1 //===-- Bitcode/Writer/ValueEnumerator.h - Number values --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This class gives values and types Unique ID's.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
15 #define LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/UniqueVector.h"
19 #include "llvm/IR/Attributes.h"
20 #include "llvm/IR/Metadata.h"
21 #include "llvm/IR/Type.h"
22 #include "llvm/IR/UseListOrder.h"
35 class LocalAsMetadata;
40 class ValueSymbolTable;
44 class ValueEnumerator {
46 typedef std::vector<Type*> TypeList;
48 // For each value, we remember its Value* and occurrence frequency.
49 typedef std::vector<std::pair<const Value*, unsigned> > ValueList;
51 /// Attribute groups as encoded in bitcode are almost AttributeSets, but they
52 /// include the AttributeList index, so we have to track that in our map.
53 typedef std::pair<unsigned, AttributeSet> IndexAndAttrSet;
55 UseListOrderStack UseListOrders;
58 typedef DenseMap<Type*, unsigned> TypeMapType;
62 typedef DenseMap<const Value*, unsigned> ValueMapType;
63 ValueMapType ValueMap;
66 typedef UniqueVector<const Comdat *> ComdatSetType;
67 ComdatSetType Comdats;
69 std::vector<const Metadata *> MDs;
70 std::vector<const Metadata *> FunctionMDs;
72 /// Index of information about a piece of metadata.
74 unsigned F = 0; ///< The ID of the function for this metadata, if any.
75 unsigned ID = 0; ///< The implicit ID of this metadata in bitcode.
78 explicit MDIndex(unsigned F) : F(F) {}
80 /// Check if this has a function tag, and it's different from NewF.
81 bool hasDifferentFunction(unsigned NewF) const { return F && F != NewF; }
83 /// Fetch the MD this references out of the given metadata array.
84 const Metadata *get(ArrayRef<const Metadata *> MDs) const {
85 assert(ID && "Expected non-zero ID");
86 assert(ID <= MDs.size() && "Expected valid ID");
91 typedef DenseMap<const Metadata *, MDIndex> MetadataMapType;
92 MetadataMapType MetadataMap;
94 /// Range of metadata IDs, as a half-open range.
99 /// Number of strings in the prefix of the metadata range.
100 unsigned NumStrings = 0;
103 explicit MDRange(unsigned First) : First(First) {}
105 SmallDenseMap<unsigned, MDRange, 1> FunctionMDInfo;
107 bool ShouldPreserveUseListOrder;
109 typedef DenseMap<IndexAndAttrSet, unsigned> AttributeGroupMapType;
110 AttributeGroupMapType AttributeGroupMap;
111 std::vector<IndexAndAttrSet> AttributeGroups;
113 typedef DenseMap<AttributeList, unsigned> AttributeListMapType;
114 AttributeListMapType AttributeListMap;
115 std::vector<AttributeList> AttributeLists;
117 /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
118 /// the "getGlobalBasicBlockID" method.
119 mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
121 typedef DenseMap<const Instruction*, unsigned> InstructionMapType;
122 InstructionMapType InstructionMap;
123 unsigned InstructionCount;
125 /// BasicBlocks - This contains all the basic blocks for the currently
126 /// incorporated function. Their reverse mapping is stored in ValueMap.
127 std::vector<const BasicBlock*> BasicBlocks;
129 /// When a function is incorporated, this is the size of the Values list
130 /// before incorporation.
131 unsigned NumModuleValues;
133 /// When a function is incorporated, this is the size of the Metadatas list
134 /// before incorporation.
135 unsigned NumModuleMDs = 0;
136 unsigned NumMDStrings = 0;
138 unsigned FirstFuncConstantID;
139 unsigned FirstInstID;
141 ValueEnumerator(const ValueEnumerator &) = delete;
142 void operator=(const ValueEnumerator &) = delete;
144 ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
147 void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const;
148 void print(raw_ostream &OS, const MetadataMapType &Map,
149 const char *Name) const;
151 unsigned getValueID(const Value *V) const;
152 unsigned getMetadataID(const Metadata *MD) const {
153 auto ID = getMetadataOrNullID(MD);
154 assert(ID != 0 && "Metadata not in slotcalculator!");
157 unsigned getMetadataOrNullID(const Metadata *MD) const {
158 return MetadataMap.lookup(MD).ID;
160 unsigned numMDs() const { return MDs.size(); }
162 bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
164 unsigned getTypeID(Type *T) const {
165 TypeMapType::const_iterator I = TypeMap.find(T);
166 assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
170 unsigned getInstructionID(const Instruction *I) const;
171 void setInstructionID(const Instruction *I);
173 unsigned getAttributeListID(AttributeList PAL) const {
174 if (PAL.isEmpty()) return 0; // Null maps to zero.
