text: // Copyright 2013 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_ARM64
  
  #include "src/arm64/frames-arm64.h"
  #include "src/codegen.h"
  #include "src/debug/debug.h"
  #include "src/deoptimizer.h"
  #include "src/full-codegen/full-codegen.h"
  #include "src/runtime/runtime.h"
  
  namespace v8 {
  namespace internal {
  
  #define __ ACCESS_MASM(masm)
  
  // Load the built-in Array function from the current context.
  static void GenerateLoadArrayFunction(MacroAssembler* masm, Register result) {
    // Load the InternalArray function from the native context.
    __ LoadNativeContextSlot(Context::ARRAY_FUNCTION_INDEX, result);
  }
  
  // Load the built-in InternalArray function from the current context.
  static void GenerateLoadInternalArrayFunction(MacroAssembler* masm,
                                                Register result) {
    // Load the InternalArray function from the native context.
    __ LoadNativeContextSlot(Context::INTERNAL_ARRAY_FUNCTION_INDEX, result);
  }
  
  void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address,
                                  ExitFrameType exit_frame_type) {
    // ----------- S t a t e -------------
    //  -- x0                 : number of arguments excluding receiver
    //  -- x1                 : target
    //  -- x3                 : new target
    //  -- sp[0]              : last argument
    //  -- ...
    //  -- sp[4 * (argc - 1)] : first argument
    //  -- sp[4 * argc]       : receiver
    // -----------------------------------
    __ AssertFunction(x1);
  
    // Make sure we operate in the context of the called function (for example
    // ConstructStubs implemented in C++ will be run in the context of the caller
    // instead of the callee, due to the way that [[Construct]] is defined for
    // ordinary functions).
    __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
  
    // JumpToExternalReference expects x0 to contain the number of arguments
    // including the receiver and the extra arguments.
    const int num_extra_args = 3;
    __ Add(x0, x0, num_extra_args + 1);
  
    // Insert extra arguments.
    __ SmiTag(x0);
    __ Push(x0, x1, x3);
    __ SmiUntag(x0);
  
    __ JumpToExternalReference(ExternalReference(address, masm->isolate()),
                               exit_frame_type == BUILTIN_EXIT);
  }
  
  void Builtins::Generate_InternalArrayCode(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0     : number of arguments
    //  -- lr     : return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_InternalArrayCode");
    Label generic_array_code;
  
    // Get the InternalArray function.
    GenerateLoadInternalArrayFunction(masm, x1);
  
    if (FLAG_debug_code) {
      // Initial map for the builtin InternalArray functions should be maps.
      __ Ldr(x10, FieldMemOperand(x1, JSFunction::kPrototypeOrInitialMapOffset));
      __ Tst(x10, kSmiTagMask);
      __ Assert(ne, kUnexpectedInitialMapForInternalArrayFunction);
      __ CompareObjectType(x10, x11, x12, MAP_TYPE);
      __ Assert(eq, kUnexpectedInitialMapForInternalArrayFunction);
    }
  
    // Run the native code for the InternalArray function called as a normal
    // function.
    InternalArrayConstructorStub stub(masm->isolate());
    __ TailCallStub(&stub);
  }
  
  void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0     : number of arguments
    //  -- lr     : return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_ArrayCode");
    Label generic_array_code, one_or_more_arguments, two_or_more_arguments;
  
    // Get the Array function.
    GenerateLoadArrayFunction(masm, x1);
  
    if (FLAG_debug_code) {
      // Initial map for the builtin Array functions should be maps.
      __ Ldr(x10, FieldMemOperand(x1, JSFunction::kPrototypeOrInitialMapOffset));
      __ Tst(x10, kSmiTagMask);
      __ Assert(ne, kUnexpectedInitialMapForArrayFunction);
      __ CompareObjectType(x10, x11, x12, MAP_TYPE);
      __ Assert(eq, kUnexpectedInitialMapForArrayFunction);
    }
  
    // Run the native code for the Array function called as a normal function.
    __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
    __ Mov(x3, x1);
    ArrayConstructorStub stub(masm->isolate());
    __ TailCallStub(&stub);
  }
  
  // static
  void Builtins::Generate_MathMaxMin(MacroAssembler* masm, MathMaxMinKind kind) {
    // ----------- S t a t e -------------
    //  -- x0                     : number of arguments
    //  -- x1                     : function
    //  -- cp                     : context
    //  -- lr                     : return address
    //  -- sp[(argc - n - 1) * 8] : arg[n] (zero-based)
    //  -- sp[argc * 8]           : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_MathMaxMin");
  
    Heap::RootListIndex const root_index =
        (kind == MathMaxMinKind::kMin) ? Heap::kInfinityValueRootIndex
                                       : Heap::kMinusInfinityValueRootIndex;
  
    // Load the accumulator with the default return value (either -Infinity or
    // +Infinity), with the tagged value in x5 and the double value in d5.
    __ LoadRoot(x5, root_index);
    __ Ldr(d5, FieldMemOperand(x5, HeapNumber::kValueOffset));
  
    Label done_loop, loop;
    __ mov(x4, x0);
    __ Bind(&loop);
    {
      // Check if all parameters done.
      __ Subs(x4, x4, 1);
      __ B(lt, &done_loop);
  
      // Load the next parameter tagged value into x2.
      __ Peek(x2, Operand(x4, LSL, kPointerSizeLog2));
  
      // Load the double value of the parameter into d2, maybe converting the
      // parameter to a number first using the ToNumber builtin if necessary.
      Label convert_smi, convert_number, done_convert;
      __ JumpIfSmi(x2, &convert_smi);
      __ JumpIfHeapNumber(x2, &convert_number);
      {
        // Parameter is not a Number, use the ToNumber builtin to convert it.
        FrameScope scope(masm, StackFrame::MANUAL);
        __ SmiTag(x0);
        __ SmiTag(x4);
        __ EnterBuiltinFrame(cp, x1, x0);
        __ Push(x5, x4);
        __ Mov(x0, x2);
        __ Call(masm->isolate()->builtins()->ToNumber(), RelocInfo::CODE_TARGET);
        __ Mov(x2, x0);
        __ Pop(x4, x5);
        __ LeaveBuiltinFrame(cp, x1, x0);
        __ SmiUntag(x4);
        __ SmiUntag(x0);
        {
          // Restore the double accumulator value (d5).
          Label done_restore;
          __ SmiUntagToDouble(d5, x5, kSpeculativeUntag);
          __ JumpIfSmi(x5, &done_restore);
          __ Ldr(d5, FieldMemOperand(x5, HeapNumber::kValueOffset));
          __ Bind(&done_restore);
        }
      }
      __ AssertNumber(x2);
      __ JumpIfSmi(x2, &convert_smi);
  
      __ Bind(&convert_number);
      __ Ldr(d2, FieldMemOperand(x2, HeapNumber::kValueOffset));
      __ B(&done_convert);
  
      __ Bind(&convert_smi);
      __ SmiUntagToDouble(d2, x2);
      __ Bind(&done_convert);
  
      // We can use a single fmin/fmax for the operation itself, but we then need
      // to work out which HeapNumber (or smi) the result came from.
      __ Fmov(x11, d5);
      if (kind == MathMaxMinKind::kMin) {
        __ Fmin(d5, d5, d2);
      } else {
        DCHECK(kind == MathMaxMinKind::kMax);
        __ Fmax(d5, d5, d2);
      }
      __ Fmov(x10, d5);
      __ Cmp(x10, x11);
      __ Csel(x5, x5, x2, eq);
      __ B(&loop);
    }
  
    __ Bind(&done_loop);
    // Drop all slots, including the receiver.
    __ Add(x0, x0, 1);
    __ Drop(x0);
    __ Mov(x0, x5);
    __ Ret();
  }
  
  // static
  void Builtins::Generate_NumberConstructor(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0                     : number of arguments
    //  -- x1                     : constructor function
    //  -- cp                     : context
    //  -- lr                     : return address
    //  -- sp[(argc - n - 1) * 8] : arg[n] (zero based)
    //  -- sp[argc * 8]           : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_NumberConstructor");
  
    // 1. Load the first argument into x0.
    Label no_arguments;
    {
      __ Cbz(x0, &no_arguments);
      __ Mov(x2, x0);  // Store argc in x2.
      __ Sub(x0, x0, 1);
      __ Ldr(x0, MemOperand(jssp, x0, LSL, kPointerSizeLog2));
    }
  
    // 2a. Convert first argument to number.
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ SmiTag(x2);
      __ EnterBuiltinFrame(cp, x1, x2);
      __ Call(masm->isolate()->builtins()->ToNumber(), RelocInfo::CODE_TARGET);
      __ LeaveBuiltinFrame(cp, x1, x2);
      __ SmiUntag(x2);
    }
  
    {
      // Drop all arguments.
      __ Drop(x2);
    }
  
    // 2b. No arguments, return +0 (already in x0).
    __ Bind(&no_arguments);
    __ Drop(1);
    __ Ret();
  }
  
  // static
  void Builtins::Generate_NumberConstructor_ConstructStub(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0                     : number of arguments
    //  -- x1                     : constructor function
    //  -- x3                     : new target
    //  -- cp                     : context
    //  -- lr                     : return address
    //  -- sp[(argc - n - 1) * 8] : arg[n] (zero based)
    //  -- sp[argc * 8]           : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_NumberConstructor_ConstructStub");
  
    // 1. Make sure we operate in the context of the called function.
    __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
  
    // 2. Load the first argument into x2.
    {
      Label no_arguments, done;
      __ Move(x6, x0);  // Store argc in x6.
      __ Cbz(x0, &no_arguments);
      __ Sub(x0, x0, 1);
      __ Ldr(x2, MemOperand(jssp, x0, LSL, kPointerSizeLog2));
      __ B(&done);
      __ Bind(&no_arguments);
      __ Mov(x2, Smi::kZero);
      __ Bind(&done);
    }
  
    // 3. Make sure x2 is a number.
    {
      Label done_convert;
      __ JumpIfSmi(x2, &done_convert);
      __ JumpIfObjectType(x2, x4, x4, HEAP_NUMBER_TYPE, &done_convert, eq);
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ SmiTag(x6);
        __ EnterBuiltinFrame(cp, x1, x6);
        __ Push(x3);
        __ Move(x0, x2);
        __ Call(masm->isolate()->builtins()->ToNumber(), RelocInfo::CODE_TARGET);
        __ Move(x2, x0);
        __ Pop(x3);
        __ LeaveBuiltinFrame(cp, x1, x6);
        __ SmiUntag(x6);
      }
      __ Bind(&done_convert);
    }
  
    // 4. Check if new target and constructor differ.
    Label drop_frame_and_ret, new_object;
    __ Cmp(x1, x3);
    __ B(ne, &new_object);
  
    // 5. Allocate a JSValue wrapper for the number.
    __ AllocateJSValue(x0, x1, x2, x4, x5, &new_object);
    __ B(&drop_frame_and_ret);
  
    // 6. Fallback to the runtime to create new object.
    __ bind(&new_object);
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      FastNewObjectStub stub(masm->isolate());
      __ SmiTag(x6);
      __ EnterBuiltinFrame(cp, x1, x6);
      __ Push(x2);  // first argument
      __ CallStub(&stub);
      __ Pop(x2);
      __ LeaveBuiltinFrame(cp, x1, x6);
      __ SmiUntag(x6);
    }
    __ Str(x2, FieldMemOperand(x0, JSValue::kValueOffset));
  
    __ bind(&drop_frame_and_ret);
    {
      __ Drop(x6);
      __ Drop(1);
      __ Ret();
    }
  }
  
  // static
  void Builtins::Generate_StringConstructor(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0                     : number of arguments
    //  -- x1                     : constructor function
    //  -- cp                     : context
    //  -- lr                     : return address
    //  -- sp[(argc - n - 1) * 8] : arg[n] (zero based)
    //  -- sp[argc * 8]           : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_StringConstructor");
  
    // 1. Load the first argument into x0.
    Label no_arguments;
    {
      __ Cbz(x0, &no_arguments);
      __ Mov(x2, x0);  // Store argc in x2.
      __ Sub(x0, x0, 1);
      __ Ldr(x0, MemOperand(jssp, x0, LSL, kPointerSizeLog2));
    }
  
    // 2a. At least one argument, return x0 if it's a string, otherwise
    // dispatch to appropriate conversion.
    Label drop_frame_and_ret, to_string, symbol_descriptive_string;
    {
      __ JumpIfSmi(x0, &to_string);
      STATIC_ASSERT(FIRST_NONSTRING_TYPE == SYMBOL_TYPE);
      __ CompareObjectType(x0, x3, x3, FIRST_NONSTRING_TYPE);
      __ B(hi, &to_string);
      __ B(eq, &symbol_descriptive_string);
      __ b(&drop_frame_and_ret);
    }
  
    // 2b. No arguments, return the empty string (and pop the receiver).
    __ Bind(&no_arguments);
    {
      __ LoadRoot(x0, Heap::kempty_stringRootIndex);
      __ Drop(1);
      __ Ret();
    }
  
    // 3a. Convert x0 to a string.
    __ Bind(&to_string);
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ SmiTag(x2);
      __ EnterBuiltinFrame(cp, x1, x2);
      __ Call(masm->isolate()->builtins()->ToString(), RelocInfo::CODE_TARGET);
      __ LeaveBuiltinFrame(cp, x1, x2);
      __ SmiUntag(x2);
    }
    __ b(&drop_frame_and_ret);
  
