v8/src/code-stub-assembler.h

// Copyright 2016 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.

#ifndef V8_CODE_STUB_ASSEMBLER_H_
#define V8_CODE_STUB_ASSEMBLER_H_

#include <functional>

#include "src/compiler/code-assembler.h"
#include "src/globals.h"
#include "src/objects.h"

namespace v8 {
namespace internal {

class CallInterfaceDescriptor;
class CodeStubArguments;
class StatsCounter;
class StubCache;

enum class PrimitiveType { kBoolean, kNumber, kString, kSymbol };

#define HEAP_CONSTANT_LIST(V)                         \
  V(AccessorInfoMap, AccessorInfoMap)                 \
  V(BooleanMap, BooleanMap)                           \
  V(CodeMap, CodeMap)                                 \
  V(empty_string, EmptyString)                        \
  V(EmptyFixedArray, EmptyFixedArray)                 \
  V(FalseValue, False)                                \
  V(FixedArrayMap, FixedArrayMap)                     \
  V(FixedCOWArrayMap, FixedCOWArrayMap)               \
  V(FixedDoubleArrayMap, FixedDoubleArrayMap)         \
  V(FunctionTemplateInfoMap, FunctionTemplateInfoMap) \
  V(HeapNumberMap, HeapNumberMap)                     \
  V(MinusZeroValue, MinusZero)                        \
  V(NanValue, Nan)                                    \
  V(NullValue, Null)                                  \
  V(SymbolMap, SymbolMap)                             \
  V(TheHoleValue, TheHole)                            \
  V(TrueValue, True)                                  \
  V(UndefinedValue, Undefined)

// Provides JavaScript-specific "macro-assembler" functionality on top of the
// CodeAssembler. By factoring the JavaScript-isms out of the CodeAssembler,
// it's possible to add JavaScript-specific useful CodeAssembler "macros"
// without modifying files in the compiler directory (and requiring a review
// from a compiler directory OWNER).
class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 public:
  typedef compiler::Node Node;

  CodeStubAssembler(compiler::CodeAssemblerState* state)
      : compiler::CodeAssembler(state) {}

  enum AllocationFlag : uint8_t {
    kNone = 0,
    kDoubleAlignment = 1,
    kPretenured = 1 << 1
  };

  typedef base::Flags<AllocationFlag> AllocationFlags;

  // TODO(ishell): Fix all loads/stores from arrays by int32 offsets/indices
  // and eventually remove INTEGER_PARAMETERS in favour of INTPTR_PARAMETERS.
  enum ParameterMode { INTEGER_PARAMETERS, SMI_PARAMETERS, INTPTR_PARAMETERS };

  // On 32-bit platforms, there is a slight performance advantage to doing all
  // of the array offset/index arithmetic with SMIs, since it's possible
  // to save a few tag/untag operations without paying an extra expense when
  // calculating array offset (the smi math can be folded away) and there are
  // fewer live ranges. Thus only convert indices to untagged value on 64-bit
  // platforms.
  ParameterMode OptimalParameterMode() const {
    return Is64() ? INTPTR_PARAMETERS : SMI_PARAMETERS;
  }

  MachineRepresentation OptimalParameterRepresentation() const {
    return OptimalParameterMode() == INTPTR_PARAMETERS
               ? MachineType::PointerRepresentation()
               : MachineRepresentation::kTaggedSigned;
  }

  Node* UntagParameter(Node* value, ParameterMode mode) {
    if (mode != SMI_PARAMETERS) value = SmiUntag(value);
    return value;
  }

  Node* TagParameter(Node* value, ParameterMode mode) {
    if (mode != SMI_PARAMETERS) value = SmiTag(value);
    return value;
  }

  Node* NoContextConstant();
#define HEAP_CONSTANT_ACCESSOR(rootName, name) Node* name##Constant();
  HEAP_CONSTANT_LIST(HEAP_CONSTANT_ACCESSOR)
#undef HEAP_CONSTANT_ACCESSOR

#define HEAP_CONSTANT_TEST(rootName, name) Node* Is##name(Node* value);
  HEAP_CONSTANT_LIST(HEAP_CONSTANT_TEST)
#undef HEAP_CONSTANT_TEST

  Node* HashSeed();
  Node* StaleRegisterConstant();

  Node* IntPtrOrSmiConstant(int value, ParameterMode mode);

  Node* IntPtrAddFoldConstants(Node* left, Node* right);
  Node* IntPtrSubFoldConstants(Node* left, Node* right);
  // Round the 32bits payload of the provided word up to the next power of two.
  Node* IntPtrRoundUpToPowerOfTwo32(Node* value);
  Node* IntPtrMax(Node* left, Node* right);

  // Float64 operations.
  Node* Float64Ceil(Node* x);
  Node* Float64Floor(Node* x);
  Node* Float64Round(Node* x);
  Node* Float64Trunc(Node* x);

  // Tag a Word as a Smi value.
  Node* SmiTag(Node* value);
  // Untag a Smi value as a Word.
  Node* SmiUntag(Node* value);

  // Smi conversions.
  Node* SmiToFloat64(Node* value);
  Node* SmiFromWord(Node* value) { return SmiTag(value); }
  Node* SmiFromWord32(Node* value);
  Node* SmiToWord(Node* value) { return SmiUntag(value); }
  Node* SmiToWord32(Node* value);

  // Smi operations.
  Node* SmiAdd(Node* a, Node* b);
  Node* SmiSub(Node* a, Node* b);
  Node* SmiEqual(Node* a, Node* b);
  Node* SmiAbove(Node* a, Node* b);
  Node* SmiAboveOrEqual(Node* a, Node* b);
  Node* SmiBelow(Node* a, Node* b);
  Node* SmiLessThan(Node* a, Node* b);
  Node* SmiLessThanOrEqual(Node* a, Node* b);
  Node* SmiMax(Node* a, Node* b);
  Node* SmiMin(Node* a, Node* b);
  // Computes a % b for Smi inputs a and b; result is not necessarily a Smi.
  Node* SmiMod(Node* a, Node* b);
  // Computes a * b for Smi inputs a and b; result is not necessarily a Smi.
  Node* SmiMul(Node* a, Node* b);
  Node* SmiOr(Node* a, Node* b) {
    return BitcastWordToTaggedSigned(
        WordOr(BitcastTaggedToWord(a), BitcastTaggedToWord(b)));
  }

