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_MIPS64
  
  #include "src/api/api-arguments.h"
  #include "src/codegen/code-factory.h"
  #include "src/codegen/interface-descriptors-inl.h"
  #include "src/debug/debug.h"
  #include "src/deoptimizer/deoptimizer.h"
  #include "src/execution/frame-constants.h"
  #include "src/execution/frames.h"
  #include "src/logging/counters.h"
  // For interpreter_entry_return_pc_offset. TODO(jkummerow): Drop.
  #include "src/codegen/macro-assembler-inl.h"
  #include "src/codegen/mips64/constants-mips64.h"
  #include "src/codegen/register-configuration.h"
  #include "src/heap/heap-inl.h"
  #include "src/objects/cell.h"
  #include "src/objects/foreign.h"
  #include "src/objects/heap-number.h"
  #include "src/objects/js-generator.h"
  #include "src/objects/objects-inl.h"
  #include "src/objects/smi.h"
  #include "src/runtime/runtime.h"
  
  #if V8_ENABLE_WEBASSEMBLY
  #include "src/wasm/wasm-linkage.h"
  #include "src/wasm/wasm-objects.h"
  #endif  // V8_ENABLE_WEBASSEMBLY
  
  namespace v8 {
  namespace internal {
  
  #define __ ACCESS_MASM(masm)
  
  void Builtins::Generate_Adaptor(MacroAssembler* masm, Address address) {
    __ li(kJavaScriptCallExtraArg1Register, ExternalReference::Create(address));
    __ Jump(BUILTIN_CODE(masm->isolate(), AdaptorWithBuiltinExitFrame),
            RelocInfo::CODE_TARGET);
  }
  
  static void GenerateTailCallToReturnedCode(MacroAssembler* masm,
                                             Runtime::FunctionId function_id) {
    // ----------- S t a t e -------------
    //  -- a0 : actual argument count
    //  -- a1 : target function (preserved for callee)
    //  -- a3 : new target (preserved for callee)
    // -----------------------------------
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      // Push a copy of the target function, the new target and the actual
      // argument count.
      // Push function as parameter to the runtime call.
      __ SmiTag(kJavaScriptCallArgCountRegister);
      __ Push(kJavaScriptCallTargetRegister, kJavaScriptCallNewTargetRegister,
              kJavaScriptCallArgCountRegister, kJavaScriptCallTargetRegister);
  
      __ CallRuntime(function_id, 1);
      // Restore target function, new target and actual argument count.
      __ Pop(kJavaScriptCallTargetRegister, kJavaScriptCallNewTargetRegister,
             kJavaScriptCallArgCountRegister);
      __ SmiUntag(kJavaScriptCallArgCountRegister);
    }
  
    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
    __ Daddu(a2, v0, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Jump(a2);
  }
  
  namespace {
  
  enum class ArgumentsElementType {
    kRaw,    // Push arguments as they are.
    kHandle  // Dereference arguments before pushing.
  };
  
  void Generate_PushArguments(MacroAssembler* masm, Register array, Register argc,
                              Register scratch, Register scratch2,
                              ArgumentsElementType element_type) {
    DCHECK(!AreAliased(array, argc, scratch));
    Label loop, entry;
    __ Dsubu(scratch, argc, Operand(kJSArgcReceiverSlots));
    __ Branch(&entry);
    __ bind(&loop);
    __ Dlsa(scratch2, array, scratch, kSystemPointerSizeLog2);
    __ Ld(scratch2, MemOperand(scratch2));
    if (element_type == ArgumentsElementType::kHandle) {
      __ Ld(scratch2, MemOperand(scratch2));
    }
    __ push(scratch2);
    __ bind(&entry);
    __ Daddu(scratch, scratch, Operand(-1));
    __ Branch(&loop, greater_equal, scratch, Operand(zero_reg));
  }
  
  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);
  
      // Set up pointer to first argument (skip receiver).
      __ Daddu(
          t2, fp,
          Operand(StandardFrameConstants::kCallerSPOffset + kSystemPointerSize));
      // Copy arguments and receiver to the expression stack.
      // t2: Pointer to start of arguments.
      // a0: Number of arguments.
      Generate_PushArguments(masm, t2, a0, t3, t0, ArgumentsElementType::kRaw);
      // The receiver for the builtin/api call.
      __ PushRoot(RootIndex::kTheHoleValue);
  
      // Call the function.
      // a0: number of arguments (untagged)
      // a1: constructor function
      // a3: new target
      __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
  
      // Restore context from the frame.
      __ Ld(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
      // Restore smi-tagged arguments count from the frame.
      __ Ld(t3, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
      // Leave construct frame.
    }
  
    // Remove caller arguments from the stack and return.
    __ DropArguments(t3, TurboAssembler::kCountIsSmi,
                     TurboAssembler::kCountIncludesReceiver, t3);
    __ 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::MANUAL);
    Label post_instantiation_deopt_entry, not_create_implicit_receiver;
    __ EnterFrame(StackFrame::CONSTRUCT);
  
    // Preserve the incoming parameters on the stack.
    __ SmiTag(a0);
    __ Push(cp, a0, a1);
    __ PushRoot(RootIndex::kUndefinedValue);
    __ 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
    // -----------------------------------
  
    __ Ld(t2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
    __ lwu(t2, FieldMemOperand(t2, SharedFunctionInfo::kFlagsOffset));
    __ DecodeField<SharedFunctionInfo::FunctionKindBits>(t2);
    __ JumpIfIsInRange(
        t2, static_cast<uint32_t>(FunctionKind::kDefaultDerivedConstructor),
        static_cast<uint32_t>(FunctionKind::kDerivedConstructor),
        &not_create_implicit_receiver);
  
    // 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.
    __ Push(v0);
  
    // We need two copies because we may have to return the original one
    // and the calling conventions dictate that the called function pops the
    // receiver. The second copy is pushed after the arguments, we saved in a6
    // since v0 will store the return value of callRuntime.
    __ mov(a6, v0);
  
    // Set up pointer to last argument.
    __ Daddu(t2, fp, Operand(StandardFrameConstants::kCallerSPOffset +
                             kSystemPointerSize));
  
    // ----------- S t a t e -------------
    //  --                 a3: 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.
    __ Ld(a1, MemOperand(fp, ConstructFrameConstants::kConstructorOffset));
    __ Ld(a0, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
    __ SmiUntag(a0);
  
    Label stack_overflow;
    __ StackOverflowCheck(a0, t0, t1, &stack_overflow);
  
    // TODO(victorgomes): When the arguments adaptor is completely removed, we
    // should get the formal parameter count and copy the arguments in its
    // correct position (including any undefined), instead of delaying this to
    // InvokeFunction.
  
    // Copy arguments and receiver to the expression stack.
    // t2: Pointer to start of argument.
    // a0: Number of arguments.
    Generate_PushArguments(masm, t2, a0, t0, t1, ArgumentsElementType::kRaw);
    // We need two copies because we may have to return the original one
    // and the calling conventions dictate that the called function pops the
    // receiver. The second copy is pushed after the arguments,
    __ Push(a6);
  
    // Call the function.
    __ InvokeFunctionWithNewTarget(a1, a3, a0, InvokeType::kCall);
  
    // ----------- 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());
  
    // 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_and_return, check_receiver;
  
    // If the result is undefined, we jump out to using the implicit receiver.
    __ JumpIfNotRoot(v0, RootIndex::kUndefinedValue, &check_receiver);
  
    // Otherwise we do a smi check and fall through to check if the return value
    // is a valid receiver.
  
    // Throw away the result of the constructor invocation and use the
    // on-stack receiver as the result.
    __ bind(&use_receiver);
    __ Ld(v0, MemOperand(sp, 0 * kPointerSize));
    __ JumpIfRoot(v0, RootIndex::kTheHoleValue, &do_throw);
  
    __ bind(&leave_and_return);
    // Restore smi-tagged arguments count from the frame.
    __ Ld(a1, MemOperand(fp, ConstructFrameConstants::kLengthOffset));
    // Leave construct frame.
    __ LeaveFrame(StackFrame::CONSTRUCT);
  
    // Remove caller arguments from the stack and return.
    __ DropArguments(a1, TurboAssembler::kCountIsSmi,
                     TurboAssembler::kCountIncludesReceiver, a4);
    __ Ret();
  
    __ bind(&check_receiver);
    __ 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_and_return, greater_equal, t2,
              Operand(FIRST_JS_RECEIVER_TYPE));
    __ Branch(&use_receiver);
  
    __ bind(&do_throw);
    // Restore the context from the frame.
    __ Ld(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
    __ CallRuntime(Runtime::kThrowConstructorReturnedNonObject);
    __ break_(0xCC);
  
    __ bind(&stack_overflow);
    // Restore the context from the frame.
    __ Ld(cp, MemOperand(fp, ConstructFrameConstants::kContextOffset));
    __ CallRuntime(Runtime::kThrowStackOverflow);
    __ break_(0xCC);
  }
  
  void Builtins::Generate_JSBuiltinsConstructStub(MacroAssembler* masm) {
    Generate_JSBuiltinsConstructStubHelper(masm);
  }
  
  static void AssertCodeIsBaseline(MacroAssembler* masm, Register code,
                                   Register scratch) {
    DCHECK(!AreAliased(code, scratch));
    // Verify that the code kind is baseline code via the CodeKind.
    __ Ld(scratch, FieldMemOperand(code, Code::kFlagsOffset));
    __ DecodeField<Code::KindField>(scratch);
    __ Assert(eq, AbortReason::kExpectedBaselineData, scratch,
              Operand(static_cast<int>(CodeKind::BASELINE)));
  }
  
  // TODO(v8:11429): Add a path for "not_compiled" and unify the two uses under
  // the more general dispatch.
  static void GetSharedFunctionInfoBytecodeOrBaseline(MacroAssembler* masm,
                                                      Register sfi_data,
                                                      Register scratch1,
                                                      Label* is_baseline) {
    Label done;
  
    __ GetObjectType(sfi_data, scratch1, scratch1);
    if (FLAG_debug_code) {
      Label not_baseline;
      __ Branch(&not_baseline, ne, scratch1, Operand(CODET_TYPE));
      AssertCodeIsBaseline(masm, sfi_data, scratch1);
      __ Branch(is_baseline);
      __ bind(&not_baseline);
    } else {
      __ Branch(is_baseline, eq, scratch1, Operand(CODET_TYPE));
    }
    __ Branch(&done, ne, scratch1, Operand(INTERPRETER_DATA_TYPE));
    __ Ld(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
    // -----------------------------------
    // Store input value into generator object.
    __ Sd(v0, FieldMemOperand(a1, JSGeneratorObject::kInputOrDebugPosOffset));
    __ RecordWriteField(a1, JSGeneratorObject::kInputOrDebugPosOffset, v0, a3,
                        kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore);
    // Check that a1 is still valid, RecordWrite might have clobbered it.
    __ AssertGeneratorObject(a1);
  
    // Load suspended function and context.
    __ Ld(a4, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
    __ Ld(cp, FieldMemOperand(a4, 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(a5, debug_hook);
    __ Lb(a5, MemOperand(a5));
    __ Branch(&prepare_step_in_if_stepping, ne, a5, 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(a5, debug_suspended_generator);
    __ Ld(a5, MemOperand(a5));
    __ Branch(&prepare_step_in_suspended_generator, eq, a1, Operand(a5));
    __ 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;
    __ LoadStackLimit(kScratchReg,
                      MacroAssembler::StackLimitKind::kRealStackLimit);
    __ Branch(&stack_overflow, lo, sp, Operand(kScratchReg));
  
    // ----------- S t a t e -------------
    //  -- a1    : the JSGeneratorObject to resume
    //  -- a4    : generator function
    //  -- cp    : generator context
    //  -- ra    : return address
    // -----------------------------------
  
    // Push holes for arguments to generator function. Since the parser forced
    // context allocation for any variables in generators, the actual argument
    // values have already been copied into the context and these dummy values
    // will never be used.
    __ Ld(a3, FieldMemOperand(a4, JSFunction::kSharedFunctionInfoOffset));
    __ Lhu(a3,
           FieldMemOperand(a3, SharedFunctionInfo::kFormalParameterCountOffset));
    __ Dsubu(a3, a3, Operand(kJSArgcReceiverSlots));
    __ Ld(t1,
          FieldMemOperand(a1, JSGeneratorObject::kParametersAndRegistersOffset));
    {
      Label done_loop, loop;
      __ bind(&loop);
      __ Dsubu(a3, a3, Operand(1));
      __ Branch(&done_loop, lt, a3, Operand(zero_reg));
      __ Dlsa(kScratchReg, t1, a3, kPointerSizeLog2);
      __ Ld(kScratchReg, FieldMemOperand(kScratchReg, FixedArray::kHeaderSize));
      __ Push(kScratchReg);
      __ Branch(&loop);
      __ bind(&done_loop);
      // Push receiver.
      __ Ld(kScratchReg, FieldMemOperand(a1, JSGeneratorObject::kReceiverOffset));
      __ Push(kScratchReg);
    }
  
    // Underlying function needs to have bytecode available.
    if (FLAG_debug_code) {
      Label is_baseline;
      __ Ld(a3, FieldMemOperand(a4, JSFunction::kSharedFunctionInfoOffset));
      __ Ld(a3, FieldMemOperand(a3, SharedFunctionInfo::kFunctionDataOffset));
      GetSharedFunctionInfoBytecodeOrBaseline(masm, a3, a0, &is_baseline);
      __ GetObjectType(a3, a3, a3);
      __ Assert(eq, AbortReason::kMissingBytecodeArray, a3,
                Operand(BYTECODE_ARRAY_TYPE));
      __ bind(&is_baseline);
    }
  
    // Resume (Ignition/TurboFan) generator object.
    {
      __ Ld(a0, FieldMemOperand(a4, 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, a4);
      static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
      __ Ld(a2, FieldMemOperand(a1, JSFunction::kCodeOffset));
      __ Daddu(a2, a2, Operand(Code::kHeaderSize - kHeapObjectTag));
      __ Jump(a2);
    }
  
    __ bind(&prepare_step_in_if_stepping);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(a1, a4);
      // 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);
    __ Ld(a4, 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);
    __ Ld(a4, FieldMemOperand(a1, JSGeneratorObject::kFunctionOffset));
  
    __ bind(&stack_overflow);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kThrowStackOverflow);
      __ break_(0xCC);  // This should be unreachable.
    }
  }
  
  void Builtins::Generate_ConstructedNonConstructable(MacroAssembler* masm) {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(a1);
    __ CallRuntime(Runtime::kThrowConstructedNonConstructable);
  }
  
  // Clobbers scratch1 and scratch2; preserves all other registers.
  static void Generate_CheckStackOverflow(MacroAssembler* masm, Register argc,
                                          Register scratch1, Register scratch2) {
    // Check the stack for overflow. We are not trying to catch
    // interruptions (e.g. debug break and preemption) here, so the "real stack
    // limit" is checked.
    Label okay;
    __ LoadStackLimit(scratch1, MacroAssembler::StackLimitKind::kRealStackLimit);
    // Make a2 the space we have left. The stack might already be overflowed
    // here which will cause r2 to become negative.
    __ dsubu(scratch1, sp, scratch1);
    // Check if the arguments will overflow the stack.
    __ dsll(scratch2, argc, kPointerSizeLog2);
    __ Branch(&okay, gt, scratch1, Operand(scratch2));  // Signed comparison.
  
