opm-simulators/opm/simulators/linalg/bda/openclKernels.cpp
2021-11-04 14:25:22 +01:00

930 lines
38 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 <config.h>
#include <cmath>
#include <sstream>
#include <opm/common/OpmLog/OpmLog.hpp>
#include <dune/common/timer.hh>
#include <opm/simulators/linalg/bda/openclKernels.hpp>
#include <opm/simulators/linalg/bda/ChowPatelIlu.hpp> // defines CHOW_PATEL
namespace bda
{
using Opm::OpmLog;
using Dune::Timer;
// define static variables and kernels
int OpenclKernels::verbosity;
cl::CommandQueue *OpenclKernels::queue;
std::vector<double> OpenclKernels::tmp;
bool OpenclKernels::initialized = false;
std::unique_ptr<cl::KernelFunctor<cl::Buffer&, cl::Buffer&, cl::Buffer&, const unsigned int, cl::LocalSpaceArg> > OpenclKernels::dot_k;
std::unique_ptr<cl::KernelFunctor<cl::Buffer&, cl::Buffer&, const unsigned int, cl::LocalSpaceArg> > OpenclKernels::norm_k;
std::unique_ptr<cl::KernelFunctor<cl::Buffer&, const double, cl::Buffer&, const unsigned int> > OpenclKernels::axpy_k;
std::unique_ptr<cl::KernelFunctor<cl::Buffer&, const double, const unsigned int> > OpenclKernels::scale_k;
std::unique_ptr<cl::KernelFunctor<cl::Buffer&, cl::Buffer&, cl::Buffer&, const double, const double, const unsigned int> > OpenclKernels::custom_k;
std::unique_ptr<spmv_kernel_type> OpenclKernels::spmv_blocked_k;
std::unique_ptr<ilu_apply1_kernel_type> OpenclKernels::ILU_apply1_k;
std::unique_ptr<ilu_apply2_kernel_type> OpenclKernels::ILU_apply2_k;
std::unique_ptr<stdwell_apply_kernel_type> OpenclKernels::stdwell_apply_k;
std::unique_ptr<stdwell_apply_no_reorder_kernel_type> OpenclKernels::stdwell_apply_no_reorder_k;
std::unique_ptr<ilu_decomp_kernel_type> OpenclKernels::ilu_decomp_k;
// divide A by B, and round up: return (int)ceil(A/B)
unsigned int ceilDivision(const unsigned int A, const unsigned int B)
{
return A / B + (A % B > 0);
}
void add_kernel_string(cl::Program::Sources &sources, std::string &source) {
sources.emplace_back(source);
}
void OpenclKernels::init(cl::Context *context, cl::CommandQueue *queue_, std::vector<cl::Device>& devices, int verbosity_) {
if (initialized) {
OpmLog::warning("Warning OpenclKernels is already initialized");
return;
}
queue = queue_;
verbosity = verbosity_;
cl::Program::Sources sources;
std::string axpy_s = get_axpy_string();
add_kernel_string(sources, axpy_s);
std::string scale_s = get_scale_string();
add_kernel_string(sources, scale_s);
std::string dot_1_s = get_dot_1_string();
add_kernel_string(sources, dot_1_s);
std::string norm_s = get_norm_string();
add_kernel_string(sources, norm_s);
std::string custom_s = get_custom_string();
add_kernel_string(sources, custom_s);
std::string spmv_blocked_s = get_spmv_blocked_string();
add_kernel_string(sources, spmv_blocked_s);
#if CHOW_PATEL
bool ilu_operate_on_full_matrix = false;
#else
bool ilu_operate_on_full_matrix = true;
#endif
std::string ILU_apply1_s = get_ILU_apply1_string(ilu_operate_on_full_matrix);
add_kernel_string(sources, ILU_apply1_s);
std::string ILU_apply2_s = get_ILU_apply2_string(ilu_operate_on_full_matrix);
add_kernel_string(sources, ILU_apply2_s);
std::string stdwell_apply_s = get_stdwell_apply_string(true);
add_kernel_string(sources, stdwell_apply_s);
std::string stdwell_apply_no_reorder_s = get_stdwell_apply_string(false);
add_kernel_string(sources, stdwell_apply_no_reorder_s);
std::string ilu_decomp_s = get_ilu_decomp_string();
add_kernel_string(sources, ilu_decomp_s);
cl::Program program = cl::Program(*context, sources);
program.build(devices);
// queue.enqueueNDRangeKernel() is a blocking/synchronous call, at least for NVIDIA
// cl::KernelFunctor<> myKernel(); myKernel(args, arg1, arg2); is also blocking
// actually creating the kernels
dot_k.reset(new cl::KernelFunctor<cl::Buffer&, cl::Buffer&, cl::Buffer&, const unsigned int, cl::LocalSpaceArg>(cl::Kernel(program, "dot_1")));
norm_k.reset(new cl::KernelFunctor<cl::Buffer&, cl::Buffer&, const unsigned int, cl::LocalSpaceArg>(cl::Kernel(program, "norm")));
axpy_k.reset(new cl::KernelFunctor<cl::Buffer&, const double, cl::Buffer&, const unsigned int>(cl::Kernel(program, "axpy")));
scale_k.reset(new cl::KernelFunctor<cl::Buffer&, const double, const unsigned int>(cl::Kernel(program, "scale")));
custom_k.reset(new cl::KernelFunctor<cl::Buffer&, cl::Buffer&, cl::Buffer&, const double, const double, const unsigned int>(cl::Kernel(program, "custom")));
spmv_blocked_k.reset(new spmv_kernel_type(cl::Kernel(program, "spmv_blocked")));
ILU_apply1_k.reset(new ilu_apply1_kernel_type(cl::Kernel(program, "ILU_apply1")));
ILU_apply2_k.reset(new ilu_apply2_kernel_type(cl::Kernel(program, "ILU_apply2")));
stdwell_apply_k.reset(new stdwell_apply_kernel_type(cl::Kernel(program, "stdwell_apply")));
stdwell_apply_no_reorder_k.reset(new stdwell_apply_no_reorder_kernel_type(cl::Kernel(program, "stdwell_apply_no_reorder")));
ilu_decomp_k.reset(new ilu_decomp_kernel_type(cl::Kernel(program, "ilu_decomp")));
initialized = true;
} // end get_opencl_kernels()
double OpenclKernels::dot(cl::Buffer& in1, cl::Buffer& in2, cl::Buffer& out, int N)
{
const unsigned int work_group_size = 256;
const unsigned int num_work_groups = ceilDivision(N, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
const unsigned int lmem_per_work_group = sizeof(double) * work_group_size;
Timer t_dot;
tmp.resize(num_work_groups);
cl::Event event = (*dot_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), in1, in2, out, N, cl::Local(lmem_per_work_group));
queue->enqueueReadBuffer(out, CL_TRUE, 0, sizeof(double) * num_work_groups, tmp.data());
double gpu_sum = 0.0;
for (unsigned int i = 0; i < num_work_groups; ++i) {
gpu_sum += tmp[i];
}
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels dot() time: " << t_dot.stop() << " s";
OpmLog::info(oss.str());
}
return gpu_sum;
}
double OpenclKernels::norm(cl::Buffer& in, cl::Buffer& out, int N)
{
const unsigned int work_group_size = 256;
const unsigned int num_work_groups = ceilDivision(N, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
const unsigned int lmem_per_work_group = sizeof(double) * work_group_size;
Timer t_norm;
tmp.resize(num_work_groups);
cl::Event event = (*norm_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), in, out, N, cl::Local(lmem_per_work_group));
queue->enqueueReadBuffer(out, CL_TRUE, 0, sizeof(double) * num_work_groups, tmp.data());
double gpu_norm = 0.0;
for (unsigned int i = 0; i < num_work_groups; ++i) {
gpu_norm += tmp[i];
}
gpu_norm = sqrt(gpu_norm);
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels norm() time: " << t_norm.stop() << " s";
OpmLog::info(oss.str());
}
return gpu_norm;
}
void OpenclKernels::axpy(cl::Buffer& in, const double a, cl::Buffer& out, int N)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(N, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
Timer t_axpy;
cl::Event event = (*axpy_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), in, a, out, N);
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels axpy() time: " << t_axpy.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::scale(cl::Buffer& in, const double a, int N)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(N, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
Timer t_scale;
cl::Event event = (*scale_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), in, a, N);
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels scale() time: " << t_scale.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::custom(cl::Buffer& p, cl::Buffer& v, cl::Buffer& r, const double omega, const double beta, int N)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(N, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
Timer t_custom;
cl::Event event = (*custom_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), p, v, r, omega, beta, N);
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels custom() time: " << t_custom.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::spmv_blocked(cl::Buffer& vals, cl::Buffer& cols, cl::Buffer& rows, cl::Buffer& x, cl::Buffer& b, int Nb, unsigned int block_size)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(Nb, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
const unsigned int lmem_per_work_group = sizeof(double) * work_group_size;
Timer t_spmv;
cl::Event event = (*spmv_blocked_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), vals, cols, rows, Nb, x, b, block_size, cl::Local(lmem_per_work_group));
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels spmv_blocked() time: " << t_spmv.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::ILU_apply1(cl::Buffer& vals, cl::Buffer& cols, cl::Buffer& rows, cl::Buffer& diagIndex, const cl::Buffer& y, cl::Buffer& x, cl::Buffer& rowsPerColor, int color, int Nb, unsigned int block_size)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(Nb, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
const unsigned int lmem_per_work_group = sizeof(double) * work_group_size;
Timer t_ilu_apply1;
cl::Event event = (*ILU_apply1_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), vals, cols, rows, diagIndex, y, x, rowsPerColor, color, block_size, cl::Local(lmem_per_work_group));
if (verbosity >= 5) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels ILU_apply1() time: " << t_ilu_apply1.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::ILU_apply2(cl::Buffer& vals, cl::Buffer& cols, cl::Buffer& rows, cl::Buffer& diagIndex, cl::Buffer& invDiagVals, cl::Buffer& x, cl::Buffer& rowsPerColor, int color, int Nb, unsigned int block_size)
{
const unsigned int work_group_size = 32;
const unsigned int num_work_groups = ceilDivision(Nb, work_group_size);
const unsigned int total_work_items = num_work_groups * work_group_size;
const unsigned int lmem_per_work_group = sizeof(double) * work_group_size;
Timer t_ilu_apply2;
cl::Event event = (*ILU_apply2_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items), cl::NDRange(work_group_size)), vals, cols, rows, diagIndex, invDiagVals, x, rowsPerColor, color, block_size, cl::Local(lmem_per_work_group));
if (verbosity >= 5) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels ILU_apply2() time: " << t_ilu_apply2.stop() << " s";
OpmLog::info(oss.str());
}
}
void OpenclKernels::ILU_decomp(int firstRow, int lastRow, cl::Buffer& vals, cl::Buffer& cols, cl::Buffer& rows, cl::Buffer& diagIndex, cl::Buffer& invDiagVals, int Nb, unsigned int block_size)
{
const unsigned int work_group_size2 = 128;
const unsigned int num_work_groups2 = 1024;
const unsigned int total_work_items2 = num_work_groups2 * work_group_size2;
const unsigned int num_hwarps_per_group = work_group_size2 / 16;
const unsigned int lmem_per_work_group2 = num_hwarps_per_group * block_size * block_size * sizeof(double); // each block needs a pivot
Timer t_ilu_decomp;
cl::Event event = (*ilu_decomp_k)(cl::EnqueueArgs(*queue, cl::NDRange(total_work_items2), cl::NDRange(work_group_size2)), firstRow, lastRow, vals, cols, rows, invDiagVals, diagIndex, Nb, cl::Local(lmem_per_work_group2));
if (verbosity >= 4) {
event.wait();
std::ostringstream oss;
oss << std::scientific << "OpenclKernels ILU_decomp() time: " << t_ilu_decomp.stop() << " s";
OpmLog::info(oss.str());
}
}
std::string OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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 OpenclKernels::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