builtins-x64.cc

Go to the documentation of this file.

// 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.
 
#include "src/v8.h"
 
#if V8_TARGET_ARCH_X64
 
#include "src/code-factory.h"
#include "src/codegen.h"
#include "src/deoptimizer.h"
#include "src/full-codegen.h"
 
namespace v8 {
namespace internal {
 
 
#define __ ACCESS_MASM(masm)
 
 
void Builtins::Generate_Adaptor(MacroAssembler* masm,
                                CFunctionId id,
                                BuiltinExtraArguments extra_args) {
  // ----------- S t a t e -------------
  //  -- rax                 : number of arguments excluding receiver
  //  -- rdi                 : called function (only guaranteed when
  //                           extra_args requires it)
  //  -- rsi                 : context
  //  -- rsp[0]              : return address
  //  -- rsp[8]              : last argument
  //  -- ...
  //  -- rsp[8 * argc]       : first argument (argc == rax)
  //  -- rsp[8 * (argc + 1)] : receiver
  // -----------------------------------
 
  // Insert extra arguments.
  int num_extra_args = 0;
  if (extra_args == NEEDS_CALLED_FUNCTION) {
    num_extra_args = 1;
    __ PopReturnAddressTo(kScratchRegister);
    __ Push(rdi);
    __ PushReturnAddressFrom(kScratchRegister);
  } else {
    DCHECK(extra_args == NO_EXTRA_ARGUMENTS);
  }
 
  // JumpToExternalReference expects rax to contain the number of arguments
  // including the receiver and the extra arguments.
  __ addp(rax, Immediate(num_extra_args + 1));
  __ JumpToExternalReference(ExternalReference(id, masm->isolate()), 1);
}
 
 
static void CallRuntimePassFunction(
    MacroAssembler* masm, Runtime::FunctionId function_id) {
  FrameScope scope(masm, StackFrame::INTERNAL);
  // Push a copy of the function onto the stack.
  __ Push(rdi);
  // Function is also the parameter to the runtime call.
  __ Push(rdi);
 
  __ CallRuntime(function_id, 1);
  // Restore receiver.
  __ Pop(rdi);
}
 
 
static void GenerateTailCallToSharedCode(MacroAssembler* masm) {
  __ movp(kScratchRegister,
          FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
  __ movp(kScratchRegister,
          FieldOperand(kScratchRegister, SharedFunctionInfo::kCodeOffset));
  __ leap(kScratchRegister, FieldOperand(kScratchRegister, Code::kHeaderSize));
  __ jmp(kScratchRegister);
}
 
 
static void GenerateTailCallToReturnedCode(MacroAssembler* masm) {
  __ leap(rax, FieldOperand(rax, Code::kHeaderSize));
  __ jmp(rax);
}
 
 
void Builtins::Generate_InOptimizationQueue(MacroAssembler* masm) {
  // Checking whether the queued function is ready for install is optional,
  // since we come across interrupts and stack checks elsewhere.  However,
  // not checking may delay installing ready functions, and always checking
  // would be quite expensive.  A good compromise is to first check against
  // stack limit as a cue for an interrupt signal.
  Label ok;
  __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
  __ j(above_equal, &ok);
 
  CallRuntimePassFunction(masm, Runtime::kTryInstallOptimizedCode);
  GenerateTailCallToReturnedCode(masm);
 
  __ bind(&ok);
  GenerateTailCallToSharedCode(masm);
}
 
 
static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                           bool is_api_function,
                                           bool create_memento) {
  // ----------- S t a t e -------------
  //  -- rax: number of arguments
  //  -- rdi: constructor function
  //  -- rbx: allocation site or undefined
  // -----------------------------------
 
  // Should never create mementos for api functions.
  DCHECK(!is_api_function || !create_memento);
 
  // Enter a construct frame.
  {
    FrameScope scope(masm, StackFrame::CONSTRUCT);
 
    if (create_memento) {
      __ AssertUndefinedOrAllocationSite(rbx);
      __ Push(rbx);
    }
 
    // Store a smi-tagged arguments count on the stack.
    __ Integer32ToSmi(rax, rax);
    __ Push(rax);
 
    // Push the function to invoke on the stack.
    __ Push(rdi);
 
    // Try to allocate the object without transitioning into C code. If any of
    // the preconditions is not met, the code bails out to the runtime call.
    Label rt_call, allocated;
    if (FLAG_inline_new) {
      Label undo_allocation;
 
      ExternalReference debug_step_in_fp =
          ExternalReference::debug_step_in_fp_address(masm->isolate());
      __ Move(kScratchRegister, debug_step_in_fp);
      __ cmpp(Operand(kScratchRegister, 0), Immediate(0));
      __ j(not_equal, &rt_call);
 
      // Verified that the constructor is a JSFunction.
      // Load the initial map and verify that it is in fact a map.
      // rdi: constructor
      __ movp(rax, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
      // Will both indicate a NULL and a Smi
      DCHECK(kSmiTag == 0);
      __ JumpIfSmi(rax, &rt_call);
      // rdi: constructor
      // rax: initial map (if proven valid below)
      __ CmpObjectType(rax, MAP_TYPE, rbx);
      __ j(not_equal, &rt_call);
 
      // Check that the constructor is not constructing a JSFunction (see
      // comments in Runtime_NewObject in runtime.cc). In which case the
      // initial map's instance type would be JS_FUNCTION_TYPE.
      // rdi: constructor
      // rax: initial map
      __ CmpInstanceType(rax, JS_FUNCTION_TYPE);
      __ j(equal, &rt_call);
 
      if (!is_api_function) {
        Label allocate;
        // The code below relies on these assumptions.
        STATIC_ASSERT(JSFunction::kNoSlackTracking == 0);
        STATIC_ASSERT(Map::ConstructionCount::kShift +
                      Map::ConstructionCount::kSize == 32);
        // Check if slack tracking is enabled.
        __ movl(rsi, FieldOperand(rax, Map::kBitField3Offset));
        __ shrl(rsi, Immediate(Map::ConstructionCount::kShift));
        __ j(zero, &allocate);  // JSFunction::kNoSlackTracking
        // Decrease generous allocation count.
        __ subl(FieldOperand(rax, Map::kBitField3Offset),
                Immediate(1 << Map::ConstructionCount::kShift));
 
