Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/openmp/libomptarget/plugins/CMakeLists.txt

@@ -0,0 +1,72 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     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 plugins for the user system if available.
+#
+##===----------------------------------------------------------------------===##
+
+# void build_generic_elf64(string tmachine, string tmachine_name, string tmachine_libname, string elf_machine_id);
+# - build a plugin for an ELF based generic 64-bit target based on libffi.
+# - tmachine: name of the machine processor as used in the cmake build system.
+# - tmachine_name: name of the machine to be printed with the debug messages.
+# - tmachine_libname: machine name to be appended to the plugin library name.
+macro(build_generic_elf64 tmachine tmachine_name tmachine_libname tmachine_triple elf_machine_id)
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "${tmachine}$")
+  if(LIBOMPTARGET_DEP_LIBELF_FOUND)
+    if(LIBOMPTARGET_DEP_LIBFFI_FOUND)
+    
+      libomptarget_say("Building ${tmachine_name} offloading plugin.")
+    
+      include_directories(${LIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIR})
+      include_directories(${LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIR})
+      
+      # Define macro to be used as prefix of the runtime messages for this target.
+      add_definitions("-DTARGET_NAME=${tmachine_name}")
+      
+      # Define macro with the ELF ID for this target.
+      add_definitions("-DTARGET_ELF_ID=${elf_machine_id}")
+    
+      add_library("omptarget.rtl.${tmachine_libname}" SHARED 
+        ${CMAKE_CURRENT_SOURCE_DIR}/../generic-elf-64bit/src/rtl.cpp)
+        
+      # Install plugin under the lib destination folder.
+      install(TARGETS "omptarget.rtl.${tmachine_libname}" 
+        LIBRARY DESTINATION lib${OPENMP_LIBDIR_SUFFIX})
+        
+      target_link_libraries(
+        "omptarget.rtl.${tmachine_libname}"
+        ${LIBOMPTARGET_DEP_LIBFFI_LIBRARIES} 
+        ${LIBOMPTARGET_DEP_LIBELF_LIBRARIES}
+        dl
+        "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/../exports")
+    
+      # Report to the parent scope that we are building a plugin.
+      set(LIBOMPTARGET_SYSTEM_TARGETS 
+        "${LIBOMPTARGET_SYSTEM_TARGETS} ${tmachine_triple}" PARENT_SCOPE)
+      
+    else(LIBOMPTARGET_DEP_LIBFFI_FOUND)
+      libomptarget_say("Not building ${tmachine_name} offloading plugin: libffi dependency not found.")
+    endif(LIBOMPTARGET_DEP_LIBFFI_FOUND)
+  else(LIBOMPTARGET_DEP_LIBELF_FOUND)
+    libomptarget_say("Not building ${tmachine_name} offloading plugin: libelf dependency not found.")
+  endif(LIBOMPTARGET_DEP_LIBELF_FOUND)
+else()
+  libomptarget_say("Not building ${tmachine_name} offloading plugin: machine not found in the system.")
+endif()
+endmacro()
+
+add_subdirectory(aarch64)
+add_subdirectory(cuda)
+add_subdirectory(ppc64)
+add_subdirectory(ppc64le)
+add_subdirectory(x86_64)
+
+# Make sure the parent scope can see the plugins that will be created.
+set(LIBOMPTARGET_SYSTEM_TARGETS "${LIBOMPTARGET_SYSTEM_TARGETS}" PARENT_SCOPE)
+

external/llvm-project/openmp/libomptarget/plugins/aarch64/CMakeLists.txt

@@ -0,0 +1,18 @@
+##===----------------------------------------------------------------------===##
+#
+#                     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 a plugin for an aarch64 machine if available.
+#
+##===----------------------------------------------------------------------===##
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+  build_generic_elf64("aarch64" "aarch64" "aarch64" "aarch64-unknown-linux-gnu" "183")
+else()
+ libomptarget_say("Not building aarch64 offloading plugin: machine not found in the system.")
+endif()

