Inline ordered relative compares of mixed double/undefined values.

src/ic.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2464 matching lines @@
 
 
 CompareIC::State CompareIC::TargetState(State state,
                                         bool has_inlined_smi_code,
                                         Handle<Object> x,
                                         Handle<Object> y) {
   switch (state) {
     case UNINITIALIZED:
       if (x->IsSmi() && y->IsSmi()) return SMIS;
       if (x->IsNumber() && y->IsNumber()) return HEAP_NUMBERS;
+      if (Token::IsOrderedRelationalCompareOp(op_)) {
+        // Ordered comparisons treat undefined as NaN, so the
+        // HEAP_NUMBER stub will do the right thing.
+        if ((x->IsNumber() && y->IsUndefined()) ||
+            (y->IsNumber() && x->IsUndefined())) {
+          return HEAP_NUMBERS;
+        }
+      }
       if (!Token::IsEqualityOp(op_)) return GENERIC;
       if (x->IsSymbol() && y->IsSymbol()) return SYMBOLS;
       if (x->IsString() && y->IsString()) return STRINGS;
       if (x->IsJSObject() && y->IsJSObject()) {
         if (Handle<JSObject>::cast(x)->map() ==
             Handle<JSObject>::cast(y)->map() &&
             Token::IsEqualityOp(op_)) {
           return KNOWN_OBJECTS;
         } else {
           return OBJECTS;
@@ skipping 61 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal