src/ia32/code-stubs-ia32.cc

// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_IA32

#include "src/api-arguments.h"
#include "src/assembler-inl.h"
#include "src/base/bits.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/frame-constants.h"
#include "src/frames.h"
#include "src/heap/heap-inl.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
#include "src/isolate.h"
#include "src/objects/api-callbacks.h"
#include "src/regexp/jsregexp.h"
#include "src/regexp/regexp-macro-assembler.h"
#include "src/runtime/runtime.h"

namespace v8 {
namespace internal {

#define __ ACCESS_MASM(masm)

void ArrayNArgumentsConstructorStub::Generate(MacroAssembler* masm) {
  __ pop(ecx);
  __ mov(MemOperand(esp, eax, times_4, 0), edi);
  __ push(edi);
  __ push(ebx);
  __ push(ecx);
  __ add(eax, Immediate(3));
  __ TailCallRuntime(Runtime::kNewArray);
}

void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
  // It is important that the store buffer overflow stubs are generated first.
  CommonArrayConstructorStub::GenerateStubsAheadOfTime(isolate);
  StoreFastElementStub::GenerateAheadOfTime(isolate);
}

void JSEntryStub::Generate(MacroAssembler* masm) {
  Label invoke, handler_entry, exit;
  Label not_outermost_js, not_outermost_js_2;

  ProfileEntryHookStub::MaybeCallEntryHook(masm);

  // Set up frame.
  __ push(ebp);
  __ mov(ebp, esp);

  // Push marker in two places.
  StackFrame::Type marker = type();
  __ push(Immediate(StackFrame::TypeToMarker(marker)));  // marker
  ExternalReference context_address =
      ExternalReference::Create(IsolateAddressId::kContextAddress, isolate());
  __ push(Operand::StaticVariable(context_address));  // context
  // Save callee-saved registers (C calling conventions).
  __ push(edi);
  __ push(esi);
  __ push(ebx);

  // Save copies of the top frame descriptor on the stack.
  ExternalReference c_entry_fp =
      ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate());
  __ push(Operand::StaticVariable(c_entry_fp));

  // If this is the outermost JS call, set js_entry_sp value.
  ExternalReference js_entry_sp =
      ExternalReference::Create(IsolateAddressId::kJSEntrySPAddress, isolate());
  __ cmp(Operand::StaticVariable(js_entry_sp), Immediate(0));
  __ j(not_equal, &not_outermost_js, Label::kNear);
  __ mov(Operand::StaticVariable(js_entry_sp), ebp);
  __ push(Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ jmp(&invoke, Label::kNear);
  __ bind(&not_outermost_js);
  __ push(Immediate(StackFrame::INNER_JSENTRY_FRAME));

  // Jump to a faked try block that does the invoke, with a faked catch
  // block that sets the pending exception.
  __ jmp(&invoke);
  __ bind(&handler_entry);
  handler_offset_ = handler_entry.pos();
  // Caught exception: Store result (exception) in the pending exception
  // field in the JSEnv and return a failure sentinel.
  ExternalReference pending_exception = ExternalReference::Create(
      IsolateAddressId::kPendingExceptionAddress, isolate());
  __ mov(Operand::StaticVariable(pending_exception), eax);
  __ mov(eax, Immediate(isolate()->factory()->exception()));
  __ jmp(&exit);

  // Invoke: Link this frame into the handler chain.
  __ bind(&invoke);
  __ PushStackHandler();

  // Invoke the function by calling through JS entry trampoline builtin and
  // pop the faked function when we return. Notice that we cannot store a
  // reference to the trampoline code directly in this stub, because the
  // builtin stubs may not have been generated yet.
  __ Call(EntryTrampoline(), RelocInfo::CODE_TARGET);

  // Unlink this frame from the handler chain.
  __ PopStackHandler();

  __ bind(&exit);
  // Check if the current stack frame is marked as the outermost JS frame.
  __ pop(ebx);
  __ cmp(ebx, Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ j(not_equal, &not_outermost_js_2);
  __ mov(Operand::StaticVariable(js_entry_sp), Immediate(0));
  __ bind(&not_outermost_js_2);

  // Restore the top frame descriptor from the stack.
  __ pop(Operand::StaticVariable(ExternalReference::Create(
      IsolateAddressId::kCEntryFPAddress, isolate())));

  // Restore callee-saved registers (C calling conventions).
  __ pop(ebx);
  __ pop(esi);
  __ pop(edi);
  __ add(esp, Immediate(2 * kPointerSize));  // remove markers

  // Restore frame pointer and return.
  __ pop(ebp);
  __ ret(0);
}

void ProfileEntryHookStub::MaybeCallEntryHookDelayed(TurboAssembler* tasm,
                                                     Zone* zone) {
  if (tasm->isolate()->function_entry_hook() != nullptr) {
    tasm->CallStubDelayed(new (zone) ProfileEntryHookStub(nullptr));
  }
}

void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
  if (masm->isolate()->function_entry_hook() != nullptr) {
    ProfileEntryHookStub stub(masm->isolate());
    masm->CallStub(&stub);
  }
}


void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
  // Save volatile registers.
  const int kNumSavedRegisters = 3;
  __ push(eax);
  __ push(ecx);
  __ push(edx);

  // Calculate and push the original stack pointer.
  __ lea(eax, Operand(esp, (kNumSavedRegisters + 1) * kPointerSize));
  __ push(eax);

  // Retrieve our return address and use it to calculate the calling
  // function's address.
  __ mov(eax, Operand(esp, (kNumSavedRegisters + 1) * kPointerSize));
  __ sub(eax, Immediate(Assembler::kCallInstructionLength));
  __ push(eax);

  // Call the entry hook.
  DCHECK_NOT_NULL(isolate()->function_entry_hook());
  __ call(FUNCTION_ADDR(isolate()->function_entry_hook()),
          RelocInfo::RUNTIME_ENTRY);
  __ add(esp, Immediate(2 * kPointerSize));

  // Restore ecx.
  __ pop(edx);
  __ pop(ecx);
  __ pop(eax);

  __ ret(0);
}


template<class T>
static void CreateArrayDispatch(MacroAssembler* masm,
                                AllocationSiteOverrideMode mode) {
  if (mode == DISABLE_ALLOCATION_SITES) {
    T stub(masm->isolate(),
           GetInitialFastElementsKind(),
           mode);
    __ TailCallStub(&stub);
  } else if (mode == DONT_OVERRIDE) {
    int last_index =
        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
    for (int i = 0; i <= last_index; ++i) {
      Label next;
      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
      __ cmp(edx, kind);
      __ j(not_equal, &next);
      T stub(masm->isolate(), kind);
      __ TailCallStub(&stub);
      __ bind(&next);
    }

    // If we reached this point there is a problem.
    __ Abort(AbortReason::kUnexpectedElementsKindInArrayConstructor);
  } else {
    UNREACHABLE();
  }
}


static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
                                           AllocationSiteOverrideMode mode) {
  // ebx - allocation site (if mode != DISABLE_ALLOCATION_SITES)
  // edx - kind (if mode != DISABLE_ALLOCATION_SITES)
  // eax - number of arguments
  // edi - constructor?
  // esp[0] - return address
  // esp[4] - last argument
  STATIC_ASSERT(PACKED_SMI_ELEMENTS == 0);
  STATIC_ASSERT(HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(PACKED_ELEMENTS == 2);
  STATIC_ASSERT(HOLEY_ELEMENTS == 3);
  STATIC_ASSERT(PACKED_DOUBLE_ELEMENTS == 4);
  STATIC_ASSERT(HOLEY_DOUBLE_ELEMENTS == 5);

  if (mode == DISABLE_ALLOCATION_SITES) {
    ElementsKind initial = GetInitialFastElementsKind();
    ElementsKind holey_initial = GetHoleyElementsKind(initial);

    ArraySingleArgumentConstructorStub stub_holey(masm->isolate(),
                                                  holey_initial,
                                                  DISABLE_ALLOCATION_SITES);
    __ TailCallStub(&stub_holey);
  } else if (mode == DONT_OVERRIDE) {
    // is the low bit set? If so, we are holey and that is good.
    Label normal_sequence;
    __ test_b(edx, Immediate(1));
    __ j(not_zero, &normal_sequence);

    // We are going to create a holey array, but our kind is non-holey.
    // Fix kind and retry.
    __ inc(edx);

    if (FLAG_debug_code) {
      Handle<Map> allocation_site_map =
          masm->isolate()->factory()->allocation_site_map();
      __ cmp(FieldOperand(ebx, 0), Immediate(allocation_site_map));
      __ Assert(equal, AbortReason::kExpectedAllocationSite);
    }

    // Save the resulting elements kind in type info. We can't just store r3
    // in the AllocationSite::transition_info field because elements kind is
    // restricted to a portion of the field...upper bits need to be left alone.
    STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
    __ add(
        FieldOperand(ebx, AllocationSite::kTransitionInfoOrBoilerplateOffset),
        Immediate(Smi::FromInt(kFastElementsKindPackedToHoley)));

    __ bind(&normal_sequence);
    int last_index =
        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
    for (int i = 0; i <= last_index; ++i) {
      Label next;
      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
      __ cmp(edx, kind);
      __ j(not_equal, &next);
      ArraySingleArgumentConstructorStub stub(masm->isolate(), kind);
      __ TailCallStub(&stub);
      __ bind(&next);
    }

    // If we reached this point there is a problem.
    __ Abort(AbortReason::kUnexpectedElementsKindInArrayConstructor);
  } else {
    UNREACHABLE();
  }
}


template<class T>
static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
  int to_index =
      GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
  for (int i = 0; i <= to_index; ++i) {
    ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
    T stub(isolate, kind);
    stub.GetCode();
    if (AllocationSite::ShouldTrack(kind)) {
      T stub1(isolate, kind, DISABLE_ALLOCATION_SITES);
      stub1.GetCode();
    }
  }
}

void CommonArrayConstructorStub::GenerateStubsAheadOfTime(Isolate* isolate) {
  ArrayConstructorStubAheadOfTimeHelper<ArrayNoArgumentConstructorStub>(
      isolate);
  ArrayConstructorStubAheadOfTimeHelper<ArraySingleArgumentConstructorStub>(
      isolate);
  ArrayNArgumentsConstructorStub stub(isolate);
  stub.GetCode();

  ElementsKind kinds[2] = {PACKED_ELEMENTS, HOLEY_ELEMENTS};
  for (int i = 0; i < 2; i++) {
    // For internal arrays we only need a few things
    InternalArrayNoArgumentConstructorStub stubh1(isolate, kinds[i]);
    stubh1.GetCode();
    InternalArraySingleArgumentConstructorStub stubh2(isolate, kinds[i]);
    stubh2.GetCode();
  }
}

void ArrayConstructorStub::GenerateDispatchToArrayStub(
    MacroAssembler* masm, AllocationSiteOverrideMode mode) {
  Label not_zero_case, not_one_case;
  __ test(eax, eax);
  __ j(not_zero, &not_zero_case);
  CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);

  __ bind(&not_zero_case);
  __ cmp(eax, 1);
  __ j(greater, &not_one_case);
  CreateArrayDispatchOneArgument(masm, mode);

  __ bind(&not_one_case);
  ArrayNArgumentsConstructorStub stub(masm->isolate());
  __ TailCallStub(&stub);
}

void ArrayConstructorStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- eax : argc (only if argument_count() is ANY or MORE_THAN_ONE)
  //  -- ebx : AllocationSite or undefined
  //  -- edi : constructor
  //  -- edx : Original constructor
  //  -- esp[0] : return address
  //  -- esp[4] : last argument
  // -----------------------------------
  if (FLAG_debug_code) {
    // The array construct code is only set for the global and natives
    // builtin Array functions which always have maps.

    // Initial map for the builtin Array function should be a map.
    __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a nullptr and a Smi.
    __ test(ecx, Immediate(kSmiTagMask));
    __ Assert(not_zero, AbortReason::kUnexpectedInitialMapForArrayFunction);
    __ CmpObjectType(ecx, MAP_TYPE, ecx);
    __ Assert(equal, AbortReason::kUnexpectedInitialMapForArrayFunction);

    // We should either have undefined in ebx or a valid AllocationSite
    __ AssertUndefinedOrAllocationSite(ebx);
  }

  Label subclassing;

  // Enter the context of the Array function.
  __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));

  __ cmp(edx, edi);
  __ j(not_equal, &subclassing);

  Label no_info;
  // If the feedback vector is the undefined value call an array constructor
  // that doesn't use AllocationSites.
  __ cmp(ebx, isolate()->factory()->undefined_value());
  __ j(equal, &no_info);

  // Only look at the lower 16 bits of the transition info.
  __ mov(edx,
         FieldOperand(ebx, AllocationSite::kTransitionInfoOrBoilerplateOffset));
  __ SmiUntag(edx);
  STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
  __ and_(edx, Immediate(AllocationSite::ElementsKindBits::kMask));
  GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);

  __ bind(&no_info);
  GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);

  // Subclassing.
  __ bind(&subclassing);
  __ mov(Operand(esp, eax, times_pointer_size, kPointerSize), edi);
  __ add(eax, Immediate(3));
  __ PopReturnAddressTo(ecx);
  __ Push(edx);
  __ Push(ebx);
  __ PushReturnAddressFrom(ecx);
  __ JumpToExternalReference(ExternalReference::Create(Runtime::kNewArray));
}


void InternalArrayConstructorStub::GenerateCase(
    MacroAssembler* masm, ElementsKind kind) {
  Label not_zero_case, not_one_case;
  Label normal_sequence;

  __ test(eax, eax);
  __ j(not_zero, &not_zero_case);
  InternalArrayNoArgumentConstructorStub stub0(isolate(), kind);
  __ TailCallStub(&stub0);

  __ bind(&not_zero_case);
  __ cmp(eax, 1);
  __ j(greater, &not_one_case);

  if (IsFastPackedElementsKind(kind)) {
    // We might need to create a holey array
    // look at the first argument
    __ mov(ecx, Operand(esp, kPointerSize));
    __ test(ecx, ecx);
    __ j(zero, &normal_sequence);

    InternalArraySingleArgumentConstructorStub
        stub1_holey(isolate(), GetHoleyElementsKind(kind));
    __ TailCallStub(&stub1_holey);
  }

  __ bind(&normal_sequence);
  InternalArraySingleArgumentConstructorStub stub1(isolate(), kind);
  __ TailCallStub(&stub1);

  __ bind(&not_one_case);
  ArrayNArgumentsConstructorStub stubN(isolate());
  __ TailCallStub(&stubN);
}


void InternalArrayConstructorStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- eax : argc
  //  -- edi : constructor
  //  -- esp[0] : return address
  //  -- esp[4] : last argument
  // -----------------------------------

  if (FLAG_debug_code) {
    // The array construct code is only set for the global and natives
    // builtin Array functions which always have maps.

    // Initial map for the builtin Array function should be a map.
    __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a nullptr and a Smi.
    __ test(ecx, Immediate(kSmiTagMask));
    __ Assert(not_zero, AbortReason::kUnexpectedInitialMapForArrayFunction);
    __ CmpObjectType(ecx, MAP_TYPE, ecx);
    __ Assert(equal, AbortReason::kUnexpectedInitialMapForArrayFunction);
  }

  // Figure out the right elements kind
  __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));

  // Load the map's "bit field 2" into |result|. We only need the first byte,
  // but the following masking takes care of that anyway.
  __ mov(ecx, FieldOperand(ecx, Map::kBitField2Offset));
  // Retrieve elements_kind from bit field 2.
  __ DecodeField<Map::ElementsKindBits>(ecx);

  if (FLAG_debug_code) {
    Label done;
    __ cmp(ecx, Immediate(PACKED_ELEMENTS));
    __ j(equal, &done);
    __ cmp(ecx, Immediate(HOLEY_ELEMENTS));
    __ Assert(
        equal,
        AbortReason::kInvalidElementsKindForInternalArrayOrInternalPackedArray);
    __ bind(&done);
  }

