Push raw_null instead of smi 0 in all places were we setup the return value location before calli...

vm/stub_code_ia32.cc

Index: vm/stub_code_ia32.cc
===================================================================
--- vm/stub_code_ia32.cc	(revision 2842)
+++ vm/stub_code_ia32.cc	(working copy)
@@ -420,8 +420,7 @@
   __ pushl(ECX);  // Preserve ic-data array.
   // First resolve the function to get the function object.
 
-  // Setup space for return value on stack by pushing smi 0.
-  __ pushl(Immediate(0));
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ pushl(EAX);  // Push receiver.
   __ CallRuntimeFromStub(kResolveCompileInstanceFunctionRuntimeEntry);
   __ popl(EAX);  // Remove receiver pushed earlier.
@@ -456,7 +455,7 @@
   __ pushl(EDX);  // Preserve ic-data array.
   __ pushl(EDI);  // Preserve arguments descriptor array.
 
-  __ pushl(Immediate(0));
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ pushl(EAX);  // Push receiver.
   __ pushl(EDX);  // Ic-data array.
   __ CallRuntimeFromStub(kResolveImplicitClosureFunctionRuntimeEntry);
@@ -491,7 +490,7 @@
   __ pushl(EDX);  // Preserve ic-data array.
   __ pushl(EDI);  // Preserve arguments descriptor array.
 
-  __ pushl(Immediate(0));
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ pushl(EAX);  // Push receiver.
   __ pushl(EDX);  // Ic-data array.
   __ CallRuntimeFromStub(kResolveImplicitClosureThroughGetterRuntimeEntry);
@@ -510,7 +509,7 @@
 
   // ECX: Closure object.
   // EDI: Arguments descriptor array.
-  __ pushl(Immediate(0));  // Result from invoking Closure.
+  __ pushl(raw_null);  // Setup space on stack for result from invoking Closure.
   __ pushl(ECX);  // Closure object.
   __ pushl(EDI);  // Arguments descriptor.
   __ movl(EDI, FieldAddress(EDI, Array::data_offset()));
@@ -546,8 +545,7 @@
   //   ECX: raw_null.
   //   EDI: argument descriptor array.
 
-  // Setup space for return value on stack by pushing smi 0.
-  __ pushl(Immediate(0));  // Result from noSuchMethod.
+  __ pushl(raw_null);  // Setup space on stack for result from noSuchMethod.
   __ pushl(EAX);  // Receiver.
   __ pushl(EDX);  // IC-data array.
   __ pushl(EDI);  // Argument descriptor array.
@@ -702,7 +700,7 @@
   // into the runtime.
   __ Bind(&slow_case);
   __ EnterFrame(0);
-  __ pushl(raw_null);  // Push Null object for return value.
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ pushl(EDX);  // Array length as Smi.
   __ pushl(ECX);  // Element type.
   __ pushl(raw_null);  // Null instantiator.
@@ -794,8 +792,7 @@
   // calling into the runtime.
   __ EnterFrame(0);
 
-  // Setup space for return value on stack by pushing smi 0.
-  __ pushl(Immediate(0));  // Result from reporting the error.
+  __ pushl(raw_null);  // Setup space on stack for result from error reporting.
   __ pushl(EDI);  // Non-closure object.
     // Total number of args is the first Smi in args descriptor array (EDX).
   __ movl(EDI, FieldAddress(EDX, Array::data_offset()));  // Load num_args.
@@ -938,6 +935,8 @@
 // EAX: new allocated RawContext object.
 // EBX and EDX are destroyed.
 void StubCode::GenerateAllocateContextStub(Assembler* assembler) {
+  const Immediate raw_null =
+      Immediate(reinterpret_cast<intptr_t>(Object::null()));
   if (FLAG_inline_alloc) {
     const Class& context_class = Class::ZoneHandle(Object::context_class());
     Label slow_case;
@@ -1024,8 +1023,7 @@
   }
   // Create a stub frame.
   __ EnterFrame(0);
-  const Context& new_context = Context::ZoneHandle();
-  __ PushObject(new_context);  // Push Null context for return value.
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ SmiTag(EDX);
   __ pushl(EDX);
   __ CallRuntimeFromStub(kAllocateContextRuntimeEntry);  // Allocate context.
@@ -1205,8 +1203,7 @@
   }
   // Create a stub frame.
   __ EnterFrame(0);
-  const Object& new_object = Object::ZoneHandle();
-  __ PushObject(new_object);  // Push Null object for return value.
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ PushObject(cls);  // Push class of object to be allocated.
   if (is_cls_parameterized) {
     __ pushl(EAX);  // Push type arguments of object to be allocated.
@@ -1354,8 +1351,7 @@
   }
   // Create a stub frame.
   __ EnterFrame(0);
-  const Closure& new_closure = Closure::ZoneHandle();
-  __ PushObject(new_closure);  // Push Null closure for return value.
+  __ pushl(raw_null);  // Setup space on stack for return value.
   __ PushObject(func);
   if (is_implicit_static_closure) {
     __ CallRuntimeFromStub(kAllocateImplicitStaticClosureRuntimeEntry);
@@ -1408,13 +1404,14 @@
   // noSuchMethod(InvocationMirror call).
   // Also, the class NoSuchMethodException has to be modified accordingly.
   // Total number of args is the first Smi in args descriptor array (EDX).
+  const Immediate raw_null =
+      Immediate(reinterpret_cast<intptr_t>(Object::null()));
   __ movl(EDI, FieldAddress(EDX, Array::data_offset()));
   __ SmiUntag(EDI);
   __ movl(EAX, Address(EBP, EDI, TIMES_4, kWordSize));  // Get receiver.
 
   __ EnterFrame(0);
-  // Setup space for return value on stack by pushing smi 0.
-  __ pushl(Immediate(0));  // Result from noSuchMethod.
+  __ pushl(raw_null);  // Setup space on stack for result from noSuchMethod.
   __ pushl(EAX);  // Receiver.
   __ pushl(ECX);  // IC data array.
   __ pushl(EDX);  // Arguments descriptor array.
@@ -1532,10 +1529,9 @@
   __ movl(EAX, FieldAddress(EDX, Array::data_offset()));
   __ leal(EAX, Address(ESP, EAX, TIMES_2, 0));  // EAX is Smi.
   __ EnterFrame(0);
-  // Setup space for return value on stack by pushing smi 0.
   __ pushl(EDX);  // Preserve arguments array.
   __ pushl(ECX);  // Preserve IC data array
-  __ pushl(Immediate(0));  // Space for result (target code object).
+  __ pushl(raw_null);  // Setup space on stack for result (target code object).
   __ movl(EDX, FieldAddress(EDX, Array::data_offset()));
   // Push call arguments.
   for (intptr_t i = 0; i < num_args; i++) {