Method and apparatus for resteering failing speculation check instructions

摘要

The system is a method and an apparatus for resteering failing speculation check instructions in the pipeline of a processor. A branch offset immediate value and an instruction pointer correspond to each failing instruction. These values are used to determine the correct target recovery address. A relative adder adds the immediate value and the instruction pointer value to arrive at the target recovery address. This is done by flushing the pipeline upon the occurrence of a failing speculation check instruction. The pipeline flush is extended to allow the instruction stream to be resteered. The immediate value and the instruction pointer are then routed through the existing data paths of the pipeline, into the relative adder, which calculates the correct address. A sequencer tracks the progression of these values through the pipeline and causes a branch at the desired time.