Efficient Placement of Compressed Code for Parallel Decompression

Abstract

Code compression is important in embedded systems design since it reduces the code size (memory requirement) and thereby improves overall area, power and performance. Existing researches in this field have explored two directions: efficient compression with slow decompression, or fast decompression at the cost of compression efficiency. This paper combines the advantages of both approaches by introducing a novel bitstream placement method. The contribution of this paper is a novel code placement technique to enable parallel decompression without sacrificing the compression efficiency. The proposed technique splits a single bitstream (instruction binary) fetched from memory into multiple bitstreams, which are then fed into different decoders. As a result, multiple slow-decoders can work simultaneously to produce the effect of high decode bandwidth. Our experimental results demonstrate that our approach can improve decode bandwidth up to four times with minor impact (less than 1%) on compression efficiency.