text: //
  // Copyright (c) 2017 The Khronos Group Inc.
  // 
  // 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.
  //
  #include "../../test_common/harness/compat.h"
  
  #include <stdio.h>
  #include <string.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  
  #include "procs.h"
  
  const char *mix_kernel_code =
  "__kernel void test_mix(__global float *srcA, __global float *srcB, __global float *srcC, __global float *dst)\n"
  "{\n"
  "    int  tid = get_global_id(0);\n"
  "\n"
  "    dst[tid] = mix(srcA[tid], srcB[tid], srcC[tid]);\n"
  "}\n";
  
  #define MAX_ERR 1e-3
  
  float
  verify_mix(float *inptrA, float *inptrB, float *inptrC, float *outptr, int n)
  {
      float       r, delta, max_err = 0.0f;
      int         i;
  
      for (i=0; i<n; i++)
      {
          r = inptrA[i] + ((inptrB[i] - inptrA[i]) * inptrC[i]);
          delta = fabsf(r - outptr[i]) / r;
          if(delta > max_err) max_err = delta;
      }
      return max_err;
  }
  
  int
  test_mix(cl_device_id device, cl_context context, cl_command_queue queue, int num_elements)
  {
      cl_mem            streams[4];
      cl_float        *input_ptr[3], *output_ptr, *p;
      cl_program        program;
      cl_kernel        kernel;
      void            *values[4];
      size_t            lengths[1];
      size_t    threads[1];
      float            max_err;
      int                err;
      int                i;
      MTdata          d;
  
      input_ptr[0] = (cl_float*)malloc(sizeof(cl_float) * num_elements);
      input_ptr[1] = (cl_float*)malloc(sizeof(cl_float) * num_elements);
      input_ptr[2] = (cl_float*)malloc(sizeof(cl_float) * num_elements);
      output_ptr = (cl_float*)malloc(sizeof(cl_float) * num_elements);
      streams[0] = clCreateBuffer( context, (cl_mem_flags)(CL_MEM_READ_WRITE),  sizeof(cl_float) * num_elements, NULL, NULL );
      if (!streams[0])
      {
          log_error("clCreateBuffer failed\n");
          return -1;
      }
      streams[1] = clCreateBuffer( context, (cl_mem_flags)(CL_MEM_READ_WRITE),  sizeof(cl_float) * num_elements, NULL, NULL );
      if (!streams[1])
      {
          log_error("clCreateBuffer failed\n");
          return -1;
      }
      streams[2] = clCreateBuffer( context, (cl_mem_flags)(CL_MEM_READ_WRITE),  sizeof(cl_float) * num_elements, NULL, NULL );
      if (!streams[2])
      {
          log_error("clCreateBuffer failed\n");
          return -1;
      }
  
      streams[3] = clCreateBuffer( context, (cl_mem_flags)(CL_MEM_READ_WRITE),  sizeof(cl_float) * num_elements, NULL, NULL );
      if (!streams[3])
      {
          log_error("clCreateBuffer failed\n");
          return -1;
      }
  
      p = input_ptr[0];
      d = init_genrand( gRandomSeed );
      for (i=0; i<num_elements; i++)
      {
          p[i] =  (float) genrand_real1(d);
      }
      p = input_ptr[1];
      for (i=0; i<num_elements; i++)
      {
          p[i] = (float) genrand_real1(d);
      }
      p = input_ptr[2];
      for (i=0; i<num_elements; i++)
      {
          p[i] = (float) genrand_real1(d);
      }
      free_mtdata(d); d = NULL;
  
      err = clEnqueueWriteBuffer( queue, streams[0], true, 0, sizeof(cl_float)*num_elements, (void *)input_ptr[0], 0, NULL, NULL );
      if (err != CL_SUCCESS)
      {
          log_error("clWriteArray failed\n");
          return -1;
      }
      err = clEnqueueWriteBuffer( queue, streams[1], true, 0, sizeof(cl_float)*num_elements, (void *)input_ptr[1], 0, NULL, NULL );
      if (err != CL_SUCCESS)
      {
          log_error("clWriteArray failed\n");
          return -1;
      }
      err = clEnqueueWriteBuffer( queue, streams[2], true, 0, sizeof(cl_float)*num_elements, (void *)input_ptr[2], 0, NULL, NULL );
      if (err != CL_SUCCESS)
      {
          log_error("clWriteArray failed\n");
          return -1;
      }
  
      lengths[0] = strlen(mix_kernel_code);
      err = create_single_kernel_helper( context, &program, &kernel, 1, &mix_kernel_code, "test_mix" );
      test_error( err, "Unable to create test kernel" );
  
  
      values[0] = streams[0];
      values[1] = streams[1];
      values[2] = streams[2];
      values[3] = streams[3];
    err = clSetKernelArg(kernel, 0, sizeof streams[0], &streams[0] );
    err |= clSetKernelArg(kernel, 1, sizeof streams[1], &streams[1] );
    err |= clSetKernelArg(kernel, 2, sizeof streams[2], &streams[2] );
    err |= clSetKernelArg(kernel, 3, sizeof streams[3], &streams[3] );
      if (err != CL_SUCCESS)
      {
          log_error("clSetKernelArgs failed\n");
          return -1;
      }
  
      threads[0] = (size_t)num_elements;
      err = clEnqueueNDRangeKernel( queue, kernel, 1, NULL, threads, NULL, 0, NULL, NULL );
      if (err != CL_SUCCESS)
      {
          log_error("clEnqueueNDRangeKernel failed\n");
          return -1;
      }
  
      err = clEnqueueReadBuffer( queue, streams[3], true, 0, sizeof(cl_float)*num_elements, (void *)output_ptr, 0, NULL, NULL );
      if (err != CL_SUCCESS)
      {
          log_error("clEnqueueReadBuffer failed\n");
          return -1;
      }
  
      max_err = verify_mix(input_ptr[0], input_ptr[1], input_ptr[2], output_ptr, num_elements);
      if (max_err > MAX_ERR)
      {
          log_error("MIX test failed %g max err\n", max_err);
          err = -1;
      }
      else
      {
          log_info("MIX test passed %g max err\n", max_err);
          err = 0;
      }
  
      clReleaseMemObject(streams[0]);
      clReleaseMemObject(streams[1]);
      clReleaseMemObject(streams[2]);
      clReleaseMemObject(streams[3]);
      clReleaseKernel(kernel);
      clReleaseProgram(program);
      free(input_ptr[0]);
      free(input_ptr[1]);
      free(input_ptr[2]);
      free(output_ptr);
  
      return err;
  }
  
  
  
  
  
  