atomic_add ?

["Linux Newbie" <learner@corewars.org>]

Hi,

Can anybody explain what is going on this function?

static __inline__ void atomic_add(int i, atomic_t *v)
{
     __asm__ __volatile__(
               LOCK "addl %1,%0"
               :"=m" (v->counter)
               :"ir" (i), "m" (v->counter));
}

I understand that the LOCK (0xf0) makes the instruction atomic on systems
with multiple cpus. But besides that what is .. "=m", :"ir" etc?

-Learner


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