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| 1 | +//===- CodeGenData.h --------------------------------------------*- 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 contains support for codegen data that has stable summary which |
| 10 | +// can be used to optimize the code in the subsequent codegen. |
| 11 | +// |
| 12 | +//===----------------------------------------------------------------------===// |
| 13 | + |
| 14 | +#ifndef LLVM_CODEGENDATA_CODEGENDATA_H |
| 15 | +#define LLVM_CODEGENDATA_CODEGENDATA_H |
| 16 | + |
| 17 | +#include "llvm/ADT/BitmaskEnum.h" |
| 18 | +#include "llvm/Bitcode/BitcodeReader.h" |
| 19 | +#include "llvm/CodeGenData/OutlinedHashTree.h" |
| 20 | +#include "llvm/CodeGenData/OutlinedHashTreeRecord.h" |
| 21 | +#include "llvm/IR/Module.h" |
| 22 | +#include "llvm/Object/ObjectFile.h" |
| 23 | +#include "llvm/Support/ErrorHandling.h" |
| 24 | +#include "llvm/TargetParser/Triple.h" |
| 25 | +#include <mutex> |
| 26 | + |
| 27 | +namespace llvm { |
| 28 | + |
| 29 | +enum CGDataSectKind { |
| 30 | +#define CG_DATA_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix) Kind, |
| 31 | +#include "llvm/CodeGenData/CodeGenData.inc" |
| 32 | +}; |
| 33 | + |
| 34 | +std::string getCodeGenDataSectionName(CGDataSectKind CGSK, |
| 35 | + Triple::ObjectFormatType OF, |
| 36 | + bool AddSegmentInfo = true); |
| 37 | + |
| 38 | +enum class CGDataKind { |
| 39 | + Unknown = 0x0, |
| 40 | + // A function outlining info. |
| 41 | + FunctionOutlinedHashTree = 0x1, |
| 42 | + LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/FunctionOutlinedHashTree) |
| 43 | +}; |
| 44 | + |
| 45 | +const std::error_category &cgdata_category(); |
| 46 | + |
| 47 | +enum class cgdata_error { |
| 48 | + success = 0, |
| 49 | + eof, |
| 50 | + bad_magic, |
| 51 | + bad_header, |
| 52 | + empty_cgdata, |
| 53 | + malformed, |
| 54 | + unsupported_version, |
| 55 | +}; |
| 56 | + |
| 57 | +inline std::error_code make_error_code(cgdata_error E) { |
| 58 | + return std::error_code(static_cast<int>(E), cgdata_category()); |
| 59 | +} |
| 60 | + |
| 61 | +class CGDataError : public ErrorInfo<CGDataError> { |
| 62 | +public: |
| 63 | + CGDataError(cgdata_error Err, const Twine &ErrStr = Twine()) |
| 64 | + : Err(Err), Msg(ErrStr.str()) { |
| 65 | + assert(Err != cgdata_error::success && "Not an error"); |
| 66 | + } |
| 67 | + |
| 68 | + std::string message() const override; |
| 69 | + |
| 70 | + void log(raw_ostream &OS) const override { OS << message(); } |
| 71 | + |
| 72 | + std::error_code convertToErrorCode() const override { |
| 73 | + return make_error_code(Err); |
| 74 | + } |
| 75 | + |
| 76 | + cgdata_error get() const { return Err; } |
| 77 | + const std::string &getMessage() const { return Msg; } |
| 78 | + |
| 79 | + /// Consume an Error and return the raw enum value contained within it, and |
| 80 | + /// the optional error message. The Error must either be a success value, or |
| 81 | + /// contain a single CGDataError. |
| 82 | + static std::pair<cgdata_error, std::string> take(Error E) { |
| 83 | + auto Err = cgdata_error::success; |
| 84 | + std::string Msg; |
| 85 | + handleAllErrors(std::move(E), [&Err, &Msg](const CGDataError &IPE) { |
| 86 | + assert(Err == cgdata_error::success && "Multiple errors encountered"); |
| 87 | + Err = IPE.get(); |
| 88 | + Msg = IPE.getMessage(); |
| 89 | + }); |
| 90 | + return {Err, Msg}; |
| 91 | + } |
| 92 | + |
| 93 | + static char ID; |
| 94 | + |
| 95 | +private: |
| 96 | + cgdata_error Err; |
| 97 | + std::string Msg; |
| 98 | +}; |
| 99 | + |
| 100 | +enum CGDataMode { |
| 101 | + None, |
| 102 | + Read, |
| 103 | + Write, |
| 104 | +}; |
| 105 | + |
| 106 | +class CodeGenData { |
| 107 | + /// Global outlined hash tree that has oulined hash sequences across modules. |
| 108 | + std::unique_ptr<OutlinedHashTree> PublishedHashTree; |
| 109 | + |