external/llvm-project/openmp/libomptarget/plugins/common/elf_common.c

@@ -0,0 +1,73 @@
+//===-- elf_common.c - Common ELF functionality -------------------*- 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// Common ELF functionality for target plugins.
+// Must be included in the plugin source file AFTER omptarget.h has been
+// included and macro DP(...) has been defined.
+// .
+//
+//===----------------------------------------------------------------------===//
+
+#if !(defined(_OMPTARGET_H_) && defined(DP))
+#error Include elf_common.c in the plugin source AFTER omptarget.h has been\
+ included and macro DP(...) has been defined.
+#endif
+
+#include <elf.h>
+#include <libelf.h>
+
+// Check whether an image is valid for execution on target_id
+static inline int32_t elf_check_machine(__tgt_device_image *image,
+    uint16_t target_id) {
+
+  // Is the library version incompatible with the header file?
+  if (elf_version(EV_CURRENT) == EV_NONE) {
+    DP("Incompatible ELF library!\n");
+    return 0;
+  }
+
+  char *img_begin = (char *)image->ImageStart;
+  char *img_end = (char *)image->ImageEnd;
+  size_t img_size = img_end - img_begin;
+
+  // Obtain elf handler
+  Elf *e = elf_memory(img_begin, img_size);
+  if (!e) {
+    DP("Unable to get ELF handle: %s!\n", elf_errmsg(-1));
+    return 0;
+  }
+
+  // Check if ELF is the right kind.
+  if (elf_kind(e) != ELF_K_ELF) {
+    DP("Unexpected ELF type!\n");
+    return 0;
+  }
+  Elf64_Ehdr *eh64 = elf64_getehdr(e);
+  Elf32_Ehdr *eh32 = elf32_getehdr(e);
+
+  if (!eh64 && !eh32) {
+    DP("Unable to get machine ID from ELF file!\n");
+    elf_end(e);
+    return 0;
+  }
+
+  uint16_t MachineID;
+  if (eh64 && !eh32)
+    MachineID = eh64->e_machine;
+  else if (eh32 && !eh64)
+    MachineID = eh32->e_machine;
+  else {
+    DP("Ambiguous ELF header!\n");
+    elf_end(e);
+    return 0;
+  }
+
+  elf_end(e);
+  return MachineID == target_id;
+}

external/llvm-project/openmp/libomptarget/plugins/cuda/CMakeLists.txt

@@ -0,0 +1,50 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     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 a plugin for a CUDA machine if available.
+#
+##===----------------------------------------------------------------------===##
+if(LIBOMPTARGET_DEP_LIBELF_FOUND)
+  if(LIBOMPTARGET_DEP_CUDA_FOUND)
+    if(CMAKE_SYSTEM_PROCESSOR MATCHES "(x86_64)|(ppc64le)$" AND CMAKE_SYSTEM_NAME MATCHES "Linux")
+    
+      libomptarget_say("Building CUDA offloading plugin.")
+    
+      # Define the suffix for the runtime messaging dumps.
+      add_definitions(-DTARGET_NAME=CUDA)
+    
+      if(LIBOMPTARGET_CMAKE_BUILD_TYPE MATCHES debug)
+          add_definitions(-DCUDA_ERROR_REPORT)
+      endif()
+      
+      include_directories(${LIBOMPTARGET_DEP_CUDA_INCLUDE_DIRS})
+      include_directories(${LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIRS})
+    
+      add_library(omptarget.rtl.cuda SHARED src/rtl.cpp)
+      
+      # Install plugin under the lib destination folder.
+      install(TARGETS omptarget.rtl.cuda LIBRARY DESTINATION lib${OPENMP_LIBDIR_SUFFIX})
+      
+      target_link_libraries(omptarget.rtl.cuda 
+        ${LIBOMPTARGET_DEP_CUDA_LIBRARIES} 
+        cuda 
+        ${LIBOMPTARGET_DEP_LIBELF_LIBRARIES}
+        "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/../exports")
+    
+      # Report to the parent scope that we are building a plugin for CUDA.
+      set(LIBOMPTARGET_SYSTEM_TARGETS "${LIBOMPTARGET_SYSTEM_TARGETS} nvptx64-nvidia-cuda" PARENT_SCOPE)
+    else()
+      libomptarget_say("Not building CUDA offloading plugin: only support CUDA in Linux x86_64 or ppc64le hosts.")
+    endif()
+  else()
+    libomptarget_say("Not building CUDA offloading plugin: CUDA not found in system.")
+  endif()
+else(LIBOMPTARGET_DEP_LIBELF_FOUND)
+  libomptarget_say("Not building CUDA offloading plugin: libelf dependency not found.")
+endif(LIBOMPTARGET_DEP_LIBELF_FOUND)

external/llvm-project/openmp/libomptarget/plugins/exports

@@ -0,0 +1,15 @@
+VERS1.0 {
+  global:
+    __tgt_rtl_is_valid_binary;
+    __tgt_rtl_number_of_devices;
+    __tgt_rtl_init_device;
+    __tgt_rtl_load_binary;
+    __tgt_rtl_data_alloc;
+    __tgt_rtl_data_submit;
+    __tgt_rtl_data_retrieve;
+    __tgt_rtl_data_delete;
+    __tgt_rtl_run_target_team_region;
+    __tgt_rtl_run_target_region;
+  local:
+    *;
+};

