[OpenMP] Initial implementation of OpenMP offloading library - libomptarget.

This is the patch upstreaming the device-agnostic part of libomptarget.

Differential Revision: https://reviews.llvm.org/D14031



git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@293094 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3d60633..35b6f6c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,3 +3,4 @@
 set(OPENMP_LLVM_TOOLS_DIR "" CACHE PATH "Path to LLVM tools for testing")
 
 add_subdirectory(runtime)
+add_subdirectory(libomptarget)
diff --git a/libomptarget/Build_With_CMake.txt b/libomptarget/Build_With_CMake.txt
new file mode 100644
index 0000000..c7c9b03
--- /dev/null
+++ b/libomptarget/Build_With_CMake.txt
@@ -0,0 +1,142 @@
+#
+#//===----------------------------------------------------------------------===//
+#//
+#//                     The LLVM Compiler Infrastructure
+#//
+#// This file is dual licensed under the MIT and the University of Illinois Open
+#// Source Licenses. See LICENSE.txt for details.
+#//
+#//===----------------------------------------------------------------------===//
+#
+
+=====================================================================
+How to Build the LLVM* OpenMP* Offloading Runtime Library using CMake
+=====================================================================
+
+==== Version of CMake required: v2.8.0 or above ====
+ 
+============================================
+How to call cmake initially, then repeatedly
+============================================
+- When calling cmake for the first time, all needed compiler options
+  must be specified on the command line.  After this initial call to
+  cmake, the compiler definitions must not be included for further calls
+  to cmake.  Other options can be specified on the command line multiple
+  times including all definitions in the Build options section below.
+- Example of configuring, building, reconfiguring, rebuilding:
+  $ mkdir build
+  $ cd build
+  $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ ..  # Initial configuration
+  $ make
+  ...
+  $ make clean
+  $ cmake -DCMAKE_BUILD_TYPE=Debug ..                         # Second configuration
+  $ make
+  ...
+  $ rm -rf *
+  $ cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ ..  # Third configuration
+  $ make
+- Notice in the example how the compiler definitions are only specified
+  for an empty build directory, but other Build options are used at any time.
+- The file CMakeCache.txt which is created after the first call to cmake
+  is a configuration file which holds all the values for the Build options.
+  These configuration values can be changed using a text editor to modify 
+  CMakeCache.txt as opposed to using definitions on the command line.
+- To have cmake create a particular type of build generator file simply 
+  inlude the -G <Generator name> option:
+  $ cmake -G "Unix Makefiles" ...
+  You can see a list of generators cmake supports by executing cmake with
+  no arguments and a list will be printed.
+
+=====================
+Instructions to Build
+=====================
+ $ cd libomptarget_top_level/ [ directory with plugins/ , deviceRTLs/ , etc. ]
+ $ mkdir build
+ $ cd build
+
+ [ Unix* Libraries ]
+ $ cmake -DCMAKE_C_COMPILER=<C Compiler> -DCMAKE_CXX_COMPILER=<C++ Compiler> ..
+
+ $ make
+ $ make install
+
+===========
+Tests
+===========
+After the library has been built, there are optional tests that can be 
+performed.  Some will be skipped based upon the platform.
+To run the tests,
+$ make check-libomptarget
+
+=============
+CMake options
+=============
+-DCMAKE_C_COMPILER=<C compiler name>
+Specify the C compiler
+
+-DCMAKE_CXX_COMPILER=<C++ compiler name>
+Specify the C++ compiler
+
+==== First values listed are the default value ====
+-DCMAKE_BUILD_TYPE=Release|Debug|RelWithDebInfo
+Build type can be Release, Debug, or RelWithDebInfo.
+
+-DLIBOMPTARGET_ENABLE_WERROR=true|false
+Should consider warnings as errors.
+
+-DLIBOMPTARGET_LLVM_LIT_EXECUTABLE=""
+Full path to the llvm-lit tool. Required for testing in out-of-tree builds.
+
+-DLIBOMPTARGET_FILECHECK_EXECUTABLE=""
+Full path to the FileCheck tool. Required for testing in out-of-tree builds.
+
+-DLIBOMPTARGET_OPENMP_HEADER_FOLDER=""
+Path of the folder that contains omp.h. This is required for testing 
+out-of-tree builds.
+
+-DLIBOMPTARGET_OPENMP_HOST_RTL_FOLDER=""
+Path of the folder that contains libomp.so. This is required for testing 
+out-of-tree builds.
+
+==== NVPTX device RTL specific ====
+-DLIBOMPTARGET_NVPTX_ENABLE_BCLIB=false|true
+Enable CUDA LLVM bitcode offloading device RTL. This is used for
+link time optimization of the omp runtime and application code.
+
+-DLIBOMPTARGET_NVPTX_CUDA_COMPILER=<CUDA compiler name>
+Location of a CUDA compiler capable of emitting LLVM bitcode.
+Currently only the Clang compiler is supported. This is only used
+when building the CUDA LLVM bitcode offloading device RTL. If
+unspecified, the default paths are inspected.
+
+-DLIBOMPTARGET_NVPTX_BC_LINKER=<LLVM bitcode linker>
+Location of a linker capable of linking LLVM bitcode objects.
+This is only used when building the CUDA LLVM bitcode offloading
+device RTL. If unspecified, the default paths are inspected.
+
+-DLIBOMPTARGET_NVPTX_ALTERNATE_HOST_COMPILER=""
+Host compiler to use with NVCC. This compiler is not going to be used to produce
+any binary. Instead, this is used to overcome the input compiler checks done by
+NVCC. E.g. if using a default host compiler that is not compatible with NVCC,
+this option can be use to pass to NVCC a valid compiler to avoid the error. 
+
+-DLIBOMPTARGET_NVPTX_COMPUTE_CAPABILITY="35"
+Comma-separated list of CUDA compute capabilities that should be supported by
+the NVPTX device RTL. E.g. for compute capabilities 3.0 and 3.5, the option 
+"30,35" should be used.
+
+=======================
+Example usages of CMake
+=======================
+---- Typical usage ----
+cmake -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ ..
+cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ..
+
+---- Request an NVPTX runtime library that supports compute capability 5.0 ----
+cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DLIBOMPTARGET_NVPTX_COMPUTE_CAPABILITY="50"
+
+=========
+Footnotes
+=========
+[*] Other names and brands may be claimed as the property of others.
diff --git a/libomptarget/CMakeLists.txt b/libomptarget/CMakeLists.txt
new file mode 100644
index 0000000..519f9e7
--- /dev/null
+++ b/libomptarget/CMakeLists.txt
@@ -0,0 +1,115 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is dual licensed under the MIT and the University of Illinois Open
+# Source Licenses. See LICENSE.txt for details.
+# 
+##===----------------------------------------------------------------------===##
+#
+# Build offloading library libomptarget.so.
+#
+##===----------------------------------------------------------------------===##
+
+# CMAKE libomptarget
+cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+
+# Add cmake directory to search for custom cmake functions.
+set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules ${CMAKE_MODULE_PATH})
+
+# Standalone build or part of LLVM?
+set(LIBOMPTARGET_STANDALONE_BUILD FALSE)
+if("${CMAKE_SOURCE_DIR}" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}" OR
+   "${CMAKE_SOURCE_DIR}/libomptarget" STREQUAL "${CMAKE_CURRENT_SOURCE_DIR}")
+  project(libomptarget C CXX)
+  set(LIBOMPTARGET_STANDALONE_BUILD TRUE)
+endif()
+  
+  
+if(${LIBOMPTARGET_STANDALONE_BUILD})
+  set(LIBOMPTARGET_ENABLE_WERROR FALSE CACHE BOOL
+    "Enable -Werror flags to turn warnings into errors for supporting compilers.")
+  # CMAKE_BUILD_TYPE was not defined, set default to Release
+  if(NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE Release)
+  endif()
+  set(LIBOMPTARGET_LIBDIR_SUFFIX "" CACHE STRING
+    "suffix of lib installation directory, e.g. 64 => lib64")
+else()
+  set(LIBOMPTARGET_ENABLE_WERROR ${LLVM_ENABLE_WERROR})
+  # If building in tree, we honor the same install suffix LLVM uses.
+  set(LIBOMPTARGET_LIBDIR_SUFFIX ${LLVM_LIBDIR_SUFFIX})
+endif()
+
+# Compiler flag checks.
+include(config-ix)
+
+# Message utilities.
+include(LibomptargetUtils)
+
+# Get dependencies for the different components of the project.
+include(LibomptargetGetDependencies)
+
+# This is a list of all the targets that are supported/tested right now.
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64le-ibm-linux-gnu")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64-ibm-linux-gnu")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} x86_64-pc-linux-gnu")
+set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} nvptx64-nvidia-cuda")
+
+# Once the plugins for the different targets are validated, they will be added to
+# the list of supported targets in the current system.
+set (LIBOMPTARGET_SYSTEM_TARGETS "")
+
+# Set base directories - required for lit to locate the tests.
+set(LIBOMPTARGET_BASE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
+set(LIBOMPTARGET_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+
+# We need C++11 support.
+if(LIBOMPTARGET_HAVE_STD_CPP11_FLAG)
+  
+  libomptarget_say("Building offloading runtime library libomptarget.")
+
+  # Enable support for C++11.
+  add_definitions(-std=c++11)
+  
+  if(LIBOMPTARGET_ENABLE_WERROR AND LIBOMPTARGET_HAVE_WERROR_FLAG)
+    add_definitions(-Werror)
+  endif()
+  
+  # If building this library in debug mode, we define a macro to enable
+  # dumping progress messages at runtime.
+  string( TOLOWER "${CMAKE_BUILD_TYPE}" LIBOMPTARGET_CMAKE_BUILD_TYPE)
+  if(LIBOMPTARGET_CMAKE_BUILD_TYPE MATCHES debug)
+    add_definitions(-DOMPTARGET_DEBUG)
+    add_definitions(-g)
+    add_definitions(-O0)
+  endif()
+  
+  set(src_files
+    src/omptarget.cpp
+  )
+  
+  include_directories(src/)
+  
+  # Build libomptarget library with libdl dependency.
+  add_library(omptarget SHARED ${src_files})
+  target_link_libraries(omptarget
+    dl
+    "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/exports")
+  
+  # Install libomptarget under the lib destination folder.
+  install(TARGETS omptarget LIBRARY DESTINATION lib${LIBOMPTARGET_LIBDIR_SUFFIX})
+  
+  # Retrieve the path to the resulting library so that it can be used for 
+  # testing.
+  get_target_property(LIBOMPTARGET_LIBRARY_DIR omptarget LIBRARY_OUTPUT_DIRECTORY)
+  if(NOT LIBOMPTARGET_LIBRARY_DIR)
+    set(LIBOMPTARGET_LIBRARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
+  endif()
+
+  # Add tests.
+  add_subdirectory(test)
+  
+else(LIBOMPTARGET_HAVE_STD_CPP11_FLAG)
+  libomptarget_say("Not building offloading runtime library libomptarget: host compiler must have c++11 support.")
+endif(LIBOMPTARGET_HAVE_STD_CPP11_FLAG)
diff --git a/libomptarget/README.txt b/libomptarget/README.txt
new file mode 100644
index 0000000..195c8df
--- /dev/null
+++ b/libomptarget/README.txt
@@ -0,0 +1,72 @@
+
+    README for the LLVM* OpenMP* Offloading Runtime Library (libomptarget)
+    ======================================================================
+
+How to Build the LLVM* OpenMP* Offloading Runtime Library (libomptarget)
+========================================================================
+In-tree build:
+
+$ cd where-you-want-to-live
+Check out openmp (libomptarget lives under ./libomptarget) into llvm/projects
+$ cd where-you-want-to-build
+$ mkdir build && cd build
+$ cmake path/to/llvm -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
+$ make omptarget
+
+Out-of-tree build:
+
+$ cd where-you-want-to-live
+Check out openmp (libomptarget lives under ./libomptarget)
+$ cd where-you-want-to-live/openmp/libomptarget
+$ mkdir build && cd build
+$ cmake path/to/openmp -DCMAKE_C_COMPILER=<C compiler> -DCMAKE_CXX_COMPILER=<C++ compiler>
+$ make
+
+For details about building, please look at Build_With_CMake.txt
+
+Architectures Supported
+=======================
+The current library has been only tested in Linux operating system and the 
+following host architectures: 
+* Intel(R) 64 architecture
+* IBM(R) Power architecture (big endian)
+* IBM(R) Power architecture (little endian)
+
+The currently supported offloading device architectures are:
+* Intel(R) 64 architecture (generic 64-bit plugin - mostly for testing purposes)
+* IBM(R) Power architecture (big endian) (generic 64-bit plugin - mostly for testing purposes)
+* IBM(R) Power architecture (little endian) (generic 64-bit plugin - mostly for testing purposes)
+* CUDA(R) enabled 64-bit NVIDIA(R) GPU architectures
+
+Supported RTL Build Configurations
+==================================
+Supported Architectures: Intel(R) 64, IBM(R) Power 7 and Power 8
+
+              ---------------------------
+              |   gcc      |   clang    |
+--------------|------------|------------|
+| Linux* OS   |  Yes(1)    |  Yes(2)    |
+-----------------------------------------
+
+(1) gcc version 4.8.2 or later is supported.
+(2) clang version 3.7 or later is supported.
+
+
+Front-end Compilers that work with this RTL
+===========================================
+
+The following compilers are known to do compatible code generation for
+this RTL: 
+  - clang (from https://github.com/clang-ykt )
+  - clang (development branch at http://clang.llvm.org - several features still 
+    under development)
+
+-----------------------------------------------------------------------
+
+Notices
+=======
+This library and related compiler support is still under development, so the 
+employed interface is likely to change in the future.
+
+*Other names and brands may be claimed as the property of others.
+
diff --git a/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake b/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake
new file mode 100644
index 0000000..37227c0
--- /dev/null
+++ b/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake
@@ -0,0 +1,124 @@
+#
+#//===----------------------------------------------------------------------===//
+#//
+#//                     The LLVM Compiler Infrastructure
+#//
+#// This file is dual licensed under the MIT and the University of Illinois Open
+#// Source Licenses. See LICENSE.txt for details.
+#//
+#//===----------------------------------------------------------------------===//
+#
+
+# Try to detect in the system several dependencies required by the different
+# components of libomptarget. These are the dependencies we have:
+#
+# libelf : required by some targets to handle the ELF files at runtime.
+# libffi : required to launch target kernels given function and argument 
+#          pointers.
+# CUDA : required to control offloading to NVIDIA GPUs.
+
+include (FindPackageHandleStandardArgs)
+
+################################################################################
+# Looking for libelf...
+################################################################################
+
+find_path (
+  LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIR
+  NAMES
+    libelf.h
+  PATHS
+    /usr/include
+    /usr/local/include
+    /opt/local/include
+    /sw/include
+    ENV CPATH
+  PATH_SUFFIXES
+    libelf)
+
+find_library (
+  LIBOMPTARGET_DEP_LIBELF_LIBRARIES
+  NAMES
+    elf
+  PATHS
+    /usr/lib
+    /usr/local/lib
+    /opt/local/lib
+    /sw/lib
+    ENV LIBRARY_PATH
+    ENV LD_LIBRARY_PATH)
+    
+set(LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIRS ${LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIR})
+find_package_handle_standard_args(
+  LIBOMPTARGET_DEP_LIBELF 
+  DEFAULT_MSG
+  LIBOMPTARGET_DEP_LIBELF_LIBRARIES
+  LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIRS)
+
+mark_as_advanced(
+  LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIRS 
+  LIBOMPTARGET_DEP_LIBELF_LIBRARIES)
+  
+################################################################################
+# Looking for libffi...
+################################################################################
+find_package(PkgConfig)
+
+pkg_check_modules(LIBOMPTARGET_SEARCH_LIBFFI QUIET libffi)
+
+find_path (
+  LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIR
+  NAMES
+    ffi.h
+  HINTS
+    ${LIBOMPTARGET_SEARCH_LIBFFI_INCLUDEDIR}
+    ${LIBOMPTARGET_SEARCH_LIBFFI_INCLUDE_DIRS}
+  PATHS
+    /usr/include
+    /usr/local/include
+    /opt/local/include
+    /sw/include
+    ENV CPATH)
+
+# Don't bother look for the library if the header files were not found.
+if (LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIR)
+  find_library (
+      LIBOMPTARGET_DEP_LIBFFI_LIBRARIES
+    NAMES
+      ffi
+    HINTS
+      ${LIBOMPTARGET_SEARCH_LIBFFI_LIBDIR}
+      ${LIBOMPTARGET_SEARCH_LIBFFI_LIBRARY_DIRS}
+    PATHS
+      /usr/lib
+      /usr/local/lib
+      /opt/local/lib
+      /sw/lib
+      ENV LIBRARY_PATH
+      ENV LD_LIBRARY_PATH)
+endif()
+
+set(LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIRS ${LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIR})
+find_package_handle_standard_args(
+  LIBOMPTARGET_DEP_LIBFFI 
+  DEFAULT_MSG
+  LIBOMPTARGET_DEP_LIBFFI_LIBRARIES
+  LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIRS)
+
+mark_as_advanced(
+  LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIRS 
+  LIBOMPTARGET_DEP_LIBFFI_LIBRARIES)
+  
+################################################################################
+# Looking for CUDA...
+################################################################################
+find_package(CUDA QUIET)
+
+set(LIBOMPTARGET_DEP_CUDA_FOUND ${CUDA_FOUND})
+set(LIBOMPTARGET_DEP_CUDA_LIBRARIES ${CUDA_LIBRARIES})
+set(LIBOMPTARGET_DEP_CUDA_INCLUDE_DIRS ${CUDA_INCLUDE_DIRS})
+
+mark_as_advanced(
+  LIBOMPTARGET_DEP_CUDA_FOUND 
+  LIBOMPTARGET_DEP_CUDA_INCLUDE_DIRS
+  LIBOMPTARGET_DEP_CUDA_LIBRARIES)
diff --git a/libomptarget/cmake/Modules/LibomptargetUtils.cmake b/libomptarget/cmake/Modules/LibomptargetUtils.cmake
new file mode 100644
index 0000000..d964903
--- /dev/null
+++ b/libomptarget/cmake/Modules/LibomptargetUtils.cmake
@@ -0,0 +1,28 @@
+#
+#//===----------------------------------------------------------------------===//
+#//
+#//                     The LLVM Compiler Infrastructure
+#//
+#// This file is dual licensed under the MIT and the University of Illinois Open
+#// Source Licenses. See LICENSE.txt for details.
