[turbofan] Optimize loads from the global object in JSTypeFeedbackSpecializer.

test/unittests/compiler/js-type-feedback-unittest.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/compiler.h"
+
+#include "src/compiler/access-builder.h"
+#include "src/compiler/js-graph.h"
+#include "src/compiler/js-operator.h"
+#include "src/compiler/js-type-feedback.h"
+#include "src/compiler/machine-operator.h"
+#include "src/compiler/node-matchers.h"
+#include "src/compiler/node-properties.h"
+#include "src/compiler/operator-properties.h"
+
+#include "test/unittests/compiler/compiler-test-utils.h"
+#include "test/unittests/compiler/graph-unittest.h"
+#include "test/unittests/compiler/node-test-utils.h"
+#include "testing/gmock-support.h"
+
+using testing::Capture;
+
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+class JSTypeFeedbackTest : public TypedGraphTest {
+ public:
+  JSTypeFeedbackTest()
+      : TypedGraphTest(3),
+        javascript_(zone()),
+        dependencies_(isolate(), zone()) {}
+  ~JSTypeFeedbackTest() override { dependencies_.Rollback(); }
+
+ protected:
+  Reduction Reduce(Node* node) {
+    Handle<GlobalObject> global_object(
+        isolate()->native_context()->global_object(), isolate());
+
+    MachineOperatorBuilder machine(zone());
+    JSGraph jsgraph(isolate(), graph(), common(), javascript(), &machine);
+    JSTypeFeedbackTable table(zone());
+    JSTypeFeedbackSpecializer reducer(&jsgraph, &table, nullptr, global_object,
+                                      &dependencies_);
+    return reducer.Reduce(node);
+  }
+
+  Node* EmptyFrameState() {
+    MachineOperatorBuilder machine(zone());
+    JSGraph jsgraph(isolate(), graph(), common(), javascript(), &machine);
+    return jsgraph.EmptyFrameState();
+  }
+
+  JSOperatorBuilder* javascript() { return &javascript_; }
+
+  void SetGlobalProperty(const char* string, int value) {
+    SetGlobalProperty(string, Handle<Smi>(Smi::FromInt(value), isolate()));
+  }
+
+  void SetGlobalProperty(const char* string, double value) {
+    SetGlobalProperty(string, isolate()->factory()->NewNumber(value));
+  }
+
+  void SetGlobalProperty(const char* string, Handle<Object> value) {
+    Handle<JSObject> global(isolate()->context()->global_object(), isolate());
+    Handle<String> name =
+        isolate()->factory()->NewStringFromAsciiChecked(string);
+    MaybeHandle<Object> result =
+        JSReceiver::SetProperty(global, name, value, SLOPPY);
+    USE(result);

[Michael Starzinger, 2015/04/21 12:34:01]

nit: result.Check() or at least result.Assert() here.

[titzer, 2015/04/21 12:56:52]

Done.

+  }
+
+  Node* ReturnLoadNamedFromGlobal(const char* string, Node* effect,
+                                  Node* control) {
+    VectorSlotPair feedback(Handle<TypeFeedbackVector>::null(),
+                            FeedbackVectorICSlot::Invalid());
+    Node* global = Parameter(Type::GlobalObject());
+    Node* context = UndefinedConstant();
+
+    Unique<Name> name = Unique<Name>::CreateUninitialized(
+        isolate()->factory()->NewStringFromAsciiChecked(string));
+    Node* load = graph()->NewNode(javascript()->LoadNamed(name, feedback),
+                                  global, context);
+    if (FLAG_turbo_deoptimization) {
+      load->AppendInput(zone(), EmptyFrameState());
+    }
+    load->AppendInput(zone(), effect);
+    load->AppendInput(zone(), control);
+    Node* if_success = graph()->NewNode(common()->IfSuccess(), load);
+    return graph()->NewNode(common()->Return(), load, load, if_success);
+  }
+
+  CompilationDependencies* dependencies() { return &dependencies_; }
+
+ private:
+  JSOperatorBuilder javascript_;
+  CompilationDependencies dependencies_;
+};
+
+#define WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION        \
+  for (int i = FLAG_turbo_deoptimization = 0; i < 2; \

[Michael Starzinger, 2015/04/21 12:34:01]

nit: Assigning integer to boolean looks fishy.

