A pre-initialized value of contents of a memory location is identified. A load value of contents loaded from the memory location by execution of a first instruction that loads from the memory location is also identified. A comparison is made between the load value and the pre-initialized value. Based on the comparison, a determination is made that the load value and the pre-initialized value are the same. In response to this determination, it is indicated that the first instruction contains an uninitialized memory reference.