In one embodiment, a processor is configured to execute a window swap instruction. The processor comprises a register file (that comprises a plurality of registers) and first and second execution units coupled to the register file. A first pipeline associated with the first execution unit has a first number of pipeline stages, and a second pipeline associated with the second execution unit has a second number of pipeline stages. The first execution unit is configured to change the current register window from the first register window to the second register window in the register file in response to the instruction. The second execution unit is configured to perform an operation defined by the instruction and write the result to the register file. The second number of pipeline stages exceeds the first number, whereby the second register window is established in the register file prior to writing the result.