公开(公告)号：US20230342156A1

公开(公告)日：2023-10-26

申请号：US18138591

申请日：2023-04-24

Applicant: Intel Corporation

Inventor： Jason W. Brandt ,  Deepak K. Gupta ,  Rodrigo Branco ,  Joseph Nuzman ,  Robert S. Chappell ,  Sergiu Ghetie ,  Wojciech Powiertowski ,  Jared W. Stark, IV ,  Ariel Sabba ,  Scott J. Cape ,  Hisham Shafi ,  Lihu Rappoport ,  Yair Berger ,  Scott P. Bobholz ,  Gilad Holzstein ,  Sagar V. Dalvi ,  Yogesh Bijlani

IPC: G06F9/38 ,  G06F9/30

CPC classification number: G06F9/3844 ,  G06F9/30101

Abstract: Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.

公开(公告)号：US20230195469A1

公开(公告)日：2023-06-22

申请号：US17558361

申请日：2021-12-21

Applicant: Intel Corporation

Inventor： Sumeet Bandishte ,  Jayesh Gaur ,  Franck Sala ,  Alexey Yurievich Sivtsov ,  Jared Warner Stark, IV ,  Lihu Rappoport ,  Sreenivas Subramoney

IPC: G06F9/38

CPC classification number: G06F9/3848 ,  G06F9/3867 ,  G06F9/3814

Abstract: Techniques and mechanisms for a processor to determine an execution of instructions based on a prediction of a taken branch. In an embodiment, a first prediction unit generates each of multiple branch predictions in one cycle of successive branch prediction cycles. An indication of the branch predictions is provided to an execution pipeline, which prepares to execute an instruction based on the indication. Where a first one of the branch predictions is determined to be of a low confidence type, said first branch prediction is further indicated to a second prediction unit, which performs a second branch prediction based on the same branch instruction for which the first branch prediction was made. In another embodiment, the second prediction unit signals that a state of the execution pipeline is to be cleared, based on a determination that the first and second branch predictions are inconsistent with each other.

公开(公告)号：US11635965B2

公开(公告)日：2023-04-25

申请号：US16177028

申请日：2018-10-31

Applicant: Intel Corporation

Inventor： Jason W. Brandt ,  Deepak K. Gupta ,  Rodrigo Branco ,  Joseph Nuzman ,  Robert S. Chappell ,  Sergiu D. Ghetie ,  Wojciech Powiertowski ,  Jared W. Stark, IV ,  Ariel Sabba ,  Scott J. Cape ,  Hisham Shafi ,  Lihu Rappoport ,  Yair Berger ,  Scott P. Bobholz ,  Gilad Holzstein ,  Sagar V. Dalvi ,  Yogesh Bijlani

IPC: G06F9/38 ,  G06F9/30

Abstract: Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.

公开(公告)号：US20210109839A1

公开(公告)日：2021-04-15

申请号：US17128291

申请日：2020-12-21

Applicant: Intel Corporation

Inventor： Adarsh Chauhan ,  Jayesh Gaur ,  Franck Sala ,  Lihu Rappoport ,  Zeev Sperber ,  Adi Yoaz ,  Sreenivas Subramoney

IPC: G06F11/34 ,  G06F11/30 ,  G06F9/24 ,  G06F9/38 ,  G06F15/78

Abstract: A processor comprises a microarchitectural feature and dynamic tuning unit (DTU) circuitry. The processor executes a program for first and second execution windows with the microarchitectural feature disabled and enabled, respectively. The DTU circuitry automatically determines whether the processor achieved worse performance in the second execution window. In response to determining that the processor achieved worse performance in the second execution window, the DTU circuitry updates a usefulness state for a selected address of the program to denote worse performance. In response to multiple consecutive determinations that the processor achieved worse performance with the microarchitectural feature enabled, the DTU circuitry automatically updates the usefulness state to denote a confirmed bad state. In response to the usefulness state denoting the confirmed bad state, the DTU circuitry automatically disables the microarchitectural feature for the selected address for execution windows after the second execution window. Other embodiments are described and claimed.

公开(公告)号：US10949208B2

公开(公告)日：2021-03-16

申请号：US16221871

申请日：2018-12-17

Applicant: Intel Corporation

Inventor： Saurabh Gupta ,  Niranjan Soundararajan ,  Ragavendra Natarajan ,  Jared Warner Stark, IV ,  Lihu Rappoport ,  Sreenivas Subramoney

IPC: G06F9/38 ,  G06F9/30

Abstract: In one embodiment, an apparatus includes a context-based prediction circuit to receive an instruction address for a branch instruction and a plurality of predictions associated with the branch instruction from a global prediction circuit. The context-based prediction circuit may include: a table having a plurality of entries each to store a context prediction value for a corresponding branch instruction; and a control circuit to generate, for the branch instruction, an index value to index into the table, the control circuit to generate the index value based at least in part on at least some of the plurality of predictions associated with the branch instruction and the instruction address for the branch instruction. Other embodiments are described and claimed.

