Home | History | Annotate | Download | only in IR 
      1 //===---- llvm/MDBuilder.h - Builder for LLVM metadata ----------*- C++ -*-===//
      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 #ifndef LLVM_IR_MDBUILDER_H
     16 #define LLVM_IR_MDBUILDER_H
     17 
     18 #include "llvm/Support/DataTypes.h"
     19 #include <utility>
     20 
     21 namespace llvm {
     22 
     23 class APInt;
     24 template <typename T> class ArrayRef;
     25 class LLVMContext;
     26 class MDNode;
     27 class MDString;
     28 class StringRef;
     29 
     30 class MDBuilder {
     31   LLVMContext &Context;
     32 
     33 public:
     34   MDBuilder(LLVMContext &context) : Context(context) {}
     35 
     36   /// \brief Return the given string as metadata.
     37   MDString *createString(StringRef Str);
     38 
     39   //===------------------------------------------------------------------===//
     40   // FPMath metadata.
     41   //===------------------------------------------------------------------===//
     42 
     43   /// \brief Return metadata with the given settings.  The special value 0.0
     44   /// for the Accuracy parameter indicates the default (maximal precision)
     45   /// setting.
     46   MDNode *createFPMath(float Accuracy);
     47 
     48   //===------------------------------------------------------------------===//
     49   // Prof metadata.
     50   //===------------------------------------------------------------------===//
     51 
     52   /// \brief Return metadata containing two branch weights.
     53   MDNode *createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight);
     54 
     55   /// \brief Return metadata containing a number of branch weights.
     56   MDNode *createBranchWeights(ArrayRef<uint32_t> Weights);
     57 
     58   //===------------------------------------------------------------------===//
     59   // Range metadata.
     60   //===------------------------------------------------------------------===//
     61 
     62   /// \brief Return metadata describing the range [Lo, Hi).
     63   MDNode *createRange(const APInt &Lo, const APInt &Hi);
     64 
     65   //===------------------------------------------------------------------===//
     66   // TBAA metadata.
     67   //===------------------------------------------------------------------===//
     68 
     69   /// \brief Return metadata appropriate for a TBAA root node.  Each returned
     70   /// node is distinct from all other metadata and will never be identified
     71   /// (uniqued) with anything else.
     72   MDNode *createAnonymousTBAARoot();
     73 
     74   /// \brief Return metadata appropriate for a TBAA root node with the given
     75   /// name.  This may be identified (uniqued) with other roots with the same
     76   /// name.
     77   MDNode *createTBAARoot(StringRef Name);
     78 
     79   /// \brief Return metadata for a non-root TBAA node with the given name,
     80   /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
     81   MDNode *createTBAANode(StringRef Name, MDNode *Parent,
     82                          bool isConstant = false);
     83 
     84   struct TBAAStructField {
     85     uint64_t Offset;
     86     uint64_t Size;
     87     MDNode *TBAA;
     88     TBAAStructField(uint64_t Offset, uint64_t Size, MDNode *TBAA) :
     89       Offset(Offset), Size(Size), TBAA(TBAA) {}
     90   };
     91 
     92   /// \brief Return metadata for a tbaa.struct node with the given
     93   /// struct field descriptions.
     94   MDNode *createTBAAStructNode(ArrayRef<TBAAStructField> Fields);
     95 
     96   /// \brief Return metadata for a TBAA struct node in the type DAG
     97   /// with the given name, a list of pairs (offset, field type in the type DAG).
     98   MDNode *
     99   createTBAAStructTypeNode(StringRef Name,
    100                            ArrayRef<std::pair<MDNode *, uint64_t>> Fields);
    101 
    102   /// \brief Return metadata for a TBAA scalar type node with the
    103   /// given name, an offset and a parent in the TBAA type DAG.
    104   MDNode *createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
    105                                    uint64_t Offset = 0);
    106 
    107   /// \brief Return metadata for a TBAA tag node with the given
    108   /// base type, access type and offset relative to the base type.
    109   MDNode *createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
    110                                   uint64_t Offset);
    111 };
    112 
    113 } // end namespace llvm
    114 
    115 #endif
    116