starpu-max/examples/stencil/shadow.cu

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2010  Université de Bordeaux
 *
 * StarPU is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * StarPU is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * See the GNU Lesser General Public License in COPYING.LGPL for more details.
 */

#define _externC extern "C"
#include "stencil.h"

/* Perform replication of data on X and Y edges, to fold the domain on 
   itself through mere replication of the source state. */

extern "C" __global__ void
cuda_shadow( int bz, TYPE *ptr, int nx, int ny, int nz, int ldy, int ldz, int i)
{
	unsigned idx = threadIdx.x + blockIdx.x * blockDim.x;
	unsigned idy = threadIdx.y + blockIdx.y * blockDim.y;
	//unsigned idz = threadIdx.z + blockIdx.z * blockDim.z;
	unsigned idz = 0;
	unsigned stepx = blockDim.x * gridDim.x;
	unsigned stepy = blockDim.y * gridDim.y;
	//unsigned stepz = blockDim.z * gridDim.z;
	unsigned stepz = 1;
	unsigned x, y, z;

#include "shadow.h"
}

extern "C" void
cuda_shadow_host(int bz, TYPE *ptr, int nx, int ny, int nz, int ldy, int ldz, int i)
{
	unsigned max_parallelism = 512;
	unsigned threads_per_dim_x = max_parallelism;
	while (threads_per_dim_x / 2 >= nx)
		threads_per_dim_x /= 2;
	unsigned threads_per_dim_y = max_parallelism / threads_per_dim_x;
	while (threads_per_dim_y / 2 >= ny)
		threads_per_dim_y /= 2;
#if 0
	unsigned threads_per_dim_z = 4;
	dim3 dimBlock(threads_per_dim_x, threads_per_dim_y, threads_per_dim_z);
	dim3 dimGrid(nx / threads_per_dim_x, ny / threads_per_dim_y, nz / threads_per_dim_z);
#else
	dim3 dimBlock(threads_per_dim_x, threads_per_dim_y);
	dim3 dimGrid((nx + threads_per_dim_x-1) / threads_per_dim_x, (ny + threads_per_dim_y-1) / threads_per_dim_y);
#endif
	cuda_shadow <<<dimGrid, dimBlock, 0, starpu_cuda_get_local_stream()>>> (bz, ptr, nx, ny, nz, ldy, ldz, i);
}