diff --git a/src/regexp/s390/regexp-macro-assembler-s390.cc b/src/regexp/s390/regexp-macro-assembler-s390.cc
new file mode 100644
index 0000000..9dac534
--- /dev/null
+++ b/src/regexp/s390/regexp-macro-assembler-s390.cc
@@ -0,0 +1,1256 @@
+// Copyright 2015 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.
+
+#include "src/v8.h"
+
+#if V8_TARGET_ARCH_S390
+
+#include "src/base/bits.h"
+#include "src/code-stubs.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/regexp/s390/regexp-macro-assembler-s390.h"
+#include "src/unicode.h"
+
+namespace v8 {
+namespace internal {
+
+#ifndef V8_INTERPRETED_REGEXP
+/*
+ * This assembler uses the following register assignment convention
+ * - r6: Temporarily stores the index of capture start after a matching pass
+ *        for a global regexp.
+ * - r7: Pointer to current code object (Code*) including heap object tag.
+ * - r8: Current position in input, as negative offset from end of string.
+ *        Please notice that this is the byte offset, not the character offset!
+ * - r9: Currently loaded character. Must be loaded using
+ *        LoadCurrentCharacter before using any of the dispatch methods.
+ * - r13: Points to tip of backtrack stack
+ * - 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.
+ * - r15/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:
+ *  - fp[112] Isolate* isolate   (address of the current isolate)
+ *  - fp[108] secondary link/return address used by native call.
+ *  - fp[104] direct_call        (if 1, direct call from JavaScript code,
+ *                                if 0, call through the runtime system).
+ *  - fp[100] stack_area_base    (high end of the memory area to use as
+ *                                backtracking stack).
+ *  - fp[96]  capture array size (may fit multiple sets of matches)
+ *  - fp[0..96] zLinux ABI register saving area
+ *  --- sp when called ---
+ *  --- frame pointer ----
+ *  - fp[-4]  direct_call        (if 1, direct call from JavaScript code,
+ *                                if 0, call through the runtime system).
+ *  - fp[-8]  stack_area_base    (high end of the memory area to use as
+ *                                backtracking stack).
+ *  - fp[-12] capture array size (may fit multiple sets of matches)
+ *  - fp[-16] int* capture_array (int[num_saved_registers_], for output).
+ *  - fp[-20] end of input       (address of end of string).
+ *  - fp[-24] start of input     (address of first character in string).
+ *  - fp[-28] start index        (character index of start).
+ *  - fp[-32] void* input_string (location of a handle containing the string).
+ *  - fp[-36] success counter    (only for global regexps to count matches).
+ *  - fp[-40] Offset of location before start of input (effectively character
+ *            string start - 1). Used to initialize capture registers to a
+ *            non-position.
+ *  - fp[-44] At start (if 1, we are starting at the start of the
+ *    string, otherwise 0)
+ *  - fp[-48] 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 and the remaining arguments are passed in registers, e.g. 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,
+ *              byte* stack_area_base,
+ *              Address secondary_return_address,  // Only used by native call.
+ *              bool direct_call = false)
+ * The call is performed by NativeRegExpMacroAssembler::Execute()
+ * (in regexp-macro-assembler.cc) via the CALL_GENERATED_REGEXP_CODE macro
+ * in s390/simulator-s390.h.
+ * When calling as a non-direct call (i.e., from C++ code), the return address
+ * area is overwritten with the LR register by the RegExp code. When doing a
+ * direct call from generated code, the return address is placed there by
+ * the calling code, as in a normal exit frame.
+ */
+
+#define __ ACCESS_MASM(masm_)
+
+RegExpMacroAssemblerS390::RegExpMacroAssemblerS390(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_(),
+      internal_failure_label_() {
+  DCHECK_EQ(0, registers_to_save % 2);
+
+  __ b(&entry_label_);  // We'll write the entry code later.
+  // If the code gets too big or corrupted, an internal exception will be
+  // raised, and we will exit right away.
+  __ bind(&internal_failure_label_);
+  __ LoadImmP(r2, Operand(FAILURE));
+  __ Ret();
+  __ bind(&start_label_);  // And then continue from here.
+}
+
+RegExpMacroAssemblerS390::~RegExpMacroAssemblerS390() {
+  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();
+  internal_failure_label_.Unuse();
+}
+
+int RegExpMacroAssemblerS390::stack_limit_slack() {
+  return RegExpStack::kStackLimitSlack;
+}
+
+void RegExpMacroAssemblerS390::AdvanceCurrentPosition(int by) {
+  if (by != 0) {
+    __ AddP(current_input_offset(), Operand(by * char_size()));
+  }
+}
+
+void RegExpMacroAssemblerS390::AdvanceRegister(int reg, int by) {
+  DCHECK(reg >= 0);
+  DCHECK(reg < num_registers_);
+  if (by != 0) {
+    if (CpuFeatures::IsSupported(GENERAL_INSTR_EXT) && is_int8(by)) {
+      __ AddMI(register_location(reg), Operand(by));
+    } else {
+      __ LoadP(r2, register_location(reg), r0);
+      __ mov(r0, Operand(by));
+      __ AddRR(r2, r0);
+      __ StoreP(r2, register_location(reg));
+    }
+  }
+}
+
+void RegExpMacroAssemblerS390::Backtrack() {
+  CheckPreemption();
+  // Pop Code* offset from backtrack stack, add Code* and jump to location.
