VectorICs: use a vector slot to aid in array literal processing.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index f2e10ecfe5354e71c159f151c40dd48fccfb48a7..8f825fbc01515bcf8fad2d6edb783c3060e89fba 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -1911,7 +1911,6 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
   Node* closure = GetFunctionClosure();
 
   // Create node to deep-copy the literal boilerplate.
-  expr->BuildConstantElements(isolate());
   Node* literals_array =
       BuildLoadObjectField(closure, JSFunction::kLiteralsOffset);
   Node* literal_index = jsgraph()->Constant(expr->literal_index());
@@ -1929,6 +1928,7 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
 
   // Create nodes to evaluate all the non-constant subexpressions and to store
   // them into the newly cloned array.
+  VectorSlotPair pair = CreateVectorSlotPair(expr->LiteralFeedbackSlot());

[Michael Starzinger, 2015/10/13 11:59:18]

nit: Can we move this into the loop (ideally yo line 1940) so that
ArrayLiteral::LiteralFeedbackSlot is only queried when we actually have a slot?

[mvstanton, 2015/10/13 12:56:10]

Done.

   int array_index = 0;
   for (; array_index < expr->values()->length(); array_index++) {
     Expression* subexpr = expr->values()->at(array_index);
@@ -1940,11 +1940,8 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
       FrameStateBeforeAndAfter states(this, subexpr->id());
       Node* value = environment()->Pop();
       Node* index = jsgraph()->Constant(array_index);
-      // TODO(turbofan): More efficient code could be generated here. Consider
-      // that the store will be generic because we don't have a feedback vector
-      // slot.
-      Node* store = BuildKeyedStore(literal, index, value, VectorSlotPair(),
-                                    TypeFeedbackId::None());
+      Node* store =
+          BuildKeyedStore(literal, index, value, pair, TypeFeedbackId::None());
       states.AddToNode(store, expr->GetIdForElement(array_index),
                        OutputFrameStateCombine::Ignore());
     }