LLVM API Documentation

Public Types | Public Member Functions
llvm::SparseSet< ValueT, KeyFunctorT, SparseT > Class Template Reference

#include <SparseSet.h>

Inheritance diagram for llvm::SparseSet< ValueT, KeyFunctorT, SparseT >:
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List of all members.

Public Types

typedef ValueT value_type
typedef ValueT & reference
typedef const ValueT & const_reference
typedef ValueT * pointer
typedef const ValueT * const_pointer
typedef DenseT::iterator iterator
typedef DenseT::const_iterator const_iterator

Public Member Functions

 SparseSet ()
 ~SparseSet ()
void setUniverse (unsigned U)
const_iterator begin () const
const_iterator end () const
iterator begin ()
iterator end ()
bool empty () const
size_type size () const
void clear ()
iterator findIndex (unsigned Idx)
iterator find (const KeyT &Key)
const_iterator find (const KeyT &Key) const
size_type count (const KeyT &Key) const
std::pair< iterator, boolinsert (const ValueT &Val)
ValueT & operator[] (const KeyT &Key)
iterator erase (iterator I)
bool erase (const KeyT &Key)

Detailed Description

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
class llvm::SparseSet< ValueT, KeyFunctorT, SparseT >

SparseSet - Fast set implmentation for objects that can be identified by small unsigned keys.

SparseSet allocates memory proportional to the size of the key universe, so it is not recommended for building composite data structures. It is useful for algorithms that require a single set with fast operations.

Compared to DenseSet and DenseMap, SparseSet provides constant-time fast clear() and iteration as fast as a vector. The find(), insert(), and erase() operations are all constant time, and typically faster than a hash table. The iteration order doesn't depend on numerical key values, it only depends on the order of insert() and erase() operations. When no elements have been erased, the iteration order is the insertion order.

Compared to BitVector, SparseSet<unsigned> uses 8x-40x more memory, but offers constant-time clear() and size() operations as well as fast iteration independent on the size of the universe.

SparseSet contains a dense vector holding all the objects and a sparse array holding indexes into the dense vector. Most of the memory is used by the sparse array which is the size of the key universe. The SparseT template parameter provides a space/speed tradeoff for sets holding many elements.

When SparseT is uint32_t, find() only touches 2 cache lines, but the sparse array uses 4 x Universe bytes.

When SparseT is uint8_t (the default), find() touches up to 2+[N/256] cache lines, but the sparse array is 4x smaller. N is the number of elements in the set.

For sets that may grow to thousands of elements, SparseT should be set to uint16_t or uint32_t.

Template Parameters:
ValueTThe type of objects in the set.
KeyFunctorTA functor that computes an unsigned index from KeyT.
SparseTAn unsigned integer type. See above.

Definition at line 120 of file SparseSet.h.


Member Typedef Documentation

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef DenseT::const_iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::const_iterator

Definition at line 172 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef const ValueT* llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::const_pointer

Definition at line 144 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef const ValueT& llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::const_reference

Definition at line 142 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef DenseT::iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::iterator

Definition at line 171 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef ValueT* llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::pointer

Definition at line 143 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef ValueT& llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::reference

Definition at line 141 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
typedef ValueT llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::value_type

Definition at line 140 of file SparseSet.h.


Constructor & Destructor Documentation

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::SparseSet ( ) [inline]

Definition at line 146 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::~SparseSet ( ) [inline]

Definition at line 147 of file SparseSet.h.


Member Function Documentation

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
const_iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::begin ( ) const [inline]
template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::begin ( ) [inline]

Definition at line 176 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
void llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::clear ( ) [inline]

clear - Clears the set. This is a very fast constant time operation.

Definition at line 194 of file SparseSet.h.

Referenced by llvm::ScheduleDAGInstrs::buildSchedGraph(), llvm::LivePhysRegs::clear(), llvm::LivePhysRegs::init(), and llvm::RegPressureTracker::reset().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
size_type llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::count ( const KeyT &  Key) const [inline]

count - Returns 1 if this set contains an element identified by Key, 0 otherwise.

Definition at line 235 of file SparseSet.h.

Referenced by llvm::LivePhysRegs::contains(), llvm::LiveRegSet::contains(), and llvm::RegPressureTracker::hasUntiedDef().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
bool llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::empty ( ) const [inline]

empty - Returns true if the set is empty.

