1 files changed, 145 insertions, 0 deletions
diff --git a/third_party/highway/hwy/contrib/image/image.cc b/third_party/highway/hwy/contrib/image/image.cc
new file mode 100644
index 0000000000..67b37d2711
--- /dev/null
+++ b/third_party/highway/hwy/contrib/image/image.cc
@@ -0,0 +1,145 @@
+// 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.
+
+#include "hwy/contrib/image/image.h"
+
+#include <algorithm>  // std::swap
+#include <cstddef>
+
+#undef HWY_TARGET_INCLUDE
+#define HWY_TARGET_INCLUDE "hwy/contrib/image/image.cc"
+#include "hwy/foreach_target.h"  // IWYU pragma: keep
+#include "hwy/highway.h"
+
+HWY_BEFORE_NAMESPACE();
+namespace hwy {
+namespace HWY_NAMESPACE {
+size_t GetVectorSize() { return Lanes(ScalableTag<uint8_t>()); }
+// NOLINTNEXTLINE(google-readability-namespace-comments)
+}  // namespace HWY_NAMESPACE
+
+}  // namespace hwy
+HWY_AFTER_NAMESPACE();
+
+#if HWY_ONCE
+namespace hwy {
+namespace {
+HWY_EXPORT(GetVectorSize);  // Local function.
+}  // namespace
+
+size_t ImageBase::VectorSize() {
+  // Do not cache result - must return the current value, which may be greater
+  // than the first call if it was subject to DisableTargets!
+  return HWY_DYNAMIC_DISPATCH(GetVectorSize)();
+}
+
+size_t ImageBase::BytesPerRow(const size_t xsize, const size_t sizeof_t) {
+  const size_t vec_size = VectorSize();
+  size_t valid_bytes = xsize * sizeof_t;
+
+  // Allow unaligned accesses starting at the last valid value - this may raise
+  // msan errors unless the user calls InitializePaddingForUnalignedAccesses.
+  // Skip for the scalar case because no extra lanes will be loaded.
+  if (vec_size != 1) {
+    HWY_DASSERT(vec_size >= sizeof_t);
+    valid_bytes += vec_size - sizeof_t;
+  }
+
+  // Round up to vector and cache line size.
+  const size_t align = HWY_MAX(vec_size, HWY_ALIGNMENT);
+  size_t bytes_per_row = RoundUpTo(valid_bytes, align);
+
+  // During the lengthy window before writes are committed to memory, CPUs
+  // guard against read after write hazards by checking the address, but
+  // only the lower 11 bits. We avoid a false dependency between writes to
+  // consecutive rows by ensuring their sizes are not multiples of 2 KiB.
+  // Avoid2K prevents the same problem for the planes of an Image3.
+  if (bytes_per_row % HWY_ALIGNMENT == 0) {
+    bytes_per_row += align;
+  }
+
+  HWY_DASSERT(bytes_per_row % align == 0);
+  return bytes_per_row;
+}
+
+ImageBase::ImageBase(const size_t xsize, const size_t ysize,
+                     const size_t sizeof_t)
+    : xsize_(static_cast<uint32_t>(xsize)),
+      ysize_(static_cast<uint32_t>(ysize)),
+      bytes_(nullptr, AlignedFreer(&AlignedFreer::DoNothing, nullptr)) {
+  HWY_ASSERT(sizeof_t == 1 || sizeof_t == 2 || sizeof_t == 4 || sizeof_t == 8);
+
+  bytes_per_row_ = 0;
+  // Dimensions can be zero, e.g. for lazily-allocated images. Only allocate
+  // if nonzero, because "zero" bytes still have padding/bookkeeping overhead.
+  if (xsize != 0 && ysize != 0) {
+    bytes_per_row_ = BytesPerRow(xsize, sizeof_t);
+    bytes_ = AllocateAligned<uint8_t>(bytes_per_row_ * ysize);
+    HWY_ASSERT(bytes_.get() != nullptr);
+    InitializePadding(sizeof_t, Padding::kRoundUp);
+  }
+}
+
+ImageBase::ImageBase(const size_t xsize, const size_t ysize,
+                     const size_t bytes_per_row, void* const aligned)
+    : xsize_(static_cast<uint32_t>(xsize)),
+      ysize_(static_cast<uint32_t>(ysize)),
+      bytes_per_row_(bytes_per_row),
+      bytes_(static_cast<uint8_t*>(aligned),
+             AlignedFreer(&AlignedFreer::DoNothing, nullptr)) {
+  const size_t vec_size = VectorSize();
+  HWY_ASSERT(bytes_per_row % vec_size == 0);
+  HWY_ASSERT(reinterpret_cast<uintptr_t>(aligned) % vec_size == 0);
+}
+
+void ImageBase::InitializePadding(const size_t sizeof_t, Padding padding) {
+#if HWY_IS_MSAN || HWY_IDE
+  if (xsize_ == 0 || ysize_ == 0) return;
+
+  const size_t vec_size = VectorSize();  // Bytes, independent of sizeof_t!
+  if (vec_size == 1) return;             // Scalar mode: no padding needed
+
+  const size_t valid_size = xsize_ * sizeof_t;
+  const size_t initialize_size = padding == Padding::kRoundUp
+                                     ? RoundUpTo(valid_size, vec_size)
+                                     : valid_size + vec_size - sizeof_t;
+  if (valid_size == initialize_size) return;
+
+  for (size_t y = 0; y < ysize_; ++y) {
+    uint8_t* HWY_RESTRICT row = static_cast<uint8_t*>(VoidRow(y));
+#if defined(__clang__) && (__clang_major__ <= 6)
+    // There's a bug in msan in clang-6 when handling AVX2 operations. This
+    // workaround allows tests to pass on msan, although it is slower and
+    // prevents msan warnings from uninitialized images.
+    memset(row, 0, initialize_size);
+#else
+    memset(row + valid_size, 0, initialize_size - valid_size);
+#endif  // clang6
+  }
+#else
+  (void)sizeof_t;
+  (void)padding;
+#endif  // HWY_IS_MSAN
+}
+
+void ImageBase::Swap(ImageBase& other) {
+  std::swap(xsize_, other.xsize_);
+  std::swap(ysize_, other.ysize_);
+  std::swap(bytes_per_row_, other.bytes_per_row_);
+  std::swap(bytes_, other.bytes_);
+}
+
+}  // namespace hwy
+#endif  // HWY_ONCE