    // 3b. Convert symbol in x0 to a string.
    __ Bind(&symbol_descriptive_string);
    {
      __ Drop(x2);
      __ Drop(1);
      __ Push(x0);
      __ TailCallRuntime(Runtime::kSymbolDescriptiveString);
    }
  
    __ bind(&drop_frame_and_ret);
    {
      __ Drop(x2);
      __ Drop(1);
      __ Ret();
    }
  }
  
  // static
  void Builtins::Generate_StringConstructor_ConstructStub(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0                     : number of arguments
    //  -- x1                     : constructor function
    //  -- x3                     : new target
    //  -- cp                     : context
    //  -- lr                     : return address
    //  -- sp[(argc - n - 1) * 8] : arg[n] (zero based)
    //  -- sp[argc * 8]           : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_StringConstructor_ConstructStub");
  
    // 1. Make sure we operate in the context of the called function.
    __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
  
    // 2. Load the first argument into x2.
    {
      Label no_arguments, done;
      __ mov(x6, x0);  // Store argc in x6.
      __ Cbz(x0, &no_arguments);
      __ Sub(x0, x0, 1);
      __ Ldr(x2, MemOperand(jssp, x0, LSL, kPointerSizeLog2));
      __ B(&done);
      __ Bind(&no_arguments);
      __ LoadRoot(x2, Heap::kempty_stringRootIndex);
      __ Bind(&done);
    }
  
    // 3. Make sure x2 is a string.
    {
      Label convert, done_convert;
      __ JumpIfSmi(x2, &convert);
      __ JumpIfObjectType(x2, x4, x4, FIRST_NONSTRING_TYPE, &done_convert, lo);
      __ Bind(&convert);
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ SmiTag(x6);
        __ EnterBuiltinFrame(cp, x1, x6);
        __ Push(x3);
        __ Move(x0, x2);
        __ Call(masm->isolate()->builtins()->ToString(), RelocInfo::CODE_TARGET);
        __ Move(x2, x0);
        __ Pop(x3);
        __ LeaveBuiltinFrame(cp, x1, x6);
        __ SmiUntag(x6);
      }
      __ Bind(&done_convert);
    }
  
    // 4. Check if new target and constructor differ.
    Label drop_frame_and_ret, new_object;
    __ Cmp(x1, x3);
    __ B(ne, &new_object);
  
    // 5. Allocate a JSValue wrapper for the string.
    __ AllocateJSValue(x0, x1, x2, x4, x5, &new_object);
    __ B(&drop_frame_and_ret);
  
    // 6. Fallback to the runtime to create new object.
    __ bind(&new_object);
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      FastNewObjectStub stub(masm->isolate());
      __ SmiTag(x6);
      __ EnterBuiltinFrame(cp, x1, x6);
      __ Push(x2);  // first argument
      __ CallStub(&stub);
      __ Pop(x2);
      __ LeaveBuiltinFrame(cp, x1, x6);
      __ SmiUntag(x6);
    }
    __ Str(x2, FieldMemOperand(x0, JSValue::kValueOffset));
  
    __ bind(&drop_frame_and_ret);
    {
      __ Drop(x6);
      __ Drop(1);
      __ Ret();
    }
  }
  
  static void GenerateTailCallToSharedCode(MacroAssembler* masm) {
    __ Ldr(x2, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(x2, FieldMemOperand(x2, SharedFunctionInfo::kCodeOffset));
    __ Add(x2, x2, Code::kHeaderSize - kHeapObjectTag);
    __ Br(x2);
  }
  
  static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
                                             Runtime::FunctionId function_id) {
    // ----------- S t a t e -------------
    //  -- x0 : argument count (preserved for callee)
    //  -- x1 : target function (preserved for callee)
    //  -- x3 : new target (preserved for callee)
    // -----------------------------------
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Push a copy of the target function and the new target.
      // Push another copy as a parameter to the runtime call.
      __ SmiTag(x0);
      __ Push(x0, x1, x3, x1);
  
      __ CallRuntime(function_id, 1);
      __ Move(x2, x0);
  
      // Restore target function and new target.
      __ Pop(x3, x1, x0);
      __ SmiUntag(x0);
    }
  
    __ Add(x2, x2, Code::kHeaderSize - kHeapObjectTag);
    __ Br(x2);
  }
  
  void Builtins::Generate_InOptimizationQueue(MacroAssembler* masm) {
    // Checking whether the queued function is ready for install is optional,
    // since we come across interrupts and stack checks elsewhere. However, not
    // checking may delay installing ready functions, and always checking would be
    // quite expensive. A good compromise is to first check against stack limit as
    // a cue for an interrupt signal.
    Label ok;
    __ CompareRoot(masm->StackPointer(), Heap::kStackLimitRootIndex);
    __ B(hs, &ok);
  
    GenerateTailCallToReturnedCode(masm, Runtime::kTryInstallOptimizedCode);
  
    __ Bind(&ok);
    GenerateTailCallToSharedCode(masm);
  }
  
  namespace {
  
  void Generate_JSConstructStubHelper(MacroAssembler* masm, bool is_api_function,
                                      bool create_implicit_receiver,
                                      bool check_derived_construct) {
    // ----------- S t a t e -------------
    //  -- x0     : number of arguments
    //  -- x1     : constructor function
    //  -- x3     : new target
    //  -- lr     : return address
    //  -- cp     : context pointer
    //  -- sp[...]: constructor arguments
    // -----------------------------------
  
    ASM_LOCATION("Builtins::Generate_JSConstructStubHelper");
  
    Isolate* isolate = masm->isolate();
  
    // Enter a construct frame.
    {
      FrameScope scope(masm, StackFrame::CONSTRUCT);
  
      // Preserve the four incoming parameters on the stack.
      Register argc = x0;
      Register constructor = x1;
      Register new_target = x3;
  
      // Preserve the incoming parameters on the stack.
      __ SmiTag(argc);
      __ Push(cp, argc);
  
      if (create_implicit_receiver) {
        // Allocate the new receiver object.
        __ Push(constructor, new_target);
        FastNewObjectStub stub(masm->isolate());
        __ CallStub(&stub);
        __ Mov(x4, x0);
        __ Pop(new_target, constructor);
  
        // ----------- S t a t e -------------
        //  -- x1: constructor function
        //  -- x3: new target
        //  -- x4: newly allocated object
        // -----------------------------------
  
        // Reload the number of arguments from the stack.
        // Set it up in x0 for the function call below.
        // jssp[0]: number of arguments (smi-tagged)
        __ Peek(argc, 0);  // Load number of arguments.
      }
  
      __ SmiUntag(argc);
  
      if (create_implicit_receiver) {
        // Push the allocated receiver to the stack. 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(x4, x4);
      } else {
        __ PushRoot(Heap::kTheHoleValueRootIndex);
      }
  
      // Set up pointer to last argument.
      __ Add(x2, fp, StandardFrameConstants::kCallerSPOffset);
  
      // Copy arguments and receiver to the expression stack.
      // Copy 2 values every loop to use ldp/stp.
      // x0: number of arguments
      // x1: constructor function
      // x2: address of last argument (caller sp)
      // x3: new target
      // jssp[0]: receiver
      // jssp[1]: receiver
      // jssp[2]: number of arguments (smi-tagged)
      // Compute the start address of the copy in x3.
      __ Add(x4, x2, Operand(argc, LSL, kPointerSizeLog2));
      Label loop, entry, done_copying_arguments;
      __ B(&entry);
      __ Bind(&loop);
      __ Ldp(x10, x11, MemOperand(x4, -2 * kPointerSize, PreIndex));
      __ Push(x11, x10);
      __ Bind(&entry);
      __ Cmp(x4, x2);
      __ B(gt, &loop);
      // Because we copied values 2 by 2 we may have copied one extra value.
      // Drop it if that is the case.
      __ B(eq, &done_copying_arguments);
      __ Drop(1);
      __ Bind(&done_copying_arguments);
  
      // Call the function.
      // x0: number of arguments
      // x1: constructor function
      // x3: new target
      ParameterCount actual(argc);
      __ InvokeFunction(constructor, new_target, actual, CALL_FUNCTION,
                        CheckDebugStepCallWrapper());
  
      // Store offset of return address for deoptimizer.
      if (create_implicit_receiver && !is_api_function) {
        masm->isolate()->heap()->SetConstructStubDeoptPCOffset(masm->pc_offset());
      }
  
      // Restore the context from the frame.
      // x0: result
      // jssp[0]: receiver
      // jssp[1]: number of arguments (smi-tagged)
      __ Ldr(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
  
      if (create_implicit_receiver) {
        // 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, exit;
  
        // If the result is a smi, it is *not* an object in the ECMA sense.
        // x0: result
        // jssp[0]: receiver (newly allocated object)
        // jssp[1]: number of arguments (smi-tagged)
        __ JumpIfSmi(x0, &use_receiver);
  
        // 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.
        __ JumpIfObjectType(x0, x1, x3, FIRST_JS_RECEIVER_TYPE, &exit, ge);
  
        // Throw away the result of the constructor invocation and use the
        // on-stack receiver as the result.
        __ Bind(&use_receiver);
        __ Peek(x0, 0);
  
        // Remove the receiver from the stack, remove caller arguments, and
        // return.
        __ Bind(&exit);
        // x0: result
        // jssp[0]: receiver (newly allocated object)
        // jssp[1]: number of arguments (smi-tagged)
        __ Peek(x1, 1 * kXRegSize);
      } else {
        __ Peek(x1, 0);
      }
  
      // Leave construct frame.
    }
  
    // ES6 9.2.2. Step 13+
    // Check that the result is not a Smi, indicating that the constructor result
    // from a derived class is neither undefined nor an Object.
    if (check_derived_construct) {
      Label dont_throw;
      __ JumpIfNotSmi(x0, &dont_throw);
      {
        FrameScope scope(masm, StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowDerivedConstructorReturnedNonObject);
      }
      __ Bind(&dont_throw);
    }
  
    __ DropBySMI(x1);
    __ Drop(1);
    if (create_implicit_receiver) {
      __ IncrementCounter(isolate->counters()->constructed_objects(), 1, x1, x2);
    }
    __ Ret();
  }
  
  }  // namespace
  
  void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
    Generate_JSConstructStubHelper(masm, false, true, false);
  }
  
  void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
    Generate_JSConstructStubHelper(masm, true, false, false);
  }
  
  void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
    Generate_JSConstructStubHelper(masm, false, false, false);
  }
  
  void Builtins::Generate_JSBuiltinsConstructStubForDerived(
      MacroAssembler* masm) {
    Generate_JSConstructStubHelper(masm, false, false, true);
  }
  
  void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(x1);
    __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
  }
  
  // static
  void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the value to pass to the generator
    //  -- x1 : the JSGeneratorObject to resume
    //  -- x2 : the resume mode (tagged)
    //  -- lr : return address
    // -----------------------------------
    __ AssertGeneratorObject(x1);
  
    // Store input value into generator object.
    __ Str(x0, FieldMemOperand(x1, JSGeneratorObject::kInputOrDebugPosOffset));
    __ RecordWriteField(x1, JSGeneratorObject::kInputOrDebugPosOffset, x0, x3,
                        kLRHasNotBeenSaved, kDontSaveFPRegs);
  
    // Store resume mode into generator object.
    __ Str(x2, FieldMemOperand(x1, JSGeneratorObject::kResumeModeOffset));
  
    // Load suspended function and context.
    __ Ldr(cp, FieldMemOperand(x1, JSGeneratorObject::kContextOffset));
    __ Ldr(x4, FieldMemOperand(x1, JSGeneratorObject::kFunctionOffset));
  
    // Flood function if we are stepping.
    Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
    Label stepping_prepared;
    ExternalReference last_step_action =
        ExternalReference::debug_last_step_action_address(masm->isolate());
    STATIC_ASSERT(StepFrame > StepIn);
    __ Mov(x10, Operand(last_step_action));
    __ Ldrsb(x10, MemOperand(x10));
    __ CompareAndBranch(x10, Operand(StepIn), ge, &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());
    __ Mov(x10, Operand(debug_suspended_generator));
    __ Ldr(x10, MemOperand(x10));
    __ CompareAndBranch(x10, Operand(x1), eq,
                        &prepare_step_in_suspended_generator);
    __ Bind(&stepping_prepared);
  
    // Push receiver.
    __ Ldr(x5, FieldMemOperand(x1, JSGeneratorObject::kReceiverOffset));
    __ Push(x5);
  
    // ----------- S t a t e -------------
    //  -- x1      : the JSGeneratorObject to resume
    //  -- x2      : the resume mode (tagged)
    //  -- x4      : generator function
    //  -- cp      : generator context
    //  -- lr      : return address
    //  -- jssp[0] : generator receiver
    // -----------------------------------
  
    // Push holes for arguments to generator function. Since the parser forced
    // context allocation for any variables in generators, the actual argument
    // values have already been copied into the context and these dummy values
    // will never be used.
    __ Ldr(x10, FieldMemOperand(x4, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(w10,
           FieldMemOperand(x10, SharedFunctionInfo::kFormalParameterCountOffset));
    __ LoadRoot(x11, Heap::kTheHoleValueRootIndex);
    __ PushMultipleTimes(x11, w10);
  
    // Dispatch on the kind of generator object.
    Label old_generator;
    __ Ldr(x3, FieldMemOperand(x4, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(x3, FieldMemOperand(x3, SharedFunctionInfo::kFunctionDataOffset));
    __ CompareObjectType(x3, x3, x3, BYTECODE_ARRAY_TYPE);
    __ B(ne, &old_generator);
  
    // New-style (ignition/turbofan) generator object
    {
      __ Ldr(x0, FieldMemOperand(x4, JSFunction::kSharedFunctionInfoOffset));
      __ Ldr(w0, FieldMemOperand(
                     x0, 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.
      __ Move(x3, x1);
      __ Move(x1, x4);
      __ Ldr(x5, FieldMemOperand(x1, JSFunction::kCodeEntryOffset));
      __ Jump(x5);
    }
  
    // Old-style (full-codegen) generator object
    __ bind(&old_generator);
    {
      // Enter a new JavaScript frame, and initialize its slots as they were when
      // the generator was suspended.
      FrameScope scope(masm, StackFrame::MANUAL);
      __ Push(lr, fp);
      __ Move(fp, jssp);
      __ Push(cp, x4);
  
      // Restore the operand stack.
      __ Ldr(x0, FieldMemOperand(x1, JSGeneratorObject::kOperandStackOffset));
      __ Ldr(w3, UntagSmiFieldMemOperand(x0, FixedArray::kLengthOffset));
      __ Add(x0, x0, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ Add(x3, x0, Operand(x3, LSL, kPointerSizeLog2));
      {
        Label done_loop, loop;
        __ Bind(&loop);
        __ Cmp(x0, x3);
        __ B(eq, &done_loop);
        __ Ldr(x10, MemOperand(x0, kPointerSize, PostIndex));
        __ Push(x10);
        __ B(&loop);
        __ Bind(&done_loop);
      }
  
      // Reset operand stack so we don't leak.
      __ LoadRoot(x10, Heap::kEmptyFixedArrayRootIndex);
      __ Str(x10, FieldMemOperand(x1, JSGeneratorObject::kOperandStackOffset));
  
      // Resume the generator function at the continuation.
      __ Ldr(x10, FieldMemOperand(x4, JSFunction::kSharedFunctionInfoOffset));
      __ Ldr(x10, FieldMemOperand(x10, SharedFunctionInfo::kCodeOffset));
      __ Add(x10, x10, Code::kHeaderSize - kHeapObjectTag);
      __ Ldrsw(x11, UntagSmiFieldMemOperand(
                        x1, JSGeneratorObject::kContinuationOffset));
      __ Add(x10, x10, x11);
      __ Mov(x12, Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
      __ Str(x12, FieldMemOperand(x1, JSGeneratorObject::kContinuationOffset));
      __ Move(x0, x1);  // Continuation expects generator object in x0.
      __ Br(x10);
    }
  
    __ Bind(&prepare_step_in_if_stepping);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(x1, x2, x4);
      __ CallRuntime(Runtime::kDebugPrepareStepInIfStepping);
      __ Pop(x2, x1);
      __ Ldr(x4, FieldMemOperand(x1, JSGeneratorObject::kFunctionOffset));
    }
    __ B(&stepping_prepared);
  
    __ Bind(&prepare_step_in_suspended_generator);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(x1, x2);
      __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
      __ Pop(x2, x1);
      __ Ldr(x4, FieldMemOperand(x1, JSGeneratorObject::kFunctionOffset));
    }
    __ B(&stepping_prepared);
  }
  
  enum IsTagged { kArgcIsSmiTagged, kArgcIsUntaggedInt };
  
  // Clobbers x10, x15; preserves all other registers.
  static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
                                          IsTagged argc_is_tagged) {
    // 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.
    Label enough_stack_space;
    __ LoadRoot(x10, Heap::kRealStackLimitRootIndex);
    // Make x10 the space we have left. The stack might already be overflowed
    // here which will cause x10 to become negative.
    // TODO(jbramley): Check that the stack usage here is safe.
    __ Sub(x10, jssp, x10);
    // Check if the arguments will overflow the stack.
    if (argc_is_tagged == kArgcIsSmiTagged) {
      __ Cmp(x10, Operand::UntagSmiAndScale(argc, kPointerSizeLog2));
    } else {
      DCHECK(argc_is_tagged == kArgcIsUntaggedInt);
      __ Cmp(x10, Operand(argc, LSL, kPointerSizeLog2));
    }
    __ B(gt, &enough_stack_space);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    // We should never return from the APPLY_OVERFLOW builtin.
    if (__ emit_debug_code()) {
      __ Unreachable();
    }
  
    __ Bind(&enough_stack_space);
  }
  
  // Input:
  //   x0: new.target.
  //   x1: function.
  //   x2: receiver.
  //   x3: argc.
  //   x4: argv.
  // Output:
  //   x0: result.
  static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                               bool is_construct) {
    // Called from JSEntryStub::GenerateBody().
    Register new_target = x0;
    Register function = x1;
    Register receiver = x2;
    Register argc = x3;
    Register argv = x4;
    Register scratch = x10;
  
    ProfileEntryHookStub::MaybeCallEntryHook(masm);
  
    {
      // Enter an internal frame.
      FrameScope scope(masm, StackFrame::INTERNAL);
  
      // Setup the context (we need to use the caller context from the isolate).
      __ Mov(scratch, Operand(ExternalReference(Isolate::kContextAddress,
                                                masm->isolate())));
      __ Ldr(cp, MemOperand(scratch));
  
      __ InitializeRootRegister();
  
      // Push the function and the receiver onto the stack.
      __ Push(function, receiver);
  
      // Check if we have enough stack space to push all arguments.
      // Expects argument count in eax. Clobbers ecx, edx, edi.
      Generate_CheckStackOverflow(masm, argc, kArgcIsUntaggedInt);
  
      // Copy arguments to the stack in a loop, in reverse order.
      // x3: argc.
      // x4: argv.
      Label loop, entry;
      // Compute the copy end address.
      __ Add(scratch, argv, Operand(argc, LSL, kPointerSizeLog2));
  
      __ B(&entry);
      __ Bind(&loop);
      __ Ldr(x11, MemOperand(argv, kPointerSize, PostIndex));
      __ Ldr(x12, MemOperand(x11));  // Dereference the handle.
      __ Push(x12);                  // Push the argument.
      __ Bind(&entry);
      __ Cmp(scratch, argv);
      __ B(ne, &loop);
  
      __ Mov(scratch, argc);
      __ Mov(argc, new_target);
      __ Mov(new_target, scratch);
      // x0: argc.
      // x3: new.target.
  
      // Initialize all JavaScript callee-saved registers, since they will be seen
      // by the garbage collector as part of handlers.
      // The original values have been saved in JSEntryStub::GenerateBody().
      __ LoadRoot(x19, Heap::kUndefinedValueRootIndex);
      __ Mov(x20, x19);
      __ Mov(x21, x19);
      __ Mov(x22, x19);
      __ Mov(x23, x19);
      __ Mov(x24, x19);
      __ Mov(x25, x19);
      // Don't initialize the reserved registers.
      // x26 : root register (root).
      // x27 : context pointer (cp).
      // x28 : JS stack pointer (jssp).
      // x29 : frame pointer (fp).
  
      Handle<Code> builtin = is_construct
                                 ? masm->isolate()->builtins()->Construct()
                                 : masm->isolate()->builtins()->Call();
      __ Call(builtin, RelocInfo::CODE_TARGET);
  
      // Exit the JS internal frame and remove the parameters (except function),
      // and return.
    }
  
    // Result is in x0. Return.
    __ Ret();
  }
  
  void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, false);
  }
  
  void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, true);
  }
  
  static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch) {
    Register args_count = scratch;
  
    // Get the arguments + receiver count.
    __ ldr(args_count,
           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ Ldr(args_count.W(),
           FieldMemOperand(args_count, BytecodeArray::kParameterSizeOffset));
  
    // Leave the frame (also dropping the register file).
    __ LeaveFrame(StackFrame::JAVA_SCRIPT);
  
    // Drop receiver + arguments.
    __ Drop(args_count, 1);
  }
  
  // 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:
  //   - x1: the JS function object being called.
  //   - x3: the new target
  //   - cp: our context.
  //   - fp: our caller's frame pointer.
  //   - jssp: stack pointer.
  //   - lr: return address.
  //
  // The function builds an interpreter frame.  See InterpreterFrameConstants in
  // frames.h for its layout.
  void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
    ProfileEntryHookStub::MaybeCallEntryHook(masm);
  
    // 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).
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ Push(lr, fp, cp, x1);
    __ Add(fp, jssp, StandardFrameConstants::kFixedFrameSizeFromFp);
  
    // Get the bytecode array from the function object (or from the DebugInfo if
    // it is present) and load it into kInterpreterBytecodeArrayRegister.
    __ Ldr(x0, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    Register debug_info = kInterpreterBytecodeArrayRegister;
    Label load_debug_bytecode_array, bytecode_array_loaded;
    DCHECK(!debug_info.is(x0));
    __ Ldr(debug_info, FieldMemOperand(x0, SharedFunctionInfo::kDebugInfoOffset));
    __ Cmp(debug_info, Operand(DebugInfo::uninitialized()));
    __ B(ne, &load_debug_bytecode_array);
    __ Ldr(kInterpreterBytecodeArrayRegister,
           FieldMemOperand(x0, SharedFunctionInfo::kFunctionDataOffset));
    __ Bind(&bytecode_array_loaded);
  
    // Check whether we should continue to use the interpreter.
    Label switch_to_different_code_kind;
    __ Ldr(x0, FieldMemOperand(x0, SharedFunctionInfo::kCodeOffset));
    __ Cmp(x0, Operand(masm->CodeObject()));  // Self-reference to this code.
    __ B(ne, &switch_to_different_code_kind);
  
    // Increment invocation count for the function.
    __ Ldr(x11, FieldMemOperand(x1, JSFunction::kLiteralsOffset));
    __ Ldr(x11, FieldMemOperand(x11, LiteralsArray::kFeedbackVectorOffset));
    __ Ldr(x10, FieldMemOperand(x11, TypeFeedbackVector::kInvocationCountIndex *
                                             kPointerSize +
                                         TypeFeedbackVector::kHeaderSize));
    __ Add(x10, x10, Operand(Smi::FromInt(1)));
    __ Str(x10, FieldMemOperand(x11, TypeFeedbackVector::kInvocationCountIndex *
                                             kPointerSize +
                                         TypeFeedbackVector::kHeaderSize));
  
    // Check function data field is actually a BytecodeArray object.
    if (FLAG_debug_code) {
      __ AssertNotSmi(kInterpreterBytecodeArrayRegister,
                      kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
      __ CompareObjectType(kInterpreterBytecodeArrayRegister, x0, x0,
                           BYTECODE_ARRAY_TYPE);
      __ Assert(eq, kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
    }
  
    // Load the initial bytecode offset.
    __ Mov(kInterpreterBytecodeOffsetRegister,
           Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
  
    // Push new.target, bytecode array and Smi tagged bytecode array offset.
    __ SmiTag(x0, kInterpreterBytecodeOffsetRegister);
    __ Push(x3, kInterpreterBytecodeArrayRegister, x0);
  
    // Allocate the local and temporary register file on the stack.
    {
      // Load frame size from the BytecodeArray object.
      __ Ldr(w11, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                  BytecodeArray::kFrameSizeOffset));
  
      // Do a stack check to ensure we don't go over the limit.
      Label ok;
      DCHECK(jssp.Is(__ StackPointer()));
      __ Sub(x10, jssp, Operand(x11));
      __ CompareRoot(x10, Heap::kRealStackLimitRootIndex);
      __ B(hs, &ok);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ Bind(&ok);
  
      // If ok, push undefined as the initial value for all register file entries.
      // Note: there should always be at least one stack slot for the return
      // register in the register file.
      Label loop_header;
      __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
      // TODO(rmcilroy): Ensure we always have an even number of registers to
      // allow stack to be 16 bit aligned (and remove need for jssp).
      __ Lsr(x11, x11, kPointerSizeLog2);
      __ PushMultipleTimes(x10, x11);
      __ Bind(&loop_header);
    }
  
    // Load accumulator and dispatch table into registers.
    __ LoadRoot(kInterpreterAccumulatorRegister, Heap::kUndefinedValueRootIndex);
    __ Mov(kInterpreterDispatchTableRegister,
           Operand(ExternalReference::interpreter_dispatch_table_address(
               masm->isolate())));
  
    // Dispatch to the first bytecode handler for the function.
    __ Ldrb(x1, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
    __ Mov(x1, Operand(x1, LSL, kPointerSizeLog2));
    __ Ldr(ip0, MemOperand(kInterpreterDispatchTableRegister, x1));
    __ Call(ip0);
    masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
  
    // The return value is in x0.
    LeaveInterpreterFrame(masm, x2);
    __ Ret();
  
    // Load debug copy of the bytecode array.
    __ Bind(&load_debug_bytecode_array);
    __ Ldr(kInterpreterBytecodeArrayRegister,
           FieldMemOperand(debug_info, DebugInfo::kDebugBytecodeArrayIndex));
    __ B(&bytecode_array_loaded);
  
    // If the shared code is no longer this entry trampoline, then the underlying
    // function has been switched to a different kind of code and we heal the
    // closure by switching the code entry field over to the new code as well.
    __ bind(&switch_to_different_code_kind);
    __ LeaveFrame(StackFrame::JAVA_SCRIPT);
    __ Ldr(x7, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(x7, FieldMemOperand(x7, SharedFunctionInfo::kCodeOffset));
    __ Add(x7, x7, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Str(x7, FieldMemOperand(x1, JSFunction::kCodeEntryOffset));
    __ RecordWriteCodeEntryField(x1, x7, x5);
    __ Jump(x7);
  }
  
  void Builtins::Generate_InterpreterMarkBaselineOnReturn(MacroAssembler* masm) {
    // Save the function and context for call to CompileBaseline.
    __ ldr(x1, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
    __ ldr(kContextRegister,
           MemOperand(fp, StandardFrameConstants::kContextOffset));
  
    // Leave the frame before recompiling for baseline so that we don't count as
    // an activation on the stack.
    LeaveInterpreterFrame(masm, x2);
  
    {
      FrameScope frame_scope(masm, StackFrame::INTERNAL);
      // Push return value.
      __ push(x0);
  
      // Push function as argument and compile for baseline.
      __ push(x1);
      __ CallRuntime(Runtime::kCompileBaseline);
  
      // Restore return value.
      __ pop(x0);
    }
    __ Ret();
  }
  
  static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
                                          Register scratch,
                                          Label* stack_overflow) {
    // 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.
    Label enough_stack_space;
    __ LoadRoot(scratch, Heap::kRealStackLimitRootIndex);
    // Make scratch the space we have left. The stack might already be overflowed
    // here which will cause scratch to become negative.
    __ Sub(scratch, jssp, scratch);
    // Check if the arguments will overflow the stack.
    __ Cmp(scratch, Operand(num_args, LSL, kPointerSizeLog2));
    __ B(le, stack_overflow);
  }
  
  static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                           Register num_args, Register index,
                                           Register last_arg, Register stack_addr,
                                           Register scratch,
                                           Label* stack_overflow) {
    // Add a stack check before pushing arguments.
    Generate_StackOverflowCheck(masm, num_args, scratch, stack_overflow);
  
    __ Mov(scratch, num_args);
    __ lsl(scratch, scratch, kPointerSizeLog2);
    __ sub(last_arg, index, scratch);
  
    // Set stack pointer and where to stop.
    __ Mov(stack_addr, jssp);
    __ Claim(scratch, 1);
  
    // Push the arguments.
    Label loop_header, loop_check;
    __ B(&loop_check);
    __ Bind(&loop_header);
    // TODO(rmcilroy): Push two at a time once we ensure we keep stack aligned.
    __ Ldr(scratch, MemOperand(index, -kPointerSize, PostIndex));
    __ Str(scratch, MemOperand(stack_addr, -kPointerSize, PreIndex));
    __ Bind(&loop_check);
    __ Cmp(index, last_arg);
    __ B(gt, &loop_header);
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsAndCallImpl(
      MacroAssembler* masm, TailCallMode tail_call_mode,
      CallableType function_type) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x2 : 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.
    //  -- x1 : the target to call (can be any Object).
    // -----------------------------------
    Label stack_overflow;
  
    // Add one for the receiver.
    __ add(x3, x0, Operand(1));
  
    // Push the arguments. x2, x4, x5, x6 will be modified.
    Generate_InterpreterPushArgs(masm, x3, x2, x4, x5, x6, &stack_overflow);
  
    // Call the target.
    if (function_type == CallableType::kJSFunction) {
      __ Jump(masm->isolate()->builtins()->CallFunction(ConvertReceiverMode::kAny,
                                                        tail_call_mode),
              RelocInfo::CODE_TARGET);
    } else {
      DCHECK_EQ(function_type, CallableType::kAny);
      __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny,
                                                tail_call_mode),
              RelocInfo::CODE_TARGET);
    }
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      __ Unreachable();
    }
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsAndConstructImpl(
      MacroAssembler* masm, CallableType construct_type) {
    // ----------- S t a t e -------------
    // -- x0 : argument count (not including receiver)
    // -- x3 : new target
    // -- x1 : constructor to call
    // -- x2 : allocation site feedback if available, undefined otherwise
    // -- x4 : address of the first argument
    // -----------------------------------
    Label stack_overflow;
  
    // Push a slot for the receiver.
    __ Push(xzr);
  
    // Push the arguments. x5, x4, x6, x7 will be modified.
    Generate_InterpreterPushArgs(masm, x0, x4, x5, x6, x7, &stack_overflow);
  
    __ AssertUndefinedOrAllocationSite(x2, x6);
    if (construct_type == CallableType::kJSFunction) {
      __ AssertFunction(x1);
  
      // Tail call to the function-specific construct stub (still in the caller
      // context at this point).
      __ Ldr(x4, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
      __ Ldr(x4, FieldMemOperand(x4, SharedFunctionInfo::kConstructStubOffset));
      __ Add(x4, x4, Code::kHeaderSize - kHeapObjectTag);
      __ Br(x4);
    } else {
      DCHECK_EQ(construct_type, CallableType::kAny);
      // Call the constructor with x0, x1, and x3 unmodified.
      __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
    }
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      __ Unreachable();
    }
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsAndConstructArray(
      MacroAssembler* masm) {
    // ----------- S t a t e -------------
    // -- x0 : argument count (not including receiver)
    // -- x1 : target to call verified to be Array function
    // -- x2 : allocation site feedback if available, undefined otherwise.
    // -- x3 : address of the first argument
    // -----------------------------------
    Label stack_overflow;
  
    __ add(x4, x0, Operand(1));  // Add one for the receiver.
  
    // Push the arguments. x3, x5, x6, x7 will be modified.
    Generate_InterpreterPushArgs(masm, x4, x3, x5, x6, x7, &stack_overflow);
  
    // Array constructor expects constructor in x3. It is same as call target.
    __ mov(x3, x1);
  
    ArrayConstructorStub stub(masm->isolate());
    __ TailCallStub(&stub);
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      __ Unreachable();
    }
  }
  
  void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
    // Set the return address to the correct point in the interpreter entry
    // trampoline.
    Smi* interpreter_entry_return_pc_offset(
        masm->isolate()->heap()->interpreter_entry_return_pc_offset());
    DCHECK_NE(interpreter_entry_return_pc_offset, Smi::kZero);
    __ LoadObject(x1, masm->isolate()->builtins()->InterpreterEntryTrampoline());
    __ Add(lr, x1, Operand(interpreter_entry_return_pc_offset->value() +
                           Code::kHeaderSize - kHeapObjectTag));
  
    // Initialize the dispatch table register.
    __ Mov(kInterpreterDispatchTableRegister,
           Operand(ExternalReference::interpreter_dispatch_table_address(
               masm->isolate())));
  
    // Get the bytecode array pointer from the frame.
    __ Ldr(kInterpreterBytecodeArrayRegister,
           MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  
    if (FLAG_debug_code) {
      // Check function data field is actually a BytecodeArray object.
      __ AssertNotSmi(kInterpreterBytecodeArrayRegister,
                      kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
      __ CompareObjectType(kInterpreterBytecodeArrayRegister, x1, x1,
                           BYTECODE_ARRAY_TYPE);
      __ Assert(eq, kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
    }
  
    // Get the target bytecode offset from the frame.
    __ Ldr(kInterpreterBytecodeOffsetRegister,
           MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Dispatch to the target bytecode.
    __ Ldrb(x1, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
    __ Mov(x1, Operand(x1, LSL, kPointerSizeLog2));
    __ Ldr(ip0, MemOperand(kInterpreterDispatchTableRegister, x1));
    __ Jump(ip0);
  }
  
  void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : argument count (preserved for callee)
    //  -- x3 : new target (preserved for callee)
    //  -- x1 : target function (preserved for callee)
    // -----------------------------------
    // First lookup code, maybe we don't need to compile!
    Label gotta_call_runtime;
    Label try_shared;
    Label loop_top, loop_bottom;
  
    Register closure = x1;
    Register map = x13;
    Register index = x2;
    __ Ldr(map, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(map,
           FieldMemOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
    __ Ldrsw(index, UntagSmiFieldMemOperand(map, FixedArray::kLengthOffset));
    __ Cmp(index, Operand(2));
    __ B(lt, &gotta_call_runtime);
  
    // Find literals.
    // x3  : native context
    // x2  : length / index
    // x13 : optimized code map
    // stack[0] : new target
    // stack[4] : closure
    Register native_context = x4;
    __ Ldr(native_context, NativeContextMemOperand());
  
    __ Bind(&loop_top);
    Register temp = x5;
    Register array_pointer = x6;
  
    // Does the native context match?
    __ Add(array_pointer, map, Operand(index, LSL, kPointerSizeLog2));
    __ Ldr(temp, FieldMemOperand(array_pointer,
                                 SharedFunctionInfo::kOffsetToPreviousContext));
    __ Ldr(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
    __ Cmp(temp, native_context);
    __ B(ne, &loop_bottom);
    // OSR id set to none?
    __ Ldr(temp, FieldMemOperand(array_pointer,
                                 SharedFunctionInfo::kOffsetToPreviousOsrAstId));
    const int bailout_id = BailoutId::None().ToInt();
    __ Cmp(temp, Operand(Smi::FromInt(bailout_id)));
    __ B(ne, &loop_bottom);
    // Literals available?
    __ Ldr(temp, FieldMemOperand(array_pointer,
                                 SharedFunctionInfo::kOffsetToPreviousLiterals));
    __ Ldr(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
    __ JumpIfSmi(temp, &gotta_call_runtime);
  
    // Save the literals in the closure.
    __ Str(temp, FieldMemOperand(closure, JSFunction::kLiteralsOffset));
    __ RecordWriteField(closure, JSFunction::kLiteralsOffset, temp, x7,
                        kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
                        OMIT_SMI_CHECK);
  
    // Code available?
    Register entry = x7;
    __ Ldr(entry,
           FieldMemOperand(array_pointer,
                           SharedFunctionInfo::kOffsetToPreviousCachedCode));
    __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
    __ JumpIfSmi(entry, &try_shared);
  
    // Found literals and code. Get them into the closure and return.
    __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
    __ RecordWriteCodeEntryField(closure, entry, x5);
  
    // Link the closure into the optimized function list.
    // x7 : code entry
    // x4 : native context
    // x1 : closure
    __ Ldr(x8,
           ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
    __ Str(x8, FieldMemOperand(closure, JSFunction::kNextFunctionLinkOffset));
    __ RecordWriteField(closure, JSFunction::kNextFunctionLinkOffset, x8, x13,
                        kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
                        OMIT_SMI_CHECK);
    const int function_list_offset =
        Context::SlotOffset(Context::OPTIMIZED_FUNCTIONS_LIST);
    __ Str(closure,
           ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
    __ Mov(x5, closure);
    __ RecordWriteContextSlot(native_context, function_list_offset, x5, x13,
                              kLRHasNotBeenSaved, kDontSaveFPRegs);
    __ Jump(entry);
  
    __ Bind(&loop_bottom);
    __ Sub(index, index, Operand(SharedFunctionInfo::kEntryLength));
    __ Cmp(index, Operand(1));
    __ B(gt, &loop_top);
  
    // We found neither literals nor code.
    __ B(&gotta_call_runtime);
  
    __ Bind(&try_shared);
    __ Ldr(entry,
           FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    // Is the shared function marked for optimization?
    __ Ldrb(temp,
            FieldMemOperand(
                entry, SharedFunctionInfo::kWasMarkedForOptimizationByteOffset));
    __ TestAndBranchIfAnySet(
        temp, 1 << SharedFunctionInfo::kWasMarkedForOptimizationBitWithinByte,
        &gotta_call_runtime);
    // Is the full code valid?
    __ Ldr(entry, FieldMemOperand(entry, SharedFunctionInfo::kCodeOffset));
    __ Ldr(x5, FieldMemOperand(entry, Code::kFlagsOffset));
    __ and_(x5, x5, Operand(Code::KindField::kMask));
    __ Mov(x5, Operand(x5, LSR, Code::KindField::kShift));
    __ Cmp(x5, Operand(Code::BUILTIN));
    __ B(eq, &gotta_call_runtime);
    // Yes, install the full code.
    __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
    __ RecordWriteCodeEntryField(closure, entry, x5);
    __ Jump(entry);
  
    __ Bind(&gotta_call_runtime);
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
  }
  
  void Builtins::Generate_CompileBaseline(MacroAssembler* masm) {
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileBaseline);
  }
  
  void Builtins::Generate_CompileOptimized(MacroAssembler* masm) {
    GenerateTailCallToReturnedCode(masm,
                                   Runtime::kCompileOptimized_NotConcurrent);
  }
  
  void Builtins::Generate_CompileOptimizedConcurrent(MacroAssembler* masm) {
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileOptimized_Concurrent);
  }
  
  void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : argument count (preserved for callee)
    //  -- x1 : new target (preserved for callee)
    //  -- x3 : target function (preserved for callee)
    // -----------------------------------
    Label failed;
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Preserve argument count for later compare.
      __ Move(x4, x0);
      // Push a copy of the target function and the new target.
      __ SmiTag(x0);
      // Push another copy as a parameter to the runtime call.
      __ Push(x0, x1, x3, x1);
  
      // Copy arguments from caller (stdlib, foreign, heap).
      Label args_done;
      for (int j = 0; j < 4; ++j) {
        Label over;
        if (j < 3) {
          __ cmp(x4, Operand(j));
          __ B(ne, &over);
        }
        for (int i = j - 1; i >= 0; --i) {
          __ ldr(x4, MemOperand(fp, StandardFrameConstants::kCallerSPOffset +
                                        i * kPointerSize));
          __ push(x4);
        }
        for (int i = 0; i < 3 - j; ++i) {
          __ PushRoot(Heap::kUndefinedValueRootIndex);
        }
        if (j < 3) {
          __ jmp(&args_done);
          __ bind(&over);
        }
      }
      __ bind(&args_done);
  
      // Call runtime, on success unwind frame, and parent frame.
      __ CallRuntime(Runtime::kInstantiateAsmJs, 4);
      // A smi 0 is returned on failure, an object on success.
      __ JumpIfSmi(x0, &failed);
  
      __ Drop(2);
      __ pop(x4);
      __ SmiUntag(x4);
      scope.GenerateLeaveFrame();
  
      __ add(x4, x4, Operand(1));
      __ Drop(x4);
      __ Ret();
  
      __ bind(&failed);
      // Restore target function and new target.
      __ Pop(x3, x1, x0);
      __ SmiUntag(x0);
    }
    // On failure, tail call back to regular js.
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
  }
  
  static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
    // For now, we are relying on the fact that make_code_young doesn't do any
    // garbage collection which allows us to save/restore the registers without
    // worrying about which of them contain pointers. We also don't build an
    // internal frame to make the code fast, since we shouldn't have to do stack
    // crawls in MakeCodeYoung. This seems a bit fragile.
  
