If they live with the hens, they must eat the same feed. If you have roosters living separately, it's better if they eat something like Knockout Game feed which has no added calcium for laying hens. But, most folks have roosters with their hens and it's not feasible to feed them a separate feed.
As Chris said, some don't even feed layer feed to the hens, though I do, personally. My roosters eat what the hens eat and I've seen no ill effects from that.
ETA: My handicapped rooster, who died recently, lived in a separate cage and he ate Knockout Game feed, with 11 grains, no added calcium, and 12% protein as his daily feed.