LLVM  4.0.0
ValueEnumerator.h
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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/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"
23 #include <vector>
24 
25 namespace llvm {
26 
27 class Type;
28 class Value;
29 class Instruction;
30 class BasicBlock;
31 class Comdat;
32 class Function;
33 class Module;
34 class Metadata;
35 class LocalAsMetadata;
36 class MDNode;
37 class MDOperand;
38 class NamedMDNode;
39 class AttributeSet;
40 class ValueSymbolTable;
41 class MDSymbolTable;
42 class raw_ostream;
43 
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 
52 
53 private:
55  TypeMapType TypeMap;
56  TypeList Types;
57 
60  ValueList Values;
61 
63  ComdatSetType Comdats;
64 
65  std::vector<const Metadata *> MDs;
66  std::vector<const Metadata *> FunctionMDs;
67 
68  /// Index of information about a piece of metadata.
69  struct MDIndex {
70  unsigned F = 0; ///< The ID of the function for this metadata, if any.
71  unsigned ID = 0; ///< The implicit ID of this metadata in bitcode.
72 
73  MDIndex() = default;
74  explicit MDIndex(unsigned F) : F(F) {}
75 
76  /// Check if this has a function tag, and it's different from NewF.
77  bool hasDifferentFunction(unsigned NewF) const { return F && F != NewF; }
78 
79  /// Fetch the MD this references out of the given metadata array.
80  const Metadata *get(ArrayRef<const Metadata *> MDs) const {
81  assert(ID && "Expected non-zero ID");
82  assert(ID <= MDs.size() && "Expected valid ID");
83  return MDs[ID - 1];
84  }
85  };
86 
87  typedef DenseMap<const Metadata *, MDIndex> MetadataMapType;
88  MetadataMapType MetadataMap;
89 
90  /// Range of metadata IDs, as a half-open range.
91  struct MDRange {
92  unsigned First = 0;
93  unsigned Last = 0;
94 
95  /// Number of strings in the prefix of the metadata range.
96  unsigned NumStrings = 0;
97 
98  MDRange() {}
99  explicit MDRange(unsigned First) : First(First) {}
100  };
101  SmallDenseMap<unsigned, MDRange, 1> FunctionMDInfo;
102 
103  bool ShouldPreserveUseListOrder;
104 
105  typedef DenseMap<AttributeSet, unsigned> AttributeGroupMapType;
106  AttributeGroupMapType AttributeGroupMap;
107  std::vector<AttributeSet> AttributeGroups;
108 
109  typedef DenseMap<AttributeSet, unsigned> AttributeMapType;
110  AttributeMapType AttributeMap;
111  std::vector<AttributeSet> Attribute;
112 
113  /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
114  /// the "getGlobalBasicBlockID" method.
115  mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
116 
117  typedef DenseMap<const Instruction*, unsigned> InstructionMapType;
118  InstructionMapType InstructionMap;
119  unsigned InstructionCount;
120 
121  /// BasicBlocks - This contains all the basic blocks for the currently
122  /// incorporated function. Their reverse mapping is stored in ValueMap.
123  std::vector<const BasicBlock*> BasicBlocks;
124 
125  /// When a function is incorporated, this is the size of the Values list
126  /// before incorporation.
127  unsigned NumModuleValues;
128 
129  /// When a function is incorporated, this is the size of the Metadatas list
130  /// before incorporation.
131  unsigned NumModuleMDs = 0;
132  unsigned NumMDStrings = 0;
133 
134  unsigned FirstFuncConstantID;
135  unsigned FirstInstID;
136 
137  ValueEnumerator(const ValueEnumerator &) = delete;
138  void operator=(const ValueEnumerator &) = delete;
139 public:
140  ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
141 
142  void dump() const;
143  void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const;
144  void print(raw_ostream &OS, const MetadataMapType &Map,
145  const char *Name) const;
146 
147  unsigned getValueID(const Value *V) const;
148  unsigned getMetadataID(const Metadata *MD) const {
149  auto ID = getMetadataOrNullID(MD);
150  assert(ID != 0 && "Metadata not in slotcalculator!");
151  return ID - 1;
152  }
153  unsigned getMetadataOrNullID(const Metadata *MD) const {
154  return MetadataMap.lookup(MD).ID;
155  }
156  unsigned numMDs() const { return MDs.size(); }
157 
158  bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
159 
160  unsigned getTypeID(Type *T) const {
161  TypeMapType::const_iterator I = TypeMap.find(T);
162  assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
163  return I->second-1;
164  }
165 
166  unsigned getInstructionID(const Instruction *I) const;
167  void setInstructionID(const Instruction *I);
168 
169  unsigned getAttributeID(AttributeSet PAL) const {
170  if (PAL.isEmpty()) return 0; // Null maps to zero.
