text: // Copyright 2012 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #if V8_TARGET_ARCH_MIPS
  
  #include "src/code-factory.h"
  #include "src/code-stubs.h"
  #include "src/counters.h"
  #include "src/debug/debug.h"
  #include "src/deoptimizer.h"
  #include "src/frame-constants.h"
  #include "src/frames.h"
  #include "src/mips/constants-mips.h"
  #include "src/objects-inl.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,
                                  ExitFrameType exit_frame_type) {
    __ li(kJavaScriptCallExtraArg1Register, ExternalReference::Create(address));
    if (exit_frame_type == BUILTIN_EXIT) {
      __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
              RelocInfo::CODE_TARGET);
    } else {
      DCHECK(exit_frame_type == EXIT);
      __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithExitFrame),
              RelocInfo::CODE_TARGET);
    }
  }
  
  void Builtins::Generate_InternalArrayConstructor(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0     : number of arguments
    //  -- ra     : return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
    Label generic_array_code, one_or_more_arguments, two_or_more_arguments;
  
    if (FLAG_debug_code) {
      // Initial map for the builtin InternalArray functions should be maps.
      __ lw(a2, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
      __ SmiTst(a2, t0);
      __ Assert(ne, AbortReason::kUnexpectedInitialMapForInternalArrayFunction,
                t0, Operand(zero_reg));
      __ GetObjectType(a2, a3, t0);
      __ Assert(eq, AbortReason::kUnexpectedInitialMapForInternalArrayFunction,
                t0, Operand(MAP_TYPE));
    }
  
    // Run the native code for the InternalArray function called as a normal
    // function.
    __ Jump(BUILTIN_CODE(masm->isolate(), InternalArrayConstructorImpl),
            RelocInfo::CODE_TARGET);
  }
  
  static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
                                             Runtime::FunctionId function_id) {
    // ----------- S t a t e -------------
    //  -- a0 : argument count (preserved for callee)
    //  -- a1 : target function (preserved for callee)
    //  -- a3 : new target (preserved for callee)
    // -----------------------------------
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Push a copy of the target function and the new target.
      // Push function as parameter to the runtime call.
      __ SmiTag(a0);
      __ Push(a0, a1, a3, a1);
  
      __ CallRuntime(function_id, 1);
  
      // Restore target function and new target.
      __ Pop(a0, a1, a3);
      __ SmiUntag(a0);
    }
  
    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
    __ Addu(a2, v0, Code::kHeaderSize - kHeapObjectTag);
    __ Jump(a2);
  }
  
  namespace {
  
  void Generate_JSBuiltinsConstructStubHelper(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0     : number of arguments
    //  -- a1     : constructor function
    //  -- a3     : new target
    //  -- cp     : context
    //  -- ra     : return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
  
    // Enter a construct frame.
    {
      FrameScope scope(masm, StackFrame::CONSTRUCT);
  
      // Preserve the incoming parameters on the stack.
      __ SmiTag(a0);
      __ Push(cp, a0);
      __ SmiUntag(a0);
  
      // The receiver for the builtin/api call.
      __ PushRoot(RootIndex::kTheHoleValue);
  
      // Set up pointer to last argument.
      __ Addu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
  
      // Copy arguments and receiver to the expression stack.
      Label loop, entry;
      __ mov(t3, a0);
      // ----------- S t a t e -------------
      //  --                        a0: number of arguments (untagged)
      //  --                        a3: new target
      //  --                        t2: pointer to last argument
      //  --                        t3: counter
      //  --        sp[0*kPointerSize]: the hole (receiver)
      //  --        sp[1*kPointerSize]: number of arguments (tagged)
      //  --        sp[2*kPointerSize]: context
      // -----------------------------------
      __ jmp(&entry);
      __ bind(&loop);
      __ Lsa(t0, t2, t3, kPointerSizeLog2);
      __ lw(t1, MemOperand(t0));
      __ push(t1);
      __ bind(&entry);
      __ Addu(t3, t3, Operand(-1));
      __ Branch(&loop, greater_equal, t3, Operand(zero_reg));
  
      // Call the function.
      // a0: number of arguments (untagged)
      // a1: constructor function
      // a3: new target
      ParameterCount actual(a0);
      __ InvokeFunction(a1, a3, actual, CALL_FUNCTION);
  
      // Restore context from the frame.
      __ lw(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
      // Restore smi-tagged arguments count from the frame.
      __ lw(a1, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      // Leave construct frame.
    }
  
    // Remove caller arguments from the stack and return.
    __ Lsa(sp, sp, a1, kPointerSizeLog2 - 1);
    __ Addu(sp, sp, kPointerSize);
    __ Ret();
  }
  
  }  // namespace
  
  // The construct stub for ES5 constructor functions and ES6 class constructors.
  void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  --      a0: number of arguments (untagged)
    //  --      a1: constructor function
    //  --      a3: new target
    //  --      cp: context
    //  --      ra: return address
    //  -- sp[...]: constructor arguments
    // -----------------------------------
  
    // Enter a construct frame.
    {
      FrameScope scope(masm, StackFrame::CONSTRUCT);
      Label post_instantiation_deopt_entry, not_create_implicit_receiver;
  
      // Preserve the incoming parameters on the stack.
      __ SmiTag(a0);
      __ Push(cp, a0, a1);
      __ PushRoot(RootIndex::kTheHoleValue);
      __ Push(a3);
  
      // ----------- S t a t e -------------
      //  --        sp[0*kPointerSize]: new target
      //  --        sp[1*kPointerSize]: padding
      //  -- a1 and sp[2*kPointerSize]: constructor function
      //  --        sp[3*kPointerSize]: number of arguments (tagged)
      //  --        sp[4*kPointerSize]: context
      // -----------------------------------
  
      __ lw(t2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
      __ lw(t2, FieldMemOperand(t2, SharedFunctionInfo::kFlagsOffset));
      __ And(t2, t2, Operand(SharedFunctionInfo::IsDerivedConstructorBit::kMask));
      __ Branch(&not_create_implicit_receiver, ne, t2, Operand(zero_reg));
  
      // If not derived class constructor: Allocate the new receiver object.
      __ IncrementCounter(masm->isolate()->counters()->constructed_objects(), 1,
                          t2, t3);
      __ Call(BUILTIN_CODE(masm->isolate(), FastNewObject),
              RelocInfo::CODE_TARGET);
      __ Branch(&post_instantiation_deopt_entry);
  
      // Else: use TheHoleValue as receiver for constructor call
      __ bind(&not_create_implicit_receiver);
      __ LoadRoot(v0, RootIndex::kTheHoleValue);
  
      // ----------- S t a t e -------------
      //  --                          v0: 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(a3);
      // 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(v0, v0);
  
      // ----------- S t a t e -------------
      //  --                 r3: 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.
      __ lw(a1, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
      __ lw(a0, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      __ SmiUntag(a0);
  
      // Set up pointer to last argument.
      __ Addu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset));
  
      // Copy arguments and receiver to the expression stack.
      Label loop, entry;
      __ mov(t3, a0);
      // ----------- S t a t e -------------
      //  --                        a0: number of arguments (untagged)
      //  --                        a3: new target
      //  --                        t2: pointer to last argument
      //  --                        t3: counter
      //  --        sp[0*kPointerSize]: implicit receiver
      //  --        sp[1*kPointerSize]: implicit receiver
      //  --        sp[2*kPointerSize]: padding
      //  -- a1 and sp[3*kPointerSize]: constructor function
      //  --        sp[4*kPointerSize]: number of arguments (tagged)
      //  --        sp[5*kPointerSize]: context
      // -----------------------------------
      __ jmp(&entry);
      __ bind(&loop);
      __ Lsa(t0, t2, t3, kPointerSizeLog2);
      __ lw(t1, MemOperand(t0));
      __ push(t1);
      __ bind(&entry);
      __ Addu(t3, t3, Operand(-1));
      __ Branch(&loop, greater_equal, t3, Operand(zero_reg));
  
      // Call the function.
      ParameterCount actual(a0);
      __ InvokeFunction(a1, a3, actual, CALL_FUNCTION);
  
      // ----------- S t a t e -------------
      //  --                 v0: 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.
      __ lw(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(v0, 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(v0, &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.
      __ GetObjectType(v0, t2, t2);
      STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
      __ Branch(&leave_frame, greater_equal, t2, Operand(FIRST_JS_RECEIVER_TYPE));
      __ Branch(&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);
      __ lw(v0, MemOperand(sp, 0 * kPointerSize));
      __ JumpIfRoot(v0, RootIndex::kTheHoleValue, &do_throw);
  
      __ bind(&leave_frame);
      // Restore smi-tagged arguments count from the frame.
      __ lw(a1, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      // Leave construct frame.
    }
    // Remove caller arguments from the stack and return.
    __ Lsa(sp, sp, a1, kPointerSizeLog2 - kSmiTagSize);
    __ Addu(sp, sp, kPointerSize);
    __ Ret();
  }
  
  void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
    Generate_JSBuiltinsConstructStubHelper(masm);
  }
  
  void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(a1);
    __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
  }
  
  // Clobbers a2; preserves all other registers.
  static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc) {
    // 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;
    __ LoadRoot(a2, RootIndex::kRealStackLimit);
    // Make a2 the space we have left. The stack might already be overflowed
    // here which will cause a2 to become negative.
    __ Subu(a2, sp, a2);
    // Check if the arguments will overflow the stack.
    __ sll(t3, argc, kPointerSizeLog2);
    // Signed comparison.
    __ Branch(&okay, gt, a2, Operand(t3));
  
    // Out of stack space.
    __ CallRuntime(Runtime::kThrowStackOverflow);
  
    __ bind(&okay);
  }
  
  static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                               bool is_construct) {
    // ----------- S t a t e -------------
    //  -- a0: new.target
    //  -- a1: function
    //  -- a2: receiver_pointer
    //  -- a3: argc
    //  -- s0: argv
    // -----------------------------------
    ProfileEntryHookStub::MaybeCallEntryHook(masm);
  
    // Enter an internal frame.
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
  
      // Setup the context (we need to use the caller context from the isolate).
      ExternalReference context_address = ExternalReference::Create(
          IsolateAddressId::kContextAddress, masm->isolate());
      __ li(cp, context_address);
      __ lw(cp, MemOperand(cp));
  
      // Push the function and the receiver onto the stack.
      __ Push(a1, a2);
  
      // Check if we have enough stack space to push all arguments.
      // Clobbers a2.
      Generate_CheckStackOverflow(masm, a3);
  
      // Remember new.target.
      __ mov(t1, a0);
  
      // Copy arguments to the stack in a loop.
      // a3: argc
      // s0: argv, i.e. points to first arg
      Label loop, entry;
      __ Lsa(t2, s0, a3, kPointerSizeLog2);
      __ b(&entry);
      __ nop();  // Branch delay slot nop.
      // t2 points past last arg.
      __ bind(&loop);
      __ lw(t0, MemOperand(s0));  // Read next parameter.
      __ addiu(s0, s0, kPointerSize);
      __ lw(t0, MemOperand(t0));  // Dereference handle.
      __ push(t0);                // Push parameter.
      __ bind(&entry);
      __ Branch(&loop, ne, s0, Operand(t2));
  
      // Setup new.target and argc.
      __ mov(a0, a3);
      __ mov(a3, t1);
  
      // Initialize all JavaScript callee-saved registers, since they will be seen
      // by the garbage collector as part of handlers.
      __ LoadRoot(t0, RootIndex::kUndefinedValue);
      __ mov(s1, t0);
      __ mov(s2, t0);
      __ mov(s3, t0);
      __ mov(s4, t0);
      __ mov(s5, t0);
      // s6 holds the root address. Do not clobber.
      // s7 is cp. Do not init.
  
