[turbofan] Optimized lowering of DYNAMIC_GLOBAL lookup slot loads.

src/compiler/ast-graph-builder.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/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 2731 matching lines @@
 
 
 VectorSlotPair AstGraphBuilder::CreateVectorSlotPair(
     FeedbackVectorICSlot slot) const {
   return VectorSlotPair(handle(info()->shared_info()->feedback_vector()), slot);
 }
 
 
 uint32_t AstGraphBuilder::ComputeBitsetForDynamicGlobal(Variable* variable) {
   DCHECK_EQ(DYNAMIC_GLOBAL, variable->mode());
+  bool found_eval_scope = false;
   EnumSet<int, uint32_t> check_depths;
   for (Scope* s = current_scope(); s != nullptr; s = s->outer_scope()) {
     if (s->num_heap_slots() <= 0) continue;
-    // TODO(mstarzinger): Be smarter about which checks to require!
+    // TODO(mstarzinger): If we have reached an eval scope, we check all
+    // extensions from this point. Replicated from full-codegen, figure out
+    // whether this is still needed. If not, drop {found_eval_scope} below.
+    if (s->is_eval_scope()) found_eval_scope = true;
+    if (!s->calls_sloppy_eval() && !found_eval_scope) continue;
     int depth = current_scope()->ContextChainLength(s);
     if (depth > DynamicGlobalAccess::kMaxCheckDepth) {
       return DynamicGlobalAccess::kFullCheckRequired;
     }
     check_depths.Add(depth);
   }
   return check_depths.ToIntegral();
 }
 
 
@@ skipping 249 matching lines @@
         value = BuildHoleCheckThrow(value, variable, value, bailout_id);
       }
       return value;
     }
     case Variable::LOOKUP: {
       // Dynamic lookup of context variable (anywhere in the chain).
       Node* value = jsgraph()->TheHoleConstant();
       Handle<String> name = variable->name();
       if (mode == DYNAMIC_GLOBAL) {
         uint32_t check_bitset = ComputeBitsetForDynamicGlobal(variable);
-        const Operator* op = javascript()->LoadDynamicGlobal(name, check_bitset,
-                                                             contextual_mode);
+        const Operator* op = javascript()->LoadDynamicGlobal(
+            name, check_bitset, feedback, contextual_mode);
         value = NewNode(op, current_context());
+        states.AddToNode(value, bailout_id, combine);
       } else if (mode == DYNAMIC_LOCAL) {
         Variable* local = variable->local_if_not_shadowed();
         DCHECK(local->location() == Variable::CONTEXT);  // Must be context.
         int depth = current_scope()->ContextChainLength(local->scope());
         uint32_t check_bitset = ComputeBitsetForDynamicContext(variable);
         const Operator* op = javascript()->LoadDynamicContext(
             name, check_bitset, depth, local->index());
         value = NewNode(op, current_context());
+        PrepareFrameState(value, bailout_id, combine);
         // TODO(mstarzinger): Hole checks are missing here when optimized.
       } else if (mode == DYNAMIC) {
         uint32_t check_bitset = DynamicGlobalAccess::kFullCheckRequired;
-        const Operator* op = javascript()->LoadDynamicGlobal(name, check_bitset,
-                                                             contextual_mode);
+        const Operator* op = javascript()->LoadDynamicGlobal(
+            name, check_bitset, feedback, contextual_mode);
         value = NewNode(op, current_context());
+        states.AddToNode(value, bailout_id, combine);
       }
-      PrepareFrameState(value, bailout_id, combine);
       return value;
     }
   }
   UNREACHABLE();
   return NULL;
 }
 
 
 Node* AstGraphBuilder::BuildVariableDelete(Variable* variable,
                                            BailoutId bailout_id,
@@ skipping 718 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8