Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 1 | // Copyright 2013 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. |
| 4 | |
| 5 | #ifndef V8_COMPILER_SCHEDULER_H_ |
| 6 | #define V8_COMPILER_SCHEDULER_H_ |
| 7 | |
| 8 | #include "src/v8.h" |
| 9 | |
| 10 | #include "src/compiler/opcodes.h" |
| 11 | #include "src/compiler/schedule.h" |
| 12 | #include "src/zone-containers.h" |
| 13 | |
| 14 | namespace v8 { |
| 15 | namespace internal { |
| 16 | namespace compiler { |
| 17 | |
| 18 | // Computes a schedule from a graph, placing nodes into basic blocks and |
| 19 | // ordering the basic blocks in the special RPO order. |
| 20 | class Scheduler { |
| 21 | public: |
| 22 | // The complete scheduling algorithm. |
| 23 | // Create a new schedule and place all nodes from the graph into it. |
| 24 | static Schedule* ComputeSchedule(Graph* graph); |
| 25 | |
| 26 | // Compute the RPO of blocks in an existing schedule. |
| 27 | static BasicBlockVector* ComputeSpecialRPO(Schedule* schedule); |
| 28 | |
| 29 | // (Exposed for testing only) |
| 30 | // Build and connect the CFG for a node graph, but don't schedule nodes. |
| 31 | static void ComputeCFG(Graph* graph, Schedule* schedule); |
| 32 | |
| 33 | private: |
| 34 | enum Placement { kUnknown, kSchedulable, kFixed }; |
| 35 | |
| 36 | // Per-node data tracked during scheduling. |
| 37 | struct SchedulerData { |
| 38 | int unscheduled_count_; // Number of unscheduled uses of this node. |
| 39 | int minimum_rpo_; // Minimum legal RPO placement. |
| 40 | bool is_connected_control_; // {true} if control-connected to the end node. |
| 41 | bool is_floating_control_; // {true} if control, but not control-connected |
| 42 | // to the end node. |
| 43 | Placement placement_ : 3; // Whether the node is fixed, schedulable, |
| 44 | // or not yet known. |
| 45 | }; |
| 46 | |
| 47 | Zone* zone_; |
| 48 | Graph* graph_; |
| 49 | Schedule* schedule_; |
| 50 | NodeVectorVector scheduled_nodes_; |
| 51 | NodeVector schedule_root_nodes_; |
| 52 | ZoneVector<SchedulerData> node_data_; |
| 53 | bool has_floating_control_; |
| 54 | |
| 55 | Scheduler(Zone* zone, Graph* graph, Schedule* schedule); |
| 56 | |
| 57 | SchedulerData DefaultSchedulerData(); |
| 58 | |
| 59 | SchedulerData* GetData(Node* node) { |
| 60 | DCHECK(node->id() < static_cast<int>(node_data_.size())); |
| 61 | return &node_data_[node->id()]; |
| 62 | } |
| 63 | |
| 64 | void BuildCFG(); |
| 65 | |
| 66 | Placement GetPlacement(Node* node); |
| 67 | |
| 68 | int GetRPONumber(BasicBlock* block) { |
| 69 | DCHECK(block->rpo_number_ >= 0 && |
| 70 | block->rpo_number_ < static_cast<int>(schedule_->rpo_order_.size())); |
| 71 | DCHECK(schedule_->rpo_order_[block->rpo_number_] == block); |
| 72 | return block->rpo_number_; |
| 73 | } |
| 74 | |
| 75 | void GenerateImmediateDominatorTree(); |
| 76 | BasicBlock* GetCommonDominator(BasicBlock* b1, BasicBlock* b2); |
| 77 | |
| 78 | friend class CFGBuilder; |
| 79 | |
| 80 | friend class ScheduleEarlyNodeVisitor; |
| 81 | void ScheduleEarly(); |
| 82 | |
| 83 | friend class PrepareUsesVisitor; |
| 84 | void PrepareUses(); |
| 85 | |
| 86 | friend class ScheduleLateNodeVisitor; |
| 87 | void ScheduleLate(); |
| 88 | |
| 89 | bool ConnectFloatingControl(); |
| 90 | |
| 91 | void ConnectFloatingControlSubgraph(BasicBlock* block, Node* node); |
| 92 | }; |
| 93 | } |
| 94 | } |
| 95 | } // namespace v8::internal::compiler |
| 96 | |
| 97 | #endif // V8_COMPILER_SCHEDULER_H_ |