公开(公告)号：US09823929B2

公开(公告)日：2017-11-21

申请号：US13841576

申请日：2013-03-15

Applicant: QUALCOMM Incorporated

Inventor： Daren Eugene Streett ,  Brian Michael Stempel ,  Thomas Philip Speier ,  Rodney Wayne Smith ,  Michael Scott McIlvaine ,  Kenneth Alan Dockser ,  James Norris Dieffenderfer

IPC: G06F9/30 ,  G06F9/38

CPC classification number: G06F9/30098 ,  G06F9/30189 ,  G06F9/3842 ,  G06F9/3863

Abstract: A processor includes a queue for storing instructions processed within the context of a current value of a register field, where for some embodiments the instruction is undefined or defined, depending upon the register field at time of processing. After a write instruction (an instruction that writes to the register field) executes, the queue is searched for any entries that contain instructions that depend upon the executed write instruction. Each such entry stores the value of the register field at the time the instruction in the entry was processed. If such an entry is found in the queue and its stored value of the register field does not match the value that the write instruction wrote to the register field, then the processor flushes the pipeline and restarts at a state so as to correctly execute the instruction.

公开(公告)号：US09471325B2

公开(公告)日：2016-10-18

申请号：US14091340

申请日：2013-11-27

Applicant: QUALCOMM Incorporated

Inventor： Anil Krishna ,  Sandeep Suresh Navada ,  Niket Kumar Choudhary ,  Michael Scott McIlvaine ,  Thomas Andrew Sartorius ,  Rodney Wayne Smith ,  Kenneth Alan Dockser

IPC: G06F9/38

CPC classification number: G06F9/384 ,  G06F9/3824 ,  G06F9/3842 ,  G06F9/3855 ,  G06F9/3861

Abstract: A method and apparatus for allowing an out-of-order processor to reuse an in-use physical register is disclosed herein. The method and apparatus uses identifiers, such as tokens and/or other identifiers in a rename map table (RMT) and a physical register file (PRF), to indicate whether an instruction result is allowed or disallowed to be written into a physical register.

Abstract translation: 本文公开了一种允许无序处理器重用使用中物理寄存器的方法和装置。 该方法和装置使用诸如重命名映射表（RMT）和物理寄存器文件（PRF）中的令牌和/或其他标识符的标识符来指示是否允许或不允许将指令结果写入物理寄存器。

公开(公告)号：US09146741B2

公开(公告)日：2015-09-29

申请号：US13655622

申请日：2012-10-19

Applicant: QUALCOMM Incorporated

Inventor： Melinda J. Brown ,  Michael William Morrow ,  James Norris Dieffenderfer ,  Brian Michael Stempel ,  Michael Scott McIlvaine

IPC: G06F9/30 ,  G06F9/38

CPC classification number: G06F9/3017 ,  G06F9/30018 ,  G06F9/3838

Abstract: Eliminating redundant masking operations in instruction processing circuits and related processor systems, methods, and computer-readable media are disclosed. In one embodiment, a first instruction in an instruction stream indicating an operation writing a value to a first register is detected by an instruction processing circuit, the value having a value size less than a size of the first register. The circuit also detects a second instruction in the instruction stream indicating a masking operation on the first register. The masking operation is eliminated upon a determination that the masking operation indicates a read operation and a write operation on the first register and has an identity mask size equal to or greater than the value size. In this manner, the elimination of the masking operation avoids potential read-after-write hazards and improves performance of a CPU by removing redundant operations from an execution pipeline.

Abstract translation: 公开了在指令处理电路和相关处理器系统，方法和计算机可读介质中消除冗余掩蔽操作。 在一个实施例中，由指令处理电路检测指示将值写入第一寄存器的操作的指令流中的第一指令，该值具有小于第一寄存器的大小的值。 电路还检测指示流中指示在第一寄存器上的屏蔽操作的第二指令。 在确定掩蔽操作指示对第一寄存器的读取操作和写入操作并且具有等于或大于值大小的身份掩码大小的情况下，屏蔽操作被消除。 以这种方式，消除掩蔽操作可避免潜在的写后危害，并通过从执行流水线中删除冗余操作来提高CPU性能。

公开(公告)号：US20140281429A1

公开(公告)日：2014-09-18

申请号：US13829315

申请日：2013-03-14

Applicant: QUALCOMM INCORPORATED

Inventor： Melinda J. Brown ,  James Norris Dieffenderfer ,  Michael Scott McIlvaine ,  Brian Michael Stempel ,  Daren Eugene Streett

