Predicting indirect branches via data compression
John Kalamatianos, David R Kaeli · 1998
Branch prediction is a key mechanism used to achieve high performance on multiple issue, deeply pipelined processors. By predicting the branch outcome at the instruction fetch stage of the pipeline, superscalar processors are better able to exploit Instruction Level Parallelism (ILP) by providing a larger window of instructions. However, when a branch is mispredicted, instructions from the mispredicted path must be discarded. Therefore, branch prediction accuracy is critical to achieve high performance. Existing branch prediction schemes can accurately predict the direction of conditional branches, but they have difficulty predicting the correct targets of indirect branches. Indirect branches occur frequently in Object-Oriented Languages (OOL), as well as in Dynamically-Linked Libraries (DLLs), two programming environments rapidly increasing in popularity. In addition, certain language constructs such as multi-way control transfers (e.g., switches), and architectural features such as 6...