LICT: Left-uncompressed Instructions Compression Technique to improve the decoding performance of VLIW processors

Compressing program code compiled for VLIW processors to reduce the amount of memory is a necessary means to decrease costs. The main disadvantage of any code compression technique is the system performance penalty because of the extra time required to decode the compressed instructions during run time. In this paper we improve the performance of decoding compressed instructions by using our novel compression technique (LICT: left-uncompressed instruction technique) which can be used in conjunction with any compression algorithm. Furthermore, we adapt a new code compression approach called Burrows-Wheeler (BW) which has been used before in data compression. It significantly reduces the code size compared to state-of-the-art approaches for VLIW processors. Using our LICT in conjunction with the BW algorithm improves the performance explicitly (2.5times) with little impact on the compression ratio (only 3% compression ratio loss).