x64 port of r42717.

runtime/vm/assembler_x64.h

 // Copyright (c) 2013, 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_ASSEMBLER_X64_H_
 #define VM_ASSEMBLER_X64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_x64.h directly; use assembler.h instead.
 #endif
@@ skipping 499 matching lines @@
   void cmpq(const Address& address, const Immediate& imm);
   void cmpq(Register reg0, Register reg1);
   void cmpq(Register reg, const Address& address);
 
   void CompareImmediate(Register reg, const Immediate& imm, Register pp);
   void CompareImmediate(const Address& address, const Immediate& imm,
                         Register pp);
 
   void testl(Register reg1, Register reg2);
   void testl(Register reg, const Immediate& imm);
+  void testb(const Address& address, const Immediate& imm);
 
   void testq(Register reg1, Register reg2);
   void testq(Register reg, const Immediate& imm);
   void TestImmediate(Register dst, const Immediate& imm, Register pp);
 
   void andl(Register dst, Register src);
   void andl(Register dst, const Immediate& imm);
 
   void orl(Register dst, Register src);
   void orl(Register dst, const Immediate& imm);
@@ skipping 219 matching lines @@
   void Jmp(const ExternalLabel* label, Register pp);
   void J(Condition condition, const ExternalLabel* label, Register pp);
   void CallPatchable(const ExternalLabel* label);
   void Call(const ExternalLabel* label, Register pp);
   // Unaware of write barrier (use StoreInto* methods for storing to objects).
   // TODO(koda): Add StackAddress/HeapAddress types to prevent misuse.
   void StoreObject(const Address& dst, const Object& obj, Register pp);
   void PushObject(const Object& object, Register pp);
   void CompareObject(Register reg, const Object& object, Register pp);
 
+  // When storing into a heap object field, knowledge of the previous content
+  // is expressed through these constants.
+  enum FieldContent {
+    kEmptyOrSmiOrNull,  // Empty = garbage/zapped in release/debug mode.
+    kHeapObjectOrSmi,
+    kOnlySmi,
+  };
+
   // Destroys value.
   void StoreIntoObject(Register object,  // Object we are storing into.
                        const Address& dest,  // Where we are storing into.
                        Register value,  // Value we are storing.
                        bool can_value_be_smi = true);
 
   void StoreIntoObjectNoBarrier(Register object,
                                 const Address& dest,
-                                Register value);
+                                Register value,
+                                FieldContent old_content = kHeapObjectOrSmi);
+  void InitializeFieldNoBarrier(Register object,
+                                const Address& dest,
+                                Register value) {
+    return StoreIntoObjectNoBarrier(object, dest, value, kEmptyOrSmiOrNull);
+  }
   void StoreIntoObjectNoBarrier(Register object,
                                 const Address& dest,
                                 const Object& value,
-                                Register pp);
+                                Register pp,
+                                FieldContent old_content = kHeapObjectOrSmi);
+  void InitializeFieldNoBarrier(Register object,
+                                const Address& dest,
+                                const Object& value,
+                                Register pp) {
+    return StoreIntoObjectNoBarrier(object, dest, value, pp, kEmptyOrSmiOrNull);
+  }
 
   // Stores a Smi value into a heap object field that always contains a Smi.
   void StoreIntoSmiField(const Address& dest, Register value);
   void ZeroInitSmiField(const Address& dest);
   // Increments a Smi field. Leaves flags in same state as an 'addq'.
   void IncrementSmiField(const Address& dest, int64_t increment);
 
   void DoubleNegate(XmmRegister d);
   void FloatNegate(XmmRegister f);
 
@@ skipping 321 matching lines @@
 
   void EmitGenericShift(bool wide, int rm, Register reg, const Immediate& imm);
   void EmitGenericShift(bool wide, int rm, Register operand, Register shifter);
 
   void StoreIntoObjectFilter(Register object, Register value, Label* no_update);
 
   // Shorter filtering sequence that assumes that value is not a smi.
   void StoreIntoObjectFilterNoSmi(Register object,
                                   Register value,
                                   Label* no_update);
-
-  // Analogous to VerifiedMemory::Verify(address, kWordSize).
-  void VerifyHeapWord(const Address& address);
-  // Analogous to VerifiedMemory::Write.
-  void VerifiedWrite(const Address& dest, Register value);
+#if defined(DEBUG)
+  void VerifyUninitialized(const Address& address);
+  void VerifyObjectOrSmi(const Address& address);
+  void VerifySmi(const Address& address, const char* stop_msg = "Expected Smi");
+#endif  // DEBUG
+  // Like VerifiedMemory::Verify(address, kWordSize) and ::Write, but also,
+  // in DEBUG mode, verifies that 'address' has content of type 'old_content'.
+  void VerifyHeapWord(const Address& address, FieldContent old_content);
+  void VerifiedWrite(const Address& dest,
+                     Register value,
+                     FieldContent old_content);
   // Unaware of write barrier (use StoreInto* methods for storing to objects).
   void MoveImmediate(const Address& dst, const Immediate& imm, Register pp);
 
   void ComputeCounterAddressesForCid(intptr_t cid,
                                      Heap::Space space,
                                      Address* count_address,
                                      Address* size_address);
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
@@ skipping 70 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_