    // Out of stack space.
    __ CallRuntime(Runtime::kThrowStackOverflow);
  
    __ bind(&okay);
  }
  
  namespace {
  
  // Called with the native C calling convention. The corresponding function
  // signature is either:
  //
  //   using JSEntryFunction = GeneratedCode<Address(
  //       Address root_register_value, Address new_target, Address target,
  //       Address receiver, intptr_t argc, Address** args)>;
  // or
  //   using JSEntryFunction = GeneratedCode<Address(
  //       Address root_register_value, MicrotaskQueue* microtask_queue)>;
  void Generate_JSEntryVariant(MacroAssembler* masm, StackFrame::Type type,
                               Builtin entry_trampoline) {
    Label invoke, handler_entry, exit;
  
    {
      NoRootArrayScope no_root_array(masm);
  
      // TODO(plind): unify the ABI description here.
      // Registers:
      //  either
      //   a0: root register value
      //   a1: entry address
      //   a2: function
      //   a3: receiver
      //   a4: argc
      //   a5: argv
      //  or
      //   a0: root register value
      //   a1: microtask_queue
      //
      // Stack:
      // 0 arg slots on mips64 (4 args slots on mips)
  
      // Save callee saved registers on the stack.
      __ MultiPush(kCalleeSaved | ra);
  
      // Save callee-saved FPU registers.
      __ MultiPushFPU(kCalleeSavedFPU);
      // Set up the reserved register for 0.0.
      __ Move(kDoubleRegZero, 0.0);
  
      // Initialize the root register.
      // C calling convention. The first argument is passed in a0.
      __ mov(kRootRegister, a0);
    }
  
    // a1: entry address
    // a2: function
    // a3: receiver
    // a4: argc
    // a5: argv
  
    // We build an EntryFrame.
    __ li(s1, Operand(-1));  // Push a bad frame pointer to fail if it is used.
    __ li(s2, Operand(StackFrame::TypeToMarker(type)));
    __ li(s3, Operand(StackFrame::TypeToMarker(type)));
    ExternalReference c_entry_fp = ExternalReference::Create(
        IsolateAddressId::kCEntryFPAddress, masm->isolate());
    __ li(s5, c_entry_fp);
    __ Ld(s4, MemOperand(s5));
    __ Push(s1, s2, s3, s4);
  
    // Clear c_entry_fp, now we've pushed its previous value to the stack.
    // If the c_entry_fp is not already zero and we don't clear it, the
    // SafeStackFrameIterator will assume we are executing C++ and miss the JS
    // frames on top.
    __ Sd(zero_reg, MemOperand(s5));
  
    // Set up frame pointer for the frame to be pushed.
    __ daddiu(fp, sp, -EntryFrameConstants::kCallerFPOffset);
  
    // Registers:
    //  either
    //   a1: entry address
    //   a2: function
    //   a3: receiver
    //   a4: argc
    //   a5: argv
    //  or
    //   a1: microtask_queue
    //
    // Stack:
    // caller fp          |
    // function slot      | entry frame
    // context slot       |
    // bad fp (0xFF...F)  |
    // callee saved registers + ra
    // [ O32: 4 args slots]
    // args
  
    // If this is the outermost JS call, set js_entry_sp value.
    Label non_outermost_js;
    ExternalReference js_entry_sp = ExternalReference::Create(
        IsolateAddressId::kJSEntrySPAddress, masm->isolate());
    __ li(s1, js_entry_sp);
    __ Ld(s2, MemOperand(s1));
    __ Branch(&non_outermost_js, ne, s2, Operand(zero_reg));
    __ Sd(fp, MemOperand(s1));
    __ li(s3, Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
    Label cont;
    __ b(&cont);
    __ nop();  // Branch delay slot nop.
    __ bind(&non_outermost_js);
    __ li(s3, Operand(StackFrame::INNER_JSENTRY_FRAME));
    __ bind(&cont);
    __ push(s3);
  
    // Jump to a faked try block that does the invoke, with a faked catch
    // block that sets the pending exception.
    __ jmp(&invoke);
    __ bind(&handler_entry);
  
    // Store the current pc as the handler offset. It's used later to create the
    // handler table.
    masm->isolate()->builtins()->SetJSEntryHandlerOffset(handler_entry.pos());
  
    // Caught exception: Store result (exception) in the pending exception
    // field in the JSEnv and return a failure sentinel.  Coming in here the
    // fp will be invalid because the PushStackHandler below sets it to 0 to
    // signal the existence of the JSEntry frame.
    __ li(s1, ExternalReference::Create(
                  IsolateAddressId::kPendingExceptionAddress, masm->isolate()));
    __ Sd(v0, MemOperand(s1));  // We come back from 'invoke'. result is in v0.
    __ LoadRoot(v0, RootIndex::kException);
    __ b(&exit);  // b exposes branch delay slot.
    __ nop();     // Branch delay slot nop.
  
    // Invoke: Link this frame into the handler chain.
    __ bind(&invoke);
    __ PushStackHandler();
    // If an exception not caught by another handler occurs, this handler
    // returns control to the code after the bal(&invoke) above, which
    // restores all kCalleeSaved registers (including cp and fp) to their
    // saved values before returning a failure to C.
    //
    // Registers:
    //  either
    //   a0: root register value
    //   a1: entry address
    //   a2: function
    //   a3: receiver
    //   a4: argc
    //   a5: argv
    //  or
    //   a0: root register value
    //   a1: microtask_queue
    //
    // Stack:
    // handler frame
    // entry frame
    // callee saved registers + ra
    // [ O32: 4 args slots]
    // args
    //
    // Invoke the function by calling through JS entry trampoline builtin and
    // pop the faked function when we return.
  
    Handle<Code> trampoline_code =
        masm->isolate()->builtins()->code_handle(entry_trampoline);
    __ Call(trampoline_code, RelocInfo::CODE_TARGET);
  
    // Unlink this frame from the handler chain.
    __ PopStackHandler();
  
    __ bind(&exit);  // v0 holds result
    // Check if the current stack frame is marked as the outermost JS frame.
    Label non_outermost_js_2;
    __ pop(a5);
    __ Branch(&non_outermost_js_2, ne, a5,
              Operand(StackFrame::OUTERMOST_JSENTRY_FRAME));
    __ li(a5, js_entry_sp);
    __ Sd(zero_reg, MemOperand(a5));
    __ bind(&non_outermost_js_2);
  
    // Restore the top frame descriptors from the stack.
    __ pop(a5);
    __ li(a4, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress,
                                        masm->isolate()));
    __ Sd(a5, MemOperand(a4));
  
    // Reset the stack to the callee saved registers.
    __ daddiu(sp, sp, -EntryFrameConstants::kCallerFPOffset);
  
    // Restore callee-saved fpu registers.
    __ MultiPopFPU(kCalleeSavedFPU);
  
    // Restore callee saved registers from the stack.
    __ MultiPop(kCalleeSaved | ra);
    // Return.
    __ Jump(ra);
  }
  
  }  // namespace
  
  void Builtins::Generate_JSEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::ENTRY, Builtin::kJSEntryTrampoline);
  }
  
  void Builtins::Generate_JSConstructEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::CONSTRUCT_ENTRY,
                            Builtin::kJSConstructEntryTrampoline);
  }
  
  void Builtins::Generate_JSRunMicrotasksEntry(MacroAssembler* masm) {
    Generate_JSEntryVariant(masm, StackFrame::ENTRY,
                            Builtin::kRunMicrotasksTrampoline);
  }
  
  static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                               bool is_construct) {
    // ----------- S t a t e -------------
    //  -- a1: new.target
    //  -- a2: function
    //  -- a3: receiver_pointer
    //  -- a4: argc
    //  -- a5: argv
    // -----------------------------------
  
    // 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);
      __ Ld(cp, MemOperand(cp));
  
      // Push the function onto the stack.
      __ Push(a2);
  
      // Check if we have enough stack space to push all arguments.
      __ mov(a6, a4);
      Generate_CheckStackOverflow(masm, a6, a0, s2);
  
      // Copy arguments to the stack.
      // a4: argc
      // a5: argv, i.e. points to first arg
      Generate_PushArguments(masm, a5, a4, s1, s2, ArgumentsElementType::kHandle);
  
      // Push the receive.
      __ Push(a3);
  
      // a0: argc
      // a1: function
      // a3: new.target
      __ mov(a3, a1);
      __ mov(a1, a2);
      __ mov(a0, a4);
  
      // Initialize all JavaScript callee-saved registers, since they will be seen
      // by the garbage collector as part of handlers.
      __ LoadRoot(a4, RootIndex::kUndefinedValue);
      __ mov(a5, a4);
      __ mov(s1, a4);
      __ mov(s2, a4);
      __ mov(s3, a4);
      __ mov(s4, a4);
      __ mov(s5, a4);
      // 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);
  }
  
  void Builtins::Generate_RunMicrotasksTrampoline(MacroAssembler* masm) {
    // a1: microtask_queue
    __ mov(RunMicrotasksDescriptor::MicrotaskQueueRegister(), a1);
    __ Jump(BUILTIN_CODE(masm->isolate(), RunMicrotasks), RelocInfo::CODE_TARGET);
  }
  
  static void ReplaceClosureCodeWithOptimizedCode(MacroAssembler* masm,
                                                  Register optimized_code,
                                                  Register closure,
                                                  Register scratch1,
                                                  Register scratch2) {
    DCHECK(!AreAliased(optimized_code, closure, scratch1, scratch2));
    // Store code entry in the closure.
    __ Sd(optimized_code, FieldMemOperand(closure, JSFunction::kCodeOffset));
    __ mov(scratch1, optimized_code);  // Write barrier clobbers scratch1 below.
    __ RecordWriteField(closure, JSFunction::kCodeOffset, scratch1, scratch2,
                        kRAHasNotBeenSaved, SaveFPRegsMode::kIgnore,
                        RememberedSetAction::kOmit, SmiCheck::kOmit);
  }
  
  static void LeaveInterpreterFrame(MacroAssembler* masm, Register scratch1,
                                    Register scratch2) {
    Register params_size = scratch1;
  
    // Get the size of the formal parameters + receiver (in bytes).
    __ Ld(params_size,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ Lw(params_size,
          FieldMemOperand(params_size, BytecodeArray::kParameterSizeOffset));
  
    Register actual_params_size = scratch2;
    // Compute the size of the actual parameters + receiver (in bytes).
    __ Ld(actual_params_size,
          MemOperand(fp, StandardFrameConstants::kArgCOffset));
    __ dsll(actual_params_size, actual_params_size, kPointerSizeLog2);
  
    // If actual is bigger than formal, then we should use it to free up the stack
    // arguments.
    __ slt(t2, params_size, actual_params_size);
    __ movn(params_size, actual_params_size, t2);
  
    // Leave the frame (also dropping the register file).
    __ LeaveFrame(StackFrame::INTERPRETED);
  
    // Drop receiver + arguments.
    __ DropArguments(params_size, TurboAssembler::kCountIsBytes,
                     TurboAssembler::kCountIncludesReceiver);
  }
  
  // Tail-call |function_id| if |actual_marker| == |expected_marker|
  static void TailCallRuntimeIfMarkerEquals(MacroAssembler* masm,
                                            Register actual_marker,
                                            OptimizationMarker expected_marker,
                                            Runtime::FunctionId function_id) {
    Label no_match;
    __ Branch(&no_match, ne, actual_marker,
              Operand(static_cast<int>(expected_marker)));
    GenerateTailCallToReturnedCode(masm, function_id);
    __ bind(&no_match);
  }
  
  static void TailCallOptimizedCodeSlot(MacroAssembler* masm,
                                        Register optimized_code_entry,
                                        Register scratch1, Register scratch2) {
    // ----------- S t a t e -------------
    //  -- a0 : actual argument count
    //  -- a3 : new target (preserved for callee if needed, and caller)
    //  -- a1 : target function (preserved for callee if needed, and caller)
    // -----------------------------------
    DCHECK(!AreAliased(optimized_code_entry, a1, a3, scratch1, scratch2));
  
    Register closure = a1;
    Label heal_optimized_code_slot;
  
    // If the optimized code is cleared, go to runtime to update the optimization
    // marker field.
    __ LoadWeakValue(optimized_code_entry, optimized_code_entry,
                     &heal_optimized_code_slot);
  
    // Check if the optimized code is marked for deopt. If it is, call the
    // runtime to clear it.
    __ Ld(scratch1,
          FieldMemOperand(optimized_code_entry, Code::kCodeDataContainerOffset));
    __ Lw(scratch1,
          FieldMemOperand(scratch1, CodeDataContainer::kKindSpecificFlagsOffset));
    __ And(scratch1, scratch1, Operand(1 << Code::kMarkedForDeoptimizationBit));
    __ Branch(&heal_optimized_code_slot, ne, scratch1, 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,
                                        scratch1, scratch2);
  
    static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
    __ Daddu(a2, optimized_code_entry,
             Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Jump(a2);
  
    // Optimized code slot contains deoptimized code or code is cleared and
    // optimized code marker isn't updated. Evict the code, update the marker
    // and re-enter the closure's code.
    __ bind(&heal_optimized_code_slot);
    GenerateTailCallToReturnedCode(masm, Runtime::kHealOptimizedCodeSlot);
  }
  
  static void MaybeOptimizeCode(MacroAssembler* masm, Register feedback_vector,
                                Register optimization_marker) {
    // ----------- S t a t e -------------
    //  -- a0 : actual argument count
    //  -- 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)
    //  -- optimization_marker : a int32 containing a non-zero optimization
    //  marker.
    // -----------------------------------
    DCHECK(!AreAliased(feedback_vector, a1, a3, optimization_marker));
  
    TailCallRuntimeIfMarkerEquals(
        masm, optimization_marker,
        OptimizationMarker::kCompileTurbofan_NotConcurrent,
        Runtime::kCompileTurbofan_NotConcurrent);
    TailCallRuntimeIfMarkerEquals(masm, optimization_marker,
                                  OptimizationMarker::kCompileTurbofan_Concurrent,
                                  Runtime::kCompileTurbofan_Concurrent);
  
    // Marker should be one of CompileOptimized / CompileOptimizedConcurrent.
    // InOptimizationQueue and None shouldn't reach here.
    if (FLAG_debug_code) {
      __ stop();
    }
  }
  
  // Advance the current bytecode offset. This simulates what all bytecode
  // handlers do upon completion of the underlying operation. Will bail out to a
  // label if the bytecode (without prefix) is a return bytecode. Will not advance
  // the bytecode offset if the current bytecode is a JumpLoop, instead just
  // re-executing the JumpLoop to jump to the correct bytecode.
  static void AdvanceBytecodeOffsetOrReturn(MacroAssembler* masm,
                                            Register bytecode_array,
                                            Register bytecode_offset,
                                            Register bytecode, Register scratch1,
                                            Register scratch2, Register scratch3,
                                            Label* if_return) {
    Register bytecode_size_table = scratch1;
  
    // The bytecode offset value will be increased by one in wide and extra wide
    // cases. In the case of having a wide or extra wide JumpLoop bytecode, we
    // will restore the original bytecode. In order to simplify the code, we have
    // a backup of it.
    Register original_bytecode_offset = scratch3;
    DCHECK(!AreAliased(bytecode_array, bytecode_offset, bytecode,
                       bytecode_size_table, original_bytecode_offset));
    __ Move(original_bytecode_offset, bytecode_offset);
    __ 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.
    __ Daddu(bytecode_offset, bytecode_offset, Operand(1));
    __ Daddu(scratch2, bytecode_array, bytecode_offset);
    __ Lbu(bytecode, MemOperand(scratch2));
    __ Daddu(bytecode_size_table, bytecode_size_table,
             Operand(kByteSize * interpreter::Bytecodes::kBytecodeCount));
    __ jmp(&process_bytecode);
  
    __ bind(&extra_wide);
    // Load the next bytecode and update table to the extra wide scaled table.
    __ Daddu(bytecode_offset, bytecode_offset, Operand(1));
    __ Daddu(scratch2, bytecode_array, bytecode_offset);
    __ Lbu(bytecode, MemOperand(scratch2));
    __ Daddu(bytecode_size_table, bytecode_size_table,
             Operand(2 * kByteSize * 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
  
    // If this is a JumpLoop, re-execute it to perform the jump to the beginning
    // of the loop.
    Label end, not_jump_loop;
    __ Branch(&not_jump_loop, ne, bytecode,
              Operand(static_cast<int>(interpreter::Bytecode::kJumpLoop)));
    // We need to restore the original bytecode_offset since we might have
    // increased it to skip the wide / extra-wide prefix bytecode.
    __ Move(bytecode_offset, original_bytecode_offset);
    __ jmp(&end);
  
    __ bind(&not_jump_loop);
    // Otherwise, load the size of the current bytecode and advance the offset.
    __ Daddu(scratch2, bytecode_size_table, bytecode);
    __ Lb(scratch2, MemOperand(scratch2));
    __ Daddu(bytecode_offset, bytecode_offset, scratch2);
  
    __ bind(&end);
  }
  
  // Read off the optimization state in the feedback vector and check if there
  // is optimized code or a optimization marker that needs to be processed.
  static void LoadOptimizationStateAndJumpIfNeedsProcessing(
      MacroAssembler* masm, Register optimization_state, Register feedback_vector,
      Label* has_optimized_code_or_marker) {
    ASM_CODE_COMMENT(masm);
    Register scratch = t2;
    __ Lw(optimization_state,
          FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset));
    __ And(
        scratch, optimization_state,
        Operand(FeedbackVector::kHasOptimizedCodeOrCompileOptimizedMarkerMask));
    __ Branch(has_optimized_code_or_marker, ne, scratch, Operand(zero_reg));
  }
  
  static void MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(
      MacroAssembler* masm, Register optimization_state,
      Register feedback_vector) {
    ASM_CODE_COMMENT(masm);
    Label maybe_has_optimized_code;
    // Check if optimized code marker is available
    {
      UseScratchRegisterScope temps(masm);
      Register scratch = temps.Acquire();
      __ And(scratch, optimization_state,
             Operand(FeedbackVector::kHasCompileOptimizedMarker));
      __ Branch(&maybe_has_optimized_code, eq, scratch, Operand(zero_reg));
    }
  
    Register optimization_marker = optimization_state;
    __ DecodeField<FeedbackVector::OptimizationMarkerBits>(optimization_marker);
    MaybeOptimizeCode(masm, feedback_vector, optimization_marker);
  
    __ bind(&maybe_has_optimized_code);
    Register optimized_code_entry = optimization_state;
    __ Ld(optimization_marker,
          FieldMemOperand(feedback_vector,
                          FeedbackVector::kMaybeOptimizedCodeOffset));
    TailCallOptimizedCodeSlot(masm, optimized_code_entry, t3, a5);
  }
  
  // static
  void Builtins::Generate_BaselineOutOfLinePrologue(MacroAssembler* masm) {
    UseScratchRegisterScope temps(masm);
    temps.Include({s1, s2});
    auto descriptor =
        Builtins::CallInterfaceDescriptorFor(Builtin::kBaselineOutOfLinePrologue);
    Register closure = descriptor.GetRegisterParameter(
        BaselineOutOfLinePrologueDescriptor::kClosure);
    // Load the feedback vector from the closure.
    Register feedback_vector = temps.Acquire();
    __ Ld(feedback_vector,
          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
    __ Ld(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
    if (FLAG_debug_code) {
      UseScratchRegisterScope temps(masm);
      Register scratch = temps.Acquire();
      __ GetObjectType(feedback_vector, scratch, scratch);
      __ Assert(eq, AbortReason::kExpectedFeedbackVector, scratch,
                Operand(FEEDBACK_VECTOR_TYPE));
    }
    // Check for an optimization marker.
    Label has_optimized_code_or_marker;
    Register optimization_state = no_reg;
    {
      UseScratchRegisterScope temps(masm);
      optimization_state = temps.Acquire();
      // optimization_state will be used only in |has_optimized_code_or_marker|
      // and outside it can be reused.
      LoadOptimizationStateAndJumpIfNeedsProcessing(
          masm, optimization_state, feedback_vector,
          &has_optimized_code_or_marker);
    }
    // Increment invocation count for the function.
    {
      UseScratchRegisterScope temps(masm);
      Register invocation_count = temps.Acquire();
      __ Lw(invocation_count,
            FieldMemOperand(feedback_vector,
                            FeedbackVector::kInvocationCountOffset));
      __ Addu(invocation_count, invocation_count, Operand(1));
      __ Sw(invocation_count,
            FieldMemOperand(feedback_vector,
                            FeedbackVector::kInvocationCountOffset));
    }
  
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    {
      ASM_CODE_COMMENT_STRING(masm, "Frame Setup");
      // Normally the first thing we'd do here is Push(ra, fp), but we already
      // entered the frame in BaselineCompiler::Prologue, as we had to use the
      // value lr before the call to this BaselineOutOfLinePrologue builtin.
      Register callee_context = descriptor.GetRegisterParameter(
          BaselineOutOfLinePrologueDescriptor::kCalleeContext);
      Register callee_js_function = descriptor.GetRegisterParameter(
          BaselineOutOfLinePrologueDescriptor::kClosure);
      __ Push(callee_context, callee_js_function);
      DCHECK_EQ(callee_js_function, kJavaScriptCallTargetRegister);
      DCHECK_EQ(callee_js_function, kJSFunctionRegister);
  
      Register argc = descriptor.GetRegisterParameter(
          BaselineOutOfLinePrologueDescriptor::kJavaScriptCallArgCount);
      // We'll use the bytecode for both code age/OSR resetting, and pushing onto
      // the frame, so load it into a register.
      Register bytecodeArray = descriptor.GetRegisterParameter(
          BaselineOutOfLinePrologueDescriptor::kInterpreterBytecodeArray);
  
      // Reset code age and the OSR arming. The OSR field and BytecodeAgeOffset
      // are 8-bit fields next to each other, so we could just optimize by writing
      // a 16-bit. These static asserts guard our assumption is valid.
      STATIC_ASSERT(BytecodeArray::kBytecodeAgeOffset ==
                    BytecodeArray::kOsrUrgencyOffset + kCharSize);
      STATIC_ASSERT(BytecodeArray::kNoAgeBytecodeAge == 0);
      __ Sh(zero_reg,
            FieldMemOperand(bytecodeArray, BytecodeArray::kOsrUrgencyOffset));
  
      __ Push(argc, bytecodeArray);
  
      // Baseline code frames store the feedback vector where interpreter would
      // store the bytecode offset.
      if (FLAG_debug_code) {
        UseScratchRegisterScope temps(masm);
        Register invocation_count = temps.Acquire();
        __ GetObjectType(feedback_vector, invocation_count, invocation_count);
        __ Assert(eq, AbortReason::kExpectedFeedbackVector, invocation_count,
                  Operand(FEEDBACK_VECTOR_TYPE));
      }
      // Our stack is currently aligned. We have have to push something along with
      // the feedback vector to keep it that way -- we may as well start
      // initialising the register frame.
      // TODO(v8:11429,leszeks): Consider guaranteeing that this call leaves
      // `undefined` in the accumulator register, to skip the load in the baseline
      // code.
      __ Push(feedback_vector);
    }
  
    Label call_stack_guard;
    Register frame_size = descriptor.GetRegisterParameter(
        BaselineOutOfLinePrologueDescriptor::kStackFrameSize);
    {
      ASM_CODE_COMMENT_STRING(masm, "Stack/interrupt check");
      // Stack check. This folds the checks for both the interrupt stack limit
      // check and the real stack limit into one by just checking for the
      // interrupt limit. The interrupt limit is either equal to the real stack
      // limit or tighter. By ensuring we have space until that limit after
      // building the frame we can quickly precheck both at once.
      UseScratchRegisterScope temps(masm);
      Register sp_minus_frame_size = temps.Acquire();
      __ Dsubu(sp_minus_frame_size, sp, frame_size);
      Register interrupt_limit = temps.Acquire();
      __ LoadStackLimit(interrupt_limit,
                        MacroAssembler::StackLimitKind::kInterruptStackLimit);
      __ Branch(&call_stack_guard, Uless, sp_minus_frame_size,
                Operand(interrupt_limit));
    }
  
    // Do "fast" return to the caller pc in ra.
    // TODO(v8:11429): Document this frame setup better.
    __ Ret();
  
    __ bind(&has_optimized_code_or_marker);
    {
      ASM_CODE_COMMENT_STRING(masm, "Optimized marker check");
      UseScratchRegisterScope temps(masm);
      temps.Exclude(optimization_state);
      // Ensure the optimization_state is not allocated again.
      // Drop the frame created by the baseline call.
      __ Pop(ra, fp);
      MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(masm, optimization_state,
                                                   feedback_vector);
      __ Trap();
    }
  
    __ bind(&call_stack_guard);
    {
      ASM_CODE_COMMENT_STRING(masm, "Stack/interrupt call");
      FrameScope frame_scope(masm, StackFrame::INTERNAL);
      // Save incoming new target or generator
      __ Push(kJavaScriptCallNewTargetRegister);
      __ SmiTag(frame_size);
      __ Push(frame_size);
      __ CallRuntime(Runtime::kStackGuardWithGap);
      __ Pop(kJavaScriptCallNewTargetRegister);
    }
    __ Ret();
    temps.Exclude({kScratchReg, kScratchReg2});
  }
  
  // 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 live registers are:
  //   o a0 : actual argument count
  //   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
  // frame-constants.h for its layout.
  void Builtins::Generate_InterpreterEntryTrampoline(MacroAssembler* masm) {
    Register closure = a1;
    Register feedback_vector = a2;
  
    // Get the bytecode array from the function object and load it into
    // kInterpreterBytecodeArrayRegister.
    __ Ld(kScratchReg,
          FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    __ Ld(kInterpreterBytecodeArrayRegister,
          FieldMemOperand(kScratchReg, SharedFunctionInfo::kFunctionDataOffset));
    Label is_baseline;
    GetSharedFunctionInfoBytecodeOrBaseline(
        masm, kInterpreterBytecodeArrayRegister, kScratchReg, &is_baseline);
  
    // The bytecode array could have been flushed from the shared function info,
    // if so, call into CompileLazy.
    Label compile_lazy;
    __ GetObjectType(kInterpreterBytecodeArrayRegister, kScratchReg, kScratchReg);
    __ Branch(&compile_lazy, ne, kScratchReg, Operand(BYTECODE_ARRAY_TYPE));
  
    // Load the feedback vector from the closure.
    __ Ld(feedback_vector,
          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
    __ Ld(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
  
    Label push_stack_frame;
    // Check if feedback vector is valid. If valid, check for optimized code
    // and update invocation count. Otherwise, setup the stack frame.
    __ Ld(a4, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
    __ Lhu(a4, FieldMemOperand(a4, Map::kInstanceTypeOffset));
    __ Branch(&push_stack_frame, ne, a4, Operand(FEEDBACK_VECTOR_TYPE));
  
    // Read off the optimization state in the feedback vector, and if there
    // is optimized code or an optimization marker, call that instead.
    Register optimization_state = a4;
    __ Lw(optimization_state,
          FieldMemOperand(feedback_vector, FeedbackVector::kFlagsOffset));
  
    // Check if the optimized code slot is not empty or has a optimization marker.
    Label has_optimized_code_or_marker;
  
    __ andi(t0, optimization_state,
            FeedbackVector::kHasOptimizedCodeOrCompileOptimizedMarkerMask);
    __ Branch(&has_optimized_code_or_marker, ne, t0, Operand(zero_reg));
  
    Label not_optimized;
    __ bind(&not_optimized);
  
    // Increment invocation count for the function.
    __ Lw(a4, FieldMemOperand(feedback_vector,
                              FeedbackVector::kInvocationCountOffset));
    __ Addu(a4, a4, Operand(1));
    __ Sw(a4, FieldMemOperand(feedback_vector,
                              FeedbackVector::kInvocationCountOffset));
  
    // Open a frame scope to indicate that there is a frame on the stack.  The
    // MANUAL indicates that the scope shouldn't actually generate code to set up
    // the frame (that is done below).
    __ bind(&push_stack_frame);
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ PushStandardFrame(closure);
  
    // Reset code age and the OSR arming. The OSR field and BytecodeAgeOffset are
    // 8-bit fields next to each other, so we could just optimize by writing a
    // 16-bit. These static asserts guard our assumption is valid.
    STATIC_ASSERT(BytecodeArray::kBytecodeAgeOffset ==
                  BytecodeArray::kOsrUrgencyOffset + kCharSize);
    STATIC_ASSERT(BytecodeArray::kNoAgeBytecodeAge == 0);
    __ sh(zero_reg, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                    BytecodeArray::kOsrUrgencyOffset));
  
    // Load initial bytecode offset.
    __ li(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
  
    // Push bytecode array and Smi tagged bytecode array offset.
    __ SmiTag(a4, kInterpreterBytecodeOffsetRegister);
    __ Push(kInterpreterBytecodeArrayRegister, a4);
  
    // Allocate the local and temporary register file on the stack.
    Label stack_overflow;
    {
      // Load frame size (word) from the BytecodeArray object.
      __ Lw(a4, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                BytecodeArray::kFrameSizeOffset));
  
      // Do a stack check to ensure we don't go over the limit.
      __ Dsubu(a5, sp, Operand(a4));
      __ LoadStackLimit(a2, MacroAssembler::StackLimitKind::kRealStackLimit);
      __ Branch(&stack_overflow, lo, a5, Operand(a2));
  
      // If ok, push undefined as the initial value for all register file entries.
      Label loop_header;
      Label loop_check;
      __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
      __ Branch(&loop_check);
      __ bind(&loop_header);
      // TODO(rmcilroy): Consider doing more than one push per loop iteration.
      __ push(kInterpreterAccumulatorRegister);
      // Continue loop if not done.
      __ bind(&loop_check);
      __ Dsubu(a4, a4, Operand(kPointerSize));
      __ Branch(&loop_header, ge, a4, 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(a5, FieldMemOperand(
                  kInterpreterBytecodeArrayRegister,
                  BytecodeArray::kIncomingNewTargetOrGeneratorRegisterOffset));
    __ Branch(&no_incoming_new_target_or_generator_register, eq, a5,
              Operand(zero_reg));
    __ Dlsa(a5, fp, a5, kPointerSizeLog2);
    __ Sd(a3, MemOperand(a5));
    __ bind(&no_incoming_new_target_or_generator_register);
  
    // Perform interrupt stack check.
    // TODO(solanes): Merge with the real stack limit check above.
    Label stack_check_interrupt, after_stack_check_interrupt;
    __ LoadStackLimit(a5, MacroAssembler::StackLimitKind::kInterruptStackLimit);
    __ Branch(&stack_check_interrupt, lo, sp, Operand(a5));
    __ bind(&after_stack_check_interrupt);
  
    // The accumulator is already loaded with undefined.
  
