opm-simulators/opm/simulators/linalg/bda/openclKernels.cpp
2021-10-05 10:49:21 +02:00

641 lines
25 KiB
C++

/*
Copyright 2020 Equinor ASA
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#include <opm/simulators/linalg/bda/openclKernels.hpp>
namespace bda
{
std::string get_axpy_string() {
return R"(
__kernel void axpy(
__global double *in,
const double a,
__global double *out,
const int N)
{
unsigned int NUM_THREADS = get_global_size(0);
int idx = get_global_id(0);
while(idx < N){
out[idx] += a * in[idx];
idx += NUM_THREADS;
}
}
)";
}
// scale vector with scalar
std::string get_scale_string() {
return R"(
__kernel void scale(
__global double *vec,
const double a,
const int N)
{
unsigned int NUM_THREADS = get_global_size(0);
int idx = get_global_id(0);
while(idx < N){
vec[idx] *= a;
idx += NUM_THREADS;
}
}
)";
}
// returns partial sums, instead of the final dot product
std::string get_dot_1_string() {
return R"(
__kernel void dot_1(
__global double *in1,
__global double *in2,
__global double *out,
const unsigned int N,
__local double *tmp)
{
unsigned int tid = get_local_id(0);
unsigned int bsize = get_local_size(0);
unsigned int bid = get_global_id(0) / bsize;
unsigned int i = get_global_id(0);
unsigned int NUM_THREADS = get_global_size(0);
double sum = 0.0;
while(i < N){
sum += in1[i] * in2[i];
i += NUM_THREADS;
}
tmp[tid] = sum;
barrier(CLK_LOCAL_MEM_FENCE);
// do reduction in shared mem
for(unsigned int s = get_local_size(0) / 2; s > 0; s >>= 1)
{
if (tid < s)
{
tmp[tid] += tmp[tid + s];
}
barrier(CLK_LOCAL_MEM_FENCE);
}
// write result for this block to global mem
if (tid == 0) out[get_group_id(0)] = tmp[0];
}
)";
}
// returns partial sums, instead of the final norm
// the square root must be computed on CPU
std::string get_norm_string() {
return R"(
__kernel void norm(
__global double *in,
__global double *out,
const unsigned int N,
__local double *tmp)
{
unsigned int tid = get_local_id(0);
unsigned int bsize = get_local_size(0);
unsigned int bid = get_global_id(0) / bsize;
unsigned int i = get_global_id(0);
unsigned int NUM_THREADS = get_global_size(0);
double local_sum = 0.0;
while(i < N){
local_sum += in[i] * in[i];
i += NUM_THREADS;
}
tmp[tid] = local_sum;
barrier(CLK_LOCAL_MEM_FENCE);
// do reduction in shared mem
for(unsigned int s = get_local_size(0) / 2; s > 0; s >>= 1)
{
if (tid < s)
{
tmp[tid] += tmp[tid + s];
}
barrier(CLK_LOCAL_MEM_FENCE);
}
// write result for this block to global mem
if (tid == 0) out[get_group_id(0)] = tmp[0];
}
)";
}
// p = (p - omega * v) * beta + r
std::string get_custom_string() {
return R"(
__kernel void custom(
__global double *p,
__global double *v,
__global double *r,
const double omega,
const double beta,
const int N)
{
const unsigned int NUM_THREADS = get_global_size(0);
unsigned int idx = get_global_id(0);
while(idx < N){
double res = p[idx];
res -= omega * v[idx];
res *= beta;
res += r[idx];
p[idx] = res;
idx += NUM_THREADS;
}
}
)";
}
std::string get_spmv_blocked_string() {
return R"(
__kernel void spmv_blocked(
__global const double *vals,
__global const int *cols,
__global const int *rows,
const int Nb,
__global const double *x,
__global double *b,
const unsigned int block_size,
__local double *tmp)
{
