"perfectly fine" does not depend on the processor alone, it depends on the compiler. A compiler for x86 can assume dereferencing a NULL pointer is undefined beh

"perfectly fine" 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't expect. Or it could document and provide a well defined behavior of derefrencing a NULL pointer. (e.g. gcc provides -fdelete-null-pointer-checks to control this)