lib/IR/MDBuilder.cpp

   1 //===---- llvm/MDBuilder.cpp - Builder for LLVM metadata ------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines the MDBuilder class, which is used as a convenient way to
  11 // create LLVM metadata with a consistent and simplified interface.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/IR/MDBuilder.h"
  16 #include "llvm/IR/Constants.h"
  17 #include "llvm/IR/Function.h"
  18 #include "llvm/IR/Metadata.h"
  19 using namespace llvm;
  20
  21 MDString *MDBuilder::createString(StringRef Str) {
  22   return MDString::get(Context, Str);
  23 }
  24
  25 ConstantAsMetadata *MDBuilder::createConstant(Constant *C) {
  26   return ConstantAsMetadata::get(C);
  27 }
  28
  29 MDNode *MDBuilder::createFPMath(float Accuracy) {
  30   if (Accuracy == 0.0)
  31     return nullptr;
  32   assert(Accuracy > 0.0 && "Invalid fpmath accuracy!");
  33   auto *Op =
  34       createConstant(ConstantFP::get(Type::getFloatTy(Context), Accuracy));
  35   return MDNode::get(Context, Op);
  36 }
  37
  38 MDNode *MDBuilder::createBranchWeights(uint32_t TrueWeight,
  39                                        uint32_t FalseWeight) {
  40   return createBranchWeights({TrueWeight, FalseWeight});
  41 }
  42
  43 MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights) {
  44   assert(Weights.size() >= 1 && "Need at least one branch weights!");
  45
  46   SmallVector<Metadata *, 4> Vals(Weights.size() + 1);
  47   Vals[0] = createString("branch_weights");
  48
  49   Type *Int32Ty = Type::getInt32Ty(Context);
  50   for (unsigned i = 0, e = Weights.size(); i != e; ++i)
  51     Vals[i + 1] = createConstant(ConstantInt::get(Int32Ty, Weights[i]));
  52
  53   return MDNode::get(Context, Vals);
  54 }
  55
  56 MDNode *MDBuilder::createUnpredictable() {
  57   return MDNode::get(Context, None);
  58 }
  59
  60 MDNode *MDBuilder::createFunctionEntryCount(
  61     uint64_t Count, bool Synthetic,
  62     const DenseSet<GlobalValue::GUID> *Imports) {
  63   Type *Int64Ty = Type::getInt64Ty(Context);
  64   SmallVector<Metadata *, 8> Ops;
  65   if (Synthetic)
  66     Ops.push_back(createString("synthetic_function_entry_count"));
  67   else
  68     Ops.push_back(createString("function_entry_count"));
  69   Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
  70   if (Imports) {
  71     SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());
  72     std::stable_sort(OrderID.begin(), OrderID.end(),
  73       [] (GlobalValue::GUID A, GlobalValue::GUID B) {
  74         return A < B;});
  75     for (auto ID : OrderID)
  76       Ops.push_back(createConstant(ConstantInt::get(Int64Ty, ID)));
  77   }
  78   return MDNode::get(Context, Ops);
  79 }
  80
  81 MDNode *MDBuilder::createFunctionSectionPrefix(StringRef Prefix) {
  82   return MDNode::get(Context,
  83                      {createString("function_section_prefix"),
  84                       createString(Prefix)});
  85 }
  86
  87 MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
  88   assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
  89
  90   Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
  91   return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
  92 }
  93
  94 MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
  95   // If the range is everything then it is useless.
  96   if (Hi == Lo)
  97     return nullptr;
  98
  99   // Return the range [Lo, Hi).
 100   return MDNode::get(Context, {createConstant(Lo), createConstant(Hi)});
 101 }
 102
 103 MDNode *MDBuilder::createCallees(ArrayRef<Function *> Callees) {
 104   SmallVector<Metadata *, 4> Ops;
 105   for (Function *F : Callees)
 106     Ops.push_back(createConstant(F));
 107   return MDNode::get(Context, Ops);
 108 }
 109
 110 MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
 111   // To ensure uniqueness the root node is self-referential.
 112   auto Dummy = MDNode::getTemporary(Context, None);
 113
 114   SmallVector<Metadata *, 3> Args(1, Dummy.get());
 115   if (Extra)
 116     Args.push_back(Extra);
 117   if (!Name.empty())
 118     Args.push_back(createString(Name));
 119   MDNode *Root = MDNode::get(Context, Args);
 120
 121   // At this point we have
 122   //   !0 = metadata !{}            <- dummy
 123   //   !1 = metadata !{metadata !0} <- root
 124   // Replace the dummy operand with the root node itself and delete the dummy.
 125   Root->replaceOperandWith(0, Root);
 126
 127   // We now have
 128   //   !1 = metadata !{metadata !1} <- self-referential root
 129   return Root;
 130 }
 131
 132 MDNode *MDBuilder::createTBAARoot(StringRef Name) {
 133   return MDNode::get(Context, createString(Name));
 134 }
 135
 136 /// Return metadata for a non-root TBAA node with the given name,
 137 /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
 138 MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent,
 139                                   bool isConstant) {
 140   if (isConstant) {
 141     Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
 142     return MDNode::get(Context,
 143                        {createString(Name), Parent, createConstant(Flags)});
 144   }
 145   return MDNode::get(Context, {createString(Name), Parent});
 146 }
 147
 148 MDNode *MDBuilder::createAliasScopeDomain(StringRef Name) {
 149   return MDNode::get(Context, createString(Name));
 150 }
 151
 152 MDNode *MDBuilder::createAliasScope(StringRef Name, MDNode *Domain) {
 153   return MDNode::get(Context, {createString(Name), Domain});
 154 }
 155
 156 /// Return metadata for a tbaa.struct node with the given
 157 /// struct field descriptions.
 158 MDNode *MDBuilder::createTBAAStructNode(ArrayRef<TBAAStructField> Fields) {
 159   SmallVector<Metadata *, 4> Vals(Fields.size() * 3);
 160   Type *Int64 = Type::getInt64Ty(Context);
 161   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 162     Vals[i * 3 + 0] = createConstant(ConstantInt::get(Int64, Fields[i].Offset));
 163     Vals[i * 3 + 1] = createConstant(ConstantInt::get(Int64, Fields[i].Size));
 164     Vals[i * 3 + 2] = Fields[i].Type;
 165   }
 166   return MDNode::get(Context, Vals);
 167 }
 168
 169 /// Return metadata for a TBAA struct node in the type DAG
 170 /// with the given name, a list of pairs (offset, field type in the type DAG).
 171 MDNode *MDBuilder::createTBAAStructTypeNode(
 172     StringRef Name, ArrayRef<std::pair<MDNode *, uint64_t>> Fields) {
 173   SmallVector<Metadata *, 4> Ops(Fields.size() * 2 + 1);
 174   Type *Int64 = Type::getInt64Ty(Context);
 175   Ops[0] = createString(Name);
 176   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 177     Ops[i * 2 + 1] = Fields[i].first;
 178     Ops[i * 2 + 2] = createConstant(ConstantInt::get(Int64, Fields[i].second));
 179   }
 180   return MDNode::get(Context, Ops);
 181 }
 182
 183 /// Return metadata for a TBAA scalar type node with the
 184 /// given name, an offset and a parent in the TBAA type DAG.
 185 MDNode *MDBuilder::createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
 186                                             uint64_t Offset) {
 187   ConstantInt *Off = ConstantInt::get(Type::getInt64Ty(Context), Offset);
 188   return MDNode::get(Context,
 189                      {createString(Name), Parent, createConstant(Off)});
 190 }
 191
 192 /// Return metadata for a TBAA tag node with the given
 193 /// base type, access type and offset relative to the base type.
 194 MDNode *MDBuilder::createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
 195                                            uint64_t Offset, bool IsConstant) {
 196   IntegerType *Int64 = Type::getInt64Ty(Context);
 197   ConstantInt *Off = ConstantInt::get(Int64, Offset);
 198   if (IsConstant) {
 199     return MDNode::get(Context, {BaseType, AccessType, createConstant(Off),
 200                                  createConstant(ConstantInt::get(Int64, 1))});
 201   }
 202   return MDNode::get(Context, {BaseType, AccessType, createConstant(Off)});
 203 }
 204
 205 MDNode *MDBuilder::createTBAATypeNode(MDNode *Parent, uint64_t Size,
 206                                       Metadata *Id,
 207                                       ArrayRef<TBAAStructField> Fields) {
 208   SmallVector<Metadata *, 4> Ops(3 + Fields.size() * 3);
 209   Type *Int64 = Type::getInt64Ty(Context);
 210   Ops[0] = Parent;
 211   Ops[1] = createConstant(ConstantInt::get(Int64, Size));
 212   Ops[2] = Id;
 213   for (unsigned I = 0, E = Fields.size(); I != E; ++I) {
 214     Ops[I * 3 + 3] = Fields[I].Type;
 215     Ops[I * 3 + 4] = createConstant(ConstantInt::get(Int64, Fields[I].Offset));
 216     Ops[I * 3 + 5] = createConstant(ConstantInt::get(Int64, Fields[I].Size));
 217   }
 218   return MDNode::get(Context, Ops);
 219 }
 220
 221 MDNode *MDBuilder::createTBAAAccessTag(MDNode *BaseType, MDNode *AccessType,
 222                                        uint64_t Offset, uint64_t Size,
 223                                        bool IsImmutable) {
 224   IntegerType *Int64 = Type::getInt64Ty(Context);
 225   auto *OffsetNode = createConstant(ConstantInt::get(Int64, Offset));
 226   auto *SizeNode = createConstant(ConstantInt::get(Int64, Size));
 227   if (IsImmutable) {
 228     auto *ImmutabilityFlagNode = createConstant(ConstantInt::get(Int64, 1));
 229     return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode,
 230                                  ImmutabilityFlagNode});
 231   }
 232   return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode});
 233 }
 234
 235 MDNode *MDBuilder::createMutableTBAAAccessTag(MDNode *Tag) {
 236   MDNode *BaseType = cast<MDNode>(Tag->getOperand(0));
 237   MDNode *AccessType = cast<MDNode>(Tag->getOperand(1));
 238   Metadata *OffsetNode = Tag->getOperand(2);
 239   uint64_t Offset = mdconst::extract<ConstantInt>(OffsetNode)->getZExtValue();
 240
 241   bool NewFormat = isa<MDNode>(AccessType->getOperand(0));
 242
 243   // See if the tag is already mutable.
 244   unsigned ImmutabilityFlagOp = NewFormat ? 4 : 3;
 245   if (Tag->getNumOperands() <= ImmutabilityFlagOp)
 246     return Tag;
 247
 248   // If Tag is already mutable then return it.
 249   Metadata *ImmutabilityFlagNode = Tag->getOperand(ImmutabilityFlagOp);
 250   if (!mdconst::extract<ConstantInt>(ImmutabilityFlagNode)->getValue())
 251     return Tag;
 252
 253   // Otherwise, create another node.
 254   if (!NewFormat)
 255     return createTBAAStructTagNode(BaseType, AccessType, Offset);
 256
 257   Metadata *SizeNode = Tag->getOperand(3);
 258   uint64_t Size = mdconst::extract<ConstantInt>(SizeNode)->getZExtValue();
 259   return createTBAAAccessTag(BaseType, AccessType, Offset, Size);
 260 }
 261
 262 MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
 263   Metadata *Vals[] = {
 264     createString("loop_header_weight"),
 265     createConstant(ConstantInt::get(Type::getInt64Ty(Context), Weight)),
 266   };
 267   return MDNode::get(Context, Vals);
 268 }