公开(公告)号：US20130311754A1

公开(公告)日：2013-11-21

申请号：US13676146

申请日：2012-11-14

Applicant: QUALCOMM INCORPORATED

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

IPC: G06F9/38

CPC classification number: G06F9/3867 ,  G06F9/30043 ,  G06F9/30072 ,  G06F9/3017

Abstract: Fusing conditional write instructions having opposite conditions in instruction processing circuits and related processor systems, methods, and computer-readable media are disclosed. In one embodiment, a first conditional write instruction writing a first value to a target register based on evaluating a first condition is detected by an instruction processing circuit. The circuit also detects a second conditional write instruction writing a second value to the target register based on evaluating a second condition that is a logical opposite of the first condition. Either the first condition or the second condition is selected as a fused instruction condition, and corresponding values are selected as if-true and if-false values. A fused instruction is generated for selectively writing the if-true value to the target register if the fused instruction condition evaluates to true, and selectively writing the if-false value to the target register if the fused instruction condition evaluates to false.

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具有相反条件的条件写指令。 在一个实施例中，由指令处理电路检测基于评估第一条件将第一值写入目标寄存器的第一条件写入指令。 该电路还基于评估与第一条件逻辑相反的第二条件，检测向目标寄存器写入第二值的第二条件写入指令。 选择第一个条件或第二个条件作为融合指令条件，并将相应的值选为if-true和if-false值。 如果融合指令条件评估为真，则生成融合指令，以便如果融合指令条件评估为真，则将if-true值有选择地写入目标寄存器，如果融合指令条件评估为false，则选择性地将if-false值写入目标寄存器。

公开(公告)号：US10108419B2

公开(公告)日：2018-10-23

申请号：US14498938

申请日：2014-09-26

Applicant: QUALCOMM Incorporated

Inventor： Brian Michael Stempel ,  James Norris Dieffenderfer ,  Michael Scott McIlvaine ,  Melinda Joyce Brown

IPC: G06F9/40 ,  G06F9/42 ,  G06F9/44 ,  G06F9/30 ,  G06F9/38

Abstract: Systems and methods for dependency-prediction include executing instructions in an instruction pipeline of a processor and detecting a conditionality-imposing control instruction, such as an If-Then (IT) instruction, which imposes dependent behavior on a conditionality block size of one or more dependent instructions. Prior to executing a first instruction, a dependency-prediction is made to determine if the first instruction is a dependent instruction of the conditionality-imposing control instruction, based on the conditionality block size and one or more parameters of the instruction pipeline. The first instruction is executed based on the dependency-prediction. When the first instruction is dependency-mispredicted, an associated dependency-misprediction penalty is mitigated. If the first instruction is a branch instruction, the mitigation involves training a branch prediction tracking mechanism to correctly dependency-predict future occurrences of the first instruction.