Teach TurboFan to call C functions with result_size > 1.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 205 matching lines @@
 void JSGenericLowering::ReplaceWithRuntimeCall(Node* node,
                                                Runtime::FunctionId f,
                                                int nargs_override) {
   Operator::Properties properties = node->op()->properties();
   const Runtime::Function* fun = Runtime::FunctionForId(f);
   int nargs = (nargs_override < 0) ? fun->nargs : nargs_override;
   CallDescriptor* desc =
       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));
 }
 
 
 void JSGenericLowering::LowerBranch(Node* node) {
   if (!info()->is_typing_enabled()) {
     // TODO(mstarzinger): If typing is enabled then simplified lowering will
     // have inserted the correct ChangeBoolToBit, otherwise we need to perform
@@ skipping 206 matching lines @@
 
 
 void JSGenericLowering::LowerJSCallRuntime(Node* node) {
   const CallRuntimeParameters& p = CallRuntimeParametersOf(node->op());
   ReplaceWithRuntimeCall(node, p.id(), static_cast<int>(p.arity()));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8