1. A microprocessor comprising: a processor; a first module to execute a set of instructions in bytecode in the processor; a RISC module to execute a set of instructions as microcode in the processor; and a datapath in the processor shared by both modules, the datapath including a register file shared by both modules, the first module seeing a first portion of the register file as a circular operand stack and a further portion as storage registers, and the RISC module seeing register file as a register file.