diff --git a/src/ic/s390/ic-s390.cc b/src/ic/s390/ic-s390.cc
new file mode 100644
index 0000000..d4f2886
--- /dev/null
+++ b/src/ic/s390/ic-s390.cc
@@ -0,0 +1,897 @@
+// 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.
+
+#if V8_TARGET_ARCH_S390
+
+#include "src/ic/ic.h"
+#include "src/codegen.h"
+#include "src/ic/ic-compiler.h"
+#include "src/ic/stub-cache.h"
+
+namespace v8 {
+namespace internal {
+
+// ----------------------------------------------------------------------------
+// Static IC stub generators.
+//
+
+#define __ ACCESS_MASM(masm)
+
+static void GenerateGlobalInstanceTypeCheck(MacroAssembler* masm, Register type,
+                                            Label* global_object) {
+  // Register usage:
+  //   type: holds the receiver instance type on entry.
+  __ CmpP(type, Operand(JS_GLOBAL_OBJECT_TYPE));
+  __ beq(global_object);
+  __ CmpP(type, Operand(JS_GLOBAL_PROXY_TYPE));
+  __ beq(global_object);
+}
+
+// Helper function used from LoadIC GenerateNormal.
+//
+// elements: Property dictionary. It is not clobbered if a jump to the miss
+//           label is done.
+// name:     Property name. It is not clobbered if a jump to the miss label is
+//           done
+// result:   Register for the result. It is only updated if a jump to the miss
+//           label is not done. Can be the same as elements or name clobbering
+//           one of these in the case of not jumping to the miss label.
+// The two scratch registers need to be different from elements, name and
+// result.
+// The generated code assumes that the receiver has slow properties,
+// is not a global object and does not have interceptors.
+static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss,
+                                   Register elements, Register name,
+                                   Register result, Register scratch1,
+                                   Register scratch2) {
+  // Main use of the scratch registers.
+  // scratch1: Used as temporary and to hold the capacity of the property
+  //           dictionary.
+  // scratch2: Used as temporary.
+  Label done;
+
+  // Probe the dictionary.
+  NameDictionaryLookupStub::GeneratePositiveLookup(masm, miss, &done, elements,
+                                                   name, scratch1, scratch2);
+
+  // If probing finds an entry check that the value is a normal
+  // property.
+  __ bind(&done);  // scratch2 == elements + 4 * index
+  const int kElementsStartOffset =
+      NameDictionary::kHeaderSize +
+      NameDictionary::kElementsStartIndex * kPointerSize;
+  const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
+  __ LoadP(scratch1, FieldMemOperand(scratch2, kDetailsOffset));
+  __ LoadRR(r0, scratch2);
+  __ LoadSmiLiteral(scratch2, Smi::FromInt(PropertyDetails::TypeField::kMask));
+  __ AndP(scratch2, scratch1);
+  __ bne(miss);
+  __ LoadRR(scratch2, r0);
+
+  // Get the value at the masked, scaled index and return.
+  __ LoadP(result,
+           FieldMemOperand(scratch2, kElementsStartOffset + 1 * kPointerSize));
+}
+
+// Helper function used from StoreIC::GenerateNormal.
+//
+// elements: Property dictionary. It is not clobbered if a jump to the miss
+//           label is done.
+// name:     Property name. It is not clobbered if a jump to the miss label is
+//           done
+// value:    The value to store.
+// The two scratch registers need to be different from elements, name and
+// result.
+// The generated code assumes that the receiver has slow properties,
+// is not a global object and does not have interceptors.
+static void GenerateDictionaryStore(MacroAssembler* masm, Label* miss,
+                                    Register elements, Register name,
+                                    Register value, Register scratch1,
+                                    Register scratch2) {
+  // Main use of the scratch registers.
+  // scratch1: Used as temporary and to hold the capacity of the property
+  //           dictionary.
+  // scratch2: Used as temporary.
+  Label done;
+
+  // Probe the dictionary.
+  NameDictionaryLookupStub::GeneratePositiveLookup(masm, miss, &done, elements,
+                                                   name, scratch1, scratch2);
+
+  // If probing finds an entry in the dictionary check that the value
+  // is a normal property that is not read only.
+  __ bind(&done);  // scratch2 == elements + 4 * index
+  const int kElementsStartOffset =
+      NameDictionary::kHeaderSize +
+      NameDictionary::kElementsStartIndex * kPointerSize;
+  const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
+  int kTypeAndReadOnlyMask =
+      PropertyDetails::TypeField::kMask |
+      PropertyDetails::AttributesField::encode(READ_ONLY);
+  __ LoadP(scratch1, FieldMemOperand(scratch2, kDetailsOffset));
+  __ LoadRR(r0, scratch2);
+  __ LoadSmiLiteral(scratch2, Smi::FromInt(kTypeAndReadOnlyMask));
+  __ AndP(scratch2, scratch1);
+  __ bne(miss /*, cr0*/);
+  __ LoadRR(scratch2, r0);
+
+  // Store the value at the masked, scaled index and return.
+  const int kValueOffset = kElementsStartOffset + kPointerSize;
+  __ AddP(scratch2, Operand(kValueOffset - kHeapObjectTag));
+  __ StoreP(value, MemOperand(scratch2));
+
+  // Update the write barrier. Make sure not to clobber the value.
+  __ LoadRR(scratch1, value);
+  __ RecordWrite(elements, scratch2, scratch1, kLRHasNotBeenSaved,
+                 kDontSaveFPRegs);
+}
+
+// Checks the receiver for special cases (value type, slow case bits).
+// Falls through for regular JS object.
+static void GenerateKeyedLoadReceiverCheck(MacroAssembler* masm,
+                                           Register receiver, Register map,
+                                           Register scratch,
+                                           int interceptor_bit, Label* slow) {
+  // Check that the object isn't a smi.
+  __ JumpIfSmi(receiver, slow);
+  // Get the map of the receiver.
+  __ LoadP(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  // Check bit field.
+  __ LoadlB(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
+  DCHECK(((1 << Map::kIsAccessCheckNeeded) | (1 << interceptor_bit)) < 0x8000);
+  __ mov(r0,
+         Operand((1 << Map::kIsAccessCheckNeeded) | (1 << interceptor_bit)));
+  __ AndP(r0, scratch);
+  __ bne(slow /*, cr0*/);
+  // Check that the object is some kind of JS object EXCEPT JS Value type.
+  // In the case that the object is a value-wrapper object,
+  // we enter the runtime system to make sure that indexing into string
+  // objects work as intended.
+  DCHECK(JS_OBJECT_TYPE > JS_VALUE_TYPE);
+  __ LoadlB(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  __ CmpP(scratch, Operand(JS_OBJECT_TYPE));
+  __ blt(slow);
+}
+
+// Loads an indexed element from a fast case array.
+static void GenerateFastArrayLoad(MacroAssembler* masm, Register receiver,
+                                  Register key, Register elements,
+                                  Register scratch1, Register scratch2,
+                                  Register result, Label* slow) {
+  // Register use:
+  //
+  // receiver - holds the receiver on entry.
+  //            Unchanged unless 'result' is the same register.
+  //
+  // key      - holds the smi key on entry.
+  //            Unchanged unless 'result' is the same register.
+  //
+  // result   - holds the result on exit if the load succeeded.
+  //            Allowed to be the the same as 'receiver' or 'key'.
+  //            Unchanged on bailout so 'receiver' and 'key' can be safely
+  //            used by further computation.
+  //
+  // Scratch registers:
+  //
+  // elements - holds the elements of the receiver and its protoypes.
+  //
+  // scratch1 - used to hold elements length, bit fields, base addresses.
+  //
+  // scratch2 - used to hold maps, prototypes, and the loaded value.
+  Label check_prototypes, check_next_prototype;
+  Label done, in_bounds, absent;
+
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  __ AssertFastElements(elements);
+
+  // Check that the key (index) is within bounds.
+  __ LoadP(scratch1, FieldMemOperand(elements, FixedArray::kLengthOffset));
+  __ CmpLogicalP(key, scratch1);
+  __ blt(&in_bounds, Label::kNear);
+  // Out-of-bounds. Check the prototype chain to see if we can just return
+  // 'undefined'.
+  __ CmpP(key, Operand::Zero());
+  __ blt(slow);  // Negative keys can't take the fast OOB path.
+  __ bind(&check_prototypes);
+  __ LoadP(scratch2, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ bind(&check_next_prototype);
+  __ LoadP(scratch2, FieldMemOperand(scratch2, Map::kPrototypeOffset));
+  // scratch2: current prototype
+  __ CompareRoot(scratch2, Heap::kNullValueRootIndex);
+  __ beq(&absent, Label::kNear);
+  __ LoadP(elements, FieldMemOperand(scratch2, JSObject::kElementsOffset));
+  __ LoadP(scratch2, FieldMemOperand(scratch2, HeapObject::kMapOffset));
+  // elements: elements of current prototype
+  // scratch2: map of current prototype
+  __ CompareInstanceType(scratch2, scratch1, JS_OBJECT_TYPE);
+  __ blt(slow);
+  __ LoadlB(scratch1, FieldMemOperand(scratch2, Map::kBitFieldOffset));
+  __ AndP(r0, scratch1, Operand((1 << Map::kIsAccessCheckNeeded) |
+                                (1 << Map::kHasIndexedInterceptor)));
+  __ bne(slow);
+  __ CompareRoot(elements, Heap::kEmptyFixedArrayRootIndex);
+  __ bne(slow);
+  __ jmp(&check_next_prototype);
+
+  __ bind(&absent);
+  __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
+  __ jmp(&done);
+
+  __ bind(&in_bounds);
+  // Fast case: Do the load.
+  __ AddP(scratch1, elements,
+          Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  // The key is a smi.
