text: // Copyright 2014 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #if V8_TARGET_ARCH_PPC
  
  #include "src/api/api-arguments.h"
  #include "src/codegen/code-factory.h"
  #include "src/debug/debug.h"
  #include "src/deoptimizer/deoptimizer.h"
  #include "src/execution/frame-constants.h"
  #include "src/execution/frames.h"
  #include "src/logging/counters.h"
  // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
  #include "src/codegen/macro-assembler-inl.h"
  #include "src/codegen/register-configuration.h"
  #include "src/heap/heap-inl.h"
  #include "src/objects/cell.h"
  #include "src/objects/foreign.h"
  #include "src/objects/heap-number.h"
  #include "src/objects/js-generator.h"
  #include "src/objects/smi.h"
  #include "src/runtime/runtime.h"
  #include "src/wasm/wasm-objects.h"
  
  namespace v8 {
  namespace internal {
  
  #define __ ACCESS_MASM(masm)
  
  void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address) {
    __ Move(kJavaScriptCallExtraArg1Register, ExternalReference::Create(address));
    __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
            RelocInfo::CODE_TARGET);
  }
  
  static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
                                             Runtime::FunctionId function_id) {
    // ----------- S t a t e -------------
    //  -- r4 : target function (preserved for callee)
    //  -- r6 : new target (preserved for callee)
    // -----------------------------------
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      // Push a copy of the target function and the new target.
      // Push function as parameter to the runtime call.
      __ Push(r4, r6, r4);
  
      __ CallRuntime(function_id, 1);
      __ mr(r5, r3);
  
      // Restore target function and new target.
      __ Pop(r4, r6);
    }
    static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
    __ JumpCodeObject(r5);
  }
  
  namespace {
  
  void LoadRealStackLimit(MacroAssembler* masm, Register destination) {
    DCHECK(masm->root_array_available());
    Isolate* isolate = masm->isolate();
    ExternalReference limit = ExternalReference::address_of_real_jslimit(isolate);
    DCHECK(TurboAssembler::IsAddressableThroughRootRegister(isolate, limit));
  
    intptr_t offset =
        TurboAssembler::RootRegisterOffsetForExternalReference(isolate, limit);
    CHECK(is_int32(offset));
    __ LoadP(destination, MemOperand(kRootRegister, offset));
  }
  
  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.
    LoadRealStackLimit(masm, scratch);
    // Make scratch the space we have left. The stack might already be overflowed
    // here which will cause scratch to become negative.
    __ sub(scratch, sp, scratch);
    // Check if the arguments will overflow the stack.
    __ ShiftLeftImm(r0, num_args, Operand(kPointerSizeLog2));
    __ cmp(scratch, r0);
    __ ble(stack_overflow);  // Signed comparison.
  }
  
  void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3     : number of arguments
    //  -- r4     : constructor function
    //  -- r6     : new target
    //  -- cp     : context
    //  -- lr     : return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
  
    Register scratch = r5;
  
    Label stack_overflow;
  
    Generate_StackOverflowCheck(masm, r3, r8, &stack_overflow);
    // Enter a construct frame.
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::CONSTRUCT);
  
      // Preserve the incoming parameters on the stack.
  
      __ SmiTag(r3);
      __ Push(cp, r3);
      __ SmiUntag(r3, SetRC);
      // The receiver for the builtin/api call.
      __ PushRoot(RootIndex::kTheHoleValue);
      // Set up pointer to last argument.
      __ addi(r7, fp, Operand(StandardFrameConstants::kCallerSPOffset));
  
      // Copy arguments and receiver to the expression stack.
  
      Label loop, no_args;
      // ----------- S t a t e -------------
      //  --                 r3: number of arguments (untagged)
      //  --                 r4: constructor function
      //  --                 r6: new target
      //  --                 r7: pointer to last argument
      //  --                 cr0: condition indicating whether r3 is zero
      //  -- sp[0*kPointerSize]: the hole (receiver)
      //  -- sp[1*kPointerSize]: number of arguments (tagged)
      //  -- sp[2*kPointerSize]: context
      // -----------------------------------
      __ beq(&no_args, cr0);
      __ ShiftLeftImm(scratch, r3, Operand(kPointerSizeLog2));
      __ sub(sp, sp, scratch);
      __ mtctr(r3);
      __ bind(&loop);
      __ subi(scratch, scratch, Operand(kPointerSize));
      __ LoadPX(r0, MemOperand(r7, scratch));
      __ StorePX(r0, MemOperand(sp, scratch));
      __ bdnz(&loop);
      __ bind(&no_args);
  
      // Call the function.
      // r3: number of arguments (untagged)
      // r4: constructor function
      // r6: new target
      {
        ConstantPoolUnavailableScope constant_pool_unavailable(masm);
        __ InvokeFunctionWithNewTarget(r4, r6, r3, CALL_FUNCTION);
      }
  
      // Restore context from the frame.
      __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
      // Restore smi-tagged arguments count from the frame.
      __ LoadP(r4, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
  
      // Leave construct frame.
    }
    // Remove caller arguments from the stack and return.
    STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
  
    __ SmiToPtrArrayOffset(r4, r4);
    __ add(sp, sp, r4);
    __ addi(sp, sp, Operand(kPointerSize));
    __ blr();
  
    __ bind(&stack_overflow);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ bkpt(0);  // Unreachable code.
    }
  }
  
  }  // namespace
  
  // The construct stub for ES5 constructor functions and ES6 class constructors.
  void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  --      r3: number of arguments (untagged)
    //  --      r4: constructor function
    //  --      r6: new target
    //  --      cp: context
    //  --      lr: return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
  
    // Enter a construct frame.
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::CONSTRUCT);
      Label post_instantiation_deopt_entry, not_create_implicit_receiver;
  
      // Preserve the incoming parameters on the stack.
      __ SmiTag(r3);
      __ Push(cp, r3, r4);
      __ PushRoot(RootIndex::kUndefinedValue);
      __ Push(r6);
  
      // ----------- S t a t e -------------
      //  --        sp[0*kPointerSize]: new target
      //  --        sp[1*kPointerSize]: padding
      //  -- r4 and sp[2*kPointerSize]: constructor function
      //  --        sp[3*kPointerSize]: number of arguments (tagged)
      //  --        sp[4*kPointerSize]: context
      // -----------------------------------
  
      __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
      __ lwz(r7, FieldMemOperand(r7, SharedFunctionInfo::kFlagsOffset));
      __ DecodeField<SharedFunctionInfo::FunctionKindBits>(r7);
      __ JumpIfIsInRange(r7, kDefaultDerivedConstructor, kDerivedConstructor,
                         &not_create_implicit_receiver);
  
      // If not derived class constructor: Allocate the new receiver object.
      __ IncrementCounter(masm->isolate()->counters()->constructed_objects(), 1,
                          r7, r8);
      __ Call(BUILTIN_CODE(masm->isolate(), FastNewObject),
              RelocInfo::CODE_TARGET);
      __ b(&post_instantiation_deopt_entry);
  
      // Else: use TheHoleValue as receiver for constructor call
      __ bind(&not_create_implicit_receiver);
      __ LoadRoot(r3, RootIndex::kTheHoleValue);
  
      // ----------- S t a t e -------------
      //  --                          r3: receiver
      //  -- Slot 4 / sp[0*kPointerSize]: new target
      //  -- Slot 3 / sp[1*kPointerSize]: padding
      //  -- Slot 2 / sp[2*kPointerSize]: constructor function
      //  -- Slot 1 / sp[3*kPointerSize]: number of arguments (tagged)
      //  -- Slot 0 / sp[4*kPointerSize]: context
      // -----------------------------------
      // Deoptimizer enters here.
      masm->isolate()->heap()->SetConstructStubCreateDeoptPCOffset(
          masm->pc_offset());
      __ bind(&post_instantiation_deopt_entry);
  
      // Restore new target.
      __ Pop(r6);
      // 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(r3, r3);
  
      // ----------- S t a t e -------------
      //  --                 r6: new target
      //  -- sp[0*kPointerSize]: implicit receiver
      //  -- sp[1*kPointerSize]: implicit receiver
      //  -- sp[2*kPointerSize]: padding
      //  -- sp[3*kPointerSize]: constructor function
      //  -- sp[4*kPointerSize]: number of arguments (tagged)
      //  -- sp[5*kPointerSize]: context
      // -----------------------------------
  
      // Restore constructor function and argument count.
      __ LoadP(r4, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
      __ LoadP(r3, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      __ SmiUntag(r3);
  
      // Set up pointer to last argument.
      __ addi(r7, fp, Operand(StandardFrameConstants::kCallerSPOffset));
  
      Label enough_stack_space, stack_overflow;
      Generate_StackOverflowCheck(masm, r3, r8, &stack_overflow);
      __ b(&enough_stack_space);
  
      __ bind(&stack_overflow);
      // Restore the context from the frame.
      __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
      __ CallRuntime(Runtime::kThrowStackOverflow);
      // Unreachable code.
      __ bkpt(0);
  
      __ bind(&enough_stack_space);
  
      // Copy arguments and receiver to the expression stack.
      Label loop, no_args;
      // ----------- S t a t e -------------
      //  --                        r3: number of arguments (untagged)
      //  --                        r6: new target
      //  --                        r7: pointer to last argument
      //  --                        cr0: condition indicating whether r3 is zero
      //  --        sp[0*kPointerSize]: implicit receiver
      //  --        sp[1*kPointerSize]: implicit receiver
      //  --        sp[2*kPointerSize]: padding
      //  -- r4 and sp[3*kPointerSize]: constructor function
      //  --        sp[4*kPointerSize]: number of arguments (tagged)
      //  --        sp[5*kPointerSize]: context
      // -----------------------------------
      __ cmpi(r3, Operand::Zero());
      __ beq(&no_args);
      __ ShiftLeftImm(r9, r3, Operand(kPointerSizeLog2));
      __ sub(sp, sp, r9);
      __ mtctr(r3);
      __ bind(&loop);
      __ subi(r9, r9, Operand(kPointerSize));
      __ LoadPX(r0, MemOperand(r7, r9));
      __ StorePX(r0, MemOperand(sp, r9));
      __ bdnz(&loop);
      __ bind(&no_args);
  
      // Call the function.
      {
        ConstantPoolUnavailableScope constant_pool_unavailable(masm);
        __ InvokeFunctionWithNewTarget(r4, r6, r3, CALL_FUNCTION);
      }
  
      // ----------- S t a t e -------------
      //  --                 r0: constructor result
      //  -- sp[0*kPointerSize]: implicit receiver
      //  -- sp[1*kPointerSize]: padding
      //  -- sp[2*kPointerSize]: constructor function
      //  -- sp[3*kPointerSize]: number of arguments
      //  -- sp[4*kPointerSize]: context
      // -----------------------------------
  
      // Store offset of return address for deoptimizer.
      masm->isolate()->heap()->SetConstructStubInvokeDeoptPCOffset(
          masm->pc_offset());
  
      // Restore the context from the frame.
      __ LoadP(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
  
      // If the result is an object (in the ECMA sense), we should get rid
      // of the receiver and use the result; see ECMA-262 section 13.2.2-7
      // on page 74.
      Label use_receiver, do_throw, leave_frame;
  
      // If the result is undefined, we jump out to using the implicit receiver.
      __ JumpIfRoot(r3, RootIndex::kUndefinedValue, &use_receiver);
  
      // Otherwise we do a smi check and fall through to check if the return value
      // is a valid receiver.
  
      // If the result is a smi, it is *not* an object in the ECMA sense.
      __ JumpIfSmi(r3, &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.
      STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
      __ CompareObjectType(r3, r7, r7, FIRST_JS_RECEIVER_TYPE);
      __ bge(&leave_frame);
      __ b(&use_receiver);
  
      __ bind(&do_throw);
      __ CallRuntime(Runtime::kThrowConstructorReturnedNonObject);
  
      // Throw away the result of the constructor invocation and use the
      // on-stack receiver as the result.
      __ bind(&use_receiver);
      __ LoadP(r3, MemOperand(sp));
      __ JumpIfRoot(r3, RootIndex::kTheHoleValue, &do_throw);
  
      __ bind(&leave_frame);
      // Restore smi-tagged arguments count from the frame.
      __ LoadP(r4, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      // Leave construct frame.
    }
  
    // Remove caller arguments from the stack and return.
    STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
  
    __ SmiToPtrArrayOffset(r4, r4);
    __ add(sp, sp, r4);
    __ addi(sp, sp, Operand(kPointerSize));
    __ blr();
  }
  
  void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
    Generate_JSBuiltinsConstructStubHelper(masm);
  }
  
  static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
                                            Register sfi_data,
                                            Register scratch1) {
    Label done;
  
    __ CompareObjectType(sfi_data, scratch1, scratch1, INTERPRETER_DATA_TYPE);
    __ bne(&done);
    __ LoadP(sfi_data,
             FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));
    __ bind(&done);
  }
  
  // static
  void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the value to pass to the generator
    //  -- r4 : the JSGeneratorObject to resume
    //  -- lr : return address
    // -----------------------------------
    __ AssertGeneratorObject(r4);
  
    // Store input value into generator object.
    __ StoreP(r3, FieldMemOperand(r4, JSGeneratorObject::kInputOrDebugPosOffset),
              r0);
    __ RecordWriteField(r4, JSGeneratorObject::kInputOrDebugPosOffset, r3, r6,
                        kLRHasNotBeenSaved, kDontSaveFPRegs);
  
    // Load suspended function and context.
    __ LoadP(r7, FieldMemOperand(r4, JSGeneratorObject::kFunctionOffset));
    __ LoadP(cp, FieldMemOperand(r7, JSFunction::kContextOffset));
  
    // Flood function if we are stepping.
    Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
    Label stepping_prepared;
    Register scratch = r8;
    ExternalReference debug_hook =
        ExternalReference::debug_hook_on_function_call_address(masm->isolate());
    __ Move(scratch, debug_hook);
    __ LoadByte(scratch, MemOperand(scratch), r0);
    __ extsb(scratch, scratch);
    __ CmpSmiLiteral(scratch, Smi::zero(), r0);
    __ bne(&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());
  
    __ Move(scratch, debug_suspended_generator);
    __ LoadP(scratch, MemOperand(scratch));
    __ cmp(scratch, r4);
    __ beq(&prepare_step_in_suspended_generator);
    __ bind(&stepping_prepared);
  
    // Check the stack for overflow. We are not trying to catch interruptions
    // (i.e. debug break and preemption) here, so check the "real stack limit".
    Label stack_overflow;
    LoadRealStackLimit(masm, scratch);
    __ cmpl(sp, scratch);
    __ blt(&stack_overflow);
  
