Add support for leaf runtime calls

vm/stub_code_x64_test.cc

Index: vm/stub_code_x64_test.cc
===================================================================
--- vm/stub_code_x64_test.cc	(revision 8520)
+++ vm/stub_code_x64_test.cc	(working copy)
@@ -19,8 +19,17 @@
 namespace dart {
 
 DECLARE_RUNTIME_ENTRY(TestSmiSub);
+DECLARE_LEAF_RUNTIME_ENTRY(TestLeafSmiAdd);
 
 
+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;
+}
+
+
 // Test calls to stub code which calls into the runtime.
 static void GenerateCallToCallRuntimeStub(Assembler* assembler,
                                           int value1, int value2) {
@@ -44,14 +53,6 @@
 }
 
 
-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;
-}
-
-
 TEST_CASE(CallRuntimeStubCode) {
   extern const Function& RegisterFakeFunction(const char* name,
                                               const Code& code);
@@ -71,6 +72,49 @@
 }
 
 
+// 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);
+  __ CallRuntime(kTestLeafSmiAddRuntimeEntry);  // Call SmiAdd runtime func.
+  __ AddImmediate(RSP, Immediate(argc * kWordSize));
+  __ popq(RAX);  // Pop return value from return slot.
+  __ leave();
+  __ ret();
+}
+
+
+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_;
+  GenerateCallToCallLeafRuntimeStub(&_assembler_, value1, value2);
+  const Code& code = Code::Handle(Code::FinalizeCode(
+      *CreateFunction("Test_CallLeafRuntimeStubCode"), &_assembler_));
+  const Function& function = RegisterFakeFunction(kName, code);
+  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());
+}
+
+
 // Test calls to stub code which calls a native C function.
 static void GenerateCallToCallNativeCFunctionStub(Assembler* assembler,
                                                   int value1, int value2) {