[llvm] [DA] do not handle array accesses of different offsets (PR #123436)

[Michael Kruse via llvm-commits]

================
@@ -3569,6 +3569,123 @@ bool DependenceInfo::invalidate(Function &F, const PreservedAnalyses &PA,
          Inv.invalidate<LoopAnalysis>(F, PA);
 }
 
+// Check that memory access offsets in V are multiples of array element size
+// EltSize. Param records the first parametric expression. If the scalar
+// evolution V contains two or more parameters, we check that the subsequent
+// parametric expressions are multiples of the first parametric expression
+// Param.
+static bool checkOffsets(ScalarEvolution *SE, const SCEV *V, const SCEV *&Param,
+                         uint64_t EltSize) {
+  if (auto *AddRec = dyn_cast<SCEVAddRecExpr>(V)) {
+    if (!checkOffsets(SE, AddRec->getStart(), Param, EltSize))
+      return false;
+    return checkOffsets(SE, AddRec->getStepRecurrence(*SE), Param, EltSize);
----------------
Meinersbur wrote:

```suggestion
    return checkOffsets(SE, AddRec->getStart(), Param, EltSize) &&
      checkOffsets(SE, AddRec->getStepRecurrence(*SE), Param, EltSize);
```
If you think the current is more readable, that's fine too.

https://github.com/llvm/llvm-project/pull/123436