Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/lib/Bitcode/Writer/ValueEnumerator.h
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//===- Bitcode/Writer/ValueEnumerator.h - Number values ---------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This class gives values and types Unique ID's.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
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#define LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/UniqueVector.h"
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#include "llvm/IR/Attributes.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/IR/Type.h"
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#include "llvm/IR/UseListOrder.h"
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#include <cassert>
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#include <cstdint>
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#include <utility>
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#include <vector>
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namespace llvm {
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class BasicBlock;
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class Comdat;
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class Function;
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class Instruction;
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class LocalAsMetadata;
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class MDNode;
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class Metadata;
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class Module;
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class NamedMDNode;
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class raw_ostream;
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class Type;
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class Value;
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class ValueSymbolTable;
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class ValueEnumerator {
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public:
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  using TypeList = std::vector<Type *>;
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  // For each value, we remember its Value* and occurrence frequency.
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  using ValueList = std::vector<std::pair<const Value *, unsigned>>;
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  /// Attribute groups as encoded in bitcode are almost AttributeSets, but they
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  /// include the AttributeList index, so we have to track that in our map.
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  using IndexAndAttrSet = std::pair<unsigned, AttributeSet>;
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  UseListOrderStack UseListOrders;
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private:
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  using TypeMapType = DenseMap<Type *, unsigned>;
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  TypeMapType TypeMap;
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  TypeList Types;
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  using ValueMapType = DenseMap<const Value *, unsigned>;
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  ValueMapType ValueMap;
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  ValueList Values;
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  using ComdatSetType = UniqueVector<const Comdat *>;
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  ComdatSetType Comdats;
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  std::vector<const Metadata *> MDs;
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  std::vector<const Metadata *> FunctionMDs;
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  /// Index of information about a piece of metadata.
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  struct MDIndex {
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    unsigned F = 0;  ///< The ID of the function for this metadata, if any.
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    unsigned ID = 0; ///< The implicit ID of this metadata in bitcode.
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    MDIndex() = default;
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    explicit MDIndex(unsigned F) : F(F) {}
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    /// Check if this has a function tag, and it's different from NewF.
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    bool hasDifferentFunction(unsigned NewF) const { return F && 
F != NewF10.0k
; }
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    /// Fetch the MD this references out of the given metadata array.
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    const Metadata *get(ArrayRef<const Metadata *> MDs) const {
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      assert(ID && "Expected non-zero ID");
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      assert(ID <= MDs.size() && "Expected valid ID");
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      return MDs[ID - 1];
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    }
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  };
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  using MetadataMapType = DenseMap<const Metadata *, MDIndex>;
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  MetadataMapType MetadataMap;
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  /// Range of metadata IDs, as a half-open range.
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  struct MDRange {
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    unsigned First = 0;
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    unsigned Last = 0;
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    /// Number of strings in the prefix of the metadata range.
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    unsigned NumStrings = 0;
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    MDRange() = default;
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    explicit MDRange(unsigned First) : First(First) {}
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  };
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  SmallDenseMap<unsigned, MDRange, 1> FunctionMDInfo;
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  bool ShouldPreserveUseListOrder;
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  using AttributeGroupMapType = DenseMap<IndexAndAttrSet, unsigned>;
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  AttributeGroupMapType AttributeGroupMap;
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  std::vector<IndexAndAttrSet> AttributeGroups;
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  using AttributeListMapType = DenseMap<AttributeList, unsigned>;
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  AttributeListMapType AttributeListMap;
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  std::vector<AttributeList> AttributeLists;
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  /// GlobalBasicBlockIDs - This map memoizes the basic block ID's referenced by
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  /// the "getGlobalBasicBlockID" method.
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  mutable DenseMap<const BasicBlock*, unsigned> GlobalBasicBlockIDs;
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  using InstructionMapType = DenseMap<const Instruction *, unsigned>;
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  InstructionMapType InstructionMap;
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  unsigned InstructionCount;
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  /// BasicBlocks - This contains all the basic blocks for the currently
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  /// incorporated function.  Their reverse mapping is stored in ValueMap.
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  std::vector<const BasicBlock*> BasicBlocks;
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  /// When a function is incorporated, this is the size of the Values list
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  /// before incorporation.
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  unsigned NumModuleValues;
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  /// When a function is incorporated, this is the size of the Metadatas list
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  /// before incorporation.
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  unsigned NumModuleMDs = 0;
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  unsigned NumMDStrings = 0;
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  unsigned FirstFuncConstantID;
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  unsigned FirstInstID;
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public:
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  ValueEnumerator(const Module &M, bool ShouldPreserveUseListOrder);
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  ValueEnumerator(const ValueEnumerator &) = delete;
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  ValueEnumerator &operator=(const ValueEnumerator &) = delete;
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  void dump() const;
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  void print(raw_ostream &OS, const ValueMapType &Map, const char *Name) const;
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  void print(raw_ostream &OS, const MetadataMapType &Map,
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             const char *Name) const;
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  unsigned getValueID(const Value *V) const;
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  unsigned getMetadataID(const Metadata *MD) const {
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    auto ID = getMetadataOrNullID(MD);
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    assert(ID != 0 && "Metadata not in slotcalculator!");
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    return ID - 1;
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  }
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  unsigned getMetadataOrNullID(const Metadata *MD) const {
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    return MetadataMap.lookup(MD).ID;
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  }
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  unsigned numMDs() const { return MDs.size(); }
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  bool shouldPreserveUseListOrder() const { return ShouldPreserveUseListOrder; }
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  unsigned getTypeID(Type *T) const {
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    TypeMapType::const_iterator I = TypeMap.find(T);
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    assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
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    return I->second-1;
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  }
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  unsigned getInstructionID(const Instruction *I) const;
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  void setInstructionID(const Instruction *I);
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  unsigned getAttributeListID(AttributeList PAL) const {
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    if (PAL.isEmpty()) 
return 027.5k
; // Null maps to zero.
