VM: Clean up generated code for NoSuchMethod invocation of closures.

runtime/vm/stub_code_x64.cc

Index: runtime/vm/stub_code_x64.cc
===================================================================
--- runtime/vm/stub_code_x64.cc	(revision 39693)
+++ runtime/vm/stub_code_x64.cc	(working copy)
@@ -1173,7 +1173,6 @@
 // Input parameters:
 //   RSP : points to return address.
 //   RSP + 8 : address of last argument.
-//   RBX : ic-data.
 //   R10 : arguments descriptor array.
 void StubCode::GenerateCallNoSuchMethodFunctionStub(Assembler* assembler) {
   __ EnterStubFrame();
@@ -1185,16 +1184,16 @@
   __ LoadObject(R12, Object::null_object(), PP);
   __ pushq(R12);  // Setup space on stack for result from noSuchMethod.
   __ pushq(RAX);  // Receiver.
-  __ pushq(RBX);  // IC data array.
   __ pushq(R10);  // Arguments descriptor array.
 
   __ movq(R10, R13);  // Smi-tagged arguments array length.
   PushArgumentsArray(assembler);
 
-  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, 4);
+  const intptr_t kNumArgs = 3;
+  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry, kNumArgs);
 

[Vyacheslav Egorov (Google), 2014/09/02 22:28:04]

I think all the code after CallRuntime is dead because
kInvokeNoSuchMethodFunctionRuntimeEntry always throws. Just kill it on all
platforms?

[Florian Schneider, 2014/09/03 09:05:00]

Only Object::noSuchMethod throws, otherwise it can do whatever the user decides
to do.

[Florian Schneider, 2014/09/03 12:17:28]

You're right that in the case of closures, it always throws.

   // Remove arguments.
-  __ Drop(4);
+  __ Drop(kNumArgs);
   __ popq(RAX);  // Get result into RAX.
 
   // Remove the stub frame as we are about to return.