// 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_X64

#include "src/api/api-arguments.h"
#include "src/base/bits-iterator.h"
#include "src/base/iterator.h"
#include "src/codegen/code-factory.h"
// For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
#include "src/codegen/macro-assembler-inl.h"
#include "src/codegen/register-configuration.h"
#include "src/codegen/x64/assembler-x64.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/execution/frame-constants.h"
#include "src/execution/frames.h"
#include "src/heap/heap-inl.h"
#include "src/logging/counters.h"
#include "src/objects/cell.h"
#include "src/objects/debug-objects.h"
#include "src/objects/foreign.h"
#include "src/objects/heap-number.h"
#include "src/objects/js-generator.h"
#include "src/objects/objects-inl.h"
#include "src/objects/smi.h"
#include "src/wasm/baseline/liftoff-assembler-defs.h"
#include "src/wasm/wasm-linkage.h"
#include "src/wasm/wasm-objects.h"

namespace v8 {
namespace internal {

#define __ ACCESS_MASM(masm)

void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address) {
  __ LoadAddress(kJavaScriptCallExtraArg1Register,
                 ExternalReference::Create(address));
  __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
          RelocInfo::CODE_TARGET);
}

static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
                                           Runtime::FunctionId function_id) {
  // ----------- S t a t e -------------
  //  -- rdx : new target (preserved for callee)
  //  -- rdi : target function (preserved for callee)
  // -----------------------------------
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    // Push a copy of the target function and the new target.
    __ Push(rdi);
    __ Push(rdx);
    // Function is also the parameter to the runtime call.
    __ Push(rdi);

    __ CallRuntime(function_id, 1);
    __ movq(rcx, rax);

    // Restore target function and new target.
    __ Pop(rdx);
    __ Pop(rdi);
  }
  static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
  __ JumpCodeObject(rcx);
}

namespace {

enum StackLimitKind { kInterruptStackLimit, kRealStackLimit };

Operand StackLimitAsOperand(MacroAssembler* masm, StackLimitKind kind) {
  DCHECK(masm->root_array_available());
  Isolate* isolate = masm->isolate();
  ExternalReference limit =
      kind == StackLimitKind::kRealStackLimit
          ? ExternalReference::address_of_real_jslimit(isolate)
          : ExternalReference::address_of_jslimit(isolate);
  DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));

  intptr_t offset =
      TurboAssembler::RootRegisterOffsetForExternalReference(isolate, limit);
  CHECK(is_int32(offset));
  return Operand(kRootRegister, static_cast<int32_t>(offset));
}

void Generate_StackOverflowCheck(
    MacroAssembler* masm, Register num_args, Register scratch,
    Label* stack_overflow,
    Label::Distance stack_overflow_distance = Label::kFar) {
  // Check the stack for overflow. We are not trying to catch
  // interruptions (e.g. debug break and preemption) here, so the "real stack
  // limit" is checked.
  __ movq(kScratchRegister,
          StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
  __ movq(scratch, rsp);
  // Make scratch the space we have left. The stack might already be overflowed
  // here which will cause scratch to become negative.
  __ subq(scratch, kScratchRegister);
  __ sarq(scratch, Immediate(kSystemPointerSizeLog2));
  // Check if the arguments will overflow the stack.
  __ cmpq(scratch, num_args);
  // Signed comparison.
  __ j(less_equal, stack_overflow, stack_overflow_distance);
}

void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax: number of arguments
  //  -- rdi: constructor function
  //  -- rdx: new target
  //  -- rsi: context
  // -----------------------------------

  Label stack_overflow;
  Generate_StackOverflowCheck(masm, rax, rcx, &stack_overflow, Label::kFar);

  // Enter a construct frame.
  {
    FrameScope scope(masm, StackFrame::CONSTRUCT);

    // Preserve the incoming parameters on the stack.
    __ SmiTag(rcx, rax);
    __ Push(rsi);
    __ Push(rcx);

#ifdef V8_REVERSE_JSARGS
    // Set up pointer to first argument (skip receiver).
    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset +
                                  kSystemPointerSize));
    // Copy arguments to the expression stack.
    __ PushArray(rbx, rax, rcx);
    // The receiver for the builtin/api call.
    __ PushRoot(RootIndex::kTheHoleValue);
#else
    // The receiver for the builtin/api call.
    __ PushRoot(RootIndex::kTheHoleValue);
    // Set up pointer to last argument.
    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
    // Copy arguments to the expression stack.
    __ PushArray(rbx, rax, rcx);
#endif

    // Call the function.
    // rax: number of arguments (untagged)
    // rdi: constructor function
    // rdx: new target
    __ InvokeFunction(rdi, rdx, rax, CALL_FUNCTION);

    // Restore context from the frame.
    __ movq(rsi, Operand(rbp, ConstructFrameConstants::kContextOffset));
    // Restore smi-tagged arguments count from the frame.
    __ movq(rbx, Operand(rbp, ConstructFrameConstants::kLengthOffset));

    // Leave construct frame.
  }

  // Remove caller arguments from the stack and return.
  __ PopReturnAddressTo(rcx);
  SmiIndex index = masm->SmiToIndex(rbx, rbx, kSystemPointerSizeLog2);
  __ leaq(rsp, Operand(rsp, index.reg, index.scale, 1 * kSystemPointerSize));
  __ PushReturnAddressFrom(rcx);

  __ ret(0);

  __ bind(&stack_overflow);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    __ int3();  // This should be unreachable.
  }
}

}  // namespace

// The construct stub for ES5 constructor functions and ES6 class constructors.
void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax: number of arguments (untagged)
  //  -- rdi: constructor function
  //  -- rdx: new target
  //  -- rsi: context
  //  -- sp[...]: constructor arguments
  // -----------------------------------

  // Enter a construct frame.
  {
    FrameScope scope(masm, StackFrame::CONSTRUCT);
    Label post_instantiation_deopt_entry, not_create_implicit_receiver;

    // Preserve the incoming parameters on the stack.
    __ SmiTag(rcx, rax);
    __ Push(rsi);
    __ Push(rcx);
    __ Push(rdi);
    __ PushRoot(RootIndex::kTheHoleValue);
    __ Push(rdx);

    // ----------- S t a t e -------------
    //  --         sp[0*kSystemPointerSize]: new target
    //  --         sp[1*kSystemPointerSize]: padding
    //  -- rdi and sp[2*kSystemPointerSize]: constructor function
    //  --         sp[3*kSystemPointerSize]: argument count
    //  --         sp[4*kSystemPointerSize]: context
    // -----------------------------------

    __ LoadTaggedPointerField(
        rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ movl(rbx, FieldOperand(rbx, SharedFunctionInfo::kFlagsOffset));
    __ DecodeField<SharedFunctionInfo::FunctionKindBits>(rbx);
    __ JumpIfIsInRange(rbx, kDefaultDerivedConstructor, kDerivedConstructor,
                       &not_create_implicit_receiver, Label::kNear);

    // If not derived class constructor: Allocate the new receiver object.
    __ IncrementCounter(masm->isolate()->counters()->constructed_objects(), 1);
    __ Call(BUILTIN_CODE(masm->isolate(), FastNewObject),
            RelocInfo::CODE_TARGET);
    __ jmp(&post_instantiation_deopt_entry, Label::kNear);

    // Else: use TheHoleValue as receiver for constructor call
    __ bind(&not_create_implicit_receiver);
    __ LoadRoot(rax, RootIndex::kTheHoleValue);

    // ----------- S t a t e -------------
    //  -- rax                          implicit receiver
    //  -- Slot 4 / sp[0*kSystemPointerSize]  new target
    //  -- Slot 3 / sp[1*kSystemPointerSize]  padding
    //  -- Slot 2 / sp[2*kSystemPointerSize]  constructor function
    //  -- Slot 1 / sp[3*kSystemPointerSize]  number of arguments (tagged)
    //  -- Slot 0 / sp[4*kSystemPointerSize]  context
    // -----------------------------------
    // Deoptimizer enters here.
    masm->isolate()->heap()->SetConstructStubCreateDeoptPCOffset(
        masm->pc_offset());
    __ bind(&post_instantiation_deopt_entry);

    // Restore new target.
    __ Pop(rdx);

    // Push the allocated receiver to the stack.
    __ Push(rax);

#ifdef V8_REVERSE_JSARGS
    // We need two copies because we may have to return the original one
    // and the calling conventions dictate that the called function pops the
    // receiver. The second copy is pushed after the arguments, we saved in r8
    // since rax needs to store the number of arguments before
    // InvokingFunction.
    __ movq(r8, rax);

    // Set up pointer to first argument (skip receiver).
    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset +
                                  kSystemPointerSize));
#else
    // We need two copies because we may have to return the original one
    // and the calling conventions dictate that the called function pops the
    // receiver.
    __ Push(rax);

    // Set up pointer to last argument.
    __ leaq(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
#endif

    // Restore constructor function and argument count.
    __ movq(rdi, Operand(rbp, ConstructFrameConstants::kConstructorOffset));
    __ SmiUntag(rax, Operand(rbp, ConstructFrameConstants::kLengthOffset));

    // Check if we have enough stack space to push all arguments.
    // Argument count in rax. Clobbers rcx.
    Label enough_stack_space, stack_overflow;
    Generate_StackOverflowCheck(masm, rax, rcx, &stack_overflow, Label::kNear);
    __ jmp(&enough_stack_space, Label::kNear);

    __ bind(&stack_overflow);
    // Restore context from the frame.
    __ movq(rsi, Operand(rbp, ConstructFrameConstants::kContextOffset));
    __ CallRuntime(Runtime::kThrowStackOverflow);
    // This should be unreachable.
    __ int3();

    __ bind(&enough_stack_space);

    // Copy arguments to the expression stack.
    __ PushArray(rbx, rax, rcx);

#ifdef V8_REVERSE_JSARGS
    // Push implicit receiver.
    __ Push(r8);
#endif

    // Call the function.
    __ InvokeFunction(rdi, rdx, rax, CALL_FUNCTION);

    // ----------- S t a t e -------------
    //  -- rax                 constructor result
    //  -- sp[0*kSystemPointerSize]  implicit receiver
    //  -- sp[1*kSystemPointerSize]  padding
    //  -- sp[2*kSystemPointerSize]  constructor function
    //  -- sp[3*kSystemPointerSize]  number of arguments
    //  -- sp[4*kSystemPointerSize]  context
    // -----------------------------------

    // Store offset of return address for deoptimizer.
    masm->isolate()->heap()->SetConstructStubInvokeDeoptPCOffset(
        masm->pc_offset());

    // Restore context from the frame.
    __ movq(rsi, Operand(rbp, ConstructFrameConstants::kContextOffset));

    // If the result is an object (in the ECMA sense), we should get rid
    // of the receiver and use the result; see ECMA-262 section 13.2.2-7
    // on page 74.
    Label use_receiver, do_throw, leave_frame;

    // If the result is undefined, we jump out to using the implicit receiver.
    __ JumpIfRoot(rax, RootIndex::kUndefinedValue, &use_receiver, Label::kNear);

    // Otherwise we do a smi check and fall through to check if the return value
    // is a valid receiver.

    // If the result is a smi, it is *not* an object in the ECMA sense.
    __ JumpIfSmi(rax, &use_receiver, Label::kNear);

    // If the type of the result (stored in its map) is less than
    // FIRST_JS_RECEIVER_TYPE, it is not an object in the ECMA sense.
    STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
    __ CmpObjectType(rax, FIRST_JS_RECEIVER_TYPE, rcx);
    __ j(above_equal, &leave_frame, Label::kNear);
    __ jmp(&use_receiver, Label::kNear);

    __ bind(&do_throw);
    __ CallRuntime(Runtime::kThrowConstructorReturnedNonObject);

    // Throw away the result of the constructor invocation and use the
    // on-stack receiver as the result.
    __ bind(&use_receiver);
    __ movq(rax, Operand(rsp, 0 * kSystemPointerSize));
    __ JumpIfRoot(rax, RootIndex::kTheHoleValue, &do_throw, Label::kNear);

    __ bind(&leave_frame);
    // Restore the arguments count.
    __ movq(rbx, Operand(rbp, ConstructFrameConstants::kLengthOffset));
    // Leave construct frame.
  }
  // Remove caller arguments from the stack and return.
  __ PopReturnAddressTo(rcx);
  SmiIndex index = masm->SmiToIndex(rbx, rbx, kSystemPointerSizeLog2);
  __ leaq(rsp, Operand(rsp, index.reg, index.scale, 1 * kSystemPointerSize));
  __ PushReturnAddressFrom(rcx);
  __ ret(0);
}

void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
  Generate_JSBuiltinsConstructStubHelper(masm);
}

void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
  FrameScope scope(masm, StackFrame::INTERNAL);
  __ Push(rdi);
  __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
}

namespace {

// Called with the native C calling convention. The corresponding function
// signature is either:
//   using JSEntryFunction = GeneratedCode<Address(
//       Address root_register_value, Address new_target, Address target,
//       Address receiver, intptr_t argc, Address** argv)>;
// or
//   using JSEntryFunction = GeneratedCode<Address(
//       Address root_register_value, MicrotaskQueue* microtask_queue)>;
void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
                             Builtins::Name entry_trampoline) {
  Label invoke, handler_entry, exit;
  Label not_outermost_js, not_outermost_js_2;

  {  // NOLINT. Scope block confuses linter.
    NoRootArrayScope uninitialized_root_register(masm);
    // Set up frame.
    __ pushq(rbp);
    __ movq(rbp, rsp);

    // Push the stack frame type.
    __ Push(Immediate(StackFrame::TypeToMarker(type)));
    // Reserve a slot for the context. It is filled after the root register has
    // been set up.
    __ AllocateStackSpace(kSystemPointerSize);
    // Save callee-saved registers (X64/X32/Win64 calling conventions).
    __ pushq(r12);
    __ pushq(r13);
    __ pushq(r14);
    __ pushq(r15);
#ifdef V8_TARGET_OS_WIN
    __ pushq(rdi);  // Only callee save in Win64 ABI, argument in AMD64 ABI.
    __ pushq(rsi);  // Only callee save in Win64 ABI, argument in AMD64 ABI.
#endif
    __ pushq(rbx);

#ifdef V8_TARGET_OS_WIN
    // On Win64 XMM6-XMM15 are callee-save.
    __ AllocateStackSpace(EntryFrameConstants::kXMMRegistersBlockSize);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 0), xmm6);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 1), xmm7);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 2), xmm8);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 3), xmm9);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 4), xmm10);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 5), xmm11);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 6), xmm12);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 7), xmm13);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 8), xmm14);
    __ movdqu(Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 9), xmm15);
    STATIC_ASSERT(EntryFrameConstants::kCalleeSaveXMMRegisters == 10);
    STATIC_ASSERT(EntryFrameConstants::kXMMRegistersBlockSize ==
                  EntryFrameConstants::kXMMRegisterSize *
                      EntryFrameConstants::kCalleeSaveXMMRegisters);
#endif

    // Initialize the root register.
    // C calling convention. The first argument is passed in arg_reg_1.
    __ movq(kRootRegister, arg_reg_1);
  }

  // Save copies of the top frame descriptor on the stack.
  ExternalReference c_entry_fp = ExternalReference::Create(
      IsolateAddressId::kCEntryFPAddress, masm->isolate());
  {
    Operand c_entry_fp_operand = masm->ExternalReferenceAsOperand(c_entry_fp);
    __ Push(c_entry_fp_operand);
  }

  // Store the context address in the previously-reserved slot.
  ExternalReference context_address = ExternalReference::Create(
      IsolateAddressId::kContextAddress, masm->isolate());
  __ Load(kScratchRegister, context_address);
  static constexpr int kOffsetToContextSlot = -2 * kSystemPointerSize;
  __ movq(Operand(rbp, kOffsetToContextSlot), kScratchRegister);

