[turbofan] Optimized lowering of DYNAMIC_GLOBAL lookup slot loads.

src/compiler/operator-properties.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/operator-properties.h"
 
 #include "src/compiler/js-operator.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
 
@@ skipping 31 matching lines @@
     case IrOpcode::kJSEqual:
     case IrOpcode::kJSNotEqual:
     case IrOpcode::kJSHasProperty:
     case IrOpcode::kJSInstanceOf:
 
     // Object operations
     case IrOpcode::kJSCreateLiteralArray:
     case IrOpcode::kJSCreateLiteralObject:
 
     // Context operations
-    case IrOpcode::kJSLoadDynamicGlobal:
     case IrOpcode::kJSLoadDynamicContext:
     case IrOpcode::kJSCreateScriptContext:
     case IrOpcode::kJSCreateWithContext:
 
     // Conversions
     case IrOpcode::kJSToObject:
     case IrOpcode::kJSToNumber:
     case IrOpcode::kJSToName:
 
     // Misc operations
     case IrOpcode::kJSForInNext:
     case IrOpcode::kJSForInPrepare:
     case IrOpcode::kJSStackCheck:
     case IrOpcode::kJSDeleteProperty:
       return 1;
 
     // We record the frame state immediately before and immediately after
-    // every property access.
+    // every property or global variable access.
     case IrOpcode::kJSLoadNamed:
     case IrOpcode::kJSStoreNamed:
     case IrOpcode::kJSLoadProperty:
     case IrOpcode::kJSStoreProperty:
+    case IrOpcode::kJSLoadDynamicGlobal:
       return 2;
 
     // Binary operators that can deopt in the middle the operation (e.g.,
     // as a result of lazy deopt in ToNumber conversion) need a second frame
     // state so that we can resume before the operation.
     case IrOpcode::kJSMultiply:
     case IrOpcode::kJSAdd:
     case IrOpcode::kJSBitwiseAnd:
     case IrOpcode::kJSBitwiseOr:
     case IrOpcode::kJSBitwiseXor:
@@ skipping 35 matching lines @@
          opcode == IrOpcode::kDead || opcode == IrOpcode::kLoop ||
          opcode == IrOpcode::kMerge || opcode == IrOpcode::kIfTrue ||
          opcode == IrOpcode::kIfFalse || opcode == IrOpcode::kIfSuccess ||
          opcode == IrOpcode::kIfException || opcode == IrOpcode::kIfValue ||
          opcode == IrOpcode::kIfDefault;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8