[turbofan] Desugar lookup slot optimization in graph builder.

src/compiler/js-typed-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/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 1092 matching lines @@
                NodeProperties::GetValueInput(node, 0), effect, control));
   }
   node->RemoveInput(2);
   NodeProperties::ChangeOp(
       node,
       simplified()->StoreField(AccessBuilder::ForContextSlot(access.index())));
   return Changed(node);
 }
 
 
-Reduction JSTypedLowering::ReduceJSLoadDynamicGlobal(Node* node) {
-  DCHECK_EQ(IrOpcode::kJSLoadDynamicGlobal, node->opcode());
-  DynamicGlobalAccess const& access = DynamicGlobalAccessOf(node->op());
-  Node* const vector = NodeProperties::GetValueInput(node, 0);
-  Node* const context = NodeProperties::GetContextInput(node);
-  Node* const state1 = NodeProperties::GetFrameStateInput(node, 0);
-  Node* const state2 = NodeProperties::GetFrameStateInput(node, 1);
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  Node* const control = NodeProperties::GetControlInput(node);
-  if (access.RequiresFullCheck()) return NoChange();
-
-  // Perform checks whether the fast mode applies, by looking for any extension
-  // object which might shadow the optimistic declaration.
-  uint32_t bitset = access.check_bitset();
-  Node* check_true = control;
-  Node* check_false = graph()->NewNode(common()->Merge(0));
-  for (int depth = 0; bitset != 0; bitset >>= 1, depth++) {
-    if ((bitset & 1) == 0) continue;
-    Node* load = graph()->NewNode(
-        javascript()->LoadContext(depth, Context::EXTENSION_INDEX, false),
-        context, context, effect);
-    Node* check = graph()->NewNode(simplified()->ReferenceEqual(Type::Tagged()),
-                                   load, jsgraph()->ZeroConstant());
-    Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue), check,
-                                    check_true);
-    Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-    Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-    check_false->AppendInput(graph()->zone(), if_false);
-    NodeProperties::ChangeOp(check_false,
-                             common()->Merge(check_false->InputCount()));
-    check_true = if_true;
-  }
-
-  // Fast case, because variable is not shadowed. Perform global object load.
-  Node* fast = graph()->NewNode(
-      javascript()->LoadGlobal(access.name(), access.feedback(),
-                               access.typeof_mode()),
-      vector, context, state1, state2, effect, check_true);
-
-  // Slow case, because variable potentially shadowed. Perform dynamic lookup.
-  uint32_t check_bitset = DynamicGlobalAccess::kFullCheckRequired;
-  Node* slow = graph()->NewNode(
-      javascript()->LoadDynamicGlobal(access.name(), check_bitset,
-                                      access.feedback(), access.typeof_mode()),
-      vector, context, context, state1, state2, effect, check_false);
-
-  // Replace value, effect and control uses accordingly.
-  Node* new_control =
-      graph()->NewNode(common()->Merge(2), check_true, check_false);
-  Node* new_effect =
-      graph()->NewNode(common()->EffectPhi(2), fast, slow, new_control);
-  Node* new_value = graph()->NewNode(common()->Phi(kMachAnyTagged, 2), fast,
-                                     slow, new_control);
-  ReplaceWithValue(node, new_value, new_effect, new_control);
-  return Changed(new_value);
-}
-
-
-Reduction JSTypedLowering::ReduceJSLoadDynamicContext(Node* node) {
-  DCHECK_EQ(IrOpcode::kJSLoadDynamicContext, node->opcode());
-  DynamicContextAccess const& access = DynamicContextAccessOf(node->op());
-  ContextAccess const& context_access = access.context_access();
-  Node* const context = NodeProperties::GetContextInput(node);
-  Node* const state = NodeProperties::GetFrameStateInput(node, 0);
-  Node* const effect = NodeProperties::GetEffectInput(node);
-  Node* const control = NodeProperties::GetControlInput(node);
-  if (access.RequiresFullCheck()) return NoChange();
-
-  // Perform checks whether the fast mode applies, by looking for any extension
-  // object which might shadow the optimistic declaration.
