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 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 5 | #include "src/compiler/scheduler.h" |
| 6 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 7 | #include <iomanip> |
| 8 | |
| 9 | #include "src/base/adapters.h" |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 10 | #include "src/bit-vector.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 11 | #include "src/compiler/common-operator.h" |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 12 | #include "src/compiler/control-equivalence.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 13 | #include "src/compiler/graph.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 14 | #include "src/compiler/node.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 15 | #include "src/compiler/node-marker.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 16 | #include "src/compiler/node-properties.h" |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 17 | #include "src/zone-containers.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 18 | |
| 19 | namespace v8 { |
| 20 | namespace internal { |
| 21 | namespace compiler { |
| 22 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 23 | #define TRACE(...) \ |
| 24 | do { \ |
| 25 | if (FLAG_trace_turbo_scheduler) PrintF(__VA_ARGS__); \ |
| 26 | } while (false) |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 27 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 28 | Scheduler::Scheduler(Zone* zone, Graph* graph, Schedule* schedule, Flags flags) |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 29 | : zone_(zone), |
| 30 | graph_(graph), |
| 31 | schedule_(schedule), |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 32 | flags_(flags), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 33 | scheduled_nodes_(zone), |
| 34 | schedule_root_nodes_(zone), |
| 35 | schedule_queue_(zone), |
| 36 | node_data_(graph_->NodeCount(), DefaultSchedulerData(), zone) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 37 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 38 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 39 | Schedule* Scheduler::ComputeSchedule(Zone* zone, Graph* graph, Flags flags) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 40 | Schedule* schedule = new (graph->zone()) |
| 41 | Schedule(graph->zone(), static_cast<size_t>(graph->NodeCount())); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 42 | Scheduler scheduler(zone, graph, schedule, flags); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 43 | |
| 44 | scheduler.BuildCFG(); |
| 45 | scheduler.ComputeSpecialRPONumbering(); |
| 46 | scheduler.GenerateImmediateDominatorTree(); |
| 47 | |
| 48 | scheduler.PrepareUses(); |
| 49 | scheduler.ScheduleEarly(); |
| 50 | scheduler.ScheduleLate(); |
| 51 | |
| 52 | scheduler.SealFinalSchedule(); |
| 53 | |
| 54 | return schedule; |
| 55 | } |
| 56 | |
| 57 | |
| 58 | Scheduler::SchedulerData Scheduler::DefaultSchedulerData() { |
| 59 | SchedulerData def = {schedule_->start(), 0, kUnknown}; |
| 60 | return def; |
| 61 | } |
| 62 | |
| 63 | |
| 64 | Scheduler::SchedulerData* Scheduler::GetData(Node* node) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 65 | return &node_data_[node->id()]; |
| 66 | } |
| 67 | |
| 68 | |
| 69 | Scheduler::Placement Scheduler::GetPlacement(Node* node) { |
| 70 | SchedulerData* data = GetData(node); |
| 71 | if (data->placement_ == kUnknown) { // Compute placement, once, on demand. |
| 72 | switch (node->opcode()) { |
| 73 | case IrOpcode::kParameter: |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 74 | case IrOpcode::kOsrValue: |
| 75 | // Parameters and OSR values are always fixed to the start block. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 76 | data->placement_ = kFixed; |
| 77 | break; |
| 78 | case IrOpcode::kPhi: |
| 79 | case IrOpcode::kEffectPhi: { |
| 80 | // Phis and effect phis are fixed if their control inputs are, whereas |
| 81 | // otherwise they are coupled to a floating control node. |
| 82 | Placement p = GetPlacement(NodeProperties::GetControlInput(node)); |
| 83 | data->placement_ = (p == kFixed ? kFixed : kCoupled); |
| 84 | break; |
| 85 | } |
| 86 | #define DEFINE_CONTROL_CASE(V) case IrOpcode::k##V: |
| 87 | CONTROL_OP_LIST(DEFINE_CONTROL_CASE) |
| 88 | #undef DEFINE_CONTROL_CASE |
| 89 | { |
| 90 | // Control nodes that were not control-reachable from end may float. |
| 91 | data->placement_ = kSchedulable; |
| 92 | break; |
| 93 | } |
| 94 | default: |
| 95 | data->placement_ = kSchedulable; |
| 96 | break; |
| 97 | } |
| 98 | } |
| 99 | return data->placement_; |
| 100 | } |
| 101 | |
| 102 | |
| 103 | void Scheduler::UpdatePlacement(Node* node, Placement placement) { |
| 104 | SchedulerData* data = GetData(node); |
| 105 | if (data->placement_ != kUnknown) { // Trap on mutation, not initialization. |
| 106 | switch (node->opcode()) { |
| 107 | case IrOpcode::kParameter: |
| 108 | // Parameters are fixed once and for all. |
| 109 | UNREACHABLE(); |
| 110 | break; |
| 111 | case IrOpcode::kPhi: |
| 112 | case IrOpcode::kEffectPhi: { |
| 113 | // Phis and effect phis are coupled to their respective blocks. |
| 114 | DCHECK_EQ(Scheduler::kCoupled, data->placement_); |
| 115 | DCHECK_EQ(Scheduler::kFixed, placement); |
| 116 | Node* control = NodeProperties::GetControlInput(node); |
| 117 | BasicBlock* block = schedule_->block(control); |
| 118 | schedule_->AddNode(block, node); |
| 119 | break; |
| 120 | } |
| 121 | #define DEFINE_CONTROL_CASE(V) case IrOpcode::k##V: |
| 122 | CONTROL_OP_LIST(DEFINE_CONTROL_CASE) |
| 123 | #undef DEFINE_CONTROL_CASE |
| 124 | { |
| 125 | // Control nodes force coupled uses to be placed. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 126 | for (auto use : node->uses()) { |
| 127 | if (GetPlacement(use) == Scheduler::kCoupled) { |
| 128 | DCHECK_EQ(node, NodeProperties::GetControlInput(use)); |
| 129 | UpdatePlacement(use, placement); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 130 | } |
| 131 | } |
| 132 | break; |
| 133 | } |
| 134 | default: |
| 135 | DCHECK_EQ(Scheduler::kSchedulable, data->placement_); |
| 136 | DCHECK_EQ(Scheduler::kScheduled, placement); |
| 137 | break; |
| 138 | } |
| 139 | // Reduce the use count of the node's inputs to potentially make them |
| 140 | // schedulable. If all the uses of a node have been scheduled, then the node |
| 141 | // itself can be scheduled. |
| 142 | for (Edge const edge : node->input_edges()) { |
| 143 | DecrementUnscheduledUseCount(edge.to(), edge.index(), edge.from()); |
| 144 | } |
| 145 | } |
| 146 | data->placement_ = placement; |
| 147 | } |
| 148 | |
| 149 | |
| 150 | bool Scheduler::IsCoupledControlEdge(Node* node, int index) { |
| 151 | return GetPlacement(node) == kCoupled && |
| 152 | NodeProperties::FirstControlIndex(node) == index; |
| 153 | } |
| 154 | |
| 155 | |
| 156 | void Scheduler::IncrementUnscheduledUseCount(Node* node, int index, |
| 157 | Node* from) { |
| 158 | // Make sure that control edges from coupled nodes are not counted. |
| 159 | if (IsCoupledControlEdge(from, index)) return; |
| 160 | |
| 161 | // Tracking use counts for fixed nodes is useless. |
| 162 | if (GetPlacement(node) == kFixed) return; |
| 163 | |
| 164 | // Use count for coupled nodes is summed up on their control. |
| 165 | if (GetPlacement(node) == kCoupled) { |
| 166 | Node* control = NodeProperties::GetControlInput(node); |
| 167 | return IncrementUnscheduledUseCount(control, index, from); |
| 168 | } |
| 169 | |
| 170 | ++(GetData(node)->unscheduled_count_); |
| 171 | if (FLAG_trace_turbo_scheduler) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 172 | TRACE(" Use count of #%d:%s (used by #%d:%s)++ = %d\n", node->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 173 | node->op()->mnemonic(), from->id(), from->op()->mnemonic(), |
| 174 | GetData(node)->unscheduled_count_); |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | |
| 179 | void Scheduler::DecrementUnscheduledUseCount(Node* node, int index, |
| 180 | Node* from) { |
| 181 | // Make sure that control edges from coupled nodes are not counted. |
| 182 | if (IsCoupledControlEdge(from, index)) return; |
| 183 | |
| 184 | // Tracking use counts for fixed nodes is useless. |
| 185 | if (GetPlacement(node) == kFixed) return; |
| 186 | |
| 187 | // Use count for coupled nodes is summed up on their control. |
| 188 | if (GetPlacement(node) == kCoupled) { |
| 189 | Node* control = NodeProperties::GetControlInput(node); |
| 190 | return DecrementUnscheduledUseCount(control, index, from); |
| 191 | } |
| 192 | |
| 193 | DCHECK(GetData(node)->unscheduled_count_ > 0); |
| 194 | --(GetData(node)->unscheduled_count_); |
| 195 | if (FLAG_trace_turbo_scheduler) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 196 | TRACE(" Use count of #%d:%s (used by #%d:%s)-- = %d\n", node->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 197 | node->op()->mnemonic(), from->id(), from->op()->mnemonic(), |
| 198 | GetData(node)->unscheduled_count_); |
| 199 | } |
| 200 | if (GetData(node)->unscheduled_count_ == 0) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 201 | TRACE(" newly eligible #%d:%s\n", node->id(), node->op()->mnemonic()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 202 | schedule_queue_.push(node); |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 207 | // ----------------------------------------------------------------------------- |
| 208 | // Phase 1: Build control-flow graph. |
| 209 | |
| 210 | |
| 211 | // Internal class to build a control flow graph (i.e the basic blocks and edges |
| 212 | // between them within a Schedule) from the node graph. Visits control edges of |
| 213 | // the graph backwards from an end node in order to find the connected control |
| 214 | // subgraph, needed for scheduling. |
| 215 | class CFGBuilder : public ZoneObject { |
| 216 | public: |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 217 | CFGBuilder(Zone* zone, Scheduler* scheduler) |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 218 | : zone_(zone), |
| 219 | scheduler_(scheduler), |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 220 | schedule_(scheduler->schedule_), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 221 | queued_(scheduler->graph_, 2), |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 222 | queue_(zone), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 223 | control_(zone), |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 224 | component_entry_(nullptr), |
| 225 | component_start_(nullptr), |
| 226 | component_end_(nullptr) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 227 | |
| 228 | // Run the control flow graph construction algorithm by walking the graph |
| 229 | // backwards from end through control edges, building and connecting the |
| 230 | // basic blocks for control nodes. |
| 231 | void Run() { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 232 | ResetDataStructures(); |
| 233 | Queue(scheduler_->graph_->end()); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 234 | |
| 235 | while (!queue_.empty()) { // Breadth-first backwards traversal. |
| 236 | Node* node = queue_.front(); |
| 237 | queue_.pop(); |
| 238 | int max = NodeProperties::PastControlIndex(node); |
| 239 | for (int i = NodeProperties::FirstControlIndex(node); i < max; i++) { |
