Arbor: Tree Search as a Cognition Layer for Autonomous Agents

Neha Prakriya, Chaojun Hou, Zheng Gong, Huasha Zhao 2026-06-14

Arbor addresses the problem of autonomous optimization in large, stateful action spaces by introducing a multi-agent framework with structured tree search as a shared cognition layer. The method pairs an Orchestrator agent with a Critic agent in a checks-and-balances architecture, using an explicit search tree of scored hypotheses as working memory. Experimental evidence shows Arbor achieves up to 193% inference throughput-latency Pareto improvement over vendor-optimized baselines, while a single agent without the harness plateaus at +33% and crashes within hours. This matters because it enables fully autonomous, hardware-agnostic, and reproducible multi-day optimization campaigns across the full LLM inference stack.

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Partitioned Tags, Shared Data: Reconciling Strict Cache Isolation with Write-Shared Coherence

Kartik Ramkrishnan, Stephen McCamant, Antonia Zhai, Pen Chung Yew 2026-06-14

SCP solves the problem that write-shared coherence fails under strict cache partitioning, a decade-old barrier to deploying eviction-based side-channel defenses in secure shared-OS settings. The method partitions only the tags while sharing a single data pool, sizes the data pool to prevent capacity-driven cross-partition eviction, and routes writes to the LLC after a leakage threshold to mitigate coherence-based leakage. Experimental evidence from gem5 shows SCP mitigates Prime+Probe, Flush+Reload, and shared-writeable-line attacks to no better than random guessing, with a +2.8% LLC SRAM hardware cost and IPC within 0.3% of DAWG on SPEC CPU2017. This matters because SCP reconciles strict cache isolation with write-shared coherence, enabling secure partitioning without sacrificing performance or coherence correctness.

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ITME: Inference Tiered Memory Expansion with Disaggregated CXL-Hybrid Memories

Hakbeom Jang, Younghoon Min, Sunwoong Kim, Taeyoung Ahn 2026-06-14

ITME addresses the problem of scaling shared context infrastructure for TB-scale LLM inference workloads beyond individual server capacity. The method leverages CXL-hybrid memory to provide massive, byte-addressable remote memory expansion, simplifying the software stack by eliminating complex software-level optimization. Experimental evidence from production-grade SK Hynix CMM and PCIe Gen5 NVMe SSDs, along with an FPGA prototype, shows up to a 35.7% throughput improvement over conventional CPU-offloading. This matters because ITME enables cost-efficient scaling of shared context layers for agentic and long-context LLMs by proactively managing data movement across the memory-storage hierarchy.

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Structured Testbench Generation for LLM-Driven HDL Design and Verification-Oriented Data Curation

En-Ming Huang, Yu-Hung Kao, Ren-Hao Deng, Wei-Po Hsin 2026-06-14

Problem: Automated testbench generation is a bottleneck in LLM-driven RTL workflows due to stochastic, costly, and low-coverage outputs from prompt-based methods. Method: STG (Structured Testbench Generation) exploits hardware design structure to produce deterministic testbenches. Finding: STG runs 720x faster than iterative LLM-based flows, achieves higher coverage, reduces false-pass verdicts, and is 11x faster and 127x more energy-efficient than LLM-based filtering on a single CPU core. Why it matters: STG enables rapid, reliable verification for LLM-driven design, improves RTL benchmarks by exposing faulty testbenches, and yields state-of-the-art distilled models with reduced node count.

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