From: Jakob Stoklund Olesen Date: Fri, 19 Nov 2010 01:14:40 +0000 (+0000) Subject: Add ADT/IntervalMap. X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8408edffcbd7f436c05018fafbfb9911146b208a;p=oota-llvm.git Add ADT/IntervalMap. This is a sorted interval map data structure for small keys and values with automatic coalescing and bidirectional iteration over coalesced intervals. Except for coalescing intervals, it provides similar functionality to std::map. It is however much more compact for small keys and values, and hopefully faster too. The container object itself can hold the first few intervals without any allocations, then it switches to a cache conscious B+-tree representation. A recycling allocator can be shared between many containers, even between containers holding different types. The IntervalMap is initially intended to be used with SlotIndex intervals for: - Backing store for LiveIntervalUnion that is smaller and faster than std::set. - Backing store for LiveInterval with less overhead than std::vector for typical intervals and O(N log N) merging of large intervals. 99% of virtual registers need 4 entries or less and would benefit from the small object optimization. - Backing store for LiveDebugVariable which doesn't exist yet, but will track debug variables during register allocation. This is a work in progress. Missing items are: - Performance metrics. - erase(). - insert() shrinkage. - clear(). - More performance metrics. - Simplification and detemplatization. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119772 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/ADT/IntervalMap.h b/include/llvm/ADT/IntervalMap.h new file mode 100644 index 00000000000..e38789b7631 --- /dev/null +++ b/include/llvm/ADT/IntervalMap.h @@ -0,0 +1,1695 @@ +//===- llvm/ADT/IntervalMap.h - A sorted interval map -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements a coalescing interval map for small objects. +// +// KeyT objects are mapped to ValT objects. Intervals of keys that map to the +// same value are represented in a compressed form. +// +// Iterators provide ordered access to the compressed intervals rather than the +// individual keys, and insert and erase operations use key intervals as well. +// +// Like SmallVector, IntervalMap will store the first N intervals in the map +// object itself without any allocations. When space is exhausted it switches to +// a B+-tree representation with very small overhead for small key and value +// objects. +// +// A Traits class specifies how keys are compared. It also allows IntervalMap to +// work with both closed and half-open intervals. +// +// Keys and values are not stored next to each other in a std::pair, so we don't +// provide such a value_type. Dereferencing iterators only returns the mapped +// value. The interval bounds are accessible through the start() and stop() +// iterator methods. +// +// IntervalMap is optimized for small key and value objects, 4 or 8 bytes each +// is the optimal size. For large objects use std::map instead. +// +//===----------------------------------------------------------------------===// +// +// Synopsis: +// +// template +// class IntervalMap { +// public: +// typedef KeyT key_type; +// typedef ValT mapped_type; +// typedef RecyclingAllocator<...> Allocator; +// class iterator; +// class const_iterator; +// +// explicit IntervalMap(Allocator&); +// ~IntervalMap(): +// +// bool empty() const; +// KeyT start() const; +// KeyT stop() const; +// ValT lookup(KeyT x, Value NotFound = Value()) const; +// +// const_iterator begin() const; +// const_iterator end() const; +// iterator begin(); +// iterator end(); +// const_iterator find(KeyT x) const; +// iterator find(KeyT x); +// +// void insert(KeyT a, KeyT b, ValT y); +// void clear(); +// }; +// +// template +// class IntervalMap::const_iterator : +// public std::iterator { +// public: +// bool operator==(const const_iterator &) const; +// bool operator!=(const const_iterator &) const; +// bool valid() const; +// +// const KeyT &start() const; +// const KeyT &stop() const; +// const ValT &value() const; +// const ValT &operator*() const; +// const ValT *operator->() const; +// +// const_iterator &operator++(); +// const_iterator &operator++(int); +// const_iterator &operator--(); +// const_iterator &operator--(int); +// void goToBegin(); +// void goToEnd(); +// void find(KeyT x); +// void advanceTo(KeyT x); +// }; +// +// template +// class IntervalMap::iterator : public const_iterator { +// public: +// void insert(KeyT a, KeyT b, Value y); +// void erase(); +// }; +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ADT_INTERVALMAP_H +#define LLVM_ADT_INTERVALMAP_H + +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/PointerIntPair.h" +#include "llvm/Support/Allocator.h" +#include "llvm/Support/RecyclingAllocator.h" +#include +#include + +// FIXME: Remove debugging code +#ifndef NDEBUG +#include "llvm/Support/raw_ostream.h" +#endif + +namespace llvm { + + +//===----------------------------------------------------------------------===// +//--- Key traits ---// +//===----------------------------------------------------------------------===// +// +// The IntervalMap works with closed or half-open intervals. +// Adjacent intervals that map to the same value are coalesced. +// +// The IntervalMapInfo traits class is used to determine if a key is contained +// in an interval, and if two intervals are adjacent so they can be coalesced. +// The provided implementation works for closed integer intervals, other keys +// probably need a specialized version. +// +// The point x is contained in [a;b] when !startLess(x, a) && !stopLess(b, x). +// +// It is assumed that (a;b] half-open intervals are not used, only [a;b) is +// allowed. This is so that stopLess(a, b) can be used to determine if two +// intervals overlap. +// +//===----------------------------------------------------------------------===// + +template +struct IntervalMapInfo { + + /// startLess - Return true if x is not in [a;b]. + /// This is x < a both for closed intervals and for [a;b) half-open intervals. + static inline bool startLess(const T &x, const T &a) { + return x < a; + } + + /// stopLess - Return true if x is not in [a;b]. + /// This is b < x for a closed interval, b <= x for [a;b) half-open intervals. + static inline bool stopLess(const T &b, const T &x) { + return b < x; + } + + /// adjacent - Return true when the intervals [x;a] and [b;y] can coalesce. + /// This is a+1 == b for closed intervals, a == b for half-open intervals. + static inline bool adjacent(const T &a, const T &b) { + return a+1 == b; + } + +}; + +/// IntervalMapImpl - Namespace used for IntervalMap implementation details. +/// It should be considered private to the implementation. +namespace IntervalMapImpl { + +// Forward declarations. +template class Leaf; +template class Branch; + +typedef std::pair IdxPair; + + +//===----------------------------------------------------------------------===// +//--- Node Storage ---// +//===----------------------------------------------------------------------===// +// +// Both leaf and branch nodes store vectors of (key,value) pairs. +// Leaves store ((KeyT, KeyT), ValT) pairs, branches use (KeyT, NodeRef). +// +// Keys and values are stored in separate arrays to avoid padding caused by +// different object alignments. This also helps improve locality of reference +// when searching the keys. +// +// The nodes don't know how many elements they contain - that information is +// stored elsewhere. Omitting the size field prevents padding and allows a node +// to fill the allocated cache lines completely. +// +// These are typical key and value sizes, the node branching factor (N), and +// wasted space when nodes are sized to fit in three cache lines (192 bytes): +// +// KT VT N Waste Used by +// 4 4 24 0 Branch<4> (32-bit pointers) +// 4 8 16 0 Branch<4> +// 8 4 16 0 Leaf<4,4> +// 8 8 12 0 Leaf<4,8>, Branch<8> +// 16 4 9 12 Leaf<8,4> +// 16 8 8 0 Leaf<8,8> +// +//===----------------------------------------------------------------------===// + +template +class NodeBase { +public: + enum { Capacity = N }; + + KT key[N]; + VT val[N]; + + /// copy - Copy elements from another node. + /// @param other Node elements are copied from. + /// @param i Beginning of the source range in other. + /// @param j Beginning of the destination range in this. + /// @param count Number of elements to copy. + template + void copy(const NodeBase &Other, unsigned i, + unsigned j, unsigned Count) { + assert(i + Count <= M && "Invalid source range"); + assert(j + Count <= N && "Invalid dest range"); + std::copy(Other.key + i, Other.key + i + Count, key + j); + std::copy(Other.val + i, Other.val + i + Count, val + j); + } + + /// lmove - Move elements to the left. + /// @param i Beginning of the source range. + /// @param j Beginning of the destination range. + /// @param count Number of elements to copy. + void lmove(unsigned i, unsigned j, unsigned Count) { + assert(j <= i && "Use rmove shift elements right"); + copy(*this, i, j, Count); + } + + /// rmove - Move elements to the right. + /// @param i Beginning of the source range. + /// @param j Beginning of the destination range. + /// @param count Number of elements to copy. + void rmove(unsigned i, unsigned j, unsigned Count) { + assert(i <= j && "Use lmove shift elements left"); + assert(j + Count <= N && "Invalid range"); + std::copy_backward(key + i, key + i + Count, key + j + Count); + std::copy_backward(val + i, val + i + Count, val + j + Count); + } + + /// erase - Erase elements [i;j). + /// @param i Beginning of the range to erase. + /// @param j End of the range. (Exclusive). + /// @param size Number of elements in node. + void erase(unsigned i, unsigned j, unsigned Size) { + lmove(j, i, Size - j); + } + + /// shift - Shift elements [i;size) 1 position to the right. + /// @param i Beginning of the range to move. + /// @param size Number of elements in node. + void shift(unsigned i, unsigned Size) { + rmove(i, i + 1, Size - i); + } + + /// xferLeft - Transfer elements to a left sibling node. + /// @param size Number of elements in this. + /// @param sib Left sibling node. + /// @param ssize Number of elements in sib. + /// @param count Number of elements to transfer. + void xferLeft(unsigned Size, NodeBase &Sib, unsigned SSize, unsigned Count) { + Sib.copy(*this, 0, SSize, Count); + erase(0, Count, Size); + } + + /// xferRight - Transfer elements to a right sibling node. + /// @param size Number of elements in this. + /// @param sib Right sibling node. + /// @param ssize Number of elements in sib. + /// @param count Number of elements to transfer. + void xferRight(unsigned Size, NodeBase &Sib, unsigned SSize, unsigned Count) { + Sib.rmove(0, Count, SSize); + Sib.copy(*this, Size-Count, 0, Count); + } + + /// adjLeftSib - Adjust the number if elements in this node by moving + /// elements to or from a left sibling node. + /// @param size Number of elements in this. + /// @param sib Right sibling node. + /// @param ssize Number of elements in sib. + /// @param add The number of elements to add to this node, possibly < 0. + /// @return Number of elements added to this node, possibly negative. + int adjLeftSib(unsigned Size, NodeBase &Sib, unsigned SSize, int Add) { + if (Add > 0) { + // We want to grow, copy from sib. + unsigned Count = std::min(std::min(unsigned(Add), SSize), N - Size); + Sib.xferRight(SSize, *this, Size, Count); + return Count; + } else { + // We want to shrink, copy to sib. + unsigned Count = std::min(std::min(unsigned(-Add), Size), N - SSize); + xferLeft(Size, Sib, SSize, Count); + return -Count; + } + } +}; + + +//===----------------------------------------------------------------------===// +//--- NodeSizer ---// +//===----------------------------------------------------------------------===// +// +// Compute node sizes from key and value types. +// +// The branching factors are chosen to make nodes fit in three cache lines. +// This may not be possible if keys or values are very large. Such large objects +// are handled correctly, but a std::map would probably give better performance. +// +//===----------------------------------------------------------------------===// + +template +struct NodeSizer { + enum { + // Cache line size. Most architectures have 32 or 64 byte cache lines. + // We use 64 bytes here because it provides good branching factors. + Log2CacheLine = 6, + CacheLineBytes = 1 << Log2CacheLine, + + // Compute the leaf node branching factor that makes a node fit in three + // cache lines. The branching factor must be at least 3, or some B+-tree + // balancing algorithms won't work. + // LeafSize can't be larger than CacheLineBytes. This is required by the + // PointerIntPair used by NodeRef. + DesiredNodeBytes = 3 * CacheLineBytes, + DesiredLeafSize = DesiredNodeBytes / (2*sizeof(KeyT)+sizeof(ValT)), + LeafSize = DesiredLeafSize > 3 ? DesiredLeafSize : 3, + + // Now that we have the leaf branching factor, compute the actual allocation + // unit size by rounding up to a whole number of cache lines. + LeafBytes = sizeof(NodeBase, ValT, LeafSize>), + AllocBytes = (LeafBytes + CacheLineBytes-1) & ~(CacheLineBytes-1), + + // Determine the branching factor for branch nodes, constrained to + // CacheLineBytes to please NodeRef. + DesiredBranchSize = AllocBytes / (sizeof(KeyT) + sizeof(void*)), + BranchSize = DesiredBranchSize < CacheLineBytes ? + DesiredBranchSize : CacheLineBytes + }; + + /// Allocator - The recycling allocator used for both branch and leaf nodes. + /// This typedef is very likely to be identical for all IntervalMaps with + /// reasonably sized entries, so the same allocator can be shared among + /// different kinds of maps. + typedef RecyclingAllocator Allocator; + +}; + + +//===----------------------------------------------------------------------===// +//--- NodeRef ---// +//===----------------------------------------------------------------------===// +// +// B+-tree nodes can be leaves or branches, so we need a polymorphic node +// pointer that can point to both kinds. +// +// All nodes are cache line aligned and the low 6 bits of a node pointer are +// always 0. These bits are used to store the number of elements in the +// referenced node. Besides saving space, placing node sizes in the parents +// allow tree balancing algorithms to run without faulting cache lines for nodes +// that may not need to be modified. +// +// A NodeRef doesn't know whether it references a leaf node or a branch node. +// It is the responsibility of the caller to use the correct types. +// +// Nodes are never supposed to be empty, and it is invalid to store a node size +// of 0 in a NodeRef. The valid range of sizes is 1-64. +// +//===----------------------------------------------------------------------===// + +template +class NodeRef { + +public: + typedef NodeSizer NodeSizer; + typedef Leaf Leaf; + typedef Branch Branch; + +private: + struct CacheAlignedPointerTraits { + static inline void *getAsVoidPointer(void *P) { return P; } + static inline void *getFromVoidPointer(void *P) { return P; } + enum { NumLowBitsAvailable = NodeSizer::Log2CacheLine }; + }; + + PointerIntPair pip; + +public: + /// NodeRef - Create a null ref. + NodeRef() {} + + /// operator bool - Detect a null ref. + operator bool() const { return pip.getOpaqueValue(); } + + /// NodeRef - Create a reference to the leaf node p with n elements. + NodeRef(Leaf *p, unsigned n) : pip(p, n - 1) {} + + /// NodeRef - Create a reference to the branch node p with n elements. + NodeRef(Branch *p, unsigned n) : pip(p, n - 1) {} + + /// size - Return the number of elements in the referenced node. + unsigned size() const { return pip.getInt() + 1; } + + /// setSize - Update the node size. + void setSize(unsigned n) { pip.setInt(n - 1); } + + /// leaf - Return the referenced leaf node. + /// Note there are no dynamic type checks. + Leaf &leaf() const { + return *reinterpret_cast(pip.getPointer()); + } + + /// branch - Return the referenced branch node. + /// Note there are no dynamic type checks. + Branch &branch() const { + return *reinterpret_cast(pip.getPointer()); + } + + bool operator==(const NodeRef &RHS) const { + if (pip == RHS.pip) + return true; + assert(pip.getPointer() != RHS.pip.getPointer() && "Inconsistent NodeRefs"); + return false; + } + + bool operator!=(const NodeRef &RHS) const { + return !operator==(RHS); + } +}; + +//===----------------------------------------------------------------------===// +//--- Leaf nodes ---// +//===----------------------------------------------------------------------===// +// +// Leaf nodes store up to N disjoint intervals with corresponding values. +// +// The intervals are kept sorted and fully coalesced so there are no adjacent +// intervals mapping to the same value. +// +// These constraints are always satisfied: +// +// - Traits::stopLess(key[i].start, key[i].stop) - Non-empty, sane intervals. +// +// - Traits::stopLess(key[i].stop, key[i + 1].start) - Sorted. +// +// - val[i] != val[i + 1] || +// !Traits::adjacent(key[i].stop, key[i + 1].start) - Fully coalesced. +// +//===----------------------------------------------------------------------===// + +template +class Leaf : public NodeBase, ValT, N> { +public: + const KeyT &start(unsigned i) const { return this->key[i].first; } + const KeyT &stop(unsigned i) const { return this->key[i].second; } + const ValT &value(unsigned i) const { return this->val[i]; } + + KeyT &start(unsigned i) { return this->key[i].first; } + KeyT &stop(unsigned i) { return this->key[i].second; } + ValT &value(unsigned i) { return this->val[i]; } + + /// findFrom - Find the first interval after i that may contain x. + /// @param i Starting index for the search. + /// @param size Number of elements in node. + /// @param x Key to search for. + /// @return First index with !stopLess(key[i].stop, x), or size. + /// This is the first interval that can possibly contain x. + unsigned findFrom(unsigned i, unsigned Size, KeyT x) const { + assert(i <= Size && Size <= N && "Bad indices"); + assert((i == 0 || Traits::stopLess(stop(i - 1), x)) && + "Index is past the needed point"); + while (i != Size && Traits::stopLess(stop(i), x)) ++i; + return i; + } + + /// safeFind - Find an interval that is known to exist. This is the same as + /// findFrom except is it assumed that x is at least within range of the last + /// interval. + /// @param i Starting index for the search. + /// @param x Key to search for. + /// @return First index with !stopLess(key[i].stop, x), never size. + /// This is the first interval that can possibly contain x. + unsigned safeFind(unsigned i, KeyT x) const { + assert(i < N && "Bad index"); + assert((i == 0 || Traits::stopLess(stop(i - 1), x)) && + "Index is past the needed point"); + while (Traits::stopLess(stop(i), x)) ++i; + assert(i < N && "Unsafe intervals"); + return i; + } + + /// safeLookup - Lookup mapped value for a safe key. + /// It is assumed that x is within range of the last entry. + /// @param x Key to search for. + /// @param NotFound Value to return if x is not in any interval. + /// @return The mapped value at x or NotFound. + ValT safeLookup(KeyT x, ValT NotFound) const { + unsigned i = safeFind(0, x); + return Traits::startLess(x, start(i)) ? NotFound : value(i); + } + + IdxPair insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y); + unsigned extendStop(unsigned i, unsigned Size, KeyT b); + +#ifndef NDEBUG + void dump(unsigned Size) { + errs() << " N" << this << " [shape=record label=\"{ " << Size << '/' << N; + for (unsigned i = 0; i != Size; ++i) + errs() << " | {" << start(i) << '-' << stop(i) << "|" << value(i) << '}'; + errs() << "}\"];\n"; + } +#endif + +}; + +/// insertFrom - Add mapping of [a;b] to y if possible, coalescing as much as +/// possible. This may cause the node to grow by 1, or it may cause the node +/// to shrink because of coalescing. +/// @param i Starting index = insertFrom(0, size, a) +/// @param size Number of elements in node. +/// @param a Interval start. +/// @param b Interval stop. +/// @param y Value be mapped. +/// @return (insert position, new size), or (i, Capacity+1) on overflow. +template +IdxPair Leaf:: +insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y) { + assert(i <= Size && Size <= N && "Invalid index"); + assert(!Traits::stopLess(b, a) && "Invalid interval"); + + // Verify the findFrom invariant. + assert((i == 0 || Traits::stopLess(stop(i - 1), a))); + assert((i == Size || !Traits::stopLess(stop(i), a))); + + // Coalesce with previous interval. + if (i && value(i - 1) == y && Traits::adjacent(stop(i - 1), a)) + return IdxPair(i - 1, extendStop(i - 1, Size, b)); + + // Detect overflow. + if (i == N) + return IdxPair(i, N + 1); + + // Add new interval at end. + if (i == Size) { + start(i) = a; + stop(i) = b; + value(i) = y; + return IdxPair(i, Size + 1); + } + + // Overlapping intervals? + if (!Traits::stopLess(b, start(i))) { + assert(value(i) == y && "Inconsistent values in overlapping intervals"); + if (Traits::startLess(a, start(i))) + start(i) = a; + return IdxPair(i, extendStop(i, Size, b)); + } + + // Try to coalesce with following interval. + if (value(i) == y && Traits::adjacent(b, start(i))) { + start(i) = a; + return IdxPair(i, Size); + } + + // We must insert before i. Detect overflow. + if (Size == N) + return IdxPair(i, N + 1); + + // Insert before i. + this->shift(i, Size); + start(i) = a; + stop(i) = b; + value(i) = y; + return IdxPair(i, Size + 1); +} + +/// extendStop - Extend stop(i) to b, coalescing with following intervals. +/// @param i Interval to extend. +/// @param size Number of elements in node. +/// @param b New interval end point. +/// @return New node size after coalescing. +template +unsigned Leaf:: +extendStop(unsigned i, unsigned Size, KeyT b) { + assert(i < Size && Size <= N && "Bad indices"); + + // Are we even extending the interval? + if (Traits::startLess(b, stop(i))) + return Size; + + // Find the first interval that may be preserved. + unsigned j = findFrom(i + 1, Size, b); + if (j < Size) { + // Would key[i] overlap key[j] after the extension? + if (Traits::stopLess(b, start(j))) { + // Not overlapping. Perhaps adjacent and coalescable? + if (value(i) == value(j) && Traits::adjacent(b, start(j))) + b = stop(j++); + } else { + // Overlap. Include key[j] in the new interval. + assert(value(i) == value(j) && "Overlapping values"); + b = stop(j++); + } + } + stop(i) = b; + + // Entries [i+1;j) were coalesced. + if (i + 1 < j && j < Size) + this->erase(i + 1, j, Size); + return Size - (j - (i + 1)); +} + + +//===----------------------------------------------------------------------===// +//--- Branch nodes ---// +//===----------------------------------------------------------------------===// +// +// A branch node stores references to 1--N subtrees all of the same height. +// +// The key array in a branch node holds the rightmost stop key of each subtree. +// It is redundant to store the last stop key since it can be found in the +// parent node, but doing so makes tree balancing a lot simpler. +// +// It is unusual for a branch node to only have one subtree, but it can happen +// in the root node if it is smaller than the normal nodes. +// +// When all of the leaf nodes from all the subtrees are concatenated, they must +// satisfy the same constraints as a single leaf node. They must be sorted, +// sane, and fully coalesced. +// +//===----------------------------------------------------------------------===// + +template +class Branch : public NodeBase, N> { + typedef NodeRef NodeRef; +public: + const KeyT &stop(unsigned i) const { return this->key[i]; } + const NodeRef &subtree(unsigned i) const { return this->val[i]; } + + KeyT &stop(unsigned i) { return this->key[i]; } + NodeRef &subtree(unsigned i) { return this->val[i]; } + + + /// findFrom - Find the first subtree after i that may contain x. + /// @param i Starting index for the search. + /// @param size Number of elements in node. + /// @param x Key to search for. + /// @return First index with !stopLess(key[i], x), or size. + /// This is the first subtree that can possibly contain x. + unsigned findFrom(unsigned i, unsigned Size, KeyT x) const { + assert(i <= Size && Size <= N && "Bad indices"); + assert((i == 0 || Traits::stopLess(stop(i - 1), x)) && + "Index to findFrom is past the needed point"); + while (i != Size && Traits::stopLess(stop(i), x)) ++i; + return i; + } + + /// safeFind - Find a subtree that is known to exist. This is the same as + /// findFrom except is it assumed that x is in range. + /// @param i Starting index for the search. + /// @param x Key to search for. + /// @return First index with !stopLess(key[i], x), never size. + /// This is the first subtree that can possibly contain x. + unsigned safeFind(unsigned i, KeyT x) const { + assert(i < N && "Bad index"); + assert((i == 0 || Traits::stopLess(stop(i - 1), x)) && + "Index is past the needed point"); + while (Traits::stopLess(stop(i), x)) ++i; + assert(i < N && "Unsafe intervals"); + return i; + } + + /// safeLookup - Get the subtree containing x, Assuming that x is in range. + /// @param x Key to search for. + /// @return Subtree containing x + NodeRef safeLookup(KeyT x) const { + return subtree(safeFind(0, x)); + } + + /// insert - Insert a new (subtree, stop) pair. + /// @param i Insert position, following entries will be shifted. + /// @param size Number of elements in node. + /// @param node Subtree to insert. + /// @param stp Last key in subtree. + void insert(unsigned i, unsigned Size, NodeRef Node, KeyT Stop) { + assert(Size < N && "branch node overflow"); + assert(i <= Size && "Bad insert position"); + this->shift(i, Size); + subtree(i) = Node; + stop(i) = Stop; + } + +#ifndef NDEBUG + void dump(unsigned Size) { + errs() << " N" << this << " [shape=record label=\"" << Size << '/' << N; + for (unsigned i = 0; i != Size; ++i) + errs() << " | " << stop(i); + errs() << "\"];\n"; + for (unsigned i = 0; i != Size; ++i) + errs() << " N" << this << ":s" << i << " -> N" + << &subtree(i).branch() << ";\n"; + } +#endif + +}; + +} // namespace IntervalMapImpl + + +//===----------------------------------------------------------------------===// +//--- IntervalMap ----// +//===----------------------------------------------------------------------===// + +template ::LeafSize, + typename Traits = IntervalMapInfo > +class IntervalMap { + typedef IntervalMapImpl::NodeRef NodeRef; + typedef typename NodeRef::NodeSizer NodeSizer; + typedef typename NodeRef::Leaf Leaf; + typedef typename NodeRef::Branch Branch; + typedef IntervalMapImpl::Leaf RootLeaf; + typedef IntervalMapImpl::IdxPair IdxPair; + + // The RootLeaf capacity is given as a template parameter. We must compute the + // corresponding RootBranch capacity. + enum { + DesiredRootBranchCap = (sizeof(RootLeaf) - sizeof(KeyT)) / + (sizeof(KeyT) + sizeof(NodeRef)), + RootBranchCap = DesiredRootBranchCap ? DesiredRootBranchCap : 1 + }; + + typedef IntervalMapImpl::Branch RootBranch; + + // When branched, we store a global start key as well as the branch node. + struct RootBranchData { + KeyT start; + RootBranch node; + }; + + enum { + RootDataSize = sizeof(RootBranchData) > sizeof(RootLeaf) ? + sizeof(RootBranchData) : sizeof(RootLeaf) + }; + +public: + typedef typename NodeSizer::Allocator Allocator; + +private: + // The root data is either a RootLeaf or a RootBranchData instance. + // We can't put them in a union since C++03 doesn't allow non-trivial + // constructors in unions. + // Instead, we use a char array with pointer alignment. The alignment is + // ensured by the allocator member in the class, but still verified in the + // constructor. We don't support keys or values that are more aligned than a + // pointer. + char data[RootDataSize]; + + // Tree height. + // 0: Leaves in root. + // 1: Root points to leaf. + // 2: root->branch->leaf ... + unsigned height; + + // Number of entries in the root node. + unsigned rootSize; + + // Allocator used for creating external nodes. + Allocator &allocator; + + const RootLeaf &rootLeaf() const { + assert(!branched() && "Cannot acces leaf data in branched root"); + return *reinterpret_cast(data); + } + RootLeaf &rootLeaf() { + assert(!branched() && "Cannot acces leaf data in branched root"); + return *reinterpret_cast(data); + } + const RootBranchData &rootBranchData() const { + assert(branched() && "Cannot access branch data in non-branched root"); + return *reinterpret_cast(data); + } + RootBranchData &rootBranchData() { + assert(branched() && "Cannot access branch data in non-branched root"); + return *reinterpret_cast(data); + } + const RootBranch &rootBranch() const { return rootBranchData().node; } + RootBranch &rootBranch() { return rootBranchData().node; } + KeyT rootBranchStart() const { return rootBranchData().start; } + KeyT &rootBranchStart() { return rootBranchData().start; } + + Leaf *allocLeaf() { + return new(allocator.template Allocate()) Leaf(); + } + void freeLeaf(Leaf *P) { + P->~Leaf(); + allocator.Deallocate(P); + } + + Branch *allocBranch() { + return new(allocator.template Allocate()) Branch(); + } + void freeBranch(Branch *P) { + P->~Branch(); + allocator.Deallocate(P); + } + + + IdxPair branchRoot(unsigned Position); + IdxPair splitRoot(unsigned Position); + + void switchRootToBranch() { + rootLeaf().~RootLeaf(); + height = 1; + new (&rootBranchData()) RootBranchData(); + } + + void switchRootToLeaf() { + rootBranchData().~RootBranchData(); + height = 0; + new(&rootLeaf()) RootLeaf(); + } + + bool branched() const { return height > 0; } + + ValT treeSafeLookup(KeyT x, ValT NotFound) const; + + void visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Level)); + +public: + explicit IntervalMap(Allocator &a) : height(0), rootSize(0), allocator(a) { + assert((uintptr_t(data) & (alignOf() - 1)) == 0 && + "Insufficient alignment"); + new(&rootLeaf()) RootLeaf(); + } + + /// empty - Return true when no intervals are mapped. + bool empty() const { + return rootSize == 0; + } + + /// start - Return the smallest mapped key in a non-empty map. + KeyT start() const { + assert(!empty() && "Empty IntervalMap has no start"); + return !branched() ? rootLeaf().start(0) : rootBranchStart(); + } + + /// stop - Return the largest mapped key in a non-empty map. + KeyT stop() const { + assert(!empty() && "Empty IntervalMap has no stop"); + return !branched() ? rootLeaf().stop(rootSize - 1) : + rootBranch().stop(rootSize - 1); + } + + /// lookup - Return the mapped value at x or NotFound. + ValT lookup(KeyT x, ValT NotFound = ValT()) const { + if (empty() || Traits::startLess(x, start()) || Traits::stopLess(stop(), x)) + return NotFound; + return branched() ? treeSafeLookup(x, NotFound) : + rootLeaf().safeLookup(x, NotFound); + } + + /// insert - Add a mapping of [a;b] to y, coalesce with adjacent intervals. + /// It is assumed that no key in the interval is mapped to another value, but + /// overlapping intervals already mapped to y will be coalesced. + void insert(KeyT a, KeyT b, ValT y) { + find(a).insert(a, b, y); + } + + class const_iterator; + class iterator; + friend class const_iterator; + friend class iterator; + + const_iterator begin() const { + iterator I(*this); + I.goToBegin(); + return I; + } + + iterator begin() { + iterator I(*this); + I.goToBegin(); + return I; + } + + const_iterator end() const { + iterator I(*this); + I.goToEnd(); + return I; + } + + iterator end() { + iterator I(*this); + I.goToEnd(); + return I; + } + + /// find - Return an iterator pointing to the first interval ending at or + /// after x, or end(). + const_iterator find(KeyT x) const { + iterator I(*this); + I.find(x); + return I; + } + + iterator find(KeyT x) { + iterator I(*this); + I.find(x); + return I; + } + +#ifndef NDEBUG + void dump(); + void dumpNode(NodeRef Node, unsigned Height); +#endif +}; + +/// treeSafeLookup - Return the mapped value at x or NotFound, assuming a +/// branched root. +template +ValT IntervalMap:: +treeSafeLookup(KeyT x, ValT NotFound) const { + assert(branched() && "treeLookup assumes a branched root"); + + NodeRef NR = rootBranch().safeLookup(x); + for (unsigned h = height-1; h; --h) + NR = NR.branch().safeLookup(x); + return NR.leaf().safeLookup(x, NotFound); +} + + +// branchRoot - Switch from a leaf root to a branched root. +// Return the new (root offset, node offset) corresponding to Position. +template +IntervalMapImpl::IdxPair IntervalMap:: +branchRoot(unsigned Position) { + // How many external leaf nodes to hold RootLeaf+1? + const unsigned Nodes = RootLeaf::Capacity / Leaf::Capacity + 1; + + // Compute element distribution among new nodes. + unsigned size[Nodes]; + IdxPair NewOffset(0, Position); + + // Is is very common for the root node to be smaller than external nodes. + if (Nodes == 1) + size[0] = rootSize; + else + NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, size, + Position, true); + + // Allocate new nodes. + unsigned pos = 0; + NodeRef node[Nodes]; + for (unsigned n = 0; n != Nodes; ++n) { + node[n] = NodeRef(allocLeaf(), size[n]); + node[n].leaf().copy(rootLeaf(), pos, 0, size[n]); + pos += size[n]; + } + + // Destroy the old leaf node, construct branch node instead. + switchRootToBranch(); + for (unsigned n = 0; n != Nodes; ++n) { + rootBranch().stop(n) = node[n].leaf().stop(size[n]-1); + rootBranch().subtree(n) = node[n]; + } + rootBranchStart() = node[0].leaf().start(0); + rootSize = Nodes; + return NewOffset; +} + +// splitRoot - Split the current BranchRoot into multiple Branch nodes. +// Return the new (root offset, node offset) corresponding to Position. +template +IntervalMapImpl::IdxPair IntervalMap:: +splitRoot(unsigned Position) { + // How many external leaf nodes to hold RootBranch+1? + const unsigned Nodes = RootBranch::Capacity / Branch::Capacity + 1; + + // Compute element distribution among new nodes. + unsigned Size[Nodes]; + IdxPair NewOffset(0, Position); + + // Is is very common for the root node to be smaller than external nodes. + if (Nodes == 1) + Size[0] = rootSize; + else + NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, Size, + Position, true); + + // Allocate new nodes. + unsigned Pos = 0; + NodeRef Node[Nodes]; + for (unsigned n = 0; n != Nodes; ++n) { + Node[n] = NodeRef(allocBranch(), Size[n]); + Node[n].branch().copy(rootBranch(), Pos, 0, Size[n]); + Pos += Size[n]; + } + + for (unsigned n = 0; n != Nodes; ++n) { + rootBranch().stop(n) = Node[n].branch().stop(Size[n]-1); + rootBranch().subtree(n) = Node[n]; + } + rootSize = Nodes; + return NewOffset; +} + +/// visitNodes - Visit each external node. +template +void IntervalMap:: +visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Height)) { + if (!branched()) + return; + SmallVector Refs, NextRefs; + + // Collect level 0 nodes from the root. + for (unsigned i = 0; i != rootSize; ++i) + Refs.push_back(rootBranch().subtree(i)); + + // Visit all branch nodes. + for (unsigned h = height - 1; h; --h) { + for (unsigned i = 0, e = Refs.size(); i != e; ++i) { + Branch &B = Refs[i].branch(); + for (unsigned j = 0, s = Refs[i].size(); j != s; ++j) + NextRefs.push_back(B.subtree(j)); + (this->*f)(Refs[i], h); + } + Refs.clear(); + Refs.swap(NextRefs); + } + + // Visit all leaf nodes. + for (unsigned i = 0, e = Refs.size(); i != e; ++i) + (this->*f)(Refs[i], 0); +} + +#ifndef NDEBUG +template +void IntervalMap:: +dumpNode(NodeRef Node, unsigned Height) { + if (Height) + Node.branch().dump(Node.size()); + else + Node.leaf().dump(Node.size()); +} + +template +void IntervalMap:: +dump() { + errs() << "digraph {\n"; + if (branched()) + rootBranch().dump(rootSize); + else + rootLeaf().dump(rootSize); + visitNodes(&IntervalMap::dumpNode); + errs() << "}\n"; +} +#endif + +//===----------------------------------------------------------------------===// +//--- const_iterator ----// +//===----------------------------------------------------------------------===// + +template +class IntervalMap::const_iterator : + public std::iterator { +protected: + friend class IntervalMap; + typedef std::pair PathEntry; + typedef SmallVector Path; + + // The map referred to. + IntervalMap *map; + + // The offset into map's root node. + unsigned rootOffset; + + // We store a full path from the root to the current position. + // + // When rootOffset == map->rootSize, we are at end() and path() is empty. + // Otherwise, when branched these conditions hold: + // + // 1. path.front().first == rootBranch().subtree(rootOffset) + // 2. path[i].first == path[i-1].first.branch().subtree(path[i-1].second) + // 3. path.size() == map->height. + // + // Thus, path.back() always refers to the current leaf node unless the root is + // unbranched. + // + // The path may be partially filled, but never between iterator calls. + Path path; + + explicit const_iterator(IntervalMap &map) + : map(&map), rootOffset(map.rootSize) {} + + bool branched() const { + assert(map && "Invalid iterator"); + return map->branched(); + } + + NodeRef pathNode(unsigned h) const { return path[h].first; } + NodeRef &pathNode(unsigned h) { return path[h].first; } + unsigned pathOffset(unsigned h) const { return path[h].second; } + unsigned &pathOffset(unsigned h) { return path[h].second; } + + Leaf &treeLeaf() const { + assert(branched() && path.size() == map->height); + return path.back().first.leaf(); + } + unsigned treeLeafSize() const { + assert(branched() && path.size() == map->height); + return path.back().first.size(); + } + unsigned &treeLeafOffset() { + assert(branched() && path.size() == map->height); + return path.back().second; + } + unsigned treeLeafOffset() const { + assert(branched() && path.size() == map->height); + return path.back().second; + } + + // Get the next node ptr for an incomplete path. + NodeRef pathNextDown() { + assert(path.size() < map->height && "Path is already complete"); + + if (path.empty()) + return map->rootBranch().subtree(rootOffset); + else + return path.back().first.branch().subtree(path.back().second); + } + + void pathFillLeft(); + void pathFillFind(KeyT x); + void pathFillRight(); + + NodeRef leftSibling(unsigned level) const; + NodeRef rightSibling(unsigned level) const; + + void treeIncrement(); + void treeDecrement(); + void treeFind(KeyT x); + +public: + /// valid - Return true if the current position is valid, false for end(). + bool valid() const { + assert(map && "Invalid iterator"); + return rootOffset < map->rootSize; + } + + /// start - Return the beginning of the current interval. + const KeyT &start() const { + assert(valid() && "Cannot access invalid iterator"); + return branched() ? treeLeaf().start(treeLeafOffset()) : + map->rootLeaf().start(rootOffset); + } + + /// stop - Return the end of the current interval. + const KeyT &stop() const { + assert(valid() && "Cannot access invalid iterator"); + return branched() ? treeLeaf().stop(treeLeafOffset()) : + map->rootLeaf().stop(rootOffset); + } + + /// value - Return the mapped value at the current interval. + const ValT &value() const { + assert(valid() && "Cannot access invalid iterator"); + return branched() ? treeLeaf().value(treeLeafOffset()) : + map->rootLeaf().value(rootOffset); + } + + const ValT &operator*() const { + return value(); + } + + bool operator==(const const_iterator &RHS) const { + assert(map == RHS.map && "Cannot compare iterators from different maps"); + return rootOffset == RHS.rootOffset && + (!valid() || !branched() || path.back() == RHS.path.back()); + } + + bool operator!=(const const_iterator &RHS) const { + return !operator==(RHS); + } + + /// goToBegin - Move to the first interval in map. + void goToBegin() { + rootOffset = 0; + path.clear(); + if (branched()) + pathFillLeft(); + } + + /// goToEnd - Move beyond the last interval in map. + void goToEnd() { + rootOffset = map->rootSize; + path.clear(); + } + + /// preincrement - move to the next interval. + const_iterator &operator++() { + assert(valid() && "Cannot increment end()"); + if (!branched()) + ++rootOffset; + else if (treeLeafOffset() != treeLeafSize() - 1) + ++treeLeafOffset(); + else + treeIncrement(); + return *this; + } + + /// postincrement - Dont do that! + const_iterator operator++(int) { + const_iterator tmp = *this; + operator++(); + return tmp; + } + + /// predecrement - move to the previous interval. + const_iterator &operator--() { + if (!branched()) { + assert(rootOffset && "Cannot decrement begin()"); + --rootOffset; + } else if (treeLeafOffset()) + --treeLeafOffset(); + else + treeDecrement(); + return *this; + } + + /// postdecrement - Dont do that! + const_iterator operator--(int) { + const_iterator tmp = *this; + operator--(); + return tmp; + } + + /// find - Move to the first interval with stop >= x, or end(). + /// This is a full search from the root, the current position is ignored. + void find(KeyT x) { + if (branched()) + treeFind(x); + else + rootOffset = map->rootLeaf().findFrom(0, map->rootSize, x); + } + + /// advanceTo - Move to the first interval with stop >= x, or end(). + /// The search is started from the current position, and no earlier positions + /// can be found. This is much faster than find() for small moves. + void advanceTo(KeyT x) { + if (branched()) + treeAdvanceTo(x); + else + rootOffset = map->rootLeaf().findFrom(rootOffset, map->rootSize, x); + } + +}; + +// pathFillLeft - Complete path by following left-most branches. +template +void IntervalMap:: +const_iterator::pathFillLeft() { + NodeRef NR = pathNextDown(); + for (unsigned i = map->height - path.size() - 1; i; --i) { + path.push_back(PathEntry(NR, 0)); + NR = NR.branch().subtree(0); + } + path.push_back(PathEntry(NR, 0)); +} + +// pathFillFind - Complete path by searching for x. +template +void IntervalMap:: +const_iterator::pathFillFind(KeyT x) { + NodeRef NR = pathNextDown(); + for (unsigned i = map->height - path.size() - 1; i; --i) { + unsigned p = NR.branch().safeFind(0, x); + path.push_back(PathEntry(NR, p)); + NR = NR.branch().subtree(p); + } + path.push_back(PathEntry(NR, NR.leaf().safeFind(0, x))); +} + +// pathFillRight - Complete path by adding rightmost entries. +template +void IntervalMap:: +const_iterator::pathFillRight() { + NodeRef NR = pathNextDown(); + for (unsigned i = map->height - path.size() - 1; i; --i) { + unsigned p = NR.size() - 1; + path.push_back(PathEntry(NR, p)); + NR = NR.branch().subtree(p); + } + path.push_back(PathEntry(NR, NR.size() - 1)); +} + +/// leftSibling - find the left sibling node to path[level]. +/// @param level 0 is just below the root, map->height - 1 for the leaves. +/// @return The left sibling NodeRef, or NULL. +template +typename IntervalMap::NodeRef +IntervalMap:: +const_iterator::leftSibling(unsigned level) const { + assert(branched() && "Not at a branched node"); + assert(level <= path.size() && "Bad level"); + + // Go up the tree until we can go left. + unsigned h = level; + while (h && pathOffset(h - 1) == 0) + --h; + + // We are at the first leaf node, no left sibling. + if (!h && rootOffset == 0) + return NodeRef(); + + // NR is the subtree containing our left sibling. + NodeRef NR = h ? + pathNode(h - 1).branch().subtree(pathOffset(h - 1) - 1) : + map->rootBranch().subtree(rootOffset - 1); + + // Keep right all the way down. + for (; h != level; ++h) + NR = NR.branch().subtree(NR.size() - 1); + return NR; +} + +/// rightSibling - find the right sibling node to path[level]. +/// @param level 0 is just below the root, map->height - 1 for the leaves. +/// @return The right sibling NodeRef, or NULL. +template +typename IntervalMap::NodeRef +IntervalMap:: +const_iterator::rightSibling(unsigned level) const { + assert(branched() && "Not at a branched node"); + assert(level <= this->path.size() && "Bad level"); + + // Go up the tree until we can go right. + unsigned h = level; + while (h && pathOffset(h - 1) == pathNode(h - 1).size() - 1) + --h; + + // We are at the last leaf node, no right sibling. + if (!h && rootOffset == map->rootSize - 1) + return NodeRef(); + + // NR is the subtree containing our right sibling. + NodeRef NR = h ? + pathNode(h - 1).branch().subtree(pathOffset(h - 1) + 1) : + map->rootBranch().subtree(rootOffset + 1); + + // Keep left all the way down. + for (; h != level; ++h) + NR = NR.branch().subtree(0); + return NR; +} + +// treeIncrement - Move to the beginning of the next leaf node. +template +void IntervalMap:: +const_iterator::treeIncrement() { + assert(branched() && "treeIncrement is not for small maps"); + assert(path.size() == map->height && "inconsistent iterator"); + do path.pop_back(); + while (!path.empty() && path.back().second == path.back().first.size() - 1); + if (path.empty()) { + ++rootOffset; + if (!valid()) + return; + } else + ++path.back().second; + pathFillLeft(); +} + +// treeDecrement - Move to the end of the previous leaf node. +template +void IntervalMap:: +const_iterator::treeDecrement() { + assert(branched() && "treeDecrement is not for small maps"); + if (valid()) { + assert(path.size() == map->height && "inconsistent iterator"); + do path.pop_back(); + while (!path.empty() && path.back().second == 0); + } + if (path.empty()) { + assert(rootOffset && "cannot treeDecrement() on begin()"); + --rootOffset; + } else + --path.back().second; + pathFillRight(); +} + +// treeFind - Find in a branched tree. +template +void IntervalMap:: +const_iterator::treeFind(KeyT x) { + path.clear(); + rootOffset = map->rootBranch().findFrom(0, map->rootSize, x); + if (valid()) + pathFillFind(x); +} + + +//===----------------------------------------------------------------------===// +//--- iterator ----// +//===----------------------------------------------------------------------===// + +namespace IntervalMapImpl { + + /// distribute - Compute a new distribution of node elements after an overflow + /// or underflow. Reserve space for a new element at Position, and compute the + /// node that will hold Position after redistributing node elements. + /// + /// It is required that + /// + /// Elements == sum(CurSize), and + /// Elements + Grow <= Nodes * Capacity. + /// + /// NewSize[] will be filled in such that: + /// + /// sum(NewSize) == Elements, and + /// NewSize[i] <= Capacity. + /// + /// The returned index is the node where Position will go, so: + /// + /// sum(NewSize[0..idx-1]) <= Position + /// sum(NewSize[0..idx]) >= Position + /// + /// The last equality, sum(NewSize[0..idx]) == Position, can only happen when + /// Grow is set and NewSize[idx] == Capacity-1. The index points to the node + /// before the one holding the Position'th element where there is room for an + /// insertion. + /// + /// @param Nodes The number of nodes. + /// @param Elements Total elements in all nodes. + /// @param Capacity The capacity of each node. + /// @param CurSize Array[Nodes] of current node sizes, or NULL. + /// @param NewSize Array[Nodes] to receive the new node sizes. + /// @param Position Insert position. + /// @param Grow Reserve space for a new element at Position. + /// @return (node, offset) for Position. + IdxPair distribute(unsigned Nodes, unsigned Elements, unsigned Capacity, + const unsigned *CurSize, unsigned NewSize[], + unsigned Position, bool Grow); + +} + +template +class IntervalMap::iterator : public const_iterator { + friend class IntervalMap; + typedef IntervalMapImpl::IdxPair IdxPair; + + explicit iterator(IntervalMap &map) : const_iterator(map) {} + + void setNodeSize(unsigned Level, unsigned Size); + void setNodeStop(unsigned Level, KeyT Stop); + void insertNode(unsigned Level, NodeRef Node, KeyT Stop); + void overflowLeaf(); + void treeInsert(KeyT a, KeyT b, ValT y); + +public: + /// insert - Insert mapping [a;b] -> y before the current position. + void insert(KeyT a, KeyT b, ValT y); + +}; + +/// setNodeSize - Set the size of the node at path[level], updating both path +/// and the real tree. +/// @param level 0 is just below the root, map->height - 1 for the leaves. +/// @param size New node size. +template +void IntervalMap:: +iterator::setNodeSize(unsigned Level, unsigned Size) { + this->pathNode(Level).setSize(Size); + if (Level) + this->pathNode(Level-1).branch() + .subtree(this->pathOffset(Level-1)).setSize(Size); + else + this->map->rootBranch().subtree(this->rootOffset).setSize(Size); +} + +/// setNodeStop - Update the stop key of the current node at level and above. +template +void IntervalMap:: +iterator::setNodeStop(unsigned Level, KeyT Stop) { + while (Level--) { + this->pathNode(Level).branch().stop(this->pathOffset(Level)) = Stop; + if (this->pathOffset(Level) != this->pathNode(Level).size() - 1) + return; + } + this->map->rootBranch().stop(this->rootOffset) = Stop; +} + +/// insertNode - insert a node before the current path at level. +/// Leave the current path pointing at the new node. +template +void IntervalMap:: +iterator::insertNode(unsigned Level, NodeRef Node, KeyT Stop) { + if (!Level) { + // Insert into the root branch node. + IntervalMap &IM = *this->map; + if (IM.rootSize < RootBranch::Capacity) { + IM.rootBranch().insert(this->rootOffset, IM.rootSize, Node, Stop); + ++IM.rootSize; + return; + } + + // We need to split the root while keeping our position. + IdxPair Offset = IM.splitRoot(this->rootOffset); + this->rootOffset = Offset.first; + this->path.insert(this->path.begin(),std::make_pair( + this->map->rootBranch().subtree(Offset.first), Offset.second)); + Level = 1; + } + + // When inserting before end(), make sure we have a valid path. + if (!this->valid()) { + this->treeDecrement(); + ++this->pathOffset(Level-1); + } + + // Insert into the branch node at level-1. + NodeRef NR = this->pathNode(Level-1); + unsigned Offset = this->pathOffset(Level-1); + assert(NR.size() < Branch::Capacity && "Branch overflow"); + NR.branch().insert(Offset, NR.size(), Node, Stop); + setNodeSize(Level - 1, NR.size() + 1); +} + +// insert +template +void IntervalMap:: +iterator::insert(KeyT a, KeyT b, ValT y) { + if (this->branched()) + return treeInsert(a, b, y); + IdxPair IP = this->map->rootLeaf().insertFrom(this->rootOffset, + this->map->rootSize, + a, b, y); + if (IP.second <= RootLeaf::Capacity) { + this->rootOffset = IP.first; + this->map->rootSize = IP.second; + return; + } + IdxPair Offset = this->map->branchRoot(this->rootOffset); + this->rootOffset = Offset.first; + this->path.push_back(std::make_pair( + this->map->rootBranch().subtree(Offset.first), Offset.second)); + treeInsert(a, b, y); +} + + +template +void IntervalMap:: +iterator::treeInsert(KeyT a, KeyT b, ValT y) { + if (!this->valid()) { + // end() has an empty path. Go back to the last leaf node and use an + // invalid offset instead. + this->treeDecrement(); + ++this->treeLeafOffset(); + } + IdxPair IP = this->treeLeaf().insertFrom(this->treeLeafOffset(), + this->treeLeafSize(), a, b, y); + this->treeLeafOffset() = IP.first; + if (IP.second <= Leaf::Capacity) { + setNodeSize(this->map->height - 1, IP.second); + if (IP.first == IP.second - 1) + setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first)); + return; + } + // Leaf node has no space. + overflowLeaf(); + IP = this->treeLeaf().insertFrom(this->treeLeafOffset(), + this->treeLeafSize(), a, b, y); + this->treeLeafOffset() = IP.first; + setNodeSize(this->map->height-1, IP.second); + if (IP.first == IP.second - 1) + setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first)); + + // FIXME: Handle cross-node coalescing. +} + +// overflowLeaf - Distribute entries of the current leaf node evenly among +// its siblings and ensure that the current node is not full. +// This may require allocating a new node. +template +void IntervalMap:: +iterator::overflowLeaf() { + unsigned CurSize[4]; + Leaf *Node[4]; + unsigned Nodes = 0; + unsigned Elements = 0; + unsigned Offset = this->treeLeafOffset(); + + // Do we have a left sibling? + NodeRef LeftSib = this->leftSibling(this->map->height-1); + if (LeftSib) { + Offset += Elements = CurSize[Nodes] = LeftSib.size(); + Node[Nodes++] = &LeftSib.leaf(); + } + + // Current leaf node. + Elements += CurSize[Nodes] = this->treeLeafSize(); + Node[Nodes++] = &this->treeLeaf(); + + // Do we have a right sibling? + NodeRef RightSib = this->rightSibling(this->map->height-1); + if (RightSib) { + Offset += Elements = CurSize[Nodes] = RightSib.size(); + Node[Nodes++] = &RightSib.leaf(); + } + + // Do we need to allocate a new node? + unsigned NewNode = 0; + if (Elements + 1 > Nodes * Leaf::Capacity) { + // Insert NewNode at the penultimate position, or after a single node. + NewNode = Nodes == 1 ? 1 : Nodes - 1; + CurSize[Nodes] = CurSize[NewNode]; + Node[Nodes] = Node[NewNode]; + CurSize[NewNode] = 0; + Node[NewNode] = this->map->allocLeaf(); + ++Nodes; + } + + // Compute the new element distribution. + unsigned NewSize[4]; + IdxPair NewOffset = + IntervalMapImpl::distribute(Nodes, Elements, Leaf::Capacity, + CurSize, NewSize, Offset, true); + + // Move current location to the leftmost node. + if (LeftSib) + this->treeDecrement(); + + // Move elements right. + for (int n = Nodes - 1; n; --n) { + if (CurSize[n] == NewSize[n]) + continue; + for (int m = n - 1; m != -1; --m) { + int d = Node[n]->adjLeftSib(CurSize[n], *Node[m], CurSize[m], + NewSize[n] - CurSize[n]); + CurSize[m] -= d; + CurSize[n] += d; + // Keep going if the current node was exhausted. + if (CurSize[n] >= NewSize[n]) + break; + } + } + + // Move elements left. + for (unsigned n = 0; n != Nodes - 1; ++n) { + if (CurSize[n] == NewSize[n]) + continue; + for (unsigned m = n + 1; m != Nodes; ++m) { + int d = Node[m]->adjLeftSib(CurSize[m], *Node[n], CurSize[n], + CurSize[n] - NewSize[n]); + CurSize[m] += d; + CurSize[n] -= d; + // Keep going if the current node was exhausted. + if (CurSize[n] >= NewSize[n]) + break; + } + } + +#ifndef NDEBUG + for (unsigned n = 0; n != Nodes; n++) + assert(CurSize[n] == NewSize[n] && "Insufficient element shuffle"); +#endif + + // Elements have been rearranged, now update node sizes and stops. + unsigned Pos = 0; + for (;;) { + KeyT Stop = Node[Pos]->stop(NewSize[Pos]-1); + if (NewNode && Pos == NewNode) + insertNode(this->map->height - 1, NodeRef(Node[Pos], NewSize[Pos]), Stop); + else { + setNodeSize(this->map->height - 1, NewSize[Pos]); + setNodeStop(this->map->height - 1, Stop); + } + if (Pos + 1 == Nodes) + break; + this->treeIncrement(); + ++Pos; + } + + // Where was I? Find NewOffset. + while(Pos != NewOffset.first) { + this->treeDecrement(); + --Pos; + } + this->treeLeafOffset() = NewOffset.second; +} + +} // namespace llvm + +#endif diff --git a/lib/Support/CMakeLists.txt b/lib/Support/CMakeLists.txt index c9c862ce84a..8a6ed6fa6d6 100644 --- a/lib/Support/CMakeLists.txt +++ b/lib/Support/CMakeLists.txt @@ -19,6 +19,7 @@ add_llvm_library(LLVMSupport FoldingSet.cpp FormattedStream.cpp GraphWriter.cpp + IntervalMap.cpp IsInf.cpp IsNAN.cpp ManagedStatic.cpp diff --git a/lib/Support/IntervalMap.cpp b/lib/Support/IntervalMap.cpp new file mode 100644 index 00000000000..9f5c72fef1c --- /dev/null +++ b/lib/Support/IntervalMap.cpp @@ -0,0 +1,60 @@ +//===- lib/Support/IntervalMap.cpp - A sorted interval map ----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the few non-templated functions in IntervalMap. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/IntervalMap.h" + +namespace llvm { +namespace IntervalMapImpl { + +IdxPair distribute(unsigned Nodes, unsigned Elements, unsigned Capacity, + const unsigned *CurSize, unsigned NewSize[], + unsigned Position, bool Grow) { + assert(Elements + Grow <= Nodes * Capacity && "Not enough room for elements"); + assert(Position <= Elements && "Invalid position"); + if (!Nodes) + return IdxPair(); + + // Trivial algorithm: left-leaning even distribution. + const unsigned PerNode = (Elements + Grow) / Nodes; + const unsigned Extra = (Elements + Grow) % Nodes; + IdxPair PosPair = IdxPair(Nodes, 0); + unsigned Sum = 0; + for (unsigned n = 0; n != Nodes; ++n) { + Sum += NewSize[n] = PerNode + (n < Extra); + if (PosPair.first == Nodes && Sum > Position) + PosPair = IdxPair(n, Position - (Sum - NewSize[n])); + } + assert(Sum == Elements + Grow && "Bad distribution sum"); + + // Subtract the Grow element that was added. + if (Grow) { + assert(PosPair.first < Nodes && "Bad algebra"); + assert(NewSize[PosPair.first] && "Too few elements to need Grow"); + --NewSize[PosPair.first]; + } + +#ifndef NDEBUG + Sum = 0; + for (unsigned n = 0; n != Nodes; ++n) { + assert(NewSize[n] <= Capacity && "Overallocated node"); + Sum += NewSize[n]; + } + assert(Sum == Elements && "Bad distribution sum"); +#endif + + return PosPair; +} + +} // namespace IntervalMapImpl +} // namespace llvm + diff --git a/unittests/ADT/IntervalMapTest.cpp b/unittests/ADT/IntervalMapTest.cpp new file mode 100644 index 00000000000..5c8b61f278d --- /dev/null +++ b/unittests/ADT/IntervalMapTest.cpp @@ -0,0 +1,357 @@ +//===---- ADT/IntervalMapTest.cpp - IntervalMap unit tests ------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/IntervalMap.h" +#include "gtest/gtest.h" + +using namespace llvm; + +namespace { + +typedef IntervalMap UUMap; + +// Empty map tests +TEST(IntervalMapTest, EmptyMap) { + UUMap::Allocator allocator; + UUMap map(allocator); + EXPECT_TRUE(map.empty()); + + // Lookup on empty map. + EXPECT_EQ(0u, map.lookup(0)); + EXPECT_EQ(7u, map.lookup(0, 7)); + EXPECT_EQ(0u, map.lookup(~0u-1)); + EXPECT_EQ(7u, map.lookup(~0u-1, 7)); + + // Iterators. + EXPECT_TRUE(map.begin() == map.begin()); + EXPECT_TRUE(map.begin() == map.end()); + EXPECT_TRUE(map.end() == map.end()); + EXPECT_FALSE(map.begin() != map.begin()); + EXPECT_FALSE(map.begin() != map.end()); + EXPECT_FALSE(map.end() != map.end()); + EXPECT_FALSE(map.begin().valid()); + EXPECT_FALSE(map.end().valid()); + UUMap::iterator I = map.begin(); + EXPECT_FALSE(I.valid()); + EXPECT_TRUE(I == map.end()); +} + +// Single entry map tests +TEST(IntervalMapTest, SingleEntryMap) { + UUMap::Allocator allocator; + UUMap map(allocator); + map.insert(100, 150, 1); + EXPECT_FALSE(map.empty()); + + // Lookup around interval. + EXPECT_EQ(0u, map.lookup(0)); + EXPECT_EQ(0u, map.lookup(99)); + EXPECT_EQ(1u, map.lookup(100)); + EXPECT_EQ(1u, map.lookup(101)); + EXPECT_EQ(1u, map.lookup(125)); + EXPECT_EQ(1u, map.lookup(149)); + EXPECT_EQ(1u, map.lookup(150)); + EXPECT_EQ(0u, map.lookup(151)); + EXPECT_EQ(0u, map.lookup(200)); + EXPECT_EQ(0u, map.lookup(~0u-1)); + + // Iterators. + EXPECT_TRUE(map.begin() == map.begin()); + EXPECT_FALSE(map.begin() == map.end()); + EXPECT_TRUE(map.end() == map.end()); + EXPECT_TRUE(map.begin().valid()); + EXPECT_FALSE(map.end().valid()); + + // Iter deref. + UUMap::iterator I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(150u, I.stop()); + EXPECT_EQ(1u, I.value()); + + // Preincrement. + ++I; + EXPECT_FALSE(I.valid()); + EXPECT_FALSE(I == map.begin()); + EXPECT_TRUE(I == map.end()); + + // PreDecrement. + --I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(150u, I.stop()); + EXPECT_EQ(1u, I.value()); + EXPECT_TRUE(I == map.begin()); + EXPECT_FALSE(I == map.end()); +} + +// Flat coalescing tests. +TEST(IntervalMapTest, RootCoalescing) { + UUMap::Allocator allocator; + UUMap map(allocator); + map.insert(100, 150, 1); + + // Coalesce from the left. + map.insert(90, 99, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(90u, map.start()); + EXPECT_EQ(150u, map.stop()); + + // Overlap left. + map.insert(80, 100, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(80u, map.start()); + EXPECT_EQ(150u, map.stop()); + + // Inside. + map.insert(100, 130, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(80u, map.start()); + EXPECT_EQ(150u, map.stop()); + + // Overlap both. + map.insert(70, 160, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(70u, map.start()); + EXPECT_EQ(160u, map.stop()); + + // Overlap right. + map.insert(80, 170, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(70u, map.start()); + EXPECT_EQ(170u, map.stop()); + + // Coalesce from the right. + map.insert(170, 200, 1); + EXPECT_EQ(1, std::distance(map.begin(), map.end())); + EXPECT_EQ(70u, map.start()); + EXPECT_EQ(200u, map.stop()); + + // Non-coalesce from the left. + map.insert(60, 69, 2); + EXPECT_EQ(2, std::distance(map.begin(), map.end())); + EXPECT_EQ(60u, map.start()); + EXPECT_EQ(200u, map.stop()); + EXPECT_EQ(2u, map.lookup(69)); + EXPECT_EQ(1u, map.lookup(70)); + + UUMap::iterator I = map.begin(); + EXPECT_EQ(60u, I.start()); + EXPECT_EQ(69u, I.stop()); + EXPECT_EQ(2u, I.value()); + ++I; + EXPECT_EQ(70u, I.start()); + EXPECT_EQ(200u, I.stop()); + EXPECT_EQ(1u, I.value()); + ++I; + EXPECT_FALSE(I.valid()); + + // Non-coalesce from the right. + map.insert(201, 210, 2); + EXPECT_EQ(3, std::distance(map.begin(), map.end())); + EXPECT_EQ(60u, map.start()); + EXPECT_EQ(210u, map.stop()); + EXPECT_EQ(2u, map.lookup(201)); + EXPECT_EQ(1u, map.lookup(200)); +} + +// Flat multi-coalescing tests. +TEST(IntervalMapTest, RootMultiCoalescing) { + UUMap::Allocator allocator; + UUMap map(allocator); + map.insert(140, 150, 1); + map.insert(160, 170, 1); + map.insert(100, 110, 1); + map.insert(120, 130, 1); + EXPECT_EQ(4, std::distance(map.begin(), map.end())); + EXPECT_EQ(100u, map.start()); + EXPECT_EQ(170u, map.stop()); + + // Verify inserts. + UUMap::iterator I = map.begin(); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(110u, I.stop()); + ++I; + EXPECT_EQ(120u, I.start()); + EXPECT_EQ(130u, I.stop()); + ++I; + EXPECT_EQ(140u, I.start()); + EXPECT_EQ(150u, I.stop()); + ++I; + EXPECT_EQ(160u, I.start()); + EXPECT_EQ(170u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + + // Coalesce left with followers. + // [100;110] [120;130] [140;150] [160;170] + map.insert(111, 115, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(115u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(120u, I.start()); + EXPECT_EQ(130u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(140u, I.start()); + EXPECT_EQ(150u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(160u, I.start()); + EXPECT_EQ(170u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Coalesce right with followers. + // [100;115] [120;130] [140;150] [160;170] + map.insert(135, 139, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(115u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(120u, I.start()); + EXPECT_EQ(130u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(135u, I.start()); + EXPECT_EQ(150u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(160u, I.start()); + EXPECT_EQ(170u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Coalesce left and right with followers. + // [100;115] [120;130] [135;150] [160;170] + map.insert(131, 134, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(115u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(120u, I.start()); + EXPECT_EQ(150u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(160u, I.start()); + EXPECT_EQ(170u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Coalesce multiple with overlap right. + // [100;115] [120;150] [160;170] + map.insert(116, 165, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(170u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Coalesce multiple with overlap left + // [100;170] + map.insert(180, 190, 1); + map.insert(200, 210, 1); + map.insert(220, 230, 1); + // [100;170] [180;190] [200;210] [220;230] + map.insert(160, 199, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(100u, I.start()); + EXPECT_EQ(210u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(220u, I.start()); + EXPECT_EQ(230u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Overwrite 2 from gap to gap. + // [100;210] [220;230] + map.insert(50, 250, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(50u, I.start()); + EXPECT_EQ(250u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); + + // Coalesce at end of full root. + // [50;250] + map.insert(260, 270, 1); + map.insert(280, 290, 1); + map.insert(300, 310, 1); + // [50;250] [260;270] [280;290] [300;310] + map.insert(311, 320, 1); + I = map.begin(); + ASSERT_TRUE(I.valid()); + EXPECT_EQ(50u, I.start()); + EXPECT_EQ(250u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(260u, I.start()); + EXPECT_EQ(270u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(280u, I.start()); + EXPECT_EQ(290u, I.stop()); + ++I; + ASSERT_TRUE(I.valid()); + EXPECT_EQ(300u, I.start()); + EXPECT_EQ(320u, I.stop()); + ++I; + EXPECT_FALSE(I.valid()); +} + +// Branched, non-coalescing tests. +TEST(IntervalMapTest, Branched) { + UUMap::Allocator allocator; + UUMap map(allocator); + + // Insert enough intervals to force a branched tree. + // This creates 9 leaf nodes with 11 elements each, tree height = 1. + for (unsigned i = 1; i < 100; ++i) + map.insert(10*i, 10*i+5, i); + + // Tree limits. + EXPECT_FALSE(map.empty()); + EXPECT_EQ(10u, map.start()); + EXPECT_EQ(995u, map.stop()); + + // Tree lookup. + for (unsigned i = 1; i < 100; ++i) { + EXPECT_EQ(0u, map.lookup(10*i-1)); + EXPECT_EQ(i, map.lookup(10*i)); + EXPECT_EQ(i, map.lookup(10*i+5)); + EXPECT_EQ(0u, map.lookup(10*i+6)); + } + + // Forward iteration. + UUMap::iterator I = map.begin(); + for (unsigned i = 1; i < 100; ++i) { + ASSERT_TRUE(I.valid()); + EXPECT_EQ(10*i, I.start()); + EXPECT_EQ(10*i+5, I.stop()); + EXPECT_EQ(i, *I); + ++I; + } + EXPECT_FALSE(I.valid()); + EXPECT_TRUE(I == map.end()); + +} + +} // namespace diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt index 36aace5bc47..e251bdbd5c0 100644 --- a/unittests/CMakeLists.txt +++ b/unittests/CMakeLists.txt @@ -45,6 +45,7 @@ add_llvm_unittest(ADT ADT/DenseSetTest.cpp ADT/ilistTest.cpp ADT/ImmutableSetTest.cpp + ADT/IntervalMapTest.cpp ADT/SmallBitVectorTest.cpp ADT/SmallStringTest.cpp ADT/SmallVectorTest.cpp