+  Pop(r2);
+  __ AddP(r2, code_pointer());
+  __ b(r2);
+}
+
+void RegExpMacroAssemblerS390::Bind(Label* label) { __ bind(label); }
+
+void RegExpMacroAssemblerS390::CheckCharacter(uint32_t c, Label* on_equal) {
+  __ CmpLogicalP(current_character(), Operand(c));
+  BranchOrBacktrack(eq, on_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckCharacterGT(uc16 limit, Label* on_greater) {
+  __ CmpLogicalP(current_character(), Operand(limit));
+  BranchOrBacktrack(gt, on_greater);
+}
+
+void RegExpMacroAssemblerS390::CheckAtStart(Label* on_at_start) {
+  __ LoadP(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
+  __ AddP(r2, current_input_offset(), Operand(-char_size()));
+  __ CmpP(r2, r3);
+  BranchOrBacktrack(eq, on_at_start);
+}
+
+void RegExpMacroAssemblerS390::CheckNotAtStart(int cp_offset,
+                                               Label* on_not_at_start) {
+  __ LoadP(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
+  __ AddP(r2, current_input_offset(),
+          Operand(-char_size() + cp_offset * char_size()));
+  __ CmpP(r2, r3);
+  BranchOrBacktrack(ne, on_not_at_start);
+}
+
+void RegExpMacroAssemblerS390::CheckCharacterLT(uc16 limit, Label* on_less) {
+  __ CmpLogicalP(current_character(), Operand(limit));
+  BranchOrBacktrack(lt, on_less);
+}
+
+void RegExpMacroAssemblerS390::CheckGreedyLoop(Label* on_equal) {
+  Label backtrack_non_equal;
+  __ CmpP(current_input_offset(), MemOperand(backtrack_stackpointer(), 0));
+  __ bne(&backtrack_non_equal);
+  __ AddP(backtrack_stackpointer(), Operand(kPointerSize));
+
+  BranchOrBacktrack(al, on_equal);
+  __ bind(&backtrack_non_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckNotBackReferenceIgnoreCase(
+    int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
+  Label fallthrough;
+  __ LoadP(r2, register_location(start_reg));      // Index of start of
+                                                   // capture
+  __ LoadP(r3, register_location(start_reg + 1));  // Index of end
+  __ SubP(r3, r3, r2);
+
+  // 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.
+  __ beq(&fallthrough);
+
+  // Check that there are enough characters left in the input.
+  if (read_backward) {
+    __ LoadP(r5, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ AddP(r5, r5, r3);
+    __ CmpP(current_input_offset(), r5);
+    BranchOrBacktrack(le, on_no_match);
+  } else {
+    __ AddP(r0, r3, current_input_offset());
+    BranchOrBacktrack(gt, on_no_match);
+  }
+
+  if (mode_ == LATIN1) {
+    Label success;
+    Label fail;
+    Label loop_check;
+
+    // r2 - offset of start of capture
+    // r3 - length of capture
+    __ AddP(r2, end_of_input_address());
+    __ AddP(r4, current_input_offset(), end_of_input_address());
+    if (read_backward) {
+      __ SubP(r4, r4, r3);  // Offset by length when matching backwards.
+    }
+    __ mov(r1, Operand::Zero());
+
+    // r1 - Loop index
+    // r2 - Address of start of capture.
+    // r4 - Address of current input position.
+
+    Label loop;
+    __ bind(&loop);
+    __ LoadlB(r5, MemOperand(r2, r1));
+    __ LoadlB(r6, MemOperand(r4, r1));
+
+    __ CmpP(r6, r5);
+    __ beq(&loop_check);
+
+    // Mismatch, try case-insensitive match (converting letters to lower-case).
+    __ Or(r5, Operand(0x20));  // Convert capture character to lower-case.
+    __ Or(r6, Operand(0x20));  // Also convert input character.
+    __ CmpP(r6, r5);
+    __ bne(&fail);
+    __ SubP(r5, Operand('a'));
+    __ CmpLogicalP(r5, Operand('z' - 'a'));  // Is r5 a lowercase letter?
+    __ ble(&loop_check);                     // In range 'a'-'z'.
+    // Latin-1: Check for values in range [224,254] but not 247.
+    __ SubP(r5, Operand(224 - 'a'));
+    __ CmpLogicalP(r5, Operand(254 - 224));
+    __ bgt(&fail);                           // Weren't Latin-1 letters.
+    __ CmpLogicalP(r5, Operand(247 - 224));  // Check for 247.
+    __ beq(&fail);
+
+    __ bind(&loop_check);
+    __ la(r1, MemOperand(r1, char_size()));
+    __ CmpP(r1, r3);
+    __ blt(&loop);
+    __ b(&success);
+
+    __ bind(&fail);
+    BranchOrBacktrack(al, on_no_match);
+
+    __ bind(&success);
+    // Compute new value of character position after the matched part.
+    __ SubP(current_input_offset(), r4, end_of_input_address());
+    if (read_backward) {
+      __ LoadP(r2, register_location(start_reg));  // Index of start of capture
+      __ LoadP(r3,
+               register_location(start_reg + 1));  // Index of end of capture
+      __ AddP(current_input_offset(), current_input_offset(), r2);
+      __ SubP(current_input_offset(), current_input_offset(), r3);
+    }
+    __ AddP(current_input_offset(), r1);
+  } else {
+    DCHECK(mode_ == UC16);
+    int argument_count = 4;
+    __ PrepareCallCFunction(argument_count, r4);
+
+    // r2 - offset of start of capture
+    // r3 - length of capture
+
+    // Put arguments into arguments registers.
+    // Parameters are
+    //   r2: Address byte_offset1 - Address captured substring's start.
+    //   r3: Address byte_offset2 - Address of current character position.
+    //   r4: size_t byte_length - length of capture in bytes(!)
+    //   r5: Isolate* isolate or 0 if unicode flag.
+
+    // Address of start of capture.
+    __ AddP(r2, end_of_input_address());
+    // Length of capture.
+    __ LoadRR(r4, r3);
+    // Save length in callee-save register for use on return.
