Apple Inc.
Pipelined allocation for operand cache

Abstract:

Techniques are disclosed relating to controlling an operand cache in a pipelined fashion. An operand cache may cache operands fetched from the register file or generated by previous instructions to improve performance and/or reduce power consumption. In some embodiments, instructions are pipelined and separate tag information is maintained to indicate allocation of an operand cache entry and ownership of the operand cache entry. In some embodiments, this may allow an operand to remain in the operand cache (and potentially be retrieved or modified) during an interval between allocation of the entry for another operand and ownership of the entry by the other operand. This may improve operand cache efficiency by allowing the entry to be used while to retrieving the other operand from the register file, for example.