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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/Function.h"
18 #include "llvm/IR/Metadata.h"
19 using namespace llvm;
20 
createString(StringRef Str)21 MDString *MDBuilder::createString(StringRef Str) {
22   return MDString::get(Context, Str);
23 }
24 
createConstant(Constant * C)25 ConstantAsMetadata *MDBuilder::createConstant(Constant *C) {
26   return ConstantAsMetadata::get(C);
27 }
28 
createFPMath(float Accuracy)29 MDNode *MDBuilder::createFPMath(float Accuracy) {
30   if (Accuracy == 0.0)
31     return nullptr;
32   assert(Accuracy > 0.0 && "Invalid fpmath accuracy!");
33   auto *Op =
34       createConstant(ConstantFP::get(Type::getFloatTy(Context), Accuracy));
35   return MDNode::get(Context, Op);
36 }
37 
createBranchWeights(uint32_t TrueWeight,uint32_t FalseWeight)38 MDNode *MDBuilder::createBranchWeights(uint32_t TrueWeight,
39                                        uint32_t FalseWeight) {
40   return createBranchWeights({TrueWeight, FalseWeight});
41 }
42 
createBranchWeights(ArrayRef<uint32_t> Weights)43 MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights) {
44   assert(Weights.size() >= 1 && "Need at least one 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 
createUnpredictable()56 MDNode *MDBuilder::createUnpredictable() {
57   return MDNode::get(Context, None);
58 }
59 
createFunctionEntryCount(uint64_t Count,bool Synthetic,const DenseSet<GlobalValue::GUID> * Imports)60 MDNode *MDBuilder::createFunctionEntryCount(
61     uint64_t Count, bool Synthetic,
62     const DenseSet<GlobalValue::GUID> *Imports) {
63   Type *Int64Ty = Type::getInt64Ty(Context);
64   SmallVector<Metadata *, 8> Ops;
65   if (Synthetic)
66     Ops.push_back(createString("synthetic_function_entry_count"));
67   else
68     Ops.push_back(createString("function_entry_count"));
69   Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
70   if (Imports) {
71     SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());
72     std::stable_sort(OrderID.begin(), OrderID.end(),
73       [] (GlobalValue::GUID A, GlobalValue::GUID B) {
74         return A < B;});
75     for (auto ID : OrderID)
76       Ops.push_back(createConstant(ConstantInt::get(Int64Ty, ID)));
77   }
78   return MDNode::get(Context, Ops);
79 }
80 
createFunctionSectionPrefix(StringRef Prefix)81 MDNode *MDBuilder::createFunctionSectionPrefix(StringRef Prefix) {
82   return MDNode::get(Context,
83                      {createString("function_section_prefix"),
84                       createString(Prefix)});
85 }
86 
createRange(const APInt & Lo,const APInt & Hi)87 MDNode *MDBuilder::createRange(const APInt &Lo, const APInt &Hi) {
88   assert(Lo.getBitWidth() == Hi.getBitWidth() && "Mismatched bitwidths!");
89 
90   Type *Ty = IntegerType::get(Context, Lo.getBitWidth());
91   return createRange(ConstantInt::get(Ty, Lo), ConstantInt::get(Ty, Hi));
92 }
93 
createRange(Constant * Lo,Constant * Hi)94 MDNode *MDBuilder::createRange(Constant *Lo, Constant *Hi) {
95   // If the range is everything then it is useless.
96   if (Hi == Lo)
97     return nullptr;
98 
99   // Return the range [Lo, Hi).
100   return MDNode::get(Context, {createConstant(Lo), createConstant(Hi)});
101 }
102 
createCallees(ArrayRef<Function * > Callees)103 MDNode *MDBuilder::createCallees(ArrayRef<Function *> Callees) {
104   SmallVector<Metadata *, 4> Ops;
105   for (Function *F : Callees)
106     Ops.push_back(createConstant(F));
107   return MDNode::get(Context, Ops);
108 }
109 
createAnonymousAARoot(StringRef Name,MDNode * Extra)110 MDNode *MDBuilder::createAnonymousAARoot(StringRef Name, MDNode *Extra) {
111   // To ensure uniqueness the root node is self-referential.