  // Smi | HeapNumber operations.
  Node* NumberInc(Node* value);
  void GotoIfNotNumber(Node* value, Label* is_not_number);
  void GotoIfNumber(Node* value, Label* is_number);

  // Allocate an object of the given size.
  Node* Allocate(Node* size, AllocationFlags flags = kNone);
  Node* Allocate(int size, AllocationFlags flags = kNone);
  Node* InnerAllocate(Node* previous, int offset);
  Node* InnerAllocate(Node* previous, Node* offset);
  Node* IsRegularHeapObjectSize(Node* size);

  typedef std::function<Node*()> ConditionBody;
  void Assert(ConditionBody condition_body, const char* string = nullptr,
              const char* file = nullptr, int line = 0);

  // Check a value for smi-ness
  Node* TaggedIsSmi(Node* a);
  Node* TaggedIsNotSmi(Node* a);
  // Check that the value is a non-negative smi.
  Node* WordIsPositiveSmi(Node* a);
  // Check that a word has a word-aligned address.
  Node* WordIsWordAligned(Node* word);
  Node* WordIsPowerOfTwo(Node* value);

  void BranchIfSmiEqual(Node* a, Node* b, Label* if_true, Label* if_false) {
    Branch(SmiEqual(a, b), if_true, if_false);
  }

  void BranchIfSmiLessThan(Node* a, Node* b, Label* if_true, Label* if_false) {
    Branch(SmiLessThan(a, b), if_true, if_false);
  }

  void BranchIfSmiLessThanOrEqual(Node* a, Node* b, Label* if_true,
                                  Label* if_false) {
    Branch(SmiLessThanOrEqual(a, b), if_true, if_false);
  }

  void BranchIfFloat64IsNaN(Node* value, Label* if_true, Label* if_false) {
    Branch(Float64Equal(value, value), if_false, if_true);
  }

  // Branches to {if_true} if ToBoolean applied to {value} yields true,
  // otherwise goes to {if_false}.
  void BranchIfToBooleanIsTrue(Node* value, Label* if_true, Label* if_false);

  void BranchIfSimd128Equal(Node* lhs, Node* lhs_map, Node* rhs, Node* rhs_map,
                            Label* if_equal, Label* if_notequal);
  void BranchIfSimd128Equal(Node* lhs, Node* rhs, Label* if_equal,
                            Label* if_notequal) {
    BranchIfSimd128Equal(lhs, LoadMap(lhs), rhs, LoadMap(rhs), if_equal,
                         if_notequal);
  }

  void BranchIfJSReceiver(Node* object, Label* if_true, Label* if_false);
  void BranchIfJSObject(Node* object, Label* if_true, Label* if_false);

  enum class FastJSArrayAccessMode { INBOUNDS_READ, ANY_ACCESS };
  void BranchIfFastJSArray(Node* object, Node* context,
                           FastJSArrayAccessMode mode, Label* if_true,
                           Label* if_false);

  // Load value from current frame by given offset in bytes.
  Node* LoadFromFrame(int offset, MachineType rep = MachineType::AnyTagged());
  // Load value from current parent frame by given offset in bytes.
  Node* LoadFromParentFrame(int offset,
                            MachineType rep = MachineType::AnyTagged());

  // Load an object pointer from a buffer that isn't in the heap.
  Node* LoadBufferObject(Node* buffer, int offset,
                         MachineType rep = MachineType::AnyTagged());
  // Load a field from an object on the heap.
  Node* LoadObjectField(Node* object, int offset,
                        MachineType rep = MachineType::AnyTagged());
  Node* LoadObjectField(Node* object, Node* offset,
                        MachineType rep = MachineType::AnyTagged());
  // Load a SMI field and untag it.
  Node* LoadAndUntagObjectField(Node* object, int offset);
  // Load a SMI field, untag it, and convert to Word32.
  Node* LoadAndUntagToWord32ObjectField(Node* object, int offset);
  // Load a SMI and untag it.
  Node* LoadAndUntagSmi(Node* base, int index);
  // Load a SMI root, untag it, and convert to Word32.
  Node* LoadAndUntagToWord32Root(Heap::RootListIndex root_index);

  // Load the floating point value of a HeapNumber.
  Node* LoadHeapNumberValue(Node* object);
  // Load the Map of an HeapObject.
  Node* LoadMap(Node* object);
  // Load the instance type of an HeapObject.
  Node* LoadInstanceType(Node* object);
  // Compare the instance the type of the object against the provided one.
  Node* HasInstanceType(Node* object, InstanceType type);
  // Load the properties backing store of a JSObject.
  Node* LoadProperties(Node* object);
  // Load the elements backing store of a JSObject.
  Node* LoadElements(Node* object);
  // Load the length of a JSArray instance.
  Node* LoadJSArrayLength(Node* array);
  // Load the length of a fixed array base instance.
  Node* LoadFixedArrayBaseLength(Node* array);
  // Load the length of a fixed array base instance.
  Node* LoadAndUntagFixedArrayBaseLength(Node* array);
  // Load the bit field of a Map.
  Node* LoadMapBitField(Node* map);
  // Load bit field 2 of a map.
  Node* LoadMapBitField2(Node* map);
  // Load bit field 3 of a map.
  Node* LoadMapBitField3(Node* map);
  // Load the instance type of a map.
  Node* LoadMapInstanceType(Node* map);
  // Load the ElementsKind of a map.
  Node* LoadMapElementsKind(Node* map);
  // Load the instance descriptors of a map.
  Node* LoadMapDescriptors(Node* map);
  // Load the prototype of a map.
  Node* LoadMapPrototype(Node* map);
  // Load the prototype info of a map. The result has to be checked if it is a
  // prototype info object or not.
  Node* LoadMapPrototypeInfo(Node* map, Label* if_has_no_proto_info);
  // Load the instance size of a Map.
  Node* LoadMapInstanceSize(Node* map);
  // Load the inobject properties count of a Map (valid only for JSObjects).
  Node* LoadMapInobjectProperties(Node* map);
  // Load the constructor function index of a Map (only for primitive maps).
  Node* LoadMapConstructorFunctionIndex(Node* map);
  // Load the constructor of a Map (equivalent to Map::GetConstructor()).
  Node* LoadMapConstructor(Node* map);
  // Check if the map is set for slow properties.
  Node* IsDictionaryMap(Node* map);

  // Load the hash field of a name as an uint32 value.
  Node* LoadNameHashField(Node* name);
  // Load the hash value of a name as an uint32 value.
  // If {if_hash_not_computed} label is specified then it also checks if
  // hash is actually computed.
  Node* LoadNameHash(Node* name, Label* if_hash_not_computed = nullptr);

  // Load length field of a String object.
  Node* LoadStringLength(Node* object);
  // Load value field of a JSValue object.
  Node* LoadJSValueValue(Node* object);
  // Load value field of a WeakCell object.
  Node* LoadWeakCellValueUnchecked(Node* weak_cell);
  Node* LoadWeakCellValue(Node* weak_cell, Label* if_cleared = nullptr);

  // Load an array element from a FixedArray.
  Node* LoadFixedArrayElement(
      Node* object, Node* index, int additional_offset = 0,
      ParameterMode parameter_mode = INTEGER_PARAMETERS);
  // Load an array element from a FixedArray, untag it and return it as Word32.
  Node* LoadAndUntagToWord32FixedArrayElement(
      Node* object, Node* index, int additional_offset = 0,
      ParameterMode parameter_mode = INTEGER_PARAMETERS);
  // Load an array element from a FixedDoubleArray.
  Node* LoadFixedDoubleArrayElement(
      Node* object, Node* index, MachineType machine_type,
      int additional_offset = 0,
      ParameterMode parameter_mode = INTEGER_PARAMETERS,
      Label* if_hole = nullptr);

  // Load Float64 value by |base| + |offset| address. If the value is a double
  // hole then jump to |if_hole|. If |machine_type| is None then only the hole
  // check is generated.
  Node* LoadDoubleWithHoleCheck(
      Node* base, Node* offset, Label* if_hole,
      MachineType machine_type = MachineType::Float64());
  Node* LoadFixedTypedArrayElement(
      Node* data_pointer, Node* index_node, ElementsKind elements_kind,
      ParameterMode parameter_mode = INTEGER_PARAMETERS);

  // Context manipulation
  Node* LoadContextElement(Node* context, int slot_index);
  Node* LoadContextElement(Node* context, Node* slot_index);
  Node* StoreContextElement(Node* context, int slot_index, Node* value);
  Node* StoreContextElement(Node* context, Node* slot_index, Node* value);
  Node* LoadNativeContext(Node* context);

  Node* LoadJSArrayElementsMap(ElementsKind kind, Node* native_context);

  // Store the floating point value of a HeapNumber.
  Node* StoreHeapNumberValue(Node* object, Node* value);
  // Store a field to an object on the heap.
  Node* StoreObjectField(Node* object, int offset, Node* value);
  Node* StoreObjectField(Node* object, Node* offset, Node* value);
  Node* StoreObjectFieldNoWriteBarrier(
      Node* object, int offset, Node* value,
      MachineRepresentation rep = MachineRepresentation::kTagged);
  Node* StoreObjectFieldNoWriteBarrier(
      Node* object, Node* offset, Node* value,
      MachineRepresentation rep = MachineRepresentation::kTagged);
  // Store the Map of an HeapObject.
  Node* StoreMapNoWriteBarrier(Node* object, Node* map);
  Node* StoreObjectFieldRoot(Node* object, int offset,
                             Heap::RootListIndex root);
  // Store an array element to a FixedArray.
  Node* StoreFixedArrayElement(
      Node* object, int index, Node* value,
      WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER) {
    return StoreFixedArrayElement(object, IntPtrConstant(index), value,
                                  barrier_mode, 0, INTPTR_PARAMETERS);
  }

  Node* StoreFixedArrayElement(
      Node* object, Node* index, Node* value,
      WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
      int additional_offset = 0,
      ParameterMode parameter_mode = INTEGER_PARAMETERS);

  Node* StoreFixedDoubleArrayElement(
      Node* object, Node* index, Node* value,
      ParameterMode parameter_mode = INTEGER_PARAMETERS);

  Node* BuildAppendJSArray(ElementsKind kind, Node* context, Node* array,
                           CodeStubArguments& args, Variable& arg_index,
                           Label* bailout);

  void StoreFieldsNoWriteBarrier(Node* start_address, Node* end_address,
                                 Node* value);

  // Allocate a HeapNumber without initializing its value.
  Node* AllocateHeapNumber(MutableMode mode = IMMUTABLE);
  // Allocate a HeapNumber with a specific value.
  Node* AllocateHeapNumberWithValue(Node* value, MutableMode mode = IMMUTABLE);
  // Allocate a SeqOneByteString with the given length.
  Node* AllocateSeqOneByteString(int length, AllocationFlags flags = kNone);
  Node* AllocateSeqOneByteString(Node* context, Node* length,
                                 ParameterMode mode = INTPTR_PARAMETERS,
                                 AllocationFlags flags = kNone);
  // Allocate a SeqTwoByteString with the given length.
  Node* AllocateSeqTwoByteString(int length, AllocationFlags flags = kNone);
  Node* AllocateSeqTwoByteString(Node* context, Node* length,
                                 ParameterMode mode = INTPTR_PARAMETERS,
                                 AllocationFlags flags = kNone);

  // Allocate a SlicedOneByteString with the given length, parent and offset.
  // |length| and |offset| are expected to be tagged.
  Node* AllocateSlicedOneByteString(Node* length, Node* parent, Node* offset);
  // Allocate a SlicedTwoByteString with the given length, parent and offset.
  // |length| and |offset| are expected to be tagged.
  Node* AllocateSlicedTwoByteString(Node* length, Node* parent, Node* offset);

  // Allocate a one-byte ConsString with the given length, first and second
  // parts. |length| is expected to be tagged, and |first| and |second| are
  // expected to be one-byte strings.
  Node* AllocateOneByteConsString(Node* length, Node* first, Node* second,
                                  AllocationFlags flags = kNone);
  // Allocate a two-byte ConsString with the given length, first and second
  // parts. |length| is expected to be tagged, and |first| and |second| are
  // expected to be two-byte strings.
  Node* AllocateTwoByteConsString(Node* length, Node* first, Node* second,
                                  AllocationFlags flags = kNone);

  // Allocate an appropriate one- or two-byte ConsString with the first and
  // second parts specified by |first| and |second|.
  Node* NewConsString(Node* context, Node* length, Node* left, Node* right,
                      AllocationFlags flags = kNone);

  // Allocate a RegExpResult with the given length (the number of captures,
  // including the match itself), index (the index where the match starts),
  // and input string. |length| and |index| are expected to be tagged, and
  // |input| must be a string.
  Node* AllocateRegExpResult(Node* context, Node* length, Node* index,
                             Node* input);

  Node* AllocateNameDictionary(int capacity);
  Node* AllocateNameDictionary(Node* capacity);

  Node* AllocateJSObjectFromMap(Node* map, Node* properties = nullptr,
                                Node* elements = nullptr);

  void InitializeJSObjectFromMap(Node* object, Node* map, Node* size,
                                 Node* properties = nullptr,
                                 Node* elements = nullptr);

  void InitializeJSObjectBody(Node* object, Node* map, Node* size,
                              int start_offset = JSObject::kHeaderSize);

  // Allocate a JSArray without elements and initialize the header fields.
  Node* AllocateUninitializedJSArrayWithoutElements(ElementsKind kind,
                                                    Node* array_map,
                                                    Node* length,
                                                    Node* allocation_site);
  // Allocate and return a JSArray with initialized header fields and its
  // uninitialized elements.
  // The ParameterMode argument is only used for the capacity parameter.
  std::pair<Node*, Node*> AllocateUninitializedJSArrayWithElements(
      ElementsKind kind, Node* array_map, Node* length, Node* allocation_site,
      Node* capacity, ParameterMode capacity_mode = INTEGER_PARAMETERS);
  // Allocate a JSArray and fill elements with the hole.
  // The ParameterMode argument is only used for the capacity parameter.
  Node* AllocateJSArray(ElementsKind kind, Node* array_map, Node* capacity,
                        Node* length, Node* allocation_site = nullptr,
                        ParameterMode capacity_mode = INTEGER_PARAMETERS);

  Node* AllocateFixedArray(ElementsKind kind, Node* capacity,
                           ParameterMode mode = INTEGER_PARAMETERS,
                           AllocationFlags flags = kNone);

  // Perform CreateArrayIterator (ES6 #sec-createarrayiterator).
  Node* CreateArrayIterator(Node* array, Node* array_map, Node* array_type,
                            Node* context, IterationKind mode);

  Node* AllocateJSArrayIterator(Node* array, Node* array_map, Node* map);

  void FillFixedArrayWithValue(ElementsKind kind, Node* array, Node* from_index,
                               Node* to_index,
                               Heap::RootListIndex value_root_index,
                               ParameterMode mode = INTEGER_PARAMETERS);

  // Copies all elements from |from_array| of |length| size to
  // |to_array| of the same size respecting the elements kind.
  void CopyFixedArrayElements(
      ElementsKind kind, Node* from_array, Node* to_array, Node* length,
      WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
      ParameterMode mode = INTEGER_PARAMETERS) {
    CopyFixedArrayElements(kind, from_array, kind, to_array, length, length,
                           barrier_mode, mode);
  }

  // Copies |element_count| elements from |from_array| to |to_array| of
  // |capacity| size respecting both array's elements kinds.
  void CopyFixedArrayElements(
      ElementsKind from_kind, Node* from_array, ElementsKind to_kind,
      Node* to_array, Node* element_count, Node* capacity,
      WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
      ParameterMode mode = INTEGER_PARAMETERS);

  // Copies |character_count| elements from |from_string| to |to_string|
  // starting at the |from_index|'th character. |from_string| and |to_string|
  // can either be one-byte strings or two-byte strings, although if
  // |from_string| is two-byte, then |to_string| must be two-byte.
  // |from_index|, |to_index| and |character_count| must be either Smis or
  // intptr_ts depending on |mode| s.t. 0 <= |from_index| <= |from_index| +
  // |character_count| <= from_string.length and 0 <= |to_index| <= |to_index| +
  // |character_count| <= to_string.length.
  void CopyStringCharacters(Node* from_string, Node* to_string,
                            Node* from_index, Node* to_index,
                            Node* character_count,
                            String::Encoding from_encoding,
                            String::Encoding to_encoding, ParameterMode mode);

  // Loads an element from |array| of |from_kind| elements by given |offset|
  // (NOTE: not index!), does a hole check if |if_hole| is provided and
  // converts the value so that it becomes ready for storing to array of
  // |to_kind| elements.
  Node* LoadElementAndPrepareForStore(Node* array, Node* offset,
                                      ElementsKind from_kind,
                                      ElementsKind to_kind, Label* if_hole);

  Node* CalculateNewElementsCapacity(Node* old_capacity,
                                     ParameterMode mode = INTEGER_PARAMETERS);

  // Tries to grow the |elements| array of given |object| to store the |key|
  // or bails out if the growing gap is too big. Returns new elements.
  Node* TryGrowElementsCapacity(Node* object, Node* elements, ElementsKind kind,
                                Node* key, Label* bailout);

  // Tries to grow the |capacity|-length |elements| array of given |object|
  // to store the |key| or bails out if the growing gap is too big. Returns
  // new elements.
  Node* TryGrowElementsCapacity(Node* object, Node* elements, ElementsKind kind,
                                Node* key, Node* capacity, ParameterMode mode,
                                Label* bailout);