        __ cmpl(rsi, Immediate(JSFunction::kFinishSlackTracking));
        __ j(not_equal, &allocate);
 
        __ Push(rax);
        __ Push(rdi);
 
        __ Push(rdi);  // constructor
        __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
 
        __ Pop(rdi);
        __ Pop(rax);
        __ xorl(rsi, rsi);  // JSFunction::kNoSlackTracking
 
        __ bind(&allocate);
      }
 
      // Now allocate the JSObject on the heap.
      __ movzxbp(rdi, FieldOperand(rax, Map::kInstanceSizeOffset));
      __ shlp(rdi, Immediate(kPointerSizeLog2));
      if (create_memento) {
        __ addp(rdi, Immediate(AllocationMemento::kSize));
      }
      // rdi: size of new object
      __ Allocate(rdi,
                  rbx,
                  rdi,
                  no_reg,
                  &rt_call,
                  NO_ALLOCATION_FLAGS);
      Factory* factory = masm->isolate()->factory();
      // Allocated the JSObject, now initialize the fields.
      // rax: initial map
      // rbx: JSObject (not HeapObject tagged - the actual address).
      // rdi: start of next object (including memento if create_memento)
      __ movp(Operand(rbx, JSObject::kMapOffset), rax);
      __ LoadRoot(rcx, Heap::kEmptyFixedArrayRootIndex);
      __ movp(Operand(rbx, JSObject::kPropertiesOffset), rcx);
      __ movp(Operand(rbx, JSObject::kElementsOffset), rcx);
      // Set extra fields in the newly allocated object.
      // rax: initial map
      // rbx: JSObject
      // rdi: start of next object (including memento if create_memento)
      // rsi: slack tracking counter (non-API function case)
      __ leap(rcx, Operand(rbx, JSObject::kHeaderSize));
      __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
      if (!is_api_function) {
        Label no_inobject_slack_tracking;
 
        // Check if slack tracking is enabled.
        __ cmpl(rsi, Immediate(JSFunction::kNoSlackTracking));
        __ j(equal, &no_inobject_slack_tracking);
 
        // Allocate object with a slack.
        __ movzxbp(rsi,
                   FieldOperand(rax, Map::kPreAllocatedPropertyFieldsOffset));
        __ leap(rsi,
               Operand(rbx, rsi, times_pointer_size, JSObject::kHeaderSize));
        // rsi: offset of first field after pre-allocated fields
        if (FLAG_debug_code) {
          __ cmpp(rsi, rdi);
          __ Assert(less_equal,
                    kUnexpectedNumberOfPreAllocatedPropertyFields);
        }
        __ InitializeFieldsWithFiller(rcx, rsi, rdx);
        __ LoadRoot(rdx, Heap::kOnePointerFillerMapRootIndex);
        // Fill the remaining fields with one pointer filler map.
 
        __ bind(&no_inobject_slack_tracking);
      }
      if (create_memento) {
        __ leap(rsi, Operand(rdi, -AllocationMemento::kSize));
        __ InitializeFieldsWithFiller(rcx, rsi, rdx);
 
        // Fill in memento fields if necessary.
        // rsi: points to the allocated but uninitialized memento.
        __ Move(Operand(rsi, AllocationMemento::kMapOffset),
                factory->allocation_memento_map());
        // Get the cell or undefined.
        __ movp(rdx, Operand(rsp, kPointerSize*2));
        __ movp(Operand(rsi, AllocationMemento::kAllocationSiteOffset), rdx);
      } else {
        __ InitializeFieldsWithFiller(rcx, rdi, rdx);
      }
 
      // Add the object tag to make the JSObject real, so that we can continue
      // and jump into the continuation code at any time from now on. Any
      // failures need to undo the allocation, so that the heap is in a
      // consistent state and verifiable.
      // rax: initial map
      // rbx: JSObject
      // rdi: start of next object
      __ orp(rbx, Immediate(kHeapObjectTag));
 
      // Check if a non-empty properties array is needed.
      // Allocate and initialize a FixedArray if it is.
      // rax: initial map
      // rbx: JSObject
      // rdi: start of next object
      // Calculate total properties described map.
      __ movzxbp(rdx, FieldOperand(rax, Map::kUnusedPropertyFieldsOffset));
      __ movzxbp(rcx,
                 FieldOperand(rax, Map::kPreAllocatedPropertyFieldsOffset));
      __ addp(rdx, rcx);
      // Calculate unused properties past the end of the in-object properties.
      __ movzxbp(rcx, FieldOperand(rax, Map::kInObjectPropertiesOffset));
      __ subp(rdx, rcx);
      // Done if no extra properties are to be allocated.
      __ j(zero, &allocated);
      __ Assert(positive, kPropertyAllocationCountFailed);
 
      // Scale the number of elements by pointer size and add the header for
      // FixedArrays to the start of the next object calculation from above.
      // rbx: JSObject
      // rdi: start of next object (will be start of FixedArray)
      // rdx: number of elements in properties array
      __ Allocate(FixedArray::kHeaderSize,
                  times_pointer_size,
                  rdx,
                  rdi,
                  rax,
                  no_reg,
                  &undo_allocation,
                  RESULT_CONTAINS_TOP);
 
      // Initialize the FixedArray.
      // rbx: JSObject
      // rdi: FixedArray
      // rdx: number of elements
      // rax: start of next object
      __ LoadRoot(rcx, Heap::kFixedArrayMapRootIndex);
      __ movp(Operand(rdi, HeapObject::kMapOffset), rcx);  // setup the map
      __ Integer32ToSmi(rdx, rdx);
      __ movp(Operand(rdi, FixedArray::kLengthOffset), rdx);  // and length
 
      // Initialize the fields to undefined.
      // rbx: JSObject
      // rdi: FixedArray
      // rax: start of next object
      // rdx: number of elements
      { Label loop, entry;
        __ LoadRoot(rdx, Heap::kUndefinedValueRootIndex);
        __ leap(rcx, Operand(rdi, FixedArray::kHeaderSize));
        __ jmp(&entry);
        __ bind(&loop);
        __ movp(Operand(rcx, 0), rdx);
        __ addp(rcx, Immediate(kPointerSize));
        __ bind(&entry);
        __ cmpp(rcx, rax);
        __ j(below, &loop);
      }
 
      // Store the initialized FixedArray into the properties field of
      // the JSObject
      // rbx: JSObject
      // rdi: FixedArray
      __ orp(rdi, Immediate(kHeapObjectTag));  // add the heap tag
      __ movp(FieldOperand(rbx, JSObject::kPropertiesOffset), rdi);
 
 
      // Continue with JSObject being successfully allocated
      // rbx: JSObject
      __ jmp(&allocated);
 
      // Undo the setting of the new top so that the heap is verifiable. For
      // example, the map's unused properties potentially do not match the
      // allocated objects unused properties.
      // rbx: JSObject (previous new top)
      __ bind(&undo_allocation);
      __ UndoAllocationInNewSpace(rbx);
    }
 
    // Allocate the new receiver object using the runtime call.
    // rdi: function (constructor)
    __ bind(&rt_call);
    int offset = 0;
    if (create_memento) {
      // Get the cell or allocation site.
      __ movp(rdi, Operand(rsp, kPointerSize*2));
      __ Push(rdi);
      offset = kPointerSize;
    }
 
    // Must restore rsi (context) and rdi (constructor) before calling runtime.
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
    __ movp(rdi, Operand(rsp, offset));
    __ Push(rdi);
    if (create_memento) {
      __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 2);
    } else {
      __ CallRuntime(Runtime::kNewObject, 1);
    }
    __ movp(rbx, rax);  // store result in rbx
 
    // If we ended up using the runtime, and we want a memento, then the
    // runtime call made it for us, and we shouldn't do create count
    // increment.
    Label count_incremented;
    if (create_memento) {
      __ jmp(&count_incremented);
    }
 
    // New object allocated.
    // rbx: newly allocated object
    __ bind(&allocated);
 
    if (create_memento) {
      __ movp(rcx, Operand(rsp, kPointerSize*2));
      __ Cmp(rcx, masm->isolate()->factory()->undefined_value());
      __ j(equal, &count_incremented);
      // rcx is an AllocationSite. We are creating a memento from it, so we
      // need to increment the memento create count.
      __ SmiAddConstant(
          FieldOperand(rcx, AllocationSite::kPretenureCreateCountOffset),
          Smi::FromInt(1));
      __ bind(&count_incremented);
    }
 
    // Retrieve the function from the stack.
    __ Pop(rdi);
 
    // Retrieve smi-tagged arguments count from the stack.
    __ movp(rax, Operand(rsp, 0));
    __ SmiToInteger32(rax, rax);
 
    // Push the allocated receiver to the stack. We need two copies
    // because we may have to return the original one and the calling
    // conventions dictate that the called function pops the receiver.
    __ Push(rbx);
    __ Push(rbx);
 
    // Set up pointer to last argument.
    __ leap(rbx, Operand(rbp, StandardFrameConstants::kCallerSPOffset));
 
    // Copy arguments and receiver to the expression stack.
    Label loop, entry;
    __ movp(rcx, rax);
    __ jmp(&entry);
    __ bind(&loop);
    __ Push(Operand(rbx, rcx, times_pointer_size, 0));
    __ bind(&entry);
    __ decp(rcx);
    __ j(greater_equal, &loop);
 
    // Call the function.
    if (is_api_function) {
      __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
      Handle<Code> code =
          masm->isolate()->builtins()->HandleApiCallConstruct();
      __ Call(code, RelocInfo::CODE_TARGET);
    } else {
      ParameterCount actual(rax);
      __ InvokeFunction(rdi, actual, CALL_FUNCTION, NullCallWrapper());
    }
 
    // Store offset of return address for deoptimizer.
    if (!is_api_function) {
      masm->isolate()->heap()->SetConstructStubDeoptPCOffset(masm->pc_offset());
    }
 
    // Restore context from the frame.
    __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
 
    // If the result is an object (in the ECMA sense), we should get rid
    // of the receiver and use the result; see ECMA-262 section 13.2.2-7
    // on page 74.
    Label use_receiver, exit;
    // If the result is a smi, it is *not* an object in the ECMA sense.
    __ JumpIfSmi(rax, &use_receiver);
 
    // If the type of the result (stored in its map) is less than
    // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rcx);
    __ j(above_equal, &exit);
 
    // Throw away the result of the constructor invocation and use the
    // on-stack receiver as the result.
    __ bind(&use_receiver);
    __ movp(rax, Operand(rsp, 0));
 
    // Restore the arguments count and leave the construct frame.
    __ bind(&exit);
    __ movp(rbx, Operand(rsp, kPointerSize));  // Get arguments count.
 
    // Leave construct frame.
  }
 
  // Remove caller arguments from the stack and return.
  __ PopReturnAddressTo(rcx);
  SmiIndex index = masm->SmiToIndex(rbx, rbx, kPointerSizeLog2);
  __ leap(rsp, Operand(rsp, index.reg, index.scale, 1 * kPointerSize));
  __ PushReturnAddressFrom(rcx);
  Counters* counters = masm->isolate()->counters();
  __ IncrementCounter(counters->constructed_objects(), 1);
  __ ret(0);
}
 
 
void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
  Generate_JSConstructStubHelper(masm, false, FLAG_pretenuring_call_new);
}
 
 
void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
  Generate_JSConstructStubHelper(masm, true, false);
}
 
 
static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
                                             bool is_construct) {
  ProfileEntryHookStub::MaybeCallEntryHook(masm);
 
  // Expects five C++ function parameters.
  // - Address entry (ignored)
  // - JSFunction* function (
  // - Object* receiver
  // - int argc
  // - Object*** argv
  // (see Handle::Invoke in execution.cc).
 
  // Open a C++ scope for the FrameScope.
  {
    // Platform specific argument handling. After this, the stack contains
    // an internal frame and the pushed function and receiver, and
    // register rax and rbx holds the argument count and argument array,
    // while rdi holds the function pointer and rsi the context.
 
#ifdef _WIN64
    // MSVC parameters in:
    // rcx        : entry (ignored)
    // rdx        : function
    // r8         : receiver
    // r9         : argc
    // [rsp+0x20] : argv
 
    // Clear the context before we push it when entering the internal frame.
    __ Set(rsi, 0);
    // Enter an internal frame.
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    // Load the function context into rsi.
    __ movp(rsi, FieldOperand(rdx, JSFunction::kContextOffset));
 
    // Push the function and the receiver onto the stack.
    __ Push(rdx);
    __ Push(r8);
 
    // Load the number of arguments and setup pointer to the arguments.
    __ movp(rax, r9);
    // Load the previous frame pointer to access C argument on stack
    __ movp(kScratchRegister, Operand(rbp, 0));
    __ movp(rbx, Operand(kScratchRegister, EntryFrameConstants::kArgvOffset));
    // Load the function pointer into rdi.
    __ movp(rdi, rdx);
#else  // _WIN64
    // GCC parameters in:
    // rdi : entry (ignored)
    // rsi : function
    // rdx : receiver
    // rcx : argc
    // r8  : argv
 
    __ movp(rdi, rsi);
    // rdi : function
 
    // Clear the context before we push it when entering the internal frame.
    __ Set(rsi, 0);
    // Enter an internal frame.
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    // Push the function and receiver and setup the context.
    __ Push(rdi);
    __ Push(rdx);
    __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
    // Load the number of arguments and setup pointer to the arguments.
    __ movp(rax, rcx);
    __ movp(rbx, r8);
#endif  // _WIN64
 
    // Current stack contents:
    // [rsp + 2 * kPointerSize ... ] : Internal frame
    // [rsp + kPointerSize]          : function
    // [rsp]                         : receiver
    // Current register contents:
    // rax : argc
    // rbx : argv
    // rsi : context
    // rdi : function
 
    // Copy arguments to the stack in a loop.
    // Register rbx points to array of pointers to handle locations.
    // Push the values of these handles.
    Label loop, entry;
    __ Set(rcx, 0);  // Set loop variable to 0.
    __ jmp(&entry);
    __ bind(&loop);
    __ movp(kScratchRegister, Operand(rbx, rcx, times_pointer_size, 0));
    __ Push(Operand(kScratchRegister, 0));  // dereference handle
    __ addp(rcx, Immediate(1));
    __ bind(&entry);
    __ cmpp(rcx, rax);
    __ j(not_equal, &loop);
 
