LCOV - code coverage report
Current view: top level - lib/Support - SmallPtrSet.cpp (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 115 116 99.1 %
Date: 2018-06-17 00:07:59 Functions: 11 11 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- llvm/ADT/SmallPtrSet.cpp - 'Normally small' pointer set ------------===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file implements the SmallPtrSet class.  See SmallPtrSet.h for an
      11             : // overview of the algorithm.
      12             : //
      13             : //===----------------------------------------------------------------------===//
      14             : 
      15             : #include "llvm/ADT/SmallPtrSet.h"
      16             : #include "llvm/ADT/DenseMapInfo.h"
      17             : #include "llvm/Support/MathExtras.h"
      18             : #include "llvm/Support/ErrorHandling.h"
      19             : #include <algorithm>
      20             : #include <cassert>
      21             : #include <cstdlib>
      22             : 
      23             : using namespace llvm;
      24             : 
      25       93813 : void SmallPtrSetImplBase::shrink_and_clear() {
      26             :   assert(!isSmall() && "Can't shrink a small set!");
      27       93813 :   free(CurArray);
      28             : 
      29             :   // Reduce the number of buckets.
      30       93813 :   unsigned Size = size();
      31      123289 :   CurArraySize = Size > 16 ? 1 << (Log2_32_Ceil(Size) + 1) : 32;
      32       93813 :   NumNonEmpty = NumTombstones = 0;
      33             : 
      34             :   // Install the new array.  Clear all the buckets to empty.
      35       93813 :   CurArray = (const void**)safe_malloc(sizeof(void*) * CurArraySize);
      36             : 
      37       93813 :   memset(CurArray, -1, CurArraySize*sizeof(void*));
      38       93813 : }
      39             : 
      40             : std::pair<const void *const *, bool>
      41   118328895 : SmallPtrSetImplBase::insert_imp_big(const void *Ptr) {
      42   236657790 :   if (LLVM_UNLIKELY(size() * 4 >= CurArraySize * 3)) {
      43             :     // If more than 3/4 of the array is full, grow.
      44     1980930 :     Grow(CurArraySize < 64 ? 128 : CurArraySize * 2);
      45   116347965 :   } else if (LLVM_UNLIKELY(CurArraySize - NumNonEmpty < CurArraySize / 8)) {
      46             :     // If fewer of 1/8 of the array is empty (meaning that many are filled with
      47             :     // tombstones), rehash.
      48        3767 :     Grow(CurArraySize);
      49             :   }
      50             : 
      51             :   // Okay, we know we have space.  Find a hash bucket.
      52   118328895 :   const void **Bucket = const_cast<const void**>(FindBucketFor(Ptr));
      53   118328895 :   if (*Bucket == Ptr)
      54    51579017 :     return std::make_pair(Bucket, false); // Already inserted, good.
      55             : 
      56             :   // Otherwise, insert it!
      57    66749878 :   if (*Bucket == getTombstoneMarker())
      58     1749178 :     --NumTombstones;
      59             :   else
      60    65000700 :     ++NumNonEmpty; // Track density.
      61    66749878 :   *Bucket = Ptr;
      62             :   incrementEpoch();
      63    66749878 :   return std::make_pair(Bucket, true);
      64             : }
      65             : 
      66   280306205 : const void * const *SmallPtrSetImplBase::FindBucketFor(const void *Ptr) const {
      67   280306205 :   unsigned Bucket = DenseMapInfo<void *>::getHashValue(Ptr) & (CurArraySize-1);
      68             :   unsigned ArraySize = CurArraySize;
      69             :   unsigned ProbeAmt = 1;
      70   280306205 :   const void *const *Array = CurArray;
      71             :   const void *const *Tombstone = nullptr;
      72             :   while (true) {
      73             :     // If we found an empty bucket, the pointer doesn't exist in the set.
      74             :     // Return a tombstone if we've seen one so far, or the empty bucket if
      75             :     // not.
      76   600372841 :     if (LLVM_LIKELY(Array[Bucket] == getEmptyMarker()))
      77   177160341 :       return Tombstone ? Tombstone : Array+Bucket;
      78             : 
      79             :     // Found Ptr's bucket?
      80   263179182 :     if (LLVM_LIKELY(Array[Bucket] == Ptr))
      81             :       return Array+Bucket;
      82             : 
      83             :     // If this is a tombstone, remember it.  If Ptr ends up not in the set, we
      84             :     // prefer to return it than something that would require more probing.
      85   160033318 :     if (Array[Bucket] == getTombstoneMarker() && !Tombstone)
      86             :       Tombstone = Array+Bucket;  // Remember the first tombstone found.
      87             : 
      88             :     // It's a hash collision or a tombstone. Reprobe.
      89   160033318 :     Bucket = (Bucket + ProbeAmt++) & (ArraySize-1);
      90             :   }
      91             : }
      92             : 
      93             : /// Grow - Allocate a larger backing store for the buckets and move it over.
