // We have advanced the position, so it's safe to read backwards.
+  LoadCurrentCharacterUnchecked(-1, 1);
+  __ bind(&after_position);
+}
+
+
+void RegExpMacroAssemblerX87::SetRegister(int register_index, int to) {
+  DCHECK(register_index >= num_saved_registers_);  // Reserved for positions!
+  __ mov(register_location(register_index), Immediate(to));
+}
+
+
+bool RegExpMacroAssemblerX87::Succeed() {
+  __ jmp(&success_label_);
+  return global();
+}
+
+
+void RegExpMacroAssemblerX87::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 RegExpMacroAssemblerX87::ClearRegisters(int reg_from, int reg_to) {
+  DCHECK(reg_from <= reg_to);
+  __ mov(eax, Operand(ebp, kStringStartMinusOne));
+  for (int reg = reg_from; reg <= reg_to; reg++) {
+    __ mov(register_location(reg), eax);
+  }
+}
+
+
+void RegExpMacroAssemblerX87::WriteStackPointerToRegister(int reg) {
+  __ mov(eax, backtrack_stackpointer());
+  __ sub(eax, Operand(ebp, kStackHighEnd));
+  __ mov(register_location(reg), eax);
+}
+
+
+// Private methods:
+
+void RegExpMacroAssemblerX87::CallCheckStackGuardState(Register scratch) {
+  static const int num_arguments = 3;
+  __ PrepareCallCFunction(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);
+  ExternalReference check_stack_guard =
+      ExternalReference::re_check_stack_guard_state(isolate());
+  __ CallCFunction(check_stack_guard, 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));
+}
+
+
+template <typename T>
+static T* frame_entry_address(Address re_frame, int frame_offset) {
+  return reinterpret_cast<T*>(re_frame + frame_offset);
+}
+
+
+int RegExpMacroAssemblerX87::CheckStackGuardState(Address* return_address,
+                                                   Code* re_code,
+                                                   Address re_frame) {
+  return NativeRegExpMacroAssembler::CheckStackGuardState(
+      frame_entry<Isolate*>(re_frame, kIsolate),
+      frame_entry<int>(re_frame, kStartIndex),
+      frame_entry<int>(re_frame, kDirectCall) == 1, return_address, re_code,
+      frame_entry_address<String*>(re_frame, kInputString),
+      frame_entry_address<const byte*>(re_frame, kInputStart),
+      frame_entry_address<const byte*>(re_frame, kInputEnd));
+}
+
+
+Operand RegExpMacroAssemblerX87::register_location(int register_index) {
+  DCHECK(register_index < (1<<30));
+  if (num_registers_ <= register_index) {
+    num_registers_ = register_index + 1;
+  }
+  return Operand(ebp, kRegisterZero - register_index * kPointerSize);
+}
+
+
+void RegExpMacroAssemblerX87::CheckPosition(int cp_offset,
+                                             Label* on_outside_input) {
+  if (cp_offset >= 0) {
+    __ cmp(edi, -cp_offset * char_size());
+    BranchOrBacktrack(greater_equal, on_outside_input);
+  } else {
+    __ lea(eax, Operand(edi, cp_offset * char_size()));
+    __ cmp(eax, Operand(ebp, kStringStartMinusOne));
+    BranchOrBacktrack(less_equal, on_outside_input);
+  }
+}
+
+
+void RegExpMacroAssemblerX87::BranchOrBacktrack(Condition condition,
+                                                 Label* to) {
+  if (condition < 0) {  // No condition
+    if (to == NULL) {
+      Backtrack();
+      return;
+    }
+    __ jmp(to);
+    return;
+  }
+  if (to == NULL) {
+    __ j(condition, &backtrack_label_);
+    return;
+  }
+  __ j(condition, to);
+}
+
+
+void RegExpMacroAssemblerX87::SafeCall(Label* to) {
+  Label return_to;
+  __ push(Immediate::CodeRelativeOffset(&return_to));
+  __ jmp(to);
+  __ bind(&return_to);
+}
+
+
+void RegExpMacroAssemblerX87::SafeReturn() {
+  __ pop(ebx);
+  __ add(ebx, Immediate(masm_->CodeObject()));
+  __ jmp(ebx);
+}
+
+
+void RegExpMacroAssemblerX87::SafeCallTarget(Label* name) {
+  __ bind(name);
+}
+
+
+void RegExpMacroAssemblerX87::Push(Register source) {
+  DCHECK(!source.is(backtrack_stackpointer()));
+  // Notice: This updates flags, unlike normal Push.
+  __ sub(backtrack_stackpointer(), Immediate(kPointerSize));
+  __ mov(Operand(backtrack_stackpointer(), 0), source);
+}
+
+
+void RegExpMacroAssemblerX87::Push(Immediate value) {
+  // Notice: This updates flags, unlike normal Push.
+  __ sub(backtrack_stackpointer(), Immediate(kPointerSize));
+  __ mov(Operand(backtrack_stackpointer(), 0), value);
+}
+
+
+void RegExpMacroAssemblerX87::Pop(Register target) {
+  DCHECK(!target.is(backtrack_stackpointer()));
+  __ mov(target, Operand(backtrack_stackpointer(), 0));
+  // Notice: This updates flags, unlike normal Pop.
+  __ add(backtrack_stackpointer(), Immediate(kPointerSize));
+}
+
+
+void RegExpMacroAssemblerX87::CheckPreemption() {
+  // Check for preemption.
+  Label no_preempt;
+  ExternalReference stack_limit =
+      ExternalReference::address_of_stack_limit(isolate());
+  __ cmp(esp, Operand::StaticVariable(stack_limit));
+  __ j(above, &no_preempt);
+
+  SafeCall(&check_preempt_label_);
+
+  __ bind(&no_preempt);
+}
+
+
+void RegExpMacroAssemblerX87::CheckStackLimit() {
+  Label no_stack_overflow;
+  ExternalReference stack_limit =
+      ExternalReference::address_of_regexp_stack_limit(isolate());
+  __ cmp(backtrack_stackpointer(), Operand::StaticVariable(stack_limit));
+  __ j(above, &no_stack_overflow);
+
+  SafeCall(&stack_overflow_label_);
+
+  __ bind(&no_stack_overflow);
+}
+
+
+void RegExpMacroAssemblerX87::LoadCurrentCharacterUnchecked(int cp_offset,
+                                                             int characters) {
+  if (mode_ == LATIN1) {
+    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 {
+      DCHECK(characters == 1);
+      __ movzx_b(current_character(), Operand(esi, edi, times_1, cp_offset));
+    }
+  } else {
+    DCHECK(mode_ == UC16);
+    if (characters == 2) {
+      __ mov(current_character(),
+             Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
+    } else {
+      DCHECK(characters == 1);
+      __ movzx_w(current_character(),
+                 Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
+    }
+  }
+}
+
+
+#undef __
+
+#endif  // V8_INTERPRETED_REGEXP
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_X87