arrays - vectorize operation in C with Cell BE -

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i have following scenario: 1d array of dim size, , 2 arrays of dim/2 size. want copy elements of smaller arrays larger one. using following code(i running code on spu):

unsigned char  output_data1[dim/2] __attribute__ ((aligned(16))); unsigned char  output_data2[dim/2] __attribute__ ((aligned(16))); unsigned char  output_data[dim] __attribute__ ((aligned(16)));  (ix = 0; ix < dim; ix++) {     if (ix < dim / 2)     {                                output_data[ix] = output_data1[ix];              }     else     {         output_data[ix] = output_data2[ix - dim / 2];     }            }

i trying obtain same functionality, vectorizing above operation. have following code:

vector unsigned char *v = (vector unsigned char*)output_data; vector unsigned char *v1 = (vector unsigned char*)output_data1; vector unsigned char *v2 = (vector unsigned char*)output_data2;  int length=dim/(16/sizeof(unsigned char)); (j = 0; j < length; j++) {     if (j < length / 2)     {         v[j] = v1[j];       }     else     {         v[j] = v2[j - length / 2];     } }

however code doesn't seem produce right results(the chars in arrays values of pixels in images, , after using vectorized code, images missing lines). can please me out? lot.


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