handler-compiler-arm64.cc

Go to the documentation of this file.

// Copyright 2014 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_ARM64
 
#include "src/ic/call-optimization.h"
#include "src/ic/handler-compiler.h"
#include "src/ic/ic.h"
 
namespace v8 {
namespace internal {
 
#define __ ACCESS_MASM(masm)
 
 
void PropertyHandlerCompiler::GenerateDictionaryNegativeLookup(
    MacroAssembler* masm, Label* miss_label, Register receiver,
    Handle<Name> name, Register scratch0, Register scratch1) {
  DCHECK(!AreAliased(receiver, scratch0, scratch1));
  DCHECK(name->IsUniqueName());
  Counters* counters = masm->isolate()->counters();
  __ IncrementCounter(counters->negative_lookups(), 1, scratch0, scratch1);
  __ IncrementCounter(counters->negative_lookups_miss(), 1, scratch0, scratch1);
 
  Label done;
 
  const int kInterceptorOrAccessCheckNeededMask =
      (1 << Map::kHasNamedInterceptor) | (1 << Map::kIsAccessCheckNeeded);
 
  // Bail out if the receiver has a named interceptor or requires access checks.
  Register map = scratch1;
  __ Ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
  __ Ldrb(scratch0, FieldMemOperand(map, Map::kBitFieldOffset));
  __ Tst(scratch0, kInterceptorOrAccessCheckNeededMask);
  __ B(ne, miss_label);
 
  // Check that receiver is a JSObject.
  __ Ldrb(scratch0, FieldMemOperand(map, Map::kInstanceTypeOffset));
  __ Cmp(scratch0, FIRST_SPEC_OBJECT_TYPE);
  __ B(lt, miss_label);
 
  // Load properties array.
  Register properties = scratch0;
  __ Ldr(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
  // Check that the properties array is a dictionary.
  __ Ldr(map, FieldMemOperand(properties, HeapObject::kMapOffset));
  __ JumpIfNotRoot(map, Heap::kHashTableMapRootIndex, miss_label);
 
  NameDictionaryLookupStub::GenerateNegativeLookup(
      masm, miss_label, &done, receiver, properties, name, scratch1);
  __ Bind(&done);
  __ DecrementCounter(counters->negative_lookups_miss(), 1, scratch0, scratch1);
}
 
 
void NamedLoadHandlerCompiler::GenerateDirectLoadGlobalFunctionPrototype(
    MacroAssembler* masm, int index, Register prototype, Label* miss) {
  Isolate* isolate = masm->isolate();
  // Get the global function with the given index.
  Handle<JSFunction> function(
      JSFunction::cast(isolate->native_context()->get(index)));
 
  // Check we're still in the same context.
  Register scratch = prototype;
  __ Ldr(scratch, GlobalObjectMemOperand());
  __ Ldr(scratch, FieldMemOperand(scratch, GlobalObject::kNativeContextOffset));
  __ Ldr(scratch, ContextMemOperand(scratch, index));
  __ Cmp(scratch, Operand(function));
  __ B(ne, miss);
 
  // Load its initial map. The global functions all have initial maps.
  __ Mov(prototype, Operand(Handle<Map>(function->initial_map())));
  // Load the prototype from the initial map.
  __ Ldr(prototype, FieldMemOperand(prototype, Map::kPrototypeOffset));
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadFunctionPrototype(
    MacroAssembler* masm, Register receiver, Register scratch1,
    Register scratch2, Label* miss_label) {
  __ TryGetFunctionPrototype(receiver, scratch1, scratch2, miss_label);
  // TryGetFunctionPrototype can't put the result directly in x0 because the
  // 3 inputs registers can't alias and we call this function from
  // LoadIC::GenerateFunctionPrototype, where receiver is x0. So we explicitly
  // move the result in x0.
  __ Mov(x0, scratch1);
  __ Ret();
}
 
