Re: [boost] Solaris versions of sp_counted_base and atomic_countby Michael van der Westhuizen

From: Tomas Puverle (Tomas.Puverle_at_[hidden])
Date: 2006-07-03 09:05:36

> inline long compare_exchange(long* v, const long c, const long n) {
> 
>     long r;
> 
> #ifdef __arch64__
> 
>     // UltraSparc 64-bit variant
> 
>     __asm__ __volatile__("casx [%2], %3, %0         \t\n" \
>                          "                          \t\n"
>                          : "=&r"(r), "=m"(*v)
>                          : "r"(v), "r"(c), "0"(n), "m"(*v)
>                          :);
> #else
> 
>     // Legacy 32-bit variant
> 
>     __asm__ __volatile__("cas [%2], %3, %0          \t\n" \
>                          "                          \t\n"
>                          : "=&r"(r), "=m"(*v)
>                          : "r"(v), "r"(c), "0"(n), "m"(*v)
>                          :);

Here's my version:

inline uint32_t compareAndSwap(uint32_t * dest_, uint32_t compare_, uint32_t 
swap_)
{
        __asm__ __volatile__("cas %0, %1, %2 \n\t"
                                : "+m" (*dest_), "+r" (compare_)
                                : "r" (swap_)
                                : );
        return compare_;
}

inline uint64_t compareAndSwap(uint64_t * dest_, uint64_t compare_, uint64_t 
swap_)
{
        __asm__ __volatile__("casx %0, %1, %2 \n\t"
                                : "+m" (*dest_), "+r" (compare_)
                                : "r" (swap_)
                                : );
        return compare_;
}

I also have these intrinsics for the Sunpro compiler.  The only problem is 
that with Sunpro, these have to come in a separate .il file, which has to be 
included on the compile line at the same time as the .cpp being compiled.  

Tom