[unitaryHack 2025] Support component-wise decompositions

src/qibo/gates/gates.py

@@ -2413,11 +2413,7 @@ def _dagger(self) -> "Gate":
     def decompose(self, *free, use_toffolis: bool = True) -> List[Gate]:
         """Decomposition of RBS gate according to `ArXiv:2109.09685
         <https://arxiv.org/abs/2109.09685>`_."""
-        from qibo.transpiler.decompositions import (  # pylint: disable=C0415
-            standard_decompositions,
-        )
-
-        return standard_decompositions(self)
+        return _controlled_decompose(self, *free, use_toffolis=use_toffolis)
 
 
 class ECR(Gate):
@@ -2461,11 +2457,7 @@ def decompose(self, *free, use_toffolis: bool = True) -> List[Gate]:
             \\textup{ECR} = e^{i 7 \\pi / 4} \\, S(q_{0}) \\, \\sqrt{X}(q_{1}) \\,
                 \\textup{CNOT}(q_{0}, q_{1}) \\, X(q_{0})
         """
-        from qibo.transpiler.decompositions import (  # pylint: disable=C0415
-            standard_decompositions,
-        )
-
-        return standard_decompositions(self)
+        return _controlled_decompose(self, *free, use_toffolis=use_toffolis)
 
 
 class TOFFOLI(Gate):
@@ -2826,3 +2818,39 @@ def _check_engine(array):
         return torch
 
     return np
+
+
+def _controlled_decompose(self, *free, use_toffolis: bool = True) -> List[Gate]:
+    """Decompose non-conjugation gates component-wise."""
+    from qibo.transpiler.decompositions import (  # pylint: disable=C0415
+        standard_decompositions,
+    )
+
+    if self.is_controlled_by:
+        control_qubits = self.control_qubits
+        self.is_controlled_by = False
+        self.control_qubits = ()
+        decomp = standard_decompositions(self)
+        c_decomps1 = []
+        c_decomps2 = []
+        while len(decomp) > 1:
+            g1 = decomp[0].dagger()
+            g2 = decomp[-1]
+            if g1.to_json() != g2.to_json():
+                break
+
+            c_decomps1.append(decomp[0])
+            c_decomps2.append(decomp[-1])
+            decomp = decomp[1:-1]
+
+        for i, gate in enumerate(decomp):
+            gate_control_qubits = gate.control_qubits
+            gate.is_controlled_by = False
+            gate.control_qubits = ()
+            c_gate = gate.controlled_by(*control_qubits, *gate_control_qubits)
+            decomp[i] = c_gate
+        self.is_controlled_by = True
+        decomp = [*c_decomps1, *decomp, *c_decomps2[::-1]]
+        return decomp
+
+    return standard_decompositions(self)