1. A method for executing instructions comprising: in response to decoding an instruction that references an operand address, determining whether the operand address references a register among a subset of registers in a primary register file; selectively sourcing data from an extended register of an extended register file using a pointer stored in the referenced register that references the extended register responsive to determining that the operand address references a register among the subset of registers in the primary register file; and executing the instruction using the selectively sourced data.