| 110 | + /// This flag is set when -fcodegen-data-generate is passed. |
| 111 | + /// Or, it can be mutated with -fcodegen-data-thinlto-two-rounds. |
| 112 | + bool EmitCGData; |
| 113 | + |
| 114 | + /// This is a singleton instance which is thread-safe. Unlike profile data |
| 115 | + /// which is largely function-based, codegen data describes the whole module. |
| 116 | + /// Therefore, this can be initialized once, and can be used across modules |
| 117 | + /// instead of constructing the same one for each codegen backend. |
| 118 | + static std::unique_ptr<CodeGenData> Instance; |
| 119 | + static std::once_flag OnceFlag; |
| 120 | + |
| 121 | + CodeGenData() = default; |
| 122 | + |
| 123 | +public: |
| 124 | + ~CodeGenData() = default; |
| 125 | + |
| 126 | + static CodeGenData &getInstance(); |
| 127 | + |
| 128 | + /// Returns true if we have a valid outlined hash tree. |
| 129 | + bool hasOutlinedHashTree() { |
| 130 | + return PublishedHashTree && !PublishedHashTree->empty(); |
| 131 | + } |
| 132 | + |
| 133 | + /// Returns the outlined hash tree. This can be globally used in a read-only |
| 134 | + /// manner. |
| 135 | + const OutlinedHashTree *getOutlinedHashTree() { |
| 136 | + return PublishedHashTree.get(); |
| 137 | + } |
| 138 | + |
| 139 | + /// Returns true if we should write codegen data. |
| 140 | + bool emitCGData() { return EmitCGData; } |
| 141 | + |
| 142 | + /// Publish the (globally) merged or read outlined hash tree. |
| 143 | + void publishOutlinedHashTree(std::unique_ptr<OutlinedHashTree> HashTree) { |
| 144 | + PublishedHashTree = std::move(HashTree); |
| 145 | + // Ensure we disable emitCGData as we do not want to read and write both. |
| 146 | + EmitCGData = false; |
| 147 | + } |
| 148 | +}; |
| 149 | + |
| 150 | +namespace cgdata { |
| 151 | + |
| 152 | +inline bool hasOutlinedHashTree() { |
| 153 | + return CodeGenData::getInstance().hasOutlinedHashTree(); |
| 154 | +} |
| 155 | + |
| 156 | +inline const OutlinedHashTree *getOutlinedHashTree() { |
| 157 | + return CodeGenData::getInstance().getOutlinedHashTree(); |
| 158 | +} |
| 159 | + |
| 160 | +inline bool emitCGData() { return CodeGenData::getInstance().emitCGData(); } |
| 161 | + |
| 162 | +inline void |
| 163 | +publishOutlinedHashTree(std::unique_ptr<OutlinedHashTree> HashTree) { |
| 164 | + CodeGenData::getInstance().publishOutlinedHashTree(std::move(HashTree)); |
| 165 | +} |
| 166 | + |
| 167 | +void warn(Error E, StringRef Whence = ""); |
| 168 | +void warn(Twine Message, std::string Whence = "", std::string Hint = ""); |
| 169 | + |
| 170 | +} // end namespace cgdata |
| 171 | + |
| 172 | +namespace IndexedCGData { |
| 173 | + |
| 174 | +// A signature for data validation, representing "\xffcgdata\x81" in |
| 175 | +// little-endian order |
| 176 | +const uint64_t Magic = 0x81617461646763ff; |
| 177 | + |
| 178 | +enum CGDataVersion { |
| 179 | + // Version 1 is the first version. This version supports the outlined |
| 180 | + // hash tree. |
| 181 | + Version1 = 1, |
| 182 | + CurrentVersion = CG_DATA_INDEX_VERSION |
| 183 | +}; |
| 184 | +const uint64_t Version = CGDataVersion::CurrentVersion; |
| 185 | + |
| 186 | +struct Header { |
| 187 | + uint64_t Magic; |
| 188 | + uint32_t Version; |
| 189 | + uint32_t DataKind; |
| 190 | + uint64_t OutlinedHashTreeOffset; |
| 191 | + |
| 192 | + // New fields should only be added at the end to ensure that the size |
| 193 | + // computation is correct. The methods below need to be updated to ensure that |
| 194 | + // the new field is read correctly. |
| 195 | + |
| 196 | + // Reads a header struct from the buffer. |
| 197 | + static Expected<Header> readFromBuffer(const unsigned char *Curr); |
| 198 | +}; |
| 199 | + |
| 200 | +} // end namespace IndexedCGData |
| 201 | + |
| 202 | +} // end namespace llvm |
| 203 | + |
| 204 | +#endif // LLVM_CODEGEN_PREPARE_H |
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