1 //===-- BasicBlockSectionsProfileReader.h - BB sections profile reader pass ==// 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 pass creates the basic block cluster info by reading the basic block 10 // sections profile. The cluster info will be used by the basic-block-sections 11 // pass to arrange basic blocks in their sections. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H 16 #define LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H 17 18 #include "llvm/ADT/SmallString.h" 19 #include "llvm/ADT/SmallVector.h" 20 #include "llvm/ADT/StringMap.h" 21 #include "llvm/ADT/StringRef.h" 22 #include "llvm/IR/Module.h" 23 #include "llvm/IR/PassManager.h" 24 #include "llvm/InitializePasses.h" 25 #include "llvm/Pass.h" 26 #include "llvm/Support/Error.h" 27 #include "llvm/Support/LineIterator.h" 28 #include "llvm/Support/MemoryBuffer.h" 29 #include "llvm/Support/UniqueBBID.h" 30 #include "llvm/Target/TargetMachine.h" 31 32 namespace llvm { 33 34 // This struct represents the cluster information for a machine basic block, 35 // which is specifed by a unique basic block ID. 36 struct BBClusterInfo { 37 // Basic block ID. 38 UniqueBBID BBID; 39 // Cluster ID this basic block belongs to. 40 unsigned ClusterID; 41 // Position of basic block within the cluster. 42 unsigned PositionInCluster; 43 }; 44 45 // This represents the raw input profile for one function. 46 struct FunctionPathAndClusterInfo { 47 // BB Cluster information specified by `UniqueBBID`s. 48 SmallVector<BBClusterInfo> ClusterInfo; 49 // Paths to clone. A path a -> b -> c -> d implies cloning b, c, and d along 50 // the edge a -> b (a is not cloned). The index of the path in this vector 51 // determines the `UniqueBBID::CloneID` of the cloned blocks in that path. 52 SmallVector<SmallVector<unsigned>> ClonePaths; 53 }; 54 55 class BasicBlockSectionsProfileReader { 56 public: 57 friend class BasicBlockSectionsProfileReaderWrapperPass; 58 BasicBlockSectionsProfileReader(const MemoryBuffer *Buf) 59 : MBuf(Buf), LineIt(*Buf, /*SkipBlanks=*/true, /*CommentMarker=*/'#'){}; 60 61 BasicBlockSectionsProfileReader(){}; 62 63 // Returns true if basic block sections profile exist for function \p 64 // FuncName. 65 bool isFunctionHot(StringRef FuncName) const; 66 67 // Returns a pair with first element representing whether basic block sections 68 // profile exist for the function \p FuncName, and the second element 69 // representing the basic block sections profile (cluster info) for this 70 // function. If the first element is true and the second element is empty, it 71 // means unique basic block sections are desired for all basic blocks of the 72 // function. 73 std::pair<bool, SmallVector<BBClusterInfo>> 74 getClusterInfoForFunction(StringRef FuncName) const; 75 76 // Returns the path clonings for the given function. 77 SmallVector<SmallVector<unsigned>> 78 getClonePathsForFunction(StringRef FuncName) const; 79 80 private: 81 StringRef getAliasName(StringRef FuncName) const { 82 auto R = FuncAliasMap.find(FuncName); 83 return R == FuncAliasMap.end() ? FuncName : R->second; 84 } 85 86 // Returns a profile parsing error for the current line. 87 Error createProfileParseError(Twine Message) const { 88 return make_error<StringError>( 89 Twine("invalid profile " + MBuf->getBufferIdentifier() + " at line " + 90 Twine(LineIt.line_number()) + ": " + Message), 91 inconvertibleErrorCode()); 92 } 93 94 // Parses a `UniqueBBID` from `S`. `S` must be in the form "<bbid>" 95 // (representing an original block) or "<bbid>.<cloneid>" (representing a 96 // cloned block) where bbid is a non-negative integer and cloneid is a 97 // positive integer. 