prefetch

Data processing method and apparatus for prefetching

A data processing device includes processing circuitry 20 for executing a first memory access instruction to a first address of a memory device 40 and a second memory access instruction to a second address of the memory device 40, the first address being different from the second address. The data processing device also includes prefetching circuitry 30 for prefetching data from the memory device 40 based on a stride length 70 and instruction analysis circuitry 50 for determining a difference between the first address and the second address. Stride refining circuitry 60 is also provided to refine the stride length based on factors of the stride length and factors of the difference calculated by the instruction analysis circuitry 50.




prefetch

Prefetch optimizer measuring execution time of instruction sequence cycling through each selectable hardware prefetch depth and cycling through disabling each software prefetch instruction of an instruction sequence of interest

A prefetch optimizer tool for an information handling system (IHS) may improve effective memory access time by controlling both hardware prefetch operations and software prefetch operations. The prefetch optimizer tool selectively disables prefetch instructions in an instruction sequence of interest within an application. The tool measures execution times of the instruction sequence of interest when different prefetch instructions are disabled. The tool may hold hardware prefetch depth constant while cycling through disabling different prefetch instructions and taking corresponding execution time measurements. Alternatively, for each disabled prefetch instruction in the instruction sequence of interest, the tool may cycle through different hardware prefetch depths and take corresponding execution time measurements at each hardware prefetch depth. The tool selects a combination of hardware prefetch depth and prefetch instruction disablement that may improve the execution time in comparison with a baseline execution time.