PROCESSOR AND METHODS FOR IMMEDIATE HANDLING AND FLAG HANDLING

摘要

Described herein are methods and processors for flag renaming in groups to eliminate dependencies of instructions. Decoder and execution units in the processor may be configured to rename flags into groups that allow each group to be treated separately as appropriate. This flag renaming eliminates flag dependencies with respect to instructions. This allows an instruction to write exactly the flags that the instruction wants without having to create merge dependencies. Methods and processors are provided for handling immediate values embedded in instructions. A 16 bit immediate bus and a 4 bit encoding/control bus are added at the interface between decode and execution units. For an 8 or 12 bit immediate, the upper 4 bits of the immediate bus contain the encoding bits. For a 16 bit immediate, the encoding/control bus contains the encoding bits. The encoding/control bus indicates when to look at the top four bits of the immediate bus.