    // Load the dispatch table into a register and dispatch to the bytecode
    // handler at the current bytecode offset.
    Label do_dispatch;
    __ bind(&do_dispatch);
    __ li(kInterpreterDispatchTableRegister,
          ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
    __ Daddu(a0, kInterpreterBytecodeArrayRegister,
             kInterpreterBytecodeOffsetRegister);
    __ Lbu(a7, MemOperand(a0));
    __ Dlsa(kScratchReg, kInterpreterDispatchTableRegister, a7, kPointerSizeLog2);
    __ Ld(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.
    __ Ld(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ Ld(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    // Either return, or advance to the next bytecode and dispatch.
    Label do_return;
    __ Daddu(a1, kInterpreterBytecodeArrayRegister,
             kInterpreterBytecodeOffsetRegister);
    __ Lbu(a1, MemOperand(a1));
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                  a4, &do_return);
    __ jmp(&do_dispatch);
  
    __ bind(&do_return);
    // The return value is in v0.
    LeaveInterpreterFrame(masm, t0, t1);
    __ Jump(ra);
  
    __ bind(&stack_check_interrupt);
    // Modify the bytecode offset in the stack to be kFunctionEntryBytecodeOffset
    // for the call to the StackGuard.
    __ li(kInterpreterBytecodeOffsetRegister,
          Operand(Smi::FromInt(BytecodeArray::kHeaderSize - kHeapObjectTag +
                               kFunctionEntryBytecodeOffset)));
    __ Sd(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ CallRuntime(Runtime::kStackGuard);
  
    // After the call, restore the bytecode array, bytecode offset and accumulator
    // registers again. Also, restore the bytecode offset in the stack to its
    // previous value.
    __ Ld(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ li(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
    __ LoadRoot(kInterpreterAccumulatorRegister, RootIndex::kUndefinedValue);
  
    __ SmiTag(a5, kInterpreterBytecodeOffsetRegister);
    __ Sd(a5, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
  
    __ jmp(&after_stack_check_interrupt);
  
    __ bind(&has_optimized_code_or_marker);
    MaybeOptimizeCodeOrTailCallOptimizedCodeSlot(masm, optimization_state,
                                                 feedback_vector);
    __ bind(&is_baseline);
    {
      // Load the feedback vector from the closure.
      __ Ld(feedback_vector,
            FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
      __ Ld(feedback_vector,
            FieldMemOperand(feedback_vector, Cell::kValueOffset));
  
      Label install_baseline_code;
      // Check if feedback vector is valid. If not, call prepare for baseline to
      // allocate it.
      __ Ld(t0, FieldMemOperand(feedback_vector, HeapObject::kMapOffset));
      __ Lhu(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
      __ Branch(&install_baseline_code, ne, t0, Operand(FEEDBACK_VECTOR_TYPE));
  
      // Check for an optimization marker.
      LoadOptimizationStateAndJumpIfNeedsProcessing(
          masm, optimization_state, feedback_vector,
          &has_optimized_code_or_marker);
  
      // Load the baseline code into the closure.
      __ Move(a2, kInterpreterBytecodeArrayRegister);
      static_assert(kJavaScriptCallCodeStartRegister == a2, "ABI mismatch");
      ReplaceClosureCodeWithOptimizedCode(masm, a2, closure, t0, t1);
      __ JumpCodeObject(a2);
  
      __ bind(&install_baseline_code);
      GenerateTailCallToReturnedCode(masm, Runtime::kInstallBaselineCode);
    }
    __ bind(&compile_lazy);
    GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
    // Unreachable code.
    __ break_(0xCC);
  
    __ bind(&stack_overflow);
    __ CallRuntime(Runtime::kThrowStackOverflow);
    // Unreachable code.
    __ break_(0xCC);
  }
  
  static void GenerateInterpreterPushArgs(MacroAssembler* masm, Register num_args,
                                          Register start_address,
                                          Register scratch, Register scratch2) {
    // Find the address of the last argument.
    __ Dsubu(scratch, num_args, Operand(1));
    __ dsll(scratch, scratch, kPointerSizeLog2);
    __ Dsubu(start_address, start_address, scratch);
  
    // Push the arguments.
    __ PushArray(start_address, num_args, scratch, scratch2,
                 TurboAssembler::PushArrayOrder::kReverse);
  }
  
  // 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
    //  -- 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;
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // The spread argument should not be pushed.
      __ Dsubu(a0, a0, Operand(1));
    }
  
    if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
      __ Dsubu(a3, a0, Operand(kJSArgcReceiverSlots));
    } else {
      __ mov(a3, a0);
    }
  
    __ StackOverflowCheck(a3, a4, t0, &stack_overflow);
  
    // This function modifies a2, t0 and a4.
    GenerateInterpreterPushArgs(masm, a3, a2, a4, t0);
  
    if (receiver_mode == ConvertReceiverMode::kNullOrUndefined) {
      __ PushRoot(RootIndex::kUndefinedValue);
    }
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // Pass the spread in the register a2.
      // a2 already points to the penultime argument, the spread
      // is below that.
      __ Ld(a2, MemOperand(a2, -kSystemPointerSize));
    }
  
    // 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
    // -- a3 : new target
    // -- a1 : constructor to call
    // -- a2 : allocation site feedback if available, undefined otherwise.
    // -- a4 : address of the first argument
    // -----------------------------------
    Label stack_overflow;
    __ StackOverflowCheck(a0, a5, t0, &stack_overflow);
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // The spread argument should not be pushed.
      __ Dsubu(a0, a0, Operand(1));
    }
  
    Register argc_without_receiver = a6;
    __ Dsubu(argc_without_receiver, a0, Operand(kJSArgcReceiverSlots));
    // Push the arguments, This function modifies t0, a4 and a5.
    GenerateInterpreterPushArgs(masm, argc_without_receiver, a4, a5, t0);
  
    // Push a slot for the receiver.
    __ push(zero_reg);
  
    if (mode == InterpreterPushArgsMode::kWithFinalSpread) {
      // Pass the spread in the register a2.
      // a4 already points to the penultimate argument, the spread
      // lies in the next interpreter register.
      __ Ld(a2, MemOperand(a4, -kSystemPointerSize));
    } else {
      __ AssertUndefinedOrAllocationSite(a2, t0);
    }
  
    if (mode == InterpreterPushArgsMode::kArrayFunction) {
      __ AssertFunction(a1);
  
      // Tail call to the function-specific 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, the function will have a
    // custom copy of the interpreter entry trampoline for profiling. If so,
    // get the custom trampoline, otherwise grab the entry address of the global
    // trampoline.
    __ Ld(t0, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
    __ Ld(t0, FieldMemOperand(t0, JSFunction::kSharedFunctionInfoOffset));
    __ Ld(t0, FieldMemOperand(t0, SharedFunctionInfo::kFunctionDataOffset));
    __ GetObjectType(t0, kInterpreterDispatchTableRegister,
                     kInterpreterDispatchTableRegister);
    __ Branch(&builtin_trampoline, ne, kInterpreterDispatchTableRegister,
              Operand(INTERPRETER_DATA_TYPE));
  
    __ Ld(t0, FieldMemOperand(t0, InterpreterData::kInterpreterTrampolineOffset));
    __ Daddu(t0, t0, Operand(Code::kHeaderSize - kHeapObjectTag));
    __ Branch(&trampoline_loaded);
  
    __ bind(&builtin_trampoline);
    __ li(t0, ExternalReference::
                  address_of_interpreter_entry_trampoline_instruction_start(
                      masm->isolate()));
    __ Ld(t0, MemOperand(t0));
  
    __ bind(&trampoline_loaded);
    __ Daddu(ra, t0, Operand(interpreter_entry_return_pc_offset.value()));
  
    // Initialize the dispatch table register.
    __ li(kInterpreterDispatchTableRegister,
          ExternalReference::interpreter_dispatch_table_address(masm->isolate()));
  
    // Get the bytecode array pointer from the frame.
    __ Ld(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.
    __ SmiUntag(kInterpreterBytecodeOffsetRegister,
                MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
  
    if (FLAG_debug_code) {
      Label okay;
      __ Branch(&okay, ge, kInterpreterBytecodeOffsetRegister,
                Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
      // Unreachable code.
      __ break_(0xCC);
      __ bind(&okay);
    }
  
    // Dispatch to the target bytecode.
    __ Daddu(a1, kInterpreterBytecodeArrayRegister,
             kInterpreterBytecodeOffsetRegister);
    __ Lbu(a7, MemOperand(a1));
    __ Dlsa(a1, kInterpreterDispatchTableRegister, a7, kPointerSizeLog2);
    __ Ld(kJavaScriptCallCodeStartRegister, MemOperand(a1));
    __ Jump(kJavaScriptCallCodeStartRegister);
  }
  
  void Builtins::Generate_InterpreterEnterAtNextBytecode(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.
    __ Ld(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    __ Ld(kInterpreterBytecodeOffsetRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    __ SmiUntag(kInterpreterBytecodeOffsetRegister);
  
    Label enter_bytecode, function_entry_bytecode;
    __ Branch(&function_entry_bytecode, eq, kInterpreterBytecodeOffsetRegister,
              Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
                      kFunctionEntryBytecodeOffset));
  
    // Load the current bytecode.
    __ Daddu(a1, kInterpreterBytecodeArrayRegister,
             kInterpreterBytecodeOffsetRegister);
    __ Lbu(a1, MemOperand(a1));
  
    // Advance to the next bytecode.
    Label if_return;
    AdvanceBytecodeOffsetOrReturn(masm, kInterpreterBytecodeArrayRegister,
                                  kInterpreterBytecodeOffsetRegister, a1, a2, a3,
                                  a4, &if_return);
  
    __ bind(&enter_bytecode);
    // Convert new bytecode offset to a Smi and save in the stackframe.
    __ SmiTag(a2, kInterpreterBytecodeOffsetRegister);
    __ Sd(a2, MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
  
    Generate_InterpreterEnterBytecode(masm);
  
    __ bind(&function_entry_bytecode);
    // If the code deoptimizes during the implicit function entry stack interrupt
    // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
    // not a valid bytecode offset. Detect this case and advance to the first
    // actual bytecode.
    __ li(kInterpreterBytecodeOffsetRegister,
          Operand(BytecodeArray::kHeaderSize - kHeapObjectTag));
    __ Branch(&enter_bytecode);
  
    // We should never take the if_return path.
    __ bind(&if_return);
    __ Abort(AbortReason::kInvalidBytecodeAdvance);
  }
  
  void Builtins::Generate_InterpreterEnterAtBytecode(MacroAssembler* masm) {
    Generate_InterpreterEnterBytecode(masm);
  }
  
  namespace {
  void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
                                        bool java_script_builtin,
                                        bool with_result) {
    const RegisterConfiguration* config(RegisterConfiguration::Default());
    int allocatable_register_count = config->num_allocatable_general_registers();
    UseScratchRegisterScope temps(masm);
    Register scratch = temps.Acquire();
  
    if (with_result) {
    if (java_script_builtin) {
      __ mov(scratch, v0);
    } else {
      // Overwrite the hole inserted by the deoptimizer with the return value from
      // the LAZY deopt point.
      __ Sd(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));
      }
    }
  
    if (with_result && java_script_builtin) {
      // Overwrite the hole inserted by the deoptimizer with the return value from
      // the LAZY deopt point. t0 contains the arguments count, the return value
      // from LAZY is always the last argument.
      constexpr int return_value_offset =
          BuiltinContinuationFrameConstants::kFixedSlotCount -
          kJSArgcReceiverSlots;
      __ Daddu(a0, a0, Operand(return_value_offset));
      __ Dlsa(t0, sp, a0, kSystemPointerSizeLog2);
      __ Sd(scratch, MemOperand(t0));
      // Recover arguments count.
      __ Dsubu(a0, a0, Operand(return_value_offset));
    }
  
    __ Ld(fp, MemOperand(
                  sp, BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    // Load builtin index (stored as a Smi) and use it to get the builtin start
    // address from the builtins table.
    __ Pop(t0);
    __ Daddu(sp, sp,
             Operand(BuiltinContinuationFrameConstants::kFixedFrameSizeFromFp));
    __ Pop(ra);
    __ LoadEntryFromBuiltinIndex(t0);
    __ 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());
    __ Ld(v0, MemOperand(sp, 0 * kPointerSize));
    __ Ret(USE_DELAY_SLOT);
    // Safe to fill delay slot Addu will emit one instruction.
    __ Daddu(sp, sp, Operand(1 * kPointerSize));  // Remove state.
  }
  
  namespace {
  
  void Generate_OSREntry(MacroAssembler* masm, Register entry_address,
                         Operand offset = Operand(zero_reg)) {
    __ Daddu(ra, entry_address, offset);
    // And "return" to the OSR entry point of the function.
    __ Ret();
  }
  
  void OnStackReplacement(MacroAssembler* masm, bool is_interpreter) {
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ CallRuntime(Runtime::kCompileForOnStackReplacement);
    }
  
    // If the code object is null, just return to the caller.
    __ Ret(eq, v0, Operand(Smi::zero()));
    if (is_interpreter) {
      // 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]
    __ Ld(a1, MemOperand(v0, Code::kDeoptimizationDataOrInterpreterDataOffset -
                                 kHeapObjectTag));
  
    // Load the OSR entrypoint offset from the deoptimization data.
    // <osr_offset> = <deopt_data>[#header_size + #osr_pc_offset]
    __ SmiUntag(a1, MemOperand(a1, FixedArray::OffsetOfElementAt(
                                       DeoptimizationData::kOsrPcOffsetIndex) -
                                       kHeapObjectTag));
  
    // Compute the target address = code_obj + header_size + osr_offset
    // <entry_addr> = <code_obj> + #header_size + <osr_offset>
    __ Daddu(v0, v0, a1);
    Generate_OSREntry(masm, v0, Operand(Code::kHeaderSize - kHeapObjectTag));
  }
  }  // namespace
  
  void Builtins::Generate_InterpreterOnStackReplacement(MacroAssembler* masm) {
    return OnStackReplacement(masm, true);
  }
  
  void Builtins::Generate_BaselineOnStackReplacement(MacroAssembler* masm) {
    __ Ld(kContextRegister,
          MemOperand(fp, StandardFrameConstants::kContextOffset));
    return OnStackReplacement(masm, false);
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0    : argc
    //  -- sp[0] : receiver
    //  -- sp[4] : thisArg
    //  -- sp[8] : argArray
    // -----------------------------------
  
    Register argc = a0;
    Register arg_array = a2;
    Register receiver = a1;
    Register this_arg = a5;
    Register undefined_value = a3;
    Register scratch = a4;
  
