Managing synonyms in virtual-address caches

An apparatus comprising:

• memory management circuitry configured to retrieve memory pages from a main memory based on virtual addresses translated to physical addresses;
• and
• a memory system including one or more cache modules that store copies of memory blocks from memory pages stored in the main memory;
• wherein the one or more cache modules include a virtual-address cache module that, during an operating period, receives at least a portion of a virtual address and in response indicates a hit if a corresponding virtual address is presently stored in the virtual-address cache module, and indicates a miss if a corresponding virtual address is not presently stored in the virtual-address cache module, wherein the virtual-address cache module includes:
• a first cache structure that stores only memory blocks with virtual addresses that are members of a set of multiple synonym virtual addresses that have all been previously received by the virtual-address cache module during the operating period, where each member of a particular set of multiple synonym virtual addresses translates to a common physical address, and a memory block with the common physical address is stored in at most a single storage location within the first cache structure;
• and
• a second cache structure that stores only memory blocks with virtual addresses that do not have any synonym virtual addresses that have been previously received by the virtual-address cache during the operating period.