XACQUIRE
__asm __volatile(XACQUIRE MPLOCKED "cmpxchgl %2,%1; " \
__asm __volatile(XACQUIRE MPLOCKED "cmpxchgq %2,%1; " \
__asm __volatile(XACQUIRE MPLOCKED "xaddl %0,%1; " \
__asm __volatile(XACQUIRE MPLOCKED "xaddq %0,%1; " \
__asm __volatile(XACQUIRE MPLOCKED OP \