摘要:
An information handling system includes a processor with an issue unit (IU) that may perform instruction dependency tracking for successive instruction issue operations. The IU maintains non-shifting issue queue (NSIQ) and shifting issue queue (SIQ) instructions along with relative instruction to instruction dependency information. A mapper maps queue position data for instructions that dispatch to issue queue locations within the IU. The IU may test an issuing producer instruction against consumer instructions in the IU for queue position (QPOS) and register tag (RTAG) matches. A matching consumer instruction may issue in a successive manner in the case of a queue position match or in a next processor cycle in the case of a register tag match.
摘要:
A computer implemented method, apparatus, and computer usable program code for preventing soft error accumulation. A number of cycles between references to a register are counted. Instructions are injected that reference the register for preventing soft error accumulation in response to a determination that the number of cycles is greater than a threshold.
摘要:
A set of helper thread binaries is created to retrieve data used by a set of main thread binaries. If executing a portion of the set of helper thread binaries results in the retrieval of data needed by the set of main thread binaries, then that retrieved data is utilized by the set of main thread binaries.
摘要:
According to a method of data processing, a memory controller receives a prefetch load request from a processor core of a data processing system. The prefetch load request specifies a requested line of data. In response to receipt of the prefetch load request, the memory controller determines by reference to a stream of demand requests how much data is to be supplied to the processor core in response to the prefetch load request. In response to the memory controller determining to provide less than all of the requested line of data, the memory controller provides less than all of the requested line of data to the processor core.
摘要:
A method within a data processing system by which a processor executes an asynchronous memory move (AMM) store (ST) instruction to complete a corresponding AMM operation in parallel with an ongoing (not yet completed), previously issued barrier operation. The processor receives the AMM ST instruction after executing the barrier operation (or SYNC instruction) and before the completion of the barrier operation or SYNC on the system fabric. The processor continues executing the AMM ST instruction, which performs a move in virtual address space and then triggers the generation of the AMM operation. The AMM operation proceeds while the barrier operation continues, independent of the processor. The processor stops further execution of all other memory access requests, excluding AMM ST instructions that are received after the barrier operation, but before completion of the barrier operation.
摘要:
A technique for performing data prefetching using multi-level indirect data prefetching includes determining a first memory address of a pointer associated with a data prefetch instruction. Content that is included in a first data block (e.g., a first cache line of a memory) at the first memory address is then fetched. A second memory address is then determined based on the content at the first memory address. Content that is included in a second data block (e.g., a second cache line) at the second memory address is then fetched (e.g., from the memory or another memory). A third memory address is then determined based on the content at the second memory address. Finally, a third data block (e.g., a third cache line) that includes another pointer or data at the third memory address is fetched (e.g., from the memory or the another memory).
摘要:
A technique for data prefetching using indirect addressing includes monitoring data pointer values, associated with an array, in an access stream to a memory. The technique determines whether a pattern exists in the data pointer values. A prefetch table is then populated with respective entries that correspond to respective array address/data pointer pairs based on a predicted pattern in the data pointer values. Respective data blocks (e.g., respective cache lines) are then prefetched (e.g., from the memory or another memory) based on the respective entries in the prefetch table.
摘要:
A technique for performing data prefetching using indirect addressing includes determining a first memory address of a pointer associated with a data prefetch instruction. Content, that is included in a first data block (e.g., a first cache line) of a memory, at the first memory address is then fetched. An offset is then added to the content of the memory at the first memory address to provide a first offset memory address. A second memory address is then determined based on the first offset memory address. A second data block (e.g., a second cache line) that includes data at the second memory address is then fetched (e.g., from the memory or another memory). A data prefetch instruction may be indicated by a unique operational code (opcode), a unique extended opcode, or a field (including one or more bits) in an instruction.
摘要:
A system, method, and a computer readable for inserting data into a cache memory based on information in a semi-synchronous memory copy instruction are disclosed. The method comprises determining a start of a semi-synchronous memory copy operation. The semi-synchronous memory copy operation is checked for a given value in at least one cache injection bit. In response to the given value in the cache injection bit, a predefined number of lines of destination data is copied into at least one level of cache memory.
摘要:
A system, method, and computer program product for semi-synchronously copying data from a first portion of memory to a second portion of memory are disclosed. The method comprises receiving, in a processor, a call for a semi-synchronous memory copy operation. The semi-synchronous memory copy operation preserves temporal persistence of validity for a virtual source address corresponding to a source location in a memory and a virtual target address corresponding to a target location in the memory by setting a flag bit. The call includes at least the virtual source address, the virtual target address, and an indicator identifying a number of bytes to be copied. The memory copy operation is placed in a queue for execution by a memory controller. The queue is coupled to the memory controller. At least one subsequent instruction is continued to be executed as the subsequent instruction becomes available from an instruction pipeline.