blob: 437876d94cc538690ee094131298fb3ece1db967 [file] [log] [blame]
// Copyright 2018 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/objects/objects.h"
#include "src/objects/struct.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
enum InstanceType : uint16_t;
#include "torque-generated/src/objects/"
class AllocationSite : public Struct {
static const uint32_t kMaximumArrayBytesToPretransition = 8 * 1024;
static const double kPretenureRatio;
static const int kPretenureMinimumCreated = 100;
// Values for pretenure decision field.
enum PretenureDecision {
kUndecided = 0,
kDontTenure = 1,
kMaybeTenure = 2,
kTenure = 3,
kZombie = 4,
kLastPretenureDecisionValue = kZombie
const char* PretenureDecisionName(PretenureDecision decision);
// Contains either a Smi-encoded bitfield or a boilerplate. If it's a Smi the
// AllocationSite is for a constructed Array.
DECL_ACCESSORS(transition_info_or_boilerplate, Object)
DECL_ACCESSORS(boilerplate, JSObject)
// nested_site threads a list of sites that represent nested literals
// walked in a particular order. So [[1, 2], 1, 2] will have one
// nested_site, but [[1, 2], 3, [4]] will have a list of two.
DECL_ACCESSORS(nested_site, Object)
// Bitfield containing pretenuring information.
DECL_ACCESSORS(dependent_code, DependentCode)
// heap->allocation_site_list() points to the last AllocationSite which form
// a linked list through the weak_next property. The GC might remove elements
// from the list by updateing weak_next.
DECL_ACCESSORS(weak_next, Object)
inline void Initialize();
// Checks if the allocation site contain weak_next field;
inline bool HasWeakNext() const;
// This method is expensive, it should only be called for reporting.
bool IsNested();
// transition_info bitfields, for constructed array transition info.
using ElementsKindBits = base::BitField<ElementsKind, 0, 5>;
using DoNotInlineBit = base::BitField<bool, 5, 1>;
// Unused bits 6-30.
// Bitfields for pretenure_data
using MementoFoundCountBits = base::BitField<int, 0, 26>;
using PretenureDecisionBits = base::BitField<PretenureDecision, 26, 3>;
using DeoptDependentCodeBit = base::BitField<bool, 29, 1>;
STATIC_ASSERT(PretenureDecisionBits::kMax >= kLastPretenureDecisionValue);
// Increments the mementos found counter and returns true when the first
// memento was found for a given allocation site.
inline bool IncrementMementoFoundCount(int increment = 1);
inline void IncrementMementoCreateCount();
AllocationType GetAllocationType() const;
void ResetPretenureDecision();
inline PretenureDecision pretenure_decision() const;
inline void set_pretenure_decision(PretenureDecision decision);
inline bool deopt_dependent_code() const;
inline void set_deopt_dependent_code(bool deopt);
inline int memento_found_count() const;
inline void set_memento_found_count(int count);
inline int memento_create_count() const;
inline void set_memento_create_count(int count);
// The pretenuring decision is made during gc, and the zombie state allows
// us to recognize when an allocation site is just being kept alive because
// a later traversal of new space may discover AllocationMementos that point
// to this AllocationSite.
inline bool IsZombie() const;
inline bool IsMaybeTenure() const;
inline void MarkZombie();
inline bool MakePretenureDecision(PretenureDecision current_decision,
double ratio, bool maximum_size_scavenge);
inline bool DigestPretenuringFeedback(bool maximum_size_scavenge);
inline ElementsKind GetElementsKind() const;
inline void SetElementsKind(ElementsKind kind);
inline bool CanInlineCall() const;
inline void SetDoNotInlineCall();
inline bool PointsToLiteral() const;
template <AllocationSiteUpdateMode update_or_check =
static bool DigestTransitionFeedback(Handle<AllocationSite> site,
ElementsKind to_kind);
static inline bool ShouldTrack(ElementsKind boilerplate_elements_kind);
static bool ShouldTrack(ElementsKind from, ElementsKind to);
static inline bool CanTrack(InstanceType type);
// Layout description.
// AllocationSite has to start with TransitionInfoOrboilerPlateOffset
// and end with WeakNext field.
V(kStartOffset, 0) \
V(kTransitionInfoOrBoilerplateOffset, kTaggedSize) \
V(kNestedSiteOffset, kTaggedSize) \
V(kDependentCodeOffset, kTaggedSize) \
V(kCommonPointerFieldEndOffset, 0) \
V(kPretenureDataOffset, kInt32Size) \
V(kPretenureCreateCountOffset, kInt32Size) \
/* Size of AllocationSite without WeakNext field */ \
V(kSizeWithoutWeakNext, 0) \
V(kWeakNextOffset, kTaggedSize) \
/* Size of AllocationSite with WeakNext field */ \
V(kSizeWithWeakNext, 0)
class BodyDescriptor;
inline bool PretenuringDecisionMade() const;
OBJECT_CONSTRUCTORS(AllocationSite, Struct);
class AllocationMemento
: public TorqueGeneratedAllocationMemento<AllocationMemento, Struct> {
DECL_ACCESSORS(allocation_site, Object)
inline bool IsValid() const;
inline AllocationSite GetAllocationSite() const;
inline Address GetAllocationSiteUnchecked() const;
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"