http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58240
--- Comment #9 from shiyan <shiyan2016 at 126 dot com> --- (In reply to Paolo Carlini from comment #5) > Closing then. Hi Carlini, I still think it is a bug. I know the test case is not practical. In fact, I will not use such code in real case. But from compiler's side, this is a bug and I think you may still track it and lower the "importance" if possible. It it valid test case, though not practical. :) Also as you mentioned -m64 can work well, I believe it is not technically difficult to fix. Maybe the compiler front end just do something optimization too early and removed the call to strncmp when N=1? Thanks, Shiyan