[turbofan] Implement OSR for outer loops.

src/compiler/scheduler.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <deque>
 #include <queue>
 
 #include "src/compiler/scheduler.h"
 
 #include "src/bit-vector.h"
@@ skipping 57 matching lines @@
   DCHECK(node->id() < static_cast<int>(node_data_.size()));
   return &node_data_[node->id()];
 }
 
 
 Scheduler::Placement Scheduler::GetPlacement(Node* node) {
   SchedulerData* data = GetData(node);
   if (data->placement_ == kUnknown) {  // Compute placement, once, on demand.
     switch (node->opcode()) {
       case IrOpcode::kParameter:
-        // Parameters are always fixed to the start node.
+      case IrOpcode::kOsrValue:
+        // Parameters and OSR values are always fixed to the start block.
         data->placement_ = kFixed;
         break;
       case IrOpcode::kPhi:
       case IrOpcode::kEffectPhi: {
         // Phis and effect phis are fixed if their control inputs are, whereas
         // otherwise they are coupled to a floating control node.
         Placement p = GetPlacement(NodeProperties::GetControlInput(node));
         data->placement_ = (p == kFixed ? kFixed : kCoupled);
         break;
       }
@@ skipping 1385 matching lines @@
   for (NodeVectorIter i = nodes->begin(); i != nodes->end(); ++i) {
     schedule_->SetBlockForNode(to, *i);
     scheduled_nodes_[to->id().ToSize()].push_back(*i);
   }
   nodes->clear();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8