what's this syntax ?

[Michael Gong]

Hi,

Can anyone tell me what the "..." syntax is called in following function 
definition ?

***************************************************************************
struct physid_mask {
        unsigned long mask [(((256)+32-1/32)];
};
typedef struct physid_mask physid_mask_t;
static inline __attribute__((always_inline)) physid_mask_t 
ioapic_phys_id_map(physid_mask_t phys_id_map)
{

        return (
            {
                physid_mask_t __physid_mask = {
                        {
                                [0 ... (((256)+32 -1)/32)-1] = 0UL 
<--- Is it designated initializer ???
                        }
                };

                 __physid_mask.mask[0] = 0x0F;
                __physid_mask;
            }
        );
}
***************************************************************************

Thanks.

Mike