Re: [2.4] gcc3 warns about type-punned pointers ?

[insecure <insecure@mail.od.ua>]

> A collateral question: why is the reason for this function ?
> long long assignments are not atomic in gcc ?

Another question: why do we do _double_ store here?

static inline void __set_64bit (unsigned long long * ptr,
                unsigned int low, unsigned int high)
{
        __asm__ __volatile__ (
                "\n1:\t"
                "movl (%0), %%eax\n\t"
                "movl 4(%0), %%edx\n\t"
                "lock cmpxchg8b (%0)\n\t"
                "jnz 1b"
                : /* no outputs */
                :       "D"(ptr),
                        "b"(low),
                        "c"(high)
                :       "ax","dx","memory");
}

This will execute expensive locked load-compare-store operation twice
almost always (unless previous value was already equal
to the value we are about to store)

AFAIK we can safely drop that loop (jnz instruction)
-- 
vda