112   auto Dummy = MDNode::getTemporary(Context, None);
113 
114   SmallVector<Metadata *, 3> Args(1, Dummy.get());
115   if (Extra)
116     Args.push_back(Extra);
117   if (!Name.empty())
118     Args.push_back(createString(Name));
119   MDNode *Root = MDNode::get(Context, Args);
120 
121   // At this point we have
122   //   !0 = metadata !{}            <- dummy
123   //   !1 = metadata !{metadata !0} <- root
124   // Replace the dummy operand with the root node itself and delete the dummy.
125   Root->replaceOperandWith(0, Root);
126 
127   // We now have
128   //   !1 = metadata !{metadata !1} <- self-referential root
129   return Root;
130 }
131 
createTBAARoot(StringRef Name)132 MDNode *MDBuilder::createTBAARoot(StringRef Name) {
133   return MDNode::get(Context, createString(Name));
134 }
135 
136 /// Return metadata for a non-root TBAA node with the given name,
137 /// parent in the TBAA tree, and value for 'pointsToConstantMemory'.
createTBAANode(StringRef Name,MDNode * Parent,bool isConstant)138 MDNode *MDBuilder::createTBAANode(StringRef Name, MDNode *Parent,
139                                   bool isConstant) {
140   if (isConstant) {
141     Constant *Flags = ConstantInt::get(Type::getInt64Ty(Context), 1);
142     return MDNode::get(Context,
143                        {createString(Name), Parent, createConstant(Flags)});
144   }
145   return MDNode::get(Context, {createString(Name), Parent});
146 }
147 
createAliasScopeDomain(StringRef Name)148 MDNode *MDBuilder::createAliasScopeDomain(StringRef Name) {
149   return MDNode::get(Context, createString(Name));
150 }
151 
createAliasScope(StringRef Name,MDNode * Domain)152 MDNode *MDBuilder::createAliasScope(StringRef Name, MDNode *Domain) {
153   return MDNode::get(Context, {createString(Name), Domain});
154 }
155 
156 /// Return metadata for a tbaa.struct node with the given
157 /// struct field descriptions.
createTBAAStructNode(ArrayRef<TBAAStructField> Fields)158 MDNode *MDBuilder::createTBAAStructNode(ArrayRef<TBAAStructField> Fields) {
159   SmallVector<Metadata *, 4> Vals(Fields.size() * 3);
160   Type *Int64 = Type::getInt64Ty(Context);
161   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
162     Vals[i * 3 + 0] = createConstant(ConstantInt::get(Int64, Fields[i].Offset));
163     Vals[i * 3 + 1] = createConstant(ConstantInt::get(Int64, Fields[i].Size));
164     Vals[i * 3 + 2] = Fields[i].Type;
165   }
166   return MDNode::get(Context, Vals);
167 }
168 
169 /// Return metadata for a TBAA struct node in the type DAG
170 /// with the given name, a list of pairs (offset, field type in the type DAG).
createTBAAStructTypeNode(StringRef Name,ArrayRef<std::pair<MDNode *,uint64_t>> Fields)171 MDNode *MDBuilder::createTBAAStructTypeNode(
172     StringRef Name, ArrayRef<std::pair<MDNode *, uint64_t>> Fields) {
173   SmallVector<Metadata *, 4> Ops(Fields.size() * 2 + 1);
174   Type *Int64 = Type::getInt64Ty(Context);
175   Ops[0] = createString(Name);
176   for (unsigned i = 0, e = Fields.size(); i != e; ++i) {
177     Ops[i * 2 + 1] = Fields[i].first;
178     Ops[i * 2 + 2] = createConstant(ConstantInt::get(Int64, Fields[i].second));
179   }
180   return MDNode::get(Context, Ops);
181 }
182 
183 /// Return metadata for a TBAA scalar type node with the
184 /// given name, an offset and a parent in the TBAA type DAG.
createTBAAScalarTypeNode(StringRef Name,MDNode * Parent,uint64_t Offset)185 MDNode *MDBuilder::createTBAAScalarTypeNode(StringRef Name, MDNode *Parent,
186                                             uint64_t Offset) {
187   ConstantInt *Off = ConstantInt::get(Type::getInt64Ty(Context), Offset);
188   return MDNode::get(Context,
189                      {createString(Name), Parent, createConstant(Off)});
190 }
191 
192 /// Return metadata for a TBAA tag node with the given
193 /// base type, access type and offset relative to the base type.