+  __ SmiToPtrArrayOffset(scratch2, key);
+  __ LoadP(scratch2, MemOperand(scratch2, scratch1));
+  __ CompareRoot(scratch2, Heap::kTheHoleValueRootIndex);
+  // In case the loaded value is the_hole we have to check the prototype chain.
+  __ beq(&check_prototypes);
+  __ LoadRR(result, scratch2);
+  __ bind(&done);
+}
+
+// Checks whether a key is an array index string or a unique name.
+// Falls through if a key is a unique name.
+static void GenerateKeyNameCheck(MacroAssembler* masm, Register key,
+                                 Register map, Register hash,
+                                 Label* index_string, Label* not_unique) {
+  // The key is not a smi.
+  Label unique;
+  // Is it a name?
+  __ CompareObjectType(key, map, hash, LAST_UNIQUE_NAME_TYPE);
+  __ bgt(not_unique);
+  STATIC_ASSERT(LAST_UNIQUE_NAME_TYPE == FIRST_NONSTRING_TYPE);
+  __ beq(&unique, Label::kNear);
+
+  // Is the string an array index, with cached numeric value?
+  __ LoadlW(hash, FieldMemOperand(key, Name::kHashFieldOffset));
+  __ mov(r7, Operand(Name::kContainsCachedArrayIndexMask));
+  __ AndP(r0, hash, r7);
+  __ beq(index_string);
+
+  // Is the string internalized? We know it's a string, so a single
+  // bit test is enough.
+  // map: key map
+  __ LoadlB(hash, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kInternalizedTag == 0);
+  __ tmll(hash, Operand(kIsNotInternalizedMask));
+  __ bne(not_unique);
+
+  __ bind(&unique);
+}
+
+void LoadIC::GenerateNormal(MacroAssembler* masm) {
+  Register dictionary = r2;
+  DCHECK(!dictionary.is(LoadDescriptor::ReceiverRegister()));
+  DCHECK(!dictionary.is(LoadDescriptor::NameRegister()));
+
+  Label slow;
+
+  __ LoadP(dictionary, FieldMemOperand(LoadDescriptor::ReceiverRegister(),
+                                       JSObject::kPropertiesOffset));
+  GenerateDictionaryLoad(masm, &slow, dictionary,
+                         LoadDescriptor::NameRegister(), r2, r5, r6);
+  __ Ret();
+
+  // Dictionary load failed, go slow (but don't miss).
+  __ bind(&slow);
+  GenerateRuntimeGetProperty(masm);
+}
+
+// A register that isn't one of the parameters to the load ic.
+static const Register LoadIC_TempRegister() { return r5; }
+
+static void LoadIC_PushArgs(MacroAssembler* masm) {
+  Register receiver = LoadDescriptor::ReceiverRegister();
+  Register name = LoadDescriptor::NameRegister();
+  Register slot = LoadDescriptor::SlotRegister();
+  Register vector = LoadWithVectorDescriptor::VectorRegister();
+
+  __ Push(receiver, name, slot, vector);
+}
+
+void LoadIC::GenerateMiss(MacroAssembler* masm) {
+  // The return address is in lr.
+  Isolate* isolate = masm->isolate();
+
+  DCHECK(!AreAliased(r6, r7, LoadWithVectorDescriptor::SlotRegister(),
+                     LoadWithVectorDescriptor::VectorRegister()));
+  __ IncrementCounter(isolate->counters()->ic_load_miss(), 1, r6, r7);
+
+  LoadIC_PushArgs(masm);
+
+  // Perform tail call to the entry.
+  __ TailCallRuntime(Runtime::kLoadIC_Miss);
+}
+
+void LoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
+  // The return address is in lr.
+
+  __ LoadRR(LoadIC_TempRegister(), LoadDescriptor::ReceiverRegister());
+  __ Push(LoadIC_TempRegister(), LoadDescriptor::NameRegister());
+
+  // Do tail-call to runtime routine.
+  __ TailCallRuntime(Runtime::kGetProperty);
+}
+
+void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
+  // The return address is in lr.
+  Isolate* isolate = masm->isolate();
+
+  DCHECK(!AreAliased(r6, r7, LoadWithVectorDescriptor::SlotRegister(),
+                     LoadWithVectorDescriptor::VectorRegister()));
+  __ IncrementCounter(isolate->counters()->ic_keyed_load_miss(), 1, r6, r7);
+
+  LoadIC_PushArgs(masm);
+
+  // Perform tail call to the entry.
+  __ TailCallRuntime(Runtime::kKeyedLoadIC_Miss);
+}
+
+void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
+  // The return address is in lr.
+
+  __ Push(LoadDescriptor::ReceiverRegister(), LoadDescriptor::NameRegister());
+
+  // Do tail-call to runtime routine.
+  __ TailCallRuntime(Runtime::kKeyedGetProperty);
+}
+
+void KeyedLoadIC::GenerateMegamorphic(MacroAssembler* masm) {
+  // The return address is in lr.
+  Label slow, check_name, index_smi, index_name, property_array_property;
+  Label probe_dictionary, check_number_dictionary;
+
+  Register key = LoadDescriptor::NameRegister();
+  Register receiver = LoadDescriptor::ReceiverRegister();
+  DCHECK(key.is(r4));
+  DCHECK(receiver.is(r3));
+
+  Isolate* isolate = masm->isolate();
+
+  // Check that the key is a smi.
+  __ JumpIfNotSmi(key, &check_name);
+  __ bind(&index_smi);
+  // Now the key is known to be a smi. This place is also jumped to from below
+  // where a numeric string is converted to a smi.
+
+  GenerateKeyedLoadReceiverCheck(masm, receiver, r2, r5,
+                                 Map::kHasIndexedInterceptor, &slow);
+
+  // Check the receiver's map to see if it has fast elements.
+  __ CheckFastElements(r2, r5, &check_number_dictionary);
+
+  GenerateFastArrayLoad(masm, receiver, key, r2, r5, r6, r2, &slow);
+  __ IncrementCounter(isolate->counters()->ic_keyed_load_generic_smi(), 1, r6,
+                      r5);
+  __ Ret();
+
+  __ bind(&check_number_dictionary);
+  __ LoadP(r6, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  __ LoadP(r5, FieldMemOperand(r6, JSObject::kMapOffset));
+
+  // Check whether the elements is a number dictionary.
+  // r5: elements map
+  // r6: elements
+  __ CompareRoot(r5, Heap::kHashTableMapRootIndex);
+  __ bne(&slow, Label::kNear);
+  __ SmiUntag(r2, key);
+  __ LoadFromNumberDictionary(&slow, r6, key, r2, r2, r5, r7);
+  __ Ret();
+
+  // Slow case, key and receiver still in r2 and r3.
+  __ bind(&slow);
+  __ IncrementCounter(isolate->counters()->ic_keyed_load_generic_slow(), 1, r6,
+                      r5);
+  GenerateRuntimeGetProperty(masm);
+
+  __ bind(&check_name);
+  GenerateKeyNameCheck(masm, key, r2, r5, &index_name, &slow);
+
+  GenerateKeyedLoadReceiverCheck(masm, receiver, r2, r5,
+                                 Map::kHasNamedInterceptor, &slow);
+
+  // If the receiver is a fast-case object, check the stub cache. Otherwise
+  // probe the dictionary.
+  __ LoadP(r5, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  __ LoadP(r6, FieldMemOperand(r5, HeapObject::kMapOffset));
+  __ CompareRoot(r6, Heap::kHashTableMapRootIndex);
+  __ beq(&probe_dictionary);
+
+  // The handlers in the stub cache expect a vector and slot. Since we won't
+  // change the IC from any downstream misses, a dummy vector can be used.
+  Register vector = LoadWithVectorDescriptor::VectorRegister();
+  Register slot = LoadWithVectorDescriptor::SlotRegister();
+  DCHECK(!AreAliased(vector, slot, r6, r7, r8, r9));
+  Handle<TypeFeedbackVector> dummy_vector =
+      TypeFeedbackVector::DummyVector(masm->isolate());
+  int slot_index = dummy_vector->GetIndex(
+      FeedbackVectorSlot(TypeFeedbackVector::kDummyKeyedLoadICSlot));
+  __ LoadRoot(vector, Heap::kDummyVectorRootIndex);
+  __ LoadSmiLiteral(slot, Smi::FromInt(slot_index));
+
+  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
+      Code::ComputeHandlerFlags(Code::LOAD_IC));
+  masm->isolate()->stub_cache()->GenerateProbe(masm, Code::KEYED_LOAD_IC, flags,
+                                               receiver, key, r6, r7, r8, r9);
+  // Cache miss.
+  GenerateMiss(masm);
+
+  // Do a quick inline probe of the receiver's dictionary, if it
+  // exists.
+  __ bind(&probe_dictionary);
+  // r5: elements
+  __ LoadP(r2, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  __ LoadlB(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
+  GenerateGlobalInstanceTypeCheck(masm, r2, &slow);
+  // Load the property to r2.
+  GenerateDictionaryLoad(masm, &slow, r5, key, r2, r7, r6);
+  __ IncrementCounter(isolate->counters()->ic_keyed_load_generic_symbol(), 1,
+                      r6, r5);
+  __ Ret();
+
+  __ bind(&index_name);
+  __ IndexFromHash(r5, key);
+  // Now jump to the place where smi keys are handled.
+  __ b(&index_smi);
+}
+
+static void StoreIC_PushArgs(MacroAssembler* masm) {
+  __ Push(StoreDescriptor::ReceiverRegister(), StoreDescriptor::NameRegister(),
+          StoreDescriptor::ValueRegister(),
+          VectorStoreICDescriptor::SlotRegister(),
+          VectorStoreICDescriptor::VectorRegister());
+}
+
+void KeyedStoreIC::GenerateMiss(MacroAssembler* masm) {
+  StoreIC_PushArgs(masm);
+
+  __ TailCallRuntime(Runtime::kKeyedStoreIC_Miss);
+}
+
+static void KeyedStoreGenerateMegamorphicHelper(
+    MacroAssembler* masm, Label* fast_object, Label* fast_double, Label* slow,
+    KeyedStoreCheckMap check_map, KeyedStoreIncrementLength increment_length,
+    Register value, Register key, Register receiver, Register receiver_map,
+    Register elements_map, Register elements) {
+  Label transition_smi_elements;
+  Label finish_object_store, non_double_value, transition_double_elements;
+  Label fast_double_without_map_check;
+
+  // Fast case: Do the store, could be either Object or double.
