Revert "[turbofan] Lower monomorphic loads during graph building."

This reverts commit 14b424c3.

Reason for revert: Regresses benchmarks, e.g., Octane/gameboy

Original change's description:
> [turbofan] Lower monomorphic loads during graph building.
> 
> We introduce an explicit LoweringResult data structure. Until this change,
> the lowering result could be recovered from the node. However, lowering
> monomorphic loads requires wiring different value and effect, so we need
> a structure that can express such lowering result.
> 
> Bug: v8:6357
> Change-Id: I92655800890b744d9203a778a1936a8dcd465ed3
> Reviewed-on: https://chromium-review.googlesource.com/637304
> Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47992}

TBR=mstarzinger@chromium.org,jarin@chromium.org,bmeurer@chromium.org

Change-Id: I2b7db0278c13414e20c94a34d215ed92bd0d412b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6357
Reviewed-on: https://chromium-review.googlesource.com/667016Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48012}

src/compiler/bytecode-graph-builder.cc

@@ -476,8 +476,7 @@ BytecodeGraphBuilder::BytecodeGraphBuilder(
     Zone* local_zone, Handle<SharedFunctionInfo> shared_info,
     Handle<FeedbackVector> feedback_vector, BailoutId osr_offset,
     JSGraph* jsgraph, CallFrequency invocation_frequency,
-    SourcePositionTable* source_positions, Handle<Context> native_context,
-    CompilationDependencies* dependencies, int inlining_id,
+    SourcePositionTable* source_positions, int inlining_id,
     JSTypeHintLowering::Flags flags, bool stack_check)
     : local_zone_(local_zone),
       jsgraph_(jsgraph),
@@ -486,8 +485,7 @@ BytecodeGraphBuilder::BytecodeGraphBuilder(
       exception_handler_table_(
           handle(HandlerTable::cast(bytecode_array()->handler_table()))),
       feedback_vector_(feedback_vector),
-      type_hint_lowering_(jsgraph, feedback_vector, native_context,
-                          dependencies, flags, local_zone),
+      type_hint_lowering_(jsgraph, feedback_vector, flags),
       frame_state_function_info_(common()->CreateFrameStateFunctionInfo(
           FrameStateType::kInterpretedFunction,
           bytecode_array()->parameter_count(),

src/compiler/bytecode-graph-builder.h

@@ -16,9 +16,6 @@
 
 namespace v8 {
 namespace internal {
-
-class CompilationDependencies;
-
 namespace compiler {
 
 class Reduction;
@@ -32,8 +29,7 @@ class BytecodeGraphBuilder {
       Zone* local_zone, Handle<SharedFunctionInfo> shared,
       Handle<FeedbackVector> feedback_vector, BailoutId osr_offset,
       JSGraph* jsgraph, CallFrequency invocation_frequency,
-      SourcePositionTable* source_positions, Handle<Context> native_context,
-      CompilationDependencies* dependencies,
+      SourcePositionTable* source_positions,
       int inlining_id = SourcePosition::kNotInlined,
       JSTypeHintLowering::Flags flags = JSTypeHintLowering::kNoFlags,
       bool stack_check = true);

src/compiler/js-inlining.cc

@@ -350,7 +350,8 @@ bool JSInliner::DetermineCallTarget(
     // TODO(turbofan): We might want to revisit this restriction later when we
     // have a need for this, and we know how to model different native contexts
     // in the same graph in a compositional way.
-    if (function->context()->native_context() != *native_context()) {
+    if (function->context()->native_context() !=
+        info_->context()->native_context()) {
       return false;
     }
 
@@ -429,10 +430,6 @@ Reduction JSInliner::Reduce(Node* node) {
   return ReduceJSCall(node);
 }
 
-Handle<Context> JSInliner::native_context() const {
-  return handle(info_->context()->native_context());
-}
-
 Reduction JSInliner::ReduceJSCall(Node* node) {
   DCHECK(IrOpcode::IsInlineeOpcode(node->opcode()));
   Handle<SharedFunctionInfo> shared_info;
@@ -544,8 +541,7 @@ Reduction JSInliner::ReduceJSCall(Node* node) {
     }
     BytecodeGraphBuilder graph_builder(
         zone(), shared_info, feedback_vector, BailoutId::None(), jsgraph(),
-        call.frequency(), source_positions_, native_context(),
-        info_->dependencies(), inlining_id, flags, false);
+        call.frequency(), source_positions_, inlining_id, flags, false);
     graph_builder.CreateGraph();
 
     // Extract the inlinee start/end nodes.

src/compiler/js-inlining.h

@@ -47,7 +47,6 @@ class JSInliner final : public AdvancedReducer {
   SimplifiedOperatorBuilder* simplified() const;
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }
-  Handle<Context> native_context() const;
 
   Zone* const local_zone_;
   CompilationInfo* info_;

src/compiler/js-type-hint-lowering.cc

@@ -5,10 +5,8 @@
 #include "src/compiler/js-type-hint-lowering.h"
 
 #include "src/compiler/access-builder.h"
-#include "src/compiler/access-info.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/operator-properties.h"
-#include "src/compiler/property-access-builder.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/feedback-vector.h"
 #include "src/type-hints.h"
@@ -211,17 +209,8 @@ class JSSpeculativeBinopBuilder final {
 
