| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_COMPILER_NODE_MARKER_H_ |
| #define V8_COMPILER_NODE_MARKER_H_ |
| |
| #include "src/compiler/node.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| // Forward declarations. |
| class Graph; |
| |
| |
| // Base class for templatized NodeMarkers. |
| class NodeMarkerBase { |
| public: |
| NodeMarkerBase(Graph* graph, uint32_t num_states); |
| |
| V8_INLINE Mark Get(const Node* node) { |
| Mark mark = node->mark(); |
| if (mark < mark_min_) { |
| return 0; |
| } |
| DCHECK_LT(mark, mark_max_); |
| return mark - mark_min_; |
| } |
| V8_INLINE void Set(Node* node, Mark mark) { |
| DCHECK_LT(mark, mark_max_ - mark_min_); |
| DCHECK_LT(node->mark(), mark_max_); |
| node->set_mark(mark + mark_min_); |
| } |
| |
| private: |
| Mark const mark_min_; |
| Mark const mark_max_; |
| |
| DISALLOW_COPY_AND_ASSIGN(NodeMarkerBase); |
| }; |
| |
| // A NodeMarker assigns a local "state" to every node of a graph in constant |
| // memory. Only one NodeMarker per graph is valid at a given time, that is, |
| // after you create a NodeMarker you should no longer use NodeMarkers that |
| // were created earlier. Internally, the local state is stored in the Node |
| // structure. |
| // |
| // When you initialize a NodeMarker, all the local states are conceptually |
| // set to State(0) in constant time. |
| // |
| // In its current implementation, in debug mode NodeMarker will try to |
| // (efficiently) detect invalid use of an older NodeMarker. Namely, if you set a |
| // node with a NodeMarker, and then get or set that node with an older |
| // NodeMarker you will get a crash. |
| // |
| // GraphReducer uses a NodeMarker, so individual Reducers cannot use a |
| // NodeMarker. |
| template <typename State> |
| class NodeMarker : public NodeMarkerBase { |
| public: |
| V8_INLINE NodeMarker(Graph* graph, uint32_t num_states) |
| : NodeMarkerBase(graph, num_states) {} |
| |
| V8_INLINE State Get(const Node* node) { |
| return static_cast<State>(NodeMarkerBase::Get(node)); |
| } |
| |
| V8_INLINE void Set(Node* node, State state) { |
| NodeMarkerBase::Set(node, static_cast<Mark>(state)); |
| } |
| }; |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_COMPILER_NODE_MARKER_H_ |