handler-compiler-mips.cc

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// 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_MIPS
 
#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 NamedLoadHandlerCompiler::GenerateLoadViaGetter(
    MacroAssembler* masm, Handle<HeapType> type, Register receiver,
    Handle<JSFunction> getter) {
  // ----------- S t a t e -------------
  //  -- a0    : receiver
  //  -- a2    : name
  //  -- ra    : return address
  // -----------------------------------
  {
    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.
        __ lw(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.
    __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  __ Ret();
}
 
 
void NamedStoreHandlerCompiler::GenerateStoreViaSetter(
    MacroAssembler* masm, Handle<HeapType> type, Register receiver,
    Handle<JSFunction> setter) {
  // ----------- S t a t e -------------
  //  -- ra    : return address
  // -----------------------------------
  {
    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.
        __ lw(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(v0);
 
    // Restore context register.
    __ lw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  }
  __ Ret();
}
 
 
void PropertyHandlerCompiler::GenerateDictionaryNegativeLookup(
    MacroAssembler* masm, Label* miss_label, Register receiver,
    Handle<Name> name, Register scratch0, Register scratch1) {
  DCHECK(name->IsUniqueName());
  DCHECK(!receiver.is(scratch0));
  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;
  __ lw(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
  __ lbu(scratch0, FieldMemOperand(map, Map::kBitFieldOffset));
  __ And(scratch0, scratch0, Operand(kInterceptorOrAccessCheckNeededMask));
  __ Branch(miss_label, ne, scratch0, Operand(zero_reg));
 
  // Check that receiver is a JSObject.
  __ lbu(scratch0, FieldMemOperand(map, Map::kInstanceTypeOffset));
  __ Branch(miss_label, lt, scratch0, Operand(FIRST_SPEC_OBJECT_TYPE));
 
  // Load properties array.
  Register properties = scratch0;
  __ lw(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
  // Check that the properties array is a dictionary.
  __ lw(map, FieldMemOperand(properties, HeapObject::kMapOffset));
  Register tmp = properties;
  __ LoadRoot(tmp, Heap::kHashTableMapRootIndex);
  __ Branch(miss_label, ne, map, Operand(tmp));
 
  // Restore the temporarily used register.
  __ lw(properties, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
 
 
  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;
  const int offset = Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX);
  __ lw(scratch, MemOperand(cp, offset));
  __ lw(scratch, FieldMemOperand(scratch, GlobalObject::kNativeContextOffset));
  __ lw(scratch, MemOperand(scratch, Context::SlotOffset(index)));
  __ li(at, function);
  __ Branch(miss, ne, at, Operand(scratch));
 
  // Load its initial map. The global functions all have initial maps.
  __ li(prototype, Handle<Map>(function->initial_map()));
  // Load the prototype from the initial map.
  __ lw(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);
  __ Ret(USE_DELAY_SLOT);
  __ mov(v0, scratch1);
}
 
 
// 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());
  __ li(scratch, Operand(cell));
  __ lw(scratch, FieldMemOperand(scratch, Cell::kValueOffset));
  __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
  __ Branch(miss, ne, scratch, Operand(at));
}
 
 
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;
  __ li(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_in,
    bool is_store, int argc, Register* values) {
  DCHECK(!receiver.is(scratch_in));
  // Preparing to push, adjust sp.
  __ Subu(sp, sp, Operand((argc + 1) * kPointerSize));
  __ sw(receiver, MemOperand(sp, argc * kPointerSize));  // Push receiver.
  // Write the arguments to stack frame.
  for (int i = 0; i < argc; i++) {
    Register arg = values[argc - 1 - i];
    DCHECK(!receiver.is(arg));
    DCHECK(!scratch_in.is(arg));
    __ sw(arg, MemOperand(sp, (argc - 1 - i) * kPointerSize));  // Push arg.
  }
  DCHECK(optimization.is_simple_api_call());
 
