公开(公告)号：US07822954B2

公开(公告)日：2010-10-26

申请号：US12034112

申请日：2008-02-20

申请人： John W. Ward, III ,  Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

发明人： John W. Ward, III ,  Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

IPC分类号： G06F9/38 ,  G06F9/42

CPC分类号： G06F9/383 ,  G06F9/3802 ,  G06F9/3861

摘要： A branch prediction algorithm is used to generate a prediction of whether or not a branch will be taken. One or more instructions are fetched such that, for each of the fetched instructions, the prediction initiates a fetch of an instruction at a predicted target of the branch. A test is performed to ascertain whether or not the prediction was generated late relative to the fetched instructions, so that if the branch is later detected as mispredicted, that detection can be correlated to the late prediction. When the prediction is generated late relative to the fetched instructions, a latent prediction is selected by utilizing a fetching initiated by the latent prediction such that a new fetch is not started.

摘要翻译： 分支预测算法用于生成是否采用分支的预测。 取出一个或多个指令，使得对于每个获取的指令，预测启动在分支的预测目标处的指令的获取。 执行测试以确定预测是否相对于获取的指令生成较晚，使得如果稍后检测到该分支被误预测，则该检测可以与后期预测相关。 当预测相对于所获取的指令生成较晚时，通过利用由潜在预测发起的提取来选择潜在预测，使得新的获取不被开始。

公开(公告)号：US20090210684A1

公开(公告)日：2009-08-20

申请号：US12034112

申请日：2008-02-20

申请人： John W. Ward, III ,  Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

发明人： John W. Ward, III ,  Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

IPC分类号： G06F9/30

CPC分类号： G06F9/383 ,  G06F9/3802 ,  G06F9/3861

摘要： A branch prediction algorithm is used to generate a prediction of whether or not a branch will be taken. One or more instructions are fetched such that, for each of the fetched instructions, the prediction initiates a fetch of an instruction at a predicted target of the branch. A test is performed to ascertain whether or not the prediction was generated late relative to the fetched instructions, so that if the branch is later detected as mispredicted, that detection can be correlated to the late prediction. When the prediction is generated late relative to the fetched instructions, a latent prediction is selected by utilizing a fetching initiated by the latent prediction such that a new fetch is not started.

摘要翻译： 分支预测算法用于生成是否采用分支的预测。 取出一个或多个指令，使得对于每个获取的指令，预测启动在分支的预测目标处的指令的获取。 执行测试以确定预测是否相对于获取的指令生成较晚，使得如果稍后检测到该分支被误预测，则该检测可以与后期预测相关。 当预测相对于所获取的指令生成较晚时，通过利用由潜在预测发起的提取来选择潜在预测，使得新的获取不被开始。

公开(公告)号：US20090217017A1

公开(公告)日：2009-08-27

申请号：US12037137

申请日：2008-02-26

申请人： Khary J. Alexander ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III ,  John W. Ward, III

发明人： Khary J. Alexander ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III ,  John W. Ward, III

IPC分类号： G06F9/30

CPC分类号： G06F9/381 ,  G06F9/3806 ,  G06F9/3814

摘要： A method, system, and computer program product for minimizing branch prediction latency in a pipelined computer processing environment are provided. The method includes detecting a branch loop utilizing branch instruction addresses and corresponding target addresses stored in a branch target buffer (BTB). The method also includes fetching the branch loop into a pre-decode instruction buffer and qualifying the branch loop for loop lockdown. The method further includes locking an instruction stream that forms the branch loop in the pre-decode instruction buffer and processing qualified branch loop instructions from the buffer and powering down instruction fetching and branch prediction logic (BPL) associated with the BTB.

