[Mlir-commits] [mlir] [mlir][Transforms] Dialect conversion: Simplify handling of dropped arguments (PR #96207)

[Markus Böck]

================
@@ -330,34 +340,37 @@ class TypeConverter {
 
   /// Register a materialization function, which must be convertible to the
   /// following form:
-  ///   `Optional<Value> (OpBuilder &, T, ValueRange, Location)`,
-  ///   where `T` is any subclass of `Type`.
-  /// This function is responsible for creating an operation, using the
-  /// OpBuilder and Location provided, that "converts" a range of values into a
-  /// single value of the given type `T`. It must return a Value of the
-  /// converted type on success, an `std::nullopt` if it failed but other
-  /// materialization can be attempted, and `nullptr` on unrecoverable failure.
-  /// It will only be called for (sub)types of `T`.
+  ///   `std::optional<Value>(OpBuilder &, T, ValueRange, Location)`,
+  /// where `T` is any subclass of `Type`. This function is responsible for
+  /// creating an operation, using the OpBuilder and Location provided, that
+  /// "casts" a range of values into a single value of the given type `T`. It
+  /// must return a Value of the converted type on success, an `std::nullopt` if
+  /// it failed but other materialization can be attempted, and `nullptr` on
+  /// unrecoverable failure. It will only be called for (sub)types of `T`.
+  /// Materialization functions must be provided when a type conversion may
+  /// persist after the conversion has finished.
   ///
   /// This method registers a materialization that will be called when
-  /// converting an illegal block argument type, to a legal type.
+  /// converting potentially multiple replacement block arguments (of a single
+  /// original block argument), to a single SSA value with a legal type.
----------------
zero9178 wrote:

```suggestion
  /// converting block arguments that were the result of a single conversion of a block argument, to a single SSA value of a legal type.
```
Tried to made this sligthly easier to parse but not sure I succeeded

https://github.com/llvm/llvm-project/pull/96207