third_party/highway/hwy/contrib/image/image_test.cc

// Copyright (c) the JPEG XL Project
// 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 "third_party/highway/hwy/contrib/image/image.h"

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>

#include <random>

#undef HWY_TARGET_INCLUDE
#define HWY_TARGET_INCLUDE "hwy/contrib/image/image_test.cc"
#include "third_party/highway/hwy/foreach_target.h"  // IWYU pragma: keep
#include "third_party/highway/hwy/highway.h"
#include "third_party/highway/hwy/tests/test_util-inl.h"

HWY_BEFORE_NAMESPACE();
namespace hwy {
namespace HWY_NAMESPACE {
namespace {

// Ensure we can always write full aligned vectors.
struct TestAlignedT {
  template <typename T>
  void operator()(T /*unused*/) const {
    std::mt19937 rng(129);
    std::uniform_int_distribution<int> dist(0, 16);
    const ScalableTag<T> d;

    for (size_t ysize = 1; ysize < 4; ++ysize) {
      for (size_t xsize = 1; xsize < 64; ++xsize) {
        Image<T> img(xsize, ysize);

        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          for (size_t x = 0; x < xsize; x += Lanes(d)) {
            const auto values = Iota(d, dist(rng));
            Store(values, d, row + x);
          }
        }

        // Sanity check to prevent optimizing out the writes
        const auto x = std::uniform_int_distribution<size_t>(0, xsize - 1)(rng);
        const auto y = std::uniform_int_distribution<size_t>(0, ysize - 1)(rng);
        HWY_ASSERT(img.ConstRow(y)[x] < 16 + Lanes(d));
      }
    }
  }
};

void TestAligned() { ForUnsignedTypes(TestAlignedT()); }

// Ensure we can write an unaligned vector starting at the last valid value.
struct TestUnalignedT {
  template <typename T>
  void operator()(T /*unused*/) const {
    std::mt19937 rng(129);
    std::uniform_int_distribution<int> dist(0, 3);
    const ScalableTag<T> d;

    for (size_t ysize = 1; ysize < 4; ++ysize) {
      for (size_t xsize = 1; xsize < 128; ++xsize) {
        Image<T> img(xsize, ysize);
        img.InitializePaddingForUnalignedAccesses();

// This test reads padding, which only works if it was initialized,
// which only happens in MSAN builds.
#if HWY_IS_MSAN || HWY_IDE
        // Initialize only the valid samples
        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          for (size_t x = 0; x < xsize; ++x) {
            row[x] = ConvertScalarTo<T>(1u << dist(rng));
          }
        }

        // Read padding bits
        auto accum = Zero(d);
        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          for (size_t x = 0; x < xsize; ++x) {
            accum = Or(accum, LoadU(d, row + x));
          }
        }

        // Ensure padding was zero
        const size_t N = Lanes(d);
        auto lanes = AllocateAligned<T>(N);
        HWY_ASSERT(lanes);
        Store(accum, d, lanes.get());
        for (size_t i = 0; i < N; ++i) {
          HWY_ASSERT(lanes[i] < 16);
        }
#else  // Check that writing padding does not overwrite valid samples
       // Initialize only the valid samples
        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          for (size_t x = 0; x < xsize; ++x) {
            row[x] = ConvertScalarTo<T>(x);
          }
        }

        // Zero padding and rightmost sample
        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          StoreU(Zero(d), d, row + xsize - 1);
        }

        // Ensure no samples except the rightmost were overwritten
        for (size_t y = 0; y < ysize; ++y) {
          T* HWY_RESTRICT row = img.MutableRow(y);
          for (size_t x = 0; x < xsize - 1; ++x) {
            HWY_ASSERT_EQ(ConvertScalarTo<T>(x), row[x]);
          }
        }
#endif
      }
    }
  }
};

void TestUnaligned() { ForUnsignedTypes(TestUnalignedT()); }

}  // namespace
// NOLINTNEXTLINE(google-readability-namespace-comments)
}  // namespace HWY_NAMESPACE
}  // namespace hwy
HWY_AFTER_NAMESPACE();

#if HWY_ONCE
namespace hwy {
namespace {
HWY_BEFORE_TEST(ImageTest);
HWY_EXPORT_AND_TEST_P(ImageTest, TestAligned);
HWY_EXPORT_AND_TEST_P(ImageTest, TestUnaligned);
HWY_AFTER_TEST();
}  // namespace
}  // namespace hwy
HWY_TEST_MAIN();
#endif  // HWY_ONCE