+#//
+#//===----------------------------------------------------------------------===//
+#
+
+# void libomptarget_say(string message_to_user);
+# - prints out message_to_user
+macro(libomptarget_say message_to_user)
+  message(STATUS "LIBOMPTARGET: ${message_to_user}")
+endmacro()
+
+# void libomptarget_warning_say(string message_to_user);
+# - prints out message_to_user with a warning
+macro(libomptarget_warning_say message_to_user)
+  message(WARNING "LIBOMPTARGET: ${message_to_user}")
+endmacro()
+
+# void libomptarget_error_say(string message_to_user);
+# - prints out message_to_user with an error and exits cmake
+macro(libomptarget_error_say message_to_user)
+  message(FATAL_ERROR "LIBOMPTARGET: ${message_to_user}")
+endmacro()
diff --git a/libomptarget/cmake/Modules/config-ix.cmake b/libomptarget/cmake/Modules/config-ix.cmake
new file mode 100644
index 0000000..9144270
--- /dev/null
+++ b/libomptarget/cmake/Modules/config-ix.cmake
@@ -0,0 +1,17 @@
+#
+#//===----------------------------------------------------------------------===//
+#//
+#//                     The LLVM Compiler Infrastructure
+#//
+#// This file is dual licensed under the MIT and the University of Illinois Open
+#// Source Licenses. See LICENSE.txt for details.
+#//
+#//===----------------------------------------------------------------------===//
+#
+
+include(CheckCCompilerFlag)
+include(CheckCXXCompilerFlag)
+
+# Checking C, CXX
+check_cxx_compiler_flag(-std=c++11 LIBOMPTARGET_HAVE_STD_CPP11_FLAG)
+check_c_compiler_flag(-Werror LIBOMPTARGET_HAVE_WERROR_FLAG)
diff --git a/libomptarget/exports b/libomptarget/exports
new file mode 100644
index 0000000..8114751
--- /dev/null
+++ b/libomptarget/exports
@@ -0,0 +1,28 @@
+VERS1.0 {
+  global:
+    __tgt_register_lib;
+    __tgt_unregister_lib;
+    __tgt_target_data_begin;
+    __tgt_target_data_end;
+    __tgt_target_data_update;
+    __tgt_target;
+    __tgt_target_teams;
+    __tgt_target_data_begin_nowait;
+    __tgt_target_data_end_nowait;
+    __tgt_target_data_update_nowait;
+    __tgt_target_nowait;
+    __tgt_target_teams_nowait;
+    omp_get_num_devices;
+    omp_get_initial_device;
+    omp_target_alloc;
+    omp_target_free;
+    omp_target_is_present;
+    omp_target_memcpy;
+    omp_target_memcpy_rect;
+    omp_target_associate_ptr;
+    omp_target_disassociate_ptr;
+    __kmpc_push_target_tripcount;
+  local:
+    *;
+};
+
diff --git a/libomptarget/src/omptarget.cpp b/libomptarget/src/omptarget.cpp
new file mode 100644
index 0000000..93e5732
--- /dev/null
+++ b/libomptarget/src/omptarget.cpp
@@ -0,0 +1,2323 @@
+//===------ omptarget.cpp - Target independent OpenMP target RTL -- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.txt for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of the interface to be used by Clang during the codegen of a
+// target region.
+//
+//===----------------------------------------------------------------------===//
+
+#include <algorithm>
+#include <cassert>
+#include <climits>
+#include <cstdlib>
+#include <cstring>
+#include <dlfcn.h>
+#include <list>
+#include <map>
+#include <mutex>
+#include <string>
+#include <vector>
+
+// Header file global to this project
+#include "omptarget.h"
+
+#define DP(...) DEBUGP("Libomptarget", __VA_ARGS__)
+#define INF_REF_CNT (LONG_MAX>>1) // leave room for additions/subtractions
+#define CONSIDERED_INF(x) (x > (INF_REF_CNT>>1))
+
+// List of all plugins that can support offloading.
+static const char *RTLNames[] = {
+    /* PowerPC target */ "libomptarget.rtl.ppc64.so",
+    /* x86_64 target  */ "libomptarget.rtl.x86_64.so",
+    /* CUDA target    */ "libomptarget.rtl.cuda.so"};
+
+// forward declarations
+struct RTLInfoTy;
+static int target(int32_t device_id, void *host_ptr, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int64_t *arg_types,
+    int32_t team_num, int32_t thread_limit, int IsTeamConstruct);
+
+/// Map between host data and target data.
+struct HostDataToTargetTy {
+  uintptr_t HstPtrBase; // host info.
+  uintptr_t HstPtrBegin;
+  uintptr_t HstPtrEnd; // non-inclusive.
+
+  uintptr_t TgtPtrBegin; // target info.
+
+  long RefCount;
+
+  HostDataToTargetTy()
+      : HstPtrBase(0), HstPtrBegin(0), HstPtrEnd(0),
+        TgtPtrBegin(0), RefCount(0) {}
+  HostDataToTargetTy(uintptr_t BP, uintptr_t B, uintptr_t E, uintptr_t TB)
+      : HstPtrBase(BP), HstPtrBegin(B), HstPtrEnd(E),
+        TgtPtrBegin(TB), RefCount(1) {}
+};
+
+typedef std::list<HostDataToTargetTy> HostDataToTargetListTy;
+
+struct LookupResult {
+  struct {
+    unsigned IsContained   : 1;
+    unsigned ExtendsBefore : 1;
+    unsigned ExtendsAfter  : 1;
+  } Flags;
+
+  HostDataToTargetListTy::iterator Entry;
+
+  LookupResult() : Flags({0,0,0}), Entry(0) {}
+};
+
+/// Map for shadow pointers
+struct ShadowPtrValTy {
+  void *HstPtrVal;
+  void *TgtPtrAddr;
+  void *TgtPtrVal;
+};
+typedef std::map<void *, ShadowPtrValTy> ShadowPtrListTy;
+
+///
+struct PendingCtorDtorListsTy {
+  std::list<void *> PendingCtors;
+  std::list<void *> PendingDtors;
+};
+typedef std::map<__tgt_bin_desc *, PendingCtorDtorListsTy>
+    PendingCtorsDtorsPerLibrary;
+
+struct DeviceTy {
+  int32_t DeviceID;
+  RTLInfoTy *RTL;
+  int32_t RTLDeviceID;
+
+  bool IsInit;
+  std::once_flag InitFlag;
+  bool HasPendingGlobals;
+
+  HostDataToTargetListTy HostDataToTargetMap;
+  PendingCtorsDtorsPerLibrary PendingCtorsDtors;
+
+  ShadowPtrListTy ShadowPtrMap;
+
+  std::mutex DataMapMtx, PendingGlobalsMtx, ShadowMtx;
+
+  uint64_t loopTripCnt;
+
+  DeviceTy(RTLInfoTy *RTL)
+      : DeviceID(-1), RTL(RTL), RTLDeviceID(-1), IsInit(false), InitFlag(),
+        HasPendingGlobals(false), HostDataToTargetMap(),
+        PendingCtorsDtors(), ShadowPtrMap(), DataMapMtx(), PendingGlobalsMtx(),
+        ShadowMtx(), loopTripCnt(0) {}
+
+  // The existence of mutexes makes DeviceTy non-copyable. We need to
+  // provide a copy constructor and an assignment operator explicitly.
+  DeviceTy(const DeviceTy &d)
+      : DeviceID(d.DeviceID), RTL(d.RTL), RTLDeviceID(d.RTLDeviceID),
+        IsInit(d.IsInit), InitFlag(), HasPendingGlobals(d.HasPendingGlobals),
+        HostDataToTargetMap(d.HostDataToTargetMap),
+        PendingCtorsDtors(d.PendingCtorsDtors), ShadowPtrMap(d.ShadowPtrMap),
+        DataMapMtx(), PendingGlobalsMtx(),
+        ShadowMtx(), loopTripCnt(d.loopTripCnt) {}
+
+  DeviceTy& operator=(const DeviceTy &d) {
+    DeviceID = d.DeviceID;
+    RTL = d.RTL;
+    RTLDeviceID = d.RTLDeviceID;
+    IsInit = d.IsInit;
+    HasPendingGlobals = d.HasPendingGlobals;
+    HostDataToTargetMap = d.HostDataToTargetMap;
+    PendingCtorsDtors = d.PendingCtorsDtors;
+    ShadowPtrMap = d.ShadowPtrMap;
+    loopTripCnt = d.loopTripCnt;
+
+    return *this;
+  }
+
+  long getMapEntryRefCnt(void *HstPtrBegin);
+  LookupResult lookupMapping(void *HstPtrBegin, int64_t Size);
+  void *getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase, int64_t Size,
+      bool &IsNew, bool IsImplicit, bool UpdateRefCount = true);
+  void *getTgtPtrBegin(void *HstPtrBegin, int64_t Size);
+  void *getTgtPtrBegin(void *HstPtrBegin, int64_t Size, bool &IsLast,
+      bool UpdateRefCount);
+  int deallocTgtPtr(void *TgtPtrBegin, int64_t Size, bool ForceDelete);
+  int associatePtr(void *HstPtrBegin, void *TgtPtrBegin, int64_t Size);
+  int disassociatePtr(void *HstPtrBegin);
+
+  // calls to RTL
+  int32_t initOnce();
+  __tgt_target_table *load_binary(void *Img);
+
+  int32_t data_submit(void *TgtPtrBegin, void *HstPtrBegin, int64_t Size);
+  int32_t data_retrieve(void *HstPtrBegin, void *TgtPtrBegin, int64_t Size);
+
+  int32_t run_region(void *TgtEntryPtr, void **TgtVarsPtr, int32_t TgtVarsSize);
+  int32_t run_team_region(void *TgtEntryPtr, void **TgtVarsPtr,
+      int32_t TgtVarsSize, int32_t NumTeams, int32_t ThreadLimit,
+      uint64_t LoopTripCount);
+
+private:
+  // Call to RTL
+  void init(); // To be called only via DeviceTy::initOnce()
+};
+
+/// Map between Device ID (i.e. openmp device id) and its DeviceTy.
+typedef std::vector<DeviceTy> DevicesTy;
+static DevicesTy Devices;
+
+struct RTLInfoTy {
+  typedef int32_t(is_valid_binary_ty)(void *);
+  typedef int32_t(number_of_devices_ty)();
+  typedef int32_t(init_device_ty)(int32_t);
+  typedef __tgt_target_table *(load_binary_ty)(int32_t, void *);
+  typedef void *(data_alloc_ty)(int32_t, int64_t);
+  typedef int32_t(data_submit_ty)(int32_t, void *, void *, int64_t);
+  typedef int32_t(data_retrieve_ty)(int32_t, void *, void *, int64_t);
+  typedef int32_t(data_delete_ty)(int32_t, void *);
+  typedef int32_t(run_region_ty)(int32_t, void *, void **, int32_t);
+  typedef int32_t(run_team_region_ty)(int32_t, void *, void **, int32_t,
+                                      int32_t, int32_t, uint64_t);
+
+  int32_t Idx;                     // RTL index, index is the number of devices
+                                   // of other RTLs that were registered before,
+                                   // i.e. the OpenMP index of the first device
+                                   // to be registered with this RTL.
+  int32_t NumberOfDevices;         // Number of devices this RTL deals with.
+  std::vector<DeviceTy *> Devices; // one per device (NumberOfDevices in total).
+
+  void *LibraryHandler;
+
+#ifdef OMPTARGET_DEBUG
+  std::string RTLName;
+#endif
+
+  // Functions implemented in the RTL.
+  is_valid_binary_ty *is_valid_binary;
+  number_of_devices_ty *number_of_devices;
+  init_device_ty *init_device;
+  load_binary_ty *load_binary;
+  data_alloc_ty *data_alloc;
+  data_submit_ty *data_submit;
+  data_retrieve_ty *data_retrieve;
+  data_delete_ty *data_delete;
+  run_region_ty *run_region;
+  run_team_region_ty *run_team_region;
+
+  // Are there images associated with this RTL.
+  bool isUsed;
+
+  // Mutex for thread-safety when calling RTL interface functions.
+  // It is easier to enforce thread-safety at the libomptarget level,
+  // so that developers of new RTLs do not have to worry about it.
+  std::mutex Mtx;
+
+  // The existence of the mutex above makes RTLInfoTy non-copyable.
+  // We need to provide a copy constructor explicitly.
+  RTLInfoTy()
+      : Idx(-1), NumberOfDevices(-1), Devices(), LibraryHandler(0),
+#ifdef OMPTARGET_DEBUG
+        RTLName(),
+#endif
+        is_valid_binary(0), number_of_devices(0), init_device(0),
+        load_binary(0), data_alloc(0), data_submit(0), data_retrieve(0),
+        data_delete(0), run_region(0), run_team_region(0), isUsed(false),
+        Mtx() {}
+
+  RTLInfoTy(const RTLInfoTy &r) : Mtx() {
+    Idx = r.Idx;
+    NumberOfDevices = r.NumberOfDevices;
+    Devices = r.Devices;
+    LibraryHandler = r.LibraryHandler;
+#ifdef OMPTARGET_DEBUG
+    RTLName = r.RTLName;
+#endif
+    is_valid_binary = r.is_valid_binary;
+    number_of_devices = r.number_of_devices;
+    init_device = r.init_device;
+    load_binary = r.load_binary;
+    data_alloc = r.data_alloc;
+    data_submit = r.data_submit;
+    data_retrieve = r.data_retrieve;
+    data_delete = r.data_delete;
+    run_region = r.run_region;
+    run_team_region = r.run_team_region;
+    isUsed = r.isUsed;
+  }
+};
+
+/// RTLs identified in the system.
+class RTLsTy {
+private:
+  // Mutex-like object to guarantee thread-safety and unique initialization
+  // (i.e. the library attempts to load the RTLs (plugins) only once).
+  std::once_flag initFlag;
+  void LoadRTLs(); // not thread-safe
+
+public:
+  // List of the detected runtime libraries.
+  std::list<RTLInfoTy> AllRTLs;
+
+  // Array of pointers to the detected runtime libraries that have compatible
+  // binaries.
+  std::vector<RTLInfoTy *> UsedRTLs;
+
+  explicit RTLsTy() {}
+
+  // Load all the runtime libraries (plugins) if not done before.
+  void LoadRTLsOnce();
+};
+
+void RTLsTy::LoadRTLs() {
+  // Parse environment variable OMP_TARGET_OFFLOAD (if set)
+  char *envStr = getenv("OMP_TARGET_OFFLOAD");
+  if (envStr && !strcmp(envStr, "DISABLED")) {
+    DP("Target offloading disabled by environment\n");
+    return;
+  }
+
+  DP("Loading RTLs...\n");
+
+  // Attempt to open all the plugins and, if they exist, check if the interface
+  // is correct and if they are supporting any devices.
+  for (auto *Name : RTLNames) {
+    DP("Loading library '%s'...\n", Name);
+    void *dynlib_handle = dlopen(Name, RTLD_NOW);
+
+    if (!dynlib_handle) {
+      // Library does not exist or cannot be found.
+      DP("Unable to load library '%s': %s!\n", Name, dlerror());
+      continue;
+    }
+
+    DP("Successfully loaded library '%s'!\n", Name);
+
+    // Retrieve the RTL information from the runtime library.
+    RTLInfoTy R;
+
+    R.LibraryHandler = dynlib_handle;
+    R.isUsed = false;
+
+#ifdef OMPTARGET_DEBUG
+    R.RTLName = Name;
+#endif
+
+    if (!(R.is_valid_binary = (RTLInfoTy::is_valid_binary_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_is_valid_binary")))
+      continue;
+    if (!(R.number_of_devices = (RTLInfoTy::number_of_devices_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_number_of_devices")))
+      continue;
+    if (!(R.init_device = (RTLInfoTy::init_device_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_init_device")))
+      continue;
+    if (!(R.load_binary = (RTLInfoTy::load_binary_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_load_binary")))
+      continue;
+    if (!(R.data_alloc = (RTLInfoTy::data_alloc_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_data_alloc")))
+      continue;
+    if (!(R.data_submit = (RTLInfoTy::data_submit_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_data_submit")))
+      continue;
+    if (!(R.data_retrieve = (RTLInfoTy::data_retrieve_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_data_retrieve")))
+      continue;
+    if (!(R.data_delete = (RTLInfoTy::data_delete_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_data_delete")))
+      continue;
+    if (!(R.run_region = (RTLInfoTy::run_region_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_run_target_region")))
+      continue;
+    if (!(R.run_team_region = (RTLInfoTy::run_team_region_ty *)dlsym(
+              dynlib_handle, "__tgt_rtl_run_target_team_region")))
+      continue;
+
+    // No devices are supported by this RTL?
+    if (!(R.NumberOfDevices = R.number_of_devices())) {
+      DP("No devices supported in this RTL\n");
+      continue;
+    }
+
+    DP("Registering RTL %s supporting %d devices!\n",
+        R.RTLName.c_str(), R.NumberOfDevices);
+
+    // The RTL is valid! Will save the information in the RTLs list.
+    AllRTLs.push_back(R);
+  }
+
+  DP("RTLs loaded!\n");
+
+  return;
+}
+
+void RTLsTy::LoadRTLsOnce() {
+  // RTL.LoadRTLs() is called only once in a thread-safe fashion.
+  std::call_once(initFlag, &RTLsTy::LoadRTLs, this);
+}
+
+static RTLsTy RTLs;
+static std::mutex RTLsMtx;
+
+/// Map between the host entry begin and the translation table. Each
+/// registered library gets one TranslationTable. Use the map from
+/// __tgt_offload_entry so that we may quickly determine whether we
+/// are trying to (re)register an existing lib or really have a new one.
+struct TranslationTable {
+  __tgt_target_table HostTable;
+
+  // Image assigned to a given device.
+  std::vector<__tgt_device_image *> TargetsImages; // One image per device ID.
+
+  // Table of entry points or NULL if it was not already computed.
+  std::vector<__tgt_target_table *> TargetsTable; // One table per device ID.
