https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102178
--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> --- For the case of LBM what also helps is disabling PRE or using PGO (which sees the useless PRE) given that the path the expressions become partially compile-time computable is never taken at runtime. In theory we could isolate that path completely via -ftracer but the pass pipeline setup doesn't look optimal.
