We address the problem of floorplanning, a crucial step of VLSI design, and propose a novel approach named Quasi-Newton-based FloorplannER (QinFer) for the challenging fixed-outline floorplanning problem. QinFer is an effective two-phase method. The first phase recursively bipartitions the original circuit to a set of subcircuits until each leaf subcircuit contains only one module. By placing each module onto the suboutline of the leaf subcircuit, a distributed floorplan is obtained. The recursive bipartition enables the strongly connected modules to be placed closely so that the obtained floorplan has a good quality of wirelength. By bipartitioning the circuit into leaf subcircuits with only one module and using terminal propagation technology during the whole bipartitioning process, the capabilities of bipartition tool and terminal propagation technology in improving quality of wirelength are fully utilized. The second phase contributes a potential energy function to evaluate the overlap among the modules as well as the protruding portion of modules beyond the outline, and a Quasi-Newton method is employed to reduce the potential energy for the legalization of the distributed floorplan. The Quasi-Newton legalization method is a general method that can be used to calculate a floorplan without constructing any geometric representations for the modules. Moreover, the robustness of QinFer is further improved by incorporating a refined distribution algorithm to establish feasibility for the case of illegal floorplan. Extensive experimental results on public benchmarks show that, in comparison to the well-known approaches DeFer and F-FM, QinFer can generate $7.3\%$ and $2.1\%$ better half-perimeter wirelengths, respectively.

我们解决了布局规划的问题，这是VLSI设计的关键步骤，并针对具有挑战性的固定轮廓布局规划问题，提出了一种新方法，称为基于拟牛顿的FloorplannER（QinFer）。QinFer是一种有效的两阶段方法。第一阶段将原始电路递归地分成一组子电路，直到每个叶子子电路仅包含一个模块。通过将每个模块放置在分支子电路的子轮廓上，可以获得分布式平面图。递归划分可将紧密连接的模块紧密放置，从而使获得的平面图具有良好的线长质量。通过仅用一个模块将电路分为叶子子电路，并在整个二分过程中使用终端传播技术，充分利用了双向分割工具和终端传播技术在提高线长质量方面的能力。第二阶段提供势能函数，以评估模块之间的重叠以及模块超出轮廓的突出部分，并采用拟牛顿法来减少势能，以使分布式平面图合法化。拟牛顿合法化方法是一种通用方法，可用于计算布局图，而无需为模块构造任何几何表示。此外，QinFer的鲁棒性通过结合改进的分配算法来确定非法平面图的可行性而得到进一步提高。公开基准测试的大量实验结果表明，$7.3％$ 和 $2.1％$ 更好的半周线长。