✨ Implement two-qubit gate decomposition pass

mlir/include/mlir/Dialect/MQTOpt/Transforms/Passes.h

@@ -26,6 +26,7 @@ namespace mqt::ir::opt {
 #include "mlir/Dialect/MQTOpt/Transforms/Passes.h.inc" // IWYU pragma: export
 
 void populateGateEliminationPatterns(mlir::RewritePatternSet& patterns);
+void populateGateDecompositionPatterns(mlir::RewritePatternSet& patterns);
 void populateMergeRotationGatesPatterns(mlir::RewritePatternSet& patterns);
 void populateElidePermutationsPatterns(mlir::RewritePatternSet& patterns);
 void populateQuantumSinkShiftPatterns(mlir::RewritePatternSet& patterns);

mlir/lib/Dialect/MQTOpt/Transforms/GateDecomposition.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2023 - 2025 Chair for Design Automation, TUM
+ * Copyright (c) 2025 Munich Quantum Software Company GmbH
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Licensed under the MIT License
+ */
+
+#include "mlir/Dialect/MQTOpt/Transforms/Passes.h"
+
+#include <mlir/IR/PatternMatch.h>
+#include <mlir/Support/LLVM.h>
+#include <mlir/Transforms/GreedyPatternRewriteDriver.h>
+#include <utility>
+
+namespace mqt::ir::opt {
+
+#define GEN_PASS_DEF_GATEDECOMPOSITION
+#include "mlir/Dialect/MQTOpt/Transforms/Passes.h.inc"
+
+/**
+ * @brief This pass attempts to cancel consecutive self-inverse operations.
+ */
+struct GateDecomposition final
+    : impl::GateDecompositionBase<GateDecomposition> {
+
+  void runOnOperation() override {
+    // Get the current operation being operated on.
+    auto op = getOperation();
+    auto* ctx = &getContext();
+
+    // Define the set of patterns to use.
+    mlir::RewritePatternSet patterns(ctx);
+    populateGateDecompositionPatterns(patterns);
+
+    // Apply patterns in an iterative and greedy manner.
+    if (mlir::failed(mlir::applyPatternsGreedily(op, std::move(patterns)))) {
+      signalPassFailure();
+    }
+  }
+};
+
+} // namespace mqt::ir::opt