[Mlir-commits] [mlir] [mlir][toy] Update dialect conversion example (PR #150826)

[Markus Böck]

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@@ -223,8 +221,11 @@ void ToyToLLVMLoweringPass::runOnOperation() {
   populateFuncToLLVMConversionPatterns(typeConverter, patterns);
 
   // The only remaining operation to lower from the `toy` dialect, is the
-  // PrintOp.
-  patterns.add<PrintOpLowering>(&getContext());
+  // PrintOp. An identity converter is needed because the PrintOp lowering
+  // operates on MemRefType instead of the lowered LLVM struct type.
+  TypeConverter identityConverter;
+  identityConverter.addConversion([](Type type) { return type; });
+  patterns.add<PrintOpLowering>(identityConverter, &getContext());
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zero9178 wrote:

Was the previous code using `printOp.getInput()` not okay? My understanding was that it was fine to use the old operands of `op` as long as you are aware of it being of the old type. This is what is happening here with the use of `memref.load`. This is very useful IMO to drive recursive legalization.

https://github.com/llvm/llvm-project/pull/150826