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    AttributeListMapType::const_iterator I = AttributeListMap.find(PAL);
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    assert(I != AttributeListMap.end() && "Attribute not in ValueEnumerator!");
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    return I->second;
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  }
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  unsigned getAttributeGroupID(IndexAndAttrSet Group) const {
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    if (!Group.second.hasAttributes())
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      return 0; // Null maps to zero.
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    AttributeGroupMapType::const_iterator I = AttributeGroupMap.find(Group);
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    assert(I != AttributeGroupMap.end() && "Attribute not in ValueEnumerator!");
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    return I->second;
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  }
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  /// getFunctionConstantRange - Return the range of values that corresponds to
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  /// function-local constants.
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  void getFunctionConstantRange(unsigned &Start, unsigned &End) const {
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    Start = FirstFuncConstantID;
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    End = FirstInstID;
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  }
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  const ValueList &getValues() const { return Values; }
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  /// Check whether the current block has any metadata to emit.
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  bool hasMDs() const { return NumModuleMDs < MDs.size(); }
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  /// Get the MDString metadata for this block.
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  ArrayRef<const Metadata *> getMDStrings() const {
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    return makeArrayRef(MDs).slice(NumModuleMDs, NumMDStrings);
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  }
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  /// Get the non-MDString metadata for this block.
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  ArrayRef<const Metadata *> getNonMDStrings() const {
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    return makeArrayRef(MDs).slice(NumModuleMDs).slice(NumMDStrings);
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  }
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  const TypeList &getTypes() const { return Types; }
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  const std::vector<const BasicBlock*> &getBasicBlocks() const {
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    return BasicBlocks;
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  }
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  const std::vector<AttributeList> &getAttributeLists() const { return AttributeLists; }
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  const std::vector<IndexAndAttrSet> &getAttributeGroups() const {
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    return AttributeGroups;
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  }
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  const ComdatSetType &getComdats() const { return Comdats; }
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  unsigned getComdatID(const Comdat *C) const;
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  /// getGlobalBasicBlockID - This returns the function-specific ID for the
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  /// specified basic block.  This is relatively expensive information, so it
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  /// should only be used by rare constructs such as address-of-label.
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  unsigned getGlobalBasicBlockID(const BasicBlock *BB) const;
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  /// incorporateFunction/purgeFunction - If you'd like to deal with a function,
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  /// use these two methods to get its data into the ValueEnumerator!
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  void incorporateFunction(const Function &F);
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  void purgeFunction();
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  uint64_t computeBitsRequiredForTypeIndicies() const;
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private:
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  void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
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  /// Reorder the reachable metadata.
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  ///
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  /// This is not just an optimization, but is mandatory for emitting MDString
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  /// correctly.
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  void organizeMetadata();
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  /// Drop the function tag from the transitive operands of the given node.
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  void dropFunctionFromMetadata(MetadataMapType::value_type &FirstMD);
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  /// Incorporate the function metadata.
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  ///
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  /// This should be called before enumerating LocalAsMetadata for the
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  /// function.
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  void incorporateFunctionMetadata(const Function &F);
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  /// Enumerate a single instance of metadata with the given function tag.
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  ///
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  /// If \c MD has already been enumerated, check that \c F matches its
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  /// function tag.  If not, call \a dropFunctionFromMetadata().
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  ///
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  /// Otherwise, mark \c MD as visited.  Assign it an ID, or just return it if
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  /// it's an \a MDNode.
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  const MDNode *enumerateMetadataImpl(unsigned F, const Metadata *MD);
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  unsigned getMetadataFunctionID(const Function *F) const;
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  /// Enumerate reachable metadata in (almost) post-order.
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  ///
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  /// Enumerate all the metadata reachable from MD.  We want to minimize the
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  /// cost of reading bitcode records, and so the primary consideration is that
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  /// operands of uniqued nodes are resolved before the nodes are read.  This
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  /// avoids re-uniquing them on the context and factors away RAUW support.
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  ///
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  /// This algorithm guarantees that subgraphs of uniqued nodes are in
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  /// post-order.  Distinct subgraphs reachable only from a single uniqued node
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  /// will be in post-order.
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  ///
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  /// \note The relative order of a distinct and uniqued node is irrelevant.
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  /// \a organizeMetadata() will later partition distinct nodes ahead of
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  /// uniqued ones.
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  ///{
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  void EnumerateMetadata(const Function *F, const Metadata *MD);
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  void EnumerateMetadata(unsigned F, const Metadata *MD);
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  ///}
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  void EnumerateFunctionLocalMetadata(const Function &F,
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                                      const LocalAsMetadata *Local);
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  void EnumerateFunctionLocalMetadata(unsigned F, const LocalAsMetadata *Local);
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  void EnumerateNamedMDNode(const NamedMDNode *NMD);
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  void EnumerateValue(const Value *V);
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  void EnumerateType(Type *T);
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  void EnumerateOperandType(const Value *V);
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  void EnumerateAttributes(AttributeList PAL);
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  void EnumerateValueSymbolTable(const ValueSymbolTable &ST);
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  void EnumerateNamedMetadata(const Module &M);
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};
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} // end namespace llvm
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#endif // LLVM_LIB_BITCODE_WRITER_VALUEENUMERATOR_H