公开(公告)号：CA2297402A1

公开(公告)日：2000-07-29

申请号：CA2297402

申请日：2000-01-28

Applicant: IBM

Inventor： EMMA PHILIP G ,  CHARNEY MARK J ,  PUZAK THOMAS R ,  PRENER DANIEL A

IPC: G06F9/38 ,  G06F12/08 ,  G06F13/16

Abstract: A method and apparatus for storing and utilizing set prediction information regarding which set of a set-associative memory will be accessed for enhancing performance of the set-associative memory and reducing power consumption. The set prediction information is stored in various locations including a branch target buffer, instruction cache and operand history table to decrease latency for accesses to set-associative instruction and data caches.

公开(公告)号：HK1035243A1

公开(公告)日：2001-11-16

申请号：HK01105871

申请日：2001-08-21

Applicant: IBM

Inventor： PUZAK THOMAS R ,  HARTSTEIN ALLAN M ,  CHARNEY MARK ,  PRENER DANIEL A ,  ODEN PETER H

IPC: G06F20060101 ,  G06F9/38 ,  G06F9/42 ,  G06F

Abstract: A mechanism is described that predicts the usefulness of a prefetching instruction during the instruction's decode cycle. Prefetching instructions that are predicted as useful (prefetch useful data) are sent to an execution unit of the processor for execution, while instructions that are predicted as not useful are discarded. The prediction regarding the usefulness of a prefetching instructions is performed utilizing a branch prediction mask contained in the branch history mechanism. This mask is compared to information contained in the prefetching instruction that records the branch path between the prefetching instruction and actual use of the data. Both instructions and data can be prefetched using this mechanism.