Method and apparatus for tracking and update of LRU algorithm using vectors

An LRU tracking mechanism for aliased entries in a plurality of cache ways, the mechanism comprising:

• a vector table having a plurality of vector entries, each of said vector entries having a plurality of vector fields, each of said vector fields associated with one of said aliased entries in one of the plurality of cache ways;
• and
• vector r/w control, coupled to said vector table, for updating ones of said vector fields associated with an entry in said particular one of the plurality of cache ways when said entry in said particular one of the plurality of cache ways is accessed.

A method for tracking the LRU state of entries in a plurality of aliased nodes, the method establishing vectors between the entries in the plurality of aliased nodes, the vectors having a direction towards or away from an entry, the method comprising:

• determining whether an access is being made to a particular entry in a particular one of the plurality of aliased nodes;
• and
• if an access is being made, updating the direction of the vectors associated with the particular entry to reflect an LRU state after the access.