+  __ bind(fast_object);
+  Register scratch = r6;
+  Register address = r7;
+  DCHECK(!AreAliased(value, key, receiver, receiver_map, elements_map, elements,
+                     scratch, address));
+
+  if (check_map == kCheckMap) {
+    __ LoadP(elements_map, FieldMemOperand(elements, HeapObject::kMapOffset));
+    __ CmpP(elements_map,
+            Operand(masm->isolate()->factory()->fixed_array_map()));
+    __ bne(fast_double);
+  }
+
+  // HOLECHECK: guards "A[i] = V"
+  // We have to go to the runtime if the current value is the hole because
+  // there may be a callback on the element
+  Label holecheck_passed1;
+  // @TODO(joransiu) : Fold AddP into memref of LoadP
+  __ AddP(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ SmiToPtrArrayOffset(scratch, key);
+  __ LoadP(scratch, MemOperand(address, scratch));
+  __ CmpP(scratch, Operand(masm->isolate()->factory()->the_hole_value()));
+  __ bne(&holecheck_passed1, Label::kNear);
+  __ JumpIfDictionaryInPrototypeChain(receiver, elements_map, scratch, slow);
+
+  __ bind(&holecheck_passed1);
+
+  // Smi stores don't require further checks.
+  Label non_smi_value;
+  __ JumpIfNotSmi(value, &non_smi_value);
+
+  if (increment_length == kIncrementLength) {
+    // Add 1 to receiver->length.
+    __ AddSmiLiteral(scratch, key, Smi::FromInt(1), r0);
+    __ StoreP(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  }
+  // It's irrelevant whether array is smi-only or not when writing a smi.
+  __ AddP(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ SmiToPtrArrayOffset(scratch, key);
+  __ StoreP(value, MemOperand(address, scratch));
+  __ Ret();
+
+  __ bind(&non_smi_value);
+  // Escape to elements kind transition case.
+  __ CheckFastObjectElements(receiver_map, scratch, &transition_smi_elements);
+
+  // Fast elements array, store the value to the elements backing store.
+  __ bind(&finish_object_store);
+  if (increment_length == kIncrementLength) {
+    // Add 1 to receiver->length.
+    __ AddSmiLiteral(scratch, key, Smi::FromInt(1), r0);
+    __ StoreP(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  }
+  __ AddP(address, elements, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ SmiToPtrArrayOffset(scratch, key);
+  __ StoreP(value, MemOperand(address, scratch));
+  __ la(address, MemOperand(address, scratch));
+  // Update write barrier for the elements array address.
+  __ LoadRR(scratch, value);  // Preserve the value which is returned.
+  __ RecordWrite(elements, address, scratch, kLRHasNotBeenSaved,
+                 kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  __ Ret();
+
+  __ bind(fast_double);
+  if (check_map == kCheckMap) {
+    // Check for fast double array case. If this fails, call through to the
+    // runtime.
+    __ CompareRoot(elements_map, Heap::kFixedDoubleArrayMapRootIndex);
+    __ bne(slow);
+  }
+
+  // HOLECHECK: guards "A[i] double hole?"
+  // We have to see if the double version of the hole is present. If so
+  // go to the runtime.
+  // @TODO(joransiu) : Fold AddP Operand into LoadlW
+  __ AddP(address, elements,
+          Operand((FixedDoubleArray::kHeaderSize + Register::kExponentOffset -
+                   kHeapObjectTag)));
+  __ SmiToDoubleArrayOffset(scratch, key);
+  __ LoadlW(scratch, MemOperand(address, scratch));
+  __ CmpP(scratch, Operand(kHoleNanUpper32));
+  __ bne(&fast_double_without_map_check, Label::kNear);
+  __ JumpIfDictionaryInPrototypeChain(receiver, elements_map, scratch, slow);
+
+  __ bind(&fast_double_without_map_check);
+  __ StoreNumberToDoubleElements(value, key, elements, scratch, d0,
+                                 &transition_double_elements);
+  if (increment_length == kIncrementLength) {
+    // Add 1 to receiver->length.
+    __ AddSmiLiteral(scratch, key, Smi::FromInt(1), r0);
+    __ StoreP(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  }
+  __ Ret();
+
+  __ bind(&transition_smi_elements);
+  // Transition the array appropriately depending on the value type.
+  __ LoadP(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
+  __ CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
+  __ bne(&non_double_value);
+
+  // Value is a double. Transition FAST_SMI_ELEMENTS ->
+  // FAST_DOUBLE_ELEMENTS and complete the store.
