[turbofan] Use FastCloneShallow[Array|Object]Stub if possible.

src/compiler/js-intrinsic-lowering.cc

Index: src/compiler/js-intrinsic-lowering.cc
diff --git a/src/compiler/js-intrinsic-lowering.cc b/src/compiler/js-intrinsic-lowering.cc
index 6795317cffd34e72c4293f825c4baa9211c05ee7..20a8dbafbfe750b0979c1b124394ba48deddf18f 100644
--- a/src/compiler/js-intrinsic-lowering.cc
+++ b/src/compiler/js-intrinsic-lowering.cc
@@ -7,8 +7,10 @@
 
 #include <stack>
 
+#include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
+#include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ -28,6 +30,10 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
   switch (f->function_id) {
     case Runtime::kInlineConstructDouble:
       return ReduceConstructDouble(node);
+    case Runtime::kInlineCreateArrayLiteral:
+      return ReduceCreateArrayLiteral(node);
+    case Runtime::kInlineCreateObjectLiteral:
+      return ReduceCreateObjectLiteral(node);
     case Runtime::kInlineDeoptimizeNow:
       return ReduceDeoptimizeNow(node);
     case Runtime::kInlineDoubleHi:
@@ -94,6 +100,61 @@ Reduction JSIntrinsicLowering::ReduceConstructDouble(Node* node) {
 }
 
 
+Reduction JSIntrinsicLowering::ReduceCreateArrayLiteral(Node* node) {
+  HeapObjectMatcher<FixedArray> mconst(NodeProperties::GetValueInput(node, 2));
+  NumberMatcher mflags(NodeProperties::GetValueInput(node, 3));
+  int length = mconst.Value().handle()->length();
+  int flags = FastD2I(mflags.Value());
+
+  // Use the FastCloneShallowArrayStub only for shallow boilerplates up to the
+  // initial length limit for arrays with "fast" elements kind.
+  if ((flags & ArrayLiteral::kShallowElements) != 0 &&
+      length < JSObject::kInitialMaxFastElementArray) {
+    Isolate* isolate = jsgraph()->isolate();
+    Callable callable = CodeFactory::FastCloneShallowArray(isolate);
+    CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+        isolate, graph()->zone(), callable.descriptor(), 0,
+        FLAG_turbo_deoptimization ? CallDescriptor::kNeedsFrameState
+                                  : CallDescriptor::kNoFlags);
+    const Operator* new_op = common()->Call(desc);
+    Node* stub_code = jsgraph()->HeapConstant(callable.code());
+    node->InsertInput(graph()->zone(), 0, stub_code);
+    node->RemoveInput(4);

[mvstanton, 2015/04/21 12:59:14]

nit: a comment would be nice on the RemoveInput...what's being removed?

[Michael Starzinger, 2015/04/21 13:48:36]

Done. Also moved it up to before "InsertInput" so that index makes more sense.

+    node->set_op(new_op);
+    return Changed(node);
+  }
+
+  return NoChange();
+}
+
+
+Reduction JSIntrinsicLowering::ReduceCreateObjectLiteral(Node* node) {
+  HeapObjectMatcher<FixedArray> mconst(NodeProperties::GetValueInput(node, 2));
+  NumberMatcher mflags(NodeProperties::GetValueInput(node, 3));
+  int length = mconst.Value().handle()->length() / 2;
+  int flags = FastD2I(mflags.Value());
+
+  // Use the FastCloneShallowObjectStub only for shallow boilerplates without
+  // elements up to the number of properties that the stubs can handle.
+  if ((flags & ObjectLiteral::kShallowProperties) != 0 &&
+      length <= FastCloneShallowObjectStub::kMaximumClonedProperties) {
+    Isolate* isolate = jsgraph()->isolate();
+    Callable callable = CodeFactory::FastCloneShallowObject(isolate, length);
+    CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+        isolate, graph()->zone(), callable.descriptor(), 0,
+        FLAG_turbo_deoptimization ? CallDescriptor::kNeedsFrameState
+                                  : CallDescriptor::kNoFlags);
+    const Operator* new_op = common()->Call(desc);
+    Node* stub_code = jsgraph()->HeapConstant(callable.code());
+    node->InsertInput(graph()->zone(), 0, stub_code);
+    node->set_op(new_op);
+    return Changed(node);
+  }
+
+  return NoChange();
+}
+
+
 Reduction JSIntrinsicLowering::ReduceDeoptimizeNow(Node* node) {
   if (!FLAG_turbo_deoptimization) return NoChange();