https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70255
--- Comment #14 from shatz at dsit dot co.il --- (In reply to Marek Polacek from comment #13) > So what exactly is not documented? > > And I disagree that a warning isn't necessary just because something is > documented -- that applies for almost any warning. It is not documented that __attribute__((optimize(""))) works reliably when it is present in the source before the function body, but is ignored (always? occasionally?) when it specified after function body.