  // Abi for CallApiFunctionStub.
  Register callee = a0;
  Register call_data = t0;
  Register holder = a2;
  Register api_function_address = a1;
 
  // Put holder in place.
  CallOptimization::HolderLookup holder_lookup;
  Handle<JSObject> api_holder =
      optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
  switch (holder_lookup) {
    case CallOptimization::kHolderIsReceiver:
      __ Move(holder, receiver);
      break;
    case CallOptimization::kHolderFound:
      __ li(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.
  __ li(callee, function);
 
  bool call_data_undefined = false;
  // Put call_data in place.
  if (isolate->heap()->InNewSpace(*call_data_obj)) {
    __ li(call_data, api_call_info);
    __ lw(call_data, FieldMemOperand(call_data, CallHandlerInfo::kDataOffset));
  } else if (call_data_obj->IsUndefined()) {
    call_data_undefined = true;
    __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
  } else {
    __ li(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::Type type = ExternalReference::DIRECT_API_CALL;
  ExternalReference ref = ExternalReference(&fun, type, masm->isolate());
  __ li(api_function_address, Operand(ref));
 
  // Jump to stub.
  CallApiFunctionStub stub(isolate, is_store, call_data_undefined, argc);
  __ TailCallStub(&stub);
}
 
 
void NamedStoreHandlerCompiler::GenerateSlow(MacroAssembler* masm) {
  // 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::kStoreIC_Slow), masm->isolate());
  __ TailCallExternalReference(ref, 3, 1);
}
 
 
void ElementHandlerCompiler::GenerateStoreSlow(MacroAssembler* masm) {
  // 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())
 
 
void NamedStoreHandlerCompiler::GenerateRestoreName(Label* label,
                                                    Handle<Name> name) {
  if (!label->is_unused()) {
    __ bind(label);
    __ li(this->name(), Operand(name));
  }
}
 
 
// Generate StoreTransition code, value is passed in a0 register.
// After executing generated code, the receiver_reg and name_reg
// may be clobbered.
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) {
  // a0 : value.
  Label exit;
 
  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());
    __ li(scratch1, constant);
    __ Branch(miss_label, ne, value_reg, Operand(scratch1));
  } 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();
    Handle<Map> current;
    if (!it.Done()) {
      __ lw(scratch1, FieldMemOperand(value_reg, HeapObject::kMapOffset));
      Label do_store;
      while (true) {
        // Do the CompareMap() directly within the Branch() functions.
        current = it.Current();
        it.Advance();
        if (it.Done()) {
          __ Branch(miss_label, ne, scratch1, Operand(current));
          break;
        }
        __ Branch(&do_store, eq, scratch1, Operand(current));
      }
      __ bind(&do_store);
    }
  } else if (representation.IsDouble()) {
    Label do_store, heap_number;
    __ LoadRoot(scratch3, Heap::kMutableHeapNumberMapRootIndex);
    __ AllocateHeapNumber(storage_reg, scratch1, scratch2, scratch3, slow,
                          TAG_RESULT, MUTABLE);
 
    __ JumpIfNotSmi(value_reg, &heap_number);
    __ SmiUntag(scratch1, value_reg);
    __ mtc1(scratch1, f6);
    __ cvt_d_w(f4, f6);
    __ jmp(&do_store);
 
    __ bind(&heap_number);
    __ CheckMap(value_reg, scratch1, Heap::kHeapNumberMapRootIndex, miss_label,
                DONT_DO_SMI_CHECK);
    __ ldc1(f4, FieldMemOperand(value_reg, HeapNumber::kValueOffset));
 
    __ bind(&do_store);
    __ sdc1(f4, FieldMemOperand(storage_reg, HeapNumber::kValueOffset));
  }
 
  // 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.
    __ push(receiver_reg);
    __ li(a2, Operand(transition));
    __ Push(a2, a0);
    __ TailCallExternalReference(
        ExternalReference(IC_Utility(IC::kSharedStoreIC_ExtendStorage),
                          isolate()),
        3, 1);
    return;
  }
 
