src/hotspot/share/runtime/atomic.hpp

*** 633,665 ****
      CI addend = add_value;
      return PlatformAdd<sizeof(P*)>()(addend, dest, order);
    }
  };
  
- // Most platforms do not support atomic add on a 2-byte value. However,
- // if the value occupies the most significant 16 bits of an aligned 32-bit
- // word, then we can do this with an atomic add of (add_value << 16)
- // to the 32-bit word.
- //
- // The least significant parts of this 32-bit word will never be affected, even
- // in case of overflow/underflow.
- //
- // Use the ATOMIC_SHORT_PAIR macro (see macros.hpp) to get the desired alignment.
- template<>
- struct Atomic::AddImpl<short, short> {
-   short operator()(short add_value, short volatile* dest, atomic_memory_order order) const {
- #ifdef VM_LITTLE_ENDIAN
-     assert((intx(dest) & 0x03) == 0x02, "wrong alignment");
-     int new_value = Atomic::add(add_value << 16, (volatile int*)(dest-1), order);
- #else
-     assert((intx(dest) & 0x03) == 0x00, "wrong alignment");
-     int new_value = Atomic::add(add_value << 16, (volatile int*)(dest), order);
- #endif
-     return (short)(new_value >> 16); // preserves sign
-   }
- };
- 
  template<typename Derived>
  template<typename I, typename D>
  inline D Atomic::FetchAndAdd<Derived>::operator()(I add_value, D volatile* dest,
                                                    atomic_memory_order order) const {
    I addend = add_value;
--- 633,642 ----