More precise type lub for numbers

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 110 matching lines @@
     }
     return bitset;
   } else {
     Map* map = NULL;
     if (this->is_class()) {
       map = *this->as_class();
     } else {
       Handle<v8::internal::Object> value = this->as_constant();
       if (value->IsSmi()) return kSmi;
       map = HeapObject::cast(*value)->map();
+      if (map->instance_type() == HEAP_NUMBER_TYPE) {
+        int32_t i;
+        uint32_t u;
+        if (value->ToInt32(&i)) return Smi::IsValid(i) ? kSmi : kOtherSigned32;
+        if (value->ToUint32(&u)) return kUnsigned32;
+        return kDouble;
+      }
       if (map->instance_type() == ODDBALL_TYPE) {
         if (value->IsUndefined()) return kUndefined;
         if (value->IsNull()) return kNull;
         if (value->IsTrue() || value->IsFalse()) return kBoolean;
-        if (value->IsTheHole()) return kAny;
+        if (value->IsTheHole()) return kAny;  // TODO(rossberg): kNone?
       }
     }
     switch (map->instance_type()) {
       case STRING_TYPE:
       case ASCII_STRING_TYPE:
       case CONS_STRING_TYPE:
       case CONS_ASCII_STRING_TYPE:
       case SLICED_STRING_TYPE:
       case SLICED_ASCII_STRING_TYPE:
       case EXTERNAL_STRING_TYPE:
       case EXTERNAL_ASCII_STRING_TYPE:
       case EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
       case SHORT_EXTERNAL_STRING_TYPE:
       case SHORT_EXTERNAL_ASCII_STRING_TYPE:
       case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
       case INTERNALIZED_STRING_TYPE:
       case ASCII_INTERNALIZED_STRING_TYPE:
       case CONS_INTERNALIZED_STRING_TYPE:
       case CONS_ASCII_INTERNALIZED_STRING_TYPE:
       case EXTERNAL_INTERNALIZED_STRING_TYPE:
       case EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE:
       case EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
       case SHORT_EXTERNAL_INTERNALIZED_STRING_TYPE:
       case SHORT_EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE:
       case SHORT_EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:
         return kString;
       case SYMBOL_TYPE:
         return kSymbol;
       case ODDBALL_TYPE:
-        return kOddball;
       case HEAP_NUMBER_TYPE:
-        return kDouble;
+        UNREACHABLE();
       case JS_VALUE_TYPE:
       case JS_DATE_TYPE:
       case JS_OBJECT_TYPE:
       case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
       case JS_GENERATOR_OBJECT_TYPE:
       case JS_MODULE_TYPE:
       case JS_GLOBAL_OBJECT_TYPE:
       case JS_BUILTINS_OBJECT_TYPE:
       case JS_GLOBAL_PROXY_TYPE:
       case JS_ARRAY_BUFFER_TYPE:
@@ skipping 351 matching lines @@
       if (i > 0) PrintF(out, ",");
       type_i->TypePrint(out);
     }
     PrintF(out, "}");
   }
 }
 #endif
 
 
 } }  // namespace v8::internal