when local_id<32 , the code is different from local_id < 64;

[IaGumiLukaRin]

Each SM splits its own blocks into Warps (currently with a maximum size of 32 threads).

All the threads in a warp executes concurrently on the resources of the SM ?

__syncthreads();
	if (should_add)
	{
		if (local_id < 128)
		{
			color_shared[local_id] += color_shared[local_id + 128];
			xy_shared[local_id] += xy_shared[local_id + 128];
			count_shared[local_id] += count_shared[local_id + 128];
		}
		__syncthreads();

		if (local_id < 64)
		{
			color_shared[local_id] += color_shared[local_id + 64];
			xy_shared[local_id] += xy_shared[local_id + 64];
			count_shared[local_id] += count_shared[local_id + 64];
		}
		__syncthreads();

		if (local_id < 32)
		{
			color_shared[local_id] += color_shared[local_id + 32];
			color_shared[local_id] += color_shared[local_id + 16];
			color_shared[local_id] += color_shared[local_id + 8];
			color_shared[local_id] += color_shared[local_id + 4];
			color_shared[local_id] += color_shared[local_id + 2];
			color_shared[local_id] += color_shared[local_id + 1];

			xy_shared[local_id] += xy_shared[local_id + 32];
			xy_shared[local_id] += xy_shared[local_id + 16];
			xy_shared[local_id] += xy_shared[local_id + 8];
			xy_shared[local_id] += xy_shared[local_id + 4];
			xy_shared[local_id] += xy_shared[local_id + 2];
			xy_shared[local_id] += xy_shared[local_id + 1];

			count_shared[local_id] += count_shared[local_id + 32];
			count_shared[local_id] += count_shared[local_id + 16];
			count_shared[local_id] += count_shared[local_id + 8];
			count_shared[local_id] += count_shared[local_id + 4];
			count_shared[local_id] += count_shared[local_id + 2];
			count_shared[local_id] += count_shared[local_id + 1];
		}
	}
__syncthreads();

__syncthreads();
		if (local_id < 32)
		{
			color_shared[local_id] += color_shared[local_id + 32];
			xy_shared[local_id] += xy_shared[local_id + 32];
			count_shared[local_id] += count_shared[local_id + 32];
		}
__syncthreads();
if (local_id < 16)
		{
			color_shared[local_id] += color_shared[local_id + 16];
			xy_shared[local_id] += xy_shared[local_id + 16];
			count_shared[local_id] += count_shared[local_id + 16];
		}
__syncthreads();