On accelerating pattern matching for technology mapping

Pattern matching algorithm is simple and fast comparing to other matching algorithms such as Boolean matching. One major drawback of the pattern matching is that there is a case where a cell needs a lot of patterns representing its logic function. That is because patterns are decomposed into 2-AND/NOT patterns to match against decomposed subject graphs. Furthermore, the conventional technology mapper does not pay much attention to relations among patterns. Each pattern is tried to match independently. In this paper, a novel pattern matching algorithm that does not require patterns to be decomposed and couple of speeding up techniques utilizing inter-relations among cells are described. These methods are very effective for large cell libraries with complex cells. Experimental results show that our methods gain matching time up to 40 times faster.