+};
+typedef std::map<__tgt_offload_entry *, TranslationTable>
+    HostEntriesBeginToTransTableTy;
+static HostEntriesBeginToTransTableTy HostEntriesBeginToTransTable;
+static std::mutex TrlTblMtx;
+
+/// Map between the host ptr and a table index
+struct TableMap {
+  TranslationTable *Table; // table associated with the host ptr.
+  uint32_t Index; // index in which the host ptr translated entry is found.
+  TableMap() : Table(0), Index(0) {}
+  TableMap(TranslationTable *table, uint32_t index)
+      : Table(table), Index(index) {}
+};
+typedef std::map<void *, TableMap> HostPtrToTableMapTy;
+static HostPtrToTableMapTy HostPtrToTableMap;
+static std::mutex TblMapMtx;
+
+/// Check whether a device has an associated RTL and initialize it if it's not
+/// already initialized.
+static bool device_is_ready(int device_num) {
+  DP("Checking whether device %d is ready.\n", device_num);
+  // Devices.size() can only change while registering a new
+  // library, so try to acquire the lock of RTLs' mutex.
+  RTLsMtx.lock();
+  size_t Devices_size = Devices.size();
+  RTLsMtx.unlock();
+  if (Devices_size <= (size_t)device_num) {
+    DP("Device ID  %d does not have a matching RTL\n", device_num);
+    return false;
+  }
+
+  // Get device info
+  DeviceTy &Device = Devices[device_num];
+
+  DP("Is the device %d (local ID %d) initialized? %d\n", device_num,
+       Device.RTLDeviceID, Device.IsInit);
+
+  // Init the device if not done before
+  if (!Device.IsInit && Device.initOnce() != OFFLOAD_SUCCESS) {
+    DP("Failed to init device %d\n", device_num);
+    return false;
+  }
+
+  DP("Device %d is ready to use.\n", device_num);
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Target API functions
+//
+EXTERN int omp_get_num_devices(void) {
+  RTLsMtx.lock();
+  size_t Devices_size = Devices.size();
+  RTLsMtx.unlock();
+
+  DP("Call to omp_get_num_devices returning %zd\n", Devices_size);
+
+  return Devices_size;
+}
+
+EXTERN int omp_get_initial_device(void) {
+  DP("Call to omp_get_initial_device returning %d\n", HOST_DEVICE);
+  return HOST_DEVICE;
+}
+
+EXTERN void *omp_target_alloc(size_t size, int device_num) {
+  DP("Call to omp_target_alloc for device %d requesting %zu bytes\n",
+      device_num, size);
+
+  if (size <= 0) {
+    DP("Call to omp_target_alloc with non-positive length\n");
+    return NULL;
+  }
+
+  void *rc = NULL;
+
+  if (device_num == omp_get_initial_device()) {
+    rc = malloc(size);
+    DP("omp_target_alloc returns host ptr " DPxMOD "\n", DPxPTR(rc));
+    return rc;
+  }
+
+  if (!device_is_ready(device_num)) {
+    DP("omp_target_alloc returns NULL ptr\n");
+    return NULL;
+  }
+
+  DeviceTy &Device = Devices[device_num];
+  rc = Device.RTL->data_alloc(Device.RTLDeviceID, size);
+  DP("omp_target_alloc returns device ptr " DPxMOD "\n", DPxPTR(rc));
+  return rc;
+}
+
+EXTERN void omp_target_free(void *device_ptr, int device_num) {
+  DP("Call to omp_target_free for device %d and address " DPxMOD "\n",
+      device_num, DPxPTR(device_ptr));
+
+  if (!device_ptr) {
+    DP("Call to omp_target_free with NULL ptr\n");
+    return;
+  }
+
+  if (device_num == omp_get_initial_device()) {
+    free(device_ptr);
+    DP("omp_target_free deallocated host ptr\n");
+    return;
+  }
+
+  if (!device_is_ready(device_num)) {
+    DP("omp_target_free returns, nothing to do\n");
+    return;
+  }
+
+  DeviceTy &Device = Devices[device_num];
+  Device.RTL->data_delete(Device.RTLDeviceID, (void *)device_ptr);
+  DP("omp_target_free deallocated device ptr\n");
+}
+
+EXTERN int omp_target_is_present(void *ptr, int device_num) {
+  DP("Call to omp_target_is_present for device %d and address " DPxMOD "\n",
+      device_num, DPxPTR(ptr));
+
+  if (!ptr) {
+    DP("Call to omp_target_is_present with NULL ptr, returning false\n");
+    return false;
+  }
+
+  if (device_num == omp_get_initial_device()) {
+    DP("Call to omp_target_is_present on host, returning true\n");
+    return true;
+  }
+
+  RTLsMtx.lock();
+  size_t Devices_size = Devices.size();
+  RTLsMtx.unlock();
+  if (Devices_size <= (size_t)device_num) {
+    DP("Call to omp_target_is_present with invalid device ID, returning "
+        "false\n");
+    return false;
+  }
+
+  DeviceTy& Device = Devices[device_num];
+  bool IsLast; // not used
+  int rc = (Device.getTgtPtrBegin(ptr, 0, IsLast, false) != NULL);
+  DP("Call to omp_target_is_present returns %d\n", rc);
+  return rc;
+}
+
+EXTERN int omp_target_memcpy(void *dst, void *src, size_t length,
+    size_t dst_offset, size_t src_offset, int dst_device, int src_device) {
+  DP("Call to omp_target_memcpy, dst device %d, src device %d, "
+      "dst addr " DPxMOD ", src addr " DPxMOD ", dst offset %zu, "
+      "src offset %zu, length %zu\n", dst_device, src_device, DPxPTR(dst),
+      DPxPTR(src), dst_offset, src_offset, length);
+
+  if (!dst || !src || length <= 0) {
+    DP("Call to omp_target_memcpy with invalid arguments\n");
+    return OFFLOAD_FAIL;
+  }
+
+  if (src_device != omp_get_initial_device() && !device_is_ready(src_device)) {
+      DP("omp_target_memcpy returns OFFLOAD_FAIL\n");
+      return OFFLOAD_FAIL;
+  }
+
+  if (dst_device != omp_get_initial_device() && !device_is_ready(dst_device)) {
+      DP("omp_target_memcpy returns OFFLOAD_FAIL\n");
+      return OFFLOAD_FAIL;
+  }
+
+  int rc = OFFLOAD_SUCCESS;
+  void *srcAddr = (char *)src + src_offset;
+  void *dstAddr = (char *)dst + dst_offset;
+
+  if (src_device == omp_get_initial_device() &&
+      dst_device == omp_get_initial_device()) {
+    DP("copy from host to host\n");
+    const void *p = memcpy(dstAddr, srcAddr, length);
+    if (p == NULL)
+      rc = OFFLOAD_FAIL;
+  } else if (src_device == omp_get_initial_device()) {
+    DP("copy from host to device\n");
+    DeviceTy& DstDev = Devices[dst_device];
+    rc = DstDev.data_submit(dstAddr, srcAddr, length);
+  } else if (dst_device == omp_get_initial_device()) {
+    DP("copy from device to host\n");
+    DeviceTy& SrcDev = Devices[src_device];
+    rc = SrcDev.data_retrieve(dstAddr, srcAddr, length);
+  } else {
+    DP("copy from device to device\n");
+    void *buffer = malloc(length);
+    DeviceTy& SrcDev = Devices[src_device];
+    DeviceTy& DstDev = Devices[dst_device];
+    rc = SrcDev.data_retrieve(buffer, srcAddr, length);
+    if (rc == OFFLOAD_SUCCESS)
+      rc = DstDev.data_submit(dstAddr, buffer, length);
+  }
+
+  DP("omp_target_memcpy returns %d\n", rc);
+  return rc;
+}
+
+EXTERN int omp_target_memcpy_rect(void *dst, void *src, size_t element_size,
+    int num_dims, const size_t *volume, const size_t *dst_offsets,
+    const size_t *src_offsets, const size_t *dst_dimensions,
+    const size_t *src_dimensions, int dst_device, int src_device) {
+  DP("Call to omp_target_memcpy_rect, dst device %d, src device %d, "
+      "dst addr " DPxMOD ", src addr " DPxMOD ", dst offsets " DPxMOD ", "
+      "src offsets " DPxMOD ", dst dims " DPxMOD ", src dims " DPxMOD ", "
+      "volume " DPxMOD ", element size %zu, num_dims %d\n", dst_device,
+      src_device, DPxPTR(dst), DPxPTR(src), DPxPTR(dst_offsets),
+      DPxPTR(src_offsets), DPxPTR(dst_dimensions), DPxPTR(src_dimensions),
+      DPxPTR(volume), element_size, num_dims);
+
+  if (!(dst || src)) {
+    DP("Call to omp_target_memcpy_rect returns max supported dimensions %d\n",
+        INT_MAX);
+    return INT_MAX;
+  }
+
+  if (!dst || !src || element_size < 1 || num_dims < 1 || !volume ||
+      !dst_offsets || !src_offsets || !dst_dimensions || !src_dimensions) {
+    DP("Call to omp_target_memcpy_rect with invalid arguments\n");
+    return OFFLOAD_FAIL;
+  }
+
+  int rc;
+  if (num_dims == 1) {
+    rc = omp_target_memcpy(dst, src, element_size * volume[0],
+        element_size * dst_offsets[0], element_size * src_offsets[0],
+        dst_device, src_device);
+  } else {
+    size_t dst_slice_size = element_size;
+    size_t src_slice_size = element_size;
+    for (int i=1; i<num_dims; ++i) {
+      dst_slice_size *= dst_dimensions[i];
+      src_slice_size *= src_dimensions[i];
+    }
+
+    size_t dst_off = dst_offsets[0] * dst_slice_size;
+    size_t src_off = src_offsets[0] * src_slice_size;
+    for (size_t i=0; i<volume[0]; ++i) {
+      rc = omp_target_memcpy_rect((char *) dst + dst_off + dst_slice_size * i,
+          (char *) src + src_off + src_slice_size * i, element_size,
+          num_dims - 1, volume + 1, dst_offsets + 1, src_offsets + 1,
+          dst_dimensions + 1, src_dimensions + 1, dst_device, src_device);
+
+      if (rc) {
+        DP("Recursive call to omp_target_memcpy_rect returns unsuccessfully\n");
+        return rc;
+      }
+    }
+  }
+
+  DP("omp_target_memcpy_rect returns %d\n", rc);
+  return rc;
+}
+
+EXTERN int omp_target_associate_ptr(void *host_ptr, void *device_ptr,
+    size_t size, size_t device_offset, int device_num) {
+  DP("Call to omp_target_associate_ptr with host_ptr " DPxMOD ", "
+      "device_ptr " DPxMOD ", size %zu, device_offset %zu, device_num %d\n",
+      DPxPTR(host_ptr), DPxPTR(device_ptr), size, device_offset, device_num);
+
+  if (!host_ptr || !device_ptr || size <= 0) {
+    DP("Call to omp_target_associate_ptr with invalid arguments\n");
+    return OFFLOAD_FAIL;
+  }
+
+  if (device_num == omp_get_initial_device()) {
+    DP("omp_target_associate_ptr: no association possible on the host\n");
+    return OFFLOAD_FAIL;
+  }
+
+  if (!device_is_ready(device_num)) {
+    DP("omp_target_associate_ptr returns OFFLOAD_FAIL\n");
+    return OFFLOAD_FAIL;
+  }
+
+  DeviceTy& Device = Devices[device_num];
+  void *device_addr = (void *)((uint64_t)device_ptr + (uint64_t)device_offset);
+  int rc = Device.associatePtr(host_ptr, device_addr, size);
+  DP("omp_target_associate_ptr returns %d\n", rc);
+  return rc;
+}
+
+EXTERN int omp_target_disassociate_ptr(void *host_ptr, int device_num) {
+  DP("Call to omp_target_disassociate_ptr with host_ptr " DPxMOD ", "
+      "device_num %d\n", DPxPTR(host_ptr), device_num);
+
+  if (!host_ptr) {
+    DP("Call to omp_target_associate_ptr with invalid host_ptr\n");
+    return OFFLOAD_FAIL;
+  }
+
+  if (device_num == omp_get_initial_device()) {
+    DP("omp_target_disassociate_ptr: no association possible on the host\n");
+    return OFFLOAD_FAIL;
+  }
+
+  if (!device_is_ready(device_num)) {
+    DP("omp_target_disassociate_ptr returns OFFLOAD_FAIL\n");
+    return OFFLOAD_FAIL;
+  }
+
+  DeviceTy& Device = Devices[device_num];
+  int rc = Device.disassociatePtr(host_ptr);
+  DP("omp_target_disassociate_ptr returns %d\n", rc);
+  return rc;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// functionality for device
+
+int DeviceTy::associatePtr(void *HstPtrBegin, void *TgtPtrBegin, int64_t Size) {
+  DataMapMtx.lock();
+
+  // Check if entry exists
+  for (auto &HT : HostDataToTargetMap) {
+    if ((uintptr_t)HstPtrBegin == HT.HstPtrBegin) {
+      // Mapping already exists
+      bool isValid = HT.HstPtrBegin == (uintptr_t) HstPtrBegin &&
+                     HT.HstPtrEnd == (uintptr_t) HstPtrBegin + Size &&
+                     HT.TgtPtrBegin == (uintptr_t) TgtPtrBegin;
+      DataMapMtx.unlock();
+      if (isValid) {
+        DP("Attempt to re-associate the same device ptr+offset with the same "
+            "host ptr, nothing to do\n");
+        return OFFLOAD_SUCCESS;
+      } else {
+        DP("Not allowed to re-associate a different device ptr+offset with the "
+            "same host ptr\n");
+        return OFFLOAD_FAIL;
+      }
+    }
+  }
+
+  // Mapping does not exist, allocate it
+  HostDataToTargetTy newEntry;
+
+  // Set up missing fields
+  newEntry.HstPtrBase = (uintptr_t) HstPtrBegin;
+  newEntry.HstPtrBegin = (uintptr_t) HstPtrBegin;
+  newEntry.HstPtrEnd = (uintptr_t) HstPtrBegin + Size;
+  newEntry.TgtPtrBegin = (uintptr_t) TgtPtrBegin;
+  // refCount must be infinite
+  newEntry.RefCount = INF_REF_CNT;
+
+  DP("Creating new map entry: HstBase=" DPxMOD ", HstBegin=" DPxMOD ", HstEnd="
+      DPxMOD ", TgtBegin=" DPxMOD "\n", DPxPTR(newEntry.HstPtrBase),
+      DPxPTR(newEntry.HstPtrBegin), DPxPTR(newEntry.HstPtrEnd),
+      DPxPTR(newEntry.TgtPtrBegin));
+  HostDataToTargetMap.push_front(newEntry);
+
+  DataMapMtx.unlock();
+
+  return OFFLOAD_SUCCESS;
+}
+
+int DeviceTy::disassociatePtr(void *HstPtrBegin) {
+  DataMapMtx.lock();
+
+  // Check if entry exists
+  for (HostDataToTargetListTy::iterator ii = HostDataToTargetMap.begin();
+      ii != HostDataToTargetMap.end(); ++ii) {
+    if ((uintptr_t)HstPtrBegin == ii->HstPtrBegin) {
+      // Mapping exists
+      if (CONSIDERED_INF(ii->RefCount)) {
+        DP("Association found, removing it\n");
+        HostDataToTargetMap.erase(ii);
+        DataMapMtx.unlock();
+        return OFFLOAD_SUCCESS;
+      } else {
+        DP("Trying to disassociate a pointer which was not mapped via "
+            "omp_target_associate_ptr\n");
+        break;
+      }
+    }
+  }
+
+  // Mapping not found
+  DataMapMtx.unlock();
+  DP("Association not found\n");
+  return OFFLOAD_FAIL;
+}
+
+// Get ref count of map entry containing HstPtrBegin
+long DeviceTy::getMapEntryRefCnt(void *HstPtrBegin) {
+  uintptr_t hp = (uintptr_t)HstPtrBegin;
+  long RefCnt = -1;
+
+  DataMapMtx.lock();
+  for (auto &HT : HostDataToTargetMap) {
+    if (hp >= HT.HstPtrBegin && hp < HT.HstPtrEnd) {
+      DP("DeviceTy::getMapEntry: requested entry found\n");
+      RefCnt = HT.RefCount;
+      break;
+    }
+  }
+  DataMapMtx.unlock();
+
+  if (RefCnt < 0) {
+    DP("DeviceTy::getMapEntry: requested entry not found\n");
+  }
+
+  return RefCnt;
+}
+
+LookupResult DeviceTy::lookupMapping(void *HstPtrBegin, int64_t Size) {
+  uintptr_t hp = (uintptr_t)HstPtrBegin;
+  LookupResult lr;
+
+  DP("Looking up mapping(HstPtrBegin=" DPxMOD ", Size=%ld)...\n", DPxPTR(hp),
+      Size);
+  for (lr.Entry = HostDataToTargetMap.begin();
+      lr.Entry != HostDataToTargetMap.end(); ++lr.Entry) {
+    auto &HT = *lr.Entry;
+    // Is it contained?
+    lr.Flags.IsContained = hp >= HT.HstPtrBegin && hp < HT.HstPtrEnd &&
+        (hp+Size) <= HT.HstPtrEnd;
+    // Does it extend into an already mapped region?
+    lr.Flags.ExtendsBefore = hp < HT.HstPtrBegin && (hp+Size) > HT.HstPtrBegin;
+    // Does it extend beyond the mapped region?
+    lr.Flags.ExtendsAfter = hp < HT.HstPtrEnd && (hp+Size) > HT.HstPtrEnd;
+
+    if (lr.Flags.IsContained || lr.Flags.ExtendsBefore ||
+        lr.Flags.ExtendsAfter) {
+      break;
+    }
+  }
+
+  if (lr.Flags.ExtendsBefore) {
+    DP("WARNING: Pointer is not mapped but section extends into already "
+        "mapped data\n");
+  }
+  if (lr.Flags.ExtendsAfter) {
+    DP("WARNING: Pointer is already mapped but section extends beyond mapped "
+        "region\n");
+  }
+
+  return lr;
+}
+
+// Used by target_data_begin
+// Return the target pointer begin (where the data will be moved).
+// Allocate memory if this is the first occurrence if this mapping.
+// Increment the reference counter.
+// If NULL is returned, then either data allocation failed or the user tried
+// to do an illegal mapping.
+void *DeviceTy::getOrAllocTgtPtr(void *HstPtrBegin, void *HstPtrBase,
+    int64_t Size, bool &IsNew, bool IsImplicit, bool UpdateRefCount) {
+  void *rc = NULL;
+  DataMapMtx.lock();
+  LookupResult lr = lookupMapping(HstPtrBegin, Size);
+
+  // Check if the pointer is contained.
+  if (lr.Flags.IsContained ||
+      ((lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) && IsImplicit)) {
+    auto &HT = *lr.Entry;
+    IsNew = false;
+
+    if (UpdateRefCount)
+      ++HT.RefCount;
+
+    uintptr_t tp = HT.TgtPtrBegin + ((uintptr_t)HstPtrBegin - HT.HstPtrBegin);
+    DP("Mapping exists%s with HstPtrBegin=" DPxMOD ", TgtPtrBegin=" DPxMOD ", "
+        "Size=%ld,%s RefCount=%s\n", (IsImplicit ? " (implicit)" : ""),
+        DPxPTR(HstPtrBegin), DPxPTR(tp), Size,
+        (UpdateRefCount ? " updated" : ""),
+        (CONSIDERED_INF(HT.RefCount)) ? "INF" :
+            std::to_string(HT.RefCount).c_str());
+    rc = (void *)tp;
+  } else if ((lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) && !IsImplicit) {
+    // Explicit extension of mapped data - not allowed.
+    DP("Explicit extension of mapping is not allowed.\n");
+  } else if (Size) {
+    // If it is not contained and Size > 0 we should create a new entry for it.
+    IsNew = true;
+    uintptr_t tp = (uintptr_t)RTL->data_alloc(RTLDeviceID, Size);
+    DP("Creating new map entry: HstBase=" DPxMOD ", HstBegin=" DPxMOD ", "
+        "HstEnd=" DPxMOD ", TgtBegin=" DPxMOD "\n", DPxPTR(HstPtrBase),
+        DPxPTR(HstPtrBegin), DPxPTR((uintptr_t)HstPtrBegin + Size), DPxPTR(tp));
+    HostDataToTargetMap.push_front(HostDataToTargetTy((uintptr_t)HstPtrBase,
+        (uintptr_t)HstPtrBegin, (uintptr_t)HstPtrBegin + Size, tp));
+    rc = (void *)tp;
+  }
+
+  DataMapMtx.unlock();
+  return rc;
+}
+
+// Used by target_data_begin, target_data_end, target_data_update and target.
+// Return the target pointer begin (where the data will be moved).
+// Decrement the reference counter if called from target_data_end.
+void *DeviceTy::getTgtPtrBegin(void *HstPtrBegin, int64_t Size, bool &IsLast,
+    bool UpdateRefCount) {
+  void *rc = NULL;
+  DataMapMtx.lock();
+  LookupResult lr = lookupMapping(HstPtrBegin, Size);
+
+  if (lr.Flags.IsContained || lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) {
+    auto &HT = *lr.Entry;
+    IsLast = !(HT.RefCount > 1);
+
+    if (HT.RefCount > 1 && UpdateRefCount)
+      --HT.RefCount;
+
+    uintptr_t tp = HT.TgtPtrBegin + ((uintptr_t)HstPtrBegin - HT.HstPtrBegin);
+    DP("Mapping exists with HstPtrBegin=" DPxMOD ", TgtPtrBegin=" DPxMOD ", "
+        "Size=%ld,%s RefCount=%s\n", DPxPTR(HstPtrBegin), DPxPTR(tp), Size,
+        (UpdateRefCount ? " updated" : ""),
+        (CONSIDERED_INF(HT.RefCount)) ? "INF" :
+            std::to_string(HT.RefCount).c_str());
+    rc = (void *)tp;
+  } else {
+    IsLast = false;
+  }
+
+  DataMapMtx.unlock();
+  return rc;
+}
+
+// Return the target pointer begin (where the data will be moved).
+// Lock-free version called from within assertions.
+void *DeviceTy::getTgtPtrBegin(void *HstPtrBegin, int64_t Size) {
+  uintptr_t hp = (uintptr_t)HstPtrBegin;
+  LookupResult lr = lookupMapping(HstPtrBegin, Size);
+  if (lr.Flags.IsContained || lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) {
+    auto &HT = *lr.Entry;
+    uintptr_t tp = HT.TgtPtrBegin + (hp - HT.HstPtrBegin);
+    return (void *)tp;
+  }
+
+  return NULL;
+}
+
+int DeviceTy::deallocTgtPtr(void *HstPtrBegin, int64_t Size, bool ForceDelete) {
+  // Check if the pointer is contained in any sub-nodes.
+  int rc;
+  DataMapMtx.lock();
+  LookupResult lr = lookupMapping(HstPtrBegin, Size);
+  if (lr.Flags.IsContained || lr.Flags.ExtendsBefore || lr.Flags.ExtendsAfter) {
+    auto &HT = *lr.Entry;
+    if (ForceDelete)
+      HT.RefCount = 1;
+    if (--HT.RefCount <= 0) {
+      assert(HT.RefCount == 0 && "did not expect a negative ref count");
+      DP("Deleting tgt data " DPxMOD " of size %ld\n",
+          DPxPTR(HT.TgtPtrBegin), Size);
+      RTL->data_delete(RTLDeviceID, (void *)HT.TgtPtrBegin);
+      DP("Removing%s mapping with HstPtrBegin=" DPxMOD ", TgtPtrBegin=" DPxMOD
+          ", Size=%ld\n", (ForceDelete ? " (forced)" : ""),
+          DPxPTR(HT.HstPtrBegin), DPxPTR(HT.TgtPtrBegin), Size);
+      HostDataToTargetMap.erase(lr.Entry);
+    }
+    rc = OFFLOAD_SUCCESS;
+  } else {
+    DP("Section to delete (hst addr " DPxMOD ") does not exist in the allocated"
+       " memory\n", DPxPTR(HstPtrBegin));
+    rc = OFFLOAD_FAIL;
+  }
+
+  DataMapMtx.unlock();
+  return rc;
+}
+
+/// Init device, should not be called directly.
+void DeviceTy::init() {
+  int32_t rc = RTL->init_device(RTLDeviceID);
+  if (rc == OFFLOAD_SUCCESS) {
+    IsInit = true;
+  }
+}
+
+/// Thread-safe method to initialize the device only once.
+int32_t DeviceTy::initOnce() {
+  std::call_once(InitFlag, &DeviceTy::init, this);
+
+  // At this point, if IsInit is true, then either this thread or some other
+  // thread in the past successfully initialized the device, so we can return
+  // OFFLOAD_SUCCESS. If this thread executed init() via call_once() and it
+  // failed, return OFFLOAD_FAIL. If call_once did not invoke init(), it means
+  // that some other thread already attempted to execute init() and if IsInit
+  // is still false, return OFFLOAD_FAIL.
+  if (IsInit)
+    return OFFLOAD_SUCCESS;
+  else
+    return OFFLOAD_FAIL;
+}
+
+// Load binary to device.
+__tgt_target_table *DeviceTy::load_binary(void *Img) {
+  RTL->Mtx.lock();
+  __tgt_target_table *rc = RTL->load_binary(RTLDeviceID, Img);
+  RTL->Mtx.unlock();
+  return rc;
+}
+
+// Submit data to device.
+int32_t DeviceTy::data_submit(void *TgtPtrBegin, void *HstPtrBegin,
+    int64_t Size) {
+  return RTL->data_submit(RTLDeviceID, TgtPtrBegin, HstPtrBegin, Size);
+}
+
+// Retrieve data from device.
+int32_t DeviceTy::data_retrieve(void *HstPtrBegin, void *TgtPtrBegin,
+    int64_t Size) {
+  return RTL->data_retrieve(RTLDeviceID, HstPtrBegin, TgtPtrBegin, Size);
+}
+
+// Run region on device
+int32_t DeviceTy::run_region(void *TgtEntryPtr, void **TgtVarsPtr,
+    int32_t TgtVarsSize) {
+  return RTL->run_region(RTLDeviceID, TgtEntryPtr, TgtVarsPtr, TgtVarsSize);
+}
+
+// Run team region on device.
+int32_t DeviceTy::run_team_region(void *TgtEntryPtr, void **TgtVarsPtr,
+    int32_t TgtVarsSize, int32_t NumTeams, int32_t ThreadLimit,
+    uint64_t LoopTripCount) {
+  return RTL->run_team_region(RTLDeviceID, TgtEntryPtr, TgtVarsPtr, TgtVarsSize,
+      NumTeams, ThreadLimit, LoopTripCount);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Functionality for registering libs
+
+static void RegisterImageIntoTranslationTable(TranslationTable &TT,
+    RTLInfoTy &RTL, __tgt_device_image *image) {
+
+  // same size, as when we increase one, we also increase the other.
+  assert(TT.TargetsTable.size() == TT.TargetsImages.size() &&
+         "We should have as many images as we have tables!");
+
+  // Resize the Targets Table and Images to accommodate the new targets if
+  // required
+  unsigned TargetsTableMinimumSize = RTL.Idx + RTL.NumberOfDevices;
+
+  if (TT.TargetsTable.size() < TargetsTableMinimumSize) {
+    TT.TargetsImages.resize(TargetsTableMinimumSize, 0);
+    TT.TargetsTable.resize(TargetsTableMinimumSize, 0);
+  }
+
+  // Register the image in all devices for this target type.
+  for (int32_t i = 0; i < RTL.NumberOfDevices; ++i) {
+    // If we are changing the image we are also invalidating the target table.
+    if (TT.TargetsImages[RTL.Idx + i] != image) {
+      TT.TargetsImages[RTL.Idx + i] = image;
+      TT.TargetsTable[RTL.Idx + i] = 0; // lazy initialization of target table.
+    }
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Functionality for registering Ctors/Dtors
+
+static void RegisterGlobalCtorsDtorsForImage(__tgt_bin_desc *desc,
+    __tgt_device_image *img, RTLInfoTy *RTL) {
+
+  for (int32_t i = 0; i < RTL->NumberOfDevices; ++i) {
+    DeviceTy &Device = Devices[RTL->Idx + i];
+    Device.PendingGlobalsMtx.lock();
+    Device.HasPendingGlobals = true;
+    for (__tgt_offload_entry *entry = img->EntriesBegin;
+        entry != img->EntriesEnd; ++entry) {
+      if (entry->flags & OMP_DECLARE_TARGET_CTOR) {
+        DP("Adding ctor " DPxMOD " to the pending list.\n",
+            DPxPTR(entry->addr));
+        Device.PendingCtorsDtors[desc].PendingCtors.push_back(entry->addr);
+      } else if (entry->flags & OMP_DECLARE_TARGET_DTOR) {
+        // Dtors are pushed in reverse order so they are executed from end
+        // to beginning when unregistering the library!
+        DP("Adding dtor " DPxMOD " to the pending list.\n",
+            DPxPTR(entry->addr));
+        Device.PendingCtorsDtors[desc].PendingDtors.push_front(entry->addr);
+      }
+
+      if (entry->flags & OMP_DECLARE_TARGET_LINK) {
+        DP("The \"link\" attribute is not yet supported!\n");
+      }
+    }
+    Device.PendingGlobalsMtx.unlock();
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// adds a target shared library to the target execution image
+EXTERN void __tgt_register_lib(__tgt_bin_desc *desc) {
+
+  // Attempt to load all plugins available in the system.
+  RTLs.LoadRTLsOnce();
+
+  RTLsMtx.lock();
+  // Register the images with the RTLs that understand them, if any.
+  for (int32_t i = 0; i < desc->NumDeviceImages; ++i) {
+    // Obtain the image.
+    __tgt_device_image *img = &desc->DeviceImages[i];
+
+    RTLInfoTy *FoundRTL = NULL;
+
+    // Scan the RTLs that have associated images until we find one that supports
+    // the current image.
+    for (auto &R : RTLs.AllRTLs) {
+      if (!R.is_valid_binary(img)) {
+        DP("Image " DPxMOD " is NOT compatible with RTL %s!\n",
+            DPxPTR(img->ImageStart), R.RTLName.c_str());
+        continue;
+      }
+
+      DP("Image " DPxMOD " is compatible with RTL %s!\n",
+          DPxPTR(img->ImageStart), R.RTLName.c_str());
+
+      // If this RTL is not already in use, initialize it.
+      if (!R.isUsed) {
+        // Initialize the device information for the RTL we are about to use.
+        DeviceTy device(&R);
+
+        size_t start = Devices.size();
+        Devices.resize(start + R.NumberOfDevices, device);
+        for (int32_t device_id = 0; device_id < R.NumberOfDevices;
+            device_id++) {
+          // global device ID
+          Devices[start + device_id].DeviceID = start + device_id;
+          // RTL local device ID
+          Devices[start + device_id].RTLDeviceID = device_id;
+
+          // Save pointer to device in RTL in case we want to unregister the RTL
+          R.Devices.push_back(&Devices[start + device_id]);
+        }
+
+        // Initialize the index of this RTL and save it in the used RTLs.
+        R.Idx = (RTLs.UsedRTLs.empty())
+                    ? 0
+                    : RTLs.UsedRTLs.back()->Idx +
+                          RTLs.UsedRTLs.back()->NumberOfDevices;
+        assert((size_t) R.Idx == start &&
+            "RTL index should equal the number of devices used so far.");
+        R.isUsed = true;
+        RTLs.UsedRTLs.push_back(&R);
+
+        DP("RTL " DPxMOD " has index %d!\n", DPxPTR(R.LibraryHandler), R.Idx);
+      }
+
+      // Initialize (if necessary) translation table for this library.
+      TrlTblMtx.lock();
+      if(!HostEntriesBeginToTransTable.count(desc->HostEntriesBegin)){
+        TranslationTable &tt =
+            HostEntriesBeginToTransTable[desc->HostEntriesBegin];
+        tt.HostTable.EntriesBegin = desc->HostEntriesBegin;
+        tt.HostTable.EntriesEnd = desc->HostEntriesEnd;
+      }
+
+      // Retrieve translation table for this library.
+      TranslationTable &TransTable =
+          HostEntriesBeginToTransTable[desc->HostEntriesBegin];
+
+      DP("Registering image " DPxMOD " with RTL %s!\n",
+          DPxPTR(img->ImageStart), R.RTLName.c_str());
+      RegisterImageIntoTranslationTable(TransTable, R, img);
+      TrlTblMtx.unlock();
+      FoundRTL = &R;
+
+      // Load ctors/dtors for static objects
+      RegisterGlobalCtorsDtorsForImage(desc, img, FoundRTL);
+
+      // if an RTL was found we are done - proceed to register the next image
+      break;
+    }
+
+    if (!FoundRTL) {
+      DP("No RTL found for image " DPxMOD "!\n", DPxPTR(img->ImageStart));
+    }
+  }
+  RTLsMtx.unlock();
+
+
+  DP("Done registering entries!\n");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// unloads a target shared library
+EXTERN void __tgt_unregister_lib(__tgt_bin_desc *desc) {
+  DP("Unloading target library!\n");
+
+  RTLsMtx.lock();
+  // Find which RTL understands each image, if any.
+  for (int32_t i = 0; i < desc->NumDeviceImages; ++i) {
+    // Obtain the image.
+    __tgt_device_image *img = &desc->DeviceImages[i];
+
+    RTLInfoTy *FoundRTL = NULL;
+
+    // Scan the RTLs that have associated images until we find one that supports
+    // the current image. We only need to scan RTLs that are already being used.
+    for (auto *R : RTLs.UsedRTLs) {
+
+      assert(R->isUsed && "Expecting used RTLs.");
+
+      if (!R->is_valid_binary(img)) {
+        DP("Image " DPxMOD " is NOT compatible with RTL " DPxMOD "!\n",
+            DPxPTR(img->ImageStart), DPxPTR(R->LibraryHandler));
+        continue;
+      }
+
+      DP("Image " DPxMOD " is compatible with RTL " DPxMOD "!\n",
+          DPxPTR(img->ImageStart), DPxPTR(R->LibraryHandler));
+
+      FoundRTL = R;
+
+      // Execute dtors for static objects if the device has been used, i.e.
+      // if its PendingCtors list has been emptied.
+      for (int32_t i = 0; i < FoundRTL->NumberOfDevices; ++i) {
+        DeviceTy &Device = Devices[FoundRTL->Idx + i];
+        Device.PendingGlobalsMtx.lock();
+        if (Device.PendingCtorsDtors[desc].PendingCtors.empty()) {
+          for (auto &dtor : Device.PendingCtorsDtors[desc].PendingDtors) {
+            int rc = target(Device.DeviceID, dtor, 0, NULL, NULL, NULL, NULL, 1,
+                1, true /*team*/);
+            if (rc != OFFLOAD_SUCCESS) {
+              DP("Running destructor " DPxMOD " failed.\n", DPxPTR(dtor));
+            }
+          }
+          // Remove this library's entry from PendingCtorsDtors
+          Device.PendingCtorsDtors.erase(desc);
+        }
+        Device.PendingGlobalsMtx.unlock();
+      }
+
+      DP("Unregistered image " DPxMOD " from RTL " DPxMOD "!\n",
+          DPxPTR(img->ImageStart), DPxPTR(R->LibraryHandler));
+
+      break;
+    }
+
+    // if no RTL was found proceed to unregister the next image
+    if (!FoundRTL){
+      DP("No RTLs in use support the image " DPxMOD "!\n",
+          DPxPTR(img->ImageStart));
+    }
+  }
+  RTLsMtx.unlock();
+  DP("Done unregistering images!\n");
+
+  // Remove entries from HostPtrToTableMap
+  TblMapMtx.lock();
+  for (__tgt_offload_entry *cur = desc->HostEntriesBegin;
+      cur < desc->HostEntriesEnd; ++cur) {
+    HostPtrToTableMap.erase(cur->addr);
+  }
+
+  // Remove translation table for this descriptor.
+  auto tt = HostEntriesBeginToTransTable.find(desc->HostEntriesBegin);
+  if (tt != HostEntriesBeginToTransTable.end()) {
+    DP("Removing translation table for descriptor " DPxMOD "\n",
+        DPxPTR(desc->HostEntriesBegin));
+    HostEntriesBeginToTransTable.erase(tt);
+  } else {
+    DP("Translation table for descriptor " DPxMOD " cannot be found, probably "
+        "it has been already removed.\n", DPxPTR(desc->HostEntriesBegin));
+  }
+
+  TblMapMtx.unlock();
+
+  // TODO: Remove RTL and the devices it manages if it's not used anymore?
