[llvm] [LoopInterchange] Improve profitability check for vectorization (PR #133672)

[Michael Kruse via llvm-commits]

================
@@ -103,3 +103,135 @@ for.i.inc:
 exit:
   ret void
 }
+
+; Check that the below loops are exchanged to allow innermost loop
+; vectorization. We cannot vectorize the j-loop because it has a lexically
+; backward dependency, but the i-loop can be vectorized because all the
+; loop-carried dependencies are lexically forward.
----------------
Meinersbur wrote:

One problem: The current `LoopVectorize` pass does not do outer loop vectorization.

https://github.com/llvm/llvm-project/pull/133672