METHOD AND APPARATUS FOR FORWARDING LITERAL GENERATED DATA TO DEPENDENT INSTRUCTIONS MORE EFFICIENTLY USING A CONSTANT CACHE

摘要

A processor to a store constant value (immediate or literal) in a cache upon decoding a move immediate instruction in which the immediate is to be moved (copied or written) to an architected register. The constant value is stored in an entry in the cache. Each entry in the cache includes a field to indicate whether its stored constant value is valid, and a field to associate the entry with an architected register. Once a constant value is stored in the cache, it is immediately available for forwarding to a processor pipeline where a decoded instruction may need the constant value as an operand.

主权项

1. An apparatus comprising:
a register; a first pipeline; a cache; and a controller to store a value in an entry in the cache in response to the first pipeline decoding an instruction, wherein the instruction writes the value to the register upon completing execution, and wherein the value is determined or available when the first pipeline decodes the instruction; the controller to set a tag field in the entry to tag the entry with the register, and to set a flag field in the entry to indicate the entry is valid.