[llvm-branch-commits] [llvm] [DA] Add tests where dependencies are missed due to overflow (PR #164246)

[Ryotaro Kasuga via llvm-branch-commits]

kasuga-fj wrote:

@sjoerdmeijer These are the cases I was able to find where intermediate computations cause overflow, leading to incorrect results being reported. Note that

- I didn't check all functions, especially those that based on greatest common divisor algorithms (exactSIV, exactRDIV and gcdMIV).
  - It is more difficult to reason about the absence of overflow in them. I personally think we should conservatively insert overflow checks in these functions, even if we cannot find any test cases that trigger an overflow.
- I also didn't investigate functions that I believe should be removed (e.g., banerjeeMIV).
- These issues are not related to monotonicity checks. As far as I can tell, all of these cases are monotonic.
- There are other correctness issues due to other reasons. I'll share them separately.

https://github.com/llvm/llvm-project/pull/164246