Method and system for buffering condition code data in a data processing system having out-of-order and speculative instruction execution

摘要

In response to dispatching a condition register modifying instruction to an execution unit, a condition register rename buffer is associated with such a condition register modifying instruction. The instruction is then executed in the execution unit. Following the execution of the condition register modifying instruction, condition register data is set in the condition register rename buffer to reflect the result of such instruction execution. Additionally, an indicator is set to indicate the condition register data is valid. At the time for completing the condition register modifying instruction, the condition register data is transferred from the condition register rename buffer to the architected condition register, thereby permitting condition register modifying instructions to be dispatched, executed, and finished before the condition register is available to complete each condition register modifying instruction.