 |
|
|
|
|
|
 Title: |
US6189088:
Forwarding stored dara fetched for out-of-order load/read operation to over-taken operation read-accessing same memory location
[ Derwent Title ]
|
| Country: |
US United States of America
|
| |
| Inventor: |
Gschwind, Michael K.; Danbury, CT
|
| Assignee: |
International Business Machines Corporation, Armonk, NY
other patents from INTERNATIONAL BUSINESS MACHINES CORPORATION (280070) (approx. 44,393)
News, Profiles, Stocks and More about this company
|
| Published / Filed: |
2001-02-13
/ 1999-02-03
|
| Application Number: |
US1999000243721
|
| IPC Code: |
Advanced:
G06F 9/318;
G06F 9/38;
G06F 9/45;
Core:
more...
IPC-7:
G06F 9/312;
|
| ECLA Code: |
G06F9/318; G06F9/38D4; G06F9/38E2; G06F9/45E5;
|
| U.S. Class: |
Current:
712/216;
712/023;
712/225;
712/E09.035;
712/E09.048;
712/E09.05;
Original:
712/216;
712/023;
712/225;
|
| Field of Search: |
712/023,216,225
|
| Priority Number: |
| 1999-02-03 |
US1999000243721 |
|
| Abstract: |
The present invention is directed to method and apparatus for reordering load operations in a computer processing system. In one aspect of the invention, a method for scheduling instructions for execution in a computer processing system implementing out-of-order execution, includes the steps of: selecting and moving a next instruction from its current position in a sequence of instructions to an earlier position; determining whether the selected instruction may reference a memory location for read-access; determining whether non-selected instructions, which may ambiguously reference the memory location for read-access, were previously moved over the selected instruction, when the selected instruction may reference the memory location for read-access; establishing a bypass sequence to be performed during an execution of the selected instruction and which passes data previously read-accessed by the non-selected instructions to the selected instruction, when the non-selected instructions were previously moved over the selected instruction and addresses of memory locations from which the non-selected instructions have read-accessed the data are the same as an address of the memory location from which the selected instruction is to read-access data; determining whether the selected instruction was previously moved over the non-selected instructions, when the selected instruction may reference the memory location for read-access; and adding a mechanism for storing a record of the selected instruction for future reference by the non-selected instructions.
|
| Attorney, Agent or Firm: |
F. Chau & Associates, LLP ;
|
| Primary / Asst. Examiners: |
Kim, Kenneth S.;
|
| Maintenance Status: |
E1 Expired Check current status
|
| INPADOC Legal Status: |
Show legal status actions
Family Legal Status Report
|
| Family: |
Show 5 known family members
|
First Claim:
Show all 37 claims |
What is claimed is:
1. A method for scheduling instructions for execution in a computer processing system implementing out-of-order execution, the method comprising the steps of:
- selecting and moving a next instruction from its current position in a sequence of instructions to an earlier position;
- determining whether the selected instruction may reference a memory location for read-access;
- determining whether non-selected instructions, which may ambiguously reference the memory location for read-access, were previously moved over the selected instruction, when the selected instruction may reference the memory location for read-access;
- establishing a bypass sequence to be performed during an execution of the selected instruction and which passes data previously read-accessed by the non-selected instructions to the selected instruction, when the non-selected instructions were previously moved over the selected instruction and addresses of memory locations from which the non-selected instructions have read-accessed the data are the same as an address of the memory location from which the selected instruction is to read-access data;
- determining whether the selected instruction was previously moved over the non-selected instructions, when the selected instruction may reference the memory location for read-access; and
- adding a mechanism for storing a record of the selected instruction for future reference by the non-selected instructions.
|
| Background / Summary: |
Show background / summary
|
| Drawing Descriptions: |
Show drawing descriptions
|
| Description: |
Show description
|
| Forward References: |
Show 11 U.S. patent(s) that reference this one
|
