[llvm] [InstCombine] Fold X + umax(X, 1) -> umax(X << 1, 1) (PR #222727)

[Nikita Popov via llvm-commits]

================
@@ -1984,6 +1984,21 @@ Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
     I.setHasNoUnsignedWrap(true);
   }
 
+  // X + umax(X, 1) --> umax(X << 1, 1) if X + X does not overflow.
----------------
nikic wrote:

```suggestion
  // X + umax(X, 1) --> umax(X << 1, 1) if the addition does not overflow.
```
nit: To make the comment match what the implementation actually checks.

https://github.com/llvm/llvm-project/pull/222727