Ensure lower <= upper bound

src/types.cc

 // Copyright 2013 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 222 matching lines @@
     return union_get(this->as_union(), 0)->GlbBitset();
   } else {
     return kNone;
   }
 }
 
 
 // Check this <= that.
 bool Type::SlowIs(Type* that) {
   // Fast path for bitsets.
+  if (this->is_none()) return true;
   if (that->is_bitset()) {
     return (this->LubBitset() | that->as_bitset()) == that->as_bitset();
   }
 
   if (that->is_class()) {
     return this->is_class() && *this->as_class() == *that->as_class();
   }
   if (that->is_constant()) {
     return this->is_constant() && *this->as_constant() == *that->as_constant();
   }
@@ skipping 266 matching lines @@
     for (unsigned i = 0; i < sizeof(val)*8; ++i) {
       int mask = (1 << i);
       if ((val & mask) != 0) {
         if (!first_entry) PrintF(out, ",");
         first_entry = false;
         PrintF(out, "%s", GetPrimitiveName(mask));
       }
     }
     PrintF(out, "}");
   } else if (is_constant()) {
-    PrintF(out, "Constant(%p)", static_cast<void*>(*as_constant()));
+    PrintF(out, "Constant(%p : ", static_cast<void*>(*as_constant()));
+    from_bitset(LubBitset())->TypePrint(out);
+    PrintF(")");
   } else if (is_class()) {
-    PrintF(out, "Class(%p)", static_cast<void*>(*as_class()));
+    PrintF(out, "Class(%p < ", static_cast<void*>(*as_class()));
+    from_bitset(LubBitset())->TypePrint(out);
+    PrintF(")");
   } else if (is_union()) {
     PrintF(out, "{");
     Handle<Unioned> unioned = as_union();
     for (int i = 0; i < unioned->length(); ++i) {
       Handle<Type> type_i = union_get(unioned, i);
       if (i > 0) PrintF(out, ",");
       type_i->TypePrint(out);
     }
     PrintF(out, "}");
   }
 }
 #endif
 
 
 } }  // namespace v8::internal