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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:44:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:44:51 +0000
commit9e3c08db40b8916968b9f30096c7be3f00ce9647 (patch)
treea68f146d7fa01f0134297619fbe7e33db084e0aa /third_party/highway/hwy/aligned_allocator.h
parentInitial commit. (diff)
downloadthunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.tar.xz
thunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.zip
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// Copyright 2020 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef HIGHWAY_HWY_ALIGNED_ALLOCATOR_H_
+#define HIGHWAY_HWY_ALIGNED_ALLOCATOR_H_
+
+// Memory allocator with support for alignment and offsets.
+
+#include <stddef.h>
+
+#include <memory>
+
+#include "hwy/highway_export.h"
+
+namespace hwy {
+
+// Minimum alignment of allocated memory for use in HWY_ASSUME_ALIGNED, which
+// requires a literal. This matches typical L1 cache line sizes, which prevents
+// false sharing.
+#define HWY_ALIGNMENT 64
+
+// Pointers to functions equivalent to malloc/free with an opaque void* passed
+// to them.
+using AllocPtr = void* (*)(void* opaque, size_t bytes);
+using FreePtr = void (*)(void* opaque, void* memory);
+
+// Returns null or a pointer to at least `payload_size` (which can be zero)
+// bytes of newly allocated memory, aligned to the larger of HWY_ALIGNMENT and
+// the vector size. Calls `alloc` with the passed `opaque` pointer to obtain
+// memory or malloc() if it is null.
+HWY_DLLEXPORT void* AllocateAlignedBytes(size_t payload_size,
+ AllocPtr alloc_ptr, void* opaque_ptr);
+
+// Frees all memory. No effect if `aligned_pointer` == nullptr, otherwise it
+// must have been returned from a previous call to `AllocateAlignedBytes`.
+// Calls `free_ptr` with the passed `opaque_ptr` pointer to free the memory; if
+// `free_ptr` function is null, uses the default free().
+HWY_DLLEXPORT void FreeAlignedBytes(const void* aligned_pointer,
+ FreePtr free_ptr, void* opaque_ptr);
+
+// Class that deletes the aligned pointer passed to operator() calling the
+// destructor before freeing the pointer. This is equivalent to the
+// std::default_delete but for aligned objects. For a similar deleter equivalent
+// to free() for aligned memory see AlignedFreer().
+class AlignedDeleter {
+ public:
+ AlignedDeleter() : free_(nullptr), opaque_ptr_(nullptr) {}
+ AlignedDeleter(FreePtr free_ptr, void* opaque_ptr)
+ : free_(free_ptr), opaque_ptr_(opaque_ptr) {}
+
+ template <typename T>
+ void operator()(T* aligned_pointer) const {
+ return DeleteAlignedArray(aligned_pointer, free_, opaque_ptr_,
+ TypedArrayDeleter<T>);
+ }
+
+ private:
+ template <typename T>
+ static void TypedArrayDeleter(void* ptr, size_t size_in_bytes) {
+ size_t elems = size_in_bytes / sizeof(T);
+ for (size_t i = 0; i < elems; i++) {
+ // Explicitly call the destructor on each element.
+ (static_cast<T*>(ptr) + i)->~T();
+ }
+ }
+
+ // Function prototype that calls the destructor for each element in a typed
+ // array. TypeArrayDeleter<T> would match this prototype.
+ using ArrayDeleter = void (*)(void* t_ptr, size_t t_size);
+
+ HWY_DLLEXPORT static void DeleteAlignedArray(void* aligned_pointer,
+ FreePtr free_ptr,
+ void* opaque_ptr,
+ ArrayDeleter deleter);
+
+ FreePtr free_;
+ void* opaque_ptr_;
+};
+
+// Unique pointer to T with custom aligned deleter. This can be a single
+// element U or an array of element if T is a U[]. The custom aligned deleter
+// will call the destructor on U or each element of a U[] in the array case.
+template <typename T>
+using AlignedUniquePtr = std::unique_ptr<T, AlignedDeleter>;
+
+// Aligned memory equivalent of make_unique<T> using the custom allocators
+// alloc/free with the passed `opaque` pointer. This function calls the
+// constructor with the passed Args... and calls the destructor of the object
+// when the AlignedUniquePtr is destroyed.
+template <typename T, typename... Args>
+AlignedUniquePtr<T> MakeUniqueAlignedWithAlloc(AllocPtr alloc, FreePtr free,
+ void* opaque, Args&&... args) {
+ T* ptr = static_cast<T*>(AllocateAlignedBytes(sizeof(T), alloc, opaque));
+ return AlignedUniquePtr<T>(new (ptr) T(std::forward<Args>(args)...),
+ AlignedDeleter(free, opaque));
+}
+
+// Similar to MakeUniqueAlignedWithAlloc but using the default alloc/free
+// functions.
