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       1             : //===- llvm/ADT/IndexedMap.h - An index map implementation ------*- 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 file implements an indexed map. The index map template takes two
      11             : // types. The first is the mapped type and the second is a functor
      12             : // that maps its argument to a size_t. On instantiation a "null" value
      13             : // can be provided to be used as a "does not exist" indicator in the
      14             : // map. A member function grow() is provided that given the value of
      15             : // the maximally indexed key (the argument of the functor) makes sure
      16             : // the map has enough space for it.
      17             : //
      18             : //===----------------------------------------------------------------------===//
      19             : 
      20             : #ifndef LLVM_ADT_INDEXEDMAP_H
      21             : #define LLVM_ADT_INDEXEDMAP_H
      22             : 
      23             : #include "llvm/ADT/SmallVector.h"
      24             : #include "llvm/ADT/STLExtras.h"
      25             : #include <cassert>
      26             : 
      27             : namespace llvm {
      28             : 
      29             : template <typename T, typename ToIndexT = identity<unsigned>>
      30       24432 :   class IndexedMap {
      31             :     using IndexT = typename ToIndexT::argument_type;
      32             :     // Prefer SmallVector with zero inline storage over std::vector. IndexedMaps
      33             :     // can grow very large and SmallVector grows more efficiently as long as T
      34             :     // is trivially copyable.
      35             :     using StorageT = SmallVector<T, 0>;
      36             : 
      37             :     StorageT storage_;
      38             :     T nullVal_;
      39             :     ToIndexT toIndex_;
      40             : 
      41             :   public:
      42     2526522 :     IndexedMap() : nullVal_(T()) {}
      43             : 
      44       92620 :     explicit IndexedMap(const T& val) : nullVal_(val) {}
      45             : 
      46             :     typename StorageT::reference operator[](IndexT n) {
      47             :       assert(toIndex_(n) < storage_.size() && "index out of bounds!");
      48   168734888 :       return storage_[toIndex_(n)];
      49             :     }
      50             : 
      51             :     typename StorageT::const_reference operator[](IndexT n) const {
      52             :       assert(toIndex_(n) < storage_.size() && "index out of bounds!");
      53   369142666 :       return storage_[toIndex_(n)];
      54             :     }
      55             : 
      56             :     void reserve(typename StorageT::size_type s) {
      57             :       storage_.reserve(s);
      58             :     }
      59             : 
      60             :     void resize(typename StorageT::size_type s) {
      61    64153096 :       storage_.resize(s, nullVal_);
      62             :     }
      63             : 
      64             :     void clear() {
      65             :       storage_.clear();
      66             :     }
      67             : 
      68             :     void grow(IndexT n) {
      69    39931070 :       unsigned NewSize = toIndex_(n) + 1;
      70    66979092 :       if (NewSize > storage_.size())
      71             :         resize(NewSize);
      72             :     }
      73             : 
      74             :     bool inBounds(IndexT n) const {
      75    58916244 :       return toIndex_(n) < storage_.size();
      76             :     }
      77             : 
      78             :     typename StorageT::size_type size() const {
      79    33465466 :       return storage_.size();
      80             :     }
      81             :   };
      82             : 
      83             : } // end namespace llvm
      84             : 
      85             : #endif // LLVM_ADT_INDEXEDMAP_H