| /** |
| * 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. |
| */ |
| #pragma once |
| |
| #if ENABLE(DFG_JIT) |
| |
| #include "DFGCommon.h" |
| |
| namespace JSC { namespace DFG { |
| |
| class Graph; |
| |
| // Block-local common subexpression elimination. It uses clobberize() for heap |
| // modeling, which is quite precise. This phase is known to produce big wins on |
| // a few benchmarks, and is relatively cheap to run. |
| // |
| // Note that this phase also gets rid of Identity nodes, which means that it's |
| // currently not an optional phase. Basically, DFG IR doesn't have use-lists, |
| // so there is no instantaneous replaceAllUsesWith operation. Instead, you turn |
| // a node into an Identity and wait for CSE to clean it up. |
| bool performLocalCSE(Graph&); |
| |
| // Same, but global. Only works for SSA. This will find common subexpressions |
| // both in the same block and in any block that dominates the current block. It |
| // has no limits on how far it will look for load-elimination opportunities. |
| bool performGlobalCSE(Graph&); |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |
