Test StringLengthStub generation via TurboFan.

For now we just use the RawMachineAssembler, this will be changed
later to use the whole TurboFan pipeline.

Review URL: https://codereview.chromium.org/925373002

Cr-Commit-Position: refs/heads/master@{#26902}

test/cctest/cctest.gyp

@@ -86,6 +86,7 @@
         'compiler/test-run-machops.cc',
         'compiler/test-run-properties.cc',
         'compiler/test-run-stackcheck.cc',
+        'compiler/test-run-stubs.cc',
         'compiler/test-run-variables.cc',
         'compiler/test-simplified-lowering.cc',
         'cctest.cc',

test/cctest/compiler/test-run-stubs.cc

+// Copyright 2015 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-stubs.h"
+#include "src/compiler/graph.h"
+#include "src/compiler/linkage.h"
+#include "src/compiler/pipeline.h"
+#include "src/compiler/raw-machine-assembler.h"
+#include "src/globals.h"
+#include "src/handles.h"
+#include "test/cctest/compiler/function-tester.h"
+
+#if V8_TURBOFAN_TARGET
+
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+
+
+class StringLengthStubTF : public CodeStub {
+ public:
+  explicit StringLengthStubTF(Isolate* isolate) : CodeStub(isolate) {}
+
+  StringLengthStubTF(uint32_t key, Isolate* isolate) : CodeStub(key, isolate) {}
+
+  CallInterfaceDescriptor GetCallInterfaceDescriptor() OVERRIDE {
+    return LoadDescriptor(isolate());
+  };
+
+  Handle<Code> GenerateCode() OVERRIDE {
+    CompilationInfoWithZone info(this, isolate());
+    Graph graph(info.zone());
+    CallDescriptor* descriptor = Linkage::ComputeIncoming(info.zone(), &info);
+    RawMachineAssembler m(isolate(), &graph, descriptor->GetMachineSignature());
+
+    Node* str = m.Load(kMachAnyTagged, m.Parameter(0),
+                       m.Int32Constant(JSValue::kValueOffset - kHeapObjectTag));
+    Node* len = m.Load(kMachAnyTagged, str,
+                       m.Int32Constant(String::kLengthOffset - kHeapObjectTag));
+    m.Return(len);
+
+    return Pipeline::GenerateCodeForTesting(&info, &graph, m.Export());
+  }
+
+  Major MajorKey() const OVERRIDE { return StringLength; };
+  Code::Kind GetCodeKind() const OVERRIDE { return Code::HANDLER; }
+  InlineCacheState GetICState() const OVERRIDE { return MONOMORPHIC; }
+  ExtraICState GetExtraICState() const OVERRIDE { return Code::LOAD_IC; }
+  Code::StubType GetStubType() const OVERRIDE { return Code::FAST; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(StringLengthStubTF);
+};
+
+
+TEST(RunStringLengthStubTF) {
+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+  Zone* zone = scope.main_zone();
+
+  // Create code and an accompanying descriptor.
+  StringLengthStubTF stub(isolate);
+  Handle<Code> code = stub.GenerateCode();
+  CompilationInfo info(&stub, isolate, zone);
+  CallDescriptor* descriptor = Linkage::ComputeIncoming(zone, &info);
+
+  // Create a function to call the code using the descriptor.
+  Graph graph(zone);
+  CommonOperatorBuilder common(zone);
+  // FunctionTester (ab)uses a 2-argument function
+  Node* start = graph.NewNode(common.Start(2));
+  // Parameter 0 is the receiver
+  Node* receiverParam = graph.NewNode(common.Parameter(1), start);
+  Node* nameParam = graph.NewNode(common.Parameter(2), start);
+  Unique<HeapObject> u = Unique<HeapObject>::CreateImmovable(code);
+  Node* theCode = graph.NewNode(common.HeapConstant(u));
+  Node* dummyContext = graph.NewNode(common.NumberConstant(0.0));
+  Node* call = graph.NewNode(common.Call(descriptor), theCode, receiverParam,
+                             nameParam, dummyContext, start, start);
+  Node* ret = graph.NewNode(common.Return(), call, call, start);
+  Node* end = graph.NewNode(common.End(), ret);
+  graph.SetStart(start);
+  graph.SetEnd(end);
+  FunctionTester ft(&graph);
+
+  // Actuall call through to the stub, verifying its result.
+  const char* testString = "Und das Lamm schrie HURZ!";
+  Handle<JSReceiver> receiverArg =
+      Object::ToObject(isolate, ft.Val(testString)).ToHandleChecked();
+  Handle<String> nameArg = ft.Val("length");
+  Handle<Object> result = ft.Call(receiverArg, nameArg).ToHandleChecked();
+  CHECK_EQ(static_cast<int>(strlen(testString)), Smi::cast(*result)->value());
+}
+
+#endif  // V8_TURBOFAN_TARGET