[llvm-branch-commits] [llvm] [DA] Add test where ExactSIV misses dependency due to overflow (NFC) (PR #157085)

[Michael Kruse via llvm-branch-commits]

================
@@ -807,3 +807,123 @@ for.body:                                         ; preds = %entry, %for.body
 for.end:                                          ; preds = %for.body
   ret void
 }
+
+;; max_i = INT64_MAX/6  // 1537228672809129301
+;; for (long long i = 0; i <= max_i; i++) {
+;;   A[-6*i + INT64_MAX] = 0;
+;;   if (i)
+;;     A[3*i - 2] = 1;
+;; }
+;;
+;; FIXME: There is a loop-carried dependency between
+;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`. For example,
----------------
Meinersbur wrote:

```suggestion
;; FIXME: DependencyAnalsysis currently detects no dependency, but there is a loop-carried dependency between
;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`. For example,
```
[suggestion] Just to make clear what DA's current wrong behaviour is

https://github.com/llvm/llvm-project/pull/157085