llvm/lib/IR/MDBuilder.cpp

   1 //===---- llvm/MDBuilder.cpp - Builder for LLVM metadata ------------------===//
   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 // This file defines the MDBuilder class, which is used as a convenient way to
  10 // create LLVM metadata with a consistent and simplified interface.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/IR/MDBuilder.h"
  15 #include "llvm/IR/Constants.h"
  16 #include "llvm/IR/Function.h"
  17 #include "llvm/IR/Metadata.h"
  18 using namespace llvm;
  19
  20 MDString *MDBuilder::createString(StringRef Str) {
  21   return MDString::get(Context, Str);
  22 }
  23
  24 ConstantAsMetadata *MDBuilder::createConstant(Constant *C) {
  25   return ConstantAsMetadata::get(C);
  26 }
  27
  28 MDNode *MDBuilder::createFPMath(float Accuracy) {
  29   if (Accuracy == 0.0)
  30     return nullptr;
  31   assert(Accuracy > 0.0 && "Invalid fpmath accuracy!");
  32   auto *Op =
  33       createConstant(ConstantFP::get(Type::getFloatTy(Context), Accuracy));
  34   return MDNode::get(Context, Op);
  35 }
  36
  37 MDNode *MDBuilder::createBranchWeights(uint32_t TrueWeight,
  38                                        uint32_t FalseWeight, bool IsExpected) {
  39   return createBranchWeights({TrueWeight, FalseWeight}, IsExpected);
  40 }
  41
  42 MDNode *MDBuilder::createLikelyBranchWeights() {
  43   // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
  44   return createBranchWeights((1U << 20) - 1, 1);
  45 }
  46
  47 MDNode *MDBuilder::createUnlikelyBranchWeights() {
  48   // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
  49   return createBranchWeights(1, (1U << 20) - 1);
  50 }
  51
  52 MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights,
  53                                        bool IsExpected) {
  54   assert(Weights.size() >= 1 && "Need at least one branch weights!");
  55
  56   unsigned int Offset = IsExpected ? 2 : 1;
  57   SmallVector<Metadata *, 4> Vals(Weights.size() + Offset);
  58   Vals[0] = createString("branch_weights");
  59   if (IsExpected)
  60     Vals[1] = createString("expected");
  61
  62   Type *Int32Ty = Type::getInt32Ty(Context);
  63   for (unsigned i = 0, e = Weights.size(); i != e; ++i)
  64     Vals[i + Offset] = createConstant(ConstantInt::get(Int32Ty, Weights[i]));
  65
  66   return MDNode::get(Context, Vals);
  67 }
  68
  69 MDNode *MDBuilder::createUnpredictable() { return MDNode::get(Context, {}); }
  70
  71 MDNode *MDBuilder::createFunctionEntryCount(
  72     uint64_t Count, bool Synthetic,
  73     const DenseSet<GlobalValue::GUID> *Imports) {
  74   Type *Int64Ty = Type::getInt64Ty(Context);
  75   SmallVector<Metadata *, 8> Ops;
  76   if (Synthetic)
  77     Ops.push_back(createString("synthetic_function_entry_count"));
  78   else
  79     Ops.push_back(createString("function_entry_count"));
  80   Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
  81   if (Imports) {
  82     SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());
  83     llvm::sort(OrderID);
  84     for (auto ID : OrderID)
  85       Ops.push_back(createConstant(ConstantInt::get(Int64Ty, ID)));
  86   }
  87   return MDNode::get(Context, Ops);
  88 }
  89
  90 MDNode *MDBuilder::createFunctionSectionPrefix(StringRef Prefix) {
  91   return MDNode::get(
  92       Context, {createString("function_section_prefix"), createString(Prefix)});
  93 }
  94
  95 MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
  96   assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
  97
  98   Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
  99   return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
 100 }
 101
 102 MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
 103   // If the range is everything then it is useless.
 104   if (Hi == Lo)
 105     return nullptr;
 106
 107   // Return the range [Lo, Hi).
