include/llvm/IR/MDBuilder.h

   1 //===---- llvm/MDBuilder.h - Builder for LLVM metadata ----------*- C++ -*-===//
   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 #ifndef LLVM_IR_MDBUILDER_H
  15 #define LLVM_IR_MDBUILDER_H
  16
  17 #include "llvm/ADT/DenseSet.h"
  18 #include "llvm/ADT/StringRef.h"
  19 #include "llvm/IR/Constants.h"
  20 #include "llvm/IR/GlobalValue.h"
  21 #include "llvm/Support/DataTypes.h"
  22 #include <utility>
  23
  24 namespace llvm {
  25
  26 class APInt;
  27 template <typename T> class ArrayRef;
  28 class LLVMContext;
  29 class Constant;
  30 class ConstantAsMetadata;
  31 class MDNode;
  32 class MDString;
  33 class Metadata;
  34
  35 class MDBuilder {
  36   LLVMContext &Context;
  37
  38 public:
  39   MDBuilder(LLVMContext &context) : Context(context) {}
  40
  41   /// Return the given string as metadata.
  42   MDString *createString(StringRef Str);
  43
  44   /// Return the given constant as metadata.
  45   ConstantAsMetadata *createConstant(Constant *C);
  46
  47   //===------------------------------------------------------------------===//
  48   // FPMath metadata.
  49   //===------------------------------------------------------------------===//
  50
  51   /// Return metadata with the given settings.  The special value 0.0
  52   /// for the Accuracy parameter indicates the default (maximal precision)
  53   /// setting.
  54   MDNode *createFPMath(float Accuracy);
  55
  56   //===------------------------------------------------------------------===//
  57   // Prof metadata.
  58   //===------------------------------------------------------------------===//
  59
  60   /// Return metadata containing two branch weights.
  61   MDNode *createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight);
  62
  63   /// Return metadata containing a number of branch weights.
  64   MDNode *createBranchWeights(ArrayRef<uint32_t> Weights);
  65
  66   /// Return metadata specifying that a branch or switch is unpredictable.
  67   MDNode *createUnpredictable();
  68
  69   /// Return metadata containing the entry \p Count for a function, a boolean
  70   /// \Synthetic indicating whether the counts were synthetized, and the
  71   /// GUIDs stored in \p Imports that need to be imported for sample PGO, to
  72   /// enable the same inlines as the profiled optimized binary
  73   MDNode *createFunctionEntryCount(uint64_t Count, bool Synthetic,
  74                                    const DenseSet<GlobalValue::GUID> *Imports);
  75
  76   /// Return metadata containing the section prefix for a function.
  77   MDNode *createFunctionSectionPrefix(StringRef Prefix);
  78
  79   /// return metadata containing expected value
  80   MDNode *createMisExpect(uint64_t Index, uint64_t LikelyWeight,
  81                           uint64_t UnlikelyWeight);
  82
  83   //===------------------------------------------------------------------===//
  84   // Range metadata.
  85   //===------------------------------------------------------------------===//
  86
  87   /// Return metadata describing the range [Lo, Hi).
  88   MDNode *createRange(const APInt &Lo, const APInt &Hi);
  89
  90   /// Return metadata describing the range [Lo, Hi).
  91   MDNode *createRange(Constant *Lo, Constant *Hi);
  92
  93   //===------------------------------------------------------------------===//
  94   // Callees metadata.
  95   //===------------------------------------------------------------------===//
  96
  97   /// Return metadata indicating the possible callees of indirect
  98   /// calls.
  99   MDNode *createCallees(ArrayRef<Function *> Callees);
 100
 101   //===------------------------------------------------------------------===//
 102   // Callback metadata.
 103   //===------------------------------------------------------------------===//
 104
 105   /// Return metadata describing a callback (see llvm::AbstractCallSite).
 106   MDNode *createCallbackEncoding(unsigned CalleeArgNo, ArrayRef<int> Arguments,
 107                                  bool VarArgsArePassed);
 108
 109   /// Merge the new callback encoding \p NewCB into \p ExistingCallbacks.
 110   MDNode *mergeCallbackEncodings(MDNode *ExistingCallbacks, MDNode *NewCB);
 111
 112   //===------------------------------------------------------------------===//
 113   // AA metadata.
 114   //===------------------------------------------------------------------===//
 115
 116 protected:
 117   /// Return metadata appropriate for a AA root node (scope or TBAA).
 118   /// Each returned node is distinct from all other metadata and will never
 119   /// be identified (uniqued) with anything else.