  // Update the map of the object.
  __ li(scratch1, Operand(transition));
  __ sw(scratch1, FieldMemOperand(receiver_reg, HeapObject::kMapOffset));
 
  // Update the write barrier for the map field.
  __ RecordWriteField(receiver_reg, HeapObject::kMapOffset, scratch1, scratch2,
                      kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
                      OMIT_SMI_CHECK);
 
  if (details.type() == CONSTANT) {
    DCHECK(value_reg.is(a0));
    __ Ret(USE_DELAY_SLOT);
    __ mov(v0, a0);
    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;
  if (index < 0) {
    // Set the property straight into the object.
    int offset = transition->instance_size() + (index * kPointerSize);
    if (representation.IsDouble()) {
      __ sw(storage_reg, FieldMemOperand(receiver_reg, offset));
    } else {
      __ sw(value_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,
                          kRAHasNotBeenSaved, kDontSaveFPRegs,
                          EMIT_REMEMBERED_SET, smi_check);
    }
  } else {
    // Write to the properties array.
    int offset = index * kPointerSize + FixedArray::kHeaderSize;
    // Get the properties array
    __ lw(scratch1, FieldMemOperand(receiver_reg, JSObject::kPropertiesOffset));
    if (representation.IsDouble()) {
      __ sw(storage_reg, FieldMemOperand(scratch1, offset));
    } else {
      __ sw(value_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,
                          kRAHasNotBeenSaved, kDontSaveFPRegs,
                          EMIT_REMEMBERED_SET, smi_check);
    }
  }
 
  // Return the value (register v0).
  DCHECK(value_reg.is(a0));
  __ bind(&exit);
  __ Ret(USE_DELAY_SLOT);
  __ mov(v0, a0);
}
 
 
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();
  __ lw(scratch1(), FieldMemOperand(value_reg, HeapObject::kMapOffset));
  Label do_store;
  Handle<Map> current;
  while (true) {
    // Do the CompareMap() directly within the Branch() functions.
    current = it.Current();
    it.Advance();
    if (it.Done()) {
      __ Branch(miss_label, ne, scratch1(), Operand(current));
      break;
    }
    __ Branch(&do_store, eq, scratch1(), Operand(current));
  }
  __ 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()));
 
  // Make sure there's no overlap between holder and object registers.
  DCHECK(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
  DCHECK(!scratch2.is(object_reg) && !scratch2.is(holder_reg) &&
         !scratch2.is(scratch1));
 
  // 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);
 
      __ lw(scratch1, FieldMemOperand(reg, HeapObject::kMapOffset));
      reg = holder_reg;  // From now on the object will be in holder_reg.
      __ lw(reg, FieldMemOperand(scratch1, Map::kPrototypeOffset));
    } else {
      Register map_reg = scratch1;
      if (depth != 1 || check == CHECK_ALL_MAPS) {
        // CheckMap implicitly loads the map of |reg| into |map_reg|.
        __ CheckMap(reg, map_reg, current_map, miss, DONT_DO_SMI_CHECK);
      } else {
        __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
      }
 
      // 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()) {
        __ CheckAccessGlobalProxy(reg, scratch2, 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.
 
      // 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;
      if (load_prototype_from_map) {
        __ lw(reg, FieldMemOperand(map_reg, Map::kPrototypeOffset));
      } else {
        __ li(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));
 
  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, miss);
  }
 
  // Return the register containing the holder.
  return reg;
}
 
 
void NamedLoadHandlerCompiler::FrontendFooter(Handle<Name> name, Label* miss) {
  if (!miss->is_unused()) {
    Label success;
    __ Branch(&success);
    __ bind(miss);
    TailCallBuiltin(masm(), MissBuiltin(kind()));
    __ bind(&success);
  }
}
 
 
void NamedStoreHandlerCompiler::FrontendFooter(Handle<Name> name, Label* miss) {
  if (!miss->is_unused()) {
    Label success;
    __ Branch(&success);
    GenerateRestoreName(miss, name);
    TailCallBuiltin(masm(), MissBuiltin(kind()));
    __ bind(&success);
  }
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadConstant(Handle<Object> value) {
  // Return the constant value.
  __ li(v0, value);
  __ Ret();
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadCallback(
    Register reg, Handle<ExecutableAccessorInfo> callback) {
  // Build AccessorInfo::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);
  DCHECK(!scratch2().is(reg));
  DCHECK(!scratch3().is(reg));
  DCHECK(!scratch4().is(reg));
  __ push(receiver());
  if (heap()->InNewSpace(callback->data())) {
    __ li(scratch3(), callback);
    __ lw(scratch3(),
          FieldMemOperand(scratch3(), ExecutableAccessorInfo::kDataOffset));
  } else {
    __ li(scratch3(), Handle<Object>(callback->data(), isolate()));
  }
  __ Subu(sp, sp, 6 * kPointerSize);
  __ sw(scratch3(), MemOperand(sp, 5 * kPointerSize));
  __ LoadRoot(scratch3(), Heap::kUndefinedValueRootIndex);
  __ sw(scratch3(), MemOperand(sp, 4 * kPointerSize));
  __ sw(scratch3(), MemOperand(sp, 3 * kPointerSize));
  __ li(scratch4(), Operand(ExternalReference::isolate_address(isolate())));
  __ sw(scratch4(), MemOperand(sp, 2 * kPointerSize));
  __ sw(reg, MemOperand(sp, 1 * kPointerSize));
  __ sw(name(), MemOperand(sp, 0 * kPointerSize));
  __ Addu(scratch2(), sp, 1 * kPointerSize);
 
  __ mov(a2, scratch2());  // Saved in case scratch2 == a1.
  // Abi for CallApiGetter.
  Register getter_address_reg = ApiGetterDescriptor::function_address();
 
  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());
  __ li(getter_address_reg, Operand(ref));
 
  CallApiGetterStub stub(isolate());
  __ TailCallStub(&stub);
}
 
 
void NamedLoadHandlerCompiler::GenerateLoadInterceptorWithFollowup(
    LookupIterator* it, Register holder_reg) {
  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;
    __ LoadRoot(scratch1(), Heap::kNoInterceptorResultSentinelRootIndex);
    __ Branch(&interceptor_failed, eq, v0, Operand(scratch1()));
    frame_scope.GenerateLeaveFrame();
    __ Ret();
 
    __ bind(&interceptor_failed);
    if (must_preserve_receiver_reg) {
      __ Pop(receiver(), holder_reg, this->name());
    } else {
      __ Pop(holder_reg, this->name());
    }
    // 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) {
  Register holder_reg = Frontend(receiver(), name);
 
  __ Push(receiver(), holder_reg);  // Receiver.
  __ li(at, Operand(callback));     // Callback info.
  __ push(at);
  __ li(at, Operand(name));
  __ Push(at, 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);
}
 
 
Handle<Code> NamedStoreHandlerCompiler::CompileStoreInterceptor(
    Handle<Name> name) {
  __ 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();
}
 
 
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();
  __ li(result, Operand(cell));
  __ lw(result, FieldMemOperand(result, Cell::kValueOffset));
 
  // Check for deleted property if property can actually be deleted.
  if (is_configurable) {
    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
    __ Branch(&miss, eq, result, Operand(at));
  }
 
  Counters* counters = isolate()->counters();
  __ IncrementCounter(counters->named_load_global_stub(), 1, a1, a3);
  __ Ret(USE_DELAY_SLOT);
  __ mov(v0, result);
 
  FrontendFooter(name, &miss);
 
  // Return the generated code.
  return GetCode(kind(), Code::NORMAL, name);
}
 
 
#undef __
}
}  // namespace v8::internal
 
#endif  // V8_TARGET_ARCH_MIPS