def get_big_module(nDim, nPts, nClusters,
blocksize_step4, seqcount_step4, gridsize_step4,
blocksize_step4part2, useTextureForData):
# module to calculate distances between each cluster and half distance to closest
modString = """
#define NCLUSTERS """ + str(nClusters) + """
#define NDIM """ + str(nDim) + """
#define NPTS """ + str(nPts) + """
//#define CLUSTERS_SIZE """ + str(nClusters*nDim) + """
#define SHARED_CLUSTERS """ + str((4000-32)/nDim) + """
#define THREADS4 """ + str(blocksize_step4) + """
#define BLOCKS4 """ + str(gridsize_step4) + """
#define SEQ_COUNT4 """ + str(seqcount_step4) + """
#define RED_OUT_WIDTH """ + str(gridsize_step4*nClusters) + """
#define THREADS4PART2 """ + str(blocksize_step4part2) + """
texture<float, 2, cudaReadModeElementType>texData;
//-----------------------------------------------------------------------
// misc functions
//-----------------------------------------------------------------------
// calculate the distance beteen two clusters
__device__ float calc_dist(float *clusterA, float *clusterB)
{
float dist = (clusterA[0]-clusterB[0]) * (clusterA[0]-clusterB[0]);
for (int i=NCLUSTERS; i<NDIM*NCLUSTERS; i+= NCLUSTERS) {
float diff = clusterA[i] - clusterB[i];
dist += diff*diff;
}
//------------------------------------------------------------------------
// + loop(1, nDim, 16,
// dist += (clusterA[{0}*NCLUSTERS] - clusterB[{0}*NCLUSTERS])
// *(clusterA[{0}*NCLUSTERS] - clusterB[{0}*NCLUSTERS]);
// ) +
//------------------------------------------------------------------------
return sqrt(dist);
}
__device__ float calc_dist_shared(float *clusterA, float *clusterB, int nFit)
{
float dist = (clusterA[0]-clusterB[0]) * (clusterA[0]-clusterB[0]);
for (int i=1; i<NDIM; i++) {
float diff = clusterA[i*nFit] - clusterB[i*NCLUSTERS];
dist += diff*diff;
}
return sqrt(dist);
}
// calculate the distance from a data point to a cluster
__device__ float dc_dist(float *data, float *cluster)
{
float dist = (data[0]-cluster[0]) * (data[0]-cluster[0]);
//------------------------------------------------------------------------
""" + meta.loop(1, nDim, 16, """
dist += (data[{0}*NPTS] - cluster[{0}*NCLUSTERS])
*(data[{0}*NPTS] - cluster[{0}*NCLUSTERS]);
""" ) + """
//------------------------------------------------------------------------
return sqrt(dist);
}
// calculate the distance from a data point in texture to a cluster
__device__ float dc_dist_tex(int pt, float *cluster)
{
float dist = (tex2D(texData, 0, pt)-cluster[0]) * (tex2D(texData, 0, pt)-cluster[0]);
for(int i=1; i<NDIM; i++){
float diff = tex2D(texData, i, pt) - cluster[i*NCLUSTERS];
dist += diff * diff;
}
return sqrt(dist);
}
//-----------------------------------------------------------------------
// ccdist
//-----------------------------------------------------------------------
#define NFIT 4
// **TODO** need to loop through clusters if all of them don't fit into shared memory
// Calculate cluster - cluster distances
__global__ void ccdist(float *clusters, float *cc_dists, float *hdClosest)
{
""" + meta.copy_to_shared("float", "clusters", "s_clusters", nClusters*nDim) + """
// calculate distance between this cluster and all lower clusters
// then store the distance in the table in two places: (this, lower) and (lower, this)
int idx = threadIdx.x + blockDim.x * blockIdx.x;
if(idx >= NCLUSTERS) return;
for(int c=0; c<idx; c++){
float d = 0.5f * calc_dist(s_clusters+c, s_clusters + idx); // store 1/2 distance
cc_dists[c * NCLUSTERS + idx] = d;
cc_dists[idx * NCLUSTERS + c] = d;
}
}
//-----------------------------------------------------------------------
// calc_hdClosest
//-----------------------------------------------------------------------
// Determination of hdClosest
__global__ void calc_hdclosest(float *cc_dists, float *hdClosest)
{
int idx = threadIdx.x + blockIdx.x * blockDim.x;
hdClosest[idx] = 1.0e10;
for(int c=0; c<NCLUSTERS; c++){