 
// Generate code to check that a global property cell is empty. Create
// the property cell at compilation time if no cell exists for the
// property.
void PropertyHandlerCompiler::GenerateCheckPropertyCell(
    MacroAssembler* masm, Handle<JSGlobalObject> global, Handle<Name> name,
    Register scratch, Label* miss) {
  Handle<Cell> cell = JSGlobalObject::EnsurePropertyCell(global, name);
  DCHECK(cell->value()->IsTheHole());
  __ Mov(scratch, Operand(cell));
  __ Ldr(scratch, FieldMemOperand(scratch, Cell::kValueOffset));
  __ JumpIfNotRoot(scratch, Heap::kTheHoleValueRootIndex, miss);
}
 
 
static void PushInterceptorArguments(MacroAssembler* masm, Register receiver,
                                     Register holder, Register name,
                                     Handle<JSObject> holder_obj) {
  STATIC_ASSERT(NamedLoadHandlerCompiler::kInterceptorArgsNameIndex == 0);
  STATIC_ASSERT(NamedLoadHandlerCompiler::kInterceptorArgsInfoIndex == 1);
  STATIC_ASSERT(NamedLoadHandlerCompiler::kInterceptorArgsThisIndex == 2);
  STATIC_ASSERT(NamedLoadHandlerCompiler::kInterceptorArgsHolderIndex == 3);
  STATIC_ASSERT(NamedLoadHandlerCompiler::kInterceptorArgsLength == 4);
 
  __ Push(name);
  Handle<InterceptorInfo> interceptor(holder_obj->GetNamedInterceptor());
  DCHECK(!masm->isolate()->heap()->InNewSpace(*interceptor));
  Register scratch = name;
  __ Mov(scratch, Operand(interceptor));
  __ Push(scratch, receiver, holder);
}
 
 
static void CompileCallLoadPropertyWithInterceptor(
    MacroAssembler* masm, Register receiver, Register holder, Register name,
    Handle<JSObject> holder_obj, IC::UtilityId id) {
  PushInterceptorArguments(masm, receiver, holder, name, holder_obj);
 
  __ CallExternalReference(ExternalReference(IC_Utility(id), masm->isolate()),
                           NamedLoadHandlerCompiler::kInterceptorArgsLength);
}
 
 
// Generate call to api function.
void PropertyHandlerCompiler::GenerateFastApiCall(
    MacroAssembler* masm, const CallOptimization& optimization,
    Handle<Map> receiver_map, Register receiver, Register scratch,
    bool is_store, int argc, Register* values) {
  DCHECK(!AreAliased(receiver, scratch));
 
  MacroAssembler::PushPopQueue queue(masm);
  queue.Queue(receiver);
  // Write the arguments to the stack frame.
  for (int i = 0; i < argc; i++) {
    Register arg = values[argc - 1 - i];
    DCHECK(!AreAliased(receiver, scratch, arg));
    queue.Queue(arg);
  }
  queue.PushQueued();
 
  DCHECK(optimization.is_simple_api_call());
 
  // Abi for CallApiFunctionStub.
  Register callee = x0;
  Register call_data = x4;
  Register holder = x2;
  Register api_function_address = x1;
 
  // Put holder in place.
  CallOptimization::HolderLookup holder_lookup;
  Handle<JSObject> api_holder =
      optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
  switch (holder_lookup) {
    case CallOptimization::kHolderIsReceiver:
      __ Mov(holder, receiver);
      break;
    case CallOptimization::kHolderFound:
      __ LoadObject(holder, api_holder);
      break;
    case CallOptimization::kHolderNotFound:
      UNREACHABLE();
      break;
  }
 
  Isolate* isolate = masm->isolate();
  Handle<JSFunction> function = optimization.constant_function();
  Handle<CallHandlerInfo> api_call_info = optimization.api_call_info();
  Handle<Object> call_data_obj(api_call_info->data(), isolate);
 
  // Put callee in place.
  __ LoadObject(callee, function);
 
  bool call_data_undefined = false;
  // Put call_data in place.
  if (isolate->heap()->InNewSpace(*call_data_obj)) {
    __ LoadObject(call_data, api_call_info);
    __ Ldr(call_data, FieldMemOperand(call_data, CallHandlerInfo::kDataOffset));
  } else if (call_data_obj->IsUndefined()) {
    call_data_undefined = true;
    __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
  } else {
    __ LoadObject(call_data, call_data_obj);
  }
 
