blob: 5b7b3585ac3fbd7912d89d14147c84b5242d32c2 [file] [log] [blame]
// 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.
#ifndef V8_OBJECTS_ELEMENTS_KIND_H_
#define V8_OBJECTS_ELEMENTS_KIND_H_
#include "src/base/macros.h"
#include "src/common/checks.h"
#include "src/flags/flags.h"
#include "src/utils/utils.h"
namespace v8 {
namespace internal {
// V has parameters (Type, type, TYPE, C type)
#define TYPED_ARRAYS(V) \
V(Uint8, uint8, UINT8, uint8_t) \
V(Int8, int8, INT8, int8_t) \
V(Uint16, uint16, UINT16, uint16_t) \
V(Int16, int16, INT16, int16_t) \
V(Uint32, uint32, UINT32, uint32_t) \
V(Int32, int32, INT32, int32_t) \
V(Float32, float32, FLOAT32, float) \
V(Float64, float64, FLOAT64, double) \
V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t) \
V(BigUint64, biguint64, BIGUINT64, uint64_t) \
V(BigInt64, bigint64, BIGINT64, int64_t)
enum ElementsKind : uint8_t {
// The "fast" kind for elements that only contain SMI values. Must be first
// to make it possible to efficiently check maps for this kind.
PACKED_SMI_ELEMENTS,
HOLEY_SMI_ELEMENTS,
// The "fast" kind for tagged values. Must be second to make it possible to
// efficiently check maps for this and the PACKED_SMI_ELEMENTS kind
// together at once.
PACKED_ELEMENTS,
HOLEY_ELEMENTS,
// The "fast" kind for unwrapped, non-tagged double values.
PACKED_DOUBLE_ELEMENTS,
HOLEY_DOUBLE_ELEMENTS,
// The sealed kind for elements.
PACKED_SEALED_ELEMENTS,
HOLEY_SEALED_ELEMENTS,
// The frozen kind for elements.
PACKED_FROZEN_ELEMENTS,
HOLEY_FROZEN_ELEMENTS,
// The "slow" kind.
DICTIONARY_ELEMENTS,
// Elements kind of the "arguments" object (only in sloppy mode).
FAST_SLOPPY_ARGUMENTS_ELEMENTS,
SLOW_SLOPPY_ARGUMENTS_ELEMENTS,
// For string wrapper objects ("new String('...')"), the string's characters
// are overlaid onto a regular elements backing store.
FAST_STRING_WRAPPER_ELEMENTS,
SLOW_STRING_WRAPPER_ELEMENTS,
// Fixed typed arrays.
#define TYPED_ARRAY_ELEMENTS_KIND(Type, type, TYPE, ctype) TYPE##_ELEMENTS,
TYPED_ARRAYS(TYPED_ARRAY_ELEMENTS_KIND)
#undef TYPED_ARRAY_ELEMENTS_KIND
// Sentinel ElementsKind for objects with no elements.
NO_ELEMENTS,
// Derived constants from ElementsKind.
FIRST_ELEMENTS_KIND = PACKED_SMI_ELEMENTS,
LAST_ELEMENTS_KIND = BIGINT64_ELEMENTS,
FIRST_FAST_ELEMENTS_KIND = PACKED_SMI_ELEMENTS,
LAST_FAST_ELEMENTS_KIND = HOLEY_DOUBLE_ELEMENTS,
FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_ELEMENTS,
LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = BIGINT64_ELEMENTS,
TERMINAL_FAST_ELEMENTS_KIND = HOLEY_ELEMENTS,
LAST_FROZEN_ELEMENTS_KIND = HOLEY_FROZEN_ELEMENTS,
// Alias for kSystemPointerSize-sized elements
#ifdef V8_COMPRESS_POINTERS
SYSTEM_POINTER_ELEMENTS = PACKED_DOUBLE_ELEMENTS,
#else
SYSTEM_POINTER_ELEMENTS = PACKED_ELEMENTS,
#endif
};
constexpr int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1;
constexpr int kFastElementsKindCount =
LAST_FAST_ELEMENTS_KIND - FIRST_FAST_ELEMENTS_KIND + 1;
// The number to add to a packed elements kind to reach a holey elements kind
constexpr int kFastElementsKindPackedToHoley =
HOLEY_SMI_ELEMENTS - PACKED_SMI_ELEMENTS;
V8_EXPORT_PRIVATE int ElementsKindToShiftSize(ElementsKind elements_kind);
V8_EXPORT_PRIVATE int ElementsKindToByteSize(ElementsKind elements_kind);