 JSTypeHintLowering::JSTypeHintLowering(JSGraph* jsgraph,
                                        Handle<FeedbackVector> feedback_vector,
-                                       Handle<Context> native_context,
-                                       CompilationDependencies* dependencies,
-                                       Flags flags, Zone* local_zone)
-    : jsgraph_(jsgraph),
-      flags_(flags),
-      feedback_vector_(feedback_vector),
-      native_context_(native_context),
-      dependencies_(dependencies),
-      local_zone_(local_zone) {}
-
-Graph* JSTypeHintLowering::graph() const { return jsgraph_->graph(); }
+                                       Flags flags)
+    : jsgraph_(jsgraph), flags_(flags), feedback_vector_(feedback_vector) {}
 
 JSTypeHintLowering::LoweringResult JSTypeHintLowering::ReduceBinaryOperation(
     const Operator* op, Node* left, Node* right, Node* effect, Node* control,
@@ -371,59 +360,7 @@ JSTypeHintLowering::LoweringResult JSTypeHintLowering::ReduceLoadNamedOperation(
           DeoptimizeReason::kInsufficientTypeFeedbackForGenericNamedAccess)) {
     return LoweringResult::Exit(node);
   }
-
-  // Try to extract maps from the feedback vector. Give up if the IC
-  // is megamorphic or unitialized.
-  MapHandles receiver_maps;
-  if (nexus.ExtractMaps(&receiver_maps) == 0) {
-    return LoweringResult::NoChange();
-  }
-
-  // Extract information about accesses from the maps.
-  NamedAccess const& p = NamedAccessOf(op);
-  AccessInfoFactory access_info_factory(dependencies(), native_context(),
-                                        graph()->zone());
-
-  ZoneVector<PropertyAccessInfo> access_infos(local_zone());
-  if (!access_info_factory.ComputePropertyAccessInfos(
-          receiver_maps, p.name(), AccessMode::kLoad, &access_infos)) {
-    return LoweringResult::NoChange();
-  }
-
-  // Bail out if not monomorphic.
-  if (access_infos.size() != 1) return LoweringResult::NoChange();
-
-  // We only lower data fields and data constants.
-  PropertyAccessInfo const& access_info = access_infos[0];
-  if (!access_info.IsDataField() && !access_info.IsDataConstant()) {
-    return LoweringResult::NoChange();
-  }
-
-  PropertyAccessBuilder access_builder(jsgraph(), dependencies());
-  if (!access_builder.TryBuildStringCheck(access_info.receiver_maps(),
-                                          &receiver, &effect, control) &&
-      !access_builder.TryBuildNumberCheck(access_info.receiver_maps(),
-                                          &receiver, &effect, control)) {
-    receiver = access_builder.BuildCheckHeapObject(receiver, &effect, control);
-    access_builder.BuildCheckMaps(receiver, &effect, control,
-                                  access_info.receiver_maps());
-  }
-
-  Handle<JSObject> holder;
-  if (access_info.holder().ToHandle(&holder)) {
-    access_builder.AssumePrototypesStable(native_context(),
-                                          access_info.receiver_maps(), holder);
-  }
-
-  Node* value = nullptr;
-  if (access_info.IsDataConstant()) {
-    value = jsgraph()->Constant(access_info.constant());
-  } else {
-    DCHECK(access_info.IsDataField());
-    value = access_builder.BuildLoadDataField(p.name(), access_info, receiver,
-                                              &effect, &control);
-  }
-  return LoweringResult::SideEffectFree(value, effect, control);
+  return LoweringResult::NoChange();
 }
 
 JSTypeHintLowering::LoweringResult JSTypeHintLowering::ReduceLoadKeyedOperation(

src/compiler/js-type-hint-lowering.h

@@ -14,7 +14,6 @@ namespace v8 {
 namespace internal {
 
 // Forward declarations.
-class CompilationDependencies;
 class FeedbackNexus;
 class FeedbackSlot;
 
@@ -43,9 +42,7 @@ class JSTypeHintLowering {
   typedef base::Flags<Flag> Flags;
 
   JSTypeHintLowering(JSGraph* jsgraph, Handle<FeedbackVector> feedback_vector,
-                     Handle<Context> native_context,
-                     CompilationDependencies* dependencies, Flags flags,
-                     Zone* local_zone);
+                     Flags flags);
 
   // {LoweringResult} describes the result of lowering. The following outcomes
   // are possible:
@@ -159,21 +156,11 @@ class JSTypeHintLowering {
   const Handle<FeedbackVector>& feedback_vector() const {
     return feedback_vector_;
   }
-  Graph* graph() const;
-  Zone* local_zone() const { return local_zone_; }
-
-  Handle<Context> native_context() const { return native_context_; }
-  CompilationDependencies* dependencies() const { return dependencies_; }
 
   JSGraph* jsgraph_;
   Flags const flags_;
   Handle<FeedbackVector> feedback_vector_;
 
-  Handle<Context> native_context_;
-  CompilationDependencies* dependencies_;
-
-  Zone* local_zone_;
-
   DISALLOW_COPY_AND_ASSIGN(JSTypeHintLowering);
 };
 

src/compiler/pipeline.cc

@@ -893,8 +893,7 @@ struct GraphBuilderPhase {
         temp_zone, data->info()->shared_info(),
         handle(data->info()->closure()->feedback_vector()),
         data->info()->osr_offset(), data->jsgraph(), CallFrequency(1.0f),
-        data->source_positions(), data->native_context(),
-        data->info()->dependencies(), SourcePosition::kNotInlined, flags);
+        data->source_positions(), SourcePosition::kNotInlined, flags);
     graph_builder.CreateGraph();
   }
 };