const unsigned int warpsize = 32;
const unsigned int bsize = get_local_size(0);
const unsigned int idx_b = get_global_id(0) / bsize;
const unsigned int idx_t = get_local_id(0);
unsigned int idx = idx_b * bsize + idx_t;
const unsigned int bs = block_size;
const unsigned int num_active_threads = (warpsize/bs/bs)*bs*bs;
const unsigned int num_blocks_per_warp = warpsize/bs/bs;
const unsigned int NUM_THREADS = get_global_size(0);
const unsigned int num_warps_in_grid = NUM_THREADS / warpsize;
unsigned int target_block_row = idx / warpsize;
const unsigned int lane = idx_t % warpsize;
const unsigned int c = (lane / bs) % bs;
const unsigned int r = lane % bs;
// for 3x3 blocks:
// num_active_threads: 27
// num_blocks_per_warp: 3
while(target_block_row < Nb){
unsigned int first_block = rows[target_block_row];
unsigned int last_block = rows[target_block_row+1];
unsigned int block = first_block + lane / (bs*bs);
double local_out = 0.0;
if(lane < num_active_threads){
for(; block < last_block; block += num_blocks_per_warp){
double x_elem = x[cols[block]*bs + c];
double A_elem = vals[block*bs*bs + c + r*bs];
local_out += x_elem * A_elem;
}
}
// do reduction in shared mem
tmp[lane] = local_out;
barrier(CLK_LOCAL_MEM_FENCE);
for(unsigned int offset = 3; offset <= 24; offset <<= 1)
{
if (lane + offset < warpsize)
{
tmp[lane] += tmp[lane + offset];
}
barrier(CLK_LOCAL_MEM_FENCE);
}
if(lane < bs){
unsigned int row = target_block_row*bs + lane;
b[row] = tmp[lane];
}
target_block_row += num_warps_in_grid;
}
}
)";
}
std::string get_ILU_apply1_string(bool full_matrix) {
std::string s = R"(
__kernel void ILU_apply1(
__global const double *LUvals,
__global const unsigned int *LUcols,
__global const unsigned int *LUrows,
__global const int *diagIndex,
__global const double *y,
__global double *x,
__global const unsigned int *nodesPerColorPrefix,
const unsigned int color,
const unsigned int block_size,
__local double *tmp)
{
const unsigned int warpsize = 32;
const unsigned int bs = block_size;
const unsigned int idx_t = get_local_id(0);
const unsigned int num_active_threads = (warpsize/bs/bs)*bs*bs;
const unsigned int num_blocks_per_warp = warpsize/bs/bs;
const unsigned int NUM_THREADS = get_global_size(0);
const unsigned int num_warps_in_grid = NUM_THREADS / warpsize;
unsigned int idx = get_global_id(0);
unsigned int target_block_row = idx / warpsize;
target_block_row += nodesPerColorPrefix[color];
const unsigned int lane = idx_t % warpsize;
const unsigned int c = (lane / bs) % bs;
const unsigned int r = lane % bs;
while(target_block_row < nodesPerColorPrefix[color+1]){
const unsigned int first_block = LUrows[target_block_row];
)";
if (full_matrix) {
s += "const unsigned int last_block = diagIndex[target_block_row]; ";
} else {
s += "const unsigned int last_block = LUrows[target_block_row+1]; ";
}
s += R"(
unsigned int block = first_block + lane / (bs*bs);
double local_out = 0.0;
if(lane < num_active_threads){
if(lane < bs){
local_out = y[target_block_row*bs+lane];
}
for(; block < last_block; block += num_blocks_per_warp){
const double x_elem = x[LUcols[block]*bs + c];
const double A_elem = LUvals[block*bs*bs + c + r*bs];
local_out -= x_elem * A_elem;
}
}
