Avoiding Cross-Interrogates in a Streaming Data Optimized L1 Cache

A computer program product comprising a computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a computing device, causes the computing device to:

• receive from a first processor a fetch operation for a cache line to be exclusively held by the first processor, wherein the fetch operation includes a fetch address;
• receive from the first processor an indication of a selected register from a set of registers for which the fetch operation is intended;
• write the fetch address into the selected register;
• responsive to receiving an operation from a second processor requiring cache directory lookup for a lookup address, perform a comparison of the lookup address to the set of registers;
• and
• determine whether the first processor exclusively owns a cache line corresponding to the lookup address based on the comparison.

A cache lookup apparatus, comprising:

• a set of registers;
• a set of comparators, wherein each comparator within the set of comparators corresponds to a register within the set of registers;
• and
• a cache directory,
• wherein the cache lookup apparatus receives from a first processor a fetch operation for a cache line to be exclusively held by the first processor, wherein the fetch operation includes a fetch address;
• wherein the cache lookup apparatus receives from the first processor an indication of a selected register from the set of registers for which the fetch operation is intended;
• wherein the cache lookup apparatus writes the fetch address into the selected register;
• wherein responsive to receiving an operation from a second processor requiring cache directory lookup for a lookup address, the cache lookup apparatus performs a comparison of the lookup address to the set of registers;
• and
• wherein the cache lookup apparatus determines whether the first processor exclusively owns a cache line corresponding to the lookup address based on the comparison and a lookup of the lookup address in the cache directory.