AutoProfiler learned that collecting more GPU profiling metrics does not help, and picking which ones to collect per kernel beat every fixed profiling setup
AspireAI community · arXiv
Automated GPU kernel optimization systems usually collect a fixed set of hardware counters before handing the data to an LLM rewriter. AutoProfiler argues that is the wrong shape, because profiling information is expensive and its usefulness depends on the kernel. The paper shows that adding more metrics does not monotonically improve the rewritten kernel, and that the most useful counters vary from kernel to kernel, so a kernel-conditioned selection can beat any single fixed profiling configuration. The method learns a deterministic profiling tree from optimization feedback, refined through REWRITE and SPLIT operations where an LLM proposes a change and empirical evaluation decides whether to accept it. Once the tree exists it gathers the right counters for any kernel and the LLM rewriter runs only once. Results on KernelBench show improvement over fixed profiling under constrained profiling budgets. The limitation is that the tree has to be built by running the optimizer, so the first run is more expensive than a fixed pipeline.
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Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.