external/llvm-project/openmp/libomptarget/plugins/generic-elf-64bit/src/rtl.cpp

@@ -0,0 +1,339 @@
+//===-RTLs/generic-64bit/src/rtl.cpp - Target RTLs Implementation - 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// RTL for generic 64-bit machine
+//
+//===----------------------------------------------------------------------===//
+
+#include <cassert>
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <dlfcn.h>
+#include <ffi.h>
+#include <gelf.h>
+#include <link.h>
+#include <list>
+#include <string>
+#include <vector>
+
+#include "omptargetplugin.h"
+
+#ifndef TARGET_NAME
+#define TARGET_NAME Generic ELF - 64bit
+#endif
+
+#ifndef TARGET_ELF_ID
+#define TARGET_ELF_ID 0
+#endif
+
+#ifdef OMPTARGET_DEBUG
+static int DebugLevel = 0;
+
+#define GETNAME2(name) #name
+#define GETNAME(name) GETNAME2(name)
+#define DP(...) \
+  do { \
+    if (DebugLevel > 0) { \
+      DEBUGP("Target " GETNAME(TARGET_NAME) " RTL", __VA_ARGS__); \
+    } \
+  } while (false)
+#else // OMPTARGET_DEBUG
+#define DP(...) {}
+#endif // OMPTARGET_DEBUG
+
+#include "../../common/elf_common.c"
+
+#define NUMBER_OF_DEVICES 4
+#define OFFLOADSECTIONNAME ".omp_offloading.entries"
+
+/// Array of Dynamic libraries loaded for this target.
+struct DynLibTy {
+  char *FileName;
+  void *Handle;
+};
+
+/// Keep entries table per device.
+struct FuncOrGblEntryTy {
+  __tgt_target_table Table;
+};
+
+/// Class containing all the device information.
+class RTLDeviceInfoTy {
+  std::vector<FuncOrGblEntryTy> FuncGblEntries;
+
+public:
+  std::list<DynLibTy> DynLibs;
+
+  // Record entry point associated with device.
+  void createOffloadTable(int32_t device_id, __tgt_offload_entry *begin,
+                          __tgt_offload_entry *end) {
+    assert(device_id < (int32_t)FuncGblEntries.size() &&
+           "Unexpected device id!");
+    FuncOrGblEntryTy &E = FuncGblEntries[device_id];
+
+    E.Table.EntriesBegin = begin;
+    E.Table.EntriesEnd = end;
+  }
+
+  // Return true if the entry is associated with device.
+  bool findOffloadEntry(int32_t device_id, void *addr) {
+    assert(device_id < (int32_t)FuncGblEntries.size() &&
+           "Unexpected device id!");
+    FuncOrGblEntryTy &E = FuncGblEntries[device_id];
+
+    for (__tgt_offload_entry *i = E.Table.EntriesBegin, *e = E.Table.EntriesEnd;
+         i < e; ++i) {
+      if (i->addr == addr)
+        return true;
+    }
+
+    return false;
+  }
+
+  // Return the pointer to the target entries table.
+  __tgt_target_table *getOffloadEntriesTable(int32_t device_id) {
+    assert(device_id < (int32_t)FuncGblEntries.size() &&
+           "Unexpected device id!");
+    FuncOrGblEntryTy &E = FuncGblEntries[device_id];
+
+    return &E.Table;
+  }
+
+  RTLDeviceInfoTy(int32_t num_devices) {
+#ifdef OMPTARGET_DEBUG
+    if (char *envStr = getenv("LIBOMPTARGET_DEBUG")) {
+      DebugLevel = std::stoi(envStr);
+    }
+#endif // OMPTARGET_DEBUG
+
+    FuncGblEntries.resize(num_devices);
+  }
+
+  ~RTLDeviceInfoTy() {
+    // Close dynamic libraries
+    for (auto &lib : DynLibs) {
+      if (lib.Handle) {
+        dlclose(lib.Handle);
+        remove(lib.FileName);
+      }
+    }
+  }
+};
+
+static RTLDeviceInfoTy DeviceInfo(NUMBER_OF_DEVICES);
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int32_t __tgt_rtl_is_valid_binary(__tgt_device_image *image) {
+// If we don't have a valid ELF ID we can just fail.
+#if TARGET_ELF_ID < 1
+  return 0;
+#else
+  return elf_check_machine(image, TARGET_ELF_ID);
+#endif
+}
+
+int32_t __tgt_rtl_number_of_devices() { return NUMBER_OF_DEVICES; }
+
+int32_t __tgt_rtl_init_device(int32_t device_id) { return OFFLOAD_SUCCESS; }
+
+__tgt_target_table *__tgt_rtl_load_binary(int32_t device_id,
+                                          __tgt_device_image *image) {
+
+  DP("Dev %d: load binary from " DPxMOD " image\n", device_id,
+     DPxPTR(image->ImageStart));
+
+  assert(device_id >= 0 && device_id < NUMBER_OF_DEVICES && "bad dev id");
+
+  size_t ImageSize = (size_t)image->ImageEnd - (size_t)image->ImageStart;
+  size_t NumEntries = (size_t)(image->EntriesEnd - image->EntriesBegin);
+  DP("Expecting to have %zd entries defined.\n", NumEntries);
+
+  // Is the library version incompatible with the header file?
+  if (elf_version(EV_CURRENT) == EV_NONE) {
+    DP("Incompatible ELF library!\n");
+    return NULL;
+  }
+
+  // Obtain elf handler
+  Elf *e = elf_memory((char *)image->ImageStart, ImageSize);
+  if (!e) {
+    DP("Unable to get ELF handle: %s!\n", elf_errmsg(-1));
+    return NULL;
+  }
+
+  if (elf_kind(e) != ELF_K_ELF) {
+    DP("Invalid Elf kind!\n");
+    elf_end(e);
+    return NULL;