IPC: G06F9/30

CPC classification number: G06F9/30087

Abstract: Embodiments disclosed herein include eliminating redundant synchronization barriers from execution pipelines in instruction processing circuits. Related processor systems, methods, and computer-readable media are also disclosed. By tracking the occurrence of synchronization events, unnecessary software synchronization operations may be identified and eliminated, thus improving performance of a central processing unit (CPU). In one embodiment, a method for eliminating redundant synchronization barriers in an instruction stream is provided. The method comprises determining whether a next instruction comprises a synchronization barrier of a type corresponding to a first synchronization event. The method also comprises eliminating the next instruction from the instruction stream, responsive to determining that the next instruction comprises a synchronization barrier of a type corresponding to the first synchronization event. In this manner, the average number of instructions executed during each CPU clock cycle may be increased by avoiding unnecessary synchronization operations.

Abstract translation: 本文公开的实施例包括从指令处理电路中的执行管线消除冗余同步障碍。 还公开了相关处理器系统，方法和计算机可读介质。 通过跟踪同步事件的发生，可以识别和消除不必要的软件同步操作，从而提高中央处理单元（CPU）的性能。 在一个实施例中，提供了用于消除指令流中的冗余同步障碍的方法。 该方法包括确定下一条指令是否包括与第一同步事件相对应的类型的同步屏障。 响应于确定下一条指令包括与第一同步事件对应的类型的同步屏障，该方法还包括从指令流中消除下一条指令。 以这种方式，可以通过避免不必要的同步操作来增加在每个CPU时钟周期期间执行的平均指令数。

公开(公告)号：US20140149726A1

公开(公告)日：2014-05-29

申请号：US13792335

申请日：2013-03-11

Applicant: QUALCOMM INCORPORATED

Inventor： James Norris Dieffenderfer ,  Michael William Morrow ,  Michael Scott McIlvaine ,  Daren Eugene Streett ,  Vimal K. Reddy ,  Brian Michael Stempel

IPC: G06F9/38

CPC classification number: G06F9/3808 ,  G06F9/30054

Abstract: Establishing a branch target instruction cache (BTIC) entry for subroutine returns to reduce pipeline bubbles, and related systems, methods, and computer-readable media are disclosed. In one embodiment, a method of establishing a BTIC entry includes detecting a subroutine call in an execution pipeline. In response, at least one instruction fetched sequential to the subroutine call is written as a branch target instruction in a BTIC entry for a subroutine return. A next instruction fetch address is calculated, and is written into a next instruction fetch address field in the BTIC entry. In this manner, the BTIC may provide correct branch target instruction and next instruction fetch address data for the subroutine return, even if the subroutine return is encountered for the first time or the subroutine is called from different calling locations.

Abstract translation: 建立用于子程序的分支目标指令缓存（BTIC）条目返回以减少管道气泡，以及相关系统，方法和计算机可读介质。 在一个实施例中，建立BTIC条目的方法包括检测执行流水线中的子程序调用。 作为响应，在子程序返回的BTIC条目中写入与子程序调用顺序取得的至少一个指令作为分支目标指令。 计算下一个指令提取地址，并将其写入BTIC条目中的下一个指令获取地址字段。 以这种方式，即使第一次遇到子程序返回或从不同的呼叫位置调用子程序，BTIC可以为子程序返回提供正确的分支目标指令和下一个指令获取地址数据。

公开(公告)号：US20140149722A1

公开(公告)日：2014-05-29

申请号：US13686229

申请日：2012-11-27

Applicant: QUALCOMM INCORPORATED

Inventor： Melinda J. Brown ,  Michael William Morrow ,  James Norris Dieffenderfer ,  Brian Michael Stempel ,  Michael Scott McIlvaine ,  Rodney Wayne Smith ,  Jeffrey M. Schottmiller ,  Andrew S. Irwin

IPC: G06F9/30

CPC classification number: G06F9/3017 ,  G06F9/30167

Abstract: Fusing immediate value, write-based instructions in instruction processing circuits, and related processor systems, methods, and computer-readable media are disclosed. In one embodiment, a first instruction indicating an operation writing an immediate value to a register is detected by an instruction processing circuit. The circuit also detects at least one subsequent instruction indicating an operation that overwrites at least one first portion of the register while maintaining a value of a second portion of the register. The at least one subsequent instruction is converted (or replaced) with a fused instruction(s), which indicates an operation writing the at least one first portion and the second portion of the register. In this manner, conversion of multiple instructions for generating a constant into the fused instruction(s) removes the potential for a read-after-write hazard and associated consequences caused by dependencies between certain instructions, while reducing a number of clock cycles required to process the instructions.

