[PATCH] D18867: [IndVarSimplify] Eliminate zext of a signed IV when the IV is known to be non-negative

[Sanjoy Das via llvm-commits]

sanjoy requested changes to this revision.
sanjoy added a comment.
This revision now requires changes to proceed.

+1 to both comments by @mbodart

Specifically with regards to the `isKnownNonNegative` comment:  if `isKnownPredicate` is failing here, you might consider teaching it to use `getSignedRange` internally, since the range SCEV computes for `%i.0` is `[0,-2147483648)` (all positive integers) so we should be able to use that information.


http://reviews.llvm.org/D18867