  Label fast_elements_case;
  __ cmp(ecx, Immediate(PACKED_ELEMENTS));
  __ j(equal, &fast_elements_case);
  GenerateCase(masm, HOLEY_ELEMENTS);

  __ bind(&fast_elements_case);
  GenerateCase(masm, PACKED_ELEMENTS);
}

// Generates an Operand for saving parameters after PrepareCallApiFunction.
static Operand ApiParameterOperand(int index) {
  return Operand(esp, index * kPointerSize);
}


// Prepares stack to put arguments (aligns and so on). Reserves
// space for return value if needed (assumes the return value is a handle).
// Arguments must be stored in ApiParameterOperand(0), ApiParameterOperand(1)
// etc. Saves context (esi). If space was reserved for return value then
// stores the pointer to the reserved slot into esi.
static void PrepareCallApiFunction(MacroAssembler* masm, int argc) {
  __ EnterApiExitFrame(argc);
  if (__ emit_debug_code()) {
    __ mov(esi, Immediate(bit_cast<int32_t>(kZapValue)));
  }
}


// Calls an API function.  Allocates HandleScope, extracts returned value
// from handle and propagates exceptions.  Clobbers ebx, edi and
// caller-save registers.  Restores context.  On return removes
// stack_space * kPointerSize (GCed).
static void CallApiFunctionAndReturn(MacroAssembler* masm,
                                     Register function_address,
                                     ExternalReference thunk_ref,
                                     Operand thunk_last_arg, int stack_space,
                                     Operand* stack_space_operand,
                                     Operand return_value_operand) {
  Isolate* isolate = masm->isolate();

  ExternalReference next_address =
      ExternalReference::handle_scope_next_address(isolate);
  ExternalReference limit_address =
      ExternalReference::handle_scope_limit_address(isolate);
  ExternalReference level_address =
      ExternalReference::handle_scope_level_address(isolate);

  DCHECK(edx == function_address);
  // Allocate HandleScope in callee-save registers.
  __ mov(ebx, Operand::StaticVariable(next_address));
  __ mov(edi, Operand::StaticVariable(limit_address));
  __ add(Operand::StaticVariable(level_address), Immediate(1));

  if (FLAG_log_timer_events) {
    FrameScope frame(masm, StackFrame::MANUAL);
    __ PushSafepointRegisters();
    __ PrepareCallCFunction(1, eax);
    __ mov(Operand(esp, 0),
           Immediate(ExternalReference::isolate_address(isolate)));
    __ CallCFunction(ExternalReference::log_enter_external_function(), 1);
    __ PopSafepointRegisters();
  }


  Label profiler_disabled;
  Label end_profiler_check;
  __ mov(eax, Immediate(ExternalReference::is_profiling_address(isolate)));
  __ cmpb(Operand(eax, 0), Immediate(0));
  __ j(zero, &profiler_disabled);

  // Additional parameter is the address of the actual getter function.
  __ mov(thunk_last_arg, function_address);
  // Call the api function.
  __ mov(eax, Immediate(thunk_ref));
  __ call(eax);
  __ jmp(&end_profiler_check);

  __ bind(&profiler_disabled);
  // Call the api function.
  __ call(function_address);
  __ bind(&end_profiler_check);

  if (FLAG_log_timer_events) {
    FrameScope frame(masm, StackFrame::MANUAL);
    __ PushSafepointRegisters();
    __ PrepareCallCFunction(1, eax);
    __ mov(Operand(esp, 0),
           Immediate(ExternalReference::isolate_address(isolate)));
    __ CallCFunction(ExternalReference::log_leave_external_function(), 1);
    __ PopSafepointRegisters();
  }

  Label prologue;
  // Load the value from ReturnValue
  __ mov(eax, return_value_operand);

  Label promote_scheduled_exception;
  Label delete_allocated_handles;
  Label leave_exit_frame;

  __ bind(&prologue);
  // No more valid handles (the result handle was the last one). Restore
  // previous handle scope.
  __ mov(Operand::StaticVariable(next_address), ebx);
  __ sub(Operand::StaticVariable(level_address), Immediate(1));
  __ Assert(above_equal, AbortReason::kInvalidHandleScopeLevel);
  __ cmp(edi, Operand::StaticVariable(limit_address));
  __ j(not_equal, &delete_allocated_handles);

