https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60664
--- Comment #3 from David Binderman <dcb314 at hotmail dot com> --- (In reply to David Binderman from comment #0) > I've just built gcc trunk with clang and it looks as if producing > a similar warning to clang will flush out five bugs in gcc trunk. Five is now one. $ fgrep "Wtautological-constant-out-of-range-compare" mk.out ../../src/trunk/gcc/expr.c:5230:9: warning: comparison of constant -1 with expression of type 'unsigned int' is always false [-Wtautological-constant-out-of-range-compare] $ if (!SUBREG_CHECK_PROMOTED_SIGN (target, TYPE_UNSIGNED (TREE_TYPE (exp)))) { However, for a build of most of Redhat Linux with clang, there are about 460 occurrences of this warning, so it still looks to be of value for the wider world.