  // If this is the outermost JS call, set js_entry_sp value.
  ExternalReference js_entry_sp = ExternalReference::Create(
      IsolateAddressId::kJSEntrySPAddress, masm->isolate());
  __ Load(rax, js_entry_sp);
  __ testq(rax, rax);
  __ j(not_zero, &not_outermost_js);
  __ Push(Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ movq(rax, rbp);
  __ Store(js_entry_sp, rax);
  Label cont;
  __ jmp(&cont);
  __ bind(&not_outermost_js);
  __ Push(Immediate(StackFrame::INNER_JSENTRY_FRAME));
  __ bind(&cont);

  // 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);

  // Store the current pc as the handler offset. It's used later to create the
  // handler table.
  masm->isolate()->builtins()->SetJSEntryHandlerOffset(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, masm->isolate());
  __ Store(pending_exception, rax);
  __ LoadRoot(rax, RootIndex::kException);
  __ 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.
  Handle<Code> trampoline_code =
      masm->isolate()->builtins()->builtin_handle(entry_trampoline);
  __ Call(trampoline_code, 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(rbx);
  __ cmpq(rbx, Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ j(not_equal, &not_outermost_js_2);
  __ Move(kScratchRegister, js_entry_sp);
  __ movq(Operand(kScratchRegister, 0), Immediate(0));
  __ bind(&not_outermost_js_2);

  // Restore the top frame descriptor from the stack.
  {
    Operand c_entry_fp_operand = masm->ExternalReferenceAsOperand(c_entry_fp);
    __ Pop(c_entry_fp_operand);
  }

  // Restore callee-saved registers (X64 conventions).
#ifdef V8_TARGET_OS_WIN
  // On Win64 XMM6-XMM15 are callee-save
  __ movdqu(xmm6, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 0));
  __ movdqu(xmm7, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 1));
  __ movdqu(xmm8, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 2));
  __ movdqu(xmm9, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 3));
  __ movdqu(xmm10, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 4));
  __ movdqu(xmm11, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 5));
  __ movdqu(xmm12, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 6));
  __ movdqu(xmm13, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 7));
  __ movdqu(xmm14, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 8));
  __ movdqu(xmm15, Operand(rsp, EntryFrameConstants::kXMMRegisterSize * 9));
  __ addq(rsp, Immediate(EntryFrameConstants::kXMMRegistersBlockSize));
#endif

  __ popq(rbx);
#ifdef V8_TARGET_OS_WIN
  // Callee save on in Win64 ABI, arguments/volatile in AMD64 ABI.
  __ popq(rsi);
  __ popq(rdi);
#endif
  __ popq(r15);
  __ popq(r14);
  __ popq(r13);
  __ popq(r12);
  __ addq(rsp, Immediate(2 * kSystemPointerSize));  // remove markers

  // Restore frame pointer and return.
  __ popq(rbp);
  __ ret(0);
}

}  // namespace

void Builtins::Generate_JSEntry(MacroAssembler* masm) {
  Generate_JSEntryVariant(masm, StackFrame::ENTRY,
                          Builtins::kJSEntryTrampoline);
}

void Builtins::Generate_JSConstructEntry(MacroAssembler* masm) {
  Generate_JSEntryVariant(masm, StackFrame::CONSTRUCT_ENTRY,
                          Builtins::kJSConstructEntryTrampoline);
}

void Builtins::Generate_JSRunMicrotasksEntry(MacroAssembler* masm) {
  Generate_JSEntryVariant(masm, StackFrame::ENTRY,
                          Builtins::kRunMicrotasksTrampoline);
}

static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                             bool is_construct) {
  // Expects six C++ function parameters.
  // - Address root_register_value
  // - Address new_target (tagged Object pointer)
  // - Address function (tagged JSFunction pointer)
  // - Address receiver (tagged Object pointer)
  // - intptr_t argc
  // - Address** argv (pointer to array of tagged Object pointers)
  // (see Handle::Invoke in execution.cc).

  // Open a C++ scope for the FrameScope.
  {
    // Platform specific argument handling. After this, the stack contains
    // an internal frame and the pushed function and receiver, and
    // register rax and rbx holds the argument count and argument array,
    // while rdi holds the function pointer, rsi the context, and rdx the
    // new.target.

    // MSVC parameters in:
    // rcx        : root_register_value
    // rdx        : new_target
    // r8         : function
    // r9         : receiver
    // [rsp+0x20] : argc
    // [rsp+0x28] : argv
    //
    // GCC parameters in:
    // rdi : root_register_value
    // rsi : new_target
    // rdx : function
    // rcx : receiver
    // r8  : argc
    // r9  : argv

    __ movq(rdi, arg_reg_3);
    __ Move(rdx, arg_reg_2);
    // rdi : function
    // rdx : new_target

    // Clear the context before we push it when entering the internal frame.
    __ Set(rsi, 0);

    // Enter an internal frame.
    FrameScope scope(masm, StackFrame::INTERNAL);

    // Setup the context (we need to use the caller context from the isolate).
    ExternalReference context_address = ExternalReference::Create(
        IsolateAddressId::kContextAddress, masm->isolate());
    __ movq(rsi, masm->ExternalReferenceAsOperand(context_address));

    // Push the function onto the stack.
    __ Push(rdi);

#ifndef V8_REVERSE_JSARGS
    // Push the receiver onto the stack.
    __ Push(arg_reg_4);
#endif

#ifdef V8_TARGET_OS_WIN
    // Load the previous frame pointer to access C arguments on stack
    __ movq(kScratchRegister, Operand(rbp, 0));
    // Load the number of arguments and setup pointer to the arguments.
    __ movq(rax, Operand(kScratchRegister, EntryFrameConstants::kArgcOffset));
    __ movq(rbx, Operand(kScratchRegister, EntryFrameConstants::kArgvOffset));
#else   // V8_TARGET_OS_WIN
    // Load the number of arguments and setup pointer to the arguments.
    __ movq(rax, r8);
    __ movq(rbx, r9);
#ifdef V8_REVERSE_JSARGS
    __ movq(r9, arg_reg_4);  // Temporarily saving the receiver.
#endif
#endif  // V8_TARGET_OS_WIN

    // Current stack contents if V8_REVERSE_JSARGS:
    // [rsp + kSystemPointerSize]     : Internal frame
    // [rsp]                          : function
    // Current stack contents if not V8_REVERSE_JSARGS:
    // [rsp + 2 * kSystemPointerSize] : Internal frame
    // [rsp +     kSystemPointerSize] : function
    // [rsp]                          : receiver
    // Current register contents:
    // rax : argc
    // rbx : argv
    // rsi : context
    // rdi : function
    // rdx : new.target
    // r9  : receiver, if V8_REVERSE_JSARGS

    // Check if we have enough stack space to push all arguments.
    // Argument count in rax. Clobbers rcx.
    Label enough_stack_space, stack_overflow;
    Generate_StackOverflowCheck(masm, rax, rcx, &stack_overflow, Label::kNear);
    __ jmp(&enough_stack_space, Label::kNear);

    __ bind(&stack_overflow);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    // This should be unreachable.
    __ int3();

    __ bind(&enough_stack_space);

    // Copy arguments to the stack in a loop.
    // Register rbx points to array of pointers to handle locations.
    // Push the values of these handles.
#ifdef V8_REVERSE_JSARGS
    Label loop, entry;
    __ movq(rcx, rax);
    __ jmp(&entry, Label::kNear);
    __ bind(&loop);
    __ movq(kScratchRegister, Operand(rbx, rcx, times_system_pointer_size, 0));
    __ Push(Operand(kScratchRegister, 0));  // dereference handle
    __ bind(&entry);
    __ decq(rcx);
    __ j(greater_equal, &loop, Label::kNear);

    // Push the receiver.
    __ Push(r9);
#else
    Label loop, entry;
    __ Set(rcx, 0);  // Set loop variable to 0.
    __ jmp(&entry, Label::kNear);
    __ bind(&loop);
    __ movq(kScratchRegister, Operand(rbx, rcx, times_system_pointer_size, 0));
    __ Push(Operand(kScratchRegister, 0));  // dereference handle
    __ addq(rcx, Immediate(1));
    __ bind(&entry);
    __ cmpq(rcx, rax);
    __ j(not_equal, &loop, Label::kNear);
#endif

    // Invoke the builtin code.
    Handle<Code> builtin = is_construct
                               ? BUILTIN_CODE(masm->isolate(), Construct)
                               : masm->isolate()->builtins()->Call();
    __ Call(builtin, RelocInfo::CODE_TARGET);

    // Exit the internal frame. Notice that this also removes the empty
    // context and the function left on the stack by the code
    // invocation.
  }

  __ ret(0);
}

void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
  Generate_JSEntryTrampolineHelper(masm, false);
}

void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
  Generate_JSEntryTrampolineHelper(masm, true);
}

void Builtins::Generate_RunMicrotasksTrampoline(MacroAssembler* masm) {
  // arg_reg_2: microtask_queue
  __ movq(RunMicrotasksDescriptor::MicrotaskQueueRegister(), arg_reg_2);
  __ Jump(BUILTIN_CODE(masm->isolate(), RunMicrotasks), RelocInfo::CODE_TARGET);
}

static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
                                          Register sfi_data,
                                          Register scratch1) {
  Label done;

  __ CmpObjectType(sfi_data, INTERPRETER_DATA_TYPE, scratch1);
  __ j(not_equal, &done, Label::kNear);

  __ LoadTaggedPointerField(
      sfi_data, FieldOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));

  __ bind(&done);
}

// static
void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax    : the value to pass to the generator
  //  -- rdx    : the JSGeneratorObject to resume
  //  -- rsp[0] : return address
  // -----------------------------------
  __ AssertGeneratorObject(rdx);

  // Store input value into generator object.
  __ StoreTaggedField(
      FieldOperand(rdx, JSGeneratorObject::kInputOrDebugPosOffset), rax);
  __ RecordWriteField(rdx, JSGeneratorObject::kInputOrDebugPosOffset, rax, rcx,
                      kDontSaveFPRegs);

  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r11 : no_reg;

  // Load suspended function and context.
  __ LoadTaggedPointerField(
      rdi, FieldOperand(rdx, JSGeneratorObject::kFunctionOffset));
  __ LoadTaggedPointerField(rsi, FieldOperand(rdi, JSFunction::kContextOffset));

  // Flood function if we are stepping.
  Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
  Label stepping_prepared;
  ExternalReference debug_hook =
      ExternalReference::debug_hook_on_function_call_address(masm->isolate());
  Operand debug_hook_operand = masm->ExternalReferenceAsOperand(debug_hook);
  __ cmpb(debug_hook_operand, Immediate(0));
  __ j(not_equal, &prepare_step_in_if_stepping);

  // Flood function if we need to continue stepping in the suspended generator.
  ExternalReference debug_suspended_generator =
      ExternalReference::debug_suspended_generator_address(masm->isolate());
  Operand debug_suspended_generator_operand =
      masm->ExternalReferenceAsOperand(debug_suspended_generator);
  __ cmpq(rdx, debug_suspended_generator_operand);
  __ j(equal, &prepare_step_in_suspended_generator);
  __ bind(&stepping_prepared);

  // Check the stack for overflow. We are not trying to catch interruptions
  // (i.e. debug break and preemption) here, so check the "real stack limit".
  Label stack_overflow;
  __ cmpq(rsp, StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
  __ j(below, &stack_overflow);

  // Pop return address.
  __ PopReturnAddressTo(rax);

#ifndef V8_REVERSE_JSARGS
  // Push receiver.
  __ PushTaggedPointerField(
      FieldOperand(rdx, JSGeneratorObject::kReceiverOffset), decompr_scratch1);
#endif

  // ----------- S t a t e -------------
  //  -- rax    : return address
  //  -- rdx    : the JSGeneratorObject to resume
  //  -- rdi    : generator function
  //  -- rsi    : generator context
  //  -- rsp[0] : generator receiver, if V8_REVERSE_JSARGS is not set
  // -----------------------------------

  // Copy the function arguments from the generator object's register file.
  __ LoadTaggedPointerField(
      rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
  __ movzxwq(
      rcx, FieldOperand(rcx, SharedFunctionInfo::kFormalParameterCountOffset));

  __ LoadTaggedPointerField(
      rbx, FieldOperand(rdx, JSGeneratorObject::kParametersAndRegistersOffset));

  {
#ifdef V8_REVERSE_JSARGS
    {
      Label done_loop, loop;
      __ movq(r9, rcx);

      __ bind(&loop);
      __ decq(r9);
      __ j(less, &done_loop, Label::kNear);
      __ PushTaggedAnyField(
          FieldOperand(rbx, r9, times_tagged_size, FixedArray::kHeaderSize),
          decompr_scratch1);
      __ jmp(&loop);

      __ bind(&done_loop);
    }

    // Push the receiver.
    __ PushTaggedPointerField(
        FieldOperand(rdx, JSGeneratorObject::kReceiverOffset),
        decompr_scratch1);
#else
    Label done_loop, loop;
    __ Set(r9, 0);

    __ bind(&loop);
    __ cmpl(r9, rcx);
    __ j(greater_equal, &done_loop, Label::kNear);
    __ PushTaggedAnyField(
        FieldOperand(rbx, r9, times_tagged_size, FixedArray::kHeaderSize),
        decompr_scratch1);
    __ addl(r9, Immediate(1));
    __ jmp(&loop);

    __ bind(&done_loop);
#endif
  }

  // Underlying function needs to have bytecode available.
  if (FLAG_debug_code) {
    __ LoadTaggedPointerField(
        rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ LoadTaggedPointerField(
        rcx, FieldOperand(rcx, SharedFunctionInfo::kFunctionDataOffset));
    GetSharedFunctionInfoBytecode(masm, rcx, kScratchRegister);
    __ CmpObjectType(rcx, BYTECODE_ARRAY_TYPE, rcx);
    __ Assert(equal, AbortReason::kMissingBytecodeArray);
  }

  // Resume (Ignition/TurboFan) generator object.
  {
    __ PushReturnAddressFrom(rax);
    __ LoadTaggedPointerField(
        rax, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ movzxwq(rax, FieldOperand(
                        rax, SharedFunctionInfo::kFormalParameterCountOffset));
    // We abuse new.target both to indicate that this is a resume call and to
    // pass in the generator object.  In ordinary calls, new.target is always
    // undefined because generator functions are non-constructable.
    static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
    __ LoadTaggedPointerField(rcx, FieldOperand(rdi, JSFunction::kCodeOffset));
    __ JumpCodeObject(rcx);
  }

  __ bind(&prepare_step_in_if_stepping);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(rdx);
    __ Push(rdi);
    // Push hole as receiver since we do not use it for stepping.
    __ PushRoot(RootIndex::kTheHoleValue);
    __ CallRuntime(Runtime::kDebugOnFunctionCall);
    __ Pop(rdx);
    __ LoadTaggedPointerField(
        rdi, FieldOperand(rdx, JSGeneratorObject::kFunctionOffset));
  }
  __ jmp(&stepping_prepared);

  __ bind(&prepare_step_in_suspended_generator);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(rdx);
    __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
    __ Pop(rdx);
    __ LoadTaggedPointerField(
        rdi, FieldOperand(rdx, JSGeneratorObject::kFunctionOffset));
  }
  __ jmp(&stepping_prepared);

  __ bind(&stack_overflow);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    __ int3();  // This should be unreachable.
  }
}

// TODO(juliana): if we remove the code below then we don't need all
// the parameters.
static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                                                Register optimized_code,
                                                Register closure,
                                                Register scratch1,
                                                Register scratch2) {
  // Store the optimized code in the closure.
  __ StoreTaggedField(FieldOperand(closure, JSFunction::kCodeOffset),
                      optimized_code);
  __ movq(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
  __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
                      kDontSaveFPRegs, OMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
}

static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
                                  Register scratch2) {
  Register args_count = scratch1;
  Register return_pc = scratch2;

  // Get the arguments + receiver count.
  __ movq(args_count,
          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  __ movl(args_count,
          FieldOperand(args_count, BytecodeArray::kParameterSizeOffset));

  // Leave the frame (also dropping the register file).
  __ leave();

  // Drop receiver + arguments.
  __ PopReturnAddressTo(return_pc);
  __ addq(rsp, args_count);
  __ PushReturnAddressFrom(return_pc);
}

// Tail-call |function_id| if |smi_entry| == |marker|
static void TailCallRuntimeIfMarkerEquals(MacroAssembler* masm,
                                          Register smi_entry,
                                          OptimizationMarker marker,
                                          Runtime::FunctionId function_id) {
  Label no_match;
  __ SmiCompare(smi_entry, Smi::FromEnum(marker));
  __ j(not_equal, &no_match);
  GenerateTailCallToReturnedCode(masm, function_id);
  __ bind(&no_match);
}

static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
                              Register optimization_marker) {
  // ----------- S t a t e -------------
  //  -- rdx : new target (preserved for callee if needed, and caller)
  //  -- rdi : target function (preserved for callee if needed, and caller)
  //  -- feedback vector (preserved for caller if needed)
  //  -- optimization_marker : a Smi containing a non-zero optimization marker.
  // -----------------------------------

  DCHECK(!AreAliased(feedback_vector, rdx, rdi, optimization_marker));

  // TODO(v8:8394): The logging of first execution will break if
  // feedback vectors are not allocated. We need to find a different way of
  // logging these events if required.
  TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                OptimizationMarker::kLogFirstExecution,
                                Runtime::kFunctionFirstExecution);
  TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                OptimizationMarker::kCompileOptimized,
                                Runtime::kCompileOptimized_NotConcurrent);
  TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                OptimizationMarker::kCompileOptimizedConcurrent,
                                Runtime::kCompileOptimized_Concurrent);

  // Otherwise, the marker is InOptimizationQueue, so fall through hoping
  // that an interrupt will eventually update the slot with optimized code.
  if (FLAG_debug_code) {
    __ SmiCompare(optimization_marker,
                  Smi::FromEnum(OptimizationMarker::kInOptimizationQueue));
    __ Assert(equal, AbortReason::kExpectedOptimizationSentinel);
  }
}

static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
                                      Register optimized_code_entry,
                                      Register scratch1, Register scratch2) {
  // ----------- S t a t e -------------
  //  -- rdx : new target (preserved for callee if needed, and caller)
  //  -- rdi : target function (preserved for callee if needed, and caller)
  // -----------------------------------

  Register closure = rdi;

  // Check if the optimized code is marked for deopt. If it is, call the
  // runtime to clear it.
  Label found_deoptimized_code;
  __ LoadTaggedPointerField(
      scratch1,
      FieldOperand(optimized_code_entry, Code::kCodeDataContainerOffset));
  __ testl(FieldOperand(scratch1, CodeDataContainer::kKindSpecificFlagsOffset),
           Immediate(1 << Code::kMarkedForDeoptimizationBit));
  __ j(not_zero, &found_deoptimized_code);

  // Optimized code is good, get it into the closure and link the closure into
  // the optimized functions list, then tail call the optimized code.
  ReplaceClosureCodeWithOptimizedCode(masm, optimized_code_entry, closure,
                                      scratch1, scratch2);
  static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
  __ Move(rcx, optimized_code_entry);
  __ JumpCodeObject(rcx);

  // Optimized code slot contains deoptimized code, evict it and re-enter the
  // closure's code.
  __ bind(&found_deoptimized_code);
  GenerateTailCallToReturnedCode(masm, Runtime::kEvictOptimizedCodeSlot);
}

// Advance the current bytecode offset. This simulates what all bytecode
// handlers do upon completion of the underlying operation. Will bail out to a
// label if the bytecode (without prefix) is a return bytecode. Will not advance
// the bytecode offset if the current bytecode is a JumpLoop, instead just
// re-executing the JumpLoop to jump to the correct bytecode.
static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                          Register bytecode_array,
                                          Register bytecode_offset,
                                          Register bytecode, Register scratch1,
                                          Register scratch2, Label* if_return) {
  Register bytecode_size_table = scratch1;

  // The bytecode offset value will be increased by one in wide and extra wide
  // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
  // will restore the original bytecode. In order to simplify the code, we have
  // a backup of it.
  Register original_bytecode_offset = scratch2;
  DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode,
                     bytecode_size_table, original_bytecode_offset));

  __ movq(original_bytecode_offset, bytecode_offset);

  __ Move(bytecode_size_table,
          ExternalReference::bytecode_size_table_address());

  // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
  Label process_bytecode, extra_wide;
  STATIC_ASSERT(0 == static_cast<int>(interpreter::Bytecode::kWide));
  STATIC_ASSERT(1 == static_cast<int>(interpreter::Bytecode::kExtraWide));
  STATIC_ASSERT(2 == static_cast<int>(interpreter::Bytecode::kDebugBreakWide));
  STATIC_ASSERT(3 ==
                static_cast<int>(interpreter::Bytecode::kDebugBreakExtraWide));
  __ cmpb(bytecode, Immediate(0x3));
  __ j(above, &process_bytecode, Label::kNear);
  // The code to load the next bytecode is common to both wide and extra wide.
  // We can hoist them up here. incl has to happen before testb since it
  // modifies the ZF flag.
  __ incl(bytecode_offset);
  __ testb(bytecode, Immediate(0x1));
  __ movzxbq(bytecode, Operand(bytecode_array, bytecode_offset, times_1, 0));
  __ j(not_equal, &extra_wide, Label::kNear);

  // Update table to the wide scaled table.
  __ addq(bytecode_size_table,
          Immediate(kIntSize * interpreter::Bytecodes::kBytecodeCount));
  __ jmp(&process_bytecode, Label::kNear);

  __ bind(&extra_wide);
  // Update table to the extra wide scaled table.
  __ addq(bytecode_size_table,
          Immediate(2 * kIntSize * interpreter::Bytecodes::kBytecodeCount));

  __ bind(&process_bytecode);

// Bailout to the return label if this is a return bytecode.
#define JUMP_IF_EQUAL(NAME)                                             \
  __ cmpb(bytecode,                                                     \
          Immediate(static_cast<int>(interpreter::Bytecode::k##NAME))); \
  __ j(equal, if_return, Label::kFar);
  RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
#undef JUMP_IF_EQUAL

  // If this is a JumpLoop, re-execute it to perform the jump to the beginning
  // of the loop.
  Label end, not_jump_loop;
  __ cmpb(bytecode,
          Immediate(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
  __ j(not_equal, &not_jump_loop, Label::kNear);
  // We need to restore the original bytecode_offset since we might have
  // increased it to skip the wide / extra-wide prefix bytecode.
  __ movq(bytecode_offset, original_bytecode_offset);
  __ jmp(&end, Label::kNear);

  __ bind(&not_jump_loop);
  // Otherwise, load the size of the current bytecode and advance the offset.
  __ addl(bytecode_offset,
          Operand(bytecode_size_table, bytecode, times_int_size, 0));

  __ bind(&end);
}

// Generate code for entering a JS function with the interpreter.
// On entry to the function the receiver and arguments have been pushed on the
// stack left to right.  The actual argument count matches the formal parameter
// count expected by the function.
//
// The live registers are:
//   o rdi: the JS function object being called
//   o rdx: the incoming new target or generator object
//   o rsi: our context
//   o rbp: the caller's frame pointer
//   o rsp: stack pointer (pointing to return address)
//
// The function builds an interpreter frame.  See InterpreterFrameConstants in
// frames.h for its layout.
void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
  Register closure = rdi;
  Register feedback_vector = rbx;

  // Get the bytecode array from the function object and load it into
  // kInterpreterBytecodeArrayRegister.
  __ LoadTaggedPointerField(
      rax, FieldOperand(closure, JSFunction::kSharedFunctionInfoOffset));
  __ LoadTaggedPointerField(
      kInterpreterBytecodeArrayRegister,
      FieldOperand(rax, SharedFunctionInfo::kFunctionDataOffset));
  GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister,
                                kScratchRegister);

  // The bytecode array could have been flushed from the shared function info,
  // if so, call into CompileLazy.
  Label compile_lazy;
  __ CmpObjectType(kInterpreterBytecodeArrayRegister, BYTECODE_ARRAY_TYPE, rax);
  __ j(not_equal, &compile_lazy);

  // Load the feedback vector from the closure.
  __ LoadTaggedPointerField(
      feedback_vector, FieldOperand(closure, JSFunction::kFeedbackCellOffset));
  __ LoadTaggedPointerField(feedback_vector,
                            FieldOperand(feedback_vector, Cell::kValueOffset));

  Label push_stack_frame;
  // Check if feedback vector is valid. If valid, check for optimized code
  // and update invocation count. Otherwise, setup the stack frame.
  __ LoadTaggedPointerField(
      rcx, FieldOperand(feedback_vector, HeapObject::kMapOffset));
  __ CmpInstanceType(rcx, FEEDBACK_VECTOR_TYPE);
  __ j(not_equal, &push_stack_frame);

  // Read off the optimized code slot in the feedback vector, and if there
  // is optimized code or an optimization marker, call that instead.

  Register optimized_code_entry = rcx;

  __ LoadAnyTaggedField(
      optimized_code_entry,
      FieldOperand(feedback_vector,
                   FeedbackVector::kOptimizedCodeWeakOrSmiOffset));

  // Check if the optimized code slot is not empty.
  Label optimized_code_slot_not_empty;
  __ Cmp(optimized_code_entry, Smi::FromEnum(OptimizationMarker::kNone));
  __ j(not_equal, &optimized_code_slot_not_empty);

  Label not_optimized;
  __ bind(&not_optimized);

  // Increment invocation count for the function.
  __ incl(
      FieldOperand(feedback_vector, FeedbackVector::kInvocationCountOffset));

  // Open a frame scope to indicate that there is a frame on the stack.  The
  // MANUAL indicates that the scope shouldn't actually generate code to set up
  // the frame (that is done below).
  __ bind(&push_stack_frame);
  FrameScope frame_scope(masm, StackFrame::MANUAL);
  __ pushq(rbp);  // Caller's frame pointer.
  __ movq(rbp, rsp);
  __ Push(rsi);  // Callee's context.
  __ Push(rdi);  // Callee's JS function.

  // Reset code age and the OSR arming. The OSR field and BytecodeAgeOffset are
  // 8-bit fields next to each other, so we could just optimize by writing a
  // 16-bit. These static asserts guard our assumption is valid.
  STATIC_ASSERT(BytecodeArray::kBytecodeAgeOffset ==
                BytecodeArray::kOsrNestingLevelOffset + kCharSize);
  STATIC_ASSERT(BytecodeArray::kNoAgeBytecodeAge == 0);
  __ movw(FieldOperand(kInterpreterBytecodeArrayRegister,
                       BytecodeArray::kOsrNestingLevelOffset),
          Immediate(0));

  // Load initial bytecode offset.
  __ movq(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));

  // Push bytecode array and Smi tagged bytecode offset.
  __ Push(kInterpreterBytecodeArrayRegister);
  __ SmiTag(rcx, kInterpreterBytecodeOffsetRegister);
  __ Push(rcx);

  // Allocate the local and temporary register file on the stack.
  Label stack_overflow;
  {
    // Load frame size from the BytecodeArray object.
    __ movl(rcx, FieldOperand(kInterpreterBytecodeArrayRegister,
                              BytecodeArray::kFrameSizeOffset));

    // Do a stack check to ensure we don't go over the limit.
    __ movq(rax, rsp);
    __ subq(rax, rcx);
    __ cmpq(rax, StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
    __ j(below, &stack_overflow);

    // If ok, push undefined as the initial value for all register file entries.
    Label loop_header;
    Label loop_check;
    __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
    __ j(always, &loop_check, Label::kNear);
    __ bind(&loop_header);
    // TODO(rmcilroy): Consider doing more than one push per loop iteration.
    __ Push(kInterpreterAccumulatorRegister);
    // Continue loop if not done.
    __ bind(&loop_check);
    __ subq(rcx, Immediate(kSystemPointerSize));
    __ j(greater_equal, &loop_header, Label::kNear);
  }

  // If the bytecode array has a valid incoming new target or generator object
  // register, initialize it with incoming value which was passed in rdx.
  Label no_incoming_new_target_or_generator_register;
  __ movsxlq(
      rcx,
      FieldOperand(kInterpreterBytecodeArrayRegister,
                   BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
  __ testl(rcx, rcx);
  __ j(zero, &no_incoming_new_target_or_generator_register, Label::kNear);
  __ movq(Operand(rbp, rcx, times_system_pointer_size, 0), rdx);
  __ bind(&no_incoming_new_target_or_generator_register);

  // Perform interrupt stack check.
  // TODO(solanes): Merge with the real stack limit check above.
  Label stack_check_interrupt, after_stack_check_interrupt;
  __ cmpq(rsp, StackLimitAsOperand(masm, StackLimitKind::kInterruptStackLimit));
  __ j(below, &stack_check_interrupt);
  __ bind(&after_stack_check_interrupt);

  // The accumulator is already loaded with undefined.

  // Load the dispatch table into a register and dispatch to the bytecode
  // handler at the current bytecode offset.
  Label do_dispatch;
  __ bind(&do_dispatch);
  __ Move(
      kInterpreterDispatchTableRegister,
      ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
  __ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister, times_1, 0));
  __ movq(kJavaScriptCallCodeStartRegister,
          Operand(kInterpreterDispatchTableRegister, r11,
                  times_system_pointer_size, 0));
  __ call(kJavaScriptCallCodeStartRegister);
  masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());

  // Any returns to the entry trampoline are either due to the return bytecode
  // or the interpreter tail calling a builtin and then a dispatch.

  // Get bytecode array and bytecode offset from the stack frame.
  __ movq(kInterpreterBytecodeArrayRegister,
          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  __ SmiUntag(kInterpreterBytecodeOffsetRegister,
              Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));

  // Either return, or advance to the next bytecode and dispatch.
  Label do_return;
  __ movzxbq(rbx, Operand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister, times_1, 0));
  AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                kInterpreterBytecodeOffsetRegister, rbx, rcx,
                                r11, &do_return);
  __ jmp(&do_dispatch);

  __ bind(&do_return);
  // The return value is in rax.
  LeaveInterpreterFrame(masm, rbx, rcx);
  __ ret(0);

  __ bind(&stack_check_interrupt);
  // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
  // for the call to the StackGuard.
  __ Move(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
          Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
                       kFunctionEntryBytecodeOffset));
  __ CallRuntime(Runtime::kStackGuard);

  // After the call, restore the bytecode array, bytecode offset and accumulator
  // registers again. Also, restore the bytecode offset in the stack to its
  // previous value.
  __ movq(kInterpreterBytecodeArrayRegister,
          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  __ movq(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
  __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);

  __ SmiTag(rcx, kInterpreterBytecodeArrayRegister);
  __ movq(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp), rcx);

  __ jmp(&after_stack_check_interrupt);

  __ bind(&compile_lazy);
  GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
  __ int3();  // Should not return.

  __ bind(&optimized_code_slot_not_empty);
  Label maybe_has_optimized_code;
  // Check if optimized code marker is actually a weak reference to the
  // optimized code as opposed to an optimization marker.
  __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
  MaybeOptimizeCode(masm, feedback_vector, optimized_code_entry);
  // Fall through if there's no runnable optimized code.
  __ jmp(&not_optimized);

  __ bind(&maybe_has_optimized_code);
  // Load code entry from the weak reference, if it was cleared, resume
  // execution of unoptimized code.
  __ LoadWeakValue(optimized_code_entry, &not_optimized);
  TailCallOptimizedCodeSlot(masm, optimized_code_entry, r11, r15);

  __ bind(&stack_overflow);
  __ CallRuntime(Runtime::kThrowStackOverflow);
  __ int3();  // Should not return.
}

static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                         Register num_args,
                                         Register start_address,
                                         Register scratch) {
  // Find the argument with lowest address.
  __ movq(scratch, num_args);
  __ negq(scratch);
  __ leaq(start_address,
          Operand(start_address, scratch, times_system_pointer_size,
                  kSystemPointerSize));
  // Push the arguments.
#ifdef V8_REVERSE_JSARGS
  __ PushArray(start_address, num_args, scratch,
               TurboAssembler::PushArrayOrder::kReverse);
#else
  __ PushArray(start_address, num_args, scratch);
#endif
}

// static
void Builtins::Generate_InterpreterPushArgsThenCallImpl(
    MacroAssembler* masm, ConvertReceiverMode receiver_mode,
    InterpreterPushArgsMode mode) {
  DCHECK(mode != InterpreterPushArgsMode::kArrayFunction);
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rbx : the address of the first argument to be pushed. Subsequent
  //           arguments should be consecutive above this, in the same order as
  //           they are to be pushed onto the stack.
  //  -- rdi : the target to call (can be any Object).
  // -----------------------------------
  Label stack_overflow;

#ifdef V8_REVERSE_JSARGS
  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    // The spread argument should not be pushed.
    __ decl(rax);
  }
#endif

  __ leal(rcx, Operand(rax, 1));  // Add one for receiver.

  // Add a stack check before pushing arguments.
  Generate_StackOverflowCheck(masm, rcx, rdx, &stack_overflow);

  // Pop return address to allow tail-call after pushing arguments.
  __ PopReturnAddressTo(kScratchRegister);

#ifdef V8_REVERSE_JSARGS
  if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
    // Don't copy receiver.
    __ decq(rcx);
  }

  // rbx and rdx will be modified.
  Generate_InterpreterPushArgs(masm, rcx, rbx, rdx);

  // Push "undefined" as the receiver arg if we need to.
  if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
    __ PushRoot(RootIndex::kUndefinedValue);
  }

  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    // Pass the spread in the register rbx.
    // rbx already points to the penultime argument, the spread
    // is below that.
    __ movq(rbx, Operand(rbx, -kSystemPointerSize));
  }
#else
  // Push "undefined" as the receiver arg if we need to.
  if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
    __ PushRoot(RootIndex::kUndefinedValue);
    __ decl(rcx);  // Subtract one for receiver.
  }

  // rbx and rdx will be modified.
  Generate_InterpreterPushArgs(masm, rcx, rbx, rdx);

  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    __ Pop(rbx);                 // Pass the spread in a register
    __ decl(rax);                // Subtract one for spread
  }
#endif

  // Call the target.
  __ PushReturnAddressFrom(kScratchRegister);  // Re-push return address.

  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    __ Jump(BUILTIN_CODE(masm->isolate(), CallWithSpread),
            RelocInfo::CODE_TARGET);
  } else {
    __ Jump(masm->isolate()->builtins()->Call(receiver_mode),
            RelocInfo::CODE_TARGET);
  }

  // Throw stack overflow exception.
  __ bind(&stack_overflow);
  {
    __ TailCallRuntime(Runtime::kThrowStackOverflow);
    // This should be unreachable.
    __ int3();
  }
}

// static
void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
    MacroAssembler* masm, InterpreterPushArgsMode mode) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the new target (either the same as the constructor or
  //           the JSFunction on which new was invoked initially)
  //  -- rdi : the constructor to call (can be any Object)
  //  -- rbx : the allocation site feedback if available, undefined otherwise
  //  -- rcx : the address of the first argument to be pushed. Subsequent
  //           arguments should be consecutive above this, in the same order as
  //           they are to be pushed onto the stack.
  // -----------------------------------
  Label stack_overflow;

  // Add a stack check before pushing arguments.
  Generate_StackOverflowCheck(masm, rax, r8, &stack_overflow);

  // Pop return address to allow tail-call after pushing arguments.
  __ PopReturnAddressTo(kScratchRegister);

#ifdef V8_REVERSE_JSARGS
  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    // The spread argument should not be pushed.
    __ decl(rax);
  }

  // rcx and r8 will be modified.
  Generate_InterpreterPushArgs(masm, rax, rcx, r8);

  // Push slot for the receiver to be constructed.
  __ Push(Immediate(0));
#else
  // Push slot for the receiver to be constructed.
  __ Push(Immediate(0));

  // rcx and r8 will be modified.
  Generate_InterpreterPushArgs(masm, rax, rcx, r8);
#endif

  if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
#ifdef V8_REVERSE_JSARGS
    // Pass the spread in the register rbx.
    __ movq(rbx, Operand(rcx, -kSystemPointerSize));
#else
    __ Pop(rbx);                 // Pass the spread in a register
    __ decl(rax);                // Subtract one for spread
#endif
    // Push return address in preparation for the tail-call.
    __ PushReturnAddressFrom(kScratchRegister);
  } else {
    __ PushReturnAddressFrom(kScratchRegister);
    __ AssertUndefinedOrAllocationSite(rbx);
  }

  if (mode == InterpreterPushArgsMode::kArrayFunction) {
    // Tail call to the array construct stub (still in the caller
    // context at this point).
    __ AssertFunction(rdi);
    // Jump to the constructor function (rax, rbx, rdx passed on).
    Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl);
    __ Jump(code, RelocInfo::CODE_TARGET);
  } else if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
    // Call the constructor (rax, rdx, rdi passed on).
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithSpread),
            RelocInfo::CODE_TARGET);
  } else {
    DCHECK_EQ(InterpreterPushArgsMode::kOther, mode);
    // Call the constructor (rax, rdx, rdi passed on).
    __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
  }

  // Throw stack overflow exception.
  __ bind(&stack_overflow);
  {
    __ TailCallRuntime(Runtime::kThrowStackOverflow);
    // This should be unreachable.
    __ int3();
  }
}

static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
  // Set the return address to the correct point in the interpreter entry
  // trampoline.
  Label builtin_trampoline, trampoline_loaded;
  Smi interpreter_entry_return_pc_offset(
      masm->isolate()->heap()->interpreter_entry_return_pc_offset());
  DCHECK_NE(interpreter_entry_return_pc_offset, Smi::zero());

  // If the SFI function_data is an InterpreterData, the function will have a
  // custom copy of the interpreter entry trampoline for profiling. If so,
  // get the custom trampoline, otherwise grab the entry address of the global
  // trampoline.
  __ movq(rbx, Operand(rbp, StandardFrameConstants::kFunctionOffset));
  __ LoadTaggedPointerField(
      rbx, FieldOperand(rbx, JSFunction::kSharedFunctionInfoOffset));
  __ LoadTaggedPointerField(
      rbx, FieldOperand(rbx, SharedFunctionInfo::kFunctionDataOffset));
  __ CmpObjectType(rbx, INTERPRETER_DATA_TYPE, kScratchRegister);
  __ j(not_equal, &builtin_trampoline, Label::kNear);

  __ LoadTaggedPointerField(
      rbx, FieldOperand(rbx, InterpreterData::kInterpreterTrampolineOffset));
  __ addq(rbx, Immediate(Code::kHeaderSize - kHeapObjectTag));
  __ jmp(&trampoline_loaded, Label::kNear);

  __ bind(&builtin_trampoline);
  // TODO(jgruber): Replace this by a lookup in the builtin entry table.
  __ movq(rbx,
          __ ExternalReferenceAsOperand(
              ExternalReference::
                  address_of_interpreter_entry_trampoline_instruction_start(
                      masm->isolate()),
              kScratchRegister));

  __ bind(&trampoline_loaded);
  __ addq(rbx, Immediate(interpreter_entry_return_pc_offset.value()));
  __ Push(rbx);

  // Initialize dispatch table register.
  __ Move(
      kInterpreterDispatchTableRegister,
      ExternalReference::interpreter_dispatch_table_address(masm->isolate()));

  // Get the bytecode array pointer from the frame.
  __ movq(kInterpreterBytecodeArrayRegister,
          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));

  if (FLAG_debug_code) {
    // Check function data field is actually a BytecodeArray object.
    __ AssertNotSmi(kInterpreterBytecodeArrayRegister);
    __ CmpObjectType(kInterpreterBytecodeArrayRegister, BYTECODE_ARRAY_TYPE,
                     rbx);
    __ Assert(
        equal,
        AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
  }

  // Get the target bytecode offset from the frame.
  __ SmiUntag(kInterpreterBytecodeOffsetRegister,
              Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));

  if (FLAG_debug_code) {
    Label okay;
    __ cmpq(kInterpreterBytecodeOffsetRegister,
            Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
    __ j(greater_equal, &okay, Label::kNear);
    __ int3();
    __ bind(&okay);
  }

  // Dispatch to the target bytecode.
  __ movzxbq(r11, Operand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister, times_1, 0));
  __ movq(kJavaScriptCallCodeStartRegister,
          Operand(kInterpreterDispatchTableRegister, r11,
                  times_system_pointer_size, 0));
  __ jmp(kJavaScriptCallCodeStartRegister);
}

void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
  // Get bytecode array and bytecode offset from the stack frame.
  __ movq(kInterpreterBytecodeArrayRegister,
          Operand(rbp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  __ SmiUntag(kInterpreterBytecodeOffsetRegister,
              Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp));

  Label enter_bytecode, function_entry_bytecode;
  __ cmpq(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag +
                    kFunctionEntryBytecodeOffset));
  __ j(equal, &function_entry_bytecode);

  // Load the current bytecode.
  __ movzxbq(rbx, Operand(kInterpreterBytecodeArrayRegister,
                          kInterpreterBytecodeOffsetRegister, times_1, 0));

  // Advance to the next bytecode.
  Label if_return;
  AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                kInterpreterBytecodeOffsetRegister, rbx, rcx,
                                r11, &if_return);

  __ bind(&enter_bytecode);
  // Convert new bytecode offset to a Smi and save in the stackframe.
  __ SmiTag(kInterpreterBytecodeOffsetRegister);
  __ movq(Operand(rbp, InterpreterFrameConstants::kBytecodeOffsetFromFp),
          kInterpreterBytecodeOffsetRegister);

  Generate_InterpreterEnterBytecode(masm);

  __ bind(&function_entry_bytecode);
  // If the code deoptimizes during the implicit function entry stack interrupt
  // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
  // not a valid bytecode offset. Detect this case and advance to the first
  // actual bytecode.
  __ movq(kInterpreterBytecodeOffsetRegister,
          Immediate(BytecodeArray::kHeaderSize - kHeapObjectTag));
  __ jmp(&enter_bytecode);

  // We should never take the if_return path.
  __ bind(&if_return);
  __ Abort(AbortReason::kInvalidBytecodeAdvance);
}

void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
  Generate_InterpreterEnterBytecode(masm);
}

namespace {
void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                                      bool java_script_builtin,
                                      bool with_result) {
  const RegisterConfiguration* config(RegisterConfiguration::Default());
  int allocatable_register_count = config->num_allocatable_general_registers();
  if (with_result) {
    // Overwrite the hole inserted by the deoptimizer with the return value from
    // the LAZY deopt point.
    __ movq(
        Operand(rsp, config->num_allocatable_general_registers() *
                             kSystemPointerSize +
                         BuiltinContinuationFrameConstants::kFixedFrameSize),
        rax);
  }
  for (int i = allocatable_register_count - 1; i >= 0; --i) {
    int code = config->GetAllocatableGeneralCode(i);
    __ popq(Register::from_code(code));
    if (java_script_builtin && code == kJavaScriptCallArgCountRegister.code()) {
      __ SmiUntag(Register::from_code(code));
    }
  }
  __ movq(
      rbp,
      Operand(rsp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
  const int offsetToPC =
      BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp -
      kSystemPointerSize;
  __ popq(Operand(rsp, offsetToPC));
  __ Drop(offsetToPC / kSystemPointerSize);

  // Replace the builtin index Smi on the stack with the instruction start
  // address of the builtin from the builtins table, and then Ret to this
  // address
  __ movq(kScratchRegister, Operand(rsp, 0));
  __ movq(kScratchRegister,
          __ EntryFromBuiltinIndexAsOperand(kScratchRegister));
  __ movq(Operand(rsp, 0), kScratchRegister);

  __ Ret();
}
}  // namespace

void Builtins::Generate_ContinueToCodeStubBuiltin(MacroAssembler* masm) {
  Generate_ContinueToBuiltinHelper(masm, false, false);
}

void Builtins::Generate_ContinueToCodeStubBuiltinWithResult(
    MacroAssembler* masm) {
  Generate_ContinueToBuiltinHelper(masm, false, true);
}

void Builtins::Generate_ContinueToJavaScriptBuiltin(MacroAssembler* masm) {
  Generate_ContinueToBuiltinHelper(masm, true, false);
}

void Builtins::Generate_ContinueToJavaScriptBuiltinWithResult(
    MacroAssembler* masm) {
  Generate_ContinueToBuiltinHelper(masm, true, true);
}

void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
  // Enter an internal frame.
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ CallRuntime(Runtime::kNotifyDeoptimized);
    // Tear down internal frame.
  }

  DCHECK_EQ(kInterpreterAccumulatorRegister.code(), rax.code());
  __ movq(rax, Operand(rsp, kPCOnStackSize));
  __ ret(1 * kSystemPointerSize);  // Remove rax.
}

// static
void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax     : argc
  //  -- rsp[0]  : return address
  // The order of args depends on V8_REVERSE_JSARGS
  //  -- args[0] : receiver
  //  -- args[1] : thisArg
  //  -- args[2] : argArray
  // -----------------------------------

  // 1. Load receiver into rdi, argArray into rbx (if present), remove all
  // arguments from the stack (including the receiver), and push thisArg (if
  // present) instead.
  {
    Label no_arg_array, no_this_arg;
    StackArgumentsAccessor args(rax);
    __ LoadRoot(rdx, RootIndex::kUndefinedValue);
    __ movq(rbx, rdx);
    __ movq(rdi, args[0]);
    __ testq(rax, rax);
    __ j(zero, &no_this_arg, Label::kNear);
    {
      __ movq(rdx, args[1]);
      __ cmpq(rax, Immediate(1));
      __ j(equal, &no_arg_array, Label::kNear);
      __ movq(rbx, args[2]);
      __ bind(&no_arg_array);
    }
    __ bind(&no_this_arg);
    __ PopReturnAddressTo(rcx);
    __ leaq(rsp,
            Operand(rsp, rax, times_system_pointer_size, kSystemPointerSize));
    __ Push(rdx);
    __ PushReturnAddressFrom(rcx);
  }

  // ----------- S t a t e -------------
  //  -- rbx     : argArray
  //  -- rdi     : receiver
  //  -- rsp[0]  : return address
  //  -- rsp[8]  : thisArg
  // -----------------------------------

  // 2. We don't need to check explicitly for callable receiver here,
  // since that's the first thing the Call/CallWithArrayLike builtins
  // will do.

  // 3. Tail call with no arguments if argArray is null or undefined.
  Label no_arguments;
  __ JumpIfRoot(rbx, RootIndex::kNullValue, &no_arguments, Label::kNear);
  __ JumpIfRoot(rbx, RootIndex::kUndefinedValue, &no_arguments, Label::kNear);

  // 4a. Apply the receiver to the given argArray.
  __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
          RelocInfo::CODE_TARGET);

  // 4b. The argArray is either null or undefined, so we tail call without any
  // arguments to the receiver. Since we did not create a frame for
  // Function.prototype.apply() yet, we use a normal Call builtin here.
  __ bind(&no_arguments);
  {
    __ Set(rax, 0);
    __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
  }
}

// static
void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
  // Stack Layout:
  // rsp[0]           : Return address
  // rsp[8]           : Argument n
  // rsp[16]          : Argument n-1
  //  ...
  // rsp[8 * n]       : Argument 1
  // rsp[8 * (n + 1)] : Argument 0 (receiver: callable to call)
  // NOTE: The order of args are reversed if V8_REVERSE_JSARGS
  // rax contains the number of arguments, n, not counting the receiver.

#ifdef V8_REVERSE_JSARGS
  // 1. Get the callable to call (passed as receiver) from the stack.
  {
    StackArgumentsAccessor args(rax);
    __ movq(rdi, args.GetReceiverOperand());
  }

  // 2. Save the return address and drop the callable.
  __ PopReturnAddressTo(rbx);
  __ Pop(kScratchRegister);

  // 3. Make sure we have at least one argument.
  {
    Label done;
    __ testq(rax, rax);
    __ j(not_zero, &done, Label::kNear);
    __ PushRoot(RootIndex::kUndefinedValue);
    __ incq(rax);
    __ bind(&done);
  }

  // 4. Push back the return address one slot down on the stack (overwriting the
  // original callable), making the original first argument the new receiver.
  __ PushReturnAddressFrom(rbx);
  __ decq(rax);  // One fewer argument (first argument is new receiver).

#else
  // 1. Make sure we have at least one argument.
  {
    Label done;
    __ testq(rax, rax);
    __ j(not_zero, &done, Label::kNear);
    __ PopReturnAddressTo(rbx);
    __ PushRoot(RootIndex::kUndefinedValue);
    __ PushReturnAddressFrom(rbx);
    __ incq(rax);
    __ bind(&done);
  }

  // 2. Get the callable to call (passed as receiver) from the stack.
  {
    StackArgumentsAccessor args(rax);
    __ movq(rdi, args.GetReceiverOperand());
  }

  // 3. Shift arguments and return address one slot down on the stack
  //    (overwriting the original receiver).  Adjust argument count to make
  //    the original first argument the new receiver.
  {
    Label loop;
    __ movq(rcx, rax);
    StackArgumentsAccessor args(rcx);
    __ bind(&loop);
    __ movq(rbx, args[1]);
    __ movq(args[0], rbx);
    __ decq(rcx);
    __ j(not_zero, &loop);              // While non-zero.
    __ DropUnderReturnAddress(1, rbx);  // Drop one slot under return address.
    __ decq(rax);  // One fewer argument (first argument is new receiver).
  }
#endif

  // 4. Call the callable.
  // Since we did not create a frame for Function.prototype.call() yet,
  // we use a normal Call builtin here.
  __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
}

void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax     : argc
  //  -- rsp[0]  : return address
  // The order of args depends on V8_REVERSE_JSARGS
  //  -- args[0] : receiver
  //  -- args[1] : target
  //  -- args[2] : thisArgument
  //  -- args[3] : argumentsList
  // -----------------------------------

  // 1. Load target into rdi (if present), argumentsList into rbx (if present),
  // remove all arguments from the stack (including the receiver), and push
  // thisArgument (if present) instead.
  {
    Label done;
    StackArgumentsAccessor args(rax);
    __ LoadRoot(rdi, RootIndex::kUndefinedValue);
    __ movq(rdx, rdi);
    __ movq(rbx, rdi);
    __ cmpq(rax, Immediate(1));
    __ j(below, &done, Label::kNear);
    __ movq(rdi, args[1]);  // target
    __ j(equal, &done, Label::kNear);
    __ movq(rdx, args[2]);  // thisArgument
    __ cmpq(rax, Immediate(3));
    __ j(below, &done, Label::kNear);
    __ movq(rbx, args[3]);  // argumentsList
    __ bind(&done);
    __ PopReturnAddressTo(rcx);
    __ leaq(rsp,
            Operand(rsp, rax, times_system_pointer_size, kSystemPointerSize));
    __ Push(rdx);
    __ PushReturnAddressFrom(rcx);
  }

  // ----------- S t a t e -------------
  //  -- rbx     : argumentsList
  //  -- rdi     : target
  //  -- rsp[0]  : return address
  //  -- rsp[8]  : thisArgument
  // -----------------------------------

  // 2. We don't need to check explicitly for callable target here,
  // since that's the first thing the Call/CallWithArrayLike builtins
  // will do.

  // 3. Apply the target to the given argumentsList.
  __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
          RelocInfo::CODE_TARGET);
}

void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax     : argc
  //  -- rsp[0]  : return address
  // The order of args depends on V8_REVERSE_JSARGS
  //  -- args[0] : receiver
  //  -- args[1] : target
  //  -- args[2] : argumentsList
  //  -- args[3] : new.target (optional)
  // -----------------------------------

  // 1. Load target into rdi (if present), argumentsList into rbx (if present),
  // new.target into rdx (if present, otherwise use target), remove all
  // arguments from the stack (including the receiver), and push thisArgument
  // (if present) instead.
  {
    Label done;
    StackArgumentsAccessor args(rax);
    __ LoadRoot(rdi, RootIndex::kUndefinedValue);
    __ movq(rdx, rdi);
    __ movq(rbx, rdi);
    __ cmpq(rax, Immediate(1));
    __ j(below, &done, Label::kNear);
    __ movq(rdi, args[1]);                     // target
    __ movq(rdx, rdi);                         // new.target defaults to target
    __ j(equal, &done, Label::kNear);
    __ movq(rbx, args[2]);  // argumentsList
    __ cmpq(rax, Immediate(3));
    __ j(below, &done, Label::kNear);
    __ movq(rdx, args[3]);  // new.target
    __ bind(&done);
    __ PopReturnAddressTo(rcx);
    __ leaq(rsp,
            Operand(rsp, rax, times_system_pointer_size, kSystemPointerSize));
    __ PushRoot(RootIndex::kUndefinedValue);
    __ PushReturnAddressFrom(rcx);
  }

  // ----------- S t a t e -------------
  //  -- rbx     : argumentsList
  //  -- rdx     : new.target
  //  -- rdi     : target
  //  -- rsp[0]  : return address
  //  -- rsp[8]  : receiver (undefined)
  // -----------------------------------

  // 2. We don't need to check explicitly for constructor target here,
  // since that's the first thing the Construct/ConstructWithArrayLike
  // builtins will do.

  // 3. We don't need to check explicitly for constructor new.target here,
  // since that's the second thing the Construct/ConstructWithArrayLike
  // builtins will do.

  // 4. Construct the target with the given new.target and argumentsList.
  __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithArrayLike),
          RelocInfo::CODE_TARGET);
}

static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
  __ pushq(rbp);
  __ movq(rbp, rsp);

  // Store the arguments adaptor context sentinel.
  __ Push(Immediate(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));

  // Push the function on the stack.
  __ Push(rdi);

  // Preserve the number of arguments on the stack. Must preserve rax,
  // rbx and rcx because these registers are used when copying the
  // arguments and the receiver.
  __ SmiTag(r8, rax);
  __ Push(r8);

  __ Push(Immediate(0));  // Padding.
}

static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
  // Retrieve the number of arguments from the stack. Number is a Smi.
  __ movq(rbx, Operand(rbp, ArgumentsAdaptorFrameConstants::kLengthOffset));

  // Leave the frame.
  __ movq(rsp, rbp);
  __ popq(rbp);

  // Remove caller arguments from the stack.
  __ PopReturnAddressTo(rcx);
  SmiIndex index = masm->SmiToIndex(rbx, rbx, kSystemPointerSizeLog2);
  __ leaq(rsp, Operand(rsp, index.reg, index.scale, 1 * kSystemPointerSize));
  __ PushReturnAddressFrom(rcx);
}

void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : actual number of arguments
  //  -- rbx : expected number of arguments
  //  -- rdx : new target (passed through to callee)
  //  -- rdi : function (passed through to callee)
  // -----------------------------------

  Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
  __ cmpq(rbx, Immediate(kDontAdaptArgumentsSentinel));
  __ j(equal, &dont_adapt_arguments);
  __ LoadTaggedPointerField(
      rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));

#ifndef V8_REVERSE_JSARGS
  // This optimization is disabled when the arguments are reversed.
  __ testl(
      FieldOperand(rcx, SharedFunctionInfo::kFlagsOffset),
      Immediate(SharedFunctionInfo::IsSafeToSkipArgumentsAdaptorBit::kMask));
  __ j(not_zero, &skip_adapt_arguments);
#endif

  // -------------------------------------------
  // Adapt arguments.
  // -------------------------------------------
  {
    EnterArgumentsAdaptorFrame(masm);
    Generate_StackOverflowCheck(masm, rbx, rcx, &stack_overflow);

    Label under_application, over_application, invoke;
    __ cmpq(rax, rbx);
    __ j(less, &under_application, Label::kNear);

    // Enough parameters: Actual >= expected.
    __ bind(&over_application);
    {
      // Copy receiver and all expected arguments.
      const int offset = StandardFrameConstants::kCallerSPOffset;
#ifdef V8_REVERSE_JSARGS
      __ leaq(r8, Operand(rbp, rbx, times_system_pointer_size, offset));
#else
      __ leaq(r8, Operand(rbp, rax, times_system_pointer_size, offset));
#endif
      __ Set(rax, -1);  // account for receiver

      Label copy;
      __ bind(&copy);
      __ incq(rax);
      __ Push(Operand(r8, 0));
      __ subq(r8, Immediate(kSystemPointerSize));
      __ cmpq(rax, rbx);
      __ j(less, &copy);
      __ jmp(&invoke, Label::kNear);
    }

    // Too few parameters: Actual < expected.
    __ bind(&under_application);
    {
#ifdef V8_REVERSE_JSARGS
      // Fill remaining expected arguments with undefined values.
      Label fill;
      __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
      __ movq(r8, rbx);
      __ subq(r8, rax);
      __ bind(&fill);
      __ Push(kScratchRegister);
      __ decq(r8);
      __ j(greater, &fill);

      // Copy receiver and all actual arguments.
      const int offset = StandardFrameConstants::kCallerSPOffset;
      __ leaq(r9, Operand(rbp, rax, times_system_pointer_size, offset));
      __ Set(r8, -1);  // account for receiver

      Label copy;
      __ bind(&copy);
      __ incq(r8);
      __ Push(Operand(r9, 0));
      __ subq(r9, Immediate(kSystemPointerSize));
      __ cmpq(r8, rax);
      __ j(less, &copy);

      // Update actual number of arguments.
      __ movq(rax, rbx);
#else   // !V8_REVERSE_JSARGS
        // Copy receiver and all actual arguments.
      const int offset = StandardFrameConstants::kCallerSPOffset;
      __ leaq(r9, Operand(rbp, rax, times_system_pointer_size, offset));
      __ Set(r8, -1);  // account for receiver

      Label copy;
      __ bind(&copy);
      __ incq(r8);
      __ Push(Operand(r9, 0));
      __ subq(r9, Immediate(kSystemPointerSize));
      __ cmpq(r8, rax);
      __ j(less, &copy);

      // Fill remaining expected arguments with undefined values.
      Label fill;
      __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
      __ bind(&fill);
      __ incq(rax);
      __ Push(kScratchRegister);
      __ cmpq(rax, rbx);
      __ j(less, &fill);
#endif  // !V8_REVERSE_JSARGS
    }

    // Call the entry point.
    __ bind(&invoke);
    // rax : expected number of arguments
    // rdx : new target (passed through to callee)
    // rdi : function (passed through to callee)
    static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
    __ LoadTaggedPointerField(rcx, FieldOperand(rdi, JSFunction::kCodeOffset));
    __ CallCodeObject(rcx);

    // Store offset of return address for deoptimizer.
    masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(
        masm->pc_offset());

    // Leave frame and return.
    LeaveArgumentsAdaptorFrame(masm);
    __ ret(0);
  }

  // -------------------------------------------
  // Skip adapt arguments.
  // -------------------------------------------
  __ bind(&skip_adapt_arguments);
  {
    // The callee cannot observe the actual arguments, so it's safe to just
    // pass the expected arguments by massaging the stack appropriately. See
    // http://bit.ly/v8-faster-calls-with-arguments-mismatch for details.
    Label under_application, over_application, invoke;
    __ PopReturnAddressTo(rcx);
    __ cmpq(rax, rbx);
    __ j(less, &under_application, Label::kNear);

    __ bind(&over_application);
    {
      // Remove superfluous parameters from the stack.
      __ xchgq(rax, rbx);
      __ subq(rbx, rax);
      __ leaq(rsp, Operand(rsp, rbx, times_system_pointer_size, 0));
      __ jmp(&invoke, Label::kNear);
    }

    __ bind(&under_application);
    {
      // Fill remaining expected arguments with undefined values.
      Label fill;
      __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
      __ bind(&fill);
      __ incq(rax);
      __ Push(kScratchRegister);
      __ cmpq(rax, rbx);
      __ j(less, &fill);
    }

    __ bind(&invoke);
    __ PushReturnAddressFrom(rcx);
  }

  // -------------------------------------------
  // Don't adapt arguments.
  // -------------------------------------------
  __ bind(&dont_adapt_arguments);
  static_assert(kJavaScriptCallCodeStartRegister == rcx, "ABI mismatch");
  __ LoadTaggedPointerField(rcx, FieldOperand(rdi, JSFunction::kCodeOffset));
  __ JumpCodeObject(rcx);

  __ bind(&stack_overflow);
  {
    FrameScope frame(masm, StackFrame::MANUAL);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    __ int3();
  }
}

// static
void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                               Handle<Code> code) {
  // ----------- S t a t e -------------
  //  -- rdi    : target
  //  -- rax    : number of parameters on the stack (not including the receiver)
  //  -- rbx    : arguments list (a FixedArray)
  //  -- rcx    : len (number of elements to push from args)
  //  -- rdx    : new.target (for [[Construct]])
  //  -- rsp[0] : return address
  // -----------------------------------
  Register scratch = r11;

  if (masm->emit_debug_code()) {
    // Allow rbx to be a FixedArray, or a FixedDoubleArray if rcx == 0.
    Label ok, fail;
    __ AssertNotSmi(rbx);
    Register map = r9;
    __ LoadTaggedPointerField(map, FieldOperand(rbx, HeapObject::kMapOffset));
    __ CmpInstanceType(map, FIXED_ARRAY_TYPE);
    __ j(equal, &ok);
    __ CmpInstanceType(map, FIXED_DOUBLE_ARRAY_TYPE);
    __ j(not_equal, &fail);
    __ cmpl(rcx, Immediate(0));
    __ j(equal, &ok);
    // Fall through.
    __ bind(&fail);
    __ Abort(AbortReason::kOperandIsNotAFixedArray);

    __ bind(&ok);
  }

  Label stack_overflow;
  Generate_StackOverflowCheck(masm, rcx, r8, &stack_overflow, Label::kNear);

  // Push additional arguments onto the stack.
#ifdef V8_REVERSE_JSARGS
  // Move the arguments already in the stack,
  // including the receiver and the return address.
  {
    Label copy, check;
    Register src = r8, dest = rsp, num = r9, current = r11;
    __ movq(src, rsp);
    __ leaq(kScratchRegister, Operand(rcx, times_system_pointer_size, 0));
    __ AllocateStackSpace(kScratchRegister);
    __ leaq(num, Operand(rax, 2));  // Number of words to copy.
                                    // +2 for receiver and return address.
    __ Set(current, 0);
    __ jmp(&check);
    __ bind(&copy);
    __ movq(kScratchRegister,
            Operand(src, current, times_system_pointer_size, 0));
    __ movq(Operand(dest, current, times_system_pointer_size, 0),
            kScratchRegister);
    __ incq(current);
    __ bind(&check);
    __ cmpq(current, num);
    __ j(less, &copy);
    __ leaq(r8, Operand(rsp, num, times_system_pointer_size, 0));
  }

