Revert of [turbofan] extend escape analysis to reduce CheckMaps

src/compiler/escape-analysis.cc

Index: src/compiler/escape-analysis.cc
diff --git a/src/compiler/escape-analysis.cc b/src/compiler/escape-analysis.cc
index c159f1ad385dd295e9f8b3537b2251d120d18a4c..9372e620248fbee46e34093c835b6bdcea8a1ad8 100644
--- a/src/compiler/escape-analysis.cc
+++ b/src/compiler/escape-analysis.cc
@@ -687,16 +687,7 @@
           RevisitInputs(rep);
           RevisitUses(rep);
         }
-      } else {
-        Node* from = NodeProperties::GetValueInput(node, 0);
-        if (SetEscaped(from)) {
-          TRACE("Setting #%d (%s) to escaped because of unresolved load #%i\n",
-                from->id(), from->op()->mnemonic(), node->id());
-          RevisitInputs(from);
-          RevisitUses(from);
-        }
-      }
-
+      }
       RevisitUses(node);
       break;
     }
@@ -800,7 +791,6 @@
       case IrOpcode::kStateValues:
       case IrOpcode::kReferenceEqual:
       case IrOpcode::kFinishRegion:
-      case IrOpcode::kCheckMaps:
         if (IsEscaped(use) && SetEscaped(rep)) {
           TRACE(
               "Setting #%d (%s) to escaped because of use by escaping node "
@@ -901,7 +891,7 @@
 
 EscapeAnalysis::~EscapeAnalysis() {}
 
-bool EscapeAnalysis::Run() {
+void EscapeAnalysis::Run() {
   replacements_.resize(graph()->NodeCount());
   status_analysis_->AssignAliases();
   if (status_analysis_->AliasCount() > 0) {
@@ -910,9 +900,6 @@
     status_analysis_->ResizeStatusVector();
     RunObjectAnalysis();
     status_analysis_->RunStatusAnalysis();
-    return true;
-  } else {
-    return false;
   }
 }
 
@@ -1118,9 +1105,6 @@
     case IrOpcode::kLoadElement:
       ProcessLoadElement(node);
       break;
-    case IrOpcode::kCheckMaps:
-      ProcessCheckMaps(node);
-      break;
     case IrOpcode::kStart:
       ProcessStart(node);
       break;
@@ -1158,10 +1142,6 @@
       case IrOpcode::kFinishRegion:
       case IrOpcode::kObjectIsSmi:
         break;
-      case IrOpcode::kCheckMaps: {
-        CheckMapsParameters params = CheckMapsParametersOf(node->op());
-        if (params.flags() == CheckMapsFlag::kNone) break;
-      }  // Fallthrough.
       default:
         VirtualState* state = virtual_states_[node->id()];
         if (VirtualObject* obj =
@@ -1512,43 +1492,6 @@
     ProcessLoadFromPhi(offset, from, node, state);
   } else {
     UpdateReplacement(state, node, nullptr);
-  }
-}
-
-void EscapeAnalysis::ProcessCheckMaps(Node* node) {
-  DCHECK_EQ(node->opcode(), IrOpcode::kCheckMaps);
-  ForwardVirtualState(node);
-  Node* checked = ResolveReplacement(NodeProperties::GetValueInput(node, 0));
-  VirtualState* state = virtual_states_[node->id()];
-  if (VirtualObject* object = GetVirtualObject(state, checked)) {
-    if (!object->IsTracked()) {
-      if (status_analysis_->SetEscaped(node)) {
-        TRACE(
-            "Setting #%d (%s) to escaped because checked object #%i is not "
-            "tracked\n",
-            node->id(), node->op()->mnemonic(), object->id());
-      }
-      return;
-    }
-    CheckMapsParameters params = CheckMapsParametersOf(node->op());
-
-    Node* value = object->GetField(HeapObject::kMapOffset / kPointerSize);
-    if (value) {
-      value = ResolveReplacement(value);
-      // TODO(tebbi): We want to extend this beyond constant folding with a
-      // CheckMapsValue operator that takes the load-eliminated map value as
-      // input.
-      if (value->opcode() == IrOpcode::kHeapConstant &&
-          params.maps().contains(ZoneHandleSet<Map>(
-              Handle<Map>::cast(OpParameter<Handle<HeapObject>>(value))))) {
-        TRACE("CheckMaps #%i seems to be redundant (until now).\n", node->id());
-        return;
-      }
-    }
-  }
-  if (status_analysis_->SetEscaped(node)) {
-    TRACE("Setting #%d (%s) to escaped (checking #%i)\n", node->id(),
-          node->op()->mnemonic(), checked->id());
   }
 }