+  __ LoadTransitionedArrayMapConditional(
+      FAST_SMI_ELEMENTS, FAST_DOUBLE_ELEMENTS, receiver_map, scratch, slow);
+  AllocationSiteMode mode =
+      AllocationSite::GetMode(FAST_SMI_ELEMENTS, FAST_DOUBLE_ELEMENTS);
+  ElementsTransitionGenerator::GenerateSmiToDouble(masm, receiver, key, value,
+                                                   receiver_map, mode, slow);
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  __ b(&fast_double_without_map_check);
+
+  __ bind(&non_double_value);
+  // Value is not a double, FAST_SMI_ELEMENTS -> FAST_ELEMENTS
+  __ LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS, FAST_ELEMENTS,
+                                         receiver_map, scratch, slow);
+  mode = AllocationSite::GetMode(FAST_SMI_ELEMENTS, FAST_ELEMENTS);
+  ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
+      masm, receiver, key, value, receiver_map, mode, slow);
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  __ b(&finish_object_store);
+
+  __ bind(&transition_double_elements);
+  // Elements are FAST_DOUBLE_ELEMENTS, but value is an Object that's not a
+  // HeapNumber. Make sure that the receiver is a Array with FAST_ELEMENTS and
+  // transition array from FAST_DOUBLE_ELEMENTS to FAST_ELEMENTS
+  __ LoadTransitionedArrayMapConditional(FAST_DOUBLE_ELEMENTS, FAST_ELEMENTS,
+                                         receiver_map, scratch, slow);
+  mode = AllocationSite::GetMode(FAST_DOUBLE_ELEMENTS, FAST_ELEMENTS);
+  ElementsTransitionGenerator::GenerateDoubleToObject(
+      masm, receiver, key, value, receiver_map, mode, slow);
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  __ b(&finish_object_store);
+}
+
+void KeyedStoreIC::GenerateMegamorphic(MacroAssembler* masm,
+                                       LanguageMode language_mode) {
+  // ---------- S t a t e --------------
+  //  -- r2     : value
+  //  -- r3     : key
+  //  -- r4     : receiver
+  //  -- lr     : return address
+  // -----------------------------------
+  Label slow, fast_object, fast_object_grow;
+  Label fast_double, fast_double_grow;
+  Label array, extra, check_if_double_array, maybe_name_key, miss;
+
+  // Register usage.
+  Register value = StoreDescriptor::ValueRegister();
+  Register key = StoreDescriptor::NameRegister();
+  Register receiver = StoreDescriptor::ReceiverRegister();
+  DCHECK(receiver.is(r3));
+  DCHECK(key.is(r4));
+  DCHECK(value.is(r2));
+  Register receiver_map = r5;
+  Register elements_map = r8;
+  Register elements = r9;  // Elements array of the receiver.
+  // r6 and r7 are used as general scratch registers.
+
+  // Check that the key is a smi.
+  __ JumpIfNotSmi(key, &maybe_name_key);
+  // Check that the object isn't a smi.
+  __ JumpIfSmi(receiver, &slow);
+  // Get the map of the object.
+  __ LoadP(receiver_map, FieldMemOperand(receiver, HeapObject::kMapOffset));
+  // Check that the receiver does not require access checks and is not observed.
+  // The generic stub does not perform map checks or handle observed objects.
+  __ LoadlB(ip, FieldMemOperand(receiver_map, Map::kBitFieldOffset));
+  __ AndP(r0, ip,
+          Operand(1 << Map::kIsAccessCheckNeeded | 1 << Map::kIsObserved));
+  __ bne(&slow, Label::kNear);
+  // Check if the object is a JS array or not.
+  __ LoadlB(r6, FieldMemOperand(receiver_map, Map::kInstanceTypeOffset));
+  __ CmpP(r6, Operand(JS_ARRAY_TYPE));
+  __ beq(&array);
+  // Check that the object is some kind of JSObject.
+  __ CmpP(r6, Operand(FIRST_JS_OBJECT_TYPE));
+  __ blt(&slow, Label::kNear);
+
+  // Object case: Check key against length in the elements array.
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+  // Check array bounds. Both the key and the length of FixedArray are smis.
+  __ CmpLogicalP(key, FieldMemOperand(elements, FixedArray::kLengthOffset));
+  __ blt(&fast_object);
+
+  // Slow case, handle jump to runtime.
+  __ bind(&slow);
+  // Entry registers are intact.
+  // r2: value.
+  // r3: key.
+  // r4: receiver.
+  PropertyICCompiler::GenerateRuntimeSetProperty(masm, language_mode);
+  // Never returns to here.
+
+  __ bind(&maybe_name_key);
+  __ LoadP(r6, FieldMemOperand(key, HeapObject::kMapOffset));
+  __ LoadlB(r6, FieldMemOperand(r6, Map::kInstanceTypeOffset));
+  __ JumpIfNotUniqueNameInstanceType(r6, &slow);
+
+  // The handlers in the stub cache expect a vector and slot. Since we won't
+  // change the IC from any downstream misses, a dummy vector can be used.
