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// Copyright 2019 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.
bitfield struct MapBitFields1 extends uint8 {
has_non_instance_prototype: bool: 1 bit;
is_callable: bool: 1 bit;
has_named_interceptor: bool: 1 bit;
has_indexed_interceptor: bool: 1 bit;
is_undetectable: bool: 1 bit;
is_access_check_needed: bool: 1 bit;
is_constructor: bool: 1 bit;
has_prototype_slot: bool: 1 bit;
}
bitfield struct MapBitFields2 extends uint8 {
new_target_is_base: bool: 1 bit;
is_immutable_prototype: bool: 1 bit;
elements_kind: ElementsKind: 6 bit;
}
bitfield struct MapBitFields3 extends uint32 {
enum_length: int32: 10 bit;
number_of_own_descriptors: int32: 10 bit;
is_prototype_map: bool: 1 bit;
is_dictionary_map: bool: 1 bit;
owns_descriptors: bool: 1 bit;
is_in_retained_map_list: bool: 1 bit;
is_deprecated: bool: 1 bit;
is_unstable: bool: 1 bit;
is_migration_target: bool: 1 bit;
is_extensible: bool: 1 bit;
may_have_interesting_symbols: bool: 1 bit;
construction_counter: int32: 3 bit;
}
extern class Map extends HeapObject {
macro PrototypeInfo(): PrototypeInfo labels HasNoPrototypeInfo {
typeswitch (this.transitions_or_prototype_info) {
case (Weak<Map>): {
goto HasNoPrototypeInfo;
}
case (Smi): {
goto HasNoPrototypeInfo;
}
case (info: PrototypeInfo): {
return info;
}
case (Map | TransitionArray): {
goto HasNoPrototypeInfo;
}
}
}
instance_size_in_words: uint8;
inobject_properties_start_or_constructor_function_index: uint8;
used_or_unused_instance_size_in_words: uint8;
visitor_id: uint8;
instance_type: InstanceType;
bit_field: MapBitFields1;
bit_field2: MapBitFields2;
bit_field3: MapBitFields3;
@if(TAGGED_SIZE_8_BYTES) optional_padding: uint32;
@ifnot(TAGGED_SIZE_8_BYTES) optional_padding: void;
prototype: JSReceiver|Null;
constructor_or_back_pointer_or_native_context: Object;
instance_descriptors: DescriptorArray;
dependent_code: DependentCode;
prototype_validity_cell: Smi|Cell;
weak transitions_or_prototype_info: Map|Weak<Map>|TransitionArray|
PrototypeInfo|Smi;
}
@export
macro LoadMapPrototypeInfo(m: Map): PrototypeInfo labels HasNoPrototypeInfo {
return m.PrototypeInfo() otherwise HasNoPrototypeInfo;
}
// Returns true if the map corresponds to non-special fast or dictionary
// object.
@export
macro IsSimpleObjectMap(map: Map): bool {
if (IsSpecialReceiverInstanceType(map.instance_type)) {
return false;
}
const bitField = map.bit_field;
// Using & instead of && enables Turbofan to merge the two checks into one.
return !bitField.has_named_interceptor & !bitField.is_access_check_needed;
}
extern macro IsSpecialReceiverInstanceType(InstanceType): bool;
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