Joseph R. Shinnerl

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The multilevel placement package mPL6 combines improved implementations of the global placer mPL5 (ISPD05) and the XDP legalizer and detailed placer (ASPDAC06). It consistently produces robust, high-quality solutions to difficult instances of mixed-size placement in fast and scalable run time. Best-choice clustering (ISPD05) is used to construct a hierarchy(More)
A new paradigm is introduced for floorplanning any combination of fixed-shape and variable-shape blocks under tight fixed-outline area constraints and a wirelength objective. Dramatic improvement over traditional floorplanning methods is achieved by explicit construction of strictly legal layouts for every partition block at every level of a cutsize-driven,(More)
A new quadratic global placer called POLAR is proposed. POLAR is based on novel techniques for rough legalization and wirelength refinement. During look-ahead rough legalization (LAL), relative positions of cells are maintained as they are relocated with minimal displacement to relieve excess area density. For each "hotspot" where placement overfill occurs,(More)
We have designed and implemented a new class of fast and highly scalable placement algorithms that directly handle complex constraints and achieve total wirelengths comparable to the state of the art. Our approach exploits recent advances in (i) multilevel methods for hierarchical computation, (ii) interior-point methods for nonconvex nonlinear programming,(More)
The ISPD~2015 placement-contest benchmarks include all the detailed pin, cell, and wire geometry constraints from the 2014 release, plus (a) added fence regions and placement blockages, (b) altered netlists including fixed macro blocks, (c) reduced standard cell area utilization via larger floorplan outlines, and (d)] specified upper limits on local(More)
A novel algorithm for rectangular floorplanning with guaranteed 100% area utilization is used to construct new sets of floorplanning benchmarks. By minimizing the maximum block aspect ratio subject to a zero-dead-space constraint, example zero-dead-space (ZDS) floorplans matching the area profiles of any existing floorplanning benchmark circuits can be(More)
This paper presents several important enhancements to therecently published multilevel placement package mPL.The improvements include (i) unconstrained quadratic relaxation on small, noncontiguous subproblems at every level of the hierarchy; (ii) improved interpolation (declustering)based on techniques from algebraic multigrid (AMG), and(iii) iterated(More)
Sparse linear equations Kd r are considered, where K is a specially structured symmetric indefinite matrix that arises in numerical optimization and elsewhere. Under certain conditions, K is quasidefinite. The Cholesky factorization PKPT LDLT is then known to exist for any permutation P, even though D is indefinite. Quasidefinite matrices have been used(More)
The public release of realistic industrial placement benchmarks by IBM and Intel Corporations from 1998--2013 has been crucial to the progress in physical-design algorithms during those years. Direct comparisons of academic tools on these test cases, including widely publicized contests, have spurred researchers to discover faster, more scalable algorithms(More)