| // Copyright 2014 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_FIELD_INDEX_H_ |
| #define V8_FIELD_INDEX_H_ |
| |
| #include "src/property-details.h" |
| #include "src/utils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class Map; |
| |
| // Wrapper class to hold a field index, usually but not necessarily generated |
| // from a property index. When available, the wrapper class captures additional |
| // information to allow the field index to be translated back into the property |
| // index it was originally generated from. |
| class FieldIndex FINAL { |
| public: |
| static FieldIndex ForPropertyIndex(Map* map, |
| int index, |
| bool is_double = false); |
| static FieldIndex ForInObjectOffset(int offset, Map* map = NULL); |
| static FieldIndex ForDescriptor(Map* map, int descriptor_index); |
| static FieldIndex ForLoadByFieldIndex(Map* map, int index); |
| static FieldIndex ForKeyedLookupCacheIndex(Map* map, int index); |
| static FieldIndex FromFieldAccessStubKey(int key); |
| |
| int GetLoadByFieldIndex() const; |
| |
| bool is_inobject() const { |
| return IsInObjectBits::decode(bit_field_); |
| } |
| |
| bool is_double() const { |
| return IsDoubleBits::decode(bit_field_); |
| } |
| |
| int offset() const { |
| return index() * kPointerSize; |
| } |
| |
| // Zero-indexed from beginning of the object. |
| int index() const { |
| return IndexBits::decode(bit_field_); |
| } |
| |
| int outobject_array_index() const { |
| DCHECK(!is_inobject()); |
| return index() - first_inobject_property_offset() / kPointerSize; |
| } |
| |
| // Zero-based from the first inobject property. Overflows to out-of-object |
| // properties. |
| int property_index() const { |
| DCHECK(!IsHiddenField::decode(bit_field_)); |
| int result = index() - first_inobject_property_offset() / kPointerSize; |
| if (!is_inobject()) { |
| result += InObjectPropertyBits::decode(bit_field_); |
| } |
| return result; |
| } |
| |
| int GetKeyedLookupCacheIndex() const; |
| |
| int GetFieldAccessStubKey() const { |
| return bit_field_ & |
| (IsInObjectBits::kMask | IsDoubleBits::kMask | IndexBits::kMask); |
| } |
| |
| private: |
| FieldIndex(bool is_inobject, int local_index, bool is_double, |
| int inobject_properties, int first_inobject_property_offset, |
| bool is_hidden = false) { |
| DCHECK((first_inobject_property_offset & (kPointerSize - 1)) == 0); |
| bit_field_ = IsInObjectBits::encode(is_inobject) | |
| IsDoubleBits::encode(is_double) | |
| FirstInobjectPropertyOffsetBits::encode(first_inobject_property_offset) | |
| IsHiddenField::encode(is_hidden) | |
| IndexBits::encode(local_index) | |
| InObjectPropertyBits::encode(inobject_properties); |
| } |
| |
| explicit FieldIndex(int bit_field) : bit_field_(bit_field) {} |
| |
| int first_inobject_property_offset() const { |
| DCHECK(!IsHiddenField::decode(bit_field_)); |
| return FirstInobjectPropertyOffsetBits::decode(bit_field_); |
| } |
| |
| static const int kIndexBitsSize = kDescriptorIndexBitCount + 1; |
| |
| // Index from beginning of object. |
| class IndexBits: public BitField<int, 0, kIndexBitsSize> {}; |
| class IsInObjectBits: public BitField<bool, IndexBits::kNext, 1> {}; |
| class IsDoubleBits: public BitField<bool, IsInObjectBits::kNext, 1> {}; |
| // Number of inobject properties. |
| class InObjectPropertyBits |
| : public BitField<int, IsDoubleBits::kNext, kDescriptorIndexBitCount> {}; |
| // Offset of first inobject property from beginning of object. |
| class FirstInobjectPropertyOffsetBits |
| : public BitField<int, InObjectPropertyBits::kNext, 7> {}; |
| class IsHiddenField |
| : public BitField<bool, FirstInobjectPropertyOffsetBits::kNext, 1> {}; |
| STATIC_ASSERT(IsHiddenField::kNext <= 32); |
| |
| int bit_field_; |
| }; |
| |
| } } // namespace v8::internal |
| |
| #endif |