if(c == idx) continue;
float d = cc_dists[c*NCLUSTERS + idx]; // cc_dists contains 1/2 distance
if(d < hdClosest[idx]) hdClosest[idx] = d;
}
}
//-----------------------------------------------------------------------
// init
//-----------------------------------------------------------------------
// **TODO** need to loop through clusters if all of them don't fit into shared memory
// Assign data points to the nearest cluster
"""
if useTextureForData:
modString += "__global__ void init(float *clusters,\n"
else:
modString += "__global__ void init(float *data, float *clusters,\n"
modString += """
float *ccdist, float *hdClosest, int *assignments,
float *lower, float *upper)
{
""" + meta.copy_to_shared("float", "clusters", "s_clusters", nClusters*nDim) + """
// calculate distance to each cluster
int idx = threadIdx.x + blockDim.x * blockIdx.x;
if (idx >= NPTS) return;
// start with cluster 0 as the closest
"""
if useTextureForData:
modString += "float min_dist = dc_dist_tex(idx, s_clusters);\n"
else:
modString += "float min_dist = dc_dist(data+idx, s_clusters);\n"
modString += """
lower[idx] = min_dist;
int closest = 0;
for(int c=1; c<NCLUSTERS; c++){
// **TODO** see if this test to skip some calculations is really worth it on the gpu versus cpu
if(min_dist <= ccdist[closest * NCLUSTERS + c]) continue;
"""
if useTextureForData:
modString += "float d = dc_dist_tex(idx, s_clusters + c);\n"
else:
modString += "float d = dc_dist(data + idx, s_clusters + c);\n"
modString += """
lower[c*NPTS + idx] = d;
if(d < min_dist){
min_dist = d;
closest = c;
}
}
assignments[idx] = closest;
upper[idx] = min_dist;
}
//-----------------------------------------------------------------------
// step3
//-----------------------------------------------------------------------
// **TODO** need to loop through clusters if all of them don't fit into shared memory
// Step 3 of the algorithm
"""
if useTextureForData:
modString += "__global__ void step3(float *clusters,\n"
else:
modString += "__global__ void step3(float *data, float *clusters,\n"
modString += """
float *ccdist, float *hdClosest, int *assignments,
float *lower, float *upper, int *badUpper,
int *cluster_changed)
{
""" + meta.copy_to_shared("float", "clusters", "s_clusters", nClusters*nDim) + """
// idx ranges over the data points
int idx = threadIdx.x + blockIdx.x * blockDim.x;
if(idx >= NPTS) return;
float ux = upper[idx];
int cx = assignments[idx];
float rx = badUpper[idx];
if(ux <= hdClosest[cx]) return; // step 2 condition
for(int c=0; c<NCLUSTERS; c++){
// step 3 conditions...
if(c == cx || ux <= lower[c*NPTS + idx] || ux <= ccdist[cx*NCLUSTERS + c])
continue;
// Step 3a: check if upper bound needs to be recalculated
float d_x_cx;
if(rx){
// distance between point idx and its currently assigned center needs to be calculated
"""
if useTextureForData:
modString += "d_x_cx = dc_dist_tex(idx, s_clusters+cx);\n"
else:
modString += "d_x_cx = dc_dist(data+idx, s_clusters+cx);\n"
modString += """
ux = d_x_cx;
lower[c*NPTS + idx] = d_x_cx;
rx = 0;
}else{
d_x_cx = ux;
}
// Step 3b: compute distance between x and c change x's assignment if necessary
if(d_x_cx > lower[c*NPTS + idx] || d_x_cx > ccdist[cx*NCLUSTERS + c]){
"""
if useTextureForData:
modString += "float d_x_c = dc_dist_tex(idx, s_clusters+c);\n"
else:
modString += "float d_x_c = dc_dist(data+idx, s_clusters+c);\n"
modString += """
lower[c*NPTS + idx] = d_x_c;
if(d_x_c < d_x_cx){
// assign x to c
// mark both c and cx as having changed
ux = d_x_c;
cx = c;
rx = 0;
}
}
}
__syncthreads();
upper[idx] = ux;
// check for new assignment and flag old and new cluster as changed
if(cx != assignments[idx]){
cluster_changed[cx] = 1;
cluster_changed[assignments[idx]] = 1;
assignments[idx] = cx;
}
badUpper[idx] = rx;
__syncthreads();
}
//-----------------------------------------------------------------------
// step4
//-----------------------------------------------------------------------
// Calculate the new cluster centers
"""
if useTextureForData:
modString += "__global__ void step4(\n"
else:
modString += "__global__ void step4(float *data,\n"
modString += """
int *cluster_changed, float *reduction_out,
int *reduction_counts, int *assignments)
{
__shared__ float s_data[THREADS4];
__shared__ int s_count[THREADS4];
int idx = threadIdx.x;
int iData = blockIdx.x * THREADS4 * SEQ_COUNT4 + idx;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
if(cluster_changed[c]){
float tot = 0.0f;
int count = 0;
for(int s=0; s<SEQ_COUNT4; s++){
if(iData >= NPTS) break;
if(assignments[iData] == c){
count += 1;
"""
if useTextureForData:
modString += "tot += tex2D(texData, dim, iData);\n"
else:
modString += "tot += data[dim*NPTS + iData];\n"
modString += """
}
}
s_data[idx] = tot;
s_count[idx] = count;
"""
modString += meta.reduction2("s_data", "s_count", blocksize_step4) + """
if(idx == 0){
reduction_out[dim * RED_OUT_WIDTH + blockIdx.x * NCLUSTERS + c] = s_data[0];
reduction_counts[blockIdx.x * NCLUSTERS + c] = s_count[0];
}
}
}
}
//-----------------------------------------------------------------------
// step4part2
//-----------------------------------------------------------------------
// Calculate new cluster centers using reduction, part 2
__global__ void step4part2(int *cluster_changed, float *reduction_out, int *reduction_counts,
float *new_clusters, float *clusters)
{
__shared__ float s_data[THREADS4PART2];
__shared__ int s_count[THREADS4PART2];
int idx = threadIdx.x;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
s_data[idx] = 0.0f;
s_count[idx] = 0;
if(cluster_changed[c]){
if(idx < BLOCKS4){
// straight copy of data into shared memory
s_data[idx] = reduction_out[dim*RED_OUT_WIDTH + idx*NCLUSTERS + c];
s_count[idx] = reduction_counts[idx*NCLUSTERS + c];
}
"""
modString += meta.reduction2("s_data", "s_count", blocksize_step4part2) + """
}
// calculate the new cluster, or copy the old one has no values or didn't change
if(idx == 0){
if(s_count[0] == 0){
new_clusters[dim * NCLUSTERS + c] = clusters[dim*NCLUSTERS + c];
}else{
new_clusters[dim * NCLUSTERS + c] = s_data[0] / s_count[0];
}
}
}
}
//-----------------------------------------------------------------------
// calc movement
//-----------------------------------------------------------------------
__global__ void calc_movement(float *clusters, float *new_clusters, float *cluster_movement,
int *cluster_changed)
{
""" + meta.copy_to_shared("float", "clusters", "s_clusters", nClusters*nDim) + """
int cluster = threadIdx.x + blockDim.x*blockIdx.x;
if(cluster_changed[cluster])
cluster_movement[cluster] = calc_dist(s_clusters + cluster, new_clusters + cluster);
}
//-----------------------------------------------------------------------
// step56
//-----------------------------------------------------------------------
// **TODO** need to loop through clusters if all of them don't fit into shared memory
// Assign data points to the nearest cluster
__global__ void step56(int *assignment,
float *lower, float * upper,
float *cluster_movement, int *badUpper)
{
""" + meta.copy_to_shared("float", "cluster_movement", "s_cluster_movement", nClusters) + """
int idx = threadIdx.x + blockDim.x * blockIdx.x;
if (idx >= NPTS) return;
// loop through all clusters and update the lower bound
for(int c=0; c < NCLUSTERS; c++){
if(s_cluster_movement[c] > 0.0f){
if(s_cluster_movement[c] < lower[c * NPTS + idx]){
lower[c*NPTS + idx] -= s_cluster_movement[c];
}else{
lower[c*NPTS + idx] = 0.0f;
}
}
}
// update the upper bound for this data point
if(s_cluster_movement[assignment[idx]] > 0.f){
upper[idx] += s_cluster_movement[assignment[idx]];
badUpper[idx] = 1;
}
}
"""
#print modString
return SourceModule(modString)
def get_cuda_module(
nDim, nPts, nClusters, blocksize_calc, seqcount_calc, gridsize_calc, blocksize_calc_part2, useTextureForData, bounds
):
modString = (
"""
#define NCLUSTERS """
+ str(nClusters)
+ """
#define NDIM """
+ str(nDim)
+ """
#define NPTS """
+ str(nPts)
+ """
#define THREADS4 """
+ str(blocksize_calc)
+ """
#define BLOCKS4 """
+ str(gridsize_calc)
+ """
#define SEQ_COUNT4 """
+ str(seqcount_calc)
+ """
#define RED_OUT_WIDTH """
+ str(gridsize_calc * nClusters)
+ """
#define THREADS4PART2 """
+ str(blocksize_calc_part2)
+ """
#define BOUNDS (float)"""
+ str(bounds)
+ """
texture<float, 2, cudaReadModeElementType>texData;
//-----------------------------------------------------------------------
// misc functions
//-----------------------------------------------------------------------
// calculate the distance squared from a data point to a cluster
__device__ float dc_dist(float *data, float *cluster)
{
float dist = (data[0]-cluster[0]) * (data[0]-cluster[0]);
//------------------------------------------------------------------------
"""
+ meta.loop(
1,
nDim,
16,
"""
dist += (data[{0}*NPTS] - cluster[{0}*NCLUSTERS])
*(data[{0}*NPTS] - cluster[{0}*NCLUSTERS]);
""",
)
+ """
//------------------------------------------------------------------------
return dist;
}
// calculate the distance squared from a data point to a cluster
__device__ float dc_dist2(float *data, float *cluster)
{
float dist = (data[0]-cluster[0]) * (data[0]-cluster[0]);
float *pData = data;
for(float *pCluster = cluster + NCLUSTERS;
pCluster < cluster + NCLUSTERS * NDIM; pCluster += NCLUSTERS){
pData += NPTS;
dist +=((*pData) - (*pCluster)) * ((*pData) - (*pCluster));
}
return dist;
}
// calculate the distance squared from a data point in texture to a cluster
__device__ float dc_dist_tex(int pt, float *cluster)
{
float dist = (tex2D(texData, 0, pt)-cluster[0]) * (tex2D(texData, 0, pt)-cluster[0]);
for(int i=1; i<NDIM; i++){
float diff = tex2D(texData, i, pt) - cluster[i*NCLUSTERS];
dist += diff * diff;
}
return dist;
}
// calculate the distance squared from a data point in texture to a cluster
__device__ float dc_dist_tex2(int pt, float *cluster)
{
float dist = (tex2D(texData, 0, pt)-cluster[0]) * (tex2D(texData, 0, pt)-cluster[0]);
int i = 0;
for(float *pCluster = cluster + NCLUSTERS;
pCluster < cluster + NCLUSTERS * NDIM; pCluster += NCLUSTERS){
i += 1;
float diff = tex2D(texData, i, pt) - *pCluster;
dist += diff * diff;
}
return dist;
}
//-----------------------------------------------------------------------
// assign
//-----------------------------------------------------------------------
// Assign data points to the nearest cluster
"""
)
if useTextureForData:
modString += "__global__ void assign(float *clusters,\n"
else:
modString += "__global__ void assign(float *data, float *clusters,\n"
modString += (
"""
int *assignments)
{
"""
+ meta.copy_to_shared("float", "clusters", "s_clusters", nClusters * nDim)
+ """
// calculate distance to each cluster
int idx = threadIdx.x + blockDim.x * blockIdx.x;
if (idx >= NPTS) return;
// start with cluster 0 as the closest
"""
)
if useTextureForData:
modString += "float min_dist = dc_dist_tex(idx, s_clusters);\n"
else:
modString += "float min_dist = dc_dist(data+idx, s_clusters);\n"
modString += """
int closest = 0;
for(int c=1; c<NCLUSTERS; c++){
"""
if useTextureForData:
modString += "float d = dc_dist_tex2(idx, s_clusters + c);\n"
else:
modString += "float d = dc_dist(data + idx, s_clusters + c);\n"
modString += """
if(d < min_dist){
min_dist = d;
closest = c;
}
}
assignments[idx] = closest;
}
//-----------------------------------------------------------------------
// calc
//-----------------------------------------------------------------------
// Calculate the new cluster centers
"""
if useTextureForData:
modString += "__global__ void calc(\n"
else:
modString += "__global__ void calc(float *data,\n"
modString += """
float *reduction_out, int *reduction_counts,
int *assignments)
{
__shared__ float s_data[THREADS4];
__shared__ int s_count[THREADS4];
int idx = threadIdx.x;
// int iData = blockIdx.x * THREADS4 * SEQ_COUNT4 + idx;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
float tot = 0.0f;
int count = 0;
for(int s=0; s<SEQ_COUNT4; s++){
int iData = blockIdx.x * THREADS4 * SEQ_COUNT4 + s * blockDim.x + idx;
if(iData >= NPTS) break;
if(assignments[iData] == c){
count += 1;
"""
if useTextureForData:
modString += "tot += tex2D(texData, dim, iData);\n"
else:
modString += "tot += data[dim*NPTS + iData];\n"
modString += """
}
}
s_data[idx] = tot;
s_count[idx] = count;
"""
modString += (
meta.reduction2("s_data", "s_count", blocksize_calc)
+ """
if(idx == 0){
reduction_out[dim * RED_OUT_WIDTH + blockIdx.x * NCLUSTERS + c] = s_data[0];
reduction_counts[blockIdx.x * NCLUSTERS + c] = s_count[0];
}
}
}
//-----------------------------------------------------------------------
// calc_part2
//-----------------------------------------------------------------------
// Calculate new cluster centers using reduction, part 2
__global__ void calc_part2(float *reduction_out, int *reduction_counts,
float *new_clusters, float *clusters)
{
__shared__ float s_data[THREADS4PART2];
__shared__ int s_count[THREADS4PART2];
int idx = threadIdx.x;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
s_data[idx] = 0.0f;
s_count[idx] = 0;
if(idx < BLOCKS4){
// straight copy of data into shared memory
s_data[idx] = reduction_out[dim*RED_OUT_WIDTH + idx*NCLUSTERS + c];
s_count[idx] = reduction_counts[idx*NCLUSTERS + c];
}
"""
)
modString += (
meta.reduction2("s_data", "s_count", blocksize_calc_part2)
+ """
// calculate the new cluster, or copy the old one if has no values or didn't change
if(idx == 0){
if(s_count[0] == 0){
new_clusters[dim * NCLUSTERS + c] = clusters[dim*NCLUSTERS + c];
}else{
new_clusters[dim * NCLUSTERS + c] = s_data[0] / s_count[0];
}
}
}
}
"""
)
# print modString
return SourceModule(modString)
def get_cuda_module(nDim, nPts, nClusters, blocksize_calc, seqcount_calc,
gridsize_calc, blocksize_calc_part2, useTextureForData,
bounds):
modString = """
#define NCLUSTERS """ + str(nClusters) + """
#define NDIM """ + str(nDim) + """
#define NPTS """ + str(nPts) + """
#define THREADS4 """ + str(blocksize_calc) + """
#define BLOCKS4 """ + str(gridsize_calc) + """
#define SEQ_COUNT4 """ + str(seqcount_calc) + """
#define RED_OUT_WIDTH """ + str(gridsize_calc * nClusters) + """
#define THREADS4PART2 """ + str(blocksize_calc_part2) + """
#define BOUNDS (float)""" + str(bounds) + """
texture<float, 2, cudaReadModeElementType>texData;
//-----------------------------------------------------------------------
// misc functions
//-----------------------------------------------------------------------
// calculate the distance squared from a data point to a cluster
__device__ float dc_dist(float *data, float *cluster)
{
float dist = (data[0]-cluster[0]) * (data[0]-cluster[0]);
//------------------------------------------------------------------------
""" + meta.loop(
1, nDim, 16, """
dist += (data[{0}*NPTS] - cluster[{0}*NCLUSTERS])
*(data[{0}*NPTS] - cluster[{0}*NCLUSTERS]);
""") + """
//------------------------------------------------------------------------
return dist;
}
// calculate the distance squared from a data point to a cluster
__device__ float dc_dist2(float *data, float *cluster)
{
float dist = (data[0]-cluster[0]) * (data[0]-cluster[0]);
float *pData = data;
for(float *pCluster = cluster + NCLUSTERS;
pCluster < cluster + NCLUSTERS * NDIM; pCluster += NCLUSTERS){
pData += NPTS;
dist +=((*pData) - (*pCluster)) * ((*pData) - (*pCluster));
}
return dist;
}
// calculate the distance squared from a data point in texture to a cluster
__device__ float dc_dist_tex(int pt, float *cluster)
{
float dist = (tex2D(texData, 0, pt)-cluster[0]) * (tex2D(texData, 0, pt)-cluster[0]);
for(int i=1; i<NDIM; i++){
float diff = tex2D(texData, i, pt) - cluster[i*NCLUSTERS];
dist += diff * diff;
