xref: /freebsd/contrib/llvm-project/llvm/include/llvm/Transforms/Utils/SplitModule.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 //===- SplitModule.h - Split a module into partitions -----------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the function llvm::SplitModule, which splits a module
10 // into multiple linkable partitions. It can be used to implement parallel code
11 // generation for link-time optimization.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TRANSFORMS_UTILS_SPLITMODULE_H
16 #define LLVM_TRANSFORMS_UTILS_SPLITMODULE_H
17 
18 #include "llvm/ADT/STLFunctionalExtras.h"
19 #include <memory>
20 
21 namespace llvm {
22 
23 class Module;
24 
25 /// Splits the module M into N linkable partitions. The function ModuleCallback
26 /// is called N times passing each individual partition as the MPart argument.
27 /// PreserveLocals: Split without externalizing locals.
28 /// RoundRobin: Use round-robin distribution of functions to modules instead
29 /// of the default name-hash-based one.
30 ///
31 /// FIXME: This function does not deal with the somewhat subtle symbol
32 /// visibility issues around module splitting, including (but not limited to):
33 ///
34 /// - Internal symbols should not collide with symbols defined outside the
35 ///   module.
36 /// - Internal symbols defined in module-level inline asm should be visible to
37 ///   each partition.
38 void SplitModule(
39     Module &M, unsigned N,
40     function_ref<void(std::unique_ptr<Module> MPart)> ModuleCallback,
41     bool PreserveLocals = false, bool RoundRobin = false);
42 
43 } // end namespace llvm
44 
45 #endif // LLVM_TRANSFORMS_UTILS_SPLITMODULE_H
46