[Mlir-commits] [mlir] [mlir][Transforms] Fix crash in `-remove-dead-values` on private functions (PR #169269)

[Matthias Springer]

================
@@ -141,6 +141,33 @@ static bool hasLive(ValueRange values, const DenseSet<Value> &nonLiveSet,
   return false;
 }
 
+/// Return true iff at least one value in `values` is dead, given the liveness
+/// information in `la`.
+static bool hasDead(ValueRange values, const DenseSet<Value> &nonLiveSet,
+                    RunLivenessAnalysis &la) {
+  for (Value value : values) {
+    if (nonLiveSet.contains(value)) {
+      LDBG() << "Value " << value << " is already marked non-live (dead)";
+      return true;
+    }
+
+    const Liveness *liveness = la.getLiveness(value);
+    if (!liveness) {
----------------
matthias-springer wrote:

This is copied from `hasLive` above:
```
    const Liveness *liveness = la.getLiveness(value);
    if (!liveness) {
      LDBG() << "Value " << value
             << " has no liveness info, conservatively considered live";
      return true;
    }
```

You may be right, but I'm not entirely sure. Maybe best to do this as a follow-up and be conservative for now?

https://github.com/llvm/llvm-project/pull/169269