ViennaCL - The Vienna Computing Library: viennacl/device_specific/templates/reduction_template.hpp Source File

ViennaCL - The Vienna Computing Library 1.7.0 Free open-source GPU-accelerated linear algebra and solver library. |

viennacl/device_specific/templates/reduction_template.hpp
Go to the documentation of this file.

    00001 #ifndef VIENNACL_DEVICE_SPECIFIC_TEMPLATES_REDUCTION_TEMPLATE_HPP
    00002 #define VIENNACL_DEVICE_SPECIFIC_TEMPLATES_REDUCTION_TEMPLATE_HPP
    00003
    00004 /* =========================================================================
    00005    Copyright (c) 2010-2015, Institute for Microelectronics,
    00006                             Institute for Analysis and Scientific Computing,
    00007                             TU Wien.
    00008    Portions of this software are copyright by UChicago Argonne, LLC.
    00009
    00010                             -----------------
    00011                   ViennaCL - The Vienna Computing Library
    00012                             -----------------
    00013
    00014    Project Head:    Karl Rupp                   rupp@iue.tuwien.ac.at
    00015
    00016    (A list of authors and contributors can be found in the manual)
    00017
    00018    License:         MIT (X11), see file LICENSE in the base directory
    00019 ============================================================================= */
    00020
    00021
    00027 #include <vector>
    00028
    00029 #include "viennacl/backend/opencl.hpp"
    00030
    00031 #include "viennacl/scheduler/forwards.h"
    00032 #include "viennacl/device_specific/tree_parsing.hpp"
    00033 #include "viennacl/device_specific/utils.hpp"
    00034
    00035 #include "viennacl/device_specific/templates/template_base.hpp"
    00036 #include "viennacl/device_specific/templates/utils.hpp"
    00037
    00038 #include "viennacl/tools/tools.hpp"
    00039
    00040 namespace viennacl
    00041 {
    00042 namespace device_specific
    00043 {
    00044
    00045 struct reduction_parameters : public template_base::parameters_type
    00046 {
    00047   reduction_parameters(unsigned int _simd_width,
    00048                        unsigned int _group_size, unsigned int _num_groups,
    00049                        fetching_policy_type _fetching_policy) : template_base::parameters_type(_simd_width, _group_size, 1, 2), num_groups(_num_groups), fetching_policy(_fetching_policy){ }
    00050
    00051   unsigned int num_groups;
    00052   fetching_policy_type fetching_policy;
    00053 };
    00054
    00055 class reduction_template : public template_base_impl<reduction_template, reduction_parameters>
    00056 {
    00057
    00058 private:
    00059   unsigned int n_lmem_elements() const
    00060   {
    00061     return p_.local_size_0;
    00062   }
    00063
    00064   int check_invalid_impl(viennacl::ocl::device const & /*dev*/) const
    00065   {
    00066     if (p_.fetching_policy==FETCH_FROM_LOCAL)
    00067       return TEMPLATE_INVALID_FETCHING_POLICY_TYPE;
    00068     return TEMPLATE_VALID;
    00069   }
    00070
    00071   inline void reduce_1d_local_memory(utils::kernel_generation_stream & stream, unsigned int size, std::vector<mapped_scalar_reduction*> exprs,
    00072                                      std::string const & buf_str, std::string const & buf_value_str) const
    00073   {
    00074     stream << "#pragma unroll" << std::endl;
    00075     stream << "for(unsigned int stride = " << size/2 << "; stride >0; stride /=2)" << std::endl;
    00076     stream << "{" << std::endl;
    00077     stream.inc_tab();
    00078     stream << "barrier(CLK_LOCAL_MEM_FENCE); " << std::endl;
    00079     stream << "if (lid <  stride)" << std::endl;
    00080     stream << "{" << std::endl;
    00081     stream.inc_tab();
    00082
    00083     for (unsigned int k = 0; k < exprs.size(); k++)
    00084       if (exprs[k]->is_index_reduction())
    00085         compute_index_reduction(stream, exprs[k]->process(buf_str+"[lid]"), exprs[k]->process(buf_str+"[lid+stride]")