| 240 | Queue(node->InputAt(i)); |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | for (NodeVector::iterator i = control_.begin(); i != control_.end(); ++i) { |
| 245 | ConnectBlocks(*i); // Connect block to its predecessor/successors. |
| 246 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 247 | } |
| 248 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 249 | // Run the control flow graph construction for a minimal control-connected |
| 250 | // component ending in {exit} and merge that component into an existing |
| 251 | // control flow graph at the bottom of {block}. |
| 252 | void Run(BasicBlock* block, Node* exit) { |
| 253 | ResetDataStructures(); |
| 254 | Queue(exit); |
| 255 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 256 | component_entry_ = nullptr; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 257 | component_start_ = block; |
| 258 | component_end_ = schedule_->block(exit); |
| 259 | scheduler_->equivalence_->Run(exit); |
| 260 | while (!queue_.empty()) { // Breadth-first backwards traversal. |
| 261 | Node* node = queue_.front(); |
| 262 | queue_.pop(); |
| 263 | |
| 264 | // Use control dependence equivalence to find a canonical single-entry |
| 265 | // single-exit region that makes up a minimal component to be scheduled. |
| 266 | if (IsSingleEntrySingleExitRegion(node, exit)) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 267 | TRACE("Found SESE at #%d:%s\n", node->id(), node->op()->mnemonic()); |
| 268 | DCHECK(!component_entry_); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 269 | component_entry_ = node; |
| 270 | continue; |
| 271 | } |
| 272 | |
| 273 | int max = NodeProperties::PastControlIndex(node); |
| 274 | for (int i = NodeProperties::FirstControlIndex(node); i < max; i++) { |
| 275 | Queue(node->InputAt(i)); |
| 276 | } |
| 277 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 278 | DCHECK(component_entry_); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 279 | |
| 280 | for (NodeVector::iterator i = control_.begin(); i != control_.end(); ++i) { |
| 281 | ConnectBlocks(*i); // Connect block to its predecessor/successors. |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | private: |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 286 | friend class ScheduleLateNodeVisitor; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 287 | friend class Scheduler; |
| 288 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 289 | void FixNode(BasicBlock* block, Node* node) { |
| 290 | schedule_->AddNode(block, node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 291 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | void Queue(Node* node) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 295 | // Mark the connected control nodes as they are queued. |
| 296 | if (!queued_.Get(node)) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 297 | BuildBlocks(node); |
| 298 | queue_.push(node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 299 | queued_.Set(node, true); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 300 | control_.push_back(node); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 301 | } |
| 302 | } |
| 303 | |
| 304 | void BuildBlocks(Node* node) { |
| 305 | switch (node->opcode()) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 306 | case IrOpcode::kEnd: |
| 307 | FixNode(schedule_->end(), node); |
| 308 | break; |
| 309 | case IrOpcode::kStart: |
| 310 | FixNode(schedule_->start(), node); |
| 311 | break; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 312 | case IrOpcode::kLoop: |
| 313 | case IrOpcode::kMerge: |
| 314 | BuildBlockForNode(node); |
| 315 | break; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 316 | case IrOpcode::kTerminate: { |
| 317 | // Put Terminate in the loop to which it refers. |
| 318 | Node* loop = NodeProperties::GetControlInput(node); |
| 319 | BasicBlock* block = BuildBlockForNode(loop); |
| 320 | FixNode(block, node); |
| 321 | break; |
| 322 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 323 | case IrOpcode::kBranch: |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 324 | case IrOpcode::kSwitch: |
| 325 | BuildBlocksForSuccessors(node); |
| 326 | break; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 327 | #define BUILD_BLOCK_JS_CASE(Name) case IrOpcode::k##Name: |
| 328 | JS_OP_LIST(BUILD_BLOCK_JS_CASE) |
| 329 | // JS opcodes are just like calls => fall through. |
| 330 | #undef BUILD_BLOCK_JS_CASE |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 331 | case IrOpcode::kCall: |
| 332 | if (NodeProperties::IsExceptionalCall(node)) { |
| 333 | BuildBlocksForSuccessors(node); |
| 334 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 335 | break; |
| 336 | default: |
| 337 | break; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | void ConnectBlocks(Node* node) { |
| 342 | switch (node->opcode()) { |
| 343 | case IrOpcode::kLoop: |
| 344 | case IrOpcode::kMerge: |
| 345 | ConnectMerge(node); |
| 346 | break; |
| 347 | case IrOpcode::kBranch: |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 348 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 349 | ConnectBranch(node); |
| 350 | break; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 351 | case IrOpcode::kSwitch: |
| 352 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
| 353 | ConnectSwitch(node); |
| 354 | break; |
| 355 | case IrOpcode::kDeoptimize: |
| 356 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
| 357 | ConnectDeoptimize(node); |
| 358 | break; |
| 359 | case IrOpcode::kTailCall: |
| 360 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
| 361 | ConnectTailCall(node); |
| 362 | break; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 363 | case IrOpcode::kReturn: |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 364 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 365 | ConnectReturn(node); |
| 366 | break; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 367 | case IrOpcode::kThrow: |
| 368 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
| 369 | ConnectThrow(node); |
| 370 | break; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame] | 371 | #define CONNECT_BLOCK_JS_CASE(Name) case IrOpcode::k##Name: |
| 372 | JS_OP_LIST(CONNECT_BLOCK_JS_CASE) |
| 373 | // JS opcodes are just like calls => fall through. |
| 374 | #undef CONNECT_BLOCK_JS_CASE |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 375 | case IrOpcode::kCall: |
| 376 | if (NodeProperties::IsExceptionalCall(node)) { |
| 377 | scheduler_->UpdatePlacement(node, Scheduler::kFixed); |
| 378 | ConnectCall(node); |
| 379 | } |
| 380 | break; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 381 | default: |
| 382 | break; |
| 383 | } |
| 384 | } |
| 385 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 386 | BasicBlock* BuildBlockForNode(Node* node) { |
| 387 | BasicBlock* block = schedule_->block(node); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 388 | if (block == nullptr) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 389 | block = schedule_->NewBasicBlock(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 390 | TRACE("Create block id:%d for #%d:%s\n", block->id().ToInt(), node->id(), |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 391 | node->op()->mnemonic()); |
| 392 | FixNode(block, node); |
| 393 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 394 | return block; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 395 | } |
| 396 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 397 | void BuildBlocksForSuccessors(Node* node) { |
| 398 | size_t const successor_cnt = node->op()->ControlOutputCount(); |
| 399 | Node** successors = zone_->NewArray<Node*>(successor_cnt); |
| 400 | NodeProperties::CollectControlProjections(node, successors, successor_cnt); |
| 401 | for (size_t index = 0; index < successor_cnt; ++index) { |
| 402 | BuildBlockForNode(successors[index]); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 403 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 404 | } |
| 405 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 406 | void CollectSuccessorBlocks(Node* node, BasicBlock** successor_blocks, |
| 407 | size_t successor_cnt) { |
| 408 | Node** successors = reinterpret_cast<Node**>(successor_blocks); |
| 409 | NodeProperties::CollectControlProjections(node, successors, successor_cnt); |
| 410 | for (size_t index = 0; index < successor_cnt; ++index) { |
| 411 | successor_blocks[index] = schedule_->block(successors[index]); |
| 412 | } |
| 413 | } |
| 414 | |
| 415 | BasicBlock* FindPredecessorBlock(Node* node) { |
| 416 | BasicBlock* predecessor_block = nullptr; |
| 417 | while (true) { |
| 418 | predecessor_block = schedule_->block(node); |
| 419 | if (predecessor_block != nullptr) break; |
| 420 | node = NodeProperties::GetControlInput(node); |
| 421 | } |
| 422 | return predecessor_block; |
| 423 | } |
| 424 | |
| 425 | void ConnectCall(Node* call) { |
| 426 | BasicBlock* successor_blocks[2]; |
| 427 | CollectSuccessorBlocks(call, successor_blocks, arraysize(successor_blocks)); |
| 428 | |
| 429 | // Consider the exception continuation to be deferred. |
| 430 | successor_blocks[1]->set_deferred(true); |
| 431 | |
| 432 | Node* call_control = NodeProperties::GetControlInput(call); |
| 433 | BasicBlock* call_block = FindPredecessorBlock(call_control); |
| 434 | TraceConnect(call, call_block, successor_blocks[0]); |
| 435 | TraceConnect(call, call_block, successor_blocks[1]); |
| 436 | schedule_->AddCall(call_block, call, successor_blocks[0], |
| 437 | successor_blocks[1]); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 438 | } |
| 439 | |
| 440 | void ConnectBranch(Node* branch) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 441 | BasicBlock* successor_blocks[2]; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 442 | CollectSuccessorBlocks(branch, successor_blocks, |
| 443 | arraysize(successor_blocks)); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 444 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 445 | // Consider branch hints. |
| 446 | switch (BranchHintOf(branch->op())) { |
| 447 | case BranchHint::kNone: |
| 448 | break; |
| 449 | case BranchHint::kTrue: |
| 450 | successor_blocks[1]->set_deferred(true); |
| 451 | break; |
| 452 | case BranchHint::kFalse: |
| 453 | successor_blocks[0]->set_deferred(true); |
| 454 | break; |
| 455 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 456 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 457 | if (branch == component_entry_) { |
| 458 | TraceConnect(branch, component_start_, successor_blocks[0]); |
| 459 | TraceConnect(branch, component_start_, successor_blocks[1]); |
| 460 | schedule_->InsertBranch(component_start_, component_end_, branch, |
| 461 | successor_blocks[0], successor_blocks[1]); |
| 462 | } else { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 463 | Node* branch_control = NodeProperties::GetControlInput(branch); |
| 464 | BasicBlock* branch_block = FindPredecessorBlock(branch_control); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 465 | TraceConnect(branch, branch_block, successor_blocks[0]); |
| 466 | TraceConnect(branch, branch_block, successor_blocks[1]); |
| 467 | schedule_->AddBranch(branch_block, branch, successor_blocks[0], |
| 468 | successor_blocks[1]); |
| 469 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 470 | } |
| 471 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 472 | void ConnectSwitch(Node* sw) { |