+    __ LoadRR(r6, r3);
+    // Address of current input position.
+    __ AddP(r3, current_input_offset(), end_of_input_address());
+    if (read_backward) {
+      __ SubP(r3, r3, r6);
+    }
+// Isolate.
+#ifdef V8_I18N_SUPPORT
+    if (unicode) {
+      __ LoadImmP(r5, Operand::Zero());
+    } else  // NOLINT
+#endif      // V8_I18N_SUPPORT
+    {
+      __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
+    }
+
+    {
+      AllowExternalCallThatCantCauseGC scope(masm_);
+      ExternalReference function =
+          ExternalReference::re_case_insensitive_compare_uc16(isolate());
+      __ CallCFunction(function, argument_count);
+    }
+
+    // Check if function returned non-zero for success or zero for failure.
+    __ CmpP(r2, Operand::Zero());
+    BranchOrBacktrack(eq, on_no_match);
+
+    // On success, advance position by length of capture.
+    if (read_backward) {
+      __ SubP(current_input_offset(), current_input_offset(), r6);
+    } else {
+      __ AddP(current_input_offset(), current_input_offset(), r6);
+    }
+  }
+
+  __ bind(&fallthrough);
+}
+
+void RegExpMacroAssemblerS390::CheckNotBackReference(int start_reg,
+                                                     bool read_backward,
+                                                     Label* on_no_match) {
+  Label fallthrough;
+  Label success;
+
+  // Find length of back-referenced capture.
+  __ LoadP(r2, register_location(start_reg));
+  __ LoadP(r3, register_location(start_reg + 1));
+  __ SubP(r3, r3, r2);  // 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.
+  __ beq(&fallthrough);
+
+  // Check that there are enough characters left in the input.
+  if (read_backward) {
+    __ LoadP(r5, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ AddP(r5, r5, r3);
+    __ CmpP(current_input_offset(), r5);
+    BranchOrBacktrack(lt, on_no_match);
+  } else {
+    __ AddP(r0, r3, current_input_offset());
+    BranchOrBacktrack(gt, on_no_match, cr0);
+  }
+
+  // r2 - offset of start of capture
+  // r3 - length of capture
+  __ la(r2, MemOperand(r2, end_of_input_address()));
+  __ la(r4, MemOperand(current_input_offset(), end_of_input_address()));
+  if (read_backward) {
+    __ SubP(r4, r4, r3);  // Offset by length when matching backwards.
+  }
+  __ mov(r1, Operand::Zero());
+
+  Label loop;
+  __ bind(&loop);
+  if (mode_ == LATIN1) {
+    __ LoadlB(r5, MemOperand(r2, r1));
+    __ LoadlB(r6, MemOperand(r4, r1));
+  } else {
+    DCHECK(mode_ == UC16);
+    __ LoadLogicalHalfWordP(r5, MemOperand(r2, r1));
+    __ LoadLogicalHalfWordP(r6, MemOperand(r4, r1));
+  }
+  __ la(r1, MemOperand(r1, char_size()));
+  __ CmpP(r5, r6);
+  BranchOrBacktrack(ne, on_no_match);
+  __ CmpP(r1, r3);
+  __ blt(&loop);
+
+  // Move current character position to position after match.
+  __ SubP(current_input_offset(), r4, end_of_input_address());
+  if (read_backward) {
+    __ LoadP(r2, register_location(start_reg));  // Index of start of capture
+    __ LoadP(r3, register_location(start_reg + 1));  // Index of end of capture
+    __ AddP(current_input_offset(), current_input_offset(), r2);
+    __ SubP(current_input_offset(), current_input_offset(), r3);
+  }
+  __ AddP(current_input_offset(), r1);
+
+  __ bind(&fallthrough);
+}
+
+void RegExpMacroAssemblerS390::CheckNotCharacter(unsigned c,
+                                                 Label* on_not_equal) {
+  __ CmpLogicalP(current_character(), Operand(c));
+  BranchOrBacktrack(ne, on_not_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckCharacterAfterAnd(uint32_t c, uint32_t mask,
+                                                      Label* on_equal) {
+  __ AndP(r2, current_character(), Operand(mask));
+  if (c != 0) {
+    __ CmpLogicalP(r2, Operand(c));
+  }
+  BranchOrBacktrack(eq, on_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckNotCharacterAfterAnd(unsigned c,
+                                                         unsigned mask,
+                                                         Label* on_not_equal) {
+  __ AndP(r2, current_character(), Operand(mask));
+  if (c != 0) {
+    __ CmpLogicalP(r2, Operand(c));
+  }
+  BranchOrBacktrack(ne, on_not_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckNotCharacterAfterMinusAnd(
+    uc16 c, uc16 minus, uc16 mask, Label* on_not_equal) {
+  DCHECK(minus < String::kMaxUtf16CodeUnit);
+  __ lay(r2, MemOperand(current_character(), -minus));
+  __ And(r2, Operand(mask));
+  if (c != 0) {
+    __ CmpLogicalP(r2, Operand(c));
+  }
+  BranchOrBacktrack(ne, on_not_equal);
+}
+
+void RegExpMacroAssemblerS390::CheckCharacterInRange(uc16 from, uc16 to,
+                                                     Label* on_in_range) {
+  __ lay(r2, MemOperand(current_character(), -from));
+  __ CmpLogicalP(r2, Operand(to - from));
+  BranchOrBacktrack(le, on_in_range);  // Unsigned lower-or-same condition.
+}
+
+void RegExpMacroAssemblerS390::CheckCharacterNotInRange(
+    uc16 from, uc16 to, Label* on_not_in_range) {
+  __ lay(r2, MemOperand(current_character(), -from));
+  __ CmpLogicalP(r2, Operand(to - from));
+  BranchOrBacktrack(gt, on_not_in_range);  // Unsigned higher condition.
+}
+
+void RegExpMacroAssemblerS390::CheckBitInTable(Handle<ByteArray> table,
+                                               Label* on_bit_set) {
+  __ mov(r2, Operand(table));
+  Register index = current_character();
+  if (mode_ != LATIN1 || kTableMask != String::kMaxOneByteCharCode) {
+    __ AndP(r3, current_character(), Operand(kTableSize - 1));
+    index = r3;
+  }
+  __ LoadlB(r2,
+            MemOperand(r2, index, (ByteArray::kHeaderSize - kHeapObjectTag)));
+  __ CmpP(r2, Operand::Zero());
+  BranchOrBacktrack(ne, on_bit_set);
+}
+
+bool RegExpMacroAssemblerS390::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;
+        __ CmpP(current_character(), Operand(' '));
+        __ beq(&success);
+        // Check range 0x09..0x0d
+        __ SubP(r2, current_character(), Operand('\t'));
+        __ CmpLogicalP(r2, Operand('\r' - '\t'));
+        __ ble(&success);
+        // \u00a0 (NBSP).
+        __ CmpLogicalP(r2, Operand(0x00a0 - '\t'));
+        BranchOrBacktrack(ne, 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')
+      __ SubP(r2, current_character(), Operand('0'));
+      __ CmpLogicalP(r2, Operand('9' - '0'));
+      BranchOrBacktrack(gt, on_no_match);
+      return true;
+    case 'D':
+      // Match non ASCII-digits
+      __ SubP(r2, current_character(), Operand('0'));
+      __ CmpLogicalP(r2, Operand('9' - '0'));
+      BranchOrBacktrack(le, on_no_match);
+      return true;
+    case '.': {
+      // Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
+      __ XorP(r2, current_character(), Operand(0x01));
+      // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+      __ SubP(r2, Operand(0x0b));
+      __ CmpLogicalP(r2, Operand(0x0c - 0x0b));
+      BranchOrBacktrack(le, 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.
+        __ SubP(r2, Operand(0x2028 - 0x0b));
+        __ CmpLogicalP(r2, Operand(1));
+        BranchOrBacktrack(le, on_no_match);
+      }
+      return true;
+    }
+    case 'n': {
+      // Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
+      __ XorP(r2, current_character(), Operand(0x01));
+      // See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
+      __ SubP(r2, Operand(0x0b));
+      __ CmpLogicalP(r2, Operand(0x0c - 0x0b));
+      if (mode_ == LATIN1) {
+        BranchOrBacktrack(gt, on_no_match);
+      } else {
+        Label done;
+        __ ble(&done);
+        // Compare original value to 0x2028 and 0x2029, using the already
+        // computed (current_char ^ 0x01 - 0x0b). I.e., check for
+        // 0x201d (0x2028 - 0x0b) or 0x201e.
+        __ SubP(r2, Operand(0x2028 - 0x0b));
+        __ CmpLogicalP(r2, Operand(1));
+        BranchOrBacktrack(gt, on_no_match);
+        __ bind(&done);
+      }
+      return true;
+    }
+    case 'w': {
+      if (mode_ != LATIN1) {
+        // Table is 1256 entries, so all LATIN1 characters can be tested.
+        __ CmpP(current_character(), Operand('z'));
+        BranchOrBacktrack(gt, on_no_match);
+      }
+      ExternalReference map = ExternalReference::re_word_character_map();
+      __ mov(r2, Operand(map));
+      __ LoadlB(r2, MemOperand(r2, current_character()));
+      __ CmpLogicalP(r2, Operand::Zero());
+      BranchOrBacktrack(eq, on_no_match);
+      return true;
+    }
+    case 'W': {
+      Label done;
+      if (mode_ != LATIN1) {
+        // Table is 256 entries, so all LATIN characters can be tested.
+        __ CmpLogicalP(current_character(), Operand('z'));
+        __ bgt(&done);
+      }
+      ExternalReference map = ExternalReference::re_word_character_map();
+      __ mov(r2, Operand(map));
+      __ LoadlB(r2, MemOperand(r2, current_character()));
+      __ CmpLogicalP(r2, Operand::Zero());
+      BranchOrBacktrack(ne, on_no_match);
+      if (mode_ != LATIN1) {
+        __ bind(&done);
+      }
+      return true;
+    }
+    case '*':
+      // Match any character.
+      return true;
+    // No custom implementation (yet): s(UC16), S(UC16).
+    default:
+      return false;
+  }
+}
+
+void RegExpMacroAssemblerS390::Fail() {
+  __ LoadImmP(r2, Operand(FAILURE));
+  __ b(&exit_label_);
+}
+
+Handle<HeapObject> RegExpMacroAssemblerS390::GetCode(Handle<String> source) {
+  Label return_r2;
+
+  // 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 is generated.
+  FrameScope scope(masm_, StackFrame::MANUAL);
+
+  // Ensure register assigments are consistent with callee save mask
+  DCHECK(r6.bit() & kRegExpCalleeSaved);
+  DCHECK(code_pointer().bit() & kRegExpCalleeSaved);
+  DCHECK(current_input_offset().bit() & kRegExpCalleeSaved);
+  DCHECK(current_character().bit() & kRegExpCalleeSaved);
+  DCHECK(backtrack_stackpointer().bit() & kRegExpCalleeSaved);
+  DCHECK(end_of_input_address().bit() & kRegExpCalleeSaved);
+  DCHECK(frame_pointer().bit() & kRegExpCalleeSaved);
+
+  // zLinux ABI
+  //    Incoming parameters:
+  //          r2: input_string
+  //          r3: start_index
+  //          r4: start addr
+  //          r5: end addr
+  //          r6: capture output arrray
+  //    Requires us to save the callee-preserved registers r6-r13
+  //    General convention is to also save r14 (return addr) and
+  //    sp/r15 as well in a single STM/STMG
+  __ StoreMultipleP(r6, sp, MemOperand(sp, 6 * kPointerSize));
+
+  // Load stack parameters from caller stack frame
+  __ LoadMultipleP(r7, r9,
+                   MemOperand(sp, kStackFrameExtraParamSlot * kPointerSize));
+  // r7 = capture array size
+  // r8 = stack area base
+  // r9 = direct call
+
+  // Actually emit code to start a new stack frame.
+  // Push arguments
+  // Save callee-save registers.
+  // Start new stack frame.
+  // Store link register in existing stack-cell.
+  // Order here should correspond to order of offset constants in header file.
+  //
+  // Set frame pointer in space for it if this is not a direct call
+  // from generated code.
+  __ LoadRR(frame_pointer(), sp);
+  __ lay(sp, MemOperand(sp, -10 * kPointerSize));
+  __ mov(r1, Operand::Zero());  // success counter
+  __ LoadRR(r0, r1);            // offset of location
+  __ StoreMultipleP(r0, r9, MemOperand(sp, 0));
+
+  // 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(r2, Operand(stack_limit));
+  __ LoadP(r2, MemOperand(r2));
+  __ SubP(r2, sp, r2);
+  // Handle it if the stack pointer is already below the stack limit.
+  __ ble(&stack_limit_hit);
+  // Check if there is room for the variable number of registers above
+  // the stack limit.
+  __ CmpLogicalP(r2, Operand(num_registers_ * kPointerSize));
+  __ bge(&stack_ok);
+  // Exit with OutOfMemory exception. There is not enough space on the stack
+  // for our working registers.
+  __ mov(r2, Operand(EXCEPTION));
+  __ b(&return_r2);
+
+  __ bind(&stack_limit_hit);
+  CallCheckStackGuardState(r2);
+  __ CmpP(r2, Operand::Zero());
+  // If returned value is non-zero, we exit with the returned value as result.
+  __ bne(&return_r2);
+
+  __ bind(&stack_ok);
+
+  // Allocate space on stack for registers.
+  __ lay(sp, MemOperand(sp, (-num_registers_ * kPointerSize)));
+  // Load string end.
+  __ LoadP(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
+  // Load input start.
+  __ LoadP(r4, MemOperand(frame_pointer(), kInputStart));
+  // Find negative length (offset of start relative to end).
+  __ SubP(current_input_offset(), r4, end_of_input_address());
+  __ LoadP(r3, MemOperand(frame_pointer(), kStartIndex));
+  // Set r1 to address of char before start of the input string
+  // (effectively string position -1).
+  __ LoadRR(r1, r4);
+  __ SubP(r1, current_input_offset(), Operand(char_size()));
+  if (mode_ == UC16) {
+    __ ShiftLeftP(r0, r3, Operand(1));
+    __ SubP(r1, r1, r0);
+  } else {
+    __ SubP(r1, r1, r3);
+  }
+  // Store this value in a local variable, for use when clearing
+  // position registers.
+  __ StoreP(r1, MemOperand(frame_pointer(), kStringStartMinusOne));
+
+  // Initialize code pointer register
+  __ mov(code_pointer(), Operand(masm_->CodeObject()));
+
+  Label load_char_start_regexp, start_regexp;
+  // Load newline if index is at start, previous character otherwise.
+  __ CmpP(r3, Operand::Zero());
+  __ bne(&load_char_start_regexp);
+  __ mov(current_character(), Operand('\n'));
+  __ b(&start_regexp);
+
+  // 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
+    if (num_saved_registers_ > 8) {
+      // One slot beyond address of register 0.
+      __ lay(r3, MemOperand(frame_pointer(), kRegisterZero + kPointerSize));
+      __ LoadImmP(r4, Operand(num_saved_registers_));
+      Label init_loop;
+      __ bind(&init_loop);
+      __ StoreP(r1, MemOperand(r3, -kPointerSize));
+      __ lay(r3, MemOperand(r3, -kPointerSize));
+      __ BranchOnCount(r4, &init_loop);
+    } else {
+      for (int i = 0; i < num_saved_registers_; i++) {
+        __ StoreP(r1, register_location(i));
+      }
+    }
+  }
+
+  // Initialize backtrack stack pointer.
+  __ LoadP(backtrack_stackpointer(),
+           MemOperand(frame_pointer(), kStackHighEnd));
+
+  __ b(&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
+      __ LoadP(r0, MemOperand(frame_pointer(), kInputStart));
+      __ LoadP(r2, MemOperand(frame_pointer(), kRegisterOutput));
+      __ LoadP(r4, MemOperand(frame_pointer(), kStartIndex));
+      __ SubP(r0, end_of_input_address(), r0);
+      // r0 is length of input in bytes.
+      if (mode_ == UC16) {
+        __ ShiftRightP(r0, r0, Operand(1));
+      }
+      // r0 is length of input in characters.
+      __ AddP(r0, r4);
+      // r0 is length of string in characters.
+
+      DCHECK_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.
+      __ lay(r2, MemOperand(r2, num_saved_registers_ * kIntSize));
+      for (int i = 0; i < num_saved_registers_;) {
+        if (false && i < num_saved_registers_ - 4) {
+          // TODO(john.yan): Can be optimized by SIMD instructions
+          __ LoadMultipleP(r3, r6, register_location(i + 3));
+          if (mode_ == UC16) {
+            __ ShiftRightArithP(r3, r3, Operand(1));
+            __ ShiftRightArithP(r4, r4, Operand(1));
+            __ ShiftRightArithP(r5, r5, Operand(1));
+            __ ShiftRightArithP(r6, r6, Operand(1));
+          }
+          __ AddP(r3, r0);
+          __ AddP(r4, r0);
+          __ AddP(r5, r0);
+          __ AddP(r6, r0);
+          __ StoreW(r3,
+                    MemOperand(r2, -(num_saved_registers_ - i - 3) * kIntSize));
+          __ StoreW(r4,
+                    MemOperand(r2, -(num_saved_registers_ - i - 2) * kIntSize));
+          __ StoreW(r5,
+                    MemOperand(r2, -(num_saved_registers_ - i - 1) * kIntSize));
+          __ StoreW(r6, MemOperand(r2, -(num_saved_registers_ - i) * kIntSize));
+          i += 4;
+        } else {
+          __ LoadMultipleP(r3, r4, register_location(i + 1));
+          if (mode_ == UC16) {
+            __ ShiftRightArithP(r3, r3, Operand(1));
+            __ ShiftRightArithP(r4, r4, Operand(1));
+          }
+          __ AddP(r3, r0);
+          __ AddP(r4, r0);
+          __ StoreW(r3,
+                    MemOperand(r2, -(num_saved_registers_ - i - 1) * kIntSize));
+          __ StoreW(r4, MemOperand(r2, -(num_saved_registers_ - i) * kIntSize));
+          i += 2;
+        }
+      }
+      if (global_with_zero_length_check()) {
+        // Keep capture start in r6 for the zero-length check later.
+        __ LoadP(r6, register_location(0));
+      }
+    }
+
+    if (global()) {
+      // Restart matching if the regular expression is flagged as global.
+      __ LoadP(r2, MemOperand(frame_pointer(), kSuccessfulCaptures));
+      __ LoadP(r3, MemOperand(frame_pointer(), kNumOutputRegisters));
+      __ LoadP(r4, MemOperand(frame_pointer(), kRegisterOutput));
+      // Increment success counter.
+      __ AddP(r2, Operand(1));
+      __ StoreP(r2, MemOperand(frame_pointer(), kSuccessfulCaptures));
+      // Capture results have been stored, so the number of remaining global
+      // output registers is reduced by the number of stored captures.
+      __ SubP(r3, Operand(num_saved_registers_));
+      // Check whether we have enough room for another set of capture results.
+      __ CmpP(r3, Operand(num_saved_registers_));
+      __ blt(&return_r2);
+
+      __ StoreP(r3, MemOperand(frame_pointer(), kNumOutputRegisters));
+      // Advance the location for output.
+      __ AddP(r4, Operand(num_saved_registers_ * kIntSize));
+      __ StoreP(r4, MemOperand(frame_pointer(), kRegisterOutput));
+
+      // Prepare r2 to initialize registers with its value in the next run.
+      __ LoadP(r2, MemOperand(frame_pointer(), kStringStartMinusOne));
+
+      if (global_with_zero_length_check()) {
+        // Special case for zero-length matches.
+        // r6: capture start index
+        __ CmpP(current_input_offset(), r6);
+        // Not a zero-length match, restart.
+        __ bne(&load_char_start_regexp);
+        // Offset from the end is zero if we already reached the end.
+        __ CmpP(current_input_offset(), Operand::Zero());
+        __ beq(&exit_label_);
+        // Advance current position after a zero-length match.
+        Label advance;
+        __ bind(&advance);
+        __ AddP(current_input_offset(), Operand((mode_ == UC16) ? 2 : 1));
+        if (global_unicode()) CheckNotInSurrogatePair(0, &advance);
+      }
+
+      __ b(&load_char_start_regexp);
+    } else {
+      __ LoadImmP(r2, Operand(SUCCESS));
+    }
+  }
+
+  // Exit and return r2
+  __ bind(&exit_label_);
+  if (global()) {
+    __ LoadP(r2, MemOperand(frame_pointer(), kSuccessfulCaptures));
+  }
+
+  __ bind(&return_r2);
+  // Skip sp past regexp registers and local variables..
+  __ LoadRR(sp, frame_pointer());
+  // Restore registers r6..r15.
+  __ LoadMultipleP(r6, sp, MemOperand(sp, 6 * kPointerSize));
+
+  __ b(r14);
+
+  // 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(r2);
+    __ CmpP(r2, Operand::Zero());
+    // If returning non-zero, we should end execution with the given
+    // result as return value.
+    __ bne(&return_r2);
+
+    // String might have moved: Reload end of string from frame.
+    __ LoadP(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(), &stack_base)
+    static const int num_arguments = 3;
+    __ PrepareCallCFunction(num_arguments, r2);
+    __ LoadRR(r2, backtrack_stackpointer());
+    __ AddP(r3, frame_pointer(), Operand(kStackHighEnd));
+    __ mov(r4, Operand(ExternalReference::isolate_address(isolate())));
+    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.
+    __ CmpP(r2, Operand::Zero());
+    __ beq(&exit_with_exception);
+    // Otherwise use return value as new stack pointer.
+    __ LoadRR(backtrack_stackpointer(), r2);
+    // 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.
+    __ LoadImmP(r2, Operand(EXCEPTION));
+    __ b(&return_r2);
+  }
+
+  CodeDesc code_desc;
+  masm_->GetCode(&code_desc);
+  Handle<Code> code = isolate()->factory()->NewCode(
+      code_desc, Code::ComputeFlags(Code::REGEXP), masm_->CodeObject());
+  PROFILE(masm_->isolate(),
+          RegExpCodeCreateEvent(AbstractCode::cast(*code), *source));
+  return Handle<HeapObject>::cast(code);
+}
+
+void RegExpMacroAssemblerS390::GoTo(Label* to) { BranchOrBacktrack(al, to); }
+
+void RegExpMacroAssemblerS390::IfRegisterGE(int reg, int comparand,
+                                            Label* if_ge) {
+  __ LoadP(r2, register_location(reg), r0);
+  __ CmpP(r2, Operand(comparand));
+  BranchOrBacktrack(ge, if_ge);
+}
+
+void RegExpMacroAssemblerS390::IfRegisterLT(int reg, int comparand,
+                                            Label* if_lt) {
+  __ LoadP(r2, register_location(reg), r0);
+  __ CmpP(r2, Operand(comparand));
+  BranchOrBacktrack(lt, if_lt);
+}
+
+void RegExpMacroAssemblerS390::IfRegisterEqPos(int reg, Label* if_eq) {
+  __ LoadP(r2, register_location(reg), r0);
+  __ CmpP(r2, current_input_offset());
+  BranchOrBacktrack(eq, if_eq);
+}
+
+RegExpMacroAssembler::IrregexpImplementation
+RegExpMacroAssemblerS390::Implementation() {
+  return kS390Implementation;
+}
+
+void RegExpMacroAssemblerS390::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 RegExpMacroAssemblerS390::PopCurrentPosition() {
+  Pop(current_input_offset());
+}
+
+void RegExpMacroAssemblerS390::PopRegister(int register_index) {
+  Pop(r2);
+  __ StoreP(r2, register_location(register_index));
+}
+
+void RegExpMacroAssemblerS390::PushBacktrack(Label* label) {
+  if (label->is_bound()) {
+    int target = label->pos();
+    __ mov(r2, Operand(target + Code::kHeaderSize - kHeapObjectTag));
+  } else {
+    masm_->load_label_offset(r2, label);
+  }
+  Push(r2);
+  CheckStackLimit();
+}
+
+void RegExpMacroAssemblerS390::PushCurrentPosition() {
+  Push(current_input_offset());
+}
+
+void RegExpMacroAssemblerS390::PushRegister(int register_index,
+                                            StackCheckFlag check_stack_limit) {
+  __ LoadP(r2, register_location(register_index), r0);
+  Push(r2);
+  if (check_stack_limit) CheckStackLimit();
+}
+
+void RegExpMacroAssemblerS390::ReadCurrentPositionFromRegister(int reg) {
+  __ LoadP(current_input_offset(), register_location(reg), r0);
+}
+
+void RegExpMacroAssemblerS390::ReadStackPointerFromRegister(int reg) {
+  __ LoadP(backtrack_stackpointer(), register_location(reg), r0);
+  __ LoadP(r2, MemOperand(frame_pointer(), kStackHighEnd));
+  __ AddP(backtrack_stackpointer(), r2);
+}
+
+void RegExpMacroAssemblerS390::SetCurrentPositionFromEnd(int by) {
+  Label after_position;
+  __ CmpP(current_input_offset(), Operand(-by * char_size()));
+  __ bge(&after_position);
+  __ mov(current_input_offset(), Operand(-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 RegExpMacroAssemblerS390::SetRegister(int register_index, int to) {
+  DCHECK(register_index >= num_saved_registers_);  // Reserved for positions!
+  __ mov(r2, Operand(to));
+  __ StoreP(r2, register_location(register_index));
+}
+
+bool RegExpMacroAssemblerS390::Succeed() {
+  __ b(&success_label_);
+  return global();
+}
+
+void RegExpMacroAssemblerS390::WriteCurrentPositionToRegister(int reg,
+                                                              int cp_offset) {
+  if (cp_offset == 0) {
+    __ StoreP(current_input_offset(), register_location(reg));
+  } else {
+    __ AddP(r2, current_input_offset(), Operand(cp_offset * char_size()));
+    __ StoreP(r2, register_location(reg));
+  }
+}
+
+void RegExpMacroAssemblerS390::ClearRegisters(int reg_from, int reg_to) {
+  DCHECK(reg_from <= reg_to);
+  __ LoadP(r2, MemOperand(frame_pointer(), kStringStartMinusOne));
+  for (int reg = reg_from; reg <= reg_to; reg++) {
+    __ StoreP(r2, register_location(reg));
+  }
+}
+
+void RegExpMacroAssemblerS390::WriteStackPointerToRegister(int reg) {
+  __ LoadP(r3, MemOperand(frame_pointer(), kStackHighEnd));
+  __ SubP(r2, backtrack_stackpointer(), r3);
+  __ StoreP(r2, register_location(reg));
+}
+
+// Private methods:
+
+void RegExpMacroAssemblerS390::CallCheckStackGuardState(Register scratch) {
+  static const int num_arguments = 3;
+  __ PrepareCallCFunction(num_arguments, scratch);
+  // RegExp code frame pointer.
+  __ LoadRR(r4, frame_pointer());
+  // Code* of self.
+  __ mov(r3, Operand(masm_->CodeObject()));
+  // r2 becomes return address pointer.