// do reduction in shared mem
tmp[lane] = local_out;
barrier(CLK_LOCAL_MEM_FENCE);
for(unsigned int offset = 3; offset <= 24; offset <<= 1)
{
if (lane + offset < warpsize)
{
tmp[lane] += tmp[lane + offset];
}
barrier(CLK_LOCAL_MEM_FENCE);
}
if(lane < bs){
const unsigned int row = target_block_row*bs + lane;
x[row] = tmp[lane];
}
target_block_row += num_warps_in_grid;
}
}
)";
return s;
}
std::string get_ILU_apply2_string(bool full_matrix) {
std::string s = R"(
__kernel void ILU_apply2(
__global const double *LUvals,
__global const int *LUcols,
__global const int *LUrows,
__global const int *diagIndex,
__global const double *invDiagVals,
__global double *x,
__global const unsigned int *nodesPerColorPrefix,
const unsigned int color,
const unsigned int block_size,
__local double *tmp)
{
const unsigned int warpsize = 32;
const unsigned int bs = block_size;
const unsigned int idx_t = get_local_id(0);
const unsigned int num_active_threads = (warpsize/bs/bs)*bs*bs;
const unsigned int num_blocks_per_warp = warpsize/bs/bs;
const unsigned int NUM_THREADS = get_global_size(0);
const unsigned int num_warps_in_grid = NUM_THREADS / warpsize;
unsigned int idx_g = get_global_id(0);
unsigned int target_block_row = idx_g / warpsize;
target_block_row += nodesPerColorPrefix[color];
const unsigned int lane = idx_t % warpsize;
const unsigned int c = (lane / bs) % bs;
const unsigned int r = lane % bs;
while(target_block_row < nodesPerColorPrefix[color+1]){
)";
if (full_matrix) {
s += "const unsigned int first_block = diagIndex[target_block_row] + 1; ";
} else {
s += "const unsigned int first_block = LUrows[target_block_row]; ";
}
s += R"(
const unsigned int last_block = LUrows[target_block_row+1];
unsigned int block = first_block + lane / (bs*bs);
double local_out = 0.0;
if(lane < num_active_threads){
if(lane < bs){
const unsigned int row = target_block_row*bs+lane;
local_out = x[row];
}
for(; block < last_block; block += num_blocks_per_warp){
const double x_elem = x[LUcols[block]*bs + c];
const double A_elem = LUvals[block*bs*bs + c + r*bs];
local_out -= x_elem * A_elem;
}
}
// do reduction in shared mem
tmp[lane] = local_out;
barrier(CLK_LOCAL_MEM_FENCE);
for(unsigned int offset = 3; offset <= 24; offset <<= 1)
{
if (lane + offset < warpsize)
{
tmp[lane] += tmp[lane + offset];
}
barrier(CLK_LOCAL_MEM_FENCE);
}
local_out = tmp[lane];
if(lane < bs){
tmp[lane + bs*idx_t/warpsize] = local_out;
double sum = 0.0;
for(int i = 0; i < bs; ++i){
sum += invDiagVals[target_block_row*bs*bs + i + lane*bs] * tmp[i + bs*idx_t/warpsize];
}
const unsigned int row = target_block_row*bs + lane;
x[row] = sum;
}
target_block_row += num_warps_in_grid;
}
}
)";
return s;
}
std::string get_stdwell_apply_string(bool reorder) {
std::string kernel_name = reorder ? "stdwell_apply" : "stdwell_apply_no_reorder";
std::string s = "__kernel void " + kernel_name + R"((
__global const double *Cnnzs,
__global const double *Dnnzs,
__global const double *Bnnzs,
__global const int *Ccols,
__global const int *Bcols,
__global const double *x,
__global double *y,
)";
if (reorder) {
s += R"(__global const int *toOrder,
)";
}
s += R"(const unsigned int dim,
const unsigned int dim_wells,
__global const unsigned int *val_pointers,
__local double *localSum,
__local double *z1,
__local double *z2){
int wgId = get_group_id(0);
int wiId = get_local_id(0);
int valSize = val_pointers[wgId + 1] - val_pointers[wgId];
int valsPerBlock = dim*dim_wells;
int numActiveWorkItems = (get_local_size(0)/valsPerBlock)*valsPerBlock;
int numBlocksPerWarp = get_local_size(0)/valsPerBlock;
int c = wiId % dim;
int r = (wiId/dim) % dim_wells;
double temp;
barrier(CLK_LOCAL_MEM_FENCE);
localSum[wiId] = 0;
if(wiId < numActiveWorkItems){
int b = wiId/valsPerBlock + val_pointers[wgId];
while(b < valSize + val_pointers[wgId]){
)";
if (reorder) {
s += "int colIdx = toOrder[Bcols[b]]; ";
} else {
s += "int colIdx = Bcols[b]; ";
}
s += R"(
localSum[wiId] += Bnnzs[b*dim*dim_wells + r*dim + c]*x[colIdx*dim + c];
b += numBlocksPerWarp;
}
if(wiId < valsPerBlock){
localSum[wiId] += localSum[wiId + valsPerBlock];
}
b = wiId/valsPerBlock + val_pointers[wgId];
if(c == 0 && wiId < valsPerBlock){
for(unsigned int stride = 2; stride > 0; stride >>= 1){
localSum[wiId] += localSum[wiId + stride];
}
z1[r] = localSum[wiId];
}
}
barrier(CLK_LOCAL_MEM_FENCE);
if(wiId < dim_wells){
temp = 0.0;
for(unsigned int i = 0; i < dim_wells; ++i){
temp += Dnnzs[wgId*dim_wells*dim_wells + wiId*dim_wells + i]*z1[i];
}
z2[wiId] = temp;
}
barrier(CLK_LOCAL_MEM_FENCE);
if(wiId < dim*valSize){
temp = 0.0;
int bb = wiId/dim + val_pointers[wgId];
for (unsigned int j = 0; j < dim_wells; ++j){
temp += Cnnzs[bb*dim*dim_wells + j*dim + c]*z2[j];
}
)";
if (reorder) {
s += "int colIdx = toOrder[Ccols[bb]]; ";
} else {
s += "int colIdx = Ccols[bb]; ";
}
s += R"(
y[colIdx*dim + c] -= temp;
}
}
)";
return s;
}
std::string get_ilu_decomp_string() {
return R"(
// a = a - (b * c)
__kernel void block_mult_sub(__global double *a, __local double *b, __global double *c)
{
const unsigned int block_size = 3;
const unsigned int hwarp_size = 16;
const unsigned int idx_t = get_local_id(0); // thread id in work group
const unsigned int thread_id_in_hwarp = idx_t % hwarp_size; // thread id in warp (16 threads)
if(thread_id_in_hwarp < block_size * block_size){
const unsigned int row = thread_id_in_hwarp / block_size;
const unsigned int col = thread_id_in_hwarp % block_size;
double temp = 0.0;
for (unsigned int k = 0; k < block_size; k++) {
temp += b[block_size * row + k] * c[block_size * k + col];
}
a[block_size * row + col] -= temp;
}
}
// c = a * b
__kernel void block_mult(__global double *a, __global double *b, __local double *c) {
const unsigned int block_size = 3;
const unsigned int hwarp_size = 16;
const unsigned int idx_t = get_local_id(0); // thread id in work group
const unsigned int thread_id_in_hwarp = idx_t % hwarp_size; // thread id in warp (16 threads)
if(thread_id_in_hwarp < block_size * block_size){
const unsigned int row = thread_id_in_hwarp / block_size;
const unsigned int col = thread_id_in_hwarp % block_size;
double temp = 0.0;
for (unsigned int k = 0; k < block_size; k++) {
temp += a[block_size * row + k] * b[block_size * k + col];
}
c[block_size * row + col] = temp;
}
}
// invert 3x3 matrix
__kernel void inverter(__global double *matrix, __global double *inverse) {
const unsigned int block_size = 3;
const unsigned int bs = block_size; // rename to shorter name
const unsigned int hwarp_size = 16;
const unsigned int idx_t = get_local_id(0); // thread id in work group
const unsigned int thread_id_in_hwarp = idx_t % hwarp_size; // thread id in warp (16 threads)
if(thread_id_in_hwarp < bs * bs){
double t4 = matrix[0] * matrix[4];
double t6 = matrix[0] * matrix[5];
double t8 = matrix[1] * matrix[3];
double t10 = matrix[2] * matrix[3];
double t12 = matrix[1] * matrix[6];
double t14 = matrix[2] * matrix[6];
double det = (t4 * matrix[8] - t6 * matrix[7] - t8 * matrix[8] +
t10 * matrix[7] + t12 * matrix[5] - t14 * matrix[4]);
double t17 = 1.0 / det;
const unsigned int r = thread_id_in_hwarp / bs;
const unsigned int c = thread_id_in_hwarp % bs;
const unsigned int r1 = (r+1) % bs;
const unsigned int c1 = (c+1) % bs;
const unsigned int r2 = (r+bs-1) % bs;
const unsigned int c2 = (c+bs-1) % bs;
inverse[c*bs+r] = ((matrix[r1*bs+c1] * matrix[r2*bs+c2]) - (matrix[r1*bs+c2] * matrix[r2*bs+c1])) * t17;
}
}
__kernel void ilu_decomp(const unsigned int firstRow,
const unsigned int lastRow,
__global double *LUvals,
__global const int *LUcols,
__global const int *LUrows,
__global double *invDiagVals,
__global int *diagIndex,
const unsigned int Nb,
__local double *pivot){
const unsigned int bs = 3;
const unsigned int hwarp_size = 16;
const unsigned int work_group_size = get_local_size(0);
const unsigned int work_group_id = get_group_id(0);
const unsigned int num_groups = get_num_groups(0);
const unsigned int hwarps_per_group = work_group_size / hwarp_size;
const unsigned int thread_id_in_group = get_local_id(0); // thread id in work group
const unsigned int thread_id_in_hwarp = thread_id_in_group % hwarp_size; // thread id in hwarp (16 threads)
const unsigned int hwarp_id_in_group = thread_id_in_group / hwarp_size;
const unsigned int lmem_offset = hwarp_id_in_group * bs * bs; // each workgroup gets some lmem, but the workitems have to share it
// every workitem in a hwarp has the same lmem_offset
// go through all rows
for (int i = firstRow + work_group_id * hwarps_per_group + hwarp_id_in_group; i < lastRow; i += num_groups * hwarps_per_group)
{
int iRowStart = LUrows[i];
int iRowEnd = LUrows[i + 1];
// go through all elements of the row
for (int ij = iRowStart; ij < iRowEnd; ij++) {
int j = LUcols[ij];
if (j < i) {
// calculate the pivot of this row
block_mult(LUvals + ij * bs * bs, invDiagVals + j * bs * bs, pivot + lmem_offset);
// copy pivot
if (thread_id_in_hwarp < bs * bs) {
LUvals[ij * bs * bs + thread_id_in_hwarp] = pivot[lmem_offset + thread_id_in_hwarp];
}
int jRowEnd = LUrows[j + 1];
int jk = diagIndex[j] + 1;
int ik = ij + 1;
// substract that row scaled by the pivot from this row.
while (ik < iRowEnd && jk < jRowEnd) {
if (LUcols[ik] == LUcols[jk]) {
block_mult_sub(LUvals + ik * bs * bs, pivot + lmem_offset, LUvals + jk * bs * bs);
ik++;
jk++;
} else {
if (LUcols[ik] < LUcols[jk])
{ ik++; }
else
{ jk++; }
}
}
}
}
// store the inverse in the diagonal
inverter(LUvals + diagIndex[i] * bs * bs, invDiagVals + i * bs * bs);
// copy inverse
if (thread_id_in_hwarp < bs * bs) {
LUvals[diagIndex[i] * bs * bs + thread_id_in_hwarp] = invDiagVals[i * bs * bs + thread_id_in_hwarp];
}
}
}
)";
}
} // end namespace bda