| 473 | size_t const successor_count = sw->op()->ControlOutputCount(); |
| 474 | BasicBlock** successor_blocks = |
| 475 | zone_->NewArray<BasicBlock*>(successor_count); |
| 476 | CollectSuccessorBlocks(sw, successor_blocks, successor_count); |
| 477 | |
| 478 | if (sw == component_entry_) { |
| 479 | for (size_t index = 0; index < successor_count; ++index) { |
| 480 | TraceConnect(sw, component_start_, successor_blocks[index]); |
| 481 | } |
| 482 | schedule_->InsertSwitch(component_start_, component_end_, sw, |
| 483 | successor_blocks, successor_count); |
| 484 | } else { |
| 485 | Node* switch_control = NodeProperties::GetControlInput(sw); |
| 486 | BasicBlock* switch_block = FindPredecessorBlock(switch_control); |
| 487 | for (size_t index = 0; index < successor_count; ++index) { |
| 488 | TraceConnect(sw, switch_block, successor_blocks[index]); |
| 489 | } |
| 490 | schedule_->AddSwitch(switch_block, sw, successor_blocks, successor_count); |
| 491 | } |
| 492 | } |
| 493 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 494 | void ConnectMerge(Node* merge) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 495 | // Don't connect the special merge at the end to its predecessors. |
| 496 | if (IsFinalMerge(merge)) return; |
| 497 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 498 | BasicBlock* block = schedule_->block(merge); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 499 | DCHECK_NOT_NULL(block); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 500 | // For all of the merge's control inputs, add a goto at the end to the |
| 501 | // merge's basic block. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 502 | for (Node* const input : merge->inputs()) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 503 | BasicBlock* predecessor_block = FindPredecessorBlock(input); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 504 | TraceConnect(merge, predecessor_block, block); |
| 505 | schedule_->AddGoto(predecessor_block, block); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 506 | } |
| 507 | } |
| 508 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 509 | void ConnectTailCall(Node* call) { |
| 510 | Node* call_control = NodeProperties::GetControlInput(call); |
| 511 | BasicBlock* call_block = FindPredecessorBlock(call_control); |
| 512 | TraceConnect(call, call_block, nullptr); |
| 513 | schedule_->AddTailCall(call_block, call); |
| 514 | } |
| 515 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 516 | void ConnectReturn(Node* ret) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 517 | Node* return_control = NodeProperties::GetControlInput(ret); |
| 518 | BasicBlock* return_block = FindPredecessorBlock(return_control); |
| 519 | TraceConnect(ret, return_block, nullptr); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 520 | schedule_->AddReturn(return_block, ret); |
| 521 | } |
| 522 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 523 | void ConnectDeoptimize(Node* deopt) { |
| 524 | Node* deoptimize_control = NodeProperties::GetControlInput(deopt); |
| 525 | BasicBlock* deoptimize_block = FindPredecessorBlock(deoptimize_control); |
| 526 | TraceConnect(deopt, deoptimize_block, nullptr); |
| 527 | schedule_->AddDeoptimize(deoptimize_block, deopt); |
| 528 | } |
| 529 | |
| 530 | void ConnectThrow(Node* thr) { |
| 531 | Node* throw_control = NodeProperties::GetControlInput(thr); |
| 532 | BasicBlock* throw_block = FindPredecessorBlock(throw_control); |
| 533 | TraceConnect(thr, throw_block, nullptr); |
| 534 | schedule_->AddThrow(throw_block, thr); |
| 535 | } |
| 536 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 537 | void TraceConnect(Node* node, BasicBlock* block, BasicBlock* succ) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 538 | DCHECK_NOT_NULL(block); |
| 539 | if (succ == nullptr) { |
| 540 | TRACE("Connect #%d:%s, id:%d -> end\n", node->id(), |
| 541 | node->op()->mnemonic(), block->id().ToInt()); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 542 | } else { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 543 | TRACE("Connect #%d:%s, id:%d -> id:%d\n", node->id(), |
| 544 | node->op()->mnemonic(), block->id().ToInt(), succ->id().ToInt()); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 545 | } |
| 546 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 547 | |
| 548 | bool IsFinalMerge(Node* node) { |
| 549 | return (node->opcode() == IrOpcode::kMerge && |
| 550 | node == scheduler_->graph_->end()->InputAt(0)); |
| 551 | } |
| 552 | |
| 553 | bool IsSingleEntrySingleExitRegion(Node* entry, Node* exit) const { |
| 554 | size_t entry_class = scheduler_->equivalence_->ClassOf(entry); |
| 555 | size_t exit_class = scheduler_->equivalence_->ClassOf(exit); |
| 556 | return entry != exit && entry_class == exit_class; |
| 557 | } |
| 558 | |
| 559 | void ResetDataStructures() { |
| 560 | control_.clear(); |
| 561 | DCHECK(queue_.empty()); |
| 562 | DCHECK(control_.empty()); |
| 563 | } |
| 564 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 565 | Zone* zone_; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 566 | Scheduler* scheduler_; |
| 567 | Schedule* schedule_; |
| 568 | NodeMarker<bool> queued_; // Mark indicating whether node is queued. |
| 569 | ZoneQueue<Node*> queue_; // Queue used for breadth-first traversal. |
| 570 | NodeVector control_; // List of encountered control nodes. |
| 571 | Node* component_entry_; // Component single-entry node. |
| 572 | BasicBlock* component_start_; // Component single-entry block. |
| 573 | BasicBlock* component_end_; // Component single-exit block. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 574 | }; |
| 575 | |
| 576 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 577 | void Scheduler::BuildCFG() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 578 | TRACE("--- CREATING CFG -------------------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 579 | |
| 580 | // Instantiate a new control equivalence algorithm for the graph. |
| 581 | equivalence_ = new (zone_) ControlEquivalence(zone_, graph_); |
| 582 | |
| 583 | // Build a control-flow graph for the main control-connected component that |
| 584 | // is being spanned by the graph's start and end nodes. |
| 585 | control_flow_builder_ = new (zone_) CFGBuilder(zone_, this); |
| 586 | control_flow_builder_->Run(); |
| 587 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 588 | // Initialize per-block data. |
| 589 | scheduled_nodes_.resize(schedule_->BasicBlockCount(), NodeVector(zone_)); |
| 590 | } |
| 591 | |
| 592 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 593 | // ----------------------------------------------------------------------------- |
| 594 | // Phase 2: Compute special RPO and dominator tree. |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 595 | |
| 596 | |
| 597 | // Compute the special reverse-post-order block ordering, which is essentially |
| 598 | // a RPO of the graph where loop bodies are contiguous. Properties: |
| 599 | // 1. If block A is a predecessor of B, then A appears before B in the order, |
| 600 | // unless B is a loop header and A is in the loop headed at B |
| 601 | // (i.e. A -> B is a backedge). |
| 602 | // => If block A dominates block B, then A appears before B in the order. |
| 603 | // => If block A is a loop header, A appears before all blocks in the loop |
| 604 | // headed at A. |
| 605 | // 2. All loops are contiguous in the order (i.e. no intervening blocks that |
| 606 | // do not belong to the loop.) |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 607 | // Note a simple RPO traversal satisfies (1) but not (2). |
| 608 | class SpecialRPONumberer : public ZoneObject { |
| 609 | public: |
| 610 | SpecialRPONumberer(Zone* zone, Schedule* schedule) |
| 611 | : zone_(zone), |
| 612 | schedule_(schedule), |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 613 | order_(nullptr), |
| 614 | beyond_end_(nullptr), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 615 | loops_(zone), |
| 616 | backedges_(zone), |
| 617 | stack_(zone), |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 618 | previous_block_count_(0), |
| 619 | empty_(0, zone) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 620 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 621 | // Computes the special reverse-post-order for the main control flow graph, |
| 622 | // that is for the graph spanned between the schedule's start and end blocks. |
| 623 | void ComputeSpecialRPO() { |
| 624 | DCHECK(schedule_->end()->SuccessorCount() == 0); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 625 | DCHECK(!order_); // Main order does not exist yet. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 626 | ComputeAndInsertSpecialRPO(schedule_->start(), schedule_->end()); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 627 | } |
| 628 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 629 | // Computes the special reverse-post-order for a partial control flow graph, |
| 630 | // that is for the graph spanned between the given {entry} and {end} blocks, |
| 631 | // then updates the existing ordering with this new information. |
| 632 | void UpdateSpecialRPO(BasicBlock* entry, BasicBlock* end) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 633 | DCHECK(order_); // Main order to be updated is present. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 634 | ComputeAndInsertSpecialRPO(entry, end); |
| 635 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 636 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 637 | // Serialize the previously computed order as a special reverse-post-order |
| 638 | // numbering for basic blocks into the final schedule. |
| 639 | void SerializeRPOIntoSchedule() { |
| 640 | int32_t number = 0; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 641 | for (BasicBlock* b = order_; b != nullptr; b = b->rpo_next()) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 642 | b->set_rpo_number(number++); |
| 643 | schedule_->rpo_order()->push_back(b); |
| 644 | } |
| 645 | BeyondEndSentinel()->set_rpo_number(number); |
| 646 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 647 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 648 | // Print and verify the special reverse-post-order. |
| 649 | void PrintAndVerifySpecialRPO() { |
| 650 | #if DEBUG |
| 651 | if (FLAG_trace_turbo_scheduler) PrintRPO(); |
| 652 | VerifySpecialRPO(); |
| 653 | #endif |
| 654 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 655 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 656 | const ZoneVector<BasicBlock*>& GetOutgoingBlocks(BasicBlock* block) { |
| 657 | if (HasLoopNumber(block)) { |
| 658 | LoopInfo const& loop = loops_[GetLoopNumber(block)]; |
| 659 | if (loop.outgoing) return *loop.outgoing; |
| 660 | } |
| 661 | return empty_; |
| 662 | } |
| 663 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 664 | private: |
| 665 | typedef std::pair<BasicBlock*, size_t> Backedge; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 666 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 667 | // Numbering for BasicBlock::rpo_number for this block traversal: |
| 668 | static const int kBlockOnStack = -2; |
| 669 | static const int kBlockVisited1 = -3; |
| 670 | static const int kBlockVisited2 = -4; |
| 671 | static const int kBlockUnvisited1 = -1; |
| 672 | static const int kBlockUnvisited2 = kBlockVisited1; |
| 673 | |
| 674 | struct SpecialRPOStackFrame { |
| 675 | BasicBlock* block; |
| 676 | size_t index; |
| 677 | }; |
| 678 | |
| 679 | struct LoopInfo { |
| 680 | BasicBlock* header; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 681 | ZoneVector<BasicBlock*>* outgoing; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 682 | BitVector* members; |
| 683 | LoopInfo* prev; |
| 684 | BasicBlock* end; |
| 685 | BasicBlock* start; |
| 686 | |
| 687 | void AddOutgoing(Zone* zone, BasicBlock* block) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 688 | if (outgoing == nullptr) { |
| 689 | outgoing = new (zone->New(sizeof(ZoneVector<BasicBlock*>))) |
| 690 | ZoneVector<BasicBlock*>(zone); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 691 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 692 | outgoing->push_back(block); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 693 | } |
| 694 | }; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 695 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 696 | int Push(ZoneVector<SpecialRPOStackFrame>& stack, int depth, |
| 697 | BasicBlock* child, int unvisited) { |
| 698 | if (child->rpo_number() == unvisited) { |
| 699 | stack[depth].block = child; |
| 700 | stack[depth].index = 0; |
| 701 | child->set_rpo_number(kBlockOnStack); |
| 702 | return depth + 1; |
| 703 | } |
| 704 | return depth; |
| 705 | } |
| 706 | |
| 707 | BasicBlock* PushFront(BasicBlock* head, BasicBlock* block) { |
| 708 | block->set_rpo_next(head); |
| 709 | return block; |
| 710 | } |
| 711 | |
| 712 | static int GetLoopNumber(BasicBlock* block) { return block->loop_number(); } |
| 713 | static void SetLoopNumber(BasicBlock* block, int loop_number) { |
| 714 | return block->set_loop_number(loop_number); |
| 715 | } |
| 716 | static bool HasLoopNumber(BasicBlock* block) { |
| 717 | return block->loop_number() >= 0; |
| 718 | } |
| 719 | |
| 720 | // TODO(mstarzinger): We only need this special sentinel because some tests |
| 721 | // use the schedule's end block in actual control flow (e.g. with end having |
| 722 | // successors). Once this has been cleaned up we can use the end block here. |
| 723 | BasicBlock* BeyondEndSentinel() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 724 | if (beyond_end_ == nullptr) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 725 | BasicBlock::Id id = BasicBlock::Id::FromInt(-1); |
| 726 | beyond_end_ = new (schedule_->zone()) BasicBlock(schedule_->zone(), id); |
| 727 | } |
| 728 | return beyond_end_; |
| 729 | } |
| 730 | |
| 731 | // Compute special RPO for the control flow graph between {entry} and {end}, |
| 732 | // mutating any existing order so that the result is still valid. |
| 733 | void ComputeAndInsertSpecialRPO(BasicBlock* entry, BasicBlock* end) { |
| 734 | // RPO should not have been serialized for this schedule yet. |
| 735 | CHECK_EQ(kBlockUnvisited1, schedule_->start()->loop_number()); |
| 736 | CHECK_EQ(kBlockUnvisited1, schedule_->start()->rpo_number()); |
| 737 | CHECK_EQ(0, static_cast<int>(schedule_->rpo_order()->size())); |
| 738 | |
| 739 | // Find correct insertion point within existing order. |
| 740 | BasicBlock* insertion_point = entry->rpo_next(); |
| 741 | BasicBlock* order = insertion_point; |
| 742 | |
| 743 | // Perform an iterative RPO traversal using an explicit stack, |
| 744 | // recording backedges that form cycles. O(|B|). |
| 745 | DCHECK_LT(previous_block_count_, schedule_->BasicBlockCount()); |
| 746 | stack_.resize(schedule_->BasicBlockCount() - previous_block_count_); |
| 747 | previous_block_count_ = schedule_->BasicBlockCount(); |
| 748 | int stack_depth = Push(stack_, 0, entry, kBlockUnvisited1); |
| 749 | int num_loops = static_cast<int>(loops_.size()); |
| 750 | |
| 751 | while (stack_depth > 0) { |
| 752 | int current = stack_depth - 1; |
| 753 | SpecialRPOStackFrame* frame = &stack_[current]; |
| 754 | |
| 755 | if (frame->block != end && |
| 756 | frame->index < frame->block->SuccessorCount()) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 757 | // Process the next successor. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 758 | BasicBlock* succ = frame->block->SuccessorAt(frame->index++); |
| 759 | if (succ->rpo_number() == kBlockVisited1) continue; |
| 760 | if (succ->rpo_number() == kBlockOnStack) { |
| 761 | // The successor is on the stack, so this is a backedge (cycle). |
| 762 | backedges_.push_back(Backedge(frame->block, frame->index - 1)); |
| 763 | if (!HasLoopNumber(succ)) { |
| 764 | // Assign a new loop number to the header if it doesn't have one. |
| 765 | SetLoopNumber(succ, num_loops++); |
| 766 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 767 | } else { |
| 768 | // Push the successor onto the stack. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 769 | DCHECK(succ->rpo_number() == kBlockUnvisited1); |
| 770 | stack_depth = Push(stack_, stack_depth, succ, kBlockUnvisited1); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 771 | } |
| 772 | } else { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 773 | // Finished with all successors; pop the stack and add the block. |
| 774 | order = PushFront(order, frame->block); |
| 775 | frame->block->set_rpo_number(kBlockVisited1); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 776 | stack_depth--; |
| 777 | } |
| 778 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 779 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 780 | // If no loops were encountered, then the order we computed was correct. |
| 781 | if (num_loops > static_cast<int>(loops_.size())) { |
| 782 | // Otherwise, compute the loop information from the backedges in order |
| 783 | // to perform a traversal that groups loop bodies together. |
| 784 | ComputeLoopInfo(stack_, num_loops, &backedges_); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 785 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 786 | // Initialize the "loop stack". Note the entry could be a loop header. |
| 787 | LoopInfo* loop = |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 788 | HasLoopNumber(entry) ? &loops_[GetLoopNumber(entry)] : nullptr; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 789 | order = insertion_point; |
| 790 | |
| 791 | // Perform an iterative post-order traversal, visiting loop bodies before |
| 792 | // edges that lead out of loops. Visits each block once, but linking loop |
| 793 | // sections together is linear in the loop size, so overall is |
| 794 | // O(|B| + max(loop_depth) * max(|loop|)) |
| 795 | stack_depth = Push(stack_, 0, entry, kBlockUnvisited2); |
| 796 | while (stack_depth > 0) { |
| 797 | SpecialRPOStackFrame* frame = &stack_[stack_depth - 1]; |
| 798 | BasicBlock* block = frame->block; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 799 | BasicBlock* succ = nullptr; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 800 | |
| 801 | if (block != end && frame->index < block->SuccessorCount()) { |
| 802 | // Process the next normal successor. |
| 803 | succ = block->SuccessorAt(frame->index++); |
| 804 | } else if (HasLoopNumber(block)) { |
| 805 | // Process additional outgoing edges from the loop header. |
| 806 | if (block->rpo_number() == kBlockOnStack) { |
| 807 | // Finish the loop body the first time the header is left on the |
| 808 | // stack. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 809 | DCHECK(loop != nullptr && loop->header == block); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 810 | loop->start = PushFront(order, block); |
| 811 | order = loop->end; |
| 812 | block->set_rpo_number(kBlockVisited2); |
| 813 | // Pop the loop stack and continue visiting outgoing edges within |
| 814 | // the context of the outer loop, if any. |
| 815 | loop = loop->prev; |
| 816 | // We leave the loop header on the stack; the rest of this iteration |
| 817 | // and later iterations will go through its outgoing edges list. |
| 818 | } |
| 819 | |
| 820 | // Use the next outgoing edge if there are any. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 821 | size_t outgoing_index = frame->index - block->SuccessorCount(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 822 | LoopInfo* info = &loops_[GetLoopNumber(block)]; |
| 823 | DCHECK(loop != info); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 824 | if (block != entry && info->outgoing != nullptr && |
| 825 | outgoing_index < info->outgoing->size()) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 826 | succ = info->outgoing->at(outgoing_index); |
| 827 | frame->index++; |
| 828 | } |
| 829 | } |
| 830 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 831 | if (succ != nullptr) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 832 | // Process the next successor. |
| 833 | if (succ->rpo_number() == kBlockOnStack) continue; |
| 834 | if (succ->rpo_number() == kBlockVisited2) continue; |
| 835 | DCHECK(succ->rpo_number() == kBlockUnvisited2); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 836 | if (loop != nullptr && !loop->members->Contains(succ->id().ToInt())) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 837 | // The successor is not in the current loop or any nested loop. |
| 838 | // Add it to the outgoing edges of this loop and visit it later. |
| 839 | loop->AddOutgoing(zone_, succ); |
| 840 | } else { |
| 841 | // Push the successor onto the stack. |
| 842 | stack_depth = Push(stack_, stack_depth, succ, kBlockUnvisited2); |
| 843 | if (HasLoopNumber(succ)) { |
| 844 | // Push the inner loop onto the loop stack. |
| 845 | DCHECK(GetLoopNumber(succ) < num_loops); |
| 846 | LoopInfo* next = &loops_[GetLoopNumber(succ)]; |
| 847 | next->end = order; |
| 848 | next->prev = loop; |
| 849 | loop = next; |
| 850 | } |
| 851 | } |
| 852 | } else { |
| 853 | // Finished with all successors of the current block. |
| 854 | if (HasLoopNumber(block)) { |
| 855 | // If we are going to pop a loop header, then add its entire body. |
| 856 | LoopInfo* info = &loops_[GetLoopNumber(block)]; |
| 857 | for (BasicBlock* b = info->start; true; b = b->rpo_next()) { |
| 858 | if (b->rpo_next() == info->end) { |
| 859 | b->set_rpo_next(order); |
| 860 | info->end = order; |
| 861 | break; |
| 862 | } |
| 863 | } |
| 864 | order = info->start; |
| 865 | } else { |
| 866 | // Pop a single node off the stack and add it to the order. |
| 867 | order = PushFront(order, block); |
| 868 | block->set_rpo_number(kBlockVisited2); |
| 869 | } |
| 870 | stack_depth--; |
| 871 | } |
| 872 | } |
| 873 | } |
| 874 | |
| 875 | // Publish new order the first time. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 876 | if (order_ == nullptr) order_ = order; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 877 | |
| 878 | // Compute the correct loop headers and set the correct loop ends. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 879 | LoopInfo* current_loop = nullptr; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 880 | BasicBlock* current_header = entry->loop_header(); |
| 881 | int32_t loop_depth = entry->loop_depth(); |
| 882 | if (entry->IsLoopHeader()) --loop_depth; // Entry might be a loop header. |
| 883 | for (BasicBlock* b = order; b != insertion_point; b = b->rpo_next()) { |
| 884 | BasicBlock* current = b; |
| 885 | |
| 886 | // Reset BasicBlock::rpo_number again. |
| 887 | current->set_rpo_number(kBlockUnvisited1); |
| 888 | |