171  AttributeMapType::const_iterator I = AttributeMap.find(PAL);
172  assert(I != AttributeMap.end() && "Attribute not in ValueEnumerator!");
173  return I->second;
174  }
175 
176  unsigned getAttributeGroupID(AttributeSet PAL) const {
177  if (PAL.isEmpty()) return 0; // Null maps to zero.
178  AttributeGroupMapType::const_iterator I = AttributeGroupMap.find(PAL);
179  assert(I != AttributeGroupMap.end() && "Attribute not in ValueEnumerator!");
180  return I->second;
181  }
182 
183  /// getFunctionConstantRange - Return the range of values that corresponds to
184  /// function-local constants.
185  void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
186  Start = FirstFuncConstantID;
187  End = FirstInstID;
188  }
189 
190  const ValueList &getValues() const { return Values; }
191 
192  /// Check whether the current block has any metadata to emit.
193  bool hasMDs() const { return NumModuleMDs < MDs.size(); }
194 
195  /// Get the MDString metadata for this block.
197  return makeArrayRef(MDs).slice(NumModuleMDs, NumMDStrings);
198  }
199 
200  /// Get the non-MDString metadata for this block.
202  return makeArrayRef(MDs).slice(NumModuleMDs).slice(NumMDStrings);
203  }
204 
205  const TypeList &getTypes() const { return Types; }
206  const std::vector<const BasicBlock*> &getBasicBlocks() const {
207  return BasicBlocks;
208  }
209  const std::vector<AttributeSet> &getAttributes() const {
210  return Attribute;
211  }
212  const std::vector<AttributeSet> &getAttributeGroups() const {
213  return AttributeGroups;
214  }
215 
216  const ComdatSetType &getComdats() const { return Comdats; }
217  unsigned getComdatID(const Comdat *C) const;
218 
219  /// getGlobalBasicBlockID - This returns the function-specific ID for the
220  /// specified basic block. This is relatively expensive information, so it
221  /// should only be used by rare constructs such as address-of-label.
222  unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
223 
224  /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
225  /// use these two methods to get its data into the ValueEnumerator!
226  ///
227  void incorporateFunction(const Function &F);
228  void purgeFunction();
229  uint64_t computeBitsRequiredForTypeIndicies() const;
230 
231 private:
232  void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
233 
234  /// Reorder the reachable metadata.
235  ///
236  /// This is not just an optimization, but is mandatory for emitting MDString
237  /// correctly.
238  void organizeMetadata();
239 
240  /// Drop the function tag from the transitive operands of the given node.
241  void dropFunctionFromMetadata(MetadataMapType::value_type &FirstMD);
242 
243  /// Incorporate the function metadata.
244  ///
245  /// This should be called before enumerating LocalAsMetadata for the
246  /// function.
247  void incorporateFunctionMetadata(const Function &F);
248 
249  /// Enumerate a single instance of metadata with the given function tag.
250  ///
251  /// If \c MD has already been enumerated, check that \c F matches its
252  /// function tag. If not, call \a dropFunctionFromMetadata().
253  ///
254  /// Otherwise, mark \c MD as visited. Assign it an ID, or just return it if
255  /// it's an \a MDNode.
256  const MDNode *enumerateMetadataImpl(unsigned F, const Metadata *MD);
257 
258  unsigned getMetadataFunctionID(const Function *F) const;
259 
260  /// Enumerate reachable metadata in (almost) post-order.
261  ///
262  /// Enumerate all the metadata reachable from MD. We want to minimize the
263  /// cost of reading bitcode records, and so the primary consideration is that
264  /// operands of uniqued nodes are resolved before the nodes are read. This
265  /// avoids re-uniquing them on the context and factors away RAUW support.
