Patents Examined by George Pappas
  • Patent number: 4901233
    Abstract: A register management system has more physical registers for general purpose use than are named in the architectural system. A renaming system identifies particular physical registers to perform as architected addressable or general purpose registers. An array control list (ACL) is provided to monitor the assignment and status of the physical registers. A decode register assignment list (DRAL) is provided to monitor the status of all of the architected registers and the correspondence to physical registers. A back-up register assignment list (BRAL) is used to preserve old status information while out of sequence and conditional branch instructions are executed. The physical registers may retain mutliple copies of individual addressable registers representing the contents at different stages of execution. The addressable register status may be restored if instruction execution is out of sequence or on a conditional branch causing a problem requiring restoration.
    Type: Grant
    Filed: July 20, 1987
    Date of Patent: February 13, 1990
    Assignee: International Business Machines Corporation
    Inventor: John S. Liptay