Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/ADT/SparseMultiSet.h b/linux-x64/clang/include/llvm/ADT/SparseMultiSet.h
new file mode 100644
index 0000000..3c86376
--- /dev/null
+++ b/linux-x64/clang/include/llvm/ADT/SparseMultiSet.h
@@ -0,0 +1,523 @@
+//===- llvm/ADT/SparseMultiSet.h - Sparse multiset --------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the SparseMultiSet class, which adds multiset behavior to
+// the SparseSet.
+//
+// A sparse multiset holds a small number of objects identified by integer keys
+// from a moderately sized universe. The sparse multiset uses more memory than
+// other containers in order to provide faster operations. Any key can map to
+// multiple values. A SparseMultiSetNode class is provided, which serves as a
+// convenient base class for the contents of a SparseMultiSet.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_SPARSEMULTISET_H
+#define LLVM_ADT_SPARSEMULTISET_H
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SparseSet.h"
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <iterator>
+#include <limits>
+#include <utility>
+
+namespace llvm {
+
+/// Fast multiset implementation for objects that can be identified by small
+/// unsigned keys.
+///
+/// SparseMultiSet 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, SparseMultiSet provides constant-time
+/// fast clear() 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. Iteration order is the
+/// insertion order. Iteration is only provided over elements of equivalent
+/// keys, but iterators are bidirectional.
+///
+/// Compared to BitVector, SparseMultiSet<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.
+///
+/// SparseMultiSet 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 up to 3 cache lines, but the
+/// sparse array uses 4 x Universe bytes.
+///
+/// When SparseT is uint8_t (the default), find() touches up to 3+[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.
+///
+/// Multiset behavior is provided by providing doubly linked lists for values
+/// that are inlined in the dense vector. SparseMultiSet is a good choice when
+/// one desires a growable number of entries per key, as it will retain the
+/// SparseSet algorithmic properties despite being growable. Thus, it is often a
+/// better choice than a SparseSet of growable containers or a vector of
+/// vectors. SparseMultiSet also keeps iterators valid after erasure (provided
+/// the iterators don't point to the element erased), allowing for more
+/// intuitive and fast removal.
+///
+/// @tparam ValueT The type of objects in the set.
+/// @tparam KeyFunctorT A functor that computes an unsigned index from KeyT.
+/// @tparam SparseT An unsigned integer type. See above.
+///
+template<typename ValueT,
+ typename KeyFunctorT = identity<unsigned>,
+ typename SparseT = uint8_t>
+class SparseMultiSet {
+ static_assert(std::numeric_limits<SparseT>::is_integer &&
+ !std::numeric_limits<SparseT>::is_signed,
+ "SparseT must be an unsigned integer type");
+
+ /// The actual data that's stored, as a doubly-linked list implemented via
+ /// indices into the DenseVector. The doubly linked list is implemented
+ /// circular in Prev indices, and INVALID-terminated in Next indices. This
+ /// provides efficient access to list tails. These nodes can also be
+ /// tombstones, in which case they are actually nodes in a single-linked
+ /// freelist of recyclable slots.
+ struct SMSNode {
+ static const unsigned INVALID = ~0U;
+
+ ValueT Data;
+ unsigned Prev;
+ unsigned Next;
+
+ SMSNode(ValueT D, unsigned P, unsigned N) : Data(D), Prev(P), Next(N) {}
+
+ /// List tails have invalid Nexts.
+ bool isTail() const {
+ return Next == INVALID;
+ }
+
+ /// Whether this node is a tombstone node, and thus is in our freelist.
+ bool isTombstone() const {
+ return Prev == INVALID;
+ }
+
+ /// Since the list is circular in Prev, all non-tombstone nodes have a valid
+ /// Prev.
+ bool isValid() const { return Prev != INVALID; }
+ };
+
+ using KeyT = typename KeyFunctorT::argument_type;
+ using DenseT = SmallVector<SMSNode, 8>;
+ DenseT Dense;
+ SparseT *Sparse = nullptr;
+ unsigned Universe = 0;
+ KeyFunctorT KeyIndexOf;
+ SparseSetValFunctor<KeyT, ValueT, KeyFunctorT> ValIndexOf;
+
+ /// We have a built-in recycler for reusing tombstone slots. This recycler
+ /// puts a singly-linked free list into tombstone slots, allowing us quick
+ /// erasure, iterator preservation, and dense size.
+ unsigned FreelistIdx = SMSNode::INVALID;
+ unsigned NumFree = 0;
+
+ unsigned sparseIndex(const ValueT &Val) const {
+ assert(ValIndexOf(Val) < Universe &&
+ "Invalid key in set. Did object mutate?");
+ return ValIndexOf(Val);
+ }
+ unsigned sparseIndex(const SMSNode &N) const { return sparseIndex(N.Data); }
+
+ /// Whether the given entry is the head of the list. List heads's previous
+ /// pointers are to the tail of the list, allowing for efficient access to the
+ /// list tail. D must be a valid entry node.
