Support verified heap pointer writes on x64.

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 632 matching lines @@
   void ffree(intptr_t value);
 
   void fsin();
   void fcos();
 
   // 'size' indicates size in bytes and must be in the range 1..8.
   void nop(int size = 1);
   void int3();
   void hlt();
 
+  // Note: verified_mem mode forces far jumps.
   void j(Condition condition, Label* label, bool near = kFarJump);
   void j(Condition condition, const ExternalLabel* label);
 
   void jmp(Register reg);
+  // Note: verified_mem mode forces far jumps.
   void jmp(Label* label, bool near = kFarJump);
   void jmp(const ExternalLabel* label);
 
   void lock();
   void cmpxchgl(const Address& address, Register reg);
   void lock_cmpxchgl(const Address& address, Register reg) {
     lock();
     cmpxchgl(address, reg);
   }
 
@@ skipping 74 matching lines @@
   // 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);
 
+  // Stores a Smi value into a heap object field that always contains a Smi.
+  void StoreIntoSmiField(const Address& dest, Register value);
+  void ZeroSmiField(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);
 
   void DoubleAbs(XmmRegister reg);
 
   void LockCmpxchgq(const Address& address, Register reg) {
     lock();
     cmpxchgq(address, reg);
   }
 
@@ skipping 308 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);
+
   void ComputeCounterAddressesForCid(intptr_t cid,
                                      Heap::Space space,
                                      Address* count_address,
                                      Address* size_address);
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 
 inline void Assembler::EmitUint8(uint8_t value) {
@@ skipping 67 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_