[llvm] r209455 - Return false if we're not going to do anything.

[Robinson, Paul]

> >> Author: echristo
> >> Date: Thu May 22 12:49:33 2014
> >> New Revision: 209455
> >>
> >> URL: http://llvm.org/viewvc/llvm-project?rev=209455&view=rev
> >> Log:
> >> Return false if we're not going to do anything.
> >
> > Is this observable (& thus testable)?
> >
> 
> Not really no. I could do what Paul suggested and put the return above
> the debug line and compile with a target that didn't want if
> conversion and then make sure that we don't see the debug line in
> asserts only builds when we compile with -debug. But I'm not sure that
> would be testing anything other than the pass not firing, not the
> return value.

This patch addresses a review comment on a prior patch that was
supposed to be "no functional change" but actually wasn't (hence
the review comment).  I don't know that any test is really feasible.
--paulr