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//===- llvm/ADT/FoldingSet.h - Uniquing Hash Set ----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines a hash set that can be used to remove duplication of nodes
/// in a graph. This code was originally created by Chris Lattner for use with
/// SelectionDAGCSEMap, but was isolated to provide use across the llvm code
/// set.
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_FOLDINGSET_H
#define LLVM_ADT_FOLDINGSET_H
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/STLForwardCompat.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/iterator.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/xxhash.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <type_traits>
#include <utility>
namespace llvm {
/// This folding set used for two purposes:
/// 1. Given information about a node we want to create, look up the unique
/// instance of the node in the set. If the node already exists, return
/// it, otherwise return the bucket it should be inserted into.
/// 2. Given a node that has already been created, remove it from the set.
///
/// This class is implemented as a single-link chained hash table, where the
/// "buckets" are actually the nodes themselves (the next pointer is in the
/// node). The last node points back to the bucket to simplify node removal.
///
/// Any node that is to be included in the folding set must be a subclass of
/// FoldingSetNode. The node class must also define a Profile method used to
/// establish the unique bits of data for the node. The Profile method is
/// passed a FoldingSetNodeID object which is used to gather the bits. Just
/// call one of the Add* functions defined in the FoldingSetBase::NodeID class.
/// NOTE: That the folding set does not own the nodes and it is the
/// responsibility of the user to dispose of the nodes.
///
/// Eg.
/// class MyNode : public FoldingSetNode {
/// private:
/// std::string Name;
/// unsigned Value;
/// public:
/// MyNode(const char *N, unsigned V) : Name(N), Value(V) {}
/// ...
/// void Profile(FoldingSetNodeID &ID) const {
/// ID.AddString(Name);
/// ID.AddInteger(Value);
/// }
/// ...
/// };
///
/// To define the folding set itself use the FoldingSet template;
///
/// Eg.
/// FoldingSet<MyNode> MyFoldingSet;
///
/// Four public methods are available to manipulate the folding set;
///
/// 1) If you have an existing node that you want add to the set but unsure
/// that the node might already exist then call;
///
/// MyNode *M = MyFoldingSet.GetOrInsertNode(N);
///
/// If The result is equal to the input then the node has been inserted.
/// Otherwise, the result is the node existing in the folding set, and the
/// input can be discarded (use the result instead.)
///
/// 2) If you are ready to construct a node but want to check if it already
/// exists, then call FindNodeOrInsertPos with a FoldingSetNodeID of the bits to
/// check;
///
/// FoldingSetNodeID ID;
/// ID.AddString(Name);
/// ID.AddInteger(Value);
/// void *InsertPoint;
///
/// MyNode *M = MyFoldingSet.FindNodeOrInsertPos(ID, InsertPoint);
///
/// If found then M will be non-NULL, else InsertPoint will point to where it
/// should be inserted using InsertNode.
///
/// 3) If you get a NULL result from FindNodeOrInsertPos then you can insert a
/// new node with InsertNode;
///
/// MyFoldingSet.InsertNode(M, InsertPoint);
///
/// 4) Finally, if you want to remove a node from the folding set call;
///
/// bool WasRemoved = MyFoldingSet.RemoveNode(M);
///
/// The result indicates whether the node existed in the folding set.
class FoldingSetNodeID;
class StringRef;
//===----------------------------------------------------------------------===//
/// FoldingSetBase - Implements the folding set functionality. The main
/// structure is an array of buckets. Each bucket is indexed by the hash of
/// the nodes it contains. The bucket itself points to the nodes contained
/// in the bucket via a singly linked list. The last node in the list points
/// back to the bucket to facilitate node removal.