  // Copy the additional arguments onto the stack.
  {
    Register value = scratch;
    Register src = rbx, dest = r8, num = rcx, current = r9;
    __ Set(current, 0);
    Label done, push, loop;
    __ bind(&loop);
    __ cmpl(current, num);
    __ j(equal, &done, Label::kNear);
    // Turn the hole into undefined as we go.
    __ LoadAnyTaggedField(value, FieldOperand(src, current, times_tagged_size,
                                              FixedArray::kHeaderSize));
    __ CompareRoot(value, RootIndex::kTheHoleValue);
    __ j(not_equal, &push, Label::kNear);
    __ LoadRoot(value, RootIndex::kUndefinedValue);
    __ bind(&push);
    __ movq(Operand(dest, current, times_system_pointer_size, 0), value);
    __ incl(current);
    __ jmp(&loop);
    __ bind(&done);
    __ addq(rax, current);
  }
#else  // !V8_REVERSE_JSARGS
  {
    Register value = scratch;
    __ PopReturnAddressTo(r8);
    __ Set(r9, 0);
    Label done, push, loop;
    __ bind(&loop);
    __ cmpl(r9, rcx);
    __ j(equal, &done, Label::kNear);
    // Turn the hole into undefined as we go.
    __ LoadAnyTaggedField(value, FieldOperand(rbx, r9, times_tagged_size,
                                              FixedArray::kHeaderSize));
    __ CompareRoot(value, RootIndex::kTheHoleValue);
    __ j(not_equal, &push, Label::kNear);
    __ LoadRoot(value, RootIndex::kUndefinedValue);
    __ bind(&push);
    __ Push(value);
    __ incl(r9);
    __ jmp(&loop);
    __ bind(&done);
    __ PushReturnAddressFrom(r8);
    __ addq(rax, r9);
  }
#endif

  // Tail-call to the actual Call or Construct builtin.
  __ Jump(code, RelocInfo::CODE_TARGET);

  __ bind(&stack_overflow);
  __ TailCallRuntime(Runtime::kThrowStackOverflow);
}

// static
void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
                                                      CallOrConstructMode mode,
                                                      Handle<Code> code) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the new target (for [[Construct]] calls)
  //  -- rdi : the target to call (can be any Object)
  //  -- rcx : start index (to support rest parameters)
  // -----------------------------------

  // Check if new.target has a [[Construct]] internal method.
  if (mode == CallOrConstructMode::kConstruct) {
    Label new_target_constructor, new_target_not_constructor;
    __ JumpIfSmi(rdx, &new_target_not_constructor, Label::kNear);
    __ LoadTaggedPointerField(rbx, FieldOperand(rdx, HeapObject::kMapOffset));
    __ testb(FieldOperand(rbx, Map::kBitFieldOffset),
             Immediate(Map::Bits1::IsConstructorBit::kMask));
    __ j(not_zero, &new_target_constructor, Label::kNear);
    __ bind(&new_target_not_constructor);
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ EnterFrame(StackFrame::INTERNAL);
      __ Push(rdx);
      __ CallRuntime(Runtime::kThrowNotConstructor);
    }
    __ bind(&new_target_constructor);
  }

  // Check if we have an arguments adaptor frame below the function frame.
  Label arguments_adaptor, arguments_done;
  __ movq(rbx, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
  __ cmpq(Operand(rbx, CommonFrameConstants::kContextOrFrameTypeOffset),
          Immediate(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
  __ j(equal, &arguments_adaptor, Label::kNear);
  {
    __ movq(r8, Operand(rbp, StandardFrameConstants::kFunctionOffset));
    __ LoadTaggedPointerField(
        r8, FieldOperand(r8, JSFunction::kSharedFunctionInfoOffset));
    __ movzxwq(
        r8, FieldOperand(r8, SharedFunctionInfo::kFormalParameterCountOffset));
    __ movq(rbx, rbp);
  }
  __ jmp(&arguments_done, Label::kNear);
  __ bind(&arguments_adaptor);
  {
    __ SmiUntag(r8,
                Operand(rbx, ArgumentsAdaptorFrameConstants::kLengthOffset));
  }
  __ bind(&arguments_done);

  Label stack_done, stack_overflow;
  __ subl(r8, rcx);
  __ j(less_equal, &stack_done);
  {
    // Check for stack overflow.
    Generate_StackOverflowCheck(masm, r8, rcx, &stack_overflow, Label::kNear);

    // Forward the arguments from the caller frame.
    {
      Label loop;
      __ addl(rax, r8);
      __ PopReturnAddressTo(rcx);
      __ bind(&loop);
      {
        __ decl(r8);
        __ Push(Operand(rbx, r8, times_system_pointer_size,
                        kFPOnStackSize + kPCOnStackSize));
        __ j(not_zero, &loop);
      }
      __ PushReturnAddressFrom(rcx);
    }
  }
  __ jmp(&stack_done, Label::kNear);
  __ bind(&stack_overflow);
  __ TailCallRuntime(Runtime::kThrowStackOverflow);
  __ bind(&stack_done);

  // Tail-call to the {code} handler.
  __ Jump(code, RelocInfo::CODE_TARGET);
}

// static
void Builtins::Generate_CallFunction(MacroAssembler* masm,
                                     ConvertReceiverMode mode) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdi : the function to call (checked to be a JSFunction)
  // -----------------------------------

  StackArgumentsAccessor args(rax);
  __ AssertFunction(rdi);

  // ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
  // Check that the function is not a "classConstructor".
  Label class_constructor;
  __ LoadTaggedPointerField(
      rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
  __ testl(FieldOperand(rdx, SharedFunctionInfo::kFlagsOffset),
           Immediate(SharedFunctionInfo::IsClassConstructorBit::kMask));
  __ j(not_zero, &class_constructor);

  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the shared function info.
  //  -- rdi : the function to call (checked to be a JSFunction)
  // -----------------------------------

  // Enter the context of the function; ToObject has to run in the function
  // context, and we also need to take the global proxy from the function
  // context in case of conversion.
  __ LoadTaggedPointerField(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
  // We need to convert the receiver for non-native sloppy mode functions.
  Label done_convert;
  __ testl(FieldOperand(rdx, SharedFunctionInfo::kFlagsOffset),
           Immediate(SharedFunctionInfo::IsNativeBit::kMask |
                     SharedFunctionInfo::IsStrictBit::kMask));
  __ j(not_zero, &done_convert);
  {
    // ----------- S t a t e -------------
    //  -- rax : the number of arguments (not including the receiver)
    //  -- rdx : the shared function info.
    //  -- rdi : the function to call (checked to be a JSFunction)
    //  -- rsi : the function context.
    // -----------------------------------

    if (mode == ConvertReceiverMode::kNullOrUndefined) {
      // Patch receiver to global proxy.
      __ LoadGlobalProxy(rcx);
    } else {
      Label convert_to_object, convert_receiver;
      __ movq(rcx, args.GetReceiverOperand());
      __ JumpIfSmi(rcx, &convert_to_object, Label::kNear);
      STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
      __ CmpObjectType(rcx, FIRST_JS_RECEIVER_TYPE, rbx);
      __ j(above_equal, &done_convert);
      if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
        Label convert_global_proxy;
        __ JumpIfRoot(rcx, RootIndex::kUndefinedValue, &convert_global_proxy,
                      Label::kNear);
        __ JumpIfNotRoot(rcx, RootIndex::kNullValue, &convert_to_object,
                         Label::kNear);
        __ bind(&convert_global_proxy);
        {
          // Patch receiver to global proxy.
          __ LoadGlobalProxy(rcx);
        }
        __ jmp(&convert_receiver);
      }
      __ bind(&convert_to_object);
      {
        // Convert receiver using ToObject.
        // TODO(bmeurer): Inline the allocation here to avoid building the frame
        // in the fast case? (fall back to AllocateInNewSpace?)
        FrameScope scope(masm, StackFrame::INTERNAL);
        __ SmiTag(rax);
        __ Push(rax);
        __ Push(rdi);
        __ movq(rax, rcx);
        __ Push(rsi);
        __ Call(BUILTIN_CODE(masm->isolate(), ToObject),
                RelocInfo::CODE_TARGET);
        __ Pop(rsi);
        __ movq(rcx, rax);
        __ Pop(rdi);
        __ Pop(rax);
        __ SmiUntag(rax);
      }
      __ LoadTaggedPointerField(
          rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
      __ bind(&convert_receiver);
    }
    __ movq(args.GetReceiverOperand(), rcx);
  }
  __ bind(&done_convert);

  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the shared function info.
  //  -- rdi : the function to call (checked to be a JSFunction)
  //  -- rsi : the function context.
  // -----------------------------------

  __ movzxwq(
      rbx, FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));

  __ InvokeFunctionCode(rdi, no_reg, rbx, rax, JUMP_FUNCTION);

  // The function is a "classConstructor", need to raise an exception.
  __ bind(&class_constructor);
  {
    FrameScope frame(masm, StackFrame::INTERNAL);
    __ Push(rdi);
    __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
  }
}

namespace {

void Generate_PushBoundArguments(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : new.target (only in case of [[Construct]])
  //  -- rdi : target (checked to be a JSBoundFunction)
  // -----------------------------------

  // Load [[BoundArguments]] into rcx and length of that into rbx.
  Label no_bound_arguments;
  __ LoadTaggedPointerField(
      rcx, FieldOperand(rdi, JSBoundFunction::kBoundArgumentsOffset));
  __ SmiUntagField(rbx, FieldOperand(rcx, FixedArray::kLengthOffset));
  __ testl(rbx, rbx);
  __ j(zero, &no_bound_arguments);
  {
    // ----------- S t a t e -------------
    //  -- rax : the number of arguments (not including the receiver)
    //  -- rdx : new.target (only in case of [[Construct]])
    //  -- rdi : target (checked to be a JSBoundFunction)
    //  -- rcx : the [[BoundArguments]] (implemented as FixedArray)
    //  -- rbx : the number of [[BoundArguments]] (checked to be non-zero)
    // -----------------------------------

    // TODO(victor): Use Generate_StackOverflowCheck here.
    // Check the stack for overflow.
    {
      Label done;
      __ shlq(rbx, Immediate(kSystemPointerSizeLog2));
      __ movq(kScratchRegister, rsp);
      __ subq(kScratchRegister, rbx);

      // We are not trying to catch interruptions (i.e. debug break and
      // preemption) here, so check the "real stack limit".
      __ cmpq(kScratchRegister,
              StackLimitAsOperand(masm, StackLimitKind::kRealStackLimit));
      __ j(above_equal, &done, Label::kNear);
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowStackOverflow);
      }
      __ bind(&done);
    }

#ifdef V8_REVERSE_JSARGS
    // Save Return Address and Receiver into registers.
    __ Pop(r8);
    __ Pop(r10);

    // Push [[BoundArguments]] to the stack.
    {
      Label loop;
      __ LoadTaggedPointerField(
          rcx, FieldOperand(rdi, JSBoundFunction::kBoundArgumentsOffset));
      __ SmiUntagField(rbx, FieldOperand(rcx, FixedArray::kLengthOffset));
      __ addq(rax, rbx);  // Adjust effective number of arguments.
      __ bind(&loop);
      // Instead of doing decl(rbx) here subtract kTaggedSize from the header
      // offset in order to be able to move decl(rbx) right before the loop
      // condition. This is necessary in order to avoid flags corruption by
      // pointer decompression code.
      __ LoadAnyTaggedField(
          r12, FieldOperand(rcx, rbx, times_tagged_size,
                            FixedArray::kHeaderSize - kTaggedSize));
      __ Push(r12);
      __ decl(rbx);
      __ j(greater, &loop);
    }

    // Recover Receiver and Return Address.
    __ Push(r10);
    __ Push(r8);
#else   // !V8_REVERSE_JSARGS
    // Reserve stack space for the [[BoundArguments]].
    __ movq(kScratchRegister, rbx);
    __ AllocateStackSpace(kScratchRegister);

    // Adjust effective number of arguments to include return address.
    __ incl(rax);

    // Relocate arguments and return address down the stack.
    {
      Label loop;
      __ Set(rcx, 0);
      __ addq(rbx, rsp);
      __ bind(&loop);
      __ movq(kScratchRegister,
              Operand(rbx, rcx, times_system_pointer_size, 0));
      __ movq(Operand(rsp, rcx, times_system_pointer_size, 0),
              kScratchRegister);
      __ incl(rcx);
      __ cmpl(rcx, rax);
      __ j(less, &loop);
    }

    // Copy [[BoundArguments]] to the stack (below the arguments).
    {
      Label loop;
      __ LoadTaggedPointerField(
          rcx, FieldOperand(rdi, JSBoundFunction::kBoundArgumentsOffset));
      __ SmiUntagField(rbx, FieldOperand(rcx, FixedArray::kLengthOffset));
      __ bind(&loop);
      // Instead of doing decl(rbx) here subtract kTaggedSize from the header
      // offset in order be able to move decl(rbx) right before the loop
      // condition. This is necessary in order to avoid flags corruption by
      // pointer decompression code.
      __ LoadAnyTaggedField(
          r12, FieldOperand(rcx, rbx, times_tagged_size,
                            FixedArray::kHeaderSize - kTaggedSize));
      __ movq(Operand(rsp, rax, times_system_pointer_size, 0), r12);
      __ leal(rax, Operand(rax, 1));
      __ decl(rbx);
      __ j(greater, &loop);
    }

    // Adjust effective number of arguments (rax contains the number of
    // arguments from the call plus return address plus the number of
    // [[BoundArguments]]), so we need to subtract one for the return address.
    __ decl(rax);
#endif  // !V8_REVERSE_JSARGS
  }
  __ bind(&no_bound_arguments);
}

}  // namespace

// static
void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdi : the function to call (checked to be a JSBoundFunction)
  // -----------------------------------
  __ AssertBoundFunction(rdi);

  // Patch the receiver to [[BoundThis]].
  StackArgumentsAccessor args(rax);
  __ LoadAnyTaggedField(rbx,
                        FieldOperand(rdi, JSBoundFunction::kBoundThisOffset));
  __ movq(args.GetReceiverOperand(), rbx);

  // Push the [[BoundArguments]] onto the stack.
  Generate_PushBoundArguments(masm);

  // Call the [[BoundTargetFunction]] via the Call builtin.
  __ LoadTaggedPointerField(
      rdi, FieldOperand(rdi, JSBoundFunction::kBoundTargetFunctionOffset));
  __ Jump(BUILTIN_CODE(masm->isolate(), Call_ReceiverIsAny),
          RelocInfo::CODE_TARGET);
}

// static
void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdi : the target to call (can be any Object)
  // -----------------------------------
  StackArgumentsAccessor args(rax);

  Label non_callable;
  __ JumpIfSmi(rdi, &non_callable);
  __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
  __ Jump(masm->isolate()->builtins()->CallFunction(mode),
          RelocInfo::CODE_TARGET, equal);

  __ CmpInstanceType(rcx, JS_BOUND_FUNCTION_TYPE);
  __ Jump(BUILTIN_CODE(masm->isolate(), CallBoundFunction),
          RelocInfo::CODE_TARGET, equal);

  // Check if target has a [[Call]] internal method.
  __ testb(FieldOperand(rcx, Map::kBitFieldOffset),
           Immediate(Map::Bits1::IsCallableBit::kMask));
  __ j(zero, &non_callable, Label::kNear);

  // Check if target is a proxy and call CallProxy external builtin
  __ CmpInstanceType(rcx, JS_PROXY_TYPE);
  __ Jump(BUILTIN_CODE(masm->isolate(), CallProxy), RelocInfo::CODE_TARGET,
          equal);

  // 2. Call to something else, which might have a [[Call]] internal method (if
  // not we raise an exception).

  // Overwrite the original receiver with the (original) target.
  __ movq(args.GetReceiverOperand(), rdi);
  // Let the "call_as_function_delegate" take care of the rest.
  __ LoadNativeContextSlot(Context::CALL_AS_FUNCTION_DELEGATE_INDEX, rdi);
  __ Jump(masm->isolate()->builtins()->CallFunction(
              ConvertReceiverMode::kNotNullOrUndefined),
          RelocInfo::CODE_TARGET);

  // 3. Call to something that is not callable.
  __ bind(&non_callable);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(rdi);
    __ CallRuntime(Runtime::kThrowCalledNonCallable);
  }
}

// static
void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the new target (checked to be a constructor)
  //  -- rdi : the constructor to call (checked to be a JSFunction)
  // -----------------------------------
  __ AssertConstructor(rdi);
  __ AssertFunction(rdi);

  // Calling convention for function specific ConstructStubs require
  // rbx to contain either an AllocationSite or undefined.
  __ LoadRoot(rbx, RootIndex::kUndefinedValue);

  // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
  __ LoadTaggedPointerField(
      rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
  __ testl(FieldOperand(rcx, SharedFunctionInfo::kFlagsOffset),
           Immediate(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
  __ Jump(BUILTIN_CODE(masm->isolate(), JSBuiltinsConstructStub),
          RelocInfo::CODE_TARGET, not_zero);

  __ Jump(BUILTIN_CODE(masm->isolate(), JSConstructStubGeneric),
          RelocInfo::CODE_TARGET);
}

// static
void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the new target (checked to be a constructor)
  //  -- rdi : the constructor to call (checked to be a JSBoundFunction)
  // -----------------------------------
  __ AssertConstructor(rdi);
  __ AssertBoundFunction(rdi);

  // Push the [[BoundArguments]] onto the stack.
  Generate_PushBoundArguments(masm);

  // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
  {
    Label done;
    __ cmpq(rdi, rdx);
    __ j(not_equal, &done, Label::kNear);
    __ LoadTaggedPointerField(
        rdx, FieldOperand(rdi, JSBoundFunction::kBoundTargetFunctionOffset));
    __ bind(&done);
  }

  // Construct the [[BoundTargetFunction]] via the Construct builtin.
  __ LoadTaggedPointerField(
      rdi, FieldOperand(rdi, JSBoundFunction::kBoundTargetFunctionOffset));
  __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
}

// static
void Builtins::Generate_Construct(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : the number of arguments (not including the receiver)
  //  -- rdx : the new target (either the same as the constructor or
  //           the JSFunction on which new was invoked initially)
  //  -- rdi : the constructor to call (can be any Object)
  // -----------------------------------
  StackArgumentsAccessor args(rax);

  // Check if target is a Smi.
  Label non_constructor;
  __ JumpIfSmi(rdi, &non_constructor);

  // Check if target has a [[Construct]] internal method.
  __ LoadTaggedPointerField(rcx, FieldOperand(rdi, HeapObject::kMapOffset));
  __ testb(FieldOperand(rcx, Map::kBitFieldOffset),
           Immediate(Map::Bits1::IsConstructorBit::kMask));
  __ j(zero, &non_constructor);

  // Dispatch based on instance type.
  __ CmpInstanceType(rcx, JS_FUNCTION_TYPE);
  __ Jump(BUILTIN_CODE(masm->isolate(), ConstructFunction),
          RelocInfo::CODE_TARGET, equal);

  // Only dispatch to bound functions after checking whether they are
  // constructors.
  __ CmpInstanceType(rcx, JS_BOUND_FUNCTION_TYPE);
  __ Jump(BUILTIN_CODE(masm->isolate(), ConstructBoundFunction),
          RelocInfo::CODE_TARGET, equal);

  // Only dispatch to proxies after checking whether they are constructors.
  __ CmpInstanceType(rcx, JS_PROXY_TYPE);
  __ Jump(BUILTIN_CODE(masm->isolate(), ConstructProxy), RelocInfo::CODE_TARGET,
          equal);

  // Called Construct on an exotic Object with a [[Construct]] internal method.
  {
    // Overwrite the original receiver with the (original) target.
    __ movq(args.GetReceiverOperand(), rdi);
    // Let the "call_as_constructor_delegate" take care of the rest.
    __ LoadNativeContextSlot(Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, rdi);
    __ Jump(masm->isolate()->builtins()->CallFunction(),
            RelocInfo::CODE_TARGET);
  }

  // Called Construct on an Object that doesn't have a [[Construct]] internal
  // method.
  __ bind(&non_constructor);
  __ Jump(BUILTIN_CODE(masm->isolate(), ConstructedNonConstructable),
          RelocInfo::CODE_TARGET);
}

void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ CallRuntime(Runtime::kCompileForOnStackReplacement);
  }

  Label skip;
  // If the code object is null, just return to the caller.
  __ testq(rax, rax);
  __ j(not_equal, &skip, Label::kNear);
  __ ret(0);

  __ bind(&skip);

  // Drop the handler frame that is be sitting on top of the actual
  // JavaScript frame. This is the case then OSR is triggered from bytecode.
  __ leave();

  // Load deoptimization data from the code object.
  __ LoadTaggedPointerField(rbx,
                            FieldOperand(rax, Code::kDeoptimizationDataOffset));

  // Load the OSR entrypoint offset from the deoptimization data.
  __ SmiUntagField(
      rbx, FieldOperand(rbx, FixedArray::OffsetOfElementAt(
                                 DeoptimizationData::kOsrPcOffsetIndex)));

  // Compute the target address = code_obj + header_size + osr_offset
  __ leaq(rax, FieldOperand(rax, rbx, times_1, Code::kHeaderSize));

  // Overwrite the return address on the stack.
  __ movq(StackOperandForReturnAddress(0), rax);

  // And "return" to the OSR entry point of the function.
  __ ret(0);
}

void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
  // The function index was pushed to the stack by the caller as int32.
  __ Pop(r11);
  // Convert to Smi for the runtime call.
  __ SmiTag(r11);
  {
    HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
    FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);

    // Save all parameter registers (see wasm-linkage.cc). They might be
    // overwritten in the runtime call below. We don't have any callee-saved
    // registers in wasm, so no need to store anything else.
    static_assert(WasmCompileLazyFrameConstants::kNumberOfSavedGpParamRegs ==
                      arraysize(wasm::kGpParamRegisters),
                  "frame size mismatch");
    for (Register reg : wasm::kGpParamRegisters) {
      __ Push(reg);
    }
    static_assert(WasmCompileLazyFrameConstants::kNumberOfSavedFpParamRegs ==
                      arraysize(wasm::kFpParamRegisters),
                  "frame size mismatch");
    __ AllocateStackSpace(kSimd128Size * arraysize(wasm::kFpParamRegisters));
    int offset = 0;
    for (DoubleRegister reg : wasm::kFpParamRegisters) {
      __ movdqu(Operand(rsp, offset), reg);
      offset += kSimd128Size;
    }

    // Push the Wasm instance as an explicit argument to WasmCompileLazy.
    __ Push(kWasmInstanceRegister);
    // Push the function index as second argument.
    __ Push(r11);
    // Initialize the JavaScript context with 0. CEntry will use it to
    // set the current context on the isolate.
    __ Move(kContextRegister, Smi::zero());
    __ CallRuntime(Runtime::kWasmCompileLazy, 2);
    // The entrypoint address is the return value.
    __ movq(r11, kReturnRegister0);

    // Restore registers.
    for (DoubleRegister reg : base::Reversed(wasm::kFpParamRegisters)) {
      offset -= kSimd128Size;
      __ movdqu(reg, Operand(rsp, offset));
    }
    DCHECK_EQ(0, offset);
    __ addq(rsp, Immediate(kSimd128Size * arraysize(wasm::kFpParamRegisters)));
    for (Register reg : base::Reversed(wasm::kGpParamRegisters)) {
      __ Pop(reg);
    }
  }
  // Finally, jump to the entrypoint.
  __ jmp(r11);
}

void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
  HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
  {
    FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);

    // Save all parameter registers. They might hold live values, we restore
    // them after the runtime call.
    for (int reg_code : base::bits::IterateBitsBackwards(
             WasmDebugBreakFrameConstants::kPushedGpRegs)) {
      __ Push(Register::from_code(reg_code));
    }

    constexpr int kFpStackSize =
        kSimd128Size * WasmDebugBreakFrameConstants::kNumPushedFpRegisters;
    __ AllocateStackSpace(kFpStackSize);
    int offset = kFpStackSize;
    for (int reg_code : base::bits::IterateBitsBackwards(
             WasmDebugBreakFrameConstants::kPushedFpRegs)) {
      offset -= kSimd128Size;
      __ movdqu(Operand(rsp, offset), DoubleRegister::from_code(reg_code));
    }

    // Initialize the JavaScript context with 0. CEntry will use it to
    // set the current context on the isolate.
    __ Move(kContextRegister, Smi::zero());
    __ CallRuntime(Runtime::kWasmDebugBreak, 0);

    // Restore registers.
    for (int reg_code :
         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedFpRegs)) {
      __ movdqu(DoubleRegister::from_code(reg_code), Operand(rsp, offset));
      offset += kSimd128Size;
    }
    __ addq(rsp, Immediate(kFpStackSize));
    for (int reg_code :
         base::bits::IterateBits(WasmDebugBreakFrameConstants::kPushedGpRegs)) {
      __ Pop(Register::from_code(reg_code));
    }
  }

  __ ret(0);
}

void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                               SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                               bool builtin_exit_frame) {
  // rax: number of arguments including receiver
  // rbx: pointer to C function  (C callee-saved)
  // rbp: frame pointer of calling JS frame (restored after C call)
  // rsp: stack pointer  (restored after C call)
  // rsi: current context (restored)
  //
  // If argv_mode == kArgvInRegister:
  // r15: pointer to the first argument

#ifdef V8_TARGET_OS_WIN
  // Windows 64-bit ABI passes arguments in rcx, rdx, r8, r9. It requires the
  // stack to be aligned to 16 bytes. It only allows a single-word to be
  // returned in register rax. Larger return sizes must be written to an address
  // passed as a hidden first argument.
  const Register kCCallArg0 = rcx;
  const Register kCCallArg1 = rdx;
  const Register kCCallArg2 = r8;
  const Register kCCallArg3 = r9;
  const int kArgExtraStackSpace = 2;
  const int kMaxRegisterResultSize = 1;
#else
  // GCC / Clang passes arguments in rdi, rsi, rdx, rcx, r8, r9. Simple results
  // are returned in rax, and a struct of two pointers are returned in rax+rdx.
  // Larger return sizes must be written to an address passed as a hidden first
  // argument.
  const Register kCCallArg0 = rdi;
  const Register kCCallArg1 = rsi;
  const Register kCCallArg2 = rdx;
  const Register kCCallArg3 = rcx;
  const int kArgExtraStackSpace = 0;
  const int kMaxRegisterResultSize = 2;
#endif  // V8_TARGET_OS_WIN

  // Enter the exit frame that transitions from JavaScript to C++.
  int arg_stack_space =
      kArgExtraStackSpace +
      (result_size <= kMaxRegisterResultSize ? 0 : result_size);
  if (argv_mode == kArgvInRegister) {
    DCHECK(save_doubles == kDontSaveFPRegs);
    DCHECK(!builtin_exit_frame);
    __ EnterApiExitFrame(arg_stack_space);
    // Move argc into r14 (argv is already in r15).
    __ movq(r14, rax);
  } else {
    __ EnterExitFrame(
        arg_stack_space, save_doubles == kSaveFPRegs,
        builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
  }

  // rbx: pointer to builtin function  (C callee-saved).
  // rbp: frame pointer of exit frame  (restored after C call).
  // rsp: stack pointer (restored after C call).
  // r14: number of arguments including receiver (C callee-saved).
  // r15: argv pointer (C callee-saved).

  // Check stack alignment.
  if (FLAG_debug_code) {
    __ CheckStackAlignment();
  }

  // Call C function. The arguments object will be created by stubs declared by
  // DECLARE_RUNTIME_FUNCTION().
  if (result_size <= kMaxRegisterResultSize) {
    // Pass a pointer to the Arguments object as the first argument.
    // Return result in single register (rax), or a register pair (rax, rdx).
    __ movq(kCCallArg0, r14);  // argc.
    __ movq(kCCallArg1, r15);  // argv.
    __ Move(kCCallArg2, ExternalReference::isolate_address(masm->isolate()));
  } else {
    DCHECK_LE(result_size, 2);
    // Pass a pointer to the result location as the first argument.
    __ leaq(kCCallArg0, StackSpaceOperand(kArgExtraStackSpace));
    // Pass a pointer to the Arguments object as the second argument.
    __ movq(kCCallArg1, r14);  // argc.
    __ movq(kCCallArg2, r15);  // argv.
    __ Move(kCCallArg3, ExternalReference::isolate_address(masm->isolate()));
  }
  __ call(rbx);

  if (result_size > kMaxRegisterResultSize) {
    // Read result values stored on stack. Result is stored
    // above the the two Arguments object slots on Win64.
    DCHECK_LE(result_size, 2);
    __ movq(kReturnRegister0, StackSpaceOperand(kArgExtraStackSpace + 0));
    __ movq(kReturnRegister1, StackSpaceOperand(kArgExtraStackSpace + 1));
  }
  // Result is in rax or rdx:rax - do not destroy these registers!

  // Check result for exception sentinel.
  Label exception_returned;
  __ CompareRoot(rax, RootIndex::kException);
  __ j(equal, &exception_returned);

  // Check that there is no pending exception, otherwise we
  // should have returned the exception sentinel.
  if (FLAG_debug_code) {
    Label okay;
    __ LoadRoot(r14, RootIndex::kTheHoleValue);
    ExternalReference pending_exception_address = ExternalReference::Create(
        IsolateAddressId::kPendingExceptionAddress, masm->isolate());
    Operand pending_exception_operand =
        masm->ExternalReferenceAsOperand(pending_exception_address);
    __ cmp_tagged(r14, pending_exception_operand);
    __ j(equal, &okay, Label::kNear);
    __ int3();
    __ bind(&okay);
  }

  // Exit the JavaScript to C++ exit frame.
  __ LeaveExitFrame(save_doubles == kSaveFPRegs, argv_mode == kArgvOnStack);
  __ ret(0);

  // Handling of exception.
  __ bind(&exception_returned);

  ExternalReference pending_handler_context_address = ExternalReference::Create(
      IsolateAddressId::kPendingHandlerContextAddress, masm->isolate());
  ExternalReference pending_handler_entrypoint_address =
      ExternalReference::Create(
          IsolateAddressId::kPendingHandlerEntrypointAddress, masm->isolate());
  ExternalReference pending_handler_fp_address = ExternalReference::Create(
      IsolateAddressId::kPendingHandlerFPAddress, masm->isolate());
  ExternalReference pending_handler_sp_address = ExternalReference::Create(
      IsolateAddressId::kPendingHandlerSPAddress, masm->isolate());

  // Ask the runtime for help to determine the handler. This will set rax to
  // contain the current pending exception, don't clobber it.
  ExternalReference find_handler =
      ExternalReference::Create(Runtime::kUnwindAndFindExceptionHandler);
  {
    FrameScope scope(masm, StackFrame::MANUAL);
    __ movq(arg_reg_1, Immediate(0));  // argc.
    __ movq(arg_reg_2, Immediate(0));  // argv.
    __ Move(arg_reg_3, ExternalReference::isolate_address(masm->isolate()));
    __ PrepareCallCFunction(3);
    __ CallCFunction(find_handler, 3);
  }
  // Retrieve the handler context, SP and FP.
  __ movq(rsi,
          masm->ExternalReferenceAsOperand(pending_handler_context_address));
  __ movq(rsp, masm->ExternalReferenceAsOperand(pending_handler_sp_address));
  __ movq(rbp, masm->ExternalReferenceAsOperand(pending_handler_fp_address));

  // If the handler is a JS frame, restore the context to the frame. Note that
  // the context will be set to (rsi == 0) for non-JS frames.
  Label skip;
  __ testq(rsi, rsi);
  __ j(zero, &skip, Label::kNear);
  __ movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);
  __ bind(&skip);

  // Reset the masking register. This is done independent of the underlying
  // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
  // with both configurations. It is safe to always do this, because the
  // underlying register is caller-saved and can be arbitrarily clobbered.
  __ ResetSpeculationPoisonRegister();

  // Compute the handler entry address and jump to it.
  __ movq(rdi,
          masm->ExternalReferenceAsOperand(pending_handler_entrypoint_address));
  __ jmp(rdi);
}

void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
  Label check_negative, process_64_bits, done;

  // Account for return address and saved regs.
  const int kArgumentOffset = 4 * kSystemPointerSize;

  MemOperand mantissa_operand(MemOperand(rsp, kArgumentOffset));
  MemOperand exponent_operand(
      MemOperand(rsp, kArgumentOffset + kDoubleSize / 2));

  // The result is returned on the stack.
  MemOperand return_operand = mantissa_operand;

  Register scratch1 = rbx;

  // Since we must use rcx for shifts below, use some other register (rax)
  // to calculate the result if ecx is the requested return register.
  Register result_reg = rax;
  // Save ecx if it isn't the return register and therefore volatile, or if it
  // is the return register, then save the temp register we use in its stead
  // for the result.
  Register save_reg = rax;
  __ pushq(rcx);
  __ pushq(scratch1);
  __ pushq(save_reg);

  __ movl(scratch1, mantissa_operand);
  __ Movsd(kScratchDoubleReg, mantissa_operand);
  __ movl(rcx, exponent_operand);

  __ andl(rcx, Immediate(HeapNumber::kExponentMask));
  __ shrl(rcx, Immediate(HeapNumber::kExponentShift));
  __ leal(result_reg, MemOperand(rcx, -HeapNumber::kExponentBias));
  __ cmpl(result_reg, Immediate(HeapNumber::kMantissaBits));
  __ j(below, &process_64_bits, Label::kNear);

  // Result is entirely in lower 32-bits of mantissa
  int delta = HeapNumber::kExponentBias + Double::kPhysicalSignificandSize;
  __ subl(rcx, Immediate(delta));
  __ xorl(result_reg, result_reg);
  __ cmpl(rcx, Immediate(31));
  __ j(above, &done, Label::kNear);
  __ shll_cl(scratch1);
  __ jmp(&check_negative, Label::kNear);

  __ bind(&process_64_bits);
  __ Cvttsd2siq(result_reg, kScratchDoubleReg);
  __ jmp(&done, Label::kNear);

  // If the double was negative, negate the integer result.
  __ bind(&check_negative);
  __ movl(result_reg, scratch1);
  __ negl(result_reg);
  __ cmpl(exponent_operand, Immediate(0));
  __ cmovl(greater, result_reg, scratch1);

  // Restore registers
  __ bind(&done);
  __ movl(return_operand, result_reg);
  __ popq(save_reg);
  __ popq(scratch1);
  __ popq(rcx);
  __ ret(0);
}

namespace {

int Offset(ExternalReference ref0, ExternalReference ref1) {
  int64_t offset = (ref0.address() - ref1.address());
  // Check that fits into int.
  DCHECK(static_cast<int>(offset) == offset);
  return static_cast<int>(offset);
}

// Calls an API function.  Allocates HandleScope, extracts returned value
// from handle and propagates exceptions.  Clobbers r14, r15, rbx and
// caller-save registers.  Restores context.  On return removes
// stack_space * kSystemPointerSize (GCed).
void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
                              ExternalReference thunk_ref,
                              Register thunk_last_arg, int stack_space,
                              Operand* stack_space_operand,
                              Operand return_value_operand) {
  Label prologue;
  Label promote_scheduled_exception;
  Label delete_allocated_handles;
  Label leave_exit_frame;

  Isolate* isolate = masm->isolate();
  Factory* factory = isolate->factory();
  ExternalReference next_address =
      ExternalReference::handle_scope_next_address(isolate);
  const int kNextOffset = 0;
  const int kLimitOffset = Offset(
      ExternalReference::handle_scope_limit_address(isolate), next_address);
  const int kLevelOffset = Offset(
      ExternalReference::handle_scope_level_address(isolate), next_address);
  ExternalReference scheduled_exception_address =
      ExternalReference::scheduled_exception_address(isolate);

  DCHECK(rdx == function_address || r8 == function_address);
  // Allocate HandleScope in callee-save registers.
  Register prev_next_address_reg = r14;
  Register prev_limit_reg = rbx;
  Register base_reg = r15;
  __ Move(base_reg, next_address);
  __ movq(prev_next_address_reg, Operand(base_reg, kNextOffset));
  __ movq(prev_limit_reg, Operand(base_reg, kLimitOffset));
  __ addl(Operand(base_reg, kLevelOffset), Immediate(1));

  Label profiler_enabled, end_profiler_check;
  __ Move(rax, ExternalReference::is_profiling_address(isolate));
  __ cmpb(Operand(rax, 0), Immediate(0));
  __ j(not_zero, &profiler_enabled);
  __ Move(rax, ExternalReference::address_of_runtime_stats_flag());
  __ cmpl(Operand(rax, 0), Immediate(0));
  __ j(not_zero, &profiler_enabled);
  {
    // Call the api function directly.
    __ Move(rax, function_address);
    __ jmp(&end_profiler_check);
  }
  __ bind(&profiler_enabled);
  {
    // Third parameter is the address of the actual getter function.
    __ Move(thunk_last_arg, function_address);
    __ Move(rax, thunk_ref);
  }
  __ bind(&end_profiler_check);

  // Call the api function!
  __ call(rax);

  // Load the value from ReturnValue
  __ movq(rax, return_value_operand);
  __ bind(&prologue);

  // No more valid handles (the result handle was the last one). Restore
  // previous handle scope.
  __ subl(Operand(base_reg, kLevelOffset), Immediate(1));
  __ movq(Operand(base_reg, kNextOffset), prev_next_address_reg);
  __ cmpq(prev_limit_reg, Operand(base_reg, kLimitOffset));
  __ j(not_equal, &delete_allocated_handles);

  // Leave the API exit frame.
  __ bind(&leave_exit_frame);
  if (stack_space_operand != nullptr) {
    DCHECK_EQ(stack_space, 0);
    __ movq(rbx, *stack_space_operand);
  }
  __ LeaveApiExitFrame();

  // Check if the function scheduled an exception.
  __ Move(rdi, scheduled_exception_address);
  __ Cmp(Operand(rdi, 0), 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 = rax;
  Register map = rcx;

  __ JumpIfSmi(return_value, &ok, Label::kNear);
  __ LoadTaggedPointerField(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);

  __ CompareRoot(map, RootIndex::kHeapNumberMap);
  __ j(equal, &ok, Label::kNear);

  __ CompareRoot(map, RootIndex::kBigIntMap);
  __ j(equal, &ok, Label::kNear);

  __ CompareRoot(return_value, RootIndex::kUndefinedValue);
  __ j(equal, &ok, Label::kNear);

  __ CompareRoot(return_value, RootIndex::kTrueValue);
  __ j(equal, &ok, Label::kNear);

  __ CompareRoot(return_value, RootIndex::kFalseValue);
  __ j(equal, &ok, Label::kNear);

  __ CompareRoot(return_value, RootIndex::kNullValue);
  __ j(equal, &ok, Label::kNear);

  __ Abort(AbortReason::kAPICallReturnedInvalidObject);

  __ bind(&ok);
#endif

  if (stack_space_operand == nullptr) {
    DCHECK_NE(stack_space, 0);
    __ ret(stack_space * kSystemPointerSize);
  } else {
    DCHECK_EQ(stack_space, 0);
    __ PopReturnAddressTo(rcx);
    __ addq(rsp, rbx);
    __ jmp(rcx);
  }

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

  // HandleScope limit has changed. Delete allocated extensions.
  __ bind(&delete_allocated_handles);
  __ movq(Operand(base_reg, kLimitOffset), prev_limit_reg);
  __ movq(prev_limit_reg, rax);
  __ LoadAddress(arg_reg_1, ExternalReference::isolate_address(isolate));
  __ LoadAddress(rax, ExternalReference::delete_handle_scope_extensions());
  __ call(rax);
  __ movq(rax, prev_limit_reg);
  __ jmp(&leave_exit_frame);
}

}  // namespace

// TODO(jgruber): Instead of explicitly setting up implicit_args_ on the stack
// in CallApiCallback, we could use the calling convention to set up the stack
// correctly in the first place.
//
// TODO(jgruber): I suspect that most of CallApiCallback could be implemented
// as a C++ trampoline, vastly simplifying the assembly implementation.

void Builtins::Generate_CallApiCallback(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rsi                 : context
  //  -- rdx                 : api function address
  //  -- rcx                 : arguments count (not including the receiver)
  //  -- rbx                 : call data
  //  -- rdi                 : holder
  //  -- rsp[0]              : return address
  //  -- rsp[8]              : argument argc
  //  -- ...
  //  -- rsp[argc * 8]       : argument 1
  //  -- rsp[(argc + 1) * 8] : argument 0 (receiver)
  // -----------------------------------
  // NOTE: The order of args are reversed if V8_REVERSE_JSARGS

  Register api_function_address = rdx;
  Register argc = rcx;
  Register call_data = rbx;
  Register holder = rdi;

  DCHECK(!AreAliased(api_function_address, argc, holder, call_data,
                     kScratchRegister));

  using FCA = FunctionCallbackArguments;

  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);

  // Set up FunctionCallbackInfo's implicit_args on the stack as follows:
  //
  // Current state:
  //   rsp[0]: return address
  //
  // Target state:
  //   rsp[0 * kSystemPointerSize]: return address
  //   rsp[1 * kSystemPointerSize]: kHolder
  //   rsp[2 * kSystemPointerSize]: kIsolate
  //   rsp[3 * kSystemPointerSize]: undefined (kReturnValueDefaultValue)
  //   rsp[4 * kSystemPointerSize]: undefined (kReturnValue)
  //   rsp[5 * kSystemPointerSize]: kData
  //   rsp[6 * kSystemPointerSize]: undefined (kNewTarget)

  __ PopReturnAddressTo(rax);
  __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
  __ Push(kScratchRegister);
  __ Push(call_data);
  __ Push(kScratchRegister);
  __ Push(kScratchRegister);
  __ PushAddress(ExternalReference::isolate_address(masm->isolate()));
  __ Push(holder);
  __ PushReturnAddressFrom(rax);

  // Keep a pointer to kHolder (= implicit_args) in a scratch register.
  // We use it below to set up the FunctionCallbackInfo object.
  Register scratch = rbx;
  __ leaq(scratch, Operand(rsp, 1 * kSystemPointerSize));

  // Allocate the v8::Arguments structure in the arguments' space since
  // it's not controlled by GC.
  static constexpr int kApiStackSpace = 4;
  __ EnterApiExitFrame(kApiStackSpace);

  // FunctionCallbackInfo::implicit_args_ (points at kHolder as set up above).
  __ movq(StackSpaceOperand(0), scratch);

  // FunctionCallbackInfo::values_ (points at the first varargs argument passed
  // on the stack).
#ifdef V8_REVERSE_JSARGS
  __ leaq(scratch,
          Operand(scratch, (FCA::kArgsLength + 1) * kSystemPointerSize));
#else
  __ leaq(scratch, Operand(scratch, argc, times_system_pointer_size,
                           (FCA::kArgsLength - 1) * kSystemPointerSize));
#endif
  __ movq(StackSpaceOperand(1), scratch);

  // FunctionCallbackInfo::length_.
  __ movq(StackSpaceOperand(2), argc);

  // We also store the number of bytes to drop from the stack after returning
  // from the API function here.
  __ leaq(kScratchRegister,
          Operand(argc, times_system_pointer_size,
                  (FCA::kArgsLength + 1 /* receiver */) * kSystemPointerSize));
  __ movq(StackSpaceOperand(3), kScratchRegister);

  Register arguments_arg = arg_reg_1;
  Register callback_arg = arg_reg_2;

  // It's okay if api_function_address == callback_arg
  // but not arguments_arg
  DCHECK(api_function_address != arguments_arg);

  // v8::InvocationCallback's argument.
  __ leaq(arguments_arg, StackSpaceOperand(0));

  ExternalReference thunk_ref = ExternalReference::invoke_function_callback();

  // There are two stack slots above the arguments we constructed on the stack:
  // the stored ebp (pushed by EnterApiExitFrame), and the return address.
  static constexpr int kStackSlotsAboveFCA = 2;
  Operand return_value_operand(
      rbp,
      (kStackSlotsAboveFCA + FCA::kReturnValueOffset) * kSystemPointerSize);

  static constexpr int kUseStackSpaceOperand = 0;
  Operand stack_space_operand = StackSpaceOperand(3);
  CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, callback_arg,
                           kUseStackSpaceOperand, &stack_space_operand,
                           return_value_operand);
}

void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
  Register name_arg = arg_reg_1;
  Register accessor_info_arg = arg_reg_2;
  Register getter_arg = arg_reg_3;
  Register api_function_address = r8;
  Register receiver = ApiGetterDescriptor::ReceiverRegister();
  Register holder = ApiGetterDescriptor::HolderRegister();
  Register callback = ApiGetterDescriptor::CallbackRegister();
  Register scratch = rax;
  Register decompr_scratch1 = COMPRESS_POINTERS_BOOL ? r11 : no_reg;

  DCHECK(!AreAliased(receiver, holder, callback, scratch, decompr_scratch1));

  // 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);

  // Insert additional parameters into the stack frame above return address.
  __ PopReturnAddressTo(scratch);
  __ Push(receiver);
  __ PushTaggedAnyField(FieldOperand(callback, AccessorInfo::kDataOffset),
                        decompr_scratch1);
  __ LoadRoot(kScratchRegister, RootIndex::kUndefinedValue);
  __ Push(kScratchRegister);  // return value
  __ Push(kScratchRegister);  // return value default
  __ PushAddress(ExternalReference::isolate_address(masm->isolate()));
  __ Push(holder);
  __ Push(Smi::zero());  // should_throw_on_error -> false
  __ PushTaggedPointerField(FieldOperand(callback, AccessorInfo::kNameOffset),
                            decompr_scratch1);
  __ PushReturnAddressFrom(scratch);

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

  // Allocate v8::PropertyCallbackInfo in non-GCed stack space.
  const int kArgStackSpace = 1;

  // Load address of v8::PropertyAccessorInfo::args_ array.
  __ leaq(scratch, Operand(rsp, 2 * kSystemPointerSize));

  __ EnterApiExitFrame(kArgStackSpace);

  // Create v8::PropertyCallbackInfo object on the stack and initialize
  // it's args_ field.
  Operand info_object = StackSpaceOperand(0);
  __ movq(info_object, scratch);

  __ leaq(name_arg, Operand(scratch, -kSystemPointerSize));
  // The context register (rsi) has been saved in EnterApiExitFrame and
  // could be used to pass arguments.
  __ leaq(accessor_info_arg, info_object);

  ExternalReference thunk_ref =
      ExternalReference::invoke_accessor_getter_callback();

  // It's okay if api_function_address == getter_arg
  // but not accessor_info_arg or name_arg
  DCHECK(api_function_address != accessor_info_arg);
  DCHECK(api_function_address != name_arg);
  __ LoadTaggedPointerField(
      scratch, FieldOperand(callback, AccessorInfo::kJsGetterOffset));
  __ LoadExternalPointerField(
      api_function_address,
      FieldOperand(scratch, Foreign::kForeignAddressOffset));

  // +3 is to skip prolog, return address and name handle.
  Operand return_value_operand(
      rbp,
      (PropertyCallbackArguments::kReturnValueOffset + 3) * kSystemPointerSize);
  Operand* const kUseStackSpaceConstant = nullptr;
  CallApiFunctionAndReturn(masm, api_function_address, thunk_ref, getter_arg,
                           kStackUnwindSpace, kUseStackSpaceConstant,
                           return_value_operand);
}

void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
  __ int3();  // Unused on this architecture.
}

#undef __

}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_X64