+ bool isHead(const SMSNode &D) const {
+ assert(D.isValid() && "Invalid node for head");
+ return Dense[D.Prev].isTail();
+ }
+
+ /// Whether the given entry is a singleton entry, i.e. the only entry with
+ /// that key.
+ bool isSingleton(const SMSNode &N) const {
+ assert(N.isValid() && "Invalid node for singleton");
+ // Is N its own predecessor?
+ return &Dense[N.Prev] == &N;
+ }
+
+ /// Add in the given SMSNode. Uses a free entry in our freelist if
+ /// available. Returns the index of the added node.
+ unsigned addValue(const ValueT& V, unsigned Prev, unsigned Next) {
+ if (NumFree == 0) {
+ Dense.push_back(SMSNode(V, Prev, Next));
+ return Dense.size() - 1;
+ }
+
+ // Peel off a free slot
+ unsigned Idx = FreelistIdx;
+ unsigned NextFree = Dense[Idx].Next;
+ assert(Dense[Idx].isTombstone() && "Non-tombstone free?");
+
+ Dense[Idx] = SMSNode(V, Prev, Next);
+ FreelistIdx = NextFree;
+ --NumFree;
+ return Idx;
+ }
+
+ /// Make the current index a new tombstone. Pushes it onto the freelist.
+ void makeTombstone(unsigned Idx) {
+ Dense[Idx].Prev = SMSNode::INVALID;
+ Dense[Idx].Next = FreelistIdx;
+ FreelistIdx = Idx;
+ ++NumFree;
+ }
+
+public:
+ using value_type = ValueT;
+ using reference = ValueT &;
+ using const_reference = const ValueT &;
+ using pointer = ValueT *;
+ using const_pointer = const ValueT *;
+ using size_type = unsigned;
+
+ SparseMultiSet() = default;
+ SparseMultiSet(const SparseMultiSet &) = delete;
+ SparseMultiSet &operator=(const SparseMultiSet &) = delete;
+ ~SparseMultiSet() { free(Sparse); }
+
+ /// Set the universe size which determines the largest key the set can hold.
+ /// The universe must be sized before any elements can be added.
+ ///
+ /// @param U Universe size. All object keys must be less than U.
+ ///
+ void setUniverse(unsigned U) {
+ // It's not hard to resize the universe on a non-empty set, but it doesn't
+ // seem like a likely use case, so we can add that code when we need it.
+ assert(empty() && "Can only resize universe on an empty map");
+ // Hysteresis prevents needless reallocations.
+ if (U >= Universe/4 && U <= Universe)
+ return;
+ free(Sparse);
+ // The Sparse array doesn't actually need to be initialized, so malloc
+ // would be enough here, but that will cause tools like valgrind to
+ // complain about branching on uninitialized data.
+ Sparse = static_cast<SparseT*>(safe_calloc(U, sizeof(SparseT)));
+ Universe = U;
+ }
+
+ /// Our iterators are iterators over the collection of objects that share a
+ /// key.
+ template<typename SMSPtrTy>
+ class iterator_base : public std::iterator<std::bidirectional_iterator_tag,
+ ValueT> {
+ friend class SparseMultiSet;
+
+ SMSPtrTy SMS;
+ unsigned Idx;
+ unsigned SparseIdx;
+
+ iterator_base(SMSPtrTy P, unsigned I, unsigned SI)
+ : SMS(P), Idx(I), SparseIdx(SI) {}
+
+ /// Whether our iterator has fallen outside our dense vector.
