diff --git a/pkg/dart2wasm/lib/translator.dart b/pkg/dart2wasm/lib/translator.dart
index 16301768039..7fcad67ede6 100644
--- a/pkg/dart2wasm/lib/translator.dart
+++ b/pkg/dart2wasm/lib/translator.dart
@@ -190,7 +190,6 @@ class Translator {
     mapFactory = lookupCollection("LinkedHashMap").procedures.firstWhere(
         (p) => p.kind == ProcedureKind.Factory && p.name.text == "_default");
     mapPut = lookupCollection("_CompactLinkedCustomHashMap")
-        .superclass! // _HashBase
         .superclass! // _LinkedHashMapMixin<K, V>
         .procedures
         .firstWhere((p) => p.name.text == "[]=");
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/class_generics_case1.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/class_generics_case1.dart.expect
index 4a919d46121..63b00b03834 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/class_generics_case1.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/class_generics_case1.dart.expect
@@ -15,7 +15,7 @@ class InheritedElement extends self::Element {
     : self::InheritedElement::_dependents = <self::Element, core::Object?>{}, super self::Element::•()
     ;
 [@vm.procedure-attributes.metadata=methodOrSetterCalledDynamically:false,getterCalledDynamically:false,hasThisUses:false,hasTearOffUses:false,methodOrSetterSelectorId:2,getterSelectorId:3]  method setDependencies([@vm.inferred-type.metadata=!] self::Element dependent, [@vm.inferred-type.metadata=dart.core::_Smi?] core::Object? value) → void {
-    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<#lib::Element, dart.core::Object?>] [@vm.direct-call.metadata=dart.collection::__InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.[]=] [@vm.inferred-type.metadata=!? (skip check)] [@vm.direct-call.metadata=#lib::InheritedElement._dependents] [@vm.inferred-type.metadata=dart.collection::_InternalLinkedHashMap<#lib::Element, dart.core::Object?>] this.{self::InheritedElement::_dependents}{core::Map<self::Element, core::Object?>}.{core::Map::[]=}(dependent, value){(self::Element, core::Object?) → void};
+    [@vm.call-site-attributes.metadata=receiverType:dart.core::Map<#lib::Element, dart.core::Object?>] [@vm.direct-call.metadata=dart.collection::__InternalLinkedHashMap&_HashVMBase&MapMixin&_HashBase&_OperatorEqualsAndHashCode&_LinkedHashMapMixin.[]=] [@vm.inferred-type.metadata=!? (skip check)] [@vm.direct-call.metadata=#lib::InheritedElement._dependents] [@vm.inferred-type.metadata=dart.collection::_InternalLinkedHashMap<#lib::Element, dart.core::Object?>] this.{self::InheritedElement::_dependents}{core::Map<self::Element, core::Object?>}.{core::Map::[]=}(dependent, value){(self::Element, core::Object?) → void};
   }
 }
 static method main() → dynamic {
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/const_map.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/const_map.dart.expect
index 6c1795ffe58..88fd00f2d82 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/const_map.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/const_map.dart.expect
@@ -11,7 +11,7 @@ class _Attribute extends core::Object {
     : super core::Object::•()
     ;
   static method fromReader() → self::_Attribute {
-    final self::_AttributeName name = [@vm.direct-call.metadata=dart.collection::_InternalImmutableLinkedHashMap.[]] [@vm.inferred-type.metadata=#lib::_AttributeName? (skip check)] #C8.{core::Map::[]}(#C1){(core::Object?) → self::_AttributeName?}!;
+    final self::_AttributeName name = [@vm.direct-call.metadata=dart.collection::__InternalImmutableLinkedHashMap&_HashVMImmutableBase&MapMixin&_HashBase&_OperatorEqualsAndCanonicalHashCode&_LinkedHashMapMixin&_UnmodifiableMapMixin&_ImmutableLinkedHashMapMixin.[]] [@vm.inferred-type.metadata=#lib::_AttributeName? (skip check)] #C8.{core::Map::[]}(#C1){(core::Object?) → self::_AttributeName?}!;
     return new self::_Attribute::_();
   }
 }
diff --git a/pkg/vm/testcases/transformations/type_flow/transformer/const_set.dart.expect b/pkg/vm/testcases/transformations/type_flow/transformer/const_set.dart.expect
index f345b4be2ea..f8d211cd09c 100644
--- a/pkg/vm/testcases/transformations/type_flow/transformer/const_set.dart.expect
+++ b/pkg/vm/testcases/transformations/type_flow/transformer/const_set.dart.expect
@@ -11,7 +11,7 @@ class _Attribute extends core::Object {
     : super core::Object::•()
     ;
   static method fromReader() → self::_Attribute {
-    final core::bool name = [@vm.direct-call.metadata=dart.collection::_CompactImmutableLinkedHashSet.contains] [@vm.inferred-type.metadata=!? (skip check)] #C3.{core::Set::contains}(#C2){(core::Object?) → core::bool};
+    final core::bool name = [@vm.direct-call.metadata=dart.collection::__CompactImmutableLinkedHashSet&_HashVMImmutableBase&SetMixin&_HashBase&_OperatorEqualsAndCanonicalHashCode&_LinkedHashSetMixin&_UnmodifiableSetMixin&_ImmutableLinkedHashSetMixin.contains] [@vm.inferred-type.metadata=!? (skip check)] #C3.{core::Set::contains}(#C2){(core::Object?) → core::bool};
     return let final self::_AttributeName #t1 = #C8.{core::List::[]}(#C2){(core::int) → self::_AttributeName} in new self::_Attribute::_();
   }
 }
diff --git a/sdk/lib/_internal/vm/lib/compact_hash.dart b/sdk/lib/_internal/vm/lib/compact_hash.dart
index fa4b32db598..f28d18d8d58 100644
--- a/sdk/lib/_internal/vm/lib/compact_hash.dart
+++ b/sdk/lib/_internal/vm/lib/compact_hash.dart
@@ -16,7 +16,29 @@ void _rehashObjects(List objects) {
   }
 }
 
