Hello everyone. I'm in my first steps with OpenCL and I have the following problem which I cannot understand at all why is happening.

I have a simple kernel:
Code :
#pragma OPENCL EXTENSION cl_khr_fp64 : enable
typedef struct
  double speeds[9];
} t_speed;
__kernel void george(__global const t_speed* cells,
                   __global double*  result,
                     const unsigned int n)
  int j, i = get_global_id(0);
  if(i >= n) return;
  result[i] = 0;
  for(j=0; j<9; j++)
    result[i] += cells[i].speeds[j];

which when I execute I get a "Floating point exception". Can anyone explain to me please why should I get such an error?