feat: toy tutorial chapter 3.

Signed-off-by: jackfiled <xcrenchangjun@outlook.com>

lib/HelloCombine.cpp

@@ -0,0 +1,41 @@
+//
+// Created by ricardo on 02/06/25.
+//
+
+#include <mlir/IR/PatternMatch.h>
+#include "Dialect.h"
+#include "HelloCombine.inc"
+
+
+struct SimplifyRedundantTranspose final : mlir::OpRewritePattern<mlir::hello::TransposeOp>
+{
+    explicit SimplifyRedundantTranspose(mlir::MLIRContext* context) : OpRewritePattern(
+        context)
+    {
+    }
+
+    /// Transpose(Transpose(x)) = x
+    mlir::LogicalResult matchAndRewrite(mlir::hello::TransposeOp op, mlir::PatternRewriter& rewriter) const override
+    {
+        mlir::Value transposeInput = op.getOperand();
+        auto transposeInputOp = transposeInput.getDefiningOp<mlir::hello::TransposeOp>();
+
+        if (!transposeInputOp)
+        {
+            return mlir::failure();
+        }
+
+        rewriter.replaceOp(op, {transposeInputOp.getOperand()});
+        return mlir::success();
+    }
+};
+
+void mlir::hello::TransposeOp::getCanonicalizationPatterns(RewritePatternSet& set, MLIRContext* context)
+{
+    set.add<SimplifyRedundantTranspose>(context);
+}
+
+void mlir::hello::ReshapeOp::getCanonicalizationPatterns(RewritePatternSet& set, MLIRContext* context)
+{
+    set.add<ReshapeReshapeOptPattern, RedundantShapeOptPattern, FoldConstantReshapeOptPattern>(context);
+}

lib/HelloCombine.td

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+#ifndef HELLO_COMBINE
+#define HELLO_COMBINE
+
+include "mlir/IR/PatternBase.td"
+include "hello/Ops.td"
+
+// Reshape(Reshape(x)) = Reshape(x)
+def ReshapeReshapeOptPattern : Pat<(ReshapeOp(ReshapeOp $arg)), (ReshapeOp $arg)>;
+
+// Reshape(Consant(x)) = x'
+
+def ReshapeConstant : NativeCodeCall<"$0.reshape(::llvm::cast<::mlir::ShapedType>($1.getType()))">;
+
+def FoldConstantReshapeOptPattern : Pat<(ReshapeOp:$res (ConstantOp $arg)), (ConstantOp (ReshapeConstant $arg, $res))>;
+
+// Reshape(x) =x , where input and output shapes are the same.
+def TypesAreSame : Constraint<CPred<"$0.getType() == $1.getType()">>;
+
+def RedundantShapeOptPattern : Pat<
+    (ReshapeOp: $res $arg), (replaceWithValue $arg),
+    [(TypesAreSame $res, $arg)]>;
+
+#endif