-abstract class _HashFieldBase {
+// Common interface for [_HashFieldBase] and [_HashVMBase].
+abstract class _HashAbstractBase {
+  Uint32List get _index;
+  void set _index(Uint32List value);
+
+  int get _hashMask;
+  void set _hashMask(int value);
+
+  List get _data;
+  void set _data(List value);
+
+  int get _usedData;
+  void set _usedData(int value);
+
+  int get _deletedKeys;
+  void set _deletedKeys(int value);
+}
+
+abstract class _HashAbstractImmutableBase extends _HashAbstractBase {
+  Uint32List? get _indexNullable;
+}
+
+abstract class _HashFieldBase implements _HashAbstractBase {
   // Each occupied entry in _index is a fixed-size integer that encodes a pair:
   //   [ hash pattern for key | index of entry in _data ]
   // The hash pattern is based on hashCode, but is guaranteed to be non-zero.
@@ -43,11 +65,11 @@ abstract class _HashFieldBase {
   // Note: All fields are initialized in a single constructor so that the VM
   // recognizes they cannot hold null values. This makes a big (20%) performance
   // difference on some operations.
-  _HashFieldBase(int dataSize);
+  _HashFieldBase();
 }
 
 // Base class for VM-internal classes; keep in sync with _HashFieldBase.
-abstract class _HashVMBase {
+abstract class _HashVMBase implements _HashAbstractBase {
   @pragma("vm:recognized", "other")
   @pragma("vm:exact-result-type", "dart:typed_data#_Uint32List")
   @pragma("vm:prefer-inline")
@@ -99,8 +121,9 @@ abstract class _HashVMBase {
   external void set _deletedKeys(int value);
 }
 
-// Base class for VM-internal classes; keep in sync with _HashFieldBase.
-abstract class _HashVMImmutableBase extends _HashVMBase {
+// Base class for immutable VM-internal classes.
+abstract class _HashVMImmutableBase extends _HashVMBase
+    implements _HashAbstractImmutableBase {
   // The data is an immutable list rather than a mutable list.
   @pragma("vm:recognized", "other")
   @pragma("vm:exact-result-type", "dart:core#_ImmutableList")
@@ -123,8 +146,7 @@ abstract class _HashVMImmutableBase extends _HashVMBase {
 // This mixin can be applied to _HashFieldBase or _HashVMBase (for
 // normal and VM-internalized classes, respectiveley), which provide the
 // actual fields/accessors that this mixin assumes.
-// TODO(koda): Consider moving field comments to _HashFieldBase.
-abstract class _HashBase implements _HashVMBase {
+mixin _HashBase on _HashAbstractBase {
   // The number of bits used for each component is determined by table size.
   // If initialized, the length of _index is (at least) twice the number of
   // entries in _data, and both are doubled when _data is full. Thus, _index
@@ -208,17 +230,22 @@ abstract class _HashBase implements _HashVMBase {
   }
 }
 
-class _OperatorEqualsAndHashCode {
+abstract class _EqualsAndHashCode {
+  int _hashCode(e);
+  bool _equals(e1, e2);
+}
+
+mixin _OperatorEqualsAndHashCode implements _EqualsAndHashCode {
   int _hashCode(e) => e.hashCode;
   bool _equals(e1, e2) => e1 == e2;
 }
 
-class _IdenticalAndIdentityHashCode {
+mixin _IdenticalAndIdentityHashCode implements _EqualsAndHashCode {
   int _hashCode(e) => identityHashCode(e);
   bool _equals(e1, e2) => identical(e1, e2);
 }
 
-class _OperatorEqualsAndCanonicalHashCode {
+mixin _OperatorEqualsAndCanonicalHashCode implements _EqualsAndHashCode {
   static final int cidSymbol = ClassID.getID(#a);
 
   int _hashCode(e) {
@@ -232,6 +259,14 @@ class _OperatorEqualsAndCanonicalHashCode {
   bool _equals(e1, e2) => e1 == e2;
 }
 
+mixin _CustomEqualsAndHashCode implements _EqualsAndHashCode {
+  dynamic get _hasher;
+  dynamic get _equality;
+
+  int _hashCode(e) => _hasher(e);
+  bool _equals(e1, e2) => _equality(e1, e2);
+}
+
 final _uninitializedIndex = new Uint32List(_HashBase._UNINITIALIZED_INDEX_SIZE);
 // Note: not const. Const arrays are made immutable by having a different class
 // than regular arrays that throws on element assignment. We want the data field
@@ -243,9 +278,9 @@ final _uninitializedData = new List.filled(0, null);
 class _InternalLinkedHashMap<K, V> extends _HashVMBase
     with
         MapMixin<K, V>,
-        _LinkedHashMapMixin<K, V>,
         _HashBase,
-        _OperatorEqualsAndHashCode
+        _OperatorEqualsAndHashCode,
+        _LinkedHashMapMixin<K, V>
     implements LinkedHashMap<K, V> {
   _InternalLinkedHashMap() {
     _index = _uninitializedIndex;
@@ -273,15 +308,19 @@ class _InternalLinkedHashMap<K, V> extends _HashVMBase
 class _InternalImmutableLinkedHashMap<K, V> extends _HashVMImmutableBase
     with
         MapMixin<K, V>,
-        _LinkedHashMapMixin<K, V>,
         _HashBase,
         _OperatorEqualsAndCanonicalHashCode,
-        _UnmodifiableMapMixin<K, V>
+        _LinkedHashMapMixin<K, V>,
+        _UnmodifiableMapMixin<K, V>,
+        _ImmutableLinkedHashMapMixin<K, V>
     implements LinkedHashMap<K, V> {
   factory _InternalImmutableLinkedHashMap._uninstantiable() {
     throw new UnsupportedError("ImmutableMap can only be allocated by the VM");
   }
+}
 
+mixin _ImmutableLinkedHashMapMixin<K, V>
+    on _LinkedHashMapMixin<K, V>, _HashAbstractImmutableBase {
   bool containsKey(Object? key) {
     if (_indexNullable == null) {
       _createIndex();
@@ -345,12 +384,7 @@ int _roundUpToPowerOfTwo(int x) {
   return x + 1;
 }
 
-abstract class _LinkedHashMapMixin<K, V> implements _HashBase {
-  int _hashCode(e);
-  bool _equals(e1, e2);
-  int get _checkSum;
-  bool _isModifiedSince(List oldData, int oldCheckSum);
-
+mixin _LinkedHashMapMixin<K, V> on _HashBase, _EqualsAndHashCode {
   int get length => (_usedData >> 1) - _deletedKeys;
   bool get isEmpty => length == 0;
   bool get isNotEmpty => !isEmpty;
@@ -592,12 +626,10 @@ abstract class _LinkedHashMapMixin<K, V> implements _HashBase {
 class _CompactLinkedIdentityHashMap<K, V> extends _HashFieldBase
     with
         MapMixin<K, V>,
-        _LinkedHashMapMixin<K, V>,
         _HashBase,
-        _IdenticalAndIdentityHashCode
+        _IdenticalAndIdentityHashCode,
+        _LinkedHashMapMixin<K, V>
     implements LinkedHashMap<K, V> {
-  _CompactLinkedIdentityHashMap() : super(_HashBase._INITIAL_INDEX_SIZE);
-
   void addAll(Map<K, V> other) {
     if (other is _CompactLinkedIdentityHashMap) {
       final otherBase = other as _CompactLinkedIdentityHashMap;
@@ -610,15 +642,15 @@ class _CompactLinkedIdentityHashMap<K, V> extends _HashFieldBase
 }
 
 class _CompactLinkedCustomHashMap<K, V> extends _HashFieldBase
-    with MapMixin<K, V>, _LinkedHashMapMixin<K, V>, _HashBase
+    with
+        MapMixin<K, V>,
+        _HashBase,
+        _CustomEqualsAndHashCode,
+        _LinkedHashMapMixin<K, V>
     implements LinkedHashMap<K, V> {
-  final _equality;
-  final _hasher;
-  final _validKey;
-
-  // TODO(koda): Ask gbracha why I cannot have fields _equals/_hashCode.
-  int _hashCode(e) => _hasher(e);
-  bool _equals(e1, e2) => _equality(e1, e2);
+  final dynamic _equality;
+  final dynamic _hasher;
+  final dynamic _validKey;
 
   bool containsKey(Object? o) => _validKey(o) ? super.containsKey(o) : false;
   V? operator [](Object? o) => _validKey(o) ? super[o] : null;
@@ -628,8 +660,7 @@ class _CompactLinkedCustomHashMap<K, V> extends _HashFieldBase
   void operator []=(K key, V value);
 
   _CompactLinkedCustomHashMap(this._equality, this._hasher, validKey)
-      : _validKey = (validKey != null) ? validKey : new _TypeTest<K>().test,
-        super(_HashBase._INITIAL_INDEX_SIZE);
+      : _validKey = (validKey != null) ? validKey : new _TypeTest<K>().test;
 }
 
 // Iterates through _data[_offset + _step], _data[_offset + 2*_step], ...
@@ -739,12 +770,7 @@ class _CompactIteratorImmutable<E> implements Iterator<E> {
   E get current => _current as E;
 }
 
-abstract class _LinkedHashSetMixin<E> implements _HashBase {
-  int _hashCode(e);
-  bool _equals(e1, e2);
-  int get _checkSum;
-  bool _isModifiedSince(List oldData, int oldCheckSum);
-
+mixin _LinkedHashSetMixin<E> on _HashBase, _EqualsAndHashCode {
   bool get isEmpty => length == 0;
   bool get isNotEmpty => !isEmpty;
   int get length => _usedData - _deletedKeys;
@@ -910,14 +936,14 @@ abstract class _LinkedHashSetMixin<E> implements _HashBase {
   }
 }
 
