[PATCH] Fix force_to_mode not to modify in place the passed rtl (PR rtl-optimization/58726)

[Eric Botcazou]

> Fixed by making sure force_to_mode doesn't modify x in place.

I think that it's the way to go, force_to_mode doesn't modify its argument 
except for these 2 cases.  I'm not sure what the story is, but calling SUBST 
for these 2 cases doesn't seem really necessary.

> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/4.8?
> 
> 2013-12-03  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR rtl-optimization/58726
> 	* combine.c (force_to_mode): Fix comment typo.  Don't destructively
> 	modify x for ROTATE, ROTATERT and IF_THEN_ELSE.
> 
> 	* gcc.c-torture/execute/pr58726.c: New test.

IMO it's the best fix at this point of the release cycles.

-- 
Eric Botcazou