https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116835
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The case where we want still do it on the back edge is something like:
```
int a;
int b;
int bar (int c) __attribute__((noipa, noinline));
int
bar (int c)
{
int *p = &a;
for (int j = 0; j < *p; ++j)
{
//asm volatile(""::"r"(p));
p = &b;
}
return *p;
}
```
But ch handles that so maybe just not doing it on back-edges are ok.
And then get the optimization back that we sometimes lost due to that we have
to rerun phiprop after ch. I think that will work.