  // Grows elements capacity of given object. Returns new elements.
  Node* GrowElementsCapacity(Node* object, Node* elements,
                             ElementsKind from_kind, ElementsKind to_kind,
                             Node* capacity, Node* new_capacity,
                             ParameterMode mode, Label* bailout);

  // Allocation site manipulation
  void InitializeAllocationMemento(Node* base_allocation,
                                   int base_allocation_size,
                                   Node* allocation_site);

  Node* TryTaggedToFloat64(Node* value, Label* if_valueisnotnumber);
  Node* TruncateTaggedToFloat64(Node* context, Node* value);
  Node* TruncateTaggedToWord32(Node* context, Node* value);
  // Truncate the floating point value of a HeapNumber to an Int32.
  Node* TruncateHeapNumberValueToWord32(Node* object);

  // Conversions.
  Node* ChangeFloat64ToTagged(Node* value);
  Node* ChangeInt32ToTagged(Node* value);
  Node* ChangeUint32ToTagged(Node* value);
  Node* ChangeNumberToFloat64(Node* value);

  // Type conversions.
  // Throws a TypeError for {method_name} if {value} is not coercible to Object,
  // or returns the {value} converted to a String otherwise.
  Node* ToThisString(Node* context, Node* value, char const* method_name);
  // Throws a TypeError for {method_name} if {value} is neither of the given
  // {primitive_type} nor a JSValue wrapping a value of {primitive_type}, or
  // returns the {value} (or wrapped value) otherwise.
  Node* ToThisValue(Node* context, Node* value, PrimitiveType primitive_type,
                    char const* method_name);

  // Throws a TypeError for {method_name} if {value} is not of the given
  // instance type. Returns {value}'s map.
  Node* ThrowIfNotInstanceType(Node* context, Node* value,
                               InstanceType instance_type,
                               char const* method_name);

  // Type checks.
  // Check whether the map is for an object with special properties, such as a
  // JSProxy or an object with interceptors.
  Node* IsSpecialReceiverMap(Node* map);
  Node* IsSpecialReceiverInstanceType(Node* instance_type);
  Node* IsStringInstanceType(Node* instance_type);
  Node* IsString(Node* object);
  Node* IsJSObject(Node* object);
  Node* IsJSGlobalProxy(Node* object);
  Node* IsJSReceiverInstanceType(Node* instance_type);
  Node* IsJSReceiver(Node* object);
  Node* IsMap(Node* object);
  Node* IsCallableMap(Node* map);
  Node* IsName(Node* object);
  Node* IsJSValue(Node* object);
  Node* IsJSArray(Node* object);
  Node* IsNativeContext(Node* object);
  Node* IsWeakCell(Node* object);
  Node* IsFixedDoubleArray(Node* object);
  Node* IsHashTable(Node* object);
  Node* IsDictionary(Node* object);
  Node* IsUnseededNumberDictionary(Node* object);

  // ElementsKind helpers:
  Node* IsFastElementsKind(Node* elements_kind);
  Node* IsHoleyFastElementsKind(Node* elements_kind);

  // String helpers.
  // Load a character from a String (might flatten a ConsString).
  Node* StringCharCodeAt(Node* string, Node* smi_index);
  // Return the single character string with only {code}.
  Node* StringFromCharCode(Node* code);
  // Return a new string object which holds a substring containing the range
  // [from,to[ of string.  |from| and |to| are expected to be tagged.
  Node* SubString(Node* context, Node* string, Node* from, Node* to);

  // Return a new string object produced by concatenating |first| with |second|.
  Node* StringAdd(Node* context, Node* first, Node* second,
                  AllocationFlags flags = kNone);

  // Return the first index >= {from} at which {needle_char} was found in
  // {string}, or -1 if such an index does not exist. The returned value is
  // a Smi, {string} is expected to be a String, {needle_char} is an intptr,
  // and {from} is expected to be tagged.
  Node* StringIndexOfChar(Node* context, Node* string, Node* needle_char,
                          Node* from);

  Node* StringFromCodePoint(Node* codepoint, UnicodeEncoding encoding);

  // Type conversion helpers.
  // Convert a String to a Number.
  Node* StringToNumber(Node* context, Node* input);
  Node* NumberToString(Node* context, Node* input);
  // Convert an object to a name.
  Node* ToName(Node* context, Node* input);
  // Convert a Non-Number object to a Number.
  Node* NonNumberToNumber(Node* context, Node* input);
  // Convert any object to a Number.
  Node* ToNumber(Node* context, Node* input);

  // Convert any object to a String.
  Node* ToString(Node* context, Node* input);

  // Convert any object to a Primitive.
  Node* JSReceiverToPrimitive(Node* context, Node* input);

  // Convert a String to a flat String.
  Node* FlattenString(Node* string);

  enum ToIntegerTruncationMode {
    kNoTruncation,
    kTruncateMinusZero,
  };

  // Convert any object to an Integer.
  Node* ToInteger(Node* context, Node* input,
                  ToIntegerTruncationMode mode = kNoTruncation);

  // Returns a node that contains a decoded (unsigned!) value of a bit
  // field |T| in |word32|. Returns result as an uint32 node.
  template <typename T>
  Node* DecodeWord32(Node* word32) {
    return DecodeWord32(word32, T::kShift, T::kMask);
  }

  // Returns a node that contains a decoded (unsigned!) value of a bit
  // field |T| in |word|. Returns result as a word-size node.
  template <typename T>
  Node* DecodeWord(Node* word) {
    return DecodeWord(word, T::kShift, T::kMask);
  }

  // Returns a node that contains a decoded (unsigned!) value of a bit
  // field |T| in |word32|. Returns result as a word-size node.
  template <typename T>
  Node* DecodeWordFromWord32(Node* word32) {
    return DecodeWord<T>(ChangeUint32ToWord(word32));
  }

  // Decodes an unsigned (!) value from |word32| to an uint32 node.
  Node* DecodeWord32(Node* word32, uint32_t shift, uint32_t mask);

  // Decodes an unsigned (!) value from |word| to a word-size node.
  Node* DecodeWord(Node* word, uint32_t shift, uint32_t mask);

  // Returns true if any of the |T|'s bits in given |word32| are set.
  template <typename T>
  Node* IsSetWord32(Node* word32) {
    return IsSetWord32(word32, T::kMask);
  }

  // Returns true if any of the mask's bits in given |word32| are set.
  Node* IsSetWord32(Node* word32, uint32_t mask) {
    return Word32NotEqual(Word32And(word32, Int32Constant(mask)),
                          Int32Constant(0));
  }

  // Returns true if any of the |T|'s bits in given |word| are set.
  template <typename T>
  Node* IsSetWord(Node* word) {
    return WordNotEqual(WordAnd(word, IntPtrConstant(T::kMask)),
                        IntPtrConstant(0));
  }

  void SetCounter(StatsCounter* counter, int value);
  void IncrementCounter(StatsCounter* counter, int delta);
  void DecrementCounter(StatsCounter* counter, int delta);

  void Increment(Variable& variable, int value = 1,
                 ParameterMode mode = INTPTR_PARAMETERS);

  // Generates "if (false) goto label" code. Useful for marking a label as
  // "live" to avoid assertion failures during graph building. In the resulting
  // code this check will be eliminated.
  void Use(Label* label);

  // Various building blocks for stubs doing property lookups.
  void TryToName(Node* key, Label* if_keyisindex, Variable* var_index,
                 Label* if_keyisunique, Label* if_bailout);

  // Calculates array index for given dictionary entry and entry field.
  // See Dictionary::EntryToIndex().
  template <typename Dictionary>
  Node* EntryToIndex(Node* entry, int field_index);
  template <typename Dictionary>
  Node* EntryToIndex(Node* entry) {
    return EntryToIndex<Dictionary>(entry, Dictionary::kEntryKeyIndex);
  }
  // Calculate a valid size for the a hash table.
  Node* HashTableComputeCapacity(Node* at_least_space_for);

  template <class Dictionary>
  Node* GetNumberOfElements(Node* dictionary);

  template <class Dictionary>
  void SetNumberOfElements(Node* dictionary, Node* num_elements_smi);

  template <class Dictionary>
  Node* GetNumberOfDeletedElements(Node* dictionary);

  template <class Dictionary>
  Node* GetCapacity(Node* dictionary);

  template <class Dictionary>
  Node* GetNextEnumerationIndex(Node* dictionary);

  template <class Dictionary>
  void SetNextEnumerationIndex(Node* dictionary, Node* next_enum_index_smi);

  // Looks up an entry in a NameDictionaryBase successor. If the entry is found
  // control goes to {if_found} and {var_name_index} contains an index of the
  // key field of the entry found. If the key is not found control goes to
  // {if_not_found}.
  static const int kInlinedDictionaryProbes = 4;
  enum LookupMode { kFindExisting, kFindInsertionIndex };
  template <typename Dictionary>
  void NameDictionaryLookup(Node* dictionary, Node* unique_name,
                            Label* if_found, Variable* var_name_index,
                            Label* if_not_found,
                            int inlined_probes = kInlinedDictionaryProbes,
                            LookupMode mode = kFindExisting);

  Node* ComputeIntegerHash(Node* key, Node* seed);

  template <typename Dictionary>
  void NumberDictionaryLookup(Node* dictionary, Node* intptr_index,
                              Label* if_found, Variable* var_entry,
                              Label* if_not_found);

  template <class Dictionary>
  void FindInsertionEntry(Node* dictionary, Node* key, Variable* var_key_index);

  template <class Dictionary>
  void InsertEntry(Node* dictionary, Node* key, Node* value, Node* index,
                   Node* enum_index);

  template <class Dictionary>
  void Add(Node* dictionary, Node* key, Node* value, Label* bailout);

  // Tries to check if {object} has own {unique_name} property.
  void TryHasOwnProperty(Node* object, Node* map, Node* instance_type,
                         Node* unique_name, Label* if_found,
                         Label* if_not_found, Label* if_bailout);

  // Tries to get {object}'s own {unique_name} property value. If the property
  // is an accessor then it also calls a getter. If the property is a double
  // field it re-wraps value in an immutable heap number.
  void TryGetOwnProperty(Node* context, Node* receiver, Node* object, Node* map,
                         Node* instance_type, Node* unique_name,
                         Label* if_found, Variable* var_value,
                         Label* if_not_found, Label* if_bailout);

  void LoadPropertyFromFastObject(Node* object, Node* map, Node* descriptors,
                                  Node* name_index, Variable* var_details,
                                  Variable* var_value);

  void LoadPropertyFromNameDictionary(Node* dictionary, Node* entry,
                                      Variable* var_details,
                                      Variable* var_value);

  void LoadPropertyFromGlobalDictionary(Node* dictionary, Node* entry,
                                        Variable* var_details,
                                        Variable* var_value, Label* if_deleted);

  // Generic property lookup generator. If the {object} is fast and
  // {unique_name} property is found then the control goes to {if_found_fast}
  // label and {var_meta_storage} and {var_name_index} will contain
  // DescriptorArray and an index of the descriptor's name respectively.
  // If the {object} is slow or global then the control goes to {if_found_dict}
  // or {if_found_global} and the {var_meta_storage} and {var_name_index} will
  // contain a dictionary and an index of the key field of the found entry.
  // If property is not found or given lookup is not supported then
  // the control goes to {if_not_found} or {if_bailout} respectively.
  //
  // Note: this code does not check if the global dictionary points to deleted
  // entry! This has to be done by the caller.
  void TryLookupProperty(Node* object, Node* map, Node* instance_type,
                         Node* unique_name, Label* if_found_fast,
                         Label* if_found_dict, Label* if_found_global,
                         Variable* var_meta_storage, Variable* var_name_index,
                         Label* if_not_found, Label* if_bailout);

  void TryLookupElement(Node* object, Node* map, Node* instance_type,
                        Node* intptr_index, Label* if_found,
                        Label* if_not_found, Label* if_bailout);

