1//===-LTOBackend.h - LLVM Link Time Optimizer Backend ---------------------===//
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 implements the "backend" phase of LTO, i.e. it performs
10// optimization and code generation on a loaded module. It is generally used
11// internally by the LTO class but can also be used independently, for example
12// to implement a standalone ThinLTO backend.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_LTO_LTOBACKEND_H
17#define LLVM_LTO_LTOBACKEND_H
18
19#include "llvm/ADT/MapVector.h"
20#include "llvm/IR/DiagnosticInfo.h"
21#include "llvm/IR/ModuleSummaryIndex.h"
22#include "llvm/LTO/LTO.h"
23#include "llvm/Support/MemoryBuffer.h"
24#include "llvm/Target/TargetOptions.h"
25#include "llvm/Transforms/IPO/FunctionImport.h"
26
27namespace llvm {
28
29class BitcodeModule;
30class Error;
31class Module;
32class Target;
33
34namespace lto {
35
36/// Runs middle-end LTO optimizations on \p Mod.
37bool opt(const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
38 bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
39 const ModuleSummaryIndex *ImportSummary,
40 const std::vector<uint8_t> &CmdArgs);
41
42/// Runs a regular LTO backend. The regular LTO backend can also act as the
43/// regular LTO phase of ThinLTO, which may need to access the combined index.
44Error backend(const Config &C, AddStreamFn AddStream,
45 unsigned ParallelCodeGenParallelismLevel, Module &M,
46 ModuleSummaryIndex &CombinedIndex);
47
48/// Runs a ThinLTO backend.
49/// If \p ModuleMap is not nullptr, all the module files to be imported have
50/// already been mapped to memory and the corresponding BitcodeModule objects
51/// are saved in the ModuleMap. If \p ModuleMap is nullptr, module files will
52/// be mapped to memory on demand and at any given time during importing, only
53/// one source module will be kept open at the most.
54Error thinBackend(const Config &C, unsigned Task, AddStreamFn AddStream,
55 Module &M, const ModuleSummaryIndex &CombinedIndex,
56 const FunctionImporter::ImportMapTy &ImportList,
57 const GVSummaryMapTy &DefinedGlobals,
58 MapVector<StringRef, BitcodeModule> *ModuleMap,
59 const std::vector<uint8_t> &CmdArgs = std::vector<uint8_t>());
60
61Error finalizeOptimizationRemarks(
62 std::unique_ptr<ToolOutputFile> DiagOutputFile);
63
64/// Returns the BitcodeModule that is ThinLTO.
65BitcodeModule *findThinLTOModule(MutableArrayRef<BitcodeModule> BMs);
66
67/// Variant of the above.
68Expected<BitcodeModule> findThinLTOModule(MemoryBufferRef MBRef);
69
70/// Distributed ThinLTO: collect the referenced modules based on
71/// module summary and initialize ImportList. Returns false if the
72/// operation failed.
73bool initImportList(const Module &M, const ModuleSummaryIndex &CombinedIndex,
74 FunctionImporter::ImportMapTy &ImportList);
75}
76}
77
78#endif
79