| /* |
| * 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 fast_math.cc |
| * \brief Replaces non linear activation functions with their fast but approximate counterparts. |
| */ |
| #include <tvm/relay/analysis.h> |
| #include <tvm/relay/attrs/nn.h> |
| #include <tvm/relay/expr_functor.h> |
| #include <tvm/relay/op.h> |
| #include <tvm/relay/transform.h> |
| |
| #include "pattern_util.h" |
| |
| namespace tvm { |
| namespace relay { |
| |
| class FastMathMutator : public ExprRewriter { |
| public: |
| FastMathMutator() : exp_op_(Op::Get("exp")), erf_op_(Op::Get("erf")), tanh_op_(Op::Get("tanh")) {} |
| |
| Expr Rewrite_(const CallNode* pre, const Expr& post) override { |
| if (pre->op == exp_op_) { |
| return FastExp(post.as<CallNode>()->args[0]); |
| } else if (pre->op == erf_op_) { |
| return FastErf(post.as<CallNode>()->args[0]); |
| } else if (pre->op == tanh_op_) { |
| return FastTanh(post.as<CallNode>()->args[0]); |
| } |
| return post; |
| } |
| |
| private: |
| // Cache the following ops. They will be used in the passes repeatedly for |
| // operator equivalence checking so that the registry lookup overhead can be |
| // reduced. |
| const Op& exp_op_; |
| const Op& erf_op_; |
| const Op& tanh_op_; |
| }; |
| |
| Expr FastMath(const Expr& e) { |
| auto rewriter = FastMathMutator(); |
| return PostOrderRewrite(e, &rewriter); |
| } |
| |
| namespace transform { |
| |
| Pass FastMath() { |
| runtime::TypedPackedFunc<Function(Function, IRModule, PassContext)> pass_func = |
| [=](Function f, IRModule m, PassContext pc) { return Downcast<Function>(FastMath(f)); }; |
| return CreateFunctionPass(pass_func, 4, "FastMath", {"InferType"}); |
| } |
| |
| TVM_REGISTER_GLOBAL("relay._transform.FastMath").set_body_typed(FastMath); |
| |
| } // namespace transform |
| |
| } // namespace relay |
| } // namespace tvm |