manupa-arm commented on a change in pull request #7398: URL: https://github.com/apache/tvm/pull/7398#discussion_r570449159
########## File path: src/target/metadata_module.cc ########## @@ -0,0 +1,108 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/*! + * \file metadata_module.cc + * \brief Defines functions that build MetadataModules for C++ and C runtimes. + */ + +#include "metadata_module.h" + +#include "../runtime/meta_data.h" +#include "llvm/llvm_module.h" +#include "source/source_module.h" + +namespace tvm { +namespace codegen { + +/*! + * \brief Create a metadata module wrapper. The helper is used by different + * codegens, such as graph runtime codegen and the vm compiler. + * + * \param params The metadata for initialization of all modules. + * \param target_module the internal module that is compiled by tvm. + * \param ext_modules The external modules that needs to be imported inside the metadata + * module(s). + * \param target The target that all the modules are compiled for + * \return The created metadata module that manages initialization of metadata. + */ +runtime::Module CreateMetadataModule( + const std::unordered_map<std::string, runtime::NDArray>& params, + tvm::runtime::Module target_module, const Array<runtime::Module>& ext_modules, Target target) { + Array<tvm::runtime::Module> csource_modules; + Array<tvm::runtime::Module> binary_modules; + + auto DSOExportable = [](tvm::runtime::Module& mod) { + return !std::strcmp(mod->type_key(), "llvm") || !std::strcmp(mod->type_key(), "c"); + }; + + // Wrap all submodules in the initialization wrapper. + std::unordered_map<std::string, std::vector<std::string>> sym_metadata; + for (tvm::runtime::Module mod : ext_modules) { + auto pf_sym = mod.GetFunction("get_symbol"); + auto pf_var = mod.GetFunction("get_const_vars"); + std::vector<std::string> arrays; + if (pf_sym != nullptr && pf_var != nullptr) { + String symbol = pf_sym(); + Array<String> variables = pf_var(); + for (size_t i = 0; i < variables.size(); i++) { + arrays.push_back(variables[i].operator std::string()); + } + ICHECK_EQ(sym_metadata.count(symbol), 0U) << "Found duplicated symbol: " << symbol; + sym_metadata[symbol] = arrays; + } + // We only need loading of serialized constant data + // if there are constants present and required by the + // runtime module to be initialized by the binary + // metadata module. If not rest of the modules are + // wrapped in c-source metadata module. + + // TODO(@manupa-arm) : we should be able to use csource_metadata + // if the variables are empty when all the runtime modules implement get_func_names + if (arrays.empty() && DSOExportable(mod) && target->kind->name == "c") { + csource_modules.push_back(mod); + } else { + binary_modules.push_back(mod); + } + } + + if (target.defined() && + target->GetAttr<String>("runtime").value_or(String("")) == kTvmRuntimeCrt) { + if (target->kind->name == "c") { + csource_modules.push_back(target_module); + target_module = CreateCSourceCrtMetadataModule(csource_modules, target); + } else if (target->kind->name == "llvm") { + binary_modules.push_back(target_module); Review comment: runtime::MetadataModuleCreate() --> is non-DSO-exportable it gets packed into to devc.{o/c} and I think we should only need this if we have modules that require constant loading. This one is of type "metadata". Im talking about the one that is created in line 96. I mean DSOExportable modules could still use constant loading -- though I think its not very useful since we have linked params now. Only remaining place is the example c byoc codegen that uses the constant loading process as a demo to all BYOC codegens -- I think. Thus, if none of the modules does not require constant loading -- that is indicated by arrays.empty() -- we dont need to create the non-DSOExportable metadata module. See the diagram here : https://discuss.tvm.apache.org/t/csourcemetadata-module-a-csourcemodule-to-hold-function-registry-for-utvm/8554. Does that make sense ? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
