National Sun Yat-Sen University
The potential performance of superscalar processors can be exploited only when processor is fed with sufficient instruction bandwidth. The front-end units, the Instruction Stream Buffer (ISB) and the fetcher, are the key elements for achieving this goal. Current ISBs could not support instruction streaming beyond a basic block. In x86 processors, the split-line instruction problem worsens this situation. In this paper, the authors proposed a basic blocks reassembling ISB. By cooperating with the proposed Line-Weighted Branch Target Buffer (LWBTB), the proposed ISB can predict upcoming branch information and reassemble current cache line together with the other cache line containing instructions for the next basic block.