General Purpose Register Extension
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
IBM System/370 architecture defines 16 general purpose registers (GPRs). At present, the IBM processors provide only 16 GPRs in the hardware. When during the course of a program a programmer needs more GPRs, he stores the contents of either some of them or all of them, reuses the GPRs, and restores them later. This is done quite often when changing sub-routines. All this storing and restoring causes added activity in the storage, thus degrading performance.