| 889 | // Finish the previous loop(s) if we just exited them. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 890 | while (current_header != nullptr && |
| 891 | current == current_header->loop_end()) { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 892 | DCHECK(current_header->IsLoopHeader()); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 893 | DCHECK_NOT_NULL(current_loop); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 894 | current_loop = current_loop->prev; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 895 | current_header = |
| 896 | current_loop == nullptr ? nullptr : current_loop->header; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 897 | --loop_depth; |
| 898 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 899 | current->set_loop_header(current_header); |
| 900 | |
| 901 | // Push a new loop onto the stack if this loop is a loop header. |
| 902 | if (HasLoopNumber(current)) { |
| 903 | ++loop_depth; |
| 904 | current_loop = &loops_[GetLoopNumber(current)]; |
| 905 | BasicBlock* end = current_loop->end; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 906 | current->set_loop_end(end == nullptr ? BeyondEndSentinel() : end); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 907 | current_header = current_loop->header; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 908 | TRACE("id:%d is a loop header, increment loop depth to %d\n", |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 909 | current->id().ToInt(), loop_depth); |
| 910 | } |
| 911 | |
| 912 | current->set_loop_depth(loop_depth); |
| 913 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 914 | if (current->loop_header() == nullptr) { |
| 915 | TRACE("id:%d is not in a loop (depth == %d)\n", current->id().ToInt(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 916 | current->loop_depth()); |
| 917 | } else { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 918 | TRACE("id:%d has loop header id:%d, (depth == %d)\n", |
| 919 | current->id().ToInt(), current->loop_header()->id().ToInt(), |
| 920 | current->loop_depth()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 921 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 922 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 923 | } |
| 924 | |
| 925 | // Computes loop membership from the backedges of the control flow graph. |
| 926 | void ComputeLoopInfo(ZoneVector<SpecialRPOStackFrame>& queue, |
| 927 | size_t num_loops, ZoneVector<Backedge>* backedges) { |
| 928 | // Extend existing loop membership vectors. |
| 929 | for (LoopInfo& loop : loops_) { |
| 930 | BitVector* new_members = new (zone_) |
| 931 | BitVector(static_cast<int>(schedule_->BasicBlockCount()), zone_); |
| 932 | new_members->CopyFrom(*loop.members); |
| 933 | loop.members = new_members; |
| 934 | } |
| 935 | |
| 936 | // Extend loop information vector. |
| 937 | loops_.resize(num_loops, LoopInfo()); |
| 938 | |
| 939 | // Compute loop membership starting from backedges. |
| 940 | // O(max(loop_depth) * max(|loop|) |
| 941 | for (size_t i = 0; i < backedges->size(); i++) { |
| 942 | BasicBlock* member = backedges->at(i).first; |
| 943 | BasicBlock* header = member->SuccessorAt(backedges->at(i).second); |
| 944 | size_t loop_num = GetLoopNumber(header); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 945 | if (loops_[loop_num].header == nullptr) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 946 | loops_[loop_num].header = header; |
| 947 | loops_[loop_num].members = new (zone_) |
| 948 | BitVector(static_cast<int>(schedule_->BasicBlockCount()), zone_); |
| 949 | } |
| 950 | |
| 951 | int queue_length = 0; |
| 952 | if (member != header) { |
| 953 | // As long as the header doesn't have a backedge to itself, |
| 954 | // Push the member onto the queue and process its predecessors. |
| 955 | if (!loops_[loop_num].members->Contains(member->id().ToInt())) { |
| 956 | loops_[loop_num].members->Add(member->id().ToInt()); |
| 957 | } |
| 958 | queue[queue_length++].block = member; |
| 959 | } |
| 960 | |
| 961 | // Propagate loop membership backwards. All predecessors of M up to the |
| 962 | // loop header H are members of the loop too. O(|blocks between M and H|). |
| 963 | while (queue_length > 0) { |
| 964 | BasicBlock* block = queue[--queue_length].block; |
| 965 | for (size_t i = 0; i < block->PredecessorCount(); i++) { |
| 966 | BasicBlock* pred = block->PredecessorAt(i); |
| 967 | if (pred != header) { |
| 968 | if (!loops_[loop_num].members->Contains(pred->id().ToInt())) { |
| 969 | loops_[loop_num].members->Add(pred->id().ToInt()); |
| 970 | queue[queue_length++].block = pred; |
| 971 | } |
| 972 | } |
| 973 | } |
| 974 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 975 | } |
| 976 | } |
| 977 | |
| 978 | #if DEBUG |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 979 | void PrintRPO() { |
| 980 | OFStream os(stdout); |
| 981 | os << "RPO with " << loops_.size() << " loops"; |
| 982 | if (loops_.size() > 0) { |
| 983 | os << " ("; |
| 984 | for (size_t i = 0; i < loops_.size(); i++) { |
| 985 | if (i > 0) os << " "; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 986 | os << "id:" << loops_[i].header->id(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 987 | } |
| 988 | os << ")"; |
| 989 | } |
| 990 | os << ":\n"; |
| 991 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 992 | for (BasicBlock* block = order_; block != nullptr; |
| 993 | block = block->rpo_next()) { |
| 994 | os << std::setw(5) << "B" << block->rpo_number() << ":"; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 995 | for (size_t i = 0; i < loops_.size(); i++) { |
| 996 | bool range = loops_[i].header->LoopContains(block); |
| 997 | bool membership = loops_[i].header != block && range; |
| 998 | os << (membership ? " |" : " "); |
| 999 | os << (range ? "x" : " "); |
| 1000 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1001 | os << " id:" << block->id() << ": "; |
| 1002 | if (block->loop_end() != nullptr) { |
| 1003 | os << " range: [B" << block->rpo_number() << ", B" |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1004 | << block->loop_end()->rpo_number() << ")"; |
| 1005 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1006 | if (block->loop_header() != nullptr) { |
| 1007 | os << " header: id:" << block->loop_header()->id(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1008 | } |
| 1009 | if (block->loop_depth() > 0) { |
| 1010 | os << " depth: " << block->loop_depth(); |
| 1011 | } |
| 1012 | os << "\n"; |
| 1013 | } |
| 1014 | } |
| 1015 | |
| 1016 | void VerifySpecialRPO() { |
| 1017 | BasicBlockVector* order = schedule_->rpo_order(); |
| 1018 | DCHECK(order->size() > 0); |
| 1019 | DCHECK((*order)[0]->id().ToInt() == 0); // entry should be first. |
| 1020 | |
| 1021 | for (size_t i = 0; i < loops_.size(); i++) { |
| 1022 | LoopInfo* loop = &loops_[i]; |
| 1023 | BasicBlock* header = loop->header; |
| 1024 | BasicBlock* end = header->loop_end(); |
| 1025 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1026 | DCHECK_NOT_NULL(header); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1027 | DCHECK(header->rpo_number() >= 0); |
| 1028 | DCHECK(header->rpo_number() < static_cast<int>(order->size())); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1029 | DCHECK_NOT_NULL(end); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1030 | DCHECK(end->rpo_number() <= static_cast<int>(order->size())); |
| 1031 | DCHECK(end->rpo_number() > header->rpo_number()); |
| 1032 | DCHECK(header->loop_header() != header); |
| 1033 | |
| 1034 | // Verify the start ... end list relationship. |
| 1035 | int links = 0; |
| 1036 | BasicBlock* block = loop->start; |
| 1037 | DCHECK_EQ(header, block); |
| 1038 | bool end_found; |
| 1039 | while (true) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1040 | if (block == nullptr || block == loop->end) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1041 | end_found = (loop->end == block); |
| 1042 | break; |
| 1043 | } |
| 1044 | // The list should be in same order as the final result. |
| 1045 | DCHECK(block->rpo_number() == links + header->rpo_number()); |
| 1046 | links++; |
| 1047 | block = block->rpo_next(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1048 | DCHECK_LT(links, static_cast<int>(2 * order->size())); // cycle? |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1049 | } |
| 1050 | DCHECK(links > 0); |
| 1051 | DCHECK(links == end->rpo_number() - header->rpo_number()); |
| 1052 | DCHECK(end_found); |
| 1053 | |
| 1054 | // Check loop depth of the header. |
| 1055 | int loop_depth = 0; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1056 | for (LoopInfo* outer = loop; outer != nullptr; outer = outer->prev) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1057 | loop_depth++; |
| 1058 | } |
| 1059 | DCHECK_EQ(loop_depth, header->loop_depth()); |
| 1060 | |
| 1061 | // Check the contiguousness of loops. |
| 1062 | int count = 0; |
| 1063 | for (int j = 0; j < static_cast<int>(order->size()); j++) { |
| 1064 | BasicBlock* block = order->at(j); |
| 1065 | DCHECK(block->rpo_number() == j); |
| 1066 | if (j < header->rpo_number() || j >= end->rpo_number()) { |
| 1067 | DCHECK(!header->LoopContains(block)); |
| 1068 | } else { |
| 1069 | DCHECK(header->LoopContains(block)); |
| 1070 | DCHECK_GE(block->loop_depth(), loop_depth); |
| 1071 | count++; |
| 1072 | } |
| 1073 | } |
| 1074 | DCHECK(links == count); |
| 1075 | } |
| 1076 | } |
| 1077 | #endif // DEBUG |
| 1078 | |
| 1079 | Zone* zone_; |
| 1080 | Schedule* schedule_; |
| 1081 | BasicBlock* order_; |
| 1082 | BasicBlock* beyond_end_; |
| 1083 | ZoneVector<LoopInfo> loops_; |
| 1084 | ZoneVector<Backedge> backedges_; |
| 1085 | ZoneVector<SpecialRPOStackFrame> stack_; |
| 1086 | size_t previous_block_count_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1087 | ZoneVector<BasicBlock*> const empty_; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1088 | }; |
| 1089 | |
| 1090 | |
| 1091 | BasicBlockVector* Scheduler::ComputeSpecialRPO(Zone* zone, Schedule* schedule) { |
| 1092 | SpecialRPONumberer numberer(zone, schedule); |
| 1093 | numberer.ComputeSpecialRPO(); |
| 1094 | numberer.SerializeRPOIntoSchedule(); |
| 1095 | numberer.PrintAndVerifySpecialRPO(); |
| 1096 | return schedule->rpo_order(); |
| 1097 | } |
| 1098 | |
| 1099 | |
| 1100 | void Scheduler::ComputeSpecialRPONumbering() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1101 | TRACE("--- COMPUTING SPECIAL RPO ----------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1102 | |
| 1103 | // Compute the special reverse-post-order for basic blocks. |
| 1104 | special_rpo_ = new (zone_) SpecialRPONumberer(zone_, schedule_); |
| 1105 | special_rpo_->ComputeSpecialRPO(); |
| 1106 | } |
| 1107 | |
| 1108 | |
| 1109 | void Scheduler::PropagateImmediateDominators(BasicBlock* block) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1110 | for (/*nop*/; block != nullptr; block = block->rpo_next()) { |
| 1111 | auto pred = block->predecessors().begin(); |
| 1112 | auto end = block->predecessors().end(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1113 | DCHECK(pred != end); // All blocks except start have predecessors. |
| 1114 | BasicBlock* dominator = *pred; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1115 | bool deferred = dominator->deferred(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1116 | // For multiple predecessors, walk up the dominator tree until a common |
| 1117 | // dominator is found. Visitation order guarantees that all predecessors |
| 1118 | // except for backwards edges have been visited. |
| 1119 | for (++pred; pred != end; ++pred) { |
| 1120 | // Don't examine backwards edges. |
| 1121 | if ((*pred)->dominator_depth() < 0) continue; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1122 | dominator = BasicBlock::GetCommonDominator(dominator, *pred); |
| 1123 | deferred = deferred & (*pred)->deferred(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1124 | } |
| 1125 | block->set_dominator(dominator); |
| 1126 | block->set_dominator_depth(dominator->dominator_depth() + 1); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1127 | block->set_deferred(deferred | block->deferred()); |
| 1128 | TRACE("Block id:%d's idom is id:%d, depth = %d\n", block->id().ToInt(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1129 | dominator->id().ToInt(), block->dominator_depth()); |
| 1130 | } |
| 1131 | } |
| 1132 | |
| 1133 | |
| 1134 | void Scheduler::GenerateImmediateDominatorTree() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1135 | TRACE("--- IMMEDIATE BLOCK DOMINATORS -----------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1136 | |
| 1137 | // Seed start block to be the first dominator. |
| 1138 | schedule_->start()->set_dominator_depth(0); |
| 1139 | |
| 1140 | // Build the block dominator tree resulting from the above seed. |
| 1141 | PropagateImmediateDominators(schedule_->start()->rpo_next()); |
| 1142 | } |
| 1143 | |
| 1144 | |
| 1145 | // ----------------------------------------------------------------------------- |
| 1146 | // Phase 3: Prepare use counts for nodes. |
| 1147 | |
| 1148 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1149 | class PrepareUsesVisitor { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1150 | public: |
| 1151 | explicit PrepareUsesVisitor(Scheduler* scheduler) |
| 1152 | : scheduler_(scheduler), schedule_(scheduler->schedule_) {} |
| 1153 | |
| 1154 | void Pre(Node* node) { |
| 1155 | if (scheduler_->GetPlacement(node) == Scheduler::kFixed) { |
| 1156 | // Fixed nodes are always roots for schedule late. |
| 1157 | scheduler_->schedule_root_nodes_.push_back(node); |
| 1158 | if (!schedule_->IsScheduled(node)) { |
| 1159 | // Make sure root nodes are scheduled in their respective blocks. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1160 | TRACE("Scheduling fixed position node #%d:%s\n", node->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1161 | node->op()->mnemonic()); |
| 1162 | IrOpcode::Value opcode = node->opcode(); |
| 1163 | BasicBlock* block = |
| 1164 | opcode == IrOpcode::kParameter |
| 1165 | ? schedule_->start() |
| 1166 | : schedule_->block(NodeProperties::GetControlInput(node)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1167 | DCHECK_NOT_NULL(block); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1168 | schedule_->AddNode(block, node); |
| 1169 | } |
| 1170 | } |
| 1171 | } |
| 1172 | |
| 1173 | void PostEdge(Node* from, int index, Node* to) { |
| 1174 | // If the edge is from an unscheduled node, then tally it in the use count |
| 1175 | // for all of its inputs. The same criterion will be used in ScheduleLate |
| 1176 | // for decrementing use counts. |
| 1177 | if (!schedule_->IsScheduled(from)) { |
| 1178 | DCHECK_NE(Scheduler::kFixed, scheduler_->GetPlacement(from)); |
| 1179 | scheduler_->IncrementUnscheduledUseCount(to, index, from); |
| 1180 | } |
| 1181 | } |
| 1182 | |
| 1183 | private: |
| 1184 | Scheduler* scheduler_; |
| 1185 | Schedule* schedule_; |
| 1186 | }; |
| 1187 | |
| 1188 | |
| 1189 | void Scheduler::PrepareUses() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1190 | TRACE("--- PREPARE USES -------------------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1191 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1192 | // Count the uses of every node, which is used to ensure that all of a |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1193 | // node's uses are scheduled before the node itself. |
| 1194 | PrepareUsesVisitor prepare_uses(this); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1195 | |
| 1196 | // TODO(turbofan): simplify the careful pre/post ordering here. |
| 1197 | BoolVector visited(graph_->NodeCount(), false, zone_); |
| 1198 | ZoneStack<Node::InputEdges::iterator> stack(zone_); |
| 1199 | Node* node = graph_->end(); |
| 1200 | prepare_uses.Pre(node); |
| 1201 | visited[node->id()] = true; |
| 1202 | stack.push(node->input_edges().begin()); |
| 1203 | while (!stack.empty()) { |
| 1204 | Edge edge = *stack.top(); |
| 1205 | Node* node = edge.to(); |
| 1206 | if (visited[node->id()]) { |
| 1207 | prepare_uses.PostEdge(edge.from(), edge.index(), edge.to()); |
| 1208 | if (++stack.top() == edge.from()->input_edges().end()) stack.pop(); |
| 1209 | } else { |
| 1210 | prepare_uses.Pre(node); |
| 1211 | visited[node->id()] = true; |
| 1212 | if (node->InputCount() > 0) stack.push(node->input_edges().begin()); |
| 1213 | } |
| 1214 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1215 | } |
| 1216 | |
| 1217 | |
| 1218 | // ----------------------------------------------------------------------------- |
| 1219 | // Phase 4: Schedule nodes early. |
| 1220 | |
| 1221 | |
| 1222 | class ScheduleEarlyNodeVisitor { |
| 1223 | public: |
| 1224 | ScheduleEarlyNodeVisitor(Zone* zone, Scheduler* scheduler) |
| 1225 | : scheduler_(scheduler), schedule_(scheduler->schedule_), queue_(zone) {} |
| 1226 | |
| 1227 | // Run the schedule early algorithm on a set of fixed root nodes. |
| 1228 | void Run(NodeVector* roots) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1229 | for (Node* const root : *roots) { |
| 1230 | queue_.push(root); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1231 | while (!queue_.empty()) { |
| 1232 | VisitNode(queue_.front()); |
| 1233 | queue_.pop(); |
| 1234 | } |
| 1235 | } |
| 1236 | } |
| 1237 | |
| 1238 | private: |
| 1239 | // Visits one node from the queue and propagates its current schedule early |
| 1240 | // position to all uses. This in turn might push more nodes onto the queue. |
| 1241 | void VisitNode(Node* node) { |
| 1242 | Scheduler::SchedulerData* data = scheduler_->GetData(node); |
| 1243 | |
| 1244 | // Fixed nodes already know their schedule early position. |
| 1245 | if (scheduler_->GetPlacement(node) == Scheduler::kFixed) { |
| 1246 | data->minimum_block_ = schedule_->block(node); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1247 | TRACE("Fixing #%d:%s minimum_block = id:%d, dominator_depth = %d\n", |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1248 | node->id(), node->op()->mnemonic(), |
| 1249 | data->minimum_block_->id().ToInt(), |
| 1250 | data->minimum_block_->dominator_depth()); |
| 1251 | } |
| 1252 | |
| 1253 | // No need to propagate unconstrained schedule early positions. |
| 1254 | if (data->minimum_block_ == schedule_->start()) return; |
| 1255 | |
| 1256 | // Propagate schedule early position. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1257 | DCHECK_NOT_NULL(data->minimum_block_); |
| 1258 | for (auto use : node->uses()) { |
| 1259 | PropagateMinimumPositionToNode(data->minimum_block_, use); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1260 | } |
| 1261 | } |
| 1262 | |
| 1263 | // Propagates {block} as another minimum position into the given {node}. This |
| 1264 | // has the net effect of computing the minimum dominator block of {node} that |
| 1265 | // still post-dominates all inputs to {node} when the queue is processed. |
| 1266 | void PropagateMinimumPositionToNode(BasicBlock* block, Node* node) { |
| 1267 | Scheduler::SchedulerData* data = scheduler_->GetData(node); |
| 1268 | |
| 1269 | // No need to propagate to fixed node, it's guaranteed to be a root. |
| 1270 | if (scheduler_->GetPlacement(node) == Scheduler::kFixed) return; |
| 1271 | |
| 1272 | // Coupled nodes influence schedule early position of their control. |
| 1273 | if (scheduler_->GetPlacement(node) == Scheduler::kCoupled) { |
| 1274 | Node* control = NodeProperties::GetControlInput(node); |
| 1275 | PropagateMinimumPositionToNode(block, control); |
| 1276 | } |
| 1277 | |
| 1278 | // Propagate new position if it is deeper down the dominator tree than the |
| 1279 | // current. Note that all inputs need to have minimum block position inside |
| 1280 | // the dominator chain of {node}'s minimum block position. |
| 1281 | DCHECK(InsideSameDominatorChain(block, data->minimum_block_)); |
| 1282 | if (block->dominator_depth() > data->minimum_block_->dominator_depth()) { |
| 1283 | data->minimum_block_ = block; |
| 1284 | queue_.push(node); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1285 | TRACE("Propagating #%d:%s minimum_block = id:%d, dominator_depth = %d\n", |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1286 | node->id(), node->op()->mnemonic(), |
| 1287 | data->minimum_block_->id().ToInt(), |
| 1288 | data->minimum_block_->dominator_depth()); |
| 1289 | } |
| 1290 | } |
| 1291 | |
| 1292 | #if DEBUG |
| 1293 | bool InsideSameDominatorChain(BasicBlock* b1, BasicBlock* b2) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1294 | BasicBlock* dominator = BasicBlock::GetCommonDominator(b1, b2); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1295 | return dominator == b1 || dominator == b2; |
| 1296 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1297 | #endif |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1298 | |
| 1299 | Scheduler* scheduler_; |
| 1300 | Schedule* schedule_; |
| 1301 | ZoneQueue<Node*> queue_; |
| 1302 | }; |
| 1303 | |
| 1304 | |
| 1305 | void Scheduler::ScheduleEarly() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1306 | TRACE("--- SCHEDULE EARLY -----------------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1307 | if (FLAG_trace_turbo_scheduler) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1308 | TRACE("roots: "); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1309 | for (Node* node : schedule_root_nodes_) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1310 | TRACE("#%d:%s ", node->id(), node->op()->mnemonic()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1311 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1312 | TRACE("\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1313 | } |
| 1314 | |
| 1315 | // Compute the minimum block for each node thereby determining the earliest |
| 1316 | // position each node could be placed within a valid schedule. |
| 1317 | ScheduleEarlyNodeVisitor schedule_early_visitor(zone_, this); |
| 1318 | schedule_early_visitor.Run(&schedule_root_nodes_); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1319 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1320 | |
| 1321 | |
| 1322 | // ----------------------------------------------------------------------------- |
| 1323 | // Phase 5: Schedule nodes late. |
| 1324 | |
| 1325 | |
| 1326 | class ScheduleLateNodeVisitor { |
| 1327 | public: |
| 1328 | ScheduleLateNodeVisitor(Zone* zone, Scheduler* scheduler) |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1329 | : scheduler_(scheduler), |
| 1330 | schedule_(scheduler_->schedule_), |
| 1331 | marked_(scheduler->zone_), |
| 1332 | marking_queue_(scheduler->zone_) {} |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1333 | |
| 1334 | // Run the schedule late algorithm on a set of fixed root nodes. |
| 1335 | void Run(NodeVector* roots) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1336 | for (Node* const root : *roots) { |
| 1337 | ProcessQueue(root); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1338 | } |
| 1339 | } |
| 1340 | |
| 1341 | private: |
| 1342 | void ProcessQueue(Node* root) { |
| 1343 | ZoneQueue<Node*>* queue = &(scheduler_->schedule_queue_); |
| 1344 | for (Node* node : root->inputs()) { |
| 1345 | // Don't schedule coupled nodes on their own. |
| 1346 | if (scheduler_->GetPlacement(node) == Scheduler::kCoupled) { |
| 1347 | node = NodeProperties::GetControlInput(node); |
| 1348 | } |
| 1349 | |
| 1350 | // Test schedulability condition by looking at unscheduled use count. |
| 1351 | if (scheduler_->GetData(node)->unscheduled_count_ != 0) continue; |
| 1352 | |
| 1353 | queue->push(node); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1354 | do { |
| 1355 | Node* const node = queue->front(); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1356 | queue->pop(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1357 | VisitNode(node); |
| 1358 | } while (!queue->empty()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1359 | } |
| 1360 | } |
| 1361 | |
| 1362 | // Visits one node from the queue of schedulable nodes and determines its |
| 1363 | // schedule late position. Also hoists nodes out of loops to find a more |
| 1364 | // optimal scheduling position. |
| 1365 | void VisitNode(Node* node) { |
| 1366 | DCHECK_EQ(0, scheduler_->GetData(node)->unscheduled_count_); |
| 1367 | |
| 1368 | // Don't schedule nodes that are already scheduled. |
| 1369 | if (schedule_->IsScheduled(node)) return; |
| 1370 | DCHECK_EQ(Scheduler::kSchedulable, scheduler_->GetPlacement(node)); |
| 1371 | |
| 1372 | // Determine the dominating block for all of the uses of this node. It is |
| 1373 | // the latest block that this node can be scheduled in. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1374 | TRACE("Scheduling #%d:%s\n", node->id(), node->op()->mnemonic()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1375 | BasicBlock* block = GetCommonDominatorOfUses(node); |
| 1376 | DCHECK_NOT_NULL(block); |
| 1377 | |
| 1378 | // The schedule early block dominates the schedule late block. |
| 1379 | BasicBlock* min_block = scheduler_->GetData(node)->minimum_block_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1380 | DCHECK_EQ(min_block, BasicBlock::GetCommonDominator(block, min_block)); |
| 1381 | TRACE( |
| 1382 | "Schedule late of #%d:%s is id:%d at loop depth %d, minimum = id:%d\n", |
| 1383 | node->id(), node->op()->mnemonic(), block->id().ToInt(), |
| 1384 | block->loop_depth(), min_block->id().ToInt()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1385 | |
| 1386 | // Hoist nodes out of loops if possible. Nodes can be hoisted iteratively |
| 1387 | // into enclosing loop pre-headers until they would preceed their schedule |
| 1388 | // early position. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1389 | BasicBlock* hoist_block = GetHoistBlock(block); |
| 1390 | if (hoist_block && |
| 1391 | hoist_block->dominator_depth() >= min_block->dominator_depth()) { |
| 1392 | do { |
| 1393 | TRACE(" hoisting #%d:%s to block id:%d\n", node->id(), |
| 1394 | node->op()->mnemonic(), hoist_block->id().ToInt()); |
| 1395 | DCHECK_LT(hoist_block->loop_depth(), block->loop_depth()); |
| 1396 | block = hoist_block; |
| 1397 | hoist_block = GetHoistBlock(hoist_block); |
| 1398 | } while (hoist_block && |
| 1399 | hoist_block->dominator_depth() >= min_block->dominator_depth()); |
| 1400 | } else if (scheduler_->flags_ & Scheduler::kSplitNodes) { |
| 1401 | // Split the {node} if beneficial and return the new {block} for it. |
| 1402 | block = SplitNode(block, node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1403 | } |
| 1404 | |
| 1405 | // Schedule the node or a floating control structure. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1406 | if (IrOpcode::IsMergeOpcode(node->opcode())) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1407 | ScheduleFloatingControl(block, node); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1408 | } else if (node->opcode() == IrOpcode::kFinishRegion) { |
| 1409 | ScheduleRegion(block, node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1410 | } else { |
| 1411 | ScheduleNode(block, node); |
| 1412 | } |
| 1413 | } |
| 1414 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1415 | // Mark {block} and push its non-marked predecessor on the marking queue. |
| 1416 | void MarkBlock(BasicBlock* block) { |
| 1417 | DCHECK_LT(block->id().ToSize(), marked_.size()); |
| 1418 | marked_[block->id().ToSize()] = true; |
| 1419 | for (BasicBlock* pred_block : block->predecessors()) { |
| 1420 | DCHECK_LT(pred_block->id().ToSize(), marked_.size()); |
| 1421 | if (marked_[pred_block->id().ToSize()]) continue; |
| 1422 | marking_queue_.push_back(pred_block); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1423 | } |
| 1424 | } |
| 1425 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1426 | BasicBlock* SplitNode(BasicBlock* block, Node* node) { |
| 1427 | // For now, we limit splitting to pure nodes. |
| 1428 | if (!node->op()->HasProperty(Operator::kPure)) return block; |
| 1429 | // TODO(titzer): fix the special case of splitting of projections. |
| 1430 | if (node->opcode() == IrOpcode::kProjection) return block; |
| 1431 | |
| 1432 | // The {block} is common dominator of all uses of {node}, so we cannot |
| 1433 | // split anything unless the {block} has at least two successors. |
| 1434 | DCHECK_EQ(block, GetCommonDominatorOfUses(node)); |
| 1435 | if (block->SuccessorCount() < 2) return block; |
| 1436 | |
| 1437 | // Clear marking bits. |
| 1438 | DCHECK(marking_queue_.empty()); |
| 1439 | std::fill(marked_.begin(), marked_.end(), false); |
| 1440 | marked_.resize(schedule_->BasicBlockCount() + 1, false); |
| 1441 | |
| 1442 | // Check if the {node} has uses in {block}. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1443 | for (Edge edge : node->use_edges()) { |
| 1444 | BasicBlock* use_block = GetBlockForUse(edge); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1445 | if (use_block == nullptr || marked_[use_block->id().ToSize()]) continue; |
| 1446 | if (use_block == block) { |
| 1447 | TRACE(" not splitting #%d:%s, it is used in id:%d\n", node->id(), |
| 1448 | node->op()->mnemonic(), block->id().ToInt()); |
| 1449 | marking_queue_.clear(); |
| 1450 | return block; |
| 1451 | } |
| 1452 | MarkBlock(use_block); |
| 1453 | } |
| 1454 | |
| 1455 | // Compute transitive marking closure; a block is marked if all its |
| 1456 | // successors are marked. |
| 1457 | do { |
| 1458 | BasicBlock* top_block = marking_queue_.front(); |
| 1459 | marking_queue_.pop_front(); |
| 1460 | if (marked_[top_block->id().ToSize()]) continue; |
| 1461 | bool marked = true; |
| 1462 | for (BasicBlock* successor : top_block->successors()) { |
| 1463 | if (!marked_[successor->id().ToSize()]) { |
| 1464 | marked = false; |
| 1465 | break; |
| 1466 | } |
| 1467 | } |
| 1468 | if (marked) MarkBlock(top_block); |
| 1469 | } while (!marking_queue_.empty()); |
| 1470 | |
| 1471 | // If the (common dominator) {block} is marked, we know that all paths from |
| 1472 | // {block} to the end contain at least one use of {node}, and hence there's |
| 1473 | // no point in splitting the {node} in this case. |
| 1474 | if (marked_[block->id().ToSize()]) { |
| 1475 | TRACE(" not splitting #%d:%s, its common dominator id:%d is perfect\n", |
| 1476 | node->id(), node->op()->mnemonic(), block->id().ToInt()); |
| 1477 | return block; |
| 1478 | } |
| 1479 | |
| 1480 | // Split {node} for uses according to the previously computed marking |
| 1481 | // closure. Every marking partition has a unique dominator, which get's a |
| 1482 | // copy of the {node} with the exception of the first partition, which get's |
| 1483 | // the {node} itself. |
| 1484 | ZoneMap<BasicBlock*, Node*> dominators(scheduler_->zone_); |
| 1485 | for (Edge edge : node->use_edges()) { |
| 1486 | BasicBlock* use_block = GetBlockForUse(edge); |
| 1487 | if (use_block == nullptr) continue; |
| 1488 | while (marked_[use_block->dominator()->id().ToSize()]) { |
| 1489 | use_block = use_block->dominator(); |
| 1490 | } |
| 1491 | auto& use_node = dominators[use_block]; |
| 1492 | if (use_node == nullptr) { |
| 1493 | if (dominators.size() == 1u) { |
| 1494 | // Place the {node} at {use_block}. |
| 1495 | block = use_block; |
| 1496 | use_node = node; |
| 1497 | TRACE(" pushing #%d:%s down to id:%d\n", node->id(), |
| 1498 | node->op()->mnemonic(), block->id().ToInt()); |
| 1499 | } else { |
| 1500 | // Place a copy of {node} at {use_block}. |
| 1501 | use_node = CloneNode(node); |
| 1502 | TRACE(" cloning #%d:%s for id:%d\n", use_node->id(), |
| 1503 | use_node->op()->mnemonic(), use_block->id().ToInt()); |
| 1504 | scheduler_->schedule_queue_.push(use_node); |
| 1505 | } |
| 1506 | } |
| 1507 | edge.UpdateTo(use_node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1508 | } |
| 1509 | return block; |
| 1510 | } |
| 1511 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1512 | BasicBlock* GetHoistBlock(BasicBlock* block) { |
| 1513 | if (block->IsLoopHeader()) return block->dominator(); |
| 1514 | // We have to check to make sure that the {block} dominates all |
| 1515 | // of the outgoing blocks. If it doesn't, then there is a path |
| 1516 | // out of the loop which does not execute this {block}, so we |
| 1517 | // can't hoist operations from this {block} out of the loop, as |
| 1518 | // that would introduce additional computations. |
| 1519 | if (BasicBlock* header_block = block->loop_header()) { |
| 1520 | for (BasicBlock* outgoing_block : |
| 1521 | scheduler_->special_rpo_->GetOutgoingBlocks(header_block)) { |
| 1522 | if (BasicBlock::GetCommonDominator(block, outgoing_block) != block) { |
| 1523 | return nullptr; |
| 1524 | } |
| 1525 | } |
| 1526 | return header_block->dominator(); |
| 1527 | } |
| 1528 | return nullptr; |
| 1529 | } |
| 1530 | |
| 1531 | BasicBlock* GetCommonDominatorOfUses(Node* node) { |
| 1532 | BasicBlock* block = nullptr; |
| 1533 | for (Edge edge : node->use_edges()) { |
| 1534 | BasicBlock* use_block = GetBlockForUse(edge); |
| 1535 | block = block == nullptr |
| 1536 | ? use_block |
| 1537 | : use_block == nullptr |
| 1538 | ? block |
| 1539 | : BasicBlock::GetCommonDominator(block, use_block); |
| 1540 | } |
| 1541 | return block; |
| 1542 | } |
| 1543 | |
| 1544 | BasicBlock* FindPredecessorBlock(Node* node) { |
| 1545 | return scheduler_->control_flow_builder_->FindPredecessorBlock(node); |
| 1546 | } |
| 1547 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1548 | BasicBlock* GetBlockForUse(Edge edge) { |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 1549 | // TODO(titzer): ignore uses from dead nodes (not visited in PrepareUses()). |
| 1550 | // Dead uses only occur if the graph is not trimmed before scheduling. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1551 | Node* use = edge.from(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1552 | if (IrOpcode::IsPhiOpcode(use->opcode())) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1553 | // If the use is from a coupled (i.e. floating) phi, compute the common |
| 1554 | // dominator of its uses. This will not recurse more than one level. |
