Use null type argument vector instead of vector of Dynamic for a generic raw

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/code_generator.h"
 #include "vm/compiler.h"
 #include "vm/object_store.h"
@@ skipping 720 matching lines @@
     __ ret();
   }
 
   // Unable to allocate the array using the fast inline code, just call
   // into the runtime.
   __ Bind(&slow_case);
   __ EnterFrame(0);
   __ pushq(raw_null);  // Setup space on stack for return value.
   __ pushq(R10);  // Array length as Smi.
   __ pushq(RBX);  // Element type.
-  __ pushq(raw_null);  // Null instantiator.
   __ CallRuntimeFromStub(kAllocateArrayRuntimeEntry);
-  __ popq(RAX);  // Pop instantiator.
   __ popq(RAX);  // Pop element type argument.
   __ popq(R10);  // Pop array length argument.
   __ popq(RAX);  // Pop return value from return slot.
   __ LeaveFrame();
   __ ret();
 }
 
 
 // Input parameters:
 //   R10: Arguments descriptor array (num_args is first Smi element, closure
@@ skipping 360 matching lines @@
   if (FLAG_inline_alloc &&
       PageSpace::IsPageAllocatableSize(instance_size + type_args_size)) {
     Label slow_case;
     Heap* heap = Isolate::Current()->heap();
     __ movq(RAX, Immediate(heap->TopAddress()));
     __ movq(RAX, Address(RAX, 0));
     __ leaq(RBX, Address(RAX, instance_size));
     if (is_cls_parameterized) {
       __ movq(RCX, RBX);
       // A new InstantiatedTypeArguments object only needs to be allocated if
-      // the instantiator is non-null.
-      Label null_instantiator;
-      __ cmpq(Address(RSP, kInstantiatorTypeArgumentsOffset), raw_null);
-      __ j(EQUAL, &null_instantiator, Assembler::kNearJump);
+      // the instantiator is provided (not kNoInstantiator, but may be null).
+      Label no_instantiator;
+      __ cmpq(Address(RSP, kInstantiatorTypeArgumentsOffset),
+              Immediate(Smi::RawValue(StubCode::kNoInstantiator)));
+      __ j(EQUAL, &no_instantiator, Assembler::kNearJump);
       __ addq(RBX, Immediate(type_args_size));
-      __ Bind(&null_instantiator);
+      __ Bind(&no_instantiator);
       // RCX: potential new object end and, if RCX != RBX, potential new
       // InstantiatedTypeArguments object start.
     }
     // Check if the allocation fits into the remaining space.
     // RAX: potential new object start.
     // RBX: potential next object start.
     __ movq(RDI, Immediate(heap->EndAddress()));
     __ cmpq(RBX, Address(RDI, 0));
     if (FLAG_use_slow_path) {
       __ jmp(&slow_case);
@@ skipping 123 matching lines @@
   }
   // Create a stub frame.
   __ EnterFrame(0);
   __ pushq(raw_null);  // Setup space on stack for return value.
   __ PushObject(cls);  // Push class of object to be allocated.
   if (is_cls_parameterized) {
     __ pushq(RAX);  // Push type arguments of object to be allocated.
     __ pushq(RDX);  // Push type arguments of instantiator.
   } else {
     __ pushq(raw_null);  // Push null type arguments.
-    __ pushq(raw_null);  // Push null instantiator.
+    __ pushq(Immediate(Smi::RawValue(StubCode::kNoInstantiator)));
   }
   __ CallRuntimeFromStub(kAllocateObjectRuntimeEntry);  // Allocate object.
   __ popq(RAX);  // Pop argument (instantiator).
   __ popq(RAX);  // Pop argument (type arguments of object).
   __ popq(RAX);  // Pop argument (class of object).
   __ popq(RAX);  // Pop result (newly allocated object).
   // RAX: new object
   // Restore the frame pointer.
   __ LeaveFrame();
   __ ret();
@@ skipping 446 matching lines @@
 }
 
 
 void StubCode::GenerateIsRawSubTypeStub(Assembler* assembler) {
   __ Unimplemented("IsRawSubType Stub");
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64