公开(公告)号：US20190243684A1

公开(公告)日：2019-08-08

申请号：US15890984

申请日：2018-02-07

Applicant: Intel Corporation

Inventor： Pooja Roy ,  Jayesh Gaur ,  Sreenivas Subramoney ,  Zeev Sperber ,  Alexandr Titov ,  Lihu Rappoport ,  Stanislav Shwartsman ,  Hong Wang ,  Adi Yoaz ,  Ronak Singhal ,  Robert S. Chappell

IPC: G06F9/48 ,  G06F9/38

Abstract: A processor including an execution unit, an instruction scheduler circuit to identify a first instruction of an instruction stream, identify a second instruction on which execution of the first instruction depends, and assign a first dispatch priority value to the first instruction and the second instruction, and a dispatch circuit to dispatch, based on the first dispatch priority value, the first instruction and the second instruction to an instruction execution circuit.

公开(公告)号：US20190171515A1

公开(公告)日：2019-06-06

申请号：US15831195

申请日：2017-12-04

Applicant: Intel Corporation

Inventor： Zeev Sperber ,  Stanislav Shwartsman ,  Jared W. Stark, IV ,  Lihu Rappoport ,  Igor Yanover ,  George Leifman

IPC: G06F11/07 ,  G06F12/02 ,  G06F9/38 ,  G06F9/30

CPC classification number: G06F11/0793 ,  G06F9/30043 ,  G06F9/30058 ,  G06F9/3802 ,  G06F9/3855 ,  G06F11/0721 ,  G06F12/0215 ,  G06F12/0253 ,  G06F2212/654 ,  G06F2212/702

Abstract: A method for handling load faults in an out-of-order processor is described. The method includes detecting, by a memory ordering buffer of the out-of-order processor, a load fault corresponding to a load instruction that was executed out-of-order by the out-of-order processor; determining, by the memory ordering buffer, whether instant reclamation is available for resolving the load fault of the load instruction; and performing, in response to determining that instant reclamation is available for resolving the load fault of the load instruction, instant reclamation to re-fetch the load instruction for execution prior to attempting to retire the load instruction.

公开(公告)号：US12236243B2

公开(公告)日：2025-02-25

申请号：US18138591

申请日：2023-04-24

Applicant: Intel Corporation

Inventor： Jason W. Brandt ,  Deepak K. Gupta ,  Rodrigo Branco ,  Joseph Nuzman ,  Robert S. Chappell ,  Sergiu Ghetie ,  Wojciech Powiertowski ,  Jared W. Stark, IV ,  Ariel Sabba ,  Scott J. Cape ,  Hisham Shafi ,  Lihu Rappoport ,  Yair Berger ,  Scott P. Bobholz ,  Gilad Holzstein ,  Sagar V. Dalvi ,  Yogesh Bijlani

IPC: G06F9/38 ,  G06F9/30

Abstract: Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.

公开(公告)号：US12130740B2

公开(公告)日：2024-10-29

申请号：US17712632

申请日：2022-04-04

Applicant: Intel Corporation

Inventor： Jason W. Brandt ,  Robert S. Chappell ,  Jesus Corbal ,  Edward T. Grochowski ,  Stephen H. Gunther ,  Buford M. Guy ,  Thomas R. Huff ,  Christopher J. Hughes ,  Elmoustapha Ould-Ahmed-Vall ,  Ronak Singhal ,  Seyed Yahya Sotoudeh ,  Bret L. Toll ,  Lihu Rappoport ,  David B. Papworth ,  James D. Allen

IPC: G06F12/0831 ,  G06F9/30 ,  G06F9/38 ,  G06F12/1009 ,  G06F12/1027

CPC classification number: G06F12/0831 ,  G06F9/30043 ,  G06F9/384 ,  G06F12/1009 ,  G06F12/1027 ,  G06F2212/1016 ,  G06F2212/621 ,  G06F2212/68

Abstract: Embodiments of an invention a processor architecture are disclosed. In an embodiment, a processor includes a decoder, an execution unit, a coherent cache, and an interconnect. The decoder is to decode an instruction to zero a cache line. The execution unit is to issue a write command to initiate a cache line sized write of zeros. The coherent cache is to receive the write command, to determine whether there is a hit in the coherent cache and whether a cache coherency protocol state of the hit cache line is a modified state or an exclusive state, to configure a cache line to indicate all zeros, and to issue the write command toward the interconnect. The interconnect is to, responsive to receipt of the write command, issue a snoop to each of a plurality of other coherent caches for which it must be determined if there is a hit.

公开(公告)号：US10719355B2

公开(公告)日：2020-07-21

申请号：US15890984

申请日：2018-02-07

Applicant: Intel Corporation

Inventor： Pooja Roy ,  Jayesh Gaur ,  Sreenivas Subramoney ,  Zeev Sperber ,  Alexandr Titov ,  Lihu Rappoport ,  Stanislav Shwartsman ,  Hong Wang ,  Adi Yoaz ,  Ronak Singhal ,  Robert S. Chappell

IPC: G06F9/48 ,  G06F9/38

Abstract: A processor including an execution unit, an instruction scheduler circuit to identify a first instruction of an instruction stream, identify a second instruction on which execution of the first instruction depends, and assign a first dispatch priority value to the first instruction and the second instruction, and a dispatch circuit to dispatch, based on the first dispatch priority value, the first instruction and the second instruction to an instruction execution circuit.