1 //===-- SnippetFile.cpp -----------------------------------------*- 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 #include "SnippetFile.h" 10 #include "Error.h" 11 #include "llvm/MC/MCContext.h" 12 #include "llvm/MC/MCInstPrinter.h" 13 #include "llvm/MC/MCObjectFileInfo.h" 14 #include "llvm/MC/MCParser/MCAsmLexer.h" 15 #include "llvm/MC/MCParser/MCAsmParser.h" 16 #include "llvm/MC/MCParser/MCTargetAsmParser.h" 17 #include "llvm/MC/MCRegisterInfo.h" 18 #include "llvm/MC/MCStreamer.h" 19 #include "llvm/MC/TargetRegistry.h" 20 #include "llvm/Support/Format.h" 21 #include "llvm/Support/Path.h" 22 #include "llvm/Support/SourceMgr.h" 23 #include <string> 24 25 namespace llvm { 26 namespace exegesis { 27 namespace { 28 29 // An MCStreamer that reads a BenchmarkCode definition from a file. 30 class BenchmarkCodeStreamer : public MCStreamer, public AsmCommentConsumer { 31 public: 32 explicit BenchmarkCodeStreamer(MCContext *Context, 33 const MCRegisterInfo *TheRegInfo, 34 BenchmarkCode *Result) 35 : MCStreamer(*Context), RegInfo(TheRegInfo), Result(Result) {} 36 37 // Implementation of the MCStreamer interface. We only care about 38 // instructions. 39 void emitInstruction(const MCInst &Instruction, 40 const MCSubtargetInfo &STI) override { 41 Result->Key.Instructions.push_back(Instruction); 42 } 43 44 // Implementation of the AsmCommentConsumer. 45 void HandleComment(SMLoc Loc, StringRef CommentText) override { 46 CommentText = CommentText.trim(); 47 if (!CommentText.consume_front("LLVM-EXEGESIS-")) 48 return; 49 if (CommentText.consume_front("DEFREG")) { 50 // LLVM-EXEGESIS-DEFREF <reg> <hex_value> 51 RegisterValue RegVal; 52 SmallVector<StringRef, 2> Parts; 53 CommentText.split(Parts, ' ', /*unlimited splits*/ -1, 54 /*do not keep empty strings*/ false); 55 if (Parts.size() != 2) { 56 errs() << "invalid comment 'LLVM-EXEGESIS-DEFREG " << CommentText 57 << "', expected two parameters <REG> <HEX_VALUE>\n"; 58 ++InvalidComments; 59 return; 60 } 61 if (!(RegVal.Register = findRegisterByName(Parts[0].trim()))) { 62 errs() << "unknown register '" << Parts[0] 63 << "' in 'LLVM-EXEGESIS-DEFREG " << CommentText << "'\n"; 64 ++InvalidComments; 65 return; 66 } 67 const StringRef HexValue = Parts[1].trim(); 68 RegVal.Value = APInt( 69 /* each hex digit is 4 bits */ HexValue.size() * 4, HexValue, 16); 70 Result->Key.RegisterInitialValues.push_back(std::move(RegVal)); 71 return; 72 } 73 if (CommentText.consume_front("LIVEIN")) { 74 // LLVM-EXEGESIS-LIVEIN <reg> 75 const auto RegName = CommentText.ltrim(); 76 if (unsigned Reg = findRegisterByName(RegName)) 77 Result->LiveIns.push_back(Reg); 78 else { 79 errs() << "unknown register '" << RegName 80 << "' in 'LLVM-EXEGESIS-LIVEIN " << CommentText << "'\n"; 81 ++InvalidComments; 82 } 83 return; 84 } 85 } 86 87 unsigned numInvalidComments() const { return InvalidComments; } 88 89 private: 90 // We only care about instructions, we don't implement this part of the API. 91 void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 92 unsigned ByteAlignment) override {} 93 bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override { 94 return false; 95 } 96 void emitValueToAlignment(Align Alignment, int64_t Value, unsigned ValueSize, 97 unsigned MaxBytesToEmit) override {} 98 void emitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size, 99 unsigned ByteAlignment, SMLoc Loc) override {} 100 101 unsigned findRegisterByName(const StringRef RegName) const { 102 // FIXME: Can we do better than this ? 103 for (unsigned I = 0, E = RegInfo->getNumRegs(); I < E; ++I) { 104 if (RegName == RegInfo->getName(I)) 105 return I; 106 } 107 errs() << "'" << RegName 108 << "' is not a valid register name for the target\n"; 109 return 0; 110 } 111 112 const MCRegisterInfo *const RegInfo; 113 BenchmarkCode *const Result; 114 unsigned InvalidComments = 0; 115 }; 116 117 } // namespace 118 119 // Reads code snippets from file `Filename`. 120 Expected<std::vector<BenchmarkCode>> readSnippets(const LLVMState &State, 121 StringRef Filename) { 122 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr = 123 MemoryBuffer::getFileOrSTDIN(Filename); 124 if (std::error_code EC = BufferPtr.getError()) { 125 return make_error<Failure>("cannot read snippet: " + Filename + ": " + 126 EC.message()); 127 } 128 SourceMgr SM; 129 SM.AddNewSourceBuffer(std::move(BufferPtr.get()), SMLoc()); 130 131 BenchmarkCode Result; 132 133 const TargetMachine &TM = State.getTargetMachine(); 134 MCContext Context(TM.getTargetTriple(), TM.getMCAsmInfo(), 135 TM.getMCRegisterInfo(), TM.getMCSubtargetInfo()); 136 std::unique_ptr<MCObjectFileInfo> ObjectFileInfo( 137 TM.getTarget().createMCObjectFileInfo(Context, /*PIC=*/false)); 138 Context.setObjectFileInfo(ObjectFileInfo.get()); 139 Context.initInlineSourceManager(); 140 BenchmarkCodeStreamer Streamer(&Context, TM.getMCRegisterInfo(), &Result); 141 142 std::string Error; 143 raw_string_ostream ErrorStream(Error); 144 formatted_raw_ostream InstPrinterOStream(ErrorStream); 145 const std::unique_ptr<MCInstPrinter> InstPrinter( 146 TM.getTarget().createMCInstPrinter( 147 TM.getTargetTriple(), TM.getMCAsmInfo()->getAssemblerDialect(), 148 *TM.getMCAsmInfo(), *TM.getMCInstrInfo(), *TM.getMCRegisterInfo())); 149 // The following call will take care of calling Streamer.setTargetStreamer. 150 TM.getTarget().createAsmTargetStreamer(Streamer, InstPrinterOStream, 151 InstPrinter.get(), 152 TM.Options.MCOptions.AsmVerbose); 153 if (!Streamer.getTargetStreamer()) 154 return make_error<Failure>("cannot create target asm streamer"); 155 156 const std::unique_ptr<MCAsmParser> AsmParser( 157 createMCAsmParser(SM, Context, Streamer, *TM.getMCAsmInfo())); 158 if (!AsmParser) 159 return make_error<Failure>("cannot create asm parser"); 160 AsmParser->getLexer().setCommentConsumer(&Streamer); 161 162 const std::unique_ptr<MCTargetAsmParser> TargetAsmParser( 163 TM.getTarget().createMCAsmParser(*TM.getMCSubtargetInfo(), *AsmParser, 164 *TM.getMCInstrInfo(), 165 MCTargetOptions())); 166 167 if (!TargetAsmParser) 168 return make_error<Failure>("cannot create target asm parser"); 169 AsmParser->setTargetParser(*TargetAsmParser); 170 171 if (AsmParser->Run(false)) 172 return make_error<Failure>("cannot parse asm file"); 173 if (Streamer.numInvalidComments()) 174 return make_error<Failure>(Twine("found ") 175 .concat(Twine(Streamer.numInvalidComments())) 176 .concat(" invalid LLVM-EXEGESIS comments")); 177 return std::vector<BenchmarkCode>{std::move(Result)}; 178 } 179 180 } // namespace exegesis 181 } // namespace llvm 182