Revert of [turbofan] extend escape analysis to reduce CheckMaps (patchset #7...

Revert of [turbofan] extend escape analysis to reduce CheckMaps (patchset #7 id:140001 of https://codereview.chromium.org/2680973013/ )

Reason for revert:
Likely causing http://crbug.com/692254

BUG=chromium:692254

Original issue's description:
> [turbofan] extend escape analysis to reduce CheckMaps
>
> R=bmeurer@chromium.org
>
> BUG=
>
> Review-Url: https://codereview.chromium.org/2680973013
> Cr-Commit-Position: refs/heads/master@{#43163}
> Committed: https://chromium.googlesource.com/v8/v8/+/f01c8a6e4b24ab38e58bb141fc251bc6b75dbe21

TBR=bmeurer@chromium.org,tebbi@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Review-Url: https://codereview.chromium.org/2704573003
Cr-Commit-Position: refs/heads/master@{#43282}

src/compiler/escape-analysis-reducer.cc

@@ -44,8 +44,6 @@ Reduction EscapeAnalysisReducer::ReduceNode(Node* node) {
     case IrOpcode::kStoreField:
     case IrOpcode::kStoreElement:
       return ReduceStore(node);
-    case IrOpcode::kCheckMaps:
-      return ReduceCheckMaps(node);
     case IrOpcode::kAllocate:
       return ReduceAllocate(node);
     case IrOpcode::kFinishRegion:
@@ -168,21 +166,6 @@ Reduction EscapeAnalysisReducer::ReduceStore(Node* node) {
   return NoChange();
 }
 
-Reduction EscapeAnalysisReducer::ReduceCheckMaps(Node* node) {
-  DCHECK(node->opcode() == IrOpcode::kCheckMaps);
-  if (node->id() < static_cast<NodeId>(fully_reduced_.length())) {
-    fully_reduced_.Add(node->id());
-  }
-  if (escape_analysis()->IsVirtual(
-          SkipTypeGuards(NodeProperties::GetValueInput(node, 0))) &&
-      !escape_analysis()->IsEscaped(node)) {
-    TRACE("Removed #%d (%s) from effect chain\n", node->id(),
-          node->op()->mnemonic());
-    RelaxEffectsAndControls(node);
-    return Changed(node);
-  }
-  return NoChange();
-}
 
 Reduction EscapeAnalysisReducer::ReduceAllocate(Node* node) {
   DCHECK_EQ(node->opcode(), IrOpcode::kAllocate);

src/compiler/escape-analysis-reducer.h

@@ -36,7 +36,6 @@ class V8_EXPORT_PRIVATE EscapeAnalysisReducer final
   Reduction ReduceNode(Node* node);
   Reduction ReduceLoad(Node* node);
   Reduction ReduceStore(Node* node);
-  Reduction ReduceCheckMaps(Node* node);
   Reduction ReduceAllocate(Node* node);
   Reduction ReduceFinishRegion(Node* node);
   Reduction ReduceReferenceEqual(Node* node);

src/compiler/escape-analysis.cc

@@ -694,16 +694,7 @@ void EscapeStatusAnalysis::Process(Node* node) {
           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;
     }
@@ -807,7 +798,6 @@ bool EscapeStatusAnalysis::CheckUsesForEscape(Node* uses, Node* rep,
       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 "
@@ -908,7 +898,7 @@ EscapeAnalysis::EscapeAnalysis(Graph* graph, CommonOperatorBuilder* common,
 
 EscapeAnalysis::~EscapeAnalysis() {}
 
-bool EscapeAnalysis::Run() {
+void EscapeAnalysis::Run() {
   replacements_.resize(graph()->NodeCount());
   status_analysis_->AssignAliases();
   if (status_analysis_->AliasCount() > 0) {
@@ -917,9 +907,6 @@ bool EscapeAnalysis::Run() {
     status_analysis_->ResizeStatusVector();
     RunObjectAnalysis();
     status_analysis_->RunStatusAnalysis();
-    return true;
-  } else {
-    return false;
   }
 }
 
@@ -1125,9 +1112,6 @@ bool EscapeAnalysis::Process(Node* node) {
     case IrOpcode::kLoadElement:
       ProcessLoadElement(node);
       break;
-    case IrOpcode::kCheckMaps:
-      ProcessCheckMaps(node);
-      break;
     case IrOpcode::kStart:
       ProcessStart(node);
       break;
@@ -1165,10 +1149,6 @@ void EscapeAnalysis::ProcessAllocationUsers(Node* node) {
       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 =
@@ -1522,43 +1502,6 @@ void EscapeAnalysis::ProcessLoadField(Node* node) {
   }
 }
 
-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());
-  }
-}
-
 void EscapeAnalysis::ProcessLoadElement(Node* node) {
   DCHECK_EQ(node->opcode(), IrOpcode::kLoadElement);
   ForwardVirtualState(node);

src/compiler/escape-analysis.h

@@ -26,7 +26,7 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
   EscapeAnalysis(Graph* graph, CommonOperatorBuilder* common, Zone* zone);
   ~EscapeAnalysis();
 
-  bool Run();
+  void Run();
 
   Node* GetReplacement(Node* node);
   bool IsVirtual(Node* node);
@@ -44,7 +44,6 @@ class V8_EXPORT_PRIVATE EscapeAnalysis {
   void ProcessStoreField(Node* node);
   void ProcessLoadElement(Node* node);
   void ProcessStoreElement(Node* node);
-  void ProcessCheckMaps(Node* node);
   void ProcessAllocationUsers(Node* node);
   void ProcessAllocation(Node* node);
   void ProcessFinishRegion(Node* node);

src/compiler/pipeline.cc

@@ -949,7 +949,7 @@ struct EscapeAnalysisPhase {
   void Run(PipelineData* data, Zone* temp_zone) {
     EscapeAnalysis escape_analysis(data->graph(), data->jsgraph()->common(),
                                    temp_zone);
-    if (!escape_analysis.Run()) return;
+    escape_analysis.Run();
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     EscapeAnalysisReducer escape_reducer(&graph_reducer, data->jsgraph(),
                                          &escape_analysis, temp_zone);