text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #include "v8.h"
  
  #if V8_TARGET_ARCH_X64
  
  #include "codegen.h"
  #include "ic-inl.h"
  #include "runtime.h"
  #include "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.
    __ cmpb(type, Immediate(JS_GLOBAL_OBJECT_TYPE));
    __ j(equal, global_object);
    __ cmpb(type, Immediate(JS_BUILTINS_OBJECT_TYPE));
    __ j(equal, global_object);
    __ cmpb(type, Immediate(JS_GLOBAL_PROXY_TYPE));
    __ j(equal, global_object);
  }
  
  
  // Generated code falls through if the receiver is a regular non-global
  // JS object with slow properties and no interceptors.
  static void GenerateNameDictionaryReceiverCheck(MacroAssembler* masm,
                                                  Register receiver,
                                                  Register r0,
                                                  Register r1,
                                                  Label* miss) {
    // Register usage:
    //   receiver: holds the receiver on entry and is unchanged.
    //   r0: used to hold receiver instance type.
    //       Holds the property dictionary on fall through.
    //   r1: used to hold receivers map.
  
    __ JumpIfSmi(receiver, miss);
  
    // Check that the receiver is a valid JS object.
    __ movp(r1, FieldOperand(receiver, HeapObject::kMapOffset));
    __ movb(r0, FieldOperand(r1, Map::kInstanceTypeOffset));
    __ cmpb(r0, Immediate(FIRST_SPEC_OBJECT_TYPE));
    __ j(below, miss);
  
    // If this assert fails, we have to check upper bound too.
    STATIC_ASSERT(LAST_TYPE == LAST_SPEC_OBJECT_TYPE);
  
    GenerateGlobalInstanceTypeCheck(masm, r0, miss);
  
    // Check for non-global object that requires access check.
    __ testb(FieldOperand(r1, Map::kBitFieldOffset),
             Immediate((1 << Map::kIsAccessCheckNeeded) |
                       (1 << Map::kHasNamedInterceptor)));
    __ j(not_zero, miss);
  
    __ movp(r0, FieldOperand(receiver, JSObject::kPropertiesOffset));
    __ CompareRoot(FieldOperand(r0, HeapObject::kMapOffset),
                   Heap::kHashTableMapRootIndex);
    __ j(not_equal, miss);
  }
  
  
  
  // Helper function used to load a property from a dictionary backing storage.
  // This function may return false negatives, so miss_label
  // must always call a backup property load that is complete.
  // This function is safe to call if name is not an internalized string,
  // and will jump to the miss_label in that case.
  // 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_label,
                                     Register elements,
                                     Register name,
                                     Register r0,
                                     Register r1,
                                     Register result) {
    // Register use:
    //
    // elements - holds the property dictionary on entry and is unchanged.
    //
    // name - holds the name of the property on entry and is unchanged.
    //
    // r0   - used to hold the capacity of the property dictionary.
    //
    // r1   - used to hold the index into the property dictionary.
    //
    // result - holds the result on exit if the load succeeded.
  
    Label done;
  
    // Probe the dictionary.
    NameDictionaryLookupStub::GeneratePositiveLookup(masm,
                                                     miss_label,
                                                     &done,
                                                     elements,
                                                     name,
                                                     r0,
                                                     r1);
  
    // If probing finds an entry in the dictionary, r1 contains the
    // index into the dictionary. Check that the value is a normal
    // property.
    __ bind(&done);
    const int kElementsStartOffset =
        NameDictionary::kHeaderSize +
        NameDictionary::kElementsStartIndex * kPointerSize;
    const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
    __ Test(Operand(elements, r1, times_pointer_size,
                    kDetailsOffset - kHeapObjectTag),
            Smi::FromInt(PropertyDetails::TypeField::kMask));
    __ j(not_zero, miss_label);
  
    // Get the value at the masked, scaled index.
    const int kValueOffset = kElementsStartOffset + kPointerSize;
    __ movp(result,
            Operand(elements, r1, times_pointer_size,
                    kValueOffset - kHeapObjectTag));
  }
  
  
  // Helper function used to store a property to a dictionary backing
  // storage. This function may fail to store a property even though it
  // is in the dictionary, so code at miss_label must always call a
  // backup property store that is complete. This function is safe to
  // call if name is not an internalized string, and will jump to the miss_label
  // in that case. 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_label,
                                      Register elements,
                                      Register name,
                                      Register value,
                                      Register scratch0,
                                      Register scratch1) {
    // Register use:
    //
    // elements - holds the property dictionary on entry and is clobbered.
    //
    // name - holds the name of the property on entry and is unchanged.
    //
    // value - holds the value to store and is unchanged.
    //
    // scratch0 - used during the positive dictionary lookup and is clobbered.
    //
    // scratch1 - used for index into the property dictionary and is clobbered.
    Label done;
  
    // Probe the dictionary.
    NameDictionaryLookupStub::GeneratePositiveLookup(masm,
                                                     miss_label,
                                                     &done,
                                                     elements,
                                                     name,
                                                     scratch0,
                                                     scratch1);
  
