LLVM  10.0.0svn
ValueEnumerator.h
Go to the documentation of this file.
1 //===- Bitcode/Writer/ValueEnumerator.h - Number values ---------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This class gives values and types Unique ID's.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
14 #define LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
15 
16 #include "llvm/ADT/ArrayRef.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"
23 #include <cassert>
24 #include <cstdint>
25 #include <utility>
26 #include <vector>
27 
28 namespace llvm {
29 
30 class BasicBlock;
31 class Comdat;
32 class Function;
33 class Instruction;
34 class LocalAsMetadata;
35 class MDNode;
36 class Metadata;
37 class Module;
38 class NamedMDNode;
39 class raw_ostream;
40 class Type;
41 class Value;
42 class ValueSymbolTable;
43 
45 public:
46  using TypeList = std::vector<Type *>;
47 
48  // For each value, we remember its Value* and occurrence frequency.
49  using ValueList = std::vector<std::pair<const Value *, unsigned>>;
50 
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  using IndexAndAttrSet = std::pair<unsigned, AttributeSet>;
54 
56 
57 private:
59  TypeMapType TypeMap;
60  TypeList Types;
61 
64  ValueList Values;
65 
67  ComdatSetType Comdats;
68 
69  std::vector<const Metadata *> MDs;
70  std::vector<const Metadata *> FunctionMDs;
71 
72  /// Index of information about a piece of metadata.
73  struct MDIndex {
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.
76 
77  MDIndex() = default;
78  explicit MDIndex(unsigned F) : F(F) {}
79 
80  /// Check if this has a function tag, and it's different from NewF.
81  bool hasDifferentFunction(unsigned NewF) const { return F && F != NewF; }
82 
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");
87  return MDs[ID - 1];
88  }
89  };
90 
92  MetadataMapType MetadataMap;
93 
94  /// Range of metadata IDs, as a half-open range.
95  struct MDRange {
96  unsigned First = 0;
97  unsigned Last = 0;
98 
99  /// Number of strings in the prefix of the metadata range.
100  unsigned NumStrings = 0;
101 
102  MDRange() = default;
103  explicit MDRange(unsigned First) : First(First) {}
104  };
106 
107  bool ShouldPreserveUseListOrder;
108 
110  AttributeGroupMapType AttributeGroupMap;
111  std::vector<IndexAndAttrSet> AttributeGroups;
112 
114  AttributeListMapType AttributeListMap;
115  std::vector<AttributeList> AttributeLists;
116 
117  /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
118  /// the "getGlobalBasicBlockID" method.
119  mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
120 
122  InstructionMapType InstructionMap;
123  unsigned InstructionCount;
124 
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;
128 
129  /// When a function is incorporated, this is the size of the Values list
130  /// before incorporation.
131  unsigned NumModuleValues;
132 
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;
137 
138  unsigned FirstFuncConstantID;
139  unsigned FirstInstID;
140 
141 public:
142  ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
143  ValueEnumerator(const ValueEnumerator &) = delete;
144  ValueEnumerator &operator=(const ValueEnumerator &) = delete;
145 
146  void dump() const;
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;
150 
151  unsigned getValueID(const Value *V) const;
152 
153  unsigned getMetadataID(const Metadata *MD) const {
154  auto ID = getMetadataOrNullID(MD);
155  assert(ID != 0 && "Metadata not in slotcalculator!");
156  return ID - 1;
157  }
158 
159  unsigned getMetadataOrNullID(const Metadata *MD) const {
160  return MetadataMap.lookup(MD).ID;
161  }
162 
163  unsigned numMDs() const { return MDs.size(); }
164 
165  bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
166 
167  unsigned getTypeID(Type *T) const {
168  TypeMapType::const_iterator I = TypeMap.find(T);
169  assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
170  return I->second-1;
171  }
172 
173  unsigned getInstructionID(const Instruction *I) const;
174  void setInstructionID(const Instruction *I);
175 
176  unsigned getAttributeListID(AttributeList PAL) const {
177  if (PAL.isEmpty()) return 0; // Null maps to zero.
