1 /* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #include <vector>
17 
18 #include "llvm/ADT/DenseMap.h"
19 #include "mlir/Dialect/Func/IR/FuncOps.h"  // from @llvm-project
20 #include "mlir/IR/BuiltinOps.h"  // from @llvm-project
21 #include "mlir/Pass/Pass.h"  // from @llvm-project
22 #include "mlir/Support/LLVM.h"  // from @llvm-project
23 #include "tensorflow/compiler/mlir/tensorflow/ir/tf_ops.h"
24 #include "tensorflow/compiler/mlir/tensorflow/ir/tf_saved_model.h"
25 #include "tensorflow/compiler/mlir/tensorflow/transforms/savedmodel_passes_detail.h"
26 
27 namespace mlir {
28 namespace tf_saved_model {
29 namespace {
30 
31 class DedupBoundInputBindingPass
32     : public DedupBoundInputBindingPassBase<DedupBoundInputBindingPass> {
33   void runOnOperation() final;
34 };
35 
runOnOperation()36 void DedupBoundInputBindingPass::runOnOperation() {
37   func::FuncOp func = getOperation();
38   if (!mlir::tf_saved_model::IsExported(func)) return;
39   llvm::SmallDenseMap<Attribute, unsigned, 8> unique_bound_inputs;
40   llvm::BitVector arg_indices_to_erase(func.getNumArguments());
41   for (unsigned i = 0, e = func.getNumArguments(); i < e; i++) {
42     auto attr = func.getArgAttrOfType<FlatSymbolRefAttr>(
43         i, "tf_saved_model.bound_input");
44     if (!attr) continue;
45     auto inserted = unique_bound_inputs.insert(std::make_pair(attr, i));
46     if (inserted.second) continue;
47     auto duplicate_arg = func.getArgument(i);
48     auto original_arg = func.getArgument(unique_bound_inputs[attr]);
49     duplicate_arg.replaceAllUsesWith(original_arg);
50     arg_indices_to_erase.set(i);
51   }
52   func.eraseArguments(arg_indices_to_erase);
53 }
54 
55 }  // namespace
56 
57 std::unique_ptr<OperationPass<func::FuncOp>>
CreateDedupBoundInputBindingPass()58 CreateDedupBoundInputBindingPass() {
59   return std::make_unique<DedupBoundInputBindingPass>();
60 }
61 
62 }  // namespace tf_saved_model
63 }  // namespace mlir
64