      // Invoke the code.
      Handle<Code> builtin = is_construct
                                 ? BUILTIN_CODE(masm->isolate(), Construct)
                                 : masm->isolate()->builtins()->Call();
      __ Call(builtin, RelocInfo::CODE_TARGET);
  
      // Leave internal frame.
    }
  
    __ Jump(ra);
  }
  
  void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, false);
  }
  
  void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
    Generate_JSEntryTrampolineHelper(masm, true);
  }
  
  static void GetSharedFunctionInfoBytecode(MacroAssembler* masm,
                                            Register sfi_data,
                                            Register scratch1) {
    Label done;
  
    __ GetObjectType(sfi_data, scratch1, scratch1);
    __ Branch(&done, ne, scratch1, Operand(INTERPRETER_DATA_TYPE));
    __ lw(sfi_data,
          FieldMemOperand(sfi_data, InterpreterData::kBytecodeArrayOffset));
  
    __ bind(&done);
  }
  
  // static
  void Builtins::Generate_ResumeGeneratorTrampoline(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- v0 : the value to pass to the generator
    //  -- a1 : the JSGeneratorObject to resume
    //  -- ra : return address
    // -----------------------------------
  
    __ AssertGeneratorObject(a1);
  
    // Store input value into generator object.
    __ sw(v0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
    __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, v0, a3,
                        kRAHasNotBeenSaved, kDontSaveFPRegs);
  
    // Load suspended function and context.
    __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
    __ lw(cp, FieldMemOperand(t0, JSFunction::kContextOffset));
  
    // Flood function if we are stepping.
    Label prepare_step_in_if_stepping, prepare_step_in_suspended_generator;
    Label stepping_prepared;
    ExternalReference debug_hook =
        ExternalReference::debug_hook_on_function_call_address(masm->isolate());
    __ li(t1, debug_hook);
    __ lb(t1, MemOperand(t1));
    __ Branch(&prepare_step_in_if_stepping, ne, t1, Operand(zero_reg));
  
    // Flood function if we need to continue stepping in the suspended generator.
    ExternalReference debug_suspended_generator =
        ExternalReference::debug_suspended_generator_address(masm->isolate());
    __ li(t1, debug_suspended_generator);
    __ lw(t1, MemOperand(t1));
    __ Branch(&prepare_step_in_suspended_generator, eq, a1, Operand(t1));
    __ 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;
    __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
    __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
  
    // Push receiver.
    __ lw(t1, FieldMemOperand(a1, JSGeneratorObject::kReceiverOffset));
    __ Push(t1);
  
    // ----------- S t a t e -------------
    //  -- a1    : the JSGeneratorObject to resume
    //  -- t0    : generator function
    //  -- cp    : generator context
    //  -- ra    : return address
    //  -- sp[0] : generator receiver
    // -----------------------------------
  
    // Copy the function arguments from the generator object's register file.
  
    __ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
    __ lhu(a3,
           FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
    __ lw(t1,
          FieldMemOperand(a1, JSGeneratorObject::kParametersAndRegistersOffset));
    {
      Label done_loop, loop;
      __ Move(t2, zero_reg);
      __ bind(&loop);
      __ Subu(a3, a3, Operand(1));
      __ Branch(&done_loop, lt, a3, Operand(zero_reg));
      __ Lsa(kScratchReg, t1, t2, kPointerSizeLog2);
      __ lw(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
      __ Push(kScratchReg);
      __ Addu(t2, t2, Operand(1));
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Underlying function needs to have bytecode available.
    if (FLAG_debug_code) {
      __ lw(a3, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
      __ lw(a3, FieldMemOperand(a3, SharedFunctionInfo::kFunctionDataOffset));
      GetSharedFunctionInfoBytecode(masm, a3, a0);
      __ GetObjectType(a3, a3, a3);
      __ Assert(eq, AbortReason::kMissingBytecodeArray, a3,
                Operand(BYTECODE_ARRAY_TYPE));
    }
  
    // Resume (Ignition/TurboFan) generator object.
    {
      __ lw(a0, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
      __ lhu(a0, FieldMemOperand(
                     a0, SharedFunctionInfo::kFormalParameterCountOffset));
      // We abuse new.target both to indicate that this is a resume call and to
      // pass in the generator object.  In ordinary calls, new.target is always
      // undefined because generator functions are non-constructable.
      __ Move(a3, a1);
      __ Move(a1, t0);
      static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
      __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
      __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
      __ Jump(a2);
    }
  
    __ bind(&prepare_step_in_if_stepping);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(a1, t0);
      // Push hole as receiver since we do not use it for stepping.
      __ PushRoot(RootIndex::kTheHoleValue);
      __ CallRuntime(Runtime::kDebugOnFunctionCall);
      __ Pop(a1);
    }
    __ Branch(USE_DELAY_SLOT, &stepping_prepared);
    __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
  
    __ bind(&prepare_step_in_suspended_generator);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(a1);
      __ CallRuntime(Runtime::kDebugPrepareStepInSuspendedGenerator);
      __ Pop(a1);
    }
    __ Branch(USE_DELAY_SLOT, &stepping_prepared);
    __ lw(t0, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
  
    __ bind(&stack_overflow);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ break_(0xCC);  // This should be unreachable.
    }
  }
  
  static void ReplaceClosureCodeWithOptimizedCode(
      MacroAssembler* masm, Register optimized_code, Register closure,
      Register scratch1, Register scratch2, Register scratch3) {
    // Store code entry in the closure.
    __ sw(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
    __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
    __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
                        kRAHasNotBeenSaved, kDontSaveFPRegs, OMIT_REMEMBERED_SET,
                        OMIT_SMI_CHECK);
  }
  
  static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch) {
    Register args_count = scratch;
  
    // Get the arguments + receiver count.
    __ lw(args_count,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ lw(args_count,
          FieldMemOperand(args_count, BytecodeArray::kParameterSizeOffset));
  
    // Leave the frame (also dropping the register file).
    __ LeaveFrame(StackFrame::INTERPRETED);
  
    // Drop receiver + arguments.
    __ Addu(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;
    __ Branch(&no_match, ne, smi_entry, Operand(Smi::FromEnum(marker)));
    GenerateTailCallToReturnedCode(masm, function_id);
    __ bind(&no_match);
  }
  
  static void MaybeTailCallOptimizedCodeSlot(MacroAssembler* masm,
                                             Register feedback_vector,
                                             Register scratch1, Register scratch2,
                                             Register scratch3) {
    // ----------- S t a t e -------------
    //  -- a0 : argument count (preserved for callee if needed, and caller)
    //  -- a3 : new target (preserved for callee if needed, and caller)
    //  -- a1 : target function (preserved for callee if needed, and caller)
    //  -- feedback vector (preserved for caller if needed)
    // -----------------------------------
    DCHECK(
        !AreAliased(feedback_vector, a0, a1, a3, scratch1, scratch2, scratch3));
  
    Label optimized_code_slot_is_weak_ref, fallthrough;
  
    Register closure = a1;
    Register optimized_code_entry = scratch1;
  
    __ lw(optimized_code_entry,
          FieldMemOperand(feedback_vector, FeedbackVector::kOptimizedCodeOffset));
  
    // Check if the code entry is a Smi. If yes, we interpret it as an
    // optimisation marker. Otherwise, interpret it as a weak cell to a code
    // object.
    __ JumpIfNotSmi(optimized_code_entry, &optimized_code_slot_is_weak_ref);
  
    {
      // Optimized code slot is a Smi optimization marker.
  
      // Fall through if no optimization trigger.
      __ Branch(&fallthrough, eq, optimized_code_entry,
                Operand(Smi::FromEnum(OptimizationMarker::kNone)));
  
      TailCallRuntimeIfMarkerEquals(masm, optimized_code_entry,
                                    OptimizationMarker::kLogFirstExecution,
                                    Runtime::kFunctionFirstExecution);
      TailCallRuntimeIfMarkerEquals(masm, optimized_code_entry,
                                    OptimizationMarker::kCompileOptimized,
                                    Runtime::kCompileOptimized_NotConcurrent);
      TailCallRuntimeIfMarkerEquals(
          masm, optimized_code_entry,
          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) {
          __ Assert(
              eq, AbortReason::kExpectedOptimizationSentinel,
              optimized_code_entry,
              Operand(Smi::FromEnum(OptimizationMarker::kInOptimizationQueue)));
        }
        __ jmp(&fallthrough);
      }
    }
  
    {
      // Optimized code slot is a weak reference.
      __ bind(&optimized_code_slot_is_weak_ref);
  
      __ LoadWeakValue(optimized_code_entry, optimized_code_entry, &fallthrough);
  
      // Check if the optimized code is marked for deopt. If it is, call the
      // runtime to clear it.
      Label found_deoptimized_code;
      __ lw(scratch2, FieldMemOperand(optimized_code_entry,
                                      Code::kCodeDataContainerOffset));
      __ lw(scratch2, FieldMemOperand(
                          scratch2, CodeDataContainer::kKindSpecificFlagsOffset));
      __ And(scratch2, scratch2, Operand(1 << Code::kMarkedForDeoptimizationBit));
      __ Branch(&found_deoptimized_code, ne, scratch2, Operand(zero_reg));
  
      // Optimized code is good, get it into the closure and link the closure into
      // the optimized functions list, then tail call the optimized code.
      // The feedback vector is no longer used, so re-use it as a scratch
      // register.
      ReplaceClosureCodeWithOptimizedCode(masm, optimized_code_entry, closure,
                                          scratch2, scratch3, feedback_vector);
      static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
      __ Addu(a2, optimized_code_entry, Code::kHeaderSize - kHeapObjectTag);
      __ Jump(a2);
  
