Add paper: LLM Program Optimization via Retrieval Augmented Search

Hi there!

Thank you for curating this repository! If you're still accepting new papers, I would like to suggest our work "LLM Program Optimization via Retrieval Augmented Search", [[arxiv]](https://arxiv.org/abs/2501.18916) [[code]](https://github.com/sagnikanupam/llmprogramoptimization) published in ACL 2026 Findings - it achieves large performance improvements on the PIE benchmark (proposed in "Learning Performance-Improving Code Edits", ICLR 2024).

Disclosure: I am one of the authors of the ACL paper. Please let me know if you would prefer I open a pull request instead.

Best,
Sagnik

Review the repository’s existing paper-list format and locate the appropriate entry point for adding a paper. Use the linked arXiv page and code repository to verify the title, publication details, and links, then follow the surrounding formatting conventions. Done means the paper appears in the relevant list with working links and no formatting inconsistencies.

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