Data prefetching apparatus in a data processing system and method therefor

A data processing system for prefetching data for loading into a cache in response to a parameter-selectable prefetch instruction, comprising:

• detection means for determining if the parameter-selectable instruction has a first programmed condition that causes fetching of redundant data during a prefetch operation;
• and
• execution means, coupled to the detection means, for executing the instruction by generating cache line requests, in response to the parameter-selectable prefetch instruction, that are mutually exclusive in order to avoid fetching redundant data during the same prefetch operation.

In a data processing system, a method for prefetching blocks of data for loading into a cache in response to a parameter-selectable prefetch instruction, comprising:

• determining if the parameter-selectable prefetch instruction has a first programmed condition that causes fetching of at least a portion of a prefetched block of data at least twice during prefetching of the block data;
• and
• executing the parameter-selectable prefetch instruction by generating cache line requests, in response to the parameter-selectable prefetch instruction, that are mutually exclusive in order to avoid fetching the at least a portion of the prefetched block of data at least twice.