LRA reload produces invalid insn

[Paul Koning]

> On Nov 2, 2018, at 9:34 AM, Peter Bergner <bergner@linux.ibm.com> wrote:
> 
> On 11/1/18 10:37 PM, Vladimir Makarov wrote:
>> On 11/01/2018 08:25 PM, Paul Koning wrote:
>>> Is this an LRA bug, or is there something I need to do in the target to prevent this happening?
>> It is hard to say whose code is responsible for this.  It might be a wrong machine-dependent code or a LRA bug.
>> 
>> Paul, could you send me full LRA dump file (.reload).  It might help me to say more specific reason for the bug.  LRA has iterated sub-passes and the full dump can say where LRA started to behave wrongly.
>> 
> 
> I'll note that when we ported the rs6000 (ie, ppc*) port over to LRA
> from reload, we hit many target problems.  It seems LRA is much less
> forgiving to bad constraints, predicates, etc. than reload was.
> I think that's actually a good thing.
> 
> Peter

Yes, I ran into that, and Segher (I think) helped me with a bad predicate case.  It doesn't help that the documentation isn't all that explicit about what the requirements are.  

	paul