[llvm] [ValueTracking] Augment isImpliedByDomCondition by data-relation (PR #187224)

[Kunqiu Chen via llvm-commits]

Camsyn wrote:

Maybe `simplifyCmpInst` is a more precise but expensive replacement of `isTruePredicate`.
As `simplifyCmpInst` calls `isImpliedByDomCondition` internally, such a replacement might cause heavy recursion.

If `simplifyCmpInst` has already considered both the dom condition and the data relation. Maybe we should provide a new wrapper function `isTrueOrFalse` as follows, and replace some calls from `isImpliedByDomCondition` to`isTrueOrFalse`:
```cpp
std::optional<bool> llvm::isTrueOrFalse(CmpPredicate Pred, const Value *LHS,
                                        const Value *RHS,
                                        const Instruction *ContextI,
                                        const DataLayout &DL) {
  if (auto *C = dyn_cast_or_null<ConstantInt>(simplifyCmpInst(
          Pred, LHS, RHS, {DL, ContextI}))) {
    return C.isOne();
  }
  return std::nullopt;
}
```




https://github.com/llvm/llvm-project/pull/187224