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) {
  39   return createBranchWeights({TrueWeight, FalseWeight});
  40 }
  41
  42 MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights) {
  43   assert(Weights.size() >= 1 && "Need at least one branch weights!");
  44
  45   SmallVector<Metadata *, 4> Vals(Weights.size() + 1);
  46   Vals[0] = createString("branch_weights");
  47
  48   Type *Int32Ty = Type::getInt32Ty(Context);
  49   for (unsigned i = 0, e = Weights.size(); i != e; ++i)
  50     Vals[i + 1] = createConstant(ConstantInt::get(Int32Ty, Weights[i]));
  51
  52   return MDNode::get(Context, Vals);
  53 }
  54
  55 MDNode *MDBuilder::createUnpredictable() {
  56   return MDNode::get(Context, None);
  57 }
  58
  59 MDNode *MDBuilder::createFunctionEntryCount(
  60     uint64_t Count, bool Synthetic,
  61     const DenseSet<GlobalValue::GUID> *Imports) {
  62   Type *Int64Ty = Type::getInt64Ty(Context);
  63   SmallVector<Metadata *, 8> Ops;
  64   if (Synthetic)
  65     Ops.push_back(createString("synthetic_function_entry_count"));
  66   else
  67     Ops.push_back(createString("function_entry_count"));
  68   Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
  69   if (Imports) {
  70     SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());
  71     llvm::stable_sort(OrderID);
  72     for (auto ID : OrderID)
  73       Ops.push_back(createConstant(ConstantInt::get(Int64Ty, ID)));
  74   }
  75   return MDNode::get(Context, Ops);
  76 }
  77
  78 MDNode *MDBuilder::createFunctionSectionPrefix(StringRef Prefix) {
  79   return MDNode::get(Context,
  80                      {createString("function_section_prefix"),
  81                       createString(Prefix)});
  82 }
  83
  84 MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
  85   assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
  86
  87   Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
  88   return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
  89 }
  90
  91 MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
  92   // If the range is everything then it is useless.
  93   if (Hi == Lo)
  94     return nullptr;
  95
  96   // Return the range [Lo, Hi).
  97   return MDNode::get(Context, {createConstant(Lo), createConstant(Hi)});
  98 }
  99
 100 MDNode *MDBuilder::createCallees(ArrayRef<Function *> Callees) {
 101   SmallVector<Metadata *, 4> Ops;
 102   for (Function *F : Callees)
 103     Ops.push_back(createConstant(F));
 104   return MDNode::get(Context, Ops);
 105 }
 106
 107 MDNode *MDBuilder::createCallbackEncoding(unsigned CalleeArgNo,
 108                                           ArrayRef<int> Arguments,
 109                                           bool VarArgArePassed) {
 110   SmallVector<Metadata *, 4> Ops;
 111
 112   Type *Int64 = Type::getInt64Ty(Context);
 113   Ops.push_back(createConstant(ConstantInt::get(Int64, CalleeArgNo)));
 114
 115   for (int ArgNo : Arguments)
 116     Ops.push_back(createConstant(ConstantInt::get(Int64, ArgNo, true)));
 117
 118   Type *Int1 = Type::getInt1Ty(Context);
 119   Ops.push_back(createConstant(ConstantInt::get(Int1, VarArgArePassed)));
 120
 121   return MDNode::get(Context, Ops);
 122 }
 123
 124 MDNode *MDBuilder::mergeCallbackEncodings(MDNode *ExistingCallbacks,
 125                                           MDNode *NewCB) {
 126   if (!ExistingCallbacks)
 127     return MDNode::get(Context, {NewCB});
 128
 129   auto *NewCBCalleeIdxAsCM = cast<ConstantAsMetadata>(NewCB->getOperand(0));
 130   uint64_t NewCBCalleeIdx =
 131       cast<ConstantInt>(NewCBCalleeIdxAsCM->getValue())->getZExtValue();
 132   (void)NewCBCalleeIdx;
 133
 134   SmallVector<Metadata *, 4> Ops;
 135   unsigned NumExistingOps = ExistingCallbacks->getNumOperands();
 136   Ops.resize(NumExistingOps + 1);
 137
 138   for (unsigned u = 0; u < NumExistingOps; u++) {
 139     Ops[u] = ExistingCallbacks->getOperand(u);
 140
 141     auto *OldCBCalleeIdxAsCM = cast<ConstantAsMetadata>(Ops[u]);
 142     uint64_t OldCBCalleeIdx =
 143       cast<ConstantInt>(OldCBCalleeIdxAsCM->getValue())->getZExtValue();
 144     (void)OldCBCalleeIdx;
 145     assert(NewCBCalleeIdx != OldCBCalleeIdx &&
 146            "Cannot map a callback callee index twice!");
 147   }
 148
 149   Ops[NumExistingOps] = NewCB;
 150   return MDNode::get(Context, Ops);
 151 }
 152
 153 MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
 154   // To ensure uniqueness the root node is self-referential.