    // Invoke the code.
    if (is_construct) {
      // No type feedback cell is available
      __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
      // Expects rdi to hold function pointer.
      CallConstructStub stub(masm->isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
      __ CallStub(&stub);
    } else {
      ParameterCount actual(rax);
      // Function must be in rdi.
      __ InvokeFunction(rdi, actual, CALL_FUNCTION, NullCallWrapper());
    }
    // Exit the internal frame. Notice that this also removes the empty
    // context and the function left on the stack by the code
    // invocation.
  }
 
  // TODO(X64): Is argument correct? Is there a receiver to remove?
  __ ret(1 * kPointerSize);  // Remove receiver.
}
 
 
void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
  Generate_JSEntryTrampolineHelper(masm, false);
}
 
 
void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
  Generate_JSEntryTrampolineHelper(masm, true);
}
 
 
void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
  CallRuntimePassFunction(masm, Runtime::kCompileLazy);
  GenerateTailCallToReturnedCode(masm);
}
 
 
static void CallCompileOptimized(MacroAssembler* masm,
                                            bool concurrent) {
  FrameScope scope(masm, StackFrame::INTERNAL);
  // Push a copy of the function onto the stack.
  __ Push(rdi);
  // Function is also the parameter to the runtime call.
  __ Push(rdi);
  // Whether to compile in a background thread.
  __ Push(masm->isolate()->factory()->ToBoolean(concurrent));
 
  __ CallRuntime(Runtime::kCompileOptimized, 2);
  // Restore receiver.
  __ Pop(rdi);
}
 
 
void Builtins::Generate_CompileOptimized(MacroAssembler* masm) {
  CallCompileOptimized(masm, false);
  GenerateTailCallToReturnedCode(masm);
}
 
 
void Builtins::Generate_CompileOptimizedConcurrent(MacroAssembler* masm) {
  CallCompileOptimized(masm, true);
  GenerateTailCallToReturnedCode(masm);
}
 
 
static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
  // For now, we are relying on the fact that make_code_young doesn't do any
  // garbage collection which allows us to save/restore the registers without
  // worrying about which of them contain pointers. We also don't build an
  // internal frame to make the code faster, since we shouldn't have to do stack
  // crawls in MakeCodeYoung. This seems a bit fragile.
 
  // Re-execute the code that was patched back to the young age when
  // the stub returns.
  __ subp(Operand(rsp, 0), Immediate(5));
  __ Pushad();
  __ Move(arg_reg_2, ExternalReference::isolate_address(masm->isolate()));
  __ movp(arg_reg_1, Operand(rsp, kNumSafepointRegisters * kPointerSize));
  {  // NOLINT
    FrameScope scope(masm, StackFrame::MANUAL);
    __ PrepareCallCFunction(2);
    __ CallCFunction(
        ExternalReference::get_make_code_young_function(masm->isolate()), 2);
  }
  __ Popad();
  __ ret(0);
}
 
 
#define DEFINE_CODE_AGE_BUILTIN_GENERATOR(C)                 \
void Builtins::Generate_Make##C##CodeYoungAgainEvenMarking(  \
    MacroAssembler* masm) {                                  \
  GenerateMakeCodeYoungAgainCommon(masm);                    \
}                                                            \
void Builtins::Generate_Make##C##CodeYoungAgainOddMarking(   \
    MacroAssembler* masm) {                                  \
  GenerateMakeCodeYoungAgainCommon(masm);                    \
}
CODE_AGE_LIST(DEFINE_CODE_AGE_BUILTIN_GENERATOR)
#undef DEFINE_CODE_AGE_BUILTIN_GENERATOR
 
 
void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
  // For now, as in GenerateMakeCodeYoungAgainCommon, we are relying on the fact
  // that make_code_young doesn't do any garbage collection which allows us to
  // save/restore the registers without worrying about which of them contain
  // pointers.
  __ Pushad();
  __ Move(arg_reg_2, ExternalReference::isolate_address(masm->isolate()));
  __ movp(arg_reg_1, Operand(rsp, kNumSafepointRegisters * kPointerSize));
  __ subp(arg_reg_1, Immediate(Assembler::kShortCallInstructionLength));
  {  // NOLINT
    FrameScope scope(masm, StackFrame::MANUAL);
    __ PrepareCallCFunction(2);
    __ CallCFunction(
        ExternalReference::get_mark_code_as_executed_function(masm->isolate()),
        2);
  }
  __ Popad();
 
  // Perform prologue operations usually performed by the young code stub.
  __ PopReturnAddressTo(kScratchRegister);
  __ pushq(rbp);  // Caller's frame pointer.
  __ movp(rbp, rsp);
  __ Push(rsi);  // Callee's context.
  __ Push(rdi);  // Callee's JS Function.
  __ PushReturnAddressFrom(kScratchRegister);
 
  // Jump to point after the code-age stub.
  __ ret(0);
}
 
 
void Builtins::Generate_MarkCodeAsExecutedTwice(MacroAssembler* masm) {
  GenerateMakeCodeYoungAgainCommon(masm);
}
 
 
static void Generate_NotifyStubFailureHelper(MacroAssembler* masm,
                                             SaveFPRegsMode save_doubles) {
  // Enter an internal frame.
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    // Preserve registers across notification, this is important for compiled
    // stubs that tail call the runtime on deopts passing their parameters in
    // registers.
    __ Pushad();
    __ CallRuntime(Runtime::kNotifyStubFailure, 0, save_doubles);
    __ Popad();
    // Tear down internal frame.
  }
 
  __ DropUnderReturnAddress(1);  // Ignore state offset
  __ ret(0);  // Return to IC Miss stub, continuation still on stack.
}
 
 
void Builtins::Generate_NotifyStubFailure(MacroAssembler* masm) {
  Generate_NotifyStubFailureHelper(masm, kDontSaveFPRegs);
}
 
 
void Builtins::Generate_NotifyStubFailureSaveDoubles(MacroAssembler* masm) {
  Generate_NotifyStubFailureHelper(masm, kSaveFPRegs);
}
 
 
static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
                                             Deoptimizer::BailoutType type) {
  // Enter an internal frame.
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
 
    // Pass the deoptimization type to the runtime system.
    __ Push(Smi::FromInt(static_cast<int>(type)));
 
    __ CallRuntime(Runtime::kNotifyDeoptimized, 1);
    // Tear down internal frame.
  }
 
  // Get the full codegen state from the stack and untag it.
  __ SmiToInteger32(kScratchRegister, Operand(rsp, kPCOnStackSize));
 
  // Switch on the state.
  Label not_no_registers, not_tos_rax;
  __ cmpp(kScratchRegister, Immediate(FullCodeGenerator::NO_REGISTERS));
  __ j(not_equal, &not_no_registers, Label::kNear);
  __ ret(1 * kPointerSize);  // Remove state.
 
  __ bind(&not_no_registers);
  __ movp(rax, Operand(rsp, kPCOnStackSize + kPointerSize));
  __ cmpp(kScratchRegister, Immediate(FullCodeGenerator::TOS_REG));
  __ j(not_equal, &not_tos_rax, Label::kNear);
  __ ret(2 * kPointerSize);  // Remove state, rax.
 
  __ bind(&not_tos_rax);
  __ Abort(kNoCasesLeft);
}
 
 
void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
  Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::EAGER);
}
 
 
void Builtins::Generate_NotifySoftDeoptimized(MacroAssembler* masm) {
  Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::SOFT);
}
 
 
void Builtins::Generate_NotifyLazyDeoptimized(MacroAssembler* masm) {
  Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::LAZY);
}
 
 
void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
  // Stack Layout:
  // rsp[0]           : Return address
  // rsp[8]           : Argument n
  // rsp[16]          : Argument n-1
  //  ...
  // rsp[8 * n]       : Argument 1
  // rsp[8 * (n + 1)] : Receiver (function to call)
  //
  // rax contains the number of arguments, n, not counting the receiver.
  //
  // 1. Make sure we have at least one argument.
  { Label done;
    __ testp(rax, rax);
    __ j(not_zero, &done);
    __ PopReturnAddressTo(rbx);
    __ Push(masm->isolate()->factory()->undefined_value());
    __ PushReturnAddressFrom(rbx);
    __ incp(rax);
    __ bind(&done);
  }
 
  // 2. Get the function to call (passed as receiver) from the stack, check
  //    if it is a function.
  Label slow, non_function;
  StackArgumentsAccessor args(rsp, rax);
  __ movp(rdi, args.GetReceiverOperand());
  __ JumpIfSmi(rdi, &non_function);
  __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
  __ j(not_equal, &slow);
 
  // 3a. Patch the first argument if necessary when calling a function.
  Label shift_arguments;
  __ Set(rdx, 0);  // indicate regular JS_FUNCTION
  { Label convert_to_object, use_global_proxy, patch_receiver;
    // Change context eagerly in case we need the global receiver.
    __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
    // Do not transform the receiver for strict mode functions.
    __ movp(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ testb(FieldOperand(rbx, SharedFunctionInfo::kStrictModeByteOffset),
             Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
    __ j(not_equal, &shift_arguments);
 
    // Do not transform the receiver for natives.
    // SharedFunctionInfo is already loaded into rbx.
    __ testb(FieldOperand(rbx, SharedFunctionInfo::kNativeByteOffset),
             Immediate(1 << SharedFunctionInfo::kNativeBitWithinByte));
    __ j(not_zero, &shift_arguments);
 
    // Compute the receiver in sloppy mode.
    __ movp(rbx, args.GetArgumentOperand(1));
    __ JumpIfSmi(rbx, &convert_to_object, Label::kNear);
 
    __ CompareRoot(rbx, Heap::kNullValueRootIndex);
    __ j(equal, &use_global_proxy);
    __ CompareRoot(rbx, Heap::kUndefinedValueRootIndex);
    __ j(equal, &use_global_proxy);
 
    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    __ CmpObjectType(rbx, FIRST_SPEC_OBJECT_TYPE, rcx);
    __ j(above_equal, &shift_arguments);
 
    __ bind(&convert_to_object);
    {
      // Enter an internal frame in order to preserve argument count.
      FrameScope scope(masm, StackFrame::INTERNAL);
      __ Integer32ToSmi(rax, rax);
      __ Push(rax);
 
      __ Push(rbx);
      __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
      __ movp(rbx, rax);
      __ Set(rdx, 0);  // indicate regular JS_FUNCTION
 
      __ Pop(rax);
      __ SmiToInteger32(rax, rax);
    }
 
    // Restore the function to rdi.
    __ movp(rdi, args.GetReceiverOperand());
    __ jmp(&patch_receiver, Label::kNear);
 
    __ bind(&use_global_proxy);
    __ movp(rbx,
            Operand(rsi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
    __ movp(rbx, FieldOperand(rbx, GlobalObject::kGlobalProxyOffset));
 
    __ bind(&patch_receiver);
    __ movp(args.GetArgumentOperand(1), rbx);
 
    __ jmp(&shift_arguments);
  }
 
  // 3b. Check for function proxy.
  __ bind(&slow);
  __ Set(rdx, 1);  // indicate function proxy
  __ CmpInstanceType(rcx, JS_FUNCTION_PROXY_TYPE);
  __ j(equal, &shift_arguments);
  __ bind(&non_function);
  __ Set(rdx, 2);  // indicate non-function
 
  // 3c. Patch the first argument when calling a non-function.  The
  //     CALL_NON_FUNCTION builtin expects the non-function callee as
  //     receiver, so overwrite the first argument which will ultimately
  //     become the receiver.
  __ movp(args.GetArgumentOperand(1), rdi);
 
  // 4. Shift arguments and return address one slot down on the stack
  //    (overwriting the original receiver).  Adjust argument count to make
  //    the original first argument the new receiver.
  __ bind(&shift_arguments);
  { Label loop;
    __ movp(rcx, rax);
    StackArgumentsAccessor args(rsp, rcx);
    __ bind(&loop);
    __ movp(rbx, args.GetArgumentOperand(1));
    __ movp(args.GetArgumentOperand(0), rbx);
    __ decp(rcx);
    __ j(not_zero, &loop);  // While non-zero.
    __ DropUnderReturnAddress(1, rbx);  // Drop one slot under return address.
    __ decp(rax);  // One fewer argument (first argument is new receiver).
  }
 
  // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin,
  //     or a function proxy via CALL_FUNCTION_PROXY.
  { Label function, non_proxy;
    __ testp(rdx, rdx);
    __ j(zero, &function);
    __ Set(rbx, 0);
    __ cmpp(rdx, Immediate(1));
    __ j(not_equal, &non_proxy);
 
    __ PopReturnAddressTo(rdx);
    __ Push(rdi);  // re-add proxy object as additional argument
    __ PushReturnAddressFrom(rdx);
    __ incp(rax);
    __ GetBuiltinEntry(rdx, Builtins::CALL_FUNCTION_PROXY);
    __ jmp(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
           RelocInfo::CODE_TARGET);
 
    __ bind(&non_proxy);
    __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION);
    __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
            RelocInfo::CODE_TARGET);
    __ bind(&function);
  }
 
  // 5b. Get the code to call from the function and check that the number of
  //     expected arguments matches what we're providing.  If so, jump
  //     (tail-call) to the code in register edx without checking arguments.
  __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
  __ LoadSharedFunctionInfoSpecialField(rbx, rdx,
      SharedFunctionInfo::kFormalParameterCountOffset);
  __ movp(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
  __ cmpp(rax, rbx);
  __ j(not_equal,
       masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
       RelocInfo::CODE_TARGET);
 
