RePlAce
RePlAce: Advancing Solution Quality and Routability Validation in Global Placement
Features
- Analytic and nonlinear placement algorithm. Solves electrostatic force equations using Nesterov's method. (link)
- Verified with various commercial technologies using OpenDB (7/14/16/28/45/55/65nm).
- Verified deterministic solution generation with various compilers and OS.
- Compiler: gcc4.8-9.1/clang-7-9/apple-clang-11
- OS: Ubuntu 16.04-18.04 / CentOS 6-8 / OSX
- Cleanly rewritten as C++11.
- Supports Mixed-size placement mode.
- Supports fast image drawing modes with CImg library.
Visualized examples from ISPD 2006 contest; adaptec2.inf | Real-world Design: Coyote (TSMC16 7.5T) |
How to Download and Build?
- If you want to use this as part of the OpenROAD project you should build it and use it from inside the integrated OpenROAD app. The standalone version is available as a legacy code in standalone branch.
- For OpenROAD-flow users, manuals for released binaries are available in readthedocs. (Getting-Started)
- For developers, manuals for building a binary is available in OpenROAD app repo. (OpenROAD app)
- Note that RePlAce is a submodule of OpenROAD repo, and take a place as the "global_placement" command.
OpenROAD Tcl Usage (global_placement)
global_placement
[-skip_initial_place]
[-incremental]
[-bin_grid_count grid_count]
[-density density]
[-init_density_penalty init_density_penalty]
[-init_wirelength_coef init_wirelength_coef]
[-min_phi_coef min_phi_coef]
[-max_phi_coef max_phi_coef]
[-overflow overflow]
[-initial_place_max_iter max_iter]
[-initial_place_max_fanout max_fanout]
[-verbose_level verbose_level]
Flow Control
- skip_initial_place : Skip the initial placement (BiCGSTAB solving) before Nesterov placement. IP improves HPWL by ~5% on large designs. Equal to '-initial_place_max_iter 0'
- incremental : Enable the incremental global placement. Users would need to tune other parameters (e.g. init_density_penalty) with pre-placed solutions.
Tuning Parameters
- bin_grid_count : Set bin grid's counts. Default: Defined by internal algorithm. [64,128,256,512,..., int]
- density : Set target density. Default: 0.70 [0-1, float]
- init_density_penalty : Set initial density penalty. Default: 8e-5 [1e-6 - 1e6, float]
- init_wire_length__coef : Set initial wirelength coefficient. Default: 0.25 [unlimited, float]
- min_phi_coef : Set pcof_min(ยต_k Lower Bound). Default: 0.95 [0.95-1.05, float]
- max_phi_coef : Set pcof_max(ยต_k Upper Bound). Default: 1.05 [1.00-1.20, float]
- overflow : Set target overflow for termination condition. Default: 0.1 [0-1, float]
- initial_place_max_iter : Set maximum iterations in initial place. Default: 20 [0-, int]
- initial_place_max_fanout : Set net escape condition in initial place when 'fanout >= initial_place_max_fanout'. Default: 200 [1-, int]
Other Options
- verbose_level : Set verbose level for RePlAce. Default: 1 [0-10, int]
Note that all of the TCL commands are defined in the replace.tcl and replace.i.
Verified/supported Technologies
- ASAP 7
- GF 14
- TSMC 16 (7.5T/9T)
- ST FDSOI 28
- TSMC 45
- Fujitsu 55
- TSMC 65
3rd Party Module List
License
- BSD-3-clause License [Link]
- Code found under the Modules directory (e.g., submodules CImg source files) have individual copyright and license declarations at each folder.
Authors
- Paper reference: C.-K. Cheng, A. B. Kahng, I. Kang and L. Wang, "RePlAce: Advancing Solution Quality and Routability Validation in Global Placement", to appear in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2018. (Digital Object Identifier: 10.1109/TCAD.2018.2859220)
- Mingyu Woo rewrites the whole RePlAce with a clean C++11 structure.
- The timing-Driven mode has been implemented by Mingyu Woo (only available in standalone branch.)
- Timing-Driven and Routability-Driven mode are ongoing with the clean-code structure (in openroad branch.)