Compiler-Runtime Co-operative Chain of Verification for LLM-Based Code Optimization [abstract] Hyunho Kwon, Sanggyu Shin, Ju Min Lee, Hoyun Youm, Seungbin Song, Seongho Kim, Hanwoong Jung, Seungwon Lee, and Hanjun Kim To Appear: Proceedings of the 2026 International Symposium on Code Generation and Optimization (CGO), January 2026.