+  }
+
+  // Find the entries section offset
+  Elf_Scn *section = 0;
+  Elf64_Off entries_offset = 0;
+
+  size_t shstrndx;
+
+  if (elf_getshdrstrndx(e, &shstrndx)) {
+    DP("Unable to get ELF strings index!\n");
+    elf_end(e);
+    return NULL;
+  }
+
+  while ((section = elf_nextscn(e, section))) {
+    GElf_Shdr hdr;
+    gelf_getshdr(section, &hdr);
+
+    if (!strcmp(elf_strptr(e, shstrndx, hdr.sh_name), OFFLOADSECTIONNAME)) {
+      entries_offset = hdr.sh_addr;
+      break;
+    }
+  }
+
+  if (!entries_offset) {
+    DP("Entries Section Offset Not Found\n");
+    elf_end(e);
+    return NULL;
+  }
+
+  DP("Offset of entries section is (" DPxMOD ").\n", DPxPTR(entries_offset));
+
+  // load dynamic library and get the entry points. We use the dl library
+  // to do the loading of the library, but we could do it directly to avoid the
+  // dump to the temporary file.
+  //
+  // 1) Create tmp file with the library contents.
+  // 2) Use dlopen to load the file and dlsym to retrieve the symbols.
+  char tmp_name[] = "/tmp/tmpfile_XXXXXX";
+  int tmp_fd = mkstemp(tmp_name);
+
+  if (tmp_fd == -1) {
+    elf_end(e);
+    return NULL;
+  }
+
+  FILE *ftmp = fdopen(tmp_fd, "wb");
+
+  if (!ftmp) {
+    elf_end(e);
+    return NULL;
+  }
+
+  fwrite(image->ImageStart, ImageSize, 1, ftmp);
+  fclose(ftmp);
+
+  DynLibTy Lib = {tmp_name, dlopen(tmp_name, RTLD_LAZY)};
+
+  if (!Lib.Handle) {
+    DP("Target library loading error: %s\n", dlerror());
+    elf_end(e);
+    return NULL;
+  }
+
+  DeviceInfo.DynLibs.push_back(Lib);
+
+  struct link_map *libInfo = (struct link_map *)Lib.Handle;
+
+  // The place where the entries info is loaded is the library base address
+  // plus the offset determined from the ELF file.
+  Elf64_Addr entries_addr = libInfo->l_addr + entries_offset;
+
+  DP("Pointer to first entry to be loaded is (" DPxMOD ").\n",
+      DPxPTR(entries_addr));
+
+  // Table of pointers to all the entries in the target.
+  __tgt_offload_entry *entries_table = (__tgt_offload_entry *)entries_addr;
+
+  __tgt_offload_entry *entries_begin = &entries_table[0];
+  __tgt_offload_entry *entries_end = entries_begin + NumEntries;
+
+  if (!entries_begin) {
+    DP("Can't obtain entries begin\n");
+    elf_end(e);
+    return NULL;
+  }
+
+  DP("Entries table range is (" DPxMOD ")->(" DPxMOD ")\n",
+      DPxPTR(entries_begin), DPxPTR(entries_end));
+  DeviceInfo.createOffloadTable(device_id, entries_begin, entries_end);
+
+  elf_end(e);
+
+  return DeviceInfo.getOffloadEntriesTable(device_id);
+}
+
+void *__tgt_rtl_data_alloc(int32_t device_id, int64_t size, void *hst_ptr) {
+  void *ptr = malloc(size);
+  return ptr;
+}
+
+int32_t __tgt_rtl_data_submit(int32_t device_id, void *tgt_ptr, void *hst_ptr,
+                              int64_t size) {
+  memcpy(tgt_ptr, hst_ptr, size);
+  return OFFLOAD_SUCCESS;
+}
+
+int32_t __tgt_rtl_data_retrieve(int32_t device_id, void *hst_ptr, void *tgt_ptr,
+                                int64_t size) {
+  memcpy(hst_ptr, tgt_ptr, size);
+  return OFFLOAD_SUCCESS;
+}
+
+int32_t __tgt_rtl_data_delete(int32_t device_id, void *tgt_ptr) {
+  free(tgt_ptr);
+  return OFFLOAD_SUCCESS;
+}
+
+int32_t __tgt_rtl_run_target_team_region(int32_t device_id, void *tgt_entry_ptr,
+    void **tgt_args, ptrdiff_t *tgt_offsets, int32_t arg_num, int32_t team_num,
+    int32_t thread_limit, uint64_t loop_tripcount /*not used*/) {
+  // ignore team num and thread limit.
+
+  // Use libffi to launch execution.
+  ffi_cif cif;
+
+  // All args are references.
+  std::vector<ffi_type *> args_types(arg_num, &ffi_type_pointer);
+  std::vector<void *> args(arg_num);
+  std::vector<void *> ptrs(arg_num);
+
+  for (int32_t i = 0; i < arg_num; ++i) {
+    ptrs[i] = (void *)((intptr_t)tgt_args[i] + tgt_offsets[i]);
+    args[i] = &ptrs[i];
+  }
+
+  ffi_status status = ffi_prep_cif(&cif, FFI_DEFAULT_ABI, arg_num,
+                                   &ffi_type_void, &args_types[0]);
+
+  assert(status == FFI_OK && "Unable to prepare target launch!");
+
+  if (status != FFI_OK)
+    return OFFLOAD_FAIL;
+
+  DP("Running entry point at " DPxMOD "...\n", DPxPTR(tgt_entry_ptr));
+
+  void (*entry)(void);
+  *((void**) &entry) = tgt_entry_ptr;
+  ffi_call(&cif, entry, NULL, &args[0]);
+  return OFFLOAD_SUCCESS;
+}
+
+int32_t __tgt_rtl_run_target_region(int32_t device_id, void *tgt_entry_ptr,
+    void **tgt_args, ptrdiff_t *tgt_offsets, int32_t arg_num) {
+  // use one team and one thread.
+  return __tgt_rtl_run_target_team_region(device_id, tgt_entry_ptr, tgt_args,
+      tgt_offsets, arg_num, 1, 1, 0);
+}
+
+#ifdef __cplusplus
+}
+#endif

external/llvm-project/openmp/libomptarget/plugins/ppc64/CMakeLists.txt

@@ -0,0 +1,18 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     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 a plugin for a ppc64 machine if available.
+#
+##===----------------------------------------------------------------------===##
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+  build_generic_elf64("ppc64" "PPC64" "ppc64" "powerpc64-ibm-linux-gnu" "21")
+else()
+ libomptarget_say("Not building ppc64 offloading plugin: machine not found in the system.")
+endif()

external/llvm-project/openmp/libomptarget/plugins/ppc64le/CMakeLists.txt

@@ -0,0 +1,18 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     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 a plugin for a ppc64le machine if available.
+#
+##===----------------------------------------------------------------------===##
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+  build_generic_elf64("ppc64le" "PPC64le" "ppc64" "powerpc64le-ibm-linux-gnu" "21")
+else()
+ libomptarget_say("Not building ppc64le offloading plugin: machine not found in the system.")
+endif()

external/llvm-project/openmp/libomptarget/plugins/x86_64/CMakeLists.txt

@@ -0,0 +1,18 @@
+##===----------------------------------------------------------------------===##
+# 
+#                     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 a plugin for a x86_64 machine if available.
+#
+##===----------------------------------------------------------------------===##
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+  build_generic_elf64("x86_64" "x86_64" "x86_64" "x86_64-pc-linux-gnu" "62")
+else()
+ libomptarget_say("Not building x86_64 offloading plugin: machine not found in the system.")
+endif()