98 Expected<UniqueBBID> parseUniqueBBID(StringRef S) const; 99 100 // Reads the basic block sections profile for functions in this module. 101 Error ReadProfile(); 102 103 // Reads version 0 profile. 104 // TODO: Remove this function once version 0 is deprecated. 105 Error ReadV0Profile(); 106 107 // Reads version 1 profile. 108 Error ReadV1Profile(); 109 110 // This contains the basic-block-sections profile. 111 const MemoryBuffer *MBuf = nullptr; 112 113 // Iterator to the line being parsed. 114 line_iterator LineIt; 115 116 // Map from every function name in the module to its debug info filename or 117 // empty string if no debug info is available. 118 StringMap<SmallString<128>> FunctionNameToDIFilename; 119 120 // This contains the BB cluster information for the whole program. 121 // 122 // For every function name, it contains the cloning and cluster information 123 // for (all or some of) its basic blocks. The cluster information for every 124 // basic block includes its cluster ID along with the position of the basic 125 // block in that cluster. 126 StringMap<FunctionPathAndClusterInfo> ProgramPathAndClusterInfo; 127 128 // Some functions have alias names. We use this map to find the main alias 129 // name which appears in ProgramPathAndClusterInfo as a key. 130 StringMap<StringRef> FuncAliasMap; 131 }; 132 133 // Creates a BasicBlockSectionsProfileReader pass to parse the basic block 134 // sections profile. \p Buf is a memory buffer that contains the list of 135 // functions and basic block ids to selectively enable basic block sections. 136 ImmutablePass * 137 createBasicBlockSectionsProfileReaderWrapperPass(const MemoryBuffer *Buf); 138 139 /// Analysis pass providing the \c BasicBlockSectionsProfileReader. 140 /// 141 /// Note that this pass's result cannot be invalidated, it is immutable for the 142 /// life of the module. 143 class BasicBlockSectionsProfileReaderAnalysis 144 : public AnalysisInfoMixin<BasicBlockSectionsProfileReaderAnalysis> { 145 146 public: 147 static AnalysisKey Key; 148 typedef BasicBlockSectionsProfileReader Result; 149 BasicBlockSectionsProfileReaderAnalysis(const TargetMachine *TM) : TM(TM) {} 150 151 Result run(Function &F, FunctionAnalysisManager &AM); 152 153 private: 154 const TargetMachine *TM; 155 }; 156 157 class BasicBlockSectionsProfileReaderWrapperPass : public ImmutablePass { 158 public: 159 static char ID; 160 BasicBlockSectionsProfileReader BBSPR; 161 162 BasicBlockSectionsProfileReaderWrapperPass(const MemoryBuffer *Buf) 163 : ImmutablePass(ID), BBSPR(BasicBlockSectionsProfileReader(Buf)) { 164 initializeBasicBlockSectionsProfileReaderWrapperPassPass( 165 *PassRegistry::getPassRegistry()); 166 }; 167 168 BasicBlockSectionsProfileReaderWrapperPass() 169 : ImmutablePass(ID), BBSPR(BasicBlockSectionsProfileReader()) { 170 initializeBasicBlockSectionsProfileReaderWrapperPassPass( 171 *PassRegistry::getPassRegistry()); 172 } 173 174 StringRef getPassName() const override { 175 return "Basic Block Sections Profile Reader"; 176 } 177 178 bool isFunctionHot(StringRef FuncName) const; 179 180 std::pair<bool, SmallVector<BBClusterInfo>> 181 getClusterInfoForFunction(StringRef FuncName) const; 182 183 SmallVector<SmallVector<unsigned>> 184 getClonePathsForFunction(StringRef FuncName) const; 185 186 // Initializes the FunctionNameToDIFilename map for the current module and 187 // then reads the profile for the matching functions. 188 bool doInitialization(Module &M) override; 189 190 BasicBlockSectionsProfileReader &getBBSPR(); 191 }; 192 193 } // namespace llvm 194 #endif // LLVM_CODEGEN_BASICBLOCKSECTIONSPROFILEREADER_H 195