 108   return MDNode::get(Context, {createConstant(Lo), createConstant(Hi)});
 109 }
 110
 111 MDNode *MDBuilder::createCallees(ArrayRef<Function *> Callees) {
 112   SmallVector<Metadata *, 4> Ops;
 113   for (Function *F : Callees)
 114     Ops.push_back(createConstant(F));
 115   return MDNode::get(Context, Ops);
 116 }
 117
 118 MDNode *MDBuilder::createCallbackEncoding(unsigned CalleeArgNo,
 119                                           ArrayRef<int> Arguments,
 120                                           bool VarArgArePassed) {
 121   SmallVector<Metadata *, 4> Ops;
 122
 123   Type *Int64 = Type::getInt64Ty(Context);
 124   Ops.push_back(createConstant(ConstantInt::get(Int64, CalleeArgNo)));
 125
 126   for (int ArgNo : Arguments)
 127     Ops.push_back(createConstant(ConstantInt::get(Int64, ArgNo, true)));
 128
 129   Type *Int1 = Type::getInt1Ty(Context);
 130   Ops.push_back(createConstant(ConstantInt::get(Int1, VarArgArePassed)));
 131
 132   return MDNode::get(Context, Ops);
 133 }
 134
 135 MDNode *MDBuilder::mergeCallbackEncodings(MDNode *ExistingCallbacks,
 136                                           MDNode *NewCB) {
 137   if (!ExistingCallbacks)
 138     return MDNode::get(Context, {NewCB});
 139
 140   auto *NewCBCalleeIdxAsCM = cast<ConstantAsMetadata>(NewCB->getOperand(0));
 141   uint64_t NewCBCalleeIdx =
 142       cast<ConstantInt>(NewCBCalleeIdxAsCM->getValue())->getZExtValue();
 143   (void)NewCBCalleeIdx;
 144
 145   SmallVector<Metadata *, 4> Ops;
 146   unsigned NumExistingOps = ExistingCallbacks->getNumOperands();
 147   Ops.resize(NumExistingOps + 1);
 148
 149   for (unsigned u = 0; u < NumExistingOps; u++) {
 150     Ops[u] = ExistingCallbacks->getOperand(u);
 151
 152     auto *OldCBCalleeIdxAsCM =
 153         cast<ConstantAsMetadata>(cast<MDNode>(Ops[u])->getOperand(0));
 154     uint64_t OldCBCalleeIdx =
 155         cast<ConstantInt>(OldCBCalleeIdxAsCM->getValue())->getZExtValue();
 156     (void)OldCBCalleeIdx;
 157     assert(NewCBCalleeIdx != OldCBCalleeIdx &&
 158            "Cannot map a callback callee index twice!");
 159   }
 160
 161   Ops[NumExistingOps] = NewCB;
 162   return MDNode::get(Context, Ops);
 163 }
 164
 165 MDNode *MDBuilder::createRTTIPointerPrologue(Constant *PrologueSig,
 166                                              Constant *RTTI) {
 167   SmallVector<Metadata *, 4> Ops;
 168   Ops.push_back(createConstant(PrologueSig));
 169   Ops.push_back(createConstant(RTTI));
 170   return MDNode::get(Context, Ops);
 171 }
 172
 173 MDNode *MDBuilder::createPCSections(ArrayRef<PCSection> Sections) {
 174   SmallVector<Metadata *, 2> Ops;
 175
 176   for (const auto &Entry : Sections) {
 177     const StringRef &Sec = Entry.first;
 178     Ops.push_back(createString(Sec));
 179
 180     // If auxiliary data for this section exists, append it.
 181     const SmallVector<Constant *> &AuxConsts = Entry.second;
 182     if (!AuxConsts.empty()) {
 183       SmallVector<Metadata *, 1> AuxMDs;
 184       AuxMDs.reserve(AuxConsts.size());
 185       for (Constant *C : AuxConsts)
 186         AuxMDs.push_back(createConstant(C));
 187       Ops.push_back(MDNode::get(Context, AuxMDs));
 188     }
 189   }
 190
 191   return MDNode::get(Context, Ops);
 192 }
 193
 194 MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
 195   SmallVector<Metadata *, 3> Args(1, nullptr);
 196   if (Extra)
 197     Args.push_back(Extra);
 198   if (!Name.empty())
 199     Args.push_back(createString(Name));
 200   MDNode *Root = MDNode::getDistinct(Context, Args);
 201
 202   // At this point we have
 203   //   !0 = distinct !{null} <- root
 204   // Replace the reserved operand with the root node itself.
