https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111210
--- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> --- The testcase is small enough to notice the issue by inspection. Note that you get the "expected" answer with -fno-strict-aliasing, and as explained in https://gcc.gnu.org/bugs/ it is one of the things you should check when submitting a bugreport: Before reporting that GCC compiles your code incorrectly, compile it with gcc -Wall -Wextra and see whether this shows anything wrong with your code. Similarly, if compiling with -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations makes a difference, or if compiling with -fsanitize=undefined produces any run-time errors, then your code is probably not correct.