+  // TODO: Write some RTL->unload_image(...) function?
+
+  DP("Done unregistering library!\n");
+}
+
+/// Map global data and execute pending ctors
+static int InitLibrary(DeviceTy& Device) {
+  /*
+   * Map global data
+   */
+  int32_t device_id = Device.DeviceID;
+  int rc = OFFLOAD_SUCCESS;
+
+  Device.PendingGlobalsMtx.lock();
+  TrlTblMtx.lock();
+  for (HostEntriesBeginToTransTableTy::iterator
+      ii = HostEntriesBeginToTransTable.begin();
+      ii != HostEntriesBeginToTransTable.end(); ++ii) {
+    TranslationTable *TransTable = &ii->second;
+    if (TransTable->TargetsTable[device_id] != 0) {
+      // Library entries have already been processed
+      continue;
+    }
+
+    // 1) get image.
+    assert(TransTable->TargetsImages.size() > (size_t)device_id &&
+           "Not expecting a device ID outside the table's bounds!");
+    __tgt_device_image *img = TransTable->TargetsImages[device_id];
+    if (!img) {
+      DP("No image loaded for device id %d.\n", device_id);
+      rc = OFFLOAD_FAIL;
+      break;
+    }
+    // 2) load image into the target table.
+    __tgt_target_table *TargetTable =
+        TransTable->TargetsTable[device_id] = Device.load_binary(img);
+    // Unable to get table for this image: invalidate image and fail.
+    if (!TargetTable) {
+      DP("Unable to generate entries table for device id %d.\n", device_id);
+      TransTable->TargetsImages[device_id] = 0;
+      rc = OFFLOAD_FAIL;
+      break;
+    }
+
+    // Verify whether the two table sizes match.
+    size_t hsize =
+        TransTable->HostTable.EntriesEnd - TransTable->HostTable.EntriesBegin;
+    size_t tsize = TargetTable->EntriesEnd - TargetTable->EntriesBegin;
+
+    // Invalid image for these host entries!
+    if (hsize != tsize) {
+      DP("Host and Target tables mismatch for device id %d [%zx != %zx].\n",
+         device_id, hsize, tsize);
+      TransTable->TargetsImages[device_id] = 0;
+      TransTable->TargetsTable[device_id] = 0;
+      rc = OFFLOAD_FAIL;
+      break;
+    }
+
+    // process global data that needs to be mapped.
+    Device.DataMapMtx.lock();
+    __tgt_target_table *HostTable = &TransTable->HostTable;
+    for (__tgt_offload_entry *CurrDeviceEntry = TargetTable->EntriesBegin,
+                             *CurrHostEntry = HostTable->EntriesBegin,
+                             *EntryDeviceEnd = TargetTable->EntriesEnd;
+         CurrDeviceEntry != EntryDeviceEnd;
+         CurrDeviceEntry++, CurrHostEntry++) {
+      if (CurrDeviceEntry->size != 0) {
+        // has data.
+        assert(CurrDeviceEntry->size == CurrHostEntry->size &&
+               "data size mismatch");
+        assert(Device.getTgtPtrBegin(CurrHostEntry->addr,
+                                     CurrHostEntry->size) == NULL &&
+               "data in declared target should not be already mapped");
+        // add entry to map.
+        DP("Add mapping from host " DPxMOD " to device " DPxMOD " with size %zu"
+            "\n", DPxPTR(CurrHostEntry->addr), DPxPTR(CurrDeviceEntry->addr),
+            CurrDeviceEntry->size);
+        Device.HostDataToTargetMap.push_front(HostDataToTargetTy(
+            (uintptr_t)CurrHostEntry->addr, (uintptr_t)CurrHostEntry->addr,
+            (uintptr_t)CurrHostEntry->addr + CurrHostEntry->size,
+            (uintptr_t)CurrDeviceEntry->addr));
+      }
+    }
+    Device.DataMapMtx.unlock();
+  }
+  TrlTblMtx.unlock();
+
+  if (rc != OFFLOAD_SUCCESS) {
+    Device.PendingGlobalsMtx.unlock();
+    return rc;
+  }
+
+  /*
+   * Run ctors for static objects
+   */
+  if (!Device.PendingCtorsDtors.empty()) {
+    // Call all ctors for all libraries registered so far
+    for (auto &lib : Device.PendingCtorsDtors) {
+      if (!lib.second.PendingCtors.empty()) {
+        DP("Has pending ctors... call now\n");
+        for (auto &entry : lib.second.PendingCtors) {
+          void *ctor = entry;
+          int rc = target(device_id, ctor, 0, NULL, NULL, NULL,
+                          NULL, 1, 1, true /*team*/);
+          if (rc != OFFLOAD_SUCCESS) {
+            DP("Running ctor " DPxMOD " failed.\n", DPxPTR(ctor));
+            Device.PendingGlobalsMtx.unlock();
+            return OFFLOAD_FAIL;
+          }
+        }
+        // Clear the list to indicate that this device has been used
+        lib.second.PendingCtors.clear();
+        DP("Done with pending ctors for lib " DPxMOD "\n", DPxPTR(lib.first));
+      }
+    }
+  }
+  Device.HasPendingGlobals = false;
+  Device.PendingGlobalsMtx.unlock();
+
+  return OFFLOAD_SUCCESS;
+}
+
+// Check whether a device has been initialized, global ctors have been
+// executed and global data has been mapped; do so if not already done.
+static int CheckDevice(int32_t device_id) {
+  // Is device ready?
+  if (!device_is_ready(device_id)) {
+    DP("Device %d is not ready.\n", device_id);
+    return OFFLOAD_FAIL;
+  }
+
+  // Get device info.
+  DeviceTy &Device = Devices[device_id];
+
+  // Check whether global data has been mapped for this device
+  Device.PendingGlobalsMtx.lock();
+  bool hasPendingGlobals = Device.HasPendingGlobals;
+  Device.PendingGlobalsMtx.unlock();
+  if (hasPendingGlobals && InitLibrary(Device) != OFFLOAD_SUCCESS) {
+    DP("Failed to init globals on device %d\n", device_id);
+    return OFFLOAD_FAIL;
+  }
+
+  return OFFLOAD_SUCCESS;
+}
+
+// Following datatypes and functions (tgt_oldmap_type, combined_entry_t,
+// translate_map, cleanup_map) will be removed once the compiler starts using
+// the new map types.
+
+// Old map types
+enum tgt_oldmap_type {
+  OMP_TGT_OLDMAPTYPE_TO          = 0x001, // copy data from host to device
+  OMP_TGT_OLDMAPTYPE_FROM        = 0x002, // copy data from device to host
+  OMP_TGT_OLDMAPTYPE_ALWAYS      = 0x004, // copy regardless of the ref. count
+  OMP_TGT_OLDMAPTYPE_DELETE      = 0x008, // force unmapping of data
+  OMP_TGT_OLDMAPTYPE_MAP_PTR     = 0x010, // map pointer as well as pointee
+  OMP_TGT_OLDMAPTYPE_FIRST_MAP   = 0x020, // first occurrence of mapped variable
+  OMP_TGT_OLDMAPTYPE_RETURN_PTR  = 0x040, // return TgtBase addr of mapped data
+  OMP_TGT_OLDMAPTYPE_PRIVATE_PTR = 0x080, // private variable - not mapped
+  OMP_TGT_OLDMAPTYPE_PRIVATE_VAL = 0x100  // copy by value - not mapped
+};
+
+// Temporary functions for map translation and cleanup
+struct combined_entry_t {
+  int num_members; // number of members in combined entry
+  void *base_addr; // base address of combined entry
+  void *begin_addr; // begin address of combined entry
+  void *end_addr; // size of combined entry
+};
+
+static void translate_map(int32_t arg_num, void **args_base, void **args,
+    int64_t *arg_sizes, int32_t *arg_types, int32_t &new_arg_num,
+    void **&new_args_base, void **&new_args, int64_t *&new_arg_sizes,
+    int64_t *&new_arg_types, bool is_target_construct) {
+  if (arg_num <= 0) {
+    DP("Nothing to translate\n");
+    new_arg_num = 0;
+    return;
+  }
+
+  // array of combined entries
+  combined_entry_t *cmb_entries =
+      (combined_entry_t *) alloca(arg_num * sizeof(combined_entry_t));
+  // number of combined entries
+  long num_combined = 0;
+  // old entry is MAP_PTR?
+  bool *is_ptr_old = (bool *) alloca(arg_num * sizeof(bool));
+  // old entry is member of member_of[old] cmb_entry
+  int *member_of = (int *) alloca(arg_num * sizeof(int));
+
+  DP("Translating %d map entries\n", arg_num);
+  for (int i = 0; i < arg_num; ++i) {
+    member_of[i] = -1;
+    is_ptr_old[i] = false;
+    // Scan previous entries to see whether this entry shares the same base
+    for (int j = 0; j < i; ++j) {
+      void *new_begin_addr = NULL;
+      void *new_end_addr = NULL;
+
+      if (arg_types[i] & OMP_TGT_OLDMAPTYPE_MAP_PTR) {
+        if (args_base[i] == args[j]) {
+          if (!(arg_types[j] & OMP_TGT_OLDMAPTYPE_MAP_PTR)) {
+            DP("Entry %d has the same base as entry %d's begin address\n", i,
+                j);
+            new_begin_addr = args_base[i];
+            new_end_addr = (char *)args_base[i] + sizeof(void *);
+            assert(arg_sizes[j] == sizeof(void *));
+            is_ptr_old[j] = true;
+          } else {
+            DP("Entry %d has the same base as entry %d's begin address, but "
+                "%d's base was a MAP_PTR too\n", i, j, j);
+          }
+        }
+      } else {
+        if (!(arg_types[i] & OMP_TGT_OLDMAPTYPE_FIRST_MAP) &&
+            args_base[i] == args_base[j]) {
+          DP("Entry %d has the same base address as entry %d\n", i, j);
+          new_begin_addr = args[i];
+          new_end_addr = (char *)args[i] + arg_sizes[i];
+        }
+      }
+
+      // If we have combined the entry with a previous one
+      if (new_begin_addr) {
+        int id;
+        if(member_of[j] == -1) {
+          // We have a new entry
+          id = num_combined++;
+          DP("Creating new combined entry %d for old entry %d\n", id, j);
+          // Initialize new entry
+          cmb_entries[id].num_members = 1;
+          cmb_entries[id].base_addr = args_base[j];
+          if (arg_types[j] & OMP_TGT_OLDMAPTYPE_MAP_PTR) {
+            cmb_entries[id].begin_addr = args_base[j];
+            cmb_entries[id].end_addr = (char *)args_base[j] + arg_sizes[j];
+          } else {
+            cmb_entries[id].begin_addr = args[j];
+            cmb_entries[id].end_addr = (char *)args[j] + arg_sizes[j];
+          }
+          member_of[j] = id;
+        } else {
+          // Reuse existing combined entry
+          DP("Reusing existing combined entry %d\n", member_of[j]);
+          id = member_of[j];
+        }
+
+        // Update combined entry
+        DP("Adding entry %d to combined entry %d\n", i, id);
+        cmb_entries[id].num_members++;
+        // base_addr stays the same
+        cmb_entries[id].begin_addr =
+            std::min(cmb_entries[id].begin_addr, new_begin_addr);
+        cmb_entries[id].end_addr =
+            std::max(cmb_entries[id].end_addr, new_end_addr);
+        member_of[i] = id;
+        break;
+      }
+    }
+  }
+
+  DP("New entries: %ld combined + %d original\n", num_combined, arg_num);
+  new_arg_num = arg_num + num_combined;
+  new_args_base = (void **) malloc(new_arg_num * sizeof(void *));
+  new_args = (void **) malloc(new_arg_num * sizeof(void *));
+  new_arg_sizes = (int64_t *) malloc(new_arg_num * sizeof(int64_t));
+  new_arg_types = (int64_t *) malloc(new_arg_num * sizeof(int64_t));
+
+  const int64_t alignment = 8;
+
+  int next_id = 0; // next ID
+  int next_cid = 0; // next combined ID
+  int *combined_to_new_id = (int *) alloca(num_combined * sizeof(int));
+  for (int i = 0; i < arg_num; ++i) {
+    // It is member_of
+    if (member_of[i] == next_cid) {
+      int cid = next_cid++; // ID of this combined entry
+      int nid = next_id++; // ID of the new (global) entry
+      combined_to_new_id[cid] = nid;
+      DP("Combined entry %3d will become new entry %3d\n", cid, nid);
+
+      int64_t padding = (int64_t)cmb_entries[cid].begin_addr % alignment;
+      if (padding) {
+        DP("Using a padding of %" PRId64 " for begin address " DPxMOD "\n",
+            padding, DPxPTR(cmb_entries[cid].begin_addr));
+        cmb_entries[cid].begin_addr =
+            (char *)cmb_entries[cid].begin_addr - padding;
+      }
+
+      new_args_base[nid] = cmb_entries[cid].base_addr;
+      new_args[nid] = cmb_entries[cid].begin_addr;
+      new_arg_sizes[nid] = (int64_t) ((char *)cmb_entries[cid].end_addr -
+          (char *)cmb_entries[cid].begin_addr);
+      new_arg_types[nid] = OMP_TGT_MAPTYPE_TARGET_PARAM;
+      DP("Entry %3d: base_addr " DPxMOD ", begin_addr " DPxMOD ", "
+          "size %" PRId64 ", type 0x%" PRIx64 "\n", nid,
+          DPxPTR(new_args_base[nid]), DPxPTR(new_args[nid]), new_arg_sizes[nid],
+          new_arg_types[nid]);
+    } else if (member_of[i] != -1) {
+      DP("Combined entry %3d has been encountered before, do nothing\n",
+          member_of[i]);
+    }
+
+    // Now that the combined entry (the one the old entry was a member of) has
+    // been inserted into the new arguments list, proceed with the old entry.
+    int nid = next_id++;
+    DP("Old entry %3d will become new entry %3d\n", i, nid);
+
+    new_args_base[nid] = args_base[i];
+    new_args[nid] = args[i];
+    new_arg_sizes[nid] = arg_sizes[i];
+    int64_t old_type = arg_types[i];
+
+    if (is_ptr_old[i]) {
+      // Reset TO and FROM flags
+      old_type &= ~(OMP_TGT_OLDMAPTYPE_TO | OMP_TGT_OLDMAPTYPE_FROM);
+    }
+
+    if (member_of[i] == -1) {
+      if (!is_target_construct)
+        old_type &= ~OMP_TGT_MAPTYPE_TARGET_PARAM;
+      new_arg_types[nid] = old_type;
+      DP("Entry %3d: base_addr " DPxMOD ", begin_addr " DPxMOD ", size %" PRId64
+          ", type 0x%" PRIx64 " (old entry %d not MEMBER_OF)\n", nid,
+          DPxPTR(new_args_base[nid]), DPxPTR(new_args[nid]), new_arg_sizes[nid],
+          new_arg_types[nid], i);
+    } else {
+      // Old entry is not FIRST_MAP
+      old_type &= ~OMP_TGT_OLDMAPTYPE_FIRST_MAP;
+      // Add MEMBER_OF
+      int new_member_of = combined_to_new_id[member_of[i]];
+      old_type |= ((int64_t)new_member_of + 1) << 48;
+      new_arg_types[nid] = old_type;
+      DP("Entry %3d: base_addr " DPxMOD ", begin_addr " DPxMOD ", size %" PRId64
+        ", type 0x%" PRIx64 " (old entry %d MEMBER_OF %d)\n", nid,
+        DPxPTR(new_args_base[nid]), DPxPTR(new_args[nid]), new_arg_sizes[nid],
+        new_arg_types[nid], i, new_member_of);
+    }
+  }
+}
+
+static void cleanup_map(int32_t new_arg_num, void **new_args_base,
+    void **new_args, int64_t *new_arg_sizes, int64_t *new_arg_types,
+    int32_t arg_num, void **args_base) {
+  if (new_arg_num > 0) {
+    int offset = new_arg_num - arg_num;
+    for (int32_t i = 0; i < arg_num; ++i) {
+      // Restore old base address
+      args_base[i] = new_args_base[i+offset];
+    }
+    free(new_args_base);
+    free(new_args);
+    free(new_arg_sizes);
+    free(new_arg_types);
+  }
+}
+
+static short member_of(int64_t type) {
+  return ((type & OMP_TGT_MAPTYPE_MEMBER_OF) >> 48) - 1;
+}
+
+/// Internal function to do the mapping and transfer the data to the device
+static int target_data_begin(DeviceTy &Device, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int64_t *arg_types) {
+  // process each input.
+  int rc = OFFLOAD_SUCCESS;
+  for (int32_t i = 0; i < arg_num; ++i) {
+    // Ignore private variables and arrays - there is no mapping for them.
+    if ((arg_types[i] & OMP_TGT_MAPTYPE_LITERAL) ||
+        (arg_types[i] & OMP_TGT_MAPTYPE_PRIVATE))
+      continue;
+
+    void *HstPtrBegin = args[i];
+    void *HstPtrBase = args_base[i];
+    // Address of pointer on the host and device, respectively.
+    void *Pointer_HstPtrBegin, *Pointer_TgtPtrBegin;
+    bool IsNew, Pointer_IsNew;
+    bool IsImplicit = arg_types[i] & OMP_TGT_MAPTYPE_IMPLICIT;
+    bool UpdateRef = !(arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF);
+    if (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ) {
+      DP("Has a pointer entry: \n");
+      // base is address of pointer.
+      Pointer_TgtPtrBegin = Device.getOrAllocTgtPtr(HstPtrBase, HstPtrBase,
+          sizeof(void *), Pointer_IsNew, IsImplicit, UpdateRef);
+      if (!Pointer_TgtPtrBegin) {
+        DP("Call to getOrAllocTgtPtr returned null pointer (device failure or "
+            "illegal mapping).\n");
+      }
+      DP("There are %zu bytes allocated at target address " DPxMOD " - is%s new"
+          "\n", sizeof(void *), DPxPTR(Pointer_TgtPtrBegin),
+          (Pointer_IsNew ? "" : " not"));
+      Pointer_HstPtrBegin = HstPtrBase;
+      // modify current entry.
+      HstPtrBase = *(void **)HstPtrBase;
+      UpdateRef = true; // subsequently update ref count of pointee
+    }
+
+    void *TgtPtrBegin = Device.getOrAllocTgtPtr(HstPtrBegin, HstPtrBase,
+        arg_sizes[i], IsNew, IsImplicit, UpdateRef);
+    if (!TgtPtrBegin && arg_sizes[i]) {
+      // If arg_sizes[i]==0, then the argument is a pointer to NULL, so
+      // getOrAlloc() returning NULL is not an error.
+      DP("Call to getOrAllocTgtPtr returned null pointer (device failure or "
+          "illegal mapping).\n");
+    }
+    DP("There are %" PRId64 " bytes allocated at target address " DPxMOD
+        " - is%s new\n", arg_sizes[i], DPxPTR(TgtPtrBegin),
+        (IsNew ? "" : " not"));
+
+    if (arg_types[i] & OMP_TGT_MAPTYPE_RETURN_PARAM) {
+      void *ret_ptr;
+      if (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ)
+        ret_ptr = Pointer_TgtPtrBegin;
+      else {
+        bool IsLast; // not used
+        ret_ptr = Device.getTgtPtrBegin(HstPtrBegin, 0, IsLast, false);
+      }
+
+      DP("Returning device pointer " DPxMOD "\n", DPxPTR(ret_ptr));
+      args_base[i] = ret_ptr;
+    }
+
+    if (arg_types[i] & OMP_TGT_MAPTYPE_TO) {
+      bool copy = false;
+      if (IsNew || (arg_types[i] & OMP_TGT_MAPTYPE_ALWAYS)) {
+        copy = true;
+      } else if (arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF) {
+        // Copy data only if the "parent" struct has RefCount==1.
+        short parent_idx = member_of(arg_types[i]);
+        long parent_rc = Device.getMapEntryRefCnt(args[parent_idx]);
+        assert(parent_rc > 0 && "parent struct not found");
+        if (parent_rc == 1) {
+          copy = true;
+        }
+      }
+
+      if (copy) {
+        DP("Moving %" PRId64 " bytes (hst:" DPxMOD ") -> (tgt:" DPxMOD ")\n",
+            arg_sizes[i], DPxPTR(HstPtrBegin), DPxPTR(TgtPtrBegin));
+        int rt = Device.data_submit(TgtPtrBegin, HstPtrBegin, arg_sizes[i]);
+        if (rt != OFFLOAD_SUCCESS) {
+          DP("Copying data to device failed.\n");
+          rc = OFFLOAD_FAIL;
+        }
+      }
+    }
+
+    if (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ) {
+      DP("Update pointer (" DPxMOD ") -> [" DPxMOD "]\n",
+          DPxPTR(Pointer_TgtPtrBegin), DPxPTR(TgtPtrBegin));
+      uint64_t Delta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
+      void *TgtPtrBase = (void *)((uint64_t)TgtPtrBegin - Delta);
+      int rt = Device.data_submit(Pointer_TgtPtrBegin, &TgtPtrBase,
+          sizeof(void *));
+      if (rt != OFFLOAD_SUCCESS) {
+        DP("Copying data to device failed.\n");
+        rc = OFFLOAD_FAIL;
+      }
+      // create shadow pointers for this entry
+      Device.ShadowMtx.lock();
+      Device.ShadowPtrMap[Pointer_HstPtrBegin] = {HstPtrBase,
+          Pointer_TgtPtrBegin, TgtPtrBase};
+      Device.ShadowMtx.unlock();
+    }
+  }
+
+  return rc;
+}
+
+EXTERN void __tgt_target_data_begin_nowait(int32_t device_id, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types,
+    int32_t depNum, void *depList, int32_t noAliasDepNum,
+    void *noAliasDepList) {
+  if (depNum + noAliasDepNum > 0)
+    __kmpc_omp_taskwait(NULL, 0);
+
+  __tgt_target_data_begin(device_id, arg_num, args_base, args, arg_sizes,
+                          arg_types);
+}
+
+/// creates host-to-target data mapping, stores it in the
+/// libomptarget.so internal structure (an entry in a stack of data maps)
+/// and passes the data to the device.
+EXTERN void __tgt_target_data_begin(int32_t device_id, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types) {
+  DP("Entering data begin region for device %d with %d mappings\n", device_id,
+     arg_num);
+
+  // No devices available?
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+    DP("Use default device id %d\n", device_id);
+  }
+
+  if (CheckDevice(device_id) != OFFLOAD_SUCCESS) {
+    DP("Failed to get device %d ready\n", device_id);
+    return;
+  }
+
+  DeviceTy& Device = Devices[device_id];
+
+  // Translate maps
+  int32_t new_arg_num;
+  void **new_args_base;
+  void **new_args;
+  int64_t *new_arg_sizes;
+  int64_t *new_arg_types;
+  translate_map(arg_num, args_base, args, arg_sizes, arg_types, new_arg_num,
+      new_args_base, new_args, new_arg_sizes, new_arg_types, false);
+
+  //target_data_begin(Device, arg_num, args_base, args, arg_sizes, arg_types);
+  target_data_begin(Device, new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types);
+
+  // Cleanup translation memory
+  cleanup_map(new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types, arg_num, args_base);
+}
+
+/// Internal function to undo the mapping and retrieve the data from the device.
+static int target_data_end(DeviceTy &Device, int32_t arg_num, void **args_base,
+    void **args, int64_t *arg_sizes, int64_t *arg_types) {
+  int rc = OFFLOAD_SUCCESS;
+  // process each input.
+  for (int32_t i = arg_num - 1; i >= 0; --i) {
+    // Ignore private variables and arrays - there is no mapping for them.
+    // Also, ignore the use_device_ptr directive, it has no effect here.
+    if ((arg_types[i] & OMP_TGT_MAPTYPE_LITERAL) ||
+        (arg_types[i] & OMP_TGT_MAPTYPE_PRIVATE))
+      continue;
+
+    void *HstPtrBegin = args[i];
+    bool IsLast;
+    bool UpdateRef = !(arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF) ||
+        (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ);
+    bool ForceDelete = arg_types[i] & OMP_TGT_MAPTYPE_DELETE;
+
+    // If PTR_AND_OBJ, HstPtrBegin is address of pointee
+    void *TgtPtrBegin = Device.getTgtPtrBegin(HstPtrBegin, arg_sizes[i], IsLast,
+        UpdateRef);
+    DP("There are %" PRId64 " bytes allocated at target address " DPxMOD
+        " - is%s last\n", arg_sizes[i], DPxPTR(TgtPtrBegin),
+        (IsLast ? "" : " not"));
+
+    if ((arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF) &&
+        !(arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ)) {
+      IsLast = false; // protect parent struct from being deallocated
+    }
+
+    bool DelEntry = IsLast || ForceDelete;
+
+    if ((arg_types[i] & OMP_TGT_MAPTYPE_FROM) || DelEntry) {
+      // Move data back to the host
+      if (arg_types[i] & OMP_TGT_MAPTYPE_FROM) {
+        bool Always = arg_types[i] & OMP_TGT_MAPTYPE_ALWAYS;
+        bool CopyMember = false;
+        if ((arg_types[i] & OMP_TGT_MAPTYPE_MEMBER_OF) &&
+            !(arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ)) {
+          // Copy data only if the "parent" struct has RefCount==1.
+          short parent_idx = member_of(arg_types[i]);
+          long parent_rc = Device.getMapEntryRefCnt(args[parent_idx]);
+          assert(parent_rc > 0 && "parent struct not found");
+          if (parent_rc == 1) {
+            CopyMember = true;
+          }
+        }
+
+        if (DelEntry || Always || CopyMember) {
+          DP("Moving %" PRId64 " bytes (tgt:" DPxMOD ") -> (hst:" DPxMOD ")\n",
+              arg_sizes[i], DPxPTR(TgtPtrBegin), DPxPTR(HstPtrBegin));
+          int rt = Device.data_retrieve(HstPtrBegin, TgtPtrBegin, arg_sizes[i]);
+          if (rt != OFFLOAD_SUCCESS) {
+            DP("Copying data from device failed.\n");
+            rc = OFFLOAD_FAIL;
+          }
+        }
+      }
+
+      // If we copied back to the host a struct/array containing pointers, we
+      // need to restore the original host pointer values from their shadow
+      // copies. If the struct is going to be deallocated, remove any remaining
+      // shadow pointer entries for this struct.
+      uintptr_t lb = (uintptr_t) HstPtrBegin;
+      uintptr_t ub = (uintptr_t) HstPtrBegin + arg_sizes[i];
+      Device.ShadowMtx.lock();
+      for (ShadowPtrListTy::iterator it = Device.ShadowPtrMap.begin();
+          it != Device.ShadowPtrMap.end(); ++it) {
+        void **ShadowHstPtrAddr = (void**) it->first;
+
+        // An STL map is sorted on its keys; use this property
+        // to quickly determine when to break out of the loop.
+        if ((uintptr_t) ShadowHstPtrAddr < lb)
+          continue;
+        if ((uintptr_t) ShadowHstPtrAddr >= ub)
+          break;
+
+        // If we copied the struct to the host, we need to restore the pointer.
+        if (arg_types[i] & OMP_TGT_MAPTYPE_FROM) {
+          DP("Restoring original host pointer value " DPxMOD " for host "
+              "pointer " DPxMOD "\n", DPxPTR(it->second.HstPtrVal),
+              DPxPTR(ShadowHstPtrAddr));
+          *ShadowHstPtrAddr = it->second.HstPtrVal;
+        }
+        // If the struct is to be deallocated, remove the shadow entry.
+        if (DelEntry) {
+          DP("Removing shadow pointer " DPxMOD "\n", DPxPTR(ShadowHstPtrAddr));
+          Device.ShadowPtrMap.erase(it);
+        }
+      }
+      Device.ShadowMtx.unlock();
+
+      // Deallocate map
+      if (DelEntry) {
+        int rt = Device.deallocTgtPtr(HstPtrBegin, arg_sizes[i], ForceDelete);
+        if (rt != OFFLOAD_SUCCESS) {
+          DP("Deallocating data from device failed.\n");
+          rc = OFFLOAD_FAIL;
+        }
+      }
+    }
+  }
+
+  return rc;
+}
+
+/// passes data from the target, releases target memory and destroys
+/// the host-target mapping (top entry from the stack of data maps)
+/// created by the last __tgt_target_data_begin.
+EXTERN void __tgt_target_data_end(int32_t device_id, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types) {
+  DP("Entering data end region with %d mappings\n", arg_num);
+
+  // No devices available?
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+  }
+
+  RTLsMtx.lock();
+  size_t Devices_size = Devices.size();
+  RTLsMtx.unlock();
+  if (Devices_size <= (size_t)device_id) {
+    DP("Device ID  %d does not have a matching RTL.\n", device_id);
+    return;
+  }
+
+  DeviceTy &Device = Devices[device_id];
+  if (!Device.IsInit) {
+    DP("uninit device: ignore");
+    return;
+  }
+
+  // Translate maps
+  int32_t new_arg_num;
+  void **new_args_base;
+  void **new_args;
+  int64_t *new_arg_sizes;
+  int64_t *new_arg_types;
+  translate_map(arg_num, args_base, args, arg_sizes, arg_types, new_arg_num,
+      new_args_base, new_args, new_arg_sizes, new_arg_types, false);
+
+  //target_data_end(Device, arg_num, args_base, args, arg_sizes, arg_types);
+  target_data_end(Device, new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types);
+
+  // Cleanup translation memory
+  cleanup_map(new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types, arg_num, args_base);
+}
+
+EXTERN void __tgt_target_data_end_nowait(int32_t device_id, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types,
+    int32_t depNum, void *depList, int32_t noAliasDepNum,
+    void *noAliasDepList) {
+  if (depNum + noAliasDepNum > 0)
+    __kmpc_omp_taskwait(NULL, 0);
+
+  __tgt_target_data_end(device_id, arg_num, args_base, args, arg_sizes,
+                        arg_types);
+}
+
+/// passes data to/from the target.
+EXTERN void __tgt_target_data_update(int32_t device_id, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types) {
+  DP("Entering data update with %d mappings\n", arg_num);
+
+  // No devices available?
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+  }
+
+  if (CheckDevice(device_id) != OFFLOAD_SUCCESS) {
+    DP("Failed to get device %d ready\n", device_id);
+    return;
+  }
+
+  DeviceTy& Device = Devices[device_id];
+
+  // process each input.
+  for (int32_t i = 0; i < arg_num; ++i) {
+    if ((arg_types[i] & OMP_TGT_MAPTYPE_LITERAL) ||
+        (arg_types[i] & OMP_TGT_MAPTYPE_PRIVATE))
+      continue;
+
+    void *HstPtrBegin = args[i];
+    int64_t MapSize = arg_sizes[i];
+    bool IsLast;
+    void *TgtPtrBegin = Device.getTgtPtrBegin(HstPtrBegin, MapSize, IsLast,
+        false);
+
+    if (arg_types[i] & OMP_TGT_MAPTYPE_FROM) {
+      DP("Moving %" PRId64 " bytes (tgt:" DPxMOD ") -> (hst:" DPxMOD ")\n",
+          arg_sizes[i], DPxPTR(TgtPtrBegin), DPxPTR(HstPtrBegin));
+      Device.data_retrieve(HstPtrBegin, TgtPtrBegin, MapSize);
+
+      uintptr_t lb = (uintptr_t) HstPtrBegin;
+      uintptr_t ub = (uintptr_t) HstPtrBegin + MapSize;
+      Device.ShadowMtx.lock();
+      for (ShadowPtrListTy::iterator it = Device.ShadowPtrMap.begin();
+          it != Device.ShadowPtrMap.end(); ++it) {
+        void **ShadowHstPtrAddr = (void**) it->first;
+        if ((uintptr_t) ShadowHstPtrAddr < lb)
+          continue;
+        if ((uintptr_t) ShadowHstPtrAddr >= ub)
+          break;
+        DP("Restoring original host pointer value " DPxMOD " for host pointer "
+            DPxMOD "\n", DPxPTR(it->second.HstPtrVal),
+            DPxPTR(ShadowHstPtrAddr));
+        *ShadowHstPtrAddr = it->second.HstPtrVal;
+      }
+      Device.ShadowMtx.unlock();
+    }
+
+    if (arg_types[i] & OMP_TGT_MAPTYPE_TO) {
+      DP("Moving %" PRId64 " bytes (hst:" DPxMOD ") -> (tgt:" DPxMOD ")\n",
+          arg_sizes[i], DPxPTR(HstPtrBegin), DPxPTR(TgtPtrBegin));
+      Device.data_submit(TgtPtrBegin, HstPtrBegin, MapSize);
+
+      uintptr_t lb = (uintptr_t) HstPtrBegin;
+      uintptr_t ub = (uintptr_t) HstPtrBegin + MapSize;
+      Device.ShadowMtx.lock();
+      for (ShadowPtrListTy::iterator it = Device.ShadowPtrMap.begin();
+          it != Device.ShadowPtrMap.end(); ++it) {
+        void **ShadowHstPtrAddr = (void**) it->first;
+        if ((uintptr_t) ShadowHstPtrAddr < lb)
+          continue;
+        if ((uintptr_t) ShadowHstPtrAddr >= ub)
+          break;
+        DP("Restoring original target pointer value " DPxMOD " for target "
+            "pointer " DPxMOD "\n", DPxPTR(it->second.TgtPtrVal),
+            DPxPTR(it->second.TgtPtrAddr));
+        Device.data_submit(it->second.TgtPtrAddr,
+            &it->second.TgtPtrVal, sizeof(void *));
+      }
+      Device.ShadowMtx.unlock();
+    }
+  }
+}
+
+EXTERN void __tgt_target_data_update_nowait(
+    int32_t device_id, int32_t arg_num, void **args_base, void **args,
+    int64_t *arg_sizes, int32_t *arg_types, int32_t depNum, void *depList,
+    int32_t noAliasDepNum, void *noAliasDepList) {
+  if (depNum + noAliasDepNum > 0)
+    __kmpc_omp_taskwait(NULL, 0);
+
+  __tgt_target_data_update(device_id, arg_num, args_base, args, arg_sizes,
+                           arg_types);
+}
+
+/// performs the same actions as data_begin in case arg_num is
+/// non-zero and initiates run of the offloaded region on the target platform;
+/// if arg_num is non-zero after the region execution is done it also
+/// performs the same action as data_update and data_end above. This function
+/// returns 0 if it was able to transfer the execution to a target and an
+/// integer different from zero otherwise.
+static int target(int32_t device_id, void *host_ptr, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int64_t *arg_types,
+    int32_t team_num, int32_t thread_limit, int IsTeamConstruct) {
+  DeviceTy &Device = Devices[device_id];
+
+  // Find the table information in the map or look it up in the translation
+  // tables.
+  TableMap *TM = 0;
+  TblMapMtx.lock();
+  HostPtrToTableMapTy::iterator TableMapIt = HostPtrToTableMap.find(host_ptr);
+  if (TableMapIt == HostPtrToTableMap.end()) {
+    // We don't have a map. So search all the registered libraries.
+    TrlTblMtx.lock();
+    for (HostEntriesBeginToTransTableTy::iterator
+             ii = HostEntriesBeginToTransTable.begin(),
+             ie = HostEntriesBeginToTransTable.end();
+         !TM && ii != ie; ++ii) {
+      // get the translation table (which contains all the good info).
+      TranslationTable *TransTable = &ii->second;
+      // iterate over all the host table entries to see if we can locate the
+      // host_ptr.
+      __tgt_offload_entry *begin = TransTable->HostTable.EntriesBegin;
+      __tgt_offload_entry *end = TransTable->HostTable.EntriesEnd;
+      __tgt_offload_entry *cur = begin;
+      for (uint32_t i = 0; cur < end; ++cur, ++i) {
+        if (cur->addr != host_ptr)
+          continue;
+        // we got a match, now fill the HostPtrToTableMap so that we
+        // may avoid this search next time.
+        TM = &HostPtrToTableMap[host_ptr];
+        TM->Table = TransTable;
+        TM->Index = i;
+        break;
+      }
+    }
+    TrlTblMtx.unlock();
+  } else {
+    TM = &TableMapIt->second;
+  }
+  TblMapMtx.unlock();
+
+  // No map for this host pointer found!
+  if (!TM) {
+    DP("Host ptr " DPxMOD " does not have a matching target pointer.\n",
+       DPxPTR(host_ptr));
+    return OFFLOAD_FAIL;
+  }
+
+  // get target table.