 205   Root->replaceOperandWith(0, Root);
 206
 207   // We now have
 208   //   !0 = distinct !{!0} <- root
 209   return Root;
 210 }
 211
 212 MDNode *MDBuilder::createTBAARoot(StringRef Name) {
 213   return MDNode::get(Context, createString(Name));
 214 }
 215
 216 /// Return metadata for a non-root TBAA node with the given name,
 217 /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
 218 MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent,
 219                                   bool isConstant) {
 220   if (isConstant) {
 221     Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
 222     return MDNode::get(Context,
 223                        {createString(Name), Parent, createConstant(Flags)});
 224   }
 225   return MDNode::get(Context, {createString(Name), Parent});
 226 }
 227
 228 MDNode *MDBuilder::createAliasScopeDomain(StringRef Name) {
 229   return MDNode::get(Context, createString(Name));
 230 }
 231
 232 MDNode *MDBuilder::createAliasScope(StringRef Name, MDNode *Domain) {
 233   return MDNode::get(Context, {createString(Name), Domain});
 234 }
 235
 236 /// Return metadata for a tbaa.struct node with the given
 237 /// struct field descriptions.
 238 MDNode *MDBuilder::createTBAAStructNode(ArrayRef<TBAAStructField> Fields) {
 239   SmallVector<Metadata *, 4> Vals(Fields.size() * 3);
 240   Type *Int64 = Type::getInt64Ty(Context);
 241   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 242     Vals[i * 3 + 0] = createConstant(ConstantInt::get(Int64, Fields[i].Offset));
 243     Vals[i * 3 + 1] = createConstant(ConstantInt::get(Int64, Fields[i].Size));
 244     Vals[i * 3 + 2] = Fields[i].Type;
 245   }
 246   return MDNode::get(Context, Vals);
 247 }
 248
 249 /// Return metadata for a TBAA struct node in the type DAG
 250 /// with the given name, a list of pairs (offset, field type in the type DAG).
 251 MDNode *MDBuilder::createTBAAStructTypeNode(
 252     StringRef Name, ArrayRef<std::pair<MDNode *, uint64_t>> Fields) {
 253   SmallVector<Metadata *, 4> Ops(Fields.size() * 2 + 1);
 254   Type *Int64 = Type::getInt64Ty(Context);
 255   Ops[0] = createString(Name);
 256   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 257     Ops[i * 2 + 1] = Fields[i].first;
 258     Ops[i * 2 + 2] = createConstant(ConstantInt::get(Int64, Fields[i].second));
 259   }
 260   return MDNode::get(Context, Ops);
 261 }
 262
 263 /// Return metadata for a TBAA scalar type node with the
 264 /// given name, an offset and a parent in the TBAA type DAG.
 265 MDNode *MDBuilder::createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
 266                                             uint64_t Offset) {
 267   ConstantInt *Off = ConstantInt::get(Type::getInt64Ty(Context), Offset);
 268   return MDNode::get(Context,
 269                      {createString(Name), Parent, createConstant(Off)});
 270 }
 271
 272 /// Return metadata for a TBAA tag node with the given
 273 /// base type, access type and offset relative to the base type.
 274 MDNode *MDBuilder::createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
 275                                            uint64_t Offset, bool IsConstant) {
 276   IntegerType *Int64 = Type::getInt64Ty(Context);
 277   ConstantInt *Off = ConstantInt::get(Int64, Offset);
 278   if (IsConstant) {
 279     return MDNode::get(Context, {BaseType, AccessType, createConstant(Off),
 280                                  createConstant(ConstantInt::get(Int64, 1))});
 281   }
 282   return MDNode::get(Context, {BaseType, AccessType, createConstant(Off)});
 283 }
 284
 285 MDNode *MDBuilder::createTBAATypeNode(MDNode *Parent, uint64_t Size,
 286                                       Metadata *Id,
 287                                       ArrayRef<TBAAStructField> Fields) {
 288   SmallVector<Metadata *, 4> Ops(3 + Fields.size() * 3);
 289   Type *Int64 = Type::getInt64Ty(Context);
 290   Ops[0] = Parent;
 291   Ops[1] = createConstant(ConstantInt::get(Int64, Size));
 292   Ops[2] = Id;
 293   for (unsigned I = 0, E = Fields.size(); I != E; ++I) {
 294     Ops[I * 3 + 3] = Fields[I].Type;
 295     Ops[I * 3 + 4] = createConstant(ConstantInt::get(Int64, Fields[I].Offset));
 296     Ops[I * 3 + 5] = createConstant(ConstantInt::get(Int64, Fields[I].Size));
 297   }
 298   return MDNode::get(Context, Ops);
 299 }
 300
 301 MDNode *MDBuilder::createTBAAAccessTag(MDNode *BaseType, MDNode *AccessType,
 302                                        uint64_t Offset, uint64_t Size,
 303                                        bool IsImmutable) {
 304   IntegerType *Int64 = Type::getInt64Ty(Context);
 305   auto *OffsetNode = createConstant(ConstantInt::get(Int64, Offset));
 306   auto *SizeNode = createConstant(ConstantInt::get(Int64, Size));
 307   if (IsImmutable) {
 308     auto *ImmutabilityFlagNode = createConstant(ConstantInt::get(Int64, 1));
 309     return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode,
 310                                  ImmutabilityFlagNode});
 311   }
 312   return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode});
 313 }
 314
 315 MDNode *MDBuilder::createMutableTBAAAccessTag(MDNode *Tag) {
 316   MDNode *BaseType = cast<MDNode>(Tag->getOperand(0));
 317   MDNode *AccessType = cast<MDNode>(Tag->getOperand(1));
 318   Metadata *OffsetNode = Tag->getOperand(2);
 319   uint64_t Offset = mdconst::extract<ConstantInt>(OffsetNode)->getZExtValue();
 320
 321   bool NewFormat = isa<MDNode>(AccessType->getOperand(0));
 322
 323   // See if the tag is already mutable.
 324   unsigned ImmutabilityFlagOp = NewFormat ? 4 : 3;
 325   if (Tag->getNumOperands() <= ImmutabilityFlagOp)
 326     return Tag;
 327
 328   // If Tag is already mutable then return it.
 329   Metadata *ImmutabilityFlagNode = Tag->getOperand(ImmutabilityFlagOp);
 330   if (!mdconst::extract<ConstantInt>(ImmutabilityFlagNode)->getValue())
 331     return Tag;
 332
 333   // Otherwise, create another node.
 334   if (!NewFormat)
 335     return createTBAAStructTagNode(BaseType, AccessType, Offset);
 336
 337   Metadata *SizeNode = Tag->getOperand(3);
 338   uint64_t Size = mdconst::extract<ConstantInt>(SizeNode)->getZExtValue();
 339   return createTBAAAccessTag(BaseType, AccessType, Offset, Size);
 340 }
 341
 342 MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
 343   Metadata *Vals[] = {
 344       createString("loop_header_weight"),
 345       createConstant(ConstantInt::get(Type::getInt64Ty(Context), Weight)),
 346   };
 347   return MDNode::get(Context, Vals);
 348 }
 349
 350 MDNode *MDBuilder::createPseudoProbeDesc(uint64_t GUID, uint64_t Hash,
 351                                          StringRef FName) {
 352   auto *Int64Ty = Type::getInt64Ty(Context);
 353   SmallVector<Metadata *, 3> Ops(3);
 354   Ops[0] = createConstant(ConstantInt::get(Int64Ty, GUID));
 355   Ops[1] = createConstant(ConstantInt::get(Int64Ty, Hash));
 356   Ops[2] = createString(FName);
 357   return MDNode::get(Context, Ops);
 358 }
 359
 360 MDNode *
 361 MDBuilder::createLLVMStats(ArrayRef<std::pair<StringRef, uint64_t>> LLVMStats) {
 362   auto *Int64Ty = Type::getInt64Ty(Context);
 363   SmallVector<Metadata *, 4> Ops(LLVMStats.size() * 2);
 364   for (size_t I = 0; I < LLVMStats.size(); I++) {
 365     Ops[I * 2] = createString(LLVMStats[I].first);
 366     Ops[I * 2 + 1] =
 367         createConstant(ConstantInt::get(Int64Ty, LLVMStats[I].second));
 368   }
 369   return MDNode::get(Context, Ops);
 370 }