 155   auto Dummy = MDNode::getTemporary(Context, None);
 156
 157   SmallVector<Metadata *, 3> Args(1, Dummy.get());
 158   if (Extra)
 159     Args.push_back(Extra);
 160   if (!Name.empty())
 161     Args.push_back(createString(Name));
 162   MDNode *Root = MDNode::get(Context, Args);
 163
 164   // At this point we have
 165   //   !0 = metadata !{}            <- dummy
 166   //   !1 = metadata !{metadata !0} <- root
 167   // Replace the dummy operand with the root node itself and delete the dummy.
 168   Root->replaceOperandWith(0, Root);
 169
 170   // We now have
 171   //   !1 = metadata !{metadata !1} <- self-referential root
 172   return Root;
 173 }
 174
 175 MDNode *MDBuilder::createTBAARoot(StringRef Name) {
 176   return MDNode::get(Context, createString(Name));
 177 }
 178
 179 /// Return metadata for a non-root TBAA node with the given name,
 180 /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
 181 MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent,
 182                                   bool isConstant) {
 183   if (isConstant) {
 184     Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
 185     return MDNode::get(Context,
 186                        {createString(Name), Parent, createConstant(Flags)});
 187   }
 188   return MDNode::get(Context, {createString(Name), Parent});
 189 }
 190
 191 MDNode *MDBuilder::createAliasScopeDomain(StringRef Name) {
 192   return MDNode::get(Context, createString(Name));
 193 }
 194
 195 MDNode *MDBuilder::createAliasScope(StringRef Name, MDNode *Domain) {
 196   return MDNode::get(Context, {createString(Name), Domain});
 197 }
 198
 199 /// Return metadata for a tbaa.struct node with the given
 200 /// struct field descriptions.
 201 MDNode *MDBuilder::createTBAAStructNode(ArrayRef<TBAAStructField> Fields) {
 202   SmallVector<Metadata *, 4> Vals(Fields.size() * 3);
 203   Type *Int64 = Type::getInt64Ty(Context);
 204   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 205     Vals[i * 3 + 0] = createConstant(ConstantInt::get(Int64, Fields[i].Offset));
 206     Vals[i * 3 + 1] = createConstant(ConstantInt::get(Int64, Fields[i].Size));
 207     Vals[i * 3 + 2] = Fields[i].Type;
 208   }
 209   return MDNode::get(Context, Vals);
 210 }
 211
 212 /// Return metadata for a TBAA struct node in the type DAG
 213 /// with the given name, a list of pairs (offset, field type in the type DAG).
 214 MDNode *MDBuilder::createTBAAStructTypeNode(
 215     StringRef Name, ArrayRef<std::pair<MDNode *, uint64_t>> Fields) {
 216   SmallVector<Metadata *, 4> Ops(Fields.size() * 2 + 1);
 217   Type *Int64 = Type::getInt64Ty(Context);
 218   Ops[0] = createString(Name);
 219   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
 220     Ops[i * 2 + 1] = Fields[i].first;
 221     Ops[i * 2 + 2] = createConstant(ConstantInt::get(Int64, Fields[i].second));
 222   }
 223   return MDNode::get(Context, Ops);
 224 }
 225
 226 /// Return metadata for a TBAA scalar type node with the
 227 /// given name, an offset and a parent in the TBAA type DAG.
 228 MDNode *MDBuilder::createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
 229                                             uint64_t Offset) {
 230   ConstantInt *Off = ConstantInt::get(Type::getInt64Ty(Context), Offset);
 231   return MDNode::get(Context,
 232                      {createString(Name), Parent, createConstant(Off)});
 233 }
 234
 235 /// Return metadata for a TBAA tag node with the given
 236 /// base type, access type and offset relative to the base type.
 237 MDNode *MDBuilder::createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
 238                                            uint64_t Offset, bool IsConstant) {
 239   IntegerType *Int64 = Type::getInt64Ty(Context);
 240   ConstantInt *Off = ConstantInt::get(Int64, Offset);
 241   if (IsConstant) {
 242     return MDNode::get(Context, {BaseType, AccessType, createConstant(Off),
 243                                  createConstant(ConstantInt::get(Int64, 1))});
 244   }
 245   return MDNode::get(Context, {BaseType, AccessType, createConstant(Off)});
 246 }
 247
 248 MDNode *MDBuilder::createTBAATypeNode(MDNode *Parent, uint64_t Size,
 249                                       Metadata *Id,
 250                                       ArrayRef<TBAAStructField> Fields) {
 251   SmallVector<Metadata *, 4> Ops(3 + Fields.size() * 3);
 252   Type *Int64 = Type::getInt64Ty(Context);
 253   Ops[0] = Parent;
 254   Ops[1] = createConstant(ConstantInt::get(Int64, Size));
 255   Ops[2] = Id;
 256   for (unsigned I = 0, E = Fields.size(); I != E; ++I) {
 257     Ops[I * 3 + 3] = Fields[I].Type;
 258     Ops[I * 3 + 4] = createConstant(ConstantInt::get(Int64, Fields[I].Offset));
 259     Ops[I * 3 + 5] = createConstant(ConstantInt::get(Int64, Fields[I].Size));
 260   }
 261   return MDNode::get(Context, Ops);
 262 }
 263
 264 MDNode *MDBuilder::createTBAAAccessTag(MDNode *BaseType, MDNode *AccessType,
 265                                        uint64_t Offset, uint64_t Size,
 266                                        bool IsImmutable) {
 267   IntegerType *Int64 = Type::getInt64Ty(Context);
 268   auto *OffsetNode = createConstant(ConstantInt::get(Int64, Offset));
 269   auto *SizeNode = createConstant(ConstantInt::get(Int64, Size));
 270   if (IsImmutable) {
 271     auto *ImmutabilityFlagNode = createConstant(ConstantInt::get(Int64, 1));
 272     return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode,
 273                                  ImmutabilityFlagNode});
 274   }
 275   return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode});
 276 }
 277
 278 MDNode *MDBuilder::createMutableTBAAAccessTag(MDNode *Tag) {
 279   MDNode *BaseType = cast<MDNode>(Tag->getOperand(0));
 280   MDNode *AccessType = cast<MDNode>(Tag->getOperand(1));
 281   Metadata *OffsetNode = Tag->getOperand(2);
 282   uint64_t Offset = mdconst::extract<ConstantInt>(OffsetNode)->getZExtValue();
 283
 284   bool NewFormat = isa<MDNode>(AccessType->getOperand(0));
 285
 286   // See if the tag is already mutable.
 287   unsigned ImmutabilityFlagOp = NewFormat ? 4 : 3;
 288   if (Tag->getNumOperands() <= ImmutabilityFlagOp)
 289     return Tag;
 290
 291   // If Tag is already mutable then return it.
 292   Metadata *ImmutabilityFlagNode = Tag->getOperand(ImmutabilityFlagOp);
 293   if (!mdconst::extract<ConstantInt>(ImmutabilityFlagNode)->getValue())
 294     return Tag;
 295
 296   // Otherwise, create another node.
 297   if (!NewFormat)
 298     return createTBAAStructTagNode(BaseType, AccessType, Offset);
 299
 300   Metadata *SizeNode = Tag->getOperand(3);
 301   uint64_t Size = mdconst::extract<ConstantInt>(SizeNode)->getZExtValue();
 302   return createTBAAAccessTag(BaseType, AccessType, Offset, Size);
 303 }
 304
 305 MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
 306   Metadata *Vals[] = {
 307     createString("loop_header_weight"),
 308     createConstant(ConstantInt::get(Type::getInt64Ty(Context), Weight)),
 309   };
 310   return MDNode::get(Context, Vals);
 311 }
 312
 313 MDNode *MDBuilder::createMisExpect(uint64_t Index, uint64_t LikleyWeight,
 314                                    uint64_t UnlikleyWeight) {
 315   auto *IntType = Type::getInt64Ty(Context);
 316   Metadata *Vals[] = {
 317       createString("misexpect"),
 318       createConstant(ConstantInt::get(IntType, Index)),
 319       createConstant(ConstantInt::get(IntType, LikleyWeight)),
 320       createConstant(ConstantInt::get(IntType, UnlikleyWeight)),
 321   };
 322   return MDNode::get(Context, Vals);
 323 }