| /* |
| * 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 to_gnf.cc |
| * |
| * \brief Turn A normal form into graph normal form. |
| */ |
| #include <tvm/relay/analysis.h> |
| #include <tvm/relay/expr_functor.h> |
| #include <tvm/relay/transform.h> |
| |
| #include "let_list.h" |
| |
| namespace tvm { |
| namespace relay { |
| |
| class UseVarVisitor : public ExprVisitor { |
| public: |
| explicit UseVarVisitor(const Var& v) : v(v) {} |
| |
| static bool UseVar(const Var& v, const Expr& e) { |
| UseVarVisitor uv(v); |
| uv(e); |
| return uv.use_var; |
| } |
| |
| private: |
| bool use_var = false; |
| Var v; |
| |
| void VisitExpr_(const VarNode* vn) override { use_var = use_var || (v == GetRef<Var>(vn)); } |
| }; |
| |
| class GNF : public ExprMutator { |
| private: |
| std::unordered_map<Var, Expr, ObjectPtrHash, ObjectPtrEqual> var_map_; |
| Expr VisitExpr_(const VarNode* vn) override { |
| Var v = GetRef<Var>(vn); |
| return var_map_.count(v) == 0 ? v : var_map_.at(v); |
| } |
| |
| static bool UseVar(const Var& v, const Expr& e) { return UseVarVisitor::UseVar(v, e); } |
| |
| static Expr WrapRec(const Var& var, const Expr& val) { |
| return UseVar(var, val) ? Let(var, val, var) : val; |
| } |
| |
| Expr VisitExpr_(const LetNode* ln) override { |
| var_map_.insert(std::pair<Var, Expr>(ln->var, WrapRec(ln->var, VisitExpr(ln->value)))); |
| return VisitExpr(ln->body); |
| } |
| }; |
| |
| Expr ToGraphNormalForm(const Expr& e) { return GNF()(e); } |
| |
| namespace transform { |
| |
| Pass ToGraphNormalForm() { |
| runtime::TypedPackedFunc<Function(Function, IRModule, PassContext)> pass_func = |
| [=](Function f, IRModule m, PassContext pc) { |
| return Downcast<Function>(ToGraphNormalForm(f)); |
| }; |
| return CreateFunctionPass(pass_func, 1, "ToGraphNormalForm", {}); |
| } |
| |
| TVM_REGISTER_GLOBAL("relay._transform.ToGraphNormalForm").set_body_typed(ToGraphNormalForm); |
| |
| } // namespace transform |
| |
| } // namespace relay |
| } // namespace tvm |