  // Put api_function_address in place.
  Address function_address = v8::ToCData<Address>(api_call_info->callback());
  ApiFunction fun(function_address);
  ExternalReference ref = ExternalReference(
      &fun, ExternalReference::DIRECT_API_CALL, masm->isolate());
  __ Mov(api_function_address, ref);
 
  // Jump to stub.
  CallApiFunctionStub stub(isolate, is_store, call_data_undefined, argc);
  __ TailCallStub(&stub);
}
 
 
void NamedStoreHandlerCompiler::GenerateStoreViaSetter(
    MacroAssembler* masm, Handle<HeapType> type, Register receiver,
    Handle<JSFunction> setter) {
  // ----------- S t a t e -------------
  //  -- lr    : return address
  // -----------------------------------
  Label miss;
 
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    // Save value register, so we can restore it later.
    __ Push(value());
 
    if (!setter.is_null()) {
      // Call the JavaScript setter with receiver and value on the stack.
      if (IC::TypeToMap(*type, masm->isolate())->IsJSGlobalObjectMap()) {
        // Swap in the global receiver.
        __ Ldr(receiver,
               FieldMemOperand(receiver, JSGlobalObject::kGlobalProxyOffset));
      }
      __ Push(receiver, value());
      ParameterCount actual(1);
      ParameterCount expected(setter);
      __ InvokeFunction(setter, expected, actual, CALL_FUNCTION,
                        NullCallWrapper());
    } else {
      // If we generate a global code snippet for deoptimization only, remember
      // the place to continue after deoptimization.
      masm->isolate()->heap()->SetSetterStubDeoptPCOffset(masm->pc_offset());
    }
 
    // We have to return the passed value, not the return value of the setter.
    __ Pop(x0);
 
    // Restore context register.
    __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  __ Ret();
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadViaGetter(
    MacroAssembler* masm, Handle<HeapType> type, Register receiver,
    Handle<JSFunction> getter) {
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    if (!getter.is_null()) {
      // Call the JavaScript getter with the receiver on the stack.
      if (IC::TypeToMap(*type, masm->isolate())->IsJSGlobalObjectMap()) {
        // Swap in the global receiver.
        __ Ldr(receiver,
               FieldMemOperand(receiver, JSGlobalObject::kGlobalProxyOffset));
      }
      __ Push(receiver);
      ParameterCount actual(0);
      ParameterCount expected(getter);
      __ InvokeFunction(getter, expected, actual, CALL_FUNCTION,
                        NullCallWrapper());
    } else {
      // If we generate a global code snippet for deoptimization only, remember
      // the place to continue after deoptimization.
      masm->isolate()->heap()->SetGetterStubDeoptPCOffset(masm->pc_offset());
    }
 
    // Restore context register.
    __ Ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  __ Ret();
}
 
 
void NamedStoreHandlerCompiler::GenerateSlow(MacroAssembler* masm) {
  // Push receiver, name and value for runtime call.
  __ Push(StoreDescriptor::ReceiverRegister(), StoreDescriptor::NameRegister(),
          StoreDescriptor::ValueRegister());
 
  // The slow case calls into the runtime to complete the store without causing
  // an IC miss that would otherwise cause a transition to the generic stub.
  ExternalReference ref =
      ExternalReference(IC_Utility(IC::kStoreIC_Slow), masm->isolate());
  __ TailCallExternalReference(ref, 3, 1);
}
 
 
void ElementHandlerCompiler::GenerateStoreSlow(MacroAssembler* masm) {
  ASM_LOCATION("ElementHandlerCompiler::GenerateStoreSlow");
 
  // Push receiver, key and value for runtime call.
  __ Push(StoreDescriptor::ReceiverRegister(), StoreDescriptor::NameRegister(),
          StoreDescriptor::ValueRegister());
 
  // The slow case calls into the runtime to complete the store without causing
  // an IC miss that would otherwise cause a transition to the generic stub.
  ExternalReference ref =
      ExternalReference(IC_Utility(IC::kKeyedStoreIC_Slow), masm->isolate());
  __ TailCallExternalReference(ref, 3, 1);
}
 
