[offload][SYCL] Add SYCL Module splitting.

llvm/include/llvm/Frontend/SYCL/SplitModule.h

@@ -0,0 +1,39 @@
+//===-------- SplitModule.h - module split ----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// Functionality to split a module for SYCL Offloading Kind.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FRONTEND_SYCL_SPLIT_MODULE_H
+#define LLVM_FRONTEND_SYCL_SPLIT_MODULE_H
+
+#include "llvm/ADT/STLFunctionalExtras.h"
+#include "llvm/Frontend/SYCL/Utils.h"
+
+#include <memory>
+#include <optional>
+#include <string>
+
+namespace llvm {
+
+class Module;
+class Function;
+
+namespace sycl {
+
+using PostSplitCallbackType = function_ref<void(std::unique_ptr<Module> Part)>;
+
+/// Splits the given module \p M.
+/// Every split image is being passed to \p Callback for further possible
+/// processing.
+void splitModule(std::unique_ptr<Module> M, IRSplitMode Mode,
+                 PostSplitCallbackType Callback);
+
+} // namespace sycl
+} // namespace llvm
+
+#endif // LLVM_FRONTEND_SYCL_SPLIT_MODULE_H

llvm/include/llvm/Frontend/SYCL/Utils.h

@@ -0,0 +1,67 @@
+//===------------ Utils.h - SYCL utility functions ------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// Utility functions for SYCL.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_FRONTEND_SYCL_UTILS_H
+#define LLVM_FRONTEND_SYCL_UTILS_H
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+
+#include <string>
+
+namespace llvm {
+
+class Module;
+class Function;
+class raw_ostream;
+
+namespace sycl {
+
+enum class IRSplitMode {
+  IRSM_PER_TU,     // one module per translation unit
+  IRSM_PER_KERNEL, // one module per kernel
+  IRSM_NONE        // no splitting
+};
+
+/// \returns IRSplitMode value if \p S is recognized. Otherwise, std::nullopt is
+/// returned.
+std::optional<IRSplitMode> convertStringToSplitMode(StringRef S);
+
+/// The structure represents a LLVM Module accompanied by additional
+/// information. Split Modules are being stored at disk due to the high RAM
+/// consumption during the whole splitting process.
+struct ModuleAndSYCLMetadata {
+  std::string ModuleFilePath;
+  std::string Symbols;
+
+  ModuleAndSYCLMetadata() = delete;
+  ModuleAndSYCLMetadata(const ModuleAndSYCLMetadata &) = default;
+  ModuleAndSYCLMetadata &operator=(const ModuleAndSYCLMetadata &) = default;
+  ModuleAndSYCLMetadata(ModuleAndSYCLMetadata &&) = default;
+  ModuleAndSYCLMetadata &operator=(ModuleAndSYCLMetadata &&) = default;
+
+  ModuleAndSYCLMetadata(const Twine &File, std::string Symbols)
+      : ModuleFilePath(File.str()), Symbols(std::move(Symbols)) {}
+};
+
+/// Checks whether the function is a SYCL entry point.
+bool isEntryPoint(const Function &F);
+
+std::string makeSymbolTable(const Module &M);
+
+using StringTable = SmallVector<SmallVector<SmallString<64>>>;
+
+void writeStringTable(const StringTable &Table, raw_ostream &OS);
+
+} // namespace sycl
+} // namespace llvm
+
+#endif // LLVM_FRONTEND_SYCL_UTILS_H

llvm/lib/Frontend/CMakeLists.txt

@@ -4,3 +4,4 @@ add_subdirectory(HLSL)
 add_subdirectory(OpenACC)
 add_subdirectory(OpenMP)
 add_subdirectory(Offloading)
+add_subdirectory(SYCL)

llvm/lib/Frontend/SYCL/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_llvm_component_library(LLVMFrontendSYCL
+  SplitModule.cpp
+  Utils.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/Frontend
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/Frontend/SYCL
+
+  LINK_COMPONENTS
+  Core
+  Support
+  TransformUtils
+  )