[PATCH] New pass: inductive range check elimination

[hfinkel at anl.gov]

In http://reviews.llvm.org/D6693#108332, @reames wrote:

> Actually, I may have accidentally misrepresented Hal's earlier comment.  
>  When I reread, it wasn't a clear LGTM.  Please do not submit until Hal 
>  has okayed the current state as well.


I'm okay with this going in at this point. As has been discussed, it needs more test cases, better comments, etc., but those can be added as they're produced.

> Philip





================
Comment at: lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp:652
@@ +651,3 @@
+  FailureReason = nullptr;
+
+  return true;
----------------
As a general comment, you really need some ASCII-art diagrams here illustrating what all these blocks are and how they tie together. The loop vectorizer has some of these, and while imperfect, they do help to explain what is going on.

http://reviews.llvm.org/D6693

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