https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103168
--- Comment #3 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
This is simple (and fairly common) case we don't optimize
struct a {
int a;
static __attribute__ ((noinline))
int ret (int v) {return v;}
__attribute__ ((noinline))
int inca () {return a++;}
};
int
test()
{
struct a av;
av.a=1;
int val = av.ret (0) + av.inca();
av.a=2;
return val + av.ret(0) + av.inca();
}
what ret is const however becaue it is in COMDAT group we only detect it as
pure which makes GVN to give up on proving that its value did not change over
av.a=2 store. We could easily work this out from modref summary (which says
that function makes no memory load)
