Add token swapping stage to routing v3 (#96)

CQCL · Oct 26, 2021 · 5b50029 · 5b50029
1 parent 8ba7968
commit 5b50029
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Showing 2 changed files with 67 additions and 1 deletion.
diff --git a/tket/src/Mapping/MappingManager.cpp b/tket/src/Mapping/MappingManager.cpp
@@ -1,6 +1,7 @@
 #include "Mapping/MappingManager.hpp"
 
 #include "OpType/OpTypeFunctions.hpp"
+#include "TokenSwapping/main_entry_functions.hpp"
 
 namespace tket {
 
@@ -59,7 +60,19 @@ bool MappingManager::route_circuit(
       // true => can use held routing method
       if (rm.get().check_method(mapping_frontier, this->architecture_)) {
         valid_methods = true;
-        rm.get().routing_method(mapping_frontier, this->architecture_);
+        unit_map_t partial_permutation =
+            rm.get().routing_method(mapping_frontier, this->architecture_);
+
+        if (partial_permutation.size() > 0) {
+          std::map<Node, Node> node_map;
+          for (const auto& x : partial_permutation) {
+            node_map.insert({Node(x.first), Node(x.second)});
+          }
+          for (const std::pair<Node, Node>& swap :
+               get_swaps(*this->architecture_, node_map)) {
+            mapping_frontier->add_swap(swap.first, swap.second);
+          }
+        }
         break;
       }
     }

diff --git a/tket/tests/test_MappingManager.cpp b/tket/tests/test_MappingManager.cpp
@@ -7,6 +7,31 @@
 
 namespace tket {
 
+class TokenSwappingTester : public RoutingMethod {
+ public:
+  TokenSwappingTester(){};
+
+  bool check_method(
+      const std::shared_ptr<MappingFrontier>& /*mapping_frontier*/,
+      const ArchitecturePtr& /*architecture*/) const {
+    return true;
+  }
+
+  /**
+   * @param mapping_frontier Contains boundary of routed/unrouted circuit for
+   * modifying
+   * @param architecture Architecture providing physical constraints
+   * @return Logical to Physical mapping at boundary due to modification.
+   *
+   */
+  unit_map_t routing_method(
+      std::shared_ptr<MappingFrontier>& /*mapping_frontier*/,
+      const ArchitecturePtr& /*architecture*/) const {
+    Node node0("test_node", 0), node1("test_node", 1), node2("test_node", 2);
+    return {{node0, node1}, {node1, node2}, {node2, node0}};
+  }
+};
+
 SCENARIO("Test MappingManager::route_circuit") {
   Node node0("test_node", 0), node1("test_node", 1), node2("test_node", 2);
   Architecture arc({{node0, node1}, {node1, node2}});
@@ -33,5 +58,33 @@ SCENARIO("Test MappingManager::route_circuit") {
     REQUIRE_THROWS_AS(
         test_mm.route_circuit(circ, test_vrm), MappingManagerError);
   }
+  GIVEN("Method that invokes a permutation from token swapping stage.") {
+    Circuit circ(3);
+    std::vector<Qubit> qubits = circ.all_qubits();
+    circ.add_op<UnitID>(OpType::CX, {qubits[0], qubits[2]});
+    std::map<UnitID, UnitID> rename_map = {
+        {qubits[0], node0}, {qubits[1], node1}, {qubits[2], node2}};
+    circ.rename_units(rename_map);
+    TokenSwappingTester tst;
+    std::vector<std::reference_wrapper<RoutingMethod>> test_ts_rm = {tst};
+    test_mm.route_circuit(circ, test_ts_rm);
+
+    std::vector<Command> commands = circ.get_commands();
+    REQUIRE(commands.size() == 3);
+    Command c0 = commands[0];
+    unit_vector_t uid_swap_12 = {node1, node2};
+    REQUIRE(c0.get_args() == uid_swap_12);
+    REQUIRE(*c0.get_op_ptr() == *get_op_ptr(OpType::SWAP));
+
+    Command c1 = commands[1];
+    unit_vector_t uid_swap_01 = {node0, node1};
+    REQUIRE(c1.get_args() == uid_swap_01);
+    REQUIRE(*c1.get_op_ptr() == *get_op_ptr(OpType::SWAP));
+
+    Command c2 = commands[2];
+    unit_vector_t uid_cx_10 = {node1, node0};
+    REQUIRE(c2.get_args() == uid_cx_10);
+    REQUIRE(*c2.get_op_ptr() == *get_op_ptr(OpType::CX));
+  }
 }
 }  // namespace tket