This invention provides a dual usage cache reload buffer (CRB) to hold both
demand loads as well as prefetch loads. A new form of a data cache block touch
(DCBT) instruction specifies which level of the cache hierarchy to prefetch data
into. A first asynchronous form of a DCBT instruction is issued to prefetch a stream
of data into a L2 cache. A second synchronous form of a DCBT instruction
is used to prefetch data from the L2 cache to the CRB in the main CPU, which
will bypass the L1 data cache and forward data directly to the register
file. This CRB has a dual usage and is used to hold both normal cache reloads as
well as the aforementioned prefetched cache lines.