 
#undef __
#define __ ACCESS_MASM(masm())
 
 
Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
    Handle<PropertyCell> cell, Handle<Name> name, bool is_configurable) {
  Label miss;
  FrontendHeader(receiver(), name, &miss);
 
  // Get the value from the cell.
  Register result = StoreDescriptor::ValueRegister();
  __ Mov(result, Operand(cell));
  __ Ldr(result, FieldMemOperand(result, Cell::kValueOffset));
 
  // Check for deleted property if property can actually be deleted.
  if (is_configurable) {
    __ JumpIfRoot(result, Heap::kTheHoleValueRootIndex, &miss);
  }
 
  Counters* counters = isolate()->counters();
  __ IncrementCounter(counters->named_load_global_stub(), 1, x1, x3);
  __ Ret();
 
  FrontendFooter(name, &miss);
 
  // Return the generated code.
  return GetCode(kind(), Code::NORMAL, name);
}
 
 
Handle<Code> NamedStoreHandlerCompiler::CompileStoreInterceptor(
    Handle<Name> name) {
  Label miss;
 
  ASM_LOCATION("NamedStoreHandlerCompiler::CompileStoreInterceptor");
 
  __ Push(receiver(), this->name(), value());
 
  // Do tail-call to the runtime system.
  ExternalReference store_ic_property = ExternalReference(
      IC_Utility(IC::kStorePropertyWithInterceptor), isolate());
  __ TailCallExternalReference(store_ic_property, 3, 1);
 
  // Return the generated code.
  return GetCode(kind(), Code::FAST, name);
}
 
 
Register NamedStoreHandlerCompiler::value() {
  return StoreDescriptor::ValueRegister();
}
 
 
void NamedStoreHandlerCompiler::GenerateRestoreName(Label* label,
                                                    Handle<Name> name) {
  if (!label->is_unused()) {
    __ Bind(label);
    __ Mov(this->name(), Operand(name));
  }
}
 
 
// Generate StoreTransition code, value is passed in x0 register.
// When leaving generated code after success, the receiver_reg and storage_reg
// may be clobbered. Upon branch to miss_label, the receiver and name registers
// have their original values.
void NamedStoreHandlerCompiler::GenerateStoreTransition(
    Handle<Map> transition, Handle<Name> name, Register receiver_reg,
    Register storage_reg, Register value_reg, Register scratch1,
    Register scratch2, Register scratch3, Label* miss_label, Label* slow) {
  Label exit;
 
  DCHECK(!AreAliased(receiver_reg, storage_reg, value_reg, scratch1, scratch2,
                     scratch3));
 
  // We don't need scratch3.
  scratch3 = NoReg;
 
  int descriptor = transition->LastAdded();
  DescriptorArray* descriptors = transition->instance_descriptors();
  PropertyDetails details = descriptors->GetDetails(descriptor);
  Representation representation = details.representation();
  DCHECK(!representation.IsNone());
 
  if (details.type() == CONSTANT) {
    Handle<Object> constant(descriptors->GetValue(descriptor), isolate());
    __ LoadObject(scratch1, constant);
    __ Cmp(value_reg, scratch1);
    __ B(ne, miss_label);
  } else if (representation.IsSmi()) {
    __ JumpIfNotSmi(value_reg, miss_label);
  } else if (representation.IsHeapObject()) {
    __ JumpIfSmi(value_reg, miss_label);
    HeapType* field_type = descriptors->GetFieldType(descriptor);
    HeapType::Iterator<Map> it = field_type->Classes();
    if (!it.Done()) {
      __ Ldr(scratch1, FieldMemOperand(value_reg, HeapObject::kMapOffset));
      Label do_store;
      while (true) {
        __ CompareMap(scratch1, it.Current());
        it.Advance();
        if (it.Done()) {
          __ B(ne, miss_label);
          break;
        }
        __ B(eq, &do_store);
      }
      __ Bind(&do_store);
    }
  } else if (representation.IsDouble()) {
    UseScratchRegisterScope temps(masm());
    DoubleRegister temp_double = temps.AcquireD();
    __ SmiUntagToDouble(temp_double, value_reg, kSpeculativeUntag);
 
