MEMORY MOVE SUPPORTING SPECULATIVE ACQUISITION OF SOURCE AND DESTINATION DATA GRANULES INCLUDING COPY-TYPE AND PASTE-TYPE INSTRUCTIONS

In a data processing system implementing a weak memory model, a lower level cache receives, from a processor core, a plurality of copy-type requests and a plurality of paste-type requests that together indicate a memory move to be performed. The lower level cache also receives, from the processor core, a barrier request that requests enforcement of ordering of memory access requests prior to the barrier request with respect to memory access requests after the barrier request. Prior to completion of processing of the barrier request by the lower level cache, the lower level cache speculatively issues a request on the interconnect fabric to obtain a copy of a data granule specified by a memory access request among the pluralities of requests that follows the barrier request in program order.