1 //===-- Bitcode/Writer/ValueEnumerator.h - Number values --------*- 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 class gives values and types Unique ID's.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
15 #define LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
16 
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/UniqueVector.h"
20 #include "llvm/IR/Attributes.h"
21 #include "llvm/IR/Metadata.h"
22 #include "llvm/IR/Type.h"
23 #include "llvm/IR/UseListOrder.h"
24 #include <vector>
25 
26 namespace llvm {
27 
28 class Type;
29 class Value;
30 class Instruction;
31 class BasicBlock;
32 class Comdat;
33 class Function;
34 class Module;
35 class Metadata;
36 class LocalAsMetadata;
37 class MDNode;
38 class NamedMDNode;
39 class AttributeSet;
40 class ValueSymbolTable;
41 class MDSymbolTable;
42 class raw_ostream;
43 
44 class ValueEnumerator {
45 public:
46   typedef std::vector<Type*> TypeList;
47 
48   // For each value, we remember its Value* and occurrence frequency.
49   typedef std::vector<std::pair<const Value*, unsigned> > ValueList;
50 
51   UseListOrderStack UseListOrders;
52 
53 private:
54   typedef DenseMap<Type*, unsigned> TypeMapType;
55   TypeMapType TypeMap;
56   TypeList Types;
57 
58   typedef DenseMap<const Value*, unsigned> ValueMapType;
59   ValueMapType ValueMap;
60   ValueList Values;
61 
62   typedef UniqueVector<const Comdat *> ComdatSetType;
63   ComdatSetType Comdats;
64 
65   std::vector<const Metadata *> MDs;
66   typedef DenseMap<const Metadata *, unsigned> MetadataMapType;
67   MetadataMapType MetadataMap;
68   unsigned NumMDStrings = 0;
69   bool ShouldPreserveUseListOrder;
70 
71   typedef DenseMap<AttributeSet, unsigned> AttributeGroupMapType;
72   AttributeGroupMapType AttributeGroupMap;
73   std::vector<AttributeSet> AttributeGroups;
74 
75   typedef DenseMap<AttributeSet, unsigned> AttributeMapType;
76   AttributeMapType AttributeMap;
77   std::vector<AttributeSet> Attribute;
78 
79   /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
80   /// the "getGlobalBasicBlockID" method.
81   mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
82 
83   typedef DenseMap<const Instruction*, unsigned> InstructionMapType;
84   InstructionMapType InstructionMap;
85   unsigned InstructionCount;
86 
87   /// BasicBlocks - This contains all the basic blocks for the currently
88   /// incorporated function.  Their reverse mapping is stored in ValueMap.
89   std::vector<const BasicBlock*> BasicBlocks;
90 
91   /// When a function is incorporated, this is the size of the Values list
92   /// before incorporation.
93   unsigned NumModuleValues;
94 
95   /// When a function is incorporated, this is the size of the Metadatas list
96   /// before incorporation.
97   unsigned NumModuleMDs;
98 
99   unsigned FirstFuncConstantID;
100   unsigned FirstInstID;
101 
102   ValueEnumerator(const ValueEnumerator &) = delete;
103   void operator=(const ValueEnumerator &) = delete;
104 public:
105   ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
106 
107   void dump() const;
108   void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const;
109   void print(raw_ostream &OS, const MetadataMapType &Map,
110              const char *Name) const;
111 
112   unsigned getValueID(const Value *V) const;
113   unsigned getMetadataID(const Metadata *MD) const {
114     auto ID = getMetadataOrNullID(MD);
115     assert(ID != 0 && "Metadata not in slotcalculator!");
116     return ID - 1;
117   }
118   unsigned getMetadataOrNullID(const Metadata *MD) const {
119     return MetadataMap.lookup(MD);
120   }
121   unsigned numMDs() const { return MDs.size(); }
122 
123   bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
124 
125   unsigned getTypeID(Type *T) const {
126     TypeMapType::const_iterator I = TypeMap.find(T);
127     assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
128     return I->second-1;
129   }
130 
131   unsigned getInstructionID(const Instruction *I) const;
132   void setInstructionID(const Instruction *I);
133 
134   unsigned getAttributeID(AttributeSet PAL) const {
135     if (PAL.isEmpty()) return 0;  // Null maps to zero.
136     AttributeMapType::const_iterator I = AttributeMap.find(PAL);
137     assert(I != AttributeMap.end() && "Attribute not in ValueEnumerator!");
138     return I->second;
139   }
140 
141   unsigned getAttributeGroupID(AttributeSet PAL) const {
142     if (PAL.isEmpty()) return 0;  // Null maps to zero.
143     AttributeGroupMapType::const_iterator I = AttributeGroupMap.find(PAL);
144     assert(I != AttributeGroupMap.end() && "Attribute not in ValueEnumerator!");
145     return I->second;
146   }
147 
148   /// getFunctionConstantRange - Return the range of values that corresponds to
149   /// function-local constants.
150   void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
151     Start = FirstFuncConstantID;
152     End = FirstInstID;
153   }
154 
155   const ValueList &getValues() const { return Values; }
156   const std::vector<const Metadata *> &getMDs() const { return MDs; }
157   ArrayRef<const Metadata *> getMDStrings() const {
158     return makeArrayRef(MDs).slice(0, NumMDStrings);
159   }
160   ArrayRef<const Metadata *> getNonMDStrings() const {
161     return makeArrayRef(MDs).slice(NumMDStrings);
162   }
163   ArrayRef<const Metadata *> getFunctionMDs() const {
164     return makeArrayRef(MDs).slice(NumModuleMDs);
165   }
166 
167   const TypeList &getTypes() const { return Types; }
168   const std::vector<const BasicBlock*> &getBasicBlocks() const {
169     return BasicBlocks;
170   }
171   const std::vector<AttributeSet> &getAttributes() const {
172     return Attribute;
173   }
174   const std::vector<AttributeSet> &getAttributeGroups() const {
175     return AttributeGroups;
176   }
177 
178   const ComdatSetType &getComdats() const { return Comdats; }
179   unsigned getComdatID(const Comdat *C) const;
180 
181   /// getGlobalBasicBlockID - This returns the function-specific ID for the
182   /// specified basic block.  This is relatively expensive information, so it
183   /// should only be used by rare constructs such as address-of-label.
184   unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
185 
186   /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
187   /// use these two methods to get its data into the ValueEnumerator!
188   ///
189   void incorporateFunction(const Function &F);
190   void purgeFunction();
191   uint64_t computeBitsRequiredForTypeIndicies() const;
192 
193 private:
194   void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
195 
196   // Reorder the reachable metadata.  This is not just an optimization, but is
197   // mandatory for emitting MDString correctly.
198   void organizeMetadata();
199 
200   void EnumerateMDNodeOperands(const MDNode *N);
201   void EnumerateMetadata(const Metadata *MD);
202   void EnumerateFunctionLocalMetadata(const LocalAsMetadata *Local);
203   void EnumerateNamedMDNode(const NamedMDNode *NMD);
204   void EnumerateValue(const Value *V);
205   void EnumerateType(Type *T);
206   void EnumerateOperandType(const Value *V);
207   void EnumerateAttributes(AttributeSet PAL);
208 
209   void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
210   void EnumerateNamedMetadata(const Module &M);
211 };
212 
213 } // End llvm namespace
214 
215 #endif
216