      // Optimized code slot contains deoptimized code, evict it and re-enter the
      // losure's code.
      __ bind(&found_deoptimized_code);
      GenerateTailCallToReturnedCode(masm, Runtime::kEvictOptimizedCodeSlot);
    }
  
    // Fall-through if the optimized code cell is clear and there is no
    // optimization marker.
    __ bind(&fallthrough);
  }
  
  // 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,
                                            Register scratch2, Label* if_return) {
    Register bytecode_size_table = scratch1;
    DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode_size_table,
                       bytecode));
  
    __ li(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));
    __ Branch(&process_bytecode, hi, bytecode, Operand(3));
    __ And(scratch2, bytecode, Operand(1));
    __ Branch(&extra_wide, ne, scratch2, Operand(zero_reg));
  
    // Load the next bytecode and update table to the wide scaled table.
    __ Addu(bytecode_offset, bytecode_offset, Operand(1));
    __ Addu(scratch2, bytecode_array, bytecode_offset);
    __ lbu(bytecode, MemOperand(scratch2));
    __ Addu(bytecode_size_table, bytecode_size_table,
            Operand(kIntSize * interpreter::Bytecodes::kBytecodeCount));
    __ jmp(&process_bytecode);
  
    __ bind(&extra_wide);
    // Load the next bytecode and update table to the extra wide scaled table.
    __ Addu(bytecode_offset, bytecode_offset, Operand(1));
    __ Addu(scratch2, bytecode_array, bytecode_offset);
    __ lbu(bytecode, MemOperand(scratch2));
    __ Addu(bytecode_size_table, bytecode_size_table,
            Operand(2 * kIntSize * interpreter::Bytecodes::kBytecodeCount));
  
    __ bind(&process_bytecode);
  
  // Bailout to the return label if this is a return bytecode.
  #define JUMP_IF_EQUAL(NAME)          \
    __ Branch(if_return, eq, bytecode, \
              Operand(static_cast<int>(interpreter::Bytecode::k##NAME)));
    RETURN_BYTECODE_LIST(JUMP_IF_EQUAL)
  #undef JUMP_IF_EQUAL
  
    // Otherwise, load the size of the current bytecode and advance the offset.
    __ Lsa(scratch2, bytecode_size_table, bytecode, 2);
    __ lw(scratch2, MemOperand(scratch2));
    __ Addu(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 a1: the JS function object being called.
  //   o a3: the incoming new target or generator object
  //   o cp: our context
  //   o fp: the caller's frame pointer
  //   o sp: stack pointer
  //   o ra: return address
  //
  // The function builds an interpreter frame.  See InterpreterFrameConstants in
  // frames.h for its layout.
  void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
    ProfileEntryHookStub::MaybeCallEntryHook(masm);
  
    Register closure = a1;
    Register feedback_vector = a2;
  
    // Load the feedback vector from the closure.
    __ lw(feedback_vector,
          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
    __ lw(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
    // Read off the optimized code slot in the feedback vector, and if there
    // is optimized code or an optimization marker, call that instead.
    MaybeTailCallOptimizedCodeSlot(masm, feedback_vector, t0, t3, t1);
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // MANUAL indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done below).
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ PushStandardFrame(closure);
  
    // Get the bytecode array from the function object and load it into
    // kInterpreterBytecodeArrayRegister.
    __ lw(a0, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    __ lw(kInterpreterBytecodeArrayRegister,
          FieldMemOperand(a0, SharedFunctionInfo::kFunctionDataOffset));
    GetSharedFunctionInfoBytecode(masm, kInterpreterBytecodeArrayRegister, t0);
  
    // Increment invocation count for the function.
    __ lw(t0, FieldMemOperand(feedback_vector,
                              FeedbackVector::kInvocationCountOffset));
    __ Addu(t0, t0, Operand(1));
    __ sw(t0, FieldMemOperand(feedback_vector,
                              FeedbackVector::kInvocationCountOffset));
  
    // Check function data field is actually a BytecodeArray object.
    if (FLAG_debug_code) {
      __ SmiTst(kInterpreterBytecodeArrayRegister, t0);
      __ Assert(ne,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                t0, Operand(zero_reg));
      __ GetObjectType(kInterpreterBytecodeArrayRegister, t0, t0);
      __ Assert(eq,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                t0, Operand(BYTECODE_ARRAY_TYPE));
    }
  
    // Reset code age.
    DCHECK_EQ(0, BytecodeArray::kNoAgeBytecodeAge);
    __ sb(zero_reg, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                    BytecodeArray::kBytecodeAgeOffset));
  
    // Load initial bytecode offset.
    __ li(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
  
    // Push bytecode array and Smi tagged bytecode array offset.
    __ SmiTag(t0, kInterpreterBytecodeOffsetRegister);
    __ Push(kInterpreterBytecodeArrayRegister, t0);
  
    // Allocate the local and temporary register file on the stack.
    {
      // Load frame size from the BytecodeArray object.
      __ lw(t0, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                BytecodeArray::kFrameSizeOffset));
  
      // Do a stack check to ensure we don't go over the limit.
      Label ok;
      __ Subu(t1, sp, Operand(t0));
      __ LoadRoot(a2, RootIndex::kRealStackLimit);
      __ Branch(&ok, hs, t1, Operand(a2));
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ bind(&ok);
  
      // If ok, push undefined as the initial value for all register file entries.
      Label loop_header;
      Label loop_check;
      __ LoadRoot(t1, RootIndex::kUndefinedValue);
      __ Branch(&loop_check);
      __ bind(&loop_header);
      // TODO(rmcilroy): Consider doing more than one push per loop iteration.
      __ push(t1);
      // Continue loop if not done.
      __ bind(&loop_check);
      __ Subu(t0, t0, Operand(kPointerSize));
      __ Branch(&loop_header, ge, t0, Operand(zero_reg));
    }
  
    // If the bytecode array has a valid incoming new target or generator object
    // register, initialize it with incoming value which was passed in r3.
    Label no_incoming_new_target_or_generator_register;
    __ lw(t1, FieldMemOperand(
                  kInterpreterBytecodeArrayRegister,
                  BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
    __ Branch(&no_incoming_new_target_or_generator_register, eq, t1,
              Operand(zero_reg));
    __ Lsa(t1, fp, t1, kPointerSizeLog2);
    __ sw(a3, MemOperand(t1));
    __ bind(&no_incoming_new_target_or_generator_register);
  
    // Load accumulator with undefined.
    __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
  
    // Load the dispatch table into a register and dispatch to the bytecode
    // handler at the current bytecode offset.
    Label do_dispatch;
    __ bind(&do_dispatch);
    __ li(kInterpreterDispatchTableRegister,
          ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
    __ Addu(a0, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
    __ lbu(t3, MemOperand(a0));
    __ Lsa(kScratchReg, kInterpreterDispatchTableRegister, t3, kPointerSizeLog2);
    __ lw(kJavaScriptCallCodeStartRegister, MemOperand(kScratchReg));
    __ 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.
    __ lw(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ lw(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
    // Either return, or advance to the next bytecode and dispatch.
    Label do_return;
    __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
    __ lbu(a1, MemOperand(a1));
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                  &do_return);
    __ jmp(&do_dispatch);
  
    __ bind(&do_return);
    // The return value is in v0.
    LeaveInterpreterFrame(masm, t0);
    __ Jump(ra);
  }
  
  
  static void Generate_StackOverflowCheck(MacroAssembler* masm, Register num_args,
                                          Register scratch1, Register scratch2,
                                          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.
    __ LoadRoot(scratch1, RootIndex::kRealStackLimit);
    // Make scratch1 the space we have left. The stack might already be overflowed
    // here which will cause scratch1 to become negative.
    __ subu(scratch1, sp, scratch1);
    // Check if the arguments will overflow the stack.
    __ sll(scratch2, num_args, kPointerSizeLog2);
    // Signed comparison.
    __ Branch(stack_overflow, le, scratch1, Operand(scratch2));
  }
  
  static void Generate_InterpreterPushArgs(MacroAssembler* masm,
                                           Register num_args, Register index,
                                           Register scratch, Register scratch2) {
    // Find the address of the last argument.
    __ mov(scratch2, num_args);
    __ sll(scratch2, scratch2, kPointerSizeLog2);
    __ Subu(scratch2, index, Operand(scratch2));
  
    // Push the arguments.
    Label loop_header, loop_check;
    __ Branch(&loop_check);
    __ bind(&loop_header);
    __ lw(scratch, MemOperand(index));
    __ Addu(index, index, Operand(-kPointerSize));
    __ push(scratch);
    __ bind(&loop_check);
    __ Branch(&loop_header, gt, index, Operand(scratch2));
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsThenCallImpl(
      MacroAssembler* masm, ConvertReceiverMode receiver_mode,
      InterpreterPushArgsMode mode) {
    DCHECK(mode != InterpreterPushArgsMode::kArrayFunction);
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a2 : 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.
    //  -- a1 : the target to call (can be any Object).
    // -----------------------------------
    Label stack_overflow;
  
    __ Addu(t0, a0, Operand(1));  // Add one for receiver.
  
    Generate_StackOverflowCheck(masm, t0, t4, t1, &stack_overflow);
  
    // Push "undefined" as the receiver arg if we need to.
    if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
      __ PushRoot(RootIndex::kUndefinedValue);
      __ mov(t0, a0);  // No receiver.
    }
  
    // This function modifies a2, t4 and t1.
    Generate_InterpreterPushArgs(masm, t0, a2, t4, t1);
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      __ Pop(a2);                   // Pass the spread in a register
      __ Subu(a0, a0, 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.
      __ break_(0xCC);
    }
  }
  
  // static
  void Builtins::Generate_InterpreterPushArgsThenConstructImpl(
      MacroAssembler* masm, InterpreterPushArgsMode mode) {
    // ----------- S t a t e -------------
    // -- a0 : argument count (not including receiver)
    // -- a3 : new target
    // -- a1 : constructor to call
    // -- a2 : allocation site feedback if available, undefined otherwise.
    // -- t4 : address of the first argument
    // -----------------------------------
    Label stack_overflow;
  
    // Push a slot for the receiver.
    __ push(zero_reg);
  
    Generate_StackOverflowCheck(masm, a0, t1, t0, &stack_overflow);
  
    // This function modified t4, t1 and t0.
    Generate_InterpreterPushArgs(masm, a0, t4, t1, t0);
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      __ Pop(a2);                   // Pass the spread in a register
      __ Subu(a0, a0, Operand(1));  // Subtract one for spread
    } else {
      __ AssertUndefinedOrAllocationSite(a2, t0);
    }
  
    if (mode == InterpreterPushArgsMode::kArrayFunction) {
      __ AssertFunction(a1);
  
      // Tail call to the array construct stub (still in the caller
      // context at this point).
      __ Jump(BUILTIN_CODE(masm->isolate(), ArrayConstructorImpl),
              RelocInfo::CODE_TARGET);
    } else if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // Call the constructor with a0, a1, and a3 unmodified.
      __ Jump(BUILTIN_CODE(masm->isolate(), ConstructWithSpread),
              RelocInfo::CODE_TARGET);
    } else {
      DCHECK_EQ(InterpreterPushArgsMode::kOther, mode);
      // Call the constructor with a0, a1, and a3 unmodified.
      __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
    }
  
    __ bind(&stack_overflow);
    {
      __ TailCallRuntime(Runtime::kThrowStackOverflow);
      // Unreachable code.
      __ break_(0xCC);
    }
  }
  
  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, get the trampoline stored
    // in it, otherwise get the trampoline from the builtins list.
    __ lw(t0, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
    __ lw(t0, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
    __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kFunctionDataOffset));
    __ GetObjectType(t0, kInterpreterDispatchTableRegister,
                     kInterpreterDispatchTableRegister);
    __ Branch(&builtin_trampoline, ne, kInterpreterDispatchTableRegister,
              Operand(INTERPRETER_DATA_TYPE));
  
    __ lw(t0, FieldMemOperand(t0, InterpreterData::kInterpreterTrampolineOffset));
    __ Branch(&trampoline_loaded);
  
    __ bind(&builtin_trampoline);
    __ li(t0, BUILTIN_CODE(masm->isolate(), InterpreterEntryTrampoline));
  
    __ bind(&trampoline_loaded);
    __ Addu(ra, t0, Operand(interpreter_entry_return_pc_offset->value() +
                            Code::kHeaderSize - kHeapObjectTag));
  
    // Initialize the dispatch table register.
    __ li(kInterpreterDispatchTableRegister,
          ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
  
    // Get the bytecode array pointer from the frame.
    __ lw(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
  
    if (FLAG_debug_code) {
      // Check function data field is actually a BytecodeArray object.
      __ SmiTst(kInterpreterBytecodeArrayRegister, kScratchReg);
      __ Assert(ne,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                kScratchReg, Operand(zero_reg));
      __ GetObjectType(kInterpreterBytecodeArrayRegister, a1, a1);
      __ Assert(eq,
                AbortReason::kFunctionDataShouldBeBytecodeArrayOnInterpreterEntry,
                a1, Operand(BYTECODE_ARRAY_TYPE));
    }
  
    // Get the target bytecode offset from the frame.
    __ lw(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Dispatch to the target bytecode.
    __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
    __ lbu(t3, MemOperand(a1));
    __ Lsa(a1, kInterpreterDispatchTableRegister, t3, kPointerSizeLog2);
    __ lw(kJavaScriptCallCodeStartRegister, MemOperand(a1));
    __ Jump(kJavaScriptCallCodeStartRegister);
  }
  
  void Builtins::Generate_InterpreterEnterBytecodeAdvance(MacroAssembler* masm) {
    // Advance the current bytecode offset stored within the given interpreter
    // stack frame. This simulates what all bytecode handlers do upon completion
    // of the underlying operation.
    __ lw(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ lw(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Load the current bytecode.
    __ Addu(a1, kInterpreterBytecodeArrayRegister,
            kInterpreterBytecodeOffsetRegister);
    __ lbu(a1, MemOperand(a1));
  
    // Advance to the next bytecode.
    Label if_return;
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                  &if_return);
  
    // Convert new bytecode offset to a Smi and save in the stackframe.
    __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
    __ sw(a2, 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 -------------
    //  -- a0 : argument count (preserved for callee)
    //  -- a1 : new target (preserved for callee)
    //  -- a3 : target function (preserved for callee)
    // -----------------------------------
    Label failed;
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Preserve argument count for later compare.
      __ Move(t4, a0);
      // Push a copy of the target function and the new target.
      // Push function as parameter to the runtime call.
      __ SmiTag(a0);
      __ Push(a0, a1, a3, a1);
  
      // Copy arguments from caller (stdlib, foreign, heap).
      Label args_done;
      for (int j = 0; j < 4; ++j) {
        Label over;
        if (j < 3) {
          __ Branch(&over, ne, t4, Operand(j));
        }
        for (int i = j - 1; i >= 0; --i) {
          __ lw(t4, MemOperand(fp, StandardFrameConstants::kCallerSPOffset +
                                       i * kPointerSize));
          __ push(t4);
        }
        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(v0, &failed);
  
      __ Drop(2);
      __ pop(t4);
      __ SmiUntag(t4);
      scope.GenerateLeaveFrame();
  
      __ Addu(t4, t4, Operand(1));
      __ Lsa(sp, sp, t4, kPointerSizeLog2);
      __ Ret();
  
      __ bind(&failed);
      // Restore target function and new target.
      __ Pop(a0, a1, a3);
      __ SmiUntag(a0);
    }
    // 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 == a2, "ABI mismatch");
    __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
    __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
    __ Jump(a2);
  }
  
  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.
      __ sw(v0,
            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));
      }
    }
    __ lw(fp, MemOperand(
                  sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    __ Pop(t0);
    __ Addu(sp, sp,
            Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    __ Pop(ra);
    __ Addu(t0, t0, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Jump(t0);
  }
  }  // 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) {
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kNotifyDeoptimized);
    }
  
    DCHECK_EQ(kInterpreterAccumulatorRegister.code(), v0.code());
    __ lw(v0, MemOperand(sp, 0 * kPointerSize));
    __ Ret(USE_DELAY_SLOT);
    // Safe to fill delay slot Addu will emit one instruction.
    __ Addu(sp, sp, Operand(1 * kPointerSize));  // Remove accumulator.
  }
  
  void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
    // Lookup the function in the JavaScript frame.
    __ lw(a0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ lw(a0, MemOperand(a0, JavaScriptFrameConstants::kFunctionOffset));
  
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Pass function as argument.
      __ push(a0);
      __ CallRuntime(Runtime::kCompileForOnStackReplacement);
    }
  
    // If the code object is null, just return to the caller.
    __ Ret(eq, v0, Operand(Smi::zero()));
  
    // 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]
    __ lw(a1, MemOperand(v0, Code::kDeoptimizationDataOffset - kHeapObjectTag));
  
    // Load the OSR entrypoint offset from the deoptimization data.
    // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
    __ lw(a1, MemOperand(a1, FixedArray::OffsetOfElementAt(
                                 DeoptimizationData::kOsrPcOffsetIndex) -
                                 kHeapObjectTag));
    __ SmiUntag(a1);
  
    // Compute the target address = code_obj + header_size + osr_offset
    // <entry_addr> = <code_obj> + #header_size + <osr_offset>
    __ Addu(v0, v0, a1);
    __ addiu(ra, v0, Code::kHeaderSize - kHeapObjectTag);
  
    // And "return" to the OSR entry point of the function.
    __ Ret();
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0    : argc
    //  -- sp[0] : argArray
    //  -- sp[4] : thisArg
    //  -- sp[8] : receiver
    // -----------------------------------
  
    // 1. Load receiver into a1, argArray into a0 (if present), remove all
    // arguments from the stack (including the receiver), and push thisArg (if
    // present) instead.
    {
      Label no_arg;
      Register scratch = t0;
      __ LoadRoot(a2, RootIndex::kUndefinedValue);
      __ mov(a3, a2);
      // Lsa() cannot be used hare as scratch value used later.
      __ sll(scratch, a0, kPointerSizeLog2);
      __ Addu(a0, sp, Operand(scratch));
      __ lw(a1, MemOperand(a0));  // receiver
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a2, MemOperand(a0));  // thisArg
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a3, MemOperand(a0));  // argArray
      __ bind(&no_arg);
      __ Addu(sp, sp, Operand(scratch));
      __ sw(a2, MemOperand(sp));
      __ mov(a2, a3);
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argArray
    //  -- a1    : 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(a2, RootIndex::kNullValue, &no_arguments);
    __ JumpIfRoot(a2, 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);
    {
      __ mov(a0, zero_reg);
      __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    }
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
    // 1. Make sure we have at least one argument.
    // a0: actual number of arguments
    {
      Label done;
      __ Branch(&done, ne, a0, Operand(zero_reg));
      __ PushRoot(RootIndex::kUndefinedValue);
      __ Addu(a0, a0, Operand(1));
      __ bind(&done);
    }
  
    // 2. Get the function to call (passed as receiver) from the stack.
    // a0: actual number of arguments
    __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
    __ lw(a1, MemOperand(kScratchReg));
  
    // 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.
    // a0: actual number of arguments
    // a1: function
    {
      Label loop;
      // Calculate the copy start address (destination). Copy end address is sp.
      __ Lsa(a2, sp, a0, kPointerSizeLog2);
  
      __ bind(&loop);
      __ lw(kScratchReg, MemOperand(a2, -kPointerSize));
      __ sw(kScratchReg, MemOperand(a2));
      __ Subu(a2, a2, Operand(kPointerSize));
      __ Branch(&loop, ne, a2, Operand(sp));
      // Adjust the actual number of arguments and remove the top element
      // (which is a copy of the last argument).
      __ Subu(a0, a0, 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 -------------
    //  -- a0     : argc
    //  -- sp[0]  : argumentsList
    //  -- sp[4]  : thisArgument
    //  -- sp[8]  : target
    //  -- sp[12] : receiver
    // -----------------------------------
  
    // 1. Load target into a1 (if present), argumentsList into a0 (if present),
    // remove all arguments from the stack (including the receiver), and push
    // thisArgument (if present) instead.
    {
      Label no_arg;
      Register scratch = t0;
      __ LoadRoot(a1, RootIndex::kUndefinedValue);
      __ mov(a2, a1);
      __ mov(a3, a1);
      __ sll(scratch, a0, kPointerSizeLog2);
      __ mov(a0, scratch);
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(zero_reg));
      __ Addu(a0, sp, Operand(a0));
      __ lw(a1, MemOperand(a0));  // target
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a2, MemOperand(a0));  // thisArgument
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a3, MemOperand(a0));  // argumentsList
      __ bind(&no_arg);
      __ Addu(sp, sp, Operand(scratch));
      __ sw(a2, MemOperand(sp));
      __ mov(a2, a3);
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argumentsList
    //  -- a1    : 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 -------------
    //  -- a0     : argc
    //  -- sp[0]  : new.target (optional)
    //  -- sp[4]  : argumentsList
    //  -- sp[8]  : target
    //  -- sp[12] : receiver
    // -----------------------------------
  