    // Push receiver.
    __ LoadP(scratch, FieldMemOperand(r4, JSGeneratorObject::kReceiverOffset));
    __ Push(scratch);
  
    // ----------- S t a t e -------------
    //  -- r4    : the JSGeneratorObject to resume
    //  -- r7    : generator function
    //  -- cp    : generator context
    //  -- lr    : return address
    //  -- sp[0] : generator receiver
    // -----------------------------------
  
    // Copy the function arguments from the generator object's register file.
    __ LoadP(r6, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
    __ LoadHalfWord(
        r6, FieldMemOperand(r6, SharedFunctionInfo::kFormalParameterCountOffset));
    __ LoadP(r5, FieldMemOperand(
                     r4, JSGeneratorObject::kParametersAndRegistersOffset));
    {
      Label loop, done_loop;
      __ cmpi(r6, Operand::Zero());
      __ ble(&done_loop);
  
      // setup r9 to first element address - kPointerSize
      __ addi(r9, r5,
              Operand(FixedArray::kHeaderSize - kHeapObjectTag - kPointerSize));
  
      __ mtctr(r6);
      __ bind(&loop);
      __ LoadPU(scratch, MemOperand(r9, kPointerSize));
      __ push(scratch);
      __ bdnz(&loop);
  
      __ bind(&done_loop);
    }
  
    // Underlying function needs to have bytecode available.
    if (FLAG_debug_code) {
      __ LoadP(r6, FieldMemOperand(r7, JSFunction::kSharedFunctionInfoOffset));
      __ LoadP(r6, FieldMemOperand(r6, SharedFunctionInfo::kFunctionDataOffset));
      GetSharedFunctionInfoBytecode(masm, r6, r3);
      __ CompareObjectType(r6, r6, r6, BYTECODE_ARRAY_TYPE);
      __ Assert(eq, AbortReason::kMissingBytecodeArray);
    }
  
    // Resume (Ignition/TurboFan) generator object.
    {
      // 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.
      __ mr(r6, r4);
      __ mr(r4, r7);
      static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
      __ LoadP(r5, FieldMemOperand(r4, JSFunction::kCodeOffset));
      __ JumpCodeObject(r5);
    }
  
    __ bind(&prepare_step_in_if_stepping);
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      __ Push(r4, r7);
      // Push hole as receiver since we do not use it for stepping.
      __ PushRoot(RootIndex::kTheHoleValue);
      __ CallRuntime(Runtime::kDebugOnFunctionCall);
      __ Pop(r4);
      __ LoadP(r7, FieldMemOperand(r4, JSGeneratorObject::kFunctionOffset));
    }
    __ b(&stepping_prepared);
  
    __ bind(&prepare_step_in_suspended_generator);
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      __ Push(r4);
      __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
      __ Pop(r4);
      __ LoadP(r7, FieldMemOperand(r4, JSGeneratorObject::kFunctionOffset));
    }
    __ b(&stepping_prepared);
  
    __ bind(&stack_overflow);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ bkpt(0);  // This should be unreachable.
    }
  }
  
  void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
    __ push(r4);
    __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
  }
  
  namespace {
  
  // Called with the native C calling convention. The corresponding function
  // signature is either:
  //
  //   using JSEntryFunction = GeneratedCode<Address(
  //       Address root_register_value, Address new_target, Address target,
  //       Address receiver, intptr_t argc, Address** args)>;
  // or
  //   using JSEntryFunction = GeneratedCode<Address(
  //       Address root_register_value, MicrotaskQueue* microtask_queue)>;
  void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
                               Builtins::Name entry_trampoline) {
    // The register state is either:
    //   r3: root_register_value
    //   r4: code entry
    //   r5: function
    //   r6: receiver
    //   r7: argc
    //   r8: argv
    // or
    //   r3: root_register_value
    //   r4: microtask_queue
  
    Label invoke, handler_entry, exit;
  
    {
      NoRootArrayScope no_root_array(masm);
  
      // PPC LINUX ABI:
      // preserve LR in pre-reserved slot in caller's frame
      __ mflr(r0);
      __ StoreP(r0, MemOperand(sp, kStackFrameLRSlot * kPointerSize));
  
      // Save callee saved registers on the stack.
      __ MultiPush(kCalleeSaved);
  
      // Save callee-saved double registers.
      __ MultiPushDoubles(kCalleeSavedDoubles);
      // Set up the reserved register for 0.0.
      __ LoadDoubleLiteral(kDoubleRegZero, Double(0.0), r0);
  
      // Initialize the root register.
      // C calling convention. The first argument is passed in r3.
      __ mr(kRootRegister, r3);
    }
  
    // Push a frame with special values setup to mark it as an entry frame.
    // r4: code entry
    // r5: function
    // r6: receiver
    // r7: argc
    // r8: argv
    __ li(r0, Operand(-1));  // Push a bad frame pointer to fail if it is used.
    __ push(r0);
    if (FLAG_enable_embedded_constant_pool) {
      __ li(kConstantPoolRegister, Operand::Zero());
      __ push(kConstantPoolRegister);
    }
    __ mov(r0, Operand(StackFrame::TypeToMarker(type)));
    __ push(r0);
    __ push(r0);
    // Save copies of the top frame descriptor on the stack.
    __ Move(r3, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress,
                                          masm->isolate()));
    __ LoadP(r0, MemOperand(r3));
    __ push(r0);
  
    Register scratch = r9;
    // Set up frame pointer for the frame to be pushed.
    __ addi(fp, sp, Operand(-EntryFrameConstants::kCallerFPOffset));
  
    // If this is the outermost JS call, set js_entry_sp value.
    Label non_outermost_js;
    ExternalReference js_entry_sp =
        ExternalReference::Create(IsolateAddressId::kJSEntrySPAddress,
                                  masm->isolate());
    __ Move(r3, js_entry_sp);
    __ LoadP(scratch, MemOperand(r3));
    __ cmpi(scratch, Operand::Zero());
    __ bne(&non_outermost_js);
    __ StoreP(fp, MemOperand(r3));
    __ mov(scratch, Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
    Label cont;
    __ b(&cont);
    __ bind(&non_outermost_js);
    __ mov(scratch, Operand(StackFrame::INNER_JSENTRY_FRAME));
    __ bind(&cont);
    __ push(scratch);  // frame-type
  
    // Jump to a faked try block that does the invoke, with a faked catch
    // block that sets the pending exception.
    __ b(&invoke);
  
    // Block literal pool emission whilst taking the position of the handler
    // entry. This avoids making the assumption that literal pools are always
    // emitted after an instruction is emitted, rather than before.
    {
      ConstantPoolUnavailableScope constant_pool_unavailable(masm);
      __ bind(&handler_entry);
  
      // Store the current pc as the handler offset. It's used later to create the
      // handler table.
      masm->isolate()->builtins()->SetJSEntryHandlerOffset(handler_entry.pos());
  
      // Caught exception: Store result (exception) in the pending exception
      // field in the JSEnv and return a failure sentinel.  Coming in here the
      // fp will be invalid because the PushStackHandler below sets it to 0 to
      // signal the existence of the JSEntry frame.
      __ Move(scratch,
              ExternalReference::Create(
                  IsolateAddressId::kPendingExceptionAddress, masm->isolate()));
    }
  
    __ StoreP(r3, MemOperand(scratch));
    __ LoadRoot(r3, RootIndex::kException);
    __ b(&exit);
  
    // Invoke: Link this frame into the handler chain.
    __ bind(&invoke);
    // Must preserve r4-r8.
    __ PushStackHandler();
    // If an exception not caught by another handler occurs, this handler
    // returns control to the code after the b(&invoke) above, which
    // restores all kCalleeSaved registers (including cp and fp) to their
    // saved values before returning a failure to C.
  
    // Invoke the function by calling through JS entry trampoline builtin.
    // Notice that we cannot store a reference to the trampoline code directly in
    // this stub, because runtime stubs are not traversed when doing GC.
  
    // Invoke the function by calling through JS entry trampoline builtin and
    // pop the faked function when we return.
    Handle<Code> trampoline_code =
        masm->isolate()->builtins()->builtin_handle(entry_trampoline);
    __ Call(trampoline_code, RelocInfo::CODE_TARGET);
  
    // Unlink this frame from the handler chain.
    __ PopStackHandler();
  
    __ bind(&exit);  // r3 holds result
    // Check if the current stack frame is marked as the outermost JS frame.
    Label non_outermost_js_2;
    __ pop(r8);
    __ cmpi(r8, Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
    __ bne(&non_outermost_js_2);
    __ mov(scratch, Operand::Zero());
    __ Move(r8, js_entry_sp);
    __ StoreP(scratch, MemOperand(r8));
    __ bind(&non_outermost_js_2);
  
    // Restore the top frame descriptors from the stack.
    __ pop(r6);
    __ Move(scratch, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress,
                                               masm->isolate()));
    __ StoreP(r6, MemOperand(scratch));
  
    // Reset the stack to the callee saved registers.
    __ addi(sp, sp, Operand(-EntryFrameConstants::kCallerFPOffset));
  
    // Restore callee-saved double registers.
    __ MultiPopDoubles(kCalleeSavedDoubles);
  
    // Restore callee-saved registers.
    __ MultiPop(kCalleeSaved);
  
    // Return
    __ LoadP(r0, MemOperand(sp, kStackFrameLRSlot * kPointerSize));
    __ mtlr(r0);
    __ blr();
  }
  
  }  // namespace
  
  void Builtins::Generate_JSEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::ENTRY,
                            Builtins::kJSEntryTrampoline);
  }
  
  void Builtins::Generate_JSConstructEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::CONSTRUCT_ENTRY,
                            Builtins::kJSConstructEntryTrampoline);
  }
  
  void Builtins::Generate_JSRunMicrotasksEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::ENTRY,
                            Builtins::kRunMicrotasksTrampoline);
  }
  
  // Clobbers scratch1 and scratch2; preserves all other registers.
  static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
                                          Register scratch1, Register scratch2) {
    // 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 okay;
    LoadRealStackLimit(masm, scratch1);
    // Make scratch1 the space we have left. The stack might already be overflowed
    // here which will cause scratch1 to become negative.
    __ sub(scratch1, sp, scratch1);
    // Check if the arguments will overflow the stack.
    __ ShiftLeftImm(scratch2, argc, Operand(kPointerSizeLog2));
    __ cmp(scratch1, scratch2);
    __ bgt(&okay);  // Signed comparison.
  
    // Out of stack space.
    __ CallRuntime(Runtime::kThrowStackOverflow);
  
    __ bind(&okay);
  }
  
  static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                               bool is_construct) {
    // Called from Generate_JS_Entry
    // r4: new.target
    // r5: function
    // r6: receiver
    // r7: argc
    // r8: argv
    // r0,r3,r9, cp may be clobbered
  
    // Enter an internal frame.
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
  
      // Setup the context (we need to use the caller context from the isolate).
      ExternalReference context_address = ExternalReference::Create(
          IsolateAddressId::kContextAddress, masm->isolate());
      __ Move(cp, context_address);
      __ LoadP(cp, MemOperand(cp));
  
      // Push the function and the receiver onto the stack.
      __ Push(r5, r6);
  
      // Check if we have enough stack space to push all arguments.
      // Clobbers r3 and r6.
      Generate_CheckStackOverflow(masm, r7, r3, r6);
  
      // r4: new.target
      // r5: function
      // r7: argc
      // r8: argv
      // r0,r3,r6,r9, cp may be clobbered
  
      // Setup new.target, argc and function.
      __ mr(r3, r7);
      __ mr(r6, r4);
      __ mr(r4, r5);
  
      // r3: argc
      // r4: function
      // r6: new.target
      // r8: argv
  
      // Copy arguments to the stack in a loop.
      // r4: function
      // r3: argc
      // r8: argv, i.e. points to first arg
      Label loop, entry;
      __ ShiftLeftImm(r0, r3, Operand(kPointerSizeLog2));
      __ add(r5, r8, r0);
      // r5 points past last arg.
      __ b(&entry);
      __ bind(&loop);
      __ LoadP(r9, MemOperand(r8));  // read next parameter
      __ addi(r8, r8, Operand(kPointerSize));
      __ LoadP(r0, MemOperand(r9));  // dereference handle
      __ push(r0);                   // push parameter
      __ bind(&entry);
      __ cmp(r8, r5);
      __ bne(&loop);
  
      // r3: argc
      // r4: function
      // r6: new.target
  
      // Initialize all JavaScript callee-saved registers, since they will be seen
      // by the garbage collector as part of handlers.
      __ LoadRoot(r7, RootIndex::kUndefinedValue);
      __ mr(r8, r7);
      __ mr(r14, r7);
      __ mr(r15, r7);
      __ mr(r16, r7);
      __ mr(r17, r7);
  
      // Invoke the code.
      Handle<Code> builtin = is_construct
                                 ? BUILTIN_CODE(masm->isolate(), Construct)
                                 : masm->isolate()->builtins()->Call();
      __ Call(builtin, RelocInfo::CODE_TARGET);
  
      // Exit the JS frame and remove the parameters (except function), and
      // return.
    }
    __ blr();
  
    // r3: result
  }
  
  void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, false);
  }
  
  void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, true);
  }
  
  void Builtins::Generate_RunMicrotasksTrampoline(MacroAssembler* masm) {
    // This expects two C++ function parameters passed by Invoke() in
    // execution.cc.
    //   r3: root_register_value
    //   r4: microtask_queue
  
    __ mr(RunMicrotasksDescriptor::MicrotaskQueueRegister(), r4);
    __ Jump(BUILTIN_CODE(masm->isolate(), RunMicrotasks), RelocInfo::CODE_TARGET);
  }
  
  static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                                                  Register optimized_code,
                                                  Register closure,
                                                  Register scratch1,
                                                  Register scratch2) {
    // Store code entry in the closure.
    __ StoreP(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset),
              r0);
    __ mr(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
    __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
                        kLRHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
                        OMIT_SMI_CHECK);
  }
  
  static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch) {
    Register args_count = scratch;
  
    // Get the arguments + receiver count.
    __ LoadP(args_count,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ lwz(args_count,
           FieldMemOperand(args_count, BytecodeArray::kParameterSizeOffset));
  
    // Leave the frame (also dropping the register file).
    __ LeaveFrame(StackFrame::INTERPRETED);
  
    __ add(sp, sp, args_count);
  }
  
  // Tail-call |function_id| if |smi_entry| == |marker|
  static void TailCallRuntimeIfMarkerEquals(MacroAssembler* masm,
                                            Register smi_entry,
                                            OptimizationMarker marker,
                                            Runtime::FunctionId function_id) {
    Label no_match;
    __ CmpSmiLiteral(smi_entry, Smi::FromEnum(marker), r0);
    __ bne(&no_match);
    GenerateTailCallToReturnedCode(masm, function_id);
    __ bind(&no_match);
  }
  
  static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
                                        Register optimized_code_entry,
                                        Register scratch) {
    // ----------- S t a t e -------------
    //  -- r6 : new target (preserved for callee if needed, and caller)
    //  -- r4 : target function (preserved for callee if needed, and caller)
    // -----------------------------------
    DCHECK(!AreAliased(r4, r6, optimized_code_entry, scratch));
  
    Register closure = r4;
  
    // Check if the optimized code is marked for deopt. If it is, call the
    // runtime to clear it.
    Label found_deoptimized_code;
    __ LoadP(scratch, FieldMemOperand(optimized_code_entry,
                                      Code::kCodeDataContainerOffset));
    __ LoadWordArith(
        scratch,
        FieldMemOperand(scratch, CodeDataContainer::kKindSpecificFlagsOffset));
    __ TestBit(scratch, Code::kMarkedForDeoptimizationBit, r0);
    __ bne(&found_deoptimized_code, cr0);
  
    // Optimized code is good, get it into the closure and link the closure
    // into the optimized functions list, then tail call the optimized code.
    ReplaceClosureCodeWithOptimizedCode(masm, optimized_code_entry, closure,
                                        scratch, r8);
    static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
    __ LoadCodeObjectEntry(r5, optimized_code_entry);
    __ Jump(r5);
  
    // Optimized code slot contains deoptimized code, evict it and re-enter
    // the closure's code.
    __ bind(&found_deoptimized_code);
    GenerateTailCallToReturnedCode(masm, Runtime::kEvictOptimizedCodeSlot);
  }
  
  static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
                                Register optimization_marker) {
    // ----------- S t a t e -------------
    //  -- r6 : new target (preserved for callee if needed, and caller)
    //  -- r4 : target function (preserved for callee if needed, and caller)
    //  -- feedback vector (preserved for caller if needed)
    //  -- optimization_marker : a Smi containing a non-zero optimization marker.
    // -----------------------------------
    DCHECK(!AreAliased(feedback_vector, r4, r6, optimization_marker));
  
    // TODO(v8:8394): The logging of first execution will break if
    // feedback vectors are not allocated. We need to find a different way of
    // logging these events if required.
    TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                  OptimizationMarker::kLogFirstExecution,
                                  Runtime::kFunctionFirstExecution);
    TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                  OptimizationMarker::kCompileOptimized,
                                  Runtime::kCompileOptimized_NotConcurrent);
    TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                  OptimizationMarker::kCompileOptimizedConcurrent,
                                  Runtime::kCompileOptimized_Concurrent);
  
    // Otherwise, the marker is InOptimizationQueue, so fall through hoping
    // that an interrupt will eventually update the slot with optimized code.
    if (FLAG_debug_code) {
      __ CmpSmiLiteral(optimization_marker,
                       Smi::FromEnum(OptimizationMarker::kInOptimizationQueue),
                       r0);
      __ Assert(eq, AbortReason::kExpectedOptimizationSentinel);
    }
  }
  
  // Advance the current bytecode offset. This simulates what all bytecode
  // handlers do upon completion of the underlying operation. Will bail out to a
  // label if the bytecode (without prefix) is a return bytecode.
  static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                            Register bytecode_array,
                                            Register bytecode_offset,
                                            Register bytecode, Register scratch1,
                                            Label* if_return) {
    Register bytecode_size_table = scratch1;
    Register scratch2 = bytecode;
    DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
                       bytecode));
    __ Move(bytecode_size_table,
            ExternalReference::bytecode_size_table_address());
  
    // Check if the bytecode is a Wide or ExtraWide prefix bytecode.
    Label process_bytecode, extra_wide;
    STATIC_ASSERT(0 == static_cast<int>(interpreter::Bytecode::kWide));
    STATIC_ASSERT(1 == static_cast<int>(interpreter::Bytecode::kExtraWide));
    STATIC_ASSERT(2 == static_cast<int>(interpreter::Bytecode::kDebugBreakWide));
    STATIC_ASSERT(3 ==
                  static_cast<int>(interpreter::Bytecode::kDebugBreakExtraWide));
    __ cmpi(bytecode, Operand(0x3));
    __ bgt(&process_bytecode);
    __ andi(r0, bytecode, Operand(0x1));
    __ bne(&extra_wide, cr0);
  
    // Load the next bytecode and update table to the wide scaled table.
    __ addi(bytecode_offset, bytecode_offset, Operand(1));
    __ lbzx(bytecode, MemOperand(bytecode_array, bytecode_offset));
    __ addi(bytecode_size_table, bytecode_size_table,
            Operand(kIntSize * interpreter::Bytecodes::kBytecodeCount));
    __ b(&process_bytecode);
  
    __ bind(&extra_wide);
    // Load the next bytecode and update table to the extra wide scaled table.
    __ addi(bytecode_offset, bytecode_offset, Operand(1));
    __ lbzx(bytecode, MemOperand(bytecode_array, bytecode_offset));
    __ addi(bytecode_size_table, bytecode_size_table,
            Operand(2 * kIntSize * interpreter::Bytecodes::kBytecodeCount));
  
    // Load the size of the current bytecode.
    __ bind(&process_bytecode);
  
  // Bailout to the return label if this is a return bytecode.
  #define JUMP_IF_EQUAL(NAME)                                           \
    __ cmpi(bytecode,                                                   \
            Operand(static_cast<int>(interpreter::Bytecode::k##NAME))); \
    __ beq(if_return);
    RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
  #undef JUMP_IF_EQUAL
  
    // Otherwise, load the size of the current bytecode and advance the offset.
    __ ShiftLeftImm(scratch2, bytecode, Operand(2));
    __ lwzx(scratch2, MemOperand(bytecode_size_table, scratch2));
    __ add(bytecode_offset, bytecode_offset, scratch2);
  }
  // Generate code for entering a JS function with the interpreter.
  // On entry to the function the receiver and arguments have been pushed on the
  // stack left to right.  The actual argument count matches the formal parameter
  // count expected by the function.
  //
  // The live registers are:
  //   o r4: the JS function object being called.
  //   o r6: the incoming new target or generator object
  //   o cp: our context
  //   o pp: the caller's constant pool pointer (if enabled)
  //   o fp: the caller's frame pointer
  //   o sp: stack pointer
  //   o lr: return address
  //
  // The function builds an interpreter frame.  See InterpreterFrameConstants in
  // frames.h for its layout.
  void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
    Register closure = r4;
    Register feedback_vector = r5;
  
    // Get the bytecode array from the function object and load it into
    // kInterpreterBytecodeArrayRegister.
    __ LoadP(r3, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    // Load original bytecode array or the debug copy.
    __ LoadP(kInterpreterBytecodeArrayRegister,
             FieldMemOperand(r3, SharedFunctionInfo::kFunctionDataOffset));
    GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister, r7);
  
    // The bytecode array could have been flushed from the shared function info,
    // if so, call into CompileLazy.
    Label compile_lazy;
    __ CompareObjectType(kInterpreterBytecodeArrayRegister, r3, no_reg,
                         BYTECODE_ARRAY_TYPE);
    __ bne(&compile_lazy);
  
    // Load the feedback vector from the closure.
    __ LoadP(feedback_vector,
             FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
    __ LoadP(feedback_vector,
             FieldMemOperand(feedback_vector, Cell::kValueOffset));
  
    Label push_stack_frame;
    // Check if feedback vector is valid. If valid, check for optimized code
    // and update invocation count. Otherwise, setup the stack frame.
    __ LoadP(r7, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
    __ LoadHalfWord(r7, FieldMemOperand(r7, Map::kInstanceTypeOffset));
    __ cmpi(r7, Operand(FEEDBACK_VECTOR_TYPE));
    __ bne(&push_stack_frame);
  
    Register optimized_code_entry = r7;
  
    // Read off the optimized code slot in the feedback vector.
    __ LoadP(optimized_code_entry,
             FieldMemOperand(feedback_vector,
                             FeedbackVector::kOptimizedCodeWeakOrSmiOffset));
    // Check if the optimized code slot is not empty.
    Label optimized_code_slot_not_empty;
    __ CmpSmiLiteral(optimized_code_entry,
                     Smi::FromEnum(OptimizationMarker::kNone), r0);
    __ bne(&optimized_code_slot_not_empty);
  
    Label not_optimized;
    __ bind(&not_optimized);
  
    // Increment invocation count for the function.
    __ LoadWord(
        r8,
        FieldMemOperand(feedback_vector, FeedbackVector::kInvocationCountOffset),
        r0);
    __ addi(r8, r8, Operand(1));
    __ StoreWord(
        r8,
        FieldMemOperand(feedback_vector, FeedbackVector::kInvocationCountOffset),
        r0);
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // MANUAL indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done below).
  
    __ bind(&push_stack_frame);
  
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ PushStandardFrame(closure);
  
    // Reset code age and the OSR arming. The OSR field and BytecodeAgeOffset are
    // 8-bit fields next to each other, so we could just optimize by writing a
    // 16-bit. These static asserts guard our assumption is valid.
    STATIC_ASSERT(BytecodeArray::kBytecodeAgeOffset ==
                  BytecodeArray::kOsrNestingLevelOffset + kCharSize);
    STATIC_ASSERT(BytecodeArray::kNoAgeBytecodeAge == 0);
    __ li(r8, Operand(0));
    __ StoreHalfWord(r8,
                     FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                     BytecodeArray::kOsrNestingLevelOffset),
                     r0);
  
    // Load initial bytecode offset.
    __ mov(kInterpreterBytecodeOffsetRegister,
           Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
  
    // Push bytecode array and Smi tagged bytecode array offset.
    __ SmiTag(r3, kInterpreterBytecodeOffsetRegister);
    __ Push(kInterpreterBytecodeArrayRegister, r3);
  
    // Allocate the local and temporary register file on the stack.
    Label stack_overflow;
    {
      // Load frame size (word) from the BytecodeArray object.
      __ lwz(r5, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                 BytecodeArray::kFrameSizeOffset));
  
      // Do a stack check to ensure we don't go over the limit.
      __ sub(r8, sp, r5);
      LoadRealStackLimit(masm, r0);
      __ cmpl(r8, r0);
      __ blt(&stack_overflow);
  
      // If ok, push undefined as the initial value for all register file entries.
      // TODO(rmcilroy): Consider doing more than one push per loop iteration.
      Label loop, no_args;
      __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
      __ ShiftRightImm(r5, r5, Operand(kPointerSizeLog2), SetRC);
      __ beq(&no_args, cr0);
      __ mtctr(r5);
      __ bind(&loop);
      __ push(kInterpreterAccumulatorRegister);
      __ bdnz(&loop);
      __ bind(&no_args);
    }
  
    // If the bytecode array has a valid incoming new target or generator object
    // register, initialize it with incoming value which was passed in r6.
    Label no_incoming_new_target_or_generator_register;
    __ LoadWordArith(
        r8, FieldMemOperand(
                kInterpreterBytecodeArrayRegister,
                BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
    __ cmpi(r8, Operand::Zero());
    __ beq(&no_incoming_new_target_or_generator_register);
    __ ShiftLeftImm(r8, r8, Operand(kPointerSizeLog2));
    __ StorePX(r6, MemOperand(fp, r8));
    __ bind(&no_incoming_new_target_or_generator_register);
  
    // The accumulator is already loaded with undefined.
  
    // Load the dispatch table into a register and dispatch to the bytecode
    // handler at the current bytecode offset.
    Label do_dispatch;
    __ bind(&do_dispatch);
    __ Move(
        kInterpreterDispatchTableRegister,
        ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
    __ lbzx(r6, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
    __ ShiftLeftImm(r6, r6, Operand(kPointerSizeLog2));
    __ LoadPX(kJavaScriptCallCodeStartRegister,
              MemOperand(kInterpreterDispatchTableRegister, r6));
    __ Call(kJavaScriptCallCodeStartRegister);
  
    masm->isolate()->heap()->SetInterpreterEntryReturnPCOffset(masm->pc_offset());
  
    // Any returns to the entry trampoline are either due to the return bytecode
    // or the interpreter tail calling a builtin and then a dispatch.
  
