[PATCH] PR20234 - [SLP Vectorizer] Canonicalize tree operands of commutitive binary operands.

[Chad Rosier]

>>! In D4680#22, @mcrosier wrote:
> Hi Erik,
> I added you to the CC list because I noticed you were working on the SLP vectorizer as well.  I suspect your patch is the more robust solution I was referring to in the original email. ;)  Does the test case in this patch still work with your patch?  If so, I have no problem with you reverting this patch and applying yours.  Please just add my test case to your patch.  If not, I would like to get the test passing with your patch.
> 
>  Chad

Note: If the test doesn't pass, please don't consider this a blocker to your patch.  We can revert my patch and apply yours as it's obviously a more general solution.  All I ask is that we try to get the test case passing in the near future.  This specific code sequence is derived from spec2k/mesa and improves performance by ~3% (AArch64/A53).

http://reviews.llvm.org/D4680