    00086                                 , exprs[k]->process(buf_value_str+"[lid]"), exprs[k]->process(buf_value_str+"[lid+stride]"),
    00087                                 exprs[k]->root_op());
    00088       else
    00089         compute_reduction(stream, exprs[k]->process(buf_str+"[lid]"), exprs[k]->process(buf_str+"[lid+stride]"), exprs[k]->root_op());
    00090     stream.dec_tab();
    00091     stream << "}" << std::endl;
    00092     stream.dec_tab();
    00093     stream << "}" << std::endl;
    00094   }
    00095
    00096   std::string generate_impl(std::string const & kernel_prefix,  statements_container const & statements, std::vector<mapping_type> const & mappings, unsigned int simd_width) const
    00097   {
    00098     utils::kernel_generation_stream stream;
    00099
    00100     std::vector<mapped_scalar_reduction*> exprs;
    00101     for (std::vector<mapping_type>::const_iterator it = mappings.begin(); it != mappings.end(); ++it)
    00102       for (mapping_type::const_iterator iit = it->begin(); iit != it->end(); ++iit)
    00103         if (mapped_scalar_reduction * p = dynamic_cast<mapped_scalar_reduction*>(iit->second.get()))
    00104           exprs.push_back(p);
    00105     vcl_size_t N = exprs.size();
    00106
    00107     std::string arguments = generate_value_kernel_argument("unsigned int", "N");
    00108     for (unsigned int k = 0; k < N; ++k)
    00109     {
    00110       std::string numeric_type = utils::numeric_type_to_string(lhs_most(exprs[k]->statement().array(),
    00111                                                                         exprs[k]->statement().root()).lhs.numeric_type);
    00112       if (exprs[k]->is_index_reduction())
    00113       {
    00114         arguments += generate_pointer_kernel_argument("__global", "unsigned int",  exprs[k]->process("#name_temp"));
    00115         arguments += generate_pointer_kernel_argument("__global", numeric_type,  exprs[k]->process("#name_temp_value"));
    00116       }
    00117       else
    00118         arguments += generate_pointer_kernel_argument("__global", numeric_type,  exprs[k]->process("#name_temp"));
    00119     }
    00120
    00121
    00122     /* ------------------------
    00123      * First Kernel
    00124      * -----------------------*/
    00125     stream << " __attribute__((reqd_work_group_size(" << p_.local_size_0 << ",1,1)))" << std::endl;
    00126     generate_prototype(stream, kernel_prefix + "_0", arguments, mappings, statements);
    00127     stream << "{" << std::endl;
    00128     stream.inc_tab();
    00129
    00130     tree_parsing::process(stream, PARENT_NODE_TYPE, "scalar", "#scalartype #namereg = *#pointer;", statements, mappings);
    00131     stream << "unsigned int lid = get_local_id(0);" << std::endl;
    00132     tree_parsing::process(stream, PARENT_NODE_TYPE, "vector", "#pointer += #start;", statements, mappings);
    00133
    00134     for (unsigned int k = 0; k < N; ++k)
    00135     {
    00136       if (exprs[k]->is_index_reduction())
    00137       {
    00138         stream << exprs[k]->process("__local #scalartype #name_buf_value[" + tools::to_string(p_.local_size_0) + "];") << std::endl;
    00139         stream << exprs[k]->process("#scalartype #name_acc_value = " + neutral_element(exprs[k]->root_op()) + ";") << std::endl;
    00140         stream << exprs[k]->process("__local unsigned int #name_buf[" + tools::to_string(p_.local_size_0) + "];") << std::endl;
    00141         stream << exprs[k]->process("unsigned int #name_acc = 0;") << std::endl;
    00142       }
    00143       else
    00144       {
    00145         stream << exprs[k]->process("__local #scalartype #name_buf[" + tools::to_string(p_.local_size_0) + "];") << std::endl;
    00146         stream << exprs[k]->process("#scalartype #name_acc = " + neutral_element(exprs[k]->root_op()) + ";") << std::endl;
    00147       }
    00148     }
    00149
    00150     class loop_body : public loop_body_base
    00151     {
    00152     public:
    00153       loop_body(std::vector<mapped_scalar_reduction*> const & exprs_) : exprs(exprs_){ }
