2025.04.24 09:07:22 (Mastodon 114392147058229639, Twitter 1915331735925252484) from Daniel J. Bernstein:
The gcc/clang excuse for changing program behavior, often introducing bugs and security holes (see https://www.usenix.org/system/files/usenixsecurity23-xu-jianhao.pdf), is performance. But a new paper https://web.ist.utl.pt/nuno.lopes/pubs/ub-pldi25.pdf modifies clang to eliminate most (all?) such changes, and finds negligible effect on benchmarks.