+  __ lay(r2, MemOperand(sp, kStackFrameRASlot * kPointerSize));
+  ExternalReference stack_guard_check =
+      ExternalReference::re_check_stack_guard_state(isolate());
+  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) {
+  DCHECK(sizeof(T) == kPointerSize);
+#ifdef V8_TARGET_ARCH_S390X
+  return reinterpret_cast<T&>(Memory::uint64_at(re_frame + frame_offset));
+#else
+  return reinterpret_cast<T&>(Memory::uint32_at(re_frame + frame_offset));
+#endif
+}
+
+template <typename T>
+static T* frame_entry_address(Address re_frame, int frame_offset) {
+  return reinterpret_cast<T*>(re_frame + frame_offset);
+}
+
+int RegExpMacroAssemblerS390::CheckStackGuardState(Address* return_address,
+                                                   Code* re_code,
+                                                   Address re_frame) {
+  return NativeRegExpMacroAssembler::CheckStackGuardState(
+      frame_entry<Isolate*>(re_frame, kIsolate),
+      frame_entry<intptr_t>(re_frame, kStartIndex),
+      frame_entry<intptr_t>(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));
+}
+
+MemOperand RegExpMacroAssemblerS390::register_location(int register_index) {
+  DCHECK(register_index < (1 << 30));
+  if (num_registers_ <= register_index) {
+    num_registers_ = register_index + 1;
+  }
+  return MemOperand(frame_pointer(),
+                    kRegisterZero - register_index * kPointerSize);
+}
+
+void RegExpMacroAssemblerS390::CheckPosition(int cp_offset,
+                                             Label* on_outside_input) {
+  if (cp_offset >= 0) {
+    __ CmpP(current_input_offset(), Operand(-cp_offset * char_size()));
+    BranchOrBacktrack(ge, on_outside_input);
+  } else {
+    __ LoadP(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
+    __ AddP(r2, current_input_offset(), Operand(cp_offset * char_size()));
+    __ CmpP(r2, r3);
+    BranchOrBacktrack(le, on_outside_input);
+  }
+}
+
+void RegExpMacroAssemblerS390::BranchOrBacktrack(Condition condition, Label* to,
+                                                 CRegister cr) {
+  if (condition == al) {  // Unconditional.
+    if (to == NULL) {
+      Backtrack();
+      return;
+    }
+    __ b(to);
+    return;
+  }
+  if (to == NULL) {
+    __ b(condition, &backtrack_label_);
+    return;
+  }
+  __ b(condition, to);
+}
+
+void RegExpMacroAssemblerS390::SafeCall(Label* to, Condition cond,
+                                        CRegister cr) {
+  Label skip;
+  __ b(NegateCondition(cond), &skip);
+  __ b(r14, to);
+  __ bind(&skip);
+}
+
+void RegExpMacroAssemblerS390::SafeReturn() {
+  __ pop(r14);
+  __ mov(ip, Operand(masm_->CodeObject()));
+  __ AddP(r14, ip);
+  __ Ret();
+}
+
+void RegExpMacroAssemblerS390::SafeCallTarget(Label* name) {
+  __ bind(name);
+  __ CleanseP(r14);
+  __ LoadRR(r0, r14);
+  __ mov(ip, Operand(masm_->CodeObject()));
+  __ SubP(r0, r0, ip);
+  __ push(r0);
+}
+
+void RegExpMacroAssemblerS390::Push(Register source) {
+  DCHECK(!source.is(backtrack_stackpointer()));
+  __ lay(backtrack_stackpointer(),
+         MemOperand(backtrack_stackpointer(), -kPointerSize));
+  __ StoreP(source, MemOperand(backtrack_stackpointer()));
+}
+
+void RegExpMacroAssemblerS390::Pop(Register target) {
+  DCHECK(!target.is(backtrack_stackpointer()));
+  __ LoadP(target, MemOperand(backtrack_stackpointer()));
+  __ la(backtrack_stackpointer(),
+        MemOperand(backtrack_stackpointer(), kPointerSize));
+}
+
+void RegExpMacroAssemblerS390::CheckPreemption() {
+  // Check for preemption.
+  ExternalReference stack_limit =
+      ExternalReference::address_of_stack_limit(isolate());
+  __ mov(r2, Operand(stack_limit));
+  __ CmpLogicalP(sp, MemOperand(r2));
+  SafeCall(&check_preempt_label_, le);
+}
+
+void RegExpMacroAssemblerS390::CheckStackLimit() {
+  ExternalReference stack_limit =
+      ExternalReference::address_of_regexp_stack_limit(isolate());
+  __ mov(r2, Operand(stack_limit));
+  __ CmpLogicalP(backtrack_stackpointer(), MemOperand(r2));
+  SafeCall(&stack_overflow_label_, le);
+}
+
+void RegExpMacroAssemblerS390::CallCFunctionUsingStub(
+    ExternalReference function, int num_arguments) {
+  // Must pass all arguments in registers. The stub pushes on the stack.
+  DCHECK(num_arguments <= 8);
+  __ mov(code_pointer(), Operand(function));
+  Label ret;
+  __ larl(r14, &ret);
+  __ StoreP(r14, MemOperand(sp, kStackFrameRASlot * kPointerSize));
+  __ b(code_pointer());
+  __ bind(&ret);
+  if (base::OS::ActivationFrameAlignment() > kPointerSize) {
+    __ LoadP(sp, MemOperand(sp, (kNumRequiredStackFrameSlots * kPointerSize)));
+  } else {
+    __ la(sp, MemOperand(sp, (kNumRequiredStackFrameSlots * kPointerSize)));
+  }
+  __ mov(code_pointer(), Operand(masm_->CodeObject()));
+}
+
+bool RegExpMacroAssemblerS390::CanReadUnaligned() {
+  return CpuFeatures::IsSupported(UNALIGNED_ACCESSES) && !slow_safe();
+}
+
+void RegExpMacroAssemblerS390::LoadCurrentCharacterUnchecked(int cp_offset,
+                                                             int characters) {
+  DCHECK(characters == 1);
+  if (mode_ == LATIN1) {
+    __ LoadlB(current_character(),
+              MemOperand(current_input_offset(), end_of_input_address(),
+                         cp_offset * char_size()));
+  } else {
+    DCHECK(mode_ == UC16);
+    __ LoadLogicalHalfWordP(
+        current_character(),
+        MemOperand(current_input_offset(), end_of_input_address(),
+                   cp_offset * char_size()));
+  }
+}
+
+#undef __
+
+#endif  // V8_INTERPRETED_REGEXP
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_S390