| /* Copyright 2019 The TensorFlow Authors. All Rights Reserved. |
| |
| Licensed 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. |
| ==============================================================================*/ |
| |
| #include <queue> |
| #include <string> |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SetVector.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "mlir/IR/Builders.h" // TF:local_config_mlir |
| #include "mlir/IR/Identifier.h" // TF:local_config_mlir |
| #include "mlir/IR/Location.h" // TF:local_config_mlir |
| #include "mlir/IR/MLIRContext.h" // TF:local_config_mlir |
| #include "mlir/IR/SymbolTable.h" // TF:local_config_mlir |
| #include "mlir/Pass/Pass.h" // TF:local_config_mlir |
| #include "mlir/StandardOps/Ops.h" // TF:local_config_mlir |
| #include "tensorflow/compiler/mlir/lite/transforms/passes.h" |
| |
| // The cmd line flag to specify the whitelist of functions. Rest are trimmed |
| // after this pass is run. |
| // NOLINTNEXTLINE |
| static llvm::cl::list<std::string> trim_funcs_whitelist( |
| "tfl-trim-funcs-whitelist", llvm::cl::value_desc("list"), |
| llvm::cl::desc("comma seprarated list of whitelisted functions. The first " |
| "function specified will be used as main."), |
| llvm::cl::CommaSeparated); |
| |
| namespace mlir { |
| namespace TFL { |
| namespace { |
| |
| // The pass to trim functions before we legalize to TFL |
| // dialect using the specified whitelist. |
| class TrimFunctionsPass : public mlir::ModulePass<TrimFunctionsPass> { |
| public: |
| explicit TrimFunctionsPass() : trim_funcs_whitelist_(trim_funcs_whitelist) {} |
| explicit TrimFunctionsPass(llvm::ArrayRef<std::string> trim_funcs_whitelist) |
| : trim_funcs_whitelist_(trim_funcs_whitelist) {} |
| |
| private: |
| void runOnModule() override; |
| bool TrimModule(); |
| void Verify(); |
| |
| llvm::ArrayRef<std::string> trim_funcs_whitelist_; |
| }; |
| |
| void TrimFunctionsPass::runOnModule() { |
| // trim the functions in the module using the trim_funcs_whitelist_ |
| // by removing functions not in the whitelist. |
| if (TrimModule()) { |
| // verify the updated module is still valid, if not signal the |
| // pass as failed. |
| Verify(); |
| } |
| } |
| |
| bool TrimFunctionsPass::TrimModule() { |
| // if no trim_funcs_whitelist_ is specified, this pass is a no-op. |
| if (trim_funcs_whitelist_.empty()) return false; |
| |
| llvm::SmallVector<FuncOp, 4> funcs_to_trim; |
| for (auto func : getModule().getOps<FuncOp>()) { |
| if (llvm::is_contained(trim_funcs_whitelist_, func.getName())) { |
| // If no main is specified in the whitelist, use the 1st func |
| // in trim_funcs_whitelist as the main. |
| // TODO(ashwinm): Currently tflite flatbuffer export assumes there is |
| // always a main. This is strictly not required for TFlite. We need to |
| // remove that restriction once we have support to attribute the main |
| // tensorflow function in MLIR TF import using an entry_point attr. |
| if (!llvm::is_contained(trim_funcs_whitelist_, "main") && |
| func.getName() == trim_funcs_whitelist_[0]) { |
| func.setName("main"); |
| } |
| } else { |
| funcs_to_trim.push_back(func); |
| } |
| } |
| |
| // remove all unexported functions from the module. |
| for (auto func : funcs_to_trim) { |
| func.erase(); |
| } |
| return true; |
| } |
| |
| // validate that all reachable functions from the remaining functions are |
| // also in the whitelist. |
| void TrimFunctionsPass::Verify() { |
| // TODO(ashwinm): Instead, we should make sure that references to all |
| // SymbolRefAttrs of all ops are present. |
| SymbolTable symbol_table = SymbolTable(getModule()); |
| llvm::SetVector<FuncOp> reachable_funcs; |
| for (auto func : getModule().getOps<FuncOp>()) { |
| func.walk<CallOp>([&](CallOp op) { |
| if (!symbol_table.lookup<FuncOp>(op.getCallee())) { |
| getModule().emitError() |
| << func.getName() << " is not in the funcs whitelist"; |
| return signalPassFailure(); |
| } |
| }); |
| } |
| } |
| |
| } // namespace |
| |
| // Creates an instance of the TensorFlow Lite dialect TrimFunctions |
| /// pass. |
| ModulePassBase *CreateTrimFunctionsPass( |
| llvm::ArrayRef<std::string> trim_funcs_whitelist) { |
| return new TrimFunctionsPass(trim_funcs_whitelist); |
| } |
| |
| static PassRegistration<TrimFunctionsPass> pass( |
| "tfl-trim-funcs-tf", |
| "Trim functions to restrict them to a specified whitelist prior to " |
| "legalization to TensorFlow lite dialect"); |
| |
| } // namespace TFL |
| } // namespace mlir |