    // If probing finds an entry in the dictionary, scratch0 contains the
    // index into the dictionary. Check that the value is a normal
    // property that is not read only.
    __ bind(&done);
    const int kElementsStartOffset =
        NameDictionary::kHeaderSize +
        NameDictionary::kElementsStartIndex * kPointerSize;
    const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
    const int kTypeAndReadOnlyMask =
        (PropertyDetails::TypeField::kMask |
         PropertyDetails::AttributesField::encode(READ_ONLY)) << kSmiTagSize;
    __ Test(Operand(elements,
                    scratch1,
                    times_pointer_size,
                    kDetailsOffset - kHeapObjectTag),
            Smi::FromInt(kTypeAndReadOnlyMask));
    __ j(not_zero, miss_label);
  
    // Store the value at the masked, scaled index.
    const int kValueOffset = kElementsStartOffset + kPointerSize;
    __ lea(scratch1, Operand(elements,
                             scratch1,
                             times_pointer_size,
                             kValueOffset - kHeapObjectTag));
    __ movp(Operand(scratch1, 0), value);
  
    // Update write barrier. Make sure not to clobber the value.
    __ movp(scratch0, value);
    __ RecordWrite(elements, scratch1, scratch0, 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,
                                             int interceptor_bit,
                                             Label* slow) {
    // Register use:
    //   receiver - holds the receiver and is unchanged.
    // Scratch registers:
    //   map - used to hold the map of the receiver.
  
    // Check that the object isn't a smi.
    __ JumpIfSmi(receiver, slow);
  
    // 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.
    ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
    __ CmpObjectType(receiver, JS_OBJECT_TYPE, map);
    __ j(below, slow);
  
    // Check bit field.
    __ testb(FieldOperand(map, Map::kBitFieldOffset),
             Immediate((1 << Map::kIsAccessCheckNeeded) |
                       (1 << interceptor_bit)));
    __ j(not_zero, slow);
  }
  
  
  // Loads an indexed element from a fast case array.
  // If not_fast_array is NULL, doesn't perform the elements map check.
  static void GenerateFastArrayLoad(MacroAssembler* masm,
                                    Register receiver,
                                    Register key,
                                    Register elements,
                                    Register scratch,
                                    Register result,
                                    Label* not_fast_array,
                                    Label* out_of_range) {
    // 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.
    //
    // elements - holds the elements of the receiver on exit.
    //
    // 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:
    //
    //   scratch - used to hold elements of the receiver and the loaded value.
  
    __ movp(elements, FieldOperand(receiver, JSObject::kElementsOffset));
    if (not_fast_array != NULL) {
      // Check that the object is in fast mode and writable.
      __ CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                     Heap::kFixedArrayMapRootIndex);
      __ j(not_equal, not_fast_array);
    } else {
      __ AssertFastElements(elements);
    }
    // Check that the key (index) is within bounds.
    __ SmiCompare(key, FieldOperand(elements, FixedArray::kLengthOffset));
    // Unsigned comparison rejects negative indices.
    __ j(above_equal, out_of_range);
    // Fast case: Do the load.
    SmiIndex index = masm->SmiToIndex(scratch, key, kPointerSizeLog2);
    __ movp(scratch, FieldOperand(elements,
                                  index.reg,
                                  index.scale,
                                  FixedArray::kHeaderSize));
    __ CompareRoot(scratch, Heap::kTheHoleValueRootIndex);
    // In case the loaded value is the_hole we have to consult GetProperty
    // to ensure the prototype chain is searched.
    __ j(equal, out_of_range);
    if (!result.is(scratch)) {
      __ movp(result, scratch);
    }
  }
  
  
  // Checks whether a key is an array index string or a unique name.
  // Falls through if the key is a unique name.
  static void GenerateKeyNameCheck(MacroAssembler* masm,
                                   Register key,
                                   Register map,
                                   Register hash,
                                   Label* index_string,
                                   Label* not_unique) {
    // Register use:
    //   key - holds the key and is unchanged. Assumed to be non-smi.
    // Scratch registers:
    //   map - used to hold the map of the key.
    //   hash - used to hold the hash of the key.
    Label unique;
    __ CmpObjectType(key, LAST_UNIQUE_NAME_TYPE, map);
    __ j(above, not_unique);
    STATIC_ASSERT(LAST_UNIQUE_NAME_TYPE == FIRST_NONSTRING_TYPE);
    __ j(equal, &unique);
  
    // Is the string an array index, with cached numeric value?
    __ movl(hash, FieldOperand(key, Name::kHashFieldOffset));
    __ testl(hash, Immediate(Name::kContainsCachedArrayIndexMask));
    __ j(zero, index_string);  // The value in hash is used at jump target.
  
