((a)) Under such instructions as the Secretary concerned may prescribe, a sentence of confinement adjudged by a court-martial or other military tribunal, whether or not the sentence includes discharge or dismissal, and whether or not the discharge or dismissal has been executed, may be carried into execution by confinement in any place of confinement under the control of any of the armed forces or in any penal or correctional institution under the control of the United States, or which the United States may be allowed to use. Persons so confined in a penal or correctional institution not under the control of one of the armed forces are subject to the same discipline and treatment as persons confined or committed by the courts of the United States or of the State, District of Columbia, or place in which the institution is situated.

((b)) The omission of the words “hard labor” from any sentence of a court-martial adjudging confinement does not deprive the authority executing that sentence of the power to require hard labor as a part of the punishment.