    // 1. Load target into a1 (if present), argumentsList into a0 (if present),
    // new.target into a3 (if present, otherwise use target), remove all
    // arguments from the stack (including the receiver), and push thisArgument
    // (if present) instead.
    {
      Label no_arg;
      Register scratch = t0;
      __ LoadRoot(a1, RootIndex::kUndefinedValue);
      __ mov(a2, a1);
      // Lsa() cannot be used hare as scratch value used later.
      __ sll(scratch, a0, kPointerSizeLog2);
      __ Addu(a0, sp, Operand(scratch));
      __ sw(a2, MemOperand(a0));  // receiver
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a1, MemOperand(a0));  // target
      __ mov(a3, a1);             // new.target defaults to target
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a2, MemOperand(a0));  // argumentsList
      __ Subu(a0, a0, Operand(kPointerSize));
      __ Branch(&no_arg, lt, a0, Operand(sp));
      __ lw(a3, MemOperand(a0));  // new.target
      __ bind(&no_arg);
      __ Addu(sp, sp, Operand(scratch));
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argumentsList
    //  -- a3    : new.target
    //  -- a1    : 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) {
    __ sll(a0, a0, kSmiTagSize);
    __ li(t0, Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
    __ MultiPush(a0.bit() | a1.bit() | t0.bit() | fp.bit() | ra.bit());
    __ Push(Smi::zero());  // Padding.
    __ Addu(fp, sp,
            Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp));
  }
  
  static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- v0 : result being passed through
    // -----------------------------------
    // Get the number of arguments passed (as a smi), tear down the frame and
    // then tear down the parameters.
    __ lw(a1, MemOperand(fp, ArgumentsAdaptorFrameConstants::kLengthOffset));
    __ mov(sp, fp);
    __ MultiPop(fp.bit() | ra.bit());
    __ Lsa(sp, sp, a1, kPointerSizeLog2 - kSmiTagSize);
    // Adjust for the receiver.
    __ Addu(sp, sp, Operand(kPointerSize));
  }
  
  // static
  void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                 Handle<Code> code) {
    // ----------- S t a t e -------------
    //  -- a1 : target
    //  -- a0 : number of parameters on the stack (not including the receiver)
    //  -- a2 : arguments list (a FixedArray)
    //  -- t0 : len (number of elements to push from args)
    //  -- a3 : new.target (for [[Construct]])
    // -----------------------------------
    if (masm->emit_debug_code()) {
      // Allow a2 to be a FixedArray, or a FixedDoubleArray if t0 == 0.
      Label ok, fail;
      __ AssertNotSmi(a2);
      __ GetObjectType(a2, t8, t8);
      __ Branch(&ok, eq, t8, Operand(FIXED_ARRAY_TYPE));
      __ Branch(&fail, ne, t8, Operand(FIXED_DOUBLE_ARRAY_TYPE));
      __ Branch(&ok, eq, t0, Operand(0));
      // Fall through.
      __ bind(&fail);
      __ Abort(AbortReason::kOperandIsNotAFixedArray);
  
      __ bind(&ok);
    }
  
    // Check for stack overflow.
    Label stack_overflow;
    Generate_StackOverflowCheck(masm, t0, kScratchReg, t1, &stack_overflow);
  
    // Push arguments onto the stack (thisArgument is already on the stack).
    {
      __ mov(t2, zero_reg);
      Label done, push, loop;
      __ LoadRoot(t1, RootIndex::kTheHoleValue);
      __ bind(&loop);
      __ Branch(&done, eq, t2, Operand(t0));
      __ Lsa(kScratchReg, a2, t2, kPointerSizeLog2);
      __ lw(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
      __ Branch(&push, ne, t1, Operand(kScratchReg));
      __ LoadRoot(kScratchReg, RootIndex::kUndefinedValue);
      __ bind(&push);
      __ Push(kScratchReg);
      __ Addu(t2, t2, Operand(1));
      __ Branch(&loop);
      __ bind(&done);
      __ Addu(a0, a0, t2);
    }
  
    // 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 -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a3 : the new.target (for [[Construct]] calls)
    //  -- a1 : the target to call (can be any Object)
    //  -- a2 : start index (to support rest parameters)
    // -----------------------------------
  
    // Check if new.target has a [[Construct]] internal method.
    if (mode == CallOrConstructMode::kConstruct) {
      Label new_target_constructor, new_target_not_constructor;
      __ JumpIfSmi(a3, &new_target_not_constructor);
      __ lw(t1, FieldMemOperand(a3, HeapObject::kMapOffset));
      __ lbu(t1, FieldMemOperand(t1, Map::kBitFieldOffset));
      __ And(t1, t1, Operand(Map::IsConstructorBit::kMask));
      __ Branch(&new_target_constructor, ne, t1, Operand(zero_reg));
      __ bind(&new_target_not_constructor);
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ Push(a3);
        __ CallRuntime(Runtime::kThrowNotConstructor);
      }
      __ bind(&new_target_constructor);
    }
  
    // Check if we have an arguments adaptor frame below the function frame.
    Label arguments_adaptor, arguments_done;
    __ lw(t3, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
    __ lw(t2, MemOperand(t3, CommonFrameConstants::kContextOrFrameTypeOffset));
    __ Branch(&arguments_adaptor, eq, t2,
              Operand(StackFrame::TypeToMarker(StackFrame::ARGUMENTS_ADAPTOR)));
    {
      __ lw(t2, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
      __ lw(t2, FieldMemOperand(t2, JSFunction::kSharedFunctionInfoOffset));
      __ lhu(t2, FieldMemOperand(
                     t2, SharedFunctionInfo::kFormalParameterCountOffset));
      __ mov(t3, fp);
    }
    __ Branch(&arguments_done);
    __ bind(&arguments_adaptor);
    {
      // Just get the length from the ArgumentsAdaptorFrame.
      __ lw(t2, MemOperand(t3, ArgumentsAdaptorFrameConstants::kLengthOffset));
      __ SmiUntag(t2);
    }
    __ bind(&arguments_done);
  
    Label stack_done, stack_overflow;
    __ Subu(t2, t2, a2);
    __ Branch(&stack_done, le, t2, Operand(zero_reg));
    {
      // Check for stack overflow.
      Generate_StackOverflowCheck(masm, t2, t0, t1, &stack_overflow);
  
      // Forward the arguments from the caller frame.
      {
        Label loop;
        __ Addu(a0, a0, t2);
        __ bind(&loop);
        {
          __ Lsa(kScratchReg, t3, t2, kPointerSizeLog2);
          __ lw(kScratchReg, MemOperand(kScratchReg, 1 * kPointerSize));
          __ push(kScratchReg);
          __ Subu(t2, t2, Operand(1));
          __ Branch(&loop, ne, t2, Operand(zero_reg));
        }
      }
    }
    __ Branch(&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 -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSFunction)
    // -----------------------------------
    __ AssertFunction(a1);
  
    // See ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
    // Check that the function is not a "classConstructor".
    Label class_constructor;
    __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
    __ lw(a3, FieldMemOperand(a2, SharedFunctionInfo::kFlagsOffset));
    __ And(kScratchReg, a3,
           Operand(SharedFunctionInfo::IsClassConstructorBit::kMask));
    __ Branch(&class_constructor, ne, kScratchReg, Operand(zero_reg));
  
    // 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.
    __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
    // We need to convert the receiver for non-native sloppy mode functions.
    Label done_convert;
    __ lw(a3, FieldMemOperand(a2, SharedFunctionInfo::kFlagsOffset));
    __ And(kScratchReg, a3,
           Operand(SharedFunctionInfo::IsNativeBit::kMask |
                   SharedFunctionInfo::IsStrictBit::kMask));
    __ Branch(&done_convert, ne, kScratchReg, Operand(zero_reg));
    {
      // ----------- S t a t e -------------
      //  -- a0 : the number of arguments (not including the receiver)
      //  -- a1 : the function to call (checked to be a JSFunction)
      //  -- a2 : the shared function info.
      //  -- cp : the function context.
      // -----------------------------------
  
      if (mode == ConvertReceiverMode::kNullOrUndefined) {
        // Patch receiver to global proxy.
        __ LoadGlobalProxy(a3);
      } else {
        Label convert_to_object, convert_receiver;
        __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
        __ lw(a3, MemOperand(kScratchReg));
        __ JumpIfSmi(a3, &convert_to_object);
        STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
        __ GetObjectType(a3, t0, t0);
        __ Branch(&done_convert, hs, t0, Operand(FIRST_JS_RECEIVER_TYPE));
        if (mode != ConvertReceiverMode::kNotNullOrUndefined) {
          Label convert_global_proxy;
          __ JumpIfRoot(a3, RootIndex::kUndefinedValue, &convert_global_proxy);
          __ JumpIfNotRoot(a3, RootIndex::kNullValue, &convert_to_object);
          __ bind(&convert_global_proxy);
          {
            // Patch receiver to global proxy.
            __ LoadGlobalProxy(a3);
          }
          __ Branch(&convert_receiver);
        }
        __ bind(&convert_to_object);
        {
          // Convert receiver using ToObject.
          // TODO(bmeurer): Inline the allocation here to avoid building the frame
          // in the fast case? (fall back to AllocateInNewSpace?)
          FrameScope scope(masm, StackFrame::INTERNAL);
          __ sll(a0, a0, kSmiTagSize);  // Smi tagged.
          __ Push(a0, a1);
          __ mov(a0, a3);
          __ Push(cp);
          __ Call(BUILTIN_CODE(masm->isolate(), ToObject),
                  RelocInfo::CODE_TARGET);
          __ Pop(cp);
          __ mov(a3, v0);
          __ Pop(a0, a1);
          __ sra(a0, a0, kSmiTagSize);  // Un-tag.
        }
        __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
        __ bind(&convert_receiver);
      }
      __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
      __ sw(a3, MemOperand(kScratchReg));
    }
    __ bind(&done_convert);
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSFunction)
    //  -- a2 : the shared function info.
    //  -- cp : the function context.
    // -----------------------------------
  
    __ lhu(a2,
           FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
    ParameterCount actual(a0);
    ParameterCount expected(a2);
    __ InvokeFunctionCode(a1, no_reg, expected, actual, JUMP_FUNCTION);
  
    // The function is a "classConstructor", need to raise an exception.
    __ bind(&class_constructor);
    {
      FrameScope frame(masm, StackFrame::INTERNAL);
      __ Push(a1);
      __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
    }
  }
  
  // static
  void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    // -----------------------------------
    __ AssertBoundFunction(a1);
  
    // Patch the receiver to [[BoundThis]].
    {
      __ lw(kScratchReg, FieldMemOperand(a1, JSBoundFunction::kBoundThisOffset));
      __ Lsa(t0, sp, a0, kPointerSizeLog2);
      __ sw(kScratchReg, MemOperand(t0));
    }
  
    // Load [[BoundArguments]] into a2 and length of that into t0.
    __ lw(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
    __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
    __ SmiUntag(t0);
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    //  -- a2 : the [[BoundArguments]] (implemented as FixedArray)
    //  -- t0 : the number of [[BoundArguments]]
    // -----------------------------------
  
