http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47913
--- Comment #12 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-03-02 12:07:13 UTC --- About int/long/long long I see what you mean, but we should double check that __builtin_clzll is unconditionally available and the same as __builtin_clz if intmax_t == int (etc): at the moment I'm not 100% sure.
