http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59892
--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- (In reply to Lukasz Dorau from comment #3) > (In reply to Markus Trippelsdorf from comment #2) > > When v.hosts[0] or v.hosts[1] is NULL the loop is fine, so there is > > no reason for a warning. > > The testcase is obviously invalid. > > > But v.hosts[0] and v.hosts[1] do not have to be NULL. What's more, they are > supposed not to be NULL. So why is it invalid? > I understand that the loop is erroneous, but I do not understand why > misoptimizing the code by dropping 'id < 2' loop condition is a right thing > to do? And even without any warning? Please note that you can use -fno-aggressive-loop-optimization if you dislike this behavior. From http://gcc.gnu.org/bugs/: »if compiling with -fno-strict-aliasing -fwrapv -fno-aggressive-loop-optimizations makes a difference, your code probably is not correct« And -Wno-aggressive-loop-optimizations doesn't handle early loop exits.
