[llvm-branch-commits] [mlir] [mlir][Transforms] `remove-dead-values`: Rely on canonicalizer for region simplification (PR #173505)

[Renato Golin via llvm-branch-commits]

================
@@ -246,7 +246,17 @@ def RemoveDeadValues : Pass<"remove-dead-values"> {
     do = square_and_double_of_y(5)
     print(do)
     ```
+
+    Note: If `canonicalize` is set to "false", this pass does not remove any
+    block arguments / op results from ops that implement the
+    RegionBranchOpInterface. Instead, it just sets dead operands to
+    "ub.poison".
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rengolin wrote:

If you run this to a fixed point with `canon=false` and then run once more with `true`, will the last time bypass all checks for the arguments that are all `poison`?

https://github.com/llvm/llvm-project/pull/173505