| /* Copyright 2020 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. |
| ==============================================================================*/ |
| |
| // Converts TF While to TFL While with single call in body and cond. |
| |
| #include "mlir/Dialect/Func/IR/FuncOps.h" // from @llvm-project |
| #include "mlir/IR/Attributes.h" // from @llvm-project |
| #include "mlir/IR/Builders.h" // from @llvm-project |
| #include "mlir/IR/Operation.h" // from @llvm-project |
| #include "mlir/IR/PatternMatch.h" // from @llvm-project |
| #include "mlir/Pass/Pass.h" // from @llvm-project |
| #include "tensorflow/compiler/mlir/lite/ir/tfl_ops.h" |
| #include "tensorflow/compiler/mlir/lite/transforms/passes.h" |
| #include "tensorflow/compiler/mlir/tensorflow/ir/tf_ops.h" |
| |
| namespace mlir { |
| namespace TFL { |
| namespace { |
| |
| // Legalize TF While to TFL While with calls to the original functions from the |
| // cond and body regions. |
| struct LegalizeWhile |
| : public PassWrapper<LegalizeWhile, OperationPass<ModuleOp>> { |
| MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(LegalizeWhile) |
| |
| void getDependentDialects(DialectRegistry& registry) const override { |
| registry.insert<TFL::TensorFlowLiteDialect>(); |
| } |
| |
| StringRef getArgument() const final { |
| // This is the argument used to refer to the pass in |
| // the textual format (on the commandline for example). |
| return "tfl-legalize-tf-while"; |
| } |
| StringRef getDescription() const final { |
| // This is a brief description of the pass. |
| return "Legalize from TensorFlow While to TensorFlow Lite While"; |
| } |
| |
| void RunOnFunction(func::FuncOp func); |
| |
| void runOnOperation() override { |
| for (auto op : getOperation().getOps<func::FuncOp>()) RunOnFunction(op); |
| } |
| }; |
| |
| } // namespace |
| |
| // Inserts call to the given function into the 'region'. |
| void CreateRegionWithCall(func::FuncOp func, Region& region, Location loc) { |
| OpBuilder builder(region); |
| auto block = builder.createBlock(®ion); |
| SmallVector<Value, 4> new_operands; |
| for (Type t : func.getFunctionType().getInputs()) |
| new_operands.push_back(block->addArgument(t, loc)); |
| auto call = builder.create<func::CallOp>(loc, func, new_operands); |
| builder.create<YieldOp>(loc, call.getResults()); |
| // Mark old function as private so that it can be DCE'd if not called. |
| func.setPrivate(); |
| } |
| |
| void RunOnWhile(TF::WhileOp while_op) { |
| Operation* op = while_op.getOperation(); |
| // Create new TFL While op that will be used to replace TF While op. |
| auto new_op = OpBuilder(op).create<TFL::WhileOp>( |
| op->getLoc(), op->getResultTypes(), op->getOperands(), |
| while_op.is_stateless()); |
| Location loc = while_op->getLoc(); |
| CreateRegionWithCall(while_op.cond_function(), new_op.cond(), loc); |
| CreateRegionWithCall(while_op.body_function(), new_op.body(), loc); |
| |
| op->replaceAllUsesWith(new_op.getResults()); |
| op->erase(); |
| } |
| |
| void LegalizeWhile::RunOnFunction(func::FuncOp func) { |
| // Convert all TF WhileOps inside the function body to TFL While ops. |
| func.getBody().walk([](TF::WhileOp while_op) { RunOnWhile(while_op); }); |
| } |
| |
| // Creates an instance of the TensorFlow While to TFLite While pass. |
| std::unique_ptr<OperationPass<ModuleOp>> CreateLegalizeTFWhilePass() { |
| return std::make_unique<LegalizeWhile>(); |
| } |
| |
| static PassRegistration<LegalizeWhile> pass; |
| |
| } // namespace TFL |
| } // namespace mlir |