| 1555 | if (scheduler_->GetPlacement(use) == Scheduler::kCoupled) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1556 | TRACE(" inspecting uses of coupled #%d:%s\n", use->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1557 | use->op()->mnemonic()); |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 1558 | // TODO(titzer): reenable once above TODO is addressed. |
| 1559 | // DCHECK_EQ(edge.to(), NodeProperties::GetControlInput(use)); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1560 | return GetCommonDominatorOfUses(use); |
| 1561 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1562 | // If the use is from a fixed (i.e. non-floating) phi, we use the |
| 1563 | // predecessor block of the corresponding control input to the merge. |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1564 | if (scheduler_->GetPlacement(use) == Scheduler::kFixed) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1565 | TRACE(" input@%d into a fixed phi #%d:%s\n", edge.index(), use->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1566 | use->op()->mnemonic()); |
| 1567 | Node* merge = NodeProperties::GetControlInput(use, 0); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1568 | DCHECK(IrOpcode::IsMergeOpcode(merge->opcode())); |
| 1569 | Node* input = NodeProperties::GetControlInput(merge, edge.index()); |
| 1570 | return FindPredecessorBlock(input); |
| 1571 | } |
| 1572 | } else if (IrOpcode::IsMergeOpcode(use->opcode())) { |
| 1573 | // If the use is from a fixed (i.e. non-floating) merge, we use the |
| 1574 | // predecessor block of the current input to the merge. |
| 1575 | if (scheduler_->GetPlacement(use) == Scheduler::kFixed) { |
| 1576 | TRACE(" input@%d into a fixed merge #%d:%s\n", edge.index(), use->id(), |
| 1577 | use->op()->mnemonic()); |
| 1578 | return FindPredecessorBlock(edge.to()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1579 | } |
| 1580 | } |
| 1581 | BasicBlock* result = schedule_->block(use); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1582 | if (result == nullptr) return nullptr; |
| 1583 | TRACE(" must dominate use #%d:%s in id:%d\n", use->id(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1584 | use->op()->mnemonic(), result->id().ToInt()); |
| 1585 | return result; |
| 1586 | } |
| 1587 | |
| 1588 | void ScheduleFloatingControl(BasicBlock* block, Node* node) { |
| 1589 | scheduler_->FuseFloatingControl(block, node); |
| 1590 | } |
| 1591 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1592 | void ScheduleRegion(BasicBlock* block, Node* region_end) { |
| 1593 | // We only allow regions of instructions connected into a linear |
| 1594 | // effect chain. The only value allowed to be produced by a node |
| 1595 | // in the chain must be the value consumed by the FinishRegion node. |
| 1596 | |
| 1597 | // We schedule back to front; we first schedule FinishRegion. |
| 1598 | CHECK_EQ(IrOpcode::kFinishRegion, region_end->opcode()); |
| 1599 | ScheduleNode(block, region_end); |
| 1600 | |
| 1601 | // Schedule the chain. |
| 1602 | Node* node = NodeProperties::GetEffectInput(region_end); |
| 1603 | while (node->opcode() != IrOpcode::kBeginRegion) { |
| 1604 | DCHECK_EQ(0, scheduler_->GetData(node)->unscheduled_count_); |
| 1605 | DCHECK_EQ(1, node->op()->EffectInputCount()); |
| 1606 | DCHECK_EQ(1, node->op()->EffectOutputCount()); |
| 1607 | DCHECK_EQ(0, node->op()->ControlOutputCount()); |
| 1608 | // The value output (if there is any) must be consumed |
| 1609 | // by the EndRegion node. |
| 1610 | DCHECK(node->op()->ValueOutputCount() == 0 || |
| 1611 | node == region_end->InputAt(0)); |
| 1612 | ScheduleNode(block, node); |
| 1613 | node = NodeProperties::GetEffectInput(node); |
| 1614 | } |
| 1615 | // Schedule the BeginRegion node. |
| 1616 | DCHECK_EQ(0, scheduler_->GetData(node)->unscheduled_count_); |
| 1617 | ScheduleNode(block, node); |
| 1618 | } |
| 1619 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1620 | void ScheduleNode(BasicBlock* block, Node* node) { |
| 1621 | schedule_->PlanNode(block, node); |
| 1622 | scheduler_->scheduled_nodes_[block->id().ToSize()].push_back(node); |
| 1623 | scheduler_->UpdatePlacement(node, Scheduler::kScheduled); |
| 1624 | } |
| 1625 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1626 | Node* CloneNode(Node* node) { |
| 1627 | int const input_count = node->InputCount(); |
| 1628 | for (int index = 0; index < input_count; ++index) { |
| 1629 | Node* const input = node->InputAt(index); |
| 1630 | scheduler_->IncrementUnscheduledUseCount(input, index, node); |
| 1631 | } |
| 1632 | Node* const copy = scheduler_->graph_->CloneNode(node); |
| 1633 | TRACE(("clone #%d:%s -> #%d\n"), node->id(), node->op()->mnemonic(), |
| 1634 | copy->id()); |
| 1635 | scheduler_->node_data_.resize(copy->id() + 1, |
| 1636 | scheduler_->DefaultSchedulerData()); |
| 1637 | scheduler_->node_data_[copy->id()] = scheduler_->node_data_[node->id()]; |
| 1638 | return copy; |
| 1639 | } |
| 1640 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1641 | Scheduler* scheduler_; |
| 1642 | Schedule* schedule_; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1643 | BoolVector marked_; |
| 1644 | ZoneDeque<BasicBlock*> marking_queue_; |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1645 | }; |
| 1646 | |
| 1647 | |
| 1648 | void Scheduler::ScheduleLate() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1649 | TRACE("--- SCHEDULE LATE ------------------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1650 | if (FLAG_trace_turbo_scheduler) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1651 | TRACE("roots: "); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1652 | for (Node* node : schedule_root_nodes_) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1653 | TRACE("#%d:%s ", node->id(), node->op()->mnemonic()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1654 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1655 | TRACE("\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1656 | } |
| 1657 | |
| 1658 | // Schedule: Places nodes in dominator block of all their uses. |
| 1659 | ScheduleLateNodeVisitor schedule_late_visitor(zone_, this); |
| 1660 | schedule_late_visitor.Run(&schedule_root_nodes_); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1661 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1662 | |
| 1663 | |
| 1664 | // ----------------------------------------------------------------------------- |
| 1665 | // Phase 6: Seal the final schedule. |
| 1666 | |
| 1667 | |
| 1668 | void Scheduler::SealFinalSchedule() { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1669 | TRACE("--- SEAL FINAL SCHEDULE ------------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1670 | |
| 1671 | // Serialize the assembly order and reverse-post-order numbering. |
| 1672 | special_rpo_->SerializeRPOIntoSchedule(); |
| 1673 | special_rpo_->PrintAndVerifySpecialRPO(); |
| 1674 | |
| 1675 | // Add collected nodes for basic blocks to their blocks in the right order. |
| 1676 | int block_num = 0; |
| 1677 | for (NodeVector& nodes : scheduled_nodes_) { |
| 1678 | BasicBlock::Id id = BasicBlock::Id::FromInt(block_num++); |
| 1679 | BasicBlock* block = schedule_->GetBlockById(id); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1680 | for (Node* node : base::Reversed(nodes)) { |
| 1681 | schedule_->AddNode(block, node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1682 | } |
| 1683 | } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1684 | } |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1685 | |
| 1686 | |
| 1687 | // ----------------------------------------------------------------------------- |
| 1688 | |
| 1689 | |
| 1690 | void Scheduler::FuseFloatingControl(BasicBlock* block, Node* node) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1691 | TRACE("--- FUSE FLOATING CONTROL ----------------------------------\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1692 | if (FLAG_trace_turbo_scheduler) { |
| 1693 | OFStream os(stdout); |
| 1694 | os << "Schedule before control flow fusion:\n" << *schedule_; |
| 1695 | } |
| 1696 | |
| 1697 | // Iterate on phase 1: Build control-flow graph. |
| 1698 | control_flow_builder_->Run(block, node); |
| 1699 | |
| 1700 | // Iterate on phase 2: Compute special RPO and dominator tree. |
| 1701 | special_rpo_->UpdateSpecialRPO(block, schedule_->block(node)); |
| 1702 | // TODO(mstarzinger): Currently "iterate on" means "re-run". Fix that. |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1703 | for (BasicBlock* b = block->rpo_next(); b != nullptr; b = b->rpo_next()) { |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1704 | b->set_dominator_depth(-1); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1705 | b->set_dominator(nullptr); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1706 | } |
| 1707 | PropagateImmediateDominators(block->rpo_next()); |
| 1708 | |
| 1709 | // Iterate on phase 4: Schedule nodes early. |
| 1710 | // TODO(mstarzinger): The following loop gathering the propagation roots is a |
| 1711 | // temporary solution and should be merged into the rest of the scheduler as |
| 1712 | // soon as the approach settled for all floating loops. |
| 1713 | NodeVector propagation_roots(control_flow_builder_->control_); |
| 1714 | for (Node* node : control_flow_builder_->control_) { |
| 1715 | for (Node* use : node->uses()) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1716 | if (NodeProperties::IsPhi(use)) propagation_roots.push_back(use); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1717 | } |
| 1718 | } |
| 1719 | if (FLAG_trace_turbo_scheduler) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1720 | TRACE("propagation roots: "); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1721 | for (Node* node : propagation_roots) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1722 | TRACE("#%d:%s ", node->id(), node->op()->mnemonic()); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1723 | } |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1724 | TRACE("\n"); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1725 | } |
| 1726 | ScheduleEarlyNodeVisitor schedule_early_visitor(zone_, this); |
| 1727 | schedule_early_visitor.Run(&propagation_roots); |
| 1728 | |
| 1729 | // Move previously planned nodes. |
| 1730 | // TODO(mstarzinger): Improve that by supporting bulk moves. |
| 1731 | scheduled_nodes_.resize(schedule_->BasicBlockCount(), NodeVector(zone_)); |
| 1732 | MovePlannedNodes(block, schedule_->block(node)); |
| 1733 | |
| 1734 | if (FLAG_trace_turbo_scheduler) { |
| 1735 | OFStream os(stdout); |
| 1736 | os << "Schedule after control flow fusion:\n" << *schedule_; |
| 1737 | } |
| 1738 | } |
| 1739 | |
| 1740 | |
| 1741 | void Scheduler::MovePlannedNodes(BasicBlock* from, BasicBlock* to) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1742 | TRACE("Move planned nodes from id:%d to id:%d\n", from->id().ToInt(), |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1743 | to->id().ToInt()); |
| 1744 | NodeVector* nodes = &(scheduled_nodes_[from->id().ToSize()]); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1745 | for (Node* const node : *nodes) { |
| 1746 | schedule_->SetBlockForNode(to, node); |
| 1747 | scheduled_nodes_[to->id().ToSize()].push_back(node); |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame] | 1748 | } |
| 1749 | nodes->clear(); |
| 1750 | } |
| 1751 | |
| 1752 | } // namespace compiler |
| 1753 | } // namespace internal |
| 1754 | } // namespace v8 |