    // Get bytecode array and bytecode offset from the stack frame.
    __ LoadP(kInterpreterBytecodeArrayRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ LoadP(kInterpreterBytecodeOffsetRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Either return, or advance to the next bytecode and dispatch.
    Label do_return;
    __ lbzx(r4, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, r4, r5,
                                  &do_return);
    __ b(&do_dispatch);
  
    __ bind(&do_return);
    // The return value is in r3.
    LeaveInterpreterFrame(masm, r5);
    __ blr();
  
    __ bind(&optimized_code_slot_not_empty);
    Label maybe_has_optimized_code;
    // Check if optimized code marker is actually a weak reference to the
    // optimized code.
    __ JumpIfNotSmi(optimized_code_entry, &maybe_has_optimized_code);
    MaybeOptimizeCode(masm, feedback_vector, optimized_code_entry);
    // Fall through if there's no runnable optimized code.
    __ jmp(&not_optimized);
  
    __ bind(&maybe_has_optimized_code);
    // Load code entry from the weak reference, if it was cleared, resume
    // execution of unoptimized code.
    __ LoadWeakValue(optimized_code_entry, optimized_code_entry, &not_optimized);
    TailCallOptimizedCodeSlot(masm, optimized_code_entry, r9);
  
    __ bind(&compile_lazy);
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
  
    __ bind(&stack_overflow);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    __ bkpt(0);  // Should not return.
  }
  
  static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                           Register num_args, Register index,
                                           Register count, Register scratch) {
    Label loop, skip;
    __ cmpi(count, Operand::Zero());
    __ beq(&skip);
    __ addi(index, index, Operand(kPointerSize));  // Bias up for LoadPU
    __ mtctr(count);
    __ bind(&loop);
    __ LoadPU(scratch, MemOperand(index, -kPointerSize));
    __ push(scratch);
    __ bdnz(&loop);
    __ bind(&skip);
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsThenCallImpl(
      MacroAssembler* masm, ConvertReceiverMode receiver_mode,
      InterpreterPushArgsMode mode) {
    DCHECK(mode != InterpreterPushArgsMode::kArrayFunction);
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r5 : 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.
    //  -- r4 : the target to call (can be any Object).
    // -----------------------------------
    Label stack_overflow;
  
    // Calculate number of arguments (add one for receiver).
    __ addi(r6, r3, Operand(1));
  
    Generate_StackOverflowCheck(masm, r6, ip, &stack_overflow);
  
    // Push "undefined" as the receiver arg if we need to.
    if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
      __ PushRoot(RootIndex::kUndefinedValue);
      __ mr(r6, r3);  // Argument count is correct.
    }
  
    // Push the arguments. r5, r6, r7 will be modified.
    Generate_InterpreterPushArgs(masm, r6, r5, r6, r7);
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      __ Pop(r5);                   // Pass the spread in a register
      __ subi(r3, r3, Operand(1));  // Subtract one for spread
    }
  
    // Call the target.
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      __ Jump(BUILTIN_CODE(masm->isolate(), CallWithSpread),
              RelocInfo::CODE_TARGET);
    } else {
      __ Jump(masm->isolate()->builtins()->Call(ConvertReceiverMode::kAny),
              RelocInfo::CODE_TARGET);
    }
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      // Unreachable Code.
      __ bkpt(0);
    }
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
      MacroAssembler* masm, InterpreterPushArgsMode mode) {
    // ----------- S t a t e -------------
    // -- r3 : argument count (not including receiver)
    // -- r6 : new target
    // -- r4 : constructor to call
    // -- r5 : allocation site feedback if available, undefined otherwise.
    // -- r7 : address of the first argument
    // -----------------------------------
    Label stack_overflow;
  
    // Push a slot for the receiver to be constructed.
    __ li(r0, Operand::Zero());
    __ push(r0);
  
    // Push the arguments (skip if none).
    Label skip;
    __ cmpi(r3, Operand::Zero());
    __ beq(&skip);
    Generate_StackOverflowCheck(masm, r3, ip, &stack_overflow);
    // Push the arguments. r8, r7, r9 will be modified.
    Generate_InterpreterPushArgs(masm, r3, r7, r3, r9);
    __ bind(&skip);
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      __ Pop(r5);                   // Pass the spread in a register
      __ subi(r3, r3, Operand(1));  // Subtract one for spread
    } else {
      __ AssertUndefinedOrAllocationSite(r5, r8);
    }
    if (mode == InterpreterPushArgsMode::kArrayFunction) {
      __ AssertFunction(r4);
  
      // Tail call to the array construct stub (still in the caller
      // context at this point).
      Handle<Code> code = BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl);
      __ Jump(code, RelocInfo::CODE_TARGET);
    } else if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // Call the constructor with r3, r4, and r6 unmodified.
      __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithSpread),
              RelocInfo::CODE_TARGET);
    } else {
      DCHECK_EQ(InterpreterPushArgsMode::kOther, mode);
      // Call the constructor with r3, r4, and r6 unmodified.
      __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
    }
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      // Unreachable Code.
      __ bkpt(0);
    }
  }
  
  static void Generate_InterpreterEnterBytecode(MacroAssembler* masm) {
    // Set the return address to the correct point in the interpreter entry
    // trampoline.
    Label builtin_trampoline, trampoline_loaded;
    Smi interpreter_entry_return_pc_offset(
        masm->isolate()->heap()->interpreter_entry_return_pc_offset());
    DCHECK_NE(interpreter_entry_return_pc_offset, Smi::zero());
  
    // If the SFI function_data is an InterpreterData, the function will have a
    // custom copy of the interpreter entry trampoline for profiling. If so,
    // get the custom trampoline, otherwise grab the entry address of the global
    // trampoline.
    __ LoadP(r5, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
    __ LoadP(r5, FieldMemOperand(r5, JSFunction::kSharedFunctionInfoOffset));
    __ LoadP(r5, FieldMemOperand(r5, SharedFunctionInfo::kFunctionDataOffset));
    __ CompareObjectType(r5, kInterpreterDispatchTableRegister,
                         kInterpreterDispatchTableRegister,
                         INTERPRETER_DATA_TYPE);
    __ bne(&builtin_trampoline);
  
    __ LoadP(r5,
             FieldMemOperand(r5, InterpreterData::kInterpreterTrampolineOffset));
    __ addi(r5, r5, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ b(&trampoline_loaded);
  
    __ bind(&builtin_trampoline);
    __ Move(r5, ExternalReference::
                    address_of_interpreter_entry_trampoline_instruction_start(
                        masm->isolate()));
    __ LoadP(r5, MemOperand(r5));
  
    __ bind(&trampoline_loaded);
    __ addi(r0, r5, Operand(interpreter_entry_return_pc_offset.value()));
    __ mtlr(r0);
  
    // Initialize the dispatch table register.
    __ Move(
        kInterpreterDispatchTableRegister,
        ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
  
    // Get the bytecode array pointer from the frame.
    __ LoadP(kInterpreterBytecodeArrayRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  
    if (FLAG_debug_code) {
      // Check function data field is actually a BytecodeArray object.
      __ TestIfSmi(kInterpreterBytecodeArrayRegister, r0);
      __ Assert(ne,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                cr0);
      __ CompareObjectType(kInterpreterBytecodeArrayRegister, r4, no_reg,
                           BYTECODE_ARRAY_TYPE);
      __ Assert(
          eq, AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry);
    }
  
    // Get the target bytecode offset from the frame.
    __ LoadP(kInterpreterBytecodeOffsetRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Dispatch to the target bytecode.
    UseScratchRegisterScope temps(masm);
    Register scratch = temps.Acquire();
    __ lbzx(ip, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
    __ ShiftLeftImm(scratch, scratch, Operand(kPointerSizeLog2));
    __ LoadPX(kJavaScriptCallCodeStartRegister,
              MemOperand(kInterpreterDispatchTableRegister, scratch));
    __ Jump(kJavaScriptCallCodeStartRegister);
  }
  
  void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
    // Get bytecode array and bytecode offset from the stack frame.
    __ LoadP(kInterpreterBytecodeArrayRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ LoadP(kInterpreterBytecodeOffsetRegister,
             MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Load the current bytecode.
    __ lbzx(r4, MemOperand(kInterpreterBytecodeArrayRegister,
                           kInterpreterBytecodeOffsetRegister));
  
    // Advance to the next bytecode.
    Label if_return;
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, r4, r5,
                                  &if_return);
  
    // Convert new bytecode offset to a Smi and save in the stackframe.
    __ SmiTag(r5, kInterpreterBytecodeOffsetRegister);
    __ StoreP(r5,
              MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
  
    Generate_InterpreterEnterBytecode(masm);
  
    // We should never take the if_return path.
    __ bind(&if_return);
    __ Abort(AbortReason::kInvalidBytecodeAdvance);
  }
  
  void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
    Generate_InterpreterEnterBytecode(masm);
  }
  
  void Builtins::Generate_InstantiateAsmJs(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : argument count (preserved for callee)
    //  -- r4 : new target (preserved for callee)
    //  -- r6 : target function (preserved for callee)
    // -----------------------------------
    Label failed;
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Preserve argument count for later compare.
      __ Move(r7, r3);
      // Push a copy of the target function and the new target.
      // Push function as parameter to the runtime call.
      __ SmiTag(r3);
      __ Push(r3, r4, r6, r4);
  
      // Copy arguments from caller (stdlib, foreign, heap).
      Label args_done;
      for (int j = 0; j < 4; ++j) {
        Label over;
        if (j < 3) {
          __ cmpi(r7, Operand(j));
          __ bne(&over);
        }
        for (int i = j - 1; i >= 0; --i) {
          __ LoadP(r7, MemOperand(fp, StandardFrameConstants::kCallerSPOffset +
                                          i * kPointerSize));
          __ push(r7);
        }
        for (int i = 0; i < 3 - j; ++i) {
          __ PushRoot(RootIndex::kUndefinedValue);
        }
        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(r3, &failed);
  
      __ Drop(2);
      __ pop(r7);
      __ SmiUntag(r7);
      scope.GenerateLeaveFrame();
  
      __ addi(r7, r7, Operand(1));
      __ Drop(r7);
      __ Ret();
  
      __ bind(&failed);
      // Restore target function and new target.
      __ Pop(r3, r4, r6);
      __ SmiUntag(r3);
    }
    // On failure, tail call back to regular js by re-calling the function
    // which has be reset to the compile lazy builtin.
    static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
    __ LoadP(r5, FieldMemOperand(r4, JSFunction::kCodeOffset));
    __ JumpCodeObject(r5);
  }
  
  namespace {
  void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                                        bool java_script_builtin,
                                        bool with_result) {
    const RegisterConfiguration* config(RegisterConfiguration::Default());
    int allocatable_register_count = config->num_allocatable_general_registers();
    if (with_result) {
      // Overwrite the hole inserted by the deoptimizer with the return value from
      // the LAZY deopt point.
      __ StoreP(
          r3, MemOperand(
                  sp, config->num_allocatable_general_registers() * kPointerSize +
                          BuiltinContinuationFrameConstants::kFixedFrameSize));
    }
    for (int i = allocatable_register_count - 1; i >= 0; --i) {
      int code = config->GetAllocatableGeneralCode(i);
      __ Pop(Register::from_code(code));
      if (java_script_builtin && code == kJavaScriptCallArgCountRegister.code()) {
        __ SmiUntag(Register::from_code(code));
      }
    }
    __ LoadP(
        fp,
        MemOperand(sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    // Load builtin index (stored as a Smi) and use it to get the builtin start
    // address from the builtins table.
    UseScratchRegisterScope temps(masm);
    Register builtin = temps.Acquire();
    __ Pop(builtin);
    __ addi(sp, sp,
            Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    __ Pop(r0);
    __ mtlr(r0);
    __ LoadEntryFromBuiltinIndex(builtin);
    __ Jump(builtin);
  }
  }  // namespace
  
  void Builtins::Generate_ContinueToCodeStubBuiltin(MacroAssembler* masm) {
    Generate_ContinueToBuiltinHelper(masm, false, false);
  }
  
  void Builtins::Generate_ContinueToCodeStubBuiltinWithResult(
      MacroAssembler* masm) {
    Generate_ContinueToBuiltinHelper(masm, false, true);
  }
  
  void Builtins::Generate_ContinueToJavaScriptBuiltin(MacroAssembler* masm) {
    Generate_ContinueToBuiltinHelper(masm, true, false);
  }
  
  void Builtins::Generate_ContinueToJavaScriptBuiltinWithResult(
      MacroAssembler* masm) {
    Generate_ContinueToBuiltinHelper(masm, true, true);
  }
  
  void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kNotifyDeoptimized);
    }
  
    DCHECK_EQ(kInterpreterAccumulatorRegister.code(), r3.code());
    __ LoadP(r3, MemOperand(sp, 0 * kPointerSize));
    __ addi(sp, sp, Operand(1 * kPointerSize));
    __ Ret();
  }
  
  void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kCompileForOnStackReplacement);
    }
  
    // If the code object is null, just return to the caller.
    Label skip;
    __ CmpSmiLiteral(r3, Smi::zero(), r0);
    __ bne(&skip);
    __ Ret();
  
    __ bind(&skip);
  
    // Drop the handler frame that is be sitting on top of the actual
    // JavaScript frame. This is the case then OSR is triggered from bytecode.
    __ LeaveFrame(StackFrame::STUB);
  
    // Load deoptimization data from the code object.
    // <deopt_data> = <code>[#deoptimization_data_offset]
    __ LoadP(r4, FieldMemOperand(r3, Code::kDeoptimizationDataOffset));
  
    {
      ConstantPoolUnavailableScope constant_pool_unavailable(masm);
      __ addi(r3, r3, Operand(Code::kHeaderSize - kHeapObjectTag));  // Code start
  
      if (FLAG_enable_embedded_constant_pool) {
        __ LoadConstantPoolPointerRegisterFromCodeTargetAddress(r3);
      }
  
      // Load the OSR entrypoint offset from the deoptimization data.
      // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
      __ LoadP(r4,
               FieldMemOperand(r4, FixedArray::OffsetOfElementAt(
                                       DeoptimizationData::kOsrPcOffsetIndex)));
      __ SmiUntag(r4);
  
      // Compute the target address = code start + osr_offset
      __ add(r0, r3, r4);
  
      // And "return" to the OSR entry point of the function.
      __ mtlr(r0);
      __ blr();
    }
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3    : argc
    //  -- sp[0] : argArray
    //  -- sp[4] : thisArg
    //  -- sp[8] : receiver
    // -----------------------------------
  
    // 1. Load receiver into r4, argArray into r5 (if present), remove all
    // arguments from the stack (including the receiver), and push thisArg (if
    // present) instead.
    {
      Label skip;
      Register arg_size = r8;
      Register new_sp = r6;
      Register scratch = r7;
      __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
      __ add(new_sp, sp, arg_size);
      __ LoadRoot(scratch, RootIndex::kUndefinedValue);
      __ mr(r5, scratch);
      __ LoadP(r4, MemOperand(new_sp, 0));  // receiver
      __ cmpi(arg_size, Operand(kPointerSize));
      __ blt(&skip);
      __ LoadP(scratch, MemOperand(new_sp, 1 * -kPointerSize));  // thisArg
      __ beq(&skip);
      __ LoadP(r5, MemOperand(new_sp, 2 * -kPointerSize));  // argArray
      __ bind(&skip);
      __ mr(sp, new_sp);
      __ StoreP(scratch, MemOperand(sp, 0));
    }
  
    // ----------- S t a t e -------------
    //  -- r5    : argArray
    //  -- r4    : receiver
    //  -- sp[0] : thisArg
    // -----------------------------------
  
    // 2. We don't need to check explicitly for callable receiver here,
    // since that's the first thing the Call/CallWithArrayLike builtins
    // will do.
  
