[PATCH] D20058: [SCEV] No-wrap flags are not propagated when folding "{S, +, X}+T ==> {S+T, +, X}"

[Oleg Ranevskyy via llvm-commits]

iid_iunknown added a comment.

In http://reviews.llvm.org/D20058#424378, @sanjoy wrote:

> This needs at least one test case (preferably more than one) demonstrating the motivation.  A simplified form of the "Minimal reproducer:" will do.


Thanks for your comments!

I added the test case and reduced it a bit but its IR is still quite big. The problem is that any attempt to shorten it further seems to hide the problem - IV elimination starts working even without our fix. Could you check if such a test is acceptable, please?

The test case checks if the optimized IR has no IV and its unnecessary sext. Another way to check this is to use `opt -debug` and look for "INDVARS: eliminating ..." in the output. Please, let me know if this way is more preferable.

Thanks!


Repository:
  rL LLVM

http://reviews.llvm.org/D20058