    Label do_store;
    __ JumpIfSmi(value_reg, &do_store);
 
    __ CheckMap(value_reg, scratch1, Heap::kHeapNumberMapRootIndex, miss_label,
                DONT_DO_SMI_CHECK);
    __ Ldr(temp_double, FieldMemOperand(value_reg, HeapNumber::kValueOffset));
 
    __ Bind(&do_store);
    __ AllocateHeapNumber(storage_reg, slow, scratch1, scratch2, temp_double,
                          NoReg, MUTABLE);
  }
 
  // Stub never generated for objects that require access checks.
  DCHECK(!transition->is_access_check_needed());
 
  // Perform map transition for the receiver if necessary.
  if (details.type() == FIELD &&
      Map::cast(transition->GetBackPointer())->unused_property_fields() == 0) {
    // The properties must be extended before we can store the value.
    // We jump to a runtime call that extends the properties array.
    __ Mov(scratch1, Operand(transition));
    __ Push(receiver_reg, scratch1, value_reg);
    __ TailCallExternalReference(
        ExternalReference(IC_Utility(IC::kSharedStoreIC_ExtendStorage),
                          isolate()),
        3, 1);
    return;
  }
 
  // Update the map of the object.
  __ Mov(scratch1, Operand(transition));
  __ Str(scratch1, FieldMemOperand(receiver_reg, HeapObject::kMapOffset));
 
  // Update the write barrier for the map field.
  __ RecordWriteField(receiver_reg, HeapObject::kMapOffset, scratch1, scratch2,
                      kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
                      OMIT_SMI_CHECK);
 
  if (details.type() == CONSTANT) {
    DCHECK(value_reg.is(x0));
    __ Ret();
    return;
  }
 
  int index = transition->instance_descriptors()->GetFieldIndex(
      transition->LastAdded());
 
  // Adjust for the number of properties stored in the object. Even in the
  // face of a transition we can use the old map here because the size of the
  // object and the number of in-object properties is not going to change.
  index -= transition->inobject_properties();
 
  // TODO(verwaest): Share this code as a code stub.
  SmiCheck smi_check =
      representation.IsTagged() ? INLINE_SMI_CHECK : OMIT_SMI_CHECK;
  Register prop_reg = representation.IsDouble() ? storage_reg : value_reg;
  if (index < 0) {
    // Set the property straight into the object.
    int offset = transition->instance_size() + (index * kPointerSize);
    __ Str(prop_reg, FieldMemOperand(receiver_reg, offset));
 
    if (!representation.IsSmi()) {
      // Update the write barrier for the array address.
      if (!representation.IsDouble()) {
        __ Mov(storage_reg, value_reg);
      }
      __ RecordWriteField(receiver_reg, offset, storage_reg, scratch1,
                          kLRHasNotBeenSaved, kDontSaveFPRegs,
                          EMIT_REMEMBERED_SET, smi_check);
    }
  } else {
    // Write to the properties array.
    int offset = index * kPointerSize + FixedArray::kHeaderSize;
    // Get the properties array
    __ Ldr(scratch1,
           FieldMemOperand(receiver_reg, JSObject::kPropertiesOffset));
    __ Str(prop_reg, FieldMemOperand(scratch1, offset));
 
    if (!representation.IsSmi()) {
      // Update the write barrier for the array address.
      if (!representation.IsDouble()) {
        __ Mov(storage_reg, value_reg);
      }
      __ RecordWriteField(scratch1, offset, storage_reg, receiver_reg,
                          kLRHasNotBeenSaved, kDontSaveFPRegs,
                          EMIT_REMEMBERED_SET, smi_check);
    }
  }
 
