Address review comments in commited cl (issue 10460002).

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/assembler_macros.h"
 #include "vm/code_generator.h"
@@ skipping 1263 matching lines @@
   __ popq(RAX);  // Pop result (newly allocated object).
   // RAX: new object
   // Restore the frame pointer.
   __ LeaveFrame();
   __ ret();
 }
 
 
 // Called for inline allocation of closures.
 // Input parameters:
-//   If the signature class is not parameterized, the receiver, if any, will be
-//   at RSP + 8 instead of RSP + 16, since no type arguments are passed.
-//   RSP + 16 (or RSP + 8): receiver (only if implicit instance closure).
-//   RSP + 8 : type arguments object (only if signature class is parameterized).
+//   RSP + 16 : receiver (null if not an implicit instance closure).
+//   RSP + 8 : type arguments object (null if class is not parameterized).
 //   RSP : points to return address.
 void StubCode::GenerateAllocationStubForClosure(Assembler* assembler,
                                                 const Function& func) {
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   ASSERT(func.IsClosureFunction());
   const bool is_implicit_static_closure =
       func.IsImplicitStaticClosureFunction();
   const bool is_implicit_instance_closure =
       func.IsImplicitInstanceClosureFunction();
   const Class& cls = Class::ZoneHandle(func.signature_class());
   const bool has_type_arguments = cls.HasTypeArguments();
   const intptr_t kTypeArgumentsOffset = 1 * kWordSize;
-  const intptr_t kReceiverOffset = (has_type_arguments ? 2 : 1) * kWordSize;
+  const intptr_t kReceiverOffset = 2 * kWordSize;
   const intptr_t closure_size = Closure::InstanceSize();
   const intptr_t context_size = Context::InstanceSize(1);  // Captured receiver.
   if (FLAG_inline_alloc &&
       PageSpace::IsPageAllocatableSize(closure_size + context_size)) {
     Label slow_case;
     Heap* heap = Isolate::Current()->heap();
     __ movq(RAX, Immediate(heap->TopAddress()));
     __ movq(RAX, Address(RAX, 0));
     __ leaq(R13, Address(RAX, closure_size));
     if (is_implicit_instance_closure) {
@@ skipping 71 matching lines @@
       __ movq(Address(RBX, Context::variable_offset(0)), R10);
 
       // Set the newly allocated context in the newly allocated closure.
       __ addq(RBX, Immediate(kHeapObjectTag));
       __ movq(Address(RAX, Closure::context_offset()), RBX);
     } else {
       __ movq(Address(RAX, Closure::context_offset()), CTX);
     }
 
     // Set the type arguments field in the newly allocated closure.
-    if (has_type_arguments) {
-      ASSERT(!is_implicit_static_closure);
-      // Use the passed-in type arguments.
-      __ movq(R10, Address(RSP, kTypeArgumentsOffset));
-      __ movq(Address(RAX, Closure::type_arguments_offset()), R10);
-    } else {
-      // Set to null.
-      __ movq(Address(RAX, Closure::type_arguments_offset()), raw_null);
-    }
+    __ movq(R10, Address(RSP, kTypeArgumentsOffset));
+    __ movq(Address(RAX, Closure::type_arguments_offset()), R10);
 
     __ movq(Address(RAX, Closure::smrck_offset()), raw_null);
 
     // Done allocating and initializing the instance.
     // RAX: new object.
     __ addq(RAX, Immediate(kHeapObjectTag));
     __ ret();
 
     __ Bind(&slow_case);
   }
@@ skipping 443 matching lines @@
 // TOS + 2: instance.
 // TOS + 3: cache array.
 // Result in RCX: null -> not found, otherwise result (true or false).
 void StubCode::GenerateSubtype3TestCacheStub(Assembler* assembler) {
   GenerateSubtypeNTestCacheStub(assembler, 3);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64