178  AttributeListMapType::const_iterator I = AttributeListMap.find(PAL);
179  assert(I != AttributeListMap.end() && "Attribute not in ValueEnumerator!");
180  return I->second;
181  }
182 
183  unsigned getAttributeGroupID(IndexAndAttrSet Group) const {
184  if (!Group.second.hasAttributes())
185  return 0; // Null maps to zero.
186  AttributeGroupMapType::const_iterator I = AttributeGroupMap.find(Group);
187  assert(I != AttributeGroupMap.end() && "Attribute not in ValueEnumerator!");
188  return I->second;
189  }
190 
191  /// getFunctionConstantRange - Return the range of values that corresponds to
192  /// function-local constants.
193  void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
194  Start = FirstFuncConstantID;
195  End = FirstInstID;
196  }
197 
198  const ValueList &getValues() const { return Values; }
199 
200  /// Check whether the current block has any metadata to emit.
201  bool hasMDs() const { return NumModuleMDs < MDs.size(); }
202 
203  /// Get the MDString metadata for this block.
205  return makeArrayRef(MDs).slice(NumModuleMDs, NumMDStrings);
206  }
207 
208  /// Get the non-MDString metadata for this block.
210  return makeArrayRef(MDs).slice(NumModuleMDs).slice(NumMDStrings);
211  }
212 
213  const TypeList &getTypes() const { return Types; }
214 
215  const std::vector<const BasicBlock*> &getBasicBlocks() const {
216  return BasicBlocks;
217  }
218 
219  const std::vector<AttributeList> &getAttributeLists() const { return AttributeLists; }
220 
221  const std::vector<IndexAndAttrSet> &getAttributeGroups() const {
222  return AttributeGroups;
223  }
224 
225  const ComdatSetType &getComdats() const { return Comdats; }
226  unsigned getComdatID(const Comdat *C) const;
227 
228  /// getGlobalBasicBlockID - This returns the function-specific ID for the
229  /// specified basic block. This is relatively expensive information, so it
230  /// should only be used by rare constructs such as address-of-label.
231  unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
232 
233  /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
234  /// use these two methods to get its data into the ValueEnumerator!
235  void incorporateFunction(const Function &F);
236 
237  void purgeFunction();
238  uint64_t computeBitsRequiredForTypeIndicies() const;
239 
240 private:
241  void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
242 
243  /// Reorder the reachable metadata.
244  ///
245  /// This is not just an optimization, but is mandatory for emitting MDString
246  /// correctly.
247  void organizeMetadata();
248 
249  /// Drop the function tag from the transitive operands of the given node.
250  void dropFunctionFromMetadata(MetadataMapType::value_type &FirstMD);
251 
252  /// Incorporate the function metadata.
253  ///
254  /// This should be called before enumerating LocalAsMetadata for the
255  /// function.
256  void incorporateFunctionMetadata(const Function &F);
257 
258  /// Enumerate a single instance of metadata with the given function tag.
259  ///
260  /// If \c MD has already been enumerated, check that \c F matches its
261  /// function tag. If not, call \a dropFunctionFromMetadata().
262  ///
263  /// Otherwise, mark \c MD as visited. Assign it an ID, or just return it if
264  /// it's an \a MDNode.
265  const MDNode *enumerateMetadataImpl(unsigned F, const Metadata *MD);
266 
267  unsigned getMetadataFunctionID(const Function *F) const;
268 
269  /// Enumerate reachable metadata in (almost) post-order.
270  ///
271  /// Enumerate all the metadata reachable from MD. We want to minimize the
272  /// cost of reading bitcode records, and so the primary consideration is that
273  /// operands of uniqued nodes are resolved before the nodes are read. This
274  /// avoids re-uniquing them on the context and factors away RAUW support.
275  ///
276  /// This algorithm guarantees that subgraphs of uniqued nodes are in
277  /// post-order. Distinct subgraphs reachable only from a single uniqued node
278  /// will be in post-order.
279  ///
280  /// \note The relative order of a distinct and uniqued node is irrelevant.
281  /// \a organizeMetadata() will later partition distinct nodes ahead of
282  /// uniqued ones.
