[Interpreter] Fixes VisitObjectLiteral to reserve consecutive registers in innerscope.

src/interpreter/bytecode-generator.cc

 // Copyright 2015 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/interpreter/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "src/interpreter/control-flow-builders.h"
@@ skipping 946 matching lines @@
                                  expr->flags());
   execution_result()->SetResultInAccumulator();
 }
 
 
 void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   // Deep-copy the literal boilerplate.
   builder()->CreateObjectLiteral(expr->constant_properties(),
                                  expr->literal_index(),
                                  expr->ComputeFlags(true));
-  Register literal;
+
+  // Allocate in the outer scope since this register is returned.

[rmcilroy, 2016/01/15 17:15:09]

/s/since.../since this register is used to return the expression's results to
the caller.

[mythria, 2016/01/18 11:34:05]

Thanks, Done.

+  Register literal = register_allocator()->outer()->NewRegister();
+  builder()->StoreAccumulatorInRegister(literal);
 
   // Store computed values into the literal.
-  bool literal_in_accumulator = true;
   int property_index = 0;
   AccessorTable accessor_table(zone());
   for (; property_index < expr->properties()->length(); property_index++) {
     ObjectLiteral::Property* property = expr->properties()->at(property_index);
     if (property->is_computed_name()) break;
     if (property->IsCompileTimeValue()) continue;
 
-    if (literal_in_accumulator) {
-      literal = register_allocator()->NewRegister();
-      builder()->StoreAccumulatorInRegister(literal);
-      literal_in_accumulator = false;
-    }
-
     RegisterAllocationScope inner_register_scope(this);
     Literal* literal_key = property->key()->AsLiteral();
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
         UNREACHABLE();
       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
         DCHECK(!CompileTimeValue::IsCompileTimeValue(property->value()));
       // Fall through.
       case ObjectLiteral::Property::COMPUTED: {
         // It is safe to use [[Put]] here because the boilerplate already
         // contains computed properties with an uninitialized value.
         if (literal_key->value()->IsInternalizedString()) {
           if (property->emit_store()) {
             VisitForAccumulatorValue(property->value());
             builder()->StoreNamedProperty(
                 literal, literal_key->AsPropertyName(),
                 feedback_index(property->GetSlot(0)), language_mode());
           } else {
             VisitForEffect(property->value());
           }
         } else {
-          register_allocator()->PrepareForConsecutiveAllocations(3);
+          register_allocator()->PrepareForConsecutiveAllocations(4);
+          Register literal_argument =
+              register_allocator()->NextConsecutiveRegister();
           Register key = register_allocator()->NextConsecutiveRegister();
           Register value = register_allocator()->NextConsecutiveRegister();
           Register language = register_allocator()->NextConsecutiveRegister();
-          // TODO(oth): This is problematic - can't assume contiguous here.
-          // literal is allocated in outer register scope, whereas key, value,
-          // language are in another.
-          DCHECK(Register::AreContiguous(literal, key, value, language));
+          DCHECK(
+              Register::AreContiguous(literal_argument, key, value, language));

[rmcilroy, 2016/01/15 17:15:09]

This DCHECK's probably not necessary anymore.

[mythria, 2016/01/18 11:34:05]

Done.

+
+          builder()->MoveRegister(literal, literal_argument);
           VisitForAccumulatorValue(property->key());
           builder()->StoreAccumulatorInRegister(key);
           VisitForAccumulatorValue(property->value());
           builder()->StoreAccumulatorInRegister(value);
           if (property->emit_store()) {
             builder()
                 ->LoadLiteral(Smi::FromInt(SLOPPY))
                 .StoreAccumulatorInRegister(language)
-                .CallRuntime(Runtime::kSetProperty, literal, 4);
+                .CallRuntime(Runtime::kSetProperty, literal_argument, 4);
             VisitSetHomeObject(value, literal, property);
           }
         }
         break;
       }
       case ObjectLiteral::Property::PROTOTYPE: {
-        register_allocator()->PrepareForConsecutiveAllocations(1);
         DCHECK(property->emit_store());
+        register_allocator()->PrepareForConsecutiveAllocations(2);
+        Register literal_argument =
+            register_allocator()->NextConsecutiveRegister();
         Register value = register_allocator()->NextConsecutiveRegister();
-        DCHECK(Register::AreContiguous(literal, value));
+        DCHECK(Register::AreContiguous(literal_argument, value));

[rmcilroy, 2016/01/15 17:15:09]

ditto

[mythria, 2016/01/18 11:34:05]

Done.

+
+        builder()->MoveRegister(literal, literal_argument);
         VisitForAccumulatorValue(property->value());
         builder()->StoreAccumulatorInRegister(value).CallRuntime(
-            Runtime::kInternalSetPrototype, literal, 2);
+            Runtime::kInternalSetPrototype, literal_argument, 2);
         break;
       }
       case ObjectLiteral::Property::GETTER:
         if (property->emit_store()) {
           accessor_table.lookup(literal_key)->second->getter = property;
         }
         break;
       case ObjectLiteral::Property::SETTER:
         if (property->emit_store()) {
           accessor_table.lookup(literal_key)->second->setter = property;
         }
         break;
     }
   }
 
   // Define accessors, using only a single call to the runtime for each pair of
   // corresponding getters and setters.
   for (AccessorTable::Iterator it = accessor_table.begin();
        it != accessor_table.end(); ++it) {
     RegisterAllocationScope inner_register_scope(this);
-    register_allocator()->PrepareForConsecutiveAllocations(4);
+    register_allocator()->PrepareForConsecutiveAllocations(5);
+    Register literal_argument = register_allocator()->NextConsecutiveRegister();
     Register name = register_allocator()->NextConsecutiveRegister();
     Register getter = register_allocator()->NextConsecutiveRegister();
     Register setter = register_allocator()->NextConsecutiveRegister();
     Register attr = register_allocator()->NextConsecutiveRegister();
-    DCHECK(Register::AreContiguous(literal, name, getter, setter, attr));
+    DCHECK(
+        Register::AreContiguous(literal_argument, name, getter, setter, attr));

[rmcilroy, 2016/01/15 17:15:09]

ditto

[mythria, 2016/01/18 11:34:05]

Done.