createTBAAStructTagNode(MDNode * BaseType,MDNode * AccessType,uint64_t Offset,bool IsConstant)194 MDNode *MDBuilder::createTBAAStructTagNode(MDNode *BaseType, MDNode *AccessType,
195                                            uint64_t Offset, bool IsConstant) {
196   IntegerType *Int64 = Type::getInt64Ty(Context);
197   ConstantInt *Off = ConstantInt::get(Int64, Offset);
198   if (IsConstant) {
199     return MDNode::get(Context, {BaseType, AccessType, createConstant(Off),
200                                  createConstant(ConstantInt::get(Int64, 1))});
201   }
202   return MDNode::get(Context, {BaseType, AccessType, createConstant(Off)});
203 }
204 
createTBAATypeNode(MDNode * Parent,uint64_t Size,Metadata * Id,ArrayRef<TBAAStructField> Fields)205 MDNode *MDBuilder::createTBAATypeNode(MDNode *Parent, uint64_t Size,
206                                       Metadata *Id,
207                                       ArrayRef<TBAAStructField> Fields) {
208   SmallVector<Metadata *, 4> Ops(3 + Fields.size() * 3);
209   Type *Int64 = Type::getInt64Ty(Context);
210   Ops[0] = Parent;
211   Ops[1] = createConstant(ConstantInt::get(Int64, Size));
212   Ops[2] = Id;
213   for (unsigned I = 0, E = Fields.size(); I != E; ++I) {
214     Ops[I * 3 + 3] = Fields[I].Type;
215     Ops[I * 3 + 4] = createConstant(ConstantInt::get(Int64, Fields[I].Offset));
216     Ops[I * 3 + 5] = createConstant(ConstantInt::get(Int64, Fields[I].Size));
217   }
218   return MDNode::get(Context, Ops);
219 }
220 
createTBAAAccessTag(MDNode * BaseType,MDNode * AccessType,uint64_t Offset,uint64_t Size,bool IsImmutable)221 MDNode *MDBuilder::createTBAAAccessTag(MDNode *BaseType, MDNode *AccessType,
222                                        uint64_t Offset, uint64_t Size,
223                                        bool IsImmutable) {
224   IntegerType *Int64 = Type::getInt64Ty(Context);
225   auto *OffsetNode = createConstant(ConstantInt::get(Int64, Offset));
226   auto *SizeNode = createConstant(ConstantInt::get(Int64, Size));
227   if (IsImmutable) {
228     auto *ImmutabilityFlagNode = createConstant(ConstantInt::get(Int64, 1));
229     return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode,
230                                  ImmutabilityFlagNode});
231   }
232   return MDNode::get(Context, {BaseType, AccessType, OffsetNode, SizeNode});
233 }
234 
createMutableTBAAAccessTag(MDNode * Tag)235 MDNode *MDBuilder::createMutableTBAAAccessTag(MDNode *Tag) {
236   MDNode *BaseType = cast<MDNode>(Tag->getOperand(0));
237   MDNode *AccessType = cast<MDNode>(Tag->getOperand(1));
238   Metadata *OffsetNode = Tag->getOperand(2);
239   uint64_t Offset = mdconst::extract<ConstantInt>(OffsetNode)->getZExtValue();
240 
241   bool NewFormat = isa<MDNode>(AccessType->getOperand(0));
242 
243   // See if the tag is already mutable.
244   unsigned ImmutabilityFlagOp = NewFormat ? 4 : 3;
245   if (Tag->getNumOperands() <= ImmutabilityFlagOp)
246     return Tag;
247 
248   // If Tag is already mutable then return it.
249   Metadata *ImmutabilityFlagNode = Tag->getOperand(ImmutabilityFlagOp);
250   if (!mdconst::extract<ConstantInt>(ImmutabilityFlagNode)->getValue())
251     return Tag;
252 
253   // Otherwise, create another node.
254   if (!NewFormat)
255     return createTBAAStructTagNode(BaseType, AccessType, Offset);
256 
257   Metadata *SizeNode = Tag->getOperand(3);
258   uint64_t Size = mdconst::extract<ConstantInt>(SizeNode)->getZExtValue();
259   return createTBAAAccessTag(BaseType, AccessType, Offset, Size);
260 }
261 
createIrrLoopHeaderWeight(uint64_t Weight)262 MDNode *MDBuilder::createIrrLoopHeaderWeight(uint64_t Weight) {
263   SmallVector<Metadata *, 2> Vals(2);
264   Vals[0] = createString("loop_header_weight");
265   Vals[1] = createConstant(ConstantInt::get(Type::getInt64Ty(Context), Weight));
266   return MDNode::get(Context, Vals);
267 }
268