Mixed-size placement with fixed macrocells using grid-warping

Zhong Xiu, Rob A. Rutenbar

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Grid-warping is a placement strategy based on a novel physical analogy: rather than move the gates to optimize their location, it elastically deforms a model of the 2-D chip surface on which the gates have been coarsely placed via a standard quadratic solve. Although the original warping idea works well for cell-based placement, it works poorly for mixed-size placements with large, fixed macrocells. The new problem is how to avoid elastically deforming gates into illegal overlaps with these background objects. We develop a new lightweight mechanism called "geometric hashing" which relocates gates to avoid these overlaps, but is efficient enough to embed directly in the nonlinear warping optimization. Results from a new placer (WARP3) running on the ISPD 2005 benchmark suite show both good quality and scalability.

Original languageEnglish (US)
Title of host publicationProceedings of ISPD'07
Subtitle of host publication2007 International Symposium on Physical Design
Number of pages8
StatePublished - 2007
Externally publishedYes
EventISPD'07: 2007 International Symposium on Physical Design - Austin, TX, United States
Duration: Mar 18 2007Mar 21 2007

Publication series

NameProceedings of the International Symposium on Physical Design


OtherISPD'07: 2007 International Symposium on Physical Design
Country/TerritoryUnited States
CityAustin, TX


  • Algorithms
  • Mixed-size placement
  • Placement

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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