283  ///{
284  void EnumerateMetadata(const Function *F, const Metadata *MD);
285  void EnumerateMetadata(unsigned F, const Metadata *MD);
286  ///}
287 
288  void EnumerateFunctionLocalMetadata(const Function &F,
289  const LocalAsMetadata *Local);
290  void EnumerateFunctionLocalMetadata(unsigned F, const LocalAsMetadata *Local);
291  void EnumerateNamedMDNode(const NamedMDNode *NMD);
292  void EnumerateValue(const Value *V);
293  void EnumerateType(Type *T);
294  void EnumerateOperandType(const Value *V);
295  void EnumerateAttributes(AttributeList PAL);
296 
297  void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
298  void EnumerateNamedMetadata(const Module &M);
299 };
300 
301 } // end namespace llvm
302 
303 #endif // LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
uint64_t CallInst * C
This class provides a symbol table of name/value pairs.
unsigned getMetadataOrNullID(const Metadata *MD) const
unsigned getValueID(const Value *V) const
const ValueList & getValues() const
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Various leaf nodes.
Definition: ISDOpcodes.h:59
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:65
amdgpu Simplify well known AMD library false FunctionCallee Value const Twine & Name
std::pair< unsigned, AttributeSet > IndexAndAttrSet
Attribute groups as encoded in bitcode are almost AttributeSets, but they include the AttributeList i...
This file contains the declarations for metadata subclasses.
void setInstructionID(const Instruction *I)
bool shouldPreserveUseListOrder() const
Metadata node.
Definition: Metadata.h:863
F(f)
bool hasMDs() const
Check whether the current block has any metadata to emit.
unsigned getAttributeGroupID(IndexAndAttrSet Group) const
unsigned getMetadataID(const Metadata *MD) const
void incorporateFunction(const Function &F)
incorporateFunction/purgeFunction - If you&#39;d like to deal with a function, use these two methods to g...
A tuple of MDNodes.
Definition: Metadata.h:1325
ArrayRef< T > makeArrayRef(const T &OneElt)
Construct an ArrayRef from a single element.
Definition: ArrayRef.h:450
const TypeList & getTypes() const
This file contains the simple types necessary to represent the attributes associated with functions a...
uint64_t computeBitsRequiredForTypeIndicies() const
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
ArrayRef< const Metadata * > getMDStrings() const
Get the MDString metadata for this block.
iterator find(const_arg_type_t< KeyT > Val)
Definition: DenseMap.h:150
std::vector< Type * > TypeList
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const
unsigned getInstructionID(const Instruction *I) const
std::vector< UseListOrder > UseListOrderStack
Definition: UseListOrder.h:39
ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder)
unsigned getGlobalBasicBlockID(const BasicBlock *BB) const
getGlobalBasicBlockID - This returns the function-specific ID for the specified basic block...
const std::vector< AttributeList > & getAttributeLists() const
ArrayRef< const Metadata * > getNonMDStrings() const
Get the non-MDString metadata for this block.
void getFunctionConstantRange(unsigned &Start, unsigned &End) const
getFunctionConstantRange - Return the range of values that corresponds to function-local constants...
std::vector< std::pair< const Value *, unsigned > > ValueList
ValueEnumerator & operator=(const ValueEnumerator &)=delete
unsigned numMDs() const
const ComdatSetType & getComdats() const
See the file comment.
Definition: ValueMap.h:85
unsigned getTypeID(Type *T) const
UseListOrderStack UseListOrders
const std::vector< IndexAndAttrSet > & getAttributeGroups() const
const std::vector< const BasicBlock * > & getBasicBlocks() const
#define I(x, y, z)
Definition: MD5.cpp:58
iterator end()
Definition: DenseMap.h:82
ValueT lookup(const_arg_type_t< KeyT > Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:185
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
LLVM Value Representation.
Definition: Value.h:73
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
unsigned getComdatID(const Comdat *C) const
unsigned getAttributeListID(AttributeList PAL) const
bool isEmpty() const
Return true if there are no attributes.
Definition: Attributes.h:669
Root of the metadata hierarchy.
Definition: Metadata.h:57
UniqueVector - This class produces a sequential ID number (base 1) for each unique entry that is adde...
Definition: UniqueVector.h:24