Fix incorrect controlled ConjugationBox handling (#1118)

* Fix incorrect controlled ConjugationBox handling * Add changelog entry * Bump tket version * run clang format * bump tket version
CQCL · Nov 9, 2023 · e5e0c3b · e5e0c3b
1 parent 57e64bd
commit e5e0c3b
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Showing 5 changed files with 36 additions and 3 deletions.
diff --git a/pytket/conanfile.py b/pytket/conanfile.py
@@ -32,7 +32,7 @@ def package(self):
         cmake.install()
 
     def requirements(self):
-        self.requires("tket/1.2.66@tket/stable")
+        self.requires("tket/1.2.67@tket/stable")
         self.requires("tklog/0.3.3@tket/stable")
         self.requires("tkrng/0.3.3@tket/stable")
         self.requires("tkassert/0.3.4@tket/stable")

diff --git a/pytket/docs/changelog.rst b/pytket/docs/changelog.rst
@@ -16,6 +16,7 @@ Fixes:
   of the bits in the expression in the resulting ``cmd.args``
 * Fix incorrect serialisation of ``PauliExpPairBox`` when the Pauli strings are of
   length 2.
+* Fix incorrect controlled ``ConjugationBox`` handling.
 
 1.21.0 (October 2023)
 ---------------------

diff --git a/tket/conanfile.py b/tket/conanfile.py
@@ -23,7 +23,7 @@
 
 class TketConan(ConanFile):
     name = "tket"
-    version = "1.2.66"
+    version = "1.2.67"
     package_type = "library"
     license = "Apache 2"
     homepage = "https://github.com/CQCL/tket"

diff --git a/tket/src/Circuit/CircUtils.cpp b/tket/src/Circuit/CircUtils.cpp
@@ -596,7 +596,10 @@ static Circuit controlled_conjugation_box(
     all_args[n_controls + i] = Qubit(n_controls + args[i].index()[0]);
     target_args[i] = Qubit(n_controls + args[i].index()[0]);
   }
-  Circuit circ(n_controls + n_targets);
+  Circuit circ;
+  for (const Qubit &q : all_args) {
+    circ.add_qubit(q);
+  }
   circ.add_op(compute, target_args);
   QControlBox controlled_action(action, n_controls);
   circ.add_box(controlled_action, all_args);
@@ -801,6 +804,9 @@ static Eigen::Matrix2cd get_target_op_matrix(const Op_ptr &op) {
 
 // A gate block containing Cn* gates that can be merged as a single CnU gate
 // a block can also contain a single Barrier, which will be left in place
+// TODO: conjugation boxs are accepted as well; however they don't fit the
+// semantics. control_qubits and target_qubit don't mean anything for a
+// conjugation box.
 struct CnGateBlock {
   enum class MergeMode { append, prepend };
   CnGateBlock(const Command &command) {

diff --git a/tket/test/src/Circuit/test_Boxes.cpp b/tket/test/src/Circuit/test_Boxes.cpp
@@ -873,6 +873,18 @@ SCENARIO("QControlBox", "[boxes]") {
       d.add_op<unsigned>(OpType::CX, {2, 1});
       REQUIRE(*c == d);
     }
+    WHEN("Wrapped in a CircBox") {
+      Circuit inner_circ(4);
+      inner_circ.add_op<unsigned>(cj_op, {1, 3});
+      Op_ptr circbox_op = std::make_shared<CircBox>(inner_circ);
+      QControlBox qbox(circbox_op);
+      std::shared_ptr<Circuit> c = qbox.to_circuit();
+      Circuit d(5);
+      d.add_op<unsigned>(OpType::CX, {4, 2});
+      d.add_op<unsigned>(OpType::CZ, {0, 2});
+      d.add_op<unsigned>(OpType::CX, {4, 2});
+      REQUIRE(*c == d);
+    }
     WHEN("Nested") {
       Circuit compute_outer(3);
       compute_outer.add_op<unsigned>(OpType::CX, {2, 1});
@@ -929,6 +941,20 @@ SCENARIO("QControlBox", "[boxes]") {
     std::shared_ptr<Circuit> c = qbox.to_circuit();
     REQUIRE(c->count_gates(OpType::CX) == 4);
   }
+  GIVEN("controlled PauliExpBox") {
+    // https://github.com/CQCL/tket/issues/1109
+    PauliExpBox pbox(
+        SymPauliTensor({Pauli::I, Pauli::Z, Pauli::I, Pauli::I}, 0.7));
+    Op_ptr op = std::make_shared<PauliExpBox>(pbox);
+    QControlBox qbox(op);
+    std::shared_ptr<Circuit> c = qbox.to_circuit();
+    // construct the expected circuit
+    Circuit correct_inner(4);
+    correct_inner.add_op<unsigned>(OpType::Rz, 0.7, {1});
+    QControlBox correct_qbox(std::make_shared<CircBox>(correct_inner));
+    std::shared_ptr<Circuit> d = correct_qbox.to_circuit();
+    REQUIRE(*c == *d);
+  }
 }
 
 SCENARIO("Unitary3qBox", "[boxes]") {