[Interpreter] Unify global and unallocated variable access.

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 9c82b4702eaa19846bfe820fd38734d8b6eab5fc..2f926a71d29d2016ae68c650feb86c1f91a92f4c 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -713,12 +713,10 @@ void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
         // contains computed properties with an uninitialized value.
         if (literal_key->value()->IsInternalizedString()) {
           if (property->emit_store()) {
-            Register name = inner_temporary_register_scope.NewRegister();
-            builder()
-                ->LoadLiteral(literal_key->AsPropertyName())
-                .StoreAccumulatorInRegister(name);
+            size_t name_index =
+                builder()->GetConstantPoolEntry(literal_key->AsPropertyName());
             VisitForAccumulatorValue(property->value());
-            builder()->StoreNamedProperty(literal, name,
+            builder()->StoreNamedProperty(literal, name_index,
                                           feedback_index(property->GetSlot(0)),
                                           language_mode());
           } else {
@@ -939,13 +937,8 @@ void BytecodeGenerator::VisitVariableLoad(Variable* variable,
     }
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
-      TemporaryRegisterScope temporary_register_scope(builder());
-      Register obj = temporary_register_scope.NewRegister();
-      builder()->LoadContextSlot(execution_context()->reg(),
-                                 Context::GLOBAL_OBJECT_INDEX);
-      builder()->StoreAccumulatorInRegister(obj);
-      builder()->LoadLiteral(variable->name());
-      builder()->LoadNamedProperty(obj, feedback_index(slot), language_mode());
+      size_t name_index = builder()->GetConstantPoolEntry(variable->name());
+      builder()->LoadGlobal(name_index, feedback_index(slot), language_mode());
       execution_result()->SetResultInAccumulator();
       break;
     }
@@ -987,21 +980,8 @@ void BytecodeGenerator::VisitVariableAssignment(Variable* variable,
     }
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
-      Register value = execution_result()->NewRegister();
-      Register obj = execution_result()->NewRegister();
-      Register name = execution_result()->NewRegister();
-
-      // TODO(rmcilroy): Investigate whether we can avoid having to stash the
-      // value in a register.
-      builder()->StoreAccumulatorInRegister(value);
-      builder()->LoadContextSlot(execution_context()->reg(),
-                                 Context::GLOBAL_OBJECT_INDEX);
-      builder()->StoreAccumulatorInRegister(obj);
-      builder()->LoadLiteral(variable->name());
-      builder()->StoreAccumulatorInRegister(name);
-      builder()->LoadAccumulatorWithRegister(value);
-      builder()->StoreNamedProperty(obj, name, feedback_index(slot),
-                                    language_mode());
+      size_t name_index = builder()->GetConstantPoolEntry(variable->name());
+      builder()->StoreGlobal(name_index, feedback_index(slot), language_mode());
       break;
     }
     case VariableLocation::CONTEXT: {
@@ -1023,6 +1003,7 @@ void BytecodeGenerator::VisitVariableAssignment(Variable* variable,
 void BytecodeGenerator::VisitAssignment(Assignment* expr) {
   DCHECK(expr->target()->IsValidReferenceExpression());
   Register object, key;
+  size_t name_index;
 
   // Left-hand side can only be a property, a global or a variable slot.
   Property* property = expr->target()->AsProperty();
@@ -1035,9 +1016,8 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
       break;
     case NAMED_PROPERTY: {
       object = VisitForRegisterValue(property->obj());
-      key = execution_result()->NewRegister();
-      builder()->LoadLiteral(property->key()->AsLiteral()->AsPropertyName());
-      builder()->StoreAccumulatorInRegister(key);
+      name_index = builder()->GetConstantPoolEntry(
+          property->key()->AsLiteral()->AsPropertyName());
       break;
     }
     case KEYED_PROPERTY: {
@@ -1069,7 +1049,7 @@ void BytecodeGenerator::VisitAssignment(Assignment* expr) {
       break;
     }
     case NAMED_PROPERTY:
-      builder()->StoreNamedProperty(object, key, feedback_index(slot),
+      builder()->StoreNamedProperty(object, name_index, feedback_index(slot),
                                     language_mode());
       break;
     case KEYED_PROPERTY:
@@ -1100,8 +1080,10 @@ void BytecodeGenerator::VisitPropertyLoad(Register obj, Property* expr) {
     case VARIABLE:
       UNREACHABLE();
     case NAMED_PROPERTY: {
-      builder()->LoadLiteral(expr->key()->AsLiteral()->AsPropertyName());
-      builder()->LoadNamedProperty(obj, feedback_index(slot), language_mode());
+      size_t name_index = builder()->GetConstantPoolEntry(
+          expr->key()->AsLiteral()->AsPropertyName());
+      builder()->LoadNamedProperty(obj, name_index, feedback_index(slot),
+                                   language_mode());
       break;
     }
     case KEYED_PROPERTY: {
@@ -1113,13 +1095,13 @@ void BytecodeGenerator::VisitPropertyLoad(Register obj, Property* expr) {
     case KEYED_SUPER_PROPERTY:
       UNIMPLEMENTED();
   }
-  execution_result()->SetResultInAccumulator();

[oth, 2015/10/22 10:54:30]

I find this function scary. It is setting the result in the accumulator, but no
longer signalling that and relying on the layer above to do so. Probably need a
comment here too or leave as-is so there's a consistent pattern.

[rmcilroy, 2015/10/22 13:27:48]

Done - added VisitPropertyLoadForAccumulator for this and added some
AccumulatorResultScopes (for documentation more than anything) to some of the
other visitors we have which store the result in the accumulator.

 }
 
 
 void BytecodeGenerator::VisitProperty(Property* expr) {
   Register obj = VisitForRegisterValue(expr->obj());
   VisitPropertyLoad(obj, expr);
+  execution_result()->SetResultInAccumulator();
 }
 
 
@@ -1173,12 +1155,9 @@ void BytecodeGenerator::VisitCall(Call* expr) {
       if (property->IsSuperAccess()) {
         UNIMPLEMENTED();
       }
+
       VisitForAccumulatorValue(property->obj());
       builder()->StoreAccumulatorInRegister(receiver);
-      // Need a result scope here to keep our consecutive
-      // temporaries.
-      AccumulatorResultScope accumulator_execution_result(this);
-      // Perform a property load of the callee.
       VisitPropertyLoad(receiver, property);
       builder()->StoreAccumulatorInRegister(callee);
       break;
@@ -1516,19 +1495,7 @@ void BytecodeGenerator::VisitSetHomeObject(Register value, Register home_object,
   Expression* expr = property->value();
   if (!FunctionLiteral::NeedsHomeObject(expr)) return;
 
-  // TODO(rmcilroy): Remove UNIMPLEMENTED once we have tests for setting the
-  // home object.
   UNIMPLEMENTED();
-
-  TemporaryRegisterScope temporary_register_scope(builder());
-  Register name = temporary_register_scope.NewRegister();
-  isolate()->factory()->home_object_symbol();
-  builder()
-      ->LoadLiteral(isolate()->factory()->home_object_symbol())
-      .StoreAccumulatorInRegister(name)
-      .StoreNamedProperty(home_object, name,
-                          feedback_index(property->GetSlot(slot_number)),
-                          language_mode());
 }