Position-based replacement policy for address synonym management in shared caches

A system comprising:

• one or more computer processors configured to:
• receive a request to access a cache entry in a shared cache, the request referencing a synonym for the cache entry, a cache directory of the shared cache comprising, for each cache entry of the shared cache, a first-ranked synonym slot for storing a most recently used synonym for the cache entry and a second-ranked synonym slot for storing a second most recently used synonym for the cache entry;
• and
• based on receiving the request:
• write contents of the first-ranked synonym slot for the cache entry to the second-ranked synonym slot for the cache entry;
• and
• write the synonym referenced in the request to the first-ranked synonym slot for the cache entry.

A computer program product for implementing a least recently used replacement policy for synonyms in a cache directory of a shared cache, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:

• receiving a request to access a cache entry in a shared cache, the request referencing a synonym for the cache entry, a cache directory of the shared cache comprising, for each cache entry of the shared cache, a first-ranked synonym slot for storing a most recently used synonym for the cache entry and a second-ranked synonym slot for storing a second most recently used synonym for the cache entry;
• and
• based on receiving the request:
• writing contents of the first-ranked synonym slot for the cache entry to the second-ranked synonym slot for the cache entry;
• and
• writing the synonym referenced in the request to the first-ranked synonym slot for the cache entry.