Abstract: Systems, methods, and apparatuses for decomposing a sequential program into multiple threads, executing these threads, and reconstructing the sequential execution of the threads are described. A plurality of data cache units (DCUs) store locally retired instructions of speculatively executed threads. A merging level cache (MLC) merges data from the lines of the DCUs. An inter-core memory coherency module (ICMC) globally retires instructions of the speculatively executed threads in the MLC.

Abstract: Systems, methods, and apparatuses for decomposing a sequential program into multiple threads, executing these threads, and reconstructing the sequential execution of the threads are described. A plurality of data cache units (DCUs) store locally retired instructions of speculatively executed threads. A merging level cache (MLC) merges data from the lines of the DCUs. An inter-core memory coherency module (ICMC) globally retire instructions of the speculatively executed threads in the MLC.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.

Abstract: A computer-readable storage medium, method and system for optimization-level aware branch prediction is described. A gear level is assigned to a set of application instructions that have been optimized. The gear level is also stored in a register of a branch prediction unit of a processor. Branch prediction is then performed by the processor based upon the gear level.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.

Abstract: Methods and apparatus are disclosed for using a register checkpointing mechanism to resolve multithreading mis-speculations. Valid architectural state is recovered and execution is rolled back. Some embodiments include memory to store checkpoint data. Multiple thread units concurrently execute threads. They execute a checkpoint mask instruction to initialize memory to store active checkpoint data including register contents and a checkpoint mask indicating the validity of stored register contents. As register contents change, threads execute checkpoint write instructions to store register contents and update the checkpoint mask. Threads also execute a recovery function instruction to store a pointer to a checkpoint recovery function, and in response to mis-speculation among the threads, branch to the checkpoint recovery function.

Abstract: Disclosed is an apparatus and method to manage instruction cache prefetching from an instruction cache. A processor may comprise: a prefetch engine; a branch prediction engine to predict the outcome of a branch; and dynamic optimizer. The dynamic optimizer may be used to control: identifying common instruction cache misses and inserting a prefetch instruction from the prefetch engine to the instruction cache.

Abstract: An image signal processor is described. The image signal processor includes a block checking circuit. The block checking circuit comprises comparison circuitry to compare a block of luminous pixel values against respective blocks of luminous pixel values that are processed by the image signal processor after the block of luminous pixel values. The block checking circuitry further comprises circuitry to record an entry in a table if one of the blocks of respective luminous pixel values match the block of luminous pixel values. The image signal processor is to store an image signal processing resultant of the block of luminous pixel values and present the stored resultant as a respective resultant for the one of the blocks of respective luminous pixel values if the one of the blocks of respective luminous pixel values matches the block of pixel values.

Abstract: Systems, methods, and apparatuses for decomposing a sequential program into multiple threads, executing these threads, and reconstructing the sequential execution of the threads are described. A plurality of data cache units (DCUs) store locally retired instructions of speculatively executed threads. A merging level cache (MLC) merges data from the lines of the DCUs. An inter-core memory coherency module (ICMC) globally retire instructions of the speculatively executed threads in the MLC.

Abstract: An image signal processor is described. The image signal processor includes a block checking circuit. The block checking circuit comprises comparison circuitry to compare a block of luminous pixel values against respective blocks of luminous pixel values that are processed by the image signal processor after the block of luminous pixel values. The block checking circuitry further comprises circuitry to record an entry in a table if one of the blocks of respective luminous pixel values match the block of luminous pixel values. The image signal processor is to store an image signal processing resultant of the block of luminous pixel values and present the stored resultant as a respective resultant for the one of the blocks of respective luminous pixel values if the one of the blocks of respective luminous pixel values matches the block of pixel values.

Abstract: Techniques for implementing identification and management of unsafe optimizations are disclosed. A method of the disclosure includes receiving, by a managed runtime environment (MRE) executed by a processing device, a notice of misprediction of optimized code, the misprediction occurring during a runtime of the optimized code, determining, by the MRE, whether a local misprediction counter (LMC) associated with a code region of the optimized code causing the misprediction exceeds a local misprediction threshold (LMT) value, and when the LMC exceeds the LMT value, compiling, by the MRE, native code of the optimized code to generate a new version of the optimized code, wherein the code region in the new version of the optimized code is not optimized.

Abstract: Systems, methods, and apparatuses for decomposing a sequential program into multiple threads, executing these threads, and reconstructing the sequential execution of the threads are described. A plurality of data cache units (DCUs) store locally retired instructions of speculatively executed threads. A merging level cache (MLC) merges data from the lines of the DCUs. An inter-core memory coherency module (ICMC) globally retire instructions of the speculatively executed threads in the MLC.

Abstract: An apparatus and method for profiling program code. In particular, an apparatus according to one embodiment comprises a filtering component identifying a first set of instructions for which profiling is desired wherein, in response to detecting that an instruction has been retired, the filtering component determines whether the instruction is within the first set of instructions for which profiling is desired; an event selection component detecting an event in response to the instruction retiring, the event selection component generating event signals in response to a designated event; and a profiling component recording the occurrence or not occurrence of the event within a first storage device responsive to signals from the filtering component and/or the event selection component.

Abstract: A mechanism for generating a path profile is disclosed. A profiling module may insert profiling instructions into instruction blocks. The profiling instructions may generate a path identifier as a processor executes an execution path executes a sequence or path of instruction blocks). A path identifier module may add path identifiers to path identifier data, such as a table, and may track the number of times an execution path associated with the path identifier is executed.

Abstract: Techniques for implementing identification and management of unsafe optimizations are disclosed. A method of the disclosure includes receiving, by a managed runtime environment (MRE) executed by a processing device, a notice of misprediction of optimized code, the misprediction occurring during a runtime of the optimized code, determining, by the MRE, whether a local misprediction counter (LMC) associated with a code region of the optimized code causing the misprediction exceeds a local misprediction threshold (LMT) value, and when the LMC exceeds the LMT value, compiling, by the MRE, native code of the optimized code to generate a new version of the optimized code, wherein the code region in the new version of the optimized code is not optimized.

Abstract: According to one example embodiment of the inventive subject matter, the method and apparatus described herein is used to generate an optimized speculative version of a static piece of code. The portion of code is optimized in the sense that the number of instructions executed will be smaller. However, since the applied optimization is speculative, the optimized version can be incorrect and some mechanism to recover from that situation is required. Thus, the quality of the produced code will be measured by taking into account both the final length of the code as well as the frequency of misspeculation.

Abstract: Techniques and mechanisms for a processor to determine whether a commit action is to be performed. In an embodiment, a processor performs operations to determine whether a commit instruction is for contingent performance of a commit action. In another embodiment, one or more conditions of processor state are evaluated in response to determining that the commit instruction is for contingent performance of the commit action, where the evaluation is performed to determine whether the commit action indicated by the commit instruction is to be performed.

Abstract: A computer-readable storage medium, method and system for optimization-level aware branch prediction is described. A gear level is assigned to a set of application instructions that have been optimized. The gear level is also stored in a register of a branch prediction unit of a processor. Branch prediction is then performed by the processor based upon the gear level.

Abstract: Disclosed is an apparatus and method to manage instruction cache prefetching from an instruction cache. A processor may comprise: a prefetch engine; a branch prediction engine to predict the outcome of a branch; and dynamic optimizer. The dynamic optimizer may be used to control: indentifying common instruction cache misses and inserting a prefetch instruction from the prefetch engine to the instruction cache.

Abstract: A combination of hardware and software collect profile data for asynchronous events, at code region granularity. An exemplary embodiment is directed to collecting metrics for prefetching events, which are asynchronous in nature. Instructions that belong to a code region are identified using one of several alternative techniques, causing a profile bit to be set for the instruction, as a marker. Each line of a data block that is prefetched is similarly marked. Events corresponding to the profile data being collected and resulting from instructions within the code region are then identified. Each time that one of the different types of events is identified, a corresponding counter is incremented. Following execution of the instructions within the code region, the profile data accumulated in the counters are collected, and the counters are reset for use with a new code region.