公开(公告)号：US11048506B2

公开(公告)日：2021-06-29

申请号：US16450897

申请日：2019-06-24

Applicant: Advanced Micro Devices, Inc.

Inventor： Krishnan V. Ramani ,  Kai Troester ,  Frank C. Galloway ,  David N. Suggs ,  Michael D. Achenbach ,  Betty Ann McDaniel ,  Marius Evers

IPC: G06F9/28 ,  G06F9/30 ,  G06F9/38

Abstract: A system and method for tracking stores and loads to reduce load latency when forming the same memory address by bypassing a load store unit within an execution unit is disclosed. Store-load pairs which have a strong history of store-to-load forwarding are identified. Once identified, the load is memory renamed to the register stored by the store. The memory dependency predictor may also be used to detect loads that are dependent on a store but cannot be renamed. In such a configuration, the dependence is signaled to the load store unit and the load store unit uses the information to issue the load after the identified store has its physical address.

公开(公告)号：US10990393B1

公开(公告)日：2021-04-27

申请号：US16658474

申请日：2019-10-21

Applicant: ADVANCED MICRO DEVICES, INC.

Inventor： John Kalamatianos ,  Krishnan V. Ramani ,  Susumu Mashimo

IPC: G06F9/30 ,  G06F9/38 ,  G06F9/35

Abstract: Address-based filtering for load/store speculation includes maintaining a filtering table including table entries associated with ranges of addresses; in response to receiving an ordering check triggering transaction, querying the filtering table using a target address of the ordering check triggering transaction to determine if an instruction dependent upon the ordering check triggering transaction has previously been generated a physical address; and in response to determining that the filtering table lacks an indication that the instruction dependent upon the ordering check triggering transaction has previously been generated a physical address, bypassing a lookup operation in an ordering violation memory structure to determine whether the instruction dependent upon the ordering check triggering transaction is currently in-flight.

公开(公告)号：US20190391808A1

公开(公告)日：2019-12-26

申请号：US16013069

申请日：2018-06-20

Applicant: Advanced Micro Devices, Inc.

Inventor： Krishnan V. Ramani ,  Chetana N. Keltcher

IPC: G06F9/30

Abstract: A method and apparatus generates control information that indicates whether to change a counter value associated with a particular load instruction. In response to the control information, the method and apparatus causes a hysteresis effect for operating between a speculative mode and a non-speculative mode based on the counter value. The hysteresis effect is in favor of the non-speculative mode. The method and apparatus causes the hysteresis effect by incrementing the counter value associated with the particular load instruction by a first value or decrementing the counter value by a second value. The first value is greater than the second value.