| //===- llvm/ADT/SmallVector.cpp - 'Normally small' vectors ----------------===// |
| // |
| // 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 SmallVector class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/SmallVector.h" |
| #include <cstdint> |
| using namespace llvm; |
| |
| // Check that no bytes are wasted and everything is well-aligned. |
| namespace { |
| struct Struct16B { |
| alignas(16) void *X; |
| }; |
| struct Struct32B { |
| alignas(32) void *X; |
| }; |
| } |
| static_assert(sizeof(SmallVector<void *, 0>) == |
| sizeof(unsigned) * 2 + sizeof(void *), |
| "wasted space in SmallVector size 0"); |
| static_assert(alignof(SmallVector<Struct16B, 0>) >= alignof(Struct16B), |
| "wrong alignment for 16-byte aligned T"); |
| static_assert(alignof(SmallVector<Struct32B, 0>) >= alignof(Struct32B), |
| "wrong alignment for 32-byte aligned T"); |
| static_assert(sizeof(SmallVector<Struct16B, 0>) >= alignof(Struct16B), |
| "missing padding for 16-byte aligned T"); |
| static_assert(sizeof(SmallVector<Struct32B, 0>) >= alignof(Struct32B), |
| "missing padding for 32-byte aligned T"); |
| static_assert(sizeof(SmallVector<void *, 1>) == |
| sizeof(unsigned) * 2 + sizeof(void *) * 2, |
| "wasted space in SmallVector size 1"); |
| |
| static_assert(sizeof(SmallVector<char, 0>) == |
| sizeof(void *) * 2 + sizeof(void *), |
| "1 byte elements have word-sized type for size and capacity"); |
| |
| // Note: Moving this function into the header may cause performance regression. |
| template <class Size_T> |
| void SmallVectorBase<Size_T>::grow_pod(void *FirstEl, size_t MinCapacity, |
| size_t TSize) { |
| // Ensure we can fit the new capacity. |
| // This is only going to be applicable when the capacity is 32 bit. |
| if (MinCapacity > SizeTypeMax()) |
| report_bad_alloc_error("SmallVector capacity overflow during allocation"); |
| |
| // Ensure we can meet the guarantee of space for at least one more element. |
| // The above check alone will not catch the case where grow is called with a |
| // default MinCapacity of 0, but the current capacity cannot be increased. |
| // This is only going to be applicable when the capacity is 32 bit. |
| if (capacity() == SizeTypeMax()) |
| report_bad_alloc_error("SmallVector capacity unable to grow"); |
| |
| // In theory 2*capacity can overflow if the capacity is 64 bit, but the |
| // original capacity would never be large enough for this to be a problem. |
| size_t NewCapacity = 2 * capacity() + 1; // Always grow. |
| NewCapacity = std::min(std::max(NewCapacity, MinCapacity), SizeTypeMax()); |
| |
| void *NewElts; |
| if (BeginX == FirstEl) { |
| NewElts = safe_malloc(NewCapacity * TSize); |
| |
| // Copy the elements over. No need to run dtors on PODs. |
| memcpy(NewElts, this->BeginX, size() * TSize); |
| } else { |
| // If this wasn't grown from the inline copy, grow the allocated space. |
| NewElts = safe_realloc(this->BeginX, NewCapacity * TSize); |
| } |
| |
| this->BeginX = NewElts; |
| this->Capacity = NewCapacity; |
| } |
| |
| template class llvm::SmallVectorBase<uint32_t>; |
| |
| // Disable the uint64_t instantiation for 32-bit builds. |
| // Both uint32_t and uint64_t instantations are needed for 64-bit builds. |
| // This instantiation will never be used in 32-bit builds, and will cause |
| // warnings when sizeof(Size_T) > sizeof(size_t). |
| #if SIZE_MAX > UINT32_MAX |
| template class llvm::SmallVectorBase<uint64_t>; |
| |
| // Assertions to ensure this #if stays in sync with SmallVectorSizeType. |
| static_assert(sizeof(SmallVectorSizeType<char>) == sizeof(uint64_t), |
| "Expected SmallVectorBase<uint64_t> variant to be in use."); |
| #else |
| static_assert(sizeof(SmallVectorSizeType<char>) == sizeof(uint32_t), |
| "Expected SmallVectorBase<uint32_t> variant to be in use."); |
| #endif |