//TU190 In this paper, the author presents a detailed placement algorithm that can handle both row-based standard cell placement and placement in presence of fixed macros. This detailed placer works on legalized placement to further improve the solution quality. It consists of a Global Swap technique to swap cells based on their optimal region, a Vertical Swap technique to fix the local errors vertically, a fast Local Re-ordering technique to fix the local order horizontally, and a Single-Segment Clustering technique that can place the cells in a segment optimally when cells not in this segment are fixed. Experiments on two sets of benchmarks show that this detailed placer can achieve better wirelength and runtime compared to Fengshui 5.0, rowIroning and Domino. 1. The author claims four main contributions in this paper: Global Swap, Vertical Swap, Local Re-ordering, and Single-Segment Clustering. However, three of these ideas (Global Swap, Local Re-ordering, and Single-Segment Clustering) are very similar to those in the detailed placement of "FastPlace: An Analytical Placer for Mixed-Mode Designs" published in ISPD05. This paper just contributes more implementation details about these ideas and provides a faster algorithm for Fixed-Order Single Segment Placement Problem. 2. The experimental results in this paper may not be an appropriate comparison. The author used the Placement Utilities in Capo9.1 to legalize MPL5's global placement result. The placement result was too much disturbed by the legalizer and shouldn't be used to compare the performance of detailed placer. The legalized wirelength by MPL5's own legalizer is 1.70e+06, which is even better then the wirelength (1.78e+06) result generated by the detailed place stated in this paper. The claim in the abstract (a legalized state-of-the-art global placement solution may still have a lot of room for improvement in wirelength) is not appropriate. 3. The paper claims that Global Swap gives the result most profit, but there isn't any experimental result in this. The readers cannot distinguish the individual contributions of the algorithms proposed in this paper. //HI112 A three-step mixed-size detailed placement is described in this paper. A combination of constraint graph and linear programming is used to remove the overlap between macros. Standard cells are legalized by an enhanced greedy method. In the end, a slidingwindow-based cell swapping is applied to further reduce wirelength. The experimental results show that it can produce legal placement for all the circuits in ICCAD04-MS, while Fengshui fails for 1/3 of them, and the wirelength produced using its algorithm is shorter by 3% on average. 1. The paper proposes a macro legalization method with a combination of constraint graph and linear programming. However, the experimental results show very little wirelength improvement compared with a simple greedy legalizer. The author claimed the method one of the two main contributions, which does not seem an efficient way to macro legalization. 2. The paper claims that it can produce legal placement for all the circuits in ICCAD04-MS, while Fengshui fails for 1/3 of them. This is not a fair comparison while the global placement results are generated by an unknown analytical placer. Why not just use Fengshui's global placement result for comparison? The experimental results will be much more convincing if the proposed method could generate better result on Fengshui's global placement compared with Fengshui's own detailed placer. -- 103 Jao-Chang Xsi, Department of Fool Engineering National TigerLand University, Taipei, Taiwan. --

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