This is not the same as BitVector::empty().

Definition at line 183 of file SparseSet.h.

Referenced by llvm::ScheduleDAGInstrs::buildSchedGraph(), llvm::RegPressureTracker::closeRegion(), llvm::LivePhysRegs::empty(), and llvm::SparseSet< RootData >::setUniverse().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
const_iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::end ( ) const [inline]
template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::end ( ) [inline]

Definition at line 177 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::erase ( iterator  I) [inline]

erase - Erases an existing element identified by a valid iterator.

This invalidates all iterators, but erase() returns an iterator pointing to the next element. This makes it possible to erase selected elements while iterating over the set:

for (SparseSet::iterator I = Set.begin(); I != Set.end();) if (test(*I)) I = Set.erase(I); else ++I;

Note that end() changes when elements are erased, unlike std::list.

Definition at line 280 of file SparseSet.h.

Referenced by llvm::LiveRegSet::erase(), llvm::SparseSet< RootData >::erase(), llvm::LivePhysRegs::removeReg(), llvm::LivePhysRegs::removeRegsInMask(), updatePhysDepsDownwards(), and updatePhysDepsUpwards().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
bool llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::erase ( const KeyT &  Key) [inline]

erase - Erases an element identified by Key, if it exists.

Parameters:
KeyThe key identifying the element to erase.
Returns:
True when an element was erased, false if no element was found.

Definition at line 299 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::find ( const KeyT &  Key) [inline]

find - Find an element by its key.

Parameters:
KeyA valid key to find.
Returns:
An iterator to the element identified by key, or end().

Definition at line 224 of file SparseSet.h.

Referenced by llvm::ScheduleDAGInstrs::addVRegDefDeps(), llvm::ScheduleDAGInstrs::addVRegUseDeps(), llvm::SparseSet< RootData >::count(), llvm::SparseSet< RootData >::erase(), updatePhysDepsDownwards(), and updatePhysDepsUpwards().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
const_iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::find ( const KeyT &  Key) const [inline]

Definition at line 228 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
iterator llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::findIndex ( unsigned  Idx) [inline]

findIndex - Find an element by its index.

Parameters:
IdxA valid index to find.
Returns:
An iterator to the element identified by key, or end().

Definition at line 204 of file SparseSet.h.

Referenced by llvm::SparseSet< RootData >::find(), and llvm::SparseSet< RootData >::insert().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
std::pair<iterator, bool> llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::insert ( const ValueT &  Val) [inline]

insert - Attempts to insert a new element.

If Val is successfully inserted, return (I, true), where I is an iterator pointing to the newly inserted element.

If the set already contains an element with the same key as Val, return (I, false), where I is an iterator pointing to the existing element.

Insertion invalidates all iterators.

Definition at line 249 of file SparseSet.h.

Referenced by llvm::LivePhysRegs::addReg(), llvm::ScheduleDAGInstrs::addVRegDefDeps(), llvm::LiveRegSet::insert(), llvm::SparseSet< RootData >::operator[](), and llvm::RegPressureTracker::recede().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
ValueT& llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::operator[] ( const KeyT &  Key) [inline]

array subscript - If an element already exists with this key, return it. Otherwise, automatically construct a new value from Key, insert it, and return the newly inserted element.

Definition at line 262 of file SparseSet.h.

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
void llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::setUniverse ( unsigned  U) [inline]

setUniverse - Set the universe size which determines the largest key the set can hold. The universe must be sized before any elements can be added.

Parameters:
UUniverse size. All object keys must be less than U.

Definition at line 155 of file SparseSet.h.

Referenced by llvm::ScheduleDAGInstrs::buildSchedGraph(), llvm::LivePhysRegs::init(), llvm::RegPressureTracker::init(), and llvm::LivePhysRegs::LivePhysRegs().

template<typename ValueT, typename KeyFunctorT = llvm::identity<unsigned>, typename SparseT = uint8_t>
size_type llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::size ( ) const [inline]

size - Returns the number of elements in the set.

This is not the same as BitVector::size() which returns the size of the universe.

Definition at line 190 of file SparseSet.h.

Referenced by llvm::RegPressureTracker::closeBottom(), llvm::RegPressureTracker::closeTop(), llvm::SparseSet< RootData >::erase(), llvm::SparseSet< RootData >::findIndex(), and llvm::SparseSet< RootData >::insert().


The documentation for this class was generated from the following file: