[AP][GlobalPlacement] Updated B2B Solver According to Feedback

Author: AlexandreSinger

doc/src/vpr/command_line_usage.rst

@@ -1197,14 +1197,17 @@ Analytical Placement is generally split into three stages:
     back to the analytical solver to make its solution more legal.
 
     * ``qp-hybrid`` Solves for a placement that minimizes the quadratic HPWL of
-      the flat placement using a hybrid clique/star net model. Uses the legalized solution
-      as anchor-points to pull the solution to a more legal solution.
+      the flat placement using a hybrid clique/star net model (as described in
+      FastPlace :cite:`Viswanathan2005_FastPlace`).
+      Uses the legalized solution as anchor-points to pull the solution to a
+      more legal solution (similar to the approach from SimPL :cite:`Kim2013_SimPL`).
 
     * ``lp-b2b`` Solves for a placement that minimizes the linear HPWL of the
-      flat placement using the Bound2Bound net model. Uses the legalized solution
-      as anchor-points to pull the solution to a more legal solution.
+      flat placement using the Bound2Bound net model (as described in Kraftwerk2 :cite:`Spindler2008_Kraftwerk2`).
+      Uses the legalized solution as anchor-points to pull the solution to a
+      more legal solution (similar to the approach from SimPL :cite:`Kim2013_SimPL`).
 
-    **Default:** ``lp-b2b``
+    **Default:** ``qp-hybrid``
 
 .. option:: --ap_partial_legalizer {bipartitioning | flow-based}
 

doc/src/z_references.bib

@@ -436,3 +436,46 @@ @inproceedings{kosar2024parallel
   booktitle={The 23rd International Conference on Field-Programmable Technology},
   year={2024}
 }
+
+@ARTICLE{Viswanathan2005_FastPlace,
+    author={Viswanathan, N. and Chu, C.C.-N.},
+    journal={IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems},
+    title={{FastPlace}: efficient analytical placement using cell shifting, iterative local refinement,and a hybrid net model},
+    year={2005},
+    volume={24},
+    number={5},
+    month=may,
+    pages={722-733},
+    keywords={Clustering algorithms;Partitioning algorithms;Algorithm design and analysis;Integrated circuit interconnections;Large-scale systems;Minimization;Delay;Simulated annealing;Iterative algorithms;Acceleration;Analytical placement;computer-aided design;net models;standard cell placement},
+    doi={10.1109/TCAD.2005.846365}
+}
+
+@article{Kim2013_SimPL,
+    author = {Kim, Myung-Chul and Lee, Dong-Jin and Markov, Igor L.},
+    journal = {Commun. ACM},
+    title = {{SimPL}: an algorithm for placing {VLSI} circuits},
+    year = {2013},
+    issue_date = {June 2013},
+    publisher = {Association for Computing Machinery},
+    address = {New York, NY, USA},
+    volume = {56},
+    number = {6},
+    issn = {0001-0782},
+    doi = {10.1145/2461256.2461279},
+    month = jun,
+    pages = {105–113},
+    numpages = {9}
+}
+
+@ARTICLE{Spindler2008_Kraftwerk2,
+    author={Spindler, Peter and Schlichtmann, Ulf and Johannes, Frank M.},
+    journal={IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems},
+    title={Kraftwerk2—A Fast Force-Directed Quadratic Placement Approach Using an Accurate Net Model},
+    year={2008},
+    volume={27},
+    number={8},
+    month=aug,
+    pages={1398-1411},
+    keywords={Cost function;Central Processing Unit;Runtime;Quality control;Convergence;Computational efficiency;Integrated circuit synthesis;Stochastic processes;Circuit simulation;Bound2Bound;force-directed;half-perimeter wirelength (HPWL);Kraftwerk2;quadratic placement;Kraftwerk2;force-directed;quadratic placement;Bound2Bound;HPWL},
+    doi={10.1109/TCAD.2008.925783}
+}