+ bool isEnd() const {
+ if (Idx == SMSNode::INVALID)
+ return true;
+
+ assert(Idx < SMS->Dense.size() && "Out of range, non-INVALID Idx?");
+ return false;
+ }
+
+ /// Whether our iterator is properly keyed, i.e. the SparseIdx is valid
+ bool isKeyed() const { return SparseIdx < SMS->Universe; }
+
+ unsigned Prev() const { return SMS->Dense[Idx].Prev; }
+ unsigned Next() const { return SMS->Dense[Idx].Next; }
+
+ void setPrev(unsigned P) { SMS->Dense[Idx].Prev = P; }
+ void setNext(unsigned N) { SMS->Dense[Idx].Next = N; }
+
+ public:
+ using super = std::iterator<std::bidirectional_iterator_tag, ValueT>;
+ using value_type = typename super::value_type;
+ using difference_type = typename super::difference_type;
+ using pointer = typename super::pointer;
+ using reference = typename super::reference;
+
+ reference operator*() const {
+ assert(isKeyed() && SMS->sparseIndex(SMS->Dense[Idx].Data) == SparseIdx &&
+ "Dereferencing iterator of invalid key or index");
+
+ return SMS->Dense[Idx].Data;
+ }
+ pointer operator->() const { return &operator*(); }
+
+ /// Comparison operators
+ bool operator==(const iterator_base &RHS) const {
+ // end compares equal
+ if (SMS == RHS.SMS && Idx == RHS.Idx) {
+ assert((isEnd() || SparseIdx == RHS.SparseIdx) &&
+ "Same dense entry, but different keys?");
+ return true;
+ }
+
+ return false;
+ }
+
+ bool operator!=(const iterator_base &RHS) const {
+ return !operator==(RHS);
+ }
+
+ /// Increment and decrement operators
+ iterator_base &operator--() { // predecrement - Back up
+ assert(isKeyed() && "Decrementing an invalid iterator");
+ assert((isEnd() || !SMS->isHead(SMS->Dense[Idx])) &&
+ "Decrementing head of list");
+
+ // If we're at the end, then issue a new find()
+ if (isEnd())
+ Idx = SMS->findIndex(SparseIdx).Prev();
+ else
+ Idx = Prev();
+
+ return *this;
+ }
+ iterator_base &operator++() { // preincrement - Advance
+ assert(!isEnd() && isKeyed() && "Incrementing an invalid/end iterator");
+ Idx = Next();
+ return *this;
+ }
+ iterator_base operator--(int) { // postdecrement
+ iterator_base I(*this);
+ --*this;
+ return I;
+ }
+ iterator_base operator++(int) { // postincrement
+ iterator_base I(*this);
+ ++*this;
+ return I;
+ }
+ };
+
+ using iterator = iterator_base<SparseMultiSet *>;
+ using const_iterator = iterator_base<const SparseMultiSet *>;
+
+ // Convenience types
+ using RangePair = std::pair<iterator, iterator>;
+
+ /// Returns an iterator past this container. Note that such an iterator cannot
+ /// be decremented, but will compare equal to other end iterators.
+ iterator end() { return iterator(this, SMSNode::INVALID, SMSNode::INVALID); }
+ const_iterator end() const {
+ return const_iterator(this, SMSNode::INVALID, SMSNode::INVALID);
+ }
+
+ /// Returns true if the set is empty.
+ ///
+ /// This is not the same as BitVector::empty().
+ ///
+ bool empty() const { return size() == 0; }
+
+ /// Returns the number of elements in the set.
+ ///
+ /// This is not the same as BitVector::size() which returns the size of the
+ /// universe.
+ ///
+ size_type size() const {
+ assert(NumFree <= Dense.size() && "Out-of-bounds free entries");
+ return Dense.size() - NumFree;
+ }
+
+ /// Clears the set. This is a very fast constant time operation.
+ ///
+ void clear() {
+ // Sparse does not need to be cleared, see find().
+ Dense.clear();
+ NumFree = 0;
+ FreelistIdx = SMSNode::INVALID;
+ }
+
+ /// Find an element by its index.
+ ///
+ /// @param Idx A valid index to find.
+ /// @returns An iterator to the element identified by key, or end().
+ ///
+ iterator findIndex(unsigned Idx) {
+ assert(Idx < Universe && "Key out of range");
+ const unsigned Stride = std::numeric_limits<SparseT>::max() + 1u;
+ for (unsigned i = Sparse[Idx], e = Dense.size(); i < e; i += Stride) {
+ const unsigned FoundIdx = sparseIndex(Dense[i]);
+ // Check that we're pointing at the correct entry and that it is the head
+ // of a valid list.
+ if (Idx == FoundIdx && Dense[i].isValid() && isHead(Dense[i]))
+ return iterator(this, i, Idx);
+ // Stride is 0 when SparseT >= unsigned. We don't need to loop.
+ if (!Stride)
+ break;
+ }
+ return end();
+ }
+
+ /// Find an element by its key.
+ ///
+ /// @param Key A valid key to find.
+ /// @returns An iterator to the element identified by key, or end().
+ ///
+ iterator find(const KeyT &Key) {
+ return findIndex(KeyIndexOf(Key));
+ }
+
+ const_iterator find(const KeyT &Key) const {
+ iterator I = const_cast<SparseMultiSet*>(this)->findIndex(KeyIndexOf(Key));
+ return const_iterator(I.SMS, I.Idx, KeyIndexOf(Key));
+ }
+
+ /// Returns the number of elements identified by Key. This will be linear in
+ /// the number of elements of that key.
+ size_type count(const KeyT &Key) const {
+ unsigned Ret = 0;
+ for (const_iterator It = find(Key); It != end(); ++It)
+ ++Ret;
+
+ return Ret;
+ }
+
+ /// Returns true if this set contains an element identified by Key.