Abstract translation: 公开了立即值的融合，指令处理电路中的基于写入的指令以及相关的处理器系统，方法和计算机可读介质。 在一个实施例中，指令处理电路检测指示向寄存器写入立即值的操作的第一指令。 电路还检测至少一个后续指令，指示在保持寄存器的第二部分的值的同时重写寄存器的至少一个第一部分的操作。 所述至少一个后续指令被转换（或替代）与一个融合指令，其指示写入寄存器的至少一个第一部分和第二部分的操作。 以这种方式，将用于产生常数的多个指令转换为融合指令消除了读写后危险和由特定指令之间的依赖性引起的相关后果的可能性，同时减少了处理所需的时钟周期数 说明。

公开(公告)号：US20130326195A1

公开(公告)日：2013-12-05

申请号：US13787907

申请日：2013-03-07

Applicant: QUALCOMM INCORPORATED

Inventor： Michael Scott McIlvaine ,  James Norris Dieffenderfer ,  Brian Michael Stempel ,  Leslie Mark DeBruyne ,  Melinda J. Brown

IPC: G06F9/30

CPC classification number: G06F9/30196 ,  G06F9/30145 ,  G06F9/3017 ,  G06F11/1064

Abstract: Preventing execution of parity-error-induced unpredictable instructions, and related processor systems, methods, and computer-readable media are disclosed. In this regard, a method for processing instructions in a central processing unit (CPU) is provided. The method comprises decoding an instruction comprising a plurality of bits, and generating a parity error indicator indicating whether a parity error exists in the plurality of bits prior to execution of the instruction. If the parity error indicator indicates that the parity error exists in the plurality of bits, one or more of the plurality of bits are modified to indicate a no execution operation (NOP), without effecting a roll back of a program counter of the CPU and without re-decoding the instruction. In this manner, the possibility of the parity error causing an inadvertent execution of an unpredictable instruction is reduced.

Abstract translation: 公开了防止奇偶校验错误引起的不可预测指令的执行以及相关的处理器系统，方法和计算机可读介质。 在这方面，提供了一种用于处理中央处理单元（CPU）中的指令的方法。 该方法包括对包含多个比特的指令进行解码，并产生一个奇偶校验错误指示符，该奇偶校验错误指示符指示执行指令之前多个比特中是否存在奇偶校验错误。 如果奇偶校验错误指示符表示多个比特中存在奇偶校验错误，则修改多个比特中的一个或多个，以指示不执行操作（NOP），而不影响CPU的程序计数器的回退，并且 无需重新解码指令。 以这种方式，减少了导致无意中执行不可预测指令的奇偶校验错误的可能性。

公开(公告)号：US20170046266A1

公开(公告)日：2017-02-16

申请号：US15084773

申请日：2016-03-30

Applicant: QUALCOMM Incorporated

Inventor： Michael Scott McIlvaine ,  Gaurav Mehta ,  Robert Douglas Clancy

IPC: G06F12/08

CPC classification number: G06F12/0862 ,  G06F12/0864 ,  G06F12/0891 ,  G06F12/126 ,  G06F12/128 ,  G06F2212/1021 ,  G06F2212/1028 ,  G06F2212/602

Abstract: Described herein are apparatuses, methods, and computer readable media for way mispredict mitigation on a way predicted set-associative cache. A way prediction array may be accessed while searching the cache for data. A predicted way to search for the data may be determined from the way prediction array. If the search for the data in the predicted way results in a miss, a first prediction index associated with a cache line in the predicted way may be determined. The first prediction index may be compared to a second prediction index. The second prediction index may be associated with a search address being used for accessing the cache during execution of an instruction. If there is a match, the predicted way may be selected as a victim way.

