Improving fpga placement with dynamically adaptive stochastic tunneling,” Computer-Aided Design of Integrated Circuits and Systems
Bibliographic record
Abstract
Abstract—This paper develops a dynamically adaptive stochastic tunneling (DAST) algorithm to avoid the “freezing ” problem commonly found when using simulated annealing for circuit placement on field-programmable gate arrays (FPGAs). The main objective is to reduce the placement runtime and improve the quality of final placement. We achieve this by allowing the DAST placer to tunnel energetically inaccessible regions of the potential solution space, adjusting the stochastic tunneling schedule adaptively by performing detrended fluctuation analysis, and selecting move types dynamically by a multi-modal scheme based on Gibbs sampling. A prototype annealing-based placer, called DAST, was developed as part of this paper. It targets the same computer-aided design flow as the standard versatile placement and routing (VPR) but replaces its original annealer with the DAST algorithm. Our experimental results using the benchmark suite and FPGA architecture file which comes with the Toronto VPR5 software package have shown a 18.3% reduction in runtime and a 7.2 % improvement in critical-path delay over that of conventional VPR. Index Terms—Field-programmable gate array (FPGA), placement, simulated annealing, stochastic tunneling. placement/routing in FPGAs is computationally infeasible due to its NP-completeness, hence can only be approximated by heuristic methods such as simulated annealing. However, conventional simulated annealing-based placement often suffer from the “freezing ” problem that traps the optimized solution in local minima, thus degrading the quality of results and prolonging total runtime [3], [4]. For example, experiments [5] have shown that for some large benchmarks with known optimal placement, state-of-the-art placers such as PAR from
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".