    // 3. Tail call with no arguments if argArray is null or undefined.
    Label no_arguments;
    __ JumpIfRoot(r5, RootIndex::kNullValue, &no_arguments);
    __ JumpIfRoot(r5, RootIndex::kUndefinedValue, &no_arguments);
  
    // 4a. Apply the receiver to the given argArray.
    __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
            RelocInfo::CODE_TARGET);
  
    // 4b. The argArray is either null or undefined, so we tail call without any
    // arguments to the receiver.
    __ bind(&no_arguments);
    {
      __ li(r3, Operand::Zero());
      __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    }
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
    // 1. Make sure we have at least one argument.
    // r3: actual number of arguments
    {
      Label done;
      __ cmpi(r3, Operand::Zero());
      __ bne(&done);
      __ PushRoot(RootIndex::kUndefinedValue);
      __ addi(r3, r3, Operand(1));
      __ bind(&done);
    }
  
    // 2. Get the callable to call (passed as receiver) from the stack.
    // r3: actual number of arguments
    __ ShiftLeftImm(r5, r3, Operand(kPointerSizeLog2));
    __ LoadPX(r4, MemOperand(sp, r5));
  
    // 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.
    // r3: actual number of arguments
    // r4: callable
    {
      Register scratch = r6;
      Label loop;
      // Calculate the copy start address (destination). Copy end address is sp.
      __ add(r5, sp, r5);
  
      __ mtctr(r3);
      __ bind(&loop);
      __ LoadP(scratch, MemOperand(r5, -kPointerSize));
      __ StoreP(scratch, MemOperand(r5));
      __ subi(r5, r5, Operand(kPointerSize));
      __ bdnz(&loop);
      // Adjust the actual number of arguments and remove the top element
      // (which is a copy of the last argument).
      __ subi(r3, r3, Operand(1));
      __ pop();
    }
  
    // 4. Call the callable.
    __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
  }
  
  void Builtins::Generate_ReflectApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3     : argc
    //  -- sp[0]  : argumentsList
    //  -- sp[4]  : thisArgument
    //  -- sp[8]  : target
    //  -- sp[12] : receiver
    // -----------------------------------
  
    // 1. Load target into r4 (if present), argumentsList into r5 (if present),
    // remove all arguments from the stack (including the receiver), and push
    // thisArgument (if present) instead.
    {
      Label skip;
      Register arg_size = r8;
      Register new_sp = r6;
      Register scratch = r7;
      __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
      __ add(new_sp, sp, arg_size);
      __ LoadRoot(r4, RootIndex::kUndefinedValue);
      __ mr(scratch, r4);
      __ mr(r5, r4);
      __ cmpi(arg_size, Operand(kPointerSize));
      __ blt(&skip);
      __ LoadP(r4, MemOperand(new_sp, 1 * -kPointerSize));  // target
      __ beq(&skip);
      __ LoadP(scratch, MemOperand(new_sp, 2 * -kPointerSize));  // thisArgument
      __ cmpi(arg_size, Operand(2 * kPointerSize));
      __ beq(&skip);
      __ LoadP(r5, MemOperand(new_sp, 3 * -kPointerSize));  // argumentsList
      __ bind(&skip);
      __ mr(sp, new_sp);
      __ StoreP(scratch, MemOperand(sp, 0));
    }
  
    // ----------- S t a t e -------------
    //  -- r5    : argumentsList
    //  -- r4    : target
    //  -- sp[0] : thisArgument
    // -----------------------------------
  
    // 2. We don't need to check explicitly for callable target here,
    // since that's the first thing the Call/CallWithArrayLike builtins
    // will do.
  
    // 3. Apply the target to the given argumentsList.
    __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
            RelocInfo::CODE_TARGET);
  }
  
  void Builtins::Generate_ReflectConstruct(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3     : argc
    //  -- sp[0]  : new.target (optional)
    //  -- sp[4]  : argumentsList
    //  -- sp[8]  : target
    //  -- sp[12] : receiver
    // -----------------------------------
  
    // 1. Load target into r4 (if present), argumentsList into r5 (if present),
    // new.target into r6 (if present, otherwise use target), remove all
    // arguments from the stack (including the receiver), and push thisArgument
    // (if present) instead.
    {
      Label skip;
      Register arg_size = r8;
      Register new_sp = r7;
      __ ShiftLeftImm(arg_size, r3, Operand(kPointerSizeLog2));
      __ add(new_sp, sp, arg_size);
      __ LoadRoot(r4, RootIndex::kUndefinedValue);
      __ mr(r5, r4);
      __ mr(r6, r4);
      __ StoreP(r4, MemOperand(new_sp, 0));  // receiver (undefined)
      __ cmpi(arg_size, Operand(kPointerSize));
      __ blt(&skip);
      __ LoadP(r4, MemOperand(new_sp, 1 * -kPointerSize));  // target
      __ mr(r6, r4);  // new.target defaults to target
      __ beq(&skip);
      __ LoadP(r5, MemOperand(new_sp, 2 * -kPointerSize));  // argumentsList
      __ cmpi(arg_size, Operand(2 * kPointerSize));
      __ beq(&skip);
      __ LoadP(r6, MemOperand(new_sp, 3 * -kPointerSize));  // new.target
      __ bind(&skip);
      __ mr(sp, new_sp);
    }
  
    // ----------- S t a t e -------------
    //  -- r5    : argumentsList
    //  -- r6    : new.target
    //  -- r4    : target
    //  -- sp[0] : receiver (undefined)
    // -----------------------------------
  
    // 2. We don't need to check explicitly for constructor target here,
    // since that's the first thing the Construct/ConstructWithArrayLike
    // builtins will do.
  
    // 3. We don't need to check explicitly for constructor new.target here,
    // since that's the second thing the Construct/ConstructWithArrayLike
    // builtins will do.
  
    // 4. Construct the target with the given new.target and argumentsList.
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithArrayLike),
            RelocInfo::CODE_TARGET);
  }
  
  static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
    __ SmiTag(r3);
    __ mov(r7, Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
    __ mflr(r0);
    __ push(r0);
    if (FLAG_enable_embedded_constant_pool) {
      __ Push(fp, kConstantPoolRegister, r7, r4, r3);
    } else {
      __ Push(fp, r7, r4, r3);
    }
    __ Push(Smi::zero());  // Padding.
    __ addi(fp, sp,
            Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp));
  }
  
  static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : result being passed through
    // -----------------------------------
    // Get the number of arguments passed (as a smi), tear down the frame and
    // then tear down the parameters.
    __ LoadP(r4, MemOperand(fp, ArgumentsAdaptorFrameConstants::kLengthOffset));
    int stack_adjustment = kPointerSize;  // adjust for receiver
    __ LeaveFrame(StackFrame::ARGUMENTS_ADAPTOR, stack_adjustment);
    __ SmiToPtrArrayOffset(r0, r4);
    __ add(sp, sp, r0);
  }
  
  // static
  void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                 Handle<Code> code) {
    // ----------- S t a t e -------------
    //  -- r4 : target
    //  -- r3 : number of parameters on the stack (not including the receiver)
    //  -- r5 : arguments list (a FixedArray)
    //  -- r7 : len (number of elements to push from args)
    //  -- r6 : new.target (for [[Construct]])
    // -----------------------------------
  
    Register scratch = ip;
  
    if (masm->emit_debug_code()) {
      // Allow r5 to be a FixedArray, or a FixedDoubleArray if r7 == 0.
      Label ok, fail;
      __ AssertNotSmi(r5);
      __ LoadP(scratch, FieldMemOperand(r5, HeapObject::kMapOffset));
      __ LoadHalfWord(scratch,
                      FieldMemOperand(scratch, Map::kInstanceTypeOffset));
      __ cmpi(scratch, Operand(FIXED_ARRAY_TYPE));
      __ beq(&ok);
      __ cmpi(scratch, Operand(FIXED_DOUBLE_ARRAY_TYPE));
      __ bne(&fail);
      __ cmpi(r7, Operand::Zero());
      __ beq(&ok);
      // Fall through.
      __ bind(&fail);
      __ Abort(AbortReason::kOperandIsNotAFixedArray);
  
      __ bind(&ok);
    }
  
    // Check for stack overflow.
    Label stack_overflow;
    Generate_StackOverflowCheck(masm, r7, scratch, &stack_overflow);
  
    // Push arguments onto the stack (thisArgument is already on the stack).
    {
      Label loop, no_args, skip;
      __ cmpi(r7, Operand::Zero());
      __ beq(&no_args);
      __ addi(r5, r5,
              Operand(FixedArray::kHeaderSize - kHeapObjectTag - kPointerSize));
      __ mtctr(r7);
      __ bind(&loop);
      __ LoadPU(scratch, MemOperand(r5, kPointerSize));
      __ CompareRoot(scratch, RootIndex::kTheHoleValue);
      __ bne(&skip);
      __ LoadRoot(scratch, RootIndex::kUndefinedValue);
      __ bind(&skip);
      __ push(scratch);
      __ bdnz(&loop);
      __ bind(&no_args);
      __ add(r3, r3, r7);
    }
  
    // Tail-call to the actual Call or Construct builtin.
    __ Jump(code, RelocInfo::CODE_TARGET);
  
    __ bind(&stack_overflow);
    __ TailCallRuntime(Runtime::kThrowStackOverflow);
  }
  
  // static
  void Builtins::Generate_CallOrConstructForwardVarargs(MacroAssembler* masm,
                                                        CallOrConstructMode mode,
                                                        Handle<Code> code) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r6 : the new.target (for [[Construct]] calls)
    //  -- r4 : the target to call (can be any Object)
    //  -- r5 : start index (to support rest parameters)
    // -----------------------------------
  
    Register scratch = r9;
  
    if (mode == CallOrConstructMode::kConstruct) {
      Label new_target_constructor, new_target_not_constructor;
      __ JumpIfSmi(r6, &new_target_not_constructor);
      __ LoadP(scratch, FieldMemOperand(r6, HeapObject::kMapOffset));
      __ lbz(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
      __ TestBit(scratch, Map::IsConstructorBit::kShift, r0);
      __ bne(&new_target_constructor, cr0);
      __ bind(&new_target_not_constructor);
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ Push(r6);
        __ CallRuntime(Runtime::kThrowNotConstructor);
      }
      __ bind(&new_target_constructor);
    }
  
    // Check if we have an arguments adaptor frame below the function frame.
    Label arguments_adaptor, arguments_done;
    __ LoadP(r7, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ LoadP(scratch,
             MemOperand(r7, CommonFrameConstants::kContextOrFrameTypeOffset));
    __ cmpi(scratch,
            Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
    __ beq(&arguments_adaptor);
    {
      __ LoadP(r8, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
      __ LoadP(r8, FieldMemOperand(r8, JSFunction::kSharedFunctionInfoOffset));
      __ LoadHalfWord(
          r8,
          FieldMemOperand(r8, SharedFunctionInfo::kFormalParameterCountOffset));
      __ mr(r7, fp);
    }
    __ b(&arguments_done);
    __ bind(&arguments_adaptor);
    {
      // Load the length from the ArgumentsAdaptorFrame.
      __ LoadP(r8, MemOperand(r7, ArgumentsAdaptorFrameConstants::kLengthOffset));
      __ SmiUntag(r8);
    }
    __ bind(&arguments_done);
  
    Label stack_done, stack_overflow;
    __ sub(r8, r8, r5);
    __ cmpi(r8, Operand::Zero());
    __ ble(&stack_done);
    {
      // Check for stack overflow.
      Generate_StackOverflowCheck(masm, r8, r5, &stack_overflow);
  
      // Forward the arguments from the caller frame.
      {
        Label loop;
        __ addi(r7, r7, Operand(kPointerSize));
        __ add(r3, r3, r8);
        __ bind(&loop);
        {
          __ ShiftLeftImm(scratch, r8, Operand(kPointerSizeLog2));
          __ LoadPX(scratch, MemOperand(r7, scratch));
          __ push(scratch);
          __ subi(r8, r8, Operand(1));
          __ cmpi(r8, Operand::Zero());
          __ bne(&loop);
        }
      }
    }
    __ b(&stack_done);
    __ bind(&stack_overflow);
    __ TailCallRuntime(Runtime::kThrowStackOverflow);
    __ bind(&stack_done);
  
    // Tail-call to the {code} handler.
    __ Jump(code, RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_CallFunction(MacroAssembler* masm,
                                       ConvertReceiverMode mode) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the function to call (checked to be a JSFunction)
    // -----------------------------------
    __ AssertFunction(r4);
  
    // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
    // Check that the function is not a "classConstructor".
    Label class_constructor;
    __ LoadP(r5, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
    __ lwz(r6, FieldMemOperand(r5, SharedFunctionInfo::kFlagsOffset));
    __ TestBitMask(r6, SharedFunctionInfo::IsClassConstructorBit::kMask, r0);
    __ bne(&class_constructor, cr0);
  
    // 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.
    __ LoadP(cp, FieldMemOperand(r4, JSFunction::kContextOffset));
    // We need to convert the receiver for non-native sloppy mode functions.
    Label done_convert;
    __ andi(r0, r6,
            Operand(SharedFunctionInfo::IsStrictBit::kMask |
                    SharedFunctionInfo::IsNativeBit::kMask));
    __ bne(&done_convert, cr0);
    {
      // ----------- S t a t e -------------
      //  -- r3 : the number of arguments (not including the receiver)
      //  -- r4 : the function to call (checked to be a JSFunction)
      //  -- r5 : the shared function info.
      //  -- cp : the function context.
      // -----------------------------------
  
      if (mode == ConvertReceiverMode::kNullOrUndefined) {
        // Patch receiver to global proxy.
        __ LoadGlobalProxy(r6);
      } else {
        Label convert_to_object, convert_receiver;
        __ ShiftLeftImm(r6, r3, Operand(kPointerSizeLog2));
        __ LoadPX(r6, MemOperand(sp, r6));
        __ JumpIfSmi(r6, &convert_to_object);
        STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
        __ CompareObjectType(r6, r7, r7, FIRST_JS_RECEIVER_TYPE);
        __ bge(&done_convert);
        if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
          Label convert_global_proxy;
          __ JumpIfRoot(r6, RootIndex::kUndefinedValue, &convert_global_proxy);
          __ JumpIfNotRoot(r6, RootIndex::kNullValue, &convert_to_object);
          __ bind(&convert_global_proxy);
          {
            // Patch receiver to global proxy.
            __ LoadGlobalProxy(r6);
          }
          __ 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?)
          FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
          __ SmiTag(r3);
          __ Push(r3, r4);
          __ mr(r3, r6);
          __ Push(cp);
          __ Call(BUILTIN_CODE(masm->isolate(), ToObject),
                  RelocInfo::CODE_TARGET);
          __ Pop(cp);
          __ mr(r6, r3);
          __ Pop(r3, r4);
          __ SmiUntag(r3);
        }
        __ LoadP(r5, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
        __ bind(&convert_receiver);
      }
      __ ShiftLeftImm(r7, r3, Operand(kPointerSizeLog2));
      __ StorePX(r6, MemOperand(sp, r7));
    }
    __ bind(&done_convert);
  
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the function to call (checked to be a JSFunction)
    //  -- r5 : the shared function info.
    //  -- cp : the function context.
    // -----------------------------------
  
    __ LoadHalfWord(
        r5, FieldMemOperand(r5, SharedFunctionInfo::kFormalParameterCountOffset));
    __ InvokeFunctionCode(r4, no_reg, r5, r3, JUMP_FUNCTION);
  
