// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <hwy/targets.h>

#include "benchmark/benchmark.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/image_ops.h"
#include "tools/gauss_blur.h"

namespace jxl {
namespace {

void BM_GaussBlur1d(benchmark::State& state) {
  // Uncomment to disable SIMD and force and scalar implementation
  // hwy::DisableTargets(~HWY_SCALAR);
  // Uncomment to run AVX2
  // hwy::DisableTargets(HWY_AVX3);

  const size_t length = state.range();
  const double sigma = 7.0;  // (from Butteraugli application)
  JXL_ASSIGN_OR_DIE(ImageF in, ImageF::Create(length, 1));
  const float expected = length;
  FillImage(expected, &in);

  JXL_ASSIGN_OR_DIE(ImageF temp, ImageF::Create(length, 1));
  JXL_ASSIGN_OR_DIE(ImageF out, ImageF::Create(length, 1));
  const auto rg = CreateRecursiveGaussian(sigma);
  for (auto _ : state) {
    FastGaussian1D(rg, length, in.Row(0), out.Row(0));
    // Prevent optimizing out
    JXL_ASSERT(std::abs(out.ConstRow(0)[length / 2] - expected) / expected <
               9E-5);
  }
  state.SetItemsProcessed(length * state.iterations());
}

void BM_GaussBlur2d(benchmark::State& state) {
  // See GaussBlur1d for SIMD changes.

  const size_t xsize = state.range();
  const size_t ysize = xsize;
  const double sigma = 7.0;  // (from Butteraugli application)
  JXL_ASSIGN_OR_DIE(ImageF in, ImageF::Create(xsize, ysize));
  const float expected = xsize + ysize;
  FillImage(expected, &in);

  JXL_ASSIGN_OR_DIE(ImageF temp, ImageF::Create(xsize, ysize));
  JXL_ASSIGN_OR_DIE(ImageF out, ImageF::Create(xsize, ysize));
  ThreadPool* null_pool = nullptr;
  const auto rg = CreateRecursiveGaussian(sigma);
  for (auto _ : state) {
    FastGaussian(rg, in, null_pool, &temp, &out);
    // Prevent optimizing out
    JXL_ASSERT(std::abs(out.ConstRow(ysize / 2)[xsize / 2] - expected) /
                   expected <
               9E-5);
  }
  state.SetItemsProcessed(xsize * ysize * state.iterations());
}

BENCHMARK(BM_GaussBlur1d)->Range(1 << 8, 1 << 14);
BENCHMARK(BM_GaussBlur2d)->Range(1 << 7, 1 << 10);

}  // namespace
}  // namespace jxl