摘要翻译： 提供了一种用于在流水线计算机处理环境中最小化分支预测延迟的方法，系统和计算机程序产品。 该方法包括利用转移指令地址和存储在分支目标缓冲器（BTB）中的对应目标地址来检测分支回路。 该方法还包括将分支循环读取到预解码指令缓冲器中，并对分支循环进行限定循环锁定。 该方法还包括将形成分支循环的指令流锁定在预解码指令缓冲器中，并且处理来自缓冲器的限定分支循环指令并且断电与BTB相关联的指令获取和分支预测逻辑（BPL）。

公开(公告)号：US07882338B2

公开(公告)日：2011-02-01

申请号：US12034066

申请日：2008-02-20

申请人： Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito, III ,  Robert J. Sonnelitter, III ,  Charles F. Webb

发明人： Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito, III ,  Robert J. Sonnelitter, III ,  Charles F. Webb

IPC分类号： G06F9/32

CPC分类号： G06F9/30054 ,  G06F9/3804 ,  G06F9/3806 ,  G06F9/3844

摘要： A method, system and computer program product for performing an implicit predicted return from a predicted subroutine are provided. The system includes a branch history table/branch target buffer (BHT/BTB) to hold branch information, including a target address of a predicted subroutine and a branch type. The system also includes instruction buffers, and instruction fetch controls to perform a method including fetching a branch instruction at a branch address and a return-point instruction. The method also includes receiving the target address and the branch type, and fetching a fixed number of instructions in response to the branch type. The method further includes referencing the return-point instruction within the instruction buffers such that the return-point instruction is available upon completing the fetching of the fixed number of instructions absent a re-fetch of the return-point instruction.

摘要翻译： 提供了一种用于从预测子程序执行隐含预测返回的方法，系统和计算机程序产品。 该系统包括用于保持分支信息的分支历史表/分支目标缓冲器（BHT / BTB），包括预测子程序的目标地址和分支类型。 该系统还包括指令缓冲器和指令获取控制，以执行包括在分支地址和返回点指令处获取分支指令的方法。 该方法还包括接收目标地址和分支类型，以及响应于分支类型取出固定数目的指令。 该方法还包括引用指令缓冲器内的返回点指令，使得在没有重新获取返回点指令的情况下完成取出固定数目的指令后，返回点指令是可用的。

公开(公告)号：US20090210661A1

公开(公告)日：2009-08-20

申请号：US12034066

申请日：2008-02-20

申请人： Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III ,  Charles F. Webb

发明人： Khary J. Alexander ,  James J. Bonanno ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III ,  Charles F. Webb

IPC分类号： G06F9/312

CPC分类号： G06F9/30054 ,  G06F9/3804 ,  G06F9/3806 ,  G06F9/3844

摘要： A method, system and computer program product for performing an implicit predicted return from a predicted subroutine are provided. The system includes a branch history table/branch target buffer (BHT/BTB) to hold branch information, including a target address of a predicted subroutine and a branch type. The system also includes instruction buffers, and instruction fetch controls to perform a method including fetching a branch instruction at a branch address and a return-point instruction. The method also includes receiving the target address and the branch type, and fetching a fixed number of instructions in response to the branch type. The method further includes referencing the return-point instruction within the instruction buffers such that the return-point instruction is available upon completing the fetching of the fixed number of instructions absent a re-fetch of the return-point instruction.

摘要翻译： 提供了一种用于从预测子程序执行隐含预测返回的方法，系统和计算机程序产品。 该系统包括用于保持分支信息的分支历史表/分支目标缓冲器（BHT / BTB），包括预测子程序的目标地址和分支类型。 该系统还包括指令缓冲器和指令获取控制，以执行包括在分支地址和返回点指令处获取分支指令的方法。 该方法还包括接收目标地址和分支类型，以及响应于分支类型取出固定数目的指令。 该方法还包括引用指令缓冲器内的返回点指令，使得在没有重新获取返回点指令的情况下完成取出固定数目的指令后，返回点指令是可用的。

公开(公告)号：US09021240B2

公开(公告)日：2015-04-28

申请号：US12035911

申请日：2008-02-22

申请人： Khary J. Alexander ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

发明人： Khary J. Alexander ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

IPC分类号： G06F9/38 ,  G06F9/32

CPC分类号： G06F9/3861 ,  G06F9/322 ,  G06F9/3804 ,  G06F9/3806 ,  G06F9/3838 ,  G06F9/3842 ,  G06F9/3867

摘要： A system and method for controlling restarting of instruction fetching using speculative address computations in a processor are provided. The system includes a predicted target queue to hold branch prediction logic (BPL) generated target address values. The system also includes target selection logic including a recycle queue. The target selection logic selects a saved branch target value between a previously speculatively calculated branch target value from the recycle queue and an address value from the predicted target queue. The system further includes a compare block to identify a wrong target in response to a mismatch between the saved branch target value and a current calculated branch target, where instruction fetching is restarted in response to the wrong target.