    __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
  
    // 1. Load receiver into a1, argArray into a2 (if present), remove all
    // arguments from the stack (including the receiver), and push thisArg (if
    // present) instead.
    {
      __ Dsubu(scratch, argc, JSParameterCount(0));
      __ Ld(this_arg, MemOperand(sp, kPointerSize));
      __ Ld(arg_array, MemOperand(sp, 2 * kPointerSize));
      __ Movz(arg_array, undefined_value, scratch);  // if argc == 0
      __ Movz(this_arg, undefined_value, scratch);   // if argc == 0
      __ Dsubu(scratch, scratch, Operand(1));
      __ Movz(arg_array, undefined_value, scratch);  // if argc == 1
      __ Ld(receiver, MemOperand(sp));
      __ DropArgumentsAndPushNewReceiver(argc, this_arg,
                                         TurboAssembler::kCountIsInteger,
                                         TurboAssembler::kCountIncludesReceiver);
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argArray
    //  -- a1    : receiver
    //  -- a3    : undefined root value
    //  -- 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(arg_array, RootIndex::kNullValue, &no_arguments);
    __ Branch(&no_arguments, eq, arg_array, Operand(undefined_value));
  
    // 4a. Apply the receiver to the given argArray.
    __ Jump(BUILTIN_CODE(masm->isolate(), CallWithArrayLike),
            RelocInfo::CODE_TARGET);
  
    // 4b. The argArray is either null or undefined, so we tail call without any
    // arguments to the receiver.
    __ bind(&no_arguments);
    {
      __ li(a0, JSParameterCount(0));
      DCHECK(receiver == a1);
      __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
    }
  }
  
  // static
  void Builtins::Generate_FunctionPrototypeCall(MacroAssembler* masm) {
    // 1. Get the callable to call (passed as receiver) from the stack.
    {
      __ Pop(a1);
    }
  
    // 2. Make sure we have at least one argument.
    // a0: actual number of arguments
    {
      Label done;
      __ Branch(&done, ne, a0, Operand(JSParameterCount(0)));
      __ PushRoot(RootIndex::kUndefinedValue);
      __ Daddu(a0, a0, Operand(1));
      __ bind(&done);
    }
  
    // 3. Adjust the actual number of arguments.
    __ daddiu(a0, a0, -1);
  
    // 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]  : receiver
    //  -- sp[8]  : target         (if argc >= 1)
    //  -- sp[16] : thisArgument   (if argc >= 2)
    //  -- sp[24] : argumentsList  (if argc == 3)
    // -----------------------------------
  
    Register argc = a0;
    Register arguments_list = a2;
    Register target = a1;
    Register this_argument = a5;
    Register undefined_value = a3;
    Register scratch = a4;
  
    __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
  
    // 1. Load target into a1 (if present), argumentsList into a2 (if present),
    // remove all arguments from the stack (including the receiver), and push
    // thisArgument (if present) instead.
    {
      // Claim (3 - argc) dummy arguments form the stack, to put the stack in a
      // consistent state for a simple pop operation.
  
      __ Dsubu(scratch, argc, Operand(JSParameterCount(0)));
      __ Ld(target, MemOperand(sp, kPointerSize));
      __ Ld(this_argument, MemOperand(sp, 2 * kPointerSize));
      __ Ld(arguments_list, MemOperand(sp, 3 * kPointerSize));
      __ Movz(arguments_list, undefined_value, scratch);  // if argc == 0
      __ Movz(this_argument, undefined_value, scratch);   // if argc == 0
      __ Movz(target, undefined_value, scratch);          // if argc == 0
      __ Dsubu(scratch, scratch, Operand(1));
      __ Movz(arguments_list, undefined_value, scratch);  // if argc == 1
      __ Movz(this_argument, undefined_value, scratch);   // if argc == 1
      __ Dsubu(scratch, scratch, Operand(1));
      __ Movz(arguments_list, undefined_value, scratch);  // if argc == 2
  
      __ DropArgumentsAndPushNewReceiver(argc, this_argument,
                                         TurboAssembler::kCountIsInteger,
                                         TurboAssembler::kCountIncludesReceiver);
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argumentsList
    //  -- a1    : target
    //  -- a3    : undefined root value
    //  -- 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]   : receiver
    //  -- sp[8]   : target
    //  -- sp[16]  : argumentsList
    //  -- sp[24]  : new.target (optional)
    // -----------------------------------
  
    Register argc = a0;
    Register arguments_list = a2;
    Register target = a1;
    Register new_target = a3;
    Register undefined_value = a4;
    Register scratch = a5;
  
    __ LoadRoot(undefined_value, RootIndex::kUndefinedValue);
  
    // 1. Load target into a1 (if present), argumentsList into a2 (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.
    {
      // Claim (3 - argc) dummy arguments form the stack, to put the stack in a
      // consistent state for a simple pop operation.
  
      __ Dsubu(scratch, argc, Operand(JSParameterCount(0)));
      __ Ld(target, MemOperand(sp, kPointerSize));
      __ Ld(arguments_list, MemOperand(sp, 2 * kPointerSize));
      __ Ld(new_target, MemOperand(sp, 3 * kPointerSize));
      __ Movz(arguments_list, undefined_value, scratch);  // if argc == 0
      __ Movz(new_target, undefined_value, scratch);      // if argc == 0
      __ Movz(target, undefined_value, scratch);          // if argc == 0
      __ Dsubu(scratch, scratch, Operand(1));
      __ Movz(arguments_list, undefined_value, scratch);  // if argc == 1
      __ Movz(new_target, target, scratch);               // if argc == 1
      __ Dsubu(scratch, scratch, Operand(1));
      __ Movz(new_target, target, scratch);               // if argc == 2
  
      __ DropArgumentsAndPushNewReceiver(argc, undefined_value,
                                         TurboAssembler::kCountIsInteger,
                                         TurboAssembler::kCountIncludesReceiver);
    }
  
    // ----------- S t a t e -------------
    //  -- a2    : argumentsList
    //  -- a1    : target
    //  -- a3    : new.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);
  }
  
  namespace {
  
  // Allocate new stack space for |count| arguments and shift all existing
  // arguments already on the stack. |pointer_to_new_space_out| points to the
  // first free slot on the stack to copy additional arguments to and
  // |argc_in_out| is updated to include |count|.
  void Generate_AllocateSpaceAndShiftExistingArguments(
      MacroAssembler* masm, Register count, Register argc_in_out,
      Register pointer_to_new_space_out, Register scratch1, Register scratch2,
      Register scratch3) {
    DCHECK(!AreAliased(count, argc_in_out, pointer_to_new_space_out, scratch1,
                       scratch2));
    Register old_sp = scratch1;
    Register new_space = scratch2;
    __ mov(old_sp, sp);
    __ dsll(new_space, count, kPointerSizeLog2);
    __ Dsubu(sp, sp, Operand(new_space));
  
    Register end = scratch2;
    Register value = scratch3;
    Register dest = pointer_to_new_space_out;
    __ mov(dest, sp);
    __ Dlsa(end, old_sp, argc_in_out, kSystemPointerSizeLog2);
    Label loop, done;
    __ Branch(&done, ge, old_sp, Operand(end));
    __ bind(&loop);
    __ Ld(value, MemOperand(old_sp, 0));
    __ Sd(value, MemOperand(dest, 0));
    __ Daddu(old_sp, old_sp, Operand(kSystemPointerSize));
    __ Daddu(dest, dest, Operand(kSystemPointerSize));
    __ Branch(&loop, lt, old_sp, Operand(end));
    __ bind(&done);
  
    // Update total number of arguments.
    __ Daddu(argc_in_out, argc_in_out, count);
  }
  
  }  // namespace
  
  // static
  void Builtins::Generate_CallOrConstructVarargs(MacroAssembler* masm,
                                                 Handle<Code> code) {
    // ----------- S t a t e -------------
    //  -- a1 : target
    //  -- a0 : number of parameters on the stack
    //  -- a2 : arguments list (a FixedArray)
    //  -- a4 : len (number of elements to push from args)
    //  -- a3 : new.target (for [[Construct]])
    // -----------------------------------
    if (FLAG_debug_code) {
      // Allow a2 to be a FixedArray, or a FixedDoubleArray if a4 == 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, a4, Operand(zero_reg));
      // Fall through.
      __ bind(&fail);
      __ Abort(AbortReason::kOperandIsNotAFixedArray);
  
      __ bind(&ok);
    }
  
    Register args = a2;
    Register len = a4;
  
    // Check for stack overflow.
    Label stack_overflow;
    __ StackOverflowCheck(len, kScratchReg, a5, &stack_overflow);
  
    // Move the arguments already in the stack,
    // including the receiver and the return address.
    // a4: Number of arguments to make room for.
    // a0: Number of arguments already on the stack.
    // a7: Points to first free slot on the stack after arguments were shifted.
    Generate_AllocateSpaceAndShiftExistingArguments(masm, a4, a0, a7, a6, t0, t1);
  
    // Push arguments onto the stack (thisArgument is already on the stack).
    {
      Label done, push, loop;
      Register src = a6;
      Register scratch = len;
  
      __ daddiu(src, args, FixedArray::kHeaderSize - kHeapObjectTag);
      __ Branch(&done, eq, len, Operand(zero_reg), i::USE_DELAY_SLOT);
      __ dsll(scratch, len, kPointerSizeLog2);
      __ Dsubu(scratch, sp, Operand(scratch));
      __ LoadRoot(t1, RootIndex::kTheHoleValue);
      __ bind(&loop);
      __ Ld(a5, MemOperand(src));
      __ daddiu(src, src, kPointerSize);
      __ Branch(&push, ne, a5, Operand(t1));
      __ LoadRoot(a5, RootIndex::kUndefinedValue);
      __ bind(&push);
      __ Sd(a5, MemOperand(a7, 0));
      __ Daddu(a7, a7, Operand(kSystemPointerSize));
      __ Daddu(scratch, scratch, Operand(kSystemPointerSize));
      __ Branch(&loop, ne, scratch, Operand(sp));
      __ bind(&done);
    }
  
    // 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
    //  -- 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);
      __ ld(t1, FieldMemOperand(a3, HeapObject::kMapOffset));
      __ lbu(t1, FieldMemOperand(t1, Map::kBitFieldOffset));
      __ And(t1, t1, Operand(Map::Bits1::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);
    }
  
    Label stack_done, stack_overflow;
    __ Ld(a7, MemOperand(fp, StandardFrameConstants::kArgCOffset));
    __ Dsubu(a7, a7, Operand(kJSArgcReceiverSlots));
    __ Dsubu(a7, a7, a2);
    __ Branch(&stack_done, le, a7, Operand(zero_reg));
    {
      // Check for stack overflow.
      __ StackOverflowCheck(a7, a4, a5, &stack_overflow);
  
      // Forward the arguments from the caller frame.
  
      // Point to the first argument to copy (skipping the receiver).
      __ Daddu(a6, fp,
               Operand(CommonFrameConstants::kFixedFrameSizeAboveFp +
                       kSystemPointerSize));
      __ Dlsa(a6, a6, a2, kSystemPointerSizeLog2);
  
      // Move the arguments already in the stack,
      // including the receiver and the return address.
      // a7: Number of arguments to make room for.
      // a0: Number of arguments already on the stack.
      // a2: Points to first free slot on the stack after arguments were shifted.
      Generate_AllocateSpaceAndShiftExistingArguments(masm, a7, a0, a2, t0, t1,
                                                      t2);
  
      // Copy arguments from the caller frame.
      // TODO(victorgomes): Consider using forward order as potentially more cache
      // friendly.
      {
        Label loop;
        __ bind(&loop);
        {
          __ Subu(a7, a7, Operand(1));
          __ Dlsa(t0, a6, a7, kPointerSizeLog2);
          __ Ld(kScratchReg, MemOperand(t0));
          __ Dlsa(t0, a2, a7, kPointerSizeLog2);
          __ Sd(kScratchReg, MemOperand(t0));
          __ Branch(&loop, ne, a7, 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
    //  -- a1 : the function to call (checked to be a JSFunction)
    // -----------------------------------
    __ AssertCallableFunction(a1);
  
    __ Ld(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
  
    // 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.
    __ Ld(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
    // We need to convert the receiver for non-native sloppy mode functions.
    Label done_convert;
    __ Lwu(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
      //  -- 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;
        __ LoadReceiver(a3, a0);
        __ JumpIfSmi(a3, &convert_to_object);
        STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
        __ GetObjectType(a3, a4, a4);
        __ Branch(&done_convert, hs, a4, 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);
          __ SmiTag(a0);
          __ 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);
          __ SmiUntag(a0);
        }
        __ Ld(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
        __ bind(&convert_receiver);
      }
      __ StoreReceiver(a3, a0, kScratchReg);
    }
    __ bind(&done_convert);
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments
    //  -- 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));
    __ InvokeFunctionCode(a1, no_reg, a2, a0, InvokeType::kJump);
  }
  
  // static
  void Builtins::Generate_CallBoundFunctionImpl(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    // -----------------------------------
    __ AssertBoundFunction(a1);
  
    // Patch the receiver to [[BoundThis]].
    {
      __ Ld(t0, FieldMemOperand(a1, JSBoundFunction::kBoundThisOffset));
      __ StoreReceiver(t0, a0, kScratchReg);
    }
  
    // Load [[BoundArguments]] into a2 and length of that into a4.
    __ Ld(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
    __ SmiUntag(a4, FieldMemOperand(a2, FixedArray::kLengthOffset));
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments
    //  -- a1 : the function to call (checked to be a JSBoundFunction)
    //  -- a2 : the [[BoundArguments]] (implemented as FixedArray)
    //  -- a4 : the number of [[BoundArguments]]
    // -----------------------------------
  
    // Reserve stack space for the [[BoundArguments]].
    {
      Label done;
      __ dsll(a5, a4, kPointerSizeLog2);
      __ Dsubu(t0, sp, Operand(a5));
      // 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".
      __ LoadStackLimit(kScratchReg,
                        MacroAssembler::StackLimitKind::kRealStackLimit);
      __ Branch(&done, hs, t0, Operand(kScratchReg));
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowStackOverflow);
      }
      __ bind(&done);
    }
  
    // Pop receiver.
    __ Pop(t0);
  
    // Push [[BoundArguments]].
    {
      Label loop, done_loop;
      __ SmiUntag(a4, FieldMemOperand(a2, FixedArray::kLengthOffset));
      __ Daddu(a0, a0, Operand(a4));
      __ Daddu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ bind(&loop);
      __ Dsubu(a4, a4, Operand(1));
      __ Branch(&done_loop, lt, a4, Operand(zero_reg));
      __ Dlsa(a5, a2, a4, kPointerSizeLog2);
      __ Ld(kScratchReg, MemOperand(a5));
      __ Push(kScratchReg);
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Push receiver.
    __ Push(t0);
  
    // Call the [[BoundTargetFunction]] via the Call builtin.
    __ Ld(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
    //  -- a1 : the target to call (can be any Object).
    // -----------------------------------
    Register argc = a0;
    Register target = a1;
    Register map = t1;
    Register instance_type = t2;
    Register scratch = t8;
    DCHECK(!AreAliased(argc, target, map, instance_type, scratch));
  
    Label non_callable, class_constructor;
    __ JumpIfSmi(target, &non_callable);
    __ LoadMap(map, target);
    __ GetInstanceTypeRange(map, instance_type, FIRST_CALLABLE_JS_FUNCTION_TYPE,
                            scratch);
    __ Jump(masm->isolate()->builtins()->CallFunction(mode),
            RelocInfo::CODE_TARGET, ls, scratch,
            Operand(LAST_CALLABLE_JS_FUNCTION_TYPE -
                    FIRST_CALLABLE_JS_FUNCTION_TYPE));
    __ Jump(BUILTIN_CODE(masm->isolate(), CallBoundFunction),
            RelocInfo::CODE_TARGET, eq, instance_type,
            Operand(JS_BOUND_FUNCTION_TYPE));
  
