/* Copyright (C) 2019-2026 Free Software Foundation, Inc.
   Copyright (C) 2019-2026 Advanced Micro Devices, Inc. All rights reserved.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <hip/hip_runtime.h>

#define CHECK(cmd)							      \
  {									      \
    hipError_t error = cmd;						      \
    if (error != hipSuccess)						      \
      {									      \
	fprintf (stderr, "error: '%s'(%d) at %s:%d\n",			      \
		 hipGetErrorString (error), error, __FILE__, __LINE__);	      \
	exit (EXIT_FAILURE);						      \
      }									      \
  }

__global__ void
bit_extract_kernel (uint32_t *C_d, const uint32_t *A_d, size_t N)
{
  size_t offset = (blockIdx.x * blockDim.x + threadIdx.x);
  size_t stride = blockDim.x * gridDim.x;

  for (size_t i = offset; i < N; i += stride)
    C_d[i] = __bitextract_u32 (A_d[i], 8, 4);
}

int
main (int argc, char *argv[])
{
  uint32_t *A_d, *C_d;
  uint32_t *A_h, *C_h;
  size_t N = 1000000;
  size_t Nbytes = N * sizeof (uint32_t);

  int deviceId;
  CHECK (hipGetDevice (&deviceId));
  hipDeviceProp_t props;
  CHECK (hipGetDeviceProperties (&props, deviceId));
  printf ("info: running on device #%d %s\n", deviceId, props.name);

  printf ("info: allocate host mem (%6.2f MB)\n",
	  2 * Nbytes / 1024.0 / 1024.0);
  A_h = (uint32_t *) malloc (Nbytes);
  CHECK (A_h == 0 ? hipErrorMemoryAllocation : hipSuccess);
  C_h = (uint32_t *) malloc (Nbytes);
  CHECK (C_h == 0 ? hipErrorMemoryAllocation : hipSuccess);

  for (size_t i = 0; i < N; i++)
    A_h[i] = i;

  printf ("info: allocate device mem (%6.2f MB)\n",
	  2 * Nbytes / 1024.0 / 1024.0);
  CHECK (hipMalloc (&A_d, Nbytes));
  CHECK (hipMalloc (&C_d, Nbytes));

  printf ("info: copy Host2Device\n");
  CHECK (hipMemcpy (A_d, A_h, Nbytes, hipMemcpyHostToDevice));

  printf ("info: launch 'bit_extract_kernel' \n");
  hipLaunchKernelGGL (bit_extract_kernel, dim3 (GRID_DIM), dim3 (BLOCK_DIM),
		     0, 0, C_d, A_d, N);

  printf ("info: copy Device2Host\n");
  CHECK (hipMemcpy (C_h, C_d, Nbytes, hipMemcpyDeviceToHost));

  printf ("info: check result\n");
  for (size_t i = 0; i < N; i++)
    {
      unsigned Agold = ((A_h[i] & 0xf00) >> 8);
      if (C_h[i] != Agold) {
	  fprintf (stderr, "mismatch detected.\n");
	  printf ("%zu: %08x =? %08x (Ain=%08x)\n", i, C_h[i], Agold, A_h[i]);
	  CHECK (hipErrorUnknown);
      }
    }
  printf ("PASSED!\n");
}