摘要翻译： 提供了一种用于使用处理器中的推测地址计算来控制重新启动指令取出的系统和方法。 该系统包括预测的目标队列以保持分支预测逻辑（BPL）生成的目标地址值。 系统还包括目标选择逻辑，包括循环队列。 目标选择逻辑从先前推测计算出的来自再循环队列的分支目标值和来自预测目标队列的地址值之间选择保存的分支目标值。 系统还包括比较块，用于响应于所保存的分支目标值与当前计算的分支目标之间的不匹配来识别错误的目标，其中响应于错误的目标重新启动指令获取。

公开(公告)号：US20090217015A1

公开(公告)日：2009-08-27

申请号：US12035911

申请日：2008-02-22

申请人： Khary J. Alexander ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

发明人： Khary J. Alexander ,  Brian R. Prasky ,  Anthony Saporito ,  Robert J. Sonnelitter, III

IPC分类号： G06F9/30

CPC分类号： G06F9/3861 ,  G06F9/322 ,  G06F9/3804 ,  G06F9/3806 ,  G06F9/3838 ,  G06F9/3842 ,  G06F9/3867

摘要： A system and method for controlling restarting of instruction fetching using speculative address computations in a processor are provided. The system includes a predicted target queue to hold branch prediction logic (BPL) generated target address values. The system also includes target selection logic including a recycle queue. The target selection logic selects a saved branch target value between a previously speculatively calculated branch target value from the recycle queue and an address value from the predicted target queue. The system further includes a compare block to identify a wrong target in response to a mismatch between the saved branch target value and a current calculated branch target, where instruction fetching is restarted in response to the wrong target.

摘要翻译： 提供了一种用于使用处理器中的推测地址计算来控制重新启动指令取出的系统和方法。 该系统包括预测的目标队列以保持分支预测逻辑（BPL）生成的目标地址值。 系统还包括目标选择逻辑，包括循环队列。 目标选择逻辑从先前推测计算出的来自再循环队列的分支目标值和来自预测目标队列的地址值之间选择保存的分支目标值。 系统还包括比较块，用于响应于所保存的分支目标值与当前计算的分支目标之间的不匹配来识别错误的目标，其中响应于错误的目标重新启动指令获取。

公开(公告)号：US08443176B2

公开(公告)日：2013-05-14

申请号：US12037042

申请日：2008-02-25

申请人： Robert J. Sonnelitter, III ,  James J. Bonanno ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito

发明人： Robert J. Sonnelitter, III ,  James J. Bonanno ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito

IPC分类号： G06F9/00

CPC分类号： G06F9/3804 ,  G06F9/30058 ,  G06F12/0862 ,  G06F2212/1021

摘要： A method for reducing cache memory pollution including fetching an instruction stream from a cache line, preventing a fetching for the instruction stream from a sequential cache line, searching for a next predicted taken branch instruction, determining whether a length of the instruction stream extends beyond a length of the cache line based on the next predicted taken branch instruction, continuing preventing the fetching for the instruction stream from the sequential cache line if the length of the instruction stream does not extend beyond the length of the cache line, and allowing the fetching for the instruction stream from the sequential cache line if the length of the instruction stream extends beyond the length of the cache line, whereby the fetching from the sequential cache line and a resulting polluting of a cache memory that stores the instruction stream is minimized. A corresponding system and computer program product.

