The disclosure relates to technology for pre-fetching data. An apparatus comprises a processor core, pre-fetch logic, and a memory hierarchy. The pre-fetch logic is configured to generate cache pre-fetch requests for a program instruction identified by a program counter. The pre-fetch logic is configured to track one or more statistics with respect to the cache pre-fetch requests. The pre-fetch logic is configured to link the one or more statistics with the program counter. The pre-fetch logic is configured to determine a degree of the cache pre-fetch requests for the program instruction based on the one or more statistics. The memory hierarchy comprises main memory and a hierarchy of caches. The memory hierarchy further comprises a memory controller configured to pre-fetch memory blocks identified in the cache pre-fetch requests from a current level in the memory hierarchy into a higher level of the memory hierarchy.

The disclosure relates to technology for pre-fetching data. An apparatus comprises a processor core, pre-fetch logic, and a memory hierarchy. The pre-fetch logic is configured to generate cache pre-fetch requests for a program instruction identified by a program counter. The pre-fetch logic is configured to track one or more statistics with respect to the cache pre-fetch requests. The pre-fetch logic is configured to link the one or more statistics with the program counter. The pre-fetch logic is configured to determine a degree of the cache pre-fetch requests for the program instruction based on the one or more statistics. The memory hierarchy comprises main memory and a hierarchy of caches. The memory hierarchy further comprises a memory controller configured to pre-fetch memory blocks identified in the cache pre-fetch requests from a current level in the memory hierarchy into a higher level of the memory hierarchy.

A memory device with non-volatile memory and persistent predictive prefetching provides highspeed storage to a computer system. The memory device uses a non-volatile memory to store data and a volatile memory to cache the data from the non-volatile memory. The computer system sends access requests to obtain data in the non-volatile memory. A prediction engine in the memory device receives the access requests. The prediction engine compute access histories based on the access requests and stores them in an access history table. The prediction engine computes prediction of non-volatile memory addresses that will be accessed in the future based on the stored access history table. The prediction engine causes to store the data from the predicted addresses of the non-volatile memory in the volatile memory. The memory device stores the prediction in the non-volatile memory so the past predictions can be used after restarting the computer system.

A data access system including a processor and a storage system including a main memory and a cache module. The cache module includes a FLC controller and a cache. The cache is configured as a FLC to be accessed prior to accessing the main memory. The processor is coupled to levels of cache separate from the FLC. The processor generates, in response to data required by the processor not being in the levels of cache, a physical address corresponding to a physical location in the storage system. The FLC controller generates a virtual address based on the physical address. The virtual address corresponds to a physical location within the FLC or the main memory. The cache module causes, in response to the virtual address not corresponding to the physical location within the FLC, the data required by the processor to be retrieved from the main memory.

A data access system including a processor and a storage system including a main memory and a cache module. The cache module includes a FLC controller and a cache. The cache is configured as a FLC to be accessed prior to accessing the main memory. The processor is coupled to levels of cache separate from the FLC. The processor generates, in response to data required by the processor not being in the levels of cache, a physical address corresponding to a physical location in the storage system. The FLC controller generates a virtual address based on the physical address. The virtual address corresponds to a physical location within the FLC or the main memory. The cache module causes, in response to the virtual address not corresponding to the physical location within the FLC, the data required by the processor to be retrieved from the main memory.

Methods, systems, and devices for memory operations are described. A first set of commands may be received for accessing a memory device. The first set of commands may include non-consecutive logical addresses that correspond to consecutively indexed physical addresses. A determination that the non-consecutive logical addresses correspond to consecutively indexed physical addresses may be determined based on a first mapping stored in a volatile memory. A second mapping may be transferred to the volatile memory based on the determination. The second mapping may include an indication of whether information stored at a set of physical address is valid. A second set of commands including non-consecutive logical addresses may be received for accessing the memory device. Data for the second set of commands that include the non-consecutive logical addresses may be retrieved from the memory device using the second mapping.

Systems and methods for coordinated memory-side cache prefetching and dynamic interleaving configuration modification involve modifying one or both of the prefetch distance or the prefetch degree used by prefetcher modules of one or more memory-side caches by modifying interleaving configuration data following detection of an interleaving reconfiguration trigger condition indicative, for example, of low prefetch accuracy, low prefetch coverage, high prefetch lateness, or a combination of these. In response an interleaving reconfiguration trigger condition, a processor modifies the interleaving configuration data for the processing system based on the prefetch performance characteristics associated with the interleaving reconfiguration trigger condition. In some embodiments, the interleaving configuration data is modified by changing which physical memory address indices are used to determine the bits that define the channel identification number to which that physical memory address is to be mapped.

Systems and methods for coordinated memory-side cache prefetching and dynamic interleaving configuration modification involve modifying one or both of the prefetch distance or the prefetch degree used by prefetcher modules of one or more memory-side caches by modifying interleaving configuration data following detection of an interleaving reconfiguration trigger condition indicative, for example, of low prefetch accuracy, low prefetch coverage, high prefetch lateness, or a combination of these. In response an interleaving reconfiguration trigger condition, a processor modifies the interleaving configuration data for the processing system based on the prefetch performance characteristics associated with the interleaving reconfiguration trigger condition. In some embodiments, the interleaving configuration data is modified by changing which physical memory address indices are used to determine the bits that define the channel identification number to which that physical memory address is to be mapped.

A technique is provided for training a prediction apparatus. The apparatus has an input interface for receiving a sequence of training events indicative of program instructions, and identifier value generation circuitry for performing an identifier value generation function to generate, for a given training event received at the input interface, an identifier value for that given training event. The identifier value generation function is arranged such that the generated identifier value is dependent on at least one register referenced by a program instruction indicated by that given training event. Prediction storage is provided with a plurality of training entries, where each training entry is allocated an identifier value as generated by the identifier value generation function, and is used to maintain training data derived from training events having that allocated identifier value. Matching circuitry is then responsive to the given training event to detect whether the prediction storage has a matching training entry (i.e. an entry whose allocated identifier value matches the identifier value for the given training event). If so, it causes the training data in the matching training entry to be updated in dependence on the given training event.

The invention comprises (i) a compilation method for automatically converting a single-threaded software program into an application-specific supercomputer, and (ii) the supercomputer system structure generated as a result of applying this method. The compilation method comprises: (a) Converting an arbitrary code fragment from the application into customized hardware whose execution is functionally equivalent to the software execution of the code fragment; and (b) Generating interfaces on the hardware and software parts of the application, which (i) Perform a software-to-hardware program state transfer at the entries of the code fragment; (ii) Perform a hardware-to-software program state transfer at the exits of the code fragment; and (iii) Maintain memory coherence between the software and hardware memories. If the resulting hardware design is large, it is divided into partitions such that each partition can fit into a single chip. Then, a single union chip is created which can realize any of the partitions.