1. A method for prefetching a data stream into a microprocessor, comprising: decoding a prefetch instruction specifying a data stream, said instruction also specifying an indicator for specifying whether a speculative load instruction hitting in the data stream triggers prefetching of the data stream; decoding a load instruction that specifies an address within the data stream; determining whether the load instruction is speculative; if the load instruction is not speculative, prefetching a portion of the data stream into the microprocessor; and if the load instruction is speculative, selectively prefetching a portion of the data stream into the microprocessor based on whether said indicator specifies that a speculative load instruction hitting in the data stream triggers prefetching of the data stream.