array bounds violation in caller-save.c : duplicate hard regs check added

[Jeff Law]

On 06/05/2012 07:59 PM, Hans-Peter Nilsson wrote:
> On Fri, 25 May 2012, DJ Delorie wrote:
>> If I apply this patch, which checks for duplicate hard registers within
>> -fira-share-save-slots, the following *-elf targets fail due to the assert:
>>
>> 	bfin cris m32c rl78 rx sh sh64 v850
>
> Oop.  An no clue as to what's wrong.
>
> Can you pretty please make the test-case n'all sent
> down-thread into a PR?
I haven't had a chance to investigate, but what we're looking for is 
multiple pseudos assigned to the same caller-saved hard reg live across 
a call.

In general, that would be the sign of a bug elsewhere, with the 
exception of the case where the pseudos are known to have the same value.

jeff