Included optimization flag in treespile (sim. annealing to minimize Pauli weight)

Author: april864

src/cmd/fham_cmd.cpp

@@ -133,7 +133,7 @@ dvlab::Command fham_qubitize_cmd(FermionHamiltonianMgr& fham_mgr, QubitHamiltoni
             qbham_mgr.set_filename(fham_mgr.get_filename());
             qbham_mgr.add_procedures(fham_mgr.get_procedures());
 
-            std::string proc_name = strategy == "jw" ? "fham_qubitize_jw" : "fham_qubitize_ternary_tree";
+            std::string proc_name = strategy == "ternary_tree" ? "fham_qubitize_ternary_tree" : "fham_qubitize_jw";
             if (strategy == "ternary_tree" && optimize) proc_name += "_optimized";
             qbham_mgr.add_procedure(proc_name);
 
@@ -194,6 +194,9 @@ dvlab::Command fham_treespile_cmd(
                 .constraint(choices_allow_prefix({"log_success_rate", "default"}))
                 .default_value("default")
                 .help("cost function for Floyd-Warshall used inside treespile");
+            parser.add_argument<bool>("-o", "--optimize")
+                .action(store_true)
+                .help("Run simulated annealing to minimize Pauli weight");
         },
         [&](ArgumentParser const& parser) {
             if (device_mgr.empty()) {
@@ -217,12 +220,13 @@ dvlab::Command fham_treespile_cmd(
 
             auto const time        = parser.get<double>("time");
             auto const cost_fn_str = parser.get<std::string>("--cost-fn");
+            bool optimize          = parser.get<bool>("--optimize");
             auto cost_fn           = device::default_floyd_warshall_cost;
             if (dvlab::str::is_prefix_of(dvlab::str::tolower_string(cost_fn_str), "log_success_rate")) {
                 cost_fn = device::log_success_rate_floyd_warshall_cost;
             }
 
-            auto const result = treespile(*f_ham, device, time, n_steps, cost_fn);
+            auto const result = treespile(*f_ham, device, time, n_steps, cost_fn, optimize);
 
             if (!result.has_value()) {
                 auto const reason = result.error();

src/hamiltonian/treespile.cpp

@@ -449,7 +449,8 @@ treespile(
     device::Device const& device,
     double time,
     size_t n_trotterization_steps,
-    device::APSPCostFnType const& cost_fn) {
+    device::APSPCostFnType const& cost_fn,
+    bool optimize) {
     //
     using FailReason = TreespileFailReason;
 
@@ -470,14 +471,18 @@ treespile(
 
     auto const apsp = floyd_warshall(device, cost_fn);
 
-    auto const tree = build_bonsai_ternary_tree(device, apsp, n_modes);
+    auto tree = build_bonsai_ternary_tree(device, apsp, n_modes);
 
     if (!tree.has_value()) {
         // NOTE: it's still possible for bonsai to fail because the device might
         // be disconnected.
         return tl::unexpected(FailReason::tt_build_failed_not_enough_qubits);
     }
 
+    if (optimize) {
+        tree = optimize_mapping(*tree, hamiltonian, &device);
+    }
+
     auto const mapping = TernaryTreeMapping(tree.value());
 
     auto const qubit_hamiltonian = qubitize(hamiltonian, mapping);

src/hamiltonian/treespile.hpp

@@ -37,7 +37,8 @@ treespile(
     device::Device const& device,
     double time,
     size_t n_trotterization_steps,
-    device::APSPCostFnType const& cost_fn = device::default_floyd_warshall_cost);
+    device::APSPCostFnType const& cost_fn = device::default_floyd_warshall_cost,
+    bool optimize = false);
 
 
 }  // namespace qsyn::hamiltonian