| /** |
| * 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 "DFGBlockMap.h" |
| #include "DFGGraph.h" |
| |
| namespace JSC { namespace DFG { |
| |
| // Returns the set of nodes live at tail, both due to due DFG and due to bytecode (i.e. OSR exit). |
| NodeSet liveNodesAtHead(Graph&, BasicBlock*); |
| |
| // WARNING: This currently does not reason about the liveness of shadow values. The execution |
| // semantics of DFG SSA are that an Upsilon stores to the shadow value of a Phi, and the Phi loads |
| // from that shadow value. Hence, the shadow values are like variables, and have liveness. The normal |
| // liveness analysis will tell you about the liveness of shadow values. It's OK to ignore shadow |
| // values if you treat Upsilon as an opaque escape, and all of the clients of CombinedLiveness do so. |
| struct CombinedLiveness { |
| CombinedLiveness() { } |
| |
| CombinedLiveness(Graph&); |
| |
| BlockMap<NodeSet> liveAtHead; |
| BlockMap<NodeSet> liveAtTail; |
| }; |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |
