text: /*
  Copyright (c) 2015-2016 Advanced Micro Devices, Inc. All rights reserved.
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  */
  
  #include <iostream>
  
  // hip header file
  #include "hip/hip_runtime.h"
  
  
  #define WIDTH 64
  
  #define NUM (WIDTH * WIDTH)
  
  #define THREADS_PER_BLOCK_X 4
  #define THREADS_PER_BLOCK_Y 4
  #define THREADS_PER_BLOCK_Z 1
  
  // Device (Kernel) function, it must be void
  // hipLaunchParm provides the execution configuration
  __global__ void matrixTranspose(hipLaunchParm lp, float* out, float* in, const int width) {
      __shared__ float sharedMem[WIDTH * WIDTH];
  
      int x = hipBlockDim_x * hipBlockIdx_x + hipThreadIdx_x;
      int y = hipBlockDim_y * hipBlockIdx_y + hipThreadIdx_y;
  
      sharedMem[y * width + x] = in[x * width + y];
  
      __syncthreads();
  
      out[y * width + x] = sharedMem[y * width + x];
  }
  
  // CPU implementation of matrix transpose
  void matrixTransposeCPUReference(float* output, float* input, const unsigned int width) {
      for (unsigned int j = 0; j < width; j++) {
          for (unsigned int i = 0; i < width; i++) {
              output[i * width + j] = input[j * width + i];
          }
      }
  }
  
  int main() {
      float* Matrix;
      float* TransposeMatrix;
      float* cpuTransposeMatrix;
  
      float* gpuMatrix;
      float* gpuTransposeMatrix;
  
      hipDeviceProp_t devProp;
      hipGetDeviceProperties(&devProp, 0);
  
      std::cout << "Device name " << devProp.name << std::endl;
  
      int i;
      int errors;
  
      Matrix = (float*)malloc(NUM * sizeof(float));
      TransposeMatrix = (float*)malloc(NUM * sizeof(float));
      cpuTransposeMatrix = (float*)malloc(NUM * sizeof(float));
  
      // initialize the input data
      for (i = 0; i < NUM; i++) {
          Matrix[i] = (float)i * 10.0f;
      }
  
      // allocate the memory on the device side
      hipMalloc((void**)&gpuMatrix, NUM * sizeof(float));
      hipMalloc((void**)&gpuTransposeMatrix, NUM * sizeof(float));
  
      // Memory transfer from host to device
      hipMemcpy(gpuMatrix, Matrix, NUM * sizeof(float), hipMemcpyHostToDevice);
  
      // Lauching kernel from host
      hipLaunchKernel(matrixTranspose, dim3(WIDTH / THREADS_PER_BLOCK_X, WIDTH / THREADS_PER_BLOCK_Y),
                      dim3(THREADS_PER_BLOCK_X, THREADS_PER_BLOCK_Y), 0, 0, gpuTransposeMatrix,
                      gpuMatrix, WIDTH);
  
      // Memory transfer from device to host
      hipMemcpy(TransposeMatrix, gpuTransposeMatrix, NUM * sizeof(float), hipMemcpyDeviceToHost);
  
      // CPU MatrixTranspose computation
      matrixTransposeCPUReference(cpuTransposeMatrix, Matrix, WIDTH);
  
      // verify the results
      errors = 0;
      double eps = 1.0E-6;
      for (i = 0; i < NUM; i++) {
          if (std::abs(TransposeMatrix[i] - cpuTransposeMatrix[i]) > eps) {
              printf("%d cpu: %f gpu  %f\n", i, cpuTransposeMatrix[i], TransposeMatrix[i]);
              errors++;
          }
      }
      if (errors != 0) {
          printf("FAILED: %d errors\n", errors);
      } else {
          printf("PASSED!\n");
      }
  
      // free the resources on device side
      hipFree(gpuMatrix);
      hipFree(gpuTransposeMatrix);
  
      // free the resources on host side
      free(Matrix);
      free(TransposeMatrix);
      free(cpuTransposeMatrix);
  
      return errors;
  }
  