    // Reserve stack space for the [[BoundArguments]].
    {
      Label done;
      __ sll(t1, t0, kPointerSizeLog2);
      __ Subu(sp, sp, Operand(t1));
      // 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".
      __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
      __ Branch(&done, hs, sp, Operand(kScratchReg));
      // Restore the stack pointer.
      __ Addu(sp, sp, Operand(t1));
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowStackOverflow);
      }
      __ bind(&done);
    }
  
    // Relocate arguments down the stack.
    {
      Label loop, done_loop;
      __ mov(t1, zero_reg);
      __ bind(&loop);
      __ Branch(&done_loop, gt, t1, Operand(a0));
      __ Lsa(t2, sp, t0, kPointerSizeLog2);
      __ lw(kScratchReg, MemOperand(t2));
      __ Lsa(t2, sp, t1, kPointerSizeLog2);
      __ sw(kScratchReg, MemOperand(t2));
      __ Addu(t0, t0, Operand(1));
      __ Addu(t1, t1, Operand(1));
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Copy [[BoundArguments]] to the stack (below the arguments).
    {
      Label loop, done_loop;
      __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
      __ SmiUntag(t0);
      __ Addu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ bind(&loop);
      __ Subu(t0, t0, Operand(1));
      __ Branch(&done_loop, lt, t0, Operand(zero_reg));
      __ Lsa(t1, a2, t0, kPointerSizeLog2);
      __ lw(kScratchReg, MemOperand(t1));
      __ Lsa(t1, sp, a0, kPointerSizeLog2);
      __ sw(kScratchReg, MemOperand(t1));
      __ Addu(a0, a0, Operand(1));
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Call the [[BoundTargetFunction]] via the Call builtin.
    __ lw(a1, FieldMemOperand(a1, 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 -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the target to call (can be any Object).
    // -----------------------------------
  
    Label non_callable, non_function, non_smi;
    __ JumpIfSmi(a1, &non_callable);
    __ bind(&non_smi);
    __ GetObjectType(a1, t1, t2);
    __ Jump(masm->isolate()->builtins()->CallFunction(mode),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_FUNCTION_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), CallBoundFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_BOUND_FUNCTION_TYPE));
  
    // Check if target has a [[Call]] internal method.
    __ lbu(t1, FieldMemOperand(t1, Map::kBitFieldOffset));
    __ And(t1, t1, Operand(Map::IsCallableBit::kMask));
    __ Branch(&non_callable, eq, t1, Operand(zero_reg));
  
    // Check if target is a proxy and call CallProxy external builtin
    __ Branch(&non_function, ne, t2, Operand(JS_PROXY_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), CallProxy), RelocInfo::CODE_TARGET);
  
    // 2. Call to something else, which might have a [[Call]] internal method (if
    // not we raise an exception).
    __ bind(&non_function);
    // Overwrite the original receiver with the (original) target.
    __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
    __ sw(a1, MemOperand(kScratchReg));
    // Let the "call_as_function_delegate" take care of the rest.
    __ LoadNativeContextSlot(Context::CALL_AS_FUNCTION_DELEGATE_INDEX, a1);
    __ Jump(masm->isolate()->builtins()->CallFunction(
                ConvertReceiverMode::kNotNullOrUndefined),
            RelocInfo::CODE_TARGET);
  
    // 3. Call to something that is not callable.
    __ bind(&non_callable);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(a1);
      __ CallRuntime(Runtime::kThrowCalledNonCallable);
    }
  }
  
  // static
  void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the constructor to call (checked to be a JSFunction)
    //  -- a3 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertConstructor(a1);
    __ AssertFunction(a1);
  
    // Calling convention for function specific ConstructStubs require
    // a2 to contain either an AllocationSite or undefined.
    __ LoadRoot(a2, RootIndex::kUndefinedValue);
  
    Label call_generic_stub;
  
    // Jump to JSBuiltinsConstructStub or JSConstructStubGeneric.
    __ lw(t0, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
    __ lw(t0, FieldMemOperand(t0, SharedFunctionInfo::kFlagsOffset));
    __ And(t0, t0, Operand(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
    __ Branch(&call_generic_stub, eq, t0, Operand(zero_reg));
  
    __ 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 -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    //  -- a3 : the new target (checked to be a constructor)
    // -----------------------------------
    __ AssertConstructor(a1);
    __ AssertBoundFunction(a1);
  
    // Load [[BoundArguments]] into a2 and length of that into t0.
    __ lw(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
    __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
    __ SmiUntag(t0);
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    //  -- a2 : the [[BoundArguments]] (implemented as FixedArray)
    //  -- a3 : the new target (checked to be a constructor)
    //  -- t0 : the number of [[BoundArguments]]
    // -----------------------------------
  
    // Reserve stack space for the [[BoundArguments]].
    {
      Label done;
      __ sll(t1, t0, kPointerSizeLog2);
      __ Subu(sp, sp, Operand(t1));
      // 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".
      __ LoadRoot(kScratchReg, RootIndex::kRealStackLimit);
      __ Branch(&done, hs, sp, Operand(kScratchReg));
      // Restore the stack pointer.
      __ Addu(sp, sp, Operand(t1));
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowStackOverflow);
      }
      __ bind(&done);
    }
  
    // Relocate arguments down the stack.
    {
      Label loop, done_loop;
      __ mov(t1, zero_reg);
      __ bind(&loop);
      __ Branch(&done_loop, ge, t1, Operand(a0));
      __ Lsa(t2, sp, t0, kPointerSizeLog2);
      __ lw(kScratchReg, MemOperand(t2));
      __ Lsa(t2, sp, t1, kPointerSizeLog2);
      __ sw(kScratchReg, MemOperand(t2));
      __ Addu(t0, t0, Operand(1));
      __ Addu(t1, t1, Operand(1));
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Copy [[BoundArguments]] to the stack (below the arguments).
    {
      Label loop, done_loop;
      __ lw(t0, FieldMemOperand(a2, FixedArray::kLengthOffset));
      __ SmiUntag(t0);
      __ Addu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ bind(&loop);
      __ Subu(t0, t0, Operand(1));
      __ Branch(&done_loop, lt, t0, Operand(zero_reg));
      __ Lsa(t1, a2, t0, kPointerSizeLog2);
      __ lw(kScratchReg, MemOperand(t1));
      __ Lsa(t1, sp, a0, kPointerSizeLog2);
      __ sw(kScratchReg, MemOperand(t1));
      __ Addu(a0, a0, Operand(1));
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
    {
      Label skip_load;
      __ Branch(&skip_load, ne, a1, Operand(a3));
      __ lw(a3, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
      __ bind(&skip_load);
    }
  
    // Construct the [[BoundTargetFunction]] via the Construct builtin.
    __ lw(a1, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
    __ Jump(BUILTIN_CODE(masm->isolate(), Construct), RelocInfo::CODE_TARGET);
  }
  
  // static
  void Builtins::Generate_Construct(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments (not including the receiver)
    //  -- a1 : the constructor to call (can be any Object)
    //  -- a3 : 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(a1, &non_constructor);
  
    // Check if target has a [[Construct]] internal method.
    __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
    __ lbu(t3, FieldMemOperand(t1, Map::kBitFieldOffset));
    __ And(t3, t3, Operand(Map::IsConstructorBit::kMask));
    __ Branch(&non_constructor, eq, t3, Operand(zero_reg));
  
    // Dispatch based on instance type.
    __ lhu(t2, FieldMemOperand(t1, Map::kInstanceTypeOffset));
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_FUNCTION_TYPE));
  
    // Only dispatch to bound functions after checking whether they are
    // constructors.
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructBoundFunction),
            RelocInfo::CODE_TARGET, eq, t2, Operand(JS_BOUND_FUNCTION_TYPE));
  
    // Only dispatch to proxies after checking whether they are constructors.
    __ Branch(&non_proxy, ne, t2, Operand(JS_PROXY_TYPE));
    __ 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.
      __ Lsa(kScratchReg, sp, a0, kPointerSizeLog2);
      __ sw(a1, MemOperand(kScratchReg));
      // Let the "call_as_constructor_delegate" take care of the rest.
      __ LoadNativeContextSlot(Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, a1);
      __ 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) {
    // State setup as expected by MacroAssembler::InvokePrologue.
    // ----------- S t a t e -------------
    //  -- a0: actual arguments count
    //  -- a1: function (passed through to callee)
    //  -- a2: expected arguments count
    //  -- a3: new target (passed through to callee)
    // -----------------------------------
  
    Label invoke, dont_adapt_arguments, stack_overflow;
  
    Label enough, too_few;
    __ Branch(&dont_adapt_arguments, eq, a2,
              Operand(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
    // We use Uless as the number of argument should always be greater than 0.
    __ Branch(&too_few, Uless, a0, Operand(a2));
  
    {  // Enough parameters: actual >= expected.
      // a0: actual number of arguments as a smi
      // a1: function
      // a2: expected number of arguments
      // a3: new target (passed through to callee)
      __ bind(&enough);
      EnterArgumentsAdaptorFrame(masm);
      Generate_StackOverflowCheck(masm, a2, t1, kScratchReg, &stack_overflow);
  
      // Calculate copy start address into a0 and copy end address into t1.
      __ Lsa(a0, fp, a0, kPointerSizeLog2 - kSmiTagSize);
      // Adjust for return address and receiver.
      __ Addu(a0, a0, Operand(2 * kPointerSize));
      // Compute copy end address.
      __ sll(t1, a2, kPointerSizeLog2);
      __ subu(t1, a0, t1);
  
      // Copy the arguments (including the receiver) to the new stack frame.
      // a0: copy start address
      // a1: function
      // a2: expected number of arguments
      // a3: new target (passed through to callee)
      // t1: copy end address
  
      Label copy;
      __ bind(&copy);
      __ lw(t0, MemOperand(a0));
      __ push(t0);
      __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(t1));
      __ addiu(a0, a0, -kPointerSize);  // In delay slot.
  
