[PATCH] Add zero-overhead looping for xtensa backend

[augustine.sterling@gmail.com]

On Tue, Oct 21, 2014 at 7:20 PM, Yangfei (Felix) <felix.yang@huawei.com> wrote:
> If the tripcount spill issue is not handled in the pattern, ICE may happen then.
> Here reload is trying to spill pseudo 173, but a memory operand is not allowed in zero_cost_loop_end pattern.
> And this is what I am trying to solve.

We have full control of the zero_cost_loop_end pattern. Plus, it
doesn't actually generate any real code. Edit it so it can take a
memory operand.