    // Is the string internalized? We already know it's a string so a single
    // bit test is enough.
    STATIC_ASSERT(kNotInternalizedTag != 0);
    __ testb(FieldOperand(map, Map::kInstanceTypeOffset),
             Immediate(kIsNotInternalizedMask));
    __ j(not_zero, not_unique);
  
    __ bind(&unique);
  }
  
  
  
  void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label slow, check_name, index_smi, index_name, property_array_property;
    Label probe_dictionary, check_number_dictionary;
  
    // Check that the key is a smi.
    __ JumpIfNotSmi(rax, &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, rdx, rcx, Map::kHasIndexedInterceptor, &slow);
  
    // Check the receiver's map to see if it has fast elements.
    __ CheckFastElements(rcx, &check_number_dictionary);
  
    GenerateFastArrayLoad(masm,
                          rdx,
                          rax,
                          rcx,
                          rbx,
                          rax,
                          NULL,
                          &slow);
    Counters* counters = masm->isolate()->counters();
    __ IncrementCounter(counters->keyed_load_generic_smi(), 1);
    __ ret(0);
  
    __ bind(&check_number_dictionary);
    __ SmiToInteger32(rbx, rax);
    __ movp(rcx, FieldOperand(rdx, JSObject::kElementsOffset));
  
    // Check whether the elements is a number dictionary.
    // rdx: receiver
    // rax: key
    // rbx: key as untagged int32
    // rcx: elements
    __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
                   Heap::kHashTableMapRootIndex);
    __ j(not_equal, &slow);
    __ LoadFromNumberDictionary(&slow, rcx, rax, rbx, r9, rdi, rax);
    __ ret(0);
  
    __ bind(&slow);
    // Slow case: Jump to runtime.
    // rdx: receiver
    // rax: key
    __ IncrementCounter(counters->keyed_load_generic_slow(), 1);
    GenerateRuntimeGetProperty(masm);
  
    __ bind(&check_name);
    GenerateKeyNameCheck(masm, rax, rcx, rbx, &index_name, &slow);
  
    GenerateKeyedLoadReceiverCheck(
        masm, rdx, rcx, Map::kHasNamedInterceptor, &slow);
  
    // If the receiver is a fast-case object, check the keyed lookup
    // cache. Otherwise probe the dictionary leaving result in rcx.
    __ movp(rbx, FieldOperand(rdx, JSObject::kPropertiesOffset));
    __ CompareRoot(FieldOperand(rbx, HeapObject::kMapOffset),
                   Heap::kHashTableMapRootIndex);
    __ j(equal, &probe_dictionary);
  
    // Load the map of the receiver, compute the keyed lookup cache hash
    // based on 32 bits of the map pointer and the string hash.
    __ movp(rbx, FieldOperand(rdx, HeapObject::kMapOffset));
    __ movl(rcx, rbx);
    __ shr(rcx, Immediate(KeyedLookupCache::kMapHashShift));
    __ movl(rdi, FieldOperand(rax, String::kHashFieldOffset));
    __ shr(rdi, Immediate(String::kHashShift));
    __ xor_(rcx, rdi);
    int mask = (KeyedLookupCache::kCapacityMask & KeyedLookupCache::kHashMask);
    __ and_(rcx, Immediate(mask));
  
    // Load the key (consisting of map and internalized string) from the cache and
    // check for match.
    Label load_in_object_property;
    static const int kEntriesPerBucket = KeyedLookupCache::kEntriesPerBucket;
    Label hit_on_nth_entry[kEntriesPerBucket];
    ExternalReference cache_keys
        = ExternalReference::keyed_lookup_cache_keys(masm->isolate());
  
    for (int i = 0; i < kEntriesPerBucket - 1; i++) {
      Label try_next_entry;
      __ movp(rdi, rcx);
      __ shl(rdi, Immediate(kPointerSizeLog2 + 1));
      __ LoadAddress(kScratchRegister, cache_keys);
      int off = kPointerSize * i * 2;
      __ cmpq(rbx, Operand(kScratchRegister, rdi, times_1, off));
      __ j(not_equal, &try_next_entry);
      __ cmpq(rax, Operand(kScratchRegister, rdi, times_1, off + kPointerSize));
      __ j(equal, &hit_on_nth_entry[i]);
      __ bind(&try_next_entry);
    }
  
    int off = kPointerSize * (kEntriesPerBucket - 1) * 2;
    __ cmpq(rbx, Operand(kScratchRegister, rdi, times_1, off));
    __ j(not_equal, &slow);
    __ cmpq(rax, Operand(kScratchRegister, rdi, times_1, off + kPointerSize));
    __ j(not_equal, &slow);
  
    // Get field offset, which is a 32-bit integer.
    ExternalReference cache_field_offsets
        = ExternalReference::keyed_lookup_cache_field_offsets(masm->isolate());
  
    // Hit on nth entry.
    for (int i = kEntriesPerBucket - 1; i >= 0; i--) {
      __ bind(&hit_on_nth_entry[i]);
      if (i != 0) {
        __ addl(rcx, Immediate(i));
      }
      __ LoadAddress(kScratchRegister, cache_field_offsets);
      __ movl(rdi, Operand(kScratchRegister, rcx, times_4, 0));
      __ movzxbq(rcx, FieldOperand(rbx, Map::kInObjectPropertiesOffset));
      __ subq(rdi, rcx);
      __ j(above_equal, &property_array_property);
      if (i != 0) {
        __ jmp(&load_in_object_property);
      }
    }
  
    // Load in-object property.
    __ bind(&load_in_object_property);
    __ movzxbq(rcx, FieldOperand(rbx, Map::kInstanceSizeOffset));
    __ addq(rcx, rdi);
    __ movp(rax, FieldOperand(rdx, rcx, times_pointer_size, 0));
    __ IncrementCounter(counters->keyed_load_generic_lookup_cache(), 1);
    __ ret(0);
  
    // Load property array property.
    __ bind(&property_array_property);
    __ movp(rax, FieldOperand(rdx, JSObject::kPropertiesOffset));
    __ movp(rax, FieldOperand(rax, rdi, times_pointer_size,
                              FixedArray::kHeaderSize));
    __ IncrementCounter(counters->keyed_load_generic_lookup_cache(), 1);
    __ ret(0);
  
    // Do a quick inline probe of the receiver's dictionary, if it
    // exists.
    __ bind(&probe_dictionary);
    // rdx: receiver
    // rax: key
    // rbx: elements
  
    __ movp(rcx, FieldOperand(rdx, JSObject::kMapOffset));
    __ movb(rcx, FieldOperand(rcx, Map::kInstanceTypeOffset));
    GenerateGlobalInstanceTypeCheck(masm, rcx, &slow);
  
    GenerateDictionaryLoad(masm, &slow, rbx, rax, rcx, rdi, rax);
    __ IncrementCounter(counters->keyed_load_generic_symbol(), 1);
    __ ret(0);
  
    __ bind(&index_name);
    __ IndexFromHash(rbx, rax);
    __ jmp(&index_smi);
  }
  
  
  void KeyedLoadIC::GenerateString(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label miss;
  
    Register receiver = rdx;
    Register index = rax;
    Register scratch = rcx;
    Register result = rax;
  
    StringCharAtGenerator char_at_generator(receiver,
                                            index,
                                            scratch,
                                            result,
                                            &miss,  // When not a string.
                                            &miss,  // When not a number.
                                            &miss,  // When index out of range.
                                            STRING_INDEX_IS_ARRAY_INDEX);
    char_at_generator.GenerateFast(masm);
    __ ret(0);
  
    StubRuntimeCallHelper call_helper;
    char_at_generator.GenerateSlow(masm, call_helper);
  
    __ bind(&miss);
    GenerateMiss(masm);
  }
  
  
  void KeyedLoadIC::GenerateIndexedInterceptor(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label slow;
  
    // Check that the receiver isn't a smi.
    __ JumpIfSmi(rdx, &slow);
  
    // Check that the key is an array index, that is Uint32.
    STATIC_ASSERT(kSmiValueSize <= 32);
    __ JumpUnlessNonNegativeSmi(rax, &slow);
  
    // Get the map of the receiver.
    __ movp(rcx, FieldOperand(rdx, HeapObject::kMapOffset));
  
    // Check that it has indexed interceptor and access checks
    // are not enabled for this object.
    __ movb(rcx, FieldOperand(rcx, Map::kBitFieldOffset));
    __ andb(rcx, Immediate(kSlowCaseBitFieldMask));
    __ cmpb(rcx, Immediate(1 << Map::kHasIndexedInterceptor));
    __ j(not_zero, &slow);
  
    // Everything is fine, call runtime.
    __ PopReturnAddressTo(rcx);
    __ push(rdx);  // receiver
    __ push(rax);  // key
    __ PushReturnAddressFrom(rcx);
  
    // Perform tail call to the entry.
    __ TailCallExternalReference(
        ExternalReference(IC_Utility(kKeyedLoadPropertyWithInterceptor),
                          masm->isolate()),
        2,
        1);
  
    __ bind(&slow);
    GenerateMiss(masm);
  }
  
  
  static void KeyedStoreGenerateGenericHelper(
      MacroAssembler* masm,
      Label* fast_object,
      Label* fast_double,
      Label* slow,
      KeyedStoreCheckMap check_map,
      KeyedStoreIncrementLength increment_length) {
    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);
    // rax: value
    // rbx: receiver's elements array (a FixedArray)
    // rcx: index
    // rdx: receiver (a JSArray)
    // r9: map of receiver
    if (check_map == kCheckMap) {
      __ movp(rdi, FieldOperand(rbx, HeapObject::kMapOffset));
      __ CompareRoot(rdi, Heap::kFixedArrayMapRootIndex);
      __ j(not_equal, 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;
    __ movp(kScratchRegister, FieldOperand(rbx,
                                           rcx,
                                           times_pointer_size,
                                           FixedArray::kHeaderSize));
    __ CompareRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
    __ j(not_equal, &holecheck_passed1);
    __ JumpIfDictionaryInPrototypeChain(rdx, rdi, kScratchRegister, slow);
  
    __ bind(&holecheck_passed1);
  
    // Smi stores don't require further checks.
    Label non_smi_value;
    __ JumpIfNotSmi(rax, &non_smi_value);
    if (increment_length == kIncrementLength) {
      // Add 1 to receiver->length.
      __ leal(rdi, Operand(rcx, 1));
      __ Integer32ToSmiField(FieldOperand(rdx, JSArray::kLengthOffset), rdi);
    }
    // It's irrelevant whether array is smi-only or not when writing a smi.
    __ movp(FieldOperand(rbx, rcx, times_pointer_size, FixedArray::kHeaderSize),
            rax);
    __ ret(0);
  
    __ bind(&non_smi_value);
    // Writing a non-smi, check whether array allows non-smi elements.
    // r9: receiver's map
    __ CheckFastObjectElements(r9, &transition_smi_elements);
  