      __ jmp(&invoke);
    }
  
    {  // Too few parameters: Actual < expected.
      __ bind(&too_few);
      EnterArgumentsAdaptorFrame(masm);
      Generate_StackOverflowCheck(masm, a2, t1, kScratchReg, &stack_overflow);
  
      // Calculate copy start address into a0 and copy end address into t3.
      // a0: actual number of arguments as a smi
      // a1: function
      // a2: expected number of arguments
      // a3: new target (passed through to callee)
      __ Lsa(a0, fp, a0, kPointerSizeLog2 - kSmiTagSize);
      // Adjust for return address and receiver.
      __ Addu(a0, a0, Operand(2 * kPointerSize));
      // Compute copy end address. Also adjust for return address.
      __ Addu(t3, fp, kPointerSize);
  
      // Copy the arguments (including the receiver) to the new stack frame.
      // a0: copy start address
      // a1: function
      // a2: expected number of arguments
      // a3: new target (passed through to callee)
      // t3: copy end address
      Label copy;
      __ bind(&copy);
      __ lw(t0, MemOperand(a0));  // Adjusted above for return addr and receiver.
      __ Subu(sp, sp, kPointerSize);
      __ Subu(a0, a0, kPointerSize);
      __ Branch(USE_DELAY_SLOT, &copy, ne, a0, Operand(t3));
      __ sw(t0, MemOperand(sp));  // In the delay slot.
  
      // Fill the remaining expected arguments with undefined.
      // a1: function
      // a2: expected number of arguments
      // a3: new target (passed through to callee)
      __ LoadRoot(t0, RootIndex::kUndefinedValue);
      __ sll(t2, a2, kPointerSizeLog2);
      __ Subu(t1, fp, Operand(t2));
      // Adjust for frame.
      __ Subu(t1, t1,
              Operand(ArgumentsAdaptorFrameConstants::kFixedFrameSizeFromFp +
                      kPointerSize));
  
      Label fill;
      __ bind(&fill);
      __ Subu(sp, sp, kPointerSize);
      __ Branch(USE_DELAY_SLOT, &fill, ne, sp, Operand(t1));
      __ sw(t0, MemOperand(sp));
    }
  
    // Call the entry point.
    __ bind(&invoke);
    __ mov(a0, a2);
    // a0 : expected number of arguments
    // a1 : function (passed through to callee)
    // a3 : new target (passed through to callee)
    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
    __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
    __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
    __ Call(a2);
  
    // Store offset of return address for deoptimizer.
    masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());
  
    // Exit frame and return.
    LeaveArgumentsAdaptorFrame(masm);
    __ Ret();
  
    // -------------------------------------------
    // Don't adapt arguments.
    // -------------------------------------------
    __ bind(&dont_adapt_arguments);
    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
    __ lw(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
    __ Addu(a2, a2, Code::kHeaderSize - kHeapObjectTag);
    __ Jump(a2);
  
    __ bind(&stack_overflow);
    {
      FrameScope frame(masm, StackFrame::MANUAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ break_(0xCC);
    }
  }
  
  void Builtins::Generate_WasmCompileLazy(MacroAssembler* masm) {
    // The function index was put in t0 by the jump table trampoline.
    // Convert to Smi for the runtime call.
    __ SmiTag(kWasmCompileLazyFuncIndexRegister);
    {
      HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
      FrameScope scope(masm, StackFrame::WASM_COMPILE_LAZY);
  
      // Save all parameter registers (see wasm-linkage.cc). They might be
      // overwritten in the runtime call below. We don't have any callee-saved
      // registers in wasm, so no need to store anything else.
      constexpr RegList gp_regs = Register::ListOf<a0, a1, a2, a3>();
      constexpr RegList fp_regs =
          DoubleRegister::ListOf<f2, f4, f6, f8, f10, f12, f14>();
      __ MultiPush(gp_regs);
      __ MultiPushFPU(fp_regs);
  
      // Pass instance and function index as an explicit arguments to the runtime
      // function.
      __ Push(kWasmInstanceRegister, kWasmCompileLazyFuncIndexRegister);
      // Load the correct CEntry builtin from the instance object.
      __ lw(a2, FieldMemOperand(kWasmInstanceRegister,
                                WasmInstanceObject::kCEntryStubOffset));
      // Initialize the JavaScript context with 0. CEntry will use it to
      // set the current context on the isolate.
      __ Move(kContextRegister, Smi::zero());
      __ CallRuntimeWithCEntry(Runtime::kWasmCompileLazy, a2);
  
      // Restore registers.
      __ MultiPopFPU(fp_regs);
      __ MultiPop(gp_regs);
    }
    // Finally, jump to the entrypoint.
    __ Jump(kScratchReg, v0, 0);
  }
  
  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
    // a0: number of arguments including receiver
    // a1: 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:
    // a2: pointer to the first argument
  
    ProfileEntryHookStub::MaybeCallEntryHook(masm);
  
    if (argv_mode == kArgvInRegister) {
      // Move argv into the correct register.
      __ mov(s1, a2);
    } else {
      // Compute the argv pointer in a callee-saved register.
      __ Lsa(s1, sp, a0, kPointerSizeLog2);
      __ Subu(s1, s1, kPointerSize);
    }
  
    // Enter the exit frame that transitions from JavaScript to C++.
    FrameScope scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(
        save_doubles == kSaveFPRegs, 0,
        builtin_exit_frame ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
  
    // s0: number of arguments  including receiver (C callee-saved)
    // s1: pointer to first argument (C callee-saved)
    // s2: pointer to builtin function (C callee-saved)
  
    // Prepare arguments for C routine.
    // a0 = argc
    __ mov(s0, a0);
    __ mov(s2, a1);
  
    // We are calling compiled C/C++ code. a0 and a1 hold our two arguments. We
    // also need to reserve the 4 argument slots on the stack.
  
    __ AssertStackIsAligned();
  
    // a0 = argc, a1 = argv, a2 = isolate
    __ li(a2, ExternalReference::isolate_address(masm->isolate()));
    __ mov(a1, s1);
  
    // To let the GC traverse the return address of the exit frames, we need to
    // know where the return address is. The CEntry is unmovable, so
    // we can store the address on the stack to be able to find it again and
    // we never have to restore it, because it will not change.
    {
      Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm);
      int kNumInstructionsToJump = 4;
      Label find_ra;
      // Adjust the value in ra to point to the correct return location, 2nd
      // instruction past the real call into C code (the jalr(t9)), and push it.
      // This is the return address of the exit frame.
      if (kArchVariant >= kMips32r6) {
        __ addiupc(ra, kNumInstructionsToJump + 1);
      } else {
        // This no-op-and-link sequence saves PC + 8 in ra register on pre-r6 MIPS
        __ nal();  // nal has branch delay slot.
        __ Addu(ra, ra, kNumInstructionsToJump * kInstrSize);
      }
      __ bind(&find_ra);
  
      // This spot was reserved in EnterExitFrame.
      __ sw(ra, MemOperand(sp));
      // Stack space reservation moved to the branch delay slot below.
      // Stack is still aligned.
  
      // Call the C routine.
      __ mov(t9, s2);  // Function pointer to t9 to conform to ABI for PIC.
      __ jalr(t9);
      // Set up sp in the delay slot.
      __ addiu(sp, sp, -kCArgsSlotsSize);
      // Make sure the stored 'ra' points to this position.
      DCHECK_EQ(kNumInstructionsToJump,
                masm->InstructionsGeneratedSince(&find_ra));
    }
  
    // Result returned in v0 or v1:v0 - do not destroy these registers!
  
    // Check result for exception sentinel.
    Label exception_returned;
    __ LoadRoot(t0, RootIndex::kException);
    __ Branch(&exception_returned, eq, t0, Operand(v0));
  
    // 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());
      __ li(a2, pending_exception_address);
      __ lw(a2, MemOperand(a2));
      __ LoadRoot(t0, RootIndex::kTheHoleValue);
      // Cannot use check here as it attempts to generate call into runtime.
      __ Branch(&okay, eq, t0, Operand(a2));
      __ stop("Unexpected pending exception");
      __ bind(&okay);
    }
  
    // Exit C frame and return.
    // v0:v1: 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
                        // s0: still holds argc (callee-saved).
                        : s0;
    __ LeaveExitFrame(save_doubles == kSaveFPRegs, argc, EMIT_RETURN);
  
    // Handling of exception.
    __ bind(&exception_returned);
  
    ExternalReference pending_handler_context_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerContextAddress, masm->isolate());
    ExternalReference pending_handler_entrypoint_address =
        ExternalReference::Create(
            IsolateAddressId::kPendingHandlerEntrypointAddress, masm->isolate());
    ExternalReference pending_handler_fp_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerFPAddress, masm->isolate());
    ExternalReference pending_handler_sp_address = ExternalReference::Create(
        IsolateAddressId::kPendingHandlerSPAddress, masm->isolate());
  
    // Ask the runtime for help to determine the handler. This will set v0 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, a0);
      __ mov(a0, zero_reg);
      __ mov(a1, zero_reg);
      __ li(a2, ExternalReference::isolate_address(masm->isolate()));
      __ CallCFunction(find_handler, 3);
    }
  
    // Retrieve the handler context, SP and FP.
    __ li(cp, pending_handler_context_address);
    __ lw(cp, MemOperand(cp));
    __ li(sp, pending_handler_sp_address);
    __ lw(sp, MemOperand(sp));
    __ li(fp, pending_handler_fp_address);
    __ lw(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 zero;
    __ Branch(&zero, eq, cp, Operand(zero_reg));
    __ sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    __ bind(&zero);
  
    // 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.
    __ li(t9, pending_handler_entrypoint_address);
    __ lw(t9, MemOperand(t9));
    __ Jump(t9);
  }
  
  void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
    Label out_of_range, only_low, negate, done;
    Register result_reg = t0;
  
    Register scratch = GetRegisterThatIsNotOneOf(result_reg);
    Register scratch2 = GetRegisterThatIsNotOneOf(result_reg, scratch);
    Register scratch3 = GetRegisterThatIsNotOneOf(result_reg, scratch, scratch2);
    DoubleRegister double_scratch = kScratchDoubleReg;
  
    // Account for saved regs.
    const int kArgumentOffset = 4 * kPointerSize;
  
    __ Push(result_reg);
    __ Push(scratch, scratch2, scratch3);
  
    // Load double input.
    __ Ldc1(double_scratch, MemOperand(sp, kArgumentOffset));
  
    // Clear cumulative exception flags and save the FCSR.
    __ cfc1(scratch2, FCSR);
    __ ctc1(zero_reg, FCSR);
  
    // Try a conversion to a signed integer.
    __ Trunc_w_d(double_scratch, double_scratch);
    // Move the converted value into the result register.
    __ mfc1(scratch3, double_scratch);
  
    // Retrieve and restore the FCSR.
    __ cfc1(scratch, FCSR);
    __ ctc1(scratch2, FCSR);
  
    // Check for overflow and NaNs.
    __ And(
        scratch, scratch,
        kFCSROverflowFlagMask | kFCSRUnderflowFlagMask | kFCSRInvalidOpFlagMask);
    // If we had no exceptions then set result_reg and we are done.
    Label error;
    __ Branch(&error, ne, scratch, Operand(zero_reg));
    __ Move(result_reg, scratch3);
    __ Branch(&done);
    __ bind(&error);
  
