公开(公告)号：DE3682700D1

公开(公告)日：1992-01-16

申请号：DE3682700

申请日：1986-03-14

Applicant: IBM

Inventor： POMERENE JAMES HERBERT ,  PUZAK THOMAS ROBERTS ,  RECHTSCHAFFEN RUDOLPH NATHAN ,  ROSENFELD PHILIP LEWIS ,  SPARACIO FRANK JOHN

IPC: G06F9/38

Abstract: A branch history table (BHT) is substantially improved by dividing it into two parts: an active area, and a backup area. The active area contains entries for a small number of branches which the processor can encounter in the near future and the backup area contains all other branch entries. Means are provided to bring entries from the backup area into the active area ahead of when the processor will use those entries. When entries are no longer needed they are removed from the active area and put into the backup area if not already there. New entries for the near future are brought in, so that the active area, though small, will almost always contain the branch information needed by the processor. The small size of the active area allows it to be fast and to be optimally located in the processor layout. The backup area can be located outside the critical part of the layout and can therefore be made larger than would be practicable for a standard BHT.

公开(公告)号：DE3583639D1

公开(公告)日：1991-09-05

申请号：DE3583639

申请日：1985-08-13

Applicant: IBM

Inventor： ROSENFELD PHILIP LEWIS ,  SO KIMMING

IPC: G06F12/08

公开(公告)号：DE3380501D1

公开(公告)日：1989-10-05

申请号：DE3380501

申请日：1983-05-02

Applicant: IBM

Inventor： ROSENFELD PHILIP LEWIS

IPC: G06F9/312 ,  G06F9/38 ,  G06F12/08

Abstract: A digital data processing system including an Instruction Unit 10, an Execute Unit 26, and a multilevel Processor Storage System 12 including a cache memory, further includes a Load Control Block Address Unit 20 for implementing a load control block address instruction which permits prefetching of data from main memory into cache simultaneously with execution of a sequence of instructions in a linked list. Information determining the starting address of a next block in the linked list is stored at a location in the current block at a fixed offset from the beginning of the block.