1 files changed, 270 insertions, 0 deletions
diff --git a/llvm/lib/Support/SmallPtrSet.cpp b/llvm/lib/Support/SmallPtrSet.cpp
new file mode 100644
index 0000000000000..f60464c8e7561
--- /dev/null
+++ b/llvm/lib/Support/SmallPtrSet.cpp
@@ -0,0 +1,270 @@
+//===- llvm/ADT/SmallPtrSet.cpp - 'Normally small' pointer set ------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the SmallPtrSet class.  See SmallPtrSet.h for an
+// overview of the algorithm.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/DenseMapInfo.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/ErrorHandling.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdlib>
+
+using namespace llvm;
+
+void SmallPtrSetImplBase::shrink_and_clear() {
+  assert(!isSmall() && "Can't shrink a small set!");
+  free(CurArray);
+
+  // Reduce the number of buckets.
+  unsigned Size = size();
+  CurArraySize = Size > 16 ? 1 << (Log2_32_Ceil(Size) + 1) : 32;
+  NumNonEmpty = NumTombstones = 0;
+
+  // Install the new array.  Clear all the buckets to empty.
+  CurArray = (const void**)safe_malloc(sizeof(void*) * CurArraySize);
+
+  memset(CurArray, -1, CurArraySize*sizeof(void*));
+}
+
+std::pair<const void *const *, bool>
+SmallPtrSetImplBase::insert_imp_big(const void *Ptr) {
+  if (LLVM_UNLIKELY(size() * 4 >= CurArraySize * 3)) {
+    // If more than 3/4 of the array is full, grow.
+    Grow(CurArraySize < 64 ? 128 : CurArraySize * 2);
+  } else if (LLVM_UNLIKELY(CurArraySize - NumNonEmpty < CurArraySize / 8)) {
+    // If fewer of 1/8 of the array is empty (meaning that many are filled with
+    // tombstones), rehash.
+    Grow(CurArraySize);
+  }
+
+  // Okay, we know we have space.  Find a hash bucket.
+  const void **Bucket = const_cast<const void**>(FindBucketFor(Ptr));
+  if (*Bucket == Ptr)
+    return std::make_pair(Bucket, false); // Already inserted, good.
+
+  // Otherwise, insert it!
+  if (*Bucket == getTombstoneMarker())
+    --NumTombstones;
+  else
+    ++NumNonEmpty; // Track density.
+  *Bucket = Ptr;
+  incrementEpoch();
+  return std::make_pair(Bucket, true);
+}
+
+const void * const *SmallPtrSetImplBase::FindBucketFor(const void *Ptr) const {
+  unsigned Bucket = DenseMapInfo<void *>::getHashValue(Ptr) & (CurArraySize-1);
+  unsigned ArraySize = CurArraySize;
+  unsigned ProbeAmt = 1;
+  const void *const *Array = CurArray;
+  const void *const *Tombstone = nullptr;
+  while (true) {
+    // If we found an empty bucket, the pointer doesn't exist in the set.
+    // Return a tombstone if we've seen one so far, or the empty bucket if
+    // not.
+    if (LLVM_LIKELY(Array[Bucket] == getEmptyMarker()))
+      return Tombstone ? Tombstone : Array+Bucket;
+
+    // Found Ptr's bucket?
+    if (LLVM_LIKELY(Array[Bucket] == Ptr))
+      return Array+Bucket;
+
+    // If this is a tombstone, remember it.  If Ptr ends up not in the set, we
+    // prefer to return it than something that would require more probing.
+    if (Array[Bucket] == getTombstoneMarker() && !Tombstone)
+      Tombstone = Array+Bucket;  // Remember the first tombstone found.
+
+    // It's a hash collision or a tombstone. Reprobe.
+    Bucket = (Bucket + ProbeAmt++) & (ArraySize-1);
+  }
+}
+
+/// Grow - Allocate a larger backing store for the buckets and move it over.
+///
+void SmallPtrSetImplBase::Grow(unsigned NewSize) {
+  const void **OldBuckets = CurArray;
+  const void **OldEnd = EndPointer();
+  bool WasSmall = isSmall();
+
+  // Install the new array.  Clear all the buckets to empty.
+  const void **NewBuckets = (const void**) safe_malloc(sizeof(void*) * NewSize);
+
+  // Reset member only if memory was allocated successfully
+  CurArray = NewBuckets;
+  CurArraySize = NewSize;
+  memset(CurArray, -1, NewSize*sizeof(void*));
+
+  // Copy over all valid entries.
+  for (const void **BucketPtr = OldBuckets; BucketPtr != OldEnd; ++BucketPtr) {
+    // Copy over the element if it is valid.
+    const void *Elt = *BucketPtr;
+    if (Elt != getTombstoneMarker() && Elt != getEmptyMarker())
+      *const_cast<void**>(FindBucketFor(Elt)) = const_cast<void*>(Elt);
+  }
+
+  if (!WasSmall)
+    free(OldBuckets);
+  NumNonEmpty -= NumTombstones;
+  NumTombstones = 0;
+}
+
+SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
+                                         const SmallPtrSetImplBase &that) {
+  SmallArray = SmallStorage;
+
+  // If we're becoming small, prepare to insert into our stack space
+  if (that.isSmall()) {
+    CurArray = SmallArray;
+  // Otherwise, allocate new heap space (unless we were the same size)
+  } else {
+    CurArray = (const void**)safe_malloc(sizeof(void*) * that.CurArraySize);
+  }
+
+  // Copy over the that array.
+  CopyHelper(that);
+}
+
+SmallPtrSetImplBase::SmallPtrSetImplBase(const void **SmallStorage,
+                                         unsigned SmallSize,
+                                         SmallPtrSetImplBase &&that) {
+  SmallArray = SmallStorage;
+  MoveHelper(SmallSize, std::move(that));
+}
+
+void SmallPtrSetImplBase::CopyFrom(const SmallPtrSetImplBase &RHS) {
+  assert(&RHS != this && "Self-copy should be handled by the caller.");
+
+  if (isSmall() && RHS.isSmall())
+    assert(CurArraySize == RHS.CurArraySize &&
+           "Cannot assign sets with different small sizes");
+
+  // If we're becoming small, prepare to insert into our stack space
+  if (RHS.isSmall()) {
+    if (!isSmall())
+      free(CurArray);
+    CurArray = SmallArray;
+  // Otherwise, allocate new heap space (unless we were the same size)
+  } else if (CurArraySize != RHS.CurArraySize) {
+    if (isSmall())
+      CurArray = (const void**)safe_malloc(sizeof(void*) * RHS.CurArraySize);
+    else {
+      const void **T = (const void**)safe_realloc(CurArray,
+                                             sizeof(void*) * RHS.CurArraySize);
+      CurArray = T;
+    }
+  }
+
+  CopyHelper(RHS);
+}
+
+void SmallPtrSetImplBase::CopyHelper(const SmallPtrSetImplBase &RHS) {
+  // Copy over the new array size
+  CurArraySize = RHS.CurArraySize;
+
+  // Copy over the contents from the other set
+  std::copy(RHS.CurArray, RHS.EndPointer(), CurArray);
+
+  NumNonEmpty = RHS.NumNonEmpty;
+  NumTombstones = RHS.NumTombstones;
+}
+
+void SmallPtrSetImplBase::MoveFrom(unsigned SmallSize,
+                                   SmallPtrSetImplBase &&RHS) {
+  if (!isSmall())
+    free(CurArray);
+  MoveHelper(SmallSize, std::move(RHS));
+}
+
+void SmallPtrSetImplBase::MoveHelper(unsigned SmallSize,
+                                     SmallPtrSetImplBase &&RHS) {
+  assert(&RHS != this && "Self-move should be handled by the caller.");
+
+  if (RHS.isSmall()) {
+    // Copy a small RHS rather than moving.
+    CurArray = SmallArray;
+    std::copy(RHS.CurArray, RHS.CurArray + RHS.NumNonEmpty, CurArray);
+  } else {
+    CurArray = RHS.CurArray;
+    RHS.CurArray = RHS.SmallArray;
+  }
+
+  // Copy the rest of the trivial members.
+  CurArraySize = RHS.CurArraySize;
+  NumNonEmpty = RHS.NumNonEmpty;
+  NumTombstones = RHS.NumTombstones;
+
+  // Make the RHS small and empty.
+  RHS.CurArraySize = SmallSize;
+  assert(RHS.CurArray == RHS.SmallArray);
+  RHS.NumNonEmpty = 0;
+  RHS.NumTombstones = 0;
+}
+
+void SmallPtrSetImplBase::swap(SmallPtrSetImplBase &RHS) {
+  if (this == &RHS) return;
+
+  // We can only avoid copying elements if neither set is small.
+  if (!this->isSmall() && !RHS.isSmall()) {
+    std::swap(this->CurArray, RHS.CurArray);
+    std::swap(this->CurArraySize, RHS.CurArraySize);
+    std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
+    std::swap(this->NumTombstones, RHS.NumTombstones);
+    return;
+  }
+
+  // FIXME: From here on we assume that both sets have the same small size.
+
+  // If only RHS is small, copy the small elements into LHS and move the pointer
+  // from LHS to RHS.
+  if (!this->isSmall() && RHS.isSmall()) {
+    assert(RHS.CurArray == RHS.SmallArray);
+    std::copy(RHS.CurArray, RHS.CurArray + RHS.NumNonEmpty, this->SmallArray);
+    std::swap(RHS.CurArraySize, this->CurArraySize);
+    std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
+    std::swap(this->NumTombstones, RHS.NumTombstones);
+    RHS.CurArray = this->CurArray;
+    this->CurArray = this->SmallArray;
+    return;
+  }
+
+  // If only LHS is small, copy the small elements into RHS and move the pointer
+  // from RHS to LHS.
+  if (this->isSmall() && !RHS.isSmall()) {
+    assert(this->CurArray == this->SmallArray);
+    std::copy(this->CurArray, this->CurArray + this->NumNonEmpty,
+              RHS.SmallArray);
+    std::swap(RHS.CurArraySize, this->CurArraySize);
+    std::swap(RHS.NumNonEmpty, this->NumNonEmpty);
+    std::swap(RHS.NumTombstones, this->NumTombstones);
+    this->CurArray = RHS.CurArray;
+    RHS.CurArray = RHS.SmallArray;
+    return;
+  }
+
+  // Both a small, just swap the small elements.
+  assert(this->isSmall() && RHS.isSmall());
+  unsigned MinNonEmpty = std::min(this->NumNonEmpty, RHS.NumNonEmpty);
+  std::swap_ranges(this->SmallArray, this->SmallArray + MinNonEmpty,
+                   RHS.SmallArray);
+  if (this->NumNonEmpty > MinNonEmpty) {
+    std::copy(this->SmallArray + MinNonEmpty,
+              this->SmallArray + this->NumNonEmpty,
+              RHS.SmallArray + MinNonEmpty);
+  } else {
+    std::copy(RHS.SmallArray + MinNonEmpty, RHS.SmallArray + RHS.NumNonEmpty,
+              this->SmallArray + MinNonEmpty);
+  }
+  assert(this->CurArraySize == RHS.CurArraySize);
+  std::swap(this->NumNonEmpty, RHS.NumNonEmpty);
+  std::swap(this->NumTombstones, RHS.NumTombstones);
+}