[ModuleSplitter] llvm module splitter

llvm/include/llvm/ModuleSplitter/ModuleSplitter.h

@@ -0,0 +1,79 @@
+//===- ModuleSplitter.h - Module Splitter Functions -------------*- 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MODULESPLITTER_MODULESPLITTER_H
+#define LLVM_MODULESPLITTER_MODULESPLITTER_H
+
+#include "llvm/ADT/FunctionExtras.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Error.h"
+namespace llvm {
+
+//===----------------------------------------------------------------------===//
+// LLVMModuleAndContext
+//===----------------------------------------------------------------------===//
+
+/// A pair of an LLVM module and the LLVM context that holds ownership of the
+/// objects. This is a useful class for parallelizing LLVM and managing
+/// ownership of LLVM instances.
+class LLVMModuleAndContext {
+public:
+  /// Expose the underlying LLVM context to create the module. This is the only
+  /// way to access the LLVM context to prevent accidental sharing.
+  Expected<bool> create(
+      function_ref<Expected<std::unique_ptr<llvm::Module>>(llvm::LLVMContext &)>
+          CreateModule);
+
+  llvm::Module &operator*() { return *Module; }
+  llvm::Module *operator->() { return Module.get(); }
+
+  void reset();
+
+private:
+  /// LLVM context stored in a unique pointer so that we can move this type.
+  std::unique_ptr<llvm::LLVMContext> Ctx =
+      std::make_unique<llvm::LLVMContext>();
+  /// The paired LLVM module.
+  std::unique_ptr<llvm::Module> Module;
+};
+
+//===----------------------------------------------------------------------===//
+// Module Splitter
+//===----------------------------------------------------------------------===//
+
+using LLVMSplitProcessFn =
+    function_ref<void(llvm::unique_function<LLVMModuleAndContext()>,
+                      std::optional<int64_t>, unsigned)>;
+
+/// Helper to create a lambda that just forwards a preexisting Module.
+inline llvm::unique_function<LLVMModuleAndContext()>
+forwardModule(LLVMModuleAndContext &&Module) {
+  return [Module = std::move(Module)]() mutable { return std::move(Module); };
+}
+
+/// Support for splitting an LLVM module into multiple parts using anchored
+/// functions (e.g. exported functions), and pull in all dependency on the
+// call stack into one module.
+void splitPerAnchored(LLVMModuleAndContext Module, LLVMSplitProcessFn ProcessFn,
+                      llvm::SmallVectorImpl<llvm::Function> &Anchors);
+
+/// Support for splitting an LLVM module into multiple parts with each part
+/// contains only one function.
+void splitPerFunction(
+    LLVMModuleAndContext Module, LLVMSplitProcessFn ProcessFn,
+    llvm::StringMap<llvm::GlobalValue::LinkageTypes> &SymbolLinkageTypes,
+    unsigned NumFunctionBase);
+
+} // namespace llvm
+
+#endif

llvm/lib/CMakeLists.txt

@@ -24,6 +24,7 @@ add_subdirectory(Analysis)
 add_subdirectory(LTO)
 add_subdirectory(MC)
 add_subdirectory(MCA)
+add_subdirectory(ModuleSplitter)
 add_subdirectory(ObjCopy)
 add_subdirectory(Object)
 add_subdirectory(ObjectYAML)

llvm/lib/ModuleSplitter/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_llvm_component_library(LLVMModuleSplitter
+  ModuleSplitter.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${LLVM_MAIN_INCLUDE_DIR}/llvm/ModuleSplitter
+
+  LINK_COMPONENTS
+  Core
+  IRReader
+  BitReader
+  BitWriter
+  Support
+  TransformUtils
+)