  __ Bind(&exit);
  // Return the value (register x0).
  DCHECK(value_reg.is(x0));
  __ Ret();
}
 
 
void NamedStoreHandlerCompiler::GenerateStoreField(LookupIterator* lookup,
                                                   Register value_reg,
                                                   Label* miss_label) {
  DCHECK(lookup->representation().IsHeapObject());
  __ JumpIfSmi(value_reg, miss_label);
  HeapType::Iterator<Map> it = lookup->GetFieldType()->Classes();
  __ Ldr(scratch1(), FieldMemOperand(value_reg, HeapObject::kMapOffset));
  Label do_store;
  while (true) {
    __ CompareMap(scratch1(), it.Current());
    it.Advance();
    if (it.Done()) {
      __ B(ne, miss_label);
      break;
    }
    __ B(eq, &do_store);
  }
  __ Bind(&do_store);
 
  StoreFieldStub stub(isolate(), lookup->GetFieldIndex(),
                      lookup->representation());
  GenerateTailCall(masm(), stub.GetCode());
}
 
 
Register PropertyHandlerCompiler::CheckPrototypes(
    Register object_reg, Register holder_reg, Register scratch1,
    Register scratch2, Handle<Name> name, Label* miss,
    PrototypeCheckType check) {
  Handle<Map> receiver_map(IC::TypeToMap(*type(), isolate()));
 
  // object_reg and holder_reg registers can alias.
  DCHECK(!AreAliased(object_reg, scratch1, scratch2));
  DCHECK(!AreAliased(holder_reg, scratch1, scratch2));
 
  // Keep track of the current object in register reg.
  Register reg = object_reg;
  int depth = 0;
 
  Handle<JSObject> current = Handle<JSObject>::null();
  if (type()->IsConstant()) {
    current = Handle<JSObject>::cast(type()->AsConstant()->Value());
  }
  Handle<JSObject> prototype = Handle<JSObject>::null();
  Handle<Map> current_map = receiver_map;
  Handle<Map> holder_map(holder()->map());
  // Traverse the prototype chain and check the maps in the prototype chain for
  // fast and global objects or do negative lookup for normal objects.
  while (!current_map.is_identical_to(holder_map)) {
    ++depth;
 
    // Only global objects and objects that do not require access
    // checks are allowed in stubs.
    DCHECK(current_map->IsJSGlobalProxyMap() ||
           !current_map->is_access_check_needed());
 
    prototype = handle(JSObject::cast(current_map->prototype()));
    if (current_map->is_dictionary_map() &&
        !current_map->IsJSGlobalObjectMap()) {
      DCHECK(!current_map->IsJSGlobalProxyMap());  // Proxy maps are fast.
      if (!name->IsUniqueName()) {
        DCHECK(name->IsString());
        name = factory()->InternalizeString(Handle<String>::cast(name));
      }
      DCHECK(current.is_null() || (current->property_dictionary()->FindEntry(
                                       name) == NameDictionary::kNotFound));
 
      GenerateDictionaryNegativeLookup(masm(), miss, reg, name, scratch1,
                                       scratch2);
 
      __ Ldr(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
      reg = holder_reg;  // From now on the object will be in holder_reg.
      __ Ldr(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
    } else {
      // Two possible reasons for loading the prototype from the map:
      // (1) Can't store references to new space in code.
      // (2) Handler is shared for all receivers with the same prototype
      //     map (but not necessarily the same prototype instance).
      bool load_prototype_from_map =
          heap()->InNewSpace(*prototype) || depth == 1;
      Register map_reg = scratch1;
      __ Ldr(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
 
      if (depth != 1 || check == CHECK_ALL_MAPS) {
        __ CheckMap(map_reg, current_map, miss, DONT_DO_SMI_CHECK);
      }
 
      // Check access rights to the global object.  This has to happen after
      // the map check so that we know that the object is actually a global
      // object.
      // This allows us to install generated handlers for accesses to the
      // global proxy (as opposed to using slow ICs). See corresponding code
      // in LookupForRead().
      if (current_map->IsJSGlobalProxyMap()) {
        UseScratchRegisterScope temps(masm());
        __ CheckAccessGlobalProxy(reg, scratch2, temps.AcquireX(), miss);
      } else if (current_map->IsJSGlobalObjectMap()) {
        GenerateCheckPropertyCell(masm(), Handle<JSGlobalObject>::cast(current),
                                  name, scratch2, miss);
      }
 
      reg = holder_reg;  // From now on the object will be in holder_reg.
 
