https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114465
--- Comment #1 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- Note that transforming x % 1 % -1 to x % -1 wouldn't strictly be valid (because of undefined behavior from INT_MIN % -1), though hopefully cases with constant 1 or -1 get optimized to 0 anyway and the undefined behavior is only a problem with a -1 that's not a constant.