A processor configured to: receive a plurality of instructions in an instruction stream from an instruction memory to be executed, the plurality of instructions comprising at least one instruction that includes a register operand (OP.S 1 - OP.S X ; OP.O. #.S 1 - OP.O. #.S X ; OP.T.O.#; OP.T.O.E#); process an instruction among the plurality of instructions ; determine if the processed instruction includes an obsolescence encoding identifying at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) associated with at least one register among a plurality of registers in the processor to be obsoleted following a number of instructions in the instruction stream following the processed instruction in the instruction stream, wherein a register that is encoded as being obsolescence means that the data value stored in such register will not be used by subsequent instructions in an instruction stream, and thus does not need to be retained; and in response to determining the processed instruction includes the obsolescence encoding identifying at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) to be obsoleted following the number of instructions in the instruction stream following the processed instruction in the instruction stream, set an obsolescence indicator (346 -346(P), 348 -348(P)) associated with the at least one register associated with the at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) to an obsolescent state indicating the at least one register is obsolete after execution of instructions in the instruction stream following the processed instruction in the instruction stream by the number of instructions. receive a plurality of instructions in an instruction stream from an instruction memory to be executed, the plurality of instructions comprising at least one instruction that includes a register operand (OP.S 1 - OP.S X ; OP.O. #.S 1 - OP.O. #.S X ; OP.T.O.#; OP.T.O.E#); process an instruction among the plurality of instructions ; determine if the processed instruction includes an obsolescence encoding identifying at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) associated with at least one register among a plurality of registers in the processor to be obsoleted following a number of instructions in the instruction stream following the processed instruction in the instruction stream, wherein a register that is encoded as being obsolescence means that the data value stored in such register will not be used by subsequent instructions in an instruction stream, and thus does not need to be retained; and in response to determining the processed instruction includes the obsolescence encoding identifying at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) to be obsoleted following the number of instructions in the instruction stream following the processed instruction in the instruction stream, set an obsolescence indicator (346 -346(P), 348 -348(P)) associated with the at least one register associated with the at least one register operand (OP.S 1 - OP.Sx; OP.O.S 1 - OP.O.Sx; OP.O.#.S 1 - OP.O.#.Sx; OP.T.O.#; OP.T.O.E#) to an obsolescent state indicating the at least one register is obsolete after execution of instructions in the instruction stream following the processed instruction in the instruction stream by the number of instructions. <EOS>