    // Check if target has a [[Call]] internal method.
    {
      Register flags = t1;
      __ Lbu(flags, FieldMemOperand(map, Map::kBitFieldOffset));
      map = no_reg;
      __ And(flags, flags, Operand(Map::Bits1::IsCallableBit::kMask));
      __ Branch(&non_callable, eq, flags, Operand(zero_reg));
    }
  
    __ Jump(BUILTIN_CODE(masm->isolate(), CallProxy), RelocInfo::CODE_TARGET, eq,
            instance_type, Operand(JS_PROXY_TYPE));
  
    // Check if target is a wrapped function and call CallWrappedFunction external
    // builtin
    __ Jump(BUILTIN_CODE(masm->isolate(), CallWrappedFunction),
            RelocInfo::CODE_TARGET, eq, instance_type,
            Operand(JS_WRAPPED_FUNCTION_TYPE));
  
    // ES6 section 9.2.1 [[Call]] ( thisArgument, argumentsList)
    // Check that the function is not a "classConstructor".
    __ Branch(&class_constructor, eq, instance_type,
              Operand(JS_CLASS_CONSTRUCTOR_TYPE));
  
    // 2. Call to something else, which might have a [[Call]] internal method (if
    // not we raise an exception).
    // Overwrite the original receiver with the (original) target.
    __ StoreReceiver(target, argc, kScratchReg);
    // Let the "call_as_function_delegate" take care of the rest.
    __ LoadNativeContextSlot(target, Context::CALL_AS_FUNCTION_DELEGATE_INDEX);
    __ 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(target);
      __ CallRuntime(Runtime::kThrowCalledNonCallable);
    }
  
    // 4. The function is a "classConstructor", need to raise an exception.
    __ bind(&class_constructor);
    {
      FrameScope frame(masm, StackFrame::INTERNAL);
      __ Push(target);
      __ CallRuntime(Runtime::kThrowConstructorNonCallableError);
    }
  }
  
  void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments
    //  -- 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.
    __ Ld(a4, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
    __ lwu(a4, FieldMemOperand(a4, SharedFunctionInfo::kFlagsOffset));
    __ And(a4, a4, Operand(SharedFunctionInfo::ConstructAsBuiltinBit::kMask));
    __ Branch(&call_generic_stub, eq, a4, 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
    //  -- 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 a4.
    __ Ld(a2, FieldMemOperand(a1, JSBoundFunction::kBoundArgumentsOffset));
    __ SmiUntag(a4, FieldMemOperand(a2, FixedArray::kLengthOffset));
  
    // ----------- S t a t e -------------
    //  -- a0 : the number of arguments
    //  -- 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)
    //  -- a4 : the number of [[BoundArguments]]
    // -----------------------------------
  
    // Reserve stack space for the [[BoundArguments]].
    {
      Label done;
      __ dsll(a5, a4, kPointerSizeLog2);
      __ Dsubu(t0, sp, Operand(a5));
      // 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".
      __ LoadStackLimit(kScratchReg,
                        MacroAssembler::StackLimitKind::kRealStackLimit);
      __ Branch(&done, hs, t0, Operand(kScratchReg));
      {
        FrameScope scope(masm, StackFrame::MANUAL);
        __ EnterFrame(StackFrame::INTERNAL);
        __ CallRuntime(Runtime::kThrowStackOverflow);
      }
      __ bind(&done);
    }
  
    // Pop receiver.
    __ Pop(t0);
  
    // Push [[BoundArguments]].
    {
      Label loop, done_loop;
      __ SmiUntag(a4, FieldMemOperand(a2, FixedArray::kLengthOffset));
      __ Daddu(a0, a0, Operand(a4));
      __ Daddu(a2, a2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
      __ bind(&loop);
      __ Dsubu(a4, a4, Operand(1));
      __ Branch(&done_loop, lt, a4, Operand(zero_reg));
      __ Dlsa(a5, a2, a4, kPointerSizeLog2);
      __ Ld(kScratchReg, MemOperand(a5));
      __ Push(kScratchReg);
      __ Branch(&loop);
      __ bind(&done_loop);
    }
  
    // Push receiver.
    __ Push(t0);
  
    // Patch new.target to [[BoundTargetFunction]] if new.target equals target.
    {
      Label skip_load;
      __ Branch(&skip_load, ne, a1, Operand(a3));
      __ Ld(a3, FieldMemOperand(a1, JSBoundFunction::kBoundTargetFunctionOffset));
      __ bind(&skip_load);
    }
  
    // Construct the [[BoundTargetFunction]] via the Construct builtin.
    __ Ld(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
    //  -- 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)
    // -----------------------------------
  
    Register argc = a0;
    Register target = a1;
    Register map = t1;
    Register instance_type = t2;
    Register scratch = t8;
    DCHECK(!AreAliased(argc, target, map, instance_type, scratch));
  
    // Check if target is a Smi.
    Label non_constructor, non_proxy;
    __ JumpIfSmi(target, &non_constructor);
  
    // Check if target has a [[Construct]] internal method.
    __ ld(map, FieldMemOperand(target, HeapObject::kMapOffset));
    {
      Register flags = t3;
      __ Lbu(flags, FieldMemOperand(map, Map::kBitFieldOffset));
      __ And(flags, flags, Operand(Map::Bits1::IsConstructorBit::kMask));
      __ Branch(&non_constructor, eq, flags, Operand(zero_reg));
    }
  
    // Dispatch based on instance type.
    __ GetInstanceTypeRange(map, instance_type, FIRST_JS_FUNCTION_TYPE, scratch);
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructFunction),
            RelocInfo::CODE_TARGET, ls, scratch,
            Operand(LAST_JS_FUNCTION_TYPE - FIRST_JS_FUNCTION_TYPE));
  
    // Only dispatch to bound functions after checking whether they are
    // constructors.
    __ Jump(BUILTIN_CODE(masm->isolate(), ConstructBoundFunction),
            RelocInfo::CODE_TARGET, eq, instance_type,
            Operand(JS_BOUND_FUNCTION_TYPE));
  
    // Only dispatch to proxies after checking whether they are constructors.
    __ Branch(&non_proxy, ne, instance_type, 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.
      __ StoreReceiver(target, argc, kScratchReg);
      // Let the "call_as_constructor_delegate" take care of the rest.
      __ LoadNativeContextSlot(target,
                               Context::CALL_AS_CONSTRUCTOR_DELEGATE_INDEX);
      __ 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);
  }
  
  #if V8_ENABLE_WEBASSEMBLY
  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.h). 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.
      RegList gp_regs;
      for (Register gp_param_reg : wasm::kGpParamRegisters) {
        gp_regs.set(gp_param_reg);
      }
  
      DoubleRegList fp_regs;
      for (DoubleRegister fp_param_reg : wasm::kFpParamRegisters) {
        fp_regs.set(fp_param_reg);
      }
  
      CHECK_EQ(gp_regs.Count(), arraysize(wasm::kGpParamRegisters));
      CHECK_EQ(fp_regs.Count(), arraysize(wasm::kFpParamRegisters));
      CHECK_EQ(WasmCompileLazyFrameConstants::kNumberOfSavedGpParamRegs,
               gp_regs.Count());
      CHECK_EQ(WasmCompileLazyFrameConstants::kNumberOfSavedFpParamRegs,
               fp_regs.Count());
  
      __ MultiPush(gp_regs);
      // Check if machine has simd enabled, if so push vector registers. If not
      // then only push double registers.
      Label push_doubles, simd_pushed;
      __ li(a1, ExternalReference::supports_wasm_simd_128_address());
      // If > 0 then simd is available.
      __ Lbu(a1, MemOperand(a1));
      __ Branch(&push_doubles, le, a1, Operand(zero_reg));
      // Save vector registers.
      {
        CpuFeatureScope msa_scope(
            masm, MIPS_SIMD, CpuFeatureScope::CheckPolicy::kDontCheckSupported);
        __ MultiPushMSA(fp_regs);
      }
      __ Branch(&simd_pushed);
      __ bind(&push_doubles);
      __ MultiPushFPU(fp_regs);
      // kFixedFrameSizeFromFp is hard coded to include space for Simd
      // registers, so we still need to allocate extra (unused) space on the stack
      // as if they were saved.
      __ Dsubu(sp, sp, fp_regs.Count() * kDoubleSize);
      __ bind(&simd_pushed);
      // Pass instance and function index as an explicit arguments to the runtime
      // function.
      __ Push(kWasmInstanceRegister, kWasmCompileLazyFuncIndexRegister);
      // Initialize the JavaScript context with 0. CEntry will use it to
      // set the current context on the isolate.
      __ Move(kContextRegister, Smi::zero());
      __ CallRuntime(Runtime::kWasmCompileLazy, 2);
  
      // Restore registers.
      Label pop_doubles, simd_popped;
      __ li(a1, ExternalReference::supports_wasm_simd_128_address());
      // If > 0 then simd is available.
      __ Lbu(a1, MemOperand(a1));
      __ Branch(&pop_doubles, le, a1, Operand(zero_reg));
      // Pop vector registers.
      {
        CpuFeatureScope msa_scope(
            masm, MIPS_SIMD, CpuFeatureScope::CheckPolicy::kDontCheckSupported);
        __ MultiPopMSA(fp_regs);
      }
      __ Branch(&simd_popped);
      __ bind(&pop_doubles);
      __ Daddu(sp, sp, fp_regs.Count() * kDoubleSize);
      __ MultiPopFPU(fp_regs);
      __ bind(&simd_popped);
      __ MultiPop(gp_regs);
    }
    // Finally, jump to the entrypoint.
    __ Jump(v0);
  }
  
  void Builtins::Generate_WasmDebugBreak(MacroAssembler* masm) {
    HardAbortScope hard_abort(masm);  // Avoid calls to Abort.
    {
      FrameScope scope(masm, StackFrame::WASM_DEBUG_BREAK);
  
      // Save all parameter registers. They might hold live values, we restore
      // them after the runtime call.
      __ MultiPush(WasmDebugBreakFrameConstants::kPushedGpRegs);
      __ MultiPushFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
  
      // Initialize the JavaScript context with 0. CEntry will use it to
      // set the current context on the isolate.
      __ Move(cp, Smi::zero());
      __ CallRuntime(Runtime::kWasmDebugBreak, 0);
  
      // Restore registers.
      __ MultiPopFPU(WasmDebugBreakFrameConstants::kPushedFpRegs);
      __ MultiPop(WasmDebugBreakFrameConstants::kPushedGpRegs);
    }
    __ Ret();
  }
  
  void Builtins::Generate_GenericJSToWasmWrapper(MacroAssembler* masm) {
    __ Trap();
  }
  
  void Builtins::Generate_WasmReturnPromiseOnSuspend(MacroAssembler* masm) {
    // TODO(v8:12191): Implement for this platform.
    __ Trap();
  }
  
  void Builtins::Generate_WasmSuspend(MacroAssembler* masm) {
    // TODO(v8:12191): Implement for this platform.
    __ Trap();
  }
  
  void Builtins::Generate_WasmResume(MacroAssembler* masm) {
    // TODO(v8:12191): Implement for this platform.
    __ Trap();
  }
  
  void Builtins::Generate_WasmOnStackReplace(MacroAssembler* masm) {
    // Only needed on x64.
    __ Trap();
  }
  
  #endif  // V8_ENABLE_WEBASSEMBLY
  
  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 == ArgvMode::kRegister:
    // a2: pointer to the first argument
  
    if (argv_mode == ArgvMode::kRegister) {
      // Move argv into the correct register.
      __ mov(s1, a2);
    } else {
      // Compute the argv pointer in a callee-saved register.
      __ Dlsa(s1, sp, a0, kPointerSizeLog2);
      __ Dsubu(s1, s1, kPointerSize);
    }
  
    // Enter the exit frame that transitions from JavaScript to C++.
    FrameScope scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(
        save_doubles == SaveFPRegsMode::kSave, 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);
  
    __ StoreReturnAddressAndCall(s2);
  
    // Result returned in v0 or v1:v0 - do not destroy these registers!
  
    // Check result for exception sentinel.
    Label exception_returned;
    __ LoadRoot(a4, RootIndex::kException);
    __ Branch(&exception_returned, eq, a4, 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);
      __ Ld(a2, MemOperand(a2));
      __ LoadRoot(a4, RootIndex::kTheHoleValue);
      // Cannot use check here as it attempts to generate call into runtime.
      __ Branch(&okay, eq, a4, Operand(a2));
      __ stop();
      __ bind(&okay);
    }
  
    // Exit C frame and return.
    // v0:v1: result
    // sp: stack pointer
    // fp: frame pointer
    Register argc = argv_mode == ArgvMode::kRegister
                        // 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 == SaveFPRegsMode::kSave, 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);
    __ Ld(cp, MemOperand(cp));
    __ li(sp, pending_handler_sp_address);
    __ Ld(sp, MemOperand(sp));
    __ li(fp, pending_handler_fp_address);
    __ Ld(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));
    __ Sd(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
    __ bind(&zero);
  
    // Clear c_entry_fp, like we do in `LeaveExitFrame`.
    {
      UseScratchRegisterScope temps(masm);
      Register scratch = temps.Acquire();
      __ li(scratch, ExternalReference::Create(IsolateAddressId::kCEntryFPAddress,
                                               masm->isolate()));
      __ Sd(zero_reg, MemOperand(scratch));
    }
  
    // Compute the handler entry address and jump to it.
    __ li(t9, pending_handler_entrypoint_address);
    __ Ld(t9, MemOperand(t9));
    __ Jump(t9);
  }
  
  void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
    Label 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));
  
    // 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 the FCSR.
    __ cfc1(scratch, FCSR);
  
    // Check for overflow and NaNs.
    __ And(scratch, scratch,
           kFCSROverflowCauseMask | kFCSRUnderflowCauseMask |
               kFCSRInvalidOpCauseMask);
    // 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;
    // 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);
  
    __ Sd(result_reg, MemOperand(sp, kArgumentOffset));
    __ Pop(scratch, scratch2, scratch3);
    __ Pop(result_reg);
    __ Ret();
  }
  
  namespace {
  
  int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
    int64_t offset = (ref0.address() - ref1.address());
    DCHECK(static_cast<int>(offset) == offset);
    return static_cast<int>(offset);
  }
  
  // Calls an API function.  Allocates HandleScope, extracts returned value
  // from handle and propagates exceptions.  Restores context.  stack_space
  // - space to be unwound on exit (includes the call JS arguments space and
  // the additional space allocated for the fast call).
  void CallApiFunctionAndReturn(MacroAssembler* masm, Register function_address,
                                ExternalReference thunk_ref, int stack_space,
                                MemOperand* stack_space_operand,
                                MemOperand return_value_operand) {
    Isolate* isolate = masm->isolate();
    ExternalReference next_address =
        ExternalReference::handle_scope_next_address(isolate);
    const int kNextOffset = 0;
    const int kLimitOffset = AddressOffset(
        ExternalReference::handle_scope_limit_address(isolate), next_address);
    const int kLevelOffset = AddressOffset(
        ExternalReference::handle_scope_level_address(isolate), next_address);
  
    DCHECK(function_address == a1 || function_address == a2);
  
    Label profiler_enabled, end_profiler_check;
    __ li(t9, ExternalReference::is_profiling_address(isolate));
    __ Lb(t9, MemOperand(t9, 0));
    __ Branch(&profiler_enabled, ne, t9, Operand(zero_reg));
    __ li(t9, ExternalReference::address_of_runtime_stats_flag());
    __ Lw(t9, MemOperand(t9, 0));
    __ Branch(&profiler_enabled, ne, t9, Operand(zero_reg));
    {
      // Call the api function directly.
      __ mov(t9, function_address);
      __ Branch(&end_profiler_check);
    }
  
    __ bind(&profiler_enabled);
    {
      // Additional parameter is the address of the actual callback.
      __ li(t9, thunk_ref);
    }
    __ bind(&end_profiler_check);
  
    // Allocate HandleScope in callee-save registers.
    __ li(s5, next_address);
    __ Ld(s0, MemOperand(s5, kNextOffset));
    __ Ld(s1, MemOperand(s5, kLimitOffset));
    __ Lw(s2, MemOperand(s5, kLevelOffset));
    __ Addu(s2, s2, Operand(1));
    __ Sw(s2, MemOperand(s5, kLevelOffset));
  
    __ StoreReturnAddressAndCall(t9);
  
    Label promote_scheduled_exception;
    Label delete_allocated_handles;
    Label leave_exit_frame;
    Label return_value_loaded;
  
    // Load value from ReturnValue.
    __ Ld(v0, return_value_operand);
    __ bind(&return_value_loaded);
  
    // No more valid handles (the result handle was the last one). Restore
    // previous handle scope.
    __ Sd(s0, MemOperand(s5, kNextOffset));
    if (FLAG_debug_code) {
      __ Lw(a1, MemOperand(s5, kLevelOffset));
      __ Check(eq, AbortReason::kUnexpectedLevelAfterReturnFromApiCall, a1,
               Operand(s2));
    }
    __ Subu(s2, s2, Operand(1));
    __ Sw(s2, MemOperand(s5, kLevelOffset));
    __ Ld(kScratchReg, MemOperand(s5, kLimitOffset));
    __ Branch(&delete_allocated_handles, ne, s1, Operand(kScratchReg));
  
    // Leave the API exit frame.
    __ bind(&leave_exit_frame);
  
    if (stack_space_operand == nullptr) {
      DCHECK_NE(stack_space, 0);
      __ li(s0, Operand(stack_space));
    } else {
      DCHECK_EQ(stack_space, 0);
      STATIC_ASSERT(kCArgSlotCount == 0);
      __ Ld(s0, *stack_space_operand);
    }
  
    static constexpr bool kDontSaveDoubles = false;
    static constexpr bool kRegisterContainsSlotCount = false;
    __ LeaveExitFrame(kDontSaveDoubles, s0, NO_EMIT_RETURN,
                      kRegisterContainsSlotCount);
  
    // Check if the function scheduled an exception.
    __ LoadRoot(a4, RootIndex::kTheHoleValue);
    __ li(kScratchReg, ExternalReference::scheduled_exception_address(isolate));
    __ Ld(a5, MemOperand(kScratchReg));
    __ Branch(&promote_scheduled_exception, ne, a4, Operand(a5));
  
    __ Ret();
  
    // Re-throw by promoting a scheduled exception.
    __ bind(&promote_scheduled_exception);
    __ TailCallRuntime(Runtime::kPromoteScheduledException);
  
    // HandleScope limit has changed. Delete allocated extensions.
    __ bind(&delete_allocated_handles);
    __ Sd(s1, MemOperand(s5, kLimitOffset));
    __ mov(s0, v0);
    __ mov(a0, v0);
    __ PrepareCallCFunction(1, s1);
    __ li(a0, ExternalReference::isolate_address(isolate));
    __ CallCFunction(ExternalReference::delete_handle_scope_extensions(), 1);
    __ mov(v0, s0);
    __ jmp(&leave_exit_frame);
  }
  
  }  // namespace
  
  void Builtins::Generate_CallApiCallback(MacroAssembler* masm) {
    // ----------- S t a t e -------------
    //  -- cp                  : context
    //  -- a1                  : api function address
    //  -- a2                  : arguments count
    //  -- a3                  : call data
    //  -- a0                  : holder
    //  -- sp[0]               : receiver
    //  -- sp[8]               : first argument
    //  -- ...
    //  -- sp[(argc) * 8]      : last argument
    // -----------------------------------
  
    Register api_function_address = a1;
    Register argc = a2;
    Register call_data = a3;
    Register holder = a0;
    Register scratch = t0;
    Register base = t1;  // For addressing MemOperands on the stack.
  
    DCHECK(!AreAliased(api_function_address, argc, call_data,
                       holder, scratch, base));
  
    using FCA = FunctionCallbackArguments;
  
    STATIC_ASSERT(FCA::kArgsLength == 6);
    STATIC_ASSERT(FCA::kNewTargetIndex == 5);
    STATIC_ASSERT(FCA::kDataIndex == 4);
    STATIC_ASSERT(FCA::kReturnValueOffset == 3);
    STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
    STATIC_ASSERT(FCA::kIsolateIndex == 1);
    STATIC_ASSERT(FCA::kHolderIndex == 0);
  
    // Set up FunctionCallbackInfo's implicit_args on the stack as follows:
    //
    // Target state:
    //   sp[0 * kPointerSize]: kHolder
    //   sp[1 * kPointerSize]: kIsolate
    //   sp[2 * kPointerSize]: undefined (kReturnValueDefaultValue)
    //   sp[3 * kPointerSize]: undefined (kReturnValue)
    //   sp[4 * kPointerSize]: kData
    //   sp[5 * kPointerSize]: undefined (kNewTarget)
  
    // Set up the base register for addressing through MemOperands. It will point
    // at the receiver (located at sp + argc * kPointerSize).
    __ Dlsa(base, sp, argc, kPointerSizeLog2);
  
    // Reserve space on the stack.
    __ Dsubu(sp, sp, Operand(FCA::kArgsLength * kPointerSize));
  
    // kHolder.
    __ Sd(holder, MemOperand(sp, 0 * kPointerSize));
  
    // kIsolate.
    __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
    __ Sd(scratch, MemOperand(sp, 1 * kPointerSize));
  
    // kReturnValueDefaultValue and kReturnValue.
    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
    __ Sd(scratch, MemOperand(sp, 2 * kPointerSize));
    __ Sd(scratch, MemOperand(sp, 3 * kPointerSize));
  
    // kData.
    __ Sd(call_data, MemOperand(sp, 4 * kPointerSize));
  
    // kNewTarget.
    __ Sd(scratch, MemOperand(sp, 5 * kPointerSize));
  
    // Keep a pointer to kHolder (= implicit_args) in a scratch register.
    // We use it below to set up the FunctionCallbackInfo object.
    __ mov(scratch, sp);
  
    // Allocate the v8::Arguments structure in the arguments' space since
    // it's not controlled by GC.
    static constexpr int kApiStackSpace = 4;
    static constexpr bool kDontSaveDoubles = false;
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(kDontSaveDoubles, kApiStackSpace);
  
    // EnterExitFrame may align the sp.
  
    // FunctionCallbackInfo::implicit_args_ (points at kHolder as set up above).
    // Arguments are after the return address (pushed by EnterExitFrame()).
    __ Sd(scratch, MemOperand(sp, 1 * kPointerSize));
  
    // FunctionCallbackInfo::values_ (points at the first varargs argument passed
    // on the stack).
    __ Daddu(scratch, scratch,
            Operand((FCA::kArgsLength + 1) * kSystemPointerSize));
  
    __ Sd(scratch, MemOperand(sp, 2 * kPointerSize));
  
    // FunctionCallbackInfo::length_.
    // Stored as int field, 32-bit integers within struct on stack always left
    // justified by n64 ABI.
    __ Sw(argc, MemOperand(sp, 3 * kPointerSize));
  
    // We also store the number of bytes to drop from the stack after returning
    // from the API function here.
    // Note: Unlike on other architectures, this stores the number of slots to
    // drop, not the number of bytes.
    __ Daddu(scratch, argc, Operand(FCA::kArgsLength + 1 /* receiver */));
    __ Sd(scratch, MemOperand(sp, 4 * kPointerSize));
  
    // v8::InvocationCallback's argument.
    DCHECK(!AreAliased(api_function_address, scratch, a0));
    __ Daddu(a0, sp, Operand(1 * kPointerSize));
  
    ExternalReference thunk_ref = ExternalReference::invoke_function_callback();
  
    // There are two stack slots above the arguments we constructed on the stack.
    // TODO(jgruber): Document what these arguments are.
    static constexpr int kStackSlotsAboveFCA = 2;
    MemOperand return_value_operand(
        fp, (kStackSlotsAboveFCA + FCA::kReturnValueOffset) * kPointerSize);
  
    static constexpr int kUseStackSpaceOperand = 0;
    MemOperand stack_space_operand(sp, 4 * kPointerSize);
  
    AllowExternalCallThatCantCauseGC scope(masm);
    CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                             kUseStackSpaceOperand, &stack_space_operand,
                             return_value_operand);
  }
  
  void Builtins::Generate_CallApiGetter(MacroAssembler* masm) {
    // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
    // name below the exit frame to make GC aware of them.
    STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
    STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
    STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
    STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
    STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
    STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
    STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
    STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);
  
    Register receiver = ApiGetterDescriptor::ReceiverRegister();
    Register holder = ApiGetterDescriptor::HolderRegister();
    Register callback = ApiGetterDescriptor::CallbackRegister();
    Register scratch = a4;
    DCHECK(!AreAliased(receiver, holder, callback, scratch));
  
    Register api_function_address = a2;
  
    // Here and below +1 is for name() pushed after the args_ array.
    using PCA = PropertyCallbackArguments;
    __ Dsubu(sp, sp, (PCA::kArgsLength + 1) * kPointerSize);
    __ Sd(receiver, MemOperand(sp, (PCA::kThisIndex + 1) * kPointerSize));
    __ Ld(scratch, FieldMemOperand(callback, AccessorInfo::kDataOffset));
    __ Sd(scratch, MemOperand(sp, (PCA::kDataIndex + 1) * kPointerSize));
    __ LoadRoot(scratch, RootIndex::kUndefinedValue);
    __ Sd(scratch, MemOperand(sp, (PCA::kReturnValueOffset + 1) * kPointerSize));
    __ Sd(scratch, MemOperand(sp, (PCA::kReturnValueDefaultValueIndex + 1) *
                                      kPointerSize));
    __ li(scratch, ExternalReference::isolate_address(masm->isolate()));
    __ Sd(scratch, MemOperand(sp, (PCA::kIsolateIndex + 1) * kPointerSize));
    __ Sd(holder, MemOperand(sp, (PCA::kHolderIndex + 1) * kPointerSize));
    // should_throw_on_error -> false
    DCHECK_EQ(0, Smi::zero().ptr());
    __ Sd(zero_reg,
          MemOperand(sp, (PCA::kShouldThrowOnErrorIndex + 1) * kPointerSize));
    __ Ld(scratch, FieldMemOperand(callback, AccessorInfo::kNameOffset));
    __ Sd(scratch, MemOperand(sp, 0 * kPointerSize));
  
    // v8::PropertyCallbackInfo::args_ array and name handle.
    const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;
  
    // Load address of v8::PropertyAccessorInfo::args_ array and name handle.
    __ mov(a0, sp);                               // a0 = Handle<Name>
    __ Daddu(a1, a0, Operand(1 * kPointerSize));  // a1 = v8::PCI::args_
  
    const int kApiStackSpace = 1;
    FrameScope frame_scope(masm, StackFrame::MANUAL);
    __ EnterExitFrame(false, kApiStackSpace);
  
    // Create v8::PropertyCallbackInfo object on the stack and initialize
    // it's args_ field.
    __ Sd(a1, MemOperand(sp, 1 * kPointerSize));
    __ Daddu(a1, sp, Operand(1 * kPointerSize));
    // a1 = v8::PropertyCallbackInfo&
  
    ExternalReference thunk_ref =
        ExternalReference::invoke_accessor_getter_callback();
  
    __ Ld(scratch, FieldMemOperand(callback, AccessorInfo::kJsGetterOffset));
    __ Ld(api_function_address,
          FieldMemOperand(scratch, Foreign::kForeignAddressOffset));
  
    // +3 is to skip prolog, return address and name handle.
    MemOperand return_value_operand(
        fp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
    MemOperand* const kUseStackSpaceConstant = nullptr;
    CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                             kStackUnwindSpace, kUseStackSpaceConstant,
                             return_value_operand);
  }
  
  void Builtins::Generate_DirectCEntry(MacroAssembler* masm) {
    // The sole purpose of DirectCEntry is for movable callers (e.g. any general
    // purpose Code object) to be able to call into C functions that may trigger
    // GC and thus move the caller.
    //
    // DirectCEntry places the return address on the stack (updated by the GC),
    // making the call GC safe. The irregexp backend relies on this.
  
    // Make place for arguments to fit C calling convention. Callers use
    // EnterExitFrame/LeaveExitFrame so they handle stack restoring and we don't
    // have to do that here. Any caller must drop kCArgsSlotsSize stack space
    // after the call.
    __ daddiu(sp, sp, -kCArgsSlotsSize);
  
    __ Sd(ra, MemOperand(sp, kCArgsSlotsSize));  // Store the return address.
    __ Call(t9);                                 // Call the C++ function.
    __ Ld(t9, MemOperand(sp, kCArgsSlotsSize));  // Return to calling code.
  
    if (FLAG_debug_code && FLAG_enable_slow_asserts) {
      // In case of an error the return address may point to a memory area
      // filled with kZapValue by the GC. Dereference the address and check for
      // this.
      __ Uld(a4, MemOperand(t9));
      __ Assert(ne, AbortReason::kReceivedInvalidReturnAddress, a4,
                Operand(reinterpret_cast<uint64_t>(kZapValue)));
    }
  
    __ Jump(t9);
  }
  
  namespace {
  
  // This code tries to be close to ia32 code so that any changes can be
  // easily ported.
  void Generate_DeoptimizationEntry(MacroAssembler* masm,
                                    DeoptimizeKind deopt_kind) {
    Isolate* isolate = masm->isolate();
  
    // Unlike on ARM we don't save all the registers, just the useful ones.
    // For the rest, there are gaps on the stack, so the offsets remain the same.
    const int kNumberOfRegisters = Register::kNumRegisters;
  
    RegList restored_regs = kJSCallerSaved | kCalleeSaved;
    RegList saved_regs = restored_regs | sp | ra;
  
    const int kDoubleRegsSize = kDoubleSize * DoubleRegister::kNumRegisters;
  
    // Save all double FPU registers before messing with them.
    __ Dsubu(sp, sp, Operand(kDoubleRegsSize));
    const RegisterConfiguration* config = RegisterConfiguration::Default();
    for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
      int code = config->GetAllocatableDoubleCode(i);
      const DoubleRegister fpu_reg = DoubleRegister::from_code(code);
      int offset = code * kDoubleSize;
      __ Sdc1(fpu_reg, MemOperand(sp, offset));
    }
  
    // Push saved_regs (needed to populate FrameDescription::registers_).
    // Leave gaps for other registers.
    __ Dsubu(sp, sp, kNumberOfRegisters * kPointerSize);
    for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) {
      if ((saved_regs.bits() & (1 << i)) != 0) {
        __ Sd(ToRegister(i), MemOperand(sp, kPointerSize * i));
      }
    }
  