  // Leave the API exit frame.
  __ bind(&leave_exit_frame);
  if (stack_space_operand != nullptr) {
    __ mov(ebx, *stack_space_operand);
  }
  __ LeaveApiExitFrame();

  // Check if the function scheduled an exception.
  ExternalReference scheduled_exception_address =
      ExternalReference::scheduled_exception_address(isolate);
  __ cmp(Operand::StaticVariable(scheduled_exception_address),
         Immediate(isolate->factory()->the_hole_value()));
  __ j(not_equal, &promote_scheduled_exception);

#if DEBUG
  // Check if the function returned a valid JavaScript value.
  Label ok;
  Register return_value = eax;
  Register map = ecx;

  __ JumpIfSmi(return_value, &ok, Label::kNear);
  __ mov(map, FieldOperand(return_value, HeapObject::kMapOffset));

  __ CmpInstanceType(map, LAST_NAME_TYPE);
  __ j(below_equal, &ok, Label::kNear);

  __ CmpInstanceType(map, FIRST_JS_RECEIVER_TYPE);
  __ j(above_equal, &ok, Label::kNear);

  __ cmp(map, isolate->factory()->heap_number_map());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->undefined_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->true_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->false_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->null_value());
  __ j(equal, &ok, Label::kNear);

  __ Abort(AbortReason::kAPICallReturnedInvalidObject);

  __ bind(&ok);
#endif

  if (stack_space_operand != nullptr) {
    DCHECK_EQ(0, stack_space);
    __ pop(ecx);
    __ add(esp, ebx);
    __ jmp(ecx);
  } else {
    __ ret(stack_space * kPointerSize);
  }

  // Re-throw by promoting a scheduled exception.
  __ bind(&promote_scheduled_exception);
  __ TailCallRuntime(Runtime::kPromoteScheduledException);

  // HandleScope limit has changed. Delete allocated extensions.
  ExternalReference delete_extensions =
      ExternalReference::delete_handle_scope_extensions();
  __ bind(&delete_allocated_handles);
  __ mov(Operand::StaticVariable(limit_address), edi);
  __ mov(edi, eax);
  __ mov(Operand(esp, 0),
         Immediate(ExternalReference::isolate_address(isolate)));
  __ mov(eax, Immediate(delete_extensions));
  __ call(eax);
  __ mov(eax, edi);
  __ jmp(&leave_exit_frame);
}

void CallApiCallbackStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ebx                 : call_data
  //  -- ecx                 : holder
  //  -- edx                 : api_function_address
  //  -- esi                 : context
  //  --
  //  -- esp[0]              : return address
  //  -- esp[4]              : last argument
  //  -- ...
  //  -- esp[argc * 4]       : first argument
  //  -- esp[(argc + 1) * 4] : receiver
  // -----------------------------------

  Register call_data = ebx;
  Register holder = ecx;
  Register api_function_address = edx;
  Register return_address = eax;

  typedef FunctionCallbackArguments FCA;

  STATIC_ASSERT(FCA::kArgsLength == 6);
  STATIC_ASSERT(FCA::kNewTargetIndex == 5);
  STATIC_ASSERT(FCA::kDataIndex == 4);
  STATIC_ASSERT(FCA::kReturnValueOffset == 3);
  STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
  STATIC_ASSERT(FCA::kIsolateIndex == 1);
  STATIC_ASSERT(FCA::kHolderIndex == 0);

  __ pop(return_address);

  // new target
  __ PushRoot(Heap::kUndefinedValueRootIndex);

  // call data
  __ push(call_data);

  // return value
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  // return value default
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  // isolate
  __ push(Immediate(ExternalReference::isolate_address(isolate())));
  // holder
  __ push(holder);

  Register scratch = call_data;

  __ mov(scratch, esp);

  // push return address
  __ push(return_address);

  // API function gets reference to the v8::Arguments. If CPU profiler
  // is enabled wrapper function will be called and we need to pass
  // address of the callback as additional parameter, always allocate
  // space for it.
  const int kApiArgc = 1 + 1;