    __ bind(&finish_object_store);
    if (increment_length == kIncrementLength) {
      // Add 1 to receiver->length.
      __ leal(rdi, Operand(rcx, 1));
      __ Integer32ToSmiField(FieldOperand(rdx, JSArray::kLengthOffset), rdi);
    }
    __ movp(FieldOperand(rbx, rcx, times_pointer_size, FixedArray::kHeaderSize),
            rax);
    __ movp(rdx, rax);  // Preserve the value which is returned.
    __ RecordWriteArray(
        rbx, rdx, rcx, kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
    __ ret(0);
  
    __ bind(fast_double);
    if (check_map == kCheckMap) {
      // Check for fast double array case. If this fails, call through to the
      // runtime.
      // rdi: elements array's map
      __ CompareRoot(rdi, Heap::kFixedDoubleArrayMapRootIndex);
      __ j(not_equal, 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.
    uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
    __ cmpl(FieldOperand(rbx, rcx, times_8, offset), Immediate(kHoleNanUpper32));
    __ j(not_equal, &fast_double_without_map_check);
    __ JumpIfDictionaryInPrototypeChain(rdx, rdi, kScratchRegister, slow);
  
    __ bind(&fast_double_without_map_check);
    __ StoreNumberToDoubleElements(rax, rbx, rcx, xmm0,
                                   &transition_double_elements);
    if (increment_length == kIncrementLength) {
      // Add 1 to receiver->length.
      __ leal(rdi, Operand(rcx, 1));
      __ Integer32ToSmiField(FieldOperand(rdx, JSArray::kLengthOffset), rdi);
    }
    __ ret(0);
  
    __ bind(&transition_smi_elements);
    __ movp(rbx, FieldOperand(rdx, HeapObject::kMapOffset));
  
    // Transition the array appropriately depending on the value type.
    __ movp(r9, FieldOperand(rax, HeapObject::kMapOffset));
    __ CompareRoot(r9, Heap::kHeapNumberMapRootIndex);
    __ j(not_equal, &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,
                                           rbx,
                                           rdi,
                                           slow);
    AllocationSiteMode mode = AllocationSite::GetMode(FAST_SMI_ELEMENTS,
                                                      FAST_DOUBLE_ELEMENTS);
    ElementsTransitionGenerator::GenerateSmiToDouble(masm, mode, slow);
    __ movp(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
    __ jmp(&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,
                                           rbx,
                                           rdi,
                                           slow);
    mode = AllocationSite::GetMode(FAST_SMI_ELEMENTS, FAST_ELEMENTS);
    ElementsTransitionGenerator::GenerateMapChangeElementsTransition(masm, mode,
                                                                     slow);
    __ movp(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
    __ jmp(&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
    __ movp(rbx, FieldOperand(rdx, HeapObject::kMapOffset));
    __ LoadTransitionedArrayMapConditional(FAST_DOUBLE_ELEMENTS,
                                           FAST_ELEMENTS,
                                           rbx,
                                           rdi,
                                           slow);
    mode = AllocationSite::GetMode(FAST_DOUBLE_ELEMENTS, FAST_ELEMENTS);
    ElementsTransitionGenerator::GenerateDoubleToObject(masm, mode, slow);
    __ movp(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
    __ jmp(&finish_object_store);
  }
  
  
  void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm,
                                     StrictModeFlag strict_mode) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label slow, slow_with_tagged_index, fast_object, fast_object_grow;
    Label fast_double, fast_double_grow;
    Label array, extra, check_if_double_array;
  
    // Check that the object isn't a smi.
    __ JumpIfSmi(rdx, &slow_with_tagged_index);
    // Get the map from the receiver.
    __ movp(r9, FieldOperand(rdx, 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.
    __ testb(FieldOperand(r9, Map::kBitFieldOffset),
             Immediate(1 << Map::kIsAccessCheckNeeded | 1 << Map::kIsObserved));
    __ j(not_zero, &slow_with_tagged_index);
    // Check that the key is a smi.
    __ JumpIfNotSmi(rcx, &slow_with_tagged_index);
    __ SmiToInteger32(rcx, rcx);
  
    __ CmpInstanceType(r9, JS_ARRAY_TYPE);
    __ j(equal, &array);
    // Check that the object is some kind of JSObject.
    __ CmpInstanceType(r9, FIRST_JS_OBJECT_TYPE);
    __ j(below, &slow);
  
    // Object case: Check key against length in the elements array.
    // rax: value
    // rdx: JSObject
    // rcx: index
    __ movp(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
    // Check array bounds.
    __ SmiCompareInteger32(FieldOperand(rbx, FixedArray::kLengthOffset), rcx);
    // rax: value
    // rbx: FixedArray
    // rcx: index
    __ j(above, &fast_object);
  
    // Slow case: call runtime.
    __ bind(&slow);
    __ Integer32ToSmi(rcx, rcx);
    __ bind(&slow_with_tagged_index);
    GenerateRuntimeSetProperty(masm, strict_mode);
    // Never returns to here.
  
