[llvm] [LoopInterchange] Bail out for Scalar Dependencies (PR #119345)

[via llvm-commits]

================
@@ -187,11 +187,19 @@ static void interChangeDependencies(CharMatrix &DepMatrix, unsigned FromIndx,
 // if the direction matrix, after the same permutation is applied to its
 // columns, has no ">" direction as the leftmost non-"=" direction in any row.
 static bool isLexicographicallyPositive(std::vector<char> &DV) {
+  bool HasScalar = false;
+  bool FirstPosScalar = true;
----------------
CongzheUalberta wrote:

I would second this. It looks to me that this patch allows some specific pattern to be interchanged without a schematic reasoning. 

https://github.com/llvm/llvm-project/pull/119345