  // This is a type of a lookup in holder generator function. In case of a
  // property lookup the {key} is guaranteed to be a unique name and in case of
  // element lookup the key is an Int32 index.
  typedef std::function<void(Node* receiver, Node* holder, Node* map,
                             Node* instance_type, Node* key, Label* next_holder,
                             Label* if_bailout)>
      LookupInHolder;

  // Generic property prototype chain lookup generator.
  // For properties it generates lookup using given {lookup_property_in_holder}
  // and for elements it uses {lookup_element_in_holder}.
  // Upon reaching the end of prototype chain the control goes to {if_end}.
  // If it can't handle the case {receiver}/{key} case then the control goes
  // to {if_bailout}.
  void TryPrototypeChainLookup(Node* receiver, Node* key,
                               LookupInHolder& lookup_property_in_holder,
                               LookupInHolder& lookup_element_in_holder,
                               Label* if_end, Label* if_bailout);

  // Instanceof helpers.
  // ES6 section 7.3.19 OrdinaryHasInstance (C, O)
  Node* OrdinaryHasInstance(Node* context, Node* callable, Node* object);

  // Load type feedback vector from the stub caller's frame.
  Node* LoadTypeFeedbackVectorForStub();

  // Update the type feedback vector.
  void UpdateFeedback(Node* feedback, Node* type_feedback_vector,
                      Node* slot_id);

  Node* LoadReceiverMap(Node* receiver);

  // Extends properties backing store by JSObject::kFieldsAdded elements.
  void ExtendPropertiesBackingStore(Node* object);

  Node* PrepareValueForWrite(Node* value, Representation representation,
                             Label* bailout);

  void StoreNamedField(Node* object, FieldIndex index,
                       Representation representation, Node* value,
                       bool transition_to_field);

  void StoreNamedField(Node* object, Node* offset, bool is_inobject,
                       Representation representation, Node* value,
                       bool transition_to_field);

  // Emits keyed sloppy arguments load. Returns either the loaded value.
  Node* LoadKeyedSloppyArguments(Node* receiver, Node* key, Label* bailout) {
    return EmitKeyedSloppyArguments(receiver, key, nullptr, bailout);
  }

  // Emits keyed sloppy arguments store.
  void StoreKeyedSloppyArguments(Node* receiver, Node* key, Node* value,
                                 Label* bailout) {
    DCHECK_NOT_NULL(value);
    EmitKeyedSloppyArguments(receiver, key, value, bailout);
  }

  // Loads script context from the script context table.
  Node* LoadScriptContext(Node* context, int context_index);

  Node* ClampedToUint8(Node* int32_value);

  // Store value to an elements array with given elements kind.
  void StoreElement(Node* elements, ElementsKind kind, Node* index, Node* value,
                    ParameterMode mode);

  void EmitElementStore(Node* object, Node* key, Node* value, bool is_jsarray,
                        ElementsKind elements_kind,
                        KeyedAccessStoreMode store_mode, Label* bailout);

  Node* CheckForCapacityGrow(Node* object, Node* elements, ElementsKind kind,
                             Node* length, Node* key, ParameterMode mode,
                             bool is_js_array, Label* bailout);

  Node* CopyElementsOnWrite(Node* object, Node* elements, ElementsKind kind,
                            Node* length, ParameterMode mode, Label* bailout);

  void TransitionElementsKind(Node* object, Node* map, ElementsKind from_kind,
                              ElementsKind to_kind, bool is_jsarray,
                              Label* bailout);

  void TrapAllocationMemento(Node* object, Label* memento_found);

  Node* PageFromAddress(Node* address);

  // Get the enumerable length from |map| and return the result as a Smi.
  Node* EnumLength(Node* map);

  // Check the cache validity for |receiver|. Branch to |use_cache| if
  // the cache is valid, otherwise branch to |use_runtime|.
  void CheckEnumCache(Node* receiver, CodeStubAssembler::Label* use_cache,
                      CodeStubAssembler::Label* use_runtime);

  // Create a new weak cell with a specified value and install it into a
  // feedback vector.
  Node* CreateWeakCellInFeedbackVector(Node* feedback_vector, Node* slot,
                                       Node* value);

  // Create a new AllocationSite and install it into a feedback vector.
  Node* CreateAllocationSiteInFeedbackVector(Node* feedback_vector, Node* slot);

  enum class IndexAdvanceMode { kPre, kPost };

  void BuildFastLoop(
      const VariableList& var_list, MachineRepresentation index_rep,
      Node* start_index, Node* end_index,
      std::function<void(CodeStubAssembler* assembler, Node* index)> body,
      int increment, IndexAdvanceMode mode = IndexAdvanceMode::kPre);

  void BuildFastLoop(
      MachineRepresentation index_rep, Node* start_index, Node* end_index,
      std::function<void(CodeStubAssembler* assembler, Node* index)> body,
      int increment, IndexAdvanceMode mode = IndexAdvanceMode::kPre) {
    BuildFastLoop(VariableList(0, zone()), index_rep, start_index, end_index,
                  body, increment, mode);
  }

  enum class ForEachDirection { kForward, kReverse };

  void BuildFastFixedArrayForEach(
      Node* fixed_array, ElementsKind kind, Node* first_element_inclusive,
      Node* last_element_exclusive,
      std::function<void(CodeStubAssembler* assembler, Node* fixed_array,
                         Node* offset)>
          body,
      ParameterMode mode = INTPTR_PARAMETERS,
      ForEachDirection direction = ForEachDirection::kReverse);

  Node* GetArrayAllocationSize(Node* element_count, ElementsKind kind,
                               ParameterMode mode, int header_size) {
    return ElementOffsetFromIndex(element_count, kind, mode, header_size);
  }

  Node* GetFixedArrayAllocationSize(Node* element_count, ElementsKind kind,
                                    ParameterMode mode) {
    return GetArrayAllocationSize(element_count, kind, mode,
                                  FixedArray::kHeaderSize);
  }

  enum RelationalComparisonMode {
    kLessThan,
    kLessThanOrEqual,
    kGreaterThan,
    kGreaterThanOrEqual
  };

  Node* RelationalComparison(RelationalComparisonMode mode, Node* lhs,
                             Node* rhs, Node* context);

  void BranchIfNumericRelationalComparison(RelationalComparisonMode mode,
                                           Node* lhs, Node* rhs, Label* if_true,
                                           Label* if_false);

  void GotoUnlessNumberLessThan(Node* lhs, Node* rhs, Label* if_false);

  enum ResultMode { kDontNegateResult, kNegateResult };

  Node* Equal(ResultMode mode, Node* lhs, Node* rhs, Node* context);

  Node* StrictEqual(ResultMode mode, Node* lhs, Node* rhs, Node* context);

  // ECMA#sec-samevalue
  // Similar to StrictEqual except that NaNs are treated as equal and minus zero
  // differs from positive zero.
  // Unlike Equal and StrictEqual, returns a value suitable for use in Branch
  // instructions, e.g. Branch(SameValue(...), &label).
  Node* SameValue(Node* lhs, Node* rhs, Node* context);

  Node* HasProperty(
      Node* object, Node* key, Node* context,
      Runtime::FunctionId fallback_runtime_function_id = Runtime::kHasProperty);
  Node* ForInFilter(Node* key, Node* object, Node* context);

  Node* Typeof(Node* value, Node* context);

  Node* InstanceOf(Node* object, Node* callable, Node* context);

  // Debug helpers
  Node* IsDebugActive();

  // TypedArray/ArrayBuffer helpers
  Node* IsDetachedBuffer(Node* buffer);

  Node* ElementOffsetFromIndex(Node* index, ElementsKind kind,
                               ParameterMode mode, int base_size = 0);

 protected:
  void DescriptorLookupLinear(Node* unique_name, Node* descriptors, Node* nof,
                              Label* if_found, Variable* var_name_index,
                              Label* if_not_found);

  Node* CallGetterIfAccessor(Node* value, Node* details, Node* context,
                             Node* receiver, Label* if_bailout);

  Node* TryToIntptr(Node* key, Label* miss);

  void BranchIfPrototypesHaveNoElements(Node* receiver_map,
                                        Label* definitely_no_elements,
                                        Label* possibly_elements);

 private:
  friend class CodeStubArguments;

  Node* AllocateRawAligned(Node* size_in_bytes, AllocationFlags flags,
                           Node* top_address, Node* limit_address);
  Node* AllocateRawUnaligned(Node* size_in_bytes, AllocationFlags flags,
                             Node* top_adddress, Node* limit_address);
  // Allocate and return a JSArray of given total size in bytes with header
  // fields initialized.
  Node* AllocateUninitializedJSArray(ElementsKind kind, Node* array_map,
                                     Node* length, Node* allocation_site,
                                     Node* size_in_bytes);

  Node* SmiShiftBitsConstant();

  // Emits keyed sloppy arguments load if the |value| is nullptr or store
  // otherwise. Returns either the loaded value or |value|.
  Node* EmitKeyedSloppyArguments(Node* receiver, Node* key, Node* value,
                                 Label* bailout);

  Node* AllocateSlicedString(Heap::RootListIndex map_root_index, Node* length,
                             Node* parent, Node* offset);

  Node* AllocateConsString(Heap::RootListIndex map_root_index, Node* length,
                           Node* first, Node* second, AllocationFlags flags);

  static const int kElementLoopUnrollThreshold = 8;
};

class CodeStubArguments {
 public:
  typedef compiler::Node Node;

  // |argc| specifies the number of arguments passed to the builtin excluding
  // the receiver.
  CodeStubArguments(CodeStubAssembler* assembler, Node* argc,
                    CodeStubAssembler::ParameterMode mode =
                        CodeStubAssembler::INTPTR_PARAMETERS);

  Node* GetReceiver() const;

  // |index| is zero-based and does not include the receiver
  Node* AtIndex(Node* index, CodeStubAssembler::ParameterMode mode =
                                 CodeStubAssembler::INTPTR_PARAMETERS) const;

  Node* AtIndex(int index) const;

  Node* GetLength() const { return argc_; }

  typedef std::function<void(CodeStubAssembler* assembler, Node* arg)>
      ForEachBodyFunction;

  // Iteration doesn't include the receiver. |first| and |last| are zero-based.
  void ForEach(ForEachBodyFunction body, Node* first = nullptr,
               Node* last = nullptr, CodeStubAssembler::ParameterMode mode =
                                         CodeStubAssembler::INTPTR_PARAMETERS) {
    CodeStubAssembler::VariableList list(0, assembler_->zone());
    ForEach(list, body, first, last);
  }

  // Iteration doesn't include the receiver. |first| and |last| are zero-based.
  void ForEach(const CodeStubAssembler::VariableList& vars,
               ForEachBodyFunction body, Node* first = nullptr,
               Node* last = nullptr, CodeStubAssembler::ParameterMode mode =
                                         CodeStubAssembler::INTPTR_PARAMETERS);

  void PopAndReturn(Node* value);

 private:
  Node* GetArguments();

  CodeStubAssembler* assembler_;
  Node* argc_;
  Node* arguments_;
  Node* fp_;
};

#ifdef DEBUG
#define CSA_ASSERT(csa, x) \
  (csa)->Assert([&] { return (x); }, #x, __FILE__, __LINE__)
#else
#define CSA_ASSERT(csa, x) ((void)0)
#endif

#ifdef ENABLE_SLOW_DCHECKS
#define CSA_SLOW_ASSERT(csa, x)                                 \
  if (FLAG_enable_slow_asserts) {                               \
    (csa)->Assert([&] { return (x); }, #x, __FILE__, __LINE__); \
  }
#else
#define CSA_SLOW_ASSERT(csa, x) ((void)0)
#endif

DEFINE_OPERATORS_FOR_FLAGS(CodeStubAssembler::AllocationFlags);

}  // namespace internal
}  // namespace v8
#endif  // V8_CODE_STUB_ASSEMBLER_H_