A new horizontal and vertical common subexpression elimination method for multiple constant multiplication
Kazunari Kato, Yasuhiro Takahashi, Toshikazu Sekine · 2009
The common subexpression elimination (CSE) techniques address the issue of minimizing the number of adders needed to implement the multiple constant multiplication (MCM) blocks. In this paper, we propose a new CSE method using a combining horizontal and vertical technique. The proposed method searches firstly the frequency of higher order horizontal common subexpression, i.e., 3-5 bits, and then searches vertical. Our simulation results show that our method offers a good tradeoff between the implementation cost and the synthesis run-time in comparison with conventional methods.