[llvm] [LoopInterchange] Update the direction of undistributed loop to EQ (PR #78951)

[Madhur Amilkanthwar via llvm-commits]

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@@ -82,6 +82,101 @@ static void printDepMatrix(CharMatrix &DepMatrix) {
 }
 #endif
 
+static bool isDirectionNegative(std::vector<Dependence::DVEntry> &DV) {
+  for (unsigned Level = 1; Level <= DV.size(); ++Level) {
+    unsigned char Direction = DV[Level - 1].Direction;
+    if (Direction == Dependence::DVEntry::EQ)
+      continue;
+    if (Direction == Dependence::DVEntry::GT ||
+        Direction == Dependence::DVEntry::GE)
+      return true;
+    return false;
+  }
+  return false;
+}
+
+static void dumpDirection(raw_ostream &OS,
+                          std::vector<Dependence::DVEntry> &DV) {
+  OS << " [";
+  for (unsigned II = 1; II <= DV.size(); ++II) {
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madhur13490 wrote:

I feel that we can start from 0 and avoid subtracting 1 each time we access `DV` but I understand that this is practice in `DA`.

https://github.com/llvm/llvm-project/pull/78951