      94             : ///
      95     1984697 : void SmallPtrSetImplBase::Grow(unsigned NewSize) {
      96     1984697 :   const void **OldBuckets = CurArray;
      97             :   const void **OldEnd = EndPointer();
      98             :   bool WasSmall = isSmall();
      99             : 
     100             :   // Install the new array.  Clear all the buckets to empty.
     101     1984697 :   const void **NewBuckets = (const void**) safe_malloc(sizeof(void*) * NewSize);
     102             : 
     103             :   // Reset member only if memory was allocated successfully
     104     1984697 :   CurArray = NewBuckets;
     105     1984697 :   CurArraySize = NewSize;
     106     1984697 :   memset(CurArray, -1, NewSize*sizeof(void*));
     107             : 
     108             :   // Copy over all valid entries.
     109   170546493 :   for (const void **BucketPtr = OldBuckets; BucketPtr != OldEnd; ++BucketPtr) {
     110             :     // Copy over the element if it is valid.
     111    84280898 :     const void *Elt = *BucketPtr;
     112    84280898 :     if (Elt != getTombstoneMarker() && Elt != getEmptyMarker())
     113    70465784 :       *const_cast<void**>(FindBucketFor(Elt)) = const_cast<void*>(Elt);
     114             :   }
     115             : 
     116     1984697 :   if (!WasSmall)
     117      217984 :     free(OldBuckets);
     118     1984697 :   NumNonEmpty -= NumTombstones;
     119     1984697 :   NumTombstones = 0;
     120     1984697 : }
     121             : 
     122    22983020 : SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
     123    22983020 :                                          const SmallPtrSetImplBase &that) {
     124    22983020 :   SmallArray = SmallStorage;
     125             : 
     126             :   // If we're becoming small, prepare to insert into our stack space
     127    22983020 :   if (that.isSmall()) {
     128    22905300 :     CurArray = SmallArray;
     129             :   // Otherwise, allocate new heap space (unless we were the same size)
     130             :   } else {
     131       77720 :     CurArray = (const void**)safe_malloc(sizeof(void*) * that.CurArraySize);
     132             :   }
     133             : 
     134             :   // Copy over the that array.
     135    22983020 :   CopyHelper(that);
     136    22983021 : }
     137             : 
     138    32213863 : SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
     139             :                                          unsigned SmallSize,
     140    32213863 :                                          SmallPtrSetImplBase &&that) {
     141    32213863 :   SmallArray = SmallStorage;
     142    32213863 :   MoveHelper(SmallSize, std::move(that));
     143    32213869 : }
     144             : 
     145      300862 : void SmallPtrSetImplBase::CopyFrom(const SmallPtrSetImplBase &RHS) {
     146             :   assert(&RHS != this && "Self-copy should be handled by the caller.");
     147             : 
     148      300862 :   if (isSmall() && RHS.isSmall())
     149             :     assert(CurArraySize == RHS.CurArraySize &&
     150             :            "Cannot assign sets with different small sizes");
     151             : 
     152             :   // If we're becoming small, prepare to insert into our stack space
     153      300862 :   if (RHS.isSmall()) {
     154      300826 :     if (!isSmall())
     155          12 :       free(CurArray);
     156      300826 :     CurArray = SmallArray;
     157             :   // Otherwise, allocate new heap space (unless we were the same size)
     158          36 :   } else if (CurArraySize != RHS.CurArraySize) {
     159          36 :     if (isSmall())
     160          34 :       CurArray = (const void**)safe_malloc(sizeof(void*) * RHS.CurArraySize);
     161             :     else {
     162           2 :       const void **T = (const void**)safe_realloc(CurArray,
     163           4 :                                              sizeof(void*) * RHS.CurArraySize);
     164           2 :       CurArray = T;
     165             :     }
     166             :   }
     167             : 
     168      300862 :   CopyHelper(RHS);
     169      300862 : }
     170             : 
     171    23283881 : void SmallPtrSetImplBase::CopyHelper(const SmallPtrSetImplBase &RHS) {
     172             :   // Copy over the new array size
     173    23283881 :   CurArraySize = RHS.CurArraySize;
     174             : 
     175             :   // Copy over the contents from the other set
     176    23283881 :   std::copy(RHS.CurArray, RHS.EndPointer(), CurArray);
     177             : 
     178    23283881 :   NumNonEmpty = RHS.NumNonEmpty;
     179    23283881 :   NumTombstones = RHS.NumTombstones;
     180    23283881 : }
     181             : 
     182       55843 : void SmallPtrSetImplBase::MoveFrom(unsigned SmallSize,
     183             :                                    SmallPtrSetImplBase &&RHS) {
     184       55843 :   if (!isSmall())
     185           0 :     free(CurArray);
     186       55843 :   MoveHelper(SmallSize, std::move(RHS));
     187       55843 : }
     188             : 
     189    32269708 : void SmallPtrSetImplBase::MoveHelper(unsigned SmallSize,
     190             :                                      SmallPtrSetImplBase &&RHS) {
     191             :   assert(&RHS != this && "Self-move should be handled by the caller.");
     192             : 
     193    32269708 :   if (RHS.isSmall()) {
     194             :     // Copy a small RHS rather than moving.
