/* Copyright 2015 The TensorFlow Authors. All Rights Reserved.

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 <random>

#include "tensorflow/core/common_runtime/kernel_benchmark_testlib.h"
#include "tensorflow/core/framework/tensor.h"
#include "tensorflow/core/platform/test.h"
#include "tensorflow/core/platform/test_benchmark.h"

namespace tensorflow {
namespace {

Tensor VecShape(int64 v) {
  if (v >= std::numeric_limits<int32>::max()) {
    Tensor shape(DT_INT64, TensorShape({1}));
    shape.vec<int64>()(0) = v;
    return shape;
  } else {
    Tensor shape(DT_INT32, TensorShape({1}));
    shape.vec<int32>()(0) = v;
    return shape;
  }
}

Tensor VecLam32(int64 n, int magnitude) {
  std::mt19937 gen(0x12345);
  std::uniform_real_distribution<float> dist(0.0, 1.0);
  Tensor lams(DT_FLOAT, TensorShape({n}));
  for (int i = 0; i < n; i++) {
    // Generate in range (magnitude, 2 * magnitude)
    lams.vec<float>()(i) = magnitude * (1 + dist(gen));
  }
  return lams;
}

Tensor VecLam64(int64 n, int magnitude) {
  std::mt19937 gen(0x12345);
  std::uniform_real_distribution<double> dist(0.0, 1.0);
  Tensor lams(DT_DOUBLE, TensorShape({n}));
  for (int i = 0; i < n; i++) {
    // Generate in range (magnitude, 2 * magnitude)
    lams.vec<double>()(i) = magnitude * (1 + dist(gen));
  }
  return lams;
}

#define BM_Poisson(DEVICE, BITS, MAGNITUDE)                            \
  static void BM_##DEVICE##_RandomPoisson_lam_##MAGNITUDE##_##BITS(    \
      int iters, int nsamp, int nlam) {                                \
    testing::ItemsProcessed(static_cast<int64>(iters) * nsamp * nlam); \
    Graph* g = new Graph(OpRegistry::Global());                        \
    test::graph::RandomPoisson(                                        \
        g, test::graph::Constant(g, VecShape(nsamp)),                  \
        test::graph::Constant(g, VecLam##BITS(nlam, MAGNITUDE)));      \
    test::Benchmark(#DEVICE, g).Run(iters);                            \
  }                                                                    \
  BENCHMARK(BM_##DEVICE##_RandomPoisson_lam_##MAGNITUDE##_##BITS)      \
      ->RangePair(1, 64, 2, 50);

BM_Poisson(cpu, 32, 1);
BM_Poisson(cpu, 32, 8);
BM_Poisson(cpu, 32, 32);

BM_Poisson(cpu, 64, 1);
BM_Poisson(cpu, 64, 8);
BM_Poisson(cpu, 64, 32);

}  // namespace
}  // namespace tensorflow