Thaw shrimp, if frozen. Rinse shrimp and set aside. Cook pasta according to package directions, omitting salt. Add the shrimp the last 3 minutes of cooking. Drain well and place in a large pasta bowl. Add 2 tablespoons of cheese, garlic, olive oil, snipped rosemary, salt and black pepper and toss until well coated. Sprinkle evenly with the 2 tablespoons of remaining cheese and garnish with rosemary sprigs, if desired.