Implement density matrix simulation via full tensor network contraction

tnqvm/TNQVM.hpp

@@ -65,9 +65,16 @@ class TNQVM : public Accelerator {
       vqeMode = config.get<bool>("vqe-mode");
     }
 
-    if (config.stringExists("tnqvm-visitor")) {
-      const auto requestedBackend = config.getString("tnqvm-visitor");
-      const auto& allVisitorServices = xacc::getServices<TNQVMVisitor>();
+    if (config.stringExists("tnqvm-visitor") ||
+        config.stringExists("backend")) {
+      // Get the specific TNQVM visitor, either using the `tnqvm-visitor` key
+      // or the `backend` key.
+      // e.g., when users use the convention "tnqvm::exatn", "exatn" will be
+      // parsed and passed in the "backend" field.
+      const auto requestedBackend = config.stringExists("tnqvm-visitor")
+                                        ? config.getString("tnqvm-visitor")
+                                        : config.getString("backend");
+      const auto &allVisitorServices = xacc::getServices<TNQVMVisitor>();
       // We must have at least one TNQVM service registered.
       assert(!allVisitorServices.empty());
       bool foundRequestedBackend = false;
@@ -133,7 +140,13 @@ class TNQVM : public Accelerator {
   const std::string& getVisitorName() const { return backendName; }
 
   virtual ~TNQVM() {}
-
+
+  virtual HeterogeneousMap getExecutionInfo() const override { 
+    auto result = visitor->getExecutionInfo();
+    result.insert("visitor", visitor->name());
+    return result; 
+  }
+
   int verbose() const { return __verbose; }
   void verbose(int level) { __verbose = level; }
   void set_verbose(int level) { __verbose = level; }

tnqvm/visitors/CMakeLists.txt

@@ -32,4 +32,5 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 add_subdirectory(itensor)
 add_subdirectory(exatn)
 add_subdirectory(exatn-mps)
-add_subdirectory(exatn-mpo)
+add_subdirectory(exatn-mpo)
+add_subdirectory(exatn-dm)

tnqvm/visitors/TNQVMVisitor.hpp

@@ -71,9 +71,14 @@ class TNQVMVisitor : public AllGateVisitor, public OptionsProvider,
   // Does this visitor implementation support VQE mode execution?
   // i.e. ability to cache the state vector after simulating the ansatz.
   virtual bool supportVqeMode() const { return false; }
+  // Execution information that visitor wants to persist.
+  HeterogeneousMap getExecutionInfo() const { return executionInfo; }
+
 protected:
   std::shared_ptr<AcceleratorBuffer> buffer;
   HeterogeneousMap options;
+  // Visitor impl to set if need be.
+  HeterogeneousMap executionInfo;
 };
 
 } // namespace tnqvm

tnqvm/visitors/exatn-dm/CMakeLists.txt

@@ -0,0 +1,79 @@
+find_package(ExaTN QUIET)
+
+if (ExaTN_FOUND)
+   message(STATUS "Found ExaTN at ${EXATN_ROOT}")
+   set (PACKAGE_NAME "TNQVM ExaTN Density Matrix Visitor")
+   set (PACKAGE_DESCIPTION "TNQVM ExaTN Density Matrix backend")
+   set (LIBRARY_NAME tnqvm-exatn-dm)
+
+  if (TNQVM_MPI_ENABLED) 
+   find_package(MPI REQUIRED)
+   message(STATUS "Found a suitable MPI compiler ${MPI_CXX_COMPILER}.")
+   message(STATUS "Compiler vendor is [${CMAKE_CXX_COMPILER_ID}]")
+   message(STATUS "Include path: ${MPI_CXX_INCLUDE_DIRS}")
+   message(STATUS "Compile flags: ${MPI_CXX_COMPILE_FLAGS}")
+   message(STATUS "Link flags: ${MPI_CXX_LINK_FLAGS}")
+   message(STATUS "Libraries: ${MPI_CXX_LIBRARIES}")
+   include_directories(${MPI_CXX_INCLUDE_DIRS})
+   link_libraries(${MPI_CXX_LIBRARIES})
+   add_definitions(-DTNQVM_MPI_ENABLED)
+  endif()  
+
+   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DTNQVM_HAS_EXATN")
+   set(CMAKE_INSTALL_RPATH "${EXATN_ROOT}/lib")
+   set(EXATN_VISITOR_CPP_FILE ExaTnDmVisitor.cpp)
+
+   if (EXATN_BLAS_LIB MATCHES MKL)
+      # Fix for bug #30
+      message(STATUS "Exatn built with MKL, updating our build: ${EXATN_MKL_PATH}")
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DTNQVM_EXATN_USES_MKL_BLAS")
+      configure_file("${CMAKE_CURRENT_SOURCE_DIR}/ExaTnDmVisitor.cpp"
+               "${CMAKE_BINARY_DIR}/tnqvm/visitors/exatn-mpo/ExaTnDmVisitor.cpp" @ONLY)
+      set(EXATN_VISITOR_CPP_FILE ${CMAKE_BINARY_DIR}/tnqvm/visitors/exatn-mpo/ExaTnDmVisitor.cpp)
+   endif()
+
+   file (GLOB HEADERS *.hpp)
+   file (GLOB SRC ${EXATN_VISITOR_CPP_FILE})
+
+   usFunctionGetResourceSource(TARGET ${LIBRARY_NAME} OUT SRC)
+   usFunctionGenerateBundleInit(TARGET ${LIBRARY_NAME} OUT SRC)
+
+   add_library(${LIBRARY_NAME} SHARED ${SRC})
+
+   set(_bundle_name tnqvm_exatn_dm)
+   set_target_properties(${LIBRARY_NAME} PROPERTIES
+   # This is required for every bundle
+   COMPILE_DEFINITIONS US_BUNDLE_NAME=${_bundle_name}
+   # This is for convenience, used by other CMake functions
+   US_BUNDLE_NAME ${_bundle_name}
+   )
+
+   # Embed meta-data from a manifest.json file
+   usFunctionEmbedResources(TARGET ${LIBRARY_NAME}
+      WORKING_DIRECTORY
+      ${CMAKE_CURRENT_SOURCE_DIR}
+      FILES
+      manifest.json
+   )
+
+   target_include_directories(${LIBRARY_NAME} PUBLIC . .. ${XACC_DIR}/include/xacc/)
+
+   # Links to ExaTN using its linker config flags.
+   target_link_libraries(${LIBRARY_NAME} PUBLIC xacc::xacc exatn::exatn xacc::quantum_gate)
+
+   if(APPLE)
+      set_target_properties(${LIBRARY_NAME} PROPERTIES INSTALL_RPATH "@loader_path/../lib")
+      set_target_properties(${LIBRARY_NAME} PROPERTIES LINK_FLAGS "-undefined dynamic_lookup")
+   else()
+      set_target_properties(${LIBRARY_NAME} PROPERTIES INSTALL_RPATH "$ORIGIN/../lib;${EXATN_ROOT}/lib;${BLAS_PATH}")
+      set_target_properties(${LIBRARY_NAME} PROPERTIES LINK_FLAGS "-shared")
+   endif()
+
+   install(TARGETS ${LIBRARY_NAME} DESTINATION ${CMAKE_INSTALL_PREFIX}/plugins)
+
+   if(TNQVM_BUILD_TESTS)
+	   add_subdirectory(tests)
+   endif()
+else()
+   message(STATUS "ExaTN not found, skipping ExaTNVisitor build")
+endif()