}
return dist;
}
// calculate the distance squared from a data point in texture to a cluster
__device__ float dc_dist_tex2(int pt, float *cluster)
{
float dist = (tex2D(texData, 0, pt)-cluster[0]) * (tex2D(texData, 0, pt)-cluster[0]);
int i = 0;
for(float *pCluster = cluster + NCLUSTERS;
pCluster < cluster + NCLUSTERS * NDIM; pCluster += NCLUSTERS){
i += 1;
float diff = tex2D(texData, i, pt) - *pCluster;
dist += diff * diff;
}
return dist;
}
//-----------------------------------------------------------------------
// assign
//-----------------------------------------------------------------------
// Assign data points to the nearest cluster
"""
if useTextureForData:
modString += "__global__ void assign(float *clusters,\n"
else:
modString += "__global__ void assign(float *data, float *clusters,\n"
modString += """
int *assignments)
{
""" + meta.copy_to_shared("float", "clusters", "s_clusters",
nClusters * nDim) + """
// calculate distance to each cluster
int idx = threadIdx.x + blockDim.x * blockIdx.x;
if (idx >= NPTS) return;
// start with cluster 0 as the closest
"""
if useTextureForData:
modString += "float min_dist = dc_dist_tex(idx, s_clusters);\n"
else:
modString += "float min_dist = dc_dist(data+idx, s_clusters);\n"
modString += """
int closest = 0;
for(int c=1; c<NCLUSTERS; c++){
"""
if useTextureForData:
modString += "float d = dc_dist_tex2(idx, s_clusters + c);\n"
else:
modString += "float d = dc_dist(data + idx, s_clusters + c);\n"
modString += """
if(d < min_dist){
min_dist = d;
closest = c;
}
}
assignments[idx] = closest;
}
//-----------------------------------------------------------------------
// calc
//-----------------------------------------------------------------------
// Calculate the new cluster centers
"""
if useTextureForData:
modString += "__global__ void calc(\n"
else:
modString += "__global__ void calc(float *data,\n"
modString += """
float *reduction_out, int *reduction_counts,
int *assignments)
{
__shared__ float s_data[THREADS4];
__shared__ int s_count[THREADS4];
int idx = threadIdx.x;
// int iData = blockIdx.x * THREADS4 * SEQ_COUNT4 + idx;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
float tot = 0.0f;
int count = 0;
for(int s=0; s<SEQ_COUNT4; s++){
int iData = blockIdx.x * THREADS4 * SEQ_COUNT4 + s * blockDim.x + idx;
if(iData >= NPTS) break;
if(assignments[iData] == c){
count += 1;
"""
if useTextureForData:
modString += "tot += tex2D(texData, dim, iData);\n"
else:
modString += "tot += data[dim*NPTS + iData];\n"
modString += """
}
}
s_data[idx] = tot;
s_count[idx] = count;
"""
modString += meta.reduction2("s_data", "s_count", blocksize_calc) + """
if(idx == 0){
reduction_out[dim * RED_OUT_WIDTH + blockIdx.x * NCLUSTERS + c] = s_data[0];
reduction_counts[blockIdx.x * NCLUSTERS + c] = s_count[0];
}
}
}
//-----------------------------------------------------------------------
// calc_part2
//-----------------------------------------------------------------------
// Calculate new cluster centers using reduction, part 2
__global__ void calc_part2(float *reduction_out, int *reduction_counts,
float *new_clusters, float *clusters)
{
__shared__ float s_data[THREADS4PART2];
__shared__ int s_count[THREADS4PART2];
int idx = threadIdx.x;
int dim = blockIdx.y;
for(int c=0; c<NCLUSTERS; c++){
s_data[idx] = 0.0f;
s_count[idx] = 0;
if(idx < BLOCKS4){
// straight copy of data into shared memory
s_data[idx] = reduction_out[dim*RED_OUT_WIDTH + idx*NCLUSTERS + c];
s_count[idx] = reduction_counts[idx*NCLUSTERS + c];
}
"""
modString += meta.reduction2("s_data", "s_count",
blocksize_calc_part2) + """
// calculate the new cluster, or copy the old one if has no values or didn't change
if(idx == 0){
if(s_count[0] == 0){
new_clusters[dim * NCLUSTERS + c] = clusters[dim*NCLUSTERS + c];
}else{
new_clusters[dim * NCLUSTERS + c] = s_data[0] / s_count[0];
}
}
}
}
"""
#print modString
return SourceModule(modString)