///
class FoldingSetBase {
protected:
/// Buckets - Array of bucket chains.
void **Buckets;
/// NumBuckets - Length of the Buckets array. Always a power of 2.
unsigned NumBuckets;
/// NumNodes - Number of nodes in the folding set. Growth occurs when NumNodes
/// is greater than twice the number of buckets.
unsigned NumNodes;
explicit FoldingSetBase(unsigned Log2InitSize = 6);
FoldingSetBase(FoldingSetBase &&Arg);
FoldingSetBase &operator=(FoldingSetBase &&RHS);
~FoldingSetBase();
public:
//===--------------------------------------------------------------------===//
/// Node - This class is used to maintain the singly linked bucket list in
/// a folding set.
class Node {
private:
// NextInFoldingSetBucket - next link in the bucket list.
void *NextInFoldingSetBucket = nullptr;
public:
Node() = default;
// Accessors
void *getNextInBucket() const { return NextInFoldingSetBucket; }
void SetNextInBucket(void *N) { NextInFoldingSetBucket = N; }
};
/// clear - Remove all nodes from the folding set.
void clear();
/// size - Returns the number of nodes in the folding set.
unsigned size() const { return NumNodes; }
/// empty - Returns true if there are no nodes in the folding set.
bool empty() const { return NumNodes == 0; }
/// capacity - Returns the number of nodes permitted in the folding set
/// before a rebucket operation is performed.
unsigned capacity() {
// We allow a load factor of up to 2.0,
// so that means our capacity is NumBuckets * 2
return NumBuckets * 2;
}
protected:
/// Functions provided by the derived class to compute folding properties.
/// This is effectively a vtable for FoldingSetBase, except that we don't
/// actually store a pointer to it in the object.
struct FoldingSetInfo {
/// GetNodeProfile - Instantiations of the FoldingSet template implement
/// this function to gather data bits for the given node.
void (*GetNodeProfile)(const FoldingSetBase *Self, Node *N,
FoldingSetNodeID &ID);
/// NodeEquals - Instantiations of the FoldingSet template implement
/// this function to compare the given node with the given ID.
bool (*NodeEquals)(const FoldingSetBase *Self, Node *N,
const FoldingSetNodeID &ID, unsigned IDHash,
FoldingSetNodeID &TempID);
/// ComputeNodeHash - Instantiations of the FoldingSet template implement
/// this function to compute a hash value for the given node.
unsigned (*ComputeNodeHash)(const FoldingSetBase *Self, Node *N,
FoldingSetNodeID &TempID);
};
private:
/// GrowHashTable - Double the size of the hash table and rehash everything.
void GrowHashTable(const FoldingSetInfo &Info);
/// GrowBucketCount - resize the hash table and rehash everything.
/// NewBucketCount must be a power of two, and must be greater than the old
/// bucket count.
void GrowBucketCount(unsigned NewBucketCount, const FoldingSetInfo &Info);
protected:
// The below methods are protected to encourage subclasses to provide a more
// type-safe API.
/// reserve - Increase the number of buckets such that adding the
/// EltCount-th node won't cause a rebucket operation. reserve is permitted
/// to allocate more space than requested by EltCount.
void reserve(unsigned EltCount, const FoldingSetInfo &Info);
/// RemoveNode - Remove a node from the folding set, returning true if one
/// was removed or false if the node was not in the folding set.
bool RemoveNode(Node *N);
/// GetOrInsertNode - If there is an existing simple Node exactly
/// equal to the specified node, return it. Otherwise, insert 'N' and return
/// it instead.
Node *GetOrInsertNode(Node *N, const FoldingSetInfo &Info);
/// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
/// return it. If not, return the insertion token that will make insertion
/// faster.
