Split GuardField into GuardFieldType and GuardFieldLength instructions.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2196 matching lines @@
   }
   // Return the list length that any list stored in this field is guaranteed
   // to have. If length is kUnknownFixedLength the length has not
   // been determined. If length is kNoFixedLength this field has multiple
   // list lengths associated with it and cannot be predicted.
   intptr_t guarded_list_length() const;
   void set_guarded_list_length(intptr_t list_length) const;
   static intptr_t guarded_list_length_offset() {
     return OFFSET_OF(RawField, guarded_list_length_);
   }
+  intptr_t guarded_list_length_in_object_offset() const;
+  void set_guarded_list_length_in_object_offset(intptr_t offset) const;
+  static intptr_t guarded_list_length_in_object_offset_offset() {
+    return OFFSET_OF(RawField, guarded_list_length_in_object_offset_);
+  }
+
   bool needs_length_check() const {
     const bool r = guarded_list_length() >= Field::kUnknownFixedLength;
     ASSERT(!r || is_final());
     return r;
   }
 
+  const char* GuardedPropertiesAsCString() const;
+
   intptr_t UnboxedFieldCid() const {
     ASSERT(IsUnboxedField());
     return guarded_cid();
   }
 
   bool IsUnboxedField() const;
 
   bool IsPotentialUnboxedField() const;
 
   bool is_unboxing_candidate() const {
     return UnboxingCandidateBit::decode(raw_ptr()->kind_bits_);
   }
   void set_is_unboxing_candidate(bool b) const {
     set_kind_bits(UnboxingCandidateBit::update(b, raw_ptr()->kind_bits_));
   }
 
   static bool IsExternalizableCid(intptr_t cid) {
     return (cid == kOneByteStringCid) || (cid == kTwoByteStringCid);
   }
 
   enum {
+    kUnknownLengthOffset = -1,
     kUnknownFixedLength = -1,
     kNoFixedLength = -2,
   };
   // Returns false if any value read from this field is guaranteed to be
   // not null.
   // Internally we is_nullable_ field contains either kNullCid (nullable) or
   // any other value (non-nullable) instead of boolean. This is done to simplify
   // guarding sequence in the generated code.
   bool is_nullable() const {
     return raw_ptr()->is_nullable_ == kNullCid;
   }
   void set_is_nullable(bool val) const {
     raw_ptr()->is_nullable_ = val ? kNullCid : kIllegalCid;
   }
   static intptr_t is_nullable_offset() {
     return OFFSET_OF(RawField, is_nullable_);
   }
 
-  // Update guarded cid and guarded length for this field. May trigger
+  // Record store of the given value into this field. May trigger
   // deoptimization of dependent optimized code.
-  bool UpdateGuardedCidAndLength(const Object& value) const;
+  void RecordStore(const Object& value) const;
+
+  void InitializeGuardedListLengthInObjectOffset() const;
 
   // Return the list of optimized code objects that were optimized under
   // assumptions about guarded class id and nullability of this field.
   // These code objects must be deoptimized when field's properties change.
   // Code objects are held weakly via an indirection through WeakProperty.
   RawArray* dependent_code() const;
   void set_dependent_code(const Array& array) const;
 
   // Add the given code object to the list of dependent ones.
   void RegisterDependentCode(const Code& code) const;
@@ skipping 24 matching lines @@
     kUnboxingCandidateBit
   };
   class ConstBit : public BitField<bool, kConstBit, 1> {};
   class StaticBit : public BitField<bool, kStaticBit, 1> {};
   class FinalBit : public BitField<bool, kFinalBit, 1> {};
   class HasInitializerBit : public BitField<bool, kHasInitializerBit, 1> {};
   class UnboxingCandidateBit : public BitField<bool,
                                                kUnboxingCandidateBit, 1> {
   };
 
-  // Update guarded class id and nullability of the field to reflect assignment
-  // of the value with the given class id to this field. Returns true, if
+  // Update guarded cid and guarded length for this field. Returns true, if
   // deoptimization of dependent code is required.
-  bool UpdateCid(intptr_t cid) const;
-
-  // Update guarded class length of the field to reflect assignment of the
-  // value with the given length. Returns true if deoptimization of dependent
-  // code is required.
-  bool UpdateLength(intptr_t length) const;
+  bool UpdateGuardedCidAndLength(const Object& value) const;
 
   void set_name(const String& value) const;
   void set_is_static(bool is_static) const {
     set_kind_bits(StaticBit::update(is_static, raw_ptr()->kind_bits_));
   }
   void set_is_final(bool is_final) const {
     set_kind_bits(FinalBit::update(is_final, raw_ptr()->kind_bits_));
   }
   void set_is_const(bool value) const {
     set_kind_bits(ConstBit::update(value, raw_ptr()->kind_bits_));
@@ skipping 1824 matching lines @@
   virtual RawInstance* CheckAndCanonicalize(const char** error_str) const;
 
   // Returns true if all fields are OK for canonicalization.
   virtual bool CheckAndCanonicalizeFields(const char** error_str) const;
 
   RawObject* GetField(const Field& field) const {
     return *FieldAddr(field);
   }
 
   void SetField(const Field& field, const Object& value) const {
-    field.UpdateGuardedCidAndLength(value);
+    field.RecordStore(value);
     StorePointer(FieldAddr(field), value.raw());
   }
 
   RawType* GetType() const;
 
   virtual RawTypeArguments* GetTypeArguments() const;
   virtual void SetTypeArguments(const TypeArguments& value) const;
 
   // Check if the type of this instance is a subtype of the given type.
   bool IsInstanceOf(const AbstractType& type,
@@ skipping 2897 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_