Teach TurboFan to call C functions with result_size > 1.

src/compiler/js-generic-lowering.cc

Index: src/compiler/js-generic-lowering.cc
diff --git a/src/compiler/js-generic-lowering.cc b/src/compiler/js-generic-lowering.cc
index fb18ba198231343efa96ce751df667d834dc2bf1..f30ce5a4481008a7311ba2e6da8195dffbe07968 100644
--- a/src/compiler/js-generic-lowering.cc
+++ b/src/compiler/js-generic-lowering.cc
@@ -223,7 +223,9 @@ void JSGenericLowering::ReplaceWithRuntimeCall(Node* node,
       linkage()->GetRuntimeCallDescriptor(f, nargs, properties);
   Node* ref = ExternalConstant(ExternalReference(f, isolate()));
   Node* arity = Int32Constant(nargs);
-  PatchInsertInput(node, 0, jsgraph()->CEntryStubConstant());
+  CEntryStub stub(isolate(), fun->result_size);

[titzer, 2014/11/07 14:41:12]

Can you make the result size a parameter to the JSGraph::CEntryStubConstant()
method? Then you can keep the caching (which I think is pretty important, since
we call the CEntryStub a lot in generic code) inside the JSGraph. You could,
e.g. only cache the 1 result size case.

[mvstanton, 2014/11/07 14:49:38]

Done.

+  Node* stub_code = CodeConstant(stub.GetCode());
+  PatchInsertInput(node, 0, stub_code);
   PatchInsertInput(node, nargs + 1, ref);
   PatchInsertInput(node, nargs + 2, arity);
   PatchOperator(node, common()->Call(desc));