Lahey/GNU Fortran

-[n]prefetch

Generate prefetch optimizations

Compile only. Default: -nprefetch

GFortran option: -fprefetch-loop-arrays

If supported by the target machine, generate instructions to prefetch memory to improve the performance of loops that access large arrays.

Specifying -prefetch may cause  faster or slower execution, as the results are highly dependent on the structure of loops within the source code.