Abstract translation: 这里描述了用于在预测的集合关联高速缓存的方式上对错误预测减轻的装置，方法和计算机可读介质。 可以在搜索高速缓存中访问数据的方式预测阵列。 可以从预测阵列的方式确定搜索数据的预测方式。 如果以预测的方式搜索数据导致错过，则可以确定与预测方式的高速缓存行相关联的第一预测索引。 可以将第一预测指数与第二预测指数进行比较。 第二预测索引可以与在执行指令期间用于访问高速缓存的搜索地址相关联。 如果有比赛，预测的方式可能被选为受害者的方式。

公开(公告)号：US09477476B2

公开(公告)日：2016-10-25

申请号：US13686229

申请日：2012-11-27

Applicant: QUALCOMM Incorporated

Inventor： Melinda J. Brown ,  Michael William Morrow ,  James Norris Dieffenderfer ,  Brian Michael Stempel ,  Michael Scott McIlvaine ,  Rodney Wayne Smith ,  Jeffrey M. Schottmiller ,  Andrew S. Irwin

IPC: G06F9/00 ,  G06F9/44 ,  G06F9/30

CPC classification number: G06F9/3017 ,  G06F9/30167

Abstract: Fusing immediate value, write-based instructions in instruction processing circuits, and related processor systems, methods, and computer-readable media are disclosed. In one embodiment, a first instruction indicating an operation writing an immediate value to a register is detected by an instruction processing circuit. The circuit also detects at least one subsequent instruction indicating an operation that overwrites at least one first portion of the register while maintaining a value of a second portion of the register. The at least one subsequent instruction is converted (or replaced) with a fused instruction(s), which indicates an operation writing the at least one first portion and the second portion of the register. In this manner, conversion of multiple instructions for generating a constant into the fused instruction(s) removes the potential for a read-after-write hazard and associated consequences caused by dependencies between certain instructions, while reducing a number of clock cycles required to process the instructions.

Abstract translation: 公开了立即值的融合，指令处理电路中的基于写入的指令以及相关的处理器系统，方法和计算机可读介质。 在一个实施例中，指令处理电路检测指示向寄存器写入立即值的操作的第一指令。 电路还检测至少一个后续指令，指示在保持寄存器的第二部分的值的同时重写寄存器的至少一个第一部分的操作。 所述至少一个后续指令被转换（或替代）与一个融合指令，其指示写入寄存器的至少一个第一部分和第二部分的操作。 以这种方式，将用于产生常数的多个指令转换为融合指令消除了读写后危险和由特定指令之间的依赖性引起的相关后果的可能性，同时减少了处理所需的时钟周期数 说明。

公开(公告)号：US20160055003A1

公开(公告)日：2016-02-25

申请号：US14490905

申请日：2014-09-19

Applicant: QUALCOMM Incorporated

Inventor： Robert Douglas Clancy ,  Michael Scott McIlvaine ,  Spencer Ellis Williams

IPC: G06F9/38 ,  G06F12/08 ,  G06F12/12

CPC classification number: G06F9/3861 ,  G06F9/3806 ,  G06F9/3844 ,  G06F9/3863 ,  G06F9/3867 ,  G06F12/0875 ,  G06F12/122 ,  G06F2212/452

Abstract: Branch prediction using Least-Recently-Used (LRU)-class linked list branch predictors, and related circuits, methods, and computer-readable media are disclosed. In one aspect, a branch predictor circuit comprises branch direction prediction logic and a linked list comprising a plurality of predictor entries, each comprising a link address register. The branch predictor circuit also comprises a LRU indicator indicative of a relative age of each of the predictor entries. The branch predictor circuit is configured to detect a first branch instruction in an instruction stream, and determine whether the first branch instruction is predicted to be taken. Responsive to determining that the first branch instruction is predicted to be taken, the branch predictor circuit allocates a least-recently-used entry of the plurality of predictor entries of the linked list based on the LRU indicator, and stores a sequential address for the first branch instruction in the link address register of the least-recently-used predictor entry.

Abstract translation: 公开了使用最近最少使用（LRU） - 链表分支预测器的分支预测，以及相关电路，方法和计算机可读介质。 一方面，分支预测器电路包括分支方向预测逻辑和包括多个预测器条目的链接列表，每个预测器条目包括链接地址寄存器。 分支预测器电路还包括指示每个预测器条目的相对年龄的LRU指示符。 分支预测电路被配置为检测指令流中的第一分支指令，并且确定是否预测第一分支指令被采用。 响应于确定预测第一分支指令被采取，分支预测器电路基于LRU指示符分配链表的多个预测项中的最近最少使用的条目，并且存储第一分支指令的顺序地址 最近最少使用的预测变量条目的链接地址寄存器中的分支指令。