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Diffstat (limited to 'contrib/llvm-project/llvm/lib/Support/SmallVector.cpp')
-rw-r--r-- | contrib/llvm-project/llvm/lib/Support/SmallVector.cpp | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Support/SmallVector.cpp b/contrib/llvm-project/llvm/lib/Support/SmallVector.cpp new file mode 100644 index 000000000000..2d7721e4e1fb --- /dev/null +++ b/contrib/llvm-project/llvm/lib/Support/SmallVector.cpp @@ -0,0 +1,153 @@ +//===- 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 "llvm/ADT/Twine.h" +#include <cstdint> +#ifdef LLVM_ENABLE_EXCEPTIONS +#include <stdexcept> +#endif +using namespace llvm; + +// Check that no bytes are wasted and everything is well-aligned. +namespace { +// These structures may cause binary compat warnings on AIX. Suppress the +// warning since we are only using these types for the static assertions below. +#if defined(_AIX) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Waix-compat" +#endif +struct Struct16B { + alignas(16) void *X; +}; +struct Struct32B { + alignas(32) void *X; +}; +#if defined(_AIX) +#pragma GCC diagnostic pop +#endif +} +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"); + +/// Report that MinSize doesn't fit into this vector's size type. Throws +/// std::length_error or calls report_fatal_error. +[[noreturn]] static void report_size_overflow(size_t MinSize, size_t MaxSize); +static void report_size_overflow(size_t MinSize, size_t MaxSize) { + std::string Reason = "SmallVector unable to grow. Requested capacity (" + + std::to_string(MinSize) + + ") is larger than maximum value for size type (" + + std::to_string(MaxSize) + ")"; +#ifdef LLVM_ENABLE_EXCEPTIONS + throw std::length_error(Reason); +#else + report_fatal_error(Twine(Reason)); +#endif +} + +/// Report that this vector is already at maximum capacity. Throws +/// std::length_error or calls report_fatal_error. +[[noreturn]] static void report_at_maximum_capacity(size_t MaxSize); +static void report_at_maximum_capacity(size_t MaxSize) { + std::string Reason = + "SmallVector capacity unable to grow. Already at maximum size " + + std::to_string(MaxSize); +#ifdef LLVM_ENABLE_EXCEPTIONS + throw std::length_error(Reason); +#else + report_fatal_error(Twine(Reason)); +#endif +} + +// Note: Moving this function into the header may cause performance regression. +template <class Size_T> +static size_t getNewCapacity(size_t MinSize, size_t TSize, size_t OldCapacity) { + constexpr size_t MaxSize = std::numeric_limits<Size_T>::max(); + + // Ensure we can fit the new capacity. + // This is only going to be applicable when the capacity is 32 bit. + if (MinSize > MaxSize) + report_size_overflow(MinSize, MaxSize); + + // 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 MinSize of 0, but the current capacity cannot be increased. + // This is only going to be applicable when the capacity is 32 bit. + if (OldCapacity == MaxSize) + report_at_maximum_capacity(MaxSize); + + // 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 * OldCapacity + 1; // Always grow. + return std::min(std::max(NewCapacity, MinSize), MaxSize); +} + +// Note: Moving this function into the header may cause performance regression. +template <class Size_T> +void *SmallVectorBase<Size_T>::mallocForGrow(size_t MinSize, size_t TSize, + size_t &NewCapacity) { + NewCapacity = getNewCapacity<Size_T>(MinSize, TSize, this->capacity()); + return llvm::safe_malloc(NewCapacity * TSize); +} + +// 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 MinSize, + size_t TSize) { + size_t NewCapacity = getNewCapacity<Size_T>(MinSize, TSize, this->capacity()); + 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 instantiations 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 |