[titzer, 2015/04/21 12:56:52]

Not sure if a static cast really would make any difference, since I think the
C++ standards defines bools as integers with values 0 or 1.

+       FLAG_turbo_deoptimization = ++i)

[Michael Starzinger, 2015/04/21 12:34:01]

nit: Likewise.

+
+
+TEST_F(JSTypeFeedbackTest, JSLoadNamedGlobalConst_smi) {
+  const int const_value = 111;
+  const char* property_name = "banana";
+  SetGlobalProperty(property_name, const_value);
+
+  WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION {
+    Node* ret = ReturnLoadNamedFromGlobal(property_name, graph()->start(),
+                                          graph()->start());
+    graph()->SetEnd(graph()->NewNode(common()->End(), ret));
+
+    Reduction r = Reduce(ret->InputAt(0));
+
+    if (FLAG_turbo_deoptimization) {
+      // Check LoadNamed(global) => HeapConstant[const_value]
+      ASSERT_TRUE(r.Changed());
+      EXPECT_THAT(r.replacement(), IsNumberConstant(const_value));
+
+      EXPECT_THAT(ret, IsReturn(IsNumberConstant(const_value), graph()->start(),
+                                graph()->start()));
+      EXPECT_THAT(graph()->end(), IsEnd(ret));
+
+      EXPECT_FALSE(dependencies()->IsEmpty());
+      dependencies()->Rollback();
+    } else {
+      ASSERT_FALSE(r.Changed());
+      EXPECT_TRUE(dependencies()->IsEmpty());
+    }
+  }
+}
+
+
+TEST_F(JSTypeFeedbackTest, JSLoadNamedGlobalConst_derble) {
+  const double const_value = -11.25;
+  const char* property_name = "kiwi";
+  SetGlobalProperty(property_name, const_value);
+
+  WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION {
+    Node* ret = ReturnLoadNamedFromGlobal(property_name, graph()->start(),
+                                          graph()->start());
+    graph()->SetEnd(graph()->NewNode(common()->End(), ret));
+
+    Reduction r = Reduce(ret->InputAt(0));
+
+    if (FLAG_turbo_deoptimization) {
+      // Check LoadNamed(global) => HeapConstant[const_value]
+      ASSERT_TRUE(r.Changed());
+      EXPECT_THAT(r.replacement(), IsNumberConstant(const_value));
+
+      EXPECT_THAT(ret, IsReturn(IsNumberConstant(const_value), graph()->start(),
+                                graph()->start()));
+      EXPECT_THAT(graph()->end(), IsEnd(ret));
+
+      EXPECT_FALSE(dependencies()->IsEmpty());
+    } else {
+      ASSERT_FALSE(r.Changed());
+      EXPECT_TRUE(dependencies()->IsEmpty());
+    }
+  }
+}
+
+
+TEST_F(JSTypeFeedbackTest, JSLoadNamedGlobalConst_string) {
+  Unique<HeapObject> const_value = Unique<HeapObject>::CreateImmovable(
+      isolate()->factory()->undefined_string());
+  const char* property_name = "mango";
+  SetGlobalProperty(property_name, const_value.handle());
+
+  WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION {
+    Node* ret = ReturnLoadNamedFromGlobal(property_name, graph()->start(),
+                                          graph()->start());
+    graph()->SetEnd(graph()->NewNode(common()->End(), ret));
+
+    Reduction r = Reduce(ret->InputAt(0));
+
+    if (FLAG_turbo_deoptimization) {
+      // Check LoadNamed(global) => HeapConstant[const_value]
+      ASSERT_TRUE(r.Changed());
+      EXPECT_THAT(r.replacement(), IsHeapConstant(const_value));
+
+      EXPECT_THAT(ret, IsReturn(IsHeapConstant(const_value), graph()->start(),
