SmallPtrSet.h revision 4d6f96d6997738419627ebe13dd6cb9c88a98fd7
1c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner//===- llvm/ADT/SmallPtrSet.h - 'Normally small' pointer set ----*- C++ -*-===// 2c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// 3c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// The LLVM Compiler Infrastructure 4c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// 5c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// This file was developed by Chris Lattner and is distributed under 6c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// the University of Illinois Open Source License. See LICENSE.TXT for details. 7c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// 8c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner//===----------------------------------------------------------------------===// 9c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// 1018b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner// This file defines the SmallPtrSet class. See the doxygen comment for 1118b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner// SmallPtrSetImpl for more details on the algorithm used. 12c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner// 13c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner//===----------------------------------------------------------------------===// 14c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 15c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner#ifndef LLVM_ADT_SMALLPTRSET_H 16c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner#define LLVM_ADT_SMALLPTRSET_H 17c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 18c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner#include <cassert> 19c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner#include <cstring> 20ea830ef21f1f863886455fabfc64ea00b172aeebChris Lattner#include "llvm/Support/DataTypes.h" 21c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 22c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnernamespace llvm { 23c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 2418b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// SmallPtrSetImpl - This is the common code shared among all the 2518b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// SmallPtrSet<>'s, which is almost everything. SmallPtrSet has two modes, one 2618b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// for small and one for large sets. 2718b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// 2818b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// Small sets use an array of pointers allocated in the SmallPtrSet object, 2918b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// which is treated as a simple array of pointers. When a pointer is added to 3018b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// the set, the array is scanned to see if the element already exists, if not 3118b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// the element is 'pushed back' onto the array. If we run out of space in the 3218b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// array, we grow into the 'large set' case. SmallSet should be used when the 3318b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// sets are often small. In this case, no memory allocation is used, and only 3418b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// light-weight and cache-efficient scanning is used. 3518b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// 3618b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// Large sets use a classic exponentially-probed hash table. Empty buckets are 3718b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// represented with an illegal pointer value (-1) to allow null pointers to be 3818b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// inserted. Tombstones are represented with another illegal pointer value 3918b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// (-2), to allow deletion. The hash table is resized when the table is 3/4 or 4018b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// more. When this happens, the table is doubled in size. 4118b69106b7a66ac6abde37d1be6d0d952796ed04Chris Lattner/// 42c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerclass SmallPtrSetImpl { 43c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerprotected: 44c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// CurArray - This is the current set of buckets. If it points to 45c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// SmallArray, then the set is in 'small mode'. 46c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void **CurArray; 47c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// CurArraySize - The allocated size of CurArray, always a power of two. 48c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// Note that CurArray points to an array that has CurArraySize+1 elements in 49c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// it, so that the end iterator actually points to valid memory. 50c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner unsigned CurArraySize; 51c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 52c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // If small, this is # elts allocated consequtively 53c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner unsigned NumElements; 54e237cf934fcb8a25746e068f543fbd6db44eaa70Chris Lattner unsigned NumTombstones; 55c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void *SmallArray[1]; // Must be last ivar. 56ac58a16f8584f38198cc7800bd37a896125268b7Jeff Cohen 57ac58a16f8584f38198cc7800bd37a896125268b7Jeff Cohen // Helper to copy construct a SmallPtrSet. 58ac58a16f8584f38198cc7800bd37a896125268b7Jeff Cohen SmallPtrSetImpl(const SmallPtrSetImpl& that); 59c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerpublic: 60c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner SmallPtrSetImpl(unsigned SmallSize) { 61c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner assert(SmallSize && (SmallSize & (SmallSize-1)) == 0 && 62c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner "Initial size must be a power of two!"); 63c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner CurArray = &SmallArray[0]; 64c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner CurArraySize = SmallSize; 65c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // The end pointer, always valid, is set to a valid element to help the 66c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // iterator. 67c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner CurArray[SmallSize] = 0; 68c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner clear(); 69c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 70c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner ~SmallPtrSetImpl() { 71c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner if (!isSmall()) 72c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner delete[] CurArray; 73c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 74c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 75894d264f3ee965645656ddd6566acbe4d3a3ed55Chris Lattner bool empty() const { return size() == 0; } 76894d264f3ee965645656ddd6566acbe4d3a3ed55Chris Lattner unsigned size() const { return NumElements; } 77894d264f3ee965645656ddd6566acbe4d3a3ed55Chris Lattner 78c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner static void *getTombstoneMarker() { return reinterpret_cast<void*>(-2); } 79c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner static void *getEmptyMarker() { 80c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // Note that -1 is chosen to make clear() efficiently implementable with 81c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // memset and because it's not a valid pointer value. 82c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return reinterpret_cast<void*>(-1); 83c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 84c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 85c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void clear() { 86c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // Fill the array with empty markers. 87c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner memset(CurArray, -1, CurArraySize*sizeof(void*)); 88c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner NumElements = 0; 89e237cf934fcb8a25746e068f543fbd6db44eaa70Chris Lattner NumTombstones = 0; 90c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 91c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 92c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// insert - This returns true if the pointer was new to the set, false if it 93c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// was already in the set. 94c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner bool insert(void *Ptr); 95c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 96086f18626750482318612a10c3027b946b4e36e4Chris Lattner template <typename IterT> 97086f18626750482318612a10c3027b946b4e36e4Chris Lattner void insert(IterT I, IterT E) { 98086f18626750482318612a10c3027b946b4e36e4Chris Lattner for (; I != E; ++I) 99086f18626750482318612a10c3027b946b4e36e4Chris Lattner insert((void*)*I); 100086f18626750482318612a10c3027b946b4e36e4Chris Lattner } 101086f18626750482318612a10c3027b946b4e36e4Chris Lattner 1020b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner /// erase - If the set contains the specified pointer, remove it and return 1030b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner /// true, otherwise return false. 1040b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner bool erase(void *Ptr); 1050b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner 106c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner bool count(void *Ptr) const { 107c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner if (isSmall()) { 108c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // Linear search for the item. 109c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner for (void *const *APtr = SmallArray, *const *E = SmallArray+NumElements; 110c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner APtr != E; ++APtr) 111c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner if (*APtr == Ptr) 112c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return true; 113c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return false; 114c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 115c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 116c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // Big set case. 117c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return *FindBucketFor(Ptr) == Ptr; 118c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 119c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 120c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerprivate: 1210b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner bool isSmall() const { return CurArray == &SmallArray[0]; } 1220b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner 123c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner unsigned Hash(void *Ptr) const { 124c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return ((uintptr_t)Ptr >> 4) & (CurArraySize-1); 125c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 126c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void * const *FindBucketFor(void *Ptr) const; 127c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 128c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// Grow - Allocate a larger backing store for the buckets and move it over. 129c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void Grow(); 13091f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner 13191f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner void operator=(const SmallPtrSetImpl &RHS); // DO NOT IMPLEMENT. 13291f0158d4d1b16b8615126b05582d421cfb14089Chris Lattnerprotected: 13391f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner void CopyFrom(const SmallPtrSetImpl &RHS); 134c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner}; 135c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 136c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner/// SmallPtrSetIteratorImpl - This is the common base class shared between all 137c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner/// instances of SmallPtrSetIterator. 138c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerclass SmallPtrSetIteratorImpl { 139c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerprotected: 140c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void *const *Bucket; 141c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerpublic: 142c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner SmallPtrSetIteratorImpl(void *const *BP) : Bucket(BP) { 143c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner AdvanceIfNotValid(); 144c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 145c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 146c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner bool operator==(const SmallPtrSetIteratorImpl &RHS) const { 147c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return Bucket == RHS.Bucket; 148c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 149c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner bool operator!=(const SmallPtrSetIteratorImpl &RHS) const { 150c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return Bucket != RHS.Bucket; 151c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 152c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 153c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerprotected: 154c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// AdvanceIfNotValid - If the current bucket isn't valid, advance to a bucket 155c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// that is. This is guaranteed to stop because the end() bucket is marked 156c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner /// valid. 157c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner void AdvanceIfNotValid() { 158c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner while (*Bucket == SmallPtrSetImpl::getEmptyMarker() || 159c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner *Bucket == SmallPtrSetImpl::getTombstoneMarker()) 160c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner ++Bucket; 161c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 162c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner}; 163c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 164c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner/// SmallPtrSetIterator - This implements a const_iterator for SmallPtrSet. 165c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnertemplate<typename PtrTy> 166c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerclass SmallPtrSetIterator : public SmallPtrSetIteratorImpl { 167c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerpublic: 168c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner SmallPtrSetIterator(void *const *BP) : SmallPtrSetIteratorImpl(BP) {} 169c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 170c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner // Most methods provided by baseclass. 171c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 172c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner PtrTy operator*() const { 173c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return static_cast<PtrTy>(*Bucket); 174c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 175c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 176c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner inline SmallPtrSetIterator& operator++() { // Preincrement 177c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner ++Bucket; 178c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner AdvanceIfNotValid(); 179c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return *this; 180c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 181c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 182c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner SmallPtrSetIterator operator++(int) { // Postincrement 183c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner SmallPtrSetIterator tmp = *this; ++*this; return tmp; 184c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 185c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner}; 186c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 187af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner/// NextPowerOfTwo - This is a helper template that rounds N up to the next 188af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner/// power of two. 189af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnertemplate<unsigned N> 190af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnerstruct NextPowerOfTwo; 191af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner 192af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner/// NextPowerOfTwoH - If N is not a power of two, increase it. This is a helper 193af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner/// template used to implement NextPowerOfTwo. 194af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnertemplate<unsigned N, bool isPowerTwo> 195af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnerstruct NextPowerOfTwoH { 196af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner enum { Val = N }; 197af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner}; 198af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnertemplate<unsigned N> 199af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnerstruct NextPowerOfTwoH<N, false> { 200af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner enum { 201af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner // We could just use NextVal = N+1, but this converges faster. N|(N-1) sets 202af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner // the right-most zero bits to one all at once, e.g. 0b0011000 -> 0b0011111. 203155b6220f79ca2dbd47193c1c061e6e129b977abChris Lattner Val = NextPowerOfTwo<(N|(N-1)) + 1>::Val 204af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner }; 205af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner}; 206af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner 207af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnertemplate<unsigned N> 208af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattnerstruct NextPowerOfTwo { 209af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner enum { Val = NextPowerOfTwoH<N, (N&(N-1)) == 0>::Val }; 210af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner}; 211af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner 212c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 2130b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner/// SmallPtrSet - This class implements a set which is optimizer for holding 2140b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner/// SmallSize or less elements. This internally rounds up SmallSize to the next 2150b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner/// power of two if it is not already a power of two. See the comments above 2160b930852cf1a9899ae82dd6c31b43e754a77dcb0Chris Lattner/// SmallPtrSetImpl for details of the algorithm. 217c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnertemplate<class PtrType, unsigned SmallSize> 218c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerclass SmallPtrSet : public SmallPtrSetImpl { 219af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner // Make sure that SmallSize is a power of two, round up if not. 220af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner enum { SmallSizePowTwo = NextPowerOfTwo<SmallSize>::Val }; 221af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner void *SmallArray[SmallSizePowTwo]; 222c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattnerpublic: 223af3056c97e56106af7c3b9a5c856d1dc1d21e358Chris Lattner SmallPtrSet() : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) {} 224ac58a16f8584f38198cc7800bd37a896125268b7Jeff Cohen SmallPtrSet(const SmallPtrSet &that) : SmallPtrSetImpl(that) {} 225c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 226ab8fea5283de0931e1da5dc91b4df2f734ba0206Chris Lattner template<typename It> 227ab8fea5283de0931e1da5dc91b4df2f734ba0206Chris Lattner SmallPtrSet(It I, It E) 228ab8fea5283de0931e1da5dc91b4df2f734ba0206Chris Lattner : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) { 229086f18626750482318612a10c3027b946b4e36e4Chris Lattner insert(I, E); 230ab8fea5283de0931e1da5dc91b4df2f734ba0206Chris Lattner } 231ab8fea5283de0931e1da5dc91b4df2f734ba0206Chris Lattner 232c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner typedef SmallPtrSetIterator<PtrType> iterator; 233c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner typedef SmallPtrSetIterator<PtrType> const_iterator; 234c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner inline iterator begin() const { 235c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return iterator(CurArray); 236c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 237c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner inline iterator end() const { 238c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner return iterator(CurArray+CurArraySize); 239c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner } 24091f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner 24191f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner // Allow assignment from any smallptrset with the same element type even if it 24291f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner // doesn't have the same smallsize. 2434d6f96d6997738419627ebe13dd6cb9c88a98fd7Owen Anderson const SmallPtrSet<PtrType, SmallSize>& 24495fd3189f84de5953c75d67403e7db9acdd5005dChris Lattner operator=(const SmallPtrSet<PtrType, SmallSize> &RHS) { 24591f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner CopyFrom(RHS); 24691f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner return *this; 24791f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner } 24891f0158d4d1b16b8615126b05582d421cfb14089Chris Lattner 249c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner}; 250c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 251c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner} 252c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner 253c95dc987e9e369c1c63819dbc4f76ab9b913772cChris Lattner#endif 254