Elide hole checks on KeyedLoads of holey double arrays.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index f38fb7d5e3d4312383c198cf23b25a7cf2f8f602..6b5d90f62a562b5db5f1a07ef34b4e83dbc395c2 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -2682,7 +2682,12 @@ bool HLoadKeyed::UsesMustHandleHole() const {
     return false;
   }
 
-  if (hole_mode() == ALLOW_RETURN_HOLE) return true;
+  if (hole_mode() == ALLOW_RETURN_HOLE) {
+    if (IsFastDoubleElementsKind(elements_kind())) {
+      return AllUsesCanTreatHoleAsNaN();
+    }
+    return true;
+  }
 
   if (IsFastDoubleElementsKind(elements_kind())) {
     return false;
@@ -2699,6 +2704,22 @@ bool HLoadKeyed::UsesMustHandleHole() const {
 }
 
 
+bool HLoadKeyed::AllUsesCanTreatHoleAsNaN() const {
+  if (!IsFastDoubleElementsKind(elements_kind())) {
+    return false;
+  }
+
+  for (HUseIterator it(uses()); !it.Done(); it.Advance()) {
+    HValue* use = it.value();
+    if (use->CheckFlag(HValue::kDeoptimizeOnUndefined)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+
 bool HLoadKeyed::RequiresHoleCheck() const {
   if (IsFastPackedElementsKind(elements_kind())) {
     return false;