    00154
    00155       void operator()(utils::kernel_generation_stream & kernel_stream, unsigned int loop_simd_width) const
    00156       {
    00157         std::string i = (loop_simd_width==1)?"i*#stride":"i";
    00158         std::string process_str;
    00159         //Fetch vector entry
    00160         {
    00161           std::set<std::string> already_fetched;
    00162           process_str = utils::append_width("#scalartype",loop_simd_width) + " #namereg = " + vload(loop_simd_width,i,"#pointer")+";";
    00163           for (std::vector<mapped_scalar_reduction*>::const_iterator it = exprs.begin(); it != exprs.end(); ++it)
    00164           {
    00165             (*it)->process_recursive(kernel_stream, PARENT_NODE_TYPE, "vector", process_str, already_fetched);
    00166             (*it)->process_recursive(kernel_stream, PARENT_NODE_TYPE, "matrix_row", "#scalartype #namereg = #pointer[$OFFSET{#row*#stride1, i*#stride2}];", already_fetched);
    00167             (*it)->process_recursive(kernel_stream, PARENT_NODE_TYPE, "matrix_column", "#scalartype #namereg = #pointer[$OFFSET{i*#stride1,#column*#stride2}];", already_fetched);
    00168             (*it)->process_recursive(kernel_stream, PARENT_NODE_TYPE, "matrix_diag", "#scalartype #namereg = #pointer[#diag_offset<0?$OFFSET{(i - #diag_offset)*#stride1, i*#stride2}:$OFFSET{i*#stride1, (i + #diag_offset)*#stride2}];", already_fetched);
    00169           }
    00170         }
    00171
    00172         //Update accumulators
    00173         std::vector<std::string> str(loop_simd_width);
    00174         if (loop_simd_width==1)
    00175           str[0] = "#namereg";
    00176         else
    00177           for (unsigned int a = 0; a < loop_simd_width; ++a)
    00178             str[a] = append_simd_suffix("#namereg.s", a);
    00179
    00180         for (unsigned int k = 0; k < exprs.size(); ++k)
    00181         {
    00182           for (unsigned int a = 0; a < loop_simd_width; ++a)
    00183           {
    00184             std::map<std::string, std::string> accessors;
    00185             accessors["vector"] = str[a];
    00186             accessors["matrix_row"] = str[a];
    00187             accessors["matrix_column"] = str[a];
    00188             accessors["matrix_diag"] = str[a];
    00189             accessors["scalar"] = "#namereg";
    00190             std::string value = exprs[k]->evaluate_recursive(LHS_NODE_TYPE, accessors);
    00191             if (exprs[k]->root_node().op.type==scheduler::OPERATION_BINARY_INNER_PROD_TYPE)
    00192               value+= "*" + exprs[k]->evaluate_recursive(RHS_NODE_TYPE, accessors);
    00193
    00194             if (exprs[k]->is_index_reduction())
    00195               compute_index_reduction(kernel_stream, exprs[k]->process("#name_acc"),  "i*"+tools::to_string(loop_simd_width) + "+" + tools::to_string(a), exprs[k]->process("#name_acc_value"), value,exprs[k]->root_op());
    00196             else
    00197               compute_reduction(kernel_stream, exprs[k]->process("#name_acc"), value,exprs[k]->root_op());
    00198           }
    00199         }
    00200       }
    00201
    00202     private:
    00203       std::vector<mapped_scalar_reduction*> exprs;
    00204     };
    00205
    00206     element_wise_loop_1D(stream, loop_body(exprs), p_.fetching_policy, simd_width, "i", "N", "get_global_id(0)", "get_global_size(0)");
    00207
    00208     //Fills local memory
    00209     for (unsigned int k = 0; k < N; ++k)
    00210     {
    00211       if (exprs[k]->is_index_reduction())
    00212         stream << exprs[k]->process("#name_buf_value[lid] = #name_acc_value;") << std::endl;
    00213       stream << exprs[k]->process("#name_buf[lid] = #name_acc;") << std::endl;
    00214     }
    00215
    00216     //Reduce local memory
    00217     reduce_1d_local_memory(stream, p_.local_size_0, exprs, "#name_buf", "#name_buf_value");
    00218
    00219     //Write to temporary buffers
    00220     stream << "if (lid==0)" << std::endl;
    00221     stream << "{" << std::endl;
