Fixed handling of polymorphic array accesses with constant index

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index c93bc1144af36376167cbac155e664ec57cda72c..cd9186c00106b0a23fcc96adcb78ad5265c9454e 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1432,20 +1432,32 @@ void HTypeof::PrintDataTo(StringStream* stream) {
 }
 
 
+static bool CanRepresentationContainDouble(Representation rep, double value) {

[Jakob Kummerow, 2014/03/12 09:16:24]

nit: How about moving this to Representation::CanRepresent(double value) {...} ?

+  if (rep.IsDouble() || rep.is_more_general_than(Representation::Double())) {
+    return true;
+  }
+  if (IsInt32Double(value)) {
+    if (rep.IsInteger32()) return true;
+    if (rep.IsSmi()) return Smi::IsValid(static_cast<int32_t>(value));
+  }
+  return false;
+}
+
+
 HInstruction* HForceRepresentation::New(Zone* zone, HValue* context,
-       HValue* value, Representation required_representation) {
+       HValue* value, Representation representation) {
   if (FLAG_fold_constants && value->IsConstant()) {
     HConstant* c = HConstant::cast(value);
     if (c->HasNumberValue()) {
       double double_res = c->DoubleValue();
-      if (IsInt32Double(double_res)) {
+      if (CanRepresentationContainDouble(representation, double_res)) {
         return HConstant::New(zone, context,
                               static_cast<int32_t>(double_res),
-                              required_representation);
+                              representation);
       }
     }
   }
-  return new(zone) HForceRepresentation(value, required_representation);
+  return new(zone) HForceRepresentation(value, representation);
 }