    // 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);
    // rax: value
    // rdx: receiver (a JSArray)
    // rbx: receiver's elements array (a FixedArray)
    // rcx: index
    // flags: smicompare (rdx.length(), rbx)
    __ j(not_equal, &slow);  // do not leave holes in the array
    __ SmiCompareInteger32(FieldOperand(rbx, FixedArray::kLengthOffset), rcx);
    __ j(below_equal, &slow);
    // Increment index to get new length.
    __ movp(rdi, FieldOperand(rbx, HeapObject::kMapOffset));
    __ CompareRoot(rdi, Heap::kFixedArrayMapRootIndex);
    __ j(not_equal, &check_if_double_array);
    __ jmp(&fast_object_grow);
  
    __ bind(&check_if_double_array);
    // rdi: elements array's map
    __ CompareRoot(rdi, Heap::kFixedDoubleArrayMapRootIndex);
    __ j(not_equal, &slow);
    __ jmp(&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);
    // rax: value
    // rdx: receiver (a JSArray)
    // rcx: index
    __ movp(rbx, FieldOperand(rdx, JSObject::kElementsOffset));
  
    // Check the key against the length in the array, compute the
    // address to store into and fall through to fast case.
    __ SmiCompareInteger32(FieldOperand(rdx, JSArray::kLengthOffset), rcx);
    __ j(below_equal, &extra);
  
    KeyedStoreGenerateGenericHelper(masm, &fast_object, &fast_double,
                                    &slow, kCheckMap, kDontIncrementLength);
    KeyedStoreGenerateGenericHelper(masm, &fast_object_grow, &fast_double_grow,
                                    &slow, kDontCheckMap, kIncrementLength);
  }
  
  
  static Operand GenerateMappedArgumentsLookup(MacroAssembler* masm,
                                               Register object,
                                               Register key,
                                               Register scratch1,
                                               Register scratch2,
                                               Register scratch3,
                                               Label* unmapped_case,
                                               Label* slow_case) {
    Heap* heap = masm->isolate()->heap();
  
    // Check that the receiver is a JSObject. Because of the elements
    // map check later, we do not need to check for interceptors or
    // whether it requires access checks.
    __ JumpIfSmi(object, slow_case);
    // Check that the object is some kind of JSObject.
    __ CmpObjectType(object, FIRST_JS_RECEIVER_TYPE, scratch1);
    __ j(below, slow_case);
  
    // Check that the key is a positive smi.
    Condition check = masm->CheckNonNegativeSmi(key);
    __ j(NegateCondition(check), slow_case);
  
    // Load the elements into scratch1 and check its map. If not, jump
    // to the unmapped lookup with the parameter map in scratch1.
    Handle<Map> arguments_map(heap->non_strict_arguments_elements_map());
    __ movp(scratch1, FieldOperand(object, JSObject::kElementsOffset));
    __ CheckMap(scratch1, arguments_map, slow_case, DONT_DO_SMI_CHECK);
  
    // Check if element is in the range of mapped arguments.
    __ movp(scratch2, FieldOperand(scratch1, FixedArray::kLengthOffset));
    __ SmiSubConstant(scratch2, scratch2, Smi::FromInt(2));
    __ cmpq(key, scratch2);
    __ j(greater_equal, unmapped_case);
  
    // Load element index and check whether it is the hole.
    const int kHeaderSize = FixedArray::kHeaderSize + 2 * kPointerSize;
    __ SmiToInteger64(scratch3, key);
    __ movp(scratch2, FieldOperand(scratch1,
                                   scratch3,
                                   times_pointer_size,
                                   kHeaderSize));
    __ CompareRoot(scratch2, Heap::kTheHoleValueRootIndex);
    __ j(equal, unmapped_case);
  
    // Load value from context and return it. We can reuse scratch1 because
    // we do not jump to the unmapped lookup (which requires the parameter
    // map in scratch1).
    __ movp(scratch1, FieldOperand(scratch1, FixedArray::kHeaderSize));
    __ SmiToInteger64(scratch3, scratch2);
    return FieldOperand(scratch1,
                        scratch3,
                        times_pointer_size,
                        Context::kHeaderSize);
  }
  
  
  static Operand GenerateUnmappedArgumentsLookup(MacroAssembler* masm,
                                                 Register key,
                                                 Register parameter_map,
                                                 Register scratch,
                                                 Label* slow_case) {
    // Element is in arguments backing store, which is referenced by the
    // second element of the parameter_map. The parameter_map register
    // must be loaded with the parameter map of the arguments object and is
    // overwritten.
    const int kBackingStoreOffset = FixedArray::kHeaderSize + kPointerSize;
    Register backing_store = parameter_map;
    __ movp(backing_store, FieldOperand(parameter_map, kBackingStoreOffset));
    Handle<Map> fixed_array_map(masm->isolate()->heap()->fixed_array_map());
    __ CheckMap(backing_store, fixed_array_map, slow_case, DONT_DO_SMI_CHECK);
    __ movp(scratch, FieldOperand(backing_store, FixedArray::kLengthOffset));
    __ cmpq(key, scratch);
    __ j(greater_equal, slow_case);
    __ SmiToInteger64(scratch, key);
    return FieldOperand(backing_store,
                        scratch,
                        times_pointer_size,
                        FixedArray::kHeaderSize);
  }
  
  
  void KeyedLoadIC::GenerateNonStrictArguments(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label slow, notin;
    Operand mapped_location =
        GenerateMappedArgumentsLookup(
            masm, rdx, rax, rbx, rcx, rdi, &notin, &slow);
    __ movp(rax, mapped_location);
    __ Ret();
    __ bind(&notin);
    // The unmapped lookup expects that the parameter map is in rbx.
    Operand unmapped_location =
        GenerateUnmappedArgumentsLookup(masm, rax, rbx, rcx, &slow);
    __ CompareRoot(unmapped_location, Heap::kTheHoleValueRootIndex);
    __ j(equal, &slow);
    __ movp(rax, unmapped_location);
    __ Ret();
    __ bind(&slow);
    GenerateMiss(masm);
  }
  
