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 11 #include "Types.h" 12 #include "llvm/Config/llvm-config.h" 13 #include "llvm/TableGen/Record.h" 14 15 #include <map> 16 17 using namespace llvm; 18 19 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 20 LLVM_DUMP_METHOD void SubtargetFeatureInfo::dump() const { 21 errs() << getEnumName() << " " << Index << "\n" << *TheDef; 22 } 23 #endif 24 25 std::vector<std::pair<Record *, SubtargetFeatureInfo>> 26 SubtargetFeatureInfo::getAll(const RecordKeeper &Records) { 27 std::vector<std::pair<Record *, SubtargetFeatureInfo>> SubtargetFeatures; 28 std::vector<Record *> AllPredicates = 29 Records.getAllDerivedDefinitions("Predicate"); 30 for (Record *Pred : AllPredicates) { 31 // Ignore predicates that are not intended for the assembler. 32 // 33 // The "AssemblerMatcherPredicate" string should be promoted to an argument 34 // if we re-use the machinery for non-assembler purposes in future. 35 if (!Pred->getValueAsBit("AssemblerMatcherPredicate")) 36 continue; 37 38 if (Pred->getName().empty()) 39 PrintFatalError(Pred->getLoc(), "Predicate has no name!"); 40 41 // Ignore always true predicates. 42 if (Pred->getValueAsString("CondString").empty()) 43 continue; 44 45 SubtargetFeatures.emplace_back( 46 Pred, SubtargetFeatureInfo(Pred, SubtargetFeatures.size())); 47 } 48 return SubtargetFeatures; 49 } 50 51 void SubtargetFeatureInfo::emitSubtargetFeatureBitEnumeration( 52 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) { 53 OS << "// Bits for subtarget features that participate in " 54 << "instruction matching.\n"; 55 OS << "enum SubtargetFeatureBits : " 56 << getMinimalTypeForRange(SubtargetFeatures.size()) << " {\n"; 57 for (const auto &SF : SubtargetFeatures) { 58 const SubtargetFeatureInfo &SFI = SF.second; 59 OS << " " << SFI.getEnumBitName() << " = " << SFI.Index << ",\n"; 60 } 61 OS << "};\n\n"; 62 } 63 64 void SubtargetFeatureInfo::emitNameTable( 65 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) { 66 // Need to sort the name table so that lookup by the log of the enum value 67 // gives the proper name. More specifically, for a feature of value 1<<n, 68 // SubtargetFeatureNames[n] should be the name of the feature. 69 uint64_t IndexUB = 0; 70 for (const auto &SF : SubtargetFeatures) 71 if (IndexUB <= SF.second.Index) 72 IndexUB = SF.second.Index+1; 73 74 std::vector<std::string> Names; 75 if (IndexUB > 0) 76 Names.resize(IndexUB); 77 for (const auto &SF : SubtargetFeatures) 78 Names[SF.second.Index] = SF.second.getEnumName(); 79 80 OS << "static const char *SubtargetFeatureNames[] = {\n"; 81 for (uint64_t I = 0; I < IndexUB; ++I) 82 OS << " \"" << Names[I] << "\",\n"; 83 84 // A small number of targets have no predicates. Null terminate the array to 85 // avoid a zero-length array. 86 OS << " nullptr\n" 87 << "};\n\n"; 88 } 89 90 void SubtargetFeatureInfo::emitComputeAvailableFeatures( 91 StringRef TargetName, StringRef ClassName, StringRef FuncName, 92 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS, 93 StringRef ExtraParams) { 94 OS << "PredicateBitset " << TargetName << ClassName << "::\n" 95 << FuncName << "(const " << TargetName << "Subtarget *Subtarget"; 96 if (!ExtraParams.empty()) 97 OS << ", " << ExtraParams; 98 OS << ") const {\n"; 99 OS << " PredicateBitset Features;\n"; 100 for (const auto &SF : SubtargetFeatures) { 101 const SubtargetFeatureInfo &SFI = SF.second; 102 StringRef CondStr = SFI.TheDef->getValueAsString("CondString"); 103 assert(!CondStr.empty() && "true predicate should have been filtered"); 104 105 OS << " if (" << CondStr << ")\n"; 106 OS << " Features.set(" << SFI.getEnumBitName() << ");\n"; 107 } 108 OS << " return Features;\n"; 109 OS << "}\n\n"; 110 } 111 112 void SubtargetFeatureInfo::emitComputeAssemblerAvailableFeatures( 113 StringRef TargetName, StringRef ClassName, StringRef FuncName, 114 SubtargetFeatureInfoMap &SubtargetFeatures, raw_ostream &OS) { 115 OS << "FeatureBitset " << TargetName << ClassName << "::\n" 116 << FuncName << "(const FeatureBitset& FB) const {\n"; 117 OS << " FeatureBitset Features;\n"; 118 for (const auto &SF : SubtargetFeatures) { 119 const SubtargetFeatureInfo &SFI = SF.second; 120 121 OS << " if ("; 122 std::string CondStorage = 123 SFI.TheDef->getValueAsString("AssemblerCondString"); 124 StringRef Conds = CondStorage; 125 std::pair<StringRef, StringRef> Comma = Conds.split(','); 126 bool First = true; 127 do { 128 if (!First) 129 OS << " && "; 130 131 bool Neg = false; 132 StringRef Cond = Comma.first; 133 if (Cond[0] == '!') { 134 Neg = true; 135 Cond = Cond.substr(1); 136 } 137 138 OS << "("; 139 if (Neg) 140 OS << "!"; 141 OS << "FB[" << TargetName << "::" << Cond << "])"; 142 143 if (Comma.second.empty()) 144 break; 145 146 First = false; 147 Comma = Comma.second.split(','); 148 } while (true); 149 150 OS << ")\n"; 151 OS << " Features.set(" << SFI.getEnumBitName() << ");\n"; 152 } 153 OS << " return Features;\n"; 154 OS << "}\n\n"; 155 } 156