Rework leaf calls as just simple C calls with a signature and not the NativeArgumentDescriptor.

vm/stub_code_x64_test.cc

 // Copyright (c) 2011, 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/isolate.h"
 #include "vm/dart_entry.h"
 #include "vm/native_entry.h"
 #include "vm/native_entry_test.h"
 #include "vm/object.h"
 #include "vm/runtime_entry.h"
 #include "vm/stub_code.h"
 #include "vm/unit_test.h"
 
 #define __ assembler->
 
 namespace dart {
 
 DECLARE_RUNTIME_ENTRY(TestSmiSub);
-DECLARE_LEAF_RUNTIME_ENTRY(TestLeafSmiAdd);
+DECLARE_LEAF_RUNTIME_ENTRY(RawObject*, TestLeafSmiAdd, RawObject*, RawObject*);
 
 
 static Function* CreateFunction(const char* name) {
   const String& function_name = String::ZoneHandle(String::NewSymbol(name));
   Function& function = Function::ZoneHandle(
       Function::New(function_name, RawFunction::kFunction, true, false, 0));
   return &function;
 }
 
 
@@ skipping 36 matching lines @@
   Smi& result = Smi::Handle();
   result ^= DartEntry::InvokeStatic(function, arguments, kNoArgumentNames);
   EXPECT_EQ((value1 - value2), result.Value());
 }
 
 
 // Test calls to stub code which calls into the runtime.
 static void GenerateCallToCallLeafRuntimeStub(Assembler* assembler,
                                               int value1,
                                               int value2) {
-  const int argc = 2;
   const Smi& smi1 = Smi::ZoneHandle(Smi::New(value1));
   const Smi& smi2 = Smi::ZoneHandle(Smi::New(value2));
-  const Object& result = Object::ZoneHandle();
-  const Context& context = Context::ZoneHandle(Context::New(0));
-  ASSERT(context.isolate() == Isolate::Current());
   __ enter(Immediate(0));
-  __ LoadObject(CTX, context);
-  __ PushObject(result);  // Push Null object for return value.
-  __ PushObject(smi1);  // Push argument 1 smi1.
-  __ PushObject(smi2);  // Push argument 2 smi2.
-  ASSERT(kTestLeafSmiAddRuntimeEntry.argument_count() == argc);
+  __ ReserveAlignedFrameSpace(2 * kWordSize);
+  __ LoadObject(RAX, smi1);
+  __ movq(Address(RSP, 0), EAX);  // Push argument 1 smi1.
+  __ LoadObject(RAX, smi2);
+  __ movq(Address(RSP, kWordSize), EAX);  // Push argument 2 smi2.
   __ CallRuntime(kTestLeafSmiAddRuntimeEntry);  // Call SmiAdd runtime func.
-  __ AddImmediate(RSP, Immediate(argc * kWordSize));
-  __ popq(RAX);  // Pop return value from return slot.
   __ leave();
-  __ ret();
+  __ ret();  // Return value is in RAX.
 }
 
 
 TEST_CASE(CallLeafRuntimeStubCode) {
   extern const Function& RegisterFakeFunction(const char* name,
                                               const Code& code);
   const int value1 = 10;
   const int value2 = 20;
   const char* kName = "Test_CallLeafRuntimeStubCode";
   Assembler _assembler_;
@@ skipping 52 matching lines @@
   GrowableArray<const Object*>  arguments;
   const Array& kNoArgumentNames = Array::Handle();
   Smi& result = Smi::Handle();
   result ^= DartEntry::InvokeStatic(function, arguments, kNoArgumentNames);
   EXPECT_EQ((value1 - value2), result.Value());
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64