https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635
--- Comment #55 from Jeffrey A. Law <law at redhat dot com> --- So to summarize some thoughts from Richi from last year. Converting the V_C_E into a NOP_EXPR is undesirable as the truncation becomes sub-optimal because we end up with an additional masking operation. So the V_C_E is really the right thing. What that implies is that other passes need to get smarter about handling a V_C_E.