Hello,
I’m running the following code from “OpenCL in action”:
__kernel void id_check(__global float *output) {
/* Access work-item/work-group information */
size_t global_id_0 = get_global_id(0);
size_t global_id_1 = get_global_id(1);
size_t global_size_0 = get_global_size(0);
size_t offset_0 = get_global_offset(0);
size_t offset_1 = get_global_offset(1);
size_t local_id_0 = get_local_id(0);
size_t local_id_1 = get_local_id(1);
/* Determine array index */
int index_0 = global_id_0 - offset_0;
int index_1 = global_id_1 - offset_1;
int index = index_1 * global_size_0 + index_0;
/* Set float data */
float f = global_id_0 * 10.0f + global_id_1 * 1.0f;
f += local_id_0 * 0.1f + local_id_1 * 0.01f;
output[index] = f;
}
If I change the input to: __global float4 *output,
The indexes of global_id are changed.
Can you tell why ?
The code of the host is the same. So the host divides data to cores as it did before.
So the value of get_global_id(0) should not change.
Thanks,
Zvika