1 // Copyright 2015 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef V8_COMPILER_LIVENESS_ANAYZER_H_
6 #define V8_COMPILER_LIVENESS_ANAYZER_H_
8 #include "src/bit-vector.h"
9 #include "src/compiler/node.h"
10 #include "src/zone-containers.h"
16 class LivenessAnalyzerBlock;
18 class StateValuesCache;
21 class NonLiveFrameStateSlotReplacer {
23 void ClearNonLiveFrameStateSlots(Node* frame_state, BitVector* liveness);
24 NonLiveFrameStateSlotReplacer(StateValuesCache* state_values_cache,
25 Node* replacement, size_t local_count,
27 : replacement_node_(replacement),
28 state_values_cache_(state_values_cache),
29 local_zone_(local_zone),
30 permanently_live_(local_count == 0 ? 1 : static_cast<int>(local_count),
32 inputs_buffer_(local_zone) {}
34 void MarkPermanentlyLive(int var) { permanently_live_.Add(var); }
37 Node* ClearNonLiveStateValues(Node* frame_state, BitVector* liveness);
39 StateValuesCache* state_values_cache() { return state_values_cache_; }
40 Zone* local_zone() { return local_zone_; }
42 // Node that replaces dead values.
43 Node* replacement_node_;
44 // Reference to state values cache so that we can create state values
46 StateValuesCache* state_values_cache_;
49 BitVector permanently_live_;
50 NodeVector inputs_buffer_;
54 class LivenessAnalyzer {
56 LivenessAnalyzer(size_t local_count, Zone* zone);
58 LivenessAnalyzerBlock* NewBlock();
59 LivenessAnalyzerBlock* NewBlock(LivenessAnalyzerBlock* predecessor);
61 void Run(NonLiveFrameStateSlotReplacer* relaxer);
63 Zone* zone() { return zone_; }
65 void Print(std::ostream& os);
67 size_t local_count() { return local_count_; }
70 void Queue(LivenessAnalyzerBlock* block);
73 ZoneDeque<LivenessAnalyzerBlock*> blocks_;
76 ZoneQueue<LivenessAnalyzerBlock*> queue_;
80 class LivenessAnalyzerBlock {
82 friend class LivenessAnalyzer;
84 void Lookup(int var) { entries_.push_back(Entry(Entry::kLookup, var)); }
85 void Bind(int var) { entries_.push_back(Entry(Entry::kBind, var)); }
86 void Checkpoint(Node* node) { entries_.push_back(Entry(node)); }
87 void AddPredecessor(LivenessAnalyzerBlock* b) { predecessors_.push_back(b); }
92 enum Kind { kBind, kLookup, kCheckpoint };
94 Kind kind() const { return kind_; }
96 DCHECK(kind() == kCheckpoint);
100 DCHECK(kind() != kCheckpoint);
104 explicit Entry(Node* node) : kind_(kCheckpoint), var_(-1), node_(node) {}
105 Entry(Kind kind, int var) : kind_(kind), var_(var), node_(nullptr) {
106 DCHECK(kind != kCheckpoint);
115 LivenessAnalyzerBlock(size_t id, size_t local_count, Zone* zone);
116 void Process(BitVector* result, NonLiveFrameStateSlotReplacer* relaxer);
117 bool UpdateLive(BitVector* working_area);
119 void SetQueued() { queued_ = true; }
120 bool IsQueued() { return queued_; }
122 ZoneDeque<LivenessAnalyzerBlock*>::const_iterator pred_begin() {
123 return predecessors_.begin();
125 ZoneDeque<LivenessAnalyzerBlock*>::const_iterator pred_end() {
126 return predecessors_.end();
129 size_t id() { return id_; }
130 void Print(std::ostream& os);
132 ZoneDeque<Entry> entries_;
133 ZoneDeque<LivenessAnalyzerBlock*> predecessors_;
142 } // namespace compiler
143 } // namespace internal
146 #endif // V8_COMPILER_AST_GRAPH_BUILDER_H_