Abstract: Load/store execution order violations in an out-of-order processor are reduced by determining whether a source address of a load instruction is the same as a destination address of a store instruction on which execution the load instruction depends. If they are the same, then execution of the load instruction is delayed until execution of the store instruction. In an system where virtual registers are mapped to a physical register, the physical registers mapped by the store and load instructions are compared. A table has entries corresponding to instructions in an instruction queue. In each table entry corresponding to a store instruction, the store instruction's destination address offset and physical register reference are saved. A load instruction's source address offset and physical reference are compared with each of the table entries corresponding to store instructions to determine whether a dependency exists.

Abstract: A technique controls memory access requests. The technique involves acquiring a first series of requests including a prefetch request for performing a prefetch operation that prefetches a first set of instructions from a memory, and adding a first entry in a request queue in response to the prefetch request. The first entry identifies the prefetch operation. The technique further involves attempting to retrieve a second set of instructions from a cache to create a cache miss, and generating, in response to the cache miss, a second series of requests including a fetch request for performing a fetch operation that fetches the second set of instructions from the memory to satisfy the cache miss. The technique further involves acquiring the second series of requests that includes the fetch request, and adding a second entry in the request queue in response to the fetch request. The second entry identifies the fetch operation.