The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 18, 1998
Filed:
May. 24, 1996
Gregg B Lesartre, Fort Collins, CO (US);
Donald Kipp, Fort Collins, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An operand dependency tracking system tracks move-to-space (MTSP) operand dependencies among instructions in a processor that executes instructions out of order. Instructions are forwarded from an instruction fetch mechanism to a reordering mechanism, where the instructions are permitted to execute out of order. After execution of an instruction by an execution unit, instructions are retired by a retire mechanism, which transforms the results of instruction execution to the architecture state. While instructions are executed in the reordering mechanism, the operand dependency tracking system detects an MTSP instruction and a load instruction. The MTSP instruction is destined to modify data in a space register that stores virtual address information. The load instruction is controlled to commence execution after the MTSP instruction commences execution. While executing the load instruction, the tracking system determines whether the load instruction is destined to use the data in the space register. When the load instruction is destined to use the data in the space register, then the tracking system performs the following steps: determines if the MTSP instruction is retired, (2) when the MTSP instruction is not retired, then aborts execution of the load instruction and repeats steps (b) and (d)(1) successively until the MTSP instruction is retired from execution; and (3) when the MTSP instruction is retired, completes execution of the load instruction. Finally, when the load instruction is not destined to use the data in the space register, then the tracking system completes execution of the load instruction regardless of when the MTSP instruction retires from execution.