https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90536
--- Comment #3 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- To make the story short: compile your code with -Wno-conversion as a work around. This is needed starting with at least 4.6.0 revision r161462 (2010-06-27), but not needed with 4.5.4 or earlier. Note that BYTE and '89'X are GNU extensions and not standard conforming. IMO this PR is INVALID.