    00222     stream.inc_tab();
    00223     for (unsigned int k = 0; k < N; ++k)
    00224     {
    00225       if (exprs[k]->is_index_reduction())
    00226         stream << exprs[k]->process("#name_temp_value[get_group_id(0)] = #name_buf_value[0];") << std::endl;
    00227       stream << exprs[k]->process("#name_temp[get_group_id(0)] = #name_buf[0];") << std::endl;
    00228     }
    00229     stream.dec_tab();
    00230     stream << "}" << std::endl;
    00231
    00232     stream.dec_tab();
    00233     stream << "}" << std::endl;
    00234
    00235     /* ------------------------
    00236      * Second kernel
    00237      * -----------------------*/
    00238     stream << " __attribute__((reqd_work_group_size(" << p_.local_size_0 << ",1,1)))" << std::endl;
    00239     generate_prototype(stream, kernel_prefix + "_1", arguments, mappings, statements);
    00240     stream << "{" << std::endl;
    00241     stream.inc_tab();
    00242
    00243     stream << "unsigned int lid = get_local_id(0);" << std::endl;
    00244
    00245     for (unsigned int k = 0; k < N; ++k)
    00246     {
    00247       if (exprs[k]->is_index_reduction())
    00248       {
    00249         stream << exprs[k]->process("__local unsigned int #name_buf[" + tools::to_string(p_.local_size_0) + "];");
    00250         stream << exprs[k]->process("unsigned int #name_acc = 0;") << std::endl;
    00251         stream << exprs[k]->process("__local #scalartype #name_buf_value[" + tools::to_string(p_.local_size_0) + "];") << std::endl;
    00252         stream << exprs[k]->process("#scalartype #name_acc_value = " + neutral_element(exprs[k]->root_op()) + ";");
    00253       }
    00254       else
    00255       {
    00256         stream << exprs[k]->process("__local #scalartype #name_buf[" + tools::to_string(p_.local_size_0) + "];") << std::endl;
    00257         stream << exprs[k]->process("#scalartype #name_acc = " + neutral_element(exprs[k]->root_op()) + ";");
    00258       }
    00259     }
    00260
    00261     stream << "for(unsigned int i = lid; i < " << p_.num_groups << "; i += get_local_size(0))" << std::endl;
    00262     stream << "{" << std::endl;
    00263     stream.inc_tab();
    00264     for (unsigned int k = 0; k < N; ++k)
    00265       if (exprs[k]->is_index_reduction())
    00266         compute_index_reduction(stream, exprs[k]->process("#name_acc"), exprs[k]->process("#name_temp[i]"),
    00267                                 exprs[k]->process("#name_acc_value"),exprs[k]->process("#name_temp_value[i]"),exprs[k]->root_op());
    00268       else
    00269         compute_reduction(stream, exprs[k]->process("#name_acc"), exprs[k]->process("#name_temp[i]"), exprs[k]->root_op());
    00270
    00271     stream.dec_tab();
    00272     stream << "}" << std::endl;
    00273
    00274     for (unsigned int k = 0; k < N; ++k)
    00275     {
    00276       if (exprs[k]->is_index_reduction())
    00277         stream << exprs[k]->process("#name_buf_value[lid] = #name_acc_value;") << std::endl;
    00278       stream << exprs[k]->process("#name_buf[lid] = #name_acc;") << std::endl;
    00279     }
    00280
    00281
    00282     //Reduce and write final result
    00283     reduce_1d_local_memory(stream, p_.local_size_0, exprs, "#name_buf", "#name_buf_value");
    00284
    00285     stream << "if (lid==0)" << std::endl;
    00286     stream << "{" << std::endl;
    00287     stream.inc_tab();
    00288     std::map<std::string, std::string> accessors;
    00289     accessors["scalar_reduction"] = "#name_buf[0]";
    00290     accessors["scalar"] = "*#pointer";
    00291     accessors["vector"] = "#pointer[#start]";
    00292     tree_parsing::evaluate(stream, PARENT_NODE_TYPE, accessors, statements, mappings);
    00293     stream.dec_tab();
    00294     stream << "}" << std::endl;
    00295
    00296     stream.dec_tab();
    00297     stream << "}" << std::endl;
    00298
    00299     return stream.str();
    00300   }
    00301
    00302   std::vector<std::string> generate_impl(std::string const & kernel_prefix,  statements_container const & statements, std::vector<mapping_type> const & mappings) const
    00303   {
    00304     std::vector<std::string> result;
    00305     result.push_back(generate_impl(kernel_prefix + "_strided", statements, mappings, 1));
    00306     result.push_back(generate_impl(kernel_prefix, statements, mappings, p_.simd_width));
    00307     return result;
    00308   }
    00309 public:
    00310   reduction_template(reduction_template::parameters_type const & parameters, binding_policy_t binding_policy = BIND_ALL_UNIQUE) : template_base_impl<reduction_template, reduction_parameters>(parameters, binding_policy) { }
    00311
    00312   void enqueue(std::string const & kernel_prefix, std::vector<lazy_program_compiler> & programs, statements_container const & statements)
    00313   {
    00314     std::vector<scheduler::statement_node const *> reductions;
    00315     cl_uint size = 0;
    00316     for (statements_container::data_type::const_iterator it = statements.data().begin(); it != statements.data().end(); ++it)
    00317     {
    00318       std::vector<vcl_size_t> reductions_idx;
    00319       tree_parsing::traverse(*it, it->root(), tree_parsing::filter(&utils::is_reduction, reductions_idx), false);
    00320       size = static_cast<cl_uint>(vector_size(lhs_most(it->array(), reductions_idx[0]), false));
    00321       for (std::vector<vcl_size_t>::iterator itt = reductions_idx.begin(); itt != reductions_idx.end(); ++itt)
    00322         reductions.push_back(&it->array()[*itt]);
    00323     }
    00324
    00325     scheduler::statement const & statement = statements.data().front();
    00326     unsigned int scalartype_size = utils::size_of(lhs_most(statement.array(), statement.root()).lhs.numeric_type);
    00327
    00328     viennacl::ocl::kernel * kernels[2];
    00329     if (has_strided_access(statements) && p_.simd_width > 1)
    00330     {
    00331       kernels[0] = &programs[0].program().get_kernel(kernel_prefix+"_strided_0");
    00332       kernels[1] = &programs[0].program().get_kernel(kernel_prefix+"_strided_1");
    00333     }
    00334     else
    00335     {
    00336       kernels[0] = &programs[1].program().get_kernel(kernel_prefix+"_0");
    00337       kernels[1] = &programs[1].program().get_kernel(kernel_prefix+"_1");
    00338     }
    00339
    00340     kernels[0]->local_work_size(0, p_.local_size_0);
    00341     kernels[0]->global_work_size(0,p_.local_size_0*p_.num_groups);
    00342
    00343     kernels[1]->local_work_size(0, p_.local_size_0);
    00344     kernels[1]->global_work_size(0,p_.local_size_0);
    00345
    00346     for (unsigned int k = 0; k < 2; k++)
    00347     {
    00348       unsigned int n_arg = 0;
    00349       kernels[k]->arg(n_arg++, size);
    00350       unsigned int i = 0;
    00351       unsigned int j = 0;
    00352       for (std::vector<scheduler::statement_node const *>::const_iterator it = reductions.begin(); it != reductions.end(); ++it)
    00353       {
    00354         if (utils::is_index_reduction((*it)->op))
    00355         {
    00356           if (tmpidx_.size() <= j)
    00357             tmpidx_.push_back(kernels[k]->context().create_memory(CL_MEM_READ_WRITE, p_.num_groups*4));
    00358           kernels[k]->arg(n_arg++, tmpidx_[j]);
    00359           j++;
    00360         }
    00361
    00362         if (tmp_.size() <= i)
    00363           tmp_.push_back(kernels[k]->context().create_memory(CL_MEM_READ_WRITE, p_.num_groups*scalartype_size));
    00364         kernels[k]->arg(n_arg++, tmp_[i]);
    00365         i++;
    00366       }
    00367       set_arguments(statements, *kernels[k], n_arg);
    00368     }
    00369
    00370     for (unsigned int k = 0; k < 2; k++)
    00371       viennacl::ocl::enqueue(*kernels[k]);
    00372
    00373   }
    00374
    00375 private:
    00376   std::vector< viennacl::ocl::handle<cl_mem> > tmp_;
    00377   std::vector< viennacl::ocl::handle<cl_mem> > tmpidx_;
    00378 };
    00379
    00380 }
    00381 }
    00382
    00383 #endif

All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines