&quot;perfectly fine&quot; does not depend on the processor alone, it depends on the compiler. A compiler for x86 can assume dereferencing a NULL pointer is undefined behavior, and optimize your code in ways you perhaps didn&#x27;t expect.<p>Or it could document and provide a well defined behavior of derefrencing a NULL pointer.<p>(e.g. gcc provides -fdelete-null-pointer-checks to control this)