1/*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19
20/*!
21 * \file expr_subst.h
22 * \brief Utility functions for substituting expressions.
23 */
24
25#include "./expr_subst.h"
26
27#include <tvm/relay/expr_functor.h>
28
29namespace tvm {
30namespace relay {
31
32class ExprSubstituter : public ExprMutator {
33 public:
34 explicit ExprSubstituter(std::unordered_map<Expr, Expr, ObjectPtrHash, ObjectPtrEqual> subst_map)
35 : subst_map_(subst_map) {}
36
37 Expr VisitExpr(const Expr& expr) final {
38 auto it = subst_map_.find(expr);
39 if (it != subst_map_.end()) {
40 return ExprMutator::VisitExpr((*it).second);
41 }
42 return ExprMutator::VisitExpr(expr);
43 }
44
45 private:
46 tvm::Map<Expr, Expr> subst_map_;
47};
48
49Expr ExprSubst(const Expr& expr,
50 std::unordered_map<Expr, Expr, ObjectPtrHash, ObjectPtrEqual> subst_map) {
51 return ExprSubstituter(std::move(subst_map)).Mutate(expr);
52}
53
54} // namespace relay
55} // namespace tvm
56