[Patch, bfin/c6x] Fix ICE for backends that rely on reorder_loops.

[Teresa Johnson]

On Sun, Jan 5, 2014 at 3:39 AM, Bernd Schmidt <bernds@codesourcery.com> wrote:
> On 01/05/2014 12:35 PM, Felix Yang wrote:
>>
>> Ping?
>> Cheers,
>
>
> I have a different patch which I'll submit next week after some more
> testing. The assert in cfgrtl is unnecessarily broad and really only needs
> to trigger if -freorder-blocks-and-partition; there's nothing wrong with
> entering cfglayout after normal bb-reorder.

Currently -freorder-blocks-and-partition is the default for x86. I
assume that hw-doloop is not enabled for any i386 targets, which is
why we haven't seen this?

And will this mean that -freorder-blocks-and-partition cannot be used
for the targets that use hw-doloop? If so, should
-freorder-blocks-and-partition be prevented with a warning for those
targets?

>
> I've also tested that Blackfin still benefits from the hw-doloop reordering
> code and generates more hardware loops if it's enabled. So we want to be
> able to run it at -O2.

I looked at hw-doloop briefly and since it seems to be doing some
manual bb reordering I guess it can't simply be moved before bbro. It
seems like a better long-term solution would be to make bbro
hw-doloop-aware as Felix suggested earlier.

Teresa

>
>
> Bernd
>
>



-- 
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413