Does (p+x)-x always result in p for pointer p and integer x in gcc linux x86-64 C++

Question

Suppose we have:

char* p;
int   x;

As recently discussed in another question, arithmetic including comparison operations on invalid pointers can generate unexpected behavior in gcc linux x86-64 C++. This new question is specifically about the expression (p+x)-x: can it generate unexpected behavior (i.e., result not beingp) in any existing GCC version running on x86-64 linux?

Note that this question is just about pointer arithmetic; there is absolutely no intention to access the location designated by *(p+x), which obviously would be unpredictable in general.

The practical interest here is non-zero-based arrays. Note that (p+x) and the subtraction by x happen in different places in the code in these applications.

If recent GCC versions on x86-64 can be shown to never generate unexpected behavior for (p+x)-x then these versions can be certified for non-zero-based arrays, and future versions generating unexpected behavior could be modified or configured to support this certification.

UPDATE

For the practical case described above, we could also assume p itself is a valid pointer and p != NULL.

Answer 1

Waitting for answers