  // Allocate the v8::Arguments structure in the arguments' space since
  // it's not controlled by GC.
  const int kApiStackSpace = 3;

  PrepareCallApiFunction(masm, kApiArgc + kApiStackSpace);

  // FunctionCallbackInfo::implicit_args_.
  __ mov(ApiParameterOperand(2), scratch);
  __ add(scratch, Immediate((argc() + FCA::kArgsLength - 1) * kPointerSize));
  // FunctionCallbackInfo::values_.
  __ mov(ApiParameterOperand(3), scratch);
  // FunctionCallbackInfo::length_.
  __ Move(ApiParameterOperand(4), Immediate(argc()));

  // v8::InvocationCallback's argument.
  __ lea(scratch, ApiParameterOperand(2));
  __ mov(ApiParameterOperand(0), scratch);

  ExternalReference thunk_ref = ExternalReference::invoke_function_callback();

  // Stores return the first js argument
  int return_value_offset = 2 + FCA::kReturnValueOffset;
  Operand return_value_operand(ebp, return_value_offset * kPointerSize);
  const int stack_space = argc() + FCA::kArgsLength + 1;
  Operand* stack_space_operand = nullptr;
  CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                           ApiParameterOperand(1), stack_space,
                           stack_space_operand, return_value_operand);
}


void CallApiGetterStub::Generate(MacroAssembler* masm) {
  // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
  // name below the exit frame to make GC aware of them.
  STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
  STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
  STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
  STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
  STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
  STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);

  Register receiver = ApiGetterDescriptor::ReceiverRegister();
  Register holder = ApiGetterDescriptor::HolderRegister();
  Register callback = ApiGetterDescriptor::CallbackRegister();
  Register scratch = ebx;
  DCHECK(!AreAliased(receiver, holder, callback, scratch));

  __ pop(scratch);  // Pop return address to extend the frame.
  __ push(receiver);
  __ push(FieldOperand(callback, AccessorInfo::kDataOffset));
  __ PushRoot(Heap::kUndefinedValueRootIndex);  // ReturnValue
  // ReturnValue default value
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  __ push(Immediate(ExternalReference::isolate_address(isolate())));
  __ push(holder);
  __ push(Immediate(Smi::kZero));  // should_throw_on_error -> false
  __ push(FieldOperand(callback, AccessorInfo::kNameOffset));
  __ push(scratch);  // Restore return address.

  // v8::PropertyCallbackInfo::args_ array and name handle.
  const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;

  // Allocate v8::PropertyCallbackInfo object, arguments for callback and
  // space for optional callback address parameter (in case CPU profiler is
  // active) in non-GCed stack space.
  const int kApiArgc = 3 + 1;

  // Load address of v8::PropertyAccessorInfo::args_ array.
  __ lea(scratch, Operand(esp, 2 * kPointerSize));

  PrepareCallApiFunction(masm, kApiArgc);
  // Create v8::PropertyCallbackInfo object on the stack and initialize
  // it's args_ field.
  Operand info_object = ApiParameterOperand(3);
  __ mov(info_object, scratch);

  // Name as handle.
  __ sub(scratch, Immediate(kPointerSize));
  __ mov(ApiParameterOperand(0), scratch);
  // Arguments pointer.
  __ lea(scratch, info_object);
  __ mov(ApiParameterOperand(1), scratch);
  // Reserve space for optional callback address parameter.
  Operand thunk_last_arg = ApiParameterOperand(2);

  ExternalReference thunk_ref =
      ExternalReference::invoke_accessor_getter_callback();

  __ mov(scratch, FieldOperand(callback, AccessorInfo::kJsGetterOffset));
  Register function_address = edx;
  __ mov(function_address,
         FieldOperand(scratch, Foreign::kForeignAddressOffset));
  // +3 is to skip prolog, return address and name handle.
  Operand return_value_operand(
      ebp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
  CallApiFunctionAndReturn(masm, function_address, thunk_ref, thunk_last_arg,
                           kStackUnwindSpace, nullptr, return_value_operand);
}

#undef __

}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_IA32