Negative Radix Patents (Class 708/519)
  • Patent number: 5996056
    Abstract: An intermediate result signal arising from a manipulation of data signals is checked and reduced without using conditional branches, thereby improving instruction processing. Data signals are represented as signed 8-bit binary values in a two's compliment format. This requires that the intermediate result signal be stored in a register that is greater than 8-bits wide to allow for the proper checking of an overflow condition. A processor operating under program control with the program has the following operations. The program determines whether the intermediate result signal is in a positive overflow state or a negative overflow state. A first mask signal is set to have 8 lower bits in an OFF position when the intermediate result signal is inside the range of a signed 8 bit integer. Otherwise, the first mask signal is set to have 8 lower bits in an ON position.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: November 30, 1999
    Assignee: Sun Microsystems, Inc.
    Inventor: Vladimir Y. Volkonsky