175 AttributeListMapType::const_iterator I = AttributeListMap.find(PAL);
176 assert(I != AttributeListMap.end() && "Attribute not in ValueEnumerator!");
180 unsigned getAttributeGroupID(IndexAndAttrSet Group) const {
181 if (!Group.second.hasAttributes())
182 return 0; // Null maps to zero.
183 AttributeGroupMapType::const_iterator I = AttributeGroupMap.find(Group);
184 assert(I != AttributeGroupMap.end() && "Attribute not in ValueEnumerator!");
188 /// getFunctionConstantRange - Return the range of values that corresponds to
189 /// function-local constants.
190 void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
191 Start = FirstFuncConstantID;
195 const ValueList &getValues() const { return Values; }
197 /// Check whether the current block has any metadata to emit.
198 bool hasMDs() const { return NumModuleMDs < MDs.size(); }
200 /// Get the MDString metadata for this block.
201 ArrayRef<const Metadata *> getMDStrings() const {
202 return makeArrayRef(MDs).slice(NumModuleMDs, NumMDStrings);
205 /// Get the non-MDString metadata for this block.
206 ArrayRef<const Metadata *> getNonMDStrings() const {
207 return makeArrayRef(MDs).slice(NumModuleMDs).slice(NumMDStrings);
210 const TypeList &getTypes() const { return Types; }
211 const std::vector<const BasicBlock*> &getBasicBlocks() const {
214 const std::vector<AttributeList> &getAttributeLists() const { return AttributeLists; }
215 const std::vector<IndexAndAttrSet> &getAttributeGroups() const {
216 return AttributeGroups;
219 const ComdatSetType &getComdats() const { return Comdats; }
220 unsigned getComdatID(const Comdat *C) const;
222 /// getGlobalBasicBlockID - This returns the function-specific ID for the
223 /// specified basic block. This is relatively expensive information, so it
224 /// should only be used by rare constructs such as address-of-label.
225 unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
227 /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
228 /// use these two methods to get its data into the ValueEnumerator!
230 void incorporateFunction(const Function &F);
231 void purgeFunction();
232 uint64_t computeBitsRequiredForTypeIndicies() const;
235 void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
237 /// Reorder the reachable metadata.
239 /// This is not just an optimization, but is mandatory for emitting MDString
241 void organizeMetadata();
243 /// Drop the function tag from the transitive operands of the given node.
244 void dropFunctionFromMetadata(MetadataMapType::value_type &FirstMD);
246 /// Incorporate the function metadata.
248 /// This should be called before enumerating LocalAsMetadata for the
250 void incorporateFunctionMetadata(const Function &F);
252 /// Enumerate a single instance of metadata with the given function tag.
254 /// If \c MD has already been enumerated, check that \c F matches its
255 /// function tag. If not, call \a dropFunctionFromMetadata().
257 /// Otherwise, mark \c MD as visited. Assign it an ID, or just return it if
258 /// it's an \a MDNode.
259 const MDNode *enumerateMetadataImpl(unsigned F, const Metadata *MD);
261 unsigned getMetadataFunctionID(const Function *F) const;
263 /// Enumerate reachable metadata in (almost) post-order.
265 /// Enumerate all the metadata reachable from MD. We want to minimize the
266 /// cost of reading bitcode records, and so the primary consideration is that
267 /// operands of uniqued nodes are resolved before the nodes are read. This
268 /// avoids re-uniquing them on the context and factors away RAUW support.
270 /// This algorithm guarantees that subgraphs of uniqued nodes are in
271 /// post-order. Distinct subgraphs reachable only from a single uniqued node
272 /// will be in post-order.
274 /// \note The relative order of a distinct and uniqued node is irrelevant.
275 /// \a organizeMetadata() will later partition distinct nodes ahead of
278 void EnumerateMetadata(const Function *F, const Metadata *MD);
279 void EnumerateMetadata(unsigned F, const Metadata *MD);
282 void EnumerateFunctionLocalMetadata(const Function &F,
283 const LocalAsMetadata *Local);
284 void EnumerateFunctionLocalMetadata(unsigned F, const LocalAsMetadata *Local);
285 void EnumerateNamedMDNode(const NamedMDNode *NMD);
286 void EnumerateValue(const Value *V);
287 void EnumerateType(Type *T);
288 void EnumerateOperandType(const Value *V);
289 void EnumerateAttributes(AttributeList PAL);
291 void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
292 void EnumerateNamedMetadata(const Module &M);
295 } // End llvm namespace