    // The following caller-saved registers must be saved and restored when
    // calling through to the runtime:
    //   x0 - The address from which to resume execution.
    //   x1 - isolate
    //   x3 - new target
    //   lr - The return address for the JSFunction itself. It has not yet been
    //        preserved on the stack because the frame setup code was replaced
    //        with a call to this stub, to handle code ageing.
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ Push(x0, x1, x3, fp, lr);
      __ Mov(x1, ExternalReference::isolate_address(masm->isolate()));
      __ CallCFunction(
          ExternalReference::get_make_code_young_function(masm->isolate()), 2);
      __ Pop(lr, fp, x3, x1, x0);
    }
  
    // The calling function has been made young again, so return to execute the
    // real frame set-up code.
    __ Br(x0);
  }
  
  #define DEFINE_CODE_AGE_BUILTIN_GENERATOR(C)                  \
    void Builtins::Generate_Make##C##CodeYoungAgainEvenMarking( \
        MacroAssembler* masm) {                                 \
      GenerateMakeCodeYoungAgainCommon(masm);                   \
    }                                                           \
    void Builtins::Generate_Make##C##CodeYoungAgainOddMarking(  \
        MacroAssembler* masm) {                                 \
      GenerateMakeCodeYoungAgainCommon(masm);                   \
    }
  CODE_AGE_LIST(DEFINE_CODE_AGE_BUILTIN_GENERATOR)
  #undef DEFINE_CODE_AGE_BUILTIN_GENERATOR
  
  void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
    // For now, as in GenerateMakeCodeYoungAgainCommon, we are relying on the fact
    // that make_code_young doesn't do any garbage collection which allows us to
    // save/restore the registers without worrying about which of them contain
    // pointers.
  
    // The following caller-saved registers must be saved and restored when
    // calling through to the runtime:
    //   x0 - The address from which to resume execution.
    //   x1 - isolate
    //   x3 - new target
    //   lr - The return address for the JSFunction itself. It has not yet been
    //        preserved on the stack because the frame setup code was replaced
    //        with a call to this stub, to handle code ageing.
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ Push(x0, x1, x3, fp, lr);
      __ Mov(x1, ExternalReference::isolate_address(masm->isolate()));
      __ CallCFunction(
          ExternalReference::get_mark_code_as_executed_function(masm->isolate()),
          2);
      __ Pop(lr, fp, x3, x1, x0);
  
      // Perform prologue operations usually performed by the young code stub.
      __ EmitFrameSetupForCodeAgePatching(masm);
    }
  
    // Jump to point after the code-age stub.
    __ Add(x0, x0, kNoCodeAgeSequenceLength);
    __ Br(x0);
  }
  
  void Builtins::Generate_MarkCodeAsExecutedTwice(MacroAssembler* masm) {
    GenerateMakeCodeYoungAgainCommon(masm);
  }
  
  void Builtins::Generate_MarkCodeAsToBeExecutedOnce(MacroAssembler* masm) {
    Generate_MarkCodeAsExecutedOnce(masm);
  }
  
  static void Generate_NotifyStubFailureHelper(MacroAssembler* masm,
                                               SaveFPRegsMode save_doubles) {
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
  
      // Preserve registers across notification, this is important for compiled
      // stubs that tail call the runtime on deopts passing their parameters in
      // registers.
      // TODO(jbramley): Is it correct (and appropriate) to use safepoint
      // registers here? According to the comment above, we should only need to
      // preserve the registers with parameters.
      __ PushXRegList(kSafepointSavedRegisters);
      // Pass the function and deoptimization type to the runtime system.
      __ CallRuntime(Runtime::kNotifyStubFailure, save_doubles);
      __ PopXRegList(kSafepointSavedRegisters);
    }
  
    // Ignore state (pushed by Deoptimizer::EntryGenerator::Generate).
    __ Drop(1);
  
    // Jump to the miss handler. Deoptimizer::EntryGenerator::Generate loads this
    // into lr before it jumps here.
    __ Br(lr);
  }
  
  void Builtins::Generate_NotifyStubFailure(MacroAssembler* masm) {
    Generate_NotifyStubFailureHelper(masm, kDontSaveFPRegs);
  }
  
  void Builtins::Generate_NotifyStubFailureSaveDoubles(MacroAssembler* masm) {
    Generate_NotifyStubFailureHelper(masm, kSaveFPRegs);
  }
  
  static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
                                               Deoptimizer::BailoutType type) {
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Pass the deoptimization type to the runtime system.
      __ Mov(x0, Smi::FromInt(static_cast<int>(type)));
      __ Push(x0);
      __ CallRuntime(Runtime::kNotifyDeoptimized);
    }
  
    // Get the full codegen state from the stack and untag it.
    Register state = x6;
    __ Peek(state, 0);
    __ SmiUntag(state);
  
    // Switch on the state.
    Label with_tos_register, unknown_state;
    __ CompareAndBranch(state,
                        static_cast<int>(Deoptimizer::BailoutState::NO_REGISTERS),
                        ne, &with_tos_register);
    __ Drop(1);  // Remove state.
    __ Ret();
  
    __ Bind(&with_tos_register);
    // Reload TOS register.
    DCHECK_EQ(kInterpreterAccumulatorRegister.code(), x0.code());
    __ Peek(x0, kPointerSize);
    __ CompareAndBranch(state,
                        static_cast<int>(Deoptimizer::BailoutState::TOS_REGISTER),
                        ne, &unknown_state);
    __ Drop(2);  // Remove state and TOS.
    __ Ret();
  
    __ Bind(&unknown_state);
    __ Abort(kInvalidFullCodegenState);
  }
  
  void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
    Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::EAGER);
  }
  
  void Builtins::Generate_NotifyLazyDeoptimized(MacroAssembler* masm) {
    Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::LAZY);
  }
  
  void Builtins::Generate_NotifySoftDeoptimized(MacroAssembler* masm) {
    Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::SOFT);
  }
  
  static void CompatibleReceiverCheck(MacroAssembler* masm, Register receiver,
                                      Register function_template_info,
                                      Register scratch0, Register scratch1,
                                      Register scratch2,
                                      Label* receiver_check_failed) {
    Register signature = scratch0;
    Register map = scratch1;
    Register constructor = scratch2;
  
    // If there is no signature, return the holder.
    __ Ldr(signature, FieldMemOperand(function_template_info,
                                      FunctionTemplateInfo::kSignatureOffset));
    __ CompareRoot(signature, Heap::kUndefinedValueRootIndex);
    Label receiver_check_passed;
    __ B(eq, &receiver_check_passed);
  
    // Walk the prototype chain.
    __ Ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
    Label prototype_loop_start;
    __ Bind(&prototype_loop_start);
  
    // Get the constructor, if any
    __ GetMapConstructor(constructor, map, x16, x16);
    __ cmp(x16, Operand(JS_FUNCTION_TYPE));
    Label next_prototype;
    __ B(ne, &next_prototype);
    Register type = constructor;
    __ Ldr(type,
           FieldMemOperand(constructor, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(type, FieldMemOperand(type, SharedFunctionInfo::kFunctionDataOffset));
  
    // Loop through the chain of inheriting function templates.
    Label function_template_loop;
    __ Bind(&function_template_loop);
  
    // If the signatures match, we have a compatible receiver.
    __ Cmp(signature, type);
    __ B(eq, &receiver_check_passed);
  
    // If the current type is not a FunctionTemplateInfo, load the next prototype
    // in the chain.
    __ JumpIfSmi(type, &next_prototype);
    __ CompareObjectType(type, x16, x17, FUNCTION_TEMPLATE_INFO_TYPE);
    __ B(ne, &next_prototype);
  
    // Otherwise load the parent function template and iterate.
    __ Ldr(type,
           FieldMemOperand(type, FunctionTemplateInfo::kParentTemplateOffset));
    __ B(&function_template_loop);
  
    // Load the next prototype.
    __ Bind(&next_prototype);
    __ Ldr(x16, FieldMemOperand(map, Map::kBitField3Offset));
    __ Tst(x16, Operand(Map::HasHiddenPrototype::kMask));
    __ B(eq, receiver_check_failed);
    __ Ldr(receiver, FieldMemOperand(map, Map::kPrototypeOffset));
    __ Ldr(map, FieldMemOperand(receiver, HeapObject::kMapOffset));
    // Iterate.
    __ B(&prototype_loop_start);
  
    __ Bind(&receiver_check_passed);
  }
  
  void Builtins::Generate_HandleFastApiCall(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0                 : number of arguments excluding receiver
    //  -- x1                 : callee
    //  -- lr                 : return address
    //  -- sp[0]              : last argument
    //  -- ...
    //  -- sp[8 * (argc - 1)] : first argument
    //  -- sp[8 * argc]       : receiver
    // -----------------------------------
  
    // Load the FunctionTemplateInfo.
    __ Ldr(x3, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(x3, FieldMemOperand(x3, SharedFunctionInfo::kFunctionDataOffset));
  
    // Do the compatible receiver check.
    Label receiver_check_failed;
    __ Ldr(x2, MemOperand(jssp, x0, LSL, kPointerSizeLog2));
    CompatibleReceiverCheck(masm, x2, x3, x4, x5, x6, &receiver_check_failed);
  
    // Get the callback offset from the FunctionTemplateInfo, and jump to the
    // beginning of the code.
    __ Ldr(x4, FieldMemOperand(x3, FunctionTemplateInfo::kCallCodeOffset));
    __ Ldr(x4, FieldMemOperand(x4, CallHandlerInfo::kFastHandlerOffset));
    __ Add(x4, x4, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Jump(x4);
  
    // Compatible receiver check failed: throw an Illegal Invocation exception.
    __ Bind(&receiver_check_failed);
    // Drop the arguments (including the receiver)
    __ add(x0, x0, Operand(1));
    __ Drop(x0);
    __ TailCallRuntime(Runtime::kThrowIllegalInvocation);
  }
  
  static void Generate_OnStackReplacementHelper(MacroAssembler* masm,
                                                bool has_handler_frame) {
    // Lookup the function in the JavaScript frame.
    if (has_handler_frame) {
      __ Ldr(x0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
      __ Ldr(x0, MemOperand(x0, JavaScriptFrameConstants::kFunctionOffset));
    } else {
      __ Ldr(x0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    }
  
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Pass function as argument.
      __ Push(x0);
      __ CallRuntime(Runtime::kCompileForOnStackReplacement);
    }
  
    // If the code object is null, just return to the caller.
    Label skip;
    __ CompareAndBranch(x0, Smi::kZero, ne, &skip);
    __ Ret();
  
    __ Bind(&skip);
  
    // Drop any potential handler frame that is be sitting on top of the actual
    // JavaScript frame. This is the case then OSR is triggered from bytecode.
    if (has_handler_frame) {
      __ LeaveFrame(StackFrame::STUB);
    }
  
    // Load deoptimization data from the code object.
    // <deopt_data> = <code>[#deoptimization_data_offset]
    __ Ldr(x1, MemOperand(x0, Code::kDeoptimizationDataOffset - kHeapObjectTag));
  
    // Load the OSR entrypoint offset from the deoptimization data.
    // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
    __ Ldrsw(w1, UntagSmiFieldMemOperand(
                     x1, FixedArray::OffsetOfElementAt(
                             DeoptimizationInputData::kOsrPcOffsetIndex)));
  
    // Compute the target address = code_obj + header_size + osr_offset
    // <entry_addr> = <code_obj> + #header_size + <osr_offset>
    __ Add(x0, x0, x1);
    __ Add(lr, x0, Code::kHeaderSize - kHeapObjectTag);
  
    // And "return" to the OSR entry point of the function.
    __ Ret();
  }
  
  void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
    Generate_OnStackReplacementHelper(masm, false);
  }
  
  void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
    Generate_OnStackReplacementHelper(masm, true);
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0       : argc
    //  -- jssp[0]  : argArray (if argc == 2)
    //  -- jssp[8]  : thisArg  (if argc >= 1)
    //  -- jssp[16] : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_FunctionPrototypeApply");
  
    Register argc = x0;
    Register arg_array = x0;
    Register receiver = x1;
    Register this_arg = x2;
    Register undefined_value = x3;
    Register null_value = x4;
  
    __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
  
    // 1. Load receiver into x1, argArray into x0 (if present), remove all
    // arguments from the stack (including the receiver), and push thisArg (if
    // present) instead.
    {
      // Claim (2 - argc) dummy arguments from the stack, to put the stack in a
      // consistent state for a simple pop operation.
      __ Claim(2);
      __ Drop(argc);
  
      // ----------- S t a t e -------------
      //  -- x0       : argc
      //  -- jssp[0]  : argArray (dummy value if argc <= 1)
      //  -- jssp[8]  : thisArg  (dummy value if argc == 0)
      //  -- jssp[16] : receiver
      // -----------------------------------
      __ Cmp(argc, 1);
      __ Pop(arg_array, this_arg);               // Overwrites argc.
      __ CmovX(this_arg, undefined_value, lo);   // undefined if argc == 0.
      __ CmovX(arg_array, undefined_value, ls);  // undefined if argc <= 1.
  
      __ Peek(receiver, 0);
      __ Poke(this_arg, 0);
    }
  
    // ----------- S t a t e -------------
    //  -- x0      : argArray
    //  -- x1      : receiver
    //  -- x3      : undefined root value
    //  -- jssp[0] : thisArg
    // -----------------------------------
  
    // 2. Make sure the receiver is actually callable.
    Label receiver_not_callable;
    __ JumpIfSmi(receiver, &receiver_not_callable);
    __ Ldr(x10, FieldMemOperand(receiver, HeapObject::kMapOffset));
    __ Ldrb(w10, FieldMemOperand(x10, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x10, 1 << Map::kIsCallable,
                               &receiver_not_callable);
  
    // 3. Tail call with no arguments if argArray is null or undefined.
    Label no_arguments;
    __ Cmp(arg_array, null_value);
    __ Ccmp(arg_array, undefined_value, ZFlag, ne);
    __ B(eq, &no_arguments);
  
    // 4a. Apply the receiver to the given argArray (passing undefined for
    // new.target in x3).
    DCHECK(undefined_value.Is(x3));
    __ Jump(masm->isolate()->builtins()->Apply(), RelocInfo::CODE_TARGET);
  
    // 4b. The argArray is either null or undefined, so we tail call without any
    // arguments to the receiver.
    __ Bind(&no_arguments);
    {
      __ Mov(x0, 0);
      DCHECK(receiver.Is(x1));
      __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    }
  
    // 4c. The receiver is not callable, throw an appropriate TypeError.
    __ Bind(&receiver_not_callable);
    {
      __ Poke(receiver, 0);
      __ TailCallRuntime(Runtime::kThrowApplyNonFunction);
    }
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
    Register argc = x0;
    Register function = x1;
    Register scratch1 = x10;
    Register scratch2 = x11;
  
    ASM_LOCATION("Builtins::Generate_FunctionPrototypeCall");
  
    // 1. Make sure we have at least one argument.
    {
      Label done;
      __ Cbnz(argc, &done);
      __ LoadRoot(scratch1, Heap::kUndefinedValueRootIndex);
      __ Push(scratch1);
      __ Mov(argc, 1);
      __ Bind(&done);
    }
  
    // 2. Get the callable to call (passed as receiver) from the stack.
    __ Peek(function, Operand(argc, LSL, kXRegSizeLog2));
  
    // 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;
      // Calculate the copy start address (destination). Copy end address is jssp.
      __ Add(scratch2, jssp, Operand(argc, LSL, kPointerSizeLog2));
      __ Sub(scratch1, scratch2, kPointerSize);
  
      __ Bind(&loop);
      __ Ldr(x12, MemOperand(scratch1, -kPointerSize, PostIndex));
      __ Str(x12, MemOperand(scratch2, -kPointerSize, PostIndex));
      __ Cmp(scratch1, jssp);
      __ B(ge, &loop);
      // Adjust the actual number of arguments and remove the top element
      // (which is a copy of the last argument).
      __ Sub(argc, argc, 1);
      __ Drop(1);
    }
  
    // 4. Call the callable.
    __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
  }
  
  void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0       : argc
    //  -- jssp[0]  : argumentsList (if argc == 3)
    //  -- jssp[8]  : thisArgument  (if argc >= 2)
    //  -- jssp[16] : target        (if argc >= 1)
    //  -- jssp[24] : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_ReflectApply");
  
    Register argc = x0;
    Register arguments_list = x0;
    Register target = x1;
    Register this_argument = x2;
    Register undefined_value = x3;
  
    __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
  
    // 1. Load target into x1 (if present), argumentsList into x0 (if present),
    // remove all arguments from the stack (including the receiver), and push
    // thisArgument (if present) instead.
    {
      // Claim (3 - argc) dummy arguments from the stack, to put the stack in a
      // consistent state for a simple pop operation.
      __ Claim(3);
      __ Drop(argc);
  
      // ----------- S t a t e -------------
      //  -- x0       : argc
      //  -- jssp[0]  : argumentsList (dummy value if argc <= 2)
      //  -- jssp[8]  : thisArgument  (dummy value if argc <= 1)
      //  -- jssp[16] : target        (dummy value if argc == 0)
      //  -- jssp[24] : receiver
      // -----------------------------------
      __ Adds(x10, argc, 0);  // Preserve argc, and set the Z flag if it is zero.
      __ Pop(arguments_list, this_argument, target);  // Overwrites argc.
      __ CmovX(target, undefined_value, eq);          // undefined if argc == 0.
      __ Cmp(x10, 2);
      __ CmovX(this_argument, undefined_value, lo);   // undefined if argc <= 1.
      __ CmovX(arguments_list, undefined_value, ls);  // undefined if argc <= 2.
  
      __ Poke(this_argument, 0);  // Overwrite receiver.
    }
  
    // ----------- S t a t e -------------
    //  -- x0      : argumentsList
    //  -- x1      : target
    //  -- jssp[0] : thisArgument
    // -----------------------------------
  
    // 2. Make sure the target is actually callable.
    Label target_not_callable;
    __ JumpIfSmi(target, &target_not_callable);
    __ Ldr(x10, FieldMemOperand(target, HeapObject::kMapOffset));
    __ Ldr(x10, FieldMemOperand(x10, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x10, 1 << Map::kIsCallable, &target_not_callable);
  
    // 3a. Apply the target to the given argumentsList (passing undefined for
    // new.target in x3).
    DCHECK(undefined_value.Is(x3));
    __ Jump(masm->isolate()->builtins()->Apply(), RelocInfo::CODE_TARGET);
  
    // 3b. The target is not callable, throw an appropriate TypeError.
    __ Bind(&target_not_callable);
    {
      __ Poke(target, 0);
      __ TailCallRuntime(Runtime::kThrowApplyNonFunction);
    }
  }
  
  void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0       : argc
    //  -- jssp[0]  : new.target (optional)
    //  -- jssp[8]  : argumentsList
    //  -- jssp[16] : target
    //  -- jssp[24] : receiver
    // -----------------------------------
    ASM_LOCATION("Builtins::Generate_ReflectConstruct");
  
    Register argc = x0;
    Register arguments_list = x0;
    Register target = x1;
    Register new_target = x3;
    Register undefined_value = x4;
  
    __ LoadRoot(undefined_value, Heap::kUndefinedValueRootIndex);
  
    // 1. Load target into x1 (if present), argumentsList into x0 (if present),
    // new.target into x3 (if present, otherwise use target), remove all
    // arguments from the stack (including the receiver), and push thisArgument
    // (if present) instead.
    {
      // Claim (3 - argc) dummy arguments from the stack, to put the stack in a
      // consistent state for a simple pop operation.
      __ Claim(3);
      __ Drop(argc);
  
      // ----------- S t a t e -------------
      //  -- x0       : argc
      //  -- jssp[0]  : new.target    (dummy value if argc <= 2)
      //  -- jssp[8]  : argumentsList (dummy value if argc <= 1)
      //  -- jssp[16] : target        (dummy value if argc == 0)
      //  -- jssp[24] : receiver
      // -----------------------------------
      __ Adds(x10, argc, 0);  // Preserve argc, and set the Z flag if it is zero.
      __ Pop(new_target, arguments_list, target);  // Overwrites argc.
      __ CmovX(target, undefined_value, eq);       // undefined if argc == 0.
      __ Cmp(x10, 2);
      __ CmovX(arguments_list, undefined_value, lo);  // undefined if argc <= 1.
      __ CmovX(new_target, target, ls);               // target if argc <= 2.
  
      __ Poke(undefined_value, 0);  // Overwrite receiver.
    }
  
    // ----------- S t a t e -------------
    //  -- x0      : argumentsList
    //  -- x1      : target
    //  -- x3      : new.target
    //  -- jssp[0] : receiver (undefined)
    // -----------------------------------
  
    // 2. Make sure the target is actually a constructor.
    Label target_not_constructor;
    __ JumpIfSmi(target, &target_not_constructor);
    __ Ldr(x10, FieldMemOperand(target, HeapObject::kMapOffset));
    __ Ldrb(x10, FieldMemOperand(x10, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x10, 1 << Map::kIsConstructor,
                               &target_not_constructor);
  
    // 3. Make sure the new.target is actually a constructor.
    Label new_target_not_constructor;
    __ JumpIfSmi(new_target, &new_target_not_constructor);
    __ Ldr(x10, FieldMemOperand(new_target, HeapObject::kMapOffset));
    __ Ldrb(x10, FieldMemOperand(x10, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x10, 1 << Map::kIsConstructor,
                               &new_target_not_constructor);
  
    // 4a. Construct the target with the given new.target and argumentsList.
    __ Jump(masm->isolate()->builtins()->Apply(), RelocInfo::CODE_TARGET);
  
    // 4b. The target is not a constructor, throw an appropriate TypeError.
    __ Bind(&target_not_constructor);
    {
      __ Poke(target, 0);
      __ TailCallRuntime(Runtime::kThrowCalledNonCallable);
    }
  
    // 4c. The new.target is not a constructor, throw an appropriate TypeError.
    __ Bind(&new_target_not_constructor);
    {
      __ Poke(new_target, 0);
      __ TailCallRuntime(Runtime::kThrowCalledNonCallable);
    }
  }
  
  static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
    __ SmiTag(x10, x0);
    __ Mov(x11, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
    __ Push(lr, fp);
    __ Push(x11, x1, x10);
    __ Add(fp, jssp,
           StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize);
  }
  
  static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : result being passed through
    // -----------------------------------
    // Get the number of arguments passed (as a smi), tear down the frame and
    // then drop the parameters and the receiver.
    __ Ldr(x10, MemOperand(fp, -(StandardFrameConstants::kFixedFrameSizeFromFp +
                                 kPointerSize)));
    __ Mov(jssp, fp);
    __ Pop(fp, lr);
    __ DropBySMI(x10, kXRegSize);
    __ Drop(1);
  }
  
  // static
  void Builtins::Generate_Apply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0      : argumentsList
    //  -- x1      : target
    //  -- x3      : new.target (checked to be constructor or undefined)
    //  -- jssp[0] : thisArgument
    // -----------------------------------
  
    Register arguments_list = x0;
    Register target = x1;
    Register new_target = x3;
  
    Register args = x0;
    Register len = x2;
  
    // Create the list of arguments from the array-like argumentsList.
    {
      Label create_arguments, create_array, create_runtime, done_create;
      __ JumpIfSmi(arguments_list, &create_runtime);
  
      // Load native context.
      Register native_context = x4;
      __ Ldr(native_context, NativeContextMemOperand());
  
      // Load the map of argumentsList.
      Register arguments_list_map = x2;
      __ Ldr(arguments_list_map,
             FieldMemOperand(arguments_list, HeapObject::kMapOffset));
  
      // Check if argumentsList is an (unmodified) arguments object.
      __ Ldr(x10, ContextMemOperand(native_context,
                                    Context::SLOPPY_ARGUMENTS_MAP_INDEX));
      __ Ldr(x11, ContextMemOperand(native_context,
                                    Context::STRICT_ARGUMENTS_MAP_INDEX));
      __ Cmp(arguments_list_map, x10);
      __ Ccmp(arguments_list_map, x11, ZFlag, ne);
      __ B(eq, &create_arguments);
  
      // Check if argumentsList is a fast JSArray.
      __ CompareInstanceType(arguments_list_map, native_context, JS_ARRAY_TYPE);
      __ B(eq, &create_array);
  
      // Ask the runtime to create the list (actually a FixedArray).
      __ Bind(&create_runtime);
      {
        FrameScope scope(masm, StackFrame::INTERNAL);
        __ Push(target, new_target, arguments_list);
        __ CallRuntime(Runtime::kCreateListFromArrayLike);
        __ Pop(new_target, target);
        __ Ldrsw(len, UntagSmiFieldMemOperand(arguments_list,
                                              FixedArray::kLengthOffset));
      }
      __ B(&done_create);
  
      // Try to create the list from an arguments object.
      __ Bind(&create_arguments);
      __ Ldrsw(len, UntagSmiFieldMemOperand(arguments_list,
                                            JSArgumentsObject::kLengthOffset));
      __ Ldr(x10, FieldMemOperand(arguments_list, JSObject::kElementsOffset));
      __ Ldrsw(x11, UntagSmiFieldMemOperand(x10, FixedArray::kLengthOffset));
      __ CompareAndBranch(len, x11, ne, &create_runtime);
      __ Mov(args, x10);
      __ B(&done_create);
  
      // Try to create the list from a JSArray object.
      __ Bind(&create_array);
      __ Ldr(x10, FieldMemOperand(arguments_list_map, Map::kBitField2Offset));
      __ DecodeField<Map::ElementsKindBits>(x10);
      STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
      STATIC_ASSERT(FAST_ELEMENTS == 2);
      // Branch for anything that's not FAST_{SMI_}ELEMENTS.
      __ TestAndBranchIfAnySet(x10, ~FAST_ELEMENTS, &create_runtime);
      __ Ldrsw(len,
               UntagSmiFieldMemOperand(arguments_list, JSArray::kLengthOffset));
      __ Ldr(args, FieldMemOperand(arguments_list, JSArray::kElementsOffset));
  
      __ Bind(&done_create);
    }
  
    // Check for stack overflow.
    {
      // 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 done;
      __ LoadRoot(x10, Heap::kRealStackLimitRootIndex);
      // Make x10 the space we have left. The stack might already be overflowed
      // here which will cause x10 to become negative.
      __ Sub(x10, masm->StackPointer(), x10);
      // Check if the arguments will overflow the stack.
      __ Cmp(x10, Operand(len, LSL, kPointerSizeLog2));
      __ B(gt, &done);  // Signed comparison.
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      __ Bind(&done);
    }
  
    // ----------- S t a t e -------------
    //  -- x0      : args (a FixedArray built from argumentsList)
    //  -- x1      : target
    //  -- x2      : len (number of elements to push from args)
    //  -- x3      : new.target (checked to be constructor or undefined)
    //  -- jssp[0] : thisArgument
    // -----------------------------------
  
    // Push arguments onto the stack (thisArgument is already on the stack).
    {
      Label done, loop;
      Register src = x4;
  
      __ Add(src, args, FixedArray::kHeaderSize - kHeapObjectTag);
      __ Mov(x0, len);  // The 'len' argument for Call() or Construct().
      __ Cbz(len, &done);
      __ Claim(len);
      __ Bind(&loop);
      __ Sub(len, len, 1);
      __ Ldr(x10, MemOperand(src, kPointerSize, PostIndex));
      __ Poke(x10, Operand(len, LSL, kPointerSizeLog2));
      __ Cbnz(len, &loop);
      __ Bind(&done);
    }
  
    // ----------- S t a t e -------------
    //  -- x0              : argument count (len)
    //  -- x1              : target
    //  -- x3              : new.target (checked to be constructor or undefined)
    //  -- jssp[0]         : args[len-1]
    //  -- jssp[8]         : args[len-2]
    //      ...            :  ...
    //  -- jssp[8*(len-2)] : args[1]
    //  -- jssp[8*(len-1)] : args[0]
    // -----------------------------------
  
    // Dispatch to Call or Construct depending on whether new.target is undefined.
    {
      __ CompareRoot(new_target, Heap::kUndefinedValueRootIndex);
      __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET, eq);
      __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
    }
  }
  
  namespace {
  
  // Drops top JavaScript frame and an arguments adaptor frame below it (if
  // present) preserving all the arguments prepared for current call.
  // Does nothing if debugger is currently active.
  // ES6 14.6.3. PrepareForTailCall
  //
  // Stack structure for the function g() tail calling f():
  //
  // ------- Caller frame: -------
  // |  ...
  // |  g()'s arg M
  // |  ...
  // |  g()'s arg 1
  // |  g()'s receiver arg
  // |  g()'s caller pc
  // ------- g()'s frame: -------
  // |  g()'s caller fp      <- fp
  // |  g()'s context
  // |  function pointer: g
  // |  -------------------------
  // |  ...
  // |  ...
  // |  f()'s arg N
  // |  ...
  // |  f()'s arg 1
  // |  f()'s receiver arg   <- sp (f()'s caller pc is not on the stack yet!)
  // ----------------------
  //
  void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
                          Register scratch1, Register scratch2,
                          Register scratch3) {
    DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
    Comment cmnt(masm, "[ PrepareForTailCall");
  
    // Prepare for tail call only if ES2015 tail call elimination is enabled.
    Label done;
    ExternalReference is_tail_call_elimination_enabled =
        ExternalReference::is_tail_call_elimination_enabled_address(
            masm->isolate());
    __ Mov(scratch1, Operand(is_tail_call_elimination_enabled));
    __ Ldrb(scratch1, MemOperand(scratch1));
    __ Cmp(scratch1, Operand(0));
    __ B(eq, &done);
  
    // Drop possible interpreter handler/stub frame.
    {
      Label no_interpreter_frame;
      __ Ldr(scratch3,
             MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
      __ Cmp(scratch3, Operand(Smi::FromInt(StackFrame::STUB)));
      __ B(ne, &no_interpreter_frame);
      __ Ldr(fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
      __ bind(&no_interpreter_frame);
    }
  
    // Check if next frame is an arguments adaptor frame.
    Register caller_args_count_reg = scratch1;
    Label no_arguments_adaptor, formal_parameter_count_loaded;
    __ Ldr(scratch2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ Ldr(scratch3,
           MemOperand(scratch2, CommonFrameConstants::kContextOrFrameTypeOffset));
    __ Cmp(scratch3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
    __ B(ne, &no_arguments_adaptor);
  
    // Drop current frame and load arguments count from arguments adaptor frame.
    __ mov(fp, scratch2);
    __ Ldr(caller_args_count_reg,
           MemOperand(fp, ArgumentsAdaptorFrameConstants::kLengthOffset));
    __ SmiUntag(caller_args_count_reg);
    __ B(&formal_parameter_count_loaded);
  
    __ bind(&no_arguments_adaptor);
    // Load caller's formal parameter count
    __ Ldr(scratch1, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
    __ Ldr(scratch1,
           FieldMemOperand(scratch1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldrsw(caller_args_count_reg,
             FieldMemOperand(scratch1,
                             SharedFunctionInfo::kFormalParameterCountOffset));
    __ bind(&formal_parameter_count_loaded);
  
    ParameterCount callee_args_count(args_reg);
    __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                          scratch3);
    __ bind(&done);
  }
  }  // namespace
  
  // static
  void Builtins::Generate_CallFunction(MacroAssembler* masm,
                                       ConvertReceiverMode mode,
                                       TailCallMode tail_call_mode) {
    ASM_LOCATION("Builtins::Generate_CallFunction");
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the function to call (checked to be a JSFunction)
    // -----------------------------------
    __ AssertFunction(x1);
  
    // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
    // Check that function is not a "classConstructor".
    Label class_constructor;
    __ Ldr(x2, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(w3, FieldMemOperand(x2, SharedFunctionInfo::kCompilerHintsOffset));
    __ TestAndBranchIfAnySet(w3, FunctionKind::kClassConstructor
                                     << SharedFunctionInfo::kFunctionKindShift,
                             &class_constructor);
  
    // 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.
    __ Ldr(cp, FieldMemOperand(x1, JSFunction::kContextOffset));
    // We need to convert the receiver for non-native sloppy mode functions.
    Label done_convert;
    __ TestAndBranchIfAnySet(w3,
                             (1 << SharedFunctionInfo::kNative) |
                                 (1 << SharedFunctionInfo::kStrictModeFunction),
                             &done_convert);
    {
      // ----------- S t a t e -------------
      //  -- x0 : the number of arguments (not including the receiver)
      //  -- x1 : the function to call (checked to be a JSFunction)
      //  -- x2 : the shared function info.
      //  -- cp : the function context.
      // -----------------------------------
  
      if (mode == ConvertReceiverMode::kNullOrUndefined) {
        // Patch receiver to global proxy.
        __ LoadGlobalProxy(x3);
      } else {
        Label convert_to_object, convert_receiver;
        __ Peek(x3, Operand(x0, LSL, kXRegSizeLog2));
        __ JumpIfSmi(x3, &convert_to_object);
        STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
        __ CompareObjectType(x3, x4, x4, FIRST_JS_RECEIVER_TYPE);
        __ B(hs, &done_convert);
        if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
          Label convert_global_proxy;
          __ JumpIfRoot(x3, Heap::kUndefinedValueRootIndex,
                        &convert_global_proxy);
          __ JumpIfNotRoot(x3, Heap::kNullValueRootIndex, &convert_to_object);
          __ Bind(&convert_global_proxy);
          {
            // Patch receiver to global proxy.
            __ LoadGlobalProxy(x3);
          }
          __ B(&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(x0);
          __ Push(x0, x1);
          __ Mov(x0, x3);
          __ Push(cp);
          __ Call(masm->isolate()->builtins()->ToObject(),
                  RelocInfo::CODE_TARGET);
          __ Pop(cp);
          __ Mov(x3, x0);
          __ Pop(x1, x0);
          __ SmiUntag(x0);
        }
        __ Ldr(x2, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
        __ Bind(&convert_receiver);
      }
      __ Poke(x3, Operand(x0, LSL, kXRegSizeLog2));
    }
    __ Bind(&done_convert);
  
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the function to call (checked to be a JSFunction)
    //  -- x2 : the shared function info.
    //  -- cp : the function context.
    // -----------------------------------
  
    if (tail_call_mode == TailCallMode::kAllow) {
      PrepareForTailCall(masm, x0, x3, x4, x5);
    }
  
    __ Ldrsw(
        x2, FieldMemOperand(x2, SharedFunctionInfo::kFormalParameterCountOffset));
    ParameterCount actual(x0);
    ParameterCount expected(x2);
    __ InvokeFunctionCode(x1, no_reg, expected, actual, JUMP_FUNCTION,
                          CheckDebugStepCallWrapper());
  
    // The function is a "classConstructor", need to raise an exception.
    __ bind(&class_constructor);
    {
      FrameScope frame(masm, StackFrame::INTERNAL);
      __ Push(x1);
      __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
    }
  }
  
  namespace {
  
  void Generate_PushBoundArguments(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : target (checked to be a JSBoundFunction)
    //  -- x3 : new.target (only in case of [[Construct]])
    // -----------------------------------
  
    // Load [[BoundArguments]] into x2 and length of that into x4.
    Label no_bound_arguments;
    __ Ldr(x2, FieldMemOperand(x1, JSBoundFunction::kBoundArgumentsOffset));
    __ Ldrsw(x4, UntagSmiFieldMemOperand(x2, FixedArray::kLengthOffset));
    __ Cmp(x4, 0);
    __ B(eq, &no_bound_arguments);
    {
      // ----------- S t a t e -------------
      //  -- x0 : the number of arguments (not including the receiver)
      //  -- x1 : target (checked to be a JSBoundFunction)
      //  -- x2 : the [[BoundArguments]] (implemented as FixedArray)
      //  -- x3 : new.target (only in case of [[Construct]])
      //  -- x4 : the number of [[BoundArguments]]
      // -----------------------------------
  
      // Reserve stack space for the [[BoundArguments]].
      {
        Label done;
        __ Claim(x4);
        // 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".
        __ CompareRoot(jssp, Heap::kRealStackLimitRootIndex);
        __ B(gt, &done);  // Signed comparison.
        // Restore the stack pointer.
        __ Drop(x4);
        {
          FrameScope scope(masm, StackFrame::MANUAL);
          __ EnterFrame(StackFrame::INTERNAL);
          __ CallRuntime(Runtime::kThrowStackOverflow);
        }
        __ Bind(&done);
      }
  
      // Relocate arguments down the stack.
      {
        Label loop, done_loop;
        __ Mov(x5, 0);
        __ Bind(&loop);
        __ Cmp(x5, x0);
        __ B(gt, &done_loop);
        __ Peek(x10, Operand(x4, LSL, kPointerSizeLog2));
        __ Poke(x10, Operand(x5, LSL, kPointerSizeLog2));
        __ Add(x4, x4, 1);
        __ Add(x5, x5, 1);
        __ B(&loop);
        __ Bind(&done_loop);
      }
  
      // Copy [[BoundArguments]] to the stack (below the arguments).
      {
        Label loop;
        __ Ldrsw(x4, UntagSmiFieldMemOperand(x2, FixedArray::kLengthOffset));
        __ Add(x2, x2, FixedArray::kHeaderSize - kHeapObjectTag);
        __ Bind(&loop);
        __ Sub(x4, x4, 1);
        __ Ldr(x10, MemOperand(x2, x4, LSL, kPointerSizeLog2));
        __ Poke(x10, Operand(x0, LSL, kPointerSizeLog2));
        __ Add(x0, x0, 1);
        __ Cmp(x4, 0);
        __ B(gt, &loop);
      }
    }
    __ Bind(&no_bound_arguments);
  }
  
  }  // namespace
  
  // static
  void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm,
                                                TailCallMode tail_call_mode) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the function to call (checked to be a JSBoundFunction)
    // -----------------------------------
    __ AssertBoundFunction(x1);
  
    if (tail_call_mode == TailCallMode::kAllow) {
      PrepareForTailCall(masm, x0, x3, x4, x5);
    }
  
    // Patch the receiver to [[BoundThis]].
    __ Ldr(x10, FieldMemOperand(x1, JSBoundFunction::kBoundThisOffset));
    __ Poke(x10, Operand(x0, LSL, kPointerSizeLog2));
  
    // Push the [[BoundArguments]] onto the stack.
    Generate_PushBoundArguments(masm);
  
    // Call the [[BoundTargetFunction]] via the Call builtin.
    __ Ldr(x1, FieldMemOperand(x1, JSBoundFunction::kBoundTargetFunctionOffset));
    __ Mov(x10,
           ExternalReference(Builtins::kCall_ReceiverIsAny, masm->isolate()));
    __ Ldr(x11, MemOperand(x10));
    __ Add(x12, x11, Code::kHeaderSize - kHeapObjectTag);
    __ Br(x12);
  }
  
  // static
  void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode,
                               TailCallMode tail_call_mode) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the target to call (can be any Object).
    // -----------------------------------
  
    Label non_callable, non_function, non_smi;
    __ JumpIfSmi(x1, &non_callable);
    __ Bind(&non_smi);
    __ CompareObjectType(x1, x4, x5, JS_FUNCTION_TYPE);
    __ Jump(masm->isolate()->builtins()->CallFunction(mode, tail_call_mode),
            RelocInfo::CODE_TARGET, eq);
    __ Cmp(x5, JS_BOUND_FUNCTION_TYPE);
    __ Jump(masm->isolate()->builtins()->CallBoundFunction(tail_call_mode),
            RelocInfo::CODE_TARGET, eq);
  
    // Check if target has a [[Call]] internal method.
    __ Ldrb(x4, FieldMemOperand(x4, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x4, 1 << Map::kIsCallable, &non_callable);
  
    __ Cmp(x5, JS_PROXY_TYPE);
    __ B(ne, &non_function);
  
    // 0. Prepare for tail call if necessary.
    if (tail_call_mode == TailCallMode::kAllow) {
      PrepareForTailCall(masm, x0, x3, x4, x5);
    }
  
    // 1. Runtime fallback for Proxy [[Call]].
    __ Push(x1);
    // Increase the arguments size to include the pushed function and the
    // existing receiver on the stack.
    __ Add(x0, x0, Operand(2));
    // Tail-call to the runtime.
    __ JumpToExternalReference(
        ExternalReference(Runtime::kJSProxyCall, masm->isolate()));
  
    // 2. Call to something else, which might have a [[Call]] internal method (if
    // not we raise an exception).
    __ Bind(&non_function);
    // Overwrite the original receiver with the (original) target.
    __ Poke(x1, Operand(x0, LSL, kXRegSizeLog2));
    // Let the "call_as_function_delegate" take care of the rest.
    __ LoadNativeContextSlot(Context::CALL_AS_FUNCTION_DELEGATE_INDEX, x1);
    __ Jump(masm->isolate()->builtins()->CallFunction(
                ConvertReceiverMode::kNotNullOrUndefined, tail_call_mode),
            RelocInfo::CODE_TARGET);
  
    // 3. Call to something that is not callable.
    __ bind(&non_callable);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(x1);
      __ CallRuntime(Runtime::kThrowCalledNonCallable);
    }
  }
  
  // static
  void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the constructor to call (checked to be a JSFunction)
    //  -- x3 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertFunction(x1);
  
    // Calling convention for function specific ConstructStubs require
    // x2 to contain either an AllocationSite or undefined.
    __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
  
    // Tail call to the function-specific construct stub (still in the caller
    // context at this point).
    __ Ldr(x4, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
    __ Ldr(x4, FieldMemOperand(x4, SharedFunctionInfo::kConstructStubOffset));
    __ Add(x4, x4, Code::kHeaderSize - kHeapObjectTag);
    __ Br(x4);
  }
  
  // static
  void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the function to call (checked to be a JSBoundFunction)
    //  -- x3 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertBoundFunction(x1);
  
    // Push the [[BoundArguments]] onto the stack.
    Generate_PushBoundArguments(masm);
  
    // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
    {
      Label done;
      __ Cmp(x1, x3);
      __ B(ne, &done);
      __ Ldr(x3,
             FieldMemOperand(x1, JSBoundFunction::kBoundTargetFunctionOffset));
      __ Bind(&done);
    }
  
    // Construct the [[BoundTargetFunction]] via the Construct builtin.
    __ Ldr(x1, FieldMemOperand(x1, JSBoundFunction::kBoundTargetFunctionOffset));
    __ Mov(x10, ExternalReference(Builtins::kConstruct, masm->isolate()));
    __ Ldr(x11, MemOperand(x10));
    __ Add(x12, x11, Code::kHeaderSize - kHeapObjectTag);
    __ Br(x12);
  }
  
  // static
  void Builtins::Generate_ConstructProxy(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the constructor to call (checked to be a JSProxy)
    //  -- x3 : the new target (either the same as the constructor or
    //          the JSFunction on which new was invoked initially)
    // -----------------------------------
  
    // Call into the Runtime for Proxy [[Construct]].
    __ Push(x1);
    __ Push(x3);
    // Include the pushed new_target, constructor and the receiver.
    __ Add(x0, x0, 3);
    // Tail-call to the runtime.
    __ JumpToExternalReference(
        ExternalReference(Runtime::kJSProxyConstruct, masm->isolate()));
  }
  
  // static
  void Builtins::Generate_Construct(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- x0 : the number of arguments (not including the receiver)
    //  -- x1 : the constructor to call (can be any Object)
    //  -- x3 : the new target (either the same as the constructor or
    //          the JSFunction on which new was invoked initially)
    // -----------------------------------
  
    // Check if target is a Smi.
    Label non_constructor;
    __ JumpIfSmi(x1, &non_constructor);
  
    // Dispatch based on instance type.
    __ CompareObjectType(x1, x4, x5, JS_FUNCTION_TYPE);
    __ Jump(masm->isolate()->builtins()->ConstructFunction(),
            RelocInfo::CODE_TARGET, eq);
  
    // Check if target has a [[Construct]] internal method.
    __ Ldrb(x2, FieldMemOperand(x4, Map::kBitFieldOffset));
    __ TestAndBranchIfAllClear(x2, 1 << Map::kIsConstructor, &non_constructor);
  
    // Only dispatch to bound functions after checking whether they are
    // constructors.
    __ Cmp(x5, JS_BOUND_FUNCTION_TYPE);
    __ Jump(masm->isolate()->builtins()->ConstructBoundFunction(),
            RelocInfo::CODE_TARGET, eq);
  
    // Only dispatch to proxies after checking whether they are constructors.
    __ Cmp(x5, JS_PROXY_TYPE);
    __ Jump(masm->isolate()->builtins()->ConstructProxy(), RelocInfo::CODE_TARGET,
            eq);
  
    // Called Construct on an exotic Object with a [[Construct]] internal method.
    {
      // Overwrite the original receiver with the (original) target.
      __ Poke(x1, Operand(x0, LSL, kXRegSizeLog2));
      // Let the "call_as_constructor_delegate" take care of the rest.
      __ LoadNativeContextSlot(Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, x1);
      __ 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(masm->isolate()->builtins()->ConstructedNonConstructable(),
            RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_AllocateInNewSpace(MacroAssembler* masm) {
    ASM_LOCATION("Builtins::Generate_AllocateInNewSpace");
    // ----------- S t a t e -------------
    //  -- x1 : requested object size (untagged)
    //  -- lr : return address
    // -----------------------------------
    __ SmiTag(x1);
    __ Push(x1);
    __ Move(cp, Smi::kZero);
    __ TailCallRuntime(Runtime::kAllocateInNewSpace);
  }
  
  // static
  void Builtins::Generate_AllocateInOldSpace(MacroAssembler* masm) {
    ASM_LOCATION("Builtins::Generate_AllocateInOldSpace");
    // ----------- S t a t e -------------
    //  -- x1 : requested object size (untagged)
    //  -- lr : return address
    // -----------------------------------
    __ SmiTag(x1);
    __ Move(x2, Smi::FromInt(AllocateTargetSpace::encode(OLD_SPACE)));
    __ Push(x1, x2);
    __ Move(cp, Smi::kZero);
    __ TailCallRuntime(Runtime::kAllocateInTargetSpace);
  }
  
  // static
  void Builtins::Generate_Abort(MacroAssembler* masm) {
    ASM_LOCATION("Builtins::Generate_Abort");
    // ----------- S t a t e -------------
    //  -- x1 : message_id as Smi
    //  -- lr : return address
    // -----------------------------------
    MacroAssembler::NoUseRealAbortsScope no_use_real_aborts(masm);
    __ Push(x1);
    __ Move(cp, Smi::kZero);
    __ TailCallRuntime(Runtime::kAbort);
  }
  
  void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
    ASM_LOCATION("Builtins::Generate_ArgumentsAdaptorTrampoline");
    // ----------- S t a t e -------------
    //  -- x0 : actual number of arguments
    //  -- x1 : function (passed through to callee)
    //  -- x2 : expected number of arguments
    //  -- x3 : new target (passed through to callee)
    // -----------------------------------
  
    Register argc_actual = x0;    // Excluding the receiver.
    Register argc_expected = x2;  // Excluding the receiver.
    Register function = x1;
    Register code_entry = x10;
  
    Label invoke, dont_adapt_arguments, stack_overflow;
  
    Label enough, too_few;
    __ Cmp(argc_actual, argc_expected);
    __ B(lt, &too_few);
    __ Cmp(argc_expected, SharedFunctionInfo::kDontAdaptArgumentsSentinel);
    __ B(eq, &dont_adapt_arguments);
  
    {  // Enough parameters: actual >= expected
      EnterArgumentsAdaptorFrame(masm);
      Generate_StackOverflowCheck(masm, x2, x10, &stack_overflow);
  
      Register copy_start = x10;
      Register copy_end = x11;
      Register copy_to = x12;
      Register scratch1 = x13, scratch2 = x14;
  
      __ Lsl(scratch2, argc_expected, kPointerSizeLog2);
  
      // Adjust for fp, lr, and the receiver.
      __ Add(copy_start, fp, 3 * kPointerSize);
      __ Add(copy_start, copy_start, Operand(argc_actual, LSL, kPointerSizeLog2));
      __ Sub(copy_end, copy_start, scratch2);
      __ Sub(copy_end, copy_end, kPointerSize);
      __ Mov(copy_to, jssp);
  
      // Claim space for the arguments, the receiver, and one extra slot.
      // The extra slot ensures we do not write under jssp. It will be popped
      // later.
      __ Add(scratch1, scratch2, 2 * kPointerSize);
      __ Claim(scratch1, 1);
  
      // Copy the arguments (including the receiver) to the new stack frame.
      Label copy_2_by_2;
      __ Bind(&copy_2_by_2);
      __ Ldp(scratch1, scratch2,
             MemOperand(copy_start, -2 * kPointerSize, PreIndex));
      __ Stp(scratch1, scratch2,
             MemOperand(copy_to, -2 * kPointerSize, PreIndex));
      __ Cmp(copy_start, copy_end);
      __ B(hi, &copy_2_by_2);
  
      // Correct the space allocated for the extra slot.
      __ Drop(1);
  
      __ B(&invoke);
    }
  
    {  // Too few parameters: Actual < expected
      __ Bind(&too_few);
  
      Register copy_from = x10;
      Register copy_end = x11;
      Register copy_to = x12;
      Register scratch1 = x13, scratch2 = x14;
  
      EnterArgumentsAdaptorFrame(masm);
      Generate_StackOverflowCheck(masm, x2, x10, &stack_overflow);
  
      __ Lsl(scratch2, argc_expected, kPointerSizeLog2);
      __ Lsl(argc_actual, argc_actual, kPointerSizeLog2);
  
      // Adjust for fp, lr, and the receiver.
      __ Add(copy_from, fp, 3 * kPointerSize);
      __ Add(copy_from, copy_from, argc_actual);
      __ Mov(copy_to, jssp);
      __ Sub(copy_end, copy_to, 1 * kPointerSize);  // Adjust for the receiver.
      __ Sub(copy_end, copy_end, argc_actual);
  
      // Claim space for the arguments, the receiver, and one extra slot.
      // The extra slot ensures we do not write under jssp. It will be popped
      // later.
      __ Add(scratch1, scratch2, 2 * kPointerSize);
      __ Claim(scratch1, 1);
  
      // Copy the arguments (including the receiver) to the new stack frame.
      Label copy_2_by_2;
      __ Bind(&copy_2_by_2);
      __ Ldp(scratch1, scratch2,
             MemOperand(copy_from, -2 * kPointerSize, PreIndex));
      __ Stp(scratch1, scratch2,
             MemOperand(copy_to, -2 * kPointerSize, PreIndex));
      __ Cmp(copy_to, copy_end);
      __ B(hi, &copy_2_by_2);
  
      __ Mov(copy_to, copy_end);
  
      // Fill the remaining expected arguments with undefined.
      __ LoadRoot(scratch1, Heap::kUndefinedValueRootIndex);
      __ Add(copy_end, jssp, kPointerSize);
  
      Label fill;
      __ Bind(&fill);
      __ Stp(scratch1, scratch1,
             MemOperand(copy_to, -2 * kPointerSize, PreIndex));
      __ Cmp(copy_to, copy_end);
      __ B(hi, &fill);
  
      // Correct the space allocated for the extra slot.
      __ Drop(1);
    }
  
    // Arguments have been adapted. Now call the entry point.
    __ Bind(&invoke);
    __ Mov(argc_actual, argc_expected);
    // x0 : expected number of arguments
    // x1 : function (passed through to callee)
    // x3 : new target (passed through to callee)
    __ Ldr(code_entry, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
    __ Call(code_entry);
  
    // Store offset of return address for deoptimizer.
    masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());
  
    // Exit frame and return.
    LeaveArgumentsAdaptorFrame(masm);
    __ Ret();
  
    // Call the entry point without adapting the arguments.
    __ Bind(&dont_adapt_arguments);
    __ Ldr(code_entry, FieldMemOperand(function, JSFunction::kCodeEntryOffset));
    __ Jump(code_entry);
  
    __ Bind(&stack_overflow);
    {
      FrameScope frame(masm, StackFrame::MANUAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ Unreachable();
    }
  }
  
  #undef __
  
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_TARGET_ARCH_ARM
  