    // The function is a "classConstructor", need to raise an exception.
    __ bind(&class_constructor);
    {
      FrameAndConstantPoolScope frame(masm, StackFrame::INTERNAL);
      __ push(r4);
      __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
    }
  }
  
  namespace {
  
  void Generate_PushBoundArguments(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : target (checked to be a JSBoundFunction)
    //  -- r6 : new.target (only in case of [[Construct]])
    // -----------------------------------
  
    // Load [[BoundArguments]] into r5 and length of that into r7.
    Label no_bound_arguments;
    __ LoadP(r5, FieldMemOperand(r4, JSBoundFunction::kBoundArgumentsOffset));
    __ LoadP(r7, FieldMemOperand(r5, FixedArray::kLengthOffset));
    __ SmiUntag(r7, SetRC);
    __ beq(&no_bound_arguments, cr0);
    {
      // ----------- S t a t e -------------
      //  -- r3 : the number of arguments (not including the receiver)
      //  -- r4 : target (checked to be a JSBoundFunction)
      //  -- r5 : the [[BoundArguments]] (implemented as FixedArray)
      //  -- r6 : new.target (only in case of [[Construct]])
      //  -- r7 : the number of [[BoundArguments]]
      // -----------------------------------
  
      Register scratch = r9;
      // Reserve stack space for the [[BoundArguments]].
      {
        Label done;
        __ mr(scratch, sp);  // preserve previous stack pointer
        __ ShiftLeftImm(r10, r7, Operand(kPointerSizeLog2));
        __ sub(sp, sp, r10);
        // 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".
        {
          UseScratchRegisterScope temps(masm);
          Register scratch = temps.Acquire();
          LoadRealStackLimit(masm, scratch);
          __ cmpl(sp, scratch);
        }
        __ bgt(&done);  // Signed comparison.
        // Restore the stack pointer.
        __ mr(sp, scratch);
        {
          FrameScope scope(masm, StackFrame::MANUAL);
          __ EnterFrame(StackFrame::INTERNAL);
          __ CallRuntime(Runtime::kThrowStackOverflow);
        }
        __ bind(&done);
      }
  
      // Relocate arguments down the stack.
      //  -- r3 : the number of arguments (not including the receiver)
      //  -- r9 : the previous stack pointer
      //  -- r10: the size of the [[BoundArguments]]
      {
        Label skip, loop;
        __ li(r8, Operand::Zero());
        __ cmpi(r3, Operand::Zero());
        __ beq(&skip);
        __ mtctr(r3);
        __ bind(&loop);
        __ LoadPX(r0, MemOperand(scratch, r8));
        __ StorePX(r0, MemOperand(sp, r8));
        __ addi(r8, r8, Operand(kPointerSize));
        __ bdnz(&loop);
        __ bind(&skip);
      }
  
      // Copy [[BoundArguments]] to the stack (below the arguments).
      {
        Label loop;
        __ addi(r5, r5, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
        __ add(r5, r5, r10);
        __ mtctr(r7);
        __ bind(&loop);
        __ LoadPU(r0, MemOperand(r5, -kPointerSize));
        __ StorePX(r0, MemOperand(sp, r8));
        __ addi(r8, r8, Operand(kPointerSize));
        __ bdnz(&loop);
        __ add(r3, r3, r7);
      }
    }
    __ bind(&no_bound_arguments);
  }
  
  }  // namespace
  
  // static
  void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the function to call (checked to be a JSBoundFunction)
    // -----------------------------------
    __ AssertBoundFunction(r4);
  
    // Patch the receiver to [[BoundThis]].
    __ LoadP(r6, FieldMemOperand(r4, JSBoundFunction::kBoundThisOffset));
    __ ShiftLeftImm(r0, r3, Operand(kPointerSizeLog2));
    __ StorePX(r6, MemOperand(sp, r0));
  
    // Push the [[BoundArguments]] onto the stack.
    Generate_PushBoundArguments(masm);
  
    // Call the [[BoundTargetFunction]] via the Call builtin.
    __ LoadP(r4,
             FieldMemOperand(r4, JSBoundFunction::kBoundTargetFunctionOffset));
    __ Jump(BUILTIN_CODE(masm->isolate(), Call_ReceiverIsAny),
            RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the target to call (can be any Object).
    // -----------------------------------
  
    Label non_callable, non_smi;
    __ JumpIfSmi(r4, &non_callable);
    __ bind(&non_smi);
    __ CompareObjectType(r4, r7, r8, JS_FUNCTION_TYPE);
    __ Jump(masm->isolate()->builtins()->CallFunction(mode),
            RelocInfo::CODE_TARGET, eq);
    __ cmpi(r8, Operand(JS_BOUND_FUNCTION_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), CallBoundFunction),
            RelocInfo::CODE_TARGET, eq);
  
    // Check if target has a [[Call]] internal method.
    __ lbz(r7, FieldMemOperand(r7, Map::kBitFieldOffset));
    __ TestBit(r7, Map::IsCallableBit::kShift, r0);
    __ beq(&non_callable, cr0);
  
    // Check if target is a proxy and call CallProxy external builtin
    __ cmpi(r8, Operand(JS_PROXY_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), CallProxy), RelocInfo::CODE_TARGET, eq);
  
    // 2. Call to something else, which might have a [[Call]] internal method (if
    // not we raise an exception).
    // Overwrite the original receiver the (original) target.
    __ ShiftLeftImm(r8, r3, Operand(kPointerSizeLog2));
    __ StorePX(r4, MemOperand(sp, r8));
    // Let the "call_as_function_delegate" take care of the rest.
    __ LoadNativeContextSlot(Context::CALL_AS_FUNCTION_DELEGATE_INDEX, r4);
    __ Jump(masm->isolate()->builtins()->CallFunction(
                ConvertReceiverMode::kNotNullOrUndefined),
            RelocInfo::CODE_TARGET);
  
    // 3. Call to something that is not callable.
    __ bind(&non_callable);
    {
      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
      __ Push(r4);
      __ CallRuntime(Runtime::kThrowCalledNonCallable);
    }
  }
  
  // static
  void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the constructor to call (checked to be a JSFunction)
    //  -- r6 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertConstructor(r4);
    __ AssertFunction(r4);
  
    // Calling convention for function specific ConstructStubs require
    // r5 to contain either an AllocationSite or undefined.
    __ LoadRoot(r5, RootIndex::kUndefinedValue);
  
    Label call_generic_stub;
  
    // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
    __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
    __ lwz(r7, FieldMemOperand(r7, SharedFunctionInfo::kFlagsOffset));
    __ mov(ip, Operand(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
    __ and_(r7, r7, ip, SetRC);
    __ beq(&call_generic_stub, cr0);
  
    __ Jump(BUILTIN_CODE(masm->isolate(), JSBuiltinsConstructStub),
            RelocInfo::CODE_TARGET);
  
    __ bind(&call_generic_stub);
    __ Jump(BUILTIN_CODE(masm->isolate(), JSConstructStubGeneric),
            RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_ConstructBoundFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the function to call (checked to be a JSBoundFunction)
    //  -- r6 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertConstructor(r4);
    __ AssertBoundFunction(r4);
  
    // Push the [[BoundArguments]] onto the stack.
    Generate_PushBoundArguments(masm);
  
    // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
    Label skip;
    __ cmp(r4, r6);
    __ bne(&skip);
    __ LoadP(r6,
             FieldMemOperand(r4, JSBoundFunction::kBoundTargetFunctionOffset));
    __ bind(&skip);
  
    // Construct the [[BoundTargetFunction]] via the Construct builtin.
    __ LoadP(r4,
             FieldMemOperand(r4, JSBoundFunction::kBoundTargetFunctionOffset));
    __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_Construct(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : the number of arguments (not including the receiver)
    //  -- r4 : the constructor to call (can be any Object)
    //  -- r6 : 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, non_proxy;
    __ JumpIfSmi(r4, &non_constructor);
  
    // Check if target has a [[Construct]] internal method.
    __ LoadP(r7, FieldMemOperand(r4, HeapObject::kMapOffset));
    __ lbz(r5, FieldMemOperand(r7, Map::kBitFieldOffset));
    __ TestBit(r5, Map::IsConstructorBit::kShift, r0);
    __ beq(&non_constructor, cr0);
  
    // Dispatch based on instance type.
    __ CompareInstanceType(r7, r8, JS_FUNCTION_TYPE);
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructFunction),
            RelocInfo::CODE_TARGET, eq);
  
    // Only dispatch to bound functions after checking whether they are
    // constructors.
    __ cmpi(r8, Operand(JS_BOUND_FUNCTION_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructBoundFunction),
            RelocInfo::CODE_TARGET, eq);
  
    // Only dispatch to proxies after checking whether they are constructors.
    __ cmpi(r8, Operand(JS_PROXY_TYPE));
    __ bne(&non_proxy);
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructProxy),
            RelocInfo::CODE_TARGET);
  
    // Called Construct on an exotic Object with a [[Construct]] internal method.
    __ bind(&non_proxy);
    {
      // Overwrite the original receiver with the (original) target.
      __ ShiftLeftImm(r8, r3, Operand(kPointerSizeLog2));
      __ StorePX(r4, MemOperand(sp, r8));
      // Let the "call_as_constructor_delegate" take care of the rest.
      __ LoadNativeContextSlot(Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, r4);
      __ Jump(masm->isolate()->builtins()->CallFunction(),
              RelocInfo::CODE_TARGET);
    }
  
    // Called Construct on an Object that doesn't have a [[Construct]] internal
    // method.
    __ bind(&non_constructor);
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructedNonConstructable),
            RelocInfo::CODE_TARGET);
  }
  
  void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- r3 : actual number of arguments
    //  -- r4 : function (passed through to callee)
    //  -- r5 : expected number of arguments
    //  -- r6 : new target (passed through to callee)
    // -----------------------------------
  
    Label dont_adapt_arguments, stack_overflow, skip_adapt_arguments;
    __ cmpli(r5, Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
    __ beq(&dont_adapt_arguments);
    __ LoadP(r7, FieldMemOperand(r4, JSFunction::kSharedFunctionInfoOffset));
    __ lwz(r7, FieldMemOperand(r7, SharedFunctionInfo::kFlagsOffset));
    __ TestBitMask(r7, SharedFunctionInfo::IsSafeToSkipArgumentsAdaptorBit::kMask,
                   r0);
    __ bne(&skip_adapt_arguments, cr0);
  
    // -------------------------------------------
    // Adapt arguments.
    // -------------------------------------------
    {
      Label under_application, over_application, invoke;
      __ cmp(r3, r5);
      __ blt(&under_application);
  
      // Enough parameters: actual >= expected
      __ bind(&over_application);
      {
        EnterArgumentsAdaptorFrame(masm);
        Generate_StackOverflowCheck(masm, r5, r8, &stack_overflow);
  
        // Calculate copy start address into r3 and copy end address into r7.
        // r3: actual number of arguments as a smi
        // r4: function
        // r5: expected number of arguments
        // r6: new target (passed through to callee)
        __ SmiToPtrArrayOffset(r3, r3);
        __ add(r3, r3, fp);
        // adjust for return address and receiver
        __ addi(r3, r3, Operand(2 * kPointerSize));
        __ ShiftLeftImm(r7, r5, Operand(kPointerSizeLog2));
        __ sub(r7, r3, r7);
  
        // Copy the arguments (including the receiver) to the new stack frame.
        // r3: copy start address
        // r4: function
        // r5: expected number of arguments
        // r6: new target (passed through to callee)
        // r7: copy end address
  
        Label copy;
        __ bind(&copy);
        __ LoadP(r0, MemOperand(r3, 0));
        __ push(r0);
        __ cmp(r3, r7);  // Compare before moving to next argument.
        __ subi(r3, r3, Operand(kPointerSize));
        __ bne(&copy);
  
        __ b(&invoke);
      }
  
      // Too few parameters: Actual < expected
      __ bind(&under_application);
      {
        EnterArgumentsAdaptorFrame(masm);
        Generate_StackOverflowCheck(masm, r5, r8, &stack_overflow);
  
        // Calculate copy start address into r0 and copy end address is fp.
        // r3: actual number of arguments as a smi
        // r4: function
        // r5: expected number of arguments
        // r6: new target (passed through to callee)
        __ SmiToPtrArrayOffset(r3, r3);
        __ add(r3, r3, fp);
  
        // Copy the arguments (including the receiver) to the new stack frame.
        // r3: copy start address
        // r4: function
        // r5: expected number of arguments
        // r6: new target (passed through to callee)
        Label copy;
        __ bind(&copy);
        // Adjust load for return address and receiver.
        __ LoadP(r0, MemOperand(r3, 2 * kPointerSize));
        __ push(r0);
        __ cmp(r3, fp);  // Compare before moving to next argument.
        __ subi(r3, r3, Operand(kPointerSize));
        __ bne(&copy);
  
        // Fill the remaining expected arguments with undefined.
        // r4: function
        // r5: expected number of arguments
        // r6: new target (passed through to callee)
        __ LoadRoot(r0, RootIndex::kUndefinedValue);
        __ ShiftLeftImm(r7, r5, Operand(kPointerSizeLog2));
        __ sub(r7, fp, r7);
        // Adjust for frame.
        __ subi(r7, r7,
                Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp +
                        kPointerSize));
  
        Label fill;
        __ bind(&fill);
        __ push(r0);
        __ cmp(sp, r7);
        __ bne(&fill);
      }
  
      // Call the entry point.
      __ bind(&invoke);
      __ mr(r3, r5);
      // r3 : expected number of arguments
      // r4 : function (passed through to callee)
      // r6 : new target (passed through to callee)
      static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
      __ LoadP(r5, FieldMemOperand(r4, JSFunction::kCodeOffset));
      __ CallCodeObject(r5);
  
      // Store offset of return address for deoptimizer.
      masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(
          masm->pc_offset());
  
      // Exit frame and return.
      LeaveArgumentsAdaptorFrame(masm);
      __ blr();
    }
  
    // -------------------------------------------
    // Skip adapt arguments.
    // -------------------------------------------
    __ bind(&skip_adapt_arguments);
    {
      // The callee cannot observe the actual arguments, so it's safe to just
      // pass the expected arguments by massaging the stack appropriately. See
      // http://bit.ly/v8-faster-calls-with-arguments-mismatch for details.
      Label under_application, over_application;
      __ cmp(r3, r5);
      __ blt(&under_application);
  