+  Register vector = VectorStoreICDescriptor::VectorRegister();
+  Register slot = VectorStoreICDescriptor::SlotRegister();
+  DCHECK(!AreAliased(vector, slot, r7, r8, r9, ip));
+  Handle<TypeFeedbackVector> dummy_vector =
+      TypeFeedbackVector::DummyVector(masm->isolate());
+  int slot_index = dummy_vector->GetIndex(
+      FeedbackVectorSlot(TypeFeedbackVector::kDummyKeyedStoreICSlot));
+  __ LoadRoot(vector, Heap::kDummyVectorRootIndex);
+  __ LoadSmiLiteral(slot, Smi::FromInt(slot_index));
+
+  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
+      Code::ComputeHandlerFlags(Code::STORE_IC));
+  masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
+                                               receiver, key, r7, r8, r9, ip);
+  // Cache miss.
+  __ b(&miss);
+
+  // Extra capacity case: Check if there is extra capacity to
+  // perform the store and update the length. Used for adding one
+  // element to the array by writing to array[array.length].
+  __ bind(&extra);
+  // Condition code from comparing key and array length is still available.
+  __ bne(&slow);  // Only support writing to writing to array[array.length].
+  // Check for room in the elements backing store.
+  // Both the key and the length of FixedArray are smis.
+  __ CmpLogicalP(key, FieldMemOperand(elements, FixedArray::kLengthOffset));
+  __ bge(&slow);
+  __ LoadP(elements_map, FieldMemOperand(elements, HeapObject::kMapOffset));
+  __ CmpP(elements_map, Operand(masm->isolate()->factory()->fixed_array_map()));
+  __ bne(&check_if_double_array, Label::kNear);
+  __ b(&fast_object_grow);
+
+  __ bind(&check_if_double_array);
+  __ CmpP(elements_map,
+          Operand(masm->isolate()->factory()->fixed_double_array_map()));
+  __ bne(&slow);
+  __ b(&fast_double_grow);
+
+  // Array case: Get the length and the elements array from the JS
+  // array. Check that the array is in fast mode (and writable); if it
+  // is the length is always a smi.
+  __ bind(&array);
+  __ LoadP(elements, FieldMemOperand(receiver, JSObject::kElementsOffset));
+
+  // Check the key against the length in the array.
+  __ CmpLogicalP(key, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ bge(&extra);
+
+  KeyedStoreGenerateMegamorphicHelper(
+      masm, &fast_object, &fast_double, &slow, kCheckMap, kDontIncrementLength,
+      value, key, receiver, receiver_map, elements_map, elements);
+  KeyedStoreGenerateMegamorphicHelper(masm, &fast_object_grow,
+                                      &fast_double_grow, &slow, kDontCheckMap,
+                                      kIncrementLength, value, key, receiver,
+                                      receiver_map, elements_map, elements);
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
+
+void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
+  Register receiver = StoreDescriptor::ReceiverRegister();
+  Register name = StoreDescriptor::NameRegister();
+  DCHECK(receiver.is(r3));
+  DCHECK(name.is(r4));
+  DCHECK(StoreDescriptor::ValueRegister().is(r2));
+
+  // Get the receiver from the stack and probe the stub cache.
+  Code::Flags flags = Code::RemoveTypeAndHolderFromFlags(
+      Code::ComputeHandlerFlags(Code::STORE_IC));
+
+  masm->isolate()->stub_cache()->GenerateProbe(masm, Code::STORE_IC, flags,
+                                               receiver, name, r5, r6, r7, r8);
+
+  // Cache miss: Jump to runtime.
+  GenerateMiss(masm);
+}
+
+void StoreIC::GenerateMiss(MacroAssembler* masm) {
+  StoreIC_PushArgs(masm);
+
+  // Perform tail call to the entry.
+  __ TailCallRuntime(Runtime::kStoreIC_Miss);
+}
+
+void StoreIC::GenerateNormal(MacroAssembler* masm) {
+  Label miss;
+  Register receiver = StoreDescriptor::ReceiverRegister();
+  Register name = StoreDescriptor::NameRegister();
+  Register value = StoreDescriptor::ValueRegister();
+  Register dictionary = r7;
+  DCHECK(receiver.is(r3));
+  DCHECK(name.is(r4));
+  DCHECK(value.is(r2));
+  DCHECK(VectorStoreICDescriptor::VectorRegister().is(r5));
+  DCHECK(VectorStoreICDescriptor::SlotRegister().is(r6));
+
+  __ LoadP(dictionary, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+
+  GenerateDictionaryStore(masm, &miss, dictionary, name, value, r8, r9);
+  Counters* counters = masm->isolate()->counters();
+  __ IncrementCounter(counters->ic_store_normal_hit(), 1, r8, r9);
+  __ Ret();
+
+  __ bind(&miss);
+  __ IncrementCounter(counters->ic_store_normal_miss(), 1, r8, r9);
+  GenerateMiss(masm);
+}
+
+#undef __
+
+Condition CompareIC::ComputeCondition(Token::Value op) {
+  switch (op) {
+    case Token::EQ_STRICT:
+    case Token::EQ:
+      return eq;
+    case Token::LT:
+      return lt;
+    case Token::GT:
+      return gt;
+    case Token::LTE:
+      return le;
+    case Token::GTE:
+      return ge;
+    default:
+      UNREACHABLE();
+      return kNoCondition;
+  }
+}
+
+bool CompareIC::HasInlinedSmiCode(Address address) {
+  // The address of the instruction following the call.