+  TrlTblMtx.lock();
+  assert(TM->Table->TargetsTable.size() > (size_t)device_id &&
+         "Not expecting a device ID outside the table's bounds!");
+  __tgt_target_table *TargetTable = TM->Table->TargetsTable[device_id];
+  TrlTblMtx.unlock();
+  assert(TargetTable && "Global data has not been mapped\n");
+
+  // Move data to device.
+  int rc = target_data_begin(Device, arg_num, args_base, args, arg_sizes,
+      arg_types);
+
+  if (rc != OFFLOAD_SUCCESS) {
+    DP("Call to target_data_begin failed, skipping target execution.\n");
+    // Call target_data_end to dealloc whatever target_data_begin allocated
+    // and return OFFLOAD_FAIL.
+    target_data_end(Device, arg_num, args_base, args, arg_sizes, arg_types);
+    return OFFLOAD_FAIL;
+  }
+
+  std::vector<void *> tgt_args;
+
+  // List of (first-)private arrays allocated for this target region
+  std::vector<void *> fpArrays;
+
+  for (int32_t i = 0; i < arg_num; ++i) {
+    if (!(arg_types[i] & OMP_TGT_MAPTYPE_TARGET_PARAM)) {
+      // This is not a target parameter, do not push it into tgt_args.
+      continue;
+    }
+    void *HstPtrBegin = args[i];
+    void *HstPtrBase = args_base[i];
+    void *TgtPtrBase;
+    bool IsLast; // unused.
+    if (arg_types[i] & OMP_TGT_MAPTYPE_LITERAL) {
+      DP("Forwarding first-private value " DPxMOD " to the target construct\n",
+          DPxPTR(HstPtrBase));
+      TgtPtrBase = HstPtrBase;
+    } else if (arg_types[i] & OMP_TGT_MAPTYPE_PRIVATE) {
+      // Allocate memory for (first-)private array
+      void *TgtPtrBegin = Device.RTL->data_alloc(Device.RTLDeviceID,
+          arg_sizes[i]);
+      if (!TgtPtrBegin) {
+        DP ("Data allocation for %sprivate array " DPxMOD " failed\n",
+            (arg_types[i] & OMP_TGT_MAPTYPE_TO ? "first-" : ""),
+            DPxPTR(HstPtrBegin));
+        rc = OFFLOAD_FAIL;
+        break;
+      } else {
+        fpArrays.push_back(TgtPtrBegin);
+        uint64_t PtrDelta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
+        TgtPtrBase = (void *)((uint64_t)TgtPtrBegin - PtrDelta);
+        DP("Allocated %" PRId64 " bytes of target memory at " DPxMOD " for "
+            "%sprivate array " DPxMOD " - pushing target argument " DPxMOD "\n",
+            arg_sizes[i], DPxPTR(TgtPtrBegin),
+            (arg_types[i] & OMP_TGT_MAPTYPE_TO ? "first-" : ""),
+            DPxPTR(HstPtrBegin), DPxPTR(TgtPtrBase));
+        // If first-private, copy data from host
+        if (arg_types[i] & OMP_TGT_MAPTYPE_TO) {
+          int rt = Device.data_submit(TgtPtrBegin, HstPtrBegin, arg_sizes[i]);
+          if (rt != OFFLOAD_SUCCESS) {
+            DP ("Copying data to device failed.\n");
+            rc = OFFLOAD_FAIL;
+            break;
+          }
+        }
+      }
+    } else if (arg_types[i] & OMP_TGT_MAPTYPE_PTR_AND_OBJ) {
+      void *TgtPtrBegin = Device.getTgtPtrBegin(HstPtrBase, sizeof(void *),
+          IsLast, false);
+      TgtPtrBase = TgtPtrBegin; // no offset for ptrs.
+      DP("Obtained target argument " DPxMOD " from host pointer " DPxMOD " to "
+         "object " DPxMOD "\n", DPxPTR(TgtPtrBegin), DPxPTR(HstPtrBase),
+         DPxPTR(HstPtrBase));
+    } else {
+      void *TgtPtrBegin = Device.getTgtPtrBegin(HstPtrBegin, arg_sizes[i],
+          IsLast, false);
+      uint64_t PtrDelta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
+      TgtPtrBase = (void *)((uint64_t)TgtPtrBegin - PtrDelta);
+      DP("Obtained target argument " DPxMOD " from host pointer " DPxMOD "\n",
+          DPxPTR(TgtPtrBase), DPxPTR(HstPtrBegin));
+    }
+    tgt_args.push_back(TgtPtrBase);
+  }
+  // Push omp handle.
+  tgt_args.push_back((void *)0);
+
+  // Pop loop trip count
+  uint64_t ltc = Device.loopTripCnt;
+  Device.loopTripCnt = 0;
+
+  // Launch device execution.
+  if (rc == OFFLOAD_SUCCESS) {
+    DP("Launching target execution %s with pointer " DPxMOD " (index=%d).\n",
+        TargetTable->EntriesBegin[TM->Index].name,
+        DPxPTR(TargetTable->EntriesBegin[TM->Index].addr), TM->Index);
+    if (IsTeamConstruct) {
+      rc = Device.run_team_region(TargetTable->EntriesBegin[TM->Index].addr,
+          &tgt_args[0], tgt_args.size(), team_num, thread_limit, ltc);
+    } else {
+      rc = Device.run_region(TargetTable->EntriesBegin[TM->Index].addr,
+          &tgt_args[0], tgt_args.size());
+    }
+  } else {
+    DP("Errors occurred while obtaining target arguments, skipping kernel "
+        "execution\n");
+  }
+
+  // Deallocate (first-)private arrays
+  for (auto it : fpArrays) {
+    int rt = Device.RTL->data_delete(Device.RTLDeviceID, it);
+    if (rt != OFFLOAD_SUCCESS) {
+      DP("Deallocation of (first-)private arrays failed.\n");
+      rc = OFFLOAD_FAIL;
+    }
+  }
+
+  // Move data from device.
+  int rt = target_data_end(Device, arg_num, args_base, args, arg_sizes,
+      arg_types);
+
+  if (rt != OFFLOAD_SUCCESS) {
+    DP("Call to target_data_end failed.\n");
+    rc = OFFLOAD_FAIL;
+  }
+
+  return rc;
+}
+
+EXTERN int __tgt_target(int32_t device_id, void *host_ptr, int32_t arg_num,
+    void **args_base, void **args, int64_t *arg_sizes, int32_t *arg_types) {
+  if (device_id == OFFLOAD_DEVICE_CONSTRUCTOR ||
+      device_id == OFFLOAD_DEVICE_DESTRUCTOR) {
+    // Return immediately for the time being, target calls with device_id
+    // -2 or -3 will be removed from the compiler in the future.
+    return OFFLOAD_SUCCESS;
+  }
+
+  DP("Entering target region with entry point " DPxMOD " and device Id %d\n",
+     DPxPTR(host_ptr), device_id);
+
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+  }
+
+  if (CheckDevice(device_id) != OFFLOAD_SUCCESS) {
+    DP("Failed to get device %d ready\n", device_id);
+    return OFFLOAD_FAIL;
+  }
+
+  // Translate maps
+  int32_t new_arg_num;
+  void **new_args_base;
+  void **new_args;
+  int64_t *new_arg_sizes;
+  int64_t *new_arg_types;
+  translate_map(arg_num, args_base, args, arg_sizes, arg_types, new_arg_num,
+      new_args_base, new_args, new_arg_sizes, new_arg_types, true);
+
+  //return target(device_id, host_ptr, arg_num, args_base, args, arg_sizes,
+  //    arg_types, 0, 0, false /*team*/, false /*recursive*/);
+  int rc = target(device_id, host_ptr, new_arg_num, new_args_base, new_args,
+      new_arg_sizes, new_arg_types, 0, 0, false /*team*/);
+
+  // Cleanup translation memory
+  cleanup_map(new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types, arg_num, args_base);
+
+  return rc;
+}
+
+EXTERN int __tgt_target_nowait(int32_t device_id, void *host_ptr,
+    int32_t arg_num, void **args_base, void **args, int64_t *arg_sizes,
+    int32_t *arg_types, int32_t depNum, void *depList, int32_t noAliasDepNum,
+    void *noAliasDepList) {
+  if (depNum + noAliasDepNum > 0)
+    __kmpc_omp_taskwait(NULL, 0);
+
+  return __tgt_target(device_id, host_ptr, arg_num, args_base, args, arg_sizes,
+                      arg_types);
+}
+
+EXTERN int __tgt_target_teams(int32_t device_id, void *host_ptr,
+    int32_t arg_num, void **args_base, void **args, int64_t *arg_sizes,
+    int32_t *arg_types, int32_t team_num, int32_t thread_limit) {
+  if (device_id == OFFLOAD_DEVICE_CONSTRUCTOR ||
+      device_id == OFFLOAD_DEVICE_DESTRUCTOR) {
+    // Return immediately for the time being, target calls with device_id
+    // -2 or -3 will be removed from the compiler in the future.
+    return OFFLOAD_SUCCESS;
+  }
+
+  DP("Entering target region with entry point " DPxMOD " and device Id %d\n",
+     DPxPTR(host_ptr), device_id);
+
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+  }
+
+  if (CheckDevice(device_id) != OFFLOAD_SUCCESS) {
+    DP("Failed to get device %d ready\n", device_id);
+    return OFFLOAD_FAIL;
+  }
+
+  // Translate maps
+  int32_t new_arg_num;
+  void **new_args_base;
+  void **new_args;
+  int64_t *new_arg_sizes;
+  int64_t *new_arg_types;
+  translate_map(arg_num, args_base, args, arg_sizes, arg_types, new_arg_num,
+      new_args_base, new_args, new_arg_sizes, new_arg_types, true);
+
+  //return target(device_id, host_ptr, arg_num, args_base, args, arg_sizes,
+  //              arg_types, team_num, thread_limit, true /*team*/,
+  //              false /*recursive*/);
+  int rc = target(device_id, host_ptr, new_arg_num, new_args_base, new_args,
+      new_arg_sizes, new_arg_types, team_num, thread_limit, true /*team*/);
+
+  // Cleanup translation memory
+  cleanup_map(new_arg_num, new_args_base, new_args, new_arg_sizes,
+      new_arg_types, arg_num, args_base);
+
+  return rc;
+}
+
+EXTERN int __tgt_target_teams_nowait(int32_t device_id, void *host_ptr,
+    int32_t arg_num, void **args_base, void **args, int64_t *arg_sizes,
+    int32_t *arg_types, int32_t team_num, int32_t thread_limit, int32_t depNum,
+    void *depList, int32_t noAliasDepNum, void *noAliasDepList) {
+  if (depNum + noAliasDepNum > 0)
+    __kmpc_omp_taskwait(NULL, 0);
+
+  return __tgt_target_teams(device_id, host_ptr, arg_num, args_base, args,
+                            arg_sizes, arg_types, team_num, thread_limit);
+}
+
+
+// The trip count mechanism will be revised - this scheme is not thread-safe.
+EXTERN void __kmpc_push_target_tripcount(int32_t device_id,
+    uint64_t loop_tripcount) {
+  if (device_id == OFFLOAD_DEVICE_DEFAULT) {
+    device_id = omp_get_default_device();
+  }
+
+  if (CheckDevice(device_id) != OFFLOAD_SUCCESS) {
+    DP("Failed to get device %d ready\n", device_id);
+    return;
+  }
+
+  DP("__kmpc_push_target_tripcount(%d, %" PRIu64 ")\n", device_id,
+      loop_tripcount);
+  Devices[device_id].loopTripCnt = loop_tripcount;
+}
+
diff --git a/libomptarget/src/omptarget.h b/libomptarget/src/omptarget.h
new file mode 100644
index 0000000..ab996be
--- /dev/null
+++ b/libomptarget/src/omptarget.h
@@ -0,0 +1,234 @@
+//===-------- omptarget.h - Target independent OpenMP target RTL -- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.txt for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Interface to be used by Clang during the codegen of a
+// target region.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _OMPTARGET_H_
+#define _OMPTARGET_H_
+
+#include <stdint.h>
+
+#define OFFLOAD_SUCCESS (0)
+#define OFFLOAD_FAIL (~0)
+
+#define OFFLOAD_DEVICE_DEFAULT     -1
+#define OFFLOAD_DEVICE_CONSTRUCTOR -2
+#define OFFLOAD_DEVICE_DESTRUCTOR  -3
+#define HOST_DEVICE                -10
+
+/// Data attributes for each data reference used in an OpenMP target region.
+enum tgt_map_type {
+  // No flags
+  OMP_TGT_MAPTYPE_NONE            = 0x000,
+  // copy data from host to device
+  OMP_TGT_MAPTYPE_TO              = 0x001,
+  // copy data from device to host
+  OMP_TGT_MAPTYPE_FROM            = 0x002,
+  // copy regardless of the reference count
+  OMP_TGT_MAPTYPE_ALWAYS          = 0x004,
+  // force unmapping of data
+  OMP_TGT_MAPTYPE_DELETE          = 0x008,
+  // map the pointer as well as the pointee
+  OMP_TGT_MAPTYPE_PTR_AND_OBJ     = 0x010,
+  // pass device base address to kernel
+  OMP_TGT_MAPTYPE_TARGET_PARAM    = 0x020,
+  // return base device address of mapped data
+  OMP_TGT_MAPTYPE_RETURN_PARAM    = 0x040,
+  // private variable - not mapped
+  OMP_TGT_MAPTYPE_PRIVATE         = 0x080,
+  // copy by value - not mapped
+  OMP_TGT_MAPTYPE_LITERAL         = 0x100,
+  // mapping is implicit
+  OMP_TGT_MAPTYPE_IMPLICIT        = 0x200,
+  // member of struct, member given by 4 MSBs - 1
+  OMP_TGT_MAPTYPE_MEMBER_OF       = 0xffff000000000000
+};
+
+enum OpenMPOffloadingDeclareTargetFlags {
+  /// Mark the entry as having a 'link' attribute.
+  OMP_DECLARE_TARGET_LINK = 0x01,
+  /// Mark the entry as being a global constructor.
+  OMP_DECLARE_TARGET_CTOR = 0x02,
+  /// Mark the entry as being a global destructor.
+  OMP_DECLARE_TARGET_DTOR = 0x04
+};
+
+/// This struct is a record of an entry point or global. For a function
+/// entry point the size is expected to be zero
+struct __tgt_offload_entry {
+  void *addr;   // Pointer to the offload entry info (function or global)
+  char *name;   // Name of the function or global
+  size_t size;  // Size of the entry info (0 if it is a function)
+  int32_t flags; // Flags associated with the entry, e.g. 'link'.
+  int32_t reserved; // Reserved, to be used by the runtime library.
+};
+
+/// This struct is a record of the device image information
+struct __tgt_device_image {
+  void *ImageStart;                  // Pointer to the target code start
+  void *ImageEnd;                    // Pointer to the target code end
+  __tgt_offload_entry *EntriesBegin; // Begin of table with all target entries
+  __tgt_offload_entry *EntriesEnd;   // End of table (non inclusive)
+};
+
+/// This struct is a record of all the host code that may be offloaded to a
+/// target.
+struct __tgt_bin_desc {
+  int32_t NumDeviceImages;           // Number of device types supported
+  __tgt_device_image *DeviceImages;  // Array of device images (1 per dev. type)
+  __tgt_offload_entry *HostEntriesBegin; // Begin of table with all host entries
+  __tgt_offload_entry *HostEntriesEnd;   // End of table (non inclusive)
+};
+
+/// This struct contains the offload entries identified by the target runtime
+struct __tgt_target_table {
+  __tgt_offload_entry *EntriesBegin; // Begin of the table with all the entries
+  __tgt_offload_entry
+      *EntriesEnd; // End of the table with all the entries (non inclusive)
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Implemented in libomp, they are called from within __tgt_* functions.
+int omp_get_default_device(void) __attribute__((weak));
+int32_t __kmpc_omp_taskwait(void *loc_ref, int32_t gtid) __attribute__((weak));
+
+int omp_get_num_devices(void);
+int omp_get_initial_device(void);
+void *omp_target_alloc(size_t size, int device_num);
+void omp_target_free(void *device_ptr, int device_num);
+int omp_target_is_present(void *ptr, int device_num);
+int omp_target_memcpy(void *dst, void *src, size_t length, size_t dst_offset,
+    size_t src_offset, int dst_device, int src_device);
+int omp_target_memcpy_rect(void *dst, void *src, size_t element_size,
+    int num_dims, const size_t *volume, const size_t *dst_offsets,
+    const size_t *src_offsets, const size_t *dst_dimensions,
+    const size_t *src_dimensions, int dst_device, int src_device);
+int omp_target_associate_ptr(void *host_ptr, void *device_ptr, size_t size,
+    size_t device_offset, int device_num);
+int omp_target_disassociate_ptr(void *host_ptr, int device_num);
+
+/// adds a target shared library to the target execution image
+void __tgt_register_lib(__tgt_bin_desc *desc);
+
+/// removes a target shared library from the target execution image
+void __tgt_unregister_lib(__tgt_bin_desc *desc);
+
+// creates the host to target data mapping, stores it in the
+// libomptarget.so internal structure (an entry in a stack of data maps) and
+// passes the data to the device;
+void __tgt_target_data_begin(int32_t device_id, int32_t arg_num,
+                             void **args_base, void **args, int64_t *arg_sizes,
+                             int32_t *arg_types);
+void __tgt_target_data_begin_nowait(int32_t device_id, int32_t arg_num,
+                                    void **args_base, void **args,
+                                    int64_t *arg_sizes, int32_t *arg_types,
+                                    int32_t depNum, void *depList,
+                                    int32_t noAliasDepNum,
+                                    void *noAliasDepList);
+
+// passes data from the target, release target memory and destroys the
+// host-target mapping (top entry from the stack of data maps) created by
+// the last __tgt_target_data_begin
+void __tgt_target_data_end(int32_t device_id, int32_t arg_num, void **args_base,
+                           void **args, int64_t *arg_sizes, int32_t *arg_types);
+void __tgt_target_data_end_nowait(int32_t device_id, int32_t arg_num,
+                                  void **args_base, void **args,
+                                  int64_t *arg_sizes, int32_t *arg_types,
+                                  int32_t depNum, void *depList,
+                                  int32_t noAliasDepNum, void *noAliasDepList);
+
+/// passes data to/from the target
+void __tgt_target_data_update(int32_t device_id, int32_t arg_num,
+                              void **args_base, void **args, int64_t *arg_sizes,
+                              int32_t *arg_types);
+void __tgt_target_data_update_nowait(int32_t device_id, int32_t arg_num,
+                                     void **args_base, void **args,
+                                     int64_t *arg_sizes, int32_t *arg_types,
+                                     int32_t depNum, void *depList,
+                                     int32_t noAliasDepNum,
+                                     void *noAliasDepList);
+
+// Performs the same actions as data_begin in case arg_num is non-zero
+// and initiates run of offloaded region on target platform; if arg_num
+// is non-zero after the region execution is done it also performs the
+// same action as data_end above. The following types are used; this
+// function returns 0 if it was able to transfer the execution to a
+// target and an int different from zero otherwise.