  ParameterCount expected(0);
  __ InvokeCode(rdx, expected, expected, JUMP_FUNCTION, NullCallWrapper());
}
 
 
void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
  // Stack at entry:
  // rsp     : return address
  // rsp[8]  : arguments
  // rsp[16] : receiver ("this")
  // rsp[24] : function
  {
    FrameScope frame_scope(masm, StackFrame::INTERNAL);
    // Stack frame:
    // rbp     : Old base pointer
    // rbp[8]  : return address
    // rbp[16] : function arguments
    // rbp[24] : receiver
    // rbp[32] : function
    static const int kArgumentsOffset = kFPOnStackSize + kPCOnStackSize;
    static const int kReceiverOffset = kArgumentsOffset + kPointerSize;
    static const int kFunctionOffset = kReceiverOffset + kPointerSize;
 
    __ Push(Operand(rbp, kFunctionOffset));
    __ Push(Operand(rbp, kArgumentsOffset));
    __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
 
    // Check the stack for overflow. We are not trying to catch
    // interruptions (e.g. debug break and preemption) here, so the "real stack
    // limit" is checked.
    Label okay;
    __ LoadRoot(kScratchRegister, Heap::kRealStackLimitRootIndex);
    __ movp(rcx, rsp);
    // Make rcx the space we have left. The stack might already be overflowed
    // here which will cause rcx to become negative.
    __ subp(rcx, kScratchRegister);
    // Make rdx the space we need for the array when it is unrolled onto the
    // stack.
    __ PositiveSmiTimesPowerOfTwoToInteger64(rdx, rax, kPointerSizeLog2);
    // Check if the arguments will overflow the stack.
    __ cmpp(rcx, rdx);
    __ j(greater, &okay);  // Signed comparison.
 
    // Out of stack space.
    __ Push(Operand(rbp, kFunctionOffset));
    __ Push(rax);
    __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
    __ bind(&okay);
    // End of stack check.
 
    // Push current index and limit.
    const int kLimitOffset =
        StandardFrameConstants::kExpressionsOffset - 1 * kPointerSize;
    const int kIndexOffset = kLimitOffset - 1 * kPointerSize;
    __ Push(rax);  // limit
    __ Push(Immediate(0));  // index
 
    // Get the receiver.
    __ movp(rbx, Operand(rbp, kReceiverOffset));
 
    // Check that the function is a JS function (otherwise it must be a proxy).
    Label push_receiver;
    __ movp(rdi, Operand(rbp, kFunctionOffset));
    __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
    __ j(not_equal, &push_receiver);
 
    // Change context eagerly to get the right global object if necessary.
    __ movp(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
 
    // Do not transform the receiver for strict mode functions.
    Label call_to_object, use_global_proxy;
    __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
    __ testb(FieldOperand(rdx, SharedFunctionInfo::kStrictModeByteOffset),
             Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
    __ j(not_equal, &push_receiver);
 
    // Do not transform the receiver for natives.
    __ testb(FieldOperand(rdx, SharedFunctionInfo::kNativeByteOffset),
             Immediate(1 << SharedFunctionInfo::kNativeBitWithinByte));
    __ j(not_equal, &push_receiver);
 
    // Compute the receiver in sloppy mode.
    __ JumpIfSmi(rbx, &call_to_object, Label::kNear);
    __ CompareRoot(rbx, Heap::kNullValueRootIndex);
    __ j(equal, &use_global_proxy);
    __ CompareRoot(rbx, Heap::kUndefinedValueRootIndex);
    __ j(equal, &use_global_proxy);
 
    // If given receiver is already a JavaScript object then there's no
    // reason for converting it.
    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    __ CmpObjectType(rbx, FIRST_SPEC_OBJECT_TYPE, rcx);
    __ j(above_equal, &push_receiver);
 
    // Convert the receiver to an object.
    __ bind(&call_to_object);
    __ Push(rbx);
    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
    __ movp(rbx, rax);
    __ jmp(&push_receiver, Label::kNear);
 
    __ bind(&use_global_proxy);
    __ movp(rbx,
            Operand(rsi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
    __ movp(rbx, FieldOperand(rbx, GlobalObject::kGlobalProxyOffset));
 
    // Push the receiver.
    __ bind(&push_receiver);
    __ Push(rbx);
 
    // Copy all arguments from the array to the stack.
    Label entry, loop;
    Register receiver = LoadDescriptor::ReceiverRegister();
    Register key = LoadDescriptor::NameRegister();
    __ movp(key, Operand(rbp, kIndexOffset));
    __ jmp(&entry);
    __ bind(&loop);
    __ movp(receiver, Operand(rbp, kArgumentsOffset));  // load arguments
 
    // Use inline caching to speed up access to arguments.
    if (FLAG_vector_ics) {
      __ Move(VectorLoadICDescriptor::SlotRegister(), Smi::FromInt(0));
    }
    Handle<Code> ic = CodeFactory::KeyedLoadIC(masm->isolate()).code();
    __ Call(ic, RelocInfo::CODE_TARGET);
    // It is important that we do not have a test instruction after the
    // call.  A test instruction after the call is used to indicate that
    // we have generated an inline version of the keyed load.  In this
    // case, we know that we are not generating a test instruction next.
 
    // Push the nth argument.
    __ Push(rax);
 
    // Update the index on the stack and in register key.
    __ movp(key, Operand(rbp, kIndexOffset));
    __ SmiAddConstant(key, key, Smi::FromInt(1));
    __ movp(Operand(rbp, kIndexOffset), key);
 
    __ bind(&entry);
    __ cmpp(key, Operand(rbp, kLimitOffset));
    __ j(not_equal, &loop);
 
    // Call the function.
    Label call_proxy;
    ParameterCount actual(rax);
    __ SmiToInteger32(rax, key);
    __ movp(rdi, Operand(rbp, kFunctionOffset));
    __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rcx);
    __ j(not_equal, &call_proxy);
    __ InvokeFunction(rdi, actual, CALL_FUNCTION, NullCallWrapper());
 
    frame_scope.GenerateLeaveFrame();
    __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
 
    // Call the function proxy.
    __ bind(&call_proxy);
    __ Push(rdi);  // add function proxy as last argument
    __ incp(rax);
    __ Set(rbx, 0);
    __ GetBuiltinEntry(rdx, Builtins::CALL_FUNCTION_PROXY);
    __ call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
            RelocInfo::CODE_TARGET);
 
    // Leave internal frame.
  }
  __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
}
 
 
void Builtins::Generate_InternalArrayCode(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax    : argc
  //  -- rsp[0] : return address
  //  -- rsp[8] : last argument
  // -----------------------------------
  Label generic_array_code;
 
  // Get the InternalArray function.
  __ LoadGlobalFunction(Context::INTERNAL_ARRAY_FUNCTION_INDEX, rdi);
 
  if (FLAG_debug_code) {
    // Initial map for the builtin InternalArray functions should be maps.
    __ movp(rbx, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a NULL and a Smi.
    STATIC_ASSERT(kSmiTag == 0);
    Condition not_smi = NegateCondition(masm->CheckSmi(rbx));
    __ Check(not_smi, kUnexpectedInitialMapForInternalArrayFunction);
    __ CmpObjectType(rbx, MAP_TYPE, rcx);
    __ Check(equal, kUnexpectedInitialMapForInternalArrayFunction);
  }
 
  // Run the native code for the InternalArray function called as a normal
  // function.
  // tail call a stub
  InternalArrayConstructorStub stub(masm->isolate());
  __ TailCallStub(&stub);
}
 
 
void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax    : argc
  //  -- rsp[0] : return address
  //  -- rsp[8] : last argument
  // -----------------------------------
  Label generic_array_code;
 
  // Get the Array function.
  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, rdi);
 
  if (FLAG_debug_code) {
    // Initial map for the builtin Array functions should be maps.
    __ movp(rbx, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a NULL and a Smi.
    STATIC_ASSERT(kSmiTag == 0);
    Condition not_smi = NegateCondition(masm->CheckSmi(rbx));
    __ Check(not_smi, kUnexpectedInitialMapForArrayFunction);
    __ CmpObjectType(rbx, MAP_TYPE, rcx);
    __ Check(equal, kUnexpectedInitialMapForArrayFunction);
  }
 
  // Run the native code for the Array function called as a normal function.
  // tail call a stub
  __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
  ArrayConstructorStub stub(masm->isolate());
  __ TailCallStub(&stub);
}
 
 
void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax                 : number of arguments
  //  -- rdi                 : constructor function
  //  -- rsp[0]              : return address
  //  -- rsp[(argc - n) * 8] : arg[n] (zero-based)
  //  -- rsp[(argc + 1) * 8] : receiver
  // -----------------------------------
  Counters* counters = masm->isolate()->counters();
  __ IncrementCounter(counters->string_ctor_calls(), 1);
 
  if (FLAG_debug_code) {
    __ LoadGlobalFunction(Context::STRING_FUNCTION_INDEX, rcx);
    __ cmpp(rdi, rcx);
    __ Assert(equal, kUnexpectedStringFunction);
  }
 
  // Load the first argument into rax and get rid of the rest
  // (including the receiver).
  StackArgumentsAccessor args(rsp, rax);
  Label no_arguments;
  __ testp(rax, rax);
  __ j(zero, &no_arguments);
  __ movp(rbx, args.GetArgumentOperand(1));
  __ PopReturnAddressTo(rcx);
  __ leap(rsp, Operand(rsp, rax, times_pointer_size, kPointerSize));
  __ PushReturnAddressFrom(rcx);
  __ movp(rax, rbx);
 
  // Lookup the argument in the number to string cache.
  Label not_cached, argument_is_string;
  __ LookupNumberStringCache(rax,  // Input.
                             rbx,  // Result.
                             rcx,  // Scratch 1.
                             rdx,  // Scratch 2.
                             &not_cached);
  __ IncrementCounter(counters->string_ctor_cached_number(), 1);
  __ bind(&argument_is_string);
 
  // ----------- S t a t e -------------
  //  -- rbx    : argument converted to string
  //  -- rdi    : constructor function
  //  -- rsp[0] : return address
  // -----------------------------------
 
  // Allocate a JSValue and put the tagged pointer into rax.
  Label gc_required;
  __ Allocate(JSValue::kSize,
              rax,  // Result.
              rcx,  // New allocation top (we ignore it).
              no_reg,
              &gc_required,
              TAG_OBJECT);
 
  // Set the map.
  __ LoadGlobalFunctionInitialMap(rdi, rcx);
  if (FLAG_debug_code) {
    __ cmpb(FieldOperand(rcx, Map::kInstanceSizeOffset),
            Immediate(JSValue::kSize >> kPointerSizeLog2));
    __ Assert(equal, kUnexpectedStringWrapperInstanceSize);
    __ cmpb(FieldOperand(rcx, Map::kUnusedPropertyFieldsOffset), Immediate(0));
    __ Assert(equal, kUnexpectedUnusedPropertiesOfStringWrapper);
  }
  __ movp(FieldOperand(rax, HeapObject::kMapOffset), rcx);
 
  // Set properties and elements.
  __ LoadRoot(rcx, Heap::kEmptyFixedArrayRootIndex);
  __ movp(FieldOperand(rax, JSObject::kPropertiesOffset), rcx);
  __ movp(FieldOperand(rax, JSObject::kElementsOffset), rcx);
 
  // Set the value.
  __ movp(FieldOperand(rax, JSValue::kValueOffset), rbx);
 
  // Ensure the object is fully initialized.
  STATIC_ASSERT(JSValue::kSize == 4 * kPointerSize);
 
  // We're done. Return.
  __ ret(0);
 
  // The argument was not found in the number to string cache. Check
  // if it's a string already before calling the conversion builtin.
  Label convert_argument;
  __ bind(&not_cached);
  STATIC_ASSERT(kSmiTag == 0);
  __ JumpIfSmi(rax, &convert_argument);
  Condition is_string = masm->IsObjectStringType(rax, rbx, rcx);
  __ j(NegateCondition(is_string), &convert_argument);
  __ movp(rbx, rax);
  __ IncrementCounter(counters->string_ctor_string_value(), 1);
  __ jmp(&argument_is_string);
 
  // Invoke the conversion builtin and put the result into rbx.
  __ bind(&convert_argument);
  __ IncrementCounter(counters->string_ctor_conversions(), 1);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(rdi);  // Preserve the function.
    __ Push(rax);
    __ InvokeBuiltin(Builtins::TO_STRING, CALL_FUNCTION);
    __ Pop(rdi);
  }
  __ movp(rbx, rax);
  __ jmp(&argument_is_string);
 
  // Load the empty string into rbx, remove the receiver from the
  // stack, and jump back to the case where the argument is a string.
  __ bind(&no_arguments);
  __ LoadRoot(rbx, Heap::kempty_stringRootIndex);
  __ PopReturnAddressTo(rcx);
  __ leap(rsp, Operand(rsp, kPointerSize));
  __ PushReturnAddressFrom(rcx);
  __ jmp(&argument_is_string);
 
