Memory select register to simplify operand mapping in subroutines

A processor may include a plurality of data memories storing operands that may be operated upon by the processor. Load/store operations may specify a memory location in one of the data memories to be accessed using a memory select value that selects the data memory and an address within the selected data memory. The memory select values may be mapped from virtual memory select values associated with the load/store operations to physical memory select values that may be used to access the data memory.