Add the offload directory which contains the code needed to support

OpenMP 4.0 "target" directives. This will need more work for
generality, but we want to get it out and visible to the community.

llvm-svn: 205909

1 files changed, 164 insertions, 0 deletions

diff --git a/openmp/offload/src/ofldbegin.cpp b/openmp/offload/src/ofldbegin.cpp
new file mode 100644
index 00000000000..945f982a4ac
--- /dev/null
+++ b/openmp/offload/src/ofldbegin.cpp
@@ -0,0 +1,164 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+
+#if HOST_LIBRARY
+#include "offload_host.h"
+#include "offload_myo_host.h"
+#else
+#include "compiler_if_target.h"
+#include "offload_target.h"
+#include "offload_myo_target.h"
+#endif
+
+#ifdef TARGET_WINNT
+#define ALLOCATE(name) __declspec(allocate(name))
+#define DLL_LOCAL
+#else // TARGET_WINNT
+#define ALLOCATE(name) __attribute__((section(name)))
+#define DLL_LOCAL  __attribute__((visibility("hidden")))
+#endif // TARGET_WINNT
+
+#if HOST_LIBRARY
+// the host program/shared library should always have __offload_target_image
+// symbol defined. This symbol specifies the beginning of the target program
+// image.
+extern "C" DLL_LOCAL const void* __offload_target_image;
+#else // HOST_LIBRARY
+// Define a weak main which would be used on target side in case usere's
+// source file containing main does not have offload code.
+#pragma weak main
+int main(void)
+{
+    OFFLOAD_TARGET_MAIN();
+    return 0;
+}
+
+#pragma weak MAIN__
+extern "C" int MAIN__(void)
+{
+    OFFLOAD_TARGET_MAIN();
+    return 0;
+}
+#endif // HOST_LIBRARY
+
+// offload section prolog
+ALLOCATE(OFFLOAD_ENTRY_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(FuncTable::Entry)))
+#endif // TARGET_WINNT
+static FuncTable::Entry __offload_entry_table_start = { 0 };
+
+// list element for the current module
+static FuncList::Node __offload_entry_node = {
+    { &__offload_entry_table_start + 1, -1 },
+    0, 0
+};
+
+// offload fp section prolog
+ALLOCATE(OFFLOAD_FUNC_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(FuncTable::Entry)))
+#endif // TARGET_WINNT
+static FuncTable::Entry __offload_func_table_start = { 0 };
+
+// list element for the current module
+static FuncList::Node __offload_func_node = {
+    { &__offload_func_table_start + 1, -1 },
+    0, 0
+};
+
+// offload fp section prolog
+ALLOCATE(OFFLOAD_VAR_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(VarTable::Entry)))
+#endif // TARGET_WINNT
+static VarTable::Entry __offload_var_table_start = { 0 };
+
+// list element for the current module
+static VarList::Node __offload_var_node = {
+    { &__offload_var_table_start + 1 },
+    0, 0
+};
+
+#ifdef MYO_SUPPORT
+
+// offload myo shared var section prolog
+ALLOCATE(OFFLOAD_MYO_SHARED_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(SharedTableEntry)))
+#endif // TARGET_WINNT
+static SharedTableEntry __offload_myo_shared_table_start = { 0 };
+
+#if HOST_LIBRARY
+// offload myo shared var init section prolog
+ALLOCATE(OFFLOAD_MYO_SHARED_INIT_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(InitTableEntry)))
+#endif // TARGET_WINNT
+static InitTableEntry __offload_myo_shared_init_table_start = { 0 };
+#endif
+
+// offload myo fptr section prolog
+ALLOCATE(OFFLOAD_MYO_FPTR_TABLE_SECTION_START)
+#ifdef TARGET_WINNT
+__declspec(align(sizeof(FptrTableEntry)))
+#endif // TARGET_WINNT
+static FptrTableEntry __offload_myo_fptr_table_start = { 0 };
+
+#endif // MYO_SUPPORT
+
+// init/fini code which adds/removes local lookup data to/from the global list
+
+static void offload_fini();
+
+#ifndef TARGET_WINNT
+static void offload_init() __attribute__((constructor(101)));
+#else // TARGET_WINNT
+static void offload_init();
+
+// Place offload initialization before user constructors
+ALLOCATE(OFFLOAD_CRTINIT_SECTION_START)
+static void (*addressof_offload_init)() = offload_init;
+#endif // TARGET_WINNT
+
+static void offload_init()
+{
+    // register offload tables
+    __offload_register_tables(&__offload_entry_node,
+                              &__offload_func_node,
+                              &__offload_var_node);
+
+#if HOST_LIBRARY
+    __offload_register_image(&__offload_target_image);
+    atexit(offload_fini);
+#endif // HOST_LIBRARY
+
+#ifdef MYO_SUPPORT
+    __offload_myoRegisterTables(
+#if HOST_LIBRARY
+        &__offload_myo_shared_init_table_start + 1,
+#endif // HOST_LIBRARY
+        &__offload_myo_shared_table_start + 1,
+        &__offload_myo_fptr_table_start + 1
+    );
+#endif // MYO_SUPPORT
+}
+
+static void offload_fini()
+{
+#if HOST_LIBRARY
+    __offload_unregister_image(&__offload_target_image);
+#endif // HOST_LIBRARY
+
+    // unregister offload tables
+    __offload_unregister_tables(&__offload_entry_node,
+                                &__offload_func_node,
+                                &__offload_var_node);
+}