int GetDefaultHeaderSizeForElementsKind(ElementsKind elements_kind);
const char* ElementsKindToString(ElementsKind kind);
inline ElementsKind GetInitialFastElementsKind() { return PACKED_SMI_ELEMENTS; }
ElementsKind GetFastElementsKindFromSequenceIndex(int sequence_number);
int GetSequenceIndexFromFastElementsKind(ElementsKind elements_kind);
ElementsKind GetNextTransitionElementsKind(ElementsKind elements_kind);
inline bool IsDictionaryElementsKind(ElementsKind kind) {
return kind == DICTIONARY_ELEMENTS;
}
inline bool IsSloppyArgumentsElementsKind(ElementsKind kind) {
return IsInRange(kind, FAST_SLOPPY_ARGUMENTS_ELEMENTS,
SLOW_SLOPPY_ARGUMENTS_ELEMENTS);
}
inline bool IsStringWrapperElementsKind(ElementsKind kind) {
return IsInRange(kind, FAST_STRING_WRAPPER_ELEMENTS,
SLOW_STRING_WRAPPER_ELEMENTS);
}
inline bool IsFixedTypedArrayElementsKind(ElementsKind kind) {
return IsInRange(kind, FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND,
LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND);
}
inline bool IsTerminalElementsKind(ElementsKind kind) {
return kind == TERMINAL_FAST_ELEMENTS_KIND ||
IsFixedTypedArrayElementsKind(kind);
}
inline bool IsFastElementsKind(ElementsKind kind) {
STATIC_ASSERT(FIRST_FAST_ELEMENTS_KIND == 0);
return kind <= LAST_FAST_ELEMENTS_KIND;
}
inline bool IsTransitionElementsKind(ElementsKind kind) {
return IsFastElementsKind(kind) || IsFixedTypedArrayElementsKind(kind) ||
kind == FAST_SLOPPY_ARGUMENTS_ELEMENTS ||
kind == FAST_STRING_WRAPPER_ELEMENTS;
}
inline bool IsDoubleElementsKind(ElementsKind kind) {
return IsInRange(kind, PACKED_DOUBLE_ELEMENTS, HOLEY_DOUBLE_ELEMENTS);
}
inline bool IsFixedFloatElementsKind(ElementsKind kind) {
return kind == FLOAT32_ELEMENTS || kind == FLOAT64_ELEMENTS;
}
inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) {
return IsDoubleElementsKind(kind) || IsFixedFloatElementsKind(kind);
}
inline bool IsFrozenOrSealedElementsKind(ElementsKind kind) {
DCHECK_IMPLIES(IsInRange(kind, PACKED_SEALED_ELEMENTS, HOLEY_FROZEN_ELEMENTS),
FLAG_enable_sealed_frozen_elements_kind);
return IsInRange(kind, PACKED_SEALED_ELEMENTS, HOLEY_FROZEN_ELEMENTS);
}
inline bool IsSealedElementsKind(ElementsKind kind) {
DCHECK_IMPLIES(IsInRange(kind, PACKED_SEALED_ELEMENTS, HOLEY_SEALED_ELEMENTS),
FLAG_enable_sealed_frozen_elements_kind);
return IsInRange(kind, PACKED_SEALED_ELEMENTS, HOLEY_SEALED_ELEMENTS);
}
inline bool IsFrozenElementsKind(ElementsKind kind) {
DCHECK_IMPLIES(IsInRange(kind, PACKED_FROZEN_ELEMENTS, HOLEY_FROZEN_ELEMENTS),
FLAG_enable_sealed_frozen_elements_kind);
return IsInRange(kind, PACKED_FROZEN_ELEMENTS, HOLEY_FROZEN_ELEMENTS);
}
inline bool IsSmiOrObjectElementsKind(ElementsKind kind) {
return IsInRange(kind, PACKED_SMI_ELEMENTS, HOLEY_ELEMENTS);
}
inline bool IsSmiElementsKind(ElementsKind kind) {
return IsInRange(kind, PACKED_SMI_ELEMENTS, HOLEY_SMI_ELEMENTS);
}
inline bool IsFastNumberElementsKind(ElementsKind kind) {
return IsSmiElementsKind(kind) || IsDoubleElementsKind(kind);
}
inline bool IsObjectElementsKind(ElementsKind kind) {
return IsInRange(kind, PACKED_ELEMENTS, HOLEY_ELEMENTS);
}
inline bool IsHoleyFrozenOrSealedElementsKind(ElementsKind kind) {
DCHECK_IMPLIES(kind == HOLEY_SEALED_ELEMENTS || kind == HOLEY_FROZEN_ELEMENTS,
FLAG_enable_sealed_frozen_elements_kind);
return kind == HOLEY_SEALED_ELEMENTS || kind == HOLEY_FROZEN_ELEMENTS;
}
inline bool IsHoleyElementsKind(ElementsKind kind) {
return kind % 2 == 1 && kind <= HOLEY_DOUBLE_ELEMENTS;
}
inline bool IsHoleyElementsKindForRead(ElementsKind kind) {
return kind % 2 == 1 && kind <= HOLEY_FROZEN_ELEMENTS;
}
inline bool IsHoleyOrDictionaryElementsKind(ElementsKind kind) {
return IsHoleyElementsKindForRead(kind) || kind == DICTIONARY_ELEMENTS;
}
inline bool IsFastPackedElementsKind(ElementsKind kind) {
return kind % 2 == 0 && kind <= PACKED_DOUBLE_ELEMENTS;
}
inline ElementsKind GetPackedElementsKind(ElementsKind holey_kind) {
if (holey_kind == HOLEY_SMI_ELEMENTS) {
return PACKED_SMI_ELEMENTS;
}
if (holey_kind == HOLEY_DOUBLE_ELEMENTS) {
return PACKED_DOUBLE_ELEMENTS;
}
if (holey_kind == HOLEY_ELEMENTS) {
return PACKED_ELEMENTS;
}
return holey_kind;
}
inline ElementsKind GetHoleyElementsKind(ElementsKind packed_kind) {
if (packed_kind == PACKED_SMI_ELEMENTS) {
return HOLEY_SMI_ELEMENTS;
}
if (packed_kind == PACKED_DOUBLE_ELEMENTS) {
return HOLEY_DOUBLE_ELEMENTS;
}
if (packed_kind == PACKED_ELEMENTS) {
return HOLEY_ELEMENTS;
}
return packed_kind;
}
inline bool UnionElementsKindUptoPackedness(ElementsKind* a_out,
ElementsKind b) {
// Assert that the union of two ElementKinds can be computed via std::max.
static_assert(PACKED_SMI_ELEMENTS < HOLEY_SMI_ELEMENTS,
"ElementsKind union not computable via std::max.");
static_assert(PACKED_ELEMENTS < HOLEY_ELEMENTS,
"ElementsKind union not computable via std::max.");
static_assert(PACKED_DOUBLE_ELEMENTS < HOLEY_DOUBLE_ELEMENTS,
"ElementsKind union not computable via std::max.");
ElementsKind a = *a_out;
switch (a) {
case HOLEY_SMI_ELEMENTS:
case PACKED_SMI_ELEMENTS:
if (b == PACKED_SMI_ELEMENTS || b == HOLEY_SMI_ELEMENTS) {
*a_out = std::max(a, b);
return true;
}
break;
case PACKED_ELEMENTS:
case HOLEY_ELEMENTS:
if (b == PACKED_ELEMENTS || b == HOLEY_ELEMENTS) {
*a_out = std::max(a, b);
return true;
}
break;
case PACKED_DOUBLE_ELEMENTS:
case HOLEY_DOUBLE_ELEMENTS:
if (b == PACKED_DOUBLE_ELEMENTS || b == HOLEY_DOUBLE_ELEMENTS) {
*a_out = std::max(a, b);
return true;
}
break;
default:
break;
}
return false;
}
bool UnionElementsKindUptoSize(ElementsKind* a_out, ElementsKind b);
inline ElementsKind FastSmiToObjectElementsKind(ElementsKind from_kind) {
DCHECK(IsSmiElementsKind(from_kind));
return (from_kind == PACKED_SMI_ELEMENTS) ? PACKED_ELEMENTS : HOLEY_ELEMENTS;
}
inline bool IsSimpleMapChangeTransition(ElementsKind from_kind,
ElementsKind to_kind) {
return (GetHoleyElementsKind(from_kind) == to_kind) ||
(IsSmiElementsKind(from_kind) && IsObjectElementsKind(to_kind));
}
bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind,
ElementsKind to_kind);
inline ElementsKind GetMoreGeneralElementsKind(ElementsKind from_kind,
ElementsKind to_kind) {
if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
return to_kind;
}
return from_kind;
}
inline bool IsTransitionableFastElementsKind(ElementsKind from_kind) {
return IsFastElementsKind(from_kind) &&
from_kind != TERMINAL_FAST_ELEMENTS_KIND;
}
inline bool ElementsKindEqual(ElementsKind a, ElementsKind b) { return a == b; }
} // namespace internal
} // namespace v8
#endif // V8_OBJECTS_ELEMENTS_KIND_H_