Abstract: One embodiment of the present invention provides a system for predicting an address of an instruction following a branch instruction in a computer instruction stream. This system receives a current address specifying an address of a current instruction. It uses this current address (or possibly a preceding address) to generate a first select signal, which is used to select a first predicted address of an instruction following the current instruction in the computer instruction stream. At the same time the system generates a second select signal, which takes more time to generate than the first select signal but achieves a more accurate selection for a predicted address of the instruction following the current instruction. The system assumes that the first predicted address is correct and proceeds with a subsequent instruction fetch operation using the first predicted address. Next, the system compares the first select signal with the second select signal.
Type:
Grant
Filed:
September 16, 1998
Date of Patent:
September 5, 2000
Assignee:
Sun Microsystems, Inc.
Inventors:
Sanjay Patel, Adam R. Talcott, Rajasekhar Cherabuddi