    // Load the double value and perform a manual truncation.
    Register input_high = scratch2;
    Register input_low = scratch3;
  
    __ lw(input_low, MemOperand(sp, kArgumentOffset + Register::kMantissaOffset));
    __ lw(input_high,
          MemOperand(sp, kArgumentOffset + Register::kExponentOffset));
  
    Label normal_exponent, restore_sign;
    // Extract the biased exponent in result.
    __ Ext(result_reg, input_high, HeapNumber::kExponentShift,
           HeapNumber::kExponentBits);
  
    // Check for Infinity and NaNs, which should return 0.
    __ Subu(scratch, result_reg, HeapNumber::kExponentMask);
    __ Movz(result_reg, zero_reg, scratch);
    __ Branch(&done, eq, scratch, Operand(zero_reg));
  
    // Express exponent as delta to (number of mantissa bits + 31).
    __ Subu(result_reg, result_reg,
            Operand(HeapNumber::kExponentBias + HeapNumber::kMantissaBits + 31));
  
    // If the delta is strictly positive, all bits would be shifted away,
    // which means that we can return 0.
    __ Branch(&normal_exponent, le, result_reg, Operand(zero_reg));
    __ mov(result_reg, zero_reg);
    __ Branch(&done);
  
    __ bind(&normal_exponent);
    const int kShiftBase = HeapNumber::kNonMantissaBitsInTopWord - 1;
    // Calculate shift.
    __ Addu(scratch, result_reg, Operand(kShiftBase + HeapNumber::kMantissaBits));
  
    // Save the sign.
    Register sign = result_reg;
    result_reg = no_reg;
    __ And(sign, input_high, Operand(HeapNumber::kSignMask));
  
    // On ARM shifts > 31 bits are valid and will result in zero. On MIPS we need
    // to check for this specific case.
    Label high_shift_needed, high_shift_done;
    __ Branch(&high_shift_needed, lt, scratch, Operand(32));
    __ mov(input_high, zero_reg);
    __ Branch(&high_shift_done);
    __ bind(&high_shift_needed);
  
    // Set the implicit 1 before the mantissa part in input_high.
    __ Or(input_high, input_high,
          Operand(1 << HeapNumber::kMantissaBitsInTopWord));
    // Shift the mantissa bits to the correct position.
    // We don't need to clear non-mantissa bits as they will be shifted away.
    // If they weren't, it would mean that the answer is in the 32bit range.
    __ sllv(input_high, input_high, scratch);
  
    __ bind(&high_shift_done);
  
    // Replace the shifted bits with bits from the lower mantissa word.
    Label pos_shift, shift_done;
    __ li(kScratchReg, 32);
    __ subu(scratch, kScratchReg, scratch);
    __ Branch(&pos_shift, ge, scratch, Operand(zero_reg));
  
    // Negate scratch.
    __ Subu(scratch, zero_reg, scratch);
    __ sllv(input_low, input_low, scratch);
    __ Branch(&shift_done);
  
    __ bind(&pos_shift);
    __ srlv(input_low, input_low, scratch);
  
    __ bind(&shift_done);
    __ Or(input_high, input_high, Operand(input_low));
    // Restore sign if necessary.
    __ mov(scratch, sign);
    result_reg = sign;
    sign = no_reg;
    __ Subu(result_reg, zero_reg, input_high);
    __ Movz(result_reg, input_high, scratch);
  
    __ bind(&done);
    __ sw(result_reg, MemOperand(sp, kArgumentOffset));
    __ Pop(scratch, scratch2, scratch3);
    __ Pop(result_reg);
    __ Ret();
  }
  
  void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
    const Register exponent = a2;
    const DoubleRegister double_base = f2;
    const DoubleRegister double_exponent = f4;
    const DoubleRegister double_result = f0;
    const DoubleRegister double_scratch = f6;
    const FPURegister single_scratch = f8;
    const Register scratch = t5;
    const Register scratch2 = t3;
  
    Label call_runtime, done, int_exponent;
  
    Label int_exponent_convert;
    // Detect integer exponents stored as double.
    __ EmitFPUTruncate(kRoundToMinusInf, scratch, double_exponent, kScratchReg,
                       double_scratch, scratch2, kCheckForInexactConversion);
    // scratch2 == 0 means there was no conversion error.
    __ Branch(&int_exponent_convert, eq, scratch2, Operand(zero_reg));
  
    __ push(ra);
    {
      AllowExternalCallThatCantCauseGC scope(masm);
      __ PrepareCallCFunction(0, 2, scratch2);
      __ MovToFloatParameters(double_base, double_exponent);
      __ CallCFunction(ExternalReference::power_double_double_function(), 0, 2);
    }
    __ pop(ra);
    __ MovFromFloatResult(double_result);
    __ jmp(&done);
  
    __ bind(&int_exponent_convert);
  
    // Calculate power with integer exponent.
    __ bind(&int_exponent);
  
    // Get two copies of exponent in the registers scratch and exponent.
    // Exponent has previously been stored into scratch as untagged integer.
    __ mov(exponent, scratch);
  
    __ mov_d(double_scratch, double_base);  // Back up base.
    __ Move(double_result, 1.0);
  
    // Get absolute value of exponent.
    Label positive_exponent, bail_out;
    __ Branch(&positive_exponent, ge, scratch, Operand(zero_reg));
    __ Subu(scratch, zero_reg, scratch);
    // Check when Subu overflows and we get negative result
    // (happens only when input is MIN_INT).
    __ Branch(&bail_out, gt, zero_reg, Operand(scratch));
    __ bind(&positive_exponent);
    __ Assert(ge, AbortReason::kUnexpectedNegativeValue, scratch,
              Operand(zero_reg));
  
    Label while_true, no_carry, loop_end;
    __ bind(&while_true);
  
    __ And(scratch2, scratch, 1);
  
    __ Branch(&no_carry, eq, scratch2, Operand(zero_reg));
    __ mul_d(double_result, double_result, double_scratch);
    __ bind(&no_carry);
  
    __ sra(scratch, scratch, 1);
  
    __ Branch(&loop_end, eq, scratch, Operand(zero_reg));
    __ mul_d(double_scratch, double_scratch, double_scratch);
  
    __ Branch(&while_true);
  
    __ bind(&loop_end);
  
    __ Branch(&done, ge, exponent, Operand(zero_reg));
    __ Move(double_scratch, 1.0);
    __ div_d(double_result, double_scratch, double_result);
    // Test whether result is zero.  Bail out to check for subnormal result.
    // Due to subnormals, x^-y == (1/x)^y does not hold in all cases.
    __ CompareF64(EQ, double_result, kDoubleRegZero);
    __ BranchFalseShortF(&done);
  
    // double_exponent may not contain the exponent value if the input was a
    // smi.  We set it with exponent value before bailing out.
    __ bind(&bail_out);
    __ mtc1(exponent, single_scratch);
    __ cvt_d_w(double_exponent, single_scratch);
  
    // Returning or bailing out.
    __ push(ra);
    {
      AllowExternalCallThatCantCauseGC scope(masm);
      __ PrepareCallCFunction(0, 2, scratch);
      __ MovToFloatParameters(double_base, double_exponent);
      __ CallCFunction(ExternalReference::power_double_double_function(), 0, 2);
    }
    __ pop(ra);
    __ MovFromFloatResult(double_result);
  
    __ bind(&done);
    __ Ret();
  }
  
  namespace {
  
  void GenerateInternalArrayConstructorCase(MacroAssembler* masm,
                                            ElementsKind kind) {
    // Load undefined into the allocation site parameter as required by
    // ArrayNArgumentsConstructor.
    __ LoadRoot(kJavaScriptCallExtraArg1Register, RootIndex::kUndefinedValue);
  
    __ Jump(CodeFactory::InternalArrayNoArgumentConstructor(masm->isolate(), kind)
                .code(),
            RelocInfo::CODE_TARGET, lo, a0, Operand(1));
  
    __ Jump(BUILTIN_CODE(masm->isolate(), ArrayNArgumentsConstructor),
            RelocInfo::CODE_TARGET, hi, a0, Operand(1));
  
    if (IsFastPackedElementsKind(kind)) {
      // We might need to create a holey array
      // look at the first argument.
      __ lw(kScratchReg, MemOperand(sp, 0));
  
      __ Jump(CodeFactory::InternalArraySingleArgumentConstructor(
                  masm->isolate(), GetHoleyElementsKind(kind))
                  .code(),
              RelocInfo::CODE_TARGET, ne, kScratchReg, Operand(zero_reg));
    }
  
    __ Jump(
        CodeFactory::InternalArraySingleArgumentConstructor(masm->isolate(), kind)
            .code(),
        RelocInfo::CODE_TARGET);
  }
  
  }  // namespace
  
  void Builtins::Generate_InternalArrayConstructorImpl(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : argc
    //  -- a1 : constructor
    //  -- sp[0] : return address
    //  -- sp[4] : last argument
    // -----------------------------------
  
    if (FLAG_debug_code) {
      // The array construct code is only set for the global and natives
      // builtin Array functions which always have maps.
  
      // Initial map for the builtin Array function should be a map.
      __ lw(a3, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
      // Will both indicate a nullptr and a Smi.
      __ SmiTst(a3, kScratchReg);
      __ Assert(ne, AbortReason::kUnexpectedInitialMapForArrayFunction,
                kScratchReg, Operand(zero_reg));
      __ GetObjectType(a3, a3, t0);
      __ Assert(eq, AbortReason::kUnexpectedInitialMapForArrayFunction, t0,
                Operand(MAP_TYPE));
    }
  
    // Figure out the right elements kind.
    __ lw(a3, FieldMemOperand(a1, JSFunction::kPrototypeOrInitialMapOffset));
  
    // Load the map's "bit field 2" into a3. We only need the first byte,
    // but the following bit field extraction takes care of that anyway.
    __ lbu(a3, FieldMemOperand(a3, Map::kBitField2Offset));
    // Retrieve elements_kind from bit field 2.
    __ DecodeField<Map::ElementsKindBits>(a3);
  
    if (FLAG_debug_code) {
      Label done;
      __ Branch(&done, eq, a3, Operand(PACKED_ELEMENTS));
      __ Assert(
          eq,
          AbortReason::kInvalidElementsKindForInternalArrayOrInternalPackedArray,
          a3, Operand(HOLEY_ELEMENTS));
      __ bind(&done);
    }
  
    Label fast_elements_case;
    __ Branch(&fast_elements_case, eq, a3, Operand(PACKED_ELEMENTS));
    GenerateInternalArrayConstructorCase(masm, HOLEY_ELEMENTS);
  
    __ bind(&fast_elements_case);
    GenerateInternalArrayConstructorCase(masm, PACKED_ELEMENTS);
  }
  
  #undef __
  
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_TARGET_ARCH_MIPS
  