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author | Devtools Arcadia <arcadia-devtools@yandex-team.ru> | 2022-02-07 18:08:42 +0300 |
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committer | Devtools Arcadia <arcadia-devtools@mous.vla.yp-c.yandex.net> | 2022-02-07 18:08:42 +0300 |
commit | 1110808a9d39d4b808aef724c861a2e1a38d2a69 (patch) | |
tree | e26c9fed0de5d9873cce7e00bc214573dc2195b7 /contrib/libs/llvm12/lib/Support/SmallPtrSet.cpp | |
download | ydb-1110808a9d39d4b808aef724c861a2e1a38d2a69.tar.gz |
intermediate changes
ref:cde9a383711a11544ce7e107a78147fb96cc4029
Diffstat (limited to 'contrib/libs/llvm12/lib/Support/SmallPtrSet.cpp')
-rw-r--r-- | contrib/libs/llvm12/lib/Support/SmallPtrSet.cpp | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/contrib/libs/llvm12/lib/Support/SmallPtrSet.cpp b/contrib/libs/llvm12/lib/Support/SmallPtrSet.cpp new file mode 100644 index 0000000000..f60464c8e7 --- /dev/null +++ b/contrib/libs/llvm12/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); +} |