Reland of [turbofan] Insert dummy values when changing from None type.

src/compiler/simplified-lowering.cc

 // Copyright 2014 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 "src/compiler/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/address-map.h"
 #include "src/base/bits.h"
@@ skipping 293 matching lines @@
       if (pushed_unvisited) continue;
 
       // Process the top of the stack.
       Node* node = current.node;
       typing_stack_.pop();
       NodeInfo* info = GetInfo(node);
       info->set_visited();
       bool updated = UpdateFeedbackType(node);
       TRACE(" visit #%d: %s\n", node->id(), node->op()->mnemonic());
       VisitNode(node, info->truncation(), nullptr);
+      TRACE("  ==> output ");
+      PrintOutputInfo(info);
+      TRACE("\n");
       if (updated) {
         for (Node* const user : node->uses()) {
           if (GetInfo(user)->visited()) {
             GetInfo(user)->set_queued();
             queue_.push(user);
           }
         }
       }
     }
 
     // Process the revisit queue.
     while (!queue_.empty()) {
       Node* node = queue_.front();
       queue_.pop();
       NodeInfo* info = GetInfo(node);
       info->set_visited();
       bool updated = UpdateFeedbackType(node);
       TRACE(" visit #%d: %s\n", node->id(), node->op()->mnemonic());
       VisitNode(node, info->truncation(), nullptr);
+      TRACE("  ==> output ");
+      PrintOutputInfo(info);
+      TRACE("\n");
       if (updated) {
         for (Node* const user : node->uses()) {
           if (GetInfo(user)->visited()) {
             GetInfo(user)->set_queued();
             queue_.push(user);
           }
         }
       }
     }
   }
@@ skipping 184 matching lines @@
     EnqueueInitial(jsgraph_->graph()->end());
     // Process nodes from the queue until it is empty.
     while (!queue_.empty()) {
       Node* node = queue_.front();
       NodeInfo* info = GetInfo(node);
       queue_.pop();
       info->set_visited();
       TRACE(" visit #%d: %s (trunc: %s)\n", node->id(), node->op()->mnemonic(),
             info->truncation().description());
       VisitNode(node, info->truncation(), nullptr);
-      TRACE("  ==> output ");
-      PrintOutputInfo(info);
-      TRACE("\n");
     }
   }
 
   void Run(SimplifiedLowering* lowering) {
     RunTruncationPropagationPhase();
 
     RunTypePropagationPhase();
 
     // Run lowering and change insertion phase.
     TRACE("--{Simplified lowering phase}--\n");
@@ skipping 429 matching lines @@
         EnqueueInput(node, i, UseInfo::Any());
       }
     } else if (lower()) {
       Zone* zone = jsgraph_->zone();
       ZoneVector<MachineType>* types =
           new (zone->New(sizeof(ZoneVector<MachineType>)))
               ZoneVector<MachineType>(node->InputCount(), zone);
       for (int i = 0; i < node->InputCount(); i++) {
         Node* input = node->InputAt(i);
         NodeInfo* input_info = GetInfo(input);
-        MachineType machine_type(input_info->representation(),
-                                 DeoptValueSemanticOf(TypeOf(input)));
+        Type* input_type = TypeOf(input);
+        MachineRepresentation rep = input_type->IsInhabited()
+                                        ? input_info->representation()
+                                        : MachineRepresentation::kNone;
+        MachineType machine_type(rep, DeoptValueSemanticOf(input_type));
         DCHECK(machine_type.representation() !=
                    MachineRepresentation::kWord32 ||
                machine_type.semantic() == MachineSemantic::kInt32 ||
                machine_type.semantic() == MachineSemantic::kUint32);
         (*types)[i] = machine_type;
       }
       NodeProperties::ChangeOp(node,
                                jsgraph_->common()->TypedStateValues(types));
     }
     SetOutput(node, MachineRepresentation::kTagged);
@@ skipping 2322 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kNoProperties);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8