中文摘要：

在VLSI物理设计中，O-Tree是一种高效简洁的布局表示法，但其对应的模块放置算法因为基于水平和垂直约束图及其操作而复杂且费时（算法时间复杂度为O（n^2））．文中算法利用模块放置过程巾右上端边沿形成的角轮廓结构的阶梯下降性，结合O-Tree编码结点间的父子关系，快速确定模块的放置位置．在模块的放置过程中不需要约束图，只保持一个角轮廓，使模块的放置更加简单高效，算法时间复杂度降低为O（nlogn）．在MCNC Benchmark上的实验结果验证了该算法的有效性．

英文摘要：

In VLSI physical design, O-Tree is regarded as one of the most effective and efficient placement/floorplan representations. However, its induced packing algorithms are complicated and time-consuming, because of their horizontal and vertical constraint graphs and involved operations. Based on stairway up-down characteristic of corner-contour, the proposed algorithm in this paper utilizes parent-son relationship embodied in a given O-Tree code to facilitate module placement. There is only one corner-contour being kept during packing, no constraint graphs and related operations are required. The time complexity of the proposed algorithm can be reduced to O（n log n）. Experimental results on MCNC Benchmarks verified the effectiveness of the our algorithm.