/*
 * SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * 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.
 */

#pragma once

#include "tensorrt_llm/common/config.h"
TRTLLM_NAMESPACE_BEGIN

namespace kernels
{

// TODO Could linear search be better for small # experts
template <class T>
__device__ inline int64_t findTotalEltsLessThanTarget(T const* sorted_indices, int64_t const arr_length, T const target)
{
    int64_t low = 0, high = arr_length - 1, target_location = -1;
    while (low <= high)
    {
        int64_t mid = (low + high) / 2;

        if (sorted_indices[mid] >= target)
        {
            high = mid - 1;
        }
        else
        {
            low = mid + 1;
            target_location = mid;
        }
    }
    return target_location + 1;
}

} // namespace kernels

TRTLLM_NAMESPACE_END