  // At this point the argument is already a string. Call runtime to
  // create a string wrapper.
  __ bind(&gc_required);
  __ IncrementCounter(counters->string_ctor_gc_required(), 1);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ Push(rbx);
    __ CallRuntime(Runtime::kNewStringWrapper, 1);
  }
  __ ret(0);
}
 
 
static void ArgumentsAdaptorStackCheck(MacroAssembler* masm,
                                       Label* stack_overflow) {
  // ----------- S t a t e -------------
  //  -- rax : actual number of arguments
  //  -- rbx : expected number of arguments
  //  -- rdi: function (passed through to callee)
  // -----------------------------------
  // Check the stack for overflow. We are not trying to catch
  // interruptions (e.g. debug break and preemption) here, so the "real stack
  // limit" is checked.
  Label okay;
  __ LoadRoot(rdx, Heap::kRealStackLimitRootIndex);
  __ movp(rcx, rsp);
  // Make rcx the space we have left. The stack might already be overflowed
  // here which will cause rcx to become negative.
  __ subp(rcx, rdx);
  // Make rdx the space we need for the array when it is unrolled onto the
  // stack.
  __ movp(rdx, rbx);
  __ shlp(rdx, Immediate(kPointerSizeLog2));
  // Check if the arguments will overflow the stack.
  __ cmpp(rcx, rdx);
  __ j(less_equal, stack_overflow);  // Signed comparison.
}
 
 
static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
  __ pushq(rbp);
  __ movp(rbp, rsp);
 
  // Store the arguments adaptor context sentinel.
  __ Push(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
 
  // Push the function on the stack.
  __ Push(rdi);
 
  // Preserve the number of arguments on the stack. Must preserve rax,
  // rbx and rcx because these registers are used when copying the
  // arguments and the receiver.
  __ Integer32ToSmi(r8, rax);
  __ Push(r8);
}
 
 
static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
  // Retrieve the number of arguments from the stack. Number is a Smi.
  __ movp(rbx, Operand(rbp, ArgumentsAdaptorFrameConstants::kLengthOffset));
 
  // Leave the frame.
  __ movp(rsp, rbp);
  __ popq(rbp);
 
  // Remove caller arguments from the stack.
  __ PopReturnAddressTo(rcx);
  SmiIndex index = masm->SmiToIndex(rbx, rbx, kPointerSizeLog2);
  __ leap(rsp, Operand(rsp, index.reg, index.scale, 1 * kPointerSize));
  __ PushReturnAddressFrom(rcx);
}
 
 
void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- rax : actual number of arguments
  //  -- rbx : expected number of arguments
  //  -- rdi: function (passed through to callee)
  // -----------------------------------
 
  Label invoke, dont_adapt_arguments;
  Counters* counters = masm->isolate()->counters();
  __ IncrementCounter(counters->arguments_adaptors(), 1);
 
  Label stack_overflow;
  ArgumentsAdaptorStackCheck(masm, &stack_overflow);
 
  Label enough, too_few;
  __ movp(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
  __ cmpp(rax, rbx);
  __ j(less, &too_few);
  __ cmpp(rbx, Immediate(SharedFunctionInfo::kDontAdaptArgumentsSentinel));
  __ j(equal, &dont_adapt_arguments);
 
  {  // Enough parameters: Actual >= expected.
    __ bind(&enough);
    EnterArgumentsAdaptorFrame(masm);
 
    // Copy receiver and all expected arguments.
    const int offset = StandardFrameConstants::kCallerSPOffset;
    __ leap(rax, Operand(rbp, rax, times_pointer_size, offset));
    __ Set(r8, -1);  // account for receiver
 
    Label copy;
    __ bind(&copy);
    __ incp(r8);
    __ Push(Operand(rax, 0));
    __ subp(rax, Immediate(kPointerSize));
    __ cmpp(r8, rbx);
    __ j(less, &copy);
    __ jmp(&invoke);
  }
 
  {  // Too few parameters: Actual < expected.
    __ bind(&too_few);
    EnterArgumentsAdaptorFrame(masm);
 
    // Copy receiver and all actual arguments.
    const int offset = StandardFrameConstants::kCallerSPOffset;
    __ leap(rdi, Operand(rbp, rax, times_pointer_size, offset));
    __ Set(r8, -1);  // account for receiver
 
    Label copy;
    __ bind(&copy);
    __ incp(r8);
    __ Push(Operand(rdi, 0));
    __ subp(rdi, Immediate(kPointerSize));
    __ cmpp(r8, rax);
    __ j(less, &copy);
 
    // Fill remaining expected arguments with undefined values.
    Label fill;
    __ LoadRoot(kScratchRegister, Heap::kUndefinedValueRootIndex);
    __ bind(&fill);
    __ incp(r8);
    __ Push(kScratchRegister);
    __ cmpp(r8, rbx);
    __ j(less, &fill);
 
    // Restore function pointer.
    __ movp(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
  }
 
  // Call the entry point.
  __ bind(&invoke);
  __ call(rdx);
 
  // Store offset of return address for deoptimizer.
  masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());
 
  // Leave frame and return.
  LeaveArgumentsAdaptorFrame(masm);
  __ ret(0);
 
  // -------------------------------------------
  // Dont adapt arguments.
  // -------------------------------------------
  __ bind(&dont_adapt_arguments);
  __ jmp(rdx);
 
  __ bind(&stack_overflow);
  {
    FrameScope frame(masm, StackFrame::MANUAL);
    EnterArgumentsAdaptorFrame(masm);
    __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
    __ int3();
  }
}
 
 
void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
  // Lookup the function in the JavaScript frame.
  __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    // Pass function as argument.
    __ Push(rax);
    __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
  }
 
  Label skip;
  // If the code object is null, just return to the unoptimized code.
  __ cmpp(rax, Immediate(0));
  __ j(not_equal, &skip, Label::kNear);
  __ ret(0);
 
  __ bind(&skip);
 
  // Load deoptimization data from the code object.
  __ movp(rbx, Operand(rax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
 
  // Load the OSR entrypoint offset from the deoptimization data.
  __ SmiToInteger32(rbx, Operand(rbx, FixedArray::OffsetOfElementAt(
      DeoptimizationInputData::kOsrPcOffsetIndex) - kHeapObjectTag));
 
  // Compute the target address = code_obj + header_size + osr_offset
  __ leap(rax, Operand(rax, rbx, times_1, Code::kHeaderSize - kHeapObjectTag));
 
  // Overwrite the return address on the stack.
  __ movq(StackOperandForReturnAddress(0), rax);
 
  // And "return" to the OSR entry point of the function.
  __ ret(0);
}
 
 
void Builtins::Generate_OsrAfterStackCheck(MacroAssembler* masm) {
  // We check the stack limit as indicator that recompilation might be done.
  Label ok;
  __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
  __ j(above_equal, &ok);
  {
    FrameScope scope(masm, StackFrame::INTERNAL);
    __ CallRuntime(Runtime::kStackGuard, 0);
  }
  __ jmp(masm->isolate()->builtins()->OnStackReplacement(),
         RelocInfo::CODE_TARGET);
 
  __ bind(&ok);
  __ ret(0);
}
 
 
#undef __
 
} }  // namespace v8::internal
 
#endif  // V8_TARGET_ARCH_X64