+template <typename T, typename... Args>
+AlignedUniquePtr<T> MakeUniqueAligned(Args&&... args) {
+ T* ptr = static_cast<T*>(AllocateAlignedBytes(
+ sizeof(T), /*alloc_ptr=*/nullptr, /*opaque_ptr=*/nullptr));
+ return AlignedUniquePtr<T>(new (ptr) T(std::forward<Args>(args)...),
+ AlignedDeleter());
+}
+
+// Helpers for array allocators (avoids overflow)
+namespace detail {
+
+// Returns x such that 1u << x == n (if n is a power of two).
+static inline constexpr size_t ShiftCount(size_t n) {
+ return (n <= 1) ? 0 : 1 + ShiftCount(n / 2);
+}
+
+template <typename T>
+T* AllocateAlignedItems(size_t items, AllocPtr alloc_ptr, void* opaque_ptr) {
+ constexpr size_t size = sizeof(T);
+
+ constexpr bool is_pow2 = (size & (size - 1)) == 0;
+ constexpr size_t bits = ShiftCount(size);
+ static_assert(!is_pow2 || (1ull << bits) == size, "ShiftCount is incorrect");
+
+ const size_t bytes = is_pow2 ? items << bits : items * size;
+ const size_t check = is_pow2 ? bytes >> bits : bytes / size;
+ if (check != items) {
+ return nullptr; // overflowed
+ }
+ return static_cast<T*>(AllocateAlignedBytes(bytes, alloc_ptr, opaque_ptr));
+}
+
+} // namespace detail
+
+// Aligned memory equivalent of make_unique<T[]> for array types using the
+// custom allocators alloc/free. This function calls the constructor with the
+// passed Args... on every created item. The destructor of each element will be
+// called when the AlignedUniquePtr is destroyed.
+template <typename T, typename... Args>
+AlignedUniquePtr<T[]> MakeUniqueAlignedArrayWithAlloc(
+ size_t items, AllocPtr alloc, FreePtr free, void* opaque, Args&&... args) {
+ T* ptr = detail::AllocateAlignedItems<T>(items, alloc, opaque);
+ if (ptr != nullptr) {
+ for (size_t i = 0; i < items; i++) {
+ new (ptr + i) T(std::forward<Args>(args)...);
+ }
+ }
+ return AlignedUniquePtr<T[]>(ptr, AlignedDeleter(free, opaque));
+}
+
+template <typename T, typename... Args>
+AlignedUniquePtr<T[]> MakeUniqueAlignedArray(size_t items, Args&&... args) {
+ return MakeUniqueAlignedArrayWithAlloc<T, Args...>(
+ items, nullptr, nullptr, nullptr, std::forward<Args>(args)...);
+}
+
+// Custom deleter for std::unique_ptr equivalent to using free() as a deleter
+// but for aligned memory.
+class AlignedFreer {
+ public:
+ // Pass address of this to ctor to skip deleting externally-owned memory.
+ static void DoNothing(void* /*opaque*/, void* /*aligned_pointer*/) {}
+
+ AlignedFreer() : free_(nullptr), opaque_ptr_(nullptr) {}
+ AlignedFreer(FreePtr free_ptr, void* opaque_ptr)
+ : free_(free_ptr), opaque_ptr_(opaque_ptr) {}
+
+ template <typename T>
+ void operator()(T* aligned_pointer) const {
+ // TODO(deymo): assert that we are using a POD type T.
+ FreeAlignedBytes(aligned_pointer, free_, opaque_ptr_);
+ }
+
+ private:
+ FreePtr free_;
+ void* opaque_ptr_;
+};
+
+// Unique pointer to single POD, or (if T is U[]) an array of POD. For non POD
+// data use AlignedUniquePtr.
+template <typename T>
+using AlignedFreeUniquePtr = std::unique_ptr<T, AlignedFreer>;
+
+// Allocate an aligned and uninitialized array of POD values as a unique_ptr.
+// Upon destruction of the unique_ptr the aligned array will be freed.
+template <typename T>
+AlignedFreeUniquePtr<T[]> AllocateAligned(const size_t items, AllocPtr alloc,
+ FreePtr free, void* opaque) {
+ return AlignedFreeUniquePtr<T[]>(
+ detail::AllocateAlignedItems<T>(items, alloc, opaque),
+ AlignedFreer(free, opaque));
+}
+
+// Same as previous AllocateAligned(), using default allocate/free functions.
+template <typename T>
+AlignedFreeUniquePtr<T[]> AllocateAligned(const size_t items) {
+ return AllocateAligned<T>(items, nullptr, nullptr, nullptr);
+}
+
+} // namespace hwy
+#endif // HIGHWAY_HWY_ALIGNED_ALLOCATOR_H_