-  uint32_t bitset = access.check_bitset();
-  Node* check_true = control;
-  Node* check_false = graph()->NewNode(common()->Merge(0));
-  for (int depth = 0; bitset != 0; bitset >>= 1, depth++) {
-    if ((bitset & 1) == 0) continue;
-    Node* load = graph()->NewNode(
-        javascript()->LoadContext(depth, Context::EXTENSION_INDEX, false),
-        context, context, effect);
-    Node* check = graph()->NewNode(simplified()->ReferenceEqual(Type::Tagged()),
-                                   load, jsgraph()->ZeroConstant());
-    Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue), check,
-                                    check_true);
-    Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-    Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-    check_false->AppendInput(graph()->zone(), if_false);
-    NodeProperties::ChangeOp(check_false,
-                             common()->Merge(check_false->InputCount()));
-    check_true = if_true;
-  }
-
-  // Fast case, because variable is not shadowed. Perform context slot load.
-  Node* fast =
-      graph()->NewNode(javascript()->LoadContext(context_access.depth(),
-                                                 context_access.index(), false),
-                       context, context, effect);
-
-  // Slow case, because variable potentially shadowed. Perform dynamic lookup.
-  uint32_t check_bitset = DynamicContextAccess::kFullCheckRequired;
-  Node* slow =
-      graph()->NewNode(javascript()->LoadDynamicContext(
-                           access.name(), check_bitset, context_access.depth(),
-                           context_access.index()),
-                       context, context, state, effect, check_false);
-
-  // Replace value, effect and control uses accordingly.
-  Node* new_control =
-      graph()->NewNode(common()->Merge(2), check_true, check_false);
-  Node* new_effect =
-      graph()->NewNode(common()->EffectPhi(2), fast, slow, new_control);
-  Node* new_value = graph()->NewNode(common()->Phi(kMachAnyTagged, 2), fast,
-                                     slow, new_control);
-  ReplaceWithValue(node, new_value, new_effect, new_control);
-  return Changed(new_value);
-}
-
-
 Reduction JSTypedLowering::ReduceJSConvertReceiver(Node* node) {
   DCHECK_EQ(IrOpcode::kJSConvertReceiver, node->opcode());
   ConvertReceiverMode mode = ConvertReceiverModeOf(node->op());
   Node* receiver = NodeProperties::GetValueInput(node, 0);
   Type* receiver_type = NodeProperties::GetType(receiver);
   Node* context = NodeProperties::GetContextInput(node);
   Type* context_type = NodeProperties::GetType(context);
   Node* frame_state = NodeProperties::GetFrameStateInput(node, 0);
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
@@ skipping 846 matching lines @@
     case IrOpcode::kJSLoadNamed:
       return ReduceJSLoadNamed(node);
     case IrOpcode::kJSLoadProperty:
       return ReduceJSLoadProperty(node);
     case IrOpcode::kJSStoreProperty:
       return ReduceJSStoreProperty(node);
     case IrOpcode::kJSLoadContext:
       return ReduceJSLoadContext(node);
     case IrOpcode::kJSStoreContext:
       return ReduceJSStoreContext(node);
-    case IrOpcode::kJSLoadDynamicGlobal:
-      return ReduceJSLoadDynamicGlobal(node);
-    case IrOpcode::kJSLoadDynamicContext:
-      return ReduceJSLoadDynamicContext(node);
     case IrOpcode::kJSConvertReceiver:
       return ReduceJSConvertReceiver(node);
     case IrOpcode::kJSCreateArguments:
       return ReduceJSCreateArguments(node);
     case IrOpcode::kJSCreateClosure:
       return ReduceJSCreateClosure(node);
     case IrOpcode::kJSCreateLiteralArray:
       return ReduceJSCreateLiteralArray(node);
     case IrOpcode::kJSCreateLiteralObject:
       return ReduceJSCreateLiteralObject(node);
@@ skipping 126 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSTypedLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8