      __ bind(&over_application);
      {
        // Remove superfluous parameters from the stack.
        __ sub(r7, r3, r5);
        __ mr(r3, r5);
        __ ShiftLeftImm(r7, r7, Operand(kPointerSizeLog2));
        __ add(sp, sp, r7);
        __ b(&dont_adapt_arguments);
      }
  
      __ bind(&under_application);
      {
        // Fill remaining expected arguments with undefined values.
        Label fill;
        __ LoadRoot(r7, RootIndex::kUndefinedValue);
        __ bind(&fill);
        __ addi(r3, r3, Operand(1));
        __ push(r7);
        __ cmp(r3, r5);
        __ blt(&fill);
        __ b(&dont_adapt_arguments);
      }
    }
  
    // -------------------------------------------
    // Dont adapt arguments.
    // -------------------------------------------
    __ bind(&dont_adapt_arguments);
    static_assert(kJavaScriptCallCodeStartRegister == r5, "ABI mismatch");
    __ LoadP(r5, FieldMemOperand(r4, JSFunction::kCodeOffset));
    __ JumpCodeObject(r5);
  
    __ bind(&stack_overflow);
    {
      FrameScope frame(masm, StackFrame::MANUAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ bkpt(0);
    }
  }
  
  void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
    // The function index was put in a register by the jump table trampoline.
    // Convert to Smi for the runtime call.
    __ SmiTag(kWasmCompileLazyFuncIndexRegister,
              kWasmCompileLazyFuncIndexRegister);
    {
      HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
      FrameAndConstantPoolScope scope(masm, StackFrame::WASM_COMPILE_LAZY);
  
      // Save all parameter registers (see wasm-linkage.cc). They might be
      // overwritten in the runtime call below. We don't have any callee-saved
      // registers in wasm, so no need to store anything else.
      constexpr RegList gp_regs =
          Register::ListOf<r3, r4, r5, r6, r7, r8, r9, r10>();
      constexpr RegList fp_regs =
          DoubleRegister::ListOf<d1, d2, d3, d4, d5, d6, d7, d8>();
      __ MultiPush(gp_regs);
      __ MultiPushDoubles(fp_regs);
  
      // Pass instance and function index as explicit arguments to the runtime
      // function.
      __ Push(kWasmInstanceRegister, kWasmCompileLazyFuncIndexRegister);
      // Load the correct CEntry builtin from the instance object.
      __ LoadP(r5, FieldMemOperand(kWasmInstanceRegister,
                                   WasmInstanceObject::kIsolateRootOffset));
      auto centry_id =
          Builtins::kCEntry_Return1_DontSaveFPRegs_ArgvOnStack_NoBuiltinExit;
      __ LoadP(r5, MemOperand(r5, IsolateData::builtin_slot_offset(centry_id)));
      // Initialize the JavaScript context with 0. CEntry will use it to
      // set the current context on the isolate.
      __ LoadSmiLiteral(cp, Smi::zero());
      __ CallRuntimeWithCEntry(Runtime::kWasmCompileLazy, r5);
      // The entrypoint address is the return value.
      __ mr(r11, kReturnRegister0);
  
      // Restore registers.
      __ MultiPopDoubles(fp_regs);
      __ MultiPop(gp_regs);
    }
    // Finally, jump to the entrypoint.
    __ Jump(r11);
  }
  
  void Builtins::Generate_CEntry(MacroAssembler* masm, int result_size,
                                 SaveFPRegsMode save_doubles, ArgvMode argv_mode,
                                 bool builtin_exit_frame) {
    // Called from JavaScript; parameters are on stack as if calling JS function.
    // r3: number of arguments including receiver
    // r4: pointer to builtin function
    // fp: frame pointer  (restored after C call)
    // sp: stack pointer  (restored as callee's sp after C call)
    // cp: current context  (C callee-saved)
    //
    // If argv_mode == kArgvInRegister:
    // r5: pointer to the first argument
  
    __ mr(r15, r4);
  
    if (argv_mode == kArgvInRegister) {
      // Move argv into the correct register.
      __ mr(r4, r5);
    } else {
      // Compute the argv pointer.
      __ ShiftLeftImm(r4, r3, Operand(kPointerSizeLog2));
      __ add(r4, r4, sp);
      __ subi(r4, r4, Operand(kPointerSize));
    }
  
    // Enter the exit frame that transitions from JavaScript to C++.
    FrameScope scope(masm, StackFrame::MANUAL);
  
    // Need at least one extra slot for return address location.
    int arg_stack_space = 1;
  
    // Pass buffer for return value on stack if necessary
    bool needs_return_buffer =
        (result_size == 2 && !ABI_RETURNS_OBJECT_PAIRS_IN_REGS);
    if (needs_return_buffer) {
      arg_stack_space += result_size;
    }
  
    __ EnterExitFrame(
        save_doubles, arg_stack_space,
        builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
  
    // Store a copy of argc in callee-saved registers for later.
    __ mr(r14, r3);
  
    // r3, r14: number of arguments including receiver  (C callee-saved)
    // r4: pointer to the first argument
    // r15: pointer to builtin function  (C callee-saved)
  
    // Result returned in registers or stack, depending on result size and ABI.
  
    Register isolate_reg = r5;
    if (needs_return_buffer) {
      // The return value is a non-scalar value.
      // Use frame storage reserved by calling function to pass return
      // buffer as implicit first argument.
      __ mr(r5, r4);
      __ mr(r4, r3);
      __ addi(r3, sp, Operand((kStackFrameExtraParamSlot + 1) * kPointerSize));
      isolate_reg = r6;
    }
  
    // Call C built-in.
    __ Move(isolate_reg, ExternalReference::isolate_address(masm->isolate()));
  
    Register target = r15;
    __ StoreReturnAddressAndCall(target);
  
    // If return value is on the stack, pop it to registers.
    if (needs_return_buffer) {
      __ LoadP(r4, MemOperand(r3, kPointerSize));
      __ LoadP(r3, MemOperand(r3));
    }
  
    // Check result for exception sentinel.
    Label exception_returned;
    __ CompareRoot(r3, RootIndex::kException);
    __ beq(&exception_returned);
  
    // Check that there is no pending exception, otherwise we
    // should have returned the exception sentinel.
    if (FLAG_debug_code) {
      Label okay;
      ExternalReference pending_exception_address = ExternalReference::Create(
          IsolateAddressId::kPendingExceptionAddress, masm->isolate());
  
      __ Move(r6, pending_exception_address);
      __ LoadP(r6, MemOperand(r6));
      __ CompareRoot(r6, RootIndex::kTheHoleValue);
      // Cannot use check here as it attempts to generate call into runtime.
      __ beq(&okay);
      __ stop();
      __ bind(&okay);
    }
  
    // Exit C frame and return.
    // r3:r4: result
    // sp: stack pointer
    // fp: frame pointer
    Register argc = argv_mode == kArgvInRegister
                        // We don't want to pop arguments so set argc to no_reg.
                        ? no_reg
                        // r14: still holds argc (callee-saved).
                        : r14;
    __ LeaveExitFrame(save_doubles, argc);
    __ blr();
  
    // Handling of exception.
    __ bind(&exception_returned);
  
    ExternalReference pending_handler_context_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerContextAddress, masm->isolate());
    ExternalReference pending_handler_entrypoint_address =
        ExternalReference::Create(
            IsolateAddressId::kPendingHandlerEntrypointAddress, masm->isolate());
    ExternalReference pending_handler_constant_pool_address =
        ExternalReference::Create(
            IsolateAddressId::kPendingHandlerConstantPoolAddress,
            masm->isolate());
    ExternalReference pending_handler_fp_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerFPAddress, masm->isolate());
    ExternalReference pending_handler_sp_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerSPAddress, masm->isolate());
  
    // Ask the runtime for help to determine the handler. This will set r3 to
    // contain the current pending exception, don't clobber it.
    ExternalReference find_handler =
        ExternalReference::Create(Runtime::kUnwindAndFindExceptionHandler);
    {
      FrameScope scope(masm, StackFrame::MANUAL);
      __ PrepareCallCFunction(3, 0, r3);
      __ li(r3, Operand::Zero());
      __ li(r4, Operand::Zero());
      __ Move(r5, ExternalReference::isolate_address(masm->isolate()));
      __ CallCFunction(find_handler, 3);
    }
  
    // Retrieve the handler context, SP and FP.
    __ Move(cp, pending_handler_context_address);
    __ LoadP(cp, MemOperand(cp));
    __ Move(sp, pending_handler_sp_address);
    __ LoadP(sp, MemOperand(sp));
    __ Move(fp, pending_handler_fp_address);
    __ LoadP(fp, MemOperand(fp));
  
    // If the handler is a JS frame, restore the context to the frame. Note that
    // the context will be set to (cp == 0) for non-JS frames.
    Label skip;
    __ cmpi(cp, Operand::Zero());
    __ beq(&skip);
    __ StoreP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    __ bind(&skip);
  
    // Reset the masking register. This is done independent of the underlying
    // feature flag {FLAG_untrusted_code_mitigations} to make the snapshot work
    // with both configurations. It is safe to always do this, because the
    // underlying register is caller-saved and can be arbitrarily clobbered.
    __ ResetSpeculationPoisonRegister();
  
    // Compute the handler entry address and jump to it.
    ConstantPoolUnavailableScope constant_pool_unavailable(masm);
    __ Move(ip, pending_handler_entrypoint_address);
    __ LoadP(ip, MemOperand(ip));
    if (FLAG_enable_embedded_constant_pool) {
      __ Move(kConstantPoolRegister, pending_handler_constant_pool_address);
      __ LoadP(kConstantPoolRegister, MemOperand(kConstantPoolRegister));
    }
    __ Jump(ip);
  }
  
  void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
    Label out_of_range, only_low, negate, done, fastpath_done;
    Register result_reg = r3;
  
    HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
  
    // Immediate values for this stub fit in instructions, so it's safe to use ip.
    Register scratch = GetRegisterThatIsNotOneOf(result_reg);
    Register scratch_low = GetRegisterThatIsNotOneOf(result_reg, scratch);
    Register scratch_high =
        GetRegisterThatIsNotOneOf(result_reg, scratch, scratch_low);
    DoubleRegister double_scratch = kScratchDoubleReg;
  
    __ Push(result_reg, scratch);
    // Account for saved regs.
    int argument_offset = 2 * kPointerSize;
  
    // Load double input.
    __ lfd(double_scratch, MemOperand(sp, argument_offset));
  
    // Do fast-path convert from double to int.
    __ ConvertDoubleToInt64(double_scratch,
  #if !V8_TARGET_ARCH_PPC64
                            scratch,
  #endif
                            result_reg, d0);
  
  // Test for overflow
  #if V8_TARGET_ARCH_PPC64
    __ TestIfInt32(result_reg, r0);
  #else
    __ TestIfInt32(scratch, result_reg, r0);
  #endif
    __ beq(&fastpath_done);
  
    __ Push(scratch_high, scratch_low);
    // Account for saved regs.
    argument_offset += 2 * kPointerSize;
  
    __ lwz(scratch_high,
           MemOperand(sp, argument_offset + Register::kExponentOffset));
    __ lwz(scratch_low,
           MemOperand(sp, argument_offset + Register::kMantissaOffset));
  
    __ ExtractBitMask(scratch, scratch_high, HeapNumber::kExponentMask);
    // Load scratch with exponent - 1. This is faster than loading
    // with exponent because Bias + 1 = 1024 which is a *PPC* immediate value.
    STATIC_ASSERT(HeapNumber::kExponentBias + 1 == 1024);
    __ subi(scratch, scratch, Operand(HeapNumber::kExponentBias + 1));
    // If exponent is greater than or equal to 84, the 32 less significant
    // bits are 0s (2^84 = 1, 52 significant bits, 32 uncoded bits),
    // the result is 0.
    // Compare exponent with 84 (compare exponent - 1 with 83).
    __ cmpi(scratch, Operand(83));
    __ bge(&out_of_range);
  
    // If we reach this code, 31 <= exponent <= 83.
    // So, we don't have to handle cases where 0 <= exponent <= 20 for
    // which we would need to shift right the high part of the mantissa.
    // Scratch contains exponent - 1.
    // Load scratch with 52 - exponent (load with 51 - (exponent - 1)).
    __ subfic(scratch, scratch, Operand(51));
    __ cmpi(scratch, Operand::Zero());
    __ ble(&only_low);
    // 21 <= exponent <= 51, shift scratch_low and scratch_high
    // to generate the result.
    __ srw(scratch_low, scratch_low, scratch);
    // Scratch contains: 52 - exponent.
    // We needs: exponent - 20.
    // So we use: 32 - scratch = 32 - 52 + exponent = exponent - 20.
    __ subfic(scratch, scratch, Operand(32));
    __ ExtractBitMask(result_reg, scratch_high, HeapNumber::kMantissaMask);
    // Set the implicit 1 before the mantissa part in scratch_high.
    STATIC_ASSERT(HeapNumber::kMantissaBitsInTopWord >= 16);
    __ oris(result_reg, result_reg,
            Operand(1 << ((HeapNumber::kMantissaBitsInTopWord)-16)));
    __ slw(r0, result_reg, scratch);
    __ orx(result_reg, scratch_low, r0);
    __ b(&negate);
  
    __ bind(&out_of_range);
    __ mov(result_reg, Operand::Zero());
    __ b(&done);
  
    __ bind(&only_low);
    // 52 <= exponent <= 83, shift only scratch_low.
    // On entry, scratch contains: 52 - exponent.
    __ neg(scratch, scratch);
    __ slw(result_reg, scratch_low, scratch);
  
    __ bind(&negate);
    // If input was positive, scratch_high ASR 31 equals 0 and
    // scratch_high LSR 31 equals zero.
    // New result = (result eor 0) + 0 = result.
    // If the input was negative, we have to negate the result.
    // Input_high ASR 31 equals 0xFFFFFFFF and scratch_high LSR 31 equals 1.
    // New result = (result eor 0xFFFFFFFF) + 1 = 0 - result.
    __ srawi(r0, scratch_high, 31);
  #if V8_TARGET_ARCH_PPC64
    __ srdi(r0, r0, Operand(32));
  #endif
    __ xor_(result_reg, result_reg, r0);
    __ srwi(r0, scratch_high, Operand(31));
    __ add(result_reg, result_reg, r0);
  
    __ bind(&done);
    __ Pop(scratch_high, scratch_low);
    // Account for saved regs.
    argument_offset -= 2 * kPointerSize;
  