+int __tgt_target(int32_t device_id, void *host_ptr, int32_t arg_num,
+                 void **args_base, void **args, int64_t *arg_sizes,
+                 int32_t *arg_types);
+int __tgt_target_nowait(int32_t device_id, void *host_ptr, int32_t arg_num,
+                        void **args_base, void **args, int64_t *arg_sizes,
+                        int32_t *arg_types, int32_t depNum, void *depList,
+                        int32_t noAliasDepNum, void *noAliasDepList);
+
+int __tgt_target_teams(int32_t device_id, void *host_ptr, int32_t arg_num,
+                       void **args_base, void **args, int64_t *arg_sizes,
+                       int32_t *arg_types, int32_t num_teams,
+                       int32_t thread_limit);
+int __tgt_target_teams_nowait(int32_t device_id, void *host_ptr,
+                              int32_t arg_num, void **args_base, void **args,
+                              int64_t *arg_sizes, int32_t *arg_types,
+                              int32_t num_teams, int32_t thread_limit,
+                              int32_t depNum, void *depList,
+                              int32_t noAliasDepNum, void *noAliasDepList);
+void __kmpc_push_target_tripcount(int32_t device_id, uint64_t loop_tripcount);
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef OMPTARGET_DEBUG
+#include <stdio.h>
+#define DEBUGP(prefix, ...)                                                    \
+  {                                                                            \
+    fprintf(stderr, "%s --> ", prefix);                                        \
+    fprintf(stderr, __VA_ARGS__);                                              \
+  }
+
+#include <inttypes.h>
+#define DPxMOD "0x%0*" PRIxPTR
+#define DPxPTR(ptr) ((int)(2*sizeof(uintptr_t))), ((uintptr_t) (ptr))
+
+/*
+ * To printf a pointer in hex with a fixed width of 16 digits and a leading 0x,
+ * use printf("ptr=" DPxMOD "...\n", DPxPTR(ptr));
+ *
+ * DPxMOD expands to:
+ *   "0x%0*" PRIxPTR
+ * where PRIxPTR expands to an appropriate modifier for the type uintptr_t on a
+ * specific platform, e.g. "lu" if uintptr_t is typedef'd as unsigned long:
+ *   "0x%0*lu"
+ *
+ * Ultimately, the whole statement expands to:
+ *   printf("ptr=0x%0*lu...\n",  // the 0* modifier expects an extra argument
+ *                               // specifying the width of the output
+ *   (int)(2*sizeof(uintptr_t)), // the extra argument specifying the width
+ *                               // 8 digits for 32bit systems
+ *                               // 16 digits for 64bit
+ *   (uintptr_t) ptr);
+ */
+#else
+#define DEBUGP(prefix, ...)                                                    \
+  {}
+#endif
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+#else
+#define EXTERN extern
+#endif
+
+#endif // _OMPTARGET_H_
diff --git a/libomptarget/test/CMakeLists.txt b/libomptarget/test/CMakeLists.txt
new file mode 100644
index 0000000..fa5931c
--- /dev/null
+++ b/libomptarget/test/CMakeLists.txt
@@ -0,0 +1,93 @@
+# CMakeLists.txt file for unit testing OpenMP Library
+include(FindPythonInterp)
+include(CheckTypeSize)
+if(NOT PYTHONINTERP_FOUND)
+  libomptarget_warning_say("Could not find Python.")
+  libomptarget_warning_say("The check-libomptarget target will not be available!")
+  return()
+endif()
+
+set(LIBOMPTARGET_TEST_CFLAGS "" CACHE STRING
+  "Extra compiler flags to send to the test compiler")
+
+if(${LIBOMPTARGET_STANDALONE_BUILD})
+  # Make sure we can use the console pool for recent cmake and ninja > 1.5
+  if(CMAKE_VERSION VERSION_LESS 3.1.20141117)
+    set(cmake_3_2_USES_TERMINAL)
+  else()
+    set(cmake_3_2_USES_TERMINAL USES_TERMINAL)
+  endif()
+  set(LIBOMPTARGET_TEST_C_COMPILER ${CMAKE_C_COMPILER} CACHE STRING
+    "C compiler to use for testing OpenMP offloading library")
+  set(LIBOMPTARGET_TEST_CXX_COMPILER ${CMAKE_CXX_COMPILER} CACHE STRING
+    "C++ compiler to use for testing OpenMP offloading library")
+  set(LIBOMPTARGET_TEST_OPENMP_FLAG -fopenmp CACHE STRING
+    "OpenMP compiler flag to use for testing OpenMP offloading library")
+  set(LIBOMPTARGET_LLVM_LIT_EXECUTABLE "" CACHE STRING
+    "Path to llvm-lit")
+  find_program(LIT_EXECUTABLE NAMES llvm-lit ${LIBOMPTARGET_LLVM_LIT_EXECUTABLE})
+  if(NOT LIT_EXECUTABLE)
+    libomptarget_say("Cannot find llvm-lit.")
+    libomptarget_say("Please put llvm-lit in your PATH or set LIBOMPTARGET_LLVM_LIT_EXECUTABLE to its full path")
+    libomptarget_warning_say("The check-libomptarget target will not be available!")
+    return()
+  endif()
+  
+  set(LIBOMPTARGET_FILECHECK_EXECUTABLE "" CACHE STRING
+    "Path to FileCheck")
+  find_program(LIBOMPTARGET_FILECHECK NAMES FileCheck ${LIBOMPTARGET_FILECHECK_EXECUTABLE})
+  if(NOT LIBOMPTARGET_FILECHECK)
+    libomptarget_say("Cannot find FileCheck.")
+    libomptarget_say("Please put FileCheck in your PATH or set LIBOMPTARGET_FILECHECK_EXECUTABLE to its full path")
+    libomptarget_warning_say("The check-libomptarget target will not be available!")
+    return()
+  endif()
+  
+  # Set lit arguments
+  # The -j 1 lets the actual tests run with the entire machine.
+  # We have one test thread that spawns the tests serially.  This allows
+  # Each test to use the entire machine.
+  set(LIBOMPTARGET_LIT_ARGS_DEFAULT "-sv --show-unsupported --show-xfail -j 1")
+  if(MSVC OR XCODE)
+    set(LIBOMPTARGET_LIT_ARGS_DEFAULT "${LIBOMPTARGET_LIT_ARGS_DEFAULT} --no-progress-bar")
+  endif()
+  set(LIBOMPTARGET_LIT_ARGS "${LIBOMPTARGET_LIT_ARGS_DEFAULT}" CACHE STRING
+    "Default options for lit")
+  separate_arguments(LIBOMPTARGET_LIT_ARGS)
+  add_custom_target(check-libomptarget
+    COMMAND ${PYTHON_EXECUTABLE} ${LIT_EXECUTABLE} ${LIBOMPTARGET_LIT_ARGS} ${CMAKE_CURRENT_BINARY_DIR}
+    DEPENDS omptarget
+    COMMENT "Running libomptarget tests"
+    ${cmake_3_2_USES_TERMINAL}
+  )
+  
+  set(LIBOMPTARGET_OPENMP_HEADER_FOLDER "${CMAKE_CURRENT_BINARY_DIR}/../../runtime/src" CACHE STRING
+    "Path to folder containing omp.h")
+  set(LIBOMPTARGET_OPENMP_HOST_RTL_FOLDER "${CMAKE_CURRENT_BINARY_DIR}/../../runtime/src" CACHE STRING
+    "Path to folder containing libomp.so")
+else()
+  # LLVM source tree build, test just-built clang
+  if(NOT MSVC)
+    set(LIBOMPTARGET_TEST_C_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
+    set(LIBOMPTARGET_TEST_CXX_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++)
+    set(LIBOMPTARGET_FILECHECK ${LLVM_RUNTIME_OUTPUT_INTDIR}/FileCheck)
+  else()
+    libomptarget_warning_say("Not prepared to run tests on Windows systems.")
+  endif()
+  set(LIBOMPTARGET_TEST_OPENMP_FLAG -fopenmp=libomp)
+  # Use add_lit_testsuite() from LLVM CMake. This also depends on OpenMP
+  # implementation because it uses omp.h.
+  add_lit_testsuite(check-libomptarget
+    "Running libomptarget tests"
+    ${CMAKE_CURRENT_BINARY_DIR}
+    ARGS "-j 1"
+    DEPENDS omptarget omp
+  )
+  
+  set(LIBOMPTARGET_OPENMP_HEADER_FOLDER "${LIBOMPTARGET_BINARY_DIR}/../runtime/src")
+endif()
+
+# Configure the lit.site.cfg.in file
+set(AUTO_GEN_COMMENT "## Autogenerated by libomptarget configuration.\n# Do not edit!")
+configure_file(lit.site.cfg.in lit.site.cfg @ONLY)
+
diff --git a/libomptarget/test/lit.cfg b/libomptarget/test/lit.cfg
new file mode 100644
index 0000000..3f64de4
--- /dev/null
+++ b/libomptarget/test/lit.cfg
@@ -0,0 +1,116 @@
+# -*- Python -*- vim: set ft=python ts=4 sw=4 expandtab tw=79:
+# Configuration file for the 'lit' test runner.
+
+import os
+import lit.formats
+
+# Tell pylint that we know config and lit_config exist somewhere.
+if 'PYLINT_IMPORT' in os.environ:
+    config = object()
+    lit_config = object()
+
+def append_dynamic_library_path(name, value, sep):
+    if name in config.environment:
+        config.environment[name] = value + sep + config.environment[name]
+    else:
+        config.environment[name] = value
+
+# name: The name of this test suite.
+config.name = 'libomptarget'
+
+# suffixes: A list of file extensions to treat as test files.
+config.suffixes = ['.c', '.cpp', '.cc']
+
+# test_source_root: The root path where tests are located.
+config.test_source_root = os.path.dirname(__file__)
+
+# test_exec_root: The root object directory where output is placed
+config.test_exec_root = config.libomptarget_obj_root
+
+# test format
+config.test_format = lit.formats.ShTest()
+
+# compiler flags
+config.test_cflags = config.test_openmp_flag + \
+    " -I " + config.test_source_root + \
+    " -I " + config.omp_header_directory + \
+    " -L " + config.library_dir;
+    
+if config.omp_host_rtl_directory:
+    config.test_cflags = config.test_cflags + " -L " + \
+        config.omp_host_rtl_directory  
+    
+config.test_cflags = config.test_cflags + " " + config.test_extra_cflags
+
+# Setup environment to find dynamic library at runtime
+if config.operating_system == 'Windows':
+    append_dynamic_library_path('PATH', config.library_dir, ";")
+    append_dynamic_library_path('PATH', config.omp_host_rtl_directory, ";")
+elif config.operating_system == 'Darwin':
+    append_dynamic_library_path('DYLD_LIBRARY_PATH', config.library_dir, ":")
+    append_dynamic_library_path('DYLD_LIBRARY_PATH', \
+        config.omp_host_rtl_directory, ";")
+    config.test_cflags += " -Wl,-rpath," + config.library_dir
+    config.test_cflags += " -Wl,-rpath," + config.omp_host_rtl_directory
+else: # Unices
+    append_dynamic_library_path('LD_LIBRARY_PATH', config.library_dir, ":")
+    append_dynamic_library_path('LD_LIBRARY_PATH', \
+        config.omp_host_rtl_directory, ":")
+    
+# substitutions
+# - for targets that exist in the system create the actual command.
+# - for valid targets that do not exist in the system, return false, so that the
+#   same test can be used for different targets.
+
+# Scan all the valid targets.
+for libomptarget_target in config.libomptarget_all_targets:
+    # Is this target in the current system? If so create a compile, run and test
+    # command. Otherwise create command that return false.
+    if libomptarget_target in config.libomptarget_system_targets:
+        config.substitutions.append(("%libomptarget-compilexx-run-and-check-" + \
+            libomptarget_target, \
+            "%libomptarget-compilexx-and-run-" + libomptarget_target + \
+            " | " + config.libomptarget_filecheck + " %s"))
+        config.substitutions.append(("%libomptarget-compile-run-and-check-" + \
+            libomptarget_target, \
+            "%libomptarget-compile-and-run-" + libomptarget_target + \
+            " | " + config.libomptarget_filecheck + " %s"))      
+        config.substitutions.append(("%libomptarget-compilexx-and-run-" + \
+            libomptarget_target, \
+            "%clangxx-" + libomptarget_target + " %s -o %t-" + \
+            libomptarget_target + " && %t-" + libomptarget_target))    
+        config.substitutions.append(("%libomptarget-compile-and-run-" + \
+            libomptarget_target, \
+            "%clang-" + libomptarget_target + " %s -o %t-" + \
+            libomptarget_target + " && %t-" + libomptarget_target))
+        config.substitutions.append(("%clangxx-" + libomptarget_target, \
+            "%clangxx %cflags -fopenmp-targets=" + libomptarget_target))    
+        config.substitutions.append(("%clang-" + libomptarget_target, \
+            "%clang %cflags -fopenmp-targets=" + libomptarget_target))
+        config.substitutions.append(("%fcheck-" + libomptarget_target, \
+            config.libomptarget_filecheck + " %s"))
+    else:
+        config.substitutions.append(("%libomptarget-compile-run-and-check-" + \
+            libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%libomptarget-compilexx-run-and-check-" + \
+            libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%libomptarget-compile-and-run-" + \
+            libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%libomptarget-compilexx-and-run-" + \
+            libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%clang-" + libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%clangxx-" + libomptarget_target, \
+            "echo ignored-command"))
+        config.substitutions.append(("%fcheck-" + libomptarget_target, \
+            "echo ignored-command"))
+
+config.substitutions.append(("%clangxx", config.test_cxx_compiler))
+config.substitutions.append(("%clang", config.test_c_compiler))
+config.substitutions.append(("%openmp_flag", config.test_openmp_flag))
+config.substitutions.append(("%cflags", config.test_cflags))
+
diff --git a/libomptarget/test/lit.site.cfg.in b/libomptarget/test/lit.site.cfg.in
new file mode 100644
index 0000000..b6ab947
--- /dev/null
+++ b/libomptarget/test/lit.site.cfg.in
@@ -0,0 +1,20 @@
+@AUTO_GEN_COMMENT@
+
+config.test_c_compiler = "@LIBOMPTARGET_TEST_C_COMPILER@"
+config.test_cxx_compiler = "@LIBOMPTARGET_TEST_CXX_COMPILER@"
+config.test_openmp_flag = "@LIBOMPTARGET_TEST_OPENMP_FLAG@"
+# For the moment we still need to pass libomptarget explicitly. Once the driver
+# patch, lands, this is not required anymore.
+config.test_extra_cflags = "-lomptarget @LIBOMPTARGET_TEST_CFLAGS@"
+config.libomptarget_obj_root = "@CMAKE_CURRENT_BINARY_DIR@"
+config.library_dir = "@LIBOMPTARGET_LIBRARY_DIR@"
+config.omp_header_directory = "@LIBOMPTARGET_OPENMP_HEADER_FOLDER@"
+config.omp_host_rtl_directory = "@LIBOMPTARGET_OPENMP_HOST_RTL_FOLDER@"
+config.operating_system = "@CMAKE_SYSTEM_NAME@"
+config.libomptarget_all_targets = "@LIBOMPTARGET_ALL_TARGETS@".split()
+config.libomptarget_system_targets = "@LIBOMPTARGET_SYSTEM_TARGETS@".split()
+config.libomptarget_filecheck = "@LIBOMPTARGET_FILECHECK@"
+
+# Let the main config do the real work.
+lit_config.load_config(config, "@LIBOMPTARGET_BASE_DIR@/test/lit.cfg")
+
diff --git a/libomptarget/test/offloading/offloading_success.c b/libomptarget/test/offloading/offloading_success.c
new file mode 100644
index 0000000..facaf70
--- /dev/null
+++ b/libomptarget/test/offloading/offloading_success.c
@@ -0,0 +1,22 @@
+// RUN: %libomptarget-compile-run-and-check-powerpc64-ibm-linux-gnu
+// RUN: %libomptarget-compile-run-and-check-powerpc64le-ibm-linux-gnu
+// RUN: %libomptarget-compile-run-and-check-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+#include <omp.h>
+
+int main(void) {
+  int isHost = -1;
+
+#pragma omp target
+  { isHost = omp_is_initial_device(); }
+
+  if (isHost < 0) {
+    printf("Runtime error, isHost=%d\n", isHost);
+  }
+
+  // CHECK: Target region executed on the device
+  printf("Target region executed on the %s\n", isHost ? "host" : "device");
+
+  return isHost;
+}
diff --git a/libomptarget/test/offloading/offloading_success.cpp b/libomptarget/test/offloading/offloading_success.cpp
new file mode 100644
index 0000000..62d5cf8
--- /dev/null
+++ b/libomptarget/test/offloading/offloading_success.cpp
@@ -0,0 +1,22 @@
+// RUN: %libomptarget-compilexx-run-and-check-powerpc64-ibm-linux-gnu
+// RUN: %libomptarget-compilexx-run-and-check-powerpc64le-ibm-linux-gnu
+// RUN: %libomptarget-compilexx-run-and-check-x86_64-pc-linux-gnu
+
+#include <stdio.h>
+#include <omp.h>
+
+int main(void) {
+  int isHost = 0;
+
+#pragma omp target
+  { isHost = omp_is_initial_device(); }
+
+  if (isHost < 0) {
+    printf("Runtime error, isHost=%d\n", isHost);
+  }
+
+  // CHECK: Target region executed on the device
+  printf("Target region executed on the %s\n", isHost ? "host" : "device");
+
+  return isHost;
+}