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/Metadata.h"
18using namespace llvm;
19
20MDString *MDBuilder::createString(StringRef Str) {
21  return MDString::get(Context, Str);
22}
23
24ConstantAsMetadata *MDBuilder::createConstant(Constant *C) {
25  return ConstantAsMetadata::get(C);
26}
27
28MDNode *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
37MDNode *MDBuilder::createBranchWeights(uint32_t TrueWeight,
38                                       uint32_t FalseWeight) {
39  uint32_t Weights[] = {TrueWeight, FalseWeight};
40  return createBranchWeights(Weights);
41}
42
43MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights) {
44  assert(Weights.size() >= 2 && "Need at least two 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
56MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
57  assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
58
59  Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
60  return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
61}
62
63MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
64  // If the range is everything then it is useless.
65  if (Hi == Lo)
66    return nullptr;
67
68  // Return the range [Lo, Hi).
69  Metadata *Range[2] = {createConstant(Lo), createConstant(Hi)};
70  return MDNode::get(Context, Range);
71}
72
73MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
74  // To ensure uniqueness the root node is self-referential.
75  auto Dummy = MDNode::getTemporary(Context, None);
76
77  SmallVector<Metadata *, 3> Args(1, Dummy.get());
78  if (Extra)
79    Args.push_back(Extra);
80  if (!Name.empty())
81    Args.push_back(createString(Name));
82  MDNode *Root = MDNode::get(Context, Args);
83
84  // At this point we have
85  //   !0 = metadata !{}            <- dummy
86  //   !1 = metadata !{metadata !0} <- root
87  // Replace the dummy operand with the root node itself and delete the dummy.
88  Root->replaceOperandWith(0, Root);
89
90  // We now have
91  //   !1 = metadata !{metadata !1} <- self-referential root
92  return Root;
93}
94
95MDNode *MDBuilder::createTBAARoot(StringRef Name) {
96  return MDNode::get(Context, createString(Name));
97}
98
99/// \brief Return metadata for a non-root TBAA node with the given name,
100/// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
101MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent,
102                                  bool isConstant) {
103  if (isConstant) {
104    Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
105    Metadata *Ops[3] = {createString(Name), Parent, createConstant(Flags)};
106    return MDNode::get(Context, Ops);
107  } else {
108    Metadata *Ops[2] = {createString(Name), Parent};
109    return MDNode::get(Context, Ops);
110  }
111}
112
113MDNode *MDBuilder::createAliasScopeDomain(StringRef Name) {
114  return MDNode::get(Context, createString(Name));
115}
116
117MDNode *MDBuilder::createAliasScope(StringRef Name, MDNode *Domain) {
118  Metadata *Ops[2] = {createString(Name), Domain};
119  return MDNode::get(Context, Ops);
120}
121
122/// \brief Return metadata for a tbaa.struct node with the given
123/// struct field descriptions.
124MDNode *MDBuilder::createTBAAStructNode(ArrayRef<TBAAStructField> Fields) {
125  SmallVector<Metadata *, 4> Vals(Fields.size() * 3);
126  Type *Int64 = Type::getInt64Ty(Context);
127  for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
128    Vals[i * 3 + 0] = createConstant(ConstantInt::get(Int64, Fields[i].Offset));
129    Vals[i * 3 + 1] = createConstant(ConstantInt::get(Int64, Fields[i].Size));
130    Vals[i * 3 + 2] = Fields[i].TBAA;
131  }
132  return MDNode::get(Context, Vals);
133}
134
135/// \brief Return metadata for a TBAA struct node in the type DAG
136/// with the given name, a list of pairs (offset, field type in the type DAG).
137MDNode *MDBuilder::createTBAAStructTypeNode(
138    StringRef Name, ArrayRef<std::pair<MDNode *, uint64_t>> Fields) {
139  SmallVector<Metadata *, 4> Ops(Fields.size() * 2 + 1);
140  Type *Int64 = Type::getInt64Ty(Context);
141  Ops[0] = createString(Name);
142  for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
143    Ops[i * 2 + 1] = Fields[i].first;
144    Ops[i * 2 + 2] = createConstant(ConstantInt::get(Int64, Fields[i].second));
145  }
146  return MDNode::get(Context, Ops);
147}
148
149/// \brief Return metadata for a TBAA scalar type node with the
150/// given name, an offset and a parent in the TBAA type DAG.
151MDNode *MDBuilder::createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
152                                            uint64_t Offset) {
153  ConstantInt *Off = ConstantInt::get(Type::getInt64Ty(Context), Offset);
154  Metadata *Ops[3] = {createString(Name), Parent, createConstant(Off)};
155  return MDNode::get(Context, Ops);
156}
157
158/// \brief Return metadata for a TBAA tag node with the given
159/// base type, access type and offset relative to the base type.
160MDNode *MDBuilder::createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
161                                           uint64_t Offset) {
162  Type *Int64 = Type::getInt64Ty(Context);
163  Metadata *Ops[3] = {BaseType, AccessType,
164                      createConstant(ConstantInt::get(Int64, Offset))};
165  return MDNode::get(Context, Ops);
166}
167