/* Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <assert.h>
#include "histogram_common.h"

extern "C" void histogram64CPU(uint *h_Histogram, void *h_Data,
                               uint byteCount) {
  for (uint i = 0; i < HISTOGRAM64_BIN_COUNT; i++) h_Histogram[i] = 0;

  assert(sizeof(uint) == 4 && (byteCount % 4) == 0);

  for (uint i = 0; i < (byteCount / 4); i++) {
    uint data = ((uint *)h_Data)[i];
    h_Histogram[(data >> 2) & 0x3FU]++;
    h_Histogram[(data >> 10) & 0x3FU]++;
    h_Histogram[(data >> 18) & 0x3FU]++;
    h_Histogram[(data >> 26) & 0x3FU]++;
  }
}

extern "C" void histogram256CPU(uint *h_Histogram, void *h_Data,
                                uint byteCount) {
  for (uint i = 0; i < HISTOGRAM256_BIN_COUNT; i++) h_Histogram[i] = 0;

  assert(sizeof(uint) == 4 && (byteCount % 4) == 0);

  for (uint i = 0; i < (byteCount / 4); i++) {
    uint data = ((uint *)h_Data)[i];
    h_Histogram[(data >> 0) & 0xFFU]++;
    h_Histogram[(data >> 8) & 0xFFU]++;
    h_Histogram[(data >> 16) & 0xFFU]++;
    h_Histogram[(data >> 24) & 0xFFU]++;
  }
}