266  ///
267  /// This algorithm guarantees that subgraphs of uniqued nodes are in
268  /// post-order. Distinct subgraphs reachable only from a single uniqued node
269  /// will be in post-order.
270  ///
271  /// \note The relative order of a distinct and uniqued node is irrelevant.
272  /// \a organizeMetadata() will later partition distinct nodes ahead of
273  /// uniqued ones.
274  ///{
275  void EnumerateMetadata(const Function *F, const Metadata *MD);
276  void EnumerateMetadata(unsigned F, const Metadata *MD);
277  ///}
278 
279  void EnumerateFunctionLocalMetadata(const Function &F,
280  const LocalAsMetadata *Local);
281  void EnumerateFunctionLocalMetadata(unsigned F, const LocalAsMetadata *Local);
282  void EnumerateNamedMDNode(const NamedMDNode *NMD);
283  void EnumerateValue(const Value *V);
284  void EnumerateType(Type *T);
285  void EnumerateOperandType(const Value *V);
286  void EnumerateAttributes(AttributeSet PAL);
287 
288  void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
289  void EnumerateNamedMetadata(const Module &M);
290 };
291 
292 } // End llvm namespace
293 
294 #endif
ArrayRef< const Metadata * > getNonMDStrings() const
Get the non-MDString metadata for this block.
This class provides a symbol table of name/value pairs.
const ComdatSetType & getComdats() const
ValueT lookup(const KeyT &Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:162
Various leaf nodes.
Definition: ISDOpcodes.h:60
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:52
This file contains the declarations for metadata subclasses.
void setInstructionID(const Instruction *I)
Metadata node.
Definition: Metadata.h:830
std::vector< std::pair< const Value *, unsigned > > ValueList
void incorporateFunction(const Function &F)
incorporateFunction/purgeFunction - If you'd like to deal with a function, use these two methods to g...
ArrayRef< const Metadata * > getMDStrings() const
Get the MDString metadata for this block.
A tuple of MDNodes.
Definition: Metadata.h:1282
unsigned getComdatID(const Comdat *C) const
bool hasMDs() const
Check whether the current block has any metadata to emit.
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:440
std::vector< UseListOrder > UseListOrderStack
Definition: UseListOrder.h:41
This file contains the simple types necessary to represent the attributes associated with functions a...
uint64_t computeBitsRequiredForTypeIndicies() const
unsigned getAttributeID(AttributeSet PAL) const
#define F(x, y, z)
Definition: MD5.cpp:51
const TypeList & getTypes() const
unsigned getInstructionID(const Instruction *I) const
unsigned getValueID(const Value *V) const
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
void getFunctionConstantRange(unsigned &Start, unsigned &End) const
getFunctionConstantRange - Return the range of values that corresponds to function-local constants...
const ValueList & getValues() const
bool shouldPreserveUseListOrder() const
const std::vector< AttributeSet > & getAttributes() const
unsigned getTypeID(Type *T) const
LLVM Basic Block Representation.
Definition: BasicBlock.h:51
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
unsigned getAttributeGroupID(AttributeSet PAL) const
static const unsigned End
unsigned numMDs() const
See the file comment.
Definition: ValueMap.h:87
const std::vector< AttributeSet > & getAttributeGroups() const
const std::vector< const BasicBlock * > & getBasicBlocks() const
static GCRegistry::Add< ShadowStackGC > C("shadow-stack","Very portable GC for uncooperative code generators")
unsigned getMetadataID(const Metadata *MD) const
UseListOrderStack UseListOrders
unsigned getMetadataOrNullID(const Metadata *MD) const
void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const
#define I(x, y, z)
Definition: MD5.cpp:54
iterator end()
Definition: DenseMap.h:69
iterator find(const KeyT &Val)
Definition: DenseMap.h:127
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
unsigned getGlobalBasicBlockID(const BasicBlock *BB) const
getGlobalBasicBlockID - This returns the function-specific ID for the specified basic block...
LLVM Value Representation.
Definition: Value.h:71
std::vector< Type * > TypeList
Root of the metadata hierarchy.
Definition: Metadata.h:55
bool isEmpty() const
Return true if there are no attributes.
Definition: Attributes.h:400
BucketT value_type
Definition: DenseMap.h:60