 120   MDNode *createAnonymousAARoot(StringRef Name = StringRef(),
 121                                 MDNode *Extra = nullptr);
 122
 123 public:
 124   /// Return metadata appropriate for a TBAA root node. Each returned
 125   /// node is distinct from all other metadata and will never be identified
 126   /// (uniqued) with anything else.
 127   MDNode *createAnonymousTBAARoot() {
 128     return createAnonymousAARoot();
 129   }
 130
 131   /// Return metadata appropriate for an alias scope domain node.
 132   /// Each returned node is distinct from all other metadata and will never
 133   /// be identified (uniqued) with anything else.
 134   MDNode *createAnonymousAliasScopeDomain(StringRef Name = StringRef()) {
 135     return createAnonymousAARoot(Name);
 136   }
 137
 138   /// Return metadata appropriate for an alias scope root node.
 139   /// Each returned node is distinct from all other metadata and will never
 140   /// be identified (uniqued) with anything else.
 141   MDNode *createAnonymousAliasScope(MDNode *Domain,
 142                                     StringRef Name = StringRef()) {
 143     return createAnonymousAARoot(Name, Domain);
 144   }
 145
 146   /// Return metadata appropriate for a TBAA root node with the given
 147   /// name.  This may be identified (uniqued) with other roots with the same
 148   /// name.
 149   MDNode *createTBAARoot(StringRef Name);
 150
 151   /// Return metadata appropriate for an alias scope domain node with
 152   /// the given name. This may be identified (uniqued) with other roots with
 153   /// the same name.
 154   MDNode *createAliasScopeDomain(StringRef Name);
 155
 156   /// Return metadata appropriate for an alias scope node with
 157   /// the given name. This may be identified (uniqued) with other scopes with
 158   /// the same name and domain.
 159   MDNode *createAliasScope(StringRef Name, MDNode *Domain);
 160
 161   /// Return metadata for a non-root TBAA node with the given name,
 162   /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
 163   MDNode *createTBAANode(StringRef Name, MDNode *Parent,
 164                          bool isConstant = false);
 165
 166   struct TBAAStructField {
 167     uint64_t Offset;
 168     uint64_t Size;
 169     MDNode *Type;
 170     TBAAStructField(uint64_t Offset, uint64_t Size, MDNode *Type) :
 171       Offset(Offset), Size(Size), Type(Type) {}
 172   };
 173
 174   /// Return metadata for a tbaa.struct node with the given
 175   /// struct field descriptions.
 176   MDNode *createTBAAStructNode(ArrayRef<TBAAStructField> Fields);
 177
 178   /// Return metadata for a TBAA struct node in the type DAG
 179   /// with the given name, a list of pairs (offset, field type in the type DAG).
 180   MDNode *
 181   createTBAAStructTypeNode(StringRef Name,
 182                            ArrayRef<std::pair<MDNode *, uint64_t>> Fields);
 183
 184   /// Return metadata for a TBAA scalar type node with the
 185   /// given name, an offset and a parent in the TBAA type DAG.
 186   MDNode *createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
 187                                    uint64_t Offset = 0);
 188
 189   /// Return metadata for a TBAA tag node with the given
 190   /// base type, access type and offset relative to the base type.
 191   MDNode *createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
 192                                   uint64_t Offset, bool IsConstant = false);
 193
 194   /// Return metadata for a TBAA type node in the TBAA type DAG with the
 195   /// given parent type, size in bytes, type identifier and a list of fields.
 196   MDNode *createTBAATypeNode(MDNode *Parent, uint64_t Size, Metadata *Id,
 197                              ArrayRef<TBAAStructField> Fields =
 198                                  ArrayRef<TBAAStructField>());
 199
 200   /// Return metadata for a TBAA access tag with the given base type,
 201   /// final access type, offset of the access relative to the base type, size of
 202   /// the access and flag indicating whether the accessed object can be
 203   /// considered immutable for the purposes of the TBAA analysis.
 204   MDNode *createTBAAAccessTag(MDNode *BaseType, MDNode *AccessType,
 205                               uint64_t Offset, uint64_t Size,
 206                               bool IsImmutable = false);
 207
 208   /// Return mutable version of the given mutable or immutable TBAA
 209   /// access tag.
 210   MDNode *createMutableTBAAAccessTag(MDNode *Tag);
 211
 212   /// Return metadata containing an irreducible loop header weight.
 213   MDNode *createIrrLoopHeaderWeight(uint64_t Weight);
 214 };
 215
 216 } // end namespace llvm
 217
 218 #endif