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