  
  void KeyedStoreIC::GenerateNonStrictArguments(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    Label slow, notin;
    Operand mapped_location = GenerateMappedArgumentsLookup(
        masm, rdx, rcx, rbx, rdi, r8, &notin, &slow);
    __ movp(mapped_location, rax);
    __ lea(r9, mapped_location);
    __ movp(r8, rax);
    __ RecordWrite(rbx,
                   r9,
                   r8,
                   kDontSaveFPRegs,
                   EMIT_REMEMBERED_SET,
                   INLINE_SMI_CHECK);
    __ Ret();
    __ bind(&notin);
    // The unmapped lookup expects that the parameter map is in rbx.
    Operand unmapped_location =
        GenerateUnmappedArgumentsLookup(masm, rcx, rbx, rdi, &slow);
    __ movp(unmapped_location, rax);
    __ lea(r9, unmapped_location);
    __ movp(r8, rax);
    __ RecordWrite(rbx,
                   r9,
                   r8,
                   kDontSaveFPRegs,
                   EMIT_REMEMBERED_SET,
                   INLINE_SMI_CHECK);
    __ Ret();
    __ bind(&slow);
    GenerateMiss(masm);
  }
  
  
  void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : receiver
    //  -- rcx    : name
    //  -- rsp[0] : return address
    // -----------------------------------
  
    // Probe the stub cache.
    Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
    masm->isolate()->stub_cache()->GenerateProbe(
        masm, flags, rax, rcx, rbx, rdx);
  
    GenerateMiss(masm);
  }
  
  
  void LoadIC::GenerateNormal(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : receiver
    //  -- rcx    : name
    //  -- rsp[0] : return address
    // -----------------------------------
    Label miss;
  
    GenerateNameDictionaryReceiverCheck(masm, rax, rdx, rbx, &miss);
  
    //  rdx: elements
    // Search the dictionary placing the result in rax.
    GenerateDictionaryLoad(masm, &miss, rdx, rcx, rbx, rdi, rax);
    __ ret(0);
  
    // Cache miss: Jump to runtime.
    __ bind(&miss);
    GenerateMiss(masm);
  }
  
  
  void LoadIC::GenerateMiss(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : receiver
    //  -- rcx    : name
    //  -- rsp[0] : return address
    // -----------------------------------
  
    Counters* counters = masm->isolate()->counters();
    __ IncrementCounter(counters->load_miss(), 1);
  
    __ PopReturnAddressTo(rbx);
    __ push(rax);  // receiver
    __ push(rcx);  // name
    __ PushReturnAddressFrom(rbx);
  
    // Perform tail call to the entry.
    ExternalReference ref =
        ExternalReference(IC_Utility(kLoadIC_Miss), masm->isolate());
    __ TailCallExternalReference(ref, 2, 1);
  }
  
  
  void LoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : receiver
    //  -- rcx    : name
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rax);  // receiver
    __ push(rcx);  // name
    __ PushReturnAddressFrom(rbx);
  
    // Perform tail call to the entry.
    __ TailCallRuntime(Runtime::kGetProperty, 2, 1);
  }
  
  
  void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    Counters* counters = masm->isolate()->counters();
    __ IncrementCounter(counters->keyed_load_miss(), 1);
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rax);  // name
    __ PushReturnAddressFrom(rbx);
  
    // Perform tail call to the entry.
    ExternalReference ref =
        ExternalReference(IC_Utility(kKeyedLoadIC_Miss), masm->isolate());
    __ TailCallExternalReference(ref, 2, 1);
  }
  
  
  void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rax);  // name
    __ PushReturnAddressFrom(rbx);
  
    // Perform tail call to the entry.
    __ TailCallRuntime(Runtime::kKeyedGetProperty, 2, 1);
  }
  
  
  void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : name
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    // Get the receiver from the stack and probe the stub cache.
    Code::Flags flags = Code::ComputeHandlerFlags(Code::STORE_IC);
    masm->isolate()->stub_cache()->GenerateProbe(
        masm, flags, rdx, rcx, rbx, no_reg);
  
    // Cache miss: Jump to runtime.
    GenerateMiss(masm);
  }
  
  
  void StoreIC::GenerateMiss(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : name
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rcx);  // name
    __ push(rax);  // value
    __ PushReturnAddressFrom(rbx);
  
    // Perform tail call to the entry.
    ExternalReference ref =
        ExternalReference(IC_Utility(kStoreIC_Miss), masm->isolate());
    __ TailCallExternalReference(ref, 3, 1);
  }
  
  
  void StoreIC::GenerateNormal(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : name
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    Label miss;
  
    GenerateNameDictionaryReceiverCheck(masm, rdx, rbx, rdi, &miss);
  
    GenerateDictionaryStore(masm, &miss, rbx, rcx, rax, r8, r9);
    Counters* counters = masm->isolate()->counters();
    __ IncrementCounter(counters->store_normal_hit(), 1);
    __ ret(0);
  