     195    32118464 :     CurArray = SmallArray;
     196    32118464 :     std::copy(RHS.CurArray, RHS.CurArray + RHS.NumNonEmpty, CurArray);
     197             :   } else {
     198      151244 :     CurArray = RHS.CurArray;
     199      151244 :     RHS.CurArray = RHS.SmallArray;
     200             :   }
     201             : 
     202             :   // Copy the rest of the trivial members.
     203    32269708 :   CurArraySize = RHS.CurArraySize;
     204    32269708 :   NumNonEmpty = RHS.NumNonEmpty;
     205    32269708 :   NumTombstones = RHS.NumTombstones;
     206             : 
     207             :   // Make the RHS small and empty.
     208    32269708 :   RHS.CurArraySize = SmallSize;
     209             :   assert(RHS.CurArray == RHS.SmallArray);
     210    32269708 :   RHS.NumNonEmpty = 0;
     211    32269708 :   RHS.NumTombstones = 0;
     212    32269708 : }
     213             : 
     214    26017641 : void SmallPtrSetImplBase::swap(SmallPtrSetImplBase &RHS) {
     215    26017641 :   if (this == &RHS) return;
     216             : 
     217             :   // We can only avoid copying elements if neither set is small.
     218    26017641 :   if (!this->isSmall() && !RHS.isSmall()) {
     219             :     std::swap(this->CurArray, RHS.CurArray);
     220             :     std::swap(this->CurArraySize, RHS.CurArraySize);
     221             :     std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
     222             :     std::swap(this->NumTombstones, RHS.NumTombstones);
     223             :     return;
     224             :   }
     225             : 
     226             :   // FIXME: From here on we assume that both sets have the same small size.
     227             : 
     228             :   // If only RHS is small, copy the small elements into LHS and move the pointer
     229             :   // from LHS to RHS.
     230    26017640 :   if (!this->isSmall() && RHS.isSmall()) {
     231             :     assert(RHS.CurArray == RHS.SmallArray);
     232        3864 :     std::copy(RHS.CurArray, RHS.CurArray + RHS.NumNonEmpty, this->SmallArray);
     233             :     std::swap(RHS.CurArraySize, this->CurArraySize);
     234             :     std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
     235             :     std::swap(this->NumTombstones, RHS.NumTombstones);
     236        3864 :     RHS.CurArray = this->CurArray;
     237        3864 :     this->CurArray = this->SmallArray;
     238        3864 :     return;
     239             :   }
     240             : 
     241             :   // If only LHS is small, copy the small elements into RHS and move the pointer
     242             :   // from RHS to LHS.
     243    52027552 :   if (this->isSmall() && !RHS.isSmall()) {
     244             :     assert(this->CurArray == this->SmallArray);
     245         637 :     std::copy(this->CurArray, this->CurArray + this->NumNonEmpty,
     246             :               RHS.SmallArray);
     247             :     std::swap(RHS.CurArraySize, this->CurArraySize);
     248             :     std::swap(RHS.NumNonEmpty, this->NumNonEmpty);
     249             :     std::swap(RHS.NumTombstones, this->NumTombstones);
     250         637 :     this->CurArray = RHS.CurArray;
     251         637 :     RHS.CurArray = RHS.SmallArray;
     252         637 :     return;
     253             :   }
     254             : 
     255             :   // Both a small, just swap the small elements.
     256             :   assert(this->isSmall() && RHS.isSmall());
     257    52026278 :   unsigned MinNonEmpty = std::min(this->NumNonEmpty, RHS.NumNonEmpty);
     258    26013139 :   std::swap_ranges(this->SmallArray, this->SmallArray + MinNonEmpty,
     259             :                    RHS.SmallArray);
     260    26013139 :   if (this->NumNonEmpty > MinNonEmpty) {
     261      279814 :     std::copy(this->SmallArray + MinNonEmpty,
     262      139907 :               this->SmallArray + this->NumNonEmpty,
     263      139907 :               RHS.SmallArray + MinNonEmpty);
     264             :   } else {
     265    25873232 :     std::copy(RHS.SmallArray + MinNonEmpty, RHS.SmallArray + RHS.NumNonEmpty,
     266    25873232 :               this->SmallArray + MinNonEmpty);
     267             :   }
     268             :   assert(this->CurArraySize == RHS.CurArraySize);
     269             :   std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
     270             :   std::swap(this->NumTombstones, RHS.NumTombstones);
     271             : }

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