-// Set implementation, analogous to _CompactLinkedHashMap.
+// Set implementation, analogous to _InternalLinkedHashMap.
 @pragma('vm:entry-point')
 class _CompactLinkedHashSet<E> extends _HashVMBase
     with
         SetMixin<E>,
-        _LinkedHashSetMixin<E>,
         _HashBase,
-        _OperatorEqualsAndHashCode
+        _OperatorEqualsAndHashCode,
+        _LinkedHashSetMixin<E>
     implements LinkedHashSet<E> {
   _CompactLinkedHashSet() {
     _index = _uninitializedIndex;
@@ -951,15 +977,19 @@ class _CompactLinkedHashSet<E> extends _HashVMBase
 class _CompactImmutableLinkedHashSet<E> extends _HashVMImmutableBase
     with
         SetMixin<E>,
-        _LinkedHashSetMixin<E>,
         _HashBase,
         _OperatorEqualsAndCanonicalHashCode,
-        _UnmodifiableSetMixin<E>
+        _LinkedHashSetMixin<E>,
+        _UnmodifiableSetMixin<E>,
+        _ImmutableLinkedHashSetMixin<E>
     implements LinkedHashSet<E> {
   factory _CompactImmutableLinkedHashSet._uninstantiable() {
     throw new UnsupportedError("ImmutableSet can only be allocated by the VM");
   }
+}
 
+mixin _ImmutableLinkedHashSetMixin<E>
+    on Set<E>, _LinkedHashSetMixin<E>, _HashAbstractImmutableBase {
   E? lookup(Object? key) {
     if (_indexNullable == null) {
       _createIndex();
@@ -1029,12 +1059,10 @@ class _CompactImmutableLinkedHashSet<E> extends _HashVMImmutableBase
 class _CompactLinkedIdentityHashSet<E> extends _HashFieldBase
     with
         SetMixin<E>,
-        _LinkedHashSetMixin<E>,
         _HashBase,
-        _IdenticalAndIdentityHashCode
+        _IdenticalAndIdentityHashCode,
+        _LinkedHashSetMixin<E>
     implements LinkedHashSet<E> {
-  _CompactLinkedIdentityHashSet() : super(_HashBase._INITIAL_INDEX_SIZE);
-
   Set<E> toSet() => new _CompactLinkedIdentityHashSet<E>()..addAll(this);
 
   static Set<R> _newEmpty<R>() => new _CompactLinkedIdentityHashSet<R>();
@@ -1053,22 +1081,22 @@ class _CompactLinkedIdentityHashSet<E> extends _HashFieldBase
 }
 
 class _CompactLinkedCustomHashSet<E> extends _HashFieldBase
-    with SetMixin<E>, _LinkedHashSetMixin<E>, _HashBase
+    with
+        SetMixin<E>,
+        _HashBase,
+        _CustomEqualsAndHashCode,
+        _LinkedHashSetMixin<E>
     implements LinkedHashSet<E> {
-  final _equality;
-  final _hasher;
-  final _validKey;
-
-  int _hashCode(e) => _hasher(e);
-  bool _equals(e1, e2) => _equality(e1, e2);
+  final dynamic _equality;
+  final dynamic _hasher;
+  final dynamic _validKey;
 
   bool contains(Object? o) => _validKey(o) ? super.contains(o) : false;
   E? lookup(Object? o) => _validKey(o) ? super.lookup(o) : null;
   bool remove(Object? o) => _validKey(o) ? super.remove(o) : false;
 
   _CompactLinkedCustomHashSet(this._equality, this._hasher, validKey)
-      : _validKey = (validKey != null) ? validKey : new _TypeTest<E>().test,
-        super(_HashBase._INITIAL_INDEX_SIZE);
+      : _validKey = (validKey != null) ? validKey : new _TypeTest<E>().test;
 
   Set<R> cast<R>() => Set.castFrom<E, R>(this);
   Set<E> toSet() =>