摘要翻译： 一种用于减少高速缓冲存储器污染的方法，包括从高速缓存线取出指令流，阻止从顺序高速缓存线取出指令流，搜索下一个预测的分支指令，确定指令流的长度是否延伸超过 基于下一个预测的分支指令的高速缓存线的长度，如果指令流的长度不超过高速缓存线的长度，则继续阻止从顺序高速缓存行获取指令流，并且允许取出 如果指令流的长度延伸超过高速缓存行的长度，则来自顺序高速缓存行的指令流被最小化，从而从顺序高速缓存行的取出和存储指令流的高速缓冲存储器的产生的污染最小化。 相应的系统和计算机程序产品。

公开(公告)号：US20090217003A1

公开(公告)日：2009-08-27

申请号：US12037042

申请日：2008-02-25

申请人： Robert J. Sonnelitter, III ,  James J. Bonanno ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito

发明人： Robert J. Sonnelitter, III ,  James J. Bonanno ,  David S. Hutton ,  Brian R. Prasky ,  Anthony Saporito

IPC分类号： G06F9/30

CPC分类号： G06F9/3804 ,  G06F9/30058 ,  G06F12/0862 ,  G06F2212/1021

摘要： A method for reducing cache memory pollution including fetching an instruction stream from a cache line, preventing a fetching for the instruction stream from a sequential cache line, searching for a next predicted taken branch instruction, determining whether a length of the instruction stream extends beyond a length of the cache line based on the next predicted taken branch instruction, continuing preventing the fetching for the instruction stream from the sequential cache line if the length of the instruction stream does not extend beyond the length of the cache line, and allowing the fetching for the instruction stream from the sequential cache line if the length of the instruction stream extends beyond the length of the cache line, whereby the fetching from the sequential cache line and a resulting polluting of a cache memory that stores the instruction stream is minimized. A corresponding system and computer program product.

摘要翻译： 一种用于减少高速缓冲存储器污染的方法，包括从高速缓存线取出指令流，阻止从顺序高速缓存线取出指令流，搜索下一个预测的分支指令，确定指令流的长度是否延伸超过 基于下一个预测的分支指令的高速缓存线的长度，如果指令流的长度不超过高速缓存线的长度，则继续阻止从顺序高速缓存行获取指令流，并且允许取出 如果指令流的长度延伸超过高速缓存行的长度，则来自顺序高速缓存行的指令流被最小化，从而从顺序高速缓存行的取出和存储指令流的高速缓冲存储器的产生的污染最小化。 相应的系统和计算机程序产品。

公开(公告)号：US20090216952A1

公开(公告)日：2009-08-27

申请号：US12037829

申请日：2008-02-26

申请人： Robert J. Sonnelitter, III ,  Gregory W. Alexander ,  Brian R. Prasky

发明人： Robert J. Sonnelitter, III ,  Gregory W. Alexander ,  Brian R. Prasky

IPC分类号： G06F12/08

CPC分类号： G06F12/121

摘要： A method for managing cache memory including receiving an instruction fetch for an instruction stream in a cache memory, wherein the instruction fetch includes an instruction fetch reference tag for the instruction stream and the instruction stream is at least partially included within a cache line, comparing the instruction fetch reference tag to a previous instruction fetch reference tag, maintaining a cache replacement status of the cache line if the instruction fetch reference tag is the same as the previous instruction fetch reference tag, and upgrading the cache replacement status of the cache line if the instruction fetch reference tag is different from the previous instruction fetch reference tag, whereby the cache replacement status of the cache line is upgraded if the instruction stream is independently fetched more than once. A corresponding system and computer program product.

摘要翻译： 一种用于管理高速缓存存储器的方法，包括接收高速缓冲存储器中的指令流的指令取出，其中指令获取包括用于指令流的指令获取参考标签，并且指令流至少部分地包括在高速缓存行内， 指令获取参考标签到先前的指令获取参考标签，如果指令获取引用标签与先前的指令获取引用标签相同，则保持高速缓存行的高速缓存替换状态，并且如果高速缓存行的高速缓存替换状态 指令获取参考标签与先前的指令获取参考标签不同，从而如果指令流被独立地提取多次，则缓存行的高速缓存替换状态被升级。 相应的系统和计算机程序产品。