// Copyright (c) 2024 PaddlePaddle 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.

#pragma once

#include "paddle/phi/kernels/funcs/slice.h"
#include "paddle/phi/kernels/gpu/reduce.h"
#include "paddle/phi/kernels/primitive/functor_primitives.h"

namespace phi {
namespace funcs {

HOSTDEVICE inline int CeilDivide(int n, int m) { return (n + m - 1) / m; }

inline int ComputeBlockSize(int col) {
  if (col > 512)
    return 1024;
  else if (col > 256 && col <= 512)
    return 512;
  else if (col > 128 && col <= 256)
    return 256;
  else if (col > 64 && col <= 128)
    return 128;
  else
    return 64;
}

// Iter for move to next row
struct SegmentOffsetIter {
  EIGEN_DEVICE_FUNC
  explicit SegmentOffsetIter(int num_cols) : num_cols_(num_cols) {}

  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE int operator()(int idx) const {
    return idx * num_cols_;
  }

  int num_cols_;
};

}  // namespace funcs
}  // namespace phi
