Evolutionary Systems
SparseMap: A Sparse Tensor Accelerator Framework Based on Evolution Strategy
Zhao, Boran, Zhai, Haiming, Yuan, Zihang, Liu, Hetian, Xia, Tian, Zhao, Wenzhe, Ren, Pengju
The growing demand for sparse tensor algebra (SpTA) in machine learning and big data has driven the development of various sparse tensor accelerators. However, most existing manually designed accelerators are limited to specific scenarios, and it's time-consuming and challenging to adjust a large number of design factors when scenarios change. Therefore, automating the design of SpTA accelerators is crucial. Nevertheless, previous works focus solely on either mapping (i.e., tiling communication and computation in space and time) or sparse strategy (i.e., bypassing zero elements for efficiency), leading to suboptimal designs due to the lack of comprehensive consideration of both. A unified framework that jointly optimizes both is urgently needed. However, integrating mapping and sparse strategies leads to a combinatorial explosion in the design space(e.g., as large as $O(10^{41})$ for the workload $P_{32 \times 64} \times Q_{64 \times 48} = Z_{32 \times 48}$). This vast search space renders most conventional optimization methods (e.g., particle swarm optimization, reinforcement learning and Monte Carlo tree search) inefficient. To address this challenge, we propose an evolution strategy-based sparse tensor accelerator optimization framework, called SparseMap. SparseMap constructing a more comprehensive design space with the consideration of both mapping and sparse strategy. We introduce a series of enhancements to genetic encoding and evolutionary operators, enabling SparseMap to efficiently explore the vast and diverse design space. We quantitatively compare SparseMap with prior works and classical optimization methods, demonstrating that SparseMap consistently finds superior solutions.
EvoCut: Strengthening Integer Programs via Evolution-Guided Language Models
Yazdani, Milad, Mostajabdaveh, Mahdi, Aref, Samin, Zhou, Zirui
Integer programming lies at the heart of crucial combinatorial optimization tasks but remains challenging due to its NP-hard nature. An effective approach for practically solving integer programs is the manual design of acceleration cuts, i.e. inequalities that improve solver performance. However, this creative process demands deep expertise and is yet to be automated. Our proposed framework, EvoCut, automates the generation of acceleration cuts by combining large language models (LLMs) with an evolutionary search. EvoCut (i) initializes a diverse population of candidate cuts via an LLM-based initializer agent; (ii) for each cut empirically evaluates both preservation of the optimal solution and its ability to cut off fractional solutions across a verification set; and (iii) iteratively refines the population through evolutionary crossover and mutation agents. We quantify each cut's utility by its relative reduction in the solver's optimality gap. Our comparisons against standard integer programming practice show that EvoCut reduces optimality gap by 17-57% within a fixed time. It obtains the same solutions up to 4 times as fast, and obtains higher-quality solutions within the same time limit. Requiring no human expert input, EvoCut reliably generates, improves, and empirically verifies cuts that generalize to unseen instances. The code is available at https://github.com/milad1378yz/EvoCut.
The Birds Flocking Back to the Fresh Kills Dump
One humid afternoon in July, José Ramírez-Garofalo drove his large Toyota truck through the lush new hills, valleys, and meadows of Freshkills Park, a twenty-two-hundred-acre green space that the city is constructing on Staten Island. Ramírez-Garofalo, a young man with dark hair, large forearms, and the beginnings of a goatee, drove and talked fast. "It's an impermeable geotextile membrane," he said, referring to the thick plastic that was used, starting in the mid-nineties, to cap the four giant trash mounds of the old Fresh Kills landfill. "On top there is playground soil." The process of capping and terraforming the four mounds that once made up the country's largest dump is complete, but the park won't be fully open until at least 2036.