+                                graph()->start()));
+      EXPECT_THAT(graph()->end(), IsEnd(ret));
+
+      EXPECT_FALSE(dependencies()->IsEmpty());
+      dependencies()->Rollback();
+    } else {
+      ASSERT_FALSE(r.Changed());
+      EXPECT_TRUE(dependencies()->IsEmpty());
+    }
+  }
+}
+
+
+TEST_F(JSTypeFeedbackTest, JSLoadNamedGlobalPropertyCell_smi) {
+  const char* property_name = "melon";
+  SetGlobalProperty(property_name, 123);
+  SetGlobalProperty(property_name, 124);
+
+  WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION {
+    Node* ret = ReturnLoadNamedFromGlobal(property_name, graph()->start(),
+                                          graph()->start());
+    graph()->SetEnd(graph()->NewNode(common()->End(), ret));
+
+    Reduction r = Reduce(ret->InputAt(0));
+
+    if (FLAG_turbo_deoptimization) {
+      // Check LoadNamed(global) => LoadField[PropertyCell::value](cell)
+      ASSERT_TRUE(r.Changed());
+      FieldAccess access = AccessBuilder::ForPropertyCellValue();
+      Capture<Node*> cell_capture;
+      Matcher<Node*> load_field_match = IsLoadField(
+          access, CaptureEq(&cell_capture), graph()->start(), graph()->start());
+      EXPECT_THAT(r.replacement(), load_field_match);
+
+      HeapObjectMatcher<PropertyCell> cell(cell_capture.value());
+      EXPECT_TRUE(cell.HasValue());
+      EXPECT_TRUE(cell.Value().handle()->IsPropertyCell());
+
+      EXPECT_THAT(
+          ret, IsReturn(load_field_match, load_field_match, graph()->start()));
+      EXPECT_THAT(graph()->end(), IsEnd(ret));
+
+      EXPECT_FALSE(dependencies()->IsEmpty());
+      dependencies()->Rollback();
+    } else {
+      ASSERT_FALSE(r.Changed());
+      EXPECT_TRUE(dependencies()->IsEmpty());
+    }
+  }
+}
+
+
+TEST_F(JSTypeFeedbackTest, JSLoadNamedGlobalPropertyCell_string) {
+  const char* property_name = "pineapple";
+  SetGlobalProperty(property_name, isolate()->factory()->undefined_string());
+  SetGlobalProperty(property_name, isolate()->factory()->undefined_value());
+
+  WITH_AND_WITHOUT_TURBO_DEOPTIMIZATION {
+    Node* ret = ReturnLoadNamedFromGlobal(property_name, graph()->start(),
+                                          graph()->start());
+    graph()->SetEnd(graph()->NewNode(common()->End(), ret));
+
+    Reduction r = Reduce(ret->InputAt(0));
+
+    if (FLAG_turbo_deoptimization) {
+      // Check LoadNamed(global) => LoadField[PropertyCell::value](cell)
+      ASSERT_TRUE(r.Changed());
+      FieldAccess access = AccessBuilder::ForPropertyCellValue();
+      Capture<Node*> cell_capture;
+      Matcher<Node*> load_field_match = IsLoadField(
+          access, CaptureEq(&cell_capture), graph()->start(), graph()->start());
+      EXPECT_THAT(r.replacement(), load_field_match);
+
+      HeapObjectMatcher<PropertyCell> cell(cell_capture.value());
+      EXPECT_TRUE(cell.HasValue());
+      EXPECT_TRUE(cell.Value().handle()->IsPropertyCell());
+
+      EXPECT_THAT(
+          ret, IsReturn(load_field_match, load_field_match, graph()->start()));
+      EXPECT_THAT(graph()->end(), IsEnd(ret));
+
+      EXPECT_FALSE(dependencies()->IsEmpty());
+      dependencies()->Rollback();
+    } else {
+      ASSERT_FALSE(r.Changed());
+      EXPECT_TRUE(dependencies()->IsEmpty());
+    }
+  }
+}
+}
+}
+}