63   assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  64   return (unsigned int)Atomic::xchg((jint)exchange_value, (volatile jint*)dest);
  65 }
  66 
  67 unsigned Atomic::cmpxchg(unsigned int exchange_value,
  68                          volatile unsigned int* dest, unsigned int compare_value) {
  69   assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  70   return (unsigned int)Atomic::cmpxchg((jint)exchange_value, (volatile jint*)dest,
  71                                        (jint)compare_value);
  72 }
  73 
  74 jlong Atomic::add(jlong    add_value, volatile jlong*    dest) {
  75   jlong old = load(dest);
  76   jlong new_value = old + add_value;
  77   while (old != cmpxchg(new_value, dest, old)) {
  78     old = load(dest);
  79     new_value = old + add_value;
  80   }
  81   return old;
  82 }

  63   assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  64   return (unsigned int)Atomic::xchg((jint)exchange_value, (volatile jint*)dest);
  65 }
  66 
  67 unsigned Atomic::cmpxchg(unsigned int exchange_value,
  68                          volatile unsigned int* dest, unsigned int compare_value) {
  69   assert(sizeof(unsigned int) == sizeof(jint), "more work to do");
  70   return (unsigned int)Atomic::cmpxchg((jint)exchange_value, (volatile jint*)dest,
  71                                        (jint)compare_value);
  72 }
  73 
  74 jlong Atomic::add(jlong    add_value, volatile jlong*    dest) {
  75   jlong old = load(dest);
  76   jlong new_value = old + add_value;
  77   while (old != cmpxchg(new_value, dest, old)) {
  78     old = load(dest);
  79     new_value = old + add_value;
  80   }
  81   return old;
  82 }
  83 
  84 void Atomic::inc(volatile short* dest) {
  85   // Most platforms do not support atomic increment on a 2-byte value. However,
  86   // if the value occupies the most significant 16 bits of an aligned 32-bit
  87   // word, then we can do this with an atomic add of 0x10000 to the 32-bit word.
  88   //
  89   // The least significant parts of this 32-bit word will never be affected, even
  90   // in case of overflow/underflow.
  91   //
  92   // Use the ATOMIC_SHORT_PAIR macro to get the desired alignment.
  93 #ifdef VM_LITTLE_ENDIAN
  94   assert((intx(dest) & 0x03) == 0x02, "wrong alignment");
  95   (void)Atomic::add(0x10000, (volatile int*)(dest-1));
  96 #else
  97   assert((intx(dest) & 0x03) == 0x00, "wrong alignment");
  98   (void)Atomic::add(0x10000, (volatile int*)(dest));
  99 #endif 
 100 }
 101 
 102 void Atomic::dec(volatile short* dest) {
 103 #ifdef VM_LITTLE_ENDIAN
 104   assert((intx(dest) & 0x03) == 0x02, "wrong alignment");
 105   (void)Atomic::add(-0x10000, (volatile int*)(dest-1));
 106 #else
 107   assert((intx(dest) & 0x03) == 0x00, "wrong alignment");
 108   (void)Atomic::add(-0x10000, (volatile int*)(dest));
 109 #endif 
 110 }
 111