what's this syntax ?

["Michael Gong" <gonwg@xxxxxxxxxxx>]

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