1 //===- SubtargetFeatureInfo.cpp - Helpers for subtarget features ----------===// 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 "SubtargetFeatureInfo.h" 10 #include "Types.h" 11 #include "llvm/Config/llvm-config.h" 12 #include "llvm/TableGen/Error.h" 13 #include "llvm/TableGen/Record.h" 14 15 using namespace llvm; 16 17 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 18 LLVM_DUMP_METHOD void SubtargetFeatureInfo::dump() const { 19 errs() << getEnumName() << " " << Index << "\n" << *TheDef; 20 } 21 #endif 22 23 SubtargetFeaturesInfoVec 24 SubtargetFeatureInfo::getAll(const RecordKeeper &Records) { 25 SubtargetFeaturesInfoVec SubtargetFeatures; 26 for (const Record *Pred : Records.getAllDerivedDefinitions("Predicate")) { 27 // Ignore predicates that are not intended for the assembler. 28 // 29 // The "AssemblerMatcherPredicate" string should be promoted to an argument 30 // if we re-use the machinery for non-assembler purposes in future. 31 if (!Pred->getValueAsBit("AssemblerMatcherPredicate")) 32 continue; 33 34 if (Pred->getName().empty()) 35 PrintFatalError(Pred->getLoc(), "Predicate has no name!"); 36 37 // Ignore always true predicates. 38 if (Pred->getValueAsString("CondString").empty()) 39 continue; 40 41 SubtargetFeatures.emplace_back( 42 Pred, SubtargetFeatureInfo(Pred, SubtargetFeatures.size())); 43 } 44 return SubtargetFeatures; 45 } 46 47 void SubtargetFeatureInfo::emitSubtargetFeatureBitEnumeration( 48 const SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS, 49 const std::map<std::string, unsigned> *HwModes) { 50 OS << "// Bits for subtarget features that participate in " 51 << "instruction matching.\n"; 52 unsigned Size = SubtargetFeatures.size(); 53 if (HwModes) 54 Size += HwModes->size(); 55 56 OS << "enum SubtargetFeatureBits : " << getMinimalTypeForRange(Size) 57 << " {\n"; 58 for (const auto &SF : SubtargetFeatures) { 59 const SubtargetFeatureInfo &SFI = SF.second; 60 OS << " " << SFI.getEnumBitName() << " = " << SFI.Index << ",\n"; 61 } 62 63 if (HwModes) { 64 unsigned Offset = SubtargetFeatures.size(); 65 for (const auto &M : *HwModes) { 66 OS << " Feature_HwMode" << M.second << "Bit = " << (M.second + Offset) 67 << ",\n"; 68 } 69 } 70 71 OS << "};\n\n"; 72 } 73 74 void SubtargetFeatureInfo::emitNameTable( 75 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) { 76 // Need to sort the name table so that lookup by the log of the enum value 77 // gives the proper name. More specifically, for a feature of value 1<<n, 78 // SubtargetFeatureNames[n] should be the name of the feature. 79 uint64_t IndexUB = 0; 80 for (const auto &SF : SubtargetFeatures) 81 if (IndexUB <= SF.second.Index) 82 IndexUB = SF.second.Index + 1; 83 84 std::vector<std::string> Names; 85 if (IndexUB > 0) 86 Names.resize(IndexUB); 87 for (const auto &SF : SubtargetFeatures) 88 Names[SF.second.Index] = SF.second.getEnumName(); 89 90 OS << "static const char *SubtargetFeatureNames[] = {\n"; 91 for (uint64_t I = 0; I < IndexUB; ++I) 92 OS << " \"" << Names[I] << "\",\n"; 93 94 // A small number of targets have no predicates. Null terminate the array to 95 // avoid a zero-length array. 96 OS << " nullptr\n" 97 << "};\n\n"; 98 } 99 100 void SubtargetFeatureInfo::emitComputeAvailableFeatures( 101 StringRef TargetName, StringRef ClassName, StringRef FuncName, 102 const SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS, 103 StringRef ExtraParams, const std::map<std::string, unsigned> *HwModes) { 104 OS << "PredicateBitset " << ClassName << "::\n" 105 << FuncName << "(const " << TargetName << "Subtarget *Subtarget"; 106 if (!ExtraParams.empty()) 107 OS << ", " << ExtraParams; 108 OS << ") const {\n"; 109 OS << " PredicateBitset Features{};\n"; 110 for (const auto &SF : SubtargetFeatures) { 111 const SubtargetFeatureInfo &SFI = SF.second; 112 StringRef CondStr = SFI.TheDef->getValueAsString("CondString"); 113 assert(!CondStr.empty() && "true predicate should have been filtered"); 114 115 OS << " if (" << CondStr << ")\n"; 116 OS << " Features.set(" << SFI.getEnumBitName() << ");\n"; 117 } 118 119 if (HwModes) { 120 for (const auto &M : *HwModes) { 121 OS << " if (" << M.first << ")\n"; 122 OS << " Features.set(Feature_HwMode" << M.second << "Bit);\n"; 123 } 124 } 125 126 OS << " return Features;\n"; 127 OS << "}\n\n"; 128 } 129 130 // If ParenIfBinOp is true, print a surrounding () if Val uses && or ||. 131 static bool emitFeaturesAux(StringRef TargetName, const Init &Val, 132 bool ParenIfBinOp, raw_ostream &OS) { 133 if (auto *D = dyn_cast<DefInit>(&Val)) { 134 if (!D->getDef()->isSubClassOf("SubtargetFeature")) 135 return true; 136 OS << "FB[" << TargetName << "::" << D->getAsString() << "]"; 137 return false; 138 } 139 if (auto *D = dyn_cast<DagInit>(&Val)) { 140 auto *Op = dyn_cast<DefInit>(D->getOperator()); 141 if (!Op) 142 return true; 143 StringRef OpName = Op->getDef()->getName(); 144 if (OpName == "not" && D->getNumArgs() == 1) { 145 OS << '!'; 146 return emitFeaturesAux(TargetName, *D->getArg(0), true, OS); 147 } 148 if ((OpName == "any_of" || OpName == "all_of") && D->getNumArgs() > 0) { 149 bool Paren = D->getNumArgs() > 1 && std::exchange(ParenIfBinOp, true); 150 if (Paren) 151 OS << '('; 152 ListSeparator LS(OpName == "any_of" ? " || " : " && "); 153 for (auto *Arg : D->getArgs()) { 154 OS << LS; 155 if (emitFeaturesAux(TargetName, *Arg, ParenIfBinOp, OS)) 156 return true; 157 } 158 if (Paren) 159 OS << ')'; 160 return false; 161 } 162 } 163 return true; 164 } 165 166 void SubtargetFeatureInfo::emitComputeAssemblerAvailableFeatures( 167 StringRef TargetName, StringRef ClassName, StringRef FuncName, 168 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) { 169 OS << "FeatureBitset "; 170 if (!ClassName.empty()) 171 OS << TargetName << ClassName << "::\n"; 172 OS << FuncName << "(const FeatureBitset &FB) "; 173 if (!ClassName.empty()) 174 OS << "const "; 175 OS << "{\n"; 176 OS << " FeatureBitset Features;\n"; 177 for (const auto &SF : SubtargetFeatures) { 178 const SubtargetFeatureInfo &SFI = SF.second; 179 180 OS << " if ("; 181 emitFeaturesAux(TargetName, *SFI.TheDef->getValueAsDag("AssemblerCondDag"), 182 /*ParenIfBinOp=*/false, OS); 183 OS << ")\n"; 184 OS << " Features.set(" << SFI.getEnumBitName() << ");\n"; 185 } 186 OS << " return Features;\n"; 187 OS << "}\n\n"; 188 } 189