+ bool contains(const KeyT &Key) const {
+ return find(Key) != end();
+ }
+
+ /// Return the head and tail of the subset's list, otherwise returns end().
+ iterator getHead(const KeyT &Key) { return find(Key); }
+ iterator getTail(const KeyT &Key) {
+ iterator I = find(Key);
+ if (I != end())
+ I = iterator(this, I.Prev(), KeyIndexOf(Key));
+ return I;
+ }
+
+ /// The bounds of the range of items sharing Key K. First member is the head
+ /// of the list, and the second member is a decrementable end iterator for
+ /// that key.
+ RangePair equal_range(const KeyT &K) {
+ iterator B = find(K);
+ iterator E = iterator(this, SMSNode::INVALID, B.SparseIdx);
+ return make_pair(B, E);
+ }
+
+ /// Insert a new element at the tail of the subset list. Returns an iterator
+ /// to the newly added entry.
+ iterator insert(const ValueT &Val) {
+ unsigned Idx = sparseIndex(Val);
+ iterator I = findIndex(Idx);
+
+ unsigned NodeIdx = addValue(Val, SMSNode::INVALID, SMSNode::INVALID);
+
+ if (I == end()) {
+ // Make a singleton list
+ Sparse[Idx] = NodeIdx;
+ Dense[NodeIdx].Prev = NodeIdx;
+ return iterator(this, NodeIdx, Idx);
+ }
+
+ // Stick it at the end.
+ unsigned HeadIdx = I.Idx;
+ unsigned TailIdx = I.Prev();
+ Dense[TailIdx].Next = NodeIdx;
+ Dense[HeadIdx].Prev = NodeIdx;
+ Dense[NodeIdx].Prev = TailIdx;
+
+ return iterator(this, NodeIdx, Idx);
+ }
+
+ /// Erases an existing element identified by a valid iterator.
+ ///
+ /// This invalidates iterators pointing at the same entry, but erase() returns
+ /// an iterator pointing to the next element in the subset's list. This makes
+ /// it possible to erase selected elements while iterating over the subset:
+ ///
+ /// tie(I, E) = Set.equal_range(Key);
+ /// while (I != E)
+ /// if (test(*I))
+ /// I = Set.erase(I);
+ /// else
+ /// ++I;
+ ///
+ /// Note that if the last element in the subset list is erased, this will
+ /// return an end iterator which can be decremented to get the new tail (if it
+ /// exists):
+ ///
+ /// tie(B, I) = Set.equal_range(Key);
+ /// for (bool isBegin = B == I; !isBegin; /* empty */) {
+ /// isBegin = (--I) == B;
+ /// if (test(I))
+ /// break;
+ /// I = erase(I);
+ /// }
+ iterator erase(iterator I) {
+ assert(I.isKeyed() && !I.isEnd() && !Dense[I.Idx].isTombstone() &&
+ "erasing invalid/end/tombstone iterator");
+
+ // First, unlink the node from its list. Then swap the node out with the
+ // dense vector's last entry
+ iterator NextI = unlink(Dense[I.Idx]);
+
+ // Put in a tombstone.
+ makeTombstone(I.Idx);
+
+ return NextI;
+ }
+
+ /// Erase all elements with the given key. This invalidates all
+ /// iterators of that key.
+ void eraseAll(const KeyT &K) {
+ for (iterator I = find(K); I != end(); /* empty */)
+ I = erase(I);
+ }
+
+private:
+ /// Unlink the node from its list. Returns the next node in the list.
+ iterator unlink(const SMSNode &N) {
+ if (isSingleton(N)) {
+ // Singleton is already unlinked
+ assert(N.Next == SMSNode::INVALID && "Singleton has next?");
+ return iterator(this, SMSNode::INVALID, ValIndexOf(N.Data));
+ }
+
+ if (isHead(N)) {
+ // If we're the head, then update the sparse array and our next.
+ Sparse[sparseIndex(N)] = N.Next;
+ Dense[N.Next].Prev = N.Prev;
+ return iterator(this, N.Next, ValIndexOf(N.Data));
+ }
+
+ if (N.isTail()) {
+ // If we're the tail, then update our head and our previous.
+ findIndex(sparseIndex(N)).setPrev(N.Prev);
+ Dense[N.Prev].Next = N.Next;
+
+ // Give back an end iterator that can be decremented
+ iterator I(this, N.Prev, ValIndexOf(N.Data));
+ return ++I;
+ }
+
+ // Otherwise, just drop us
+ Dense[N.Next].Prev = N.Prev;
+ Dense[N.Prev].Next = N.Next;
+ return iterator(this, N.Next, ValIndexOf(N.Data));
+ }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_ADT_SPARSEMULTISET_H