Node *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos,
const FoldingSetInfo &Info);
/// InsertNode - Insert the specified node into the folding set, knowing that
/// it is not already in the folding set. InsertPos must be obtained from
/// FindNodeOrInsertPos.
void InsertNode(Node *N, void *InsertPos, const FoldingSetInfo &Info);
};
//===----------------------------------------------------------------------===//
/// DefaultFoldingSetTrait - This class provides default implementations
/// for FoldingSetTrait implementations.
template<typename T> struct DefaultFoldingSetTrait {
static void Profile(const T &X, FoldingSetNodeID &ID) {
X.Profile(ID);
}
static void Profile(T &X, FoldingSetNodeID &ID) {
X.Profile(ID);
}
// Equals - Test if the profile for X would match ID, using TempID
// to compute a temporary ID if necessary. The default implementation
// just calls Profile and does a regular comparison. Implementations
// can override this to provide more efficient implementations.
static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
FoldingSetNodeID &TempID);
// ComputeHash - Compute a hash value for X, using TempID to
// compute a temporary ID if necessary. The default implementation
// just calls Profile and does a regular hash computation.
// Implementations can override this to provide more efficient
// implementations.
static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID);
};
/// FoldingSetTrait - This trait class is used to define behavior of how
/// to "profile" (in the FoldingSet parlance) an object of a given type.
/// The default behavior is to invoke a 'Profile' method on an object, but
/// through template specialization the behavior can be tailored for specific
/// types. Combined with the FoldingSetNodeWrapper class, one can add objects
/// to FoldingSets that were not originally designed to have that behavior.
template <typename T, typename Enable = void>
struct FoldingSetTrait : public DefaultFoldingSetTrait<T> {};
/// DefaultContextualFoldingSetTrait - Like DefaultFoldingSetTrait, but
/// for ContextualFoldingSets.
template<typename T, typename Ctx>
struct DefaultContextualFoldingSetTrait {
static void Profile(T &X, FoldingSetNodeID &ID, Ctx Context) {
X.Profile(ID, Context);
}
static inline bool Equals(T &X, const FoldingSetNodeID &ID, unsigned IDHash,
FoldingSetNodeID &TempID, Ctx Context);
static inline unsigned ComputeHash(T &X, FoldingSetNodeID &TempID,
Ctx Context);
};
/// ContextualFoldingSetTrait - Like FoldingSetTrait, but for
/// ContextualFoldingSets.
template<typename T, typename Ctx> struct ContextualFoldingSetTrait
: public DefaultContextualFoldingSetTrait<T, Ctx> {};
//===--------------------------------------------------------------------===//
/// FoldingSetNodeIDRef - This class describes a reference to an interned
/// FoldingSetNodeID, which can be a useful to store node id data rather
/// than using plain FoldingSetNodeIDs, since the 32-element SmallVector
/// is often much larger than necessary, and the possibility of heap
/// allocation means it requires a non-trivial destructor call.
class FoldingSetNodeIDRef {
const unsigned *Data = nullptr;
size_t Size = 0;
public:
FoldingSetNodeIDRef() = default;
FoldingSetNodeIDRef(const unsigned *D, size_t S) : Data(D), Size(S) {}
// Compute a strong hash value used to lookup the node in the FoldingSetBase.
// The hash value is not guaranteed to be deterministic across processes.
unsigned ComputeHash() const {
return static_cast<unsigned>(hash_combine_range(Data, Data + Size));
}
// Compute a deterministic hash value across processes that is suitable for
// on-disk serialization.
unsigned computeStableHash() const {
return static_cast<unsigned>(xxh3_64bits(ArrayRef(
reinterpret_cast<const uint8_t *>(Data), sizeof(unsigned) * Size)));
}
bool operator==(FoldingSetNodeIDRef) const;
bool operator!=(FoldingSetNodeIDRef RHS) const { return !(*this == RHS); }
/// Used to compare the "ordering" of two nodes as defined by the
/// profiled bits and their ordering defined by memcmp().
bool operator<(FoldingSetNodeIDRef) const;
const unsigned *getData() const { return Data; }
size_t getSize() const { return Size; }
};
//===--------------------------------------------------------------------===//
/// FoldingSetNodeID - This class is used to gather all the unique data bits of
/// a node. When all the bits are gathered this class is used to produce a
/// hash value for the node.
class FoldingSetNodeID {
/// Bits - Vector of all the data bits that make the node unique.
/// Use a SmallVector to avoid a heap allocation in the common case.
SmallVector<unsigned, 32> Bits;
public:
FoldingSetNodeID() = default;
FoldingSetNodeID(FoldingSetNodeIDRef Ref)
: Bits(Ref.getData(), Ref.getData() + Ref.getSize()) {}
/// Add* - Add various data types to Bit data.
void AddPointer(const void *Ptr) {
// Note: this adds pointers to the hash using sizes and endianness that
// depend on the host. It doesn't matter, however, because hashing on
// pointer values is inherently unstable. Nothing should depend on the
// ordering of nodes in the folding set.
static_assert(sizeof(uintptr_t) <= sizeof(unsigned long long),
"unexpected pointer size");
AddInteger(reinterpret_cast<uintptr_t>(Ptr));
}
void AddInteger(signed I) { Bits.push_back(I); }
void AddInteger(unsigned I) { Bits.push_back(I); }
void AddInteger(long I) { AddInteger((unsigned long)I); }
void AddInteger(unsigned long I) {
if (sizeof(long) == sizeof(int))
AddInteger(unsigned(I));
else if (sizeof(long) == sizeof(long long)) {
AddInteger((unsigned long long)I);
} else {
llvm_unreachable("unexpected sizeof(long)");
}
}
void AddInteger(long long I) { AddInteger((unsigned long long)I); }
void AddInteger(unsigned long long I) {
AddInteger(unsigned(I));
AddInteger(unsigned(I >> 32));
}
void AddBoolean(bool B) { AddInteger(B ? 1U : 0U); }
void AddString(StringRef String);
void AddNodeID(const FoldingSetNodeID &ID);
template <typename T>
inline void Add(const T &x) { FoldingSetTrait<T>::Profile(x, *this); }
/// clear - Clear the accumulated profile, allowing this FoldingSetNodeID
/// object to be used to compute a new profile.
inline void clear() { Bits.clear(); }
// Compute a strong hash value for this FoldingSetNodeID, used to lookup the
// node in the FoldingSetBase. The hash value is not guaranteed to be
// deterministic across processes.
unsigned ComputeHash() const {
return FoldingSetNodeIDRef(Bits.data(), Bits.size()).ComputeHash();
}
// Compute a deterministic hash value across processes that is suitable for
// on-disk serialization.
unsigned computeStableHash() const {
return FoldingSetNodeIDRef(Bits.data(), Bits.size()).computeStableHash();
}
/// operator== - Used to compare two nodes to each other.
bool operator==(const FoldingSetNodeID &RHS) const;
bool operator==(const FoldingSetNodeIDRef RHS) const;
bool operator!=(const FoldingSetNodeID &RHS) const { return !(*this == RHS); }
bool operator!=(const FoldingSetNodeIDRef RHS) const { return !(*this ==RHS);}
/// Used to compare the "ordering" of two nodes as defined by the
/// profiled bits and their ordering defined by memcmp().
bool operator<(const FoldingSetNodeID &RHS) const;
bool operator<(const FoldingSetNodeIDRef RHS) const;
/// Intern - Copy this node's data to a memory region allocated from the
/// given allocator and return a FoldingSetNodeIDRef describing the
/// interned data.
FoldingSetNodeIDRef Intern(BumpPtrAllocator &Allocator) const;
};
// Convenience type to hide the implementation of the folding set.
using FoldingSetNode = FoldingSetBase::Node;
template<class T> class FoldingSetIterator;
template<class T> class FoldingSetBucketIterator;
// Definitions of FoldingSetTrait and ContextualFoldingSetTrait functions, which
// require the definition of FoldingSetNodeID.
template<typename T>
inline bool
DefaultFoldingSetTrait<T>::Equals(T &X, const FoldingSetNodeID &ID,
unsigned /*IDHash*/,
FoldingSetNodeID &TempID) {
FoldingSetTrait<T>::Profile(X, TempID);
return TempID == ID;
}
template<typename T>
inline unsigned
DefaultFoldingSetTrait<T>::ComputeHash(T &X, FoldingSetNodeID &TempID) {
FoldingSetTrait<T>::Profile(X, TempID);
return TempID.ComputeHash();
}
template<typename T, typename Ctx>
inline bool
DefaultContextualFoldingSetTrait<T, Ctx>::Equals(T &X,
const FoldingSetNodeID &ID,
unsigned /*IDHash*/,
FoldingSetNodeID &TempID,
Ctx Context) {
ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context);
return TempID == ID;
}
template<typename T, typename Ctx>
inline unsigned
DefaultContextualFoldingSetTrait<T, Ctx>::ComputeHash(T &X,
FoldingSetNodeID &TempID,
Ctx Context) {
ContextualFoldingSetTrait<T, Ctx>::Profile(X, TempID, Context);
return TempID.ComputeHash();
}
//===----------------------------------------------------------------------===//
/// FoldingSetImpl - An implementation detail that lets us share code between
/// FoldingSet and ContextualFoldingSet.
template <class Derived, class T> class FoldingSetImpl : public FoldingSetBase {
protected:
explicit FoldingSetImpl(unsigned Log2InitSize)
: FoldingSetBase(Log2InitSize) {}
FoldingSetImpl(FoldingSetImpl &&Arg) = default;
FoldingSetImpl &operator=(FoldingSetImpl &&RHS) = default;
~FoldingSetImpl() = default;
public:
using iterator = FoldingSetIterator<T>;
iterator begin() { return iterator(Buckets); }
iterator end() { return iterator(Buckets+NumBuckets); }
using const_iterator = FoldingSetIterator<const T>;
const_iterator begin() const { return const_iterator(Buckets); }
const_iterator end() const { return const_iterator(Buckets+NumBuckets); }
using bucket_iterator = FoldingSetBucketIterator<T>;
bucket_iterator bucket_begin(unsigned hash) {
return bucket_iterator(Buckets + (hash & (NumBuckets-1)));
}
bucket_iterator bucket_end(unsigned hash) {
return bucket_iterator(Buckets + (hash & (NumBuckets-1)), true);
}
/// reserve - Increase the number of buckets such that adding the
/// EltCount-th node won't cause a rebucket operation. reserve is permitted
/// to allocate more space than requested by EltCount.
void reserve(unsigned EltCount) {
return FoldingSetBase::reserve(EltCount, Derived::getFoldingSetInfo());
}
/// RemoveNode - Remove a node from the folding set, returning true if one
/// was removed or false if the node was not in the folding set.
bool RemoveNode(T *N) {
return FoldingSetBase::RemoveNode(N);
}
/// GetOrInsertNode - If there is an existing simple Node exactly
/// equal to the specified node, return it. Otherwise, insert 'N' and
/// return it instead.
T *GetOrInsertNode(T *N) {
return static_cast<T *>(
FoldingSetBase::GetOrInsertNode(N, Derived::getFoldingSetInfo()));
}
/// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
/// return it. If not, return the insertion token that will make insertion
/// faster.
T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
return static_cast<T *>(FoldingSetBase::FindNodeOrInsertPos(
ID, InsertPos, Derived::getFoldingSetInfo()));
}
/// InsertNode - Insert the specified node into the folding set, knowing that
/// it is not already in the folding set. InsertPos must be obtained from
/// FindNodeOrInsertPos.
void InsertNode(T *N, void *InsertPos) {
FoldingSetBase::InsertNode(N, InsertPos, Derived::getFoldingSetInfo());
}
/// InsertNode - Insert the specified node into the folding set, knowing that
/// it is not already in the folding set.
void InsertNode(T *N) {
T *Inserted = GetOrInsertNode(N);
(void)Inserted;
assert(Inserted == N && "Node already inserted!");
}
};
//===----------------------------------------------------------------------===//
/// FoldingSet - This template class is used to instantiate a specialized
/// implementation of the folding set to the node class T. T must be a
/// subclass of FoldingSetNode and implement a Profile function.
///
/// Note that this set type is movable and move-assignable. However, its
/// moved-from state is not a valid state for anything other than
/// move-assigning and destroying. This is primarily to enable movable APIs
/// that incorporate these objects.
template <class T>
class FoldingSet : public FoldingSetImpl<FoldingSet<T>, T> {
using Super = FoldingSetImpl<FoldingSet, T>;
using Node = typename Super::Node;
/// GetNodeProfile - Each instantiation of the FoldingSet needs to provide a
/// way to convert nodes into a unique specifier.
static void GetNodeProfile(const FoldingSetBase *, Node *N,
FoldingSetNodeID &ID) {
T *TN = static_cast<T *>(N);
FoldingSetTrait<T>::Profile(*TN, ID);
}
/// NodeEquals - Instantiations may optionally provide a way to compare a
/// node with a specified ID.
static bool NodeEquals(const FoldingSetBase *, Node *N,
const FoldingSetNodeID &ID, unsigned IDHash,
FoldingSetNodeID &TempID) {
T *TN = static_cast<T *>(N);
return FoldingSetTrait<T>::Equals(*TN, ID, IDHash, TempID);
}
/// ComputeNodeHash - Instantiations may optionally provide a way to compute a
/// hash value directly from a node.
static unsigned ComputeNodeHash(const FoldingSetBase *, Node *N,
FoldingSetNodeID &TempID) {
T *TN = static_cast<T *>(N);
return FoldingSetTrait<T>::ComputeHash(*TN, TempID);
}
static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() {
static constexpr FoldingSetBase::FoldingSetInfo Info = {
GetNodeProfile, NodeEquals, ComputeNodeHash};
return Info;
}
friend Super;
public:
explicit FoldingSet(unsigned Log2InitSize = 6) : Super(Log2InitSize) {}
FoldingSet(FoldingSet &&Arg) = default;
FoldingSet &operator=(FoldingSet &&RHS) = default;
};
//===----------------------------------------------------------------------===//
/// ContextualFoldingSet - This template class is a further refinement
/// of FoldingSet which provides a context argument when calling
/// Profile on its nodes. Currently, that argument is fixed at
/// initialization time.
///
/// T must be a subclass of FoldingSetNode and implement a Profile
/// function with signature
/// void Profile(FoldingSetNodeID &, Ctx);
template <class T, class Ctx>
class ContextualFoldingSet
: public FoldingSetImpl<ContextualFoldingSet<T, Ctx>, T> {
// Unfortunately, this can't derive from FoldingSet<T> because the
// construction of the vtable for FoldingSet<T> requires
// FoldingSet<T>::GetNodeProfile to be instantiated, which in turn
// requires a single-argument T::Profile().
using Super = FoldingSetImpl<ContextualFoldingSet, T>;
using Node = typename Super::Node;
Ctx Context;
static const Ctx &getContext(const FoldingSetBase *Base) {
return static_cast<const ContextualFoldingSet*>(Base)->Context;
}
/// GetNodeProfile - Each instantiatation of the FoldingSet needs to provide a
/// way to convert nodes into a unique specifier.
static void GetNodeProfile(const FoldingSetBase *Base, Node *N,
FoldingSetNodeID &ID) {
T *TN = static_cast<T *>(N);
ContextualFoldingSetTrait<T, Ctx>::Profile(*TN, ID, getContext(Base));
}
static bool NodeEquals(const FoldingSetBase *Base, Node *N,
const FoldingSetNodeID &ID, unsigned IDHash,
FoldingSetNodeID &TempID) {
T *TN = static_cast<T *>(N);
return ContextualFoldingSetTrait<T, Ctx>::Equals(*TN, ID, IDHash, TempID,
getContext(Base));
}
static unsigned ComputeNodeHash(const FoldingSetBase *Base, Node *N,
FoldingSetNodeID &TempID) {
T *TN = static_cast<T *>(N);
return ContextualFoldingSetTrait<T, Ctx>::ComputeHash(*TN, TempID,
getContext(Base));
}
static const FoldingSetBase::FoldingSetInfo &getFoldingSetInfo() {
static constexpr FoldingSetBase::FoldingSetInfo Info = {
GetNodeProfile, NodeEquals, ComputeNodeHash};
return Info;
}
friend Super;
public:
explicit ContextualFoldingSet(Ctx Context, unsigned Log2InitSize = 6)
: Super(Log2InitSize), Context(Context) {}
Ctx getContext() const { return Context; }
};
//===----------------------------------------------------------------------===//
/// FoldingSetVector - This template class combines a FoldingSet and a vector
/// to provide the interface of FoldingSet but with deterministic iteration
/// order based on the insertion order. T must be a subclass of FoldingSetNode
/// and implement a Profile function.
template <class T, class VectorT = SmallVector<T*, 8>>
class FoldingSetVector {
FoldingSet<T> Set;
VectorT Vector;
public:
explicit FoldingSetVector(unsigned Log2InitSize = 6) : Set(Log2InitSize) {}
using iterator = pointee_iterator<typename VectorT::iterator>;
iterator begin() { return Vector.begin(); }
iterator end() { return Vector.end(); }
using const_iterator = pointee_iterator<typename VectorT::const_iterator>;
const_iterator begin() const { return Vector.begin(); }
const_iterator end() const { return Vector.end(); }
/// clear - Remove all nodes from the folding set.
void clear() { Set.clear(); Vector.clear(); }
/// FindNodeOrInsertPos - Look up the node specified by ID. If it exists,
/// return it. If not, return the insertion token that will make insertion
/// faster.
T *FindNodeOrInsertPos(const FoldingSetNodeID &ID, void *&InsertPos) {
return Set.FindNodeOrInsertPos(ID, InsertPos);
}
/// GetOrInsertNode - If there is an existing simple Node exactly
/// equal to the specified node, return it. Otherwise, insert 'N' and
/// return it instead.
T *GetOrInsertNode(T *N) {
T *Result = Set.GetOrInsertNode(N);
if (Result == N) Vector.push_back(N);
return Result;
}
/// InsertNode - Insert the specified node into the folding set, knowing that
/// it is not already in the folding set. InsertPos must be obtained from
/// FindNodeOrInsertPos.
void InsertNode(T *N, void *InsertPos) {
Set.InsertNode(N, InsertPos);
Vector.push_back(N);
}
/// InsertNode - Insert the specified node into the folding set, knowing that
/// it is not already in the folding set.
void InsertNode(T *N) {
Set.InsertNode(N);
Vector.push_back(N);
}
/// size - Returns the number of nodes in the folding set.
unsigned size() const { return Set.size(); }
/// empty - Returns true if there are no nodes in the folding set.
bool empty() const { return Set.empty(); }
};
//===----------------------------------------------------------------------===//
/// FoldingSetIteratorImpl - This is the common iterator support shared by all
/// folding sets, which knows how to walk the folding set hash table.
class FoldingSetIteratorImpl {
protected:
FoldingSetNode *NodePtr;
FoldingSetIteratorImpl(void **Bucket);
void advance();
public:
bool operator==(const FoldingSetIteratorImpl &RHS) const {
return NodePtr == RHS.NodePtr;
}
bool operator!=(const FoldingSetIteratorImpl &RHS) const {
return NodePtr != RHS.NodePtr;
}
};
template <class T> class FoldingSetIterator : public FoldingSetIteratorImpl {
public:
explicit FoldingSetIterator(void **Bucket) : FoldingSetIteratorImpl(Bucket) {}
T &operator*() const {
return *static_cast<T*>(NodePtr);
}
T *operator->() const {
return static_cast<T*>(NodePtr);
}
inline FoldingSetIterator &operator++() { // Preincrement
advance();
return *this;
}
FoldingSetIterator operator++(int) { // Postincrement
FoldingSetIterator tmp = *this; ++*this; return tmp;
}
};
//===----------------------------------------------------------------------===//
/// FoldingSetBucketIteratorImpl - This is the common bucket iterator support
/// shared by all folding sets, which knows how to walk a particular bucket
/// of a folding set hash table.
class FoldingSetBucketIteratorImpl {
protected:
void *Ptr;
explicit FoldingSetBucketIteratorImpl(void **Bucket);
FoldingSetBucketIteratorImpl(void **Bucket, bool) : Ptr(Bucket) {}
void advance() {
void *Probe = static_cast<FoldingSetNode*>(Ptr)->getNextInBucket();
uintptr_t x = reinterpret_cast<uintptr_t>(Probe) & ~0x1;
Ptr = reinterpret_cast<void*>(x);
}
public:
bool operator==(const FoldingSetBucketIteratorImpl &RHS) const {
return Ptr == RHS.Ptr;
}
bool operator!=(const FoldingSetBucketIteratorImpl &RHS) const {
return Ptr != RHS.Ptr;
}
};
template <class T>
class FoldingSetBucketIterator : public FoldingSetBucketIteratorImpl {
public:
explicit FoldingSetBucketIterator(void **Bucket) :
FoldingSetBucketIteratorImpl(Bucket) {}
FoldingSetBucketIterator(void **Bucket, bool) :
FoldingSetBucketIteratorImpl(Bucket, true) {}
T &operator*() const { return *static_cast<T*>(Ptr); }
T *operator->() const { return static_cast<T*>(Ptr); }
inline FoldingSetBucketIterator &operator++() { // Preincrement
advance();
return *this;
}
FoldingSetBucketIterator operator++(int) { // Postincrement
FoldingSetBucketIterator tmp = *this; ++*this; return tmp;
}
};
//===----------------------------------------------------------------------===//
/// FoldingSetNodeWrapper - This template class is used to "wrap" arbitrary
/// types in an enclosing object so that they can be inserted into FoldingSets.
template <typename T>
class FoldingSetNodeWrapper : public FoldingSetNode {
T data;
public:
template <typename... Ts>
explicit FoldingSetNodeWrapper(Ts &&... Args)
: data(std::forward<Ts>(Args)...) {}
void Profile(FoldingSetNodeID &ID) { FoldingSetTrait<T>::Profile(data, ID); }
T &getValue() { return data; }
const T &getValue() const { return data; }
operator T&() { return data; }
operator const T&() const { return data; }
};
//===----------------------------------------------------------------------===//
/// FastFoldingSetNode - This is a subclass of FoldingSetNode which stores
/// a FoldingSetNodeID value rather than requiring the node to recompute it
/// each time it is needed. This trades space for speed (which can be
/// significant if the ID is long), and it also permits nodes to drop
/// information that would otherwise only be required for recomputing an ID.
class FastFoldingSetNode : public FoldingSetNode {
FoldingSetNodeID FastID;
protected:
explicit FastFoldingSetNode(const FoldingSetNodeID &ID) : FastID(ID) {}
public:
void Profile(FoldingSetNodeID &ID) const { ID.AddNodeID(FastID); }
};
//===----------------------------------------------------------------------===//
// Partial specializations of FoldingSetTrait.
template<typename T> struct FoldingSetTrait<T*> {
static inline void Profile(T *X, FoldingSetNodeID &ID) {
ID.AddPointer(X);
}
};
template <typename T1, typename T2>
struct FoldingSetTrait<std::pair<T1, T2>> {
static inline void Profile(const std::pair<T1, T2> &P,
FoldingSetNodeID &ID) {
ID.Add(P.first);
ID.Add(P.second);
}
};
template <typename T>
struct FoldingSetTrait<T, std::enable_if_t<std::is_enum<T>::value>> {
static void Profile(const T &X, FoldingSetNodeID &ID) {
ID.AddInteger(llvm::to_underlying(X));
}
};
} // end namespace llvm
#endif // LLVM_ADT_FOLDINGSET_H
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