loop-invariant.c patch: Use validate_change to avoid breaking match_dup

[Bernd Schmidt]

On 04/08/2010 10:57 PM, Eric Botcazou wrote:
>> That's misstating the situation.  There are many other targets that have
>> patterns that could be affected.
> 
> Theoritically, yes; in practice, the code is 6 years old and AFAIK it's the 
> first time the issue arises.
> 
>> I see no better way to reorganize the  code; if you have a suggestion,
>> please post it. 
> 
> Attached.  Unless I'm mistaken, it's equivalent to your change.

Mine avoids the recursive call to move_invariant_reg if the first
attempt at validation fails.  If you are certain that that's irrelevant,
I'll happily approve your version.


Bernd