      if (load_prototype_from_map) {
        __ Ldr(reg, FieldMemOperand(map_reg, Map::kPrototypeOffset));
      } else {
        __ Mov(reg, Operand(prototype));
      }
    }
 
    // Go to the next object in the prototype chain.
    current = prototype;
    current_map = handle(current->map());
  }
 
  // Log the check depth.
  LOG(isolate(), IntEvent("check-maps-depth", depth + 1));
 
  // Check the holder map.
  if (depth != 0 || check == CHECK_ALL_MAPS) {
    // Check the holder map.
    __ CheckMap(reg, scratch1, current_map, miss, DONT_DO_SMI_CHECK);
  }
 
  // Perform security check for access to the global object.
  DCHECK(current_map->IsJSGlobalProxyMap() ||
         !current_map->is_access_check_needed());
  if (current_map->IsJSGlobalProxyMap()) {
    __ CheckAccessGlobalProxy(reg, scratch1, scratch2, miss);
  }
 
  // Return the register containing the holder.
  return reg;
}
 
 
void NamedLoadHandlerCompiler::FrontendFooter(Handle<Name> name, Label* miss) {
  if (!miss->is_unused()) {
    Label success;
    __ B(&success);
 
    __ Bind(miss);
    TailCallBuiltin(masm(), MissBuiltin(kind()));
 
    __ Bind(&success);
  }
}
 
 
void NamedStoreHandlerCompiler::FrontendFooter(Handle<Name> name, Label* miss) {
  if (!miss->is_unused()) {
    Label success;
    __ B(&success);
 
    GenerateRestoreName(miss, name);
    TailCallBuiltin(masm(), MissBuiltin(kind()));
 
    __ Bind(&success);
  }
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadConstant(Handle<Object> value) {
  // Return the constant value.
  __ LoadObject(x0, value);
  __ Ret();
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadCallback(
    Register reg, Handle<ExecutableAccessorInfo> callback) {
  DCHECK(!AreAliased(scratch2(), scratch3(), scratch4(), reg));
 
  // Build ExecutableAccessorInfo::args_ list on the stack and push property
  // name below the exit frame to make GC aware of them and store pointers to
  // them.
  STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 0);
  STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 1);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 2);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 3);
  STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 4);
  STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 5);
  STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 6);
 
  __ Push(receiver());
 
  if (heap()->InNewSpace(callback->data())) {
    __ Mov(scratch3(), Operand(callback));
    __ Ldr(scratch3(),
           FieldMemOperand(scratch3(), ExecutableAccessorInfo::kDataOffset));
  } else {
    __ Mov(scratch3(), Operand(Handle<Object>(callback->data(), isolate())));
  }
  __ LoadRoot(scratch4(), Heap::kUndefinedValueRootIndex);
  __ Mov(scratch2(), Operand(ExternalReference::isolate_address(isolate())));
  __ Push(scratch3(), scratch4(), scratch4(), scratch2(), reg, name());
 
  Register args_addr = scratch2();
  __ Add(args_addr, __ StackPointer(), kPointerSize);
 
  // Stack at this point:
  //              sp[40] callback data
  //              sp[32] undefined
  //              sp[24] undefined
  //              sp[16] isolate
  // args_addr -> sp[8]  reg
  //              sp[0]  name
 
  // Abi for CallApiGetter.
  Register getter_address_reg = x2;
 
  // Set up the call.
  Address getter_address = v8::ToCData<Address>(callback->getter());
  ApiFunction fun(getter_address);
  ExternalReference::Type type = ExternalReference::DIRECT_GETTER_CALL;
  ExternalReference ref = ExternalReference(&fun, type, isolate());
  __ Mov(getter_address_reg, ref);
 
  CallApiGetterStub stub(isolate());
  __ TailCallStub(&stub);
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadInterceptorWithFollowup(
    LookupIterator* it, Register holder_reg) {
  DCHECK(!AreAliased(receiver(), this->name(), scratch1(), scratch2(),
                     scratch3()));
  DCHECK(holder()->HasNamedInterceptor());
  DCHECK(!holder()->GetNamedInterceptor()->getter()->IsUndefined());
 
  // Compile the interceptor call, followed by inline code to load the
  // property from further up the prototype chain if the call fails.
  // Check that the maps haven't changed.
  DCHECK(holder_reg.is(receiver()) || holder_reg.is(scratch1()));
 
  // Preserve the receiver register explicitly whenever it is different from the
  // holder and it is needed should the interceptor return without any result.
  // The ACCESSOR case needs the receiver to be passed into C++ code, the FIELD
  // case might cause a miss during the prototype check.
  bool must_perform_prototype_check =
      !holder().is_identical_to(it->GetHolder<JSObject>());
  bool must_preserve_receiver_reg =
      !receiver().is(holder_reg) &&
      (it->state() == LookupIterator::ACCESSOR || must_perform_prototype_check);
 
  // Save necessary data before invoking an interceptor.
  // Requires a frame to make GC aware of pushed pointers.
  {
    FrameScope frame_scope(masm(), StackFrame::INTERNAL);
    if (must_preserve_receiver_reg) {
      __ Push(receiver(), holder_reg, this->name());
    } else {
      __ Push(holder_reg, this->name());
    }
    // Invoke an interceptor.  Note: map checks from receiver to
    // interceptor's holder has been compiled before (see a caller
    // of this method.)
    CompileCallLoadPropertyWithInterceptor(
        masm(), receiver(), holder_reg, this->name(), holder(),
        IC::kLoadPropertyWithInterceptorOnly);
 
    // Check if interceptor provided a value for property.  If it's
    // the case, return immediately.
    Label interceptor_failed;
    __ JumpIfRoot(x0, Heap::kNoInterceptorResultSentinelRootIndex,
                  &interceptor_failed);
    frame_scope.GenerateLeaveFrame();
    __ Ret();
 
    __ Bind(&interceptor_failed);
    if (must_preserve_receiver_reg) {
      __ Pop(this->name(), holder_reg, receiver());
    } else {
      __ Pop(this->name(), holder_reg);
    }
    // Leave the internal frame.
  }
 
  GenerateLoadPostInterceptor(it, holder_reg);
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadInterceptor(Register holder_reg) {
  // Call the runtime system to load the interceptor.
  DCHECK(holder()->HasNamedInterceptor());
  DCHECK(!holder()->GetNamedInterceptor()->getter()->IsUndefined());
  PushInterceptorArguments(masm(), receiver(), holder_reg, this->name(),
                           holder());
 
  ExternalReference ref = ExternalReference(
      IC_Utility(IC::kLoadPropertyWithInterceptor), isolate());
  __ TailCallExternalReference(
      ref, NamedLoadHandlerCompiler::kInterceptorArgsLength, 1);
}
 
 
Handle<Code> NamedStoreHandlerCompiler::CompileStoreCallback(
    Handle<JSObject> object, Handle<Name> name,
    Handle<ExecutableAccessorInfo> callback) {
  ASM_LOCATION("NamedStoreHandlerCompiler::CompileStoreCallback");
  Register holder_reg = Frontend(receiver(), name);
 
  // Stub never generated for non-global objects that require access checks.
  DCHECK(holder()->IsJSGlobalProxy() || !holder()->IsAccessCheckNeeded());
 
  // receiver() and holder_reg can alias.
  DCHECK(!AreAliased(receiver(), scratch1(), scratch2(), value()));
  DCHECK(!AreAliased(holder_reg, scratch1(), scratch2(), value()));
  __ Mov(scratch1(), Operand(callback));
  __ Mov(scratch2(), Operand(name));
  __ Push(receiver(), holder_reg, scratch1(), scratch2(), value());
 
  // Do tail-call to the runtime system.
  ExternalReference store_callback_property =
      ExternalReference(IC_Utility(IC::kStoreCallbackProperty), isolate());
  __ TailCallExternalReference(store_callback_property, 5, 1);
 
  // Return the generated code.
  return GetCode(kind(), Code::FAST, name);
}
 
 
#undef __
}
}  // namespace v8::internal
 
#endif  // V8_TARGET_ARCH_IA32