    __ bind(&miss);
    __ IncrementCounter(counters->store_normal_miss(), 1);
    GenerateMiss(masm);
  }
  
  
  void StoreIC::GenerateRuntimeSetProperty(MacroAssembler* masm,
                                           StrictModeFlag strict_mode) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : name
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
    __ PopReturnAddressTo(rbx);
    __ push(rdx);
    __ push(rcx);
    __ push(rax);
    __ Push(Smi::FromInt(NONE));  // PropertyAttributes
    __ Push(Smi::FromInt(strict_mode));
    __ PushReturnAddressFrom(rbx);
  
    // Do tail-call to runtime routine.
    __ TailCallRuntime(Runtime::kSetProperty, 5, 1);
  }
  
  
  void KeyedStoreIC::GenerateRuntimeSetProperty(MacroAssembler* masm,
                                                StrictModeFlag strict_mode) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rcx);  // key
    __ push(rax);  // value
    __ Push(Smi::FromInt(NONE));          // PropertyAttributes
    __ Push(Smi::FromInt(strict_mode));   // Strict mode.
    __ PushReturnAddressFrom(rbx);
  
    // Do tail-call to runtime routine.
    __ TailCallRuntime(Runtime::kSetProperty, 5, 1);
  }
  
  
  void StoreIC::GenerateSlow(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rcx);  // key
    __ push(rax);  // value
    __ PushReturnAddressFrom(rbx);
  
    // Do tail-call to runtime routine.
    ExternalReference ref(IC_Utility(kStoreIC_Slow), masm->isolate());
    __ TailCallExternalReference(ref, 3, 1);
  }
  
  
  void KeyedStoreIC::GenerateSlow(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rcx);  // key
    __ push(rax);  // value
    __ PushReturnAddressFrom(rbx);
  
    // Do tail-call to runtime routine.
    ExternalReference ref(IC_Utility(kKeyedStoreIC_Slow), masm->isolate());
    __ TailCallExternalReference(ref, 3, 1);
  }
  
  
  void KeyedStoreIC::GenerateMiss(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- rax    : value
    //  -- rcx    : key
    //  -- rdx    : receiver
    //  -- rsp[0] : return address
    // -----------------------------------
  
    __ PopReturnAddressTo(rbx);
    __ push(rdx);  // receiver
    __ push(rcx);  // key
    __ push(rax);  // value
    __ PushReturnAddressFrom(rbx);
  
    // Do tail-call to runtime routine.
    ExternalReference ref =
        ExternalReference(IC_Utility(kKeyedStoreIC_Miss), masm->isolate());
    __ TailCallExternalReference(ref, 3, 1);
  }
  
  
  #undef __
  
  
  Condition CompareIC::ComputeCondition(Token::Value op) {
    switch (op) {
      case Token::EQ_STRICT:
      case Token::EQ:
        return equal;
      case Token::LT:
        return less;
      case Token::GT:
        return greater;
      case Token::LTE:
        return less_equal;
      case Token::GTE:
        return greater_equal;
      default:
        UNREACHABLE();
        return no_condition;
    }
  }
  
  
  bool CompareIC::HasInlinedSmiCode(Address address) {
    // The address of the instruction following the call.
    Address test_instruction_address =
        address + Assembler::kCallTargetAddressOffset;
  
    // If the instruction following the call is not a test al, nothing
    // was inlined.
    return *test_instruction_address == Assembler::kTestAlByte;
  }
  
  
  void PatchInlinedSmiCode(Address address, InlinedSmiCheck check) {
    // The address of the instruction following the call.
    Address test_instruction_address =
        address + Assembler::kCallTargetAddressOffset;
  
    // If the instruction following the call is not a test al, nothing
    // was inlined.
    if (*test_instruction_address != Assembler::kTestAlByte) {
      ASSERT(*test_instruction_address == Assembler::kNopByte);
      return;
    }
  
    Address delta_address = test_instruction_address + 1;
    // The delta to the start of the map check instruction and the
    // condition code uses at the patched jump.
    int8_t delta = *reinterpret_cast<int8_t*>(delta_address);
    if (FLAG_trace_ic) {
      PrintF("[  patching ic at %p, test=%p, delta=%d\n",
             address, test_instruction_address, delta);
    }
  
    // Patch with a short conditional jump. Enabling means switching from a short
    // jump-if-carry/not-carry to jump-if-zero/not-zero, whereas disabling is the
    // reverse operation of that.
    Address jmp_address = test_instruction_address - delta;
    ASSERT((check == ENABLE_INLINED_SMI_CHECK)
           ? (*jmp_address == Assembler::kJncShortOpcode ||
              *jmp_address == Assembler::kJcShortOpcode)
           : (*jmp_address == Assembler::kJnzShortOpcode ||
              *jmp_address == Assembler::kJzShortOpcode));
    Condition cc = (check == ENABLE_INLINED_SMI_CHECK)
        ? (*jmp_address == Assembler::kJncShortOpcode ? not_zero : zero)
        : (*jmp_address == Assembler::kJnzShortOpcode ? not_carry : carry);
    *jmp_address = static_cast<byte>(Assembler::kJccShortPrefix | cc);
  }
  
  
  } }  // namespace v8::internal
  
  #endif  // V8_TARGET_ARCH_X64
  