+
+    builder()->MoveRegister(literal, literal_argument);
     VisitForAccumulatorValue(it->first);
     builder()->StoreAccumulatorInRegister(name);
     VisitObjectLiteralAccessor(literal, it->second->getter, getter);
     VisitObjectLiteralAccessor(literal, it->second->setter, setter);
     builder()
         ->LoadLiteral(Smi::FromInt(NONE))
         .StoreAccumulatorInRegister(attr)
-        .CallRuntime(Runtime::kDefineAccessorPropertyUnchecked, literal, 5);
+        .CallRuntime(Runtime::kDefineAccessorPropertyUnchecked,
+                     literal_argument, 5);
   }
 
   // Object literals have two parts. The "static" part on the left contains no
   // computed property names, and so we can compute its map ahead of time; see
   // Runtime_CreateObjectLiteralBoilerplate. The second "dynamic" part starts
   // with the first computed property name and continues with all properties to
   // its right. All the code from above initializes the static component of the
   // object literal, and arranges for the map of the result to reflect the
   // static order in which the keys appear. For the dynamic properties, we
   // compile them into a series of "SetOwnProperty" runtime calls. This will
   // preserve insertion order.
   for (; property_index < expr->properties()->length(); property_index++) {
-    if (literal_in_accumulator) {
-      literal = register_allocator()->NewRegister();
-      builder()->StoreAccumulatorInRegister(literal);
-      literal_in_accumulator = false;
-    }
-
     ObjectLiteral::Property* property = expr->properties()->at(property_index);
     RegisterAllocationScope inner_register_scope(this);
+
     if (property->kind() == ObjectLiteral::Property::PROTOTYPE) {
       DCHECK(property->emit_store());
-      Register value = register_allocator()->NewRegister();
-      DCHECK(Register::AreContiguous(literal, value));
+      register_allocator()->PrepareForConsecutiveAllocations(2);
+      Register literal_argument =
+          register_allocator()->NextConsecutiveRegister();
+      Register value = register_allocator()->NextConsecutiveRegister();
+      DCHECK(Register::AreContiguous(literal_argument, value));

[rmcilroy, 2016/01/15 17:15:09]

ditto

[mythria, 2016/01/18 11:34:05]

Done.

+
+      builder()->MoveRegister(literal, literal_argument);
       VisitForAccumulatorValue(property->value());
       builder()->StoreAccumulatorInRegister(value).CallRuntime(
-          Runtime::kInternalSetPrototype, literal, 2);
+          Runtime::kInternalSetPrototype, literal_argument, 2);
       continue;
     }
 
-    register_allocator()->PrepareForConsecutiveAllocations(3);
+    register_allocator()->PrepareForConsecutiveAllocations(4);
+    Register literal_argument = register_allocator()->NextConsecutiveRegister();
     Register key = register_allocator()->NextConsecutiveRegister();
     Register value = register_allocator()->NextConsecutiveRegister();
     Register attr = register_allocator()->NextConsecutiveRegister();
-    DCHECK(Register::AreContiguous(literal, key, value, attr));
+    DCHECK(Register::AreContiguous(literal_argument, key, value, attr));
 
+    builder()->MoveRegister(literal, literal_argument);
     VisitForAccumulatorValue(property->key());
     builder()->CastAccumulatorToName().StoreAccumulatorInRegister(key);
     VisitForAccumulatorValue(property->value());
     builder()->StoreAccumulatorInRegister(value);
     VisitSetHomeObject(value, literal, property);
     builder()->LoadLiteral(Smi::FromInt(NONE)).StoreAccumulatorInRegister(attr);
     Runtime::FunctionId function_id = static_cast<Runtime::FunctionId>(-1);
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
       case ObjectLiteral::Property::COMPUTED:
       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
         function_id = Runtime::kDefineDataPropertyUnchecked;
         break;
       case ObjectLiteral::Property::PROTOTYPE:
         UNREACHABLE();  // Handled specially above.
         break;
       case ObjectLiteral::Property::GETTER:
         function_id = Runtime::kDefineGetterPropertyUnchecked;
         break;
       case ObjectLiteral::Property::SETTER:
         function_id = Runtime::kDefineSetterPropertyUnchecked;
         break;
     }
-    builder()->CallRuntime(function_id, literal, 4);
+    builder()->CallRuntime(function_id, literal_argument, 4);
   }
 
   // Transform literals that contain functions to fast properties.
   if (expr->has_function()) {
-    DCHECK(!literal_in_accumulator);
     builder()->CallRuntime(Runtime::kToFastProperties, literal, 1);
   }
 
-  if (!literal_in_accumulator) {
-    // Restore literal array into accumulator.
-    builder()->LoadAccumulatorWithRegister(literal);
-  }
-  execution_result()->SetResultInAccumulator();
+  execution_result()->SetResultInRegister(literal);
 }
 
 
 void BytecodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   // Deep-copy the literal boilerplate.
   builder()->CreateArrayLiteral(expr->constant_elements(),
                                 expr->literal_index(),
                                 expr->ComputeFlags(true));
   Register index, literal;
 
@@ skipping 1021 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8