    __ bind(&fastpath_done);
    __ StoreP(result_reg, MemOperand(sp, argument_offset));
    __ Pop(result_reg, scratch);
  
    __ Ret();
  }
  
  namespace {
  
  static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
    return ref0.address() - ref1.address();
  }
  
  
  // Calls an API function.  Allocates HandleScope, extracts returned value
  // from handle and propagates exceptions.  Restores context.  stack_space
  // - space to be unwound on exit (includes the call JS arguments space and
  // the additional space allocated for the fast call).
  static void CallApiFunctionAndReturn(MacroAssembler* masm,
                                       Register function_address,
                                       ExternalReference thunk_ref,
                                       int stack_space,
                                       MemOperand* stack_space_operand,
                                       MemOperand return_value_operand) {
    Isolate* isolate = masm->isolate();
    ExternalReference next_address =
        ExternalReference::handle_scope_next_address(isolate);
    const int kNextOffset = 0;
    const int kLimitOffset = AddressOffset(
        ExternalReference::handle_scope_limit_address(isolate), next_address);
    const int kLevelOffset = AddressOffset(
        ExternalReference::handle_scope_level_address(isolate), next_address);
  
    // Additional parameter is the address of the actual callback.
    DCHECK(function_address == r4 || function_address == r5);
    Register scratch = r6;
  
    __ Move(scratch, ExternalReference::is_profiling_address(isolate));
    __ lbz(scratch, MemOperand(scratch, 0));
    __ cmpi(scratch, Operand::Zero());
  
    if (CpuFeatures::IsSupported(ISELECT)) {
      __ Move(scratch, thunk_ref);
      __ isel(eq, scratch, function_address, scratch);
    } else {
      Label profiler_enabled, end_profiler_check;
      __ bne(&profiler_enabled);
      __ Move(scratch, ExternalReference::address_of_runtime_stats_flag());
      __ lwz(scratch, MemOperand(scratch, 0));
      __ cmpi(scratch, Operand::Zero());
      __ bne(&profiler_enabled);
      {
        // Call the api function directly.
        __ mr(scratch, function_address);
        __ b(&end_profiler_check);
      }
      __ bind(&profiler_enabled);
      {
        // Additional parameter is the address of the actual callback.
        __ Move(scratch, thunk_ref);
      }
      __ bind(&end_profiler_check);
    }
  
    // Allocate HandleScope in callee-save registers.
    // r17 - next_address
    // r14 - next_address->kNextOffset
    // r15 - next_address->kLimitOffset
    // r16 - next_address->kLevelOffset
    __ Move(r17, next_address);
    __ LoadP(r14, MemOperand(r17, kNextOffset));
    __ LoadP(r15, MemOperand(r17, kLimitOffset));
    __ lwz(r16, MemOperand(r17, kLevelOffset));
    __ addi(r16, r16, Operand(1));
    __ stw(r16, MemOperand(r17, kLevelOffset));
  
    __ StoreReturnAddressAndCall(scratch);
  
    Label promote_scheduled_exception;
    Label delete_allocated_handles;
    Label leave_exit_frame;
    Label return_value_loaded;
  
    // load value from ReturnValue
    __ LoadP(r3, return_value_operand);
    __ bind(&return_value_loaded);
    // No more valid handles (the result handle was the last one). Restore
    // previous handle scope.
    __ StoreP(r14, MemOperand(r17, kNextOffset));
    if (__ emit_debug_code()) {
      __ lwz(r4, MemOperand(r17, kLevelOffset));
      __ cmp(r4, r16);
      __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall);
    }
    __ subi(r16, r16, Operand(1));
    __ stw(r16, MemOperand(r17, kLevelOffset));
    __ LoadP(r0, MemOperand(r17, kLimitOffset));
    __ cmp(r15, r0);
    __ bne(&delete_allocated_handles);
  
    // Leave the API exit frame.
    __ bind(&leave_exit_frame);
    // LeaveExitFrame expects unwind space to be in a register.
    if (stack_space_operand != nullptr) {
      __ LoadP(r14, *stack_space_operand);
    } else {
      __ mov(r14, Operand(stack_space));
    }
    __ LeaveExitFrame(false, r14, stack_space_operand != nullptr);
  
    // Check if the function scheduled an exception.
    __ LoadRoot(r14, RootIndex::kTheHoleValue);
    __ Move(r15, ExternalReference::scheduled_exception_address(isolate));
    __ LoadP(r15, MemOperand(r15));
    __ cmp(r14, r15);
    __ bne(&promote_scheduled_exception);
  
    __ blr();
  
    // Re-throw by promoting a scheduled exception.
    __ bind(&promote_scheduled_exception);
    __ TailCallRuntime(Runtime::kPromoteScheduledException);
  
    // HandleScope limit has changed. Delete allocated extensions.
    __ bind(&delete_allocated_handles);
    __ StoreP(r15, MemOperand(r17, kLimitOffset));
    __ mr(r14, r3);
    __ PrepareCallCFunction(1, r15);
    __ Move(r3, ExternalReference::isolate_address(isolate));
    __ CallCFunction(ExternalReference::delete_handle_scope_extensions(), 1);
    __ mr(r3, r14);
    __ b(&leave_exit_frame);
  }
  
  }  // namespace
  
  void Builtins::Generate_CallApiCallback(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- cp                  : context
    //  -- r4                  : api function address
    //  -- r5                  : arguments count (not including the receiver)
    //  -- r6                  : call data
    //  -- r3                  : holder
    //  -- sp[0]               : last argument
    //  -- ...
    //  -- sp[(argc - 1)* 4]   : first argument
    //  -- sp[(argc + 0) * 4]  : receiver
    // -----------------------------------
  
    Register api_function_address = r4;
    Register argc = r5;
    Register call_data = r6;
    Register holder = r3;
    Register scratch = r7;
    DCHECK(!AreAliased(api_function_address, argc, call_data, holder, scratch));
  
    using FCA = FunctionCallbackArguments;
  
    STATIC_ASSERT(FCA::kArgsLength == 6);
    STATIC_ASSERT(FCA::kNewTargetIndex == 5);
    STATIC_ASSERT(FCA::kDataIndex == 4);
    STATIC_ASSERT(FCA::kReturnValueOffset == 3);
    STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
    STATIC_ASSERT(FCA::kIsolateIndex == 1);
    STATIC_ASSERT(FCA::kHolderIndex == 0);
  
    // Set up FunctionCallbackInfo's implicit_args on the stack as follows:
    //
    // Target state:
    //   sp[0 * kPointerSize]: kHolder
    //   sp[1 * kPointerSize]: kIsolate
    //   sp[2 * kPointerSize]: undefined (kReturnValueDefaultValue)
    //   sp[3 * kPointerSize]: undefined (kReturnValue)
    //   sp[4 * kPointerSize]: kData
    //   sp[5 * kPointerSize]: undefined (kNewTarget)
  
    // Reserve space on the stack.
    __ subi(sp, sp, Operand(FCA::kArgsLength * kPointerSize));
  
    // kHolder.
    __ StoreP(holder, MemOperand(sp, 0 * kPointerSize));
  
    // kIsolate.
    __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
    __ StoreP(scratch, MemOperand(sp, 1 * kPointerSize));
  
    // kReturnValueDefaultValue and kReturnValue.
    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
    __ StoreP(scratch, MemOperand(sp, 2 * kPointerSize));
    __ StoreP(scratch, MemOperand(sp, 3 * kPointerSize));
  
    // kData.
    __ StoreP(call_data, MemOperand(sp, 4 * kPointerSize));
  
    // kNewTarget.
    __ StoreP(scratch, MemOperand(sp, 5 * kPointerSize));
  
    // Keep a pointer to kHolder (= implicit_args) in a scratch register.
    // We use it below to set up the FunctionCallbackInfo object.
    __ mr(scratch, sp);
  
    // Allocate the v8::Arguments structure in the arguments' space since
    // it's not controlled by GC.
    // PPC LINUX ABI:
    //
    // Create 4 extra slots on stack:
    //    [0] space for DirectCEntryStub's LR save
    //    [1-3] FunctionCallbackInfo
    //    [4] number of bytes to drop from the stack after returning
    static constexpr int kApiStackSpace = 5;
    static constexpr bool kDontSaveDoubles = false;
  
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(kDontSaveDoubles, kApiStackSpace);
  
    // FunctionCallbackInfo::implicit_args_ (points at kHolder as set up above).
    // Arguments are after the return address (pushed by EnterExitFrame()).
    __ StoreP(scratch,
              MemOperand(sp, (kStackFrameExtraParamSlot + 1) * kPointerSize));
  
    // FunctionCallbackInfo::values_ (points at the first varargs argument passed
    // on the stack).
    __ addi(scratch, scratch, Operand((FCA::kArgsLength - 1) * kPointerSize));
    __ ShiftLeftImm(ip, argc, Operand(kPointerSizeLog2));
    __ add(scratch, scratch, ip);
    __ StoreP(scratch,
              MemOperand(sp, (kStackFrameExtraParamSlot + 2) * kPointerSize));
  
    // FunctionCallbackInfo::length_.
    __ stw(argc, MemOperand(sp, (kStackFrameExtraParamSlot + 3) * kPointerSize));
  
    // We also store the number of bytes to drop from the stack after returning
    // from the API function here.
    __ mov(scratch,
           Operand((FCA::kArgsLength + 1 /* receiver */) * kPointerSize));
    __ ShiftLeftImm(ip, argc, Operand(kPointerSizeLog2));
    __ add(scratch, scratch, ip);
    __ StoreP(scratch,
              MemOperand(sp, (kStackFrameExtraParamSlot + 4) * kPointerSize));
  
    // v8::InvocationCallback's argument.
    __ addi(r3, sp, Operand((kStackFrameExtraParamSlot + 1) * kPointerSize));
  
    ExternalReference thunk_ref = ExternalReference::invoke_function_callback();
  
    // There are two stack slots above the arguments we constructed on the stack.
    // TODO(jgruber): Document what these arguments are.
    static constexpr int kStackSlotsAboveFCA = 2;
    MemOperand return_value_operand(
        fp, (kStackSlotsAboveFCA + FCA::kReturnValueOffset) * kPointerSize);
  
    static constexpr int kUseStackSpaceOperand = 0;
    MemOperand stack_space_operand(
        sp, (kStackFrameExtraParamSlot + 4) * kPointerSize);
  
    AllowExternalCallThatCantCauseGC scope(masm);
    CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                             kUseStackSpaceOperand, &stack_space_operand,
                             return_value_operand);
  }
  
  
  void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
    int arg0Slot = 0;
    int accessorInfoSlot = 0;
    int apiStackSpace = 0;
    // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
    // name below the exit frame to make GC aware of them.
    STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
    STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
    STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
    STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
    STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
    STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
    STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
    STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);
  
    Register receiver = ApiGetterDescriptor::ReceiverRegister();
    Register holder = ApiGetterDescriptor::HolderRegister();
    Register callback = ApiGetterDescriptor::CallbackRegister();
    Register scratch = r7;
    DCHECK(!AreAliased(receiver, holder, callback, scratch));
  
    Register api_function_address = r5;
  
    __ push(receiver);
    // Push data from AccessorInfo.
    __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
    __ push(scratch);
    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
    __ Push(scratch, scratch);
    __ Move(scratch, ExternalReference::isolate_address(masm->isolate()));
    __ Push(scratch, holder);
    __ Push(Smi::zero());  // should_throw_on_error -> false
    __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kNameOffset));
    __ push(scratch);
  
    // v8::PropertyCallbackInfo::args_ array and name handle.
    const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;
  
    // Load address of v8::PropertyAccessorInfo::args_ array and name handle.
    __ mr(r3, sp);                               // r3 = Handle<Name>
    __ addi(r4, r3, Operand(1 * kPointerSize));  // r4 = v8::PCI::args_
  
  // If ABI passes Handles (pointer-sized struct) in a register:
  //
  // Create 2 extra slots on stack:
  //    [0] space for DirectCEntryStub's LR save
  //    [1] AccessorInfo&
  //
  // Otherwise:
  //
  // Create 3 extra slots on stack:
  //    [0] space for DirectCEntryStub's LR save
  //    [1] copy of Handle (first arg)
  //    [2] AccessorInfo&
    if (ABI_PASSES_HANDLES_IN_REGS) {
      accessorInfoSlot = kStackFrameExtraParamSlot + 1;
      apiStackSpace = 2;
    } else {
      arg0Slot = kStackFrameExtraParamSlot + 1;
      accessorInfoSlot = arg0Slot + 1;
      apiStackSpace = 3;
    }
  
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(false, apiStackSpace);
  
    if (!ABI_PASSES_HANDLES_IN_REGS) {
      // pass 1st arg by reference
      __ StoreP(r3, MemOperand(sp, arg0Slot * kPointerSize));
      __ addi(r3, sp, Operand(arg0Slot * kPointerSize));
    }
  
    // Create v8::PropertyCallbackInfo object on the stack and initialize
    // it's args_ field.
    __ StoreP(r4, MemOperand(sp, accessorInfoSlot * kPointerSize));
    __ addi(r4, sp, Operand(accessorInfoSlot * kPointerSize));
    // r4 = v8::PropertyCallbackInfo&
  
    ExternalReference thunk_ref =
        ExternalReference::invoke_accessor_getter_callback();
  
    __ LoadP(scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
    __ LoadP(api_function_address,
          FieldMemOperand(scratch, Foreign::kForeignAddressOffset));
  
    // +3 is to skip prolog, return address and name handle.
    MemOperand return_value_operand(
        fp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
    MemOperand* const kUseStackSpaceConstant = nullptr;
    CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                             kStackUnwindSpace, kUseStackSpaceConstant,
                             return_value_operand);
  }
  
  void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
    UseScratchRegisterScope temps(masm);
    Register temp2 = temps.Acquire();
    // Place the return address on the stack, making the call
    // GC safe. The RegExp backend also relies on this.
    __ mflr(r0);
    __ StoreP(r0, MemOperand(sp, kStackFrameExtraParamSlot * kPointerSize));
  
    if (ABI_USES_FUNCTION_DESCRIPTORS) {
      // AIX/PPC64BE Linux use a function descriptor;
      __ LoadP(ToRegister(ABI_TOC_REGISTER), MemOperand(temp2, kPointerSize));
      __ LoadP(temp2, MemOperand(temp2, 0));  // Instruction address
    }
  
    __ Call(temp2);  // Call the C++ function.
    __ LoadP(r0, MemOperand(sp, kStackFrameExtraParamSlot * kPointerSize));
    __ mtlr(r0);
    __ blr();
  }
  
  #undef __
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_TARGET_ARCH_PPC
  