    __ li(a2,
          ExternalReference::Create(IsolateAddressId::kCEntryFPAddress, isolate));
    __ Sd(fp, MemOperand(a2));
  
    const int kSavedRegistersAreaSize =
        (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
  
    __ li(a2, Operand(Deoptimizer::kFixedExitSizeMarker));
    // Get the address of the location in the code object (a3) (return
    // address for lazy deoptimization) and compute the fp-to-sp delta in
    // register a4.
    __ mov(a3, ra);
    __ Daddu(a4, sp, Operand(kSavedRegistersAreaSize));
  
    __ Dsubu(a4, fp, a4);
  
    // Allocate a new deoptimizer object.
    __ PrepareCallCFunction(6, a5);
    // Pass six arguments, according to n64 ABI.
    __ mov(a0, zero_reg);
    Label context_check;
    __ Ld(a1, MemOperand(fp, CommonFrameConstants::kContextOrFrameTypeOffset));
    __ JumpIfSmi(a1, &context_check);
    __ Ld(a0, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
    __ bind(&context_check);
    __ li(a1, Operand(static_cast<int>(deopt_kind)));
    // a2: bailout id already loaded.
    // a3: code address or 0 already loaded.
    // a4: already has fp-to-sp delta.
    __ li(a5, ExternalReference::isolate_address(isolate));
  
    // Call Deoptimizer::New().
    {
      AllowExternalCallThatCantCauseGC scope(masm);
      __ CallCFunction(ExternalReference::new_deoptimizer_function(), 6);
    }
  
    // Preserve "deoptimizer" object in register v0 and get the input
    // frame descriptor pointer to a1 (deoptimizer->input_);
    // Move deopt-obj to a0 for call to Deoptimizer::ComputeOutputFrames() below.
    __ mov(a0, v0);
    __ Ld(a1, MemOperand(v0, Deoptimizer::input_offset()));
  
    // Copy core registers into FrameDescription::registers_[kNumRegisters].
    DCHECK_EQ(Register::kNumRegisters, kNumberOfRegisters);
    for (int i = 0; i < kNumberOfRegisters; i++) {
      int offset = (i * kPointerSize) + FrameDescription::registers_offset();
      if ((saved_regs.bits() & (1 << i)) != 0) {
        __ Ld(a2, MemOperand(sp, i * kPointerSize));
        __ Sd(a2, MemOperand(a1, offset));
      } else if (FLAG_debug_code) {
        __ li(a2, kDebugZapValue);
        __ Sd(a2, MemOperand(a1, offset));
      }
    }
  
    int double_regs_offset = FrameDescription::double_registers_offset();
    // Copy FPU registers to
    // double_registers_[DoubleRegister::kNumAllocatableRegisters]
    for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
      int code = config->GetAllocatableDoubleCode(i);
      int dst_offset = code * kDoubleSize + double_regs_offset;
      int src_offset = code * kDoubleSize + kNumberOfRegisters * kPointerSize;
      __ Ldc1(f0, MemOperand(sp, src_offset));
      __ Sdc1(f0, MemOperand(a1, dst_offset));
    }
  
    // Remove the saved registers from the stack.
    __ Daddu(sp, sp, Operand(kSavedRegistersAreaSize));
  
    // Compute a pointer to the unwinding limit in register a2; that is
    // the first stack slot not part of the input frame.
    __ Ld(a2, MemOperand(a1, FrameDescription::frame_size_offset()));
    __ Daddu(a2, a2, sp);
  
    // Unwind the stack down to - but not including - the unwinding
    // limit and copy the contents of the activation frame to the input
    // frame description.
    __ Daddu(a3, a1, Operand(FrameDescription::frame_content_offset()));
    Label pop_loop;
    Label pop_loop_header;
    __ BranchShort(&pop_loop_header);
    __ bind(&pop_loop);
    __ pop(a4);
    __ Sd(a4, MemOperand(a3, 0));
    __ daddiu(a3, a3, sizeof(uint64_t));
    __ bind(&pop_loop_header);
    __ BranchShort(&pop_loop, ne, a2, Operand(sp));
    // Compute the output frame in the deoptimizer.
    __ push(a0);  // Preserve deoptimizer object across call.
    // a0: deoptimizer object; a1: scratch.
    __ PrepareCallCFunction(1, a1);
    // Call Deoptimizer::ComputeOutputFrames().
    {
      AllowExternalCallThatCantCauseGC scope(masm);
      __ CallCFunction(ExternalReference::compute_output_frames_function(), 1);
    }
    __ pop(a0);  // Restore deoptimizer object (class Deoptimizer).
  
    __ Ld(sp, MemOperand(a0, Deoptimizer::caller_frame_top_offset()));
  
    // Replace the current (input) frame with the output frames.
    Label outer_push_loop, inner_push_loop, outer_loop_header, inner_loop_header;
    // Outer loop state: a4 = current "FrameDescription** output_",
    // a1 = one past the last FrameDescription**.
    __ Lw(a1, MemOperand(a0, Deoptimizer::output_count_offset()));
    __ Ld(a4, MemOperand(a0, Deoptimizer::output_offset()));  // a4 is output_.
    __ Dlsa(a1, a4, a1, kPointerSizeLog2);
    __ BranchShort(&outer_loop_header);
    __ bind(&outer_push_loop);
    // Inner loop state: a2 = current FrameDescription*, a3 = loop index.
    __ Ld(a2, MemOperand(a4, 0));  // output_[ix]
    __ Ld(a3, MemOperand(a2, FrameDescription::frame_size_offset()));
    __ BranchShort(&inner_loop_header);
    __ bind(&inner_push_loop);
    __ Dsubu(a3, a3, Operand(sizeof(uint64_t)));
    __ Daddu(a6, a2, Operand(a3));
    __ Ld(a7, MemOperand(a6, FrameDescription::frame_content_offset()));
    __ push(a7);
    __ bind(&inner_loop_header);
    __ BranchShort(&inner_push_loop, ne, a3, Operand(zero_reg));
  
    __ Daddu(a4, a4, Operand(kPointerSize));
    __ bind(&outer_loop_header);
    __ BranchShort(&outer_push_loop, lt, a4, Operand(a1));
  
    __ Ld(a1, MemOperand(a0, Deoptimizer::input_offset()));
    for (int i = 0; i < config->num_allocatable_double_registers(); ++i) {
      int code = config->GetAllocatableDoubleCode(i);
      const DoubleRegister fpu_reg = DoubleRegister::from_code(code);
      int src_offset = code * kDoubleSize + double_regs_offset;
      __ Ldc1(fpu_reg, MemOperand(a1, src_offset));
    }
  
    // Push pc and continuation from the last output frame.
    __ Ld(a6, MemOperand(a2, FrameDescription::pc_offset()));
    __ push(a6);
    __ Ld(a6, MemOperand(a2, FrameDescription::continuation_offset()));
    __ push(a6);
  
    // Technically restoring 'at' should work unless zero_reg is also restored
    // but it's safer to check for this.
    DCHECK(!(restored_regs.has(at)));
    // Restore the registers from the last output frame.
    __ mov(at, a2);
    for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
      int offset = (i * kPointerSize) + FrameDescription::registers_offset();
      if ((restored_regs.bits() & (1 << i)) != 0) {
        __ Ld(ToRegister(i), MemOperand(at, offset));
      }
    }
  
    __ pop(at);  // Get continuation, leave pc on stack.
    __ pop(ra);
    __ Jump(at);
    __ stop();
  }
  
  }  // namespace
  
  void Builtins::Generate_DeoptimizationEntry_Eager(MacroAssembler* masm) {
    Generate_DeoptimizationEntry(masm, DeoptimizeKind::kEager);
  }
  
  void Builtins::Generate_DeoptimizationEntry_Soft(MacroAssembler* masm) {
    Generate_DeoptimizationEntry(masm, DeoptimizeKind::kSoft);
  }
  
  void Builtins::Generate_DeoptimizationEntry_Lazy(MacroAssembler* masm) {
    Generate_DeoptimizationEntry(masm, DeoptimizeKind::kLazy);
  }
  
  namespace {
  
  // Restarts execution either at the current or next (in execution order)
  // bytecode. If there is baseline code on the shared function info, converts an
  // interpreter frame into a baseline frame and continues execution in baseline
  // code. Otherwise execution continues with bytecode.
  void Generate_BaselineOrInterpreterEntry(MacroAssembler* masm,
                                           bool next_bytecode,
                                           bool is_osr = false) {
    Label start;
    __ bind(&start);
  
    // Get function from the frame.
    Register closure = a1;
    __ Ld(closure, MemOperand(fp, StandardFrameConstants::kFunctionOffset));
  
    // Get the Code object from the shared function info.
    Register code_obj = s1;
    __ Ld(code_obj,
          FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
    __ Ld(code_obj,
          FieldMemOperand(code_obj, SharedFunctionInfo::kFunctionDataOffset));
  
    // Check if we have baseline code. For OSR entry it is safe to assume we
    // always have baseline code.
    if (!is_osr) {
      Label start_with_baseline;
      __ GetObjectType(code_obj, t2, t2);
      __ Branch(&start_with_baseline, eq, t2, Operand(CODET_TYPE));
  
      // Start with bytecode as there is no baseline code.
      Builtin builtin_id = next_bytecode
                               ? Builtin::kInterpreterEnterAtNextBytecode
                               : Builtin::kInterpreterEnterAtBytecode;
      __ Jump(masm->isolate()->builtins()->code_handle(builtin_id),
              RelocInfo::CODE_TARGET);
  
      // Start with baseline code.
      __ bind(&start_with_baseline);
    } else if (FLAG_debug_code) {
      __ GetObjectType(code_obj, t2, t2);
      __ Assert(eq, AbortReason::kExpectedBaselineData, t2, Operand(CODET_TYPE));
    }
  
    if (FLAG_debug_code) {
      AssertCodeIsBaseline(masm, code_obj, t2);
    }
  
    // Replace BytecodeOffset with the feedback vector.
    Register feedback_vector = a2;
    __ Ld(feedback_vector,
          FieldMemOperand(closure, JSFunction::kFeedbackCellOffset));
    __ Ld(feedback_vector, FieldMemOperand(feedback_vector, Cell::kValueOffset));
  
    Label install_baseline_code;
    // Check if feedback vector is valid. If not, call prepare for baseline to
    // allocate it.
    __ GetObjectType(feedback_vector, t2, t2);
    __ Branch(&install_baseline_code, ne, t2, Operand(FEEDBACK_VECTOR_TYPE));
  
    // Save BytecodeOffset from the stack frame.
    __ SmiUntag(kInterpreterBytecodeOffsetRegister,
                MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    // Replace BytecodeOffset with the feedback vector.
    __ Sd(feedback_vector,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeOffsetFromFp));
    feedback_vector = no_reg;
  
    // Compute baseline pc for bytecode offset.
    ExternalReference get_baseline_pc_extref;
    if (next_bytecode || is_osr) {
      get_baseline_pc_extref =
          ExternalReference::baseline_pc_for_next_executed_bytecode();
    } else {
      get_baseline_pc_extref =
          ExternalReference::baseline_pc_for_bytecode_offset();
    }
  
    Register get_baseline_pc = a3;
    __ li(get_baseline_pc, get_baseline_pc_extref);
  
    // If the code deoptimizes during the implicit function entry stack interrupt
    // check, it will have a bailout ID of kFunctionEntryBytecodeOffset, which is
    // not a valid bytecode offset.
    // TODO(pthier): Investigate if it is feasible to handle this special case
    // in TurboFan instead of here.
    Label valid_bytecode_offset, function_entry_bytecode;
    if (!is_osr) {
      __ Branch(&function_entry_bytecode, eq, kInterpreterBytecodeOffsetRegister,
                Operand(BytecodeArray::kHeaderSize - kHeapObjectTag +
                        kFunctionEntryBytecodeOffset));
    }
  
    __ Dsubu(kInterpreterBytecodeOffsetRegister,
             kInterpreterBytecodeOffsetRegister,
             (BytecodeArray::kHeaderSize - kHeapObjectTag));
  
    __ bind(&valid_bytecode_offset);
    // Get bytecode array from the stack frame.
    __ Ld(kInterpreterBytecodeArrayRegister,
          MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
    // Save the accumulator register, since it's clobbered by the below call.
    __ Push(kInterpreterAccumulatorRegister);
    {
      Register arg_reg_1 = a0;
      Register arg_reg_2 = a1;
      Register arg_reg_3 = a2;
      __ Move(arg_reg_1, code_obj);
      __ Move(arg_reg_2, kInterpreterBytecodeOffsetRegister);
      __ Move(arg_reg_3, kInterpreterBytecodeArrayRegister);
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ PrepareCallCFunction(3, 0, a4);
      __ CallCFunction(get_baseline_pc, 3, 0);
    }
    __ Daddu(code_obj, code_obj, kReturnRegister0);
    __ Pop(kInterpreterAccumulatorRegister);
  
    if (is_osr) {
      // Reset the OSR loop nesting depth to disarm back edges.
      // TODO(pthier): Separate baseline Sparkplug from TF arming and don't disarm
      // Sparkplug here.
      // TODO(liuyu): Remove Ld as arm64 after register reallocation.
      __ Ld(kInterpreterBytecodeArrayRegister,
            MemOperand(fp, InterpreterFrameConstants::kBytecodeArrayFromFp));
      __ Sh(zero_reg, FieldMemOperand(kInterpreterBytecodeArrayRegister,
                                      BytecodeArray::kOsrUrgencyOffset));
      Generate_OSREntry(masm, code_obj,
                        Operand(Code::kHeaderSize - kHeapObjectTag));
    } else {
      __ Daddu(code_obj, code_obj, Code::kHeaderSize - kHeapObjectTag);
      __ Jump(code_obj);
    }
    __ Trap();  // Unreachable.
  
    if (!is_osr) {
      __ bind(&function_entry_bytecode);
      // If the bytecode offset is kFunctionEntryOffset, get the start address of
      // the first bytecode.
      __ mov(kInterpreterBytecodeOffsetRegister, zero_reg);
      if (next_bytecode) {
        __ li(get_baseline_pc,
              ExternalReference::baseline_pc_for_bytecode_offset());
      }
      __ Branch(&valid_bytecode_offset);
    }
  
    __ bind(&install_baseline_code);
    {
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Push(kInterpreterAccumulatorRegister);
      __ Push(closure);
      __ CallRuntime(Runtime::kInstallBaselineCode, 1);
      __ Pop(kInterpreterAccumulatorRegister);
    }
    // Retry from the start after installing baseline code.
    __ Branch(&start);
  }
  
  }  // namespace
  
  void Builtins::Generate_BaselineOrInterpreterEnterAtBytecode(
      MacroAssembler* masm) {
    Generate_BaselineOrInterpreterEntry(masm, false);
  }
  
  void Builtins::Generate_BaselineOrInterpreterEnterAtNextBytecode(
      MacroAssembler* masm) {
    Generate_BaselineOrInterpreterEntry(masm, true);
  }
  
  void Builtins::Generate_InterpreterOnStackReplacement_ToBaseline(
      MacroAssembler* masm) {
    Generate_BaselineOrInterpreterEntry(masm, false, true);
  }
  
  #undef __
  
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_TARGET_ARCH_MIPS64
  