+  Address cmp_instruction_address =
+      Assembler::return_address_from_call_start(address);
+
+  // If the instruction following the call is not a CHI, nothing
+  // was inlined.
+  return (Instruction::S390OpcodeValue(cmp_instruction_address) == CHI);
+}
+
+//
+// This code is paired with the JumpPatchSite class in full-codegen-s390.cc
+//
+void PatchInlinedSmiCode(Isolate* isolate, Address address,
+                         InlinedSmiCheck check) {
+  Address cmp_instruction_address =
+      Assembler::return_address_from_call_start(address);
+
+  // If the instruction following the call is not a cmp rx, #yyy, nothing
+  // was inlined.
+  Instr instr = Assembler::instr_at(cmp_instruction_address);
+  if (Instruction::S390OpcodeValue(cmp_instruction_address) != CHI) {
+    return;
+  }
+
+  if (Instruction::S390OpcodeValue(address) != BRASL) {
+    return;
+  }
+  // The delta to the start of the map check instruction and the
+  // condition code uses at the patched jump.
+  int delta = instr & 0x0000ffff;
+
+  // If the delta is 0 the instruction is cmp r0, #0 which also signals that
+  // nothing was inlined.
+  if (delta == 0) {
+    return;
+  }
+
+  if (FLAG_trace_ic) {
+    PrintF("[  patching ic at %p, cmp=%p, delta=%d\n", address,
+           cmp_instruction_address, delta);
+  }
+
+  // Expected sequence to enable by changing the following
+  //   CR/CGR  Rx, Rx    // 2 / 4 bytes
+  //   LR  R0, R0        // 2 bytes   // 31-bit only!
+  //   BRC/BRCL          // 4 / 6 bytes
+  // into
+  //   TMLL    Rx, XXX   // 4 bytes
+  //   BRC/BRCL          // 4 / 6 bytes
+  // And vice versa to disable.
+
+  // The following constant is the size of the CR/CGR + LR + LR
+  const int kPatchAreaSizeNoBranch = 4;
+  Address patch_address = cmp_instruction_address - delta;
+  Address branch_address = patch_address + kPatchAreaSizeNoBranch;
+
+  Instr instr_at_patch = Assembler::instr_at(patch_address);
+  SixByteInstr branch_instr = Assembler::instr_at(branch_address);
+
+  // This is patching a conditional "jump if not smi/jump if smi" site.
+  size_t patch_size = 0;
+  if (Instruction::S390OpcodeValue(branch_address) == BRC) {
+    patch_size = kPatchAreaSizeNoBranch + 4;
+  } else if (Instruction::S390OpcodeValue(branch_address) == BRCL) {
+    patch_size = kPatchAreaSizeNoBranch + 6;
+  } else {
+    DCHECK(false);
+  }
+  CodePatcher patcher(isolate, patch_address, patch_size);
+  Register reg;
+  reg.reg_code = instr_at_patch & 0xf;
+  if (check == ENABLE_INLINED_SMI_CHECK) {
+    patcher.masm()->TestIfSmi(reg);
+  } else {
+    // Emit the NOP to ensure sufficient place for patching
+    // (replaced by LR + NILL)
+    DCHECK(check == DISABLE_INLINED_SMI_CHECK);
+    patcher.masm()->CmpP(reg, reg);
+#ifndef V8_TARGET_ARCH_S390X
+    patcher.masm()->nop();
+#endif
+  }
+
+  Condition cc = al;
+  if (Instruction::S390OpcodeValue(branch_address) == BRC) {
+    cc = static_cast<Condition>((branch_instr & 0x00f00000) >> 20);
+    DCHECK((cc == ne) || (cc == eq));
+    cc = (cc == ne) ? eq : ne;
+    patcher.masm()->brc(cc, Operand((branch_instr & 0xffff) << 1));
+  } else if (Instruction::S390OpcodeValue(branch_address) == BRCL) {
+    cc = static_cast<Condition>(
+        (branch_instr & (static_cast<uint64_t>(0x00f0) << 32)) >> 36);
+    DCHECK((cc == ne) || (cc == eq));
+    cc = (cc == ne) ? eq : ne;
+    patcher.masm()->brcl(cc, Operand((branch_instr & 0xffffffff) << 1));
+  } else {
+    DCHECK(false);
+  }
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_TARGET_ARCH_S390